Physical-scale models of engineered log jams in rivers

USDA-ARS?s Scientific Manuscript database

Stream restoration and river engineering projects are employing engineered log jams increasingly for stabilization and in-stream improvements. To further advance the design of these structures and their morphodynamic effects on corridors, the basis for physical-scale models of rivers with engineere...

Advanced instrumentation for aeronautical propulsion research

NASA Technical Reports Server (NTRS)

Hartmann, M. J.

1986-01-01

The development and use of advanced instrumentation and measurement systems are key to extending the understanding of the physical phenomena that limit the advancement of aeropropulsion systems. The data collected by using these systems are necessary to verify numerical models and to increase the technologists' intuition into the physical phenomena. The systems must be versatile enough to allow their use with older technology measurement systems, with computer-based data reduction systems, and with existing test facilities. Researchers in all aeropropulsion fields contribute to the development of these systems.

Physics through the 1990s: Gravitation, cosmology and cosmic-ray physics

NASA Technical Reports Server (NTRS)

1986-01-01

The volume contains recommendations for space-and ground-based programs in gravitational physics, cosmology, and cosmic-ray physics. The section on gravitation examines current and planned experimental tests of general relativity; the theory behind, and search for, gravitational waves, including sensitive laser-interferometric tests and other observations; and advances in gravitation theory (for example, incorporating quantum effects). The section on cosmology deals with the big-bang model, the standard model from elementary-particle theory, the inflationary model of the Universe. Computational needs are presented for both gravitation and cosmology. Finally, cosmic-ray physics theory (nucleosynthesis, acceleration models, high-energy physics) and experiment (ground and spaceborne detectors) are discussed.

Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake

NASA Astrophysics Data System (ADS)

Kotschenreuther, Mike; Valanju, Prashant; Covele, Brent; Mahajan, Swadesh

2013-10-01

Advanced divertors are magnetic geometries where a second X-point is added in the divertor region to address the serious challenges of burning plasma power exhaust. Invoking physical arguments, numerical work, and detailed model magnetic field analysis, we investigate the magnetic field structure of advanced divertors in the physically relevant region for power exhaust—the scrape-off layer. A primary result of our analysis is the emergence of a physical "metric," the Divertor Index DI, which quantifies the flux expansion increase as one goes from the main X-point to the strike point. It clearly separates three geometries with distinct consequences for divertor physics—the Standard Divertor (DI = 1), and two advanced geometries—the X-Divertor (XD, DI > 1) and the Snowflake (DI < 1). The XD, therefore, cannot be classified as one variant of the Snowflake. By this measure, recent National Spherical Torus Experiment and DIIID experiments are X-Divertors, not Snowflakes.

Engineering and physical sciences in oncology: challenges and opportunities.

PubMed

Mitchell, Michael J; Jain, Rakesh K; Langer, Robert

2017-11-01

The principles of engineering and physics have been applied to oncology for nearly 50 years. Engineers and physical scientists have made contributions to all aspects of cancer biology, from quantitative understanding of tumour growth and progression to improved detection and treatment of cancer. Many early efforts focused on experimental and computational modelling of drug distribution, cell cycle kinetics and tumour growth dynamics. In the past decade, we have witnessed exponential growth at the interface of engineering, physics and oncology that has been fuelled by advances in fields including materials science, microfabrication, nanomedicine, microfluidics, imaging, and catalysed by new programmes at the National Institutes of Health (NIH), including the National Institute of Biomedical Imaging and Bioengineering (NIBIB), Physical Sciences in Oncology, and the National Cancer Institute (NCI) Alliance for Nanotechnology. Here, we review the advances made at the interface of engineering and physical sciences and oncology in four important areas: the physical microenvironment of the tumour and technological advances in drug delivery; cellular and molecular imaging; and microfluidics and microfabrication. We discussthe research advances, opportunities and challenges for integrating engineering and physical sciences with oncology to develop new methods to study, detect and treat cancer, and we also describe the future outlook for these emerging areas.

75 FR 77475 - Endangered and Threatened Species; Proposed Threatened Status for Subspecies of the Ringed Seal

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-10

... ice area are linked in the IPCC climate models to GHG emissions by the physics of radiation processes... scenario), a model that is known for incorporating advanced sea ice physics, and for which snow data were...

Advanced graphical user interface for multi-physics simulations using AMST

NASA Astrophysics Data System (ADS)

Hoffmann, Florian; Vogel, Frank

2017-07-01

Numerical modelling of particulate matter has gained much popularity in recent decades. Advanced Multi-physics Simulation Technology (AMST) is a state-of-the-art three dimensional numerical modelling technique combining the eX-tended Discrete Element Method (XDEM) with Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) [1]. One major limitation of this code is the lack of a graphical user interface (GUI) meaning that all pre-processing has to be made directly in a HDF5-file. This contribution presents the first graphical pre-processor developed for AMST.

Advancing our profession: are higher educational standards the answer?

PubMed

Boyleston, Erin S; Collins, Marie A

2012-01-01

Educational models in health care professions have changed drastically since on-the-job training models. The purpose of this manuscript was to investigate how the professions of physical therapy, occupational therapy, physician assistant, nursing and respiratory therapy have advanced their educational models for entry into practice and to recommend how dental hygiene can integrate similar models to advance the profession. The recommendations are to create an accreditation council for dental hygiene education and to mandate articulation agreements for baccalaureate degree completion in developing and existing programs. Dental hygiene must continue on the path to advance our profession and glean lessons from other health professions.

Advances in understanding and parameterization of small-scale physical processes in the marine Arctic climate system: a review

NASA Astrophysics Data System (ADS)

Vihma, T.; Pirazzini, R.; Fer, I.; Renfrew, I. A.; Sedlar, J.; Tjernström, M.; Lüpkes, C.; Nygård, T.; Notz, D.; Weiss, J.; Marsan, D.; Cheng, B.; Birnbaum, G.; Gerland, S.; Chechin, D.; Gascard, J. C.

2014-09-01

The Arctic climate system includes numerous highly interactive small-scale physical processes in the atmosphere, sea ice, and ocean. During and since the International Polar Year 2007-2009, significant advances have been made in understanding these processes. Here, these recent advances are reviewed, synthesized, and discussed. In atmospheric physics, the primary advances have been in cloud physics, radiative transfer, mesoscale cyclones, coastal, and fjordic processes as well as in boundary layer processes and surface fluxes. In sea ice and its snow cover, advances have been made in understanding of the surface albedo and its relationships with snow properties, the internal structure of sea ice, the heat and salt transfer in ice, the formation of superimposed ice and snow ice, and the small-scale dynamics of sea ice. For the ocean, significant advances have been related to exchange processes at the ice-ocean interface, diapycnal mixing, double-diffusive convection, tidal currents and diurnal resonance. Despite this recent progress, some of these small-scale physical processes are still not sufficiently understood: these include wave-turbulence interactions in the atmosphere and ocean, the exchange of heat and salt at the ice-ocean interface, and the mechanical weakening of sea ice. Many other processes are reasonably well understood as stand-alone processes but the challenge is to understand their interactions with and impacts and feedbacks on other processes. Uncertainty in the parameterization of small-scale processes continues to be among the greatest challenges facing climate modelling, particularly in high latitudes. Further improvements in parameterization require new year-round field campaigns on the Arctic sea ice, closely combined with satellite remote sensing studies and numerical model experiments.

Advances in understanding and parameterization of small-scale physical processes in the marine Arctic climate system: a review

NASA Astrophysics Data System (ADS)

Vihma, T.; Pirazzini, R.; Renfrew, I. A.; Sedlar, J.; Tjernström, M.; Nygård, T.; Fer, I.; Lüpkes, C.; Notz, D.; Weiss, J.; Marsan, D.; Cheng, B.; Birnbaum, G.; Gerland, S.; Chechin, D.; Gascard, J. C.

2013-12-01

The Arctic climate system includes numerous highly interactive small-scale physical processes in the atmosphere, sea ice, and ocean. During and since the International Polar Year 2007-2008, significant advances have been made in understanding these processes. Here these advances are reviewed, synthesized and discussed. In atmospheric physics, the primary advances have been in cloud physics, radiative transfer, mesoscale cyclones, coastal and fjordic processes, as well as in boundary-layer processes and surface fluxes. In sea ice and its snow cover, advances have been made in understanding of the surface albedo and its relationships with snow properties, the internal structure of sea ice, the heat and salt transfer in ice, the formation of super-imposed ice and snow ice, and the small-scale dynamics of sea ice. In the ocean, significant advances have been related to exchange processes at the ice-ocean interface, diapycnal mixing, tidal currents and diurnal resonance. Despite this recent progress, some of these small-scale physical processes are still not sufficiently understood: these include wave-turbulence interactions in the atmosphere and ocean, the exchange of heat and salt at the ice-ocean interface, and the mechanical weakening of sea ice. Many other processes are reasonably well understood as stand-alone processes but challenge is to understand their interactions with, and impacts and feedbacks on, other processes. Uncertainty in the parameterization of small-scale processes continues to be among the largest challenges facing climate modeling, and nowhere is this more true than in the Arctic. Further improvements in parameterization require new year-round field campaigns on the Arctic sea ice, closely combined with satellite remote sensing studies and numerical model experiments.

Advances in distributed watershed modeling: a review and application of the AgroEcoSystem-Watershed (AgES-W) model

USDA-ARS?s Scientific Manuscript database

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advancements in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be ...

Development of the US3D Code for Advanced Compressible and Reacting Flow Simulations

NASA Technical Reports Server (NTRS)

Candler, Graham V.; Johnson, Heath B.; Nompelis, Ioannis; Subbareddy, Pramod K.; Drayna, Travis W.; Gidzak, Vladimyr; Barnhardt, Michael D.

2015-01-01

Aerothermodynamics and hypersonic flows involve complex multi-disciplinary physics, including finite-rate gas-phase kinetics, finite-rate internal energy relaxation, gas-surface interactions with finite-rate oxidation and sublimation, transition to turbulence, large-scale unsteadiness, shock-boundary layer interactions, fluid-structure interactions, and thermal protection system ablation and thermal response. Many of the flows have a large range of length and time scales, requiring large computational grids, implicit time integration, and large solution run times. The University of Minnesota NASA US3D code was designed for the simulation of these complex, highly-coupled flows. It has many of the features of the well-established DPLR code, but uses unstructured grids and has many advanced numerical capabilities and physical models for multi-physics problems. The main capabilities of the code are described, the physical modeling approaches are discussed, the different types of numerical flux functions and time integration approaches are outlined, and the parallelization strategy is overviewed. Comparisons between US3D and the NASA DPLR code are presented, and several advanced simulations are presented to illustrate some of novel features of the code.

Engineering and physical sciences in oncology: challenges and opportunities

PubMed Central

Mitchell, Michael J.; Jain, Rakesh K.; Langer, Robert

2017-01-01

The principles of engineering and physics have been applied to oncology for nearly 50 years. Engineers and physical scientists have made contributions to all aspects of cancer biology, from quantitative understanding of tumour growth and progression to improved detection and treatment of cancer. Many early efforts focused on experimental and computational modelling of drug distribution, cell cycle kinetics and tumour growth dynamics. In the past decade, we have witnessed exponential growth at the interface of engineering, physics and oncology that has been fuelled by advances in fields including materials science, microfabrication, nanomedicine, microfluidics, imaging, and catalysed by new programmes at the National Institutes of Health (NIH), including the National Institute of Biomedical Imaging and Bioengineering (NIBIB), Physical Sciences in Oncology, and the National Cancer Institute (NCI) Alliance for Nanotechnology. Here, we review the advances made at the interface of engineering and physical sciences and oncology in four important areas: the physical microenvironment of the tumour and technological advances in drug delivery; cellular and molecular imaging; and microfluidics and microfabrication. We discussthe research advances, opportunities and challenges for integrating engineering and physical sciences with oncology to develop new methods to study, detect and treat cancer, and we also describe the future outlook for these emerging areas. PMID:29026204

Simulating the Physical World

NASA Astrophysics Data System (ADS)

Berendsen, Herman J. C.

2004-06-01

The simulation of physical systems requires a simplified, hierarchical approach which models each level from the atomistic to the macroscopic scale. From quantum mechanics to fluid dynamics, this book systematically treats the broad scope of computer modeling and simulations, describing the fundamental theory behind each level of approximation. Berendsen evaluates each stage in relation to its applications giving the reader insight into the possibilities and limitations of the models. Practical guidance for applications and sample programs in Python are provided. With a strong emphasis on molecular models in chemistry and biochemistry, this book will be suitable for advanced undergraduate and graduate courses on molecular modeling and simulation within physics, biophysics, physical chemistry and materials science. It will also be a useful reference to all those working in the field. Additional resources for this title including solutions for instructors and programs are available online at www.cambridge.org/9780521835275. The first book to cover the wide range of modeling and simulations, from atomistic to the macroscopic scale, in a systematic fashion Providing a wealth of background material, it does not assume advanced knowledge and is eminently suitable for course use Contains practical examples and sample programs in Python

Mastery Learning in Physical Education.

ERIC Educational Resources Information Center

Annarino, Anthony

This paper discusses the design of a physical education curriculum to be used in advanced secondary physical education programs and in university basic instructional programs; the design is based on the premise of mastery learning and employs programed instructional techniques. The effective implementation of a mastery learning model necessitates…

Performance in Physical Science Education by Dint of Advance Organiser Model of Teaching

ERIC Educational Resources Information Center

Bency, P. B. Beulahbel; Raja, B. William Dharma

2010-01-01

Education should be made painless and the teaching must be made effective. Teaching is an activity, which is designed and performed for multiple objectives, in terms of changes in student behaviours. Models of teaching are just a blue print designed in advance for providing necessary structure and direction to the teacher for realizing the…

State of the art of sonic boom modeling

NASA Astrophysics Data System (ADS)

Plotkin, Kenneth J.

2002-01-01

Based on fundamental theory developed through the 1950s and 1960s, sonic boom modeling has evolved into practical tools. Over the past decade, there have been requirements for design tools for an advanced supersonic transport, and for tools for environmental assessment of various military and aerospace activities. This has resulted in a number of advances in the understanding of the physics of sonic booms, including shock wave rise times, propagation through turbulence, and blending sonic boom theory with modern computational fluid dynamics (CFD) aerodynamic design methods. This article reviews the early fundamental theory, recent advances in theory, and the application of these advances to practical models.

State of the art of sonic boom modeling.

PubMed

Plotkin, Kenneth J

2002-01-01

Based on fundamental theory developed through the 1950s and 1960s, sonic boom modeling has evolved into practical tools. Over the past decade, there have been requirements for design tools for an advanced supersonic transport, and for tools for environmental assessment of various military and aerospace activities. This has resulted in a number of advances in the understanding of the physics of sonic booms, including shock wave rise times, propagation through turbulence, and blending sonic boom theory with modern computational fluid dynamics (CFD) aerodynamic design methods. This article reviews the early fundamental theory, recent advances in theory, and the application of these advances to practical models.

The efficacy of self-directed modules for clinical learning: advanced competencies in entry-level physical therapy education.

PubMed

Peck, Kirk; Paschal, Karen; Black, Lisa; Nelson, Kelly

2014-01-01

Prior to graduation, students often express an interest to advance clinical and professional skills in teaching, research, administration, and various niche practice areas. The acquisition of advanced education in selected areas of practice is believed to improve employment opportunities, accelerate career advancement including eligibility for professional certifications, and contribute to personal satisfaction in the profession. The purpose of this paper is to (1) describe an innovative model of education, the Directed Practice Experience (DPE) elective, that incorporates a student-initiated learning process designed to achieve student-identified professional goals, and (2) report the outcomes for graduates who have completed the DPE in an entry-level program in physical therapy education. Students who met select criteria were eligible to complete a DPE. Applicants designed a 4- to 6-week clinical education experience consisting of stated rationale for personal and professional growth, examples of leadership and service, and self-directed objectives that are beyond entry-level expectations as measured by the revised Physical Therapist Clinical Performance Instrument, version 2006. Twenty-six students have completed DPEs since 2005. Fifty percent resulted in new academic partnerships. At least 25% of graduates now serve as clinical instructors for the entry-level program. Those who participated in DPEs have also completed post-graduate residencies, attained ABPTS Board certifications, authored peer-reviewed publications, and taught in both PT and residency programs. The DPE model allows qualified students to acquire advanced personal skills and knowledge prior to graduation in areas of professional practice that exceed entry-level expectations. The model is applicable to all CAPTE accredited physical therapy education programs and is especially beneficial for academic programs desiring to form new community partnerships for student clinical education.

Intuitive Physics: Current Research and Controversies.

PubMed

Kubricht, James R; Holyoak, Keith J; Lu, Hongjing

2017-10-01

Early research in the field of intuitive physics provided extensive evidence that humans succumb to common misconceptions and biases when predicting, judging, and explaining activity in the physical world. Recent work has demonstrated that, across a diverse range of situations, some biases can be explained by the application of normative physical principles to noisy perceptual inputs. However, it remains unclear how knowledge of physical principles is learned, represented, and applied to novel situations. In this review we discuss theoretical advances from heuristic models to knowledge-based, probabilistic simulation models, as well as recent deep-learning models. We also consider how recent work may be reconciled with earlier findings that favored heuristic models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of the science teaching advancement through modeling physical science professional development workshop on teachers' attitudes, beliefs and content knowledge and students' content knowledge

NASA Astrophysics Data System (ADS)

Dietz, Laura

The Science Teaching Advancement through Modeling Physical Science (STAMPS) professional development workshop was evaluated for effectiveness in improving teachers' and students' content knowledge. Previous research has shown modeling to be an effective method of instruction for improving student and teacher content knowledge, evidenced by assessment scores. Data includes teacher scores on the Force Concept Inventory (FCI; Hestenes, Wells, & Swackhamer, 1992) and the Chemistry Concept Inventory (CCI; Jenkins, Birk, Bauer, Krause, & Pavelich, 2004), as well as student scores on a physics and chemistry assessment. Quantitative data is supported by teacher responses to a post workshop survey and classroom observations. Evaluation of the data shows that the STAMPS professional development workshop was successful in improving both student and teacher content knowledge. Conclusions and suggestions for future study are also included.

SAM Theory Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Rui

The System Analysis Module (SAM) is an advanced and modern system analysis tool being developed at Argonne National Laboratory under the U.S. DOE Office of Nuclear Energy’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. SAM development aims for advances in physical modeling, numerical methods, and software engineering to enhance its user experience and usability for reactor transient analyses. To facilitate the code development, SAM utilizes an object-oriented application framework (MOOSE), and its underlying meshing and finite-element library (libMesh) and linear and non-linear solvers (PETSc), to leverage modern advanced software environments and numerical methods. SAM focuses on modeling advanced reactormore » concepts such as SFRs (sodium fast reactors), LFRs (lead-cooled fast reactors), and FHRs (fluoride-salt-cooled high temperature reactors) or MSRs (molten salt reactors). These advanced concepts are distinguished from light-water reactors in their use of single-phase, low-pressure, high-temperature, and low Prandtl number (sodium and lead) coolants. As a new code development, the initial effort has been focused on modeling and simulation capabilities of heat transfer and single-phase fluid dynamics responses in Sodium-cooled Fast Reactor (SFR) systems. The system-level simulation capabilities of fluid flow and heat transfer in general engineering systems and typical SFRs have been verified and validated. This document provides the theoretical and technical basis of the code to help users understand the underlying physical models (such as governing equations, closure models, and component models), system modeling approaches, numerical discretization and solution methods, and the overall capabilities in SAM. As the code is still under ongoing development, this SAM Theory Manual will be updated periodically to keep it consistent with the state of the development.« less

Space Electrochemical Research and Technology (SERT)

NASA Technical Reports Server (NTRS)

1987-01-01

The conference provided a forum to assess critical needs and technologies for the NASA electrochemical energy conversion and storage program. It was aimed at providing guidance to NASA on the appropriate direction and emphasis of that program. A series of related overviews were presented in the areas of NASA advanced mission models (space stations, low and geosynchronous Earth orbit missions, planetary missions, and space transportation). Papers were presented and workshops conducted in a variety of technical areas, including advanced rechargeables, advanced concepts, critical physical electrochemical issues, and modeling.

Theoretical studies of the physics of the solar atmosphere

NASA Technical Reports Server (NTRS)

Hollweg, Joseph V.

1992-01-01

Significant advances in our theoretical basis for understanding several physical processes related to dynamical phenomena on the sun were achieved. We have advanced a new model for spicules and fibrils. We have provided a simple physical view of resonance absorption of MHD surface waves; this allowed an approximate mathematical procedure for obtaining a wealth of new analytical results which we applied to coronal heating and p-mode absorption at magnetic regions. We provided the first comprehensive models for the heating and acceleration of the transition region, corona, and solar wind. We provided a new view of viscosity under coronal conditions. We provided new insights into Alfven wave propagation in the solar atmosphere. And recently we have begun work in a new direction: parametric instabilities of Alfven waves.

A test harness for accelerating physics parameterization advancements into operations

NASA Astrophysics Data System (ADS)

Firl, G. J.; Bernardet, L.; Harrold, M.; Henderson, J.; Wolff, J.; Zhang, M.

2017-12-01

The process of transitioning advances in parameterization of sub-grid scale processes from initial idea to implementation is often much quicker than the transition from implementation to use in an operational setting. After all, considerable work must be undertaken by operational centers to fully test, evaluate, and implement new physics. The process is complicated by the scarcity of like-to-like comparisons, availability of HPC resources, and the ``tuning problem" whereby advances in physics schemes are difficult to properly evaluate without first undertaking the expensive and time-consuming process of tuning to other schemes within a suite. To address this process shortcoming, the Global Model TestBed (GMTB), supported by the NWS NGGPS project and undertaken by the Developmental Testbed Center, has developed a physics test harness. It implements the concept of hierarchical testing, where the same code can be tested in model configurations of varying complexity from single column models (SCM) to fully coupled, cycled global simulations. Developers and users may choose at which level of complexity to engage. Several components of the physics test harness have been implemented, including a SCM and an end-to-end workflow that expands upon the one used at NOAA/EMC to run the GFS operationally, although the testbed components will necessarily morph to coincide with changes to the operational configuration (FV3-GFS). A standard, relatively user-friendly interface known as the Interoperable Physics Driver (IPD) is available for physics developers to connect their codes. This prerequisite exercise allows access to the testbed tools and removes a technical hurdle for potential inclusion into the Common Community Physics Package (CCPP). The testbed offers users the opportunity to conduct like-to-like comparisons between the operational physics suite and new development as well as among multiple developments. GMTB staff have demonstrated use of the testbed through a comparison between the 2017 operational GFS suite and one containing the Grell-Freitas convective parameterization. An overview of the physics test harness and its early use will be presented.

Advanced Ground Systems Maintenance Physics Models for Diagnostics Project

NASA Technical Reports Server (NTRS)

Harp, Janicce Leshay

2014-01-01

The project will use high-fidelity physics models and simulations to simulate real-time operations of cryogenic and systems and calculate the status/health of the systems. The project enables the delivery of system health advisories to ground system operators. The capability will also be used to conduct planning and analysis of cryogenic system operations.

Predicting remaining life by fusing the physics of failure modeling with diagnostics

NASA Astrophysics Data System (ADS)

Kacprzynski, G. J.; Sarlashkar, A.; Roemer, M. J.; Hess, A.; Hardman, B.

2004-03-01

Technology that enables failure prediction of critical machine components (prognostics) has the potential to significantly reduce maintenance costs and increase availability and safety. This article summarizes a research effort funded through the U.S. Defense Advanced Research Projects Agency and Naval Air System Command aimed at enhancing prognostic accuracy through more advanced physics-of-failure modeling and intelligent utilization of relevant diagnostic information. H-60 helicopter gear is used as a case study to introduce both stochastic sub-zone crack initiation and three-dimensional fracture mechanics lifing models along with adaptive model updating techniques for tuning key failure mode variables at a local material/damage site based on fused vibration features. The overall prognostic scheme is aimed at minimizing inherent modeling and operational uncertainties via sensed system measurements that evolve as damage progresses.

Grounded Learning Experience: Helping Students Learn Physics through Visuo-Haptic Priming and Instruction

NASA Astrophysics Data System (ADS)

Huang, Shih-Chieh Douglas

In this dissertation, I investigate the effects of a grounded learning experience on college students' mental models of physics systems. The grounded learning experience consisted of a priming stage and an instruction stage, and within each stage, one of two different types of visuo-haptic representation was applied: visuo-gestural simulation (visual modality and gestures) and visuo-haptic simulation (visual modality, gestures, and somatosensory information). A pilot study involving N = 23 college students examined how using different types of visuo-haptic representation in instruction affected people's mental model construction for physics systems. Participants' abilities to construct mental models were operationalized through their pretest-to-posttest gain scores for a basic physics system and their performance on a transfer task involving an advanced physics system. Findings from this pilot study revealed that, while both simulations significantly improved participants' mental modal construction for physics systems, visuo-haptic simulation was significantly better than visuo-gestural simulation. In addition, clinical interviews suggested that participants' mental model construction for physics systems benefited from receiving visuo-haptic simulation in a tutorial prior to the instruction stage. A dissertation study involving N = 96 college students examined how types of visuo-haptic representation in different applications support participants' mental model construction for physics systems. Participant's abilities to construct mental models were again operationalized through their pretest-to-posttest gain scores for a basic physics system and their performance on a transfer task involving an advanced physics system. Participants' physics misconceptions were also measured before and after the grounded learning experience. Findings from this dissertation study not only revealed that visuo-haptic simulation was significantly more effective in promoting mental model construction and remedying participants' physics misconceptions than visuo-gestural simulation, they also revealed that visuo-haptic simulation was more effective during the priming stage than during the instruction stage. Interestingly, the effects of visuo-haptic simulation in priming and visuo-haptic simulation in instruction on participants' pretest-to-posttest gain scores for a basic physics system appeared additive. These results suggested that visuo-haptic simulation is effective in physics learning, especially when it is used during the priming stage.

Simple universal models capture all classical spin physics.

PubMed

De las Cuevas, Gemma; Cubitt, Toby S

2016-03-11

Spin models are used in many studies of complex systems because they exhibit rich macroscopic behavior despite their microscopic simplicity. Here, we prove that all the physics of every classical spin model is reproduced in the low-energy sector of certain "universal models," with at most polynomial overhead. This holds for classical models with discrete or continuous degrees of freedom. We prove necessary and sufficient conditions for a spin model to be universal and show that one of the simplest and most widely studied spin models, the two-dimensional Ising model with fields, is universal. Our results may facilitate physical simulations of Hamiltonians with complex interactions. Copyright © 2016, American Association for the Advancement of Science.

NDE in aerospace-requirements for science, sensors and sense.

PubMed

Heyman, J S

1989-01-01

The complexity of modern NDE (nondestructive evaluation) arises from four main factors: quantitative measurement, science, physical models for computational analysis, realistic interfacing with engineering decisions, and direct access to management priorities. Recent advances in the four factors of NDE are addressed. Physical models of acoustic propagation are presented that have led to the development of measurement technologies advancing the ability to assure that materials and structures will perform a design. In addition, a brief discussion is given of current research for future mission needs such as smart structures that sense their own health. Such advances permit projects to integrate design for inspection into their plans, bringing NDE into engineering and management priorities. The measurement focus is on ultrasonics with generous case examples. Problem solutions highlighted include critical stress in fasteners, residual stress in steel, NDE laminography, and solid rocket motor NDE.

NDE in aerospace - Requirements for science, sensors and sense

NASA Technical Reports Server (NTRS)

Heyman, Joseph S.

1989-01-01

The complexity of modern nondestructive evaluation (NDE) arises from four main factors: quantitative measurement science, physical models for computational analysis, realistic interfacing with engineering decisions, and direct access to management priorities. Recent advances in the four factors of NDE are addressed. Physical models of acoustic propagation are presented that have led to the development of measurement technologies advancing the ability to assure that materials and structures will perform as designed. In addition, a brief discussion is given of current research for future mission needs such as smart structures that sense their own health. Such advances permit projects to integrate design for inspection into their plans, bringing NDE into engineering and management priorities. The measurement focus is on ultrasonics with generous case examples. Problem solutions highlighted include critical stress in fasteners, residual stress in steel, NDE laminography, and solid rocket motor NDE.

Improvements to Nuclear Data and Its Uncertainties by Theoretical Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danon, Yaron; Nazarewicz, Witold; Talou, Patrick

2013-02-18

This project addresses three important gaps in existing evaluated nuclear data libraries that represent a significant hindrance against highly advanced modeling and simulation capabilities for the Advanced Fuel Cycle Initiative (AFCI). This project will: Develop advanced theoretical tools to compute prompt fission neutrons and gamma-ray characteristics well beyond average spectra and multiplicity, and produce new evaluated files of U and Pu isotopes, along with some minor actinides; Perform state-of-the-art fission cross-section modeling and calculations using global and microscopic model input parameters, leading to truly predictive fission cross-sections capabilities. Consistent calculations for a suite of Pu isotopes will be performed; Implementmore » innovative data assimilation tools, which will reflect the nuclear data evaluation process much more accurately, and lead to a new generation of uncertainty quantification files. New covariance matrices will be obtained for Pu isotopes and compared to existing ones. The deployment of a fleet of safe and efficient advanced reactors that minimize radiotoxic waste and are proliferation-resistant is a clear and ambitious goal of AFCI. While in the past the design, construction and operation of a reactor were supported through empirical trials, this new phase in nuclear energy production is expected to rely heavily on advanced modeling and simulation capabilities. To be truly successful, a program for advanced simulations of innovative reactors will have to develop advanced multi-physics capabilities, to be run on massively parallel super- computers, and to incorporate adequate and precise underlying physics. And all these areas have to be developed simultaneously to achieve those ambitious goals. Of particular interest are reliable fission cross-section uncertainty estimates (including important correlations) and evaluations of prompt fission neutrons and gamma-ray spectra and uncertainties.« less

Verification of Electromagnetic Physics Models for Parallel Computing Architectures in the GeantV Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amadio, G.; et al.

An intensive R&D and programming effort is required to accomplish new challenges posed by future experimental high-energy particle physics (HEP) programs. The GeantV project aims to narrow the gap between the performance of the existing HEP detector simulation software and the ideal performance achievable, exploiting latest advances in computing technology. The project has developed a particle detector simulation prototype capable of transporting in parallel particles in complex geometries exploiting instruction level microparallelism (SIMD and SIMT), task-level parallelism (multithreading) and high-level parallelism (MPI), leveraging both the multi-core and the many-core opportunities. We present preliminary verification results concerning the electromagnetic (EM) physicsmore » models developed for parallel computing architectures within the GeantV project. In order to exploit the potential of vectorization and accelerators and to make the physics model effectively parallelizable, advanced sampling techniques have been implemented and tested. In this paper we introduce a set of automated statistical tests in order to verify the vectorized models by checking their consistency with the corresponding Geant4 models and to validate them against experimental data.« less

Physically based modeling in catchment hydrology at 50: Survey and outlook

NASA Astrophysics Data System (ADS)

Paniconi, Claudio; Putti, Mario

2015-09-01

Integrated, process-based numerical models in hydrology are rapidly evolving, spurred by novel theories in mathematical physics, advances in computational methods, insights from laboratory and field experiments, and the need to better understand and predict the potential impacts of population, land use, and climate change on our water resources. At the catchment scale, these simulation models are commonly based on conservation principles for surface and subsurface water flow and solute transport (e.g., the Richards, shallow water, and advection-dispersion equations), and they require robust numerical techniques for their resolution. Traditional (and still open) challenges in developing reliable and efficient models are associated with heterogeneity and variability in parameters and state variables; nonlinearities and scale effects in process dynamics; and complex or poorly known boundary conditions and initial system states. As catchment modeling enters a highly interdisciplinary era, new challenges arise from the need to maintain physical and numerical consistency in the description of multiple processes that interact over a range of scales and across different compartments of an overall system. This paper first gives an historical overview (past 50 years) of some of the key developments in physically based hydrological modeling, emphasizing how the interplay between theory, experiments, and modeling has contributed to advancing the state of the art. The second part of the paper examines some outstanding problems in integrated catchment modeling from the perspective of recent developments in mathematical and computational science.

Quality of life, symptom status and physical performance in patients with advanced non-small cell lung cancer undergoing chemotherapy: an exploratory analysis of secondary data.

PubMed

Shallwani, Shirin M; Simmonds, Maureen J; Kasymjanova, Goulnar; Spahija, Jadranka

2016-09-01

Our objectives were: (a) to identify predictors of change in health-related quality of life (HRQOL) in patients with advanced non-small cell lung cancer (NSCLC) undergoing chemotherapy; and (b) to characterize symptom status, nutritional status, physical performance and HRQOL in this population and to estimate the extent to which these variables change following two cycles of chemotherapy. A secondary analysis of a longitudinal observational study of 47 patients (24 men and 23 women) with newly diagnosed advanced NSCLC receiving two cycles of first-line chemotherapy was performed. Primary outcomes were changes in HRQOL (physical and mental component summaries (PCS and MCS) of the 36-item Short-Form Health Survey (SF-36)). Predictors in the models included pre-chemotherapy patient-reported symptoms (Schwartz Cancer Fatigue Scale (SCFS) and Lung Cancer Subscale), nutritional screening (Patient-Generated Subjective Global Assessment) and physical performance measures (6-min Walk Test (6MWT), one-minute chair rise test and grip strength). Mean SF-36 PCS score, 6MWT distance and grip strength declined following two cycles of chemotherapy (p<0.05). Multiple linear regression modelling revealed pre-chemotherapy SCFS score and 6MWT distance as the strongest predictors of change in the mental component of HRQOL accounting for 13% and 9% of the variance, respectively. No significant predictors were found for change in the physical component of HRQOL. Pre-chemotherapy 6MWT distance and fatigue severity predicted change in the mental component of HRQOL in patients with advanced NSCLC undergoing chemotherapy, while physical performance declined during treatment. Clinical management of these factors may be useful for HRQOL optimization in this population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Advancing investigation and physical modeling of first-order fire effects on soils

Treesearch

William J. Massman; John M. Frank; Sacha J. Mooney

2010-01-01

Heating soil during intense wildland fires or slash-pile burns can alter the soil irreversibly, resulting in many significant long-term biological, chemical, physical, and hydrological effects. To better understand these long-term effects, it is necessary to improve modeling capability and prediction of the more immediate, or first-order, effects that fire can have on...

Physics-based simulation models for EBSD: advances and challenges

NASA Astrophysics Data System (ADS)

Winkelmann, A.; Nolze, G.; Vos, M.; Salvat-Pujol, F.; Werner, W. S. M.

2016-02-01

EBSD has evolved into an effective tool for microstructure investigations in the scanning electron microscope. The purpose of this contribution is to give an overview of various simulation approaches for EBSD Kikuchi patterns and to discuss some of the underlying physical mechanisms.

A network model for characterizing brine channels in sea ice

NASA Astrophysics Data System (ADS)

Lieblappen, Ross M.; Kumar, Deip D.; Pauls, Scott D.; Obbard, Rachel W.

2018-03-01

The brine pore space in sea ice can form complex connected structures whose geometry is critical in the governance of important physical transport processes between the ocean, sea ice, and surface. Recent advances in three-dimensional imaging using X-ray micro-computed tomography have enabled the visualization and quantification of the brine network morphology and variability. Using imaging of first-year sea ice samples at in situ temperatures, we create a new mathematical network model to characterize the topology and connectivity of the brine channels. This model provides a statistical framework where we can characterize the pore networks via two parameters, depth and temperature, for use in dynamical sea ice models. Our approach advances the quantification of brine connectivity in sea ice, which can help investigations of bulk physical properties, such as fluid permeability, that are key in both global and regional sea ice models.

Physics Doctorates: Skills Used & Satisfaction with Employment. Data from the Degree Recipient Follow-Up Survey for the Classes of 2013 and 2014. Focus On

ERIC Educational Resources Information Center

Pold, Jack; Mulvey, Patrick

2016-01-01

By the time people earn physics PhDs, they have learned a great deal about physics and how research is conducted. However, physics PhDs also develop skills and knowledge in a number of related areas, such as advanced mathematics, programming, modeling, and technical writing. Physics PhDs draw upon an arsenal of skills and knowledge in their…

Recent developments in Geant4

DOE PAGES

Allison, J.; Amako, K.; Apostolakis, J.; ...

2016-07-01

Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. In conclusion, the adaptation of Geant4 to multithreading, advances in physics, detector modeling and visualization, extensions tomore » the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.« less

Design Considerations of a Virtual Laboratory for Advanced X-ray Sources

NASA Astrophysics Data System (ADS)

Luginsland, J. W.; Frese, M. H.; Frese, S. D.; Watrous, J. J.; Heileman, G. L.

2004-11-01

The field of scientific computation has greatly advanced in the last few years, resulting in the ability to perform complex computer simulations that can predict the performance of real-world experiments in a number of fields of study. Among the forces driving this new computational capability is the advent of parallel algorithms, allowing calculations in three-dimensional space with realistic time scales. Electromagnetic radiation sources driven by high-voltage, high-current electron beams offer an area to further push the state-of-the-art in high fidelity, first-principles simulation tools. The physics of these x-ray sources combine kinetic plasma physics (electron beams) with dense fluid-like plasma physics (anode plasmas) and x-ray generation (bremsstrahlung). There are a number of mature techniques and software packages for dealing with the individual aspects of these sources, such as Particle-In-Cell (PIC), Magneto-Hydrodynamics (MHD), and radiation transport codes. The current effort is focused on developing an object-oriented software environment using the Rational© Unified Process and the Unified Modeling Language (UML) to provide a framework where multiple 3D parallel physics packages, such as a PIC code (ICEPIC), a MHD code (MACH), and a x-ray transport code (ITS) can co-exist in a system-of-systems approach to modeling advanced x-ray sources. Initial software design and assessments of the various physics algorithms' fidelity will be presented.

Simulating Coupling Complexity in Space Plasmas: First Results from a new code

NASA Astrophysics Data System (ADS)

Kryukov, I.; Zank, G. P.; Pogorelov, N. V.; Raeder, J.; Ciardo, G.; Florinski, V. A.; Heerikhuisen, J.; Li, G.; Petrini, F.; Shematovich, V. I.; Winske, D.; Shaikh, D.; Webb, G. M.; Yee, H. M.

2005-12-01

The development of codes that embrace 'coupling complexity' via the self-consistent incorporation of multiple physical scales and multiple physical processes in models has been identified by the NRC Decadal Survey in Solar and Space Physics as a crucial necessary development in simulation/modeling technology for the coming decade. The National Science Foundation, through its Information Technology Research (ITR) Program, is supporting our efforts to develop a new class of computational code for plasmas and neutral gases that integrates multiple scales and multiple physical processes and descriptions. We are developing a highly modular, parallelized, scalable code that incorporates multiple scales by synthesizing 3 simulation technologies: 1) Computational fluid dynamics (hydrodynamics or magneto-hydrodynamics-MHD) for the large-scale plasma; 2) direct Monte Carlo simulation of atoms/neutral gas, and 3) transport code solvers to model highly energetic particle distributions. We are constructing the code so that a fourth simulation technology, hybrid simulations for microscale structures and particle distributions, can be incorporated in future work, but for the present, this aspect will be addressed at a test-particle level. This synthesis we will provide a computational tool that will advance our understanding of the physics of neutral and charged gases enormously. Besides making major advances in basic plasma physics and neutral gas problems, this project will address 3 Grand Challenge space physics problems that reflect our research interests: 1) To develop a temporal global heliospheric model which includes the interaction of solar and interstellar plasma with neutral populations (hydrogen, helium, etc., and dust), test-particle kinetic pickup ion acceleration at the termination shock, anomalous cosmic ray production, interaction with galactic cosmic rays, while incorporating the time variability of the solar wind and the solar cycle. 2) To develop a coronal mass ejection and interplanetary shock propagation model for the inner and outer heliosphere, including, at a test-particle level, wave-particle interactions and particle acceleration at traveling shock waves and compression regions. 3) To develop an advanced Geospace General Circulation Model (GGCM) capable of realistically modeling space weather events, in particular the interaction with CMEs and geomagnetic storms. Furthermore, by implementing scalable run-time supports and sophisticated off- and on-line prediction algorithms, we anticipate important advances in the development of automatic and intelligent system software to optimize a wide variety of 'embedded' computations on parallel computers. Finally, public domain MHD and hydrodynamic codes had a transforming effect on space and astrophysics. We expect that our new generation, open source, public domain multi-scale code will have a similar transformational effect in a variety of disciplines, opening up new classes of problems to physicists and engineers alike.

An advanced technique for the prediction of decelerator system dynamics.

NASA Technical Reports Server (NTRS)

Talay, T. A.; Morris, W. D.; Whitlock, C. H.

1973-01-01

An advanced two-body six-degree-of-freedom computer model employing an indeterminate structures approach has been developed for the parachute deployment process. The program determines both vehicular and decelerator responses to aerodynamic and physical property inputs. A better insight into the dynamic processes that occur during parachute deployment has been developed. The model is of value in sensitivity studies to isolate important parameters that affect the vehicular response.

Next Generation Community Based Unified Global Modeling System Development and Operational Implementation Strategies at NCEP

NASA Astrophysics Data System (ADS)

Tallapragada, V.

2017-12-01

NOAA's Next Generation Global Prediction System (NGGPS) has provided the unique opportunity to develop and implement a non-hydrostatic global model based on Geophysical Fluid Dynamics Laboratory (GFDL) Finite Volume Cubed Sphere (FV3) Dynamic Core at National Centers for Environmental Prediction (NCEP), making a leap-step advancement in seamless prediction capabilities across all spatial and temporal scales. Model development efforts are centralized with unified model development in the NOAA Environmental Modeling System (NEMS) infrastructure based on Earth System Modeling Framework (ESMF). A more sophisticated coupling among various earth system components is being enabled within NEMS following National Unified Operational Prediction Capability (NUOPC) standards. The eventual goal of unifying global and regional models will enable operational global models operating at convective resolving scales. Apart from the advanced non-hydrostatic dynamic core and coupling to various earth system components, advanced physics and data assimilation techniques are essential for improved forecast skill. NGGPS is spearheading ambitious physics and data assimilation strategies, concentrating on creation of a Common Community Physics Package (CCPP) and Joint Effort for Data Assimilation Integration (JEDI). Both initiatives are expected to be community developed, with emphasis on research transitioning to operations (R2O). The unified modeling system is being built to support the needs of both operations and research. Different layers of community partners are also established with specific roles/responsibilities for researchers, core development partners, trusted super-users, and operations. Stakeholders are engaged at all stages to help drive the direction of development, resources allocations and prioritization. This talk presents the current and future plans of unified model development at NCEP for weather, sub-seasonal, and seasonal climate prediction applications with special emphasis on implementation of NCEP FV3 Global Forecast System (GFS) and Global Ensemble Forecast System (GEFS) into operations by 2019.

Criteria, Methods and Implications. Proceedings of the International Symposium on the Evaluation of Physics Education (Helsinki, Finland, June 25-29, 1990). Research Report 96.

ERIC Educational Resources Information Center

Ahtee, Maija, Ed.; And Others

The main purpose of this symposium was to find new ideas and resources for the evaluation and improvement of physics education on all levels. The papers included in this document are entitled: (1) "Quality of Physics Teaching Through Building Models and Advancing Research Skills"; (2) "Evaluation of Physics Education in Terms of Its…

Collaborative Project: Improving the Representation of Coastal and Estuarine Processes in Earth System Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Frank; Dennis, John; MacCready, Parker

This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation.

Final Report Collaborative Project: Improving the Representation of Coastal and Estuarine Processes in Earth System Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Frank; Dennis, John; MacCready, Parker

This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation.

Theory, modeling, and simulation of structural and functional materials: Micromechanics, microstructures, and properties

NASA Astrophysics Data System (ADS)

Jin, Yongmei

In recent years, theoretical modeling and computational simulation of microstructure evolution and materials property has been attracting much attention. While significant advances have been made, two major challenges remain. One is the integration of multiple physical phenomena for simulation of complex materials behavior, the other is the bridging over multiple length and time scales in materials modeling and simulation. The research presented in this Thesis is focused mainly on tackling the first major challenge. In this Thesis, a unified Phase Field Microelasticity (PFM) approach is developed. This approach is an advanced version of the phase field method that takes into account the exact elasticity of arbitrarily anisotropic, elastically and structurally inhomogeneous systems. The proposed theory and models are applicable to infinite solids, elastic half-space, and finite bodies with arbitrary-shaped free surfaces, which may undergo various concomitant physical processes. The Phase Field Microelasticity approach is employed to formulate the theories and models of martensitic transformation, dislocation dynamics, and crack evolution in single crystal and polycrystalline solids. It is also used to study strain relaxation in heteroepitaxial thin films through misfit dislocation and surface roughening. Magnetic domain evolution in nanocrystalline thin films is also investigated. Numerous simulation studies are performed. Comparison with analytical predictions and experimental observations are presented. Agreement verities the theory and models as realistic simulation tools for computational materials science and engineering. The same Phase Field Microelasticity formalism of individual models of different physical phenomena makes it easy to integrate multiple physical processes into one unified simulation model, where multiple phenomena are treated as various relaxation modes that together act as one common cooperative phenomenon. The model does not impose a priori constraints on possible microstructure evolution paths. This gives the model predicting power, where material system itself "chooses" the optimal path for multiple processes. The advances made in this Thesis present a significant step forward to overcome the first challenge, mesoscale multi-physics modeling and simulation of materials. At the end of this Thesis, the way to tackle the second challenge, bridging over multiple length and time scales in materials modeling and simulation, is discussed based on connection between the mesoscale Phase Field Microelasticity modeling and microscopic atomistic calculation as well as macroscopic continuum theory.

Recent Physics Doctorates: Skills Used & Satisfaction with Employment. Data from the Degree Recipient Follow-Up Survey for the Classes of 2009 and 2010. Focus On

ERIC Educational Resources Information Center

Anderson, Garrett; Mulvey, Patrick

2013-01-01

By the time people earn physics PhDs, they have learned a great deal about physics and how research is conducted. However, physics PhDs also develop skills and knowledge in a number of related areas, such as advanced mathematics, programming, modeling, and technical writing. New physics PhDs draw upon an arsenal of skills and knowledge in their…

Advanced Machine Learning Emulators of Radiative Transfer Models

NASA Astrophysics Data System (ADS)

Camps-Valls, G.; Verrelst, J.; Martino, L.; Vicent, J.

2017-12-01

Physically-based model inversion methodologies are based on physical laws and established cause-effect relationships. A plethora of remote sensing applications rely on the physical inversion of a Radiative Transfer Model (RTM), which lead to physically meaningful bio-geo-physical parameter estimates. The process is however computationally expensive, needs expert knowledge for both the selection of the RTM, its parametrization and the the look-up table generation, as well as its inversion. Mimicking complex codes with statistical nonlinear machine learning algorithms has become the natural alternative very recently. Emulators are statistical constructs able to approximate the RTM, although at a fraction of the computational cost, providing an estimation of uncertainty, and estimations of the gradient or finite integral forms. We review the field and recent advances of emulation of RTMs with machine learning models. We posit Gaussian processes (GPs) as the proper framework to tackle the problem. Furthermore, we introduce an automatic methodology to construct emulators for costly RTMs. The Automatic Gaussian Process Emulator (AGAPE) methodology combines the interpolation capabilities of GPs with the accurate design of an acquisition function that favours sampling in low density regions and flatness of the interpolation function. We illustrate the good capabilities of our emulators in toy examples, leaf and canopy levels PROSPECT and PROSAIL RTMs, and for the construction of an optimal look-up-table for atmospheric correction based on MODTRAN5.

Investigation of mechanistic deterioration modeling for bridge design and management.

DOT National Transportation Integrated Search

2017-04-01

The ongoing deterioration of highway bridges in Colorado dictates that an effective method for allocating limited management resources be developed. In order to predict bridge deterioration in advance, mechanistic models that analyze the physical pro...

Identifiability Of Systems With Modeling Errors

NASA Technical Reports Server (NTRS)

Hadaegh, Yadolah " fred" ; Bekey, George A.

1988-01-01

Advances in theory of modeling errors reported. Recent paper on errors in mathematical models of deterministic linear or weakly nonlinear systems. Extends theoretical work described in NPO-16661 and NPO-16785. Presents concrete way of accounting for difference in structure between mathematical model and physical process or system that it represents.

DARPA Helicopter Quieting Program W911NF0410424

DTIC Science & Technology

2009-05-01

Leishman , J. G. and Beddoes , T. S., “A Semi-Empirical Model for Dynamic Stall ,” Journal of the American Heli- copter Society, Vol. 34, No. 3, July 1989...of physical phenomena that include transonic and compressibility effects on the advancing blade, dynamic stall on the retreating blades and the...research approach is that even the most advanced models of a given discipline, e.g., comprehensive structural or flight dynamics codes , concentrate on a very

Tumour and normal tissue radiobiology in mouse models: how close are mice to mini-humans?

PubMed

Koontz, Bridget F; Verhaegen, Frank; De Ruysscher, Dirk

2017-01-01

Animal modelling is essential to the study of radiobiology and the advancement of clinical radiation oncology by providing preclinical data. Mouse models in particular have been highly utilized in the study of both tumour and normal tissue radiobiology because of their cost effectiveness and versatility. Technology has significantly advanced in preclinical radiation techniques to allow highly conformal image-guided irradiation of small animals in an effort to mimic human treatment capabilities. However, the biological and physical limitations of animal modelling should be recognized and considered when interpreting preclinical radiotherapy (RT) studies. Murine tumour and normal tissue radioresponse has been shown to vary from human cellular and molecular pathways. Small animal irradiation techniques utilize different anatomical boundaries and may have different physical properties than human RT. This review addresses the difference between the human condition and mouse models and discusses possible strategies for future refinement of murine models of cancer and radiation for the benefit of both basic radiobiology and clinical translation.

Ocean Modeling in an Eddying Regime

NASA Astrophysics Data System (ADS)

Hecht, Matthew W.; Hasumi, Hiroyasu

This monograph is the first to survey progress in realistic simulation in a strongly eddying regime made possible by recent increases in computational capability. Its contributors comprise the leading researchers in this important and constantly evolving field. Divided into three parts, • Oceanographic Processes and Regimes: Fundamental Questions • Ocean Dynamics and State: From Regional to Global Scale, and • Modeling at the Mesoscale: State of the Art and Future Directions the volume details important advances in physical oceanography based on eddy resolving ocean modeling. It captures the state of the art and discusses issues that ocean modelers must consider in order to effectively contribute to advancing current knowledge, from subtleties of the underlying fluid dynamical equations to meaningful comparison with oceanographic observations and leading-edge model development. It summarizes many of the important results which have emerged from ocean modeling in an eddying regime, for those interested broadly in the physical science. More technical topics are intended to address the concerns of those actively working in the field.

Tumour and normal tissue radiobiology in mouse models: how close are mice to mini-humans?

PubMed Central

Verhaegen, Frank; De Ruysscher, Dirk

2017-01-01

Animal modelling is essential to the study of radiobiology and the advancement of clinical radiation oncology by providing preclinical data. Mouse models in particular have been highly utilized in the study of both tumour and normal tissue radiobiology because of their cost effectiveness and versatility. Technology has significantly advanced in preclinical radiation techniques to allow highly conformal image-guided irradiation of small animals in an effort to mimic human treatment capabilities. However, the biological and physical limitations of animal modelling should be recognized and considered when interpreting preclinical radiotherapy (RT) studies. Murine tumour and normal tissue radioresponse has been shown to vary from human cellular and molecular pathways. Small animal irradiation techniques utilize different anatomical boundaries and may have different physical properties than human RT. This review addresses the difference between the human condition and mouse models and discusses possible strategies for future refinement of murine models of cancer and radiation for the benefit of both basic radiobiology and clinical translation. PMID:27612010

Future Directions in Medical Physics: Models, Technology, and Translation to Medicine

NASA Astrophysics Data System (ADS)

Siewerdsen, Jeffrey

The application of physics in medicine has been integral to major advances in diagnostic and therapeutic medicine. Two primary areas represent the mainstay of medical physics research in the last century: in radiation therapy, physicists have propelled advances in conformal radiation treatment and high-precision image guidance; and in diagnostic imaging, physicists have advanced an arsenal of multi-modality imaging that includes CT, MRI, ultrasound, and PET as indispensible tools for noninvasive screening, diagnosis, and assessment of treatment response. In addition to their role in building such technologically rich fields of medicine, physicists have also become integral to daily clinical practice in these areas. The future suggests new opportunities for multi-disciplinary research bridging physics, biology, engineering, and computer science, and collaboration in medical physics carries a strong capacity for identification of significant clinical needs, access to clinical data, and translation of technologies to clinical studies. In radiation therapy, for example, the extraction of knowledge from large datasets on treatment delivery, image-based phenotypes, genomic profile, and treatment outcome will require innovation in computational modeling and connection with medical physics for the curation of large datasets. Similarly in imaging physics, the demand for new imaging technology capable of measuring physical and biological processes over orders of magnitude in scale (from molecules to whole organ systems) and exploiting new contrast mechanisms for greater sensitivity to molecular agents and subtle functional / morphological change will benefit from multi-disciplinary collaboration in physics, biology, and engineering. Also in surgery and interventional radiology, where needs for increased precision and patient safety meet constraints in cost and workflow, development of new technologies for imaging, image registration, and robotic assistance can leverage collaboration in physics, biomedical engineering, and computer science. In each area, there is major opportunity for multi-disciplinary collaboration with medical physics to accelerate the translation of such technologies to clinical use. Research supported by the National Institutes of Health, Siemens Healthcare, and Carestream Health.

Predictive Simulation of Material Failure Using Peridynamics -- Advanced Constitutive Modeling, Verification and Validation

DTIC Science & Technology

2016-03-31

particular physical model under consideration. Therefore, in the following the enrichment functions are discussed with respect to particular...some domains of influence are extended outside of the physical boundary, the reproducing conditions enforced in Eq. (6) guarantee the order of...often used in astrophysics problems, where many fluid problems are encountered and even “solid" bodies deform under their own gravity. It can also

Integrated Formulation of Beacon-Based Exception Analysis for Multimissions

NASA Technical Reports Server (NTRS)

Mackey, Ryan; James, Mark; Park, Han; Zak, Mickail

2003-01-01

Further work on beacon-based exception analysis for multimissions (BEAM), a method of real-time, automated diagnosis of a complex electromechanical systems, has greatly expanded its capability and suitability of application. This expanded formulation, which fully integrates physical models and symbolic analysis, is described. The new formulation of BEAM expands upon previous advanced techniques for analysis of signal data, utilizing mathematical modeling of the system physics, and expert-system reasoning,

NASA Iced Aerodynamics and Controls Current Research

NASA Technical Reports Server (NTRS)

Addy, Gene

2009-01-01

This slide presentation reviews the state of current research in the area of aerodynamics and aircraft control with ice conditions by the Aviation Safety Program, part of the Integrated Resilient Aircraft Controls Project (IRAC). Included in the presentation is a overview of the modeling efforts. The objective of the modeling is to develop experimental and computational methods to model and predict aircraft response during adverse flight conditions, including icing. The Aircraft icing modeling efforts includes the Ice-Contaminated Aerodynamics Modeling, which examines the effects of ice contamination on aircraft aerodynamics, and CFD modeling of ice-contaminated aircraft aerodynamics, and Advanced Ice Accretion Process Modeling which examines the physics of ice accretion, and works on computational modeling of ice accretions. The IRAC testbed, a Generic Transport Model (GTM) and its use in the investigation of the effects of icing on its aerodynamics is also reviewed. This has led to a more thorough understanding and models, both theoretical and empirical of icing physics and ice accretion for airframes, advanced 3D ice accretion prediction codes, CFD methods for iced aerodynamics and better understanding of aircraft iced aerodynamics and its effects on control surface effectiveness.

Advanced Ground Systems Maintenance Physics Models For Diagnostics Project

NASA Technical Reports Server (NTRS)

Perotti, Jose M.

2015-01-01

The project will use high-fidelity physics models and simulations to simulate real-time operations of cryogenic and systems and calculate the status/health of the systems. The project enables the delivery of system health advisories to ground system operators. The capability will also be used to conduct planning and analysis of cryogenic system operations. This project will develop and implement high-fidelity physics-based modeling techniques tosimulate the real-time operation of cryogenics and other fluids systems and, when compared to thereal-time operation of the actual systems, provide assessment of their state. Physics-modelcalculated measurements (called “pseudo-sensors”) will be compared to the system real-timedata. Comparison results will be utilized to provide systems operators with enhanced monitoring ofsystems' health and status, identify off-nominal trends and diagnose system/component failures.This capability can also be used to conduct planning and analysis of cryogenics and other fluidsystems designs. This capability will be interfaced with the ground operations command andcontrol system as a part of the Advanced Ground Systems Maintenance (AGSM) project to helpassure system availability and mission success. The initial capability will be developed for theLiquid Oxygen (LO2) ground loading systems.

Closing the loop: integrating human impacts on water resources to advanced land surface models

NASA Astrophysics Data System (ADS)

Zaitchik, B. F.; Nie, W.; Rodell, M.; Kumar, S.; Li, B.

2016-12-01

Advanced Land Surface Models (LSMs), including those used in the North American Land Data Assimilation System (NLDAS), offer a physically consistent and spatially and temporally complete analysis of the distributed water balance. These models are constrained both by physically-based process representation and by observations ingested as meteorological forcing or as data assimilation updates. As such, they have become important tools for hydrological monitoring and long-term climate analysis. The representation of water management, however, is extremely limited in these models. Recent advances have brought prognostic irrigation routines into models used in NLDAS, while assimilation of Gravity Recovery and Climate Experiment (GRACE) derived estimates of terrestrial water storage anomaly has made it possible to nudge models towards observed states in water storage below the root zone. But with few exceptions these LSMs do not account for the source of irrigation water, leading to a disconnect between the simulated water balance and the observed human impact on water resources. This inconsistency is unacceptable for long-term studies of climate change and human impact on water resources in North America. Here we define the modeling challenge, review instances of models that have begun to account for water withdrawals (e.g., CLM), and present ongoing efforts to improve representation of human impacts on water storage across models through integration of irrigation routines, water withdrawal information, and GRACE Data Assimilation in NLDAS LSMs.

Physics of the Quark Model

ERIC Educational Resources Information Center

Young, Robert D.

1973-01-01

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

Science based integrated approach to advanced nuclear fuel development - integrated multi-scale multi-physics hierarchical modeling and simulation framework Part III: cladding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tome, Carlos N; Caro, J A; Lebensohn, R A

2010-01-01

Advancing the performance of Light Water Reactors, Advanced Nuclear Fuel Cycles, and Advanced Reactors, such as the Next Generation Nuclear Power Plants, requires enhancing our fundamental understanding of fuel and materials behavior under irradiation. The capability to accurately model the nuclear fuel systems to develop predictive tools is critical. Not only are fabrication and performance models needed to understand specific aspects of the nuclear fuel, fully coupled fuel simulation codes are required to achieve licensing of specific nuclear fuel designs for operation. The backbone of these codes, models, and simulations is a fundamental understanding and predictive capability for simulating themore » phase and microstructural behavior of the nuclear fuel system materials and matrices. In this paper we review the current status of the advanced modeling and simulation of nuclear reactor cladding, with emphasis on what is available and what is to be developed in each scale of the project, how we propose to pass information from one scale to the next, and what experimental information is required for benchmarking and advancing the modeling at each scale level.« less

Images of Inherited War: Three American Presidents in Vietnam

DTIC Science & Technology

2011-06-01

Dependent Realism to demonstrate how theoretical advances in modern physical science correlate to cognitive theories in International Relations. We...Quantum Physics and Model-Dependent Realism In his book, The Grand Design, theoretical physicist and cosmologist Stephen Hawking draws on theoretical...exhibited wave-like properties and that existing scientific laws could not account for their behavior. Newtonian physics was “built on a framework

A Diagnostic Model for Impending Death in Cancer Patients: Preliminary Report

PubMed Central

Hui, David; Hess, Kenneth; dos Santos, Renata; Chisholm, Gary; Bruera, Eduardo

2015-01-01

Background We recently identified several highly specific bedside physical signs associated with impending death within 3 days among patients with advanced cancer. In this study, we developed and assessed a diagnostic model for impending death based on these physical signs. Methods We systematically documented 62 physical signs every 12 hours from admission to death or discharge in 357 patients with advanced cancer admitted to acute palliative care units (APCUs) at two tertiary care cancer centers. We used recursive partitioning analysis (RPA) to develop a prediction model for impending death in 3 days using admission data. We validated the model with 5 iterations of 10-fold cross-validation, and also applied the model to APCU days 2/3/4/5/6. Results Among 322/357 (90%) patients with complete data for all signs, the 3-day mortality was 24% on admission. The final model was based on 2 variables (palliative performance scale [PPS] and drooping of nasolabial fold) and had 4 terminal leaves: PPS≤20% and drooping of nasolabial fold present, PPS≤20% and drooping of nasolabial fold absent, PPS 30–60% and PPS ≥ 70%, with 3-day mortality of 94%, 42%, 16% and 3%, respectively. The diagnostic accuracy was 81% for the original tree, 80% for cross-validation, and 79%–84% for subsequent APCU days. Conclusion(s) We developed a diagnostic model for impending death within 3 days based on 2 objective bedside physical signs. This model was applicable to both APCU admission and subsequent days. Upon further external validation, this model may help clinicians to formulate the diagnosis of impending death. PMID:26218612

SHARP Multiphysics Tutorials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Y. Q.; Shemon, E. R.; Mahadevan, Vijay S.

SHARP, developed under the NEAMS Reactor Product Line, is an advanced modeling and simulation toolkit for the analysis of advanced nuclear reactors. SHARP is comprised of three physics modules currently including neutronics, thermal hydraulics, and structural mechanics. SHARP empowers designers to produce accurate results for modeling physical phenomena that have been identified as important for nuclear reactor analysis. SHARP can use existing physics codes and take advantage of existing infrastructure capabilities in the MOAB framework and the coupling driver/solver library, the Coupled Physics Environment (CouPE), which utilizes the widely used, scalable PETSc library. This report aims at identifying the coupled-physicsmore » simulation capability of SHARP by introducing the demonstration example called sahex in advance of the SHARP release expected by Mar 2016. sahex consists of 6 fuel pins with cladding, 1 control rod, sodium coolant and an outer duct wall that encloses all the other components. This example is carefully chosen to demonstrate the proof of concept for solving more complex demonstration examples such as EBR II assembly and ABTR full core. The workflow of preparing the input files, running the case and analyzing the results is demonstrated in this report. Moreover, an extension of the sahex model called sahex_core, which adds six homogenized neighboring assemblies to the full heterogeneous sahex model, is presented to test homogenization capabilities in both Nek5000 and PROTEUS. Some primary information on the configuration and build aspects for the SHARP toolkit, which includes capability to auto-download dependencies and configure/install with optimal flags in an architecture-aware fashion, is also covered by this report. A step-by-step instruction is provided to help users to create their cases. Details on these processes will be provided in the SHARP user manual that will accompany the first release.« less

A Simple Mechanical Model for the Isotropic Harmonic Oscillator

ERIC Educational Resources Information Center

Nita, Gelu M.

2010-01-01

A constrained elastic pendulum is proposed as a simple mechanical model for the isotropic harmonic oscillator. The conceptual and mathematical simplicity of this model recommends it as an effective pedagogical tool in teaching basic physics concepts at advanced high school and introductory undergraduate course levels. (Contains 2 figures.)

Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise.

PubMed

Rapp, Teresa L; Phillips, Susan R; Dmochowski, Ivan J

2016-12-13

The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, light-driven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes that provide a sterically bulky, photolabile moiety for transiently "caging" biologically active molecules. Photouncaging involves the use of visible (1-photon) or near-IR (2-photon) light to break one or more bonds between ruthenium and coordinated ligand(s), which can occur on short time scales and in high quantum yields. In this work we demonstrate the use of a model "caged" acetonitrile complex, Ru(2,2'-bipyridine) 2 (acetonitrile) 2 , or RuMeCN in an advanced synthesis and physical chemistry laboratory. Students made RuMeCN in an advanced synthesis laboratory course and performed UV-vis spectroscopy and electrochemistry. The following semester students investigated RuMeCN photolysis kinetics in a physical chemistry laboratory. These two exercises may also be combined to create a 2-week module in an advanced undergraduate laboratory course.

Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

PubMed Central

2016-01-01

The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, light-driven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes that provide a sterically bulky, photolabile moiety for transiently “caging” biologically active molecules. Photouncaging involves the use of visible (1-photon) or near-IR (2-photon) light to break one or more bonds between ruthenium and coordinated ligand(s), which can occur on short time scales and in high quantum yields. In this work we demonstrate the use of a model “caged” acetonitrile complex, Ru(2,2′-bipyridine)2(acetonitrile)2, or RuMeCN in an advanced synthesis and physical chemistry laboratory. Students made RuMeCN in an advanced synthesis laboratory course and performed UV–vis spectroscopy and electrochemistry. The following semester students investigated RuMeCN photolysis kinetics in a physical chemistry laboratory. These two exercises may also be combined to create a 2-week module in an advanced undergraduate laboratory course. PMID:28649139

Detailed Modeling of Physical Processes in Electron Sources for Accelerator Applications

NASA Astrophysics Data System (ADS)

Chubenko, Oksana; Afanasev, Andrei

2017-01-01

At present, electron sources are essential in a wide range of applications - from common technical use to exploring the nature of matter. Depending on the application requirements, different methods and materials are used to generate electrons. State-of-the-art accelerator applications set a number of often-conflicting requirements for electron sources (e.g., quantum efficiency vs. polarization, current density vs. lifetime, etc). Development of advanced electron sources includes modeling and design of cathodes, material growth, fabrication of cathodes, and cathode testing. The detailed simulation and modeling of physical processes is required in order to shed light on the exact mechanisms of electron emission and to develop new-generation electron sources with optimized efficiency. The purpose of the present work is to study physical processes in advanced electron sources and develop scientific tools, which could be used to predict electron emission from novel nano-structured materials. In particular, the area of interest includes bulk/superlattice gallium arsenide (bulk/SL GaAs) photo-emitters and nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) photo/field-emitters. Work supported by The George Washington University and Euclid TechLabs LLC.

Lithium Gadolinium Borate in Plastic Scintillator as an Antineutrino Detection Material

DTIC Science & Technology

2010-06-01

advancement of fundamental particle physics, development of the standard model of particle physics and our understanding many cosmological processes...MeVee). Where the light produced by by a 1MeV electron is 1 MeVee by definition , but a heavy charged particle would have a kinetic energy of several

This "Is" Rocket Science!

ERIC Educational Resources Information Center

Keith, Wayne; Martin, Cynthia; Veltkamp, Pamela

2013-01-01

Using model rockets to teach physics can be an effective way to engage students in learning. In this paper, we present a curriculum developed in response to an expressed need for helping high school students review physics equations in preparation for a state-mandated exam. This required a mode of teaching that was more advanced and analytical…

A Collaborative Model for Community-Based Health Care Screening of Homeless Adolescents.

ERIC Educational Resources Information Center

Busen, Nancy H.; Beech, Bettina

1997-01-01

A multidisciplinary team from community organizations serving the homeless and from universities collaborated in screening 150 homeless adolescents for psychosocial and physical risks. The population had a history of physical, sexual, and substance abuse as well as high rates of HIV and hepatitis B. Case management by advanced practice nurses was…

CFD for hypersonic airbreathing aircraft

NASA Technical Reports Server (NTRS)

Kumar, Ajay

1989-01-01

A general discussion is given on the use of advanced computational fluid dynamics (CFD) in analyzing the hypersonic flow field around an airbreathing aircraft. Unique features of the hypersonic flow physics are presented and an assessment is given of the current algorithms in terms of their capability to model hypersonic flows. Several examples of advanced CFD applications are then presented.

Magnetic Excitations and Geometric Confinement; Theory and simulations

NASA Astrophysics Data System (ADS)

Wysin, Gary Matthew

2015-12-01

In this book, author Gary Wysin provides an overview of model systems and their behaviour and effects, and is intended for advanced students and researchers in physics, chemistry and engineering interested in confined magnetics. It is also suitable as an auxiliary text in a class on magnetism or solid state physics. Previous physics knowledge is expected, along with some basic knowledge of classical electromagnetism and electromagnetic waves for the latter chapters.

Recent Advances in WRF Modeling for Air Quality Applications

EPA Science Inventory

The USEPA uses WRF in conjunction with the Community Multiscale Air Quality (CMAQ) for air quality regulation and research. Over the years we have added physics options and geophysical datasets to the WRF system to enhance model capabilities especially for extended retrospective...

Survey of current situation in radiation belt modeling

NASA Technical Reports Server (NTRS)

Fung, Shing F.

2004-01-01

The study of Earth's radiation belts is one of the oldest subjects in space physics. Despite the tremendous progress made in the last four decades, we still lack a complete understanding of the radiation belts in terms of their configurations, dynamics, and detailed physical accounts of their sources and sinks. The static nature of early empirical trapped radiation models, for examples, the NASA AP-8 and AE-8 models, renders those models inappropriate for predicting short-term radiation belt behaviors associated with geomagnetic storms and substorms. Due to incomplete data coverage, these models are also inaccurate at low altitudes (e.g., <1000 km) where many robotic and human space flights occur. The availability of radiation data from modern space missions and advancement in physical modeling and data management techniques have now allowed the development of new empirical and physical radiation belt models. In this paper, we will review the status of modern radiation belt modeling. Published by Elsevier Ltd on behalf of COSPAR.

Coal conversion systems design and process modeling. Volume 1: Application of MPPR and Aspen computer models

NASA Technical Reports Server (NTRS)

1981-01-01

The development of a coal gasification system design and mass and energy balance simulation program for the TVA and other similar facilities is described. The materials-process-product model (MPPM) and the advanced system for process engineering (ASPEN) computer program were selected from available steady state and dynamic models. The MPPM was selected to serve as the basis for development of system level design model structure because it provided the capability for process block material and energy balance and high-level systems sizing and costing. The ASPEN simulation serves as the basis for assessing detailed component models for the system design modeling program. The ASPEN components were analyzed to identify particular process blocks and data packages (physical properties) which could be extracted and used in the system design modeling program. While ASPEN physical properties calculation routines are capable of generating physical properties required for process simulation, not all required physical property data are available, and must be user-entered.

Validation and Calibration of Nuclear Thermal Hydraulics Multiscale Multiphysics Models - Subcooled Flow Boiling Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anh Bui; Nam Dinh; Brian Williams

In addition to validation data plan, development of advanced techniques for calibration and validation of complex multiscale, multiphysics nuclear reactor simulation codes are a main objective of the CASL VUQ plan. Advanced modeling of LWR systems normally involves a range of physico-chemical models describing multiple interacting phenomena, such as thermal hydraulics, reactor physics, coolant chemistry, etc., which occur over a wide range of spatial and temporal scales. To a large extent, the accuracy of (and uncertainty in) overall model predictions is determined by the correctness of various sub-models, which are not conservation-laws based, but empirically derived from measurement data. Suchmore » sub-models normally require extensive calibration before the models can be applied to analysis of real reactor problems. This work demonstrates a case study of calibration of a common model of subcooled flow boiling, which is an important multiscale, multiphysics phenomenon in LWR thermal hydraulics. The calibration process is based on a new strategy of model-data integration, in which, all sub-models are simultaneously analyzed and calibrated using multiple sets of data of different types. Specifically, both data on large-scale distributions of void fraction and fluid temperature and data on small-scale physics of wall evaporation were simultaneously used in this work’s calibration. In a departure from traditional (or common-sense) practice of tuning/calibrating complex models, a modern calibration technique based on statistical modeling and Bayesian inference was employed, which allowed simultaneous calibration of multiple sub-models (and related parameters) using different datasets. Quality of data (relevancy, scalability, and uncertainty) could be taken into consideration in the calibration process. This work presents a step forward in the development and realization of the “CIPS Validation Data Plan” at the Consortium for Advanced Simulation of LWRs to enable quantitative assessment of the CASL modeling of Crud-Induced Power Shift (CIPS) phenomenon, in particular, and the CASL advanced predictive capabilities, in general. This report is prepared for the Department of Energy’s Consortium for Advanced Simulation of LWRs program’s VUQ Focus Area.« less

Advances in Cell and Gene-based Therapies for Cystic Fibrosis Lung Disease

PubMed Central

Oakland, Mayumi; Sinn, Patrick L; McCray Jr, Paul B

2012-01-01

Cystic fibrosis (CF) is a disease characterized by airway infection, inflammation, remodeling, and obstruction that gradually destroy the lungs. Direct delivery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene to airway epithelia may offer advantages, as the tissue is accessible for topical delivery of vectors. Yet, physical and host immune barriers in the lung present challenges for successful gene transfer to the respiratory tract. Advances in gene transfer approaches, tissue engineering, and novel animal models are generating excitement within the CF research field. This review discusses current challenges and advancements in viral and nonviral vectors, cell-based therapies, and CF animal models. PMID:22371844

The Net Advance of Physics

Science.gov Websites

THE NET ADVANCE OF PHYSICS Review Articles and Tutorials in an Encyclopædic Format Established 1995 [Link to MIT] Computer support for The Net Advance of Physics is furnished by The Massachusetts Newest Additions SPECIAL FEATURES: Net Advance RETRO: Nineteenth Century Physics History of Science

Reviews

NASA Astrophysics Data System (ADS)

2002-11-01

CD-ROM REVIEW (551) Essential Physics BOOK REVIEWS (551) Collins Advanced Science: Physics, 2nd edition Quarks, Leptons and the Big Bang, 2nd edition Do Brilliantly: A2 Physics IGCSE Physics Geophysics in the UK Synoptic Skills in Advanced Physics Flash! The hunt for the biggest explosions in the universe Materials Maths for Advanced Physics

Physics through the 1990s: Nuclear physics

NASA Technical Reports Server (NTRS)

1986-01-01

The volume begins with a non-mathematical introduction to nuclear physics. A description of the major advances in the field follows, with chapters on nuclear structure and dynamics, fundamental forces in the nucleus, and nuclei under extreme conditions of temperature, density, and spin. Impacts of nuclear physics on astrophysics and the scientific and societal benefits of nuclear physics are then discussed. Another section deals with scientific frontiers, describing research into the realm of the quark-gluon plasma; the changing description of nuclear matter, specifically the use of the quark model; and the implications of the standard model and grand unified theories of elementary-particle physics; and finishes with recommendations and priorities for nuclear physics research facilities, instrumentation, accelerators, theory, education, and data bases. Appended are a list of national accelerator facilities, a list of reviewers, a bibliography, and a glossary.

The Australian Computational Earth Systems Simulator

NASA Astrophysics Data System (ADS)

Mora, P.; Muhlhaus, H.; Lister, G.; Dyskin, A.; Place, D.; Appelbe, B.; Nimmervoll, N.; Abramson, D.

2001-12-01

Numerical simulation of the physics and dynamics of the entire earth system offers an outstanding opportunity for advancing earth system science and technology but represents a major challenge due to the range of scales and physical processes involved, as well as the magnitude of the software engineering effort required. However, new simulation and computer technologies are bringing this objective within reach. Under a special competitive national funding scheme to establish new Major National Research Facilities (MNRF), the Australian government together with a consortium of Universities and research institutions have funded construction of the Australian Computational Earth Systems Simulator (ACcESS). The Simulator or computational virtual earth will provide the research infrastructure to the Australian earth systems science community required for simulations of dynamical earth processes at scales ranging from microscopic to global. It will consist of thematic supercomputer infrastructure and an earth systems simulation software system. The Simulator models and software will be constructed over a five year period by a multi-disciplinary team of computational scientists, mathematicians, earth scientists, civil engineers and software engineers. The construction team will integrate numerical simulation models (3D discrete elements/lattice solid model, particle-in-cell large deformation finite-element method, stress reconstruction models, multi-scale continuum models etc) with geophysical, geological and tectonic models, through advanced software engineering and visualization technologies. When fully constructed, the Simulator aims to provide the software and hardware infrastructure needed to model solid earth phenomena including global scale dynamics and mineralisation processes, crustal scale processes including plate tectonics, mountain building, interacting fault system dynamics, and micro-scale processes that control the geological, physical and dynamic behaviour of earth systems. ACcESS represents a part of Australia's contribution to the APEC Cooperation for Earthquake Simulation (ACES) international initiative. Together with other national earth systems science initiatives including the Japanese Earth Simulator and US General Earthquake Model projects, ACcESS aims to provide a driver for scientific advancement and technological breakthroughs including: quantum leaps in understanding of earth evolution at global, crustal, regional and microscopic scales; new knowledge of the physics of crustal fault systems required to underpin the grand challenge of earthquake prediction; new understanding and predictive capabilities of geological processes such as tectonics and mineralisation.

Getting the right answers for the right reasons: Linking measurements, analyses, and models to advance the science of hydrology

NASA Astrophysics Data System (ADS)

Kirchner, James W.

2006-03-01

The science of hydrology is on the threshold of major advances, driven by new hydrologic measurements, new methods for analyzing hydrologic data, and new approaches to modeling hydrologic systems. Here I suggest several promising directions forward, including (1) designing new data networks, field observations, and field experiments, with explicit recognition of the spatial and temporal heterogeneity of hydrologic processes, (2) replacing linear, additive "black box" models with "gray box" approaches that better capture the nonlinear and non-additive character of hydrologic systems, (3) developing physically based governing equations for hydrologic behavior at the catchment or hillslope scale, recognizing that they may look different from the equations that describe the small-scale physics, (4) developing models that are minimally parameterized and therefore stand some chance of failing the tests that they are subjected to, and (5) developing ways to test models more comprehensively and incisively. I argue that scientific progress will mostly be achieved through the collision of theory and data, rather than through increasingly elaborate and parameter-rich models that may succeed as mathematical marionettes, dancing to match the calibration data even if their underlying premises are unrealistic. Thus advancing the science of hydrology will require not only developing theories that get the right answers but also testing whether they get the right answers for the right reasons.

A diagnostic model for impending death in cancer patients: Preliminary report.

PubMed

Hui, David; Hess, Kenneth; dos Santos, Renata; Chisholm, Gary; Bruera, Eduardo

2015-11-01

Several highly specific bedside physical signs associated with impending death within 3 days for patients with advanced cancer were recently identified. A diagnostic model for impending death based on these physical signs was developed and assessed. Sixty-two physical signs were systematically documented every 12 hours from admission to death or discharge for 357 patients with advanced cancer who were admitted to acute palliative care units (APCUs) at 2 tertiary care cancer centers. Recursive partitioning analysis was used to develop a prediction model for impending death within 3 days with admission data. The model was validated with 5 iterations of 10-fold cross-validation, and the model was also applied to APCU days 2 to 6. For the 322 of 357 patients (90%) with complete data for all signs, the 3-day mortality rate was 24% on admission. The final model was based on 2 variables (Palliative Performance Scale [PPS] and drooping of nasolabial folds) and had 4 terminal leaves: PPS score ≤ 20% and drooping of nasolabial folds present, PPS score ≤ 20% and drooping of nasolabial folds absent, PPS score of 30% to 60%, and PPS score ≥ 70%. The 3-day mortality rates were 94%, 42%, 16%, and 3%, respectively. The diagnostic accuracy was 81% for the original tree, 80% for cross-validation, and 79% to 84% for subsequent APCU days. Based on 2 objective bedside physical signs, a diagnostic model was developed for impending death within 3 days. This model was applicable to both APCU admission and subsequent days. Upon further external validation, this model may help clinicians to formulate the diagnosis of impending death. © 2015 American Cancer Society.

Computer Simulations of Quantum Theory of Hydrogen Atom for Natural Science Education Students in a Virtual Lab

ERIC Educational Resources Information Center

Singh, Gurmukh

2012-01-01

The present article is primarily targeted for the advanced college/university undergraduate students of chemistry/physics education, computational physics/chemistry, and computer science. The most recent software system such as MS Visual Studio .NET version 2010 is employed to perform computer simulations for modeling Bohr's quantum theory of…

Advances in the physics basis for the European DEMO design

NASA Astrophysics Data System (ADS)

Wenninger, R.; Arbeiter, F.; Aubert, J.; Aho-Mantila, L.; Albanese, R.; Ambrosino, R.; Angioni, C.; Artaud, J.-F.; Bernert, M.; Fable, E.; Fasoli, A.; Federici, G.; Garcia, J.; Giruzzi, G.; Jenko, F.; Maget, P.; Mattei, M.; Maviglia, F.; Poli, E.; Ramogida, G.; Reux, C.; Schneider, M.; Sieglin, B.; Villone, F.; Wischmeier, M.; Zohm, H.

2015-06-01

In the European fusion roadmap, ITER is followed by a demonstration fusion power reactor (DEMO), for which a conceptual design is under development. This paper reports the first results of a coherent effort to develop the relevant physics knowledge for that (DEMO Physics Basis), carried out by European experts. The program currently includes investigations in the areas of scenario modeling, transport, MHD, heating & current drive, fast particles, plasma wall interaction and disruptions.

Non-collinear Generation of Angularly Isolated Circularly Polarized High Harmonics

DTIC Science & Technology

2015-09-21

collinear HHG using both intuitive physical models as well as advanced numerical calculations. In the photon picture (Fig. 1b), we show that the NCP...Department of Physics , University of Colorado and NIST, Boulder, Colorado 80309, USA. 2Grupo de Investigación en Óptica Extrema, Universidad de... Physics , Colorado School of Mines, Golden, Colorado 80401, USA. *e-mail: danhickstein@gmail.com ARTICLES PUBLISHED ONLINE: 21 SEPTEMBER 2015 | DOI

An Anticipatory Model of Cavitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allgood, G.O.; Dress, W.B., Jr.; Hylton, J.O.

1999-04-05

The Anticipatory System (AS) formalism developed by Robert Rosen provides some insight into the problem of embedding intelligent behavior in machines. AS emulates the anticipatory behavior of biological systems. AS bases its behavior on its expectations about the near future and those expectations are modified as the system gains experience. The expectation is based on an internal model that is drawn from an appeal to physical reality. To be adaptive, the model must be able to update itself. To be practical, the model must run faster than real-time. The need for a physical model and the requirement that the modelmore » execute at extreme speeds, has held back the application of AS to practical problems. Two recent advances make it possible to consider the use of AS for practical intelligent sensors. First, advances in transducer technology make it possible to obtain previously unavailable data from which a model can be derived. For example, acoustic emissions (AE) can be fed into a Bayesian system identifier that enables the separation of a weak characterizing signal, such as the signature of pump cavitation precursors, from a strong masking signal, such as a pump vibration feature. The second advance is the development of extremely fast, but inexpensive, digital signal processing hardware on which it is possible to run an adaptive Bayesian-derived model faster than real-time. This paper reports the investigation of an AS using a model of cavitation based on hydrodynamic principles and Bayesian analysis of data from high-performance AE sensors.« less

Effects of rehabilitation among patients with advances cancer: a systematic review.

PubMed

Salakari, Minna R J; Surakka, Tiina; Nurminen, Raija; Pylkkänen, Liisa

2015-05-01

In parallel with the rising incidence of cancer and improved treatment, there is a continuous increase in the number of patients living with cancer as a chronic condition. Many cancer patients experience long-term disability and require continuous oncological treatment, care and support. The aim of this review is to evaluate the most recent data on the effects of rehabilitation among patients with advanced cancer. A systematic review was conducted according to Fink's model. Only randomized controlled trials (RCTs) published in 2009-2014 were included. Medline/PubMed and Cochrane databases were searched; five groups of keywords were used. The articles were evaluated for outcome and methodological quality. Thirteen RCTs (1169 participants) were evaluated. Most studies were on the effects of physical exercise in patients with advanced cancer (N = 7). Physical exercise was associated with a significant improvement in general wellbeing and quality of life. Rehabilitation had positive effects on fatigue, general condition, mood, and coping with cancer. Rehabilitation is needed also among patients with advanced disease and in palliative care. Exercise improves physical performance and has positive effects on several other quality of life domains. More data and RCTs are needed, but current evidence gives an indication that rehabilitation is suitable and can be recommended for patients living with advanced cancer.

Accounting for the influence of salt water in the physics required for processing underwater UXO EMI signals

NASA Astrophysics Data System (ADS)

Shubitidze, Fridon; Barrowes, Benjamin E.; Shamatava, Irma; Sigman, John; O'Neill, Kevin A.

2018-05-01

Processing electromagnetic induction signals from subsurface targets, for purposes of discrimination, requires accurate physical models. To date, successful approaches for on-land cases have entailed advanced modeling of responses by the targets themselves, with quite adequate treatment of instruments as well. Responses from the environment were typically slight and/or were treated very simply. When objects are immersed in saline solutions, however, more sophisticated modeling of the diffusive EMI physics in the environment is required. One needs to account for the response of the environment itself as well as the environment's frequency and time-dependent effects on both primary and secondary fields, from sensors and targets, respectively. Here we explicate the requisite physics and identify its effects quantitatively via analytical, numerical, and experimental investigations. Results provide a path for addressing the quandaries posed by previous underwater measurements and indicate how the environmental physics may be included in more successful processing.

Physical control oriented model of large scale refrigerators to synthesize advanced control schemes. Design, validation, and first control results

NASA Astrophysics Data System (ADS)

Bonne, François; Alamir, Mazen; Bonnay, Patrick

2014-01-01

In this paper, a physical method to obtain control-oriented dynamical models of large scale cryogenic refrigerators is proposed, in order to synthesize model-based advanced control schemes. These schemes aim to replace classical user experience designed approaches usually based on many independent PI controllers. This is particularly useful in the case where cryoplants are submitted to large pulsed thermal loads, expected to take place in the cryogenic cooling systems of future fusion reactors such as the International Thermonuclear Experimental Reactor (ITER) or the Japan Torus-60 Super Advanced Fusion Experiment (JT-60SA). Advanced control schemes lead to a better perturbation immunity and rejection, to offer a safer utilization of cryoplants. The paper gives details on how basic components used in the field of large scale helium refrigeration (especially those present on the 400W @1.8K helium test facility at CEA-Grenoble) are modeled and assembled to obtain the complete dynamic description of controllable subsystems of the refrigerator (controllable subsystems are namely the Joule-Thompson Cycle, the Brayton Cycle, the Liquid Nitrogen Precooling Unit and the Warm Compression Station). The complete 400W @1.8K (in the 400W @4.4K configuration) helium test facility model is then validated against experimental data and the optimal control of both the Joule-Thompson valve and the turbine valve is proposed, to stabilize the plant under highly variable thermals loads. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.

Physical control oriented model of large scale refrigerators to synthesize advanced control schemes. Design, validation, and first control results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonne, François; Bonnay, Patrick; Alamir, Mazen

2014-01-29

In this paper, a physical method to obtain control-oriented dynamical models of large scale cryogenic refrigerators is proposed, in order to synthesize model-based advanced control schemes. These schemes aim to replace classical user experience designed approaches usually based on many independent PI controllers. This is particularly useful in the case where cryoplants are submitted to large pulsed thermal loads, expected to take place in the cryogenic cooling systems of future fusion reactors such as the International Thermonuclear Experimental Reactor (ITER) or the Japan Torus-60 Super Advanced Fusion Experiment (JT-60SA). Advanced control schemes lead to a better perturbation immunity and rejection,more » to offer a safer utilization of cryoplants. The paper gives details on how basic components used in the field of large scale helium refrigeration (especially those present on the 400W @1.8K helium test facility at CEA-Grenoble) are modeled and assembled to obtain the complete dynamic description of controllable subsystems of the refrigerator (controllable subsystems are namely the Joule-Thompson Cycle, the Brayton Cycle, the Liquid Nitrogen Precooling Unit and the Warm Compression Station). The complete 400W @1.8K (in the 400W @4.4K configuration) helium test facility model is then validated against experimental data and the optimal control of both the Joule-Thompson valve and the turbine valve is proposed, to stabilize the plant under highly variable thermals loads. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.« less

Shock-loading response of advanced materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, G.T. III

1993-08-01

Advanced materials, such as composites (metal, ceramic, or polymer-matrix), intermetallics, foams (metallic or polymeric-based), laminated materials, and nanostructured materials are receiving increasing attention because their properties can be custom tailored specific applications. The high-rate/impact response of advanced materials is relevant to a broad range of service environments such as the crashworthiness of civilian/military vehicles, foreign-object-damage in aerospace, and light-weight armor. Increased utilization of these material classes under dynamic loading conditions requires an understanding of the relationship between high-rate/shock-wave response as a function of microstructure if we are to develop models to predict material behavior. In this paper the issues relevantmore » to defect generation, storage, and the underlying physical basis needed in predictive models for several advanced materials will be reviewed.« less

Radiative Transfer Modeling and Retrievals for Advanced Hyperspectral Sensors

NASA Technical Reports Server (NTRS)

Liu, Xu; Zhou, Daniel K.; Larar, Allen M.; Smith, William L., Sr.; Mango, Stephen A.

2009-01-01

A novel radiative transfer model and a physical inversion algorithm based on principal component analysis will be presented. Instead of dealing with channel radiances, the new approach fits principal component scores of these quantities. Compared to channel-based radiative transfer models, the new approach compresses radiances into a much smaller dimension making both forward modeling and inversion algorithm more efficient.

Predictability of the geospace variations and measuring the capability to model the state of the system

NASA Astrophysics Data System (ADS)

Pulkkinen, A.

2012-12-01

Empirical modeling has been the workhorse of the past decades in predicting the state of the geospace. For example, numerous empirical studies have shown that global geoeffectiveness indices such as Kp and Dst are generally well predictable from the solar wind input. These successes have been facilitated partly by the strongly externally driven nature of the system. Although characterizing the general state of the system is valuable and empirical modeling will continue playing an important role, refined physics-based quantification of the state of the system has been the obvious next step in moving toward more mature science. Importantly, more refined and localized products are needed also for space weather purposes. Predictions of local physical quantities are necessary to make physics-based links to the impacts on specific systems. As we have introduced more localized predictions of the geospace state one central question is how predictable these local quantities are? This complex question can be addressed by rigorously measuring the model performance against the observed data. Space sciences community has made great advanced on this topic over the past few years and there are ongoing efforts in SHINE, CEDAR and GEM to carry out community-wide evaluations of the state-of-the-art solar and heliospheric, ionosphere-thermosphere and geospace models, respectively. These efforts will help establish benchmarks and thus provide means to measure the progress in the field analogous to monitoring of the improvement in lower atmospheric weather predictions carried out rigorously since 1980s. In this paper we will discuss some of the latest advancements in predicting the local geospace parameters and give an overview of some of the community efforts to rigorously measure the model performances. We will also briefly discuss some of the future opportunities for advancing the geospace modeling capability. These will include further development in data assimilation and ensemble modeling (e.g. taking into account uncertainty in the inflow boundary conditions).

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

This factsheet describes a project that developed and demonstrated a new manufacturing-informed design framework that utilizes advanced multi-scale, physics-based process modeling to dramatically improve manufacturing productivity and quality in machining operations while reducing the cost of machined components.

A fully-implicit high-order system thermal-hydraulics model for advanced non-LWR safety analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Rui

An advanced system analysis tool is being developed for advanced reactor safety analysis. This paper describes the underlying physics and numerical models used in the code, including the governing equations, the stabilization schemes, the high-order spatial and temporal discretization schemes, and the Jacobian Free Newton Krylov solution method. The effects of the spatial and temporal discretization schemes are investigated. Additionally, a series of verification test problems are presented to confirm the high-order schemes. Furthermore, it is demonstrated that the developed system thermal-hydraulics model can be strictly verified with the theoretical convergence rates, and that it performs very well for amore » wide range of flow problems with high accuracy, efficiency, and minimal numerical diffusions.« less

A fully-implicit high-order system thermal-hydraulics model for advanced non-LWR safety analyses

DOE PAGES

Hu, Rui

2016-11-19

An advanced system analysis tool is being developed for advanced reactor safety analysis. This paper describes the underlying physics and numerical models used in the code, including the governing equations, the stabilization schemes, the high-order spatial and temporal discretization schemes, and the Jacobian Free Newton Krylov solution method. The effects of the spatial and temporal discretization schemes are investigated. Additionally, a series of verification test problems are presented to confirm the high-order schemes. Furthermore, it is demonstrated that the developed system thermal-hydraulics model can be strictly verified with the theoretical convergence rates, and that it performs very well for amore » wide range of flow problems with high accuracy, efficiency, and minimal numerical diffusions.« less

Biological materials by design.

PubMed

Qin, Zhao; Dimas, Leon; Adler, David; Bratzel, Graham; Buehler, Markus J

2014-02-19

In this topical review we discuss recent advances in the use of physical insight into the way biological materials function, to design novel engineered materials 'from scratch', or from the level of fundamental building blocks upwards and by using computational multiscale methods that link chemistry to material function. We present studies that connect advances in multiscale hierarchical material structuring with material synthesis and testing, review case studies of wood and other biological materials, and illustrate how engineered fiber composites and bulk materials are designed, modeled, and then synthesized and tested experimentally. The integration of experiment and simulation in multiscale design opens new avenues to explore the physics of materials from a fundamental perspective, and using complementary strengths from models and empirical techniques. Recent developments in this field illustrate a new paradigm by which complex material functionality is achieved through hierarchical structuring in spite of simple material constituents.

NSF's Perspective on Space Weather Research for Building Forecasting Capabilities

NASA Astrophysics Data System (ADS)

Bisi, M. M.; Pulkkinen, A. A.; Bisi, M. M.; Pulkkinen, A. A.; Webb, D. F.; Oughton, E. J.; Azeem, S. I.

2017-12-01

Space weather research at the National Science Foundation (NSF) is focused on scientific discovery and on deepening knowledge of the Sun-Geospace system. The process of maturation of knowledge base is a requirement for the development of improved space weather forecast models and for the accurate assessment of potential mitigation strategies. Progress in space weather forecasting requires advancing in-depth understanding of the underlying physical processes, developing better instrumentation and measurement techniques, and capturing the advancements in understanding in large-scale physics based models that span the entire chain of events from the Sun to the Earth. This presentation will provide an overview of current and planned programs pertaining to space weather research at NSF and discuss the recommendations of the Geospace Section portfolio review panel within the context of space weather forecasting capabilities.

Taking a fresh look at boiling heat transfer on the road to improved nuclear economics and efficiency

DOE PAGES

Pointer, William David; Baglietto, Emilio

2016-05-01

Here, in the effort to reinvigorate innovation in the way we design, build, and operate the nuclear power generating stations of today and tomorrow, nothing can be taken for granted. Not even the seemingly familiar physics of boiling water. The Consortium for the Advanced Simulation of Light Water Reactors, or CASL, is focused on the deployment of advanced modeling and simulation capabilities to enable the nuclear industry to reduce uncertainties in the prediction of multi-physics phenomena and continue to improve the performance of today’s Light Water Reactors and their fuel. An important part of the CASL mission is the developmentmore » of a next generation thermal hydraulics simulation capability, integrating the history of engineering models based on experimental experience with the computing technology of the future.« less

Fear of Failure, 2x2 Achievement Goal and Self-Handicapping: An Examination of the Hierarchical Model of Achievement Motivation in Physical Education

ERIC Educational Resources Information Center

Chen, Lung Hung; Wu, Chia-Huei; Kee, Ying Hwa; Lin, Meng-Shyan; Shui, Shang-Hsueh

2009-01-01

In this study, the hierarchical model of achievement motivation [Elliot, A. J. (1997). Integrating the "classic" and "contemporary" approaches to achievement motivation: A hierarchical model of approach and avoidance achievement motivation. In P. Pintrich & M. Maehr (Eds.), "Advances in motivation and achievement"…

Advanced Chemical Modeling for Turbulent Combustion Simulations

DTIC Science & Technology

2012-05-03

premixed combustion. The chemistry work proposes a method for defining jet fuel surrogates, describes how different sub- mechanisms can be incorporated...Chemical Modeling For Turbulent Combustion Simulations Final Report submitted by: Heinz Pitsch (PI) Stanford University Mechanical Engineering Flow Physics...predict the combustion characteristics of fuel oxidation and pollutant emissions from engines . The relevant fuel chemistry must be accurately modeled

Physical-Biological-Optics Model Development and Simulation for the Pacific Ocean and Monterey Bay, California

DTIC Science & Technology

2011-04-01

advanced ROMS-CoSiNE-Optics model in a full three-dimensional environment. We collaborate with Dr. Curt Mobley at Sequoia Scientific to implement...projects. Besides working closely with the modeling group at the NRL and their BioSpace project, we are collaborating with Dr. Curtis Mobley of Sequoia

Phenomenological Modeling of Infrared Sources: Recent Advances

NASA Technical Reports Server (NTRS)

Leung, Chun Ming; Kwok, Sun (Editor)

1993-01-01

Infrared observations from planned space facilities (e.g., ISO (Infrared Space Observatory), SIRTF (Space Infrared Telescope Facility)) will yield a large and uniform sample of high-quality data from both photometric and spectroscopic measurements. To maximize the scientific returns of these space missions, complementary theoretical studies must be undertaken to interpret these observations. A crucial step in such studies is the construction of phenomenological models in which we parameterize the observed radiation characteristics in terms of the physical source properties. In the last decade, models with increasing degree of physical realism (in terms of grain properties, physical processes, and source geometry) have been constructed for infrared sources. Here we review current capabilities available in the phenomenological modeling of infrared sources and discuss briefly directions for future research in this area.

Annual research briefs, 1988

NASA Technical Reports Server (NTRS)

1989-01-01

The primary objective of the Center for Turbulence Research (CTR) is to stimulate and produce advances in physical understanding of turbulence, in turbulence modeling and simulation, and in turbulence control. Topics addressed include: fundamental modeling of turbulence; turbulence structure and control; transition and turbulence in high-speed compressible flows; and turbulent reacting flows.

Benchmarking and Modeling of a Conventional Mid-Size Car Using ALPHA (SAE Paper 2015-01-1140)

EPA Science Inventory

The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) modeling tool was created by EPA to estimate greenhouse gas (GHG) emissions of light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle type...

The thermal and mechanical stability of composite materials for space structures

NASA Technical Reports Server (NTRS)

Tompkins, S. S.; Sykes, G. F.; Bowles, D. E.

1985-01-01

A continuing research objective of the National Aeronautical and Space Administration (NASA) is to develop advanced composite materials for space structures. The thrust of this research is to gain fundamental understanding of the performance of advanced composites in the space environment. The emphasis has been to identify and model changes in the thermal-physical properties due to induced damage and develop improved materials.

Advanced Electronic Structures

DTIC Science & Technology

1992-10-01

Physicist Physical Electronics Laboratory SRI Project 2407 D T IC Prepared for: S ELECTEr’ Office of Naval Research DEC 0 81992 800 North Quincy Street...talk at the March 1992 meeting of the American Physical Society. The sub- ject was the use of pressure as a new variable for testing the underlying...on the MIGS model. We intend to submit to Physical Review Letters, and are only waiting for Eike to complete a draft of the ma iuscript. 1 2.1.2

Recent advances in hypersonic technology

NASA Technical Reports Server (NTRS)

Dwoyer, Douglas L.

1990-01-01

This paper will focus on recent advances in hypersonic aerodynamic prediction techniques. Current capabilities of existing numerical methods for predicting high Mach number flows will be discussed and shortcomings will be identified. Physical models available for inclusion into modern codes for predicting the effects of transition and turbulence will also be outlined and their limitations identified. Chemical reaction models appropriate to high-speed flows will be addressed, and the impact of their inclusion in computational fluid dynamics codes will be discussed. Finally, the problem of validating predictive techniques for high Mach number flows will be addressed.

2D Flood Modelling Using Advanced Terrain Analysis Techniques And A Fully Continuous DEM-Based Rainfall-Runoff Algorithm

NASA Astrophysics Data System (ADS)

Nardi, F.; Grimaldi, S.; Petroselli, A.

2012-12-01

Remotely sensed Digital Elevation Models (DEMs), largely available at high resolution, and advanced terrain analysis techniques built in Geographic Information Systems (GIS), provide unique opportunities for DEM-based hydrologic and hydraulic modelling in data-scarce river basins paving the way for flood mapping at the global scale. This research is based on the implementation of a fully continuous hydrologic-hydraulic modelling optimized for ungauged basins with limited river flow measurements. The proposed procedure is characterized by a rainfall generator that feeds a continuous rainfall-runoff model producing flow time series that are routed along the channel using a bidimensional hydraulic model for the detailed representation of the inundation process. The main advantage of the proposed approach is the characterization of the entire physical process during hydrologic extreme events of channel runoff generation, propagation, and overland flow within the floodplain domain. This physically-based model neglects the need for synthetic design hyetograph and hydrograph estimation that constitute the main source of subjective analysis and uncertainty of standard methods for flood mapping. Selected case studies show results and performances of the proposed procedure as respect to standard event-based approaches.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Platania, P., E-mail: platania@ifp.cnr.it; Figini, L.; Farina, D.

The purpose of this work is the optical modeling and physical performances evaluations of the JT-60SA ECRF launcher system. The beams have been simulated with the electromagnetic code GRASP® and used as input for ECCD calculations performed with the beam tracing code GRAY, capable of modeling propagation, absorption and current drive of an EC Gaussion beam with general astigmatism. Full details of the optical analysis has been taken into account to model the launched beams. Inductive and advanced reference scenarios has been analysed for physical evaluations in the full poloidal and toroidal steering ranges for two slightly different layouts ofmore » the launcher system.« less

Automated Deployment of Advanced Controls and Analytics in Buildings

NASA Astrophysics Data System (ADS)

Pritoni, Marco

Buildings use 40% of primary energy in the US. Recent studies show that developing energy analytics and enhancing control strategies can significantly improve their energy performance. However, the deployment of advanced control software applications has been mostly limited to academic studies. Larger-scale implementations are prevented by the significant engineering time and customization required, due to significant differences among buildings. This study demonstrates how physics-inspired data-driven models can be used to develop portable analytics and control applications for buildings. Specifically, I demonstrate application of these models in all phases of the deployment of advanced controls and analytics in buildings: in the first phase, "Site Preparation and Interface with Legacy Systems" I used models to discover or map relationships among building components, automatically gathering metadata (information about data points) necessary to run the applications. During the second phase: "Application Deployment and Commissioning", models automatically learn system parameters, used for advanced controls and analytics. In the third phase: "Continuous Monitoring and Verification" I utilized models to automatically measure the energy performance of a building that has implemented advanced control strategies. In the conclusions, I discuss future challenges and suggest potential strategies for these innovative control systems to be widely deployed in the market. This dissertation provides useful new tools in terms of procedures, algorithms, and models to facilitate the automation of deployment of advanced controls and analytics and accelerate their wide adoption in buildings.

Potential Collaborative Research topics with Korea’s Agency for Defense Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrar, Charles R.; Todd, Michael D.

2012-08-23

This presentation provides a high level summary of current research activities at the Los Alamos National Laboratory (LANL)-University of California Jacobs School of Engineering (UCSD) Engineering Institute that will be presented at Korea's Agency for Defense Development (ADD). These research activities are at the basic engineering science level with different level of maturity ranging from initial concepts to field proof-of-concept demonstrations. We believe that all of these activities are appropriate for collaborative research activities with ADD subject to approval by each institution. All the activities summarized herein have the common theme that they are multi-disciplinary in nature and typically involvedmore » the integration of high-fidelity predictive modeling, advanced sensing technologies and new development in information technology. These activities include: Wireless Sensor Systems, Swarming Robot sensor systems, Advanced signal processing (compressed sensing) and pattern recognition, Model Verification and Validation, Optimal/robust sensor system design, Haptic systems for large-scale data processing, Cyber-physical security for robots, Multi-source energy harvesting, Reliability-based approaches to damage prognosis, SHMTools software development, and Cyber-physical systems advanced study institute.« less

Solitons for Describing 3-D Physical Reality:. the Current Frontier

NASA Astrophysics Data System (ADS)

Werbos, Paul J.

2013-01-01

This chapter begins with a review and assessment of four key frontiers for the fields of memristors, neural networks and chaos: (1) use of learning architectures to expand the possible markets for dense memristor chips, crucial to applications such as power grid intelligent enough to improve the economics of renewable energy; (2) advanced modeling and hardware to build such chips, from graphene to magnetoresistance; (3) second generation quantum computing; and (4) development and use of chaotic soliton models to rebuild the foundations of physics. Current more detailed reviews of the first three frontiers are summarized. The bulk of the paper discusses how a "soliton" model of the electron can fill outstanding gaps in basic physics, such as explanation of the mass and radius of the electron without a need for renormalization. It reviews the two soliton models most widely discussed in physics today, the Skyrme model and the BPS monopole, and proposes alternative Lagrangians starting from the bosonic sector of electroweak theory which may have the required properties.

Modeling Global Ocean Biogeochemistry With Physical Data Assimilation: A Pragmatic Solution to the Equatorial Instability

NASA Astrophysics Data System (ADS)

Park, Jong-Yeon; Stock, Charles A.; Yang, Xiaosong; Dunne, John P.; Rosati, Anthony; John, Jasmin; Zhang, Shaoqing

2018-03-01

Reliable estimates of historical and current biogeochemistry are essential for understanding past ecosystem variability and predicting future changes. Efforts to translate improved physical ocean state estimates into improved biogeochemical estimates, however, are hindered by high biogeochemical sensitivity to transient momentum imbalances that arise during physical data assimilation. Most notably, the breakdown of geostrophic constraints on data assimilation in equatorial regions can lead to spurious upwelling, resulting in excessive equatorial productivity and biogeochemical fluxes. This hampers efforts to understand and predict the biogeochemical consequences of El Niño and La Niña. We develop a strategy to robustly integrate an ocean biogeochemical model with an ensemble coupled-climate data assimilation system used for seasonal to decadal global climate prediction. Addressing spurious vertical velocities requires two steps. First, we find that tightening constraints on atmospheric data assimilation maintains a better equatorial wind stress and pressure gradient balance. This reduces spurious vertical velocities, but those remaining still produce substantial biogeochemical biases. The remainder is addressed by imposing stricter fidelity to model dynamics over data constraints near the equator. We determine an optimal choice of model-data weights that removed spurious biogeochemical signals while benefitting from off-equatorial constraints that still substantially improve equatorial physical ocean simulations. Compared to the unconstrained control run, the optimally constrained model reduces equatorial biogeochemical biases and markedly improves the equatorial subsurface nitrate concentrations and hypoxic area. The pragmatic approach described herein offers a means of advancing earth system prediction in parallel with continued data assimilation advances aimed at fully considering equatorial data constraints.

Observation-Based Dissipation and Input Terms for Spectral Wave Models, with End-User Testing

DTIC Science & Technology

2014-09-30

scale influence of the Great barrier reef matrix on wave attenuation, Coral Reefs [published, refereed] Ghantous, M., and A.V. Babanin, 2014: One...Observation-Based Dissipation and Input Terms for Spectral Wave Models...functions, based on advanced understanding of physics of air-sea interactions, wave breaking and swell attenuation, in wave - forecast models. OBJECTIVES The

The impact of recent advances in laboratory astrophysics on our understanding of the cosmos.

PubMed

Savin, D W; Brickhouse, N S; Cowan, J J; Drake, R P; Federman, S R; Ferland, G J; Frank, A; Gudipati, M S; Haxton, W C; Herbst, E; Profumo, S; Salama, F; Ziurys, L M; Zweibel, E G

2012-03-01

An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the observed astrophysical phenomena and the tools used to probe such phenomena-the radiation and particle spectra we observe-have their roots in atomic, molecular, condensed matter, plasma, nuclear and particle physics. Chemistry is implicitly included in both molecular and condensed matter physics. This connection is the theme of the present report, which provides a broad, though non-exhaustive, overview of progress in our understanding of the cosmos resulting from recent theoretical and experimental advances in what is commonly called laboratory astrophysics. This work, carried out by a diverse community of laboratory astrophysicists, is increasingly important as astrophysics transitions into an era of precise measurement and high fidelity modeling.

Noise in state of the art clocks and their impact for fundamental physics

NASA Technical Reports Server (NTRS)

Maleki, L.

2001-01-01

In this paper a review of the use of advanced atomic clocks in testing the fundamental physical laws will be presented. Noise sources of clocks will be discussed, together with an outline their characterization based on current models. The paper will conclude with a discussion of recent attempts to reduce the fundamental, as well as technical noise in atomic clocks.

Model-Based Control using Model and Mechanization Fusion Techniques for Image-Aided Navigation

DTIC Science & Technology

2009-03-01

Magnet Motors . Magna Physics Publishing, Hillsboro, OH, 1994. 7. Houwu Bai, Xubo Song, Eric Wan and Andriy Myronenko. “Vision-only Navi- gation and...filter”. Proceedings of the Recent Advances in Space Technologies (RAST). Nov 2003. 6. Hendershot, J.R. and Tje Miller. Design of Brushless Permanent

Challenges and progress in distributed watershed modeling: applications of the AgroEcoSystem-Watershed (AgES-W) model

USDA-ARS?s Scientific Manuscript database

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advances in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be quan...

DART: Recent Advances in Remote Sensing Data Modeling With Atmosphere, Polarization, and Chlorophyll Fluorescence

NASA Technical Reports Server (NTRS)

Gastellu-Etchegorry, Jean-Phil; Lauret, Nicolas; Yin, Tiangang; Landier, Lucas; Kallel, Abdelaziz; Malenovsky, Zbynek; Bitar, Ahmad Al; Aval, Josselin; Benhmida, Sahar; Qi, Jianbo;

ANEMOS: Development of a next generation wind power forecasting system for the large-scale integration of onshore and offshore wind farms.

NASA Astrophysics Data System (ADS)

Kariniotakis, G.; Anemos Team

2003-04-01

Objectives: Accurate forecasting of the wind energy production up to two days ahead is recognized as a major contribution for reliable large-scale wind power integration. Especially, in a liberalized electricity market, prediction tools enhance the position of wind energy compared to other forms of dispatchable generation. ANEMOS, is a new 3.5 years R&D project supported by the European Commission, that resembles research organizations and end-users with an important experience on the domain. The project aims to develop advanced forecasting models that will substantially outperform current methods. Emphasis is given to situations like complex terrain, extreme weather conditions, as well as to offshore prediction for which no specific tools currently exist. The prediction models will be implemented in a software platform and installed for online operation at onshore and offshore wind farms by the end-users participating in the project. Approach: The paper presents the methodology of the project. Initially, the prediction requirements are identified according to the profiles of the end-users. The project develops prediction models based on both a physical and an alternative statistical approach. Research on physical models gives emphasis to techniques for use in complex terrain and the development of prediction tools based on CFD techniques, advanced model output statistics or high-resolution meteorological information. Statistical models (i.e. based on artificial intelligence) are developed for downscaling, power curve representation, upscaling for prediction at regional or national level, etc. A benchmarking process is set-up to evaluate the performance of the developed models and to compare them with existing ones using a number of case studies. The synergy between statistical and physical approaches is examined to identify promising areas for further improvement of forecasting accuracy. Appropriate physical and statistical prediction models are also developed for offshore wind farms taking into account advances in marine meteorology (interaction between wind and waves, coastal effects). The benefits from the use of satellite radar images for modeling local weather patterns are investigated. A next generation forecasting software, ANEMOS, will be developed to integrate the various models. The tool is enhanced by advanced Information Communication Technology (ICT) functionality and can operate both in stand alone, or remote mode, or be interfaced with standard Energy or Distribution Management Systems (EMS/DMS) systems. Contribution: The project provides an advanced technology for wind resource forecasting applicable in a large scale: at a single wind farm, regional or national level and for both interconnected and island systems. A major milestone is the on-line operation of the developed software by the participating utilities for onshore and offshore wind farms and the demonstration of the economic benefits. The outcome of the ANEMOS project will help consistently the increase of wind integration in two levels; in an operational level due to better management of wind farms, but also, it will contribute to increasing the installed capacity of wind farms. This is because accurate prediction of the resource reduces the risk of wind farm developers, who are then more willing to undertake new wind farm installations especially in a liberalized electricity market environment.

Physical and Relativistic Numerical Cosmology.

PubMed

Anninos, Peter

1998-01-01

In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

Real time polymer nanocomposites-based physical nanosensors: theory and modeling.

PubMed

Bellucci, Stefano; Shunin, Yuri; Gopeyenko, Victor; Lobanova-Shunina, Tamara; Burlutskaya, Nataly; Zhukovskii, Yuri

2017-09-01

Functionalized carbon nanotubes and graphene nanoribbons nanostructures, serving as the basis for the creation of physical pressure and temperature nanosensors, are considered as tools for ecological monitoring and medical applications. Fragments of nanocarbon inclusions with different morphologies, presenting a disordered system, are regarded as models for nanocomposite materials based on carbon nanoсluster suspension in dielectric polymer environments (e.g., epoxy resins). We have formulated the approach of conductivity calculations for carbon-based polymer nanocomposites using the effective media cluster approach, disordered systems theory and conductivity mechanisms analysis, and obtained the calibration dependences. Providing a proper description of electric responses in nanosensoring systems, we demonstrate the implementation of advanced simulation models suitable for real time control nanosystems. We also consider the prospects and prototypes of the proposed physical nanosensor models providing the comparisons with experimental calibration dependences.

Real time polymer nanocomposites-based physical nanosensors: theory and modeling

NASA Astrophysics Data System (ADS)

Bellucci, Stefano; Shunin, Yuri; Gopeyenko, Victor; Lobanova-Shunina, Tamara; Burlutskaya, Nataly; Zhukovskii, Yuri

2017-09-01

Functionalized carbon nanotubes and graphene nanoribbons nanostructures, serving as the basis for the creation of physical pressure and temperature nanosensors, are considered as tools for ecological monitoring and medical applications. Fragments of nanocarbon inclusions with different morphologies, presenting a disordered system, are regarded as models for nanocomposite materials based on carbon nanoсluster suspension in dielectric polymer environments (e.g., epoxy resins). We have formulated the approach of conductivity calculations for carbon-based polymer nanocomposites using the effective media cluster approach, disordered systems theory and conductivity mechanisms analysis, and obtained the calibration dependences. Providing a proper description of electric responses in nanosensoring systems, we demonstrate the implementation of advanced simulation models suitable for real time control nanosystems. We also consider the prospects and prototypes of the proposed physical nanosensor models providing the comparisons with experimental calibration dependences.

Overview of NASA Heliophysics and the Science of Space Weather

NASA Astrophysics Data System (ADS)

Talaat, E. R.

2017-12-01

In this paper, an overview is presented on the various activities within NASA that address space weather-related observations, model development, and research to operations. Specific to space weather, NASA formulates and implements, through the Heliophysics division, a national research program for understanding the Sun and its interactions with the Earth and the Solar System and how these phenomena impact life and society. NASA researches and prototypes new mission and instrument capabilities in this area, providing new physics-based algorithms to advance the state of solar, space physics, and space weather modeling.

Introduction to Elementary Particle Physics

NASA Astrophysics Data System (ADS)

Bettini, Alessandro

The Standard Model is the most comprehensive physical theory ever developed. This textbook conveys the basic elements of the Standard Model using elementary concepts, without the theoretical rigor found in most other texts on this subject. It contains examples of basic experiments, allowing readers to see how measurements and theory interplay in the development of physics. The author examines leptons, hadrons and quarks, before presenting the dynamics and the surprising properties of the charges of the different forces. The textbook concludes with a brief discussion on the recent discoveries of physics beyond the Standard Model, and its connections with cosmology. Quantitative examples are given, and the reader is guided through the necessary calculations. Each chapter ends in the exercises, and solutions to some problems are included in the book. Complete solutions are available to instructors at www.cambridge.org/9780521880213. This textbook is suitable for advanced undergraduate students and graduate students.

ZERODUR thermo-mechanical modelling and advanced dilatometry for the ELT generation

NASA Astrophysics Data System (ADS)

Jedamzik, Ralf; Kunisch, Clemens; Westerhoff, Thomas

2016-07-01

Large amounts of low thermal expansion material are required for the upcoming ELT projects. The main mirror is designed using several hundreds of hexagonal 1.4 m sized mirror blanks. The M2 and M3 are monolithic 4 m class mirror blanks. The mirror blank material needs to fulfill tight requirements regarding CTE specification and homogeneity. Additionally the mirror blanks need to be dimensionally stable for more than 30 years. In particular, stress effects due to the changes in the environment shall not entail shape variation of more than 0.5 μm PV within 30 years. In 2010 SCHOTT developed a physically based model to describe the thermal and mechanical long time behavior of ZERODUR. The model enables simulation of the long time behavior of ZERODUR mirror blanks under realistic mechanical and thermal constraints. This presentation shows FEM simulation results on the long time behavior of the ELT M1, M2 and M3 mirror blanks under different loading conditions. Additionally the model results will be compared to an already 15 years lasting long time measurement of a ZERODUR sample at the German federal physical standardization institute (PTB). In recent years SCHOTT pushed the push rod dilatometer measurement technology to its limit. With the new Advanced Dilatometer CTE measurement accuracies of +- 3 ppb/K and reproducibilities of better 1 ppb/K have been achieved. The new Advanced Dilatometer exhibits excellent long time stability.

The Impact of Natural Disasters on Youth: A Focus on Emerging Research beyond Internalizing Disorders.

PubMed

Self-Brown, Shannon; Lai, Betty; Patterson, Alexandria; Glasheen, Theresa

2017-08-01

This paper reviews youth outcomes following exposure to natural disaster, with a focus on three relatively understudied outcomes: externalizing behavior problems, physical health, and posttraumatic growth. Recent, high-impact studies focusing on each outcome are summarized. Studies highlighted in this review utilize innovative and comprehensive approaches to improve our current understanding of youth broad-based physical and mental health outcomes beyond PTSD. The review concludes with recommendations to advance the field of youth disaster research by exploring how disasters may impact children across multiple domains, as well as using cutting edge ecobiological approaches and advanced modeling strategies to better understand how youth adjust and thrive following natural disaster.

Space-weather assets developed by the French space-physics community

NASA Astrophysics Data System (ADS)

Rouillard, A. P.; Pinto, R. F.; Brun, A. S.; Briand, C.; Bourdarie, S.; Dudok De Wit, T.; Amari, T.; Blelly, P.-L.; Buchlin, E.; Chambodut, A.; Claret, A.; Corbard, T.; Génot, V.; Guennou, C.; Klein, K. L.; Koechlin, L.; Lavarra, M.; Lavraud, B.; Leblanc, F.; Lemorton, J.; Lilensten, J.; Lopez-Ariste, A.; Marchaudon, A.; Masson, S.; Pariat, E.; Reville, V.; Turc, L.; Vilmer, N.; Zucarello, F. P.

2016-12-01

We present a short review of space-weather tools and services developed and maintained by the French space-physics community. They include unique data from ground-based observatories, advanced numerical models, automated identification and tracking tools, a range of space instrumentation and interconnected virtual observatories. The aim of the article is to highlight some advances achieved in this field of research at the national level over the last decade and how certain assets could be combined to produce better space-weather tools exploitable by space-weather centres and customers worldwide. This review illustrates the wide range of expertise developed nationally but is not a systematic review of all assets developed in France.

Models of determining deformations

NASA Astrophysics Data System (ADS)

Gladilin, V. N.

2016-12-01

In recent years, a lot of functions designed to determine deformation values that occur mostly as a result of settlement of structures and industrial equipment. Some authors suggest such advanced mathematical functions approximating deformations as general methods for the determination of deformations. The article describes models of deformations as physical processes. When comparing static, cinematic and dynamic models, it was found that the dynamic model reflects the deformation of structures and industrial equipment most reliably.

Inter-Disciplinary Collaboration in Support of the Post-Standby TREAT Mission

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeHart, Mark; Baker, Benjamin; Ortensi, Javier

Although analysis methods have advanced significantly in the last two decades, high fidelity multi- physics methods for reactors systems have been under development for only a few years and are not presently mature nor deployed. Furthermore, very few methods provide the ability to simulate rapid transients in three dimensions. Data for validation of advanced time-dependent multi- physics is sparse; at TREAT, historical data were not collected for the purpose of validating three-dimensional methods, let alone multi-physics simulations. Existing data continues to be collected to attempt to simulate the behavior of experiments and calibration transients, but it will be insufficient formore » the complete validation of analysis methods used for TREAT transient simulations. Hence, a 2018 restart will most likely occur without the direct application of advanced modeling and simulation methods. At present, the current INL modeling and simulation team plans to work with TREAT operations staff in performing reactor simulations with MAMMOTH, in parallel with the software packages currently being used in preparation for core restart (e.g., MCNP5, RELAP5, ABAQUS). The TREAT team has also requested specific measurements to be performed during startup testing, currently scheduled to run from February to August of 2018. These startup measurements will be crucial in validating the new analysis methods in preparation for ultimate application for TREAT operations and experiment design. This document describes the collaboration between modeling and simulation staff and restart, operations, instrumentation and experiment development teams to be able to effectively interact and achieve successful validation work during restart testing.« less

Contemporary machine learning: techniques for practitioners in the physical sciences

NASA Astrophysics Data System (ADS)

Spears, Brian

2017-10-01

Machine learning is the science of using computers to find relationships in data without explicitly knowing or programming those relationships in advance. Often without realizing it, we employ machine learning every day as we use our phones or drive our cars. Over the last few years, machine learning has found increasingly broad application in the physical sciences. This most often involves building a model relationship between a dependent, measurable output and an associated set of controllable, but complicated, independent inputs. The methods are applicable both to experimental observations and to databases of simulated output from large, detailed numerical simulations. In this tutorial, we will present an overview of current tools and techniques in machine learning - a jumping-off point for researchers interested in using machine learning to advance their work. We will discuss supervised learning techniques for modeling complicated functions, beginning with familiar regression schemes, then advancing to more sophisticated decision trees, modern neural networks, and deep learning methods. Next, we will cover unsupervised learning and techniques for reducing the dimensionality of input spaces and for clustering data. We'll show example applications from both magnetic and inertial confinement fusion. Along the way, we will describe methods for practitioners to help ensure that their models generalize from their training data to as-yet-unseen test data. We will finally point out some limitations to modern machine learning and speculate on some ways that practitioners from the physical sciences may be particularly suited to help. This work was performed by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

International comparison of observation-specific spatial buffers: maximizing the ability to estimate physical activity.

PubMed

Frank, Lawrence D; Fox, Eric H; Ulmer, Jared M; Chapman, James E; Kershaw, Suzanne E; Sallis, James F; Conway, Terry L; Cerin, Ester; Cain, Kelli L; Adams, Marc A; Smith, Graham R; Hinckson, Erica; Mavoa, Suzanne; Christiansen, Lars B; Hino, Adriano Akira F; Lopes, Adalberto A S; Schipperijn, Jasper

2017-01-23

Advancements in geographic information systems over the past two decades have increased the specificity by which an individual's neighborhood environment may be spatially defined for physical activity and health research. This study investigated how different types of street network buffering methods compared in measuring a set of commonly used built environment measures (BEMs) and tested their performance on associations with physical activity outcomes. An internationally-developed set of objective BEMs using three different spatial buffering techniques were used to evaluate the relative differences in resulting explanatory power on self-reported physical activity outcomes. BEMs were developed in five countries using 'sausage,' 'detailed-trimmed,' and 'detailed,' network buffers at a distance of 1 km around participant household addresses (n = 5883). BEM values were significantly different (p < 0.05) for 96% of sausage versus detailed-trimmed buffer comparisons and 89% of sausage versus detailed network buffer comparisons. Results showed that BEM coefficients in physical activity models did not differ significantly across buffering methods, and in most cases BEM associations with physical activity outcomes had the same level of statistical significance across buffer types. However, BEM coefficients differed in significance for 9% of the sausage versus detailed models, which may warrant further investigation. Results of this study inform the selection of spatial buffering methods to estimate physical activity outcomes using an internationally consistent set of BEMs. Using three different network-based buffering methods, the findings indicate significant variation among BEM values, however associations with physical activity outcomes were similar across each buffering technique. The study advances knowledge by presenting consistently assessed relationships between three different network buffer types and utilitarian travel, sedentary behavior, and leisure-oriented physical activity outcomes.

Kinetic Theory and Simulation of Single-Channel Water Transport

NASA Astrophysics Data System (ADS)

Tajkhorshid, Emad; Zhu, Fangqiang; Schulten, Klaus

Water translocation between various compartments of a system is a fundamental process in biology of all living cells and in a wide variety of technological problems. The process is of interest in different fields of physiology, physical chemistry, and physics, and many scientists have tried to describe the process through physical models. Owing to advances in computer simulation of molecular processes at an atomic level, water transport has been studied in a variety of molecular systems ranging from biological water channels to artificial nanotubes. While simulations have successfully described various kinetic aspects of water transport, offering a simple, unified model to describe trans-channel translocation of water turned out to be a nontrivial task.

Advancing reservoir operation description in physically based hydrological models

NASA Astrophysics Data System (ADS)

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

2016-04-01

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

TH-E-9A-01: Medical Physics 1.0 to 2.0, Session 4: Computed Tomography, Ultrasound and Nuclear Medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samei, E; Nelson, J; Hangiandreou, N

Medical Physics 2.0 is a bold vision for an existential transition of clinical imaging physics in face of the new realities of value-based and evidencebased medicine, comparative effectiveness, and meaningful use. It speaks to how clinical imaging physics can expand beyond traditional insular models of inspection and acceptance testing, oriented toward compliance, towards team-based models of operational engagement, prospective definition and assurance of effective use, and retrospective evaluation of clinical performance. Organized into four sessions of the AAPM, this particular session focuses on three specific modalities as outlined below. CT 2.0: CT has been undergoing a dramatic transition in themore » last few decades. While the changes in the technology merits discussions of their own, an important question is how clinical medical physicists are expected to effectively engage with the new realities of CT technology and practice. Consistent with the upcoming paradigm of Medical Physics 2.0, this CT presentation aims to provide definitions and demonstration of the components of the new clinical medical physics practice pertaining CT. The topics covered include physics metrics and analytics that aim to provide higher order clinicallyrelevant quantification of system performance as pertains to new (and not so new) technologies. That will include the new radiation and dose metrics (SSDE, organ dose, risk indices), image quality metrology (MTF/NPS/d’), task-based phantoms, and the effect of patient size. That will follow with a discussion of the testing implication of new CT hardware (detectors, tubes), acquisition methods (innovative helical geometries, AEC, wide beam CT, dual energy, inverse geometry, application specialties), and image processing and analysis (iterative reconstructions, quantitative CT, advanced renditions). The presentation will conclude with a discussion of clinical and operational aspects of Medical Physics 2.0 including training and communication, use optimization (dose and technique factors), automated analysis and data management (automated QC methods, protocol tracking, dose monitoring, issue tracking), and meaningful QC considerations. US 2.0: Ultrasound imaging is evolving at a rapid pace, adding new imaging functions and modes that continue to enhance its clinical utility and benefits to patients. The ultrasound talk will look ahead 10–15 years and consider how medical physicists can bring maximal value to the clinical ultrasound practices of the future. The roles of physics in accreditation and regulatory compliance, image quality and exam optimization, clinical innovation, and education of staff and trainees will all be considered. A detailed examination of expected technology evolution and impact on image quality metrics will be presented. Clinical implementation of comprehensive physics services will also be discussed. Nuclear Medicine 2.0: Although the basic science of nuclear imaging has remained relatively unchanged since its inception, advances in instrumentation continue to advance the field into new territories. With a great number of these advances occurring over the past decade, the role and testing strategies of clinical nuclear medicine physicists must evolve in parallel. The Nuclear Medicine 2.0 presentation is designed to highlight some of the recent advances from a clinical medical physicist perspective and provide ideas and motivation for designing better evaluation strategies. Topics include improvement of traditional physics metrics and analytics, testing implications of hybrid imaging and advanced detector technologies, and strategies for effective implementation into the clinic. Learning Objectives: Become familiar with new physics metrics and analytics in nuclear medicine, CT, and ultrasound. To become familiar with the major new developments of clinical physics support. To understand the physics testing implications of new technologies, hardware, software, and applications. Identify approaches for implementing comprehensive medical physics services in future imaging practices.« less

3D Printed Organ Models with Physical Properties of Tissue and Integrated Sensors.

PubMed

Qiu, Kaiyan; Zhao, Zichen; Haghiashtiani, Ghazaleh; Guo, Shuang-Zhuang; He, Mingyu; Su, Ruitao; Zhu, Zhijie; Bhuiyan, Didarul B; Murugan, Paari; Meng, Fanben; Park, Sung Hyun; Chu, Chih-Chang; Ogle, Brenda M; Saltzman, Daniel A; Konety, Badrinath R; Sweet, Robert M; McAlpine, Michael C

2018-03-01

The design and development of novel methodologies and customized materials to fabricate patient-specific 3D printed organ models with integrated sensing capabilities could yield advances in smart surgical aids for preoperative planning and rehearsal. Here, we demonstrate 3D printed prostate models with physical properties of tissue and integrated soft electronic sensors using custom-formulated polymeric inks. The models show high quantitative fidelity in static and dynamic mechanical properties, optical characteristics, and anatomical geometries to patient tissues and organs. The models offer tissue-mimicking tactile sensation and behavior and thus can be used for the prediction of organ physical behavior under deformation. The prediction results show good agreement with values obtained from simulations. The models also allow the application of surgical and diagnostic tools to their surface and inner channels. Finally, via the conformal integration of 3D printed soft electronic sensors, pressure applied to the models with surgical tools can be quantitatively measured.

3D Printed Organ Models with Physical Properties of Tissue and Integrated Sensors

PubMed Central

Qiu, Kaiyan; Zhao, Zichen; Haghiashtiani, Ghazaleh; Guo, Shuang-Zhuang; He, Mingyu; Su, Ruitao; Zhu, Zhijie; Bhuiyan, Didarul B.; Murugan, Paari; Meng, Fanben; Park, Sung Hyun; Chu, Chih-Chang; Ogle, Brenda M.; Saltzman, Daniel A.; Konety, Badrinath R.

2017-01-01

The design and development of novel methodologies and customized materials to fabricate patient-specific 3D printed organ models with integrated sensing capabilities could yield advances in smart surgical aids for preoperative planning and rehearsal. Here, we demonstrate 3D printed prostate models with physical properties of tissue and integrated soft electronic sensors using custom-formulated polymeric inks. The models show high quantitative fidelity in static and dynamic mechanical properties, optical characteristics, and anatomical geometries to patient tissues and organs. The models offer tissue-mimicking tactile sensation and behavior and thus can be used for the prediction of organ physical behavior under deformation. The prediction results show good agreement with values obtained from simulations. The models also allow the application of surgical and diagnostic tools to their surface and inner channels. Finally, via the conformal integration of 3D printed soft electronic sensors, pressure applied to the models with surgical tools can be quantitatively measured. PMID:29608202

Greening the Grid: Advances in Production Cost Modeling for India Renewable Energy Grid Integration Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochran, Jaquelin; Palchak, David

The Greening the Grid: Pathways to Integrate 175 Gigawatts of Renewable Energy into India's Electric Grid study uses advanced weather and power system modeling to explore the operational impacts of meeting India's 2022 renewable energy targets and identify actions that may be favorable for integrating high levels of renewable energy into the Indian grid. The study relies primarily on a production cost model that simulates optimal scheduling and dispatch of available generation in a future year (2022) by minimizing total production costs subject to physical, operational, and market constraints. This fact sheet provides a detailed look at each of thesemore » models, including their common assumptions and the insights provided by each.« less

Recent Advances on INSAR Temporal Decorrelation: Theory and Observations Using UAVSAR

NASA Technical Reports Server (NTRS)

Lavalle, M.; Hensley, S.; Simard, M.

2011-01-01

We review our recent advances in understanding the role of temporal decorrelation in SAR interferometry and polarimetric SAR interferometry. We developed a physical model of temporal decorrelation based on Gaussian-statistic motion that varies along the vertical direction in forest canopies. Temporal decorrelation depends on structural parameters such as forest height, is sensitive to polarization and affects coherence amplitude and phase. A model of temporal-volume decorrelation valid for arbitrary spatial baseline is discussed. We tested the inversion of this model to estimate forest height from model simulations supported by JPL/UAVSAR data and lidar LVIS data. We found a general good agreement between forest height estimated from radar data and forest height estimated from lidar data.

A study of amplitude information-frequency characteristics for underwater active electrolocation system.

PubMed

Peng, Jiegang

2015-11-04

Weakly electric fish sense their surroundings in complete darkness by their active electrolocation system. For biologists, the active electrolocation system has been investigated for near 60 years. And for engineers, bio-inspired active electrolocation sensor has been investigated for about 20 years. But how the amplitude information response will be affected by frequencies of detecting electric fields in the active electrolocation system was rarely investigated. In this paper, an electrolocation experiment system has been built. The amplitude information-frequency characteristics (AIFC) of the electrolocation system for sinusoidal electric fields of varying frequencies have been investigated. We find that AIFC of the electrolocation system have relevance to the material properties and geometric features of the probed object and conductivity of surrounding water. Detect frequency dead zone (DFDZ) and frequency inflection point (FIP) of AIFC for the electrolocation system were found. The analysis model of the electrolocation system has been investigated for many years, but DFDZ and FIP of AIFC can be difficult to explain by those models. In order to explain those AIFC phenomena for the electrolocation system, a simple relaxation model based on Cole-Cole model which is not only a mathematical explanation but it is a physical one for the electrolocation system was advanced. We also advance a hypothesis for physical mechanism of weakly electrical fish electrolocation system. It may have reference value for physical mechanism of weakly electrical fish active electrolocation system.

Advanced Relay Design and Technology for Energy-Efficient Electronics

DTIC Science & Technology

2011-07-07

Estimates and Unique Failure Mechanisms of the Digital Micromirror Device (DMD),” in Proceedings of the IEEE Annual International Reliability Physics...Symposium (IRPS 󈨦), pp. 9-16, March 1998. [18] A. B. Sontheimer, “Digital Micromirror Device (DMD) Hinge Memory Lifetime Reliability Modeling,” in...Mechanisms of the Digital Micromirror Device (DMD),” in Proceedings of the IEEE Annual International Reliability Physics Symposium (IRPS 󈨦), pp. 9-16

A computerized model for integrating the physical environmental factors into metropolitan landscape planning

Treesearch

Julius Gy Fabos; Kimball H. Ferris

1977-01-01

This paper justifies and illustrates (in simplified form) a landscape planning approach to the environmental management of the metropolitan landscape. The model utilizes a computerized assessment and mapping system, which exhibits a recent advancement in computer technology that allows for greater accuracy and the weighting of different values when mapping at the...

Advancement of a soil parameters geodatabase for the modeling assessment of conservation practice outcomes in the United States

USDA-ARS?s Scientific Manuscript database

US-ModSoilParms-TEMPLE is a database composed of a set of geographic databases functionally storing soil-spatial units and soil hydraulic, physical, and chemical parameters for three agriculture management simulation models, SWAT, APEX, and ALMANAC. This paper introduces the updated US-ModSoilParms-...

High-Performance Computational Modeling of ICRF Physics and Plasma-Surface Interactions in Alcator C-Mod

NASA Astrophysics Data System (ADS)

Jenkins, Thomas; Smithe, David

2016-10-01

Inefficiencies and detrimental physical effects may arise in conjunction with ICRF heating of tokamak plasmas. Large wall potential drops, associated with sheath formation near plasma-facing antenna hardware, give rise to high-Z impurity sputtering from plasma-facing components and subsequent radiative cooling. Linear and nonlinear wave excitations in the plasma edge/SOL also dissipate injected RF power and reduce overall antenna efficiency. Recent advances in finite-difference time-domain (FDTD) modeling techniques allow the physics of localized sheath potentials, and associated sputtering events, to be modeled concurrently with the physics of antenna near- and far-field behavior and RF power flow. The new methods enable time-domain modeling of plasma-surface interactions and ICRF physics in realistic experimental configurations at unprecedented spatial resolution. We present results/animations from high-performance (10k-100k core) FDTD/PIC simulations spanning half of Alcator C-Mod at mm-scale resolution, exploring impurity production due to localized sputtering (in response to self-consistent sheath potentials at antenna surfaces) and the physics of parasitic slow wave excitation near the antenna hardware and SOL. Supported by US DoE (Award DE-SC0009501) and the ALCC program.

[Implementation of bedside training and advanced objective structured clinical examination (OSCE) trial to learn and confirm about pharmacy clinical skills].

PubMed

Tokunaga, Jin; Takamura, Norito; Ogata, Kenji; Setoguchi, Nao; Sato, Keizo

2013-01-01

Bedside training for fourth-year students, as well as seminars in hospital pharmacy (vital sign seminars) for fifth-year students at the Department of Pharmacy of Kyushu University of Health and Welfare have been implemented using patient training models and various patient simulators. The introduction of simulation-based pharmaceutical education, where no patients are present, promotes visually, aurally, and tactilely simulated learning regarding the evaluation of vital signs and implementation of physical assessment when disease symptoms are present or adverse effects occur. A patient simulator also promotes the creation of training programs for emergency and critical care, with which basic as well as advanced life support can be practiced. In addition, an advanced objective structured clinical examination (OSCE) trial has been implemented to evaluate skills regarding vital signs and physical assessments. Pharmacists are required to examine vital signs and conduct physical assessment from a pharmaceutical point of view. The introduction of these pharmacy clinical skills will improve the efficacy of drugs, work for the prevention or early detection of adverse effects, and promote the appropriate use of drugs. It is considered that simulation-based pharmaceutical education is essential to understand physical assessment, and such education will ideally be applied and developed according to on-site practices.

Physics-model-based nonlinear actuator trajectory optimization and safety factor profile feedback control for advanced scenario development in DIII-D

DOE PAGES

Barton, Justin E.; Boyer, Mark D.; Shi, Wenyu; ...

2015-07-30

DIII-D experimental results are reported to demonstrate the potential of physics-model-based safety factor profile control for robust and reproducible sustainment of advanced scenarios. In the absence of feedback control, variability in wall conditions and plasma impurities, as well as drifts due to external disturbances, can limit the reproducibility of discharges with simple pre-programmed scenario trajectories. The control architecture utilized is a feedforward + feedback scheme where the feedforward commands are computed off-line and the feedback commands are computed on-line. In this work, firstly a first-principles-driven (FPD), physics-based model of the q profile and normalized beta (β N) dynamics is embeddedmore » into a numerical optimization algorithm to design feedforward actuator trajectories that sheer the plasma through the tokamak operating space to reach a desired stationary target state that is characterized by the achieved q profile and β N. Good agreement between experimental results and simulations demonstrates the accuracy of the models employed for physics-model-based control design. Secondly, a feedback algorithm for q profile control is designed following a FPD approach, and the ability of the controller to achieve and maintain a target q profile evolution is tested in DIII-D high confinement (H-mode) experiments. The controller is shown to be able to effectively control the q profile when β N is relatively close to the target, indicating the need for integrated q profile and β N control to further enhance the ability to achieve robust scenario execution. Furthermore, the ability of an integrated q profile + β N feedback controller to track a desired target is demonstrated through simulation.« less

Final Report on DTRA Basic Research Project #BRCALL08-Per3-C-2-0006 "High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser Targets"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colvin, Jeffrey D.

This project had two major goals. Final Goal: obtain spectrally resolved, absolutely calibrated x-ray emission data from uniquely uniform mm-scale near-critical-density high-Z plasmas not in local thermodynamic equilibrium (LTE) to benchmark modern detailed atomic physics models. Scientific significance: advance understanding of non-LTE atomic physics. Intermediate Goal: develop new nano-fabrication techniques to make suitable laser targets that form the required highly uniform non-LTE plasmas when illuminated by high-intensity laser light. Scientific significance: advance understanding of nano-science. The new knowledge will allow us to make x-ray sources that are bright at the photon energies of most interest for testing radiation hardening technologies,more » the spectral energy range where current x-ray sources are weak. All project goals were met.« less

Coarse-grained, foldable, physical model of the polypeptide chain.

PubMed

Chakraborty, Promita; Zuckermann, Ronald N

2013-08-13

Although nonflexible, scaled molecular models like Pauling-Corey's and its descendants have made significant contributions in structural biology research and pedagogy, recent technical advances in 3D printing and electronics make it possible to go one step further in designing physical models of biomacromolecules: to make them conformationally dynamic. We report here the design, construction, and validation of a flexible, scaled, physical model of the polypeptide chain, which accurately reproduces the bond rotational degrees of freedom in the peptide backbone. The coarse-grained backbone model consists of repeating amide and α-carbon units, connected by mechanical bonds (corresponding to ϕ and ψ) that include realistic barriers to rotation that closely approximate those found at the molecular scale. Longer-range hydrogen-bonding interactions are also incorporated, allowing the chain to readily fold into stable secondary structures. The model is easily constructed with readily obtainable parts and promises to be a tremendous educational aid to the intuitive understanding of chain folding as the basis for macromolecular structure. Furthermore, this physical model can serve as the basis for linking tangible biomacromolecular models directly to the vast array of existing computational tools to provide an enhanced and interactive human-computer interface.

SU-B-BRF-01: Professional Council Symposium: The Evolving US Healthcare Delivery Model, How Will the Medical Physics Profession Be Impacted and How Should We Respond?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halvorsen, P; Shine, K; White, G

The United States' healthcare delivery model is undergoing significant change. Insurance and reimbursement models are rapidly evolving, federal allocations are shifting from specialty services to preventive and generalpractice services, and Accountable Care Organizations are gaining in prominence. One area of focus is on the perceived over-utilization of expensive services such as advanced imaging and, in some cases, radiation therapy. Reimbursement incentives are increasingly aimed at quality metrics, leading to an increased interest in the core concepts of High Reliability Organizations. With the shift in federal resources away from specialty services and the increasing prominence of Accountable Care Organizations, we willmore » likely be challenged to re-assess our traditional model for delivering medical physics services. Medical physicists have a unique combination of education and training in physics principles, radiation physics applications in medicine, human anatomy, as well as safety analysis and quality control methods. An effective medical physicist recognizes that to advance the institution's mission, the medical physicist must join other professional leaders within the institution to provide clear direction and perspective for the entire team. To do that, we must first recognize the macro changes in our healthcare delivery system and candidly assess how the medical physics practice model can evolve in a prudent way to support the institution's objectives while maintaining the traditionally high level of quality and safety. This year's Professional Council Symposium will explore the many facets of the changing healthcare system and its potential impact on medical physics. Dr. Shine will provide an overview of the developing healthcare delivery and reimbursement models, with a focus on how the physician community has adapted to the changing objectives. Mr. White will describe recent changes in the reimbursement patterns for both imaging and radiation therapy services, the underlying imperatives that will influence additional changes in the near-term future, and the broader changes in the medical physics workforce that may arise due to many (often conflicting) directives and incentives both internal and external to the profession. Maintaining the integrity of the medical physics profession and the high quality of medical physics services will require a shared understanding of the changing practice environment and a firm commitment to protecting the key priorities of clinical medical physics as the healthcare system transitions to a new and very different model. To be effective as medical physicists, we must learn how to provide leadership in our respective institutions. Learning Objectives: Understand the macro changes occurring in the US healthcare delivery system. Understand the likely near-term, and possible longer-term, impact on the medical physics profession. Understand some strategies for providing leadership during this period of significant change.« less

Hybrid Physical Vapor Deposition Instrument for Advanced Functional Multilayers and Materials

DTIC Science & Technology

2016-04-27

Hybrid Physical Vapor Deposition Instrument for Advanced Functional Multilayers and Materials PI Maria received support to construct a physical... vapor deposition (PVD) system that combines electron beam (e- beam) evaporation, magnetron sputtering, pulsed laser ablation, and ion-assisted deposition ...peer-reviewed journals: Number of Papers published in non peer-reviewed journals: Final Report: Hybrid Physical Vapor Deposition Instrument for Advanced

Enabling large-scale viscoelastic calculations via neural network acceleration

NASA Astrophysics Data System (ADS)

Robinson DeVries, P.; Thompson, T. B.; Meade, B. J.

2017-12-01

One of the most significant challenges involved in efforts to understand the effects of repeated earthquake cycle activity are the computational costs of large-scale viscoelastic earthquake cycle models. Deep artificial neural networks (ANNs) can be used to discover new, compact, and accurate computational representations of viscoelastic physics. Once found, these efficient ANN representations may replace computationally intensive viscoelastic codes and accelerate large-scale viscoelastic calculations by more than 50,000%. This magnitude of acceleration enables the modeling of geometrically complex faults over thousands of earthquake cycles across wider ranges of model parameters and at larger spatial and temporal scales than have been previously possible. Perhaps most interestingly from a scientific perspective, ANN representations of viscoelastic physics may lead to basic advances in the understanding of the underlying model phenomenology. We demonstrate the potential of artificial neural networks to illuminate fundamental physical insights with specific examples.

Switching moving boundary models for two-phase flow evaporators and condensers

NASA Astrophysics Data System (ADS)

Bonilla, Javier; Dormido, Sebastián; Cellier, François E.

2015-03-01

The moving boundary method is an appealing approach for the design, testing and validation of advanced control schemes for evaporators and condensers. When it comes to advanced control strategies, not only accurate but fast dynamic models are required. Moving boundary models are fast low-order dynamic models, and they can describe the dynamic behavior with high accuracy. This paper presents a mathematical formulation based on physical principles for two-phase flow moving boundary evaporator and condenser models which support dynamic switching between all possible flow configurations. The models were implemented in a library using the equation-based object-oriented Modelica language. Several integrity tests in steady-state and transient predictions together with stability tests verified the models. Experimental data from a direct steam generation parabolic-trough solar thermal power plant is used to validate and compare the developed moving boundary models against finite volume models.

CSP - The 19th European Conference on Mathematics for Industry (ECMI 2016)

DTIC Science & Technology

2017-03-02

Quality physics in game cinematics. Conclusions Most significant advance reported The ECMI 2016 exceeded by far the expectations of the Organizing... games . 15. SUBJECT TERMS Industrial mathematics; numerical simulation ; optimization; modelling; innovation. 16. SECURITY CLASSIFICATION OF: 17

Materials used to simulate physical properties of human skin.

PubMed

Dąbrowska, A K; Rotaru, G-M; Derler, S; Spano, F; Camenzind, M; Annaheim, S; Stämpfli, R; Schmid, M; Rossi, R M

2016-02-01

For many applications in research, material development and testing, physical skin models are preferable to the use of human skin, because more reliable and reproducible results can be obtained. This article gives an overview of materials applied to model physical properties of human skin to encourage multidisciplinary approaches for more realistic testing and improved understanding of skin-material interactions. The literature databases Web of Science, PubMed and Google Scholar were searched using the terms 'skin model', 'skin phantom', 'skin equivalent', 'synthetic skin', 'skin substitute', 'artificial skin', 'skin replica', and 'skin model substrate.' Articles addressing material developments or measurements that include the replication of skin properties or behaviour were analysed. It was found that the most common materials used to simulate skin are liquid suspensions, gelatinous substances, elastomers, epoxy resins, metals and textiles. Nano- and micro-fillers can be incorporated in the skin models to tune their physical properties. While numerous physical skin models have been reported, most developments are research field-specific and based on trial-and-error methods. As the complexity of advanced measurement techniques increases, new interdisciplinary approaches are needed in future to achieve refined models which realistically simulate multiple properties of human skin. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Extreme weather and climate events with ecological relevance: a review

PubMed Central

Meehl, Gerald A.

2017-01-01

Robust evidence exists that certain extreme weather and climate events, especially daily temperature and precipitation extremes, have changed in regard to intensity and frequency over recent decades. These changes have been linked to human-induced climate change, while the degree to which climate change impacts an individual extreme climate event (ECE) is more difficult to quantify. Rapid progress in event attribution has recently been made through improved understanding of observed and simulated climate variability, methods for event attribution and advances in numerical modelling. Attribution for extreme temperature events is stronger compared with other event types, notably those related to the hydrological cycle. Recent advances in the understanding of ECEs, both in observations and their representation in state-of-the-art climate models, open new opportunities for assessing their effect on human and natural systems. Improved spatial resolution in global climate models and advances in statistical and dynamical downscaling now provide climatic information at appropriate spatial and temporal scales. Together with the continued development of Earth System Models that simulate biogeochemical cycles and interactions with the biosphere at increasing complexity, these make it possible to develop a mechanistic understanding of how ECEs affect biological processes, ecosystem functioning and adaptation capabilities. Limitations in the observational network, both for physical climate system parameters and even more so for long-term ecological monitoring, have hampered progress in understanding bio-physical interactions across a range of scales. New opportunities for assessing how ECEs modulate ecosystem structure and functioning arise from better scientific understanding of ECEs coupled with technological advances in observing systems and instrumentation. This article is part of the themed issue ‘Behavioural, ecological and evolutionary responses to extreme climatic events’. PMID:28483866

Extreme weather and climate events with ecological relevance: a review.

PubMed

Ummenhofer, Caroline C; Meehl, Gerald A

2017-06-19

Robust evidence exists that certain extreme weather and climate events, especially daily temperature and precipitation extremes, have changed in regard to intensity and frequency over recent decades. These changes have been linked to human-induced climate change, while the degree to which climate change impacts an individual extreme climate event (ECE) is more difficult to quantify. Rapid progress in event attribution has recently been made through improved understanding of observed and simulated climate variability, methods for event attribution and advances in numerical modelling. Attribution for extreme temperature events is stronger compared with other event types, notably those related to the hydrological cycle. Recent advances in the understanding of ECEs, both in observations and their representation in state-of-the-art climate models, open new opportunities for assessing their effect on human and natural systems. Improved spatial resolution in global climate models and advances in statistical and dynamical downscaling now provide climatic information at appropriate spatial and temporal scales. Together with the continued development of Earth System Models that simulate biogeochemical cycles and interactions with the biosphere at increasing complexity, these make it possible to develop a mechanistic understanding of how ECEs affect biological processes, ecosystem functioning and adaptation capabilities. Limitations in the observational network, both for physical climate system parameters and even more so for long-term ecological monitoring, have hampered progress in understanding bio-physical interactions across a range of scales. New opportunities for assessing how ECEs modulate ecosystem structure and functioning arise from better scientific understanding of ECEs coupled with technological advances in observing systems and instrumentation.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

The relationship between physical and psychological symptoms and health care utilization in hospitalized patients with advanced cancer.

PubMed

Nipp, Ryan D; El-Jawahri, Areej; Moran, Samantha M; D'Arpino, Sara M; Johnson, P Connor; Lage, Daniel E; Wong, Risa L; Pirl, William F; Traeger, Lara; Lennes, Inga T; Cashavelly, Barbara J; Jackson, Vicki A; Greer, Joseph A; Ryan, David P; Hochberg, Ephraim P; Temel, Jennifer S

2017-12-01

Patients with advanced cancer often experience frequent and prolonged hospitalizations; however, the factors associated with greater health care utilization have not been described. We sought to investigate the relation between patients' physical and psychological symptom burden and health care utilization. We enrolled patients with advanced cancer and unplanned hospitalizations from September 2014-May 2016. Upon admission, we assessed physical (Edmonton Symptom Assessment System [ESAS]) and psychological symptoms (Patient Health Questionnaire 4 [PHQ-4]). We examined the relationship between symptom burden and healthcare utilization using linear regression for hospital length of stay (LOS) and Cox regression for time to first unplanned readmission within 90 days. We adjusted all models for age, sex, marital status, comorbidity, education, time since advanced cancer diagnosis, and cancer type. We enrolled 1,036 of 1,152 (89.9%) consecutive patients approached. Over one-half reported moderate/severe fatigue, poor well being, drowsiness, pain, and lack of appetite. PHQ-4 scores indicated that 28.8% and 28.0% of patients had depression and anxiety symptoms, respectively. The mean hospital LOS was 6.3 days, and the 90-day readmission rate was 43.1%. Physical symptoms (ESAS: unstandardized coefficient [B], 0.06; P < .001), psychological distress (PHQ-4 total: B, 0.11; P = .040), and depression symptoms (PHQ-4 depression: B, 0.22; P = .017) were associated with longer hospital LOS. Physical (ESAS: hazard ratio, 1.01; P < .001), and anxiety symptoms (PHQ-4 anxiety: hazard ratio, 1.06; P = .045) were associated with a higher likelihood for readmission. Hospitalized patients with advanced cancer experience a high symptom burden, which is significantly associated with prolonged hospitalizations and readmissions. Interventions are needed to address the symptom burden of this population to improve health care delivery and utilization. Cancer 2017;123:4720-4727. © 2017 American Cancer Society. © 2017 American Cancer Society.

Junior High School Science.

ERIC Educational Resources Information Center

Brinson, Gail; And Others

Science instruction is the topic of this guide developed for the junior high schools of Duval County, Jacksonville, Florida. The subjects covered are (1) Biology I, Advanced, for grades 9-12; (2) Earth/Physical Science, Advanced, for advanced 8th graders; (3) Earth/Physical Science, Advanced (Field Test), for advanced 8th graders; (4) Earth…

Inertial Confinement Fusion quarterly report, January-March 1998, volume 8, number 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruer, W

1998-03-31

The coupling of laser light with plasmas is one of the key physics issues for the use of high-power lasers for inertial fusion, high-energy-density physics, and scientific stockpile stewardship. The coupling physics is extremely rich and challenging, particularly in the large plasmas to be accessed on the National Ignition Facility (NIF). The coupling mechanisms span the gamut from classical inverse bremsstrahlung absorption to a variety of nonlinear optical processes. These include stimulated Raman scattering (SRS) from electron plasma waves, stimulated Brillouin scattering (SBS) from ion sound waves, resonant decay into electron plasma and ion sound waves, and laser beam filamentation.more » These processes depend on laser intensity and produce effects such as changes in the efficiency and location of the energy deposition or generation of a component of very energetic electrons, which can preheat capsules. Coupling physics issues have an extremely high leverage. The coupling models are clearly very important ingredients for detailed calculations of laser-irradiated target behavior. Improved understanding and models enable a more efficient use of laser facilities, which becomes even more important as these facilities become larger and more expensive. Advances in the understanding also allow a more timely and cost-effective identification of new applications of high-power lasers, such as for generation of high-temperature hohlraums and compact x-ray sources, or for discovery of advanced fusion schemes. Finally, the interaction of intense electromagnetic waves with ionized media is a fundamental topic of interest to numerous areas of applied science and is an excellent test bed for advancing plasma science and computational modeling of complex phenomena. This issue of the ICF Quarterly Report is dedicated to laser--plasma interactions. The eight articles present a cross section of the broad progress in understanding the key interaction issues, such as laser beam bending, spraying, and scattering, as well as scaling the Nova results to NIF.« less

TDPAC and β-NMR applications in chemistry and biochemistry

NASA Astrophysics Data System (ADS)

Jancso, Attila; Correia, Joao G.; Gottberg, Alexander; Schell, Juliana; Stachura, Monika; Szunyogh, Dániel; Pallada, Stavroula; Lupascu, Doru C.; Kowalska, Magdalena; Hemmingsen, Lars

2017-06-01

Time differential perturbed angular correlation (TDPAC) of γ-rays spectroscopy has been applied in chemistry and biochemistry for decades. Herein we aim to present a comprehensive review of chemical and biochemical applications of TDPAC spectroscopy conducted at ISOLDE over the past 15 years, including elucidation of metal site structure and dynamics in proteins and model systems. β-NMR spectroscopy is well established in nuclear physics, solid state physics, and materials science, but only a limited number of applications in chemistry have appeared. Current endeavors at ISOLDE advancing applications of β-NMR towards chemistry and biochemistry are presented, including the first experiment on 31Mg2+ in an ionic liquid solution. Both techniques require the production of radioisotopes combined with advanced spectroscopic instrumentation present at ISOLDE.

Theoretical Advanced Study Institute: 2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeGrand, Thomas

The Theoretical Advanced Study Institute (TASI) was held at the University of Colorado, Boulder, during June 2-27, 2014. The topic was "Journeys through the Precision Frontier: Amplitudes for Colliders." The organizers were Professors Lance Dixon (SLAC) and Frank Petriello (Northwestern and Argonne). There were fifty-one students. Nineteen lecturers gave sixty seventy-five minute lectures. A Proceedings was published. This TASI was unique for its large emphasis on methods for calculating amplitudes. This was embedded in a program describing recent theoretical and phenomenological developments in particle physics. Topics included introductions to the Standard Model, to QCD (both in a collider context andmore » on the lattice), effective field theories, Higgs physics, neutrino interactions, an introduction to experimental techniques, and cosmology.« less

Project X

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holmes, Steve; Alber, Russ; Asner, David

2013-06-23

Particle physics has made enormous progress in understanding the nature of matter and forces at a fundamental level and has unlocked many mysteries of our world. The development of the Standard Model of particle physics has been a magnificent achievement of the field. Many deep and important questions have been answered and yet many mysteries remain. The discovery of neutrino oscillations, discrepancies in some precision measurements of Standard-Model processes, observation of matter-antimatter asymmetry, the evidence for the existence of dark matter and dark energy, all point to new physics beyond the Standard Model. The pivotal developments of our field, includingmore » the latest discovery of the Higgs Boson, have progressed within three interlocking frontiers of research – the Energy, Intensity and Cosmic frontiers – where discoveries and insights in one frontier powerfully advance the other frontiers as well.« less

Understanding Cooperative Chirality at the Nanoscale

NASA Astrophysics Data System (ADS)

Yu, Shangjie; Wang, Pengpeng; Govorov, Alexander; Ouyang, Min

Controlling chirality of organic and inorganic structures plays a key role in many physical, chemical and biochemical processes, and may offer new opportunity to create technology applications based on chiroptical effect. In this talk, we will present a theoretical model and simulation to demonstrate how to engineer nanoscale chirality in inorganic nanostructures via synergistic control of electromagnetic response of both lattice and geometry, leading to rich tunability of chirality at the nanoscale. Our model has also been applied to understand recent materials advancement of related control with excellent agreement, and can elucidate physical origins of circular dichroism features in the experiment.

Modeling the Effects of Lipid Composition on Stratum Corneum Bilayers Using Molecular Dynamics Simulations

NASA Astrophysics Data System (ADS)

Huzil, J. Torin; Sivaloganathan, Siv; Kohandel, Mohammad; Foldvari, Marianna

2011-11-01

The advancement of dermal and transdermal drug delivery requires the development of delivery systems that are suitable for large protein and nucleic acid-based therapeutic agents. However, a complete mechanistic understanding of the physical barrier properties associated with the epidermis, specifically the membrane structures within the stratum corneum, has yet to be developed. Here, we describe the assembly and computational modeling of stratum corneum lipid bilayers constructed from varying ratios of their constituent lipids (ceramide, free fatty acids and cholesterol) to determine if there is a difference in the physical properties of stratum corneum compositions.

Cirrus Susceptibility to Changes in Ice Nuclei: Physical Processes, Model Uncertainties, and Measurement Needs

NASA Technical Reports Server (NTRS)

Jensen, Eric

2017-01-01

In this talk, I will begin by discussing the physical processes that govern the competition between heterogeneous and homogeneous ice nucleation in upper tropospheric cirrus clouds. Next, I will review the current knowledge of low-temperature ice nucleation from laboratory experiments and field measurements. I will then discuss the uncertainties and deficiencies in representations of cirrus processes in global models used to estimate the climate impacts of changes in cirrus clouds. Lastly, I will review the critical field measurements needed to advance our understanding of cirrus and their susceptibility to changes in aerosol properties.

Bringing physics to bear on the phenomenon of life: the divergent positions of Bohr, Delbrück, and Schrödinger.

PubMed

Domondon, Andrew T

2006-09-01

The received view on the contributions of the physics community to the birth of molecular biology tends to present the physics community as sharing a basic level consensus on how physics should be brought to bear on biology. I argue, however, that a close examination of the views of three leading physicists involved in the birth of molecular biology, Bohr, Delbrück, and Schrödinger, suggests that there existed fundamental disagreements on how physics should be employed to solve problems in biology even within the physics community. In particular, I focus on how these three figures differed sharply in their assessment of the relevance of complementarity, the potential of chemical methods, and the relative importance of classical physics. In addition, I assess and develop Roll-Hansen's attempt to conceptualize this history in terms of models of scientific change advanced by Kuhn and Lakatos. Though neither model is fully successful in explaining the divergence of views among these three physicists, I argue that the extent and quality of difference in their views help elucidate and extend some themes that are left opaque in Kuhn's model.

Testing a self-determination theory model of children's physical activity motivation: a cross-sectional study.

PubMed

Sebire, Simon J; Jago, Russell; Fox, Kenneth R; Edwards, Mark J; Thompson, Janice L

2013-09-26

Understanding children's physical activity motivation, its antecedents and associations with behavior is important and can be advanced by using self-determination theory. However, research among youth is largely restricted to adolescents and studies of motivation within certain contexts (e.g., physical education). There are no measures of self-determination theory constructs (physical activity motivation or psychological need satisfaction) for use among children and no previous studies have tested a self-determination theory-based model of children's physical activity motivation. The purpose of this study was to test the reliability and validity of scores derived from scales adapted to measure self-determination theory constructs among children and test a motivational model predicting accelerometer-derived physical activity. Cross-sectional data from 462 children aged 7 to 11 years from 20 primary schools in Bristol, UK were analysed. Confirmatory factor analysis was used to examine the construct validity of adapted behavioral regulation and psychological need satisfaction scales. Structural equation modelling was used to test cross-sectional associations between psychological need satisfaction, motivation types and physical activity assessed by accelerometer. The construct validity and reliability of the motivation and psychological need satisfaction measures were supported. Structural equation modelling provided evidence for a motivational model in which psychological need satisfaction was positively associated with intrinsic and identified motivation types and intrinsic motivation was positively associated with children's minutes in moderate-to-vigorous physical activity. The study provides evidence for the psychometric properties of measures of motivation aligned with self-determination theory among children. Children's motivation that is based on enjoyment and inherent satisfaction of physical activity is associated with their objectively-assessed physical activity and such motivation is positively associated with perceptions of psychological need satisfaction. These psychological factors represent potential malleable targets for interventions to increase children's physical activity.

Physics-Based Computational Algorithm for the Multi-Fluid Plasma Model

DTIC Science & Technology

2014-06-30

applying it to study laser - 20 Physics-Based Multi-Fluid Plasma Algorithm Shumlak Figure 6: Blended finite element method applied to the species...separation problem in capsule implosions. Number densities and electric field are shown after the laser drive has compressed the multi-fluid plasma and...6 after the laser drive has started the compression. A separation clearly develops. The solution is found using an explicit advance (CFL=1) for the

Using exercise training to understand control of skeletal muscle metabolism.

PubMed

Gibala, Martin J

2017-01-01

Bengt Saltin believed that exercise was the unsurpassed tool to study human integrative physiology. He demonstrated this over the course of his career by employing physical training as a model to advance our understanding of skeletal muscle metabolic control and the impact of physical activity on performance and health. Bengt was also a pioneer in advocating the concept of exercise is medicine. His scientific curiosity was perhaps exceeded only by his generosity.

[Advance in researches on the effect of forest on hydrological process].

PubMed

Zhang, Zhiqiang; Yu, Xinxiao; Zhao, Yutao; Qin, Yongsheng

2003-01-01

According to the effects of forest on hydrological process, forest hydrology can be divided into three related aspects: experimental research on the effects of forest changing on hydrological process quantity and water quality; mechanism study on the effects of forest changing on hydrological cycle, and establishing and exploitating physical-based distributed forest hydrological model for resource management and engineering construction. Orientation experiment research can not only support the first-hand data for forest hydrological model, but also make clear the precipitation-runoff mechanisms. Research on runoff mechanisms can be valuable for the exploitation and improvement of physical based hydrological models. Moreover, the model can also improve the experimental and runoff mechanism researches. A review of above three aspects are summarized in this paper.

High Fidelity Modeling of Field Reversed Configuration (FRC) Thrusters

DTIC Science & Technology

2017-04-22

signatures which can be used for direct, non -invasive, comparison with experimental diagnostics can be produced. This research will be directly... experimental campaign is critical to developing general design philosophies for low-power plasmoid formation, the complexity of non -linear plasma processes...advanced space propulsion. The work consists of numerical method development, physical model development, and systematic studies of the non -linear

Relations of Transtheoretical Model Stage, Self-Efficacy, and Voluntary Physical Activity in African American Preadolescents

ERIC Educational Resources Information Center

Annesi, James J.; Faigenbaum, Avery D.; Westcott, Wayne L.

2010-01-01

The transtheoretical model (TTM; Prochaska, DiClemente, & Norcross, 1992) suggests that, at any point, an individual is in one of five stages-of-change related to adopting a behavior. People sequentially advance in stage but may also maintain or even regress, based on personal and environmental factors (Nigg, 2005). A classic study published in…

Semi-Empirical Modeling of SLD Physics

NASA Technical Reports Server (NTRS)

Wright, William B.; Potapczuk, Mark G.

2004-01-01

The effects of supercooled large droplets (SLD) in icing have been an area of much interest in recent years. As part of this effort, the assumptions used for ice accretion software have been reviewed. A literature search was performed to determine advances from other areas of research that could be readily incorporated. Experimental data in the SLD regime was also analyzed. A semi-empirical computational model is presented which incorporates first order physical effects of large droplet phenomena into icing software. This model has been added to the LEWICE software. Comparisons are then made to SLD experimental data that has been collected to date. Results will be presented for the comparison of water collection efficiency, ice shape and ice mass.

Investigation of Alien Wavelength Quality in Live Multi-Domain, Multi-Vendor Link Using Advanced Simulation Tool

NASA Astrophysics Data System (ADS)

Nordal Petersen, Martin; Nuijts, Roeland; Lange Bjørn, Lars

2014-05-01

This article presents an advanced optical model for simulation of alien wavelengths in multi-domain and multi-vendor dense wavelength-division multiplexing networks. The model aids optical network planners with a better understanding of the non-linear effects present in dense wavelength-division multiplexing systems and better utilization of alien wavelengths in future applications. The limiting physical effects for alien wavelengths are investigated in relation to power levels, channel spacing, and other factors. The simulation results are verified through experimental setup in live multi-domain dense wavelength-division multiplexing systems between two national research networks: SURFnet in Holland and NORDUnet in Denmark.

Millikan Award Lecture, 2006: Physics For All

NASA Astrophysics Data System (ADS)

Hobson, Art

2006-12-01

We physics teachers must broaden our focus from physics for physicists and other scientists to physics for all. The reason, as the American Association for the Advancement of Science puts it, is that "[w]ithout a scientifically literate population, the outlook for a better world is not promising." Physics for all (including the first course for scientists) should be conceptual, not technical. It should describe the universe as we understand it today, including special and general relativity, quantum physics, modern cosmology, nuclear physics, the standard model of particles and interactions, and quantum fields. Many science writers have shown that this description is possible. It should emphasize the scientific process and include such societal topics as global warming, nuclear weapons, and pseudoscience, because citizens need to vote intelligently on such issues.

Simulation modelling for new gas turbine fuel controller creation.

NASA Astrophysics Data System (ADS)

Vendland, L. E.; Pribylov, V. G.; Borisov, Yu A.; Arzamastsev, M. A.; Kosoy, A. A.

2017-11-01

State of the art gas turbine fuel flow control systems are based on throttle principle. Major disadvantage of such systems is that they require high pressure fuel intake. Different approach to fuel flow control is to use regulating compressor. And for this approach because of controller and gas turbine interaction a specific regulating compressor is required. Difficulties emerge as early as the requirement definition stage. To define requirements for new object, his properties must be known. Simulation modelling helps to overcome these difficulties. At the requirement definition stage the most simplified mathematical model is used. Mathematical models will get more complex and detailed as we advance in planned work. If future adjusting of regulating compressor physical model to work with virtual gas turbine and physical control system is planned.

Overview of the Meso-NH model version 5.4 and its applications

NASA Astrophysics Data System (ADS)

Lac, Christine; Chaboureau, Jean-Pierre; Masson, Valéry; Pinty, Jean-Pierre; Tulet, Pierre; Escobar, Juan; Leriche, Maud; Barthe, Christelle; Aouizerats, Benjamin; Augros, Clotilde; Aumond, Pierre; Auguste, Franck; Bechtold, Peter; Berthet, Sarah; Bielli, Soline; Bosseur, Frédéric; Caumont, Olivier; Cohard, Jean-Martial; Colin, Jeanne; Couvreux, Fleur; Cuxart, Joan; Delautier, Gaëlle; Dauhut, Thibaut; Ducrocq, Véronique; Filippi, Jean-Baptiste; Gazen, Didier; Geoffroy, Olivier; Gheusi, François; Honnert, Rachel; Lafore, Jean-Philippe; Lebeaupin Brossier, Cindy; Libois, Quentin; Lunet, Thibaut; Mari, Céline; Maric, Tomislav; Mascart, Patrick; Mogé, Maxime; Molinié, Gilles; Nuissier, Olivier; Pantillon, Florian; Peyrillé, Philippe; Pergaud, Julien; Perraud, Emilie; Pianezze, Joris; Redelsperger, Jean-Luc; Ricard, Didier; Richard, Evelyne; Riette, Sébastien; Rodier, Quentin; Schoetter, Robert; Seyfried, Léo; Stein, Joël; Suhre, Karsten; Taufour, Marie; Thouron, Odile; Turner, Sandra; Verrelle, Antoine; Vié, Benoît; Visentin, Florian; Vionnet, Vincent; Wautelet, Philippe

2018-05-01

This paper presents the Meso-NH model version 5.4. Meso-NH is an atmospheric non hydrostatic research model that is applied to a broad range of resolutions, from synoptic to turbulent scales, and is designed for studies of physics and chemistry. It is a limited-area model employing advanced numerical techniques, including monotonic advection schemes for scalar transport and fourth-order centered or odd-order WENO advection schemes for momentum. The model includes state-of-the-art physics parameterization schemes that are important to represent convective-scale phenomena and turbulent eddies, as well as flows at larger scales. In addition, Meso-NH has been expanded to provide capabilities for a range of Earth system prediction applications such as chemistry and aerosols, electricity and lightning, hydrology, wildland fires, volcanic eruptions, and cyclones with ocean coupling. Here, we present the main innovations to the dynamics and physics of the code since the pioneer paper of Lafore et al. (1998) and provide an overview of recent applications and couplings.

TIMSS Advanced 2008 Assessment Frameworks

ERIC Educational Resources Information Center

Garden, Robert A.; Lie, Svein; Robitaille, David F.; Angell, Carl; Martin, Michael O.; Mullis, Ina V.S.; Foy, Pierre; Arora, Alka

2006-01-01

Developing the Trends in International Mathematics and Science Study (TIMSS) Advanced 2008 Assessment Frameworks was a collaborative venture involving mathematics and physics experts from around the world. The document contains two frameworks for implementing TIMSS Advanced 2008--one for advanced mathematics and one for physics. It also contains…

The measurement conundrum in exercise adherence research.

PubMed

Dishman, R K

1994-11-01

This paper has two purposes. It first prefaces a symposium titled "Exercise adherence and behavior change: prospects, problems, and future directions." The symposium describes the progress made during the past 5 years toward understanding the adoption and maintenance of physical activity and exercise. Specifically, research is discussed that has tested the applicability to physical activity of four psychological models of behavior: Reasoned Action, Planned Behavior, Social-Cognitive Theory, and the Transtheoretical Model of stages of change. Recent exercise interventions in clinical/community settings also are discussed to illustrate how theoretical models can be implemented to increase and maintain exercise. The second purpose of this paper is to provide a brief summary of the contemporary literatures on the determinants of physical activity and interventions designed to increase and maintain physical activity. The summary focuses on the measurement problems that have limited the advances made in theory and application in these areas of research. Progress toward resolving the measurement problems during the past 5 years is contrasted with earlier scientific consensus.

Status Report on NEAMS System Analysis Module Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, R.; Fanning, T. H.; Sumner, T.

2015-12-01

Under the Reactor Product Line (RPL) of DOE-NE’s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, an advanced SFR System Analysis Module (SAM) is being developed at Argonne National Laboratory. The goal of the SAM development is to provide fast-running, improved-fidelity, whole-plant transient analyses capabilities. SAM utilizes an object-oriented application framework MOOSE), and its underlying meshing and finite-element library libMesh, as well as linear and non-linear solvers PETSc, to leverage modern advanced software environments and numerical methods. It also incorporates advances in physical and empirical models and seeks closure models based on information from high-fidelity simulations and experiments. This reportmore » provides an update on the SAM development, and summarizes the activities performed in FY15 and the first quarter of FY16. The tasks include: (1) implement the support of 2nd-order finite elements in SAM components for improved accuracy and computational efficiency; (2) improve the conjugate heat transfer modeling and develop pseudo 3-D full-core reactor heat transfer capabilities; (3) perform verification and validation tests as well as demonstration simulations; (4) develop the coupling requirements for SAS4A/SASSYS-1 and SAM integration.« less

Recent advances in nuclear fission theory: pre- and post-scission physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Talou, Patrick; Kawano, Toshihiko; Bouland, Olivier

2010-01-01

Recent advances in the modeling of the nuclear fission process for data evaluation purposes are reviewed. In particular, it is stressed that a more comprehensive approach to fission data is needed if predictive capability is to be achieved. The link between pre- and post-scission data is clarified, and a path forward to evaluate those data in a consistent and comprehensive manner is presented. Two examples are given: (i) the modeling of fission cross-sections in the R-matrix formalism, for which results for Pu isotopes from 239 to 242 are presented; (ii) the modeling of prompt fission neutrons in the Monte Carlomore » Hauser-Feshbach framework. Results for neutron-induced fission on {sup 235}U are discussed.« less

Cinema Fire Modelling by FDS

NASA Astrophysics Data System (ADS)

Glasa, J.; Valasek, L.; Weisenpacher, P.; Halada, L.

2013-02-01

Recent advances in computer fluid dynamics (CFD) and rapid increase of computational power of current computers have led to the development of CFD models capable to describe fire in complex geometries incorporating a wide variety of physical phenomena related to fire. In this paper, we demonstrate the use of Fire Dynamics Simulator (FDS) for cinema fire modelling. FDS is an advanced CFD system intended for simulation of the fire and smoke spread and prediction of thermal flows, toxic substances concentrations and other relevant parameters of fire. The course of fire in a cinema hall is described focusing on related safety risks. Fire properties of flammable materials used in the simulation were determined by laboratory measurements and validated by fire tests and computer simulations

Verification of a Multiphysics Toolkit against the Magnetized Target Fusion Concept

NASA Technical Reports Server (NTRS)

Thomas, Scott; Perrell, Eric; Liron, Caroline; Chiroux, Robert; Cassibry, Jason; Adams, Robert B.

2005-01-01

In the spring of 2004 the Advanced Concepts team at MSFC embarked on an ambitious project to develop a suite of modeling routines that would interact with one another. The tools would each numerically model a portion of any advanced propulsion system. The tools were divided by physics categories, hence the name multiphysics toolset. Currently most of the anticipated modeling tools have been created and integrated. Results are given in this paper for both a quarter nozzle with chemically reacting flow and the interaction of two plasma jets representative of a Magnetized Target Fusion device. The results have not been calibrated against real data as of yet, but this paper demonstrates the current capability of the multiphysics tool and planned future enhancements

Science at a crossroads.

PubMed

Bonvillian, William B

2002-07-01

Science is entering an alliance with the economy that will speed the effect of innovation through society. Despite the slowdown of the 'new economy', a cascade paradigm of innovation appears key to increasing the rate of economic growth. Yet for science to continue to thrive and make this contribution to innovation, it must traverse at least three key crossroads. First, while life sciences have built a strong advocacy model to secure growing federal research funding, the physical sciences (including mathematics and engineering) have not and must now do so to thrive. Second, the drop in the numbers of physical scientists and engineers must be reversed if we are to have the talent to maintain a strong trend of scientific advance. Third, although science advances are increasingly interdisciplinary and occurring in the space between the historic science stovepipes, the organization of federal science support is largely unchanged since the beginning of the cold war. While a decentralized model has value, we must also consider new approaches that encourage deeper cooperation across science sectors and agencies.

The Scanning Electron Microscope As An Accelerator For The Undergraduate Advanced Physics Laboratory

NASA Astrophysics Data System (ADS)

Peterson, Randolph S.; Berggren, Karl K.; Mondol, Mark

2011-06-01

Few universities or colleges have an accelerator for use with advanced physics laboratories, but many of these institutions have a scanning electron microscope (SEM) on site, often in the biology department. As an accelerator for the undergraduate, advanced physics laboratory, the SEM is an excellent substitute for an ion accelerator. Although there are no nuclear physics experiments that can be performed with a typical 30 kV SEM, there is an opportunity for experimental work on accelerator physics, atomic physics, electron-solid interactions, and the basics of modern e-beam lithography.

Physical inactivity displays a mediator role in the association of diabetes and poverty: A spatiotemporal analysis.

PubMed

Chien, Lung-Chang; Li, Xiao; Staudt, Amanda

2017-11-03

Physical inactivity is one of the risk factors of diabetes. In addition, physical inactivity is attributed to urbanization-related factors, such as poverty, which is also one of the risk factors of diabetes. We hypothesized that physical inactivity is a mediator in the association between diabetes and poverty, and that spatial heterogeneity exists in these relationships. This study adopted a spatiotemporal modelling approach to conduct this mediator analysis. From 2004-2011, data were collected at the county level in 48 contiguous states (with a total of 3,109 counties) from the Behavioral Risk Factor Surveillance System (BRFSS) and American Community Survey. Poverty percentage significantly affected physical inactivity prevalence and diabetes prevalence in two separate models. Using a model with both physical inactivity and poverty percentages as independent variables, we verified that physical inactivity prevalence is a significant mediator. In this model, physical inactivity prevalence resulted in a significant positive association with diabetes prevalence, and the influence of poverty percentage on diabetes prevalence was significantly reduced (P=0.0009). An advanced spatiotemporal analysis revealed that 32.65% of counties having a significant positive association between diabetes prevalence and physical inactivity prevalence also had a significant positive association between physical inactivity prevalence and poverty percentage. Those counties were also likely located in the South and Southeast of USA. In summary, the findings of this study demonstrate the mediating effect of physical inactivity between diabetes and poverty. When implementing diabetes prevention in communities with higher poverty, appropriate strategies to reduce the cost burden of physical activity programmes should be considered.

Advanced instrumentation for Solar System gravitational physics

NASA Astrophysics Data System (ADS)

Peron, Roberto; Bellettini, G.; Berardi, S.; Boni, A.; Cantone, C.; Coradini, A.; Currie, D. G.; Dell'Agnello, S.; Delle Monache, G. O.; Fiorenza, E.; Garattini, M.; Iafolla, V.; Intaglietta, N.; Lefevre, C.; Lops, C.; March, R.; Martini, M.; Nozzoli, S.; Patrizi, G.; Porcelli, L.; Reale, A.; Santoli, F.; Tauraso, R.; Vittori, R.

2010-05-01

The Solar System is a complex laboratory for testing gravitational physics. Indeed, its scale and hierarchical structure make possible a wide range of tests for gravitational theories, studying the motion of both natural and artificial objects. The usual methodology makes use of tracking information related to the bodies, fitted by a suitable dynamical model. Different equations of motion are provided by different theories, which can be therefore tested and compared. Future exploration scenarios show the possibility of placing deep-space probes near the Sun or in outer Solar System, thereby extending the available experimental data sets. In particular, the Earth-Moon is the most accurately known gravitational three-body laboratory, which is undergoing a new, strong wave of research and exploration (both robotic and manned). In addition, the benefits of a synergetic study of planetary science and gravitational physics are of the greatest importance (as shown by the success of the Apollo program), especially in the Earth-Moon, Mars-Phobos, Jovian and Saturnian sub-suystems. This scenarios open critical issues regarding the quality of the available dynamical models, i.e. their capability of fitting data without an excessive number of empirical hypotheses. A typical case is represented by the non-gravitational phenomena, which in general are difficult to model. More generally, gravitation tests with Lunar Laser Ranging, inner or outer Solar System probes and the appearance of the so-called 'anomalies'(like the one indicated by the Pioneers), whatever their real origin (either instrumental effects or due to new physics), show the necessity of a coordinated improvement of tracking and modelization techniques. A common research path will be discussed, employing the development and use of advanced instrumentation to cope with current limitations of Solar System gravitational tests. In particular, the use of high-sensitivity accelerometers, combined with microwave and laser tracking, will be discussed.

A Bayesian network approach for modeling local failure in lung cancer

NASA Astrophysics Data System (ADS)

Oh, Jung Hun; Craft, Jeffrey; Lozi, Rawan Al; Vaidya, Manushka; Meng, Yifan; Deasy, Joseph O.; Bradley, Jeffrey D.; El Naqa, Issam

2011-03-01

Locally advanced non-small cell lung cancer (NSCLC) patients suffer from a high local failure rate following radiotherapy. Despite many efforts to develop new dose-volume models for early detection of tumor local failure, there was no reported significant improvement in their application prospectively. Based on recent studies of biomarker proteins' role in hypoxia and inflammation in predicting tumor response to radiotherapy, we hypothesize that combining physical and biological factors with a suitable framework could improve the overall prediction. To test this hypothesis, we propose a graphical Bayesian network framework for predicting local failure in lung cancer. The proposed approach was tested using two different datasets of locally advanced NSCLC patients treated with radiotherapy. The first dataset was collected retrospectively, which comprises clinical and dosimetric variables only. The second dataset was collected prospectively in which in addition to clinical and dosimetric information, blood was drawn from the patients at various time points to extract candidate biomarkers as well. Our preliminary results show that the proposed method can be used as an efficient method to develop predictive models of local failure in these patients and to interpret relationships among the different variables in the models. We also demonstrate the potential use of heterogeneous physical and biological variables to improve the model prediction. With the first dataset, we achieved better performance compared with competing Bayesian-based classifiers. With the second dataset, the combined model had a slightly higher performance compared to individual physical and biological models, with the biological variables making the largest contribution. Our preliminary results highlight the potential of the proposed integrated approach for predicting post-radiotherapy local failure in NSCLC patients.

Quantifying the Role of Atmospheric Forcing in Ice Edge Retreat and Advance Including Wind-Wave Coupling

DTIC Science & Technology

2015-09-30

Quantifying the Role of Atmospheric Forcing in Ice Edge Retreat and Advance Including Wind- Wave Coupling Peter S. Guest (NPS Technical Contact) Naval...surface fluxes and ocean waves in coupled models in the Beaufort and Chukchi Seas. 2. Understand the physics of heat and mass transfer from the ocean...to the atmosphere. 3. Improve forecasting of waves on the open ocean and in the marginal ice zone. 2 OBJECTIVES 1. Quantifying the open-ocean

Advances on Propulsion Technology for High-Speed Aircraft. Volume 1

DTIC Science & Technology

2007-03-01

sprayed Cu -3% Ag alloys , ITSC 2001 - Singapour - 6dit6e par C.C. Berndt - K.A. Khor et E.F. Lugscheider - ASM-TSS - Materials park - OH-USA, p.633... spraying of CuCrNb powder and a more advanced approach which combines the advantages of a high temperature, low density and porous carbon-fibre...physical vapour deposition (EB-PVD), vacuum plasma spraying (VPS) and solution plasma spraying (SPS) [38-41]. A segmented sub-scale model combustor with

NASA's supercomputing experience

NASA Technical Reports Server (NTRS)

Bailey, F. Ron

1990-01-01

A brief overview of NASA's recent experience in supercomputing is presented from two perspectives: early systems development and advanced supercomputing applications. NASA's role in supercomputing systems development is illustrated by discussion of activities carried out by the Numerical Aerodynamical Simulation Program. Current capabilities in advanced technology applications are illustrated with examples in turbulence physics, aerodynamics, aerothermodynamics, chemistry, and structural mechanics. Capabilities in science applications are illustrated by examples in astrophysics and atmospheric modeling. Future directions and NASA's new High Performance Computing Program are briefly discussed.

Development of Predictive Models of Advanced Propulsion Concepts for Low Cost Space Transportation

NASA Technical Reports Server (NTRS)

Morrell, Michael Randy

2002-01-01

This final report presents the Graduate Student Research Program (GSRP) work Mr. Morrell was able to complete as a summer intern at NASA MSFS during the summer of 2001, and represents work completed from inception through project termination. The topics include: 1) NASA TD40 Organization; 2) Combustion Physics Lab; 3) Advanced Hydrocarbon Fuels; 4) GSRP Summer Tasks; 5) High Pressure Facility Installation; 6) High Pressure Combustion Issues; 7) High Energy Density Matter (HEDM) Hydrocarbons; and 8) GSRP Summer Intern Summary.

Material Protection, Accounting, and Control Technologies (MPACT): Modeling and Simulation Roadmap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cipiti, Benjamin; Dunn, Timothy; Durbin, Samual

The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal. This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools willmore » consist of instrumentation and devices as well as computer software for modeling. To aid in framing its long-term goal, during FY16, a modeling and simulation roadmap is being developed for three major areas of investigation: (1) radiation transport and sensors, (2) process and chemical models, and (3) shock physics and assessments. For each area, current modeling approaches are described, and gaps and needs are identified.« less

Gain selection method and model for coupled propulsion and airframe systems

NASA Technical Reports Server (NTRS)

Murphy, P. C.

1982-01-01

A longitudinal model is formulated for an advanced fighter from three subsystem models: the inlet, the engine, and the airframe. Notable interaction is found in the coupled system. A procedure, based on eigenvalue sensitivities, is presented which indicates the importance of the feedback gains to the optimal solution. This allows ineffectual gains to be eliminated; thus, hardware and expense may be saved in the realization of the physical controller.

How conduit models can be used to interpret volcano monitoring data

NASA Astrophysics Data System (ADS)

Thomas, M. E.; Neuberg, J. W.; Karl, S.; Collinson, A.; Pascal, K.

2012-04-01

During the last decade there have been major advances in the field of volcano monitoring, but to be able to take full advantage of these advances it is vital to link the monitoring data with the physical processes that give rise to the recorded signals. To obtain a better understanding of these physical processes it is necessary to understand the conditions of the system at depth. This can be achieved through numerical modelling. We present the results of conduit models representative of a silicic volcanic system and demonstrate how processes identified and interpreted from these models may manifest in the recorded monitoring data. Links are drawn to seismicity, deformation, and gas emissions. A key point is how these data compliment each other, and through utilising conduit models we are able to interpret how these different data may be recorded in response to a particular process. This is an invaluable tool as it is far easier to draw firm conclusions on what is happening at a volcano if there are several different data sets that suggest the same processes are occurring. Some of these interpretations appear useful in forecasting potentially catastrophic changes in eruptive behaviour, such as a dome collapse leading to violent explosive behaviour, and the role of monitoring data in this capacity will also be addressed.

Physical Constraints on Seismic Waves from Chemical and Nuclear Explosions

DTIC Science & Technology

1992-04-22

AIR FORCE SYSTEMS COMMAND HANSCOM AIR FORCE BASE , MASSACHUSETTS 01731-5000 92-23124 9 2 8 1 9 5 9 IIII!I!I l1!j lIII ii SPONSORED BY Defense Advanced...in good agreement with seismic yield esti- improve the detection capabilities of new systems. Given mates [Sykes and Ekstrom, 1989]. (1990) reports...nuclear ,eismology. physical model for spall; (4) Determination of energy balance in Many questions still remain, particularly those associated with the

Projecting changes in the distribution and productivity of living marine resources: A critical review of the suite of modelling approaches used in the large European project VECTORS

NASA Astrophysics Data System (ADS)

Peck, Myron A.; Arvanitidis, Christos; Butenschön, Momme; Canu, Donata Melaku; Chatzinikolaou, Eva; Cucco, Andrea; Domenici, Paolo; Fernandes, Jose A.; Gasche, Loic; Huebert, Klaus B.; Hufnagl, Marc; Jones, Miranda C.; Kempf, Alexander; Keyl, Friedemann; Maar, Marie; Mahévas, Stéphanie; Marchal, Paul; Nicolas, Delphine; Pinnegar, John K.; Rivot, Etienne; Rochette, Sébastien; Sell, Anne F.; Sinerchia, Matteo; Solidoro, Cosimo; Somerfield, Paul J.; Teal, Lorna R.; Travers-Trolet, Morgan; van de Wolfshaar, Karen E.

2018-02-01

We review and compare four broad categories of spatially-explicit modelling approaches currently used to understand and project changes in the distribution and productivity of living marine resources including: 1) statistical species distribution models, 2) physiology-based, biophysical models of single life stages or the whole life cycle of species, 3) food web models, and 4) end-to-end models. Single pressures are rare and, in the future, models must be able to examine multiple factors affecting living marine resources such as interactions between: i) climate-driven changes in temperature regimes and acidification, ii) reductions in water quality due to eutrophication, iii) the introduction of alien invasive species, and/or iv) (over-)exploitation by fisheries. Statistical (correlative) approaches can be used to detect historical patterns which may not be relevant in the future. Advancing predictive capacity of changes in distribution and productivity of living marine resources requires explicit modelling of biological and physical mechanisms. New formulations are needed which (depending on the question) will need to strive for more realism in ecophysiology and behaviour of individuals, life history strategies of species, as well as trophodynamic interactions occurring at different spatial scales. Coupling existing models (e.g. physical, biological, economic) is one avenue that has proven successful. However, fundamental advancements are needed to address key issues such as the adaptive capacity of species/groups and ecosystems. The continued development of end-to-end models (e.g., physics to fish to human sectors) will be critical if we hope to assess how multiple pressures may interact to cause changes in living marine resources including the ecological and economic costs and trade-offs of different spatial management strategies. Given the strengths and weaknesses of the various types of models reviewed here, confidence in projections of changes in the distribution and productivity of living marine resources will be increased by assessing model structural uncertainty through biological ensemble modelling.

COMPUTATIONAL CHALLENGES IN BUILDING MULTI-SCALE AND MULTI-PHYSICS MODELS OF CARDIAC ELECTRO-MECHANICS

PubMed Central

Plank, G; Prassl, AJ; Augustin, C

2014-01-01

Despite the evident multiphysics nature of the heart – it is an electrically controlled mechanical pump – most modeling studies considered electrophysiology and mechanics in isolation. In no small part, this is due to the formidable modeling challenges involved in building strongly coupled anatomically accurate and biophyically detailed multi-scale multi-physics models of cardiac electro-mechanics. Among the main challenges are the selection of model components and their adjustments to achieve integration into a consistent organ-scale model, dealing with technical difficulties such as the exchange of data between electro-physiological and mechanical model, particularly when using different spatio-temporal grids for discretization, and, finally, the implementation of advanced numerical techniques to deal with the substantial computational. In this study we report on progress made in developing a novel modeling framework suited to tackle these challenges. PMID:24043050

Statistical analysis of target acquisition sensor modeling experiments

NASA Astrophysics Data System (ADS)

Deaver, Dawne M.; Moyer, Steve

2015-05-01

The U.S. Army RDECOM CERDEC NVESD Modeling and Simulation Division is charged with the development and advancement of military target acquisition models to estimate expected soldier performance when using all types of imaging sensors. Two elements of sensor modeling are (1) laboratory-based psychophysical experiments used to measure task performance and calibrate the various models and (2) field-based experiments used to verify the model estimates for specific sensors. In both types of experiments, it is common practice to control or measure environmental, sensor, and target physical parameters in order to minimize uncertainty of the physics based modeling. Predicting the minimum number of test subjects required to calibrate or validate the model should be, but is not always, done during test planning. The objective of this analysis is to develop guidelines for test planners which recommend the number and types of test samples required to yield a statistically significant result.

Advances in modeling sorption and diffusion of moisture in porous reactive materials.

PubMed

Harley, Stephen J; Glascoe, Elizabeth A; Lewicki, James P; Maxwell, Robert S

2014-06-23

Water-vapor-uptake experiments were performed on a silica-filled poly(dimethylsiloxane) (PDMS) network and modeled by using two different approaches. The data was modeled by using established methods and the model parameters were used to predict moisture uptake in a sample. The predictions are reasonably good, but not outstanding; many of the shortcomings of the modeling are discussed. A high-fidelity modeling approach is derived and used to improve the modeling of moisture uptake and diffusion. Our modeling approach captures the physics and kinetics of diffusion and adsorption/desorption, simultaneously. It predicts uptake better than the established method; more importantly, it is also able to predict outgassing. The material used for these studies is a filled-PDMS network; physical interpretations concerning the sorption and diffusion of moisture in this network are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnitude, moment, and measurement: The seismic mechanism controversy and its resolution.

PubMed

Miyake, Teru

This paper examines the history of two related problems concerning earthquakes, and the way in which a theoretical advance was involved in their resolution. The first problem is the development of a physical, as opposed to empirical, scale for measuring the size of earthquakes. The second problem is that of understanding what happens at the source of an earthquake. There was a controversy about what the proper model for the seismic source mechanism is, which was finally resolved through advances in the theory of elastic dislocations. These two problems are linked, because the development of a physically-based magnitude scale requires an understanding of what goes on at the seismic source. I will show how the theoretical advances allowed seismologists to re-frame the questions they were trying to answer, so that the data they gathered could be brought to bear on the problem of seismic sources in new ways. Copyright © 2017 Elsevier Ltd. All rights reserved.

National Study of Excellence and Innovation in Physical Therapist Education: Part 2-A Call to Reform.

PubMed

Jensen, Gail M; Hack, Laurita M; Nordstrom, Terrence; Gwyer, Janet; Mostrom, Elizabeth

2017-09-01

This perspective shares recommendations that draw from (1) the National Study of Excellence and Innovation in Physical Therapist Education research findings and a conceptual model of excellence in physical therapist education, (2) the Carnegie Foundation's Preparation for the Professions Program (PPP), and (3) research in the learning sciences. The 30 recommendations are linked to the dimensions described in the conceptual model for excellence in physical therapist education: Culture of Excellence, Praxis of Learning, and Organizational Structures and Resources. This perspective proposes a transformative call for reform framed across 3 core categories: (1) creating a culture of excellence, leadership, and partnership, (2) advancing the learning sciences and understanding and enacting the social contract, and (3) implementing organizational imperatives. Similar to the Carnegie studies, this perspective identifies action items (9) that should be initiated immediately in a strategic and systematic way by the major organizational stakeholders in physical therapist education. These recommendations and action items provide a transformative agenda for physical therapist education, and thus the profession, in meeting the changing needs of society through higher levels of excellence. © 2017 American Physical Therapy Association.

Data-driven multi-scale multi-physics models to derive process-structure-property relationships for additive manufacturing

NASA Astrophysics Data System (ADS)

Yan, Wentao; Lin, Stephen; Kafka, Orion L.; Lian, Yanping; Yu, Cheng; Liu, Zeliang; Yan, Jinhui; Wolff, Sarah; Wu, Hao; Ndip-Agbor, Ebot; Mozaffar, Mojtaba; Ehmann, Kornel; Cao, Jian; Wagner, Gregory J.; Liu, Wing Kam

2018-05-01

Additive manufacturing (AM) possesses appealing potential for manipulating material compositions, structures and properties in end-use products with arbitrary shapes without the need for specialized tooling. Since the physical process is difficult to experimentally measure, numerical modeling is a powerful tool to understand the underlying physical mechanisms. This paper presents our latest work in this regard based on comprehensive material modeling of process-structure-property relationships for AM materials. The numerous influencing factors that emerge from the AM process motivate the need for novel rapid design and optimization approaches. For this, we propose data-mining as an effective solution. Such methods—used in the process-structure, structure-properties and the design phase that connects them—would allow for a design loop for AM processing and materials. We hope this article will provide a road map to enable AM fundamental understanding for the monitoring and advanced diagnostics of AM processing.

Data-driven multi-scale multi-physics models to derive process-structure-property relationships for additive manufacturing

NASA Astrophysics Data System (ADS)

Yan, Wentao; Lin, Stephen; Kafka, Orion L.; Lian, Yanping; Yu, Cheng; Liu, Zeliang; Yan, Jinhui; Wolff, Sarah; Wu, Hao; Ndip-Agbor, Ebot; Mozaffar, Mojtaba; Ehmann, Kornel; Cao, Jian; Wagner, Gregory J.; Liu, Wing Kam

2018-01-01

Additive manufacturing (AM) possesses appealing potential for manipulating material compositions, structures and properties in end-use products with arbitrary shapes without the need for specialized tooling. Since the physical process is difficult to experimentally measure, numerical modeling is a powerful tool to understand the underlying physical mechanisms. This paper presents our latest work in this regard based on comprehensive material modeling of process-structure-property relationships for AM materials. The numerous influencing factors that emerge from the AM process motivate the need for novel rapid design and optimization approaches. For this, we propose data-mining as an effective solution. Such methods—used in the process-structure, structure-properties and the design phase that connects them—would allow for a design loop for AM processing and materials. We hope this article will provide a road map to enable AM fundamental understanding for the monitoring and advanced diagnostics of AM processing.

Preface: Special Topic on Single-Molecule Biophysics

NASA Astrophysics Data System (ADS)

Makarov, Dmitrii E.; Schuler, Benjamin

2018-03-01

Single-molecule measurements are now almost routinely used to study biological systems and processes. The scope of this special topic emphasizes the physics side of single-molecule observations, with the goal of highlighting new developments in physical techniques as well as conceptual insights that single-molecule measurements bring to biophysics. This issue also comprises recent advances in theoretical physical models of single-molecule phenomena, interpretation of single-molecule signals, and fundamental areas of statistical mechanics that are related to single-molecule observations. A particular goal is to illustrate the increasing synergy between theory, simulation, and experiment in single-molecule biophysics.

Health behavior and behavioral economics: economic preferences and physical activity stages of change in a low-income African-American community.

PubMed

Leonard, Tammy; Shuval, Kerem; de Oliveira, Angela; Skinner, Celette Sugg; Eckel, Catherine; Murdoch, James C

2013-01-01

To examine the relationship between physical activity stages of change and preferences for financial risk and time. A cross-sectional, community-based study. A low-income, urban, African-American neighborhood. One hundred sixty-nine adults. Self-reported physical activity stages of change-precontemplation to maintenance, objectively measured body mass index and waist circumference, and economic preferences for time and risk measured via incentivized economic experiments. Multivariable ordered logistic regression models were used to examine the association between physical activity stages of change and economic preferences while controlling for demographic characteristics of the individuals. Individuals who are more tolerant of financial risks (odds ratio [OR] = 1.31, p < .05) and whose time preferences indicate more patience (OR = 1.68, p < .01) are more likely to be in a more advanced physical activity stage (e.g., from preparation to action). The likelihood of being in the maintenance stage increases by 5.6 and 10.9 percentage points for each one-unit increase in financial risk tolerance or one-unit increase in the time preference measure, respectively. Greater tolerance of financial risk and more patient time preferences among this low-income ethnic minority population are associated with a more advanced physical activity stage. Further exploration is clearly warranted in larger and more representative samples.

Brittle and ductile friction and the physics of tectonic tremor

USGS Publications Warehouse

Daub, Eric G.; Shelly, David R.; Guyer, Robert A.; Johnson, P.A.

2011-01-01

Observations of nonvolcanic tremor provide a unique window into the mechanisms of deformation and failure in the lower crust. At increasing depths, rock deformation gradually transitions from brittle, where earthquakes occur, to ductile, with tremor occurring in the transitional region. The physics of deformation in the transition region remain poorly constrained, limiting our basic understanding of tremor and its relation to earthquakes. We combine field and laboratory observations with a physical friction model comprised of brittle and ductile components, and use the model to provide constraints on the friction and stress state in the lower crust. A phase diagram is constructed that characterizes under what conditions all faulting behaviors occur, including earthquakes, tremor, silent transient slip, and steady sliding. Our results show that tremor occurs over a range of ductile and brittle frictional strengths, and advances our understanding of the physical conditions at which tremor and earthquakes take place.

Transforming the advanced lab: Part I - Learning goals

NASA Astrophysics Data System (ADS)

Zwickl, Benjamin; Finkelstein, Noah; Lewandowski, H. J.

2012-02-01

Within the physics education research community relatively little attention has been given to laboratory courses, especially at the upper-division undergraduate level. As part of transforming our senior-level Optics and Modern Physics Lab at the University of Colorado Boulder we are developing learning goals, revising curricula, and creating assessments. In this paper, we report on the establishment of our learning goals and a surrounding framework that have emerged from discussions with a wide variety of faculty, from a review of the literature on labs, and from identifying the goals of existing lab courses. Our goals go beyond those of specific physics content and apparatus, allowing instructors to personalize them to their contexts. We report on four broad themes and associated learning goals: Modeling (math-physics-data connection, statistical error analysis, systematic error, modeling of engineered "black boxes"), Design (of experiments, apparatus, programs, troubleshooting), Communication, and Technical Lab Skills (computer-aided data analysis, LabVIEW, test and measurement equipment).

Modeling and Controls Development of 48V Mild Hybrid Electric Vehicles

EPA Science Inventory

The Advanced Light-Duty Powertrain and Hybrid Analysis tool (ALPHA) was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles. It is a physics-based, forward-looking, full vehicle computer simulator capable of analyzing various vehicle types c...

The physical basis and future of radiation therapy.

PubMed

Bortfeld, T; Jeraj, R

2011-06-01

The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued "fuelling" of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more "professionalism" in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics.

The physical basis and future of radiation therapy

PubMed Central

Bortfeld, T; Jeraj, R

2011-01-01

The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued “fuelling” of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more “professionalism” in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics. PMID:21606068

DOE Office of Scientific and Technical Information (OSTI.GOV)

Syphers, M. J.; Chattopadhyay, S.

An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW levelmore » intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.« less

Review and perspectives of electrostatic turbulence and transport studies in the basic plasma physics device TORPEX

NASA Astrophysics Data System (ADS)

Avino, Fabio; Bovet, Alexandre; Fasoli, Ambrogio; Furno, Ivo; Gustafson, Kyle; Loizu, Joaquim; Ricci, Paolo; Theiler, Christian

2012-10-01

TORPEX is a basic plasma physics toroidal device located at the CRPP-EPFL in Lausanne. In TORPEX, a vertical magnetic field superposed on a toroidal field creates helicoidal field lines with both ends terminating on the torus vessel. We review recent advances in the understanding and control of electrostatic interchange turbulence, associated structures and their effect on suprathermal ions. These advances are obtained using high-resolution diagnostics of plasma parameters and wave fields throughout the whole device cross-section, fluid models and numerical simulations. Furthermore, we discuss future developments including the possibility of generating closed field line configurations with rotational transform using an internal toroidal wire carrying a current. This system will also allow the study of innovative fusion-relevant configurations, such as the snowflake divertor.

A qualitative study of advanced nurse practitioners' use of physical assessment skills in the community: shifting skills across professional boundaries.

PubMed

Raleigh, Mary; Allan, Helen

2017-07-01

To explore multiple perspectives on the use of physical assessment skills by advanced nurse practitioners in the UK. Physical assessment skills practices are embedded in advanced nursing practice roles in the UK. There is little evidence on how these skills are used by advanced nurse practitioners in the community. Case study. A qualitative interpretative single-embedded case study of 22 participants from South of England. A framework method analysed interview data collected by the researcher between March-August 2013. Participants included nurses, doctors, nurse educators and managers. Physical assessment skills education at universities is part of a policy shift to develop a flexible workforce in the UK. Shared physical assessment practices are less to do with role substitution and more about preparing practitioners with skills that are fit for purpose. Competence, capability and performance with physical assessment skills are an expectation of advanced nursing practice. These skills are used successfully by community advanced nurse practitioners to deliver a wide range of services in response to changing patient need. The introduction of physical assessment skills education to undergraduate professional preparation would create a firm foundation to develop these skills in postgraduate education. Physical assessment education prepares nurses with the clinical competencies to carry out healthcare reforms in the UK. Shared sets of clinical assessment competencies between disciplines have better outcomes for patients. Levels of assessment competence can depend on the professional attributes of individual practitioners. Unsupportive learning cultures can hinder professional development of advanced nursing practice. © 2016 John Wiley & Sons Ltd.

MUSiC - Model-independent search for deviations from Standard Model predictions in CMS

NASA Astrophysics Data System (ADS)

Pieta, Holger

2010-02-01

We present an approach for a model independent search in CMS. Systematically scanning the data for deviations from the standard model Monte Carlo expectations, such an analysis can help to understand the detector and tune event generators. By minimizing the theoretical bias the analysis is furthermore sensitive to a wide range of models for new physics, including the uncounted number of models not-yet-thought-of. After sorting the events into classes defined by their particle content (leptons, photons, jets and missing transverse energy), a minimally prejudiced scan is performed on a number of distributions. Advanced statistical methods are used to determine the significance of the deviating regions, rigorously taking systematic uncertainties into account. A number of benchmark scenarios, including common models of new physics and possible detector effects, have been used to gauge the power of such a method. )

Annual research briefs, 1989

NASA Technical Reports Server (NTRS)

Spinks, Debra (Compiler)

1990-01-01

This report contains the 1989 annual progress reports of the Research Fellows of the Center for Turbulence Research. It is intended as a year end report to NASA, Ames Research Center which supports this group through core funding and by making available physical and intellectual resources. The Center for Turbulence Research is devoted to the fundamental study of turbulent flows; its objectives are to simulate advances in the physical understanding of turbulence, in turbulence modeling and simulation, and in turbulence control. The reports appearing in the following pages are grouped in the general areas of modeling, experimental research, theory, simulation and numerical methods, and compressible and reacting flows.

Asteroid photometry

USGS Publications Warehouse

Li, Jian-Yang; Helfenstein, Paul; Buratti, Bonnie J.; Takir, Driss; Beth Ellen Clark,; Michel, Patrick; DeMeo, Francesca E.; Bottke, William F.

2015-01-01

Asteroid photometry has three major applications: providing clues about asteroid surface physical properties and compositions, facilitating photometric corrections, and helping design and plan ground-based and spacecraft observations. The most significant advances in asteroid photometry in the past decade were driven by spacecraft observations that collected spatially resolved imaging and spectroscopy data. In the mean time, laboratory measurements and theoretical developments are revealing controversies regarding the physical interpretations of models and model parameter values. We will review the new developments in asteroid photometry that have occurred over the past decade in the three complementary areas of observations, laboratory work, and theory. Finally we will summarize and discuss the implications of recent findings.

Foundations of anticipatory logic in biology and physics.

PubMed

Bettinger, Jesse S; Eastman, Timothy E

2017-12-01

Recent advances in modern physics and biology reveal several scenarios in which top-down effects (Ellis, 2016) and anticipatory systems (Rosen, 1980) indicate processes at work enabling active modeling and inference such that anticipated effects project onto potential causes. We extrapolate a broad landscape of anticipatory systems in the natural sciences extending to computational neuroscience of perception in the capacity of Bayesian inferential models of predictive processing. This line of reasoning also comes with philosophical foundations, which we develop in terms of counterfactual reasoning and possibility space, Whitehead's process thought, and correlations with Eastern wisdom traditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Particle Physics, 2nd Edition

NASA Astrophysics Data System (ADS)

Martin, B. R.; Shaw, G.

1998-01-01

Particle Physics, Second Edition is a concise and lucid account of the fundamental constituents of matter. The standard model of particle physics is developed carefully and systematically, without heavy mathematical formalism, to make this stimulating subject accessible to undergraduate students. Throughout, the emphasis is on the interpretation of experimental data in terms of the basic properties of quarks and leptons, and extensive use is made of symmetry principles and Feynman diagrams, which are introduced early in the book. The Second Edition brings the book fully up to date, including the discovery of the top quark and the search for the Higgs boson. A final short chapter is devoted to the continuing search for new physics beyond the standard model. Particle Physics, Second Edition features: * A carefully structured and written text to help students understand this exciting and demanding subject. * Many worked examples and problems to aid student learning. Hints for solving the problems are given in an Appendix. * Optional "starred" sections and appendices, containing more specialised and advanced material for the more ambitious reader.

Bridging the physical scales in evolutionary biology: From protein sequence space to fitness of organisms and populations

PubMed Central

Bershtein, Shimon; Serohijos, Adrian W.R.; Shakhnovich, Eugene I.

2016-01-01

Bridging the gap between the molecular properties of proteins and organismal/population fitness is essential for understanding evolutionary processes. This task requires the integration of the several physical scales of biological organization, each defined by a distinct set of mechanisms and constraints, into a single unifying model. The molecular scale is dominated by the constraints imposed by the physico-chemical properties of proteins and their substrates, which give rise to trade-offs and epistatic (non-additive) effects of mutations. At the systems scale, biological networks modulate protein expression and can either buffer or enhance the fitness effects of mutations. The population scale is influenced by the mutational input, selection regimes, and stochastic changes affecting the size and structure of populations, which eventually determine the evolutionary fate of mutations. Here, we summarize the recent advances in theory, computer simulations, and experiments that advance our understanding of the links between various physical scales in biology. PMID:27810574

Bridging the physical scales in evolutionary biology: from protein sequence space to fitness of organisms and populations.

PubMed

Bershtein, Shimon; Serohijos, Adrian Wr; Shakhnovich, Eugene I

2017-02-01

Bridging the gap between the molecular properties of proteins and organismal/population fitness is essential for understanding evolutionary processes. This task requires the integration of the several physical scales of biological organization, each defined by a distinct set of mechanisms and constraints, into a single unifying model. The molecular scale is dominated by the constraints imposed by the physico-chemical properties of proteins and their substrates, which give rise to trade-offs and epistatic (non-additive) effects of mutations. At the systems scale, biological networks modulate protein expression and can either buffer or enhance the fitness effects of mutations. The population scale is influenced by the mutational input, selection regimes, and stochastic changes affecting the size and structure of populations, which eventually determine the evolutionary fate of mutations. Here, we summarize the recent advances in theory, computer simulations, and experiments that advance our understanding of the links between various physical scales in biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integrative sensing and prediction of urban water for sustainable cities (iSPUW)

NASA Astrophysics Data System (ADS)

Seo, D. J.; Fang, N. Z.; Yu, X.; Zink, M.; Gao, J.; Kerkez, B.

2014-12-01

We describe a newly launched project in the Dallas-Fort Worth Metroplex (DFW) area to develop a cyber-physical prototype system that integrates advanced sensing, modeling and prediction of urban water, to support its early adoption by a spectrum of users and stakeholders, and to educate a new generation of future sustainability scientists and engineers. The project utilizes the very high-resolution precipitation and other sensing capabilities uniquely available in DFW as well as crowdsourcing and cloud computing to advance understanding of the urban water cycle and to improve urban sustainability from transient shocks of heavy-to-extreme precipitation under climate change and urbanization. All available water information from observations and models will be fused objectively via advanced data assimilation to produce the best estimate of the state of the uncertain system. Modeling, prediction and decision support tools will be developed in the ensemble framework to increase the information content of the analysis and prediction and to support risk-based decision making.

On entropy, financial markets and minority games

NASA Astrophysics Data System (ADS)

Zapart, Christopher A.

2009-04-01

The paper builds upon an earlier statistical analysis of financial time series with Shannon information entropy, published in [L. Molgedey, W. Ebeling, Local order, entropy and predictability of financial time series, European Physical Journal B-Condensed Matter and Complex Systems 15/4 (2000) 733-737]. A novel generic procedure is proposed for making multistep-ahead predictions of time series by building a statistical model of entropy. The approach is first demonstrated on the chaotic Mackey-Glass time series and later applied to Japanese Yen/US dollar intraday currency data. The paper also reinterprets Minority Games [E. Moro, The minority game: An introductory guide, Advances in Condensed Matter and Statistical Physics (2004)] within the context of physical entropy, and uses models derived from minority game theory as a tool for measuring the entropy of a model in response to time series. This entropy conditional upon a model is subsequently used in place of information-theoretic entropy in the proposed multistep prediction algorithm.

Final Report Collaborative Project. Improving the Representation of Coastal and Estuarine Processes in Earth System Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Frank; Dennis, John; MacCready, Parker

This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation. The main computational objectives were: 1. To develop computationally efficient, but physically based, parameterizations of estuary and continental shelf mixing processes for use in an Earth System Model (CESM). 2. Tomore » develop a two-way nested regional modeling framework in order to dynamically downscale the climate response of particular coastal ocean regions and to upscale the impact of the regional coastal processes to the global climate in an Earth System Model (CESM). 3. To develop computational infrastructure to enhance the efficiency of data transfer between specific sources and destinations, i.e., a point-to-point communication capability, (used in objective 1) within POP, the ocean component of CESM.« less

Intelligent fault management for the Space Station active thermal control system

NASA Technical Reports Server (NTRS)

Hill, Tim; Faltisco, Robert M.

1992-01-01

The Thermal Advanced Automation Project (TAAP) approach and architecture is described for automating the Space Station Freedom (SSF) Active Thermal Control System (ATCS). The baseline functionally and advanced automation techniques for Fault Detection, Isolation, and Recovery (FDIR) will be compared and contrasted. Advanced automation techniques such as rule-based systems and model-based reasoning should be utilized to efficiently control, monitor, and diagnose this extremely complex physical system. TAAP is developing advanced FDIR software for use on the SSF thermal control system. The goal of TAAP is to join Knowledge-Based System (KBS) technology, using a combination of rules and model-based reasoning, with conventional monitoring and control software in order to maximize autonomy of the ATCS. TAAP's predecessor was NASA's Thermal Expert System (TEXSYS) project which was the first large real-time expert system to use both extensive rules and model-based reasoning to control and perform FDIR on a large, complex physical system. TEXSYS showed that a method is needed for safely and inexpensively testing all possible faults of the ATCS, particularly those potentially damaging to the hardware, in order to develop a fully capable FDIR system. TAAP therefore includes the development of a high-fidelity simulation of the thermal control system. The simulation provides realistic, dynamic ATCS behavior and fault insertion capability for software testing without hardware related risks or expense. In addition, thermal engineers will gain greater confidence in the KBS FDIR software than was possible prior to this kind of simulation testing. The TAAP KBS will initially be a ground-based extension of the baseline ATCS monitoring and control software and could be migrated on-board as additional computation resources are made available.

Advanced Weapon System (AWS) Sensor Prediction Techniques Study. Volume II

DTIC Science & Technology

1981-09-01

models are suggested. TV. 1-1 ’ICourant Com’p’uter Sctence Report #9 December 1975 Scene Analysis: A Survey Carl Weiman Cou rant Institute of...some crucial differences. In the psycho- logical model of mechanical vision, the aim of scene analysis is to perceive and understand 2-0 images of 3-D...scenes. The meaning of this analogy can be clarified using a rudimentary informational model ; this yields a natural hierarchy from physical

Modeling and Validation of Lithium-ion Automotive Battery Packs (SAE 2013-01-1539)

EPA Science Inventory

The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) tool was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles. It is a physics-based, forward-looking, full vehicle computer simulator capable of analyzing various vehicle types c...

Science, Semantics, and Social Change.

ERIC Educational Resources Information Center

Lemke, J. L.

Social semiotics suggests that social and cultural formations, including the language and practice of science and the ways in which new generations and communities advance them, develop as an integral part of the evolution of social ecosystems. Some recent models of complex dynamic systems in physics, chemistry, and biology focus more on the…

On the Longitudinal Component of Paraxial Fields

ERIC Educational Resources Information Center

Carnicer, Artur; Juvells, Ignasi; Maluenda, David; Martinez-Herrero, Rosario; Mejias, Pedro M.

2012-01-01

The analysis of paraxial Gaussian beams features in most undergraduate courses in laser physics, advanced optics and photonics. These beams provide a simple model of the field generated in the resonant cavities of lasers, thus constituting a basic element for understanding laser theory. Usually, uniformly polarized beams are considered in the…

The AgroEcoSystem-Watershed (AgES-W) model: overview and application to experimental watersheds

USDA-ARS?s Scientific Manuscript database

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advances in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be quan...

Science with a selfie stick: Plant biomass estimation using smartphone based ‘Structure From Motion’ photogrammetry

USDA-ARS?s Scientific Manuscript database

Significant advancements in photogrammetric Structure-from-Motion (SfM) software, coupled with improvements in the quality and resolution of smartphone cameras, has made it possible to create ultra-fine resolution three-dimensional models of physical objects using an ordinary smartphone. Here we pre...

Using Physical Models for Anomaly Detection in Control Systems

NASA Astrophysics Data System (ADS)

Svendsen, Nils; Wolthusen, Stephen

Supervisory control and data acquisition (SCADA) systems are increasingly used to operate critical infrastructure assets. However, the inclusion of advanced information technology and communications components and elaborate control strategies in SCADA systems increase the threat surface for external and subversion-type attacks. The problems are exacerbated by site-specific properties of SCADA environments that make subversion detection impractical; and by sensor noise and feedback characteristics that degrade conventional anomaly detection systems. Moreover, potential attack mechanisms are ill-defined and may include both physical and logical aspects.

Advanced Physics Labs and Undergraduate Research: Helping Them Work Together

NASA Astrophysics Data System (ADS)

Peterson, Richard W.

2009-10-01

The 2009 Advanced Lab Topical Conference in Ann Arbor affirmed the importance of advanced labs that teach crucial skills and methodologies by carefully conducting a time-honored experiment. Others however argued that such a constrained experiment can play a complementary role to more open-ended, project experiences. A genuine ``experiment'' where neither student or faculty member is exactly sure of the best approach or anticipated result can often trigger real excitement, creativity, and career direction for students while reinforcing the advanced lab and undergraduate research interface. Several examples are cited in areas of AMO physics, optics, fluids, and acoustics. Colleges and universities that have dual-degree engineering, engineering physics, or applied physics programs may especially profit from interdisciplinary projects that utilize optical, electromagnetic, and acoustical measurements in conjunction with computational physics and simulation.

Modelling structural and plasma facing materials for fusion power plants: Recent advances and outstanding issues in the EURATOM fusion materials programme

NASA Astrophysics Data System (ADS)

Boutard, Jean-Louis; Dudarev, Sergei; Rieth, Michael

2011-10-01

EFDA Fusion Materials Topical Group was established at the end of 2007 to coordinate the EU effort on the development of structural and protection materials able to withstand the very demanding operating conditions of a future DEMO power plant. Focusing on a selection of well identified materials issues, including the behaviour of Reduced Activation Ferritic-Martensitic steels, and W-alloys under the foreseen operation conditions in a future DEMO, this paper describes recent advances in physical modelling and experimental validation, contributing to the definition of chemical composition and microstructure of materials with improved in-service stability at high temperature, high neutron flux and intense ion bombardment.

Advances in color science: from retina to behavior

PubMed Central

Chatterjee, Soumya; Field, Greg D.; Horwitz, Gregory D.; Johnson, Elizabeth N.; Koida, Kowa; Mancuso, Katherine

2010-01-01

Color has become a premier model system for understanding how information is processed by neural circuits, and for investigating the relationships among genes, neural circuits and perception. Both the physical stimulus for color and the perceptual output experienced as color are quite well characterized, but the neural mechanisms that underlie the transformation from stimulus to perception are incompletely understood. The past several years have seen important scientific and technical advances that are changing our understanding of these mechanisms. Here, and in the accompanying minisymposium, we review the latest findings and hypotheses regarding color computations in the retina, primary visual cortex and higher-order visual areas, focusing on non-human primates, a model of human color vision. PMID:21068298

TIMSS Advanced 2015 and Advanced Placement Calculus & Physics. A Framework Analysis. Research in Review 2016-1

ERIC Educational Resources Information Center

Lazzaro, Christopher; Jones, Lee; Webb, David C.; Grover, Ryan; Di Giacomo, F. Tony; Marino, Katherine Adele

2016-01-01

This report will determine to what degree the AP Physics 1 and 2 and AP Calculus AB and BC frameworks are aligned with the Trends in International Mathematics and Science Study (TIMSS) Advanced Physics and Mathematics frameworks. This will enable an exploration of any differences in content coverage and levels of complexity, and will set the stage…

A formulation of multidimensional growth models for the assessment and forecast of technology attributes

NASA Astrophysics Data System (ADS)

Danner, Travis W.

Developing technology systems requires all manner of investment---engineering talent, prototypes, test facilities, and more. Even for simple design problems the investment can be substantial; for complex technology systems, the development costs can be staggering. The profitability of a corporation in a technology-driven industry is crucially dependent on maximizing the effectiveness of research and development investment. Decision-makers charged with allocation of this investment are forced to choose between the further evolution of existing technologies and the pursuit of revolutionary technologies. At risk on the one hand is excessive investment in an evolutionary technology which has only limited availability for further improvement. On the other hand, the pursuit of a revolutionary technology may mean abandoning momentum and the potential for substantial evolutionary improvement resulting from the years of accumulated knowledge. The informed answer to this question, evolutionary or revolutionary, requires knowledge of the expected rate of improvement and the potential a technology offers for further improvement. This research is dedicated to formulating the assessment and forecasting tools necessary to acquire this knowledge. The same physical laws and principles that enable the development and improvement of specific technologies also limit the ultimate capability of those technologies. Researchers have long used this concept as the foundation for modeling technological advancement through extrapolation by analogy to biological growth models. These models are employed to depict technology development as it asymptotically approaches limits established by the fundamental principles on which the technological approach is based. This has proven an effective and accurate approach to modeling and forecasting simple single-attribute technologies. With increased system complexity and the introduction of multiple system objectives, however, the usefulness of this modeling technique begins to diminish. With the introduction of multiple objectives, researchers often abandon technology growth models for scoring models and technology frontiers. While both approaches possess advantages over current growth models for the assessment of multi-objective technologies, each lacks a necessary dimension for comprehensive technology assessment. By collapsing multiple system metrics into a single, non-intuitive technology measure, scoring models provide a succinct framework for multi-objective technology assessment and forecasting. Yet, with no consideration of physical limits, scoring models provide no insight as to the feasibility of a particular combination of system capabilities. They only indicate that a given combination of system capabilities yields a particular score. Conversely, technology frontiers are constructed with the distinct objective of providing insight into the feasibility of system capability combinations. Yet again, upper limits to overall system performance are ignored. Furthermore, the data required to forecast subsequent technology frontiers is often inhibitive. In an attempt to reincorporate the fundamental nature of technology advancement as bound by physical principles, researchers have sought to normalize multi-objective systems whereby the variability of a single system objective is eliminated as a result of changes in the remaining objectives. This drastically limits the applicability of the resulting technology model because it is only applicable for a single setting of all other system attributes. Attempts to maintain the interaction between the growth curves of each technical objective of a complex system have thus far been limited to qualitative and subjective consideration. This research proposes the formulation of multidimensional growth models as an approach to simulating the advancement of multi-objective technologies towards their upper limits. Multidimensional growth models were formulated by noticing and exploiting the correlation between technology growth models and technology frontiers. Both are frontiers in actuality. The technology growth curve is a frontier between capability levels of a single attribute and time, while a technology frontier is a frontier between the capability levels of two or more attributes. Multidimensional growth models are formulated by exploiting the mathematical significance of this correlation. The result is a model that can capture both the interaction between multiple system attributes and their expected rates of improvement over time. The fundamental nature of technology development is maintained, and interdependent growth curves are generated for each system metric with minimal data requirements. Being founded on the basic nature of technology advancement, relative to physical limits, the availability for further improvement can be determined for a single metric relative to other system measures of merit. A by-product of this modeling approach is a single n-dimensional technology frontier linking all n system attributes with time. This provides an environment capable of forecasting future system capability in the form of advancing technology frontiers. The ability of a multidimensional growth model to capture the expected improvement of a specific technological approach is dependent on accurately identifying the physical limitations to each pertinent attribute. This research investigates two potential approaches to identifying those physical limits, a physics-based approach and a regression-based approach. The regression-based approach has found limited acceptance among forecasters, although it does show potential for estimating upper limits with a specified degree of uncertainty. Forecasters have long favored physics-based approaches for establishing the upper limit to unidimensional growth models. The task of accurately identifying upper limits has become increasingly difficult with the extension of growth models into multiple dimensions. A lone researcher may be able to identify the physical limitation to a single attribute of a simple system; however, as system complexity and the number of attributes increases, the attention of researchers from multiple fields of study is required. Thus, limit identification is itself an area of research and development requiring some level of investment. Whether estimated by physics or regression-based approaches, predicted limits will always have some degree of uncertainty. This research takes the approach of quantifying the impact of that uncertainty on model forecasts rather than heavily endorsing a single technique to limit identification. In addition to formulating the multidimensional growth model, this research provides a systematic procedure for applying that model to specific technology architectures. Researchers and decision-makers are able to investigate the potential for additional improvement within that technology architecture and to estimate the expected cost of each incremental improvement relative to the cost of past improvements. In this manner, multidimensional growth models provide the necessary information to set reasonable program goals for the further evolution of a particular technological approach or to establish the need for revolutionary approaches in light of the constraining limits of conventional approaches.

Advances in physical activity monitoring and lifestyle interventions in obesity: a review.

PubMed

Bonomi, A G; Westerterp, K R

2012-02-01

Obesity represents a strong risk factor for developing chronic diseases. Strategies for disease prevention often promote lifestyle changes encouraging participation in physical activity. However, determining what amount of physical activity is necessary for achieving specific health benefits has been hampered by the lack of accurate instruments for monitoring physical activity and the related physiological outcomes. This review aims at presenting recent advances in activity-monitoring technology and their application to support interventions for health promotion. Activity monitors have evolved from step counters and measuring devices of physical activity duration and intensity to more advanced systems providing quantitative and qualitative information on the individuals' activity behavior. Correspondingly, methods to predict activity-related energy expenditure using bodily acceleration and subjects characteristics have advanced from linear regression to innovative algorithms capable of determining physical activity types and the related metabolic costs. These novel techniques can monitor modes of sedentary behavior as well as the engagement in specific activity types that helps to evaluate the effectiveness of lifestyle interventions. In conclusion, advances in activity monitoring have the potential to support the design of response-dependent physical activity recommendations that are needed to generate effective and personalized lifestyle interventions for health promotion.

Development of CFD model for augmented core tripropellant rocket engine

NASA Astrophysics Data System (ADS)

Jones, Kenneth M.

1994-10-01

The Space Shuttle era has made major advances in technology and vehicle design to the point that the concept of a single-stage-to-orbit (SSTO) vehicle appears more feasible. NASA presently is conducting studies into the feasibility of certain advanced concept rocket engines that could be utilized in a SSTO vehicle. One such concept is a tripropellant system which burns kerosene and hydrogen initially and at altitude switches to hydrogen. This system will attain a larger mass fraction because LOX-kerosene engines have a greater average propellant density and greater thrust-to-weight ratio. This report describes the investigation to model the tripropellant augmented core engine. The physical aspects of the engine, the CFD code employed, and results of the numerical model for a single modular thruster are discussed.

Comprehensive nursing case management. An advanced practice model.

PubMed

Taylor, P

1999-01-01

Under managed care and capitated reimbursement systems, case management is a core strategy for providing high-quality, cost-effective care by decreasing fragmentation, enhancing quality, ensuring efficient use of resources, and containing costs. Although case management is used in various areas of the healthcare arena, it suffers from a lack of consensus regarding its definition, essential components, and appropriate application. The purpose of this paper is to examine the components and limitations of existing case management models, outline the competencies of an effective case manager, and present a model of advanced practice nursing case management that focuses on a continuum of care that integrates medical and psychosocial resources to promote optimal clinical fiscal outcomes and enables patients to work as partners with the healthcare team in facilitating and maintaining their physical and emotional well-being.

Statistical inference of empirical constituents in partitioned analysis from integral-effect experiments: An application in thermo-mechanical coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, Garrison N.; Atamturktur, Sez; Brown, D. Andrew

Rapid advancements in parallel computing over the last two decades have enabled simulations of complex, coupled systems through partitioning. In partitioned analysis, independently developed constituent models communicate, representing dependencies between multiple physical phenomena that occur in the full system. Figure 1 schematically demonstrates a coupled system with two constituent models, each resolving different physical behavior. In this figure, the constituent model, denoted as the “consumer,” relies upon some input parameter that is being provided by the constituent model acting as a “feeder”. The role of the feeder model is to map operating conditions (i.e. those that are stimulating the process)more » to consumer inputs, thus providing functional inputs to the consumer model*. Problems arise if the feeder model cannot be built–a challenge that is prevalent for highly complex systems in extreme operational conditions that push the limits of our understanding of underlying physical behavior. Often, these are also the situations where separate-effect experiments isolating the physical phenomena are not available; meaning that experimentally determining the unknown constituent behavior is not possible (Bauer and Holland, 1995; Unal et al., 2013), and that integral-effect experiments that reflect the behavior of the complete system tend to be the only available observations. In this paper, the authors advocate for the usefulness of integral-effect experiments in furthering a model developer’s knowledge of the physics principles governing the system behavior of interest.« less

Statistical inference of empirical constituents in partitioned analysis from integral-effect experiments: An application in thermo-mechanical coupling

DOE PAGES

Stevens, Garrison N.; Atamturktur, Sez; Brown, D. Andrew; ...

2018-04-16

Rapid advancements in parallel computing over the last two decades have enabled simulations of complex, coupled systems through partitioning. In partitioned analysis, independently developed constituent models communicate, representing dependencies between multiple physical phenomena that occur in the full system. Figure 1 schematically demonstrates a coupled system with two constituent models, each resolving different physical behavior. In this figure, the constituent model, denoted as the “consumer,” relies upon some input parameter that is being provided by the constituent model acting as a “feeder”. The role of the feeder model is to map operating conditions (i.e. those that are stimulating the process)more » to consumer inputs, thus providing functional inputs to the consumer model*. Problems arise if the feeder model cannot be built–a challenge that is prevalent for highly complex systems in extreme operational conditions that push the limits of our understanding of underlying physical behavior. Often, these are also the situations where separate-effect experiments isolating the physical phenomena are not available; meaning that experimentally determining the unknown constituent behavior is not possible (Bauer and Holland, 1995; Unal et al., 2013), and that integral-effect experiments that reflect the behavior of the complete system tend to be the only available observations. In this paper, the authors advocate for the usefulness of integral-effect experiments in furthering a model developer’s knowledge of the physics principles governing the system behavior of interest.« less

Relative value of physical examination, mammography, and breast sonography in evaluating the size of the primary tumor and regional lymph node metastases in women receiving neoadjuvant chemotherapy for locally advanced breast carcinoma.

PubMed

Herrada, J; Iyer, R B; Atkinson, E N; Sneige, N; Buzdar, A U; Hortobagyi, G N

1997-09-01

The purpose of this study was to correlate physical examination and sonographic and mammographic measurements of breast tumors and regional lymph nodes with pathological findings and to evaluate the effect of neoadjuvant chemotherapy on clinical Tumor-Node-Metastasis stage by noninvasive methods. This was a retrospective analysis of 100 patients with locally advanced breast cancer registered and treated in prospective trials of neoadjuvant chemotherapy. All patients received four cycles of a doxorubicin-containing regimen and had noninvasive evaluation of the primary tumor and regional lymph nodes before and after neoadjuvant chemotherapy by physical examination, sonography, and mammography and underwent breast surgery and axillary dissection within 5 weeks after completion of neoadjuvant chemotherapy. The correlations between clinical and pathological measurements were determined by Spearman rank correlation analysis. A proportional odds model was used to examine predictive values. Eighty-three patients had both a clinically detectable primary tumor and lymph node metastases. Sixty-four patients had a decrease in Tumor-Node-Metastasis stage after chemotherapy. For 54% of patients, there was concordance in clinical response between the primary tumor and lymph node compartment; for the rest, results were discordant. Physical examination correlated best with pathological findings in the measurement of the primary tumor (P = 0.0003), whereas sonography was the most accurate predictor of size for axillary lymph nodes (P = 0.0005). The combination of physical examination and mammography worked best for assessment of the primary tumor (P = 0.003), whereas combining physical examination with sonography gave optimal evaluation of regional lymph nodes (P = 0.0001). In conclusion, physical examination is the best noninvasive predictor of the real size of locally advanced primary breast cancer, whereas sonography correlates better with the real dimensions of axillary lymph nodes. The combination of physical examination with either mammography or sonography significantly improves the accuracy of noninvasive assessment of tumor dimensions.

Modeling process-structure-property relationships for additive manufacturing

NASA Astrophysics Data System (ADS)

Yan, Wentao; Lin, Stephen; Kafka, Orion L.; Yu, Cheng; Liu, Zeliang; Lian, Yanping; Wolff, Sarah; Cao, Jian; Wagner, Gregory J.; Liu, Wing Kam

2018-02-01

This paper presents our latest work on comprehensive modeling of process-structure-property relationships for additive manufacturing (AM) materials, including using data-mining techniques to close the cycle of design-predict-optimize. To illustrate the processstructure relationship, the multi-scale multi-physics process modeling starts from the micro-scale to establish a mechanistic heat source model, to the meso-scale models of individual powder particle evolution, and finally to the macro-scale model to simulate the fabrication process of a complex product. To link structure and properties, a highefficiency mechanistic model, self-consistent clustering analyses, is developed to capture a variety of material response. The model incorporates factors such as voids, phase composition, inclusions, and grain structures, which are the differentiating features of AM metals. Furthermore, we propose data-mining as an effective solution for novel rapid design and optimization, which is motivated by the numerous influencing factors in the AM process. We believe this paper will provide a roadmap to advance AM fundamental understanding and guide the monitoring and advanced diagnostics of AM processing.

Longitudinal alterations in health-related quality of life and its impact on the clinical course of patients with advanced hepatocellular carcinoma receiving sorafenib treatment.

PubMed

Shomura, Masako; Kagawa, Tatehiro; Okabe, Haruka; Shiraishi, Koichi; Hirose, Shunji; Arase, Yoshitaka; Tsuruya, Kota; Takahira, Sachiko; Mine, Tetsuya

2016-11-11

This study aimed to identify the health-related quality of life (HRQOL) domains associated with prognosis by assessing longitudinal alterations in HRQOL in patients with advanced hepatocellular carcinoma receiving sorafenib. We prospectively assessed HRQOL by administering the SF-36 questionnaire 3-monthly to consecutive patients with advanced hepatocellular carcinoma receiving sorafenib. We evaluated the impact of HRQOL on their overall survival and duration of treatment with sorafenib using Cox's proportional hazards model. There were 54 participants: 42 (78 %) were male, the median age was 71 years, 24 (44 %) had hepatitis C virus infection, 33 (61 %) had Child-Pugh scores of 5, and 30 (56 %) had TNM stage IV hepatocellular carcinoma. The median overall survival and treatment duration were 9 and 5 months, respectively, and 40 patients (74 %) died. Thirteen patients receiving sorafenib over a 1-year period maintained all domain scores >40, without a significant decline during the treatment period. In contrast, physical functioning, physical role, and vitality scores declined continuously and significantly in the year before death (in the 40 patients who died). Previous curative treatment and physical functioning scores ≥40 at baseline were significantly associated with longer overall survival by multivariate analysis. Social functioning scores ≥40, absence of vascular invasion, and lower DCP value were significant predictors of longer treatment duration. HRQOL was not significantly impaired in those patients who were able to complete a 1-year course of sorafenib treatment. Baseline physical functioning scores ≥40 and social functioning scores ≥40 were significantly associated with longer overall survival and longer treatment duration, respectively. Thus, HRQOL could be a valuable marker to predict the clinical course of patients with advanced hepatocellular carcinoma receiving sorafenib.

Scientific Discovery through Advanced Computing in Plasma Science

NASA Astrophysics Data System (ADS)

Tang, William

2005-03-01

Advanced computing is generally recognized to be an increasingly vital tool for accelerating progress in scientific research during the 21st Century. For example, the Department of Energy's ``Scientific Discovery through Advanced Computing'' (SciDAC) Program was motivated in large measure by the fact that formidable scientific challenges in its research portfolio could best be addressed by utilizing the combination of the rapid advances in super-computing technology together with the emergence of effective new algorithms and computational methodologies. The imperative is to translate such progress into corresponding increases in the performance of the scientific codes used to model complex physical systems such as those encountered in high temperature plasma research. If properly validated against experimental measurements and analytic benchmarks, these codes can provide reliable predictive capability for the behavior of a broad range of complex natural and engineered systems. This talk reviews recent progress and future directions for advanced simulations with some illustrative examples taken from the plasma science applications area. Significant recent progress has been made in both particle and fluid simulations of fine-scale turbulence and large-scale dynamics, giving increasingly good agreement between experimental observations and computational modeling. This was made possible by the combination of access to powerful new computational resources together with innovative advances in analytic and computational methods for developing reduced descriptions of physics phenomena spanning a huge range in time and space scales. In particular, the plasma science community has made excellent progress in developing advanced codes for which computer run-time and problem size scale well with the number of processors on massively parallel machines (MPP's). A good example is the effective usage of the full power of multi-teraflop (multi-trillion floating point computations per second) MPP's to produce three-dimensional, general geometry, nonlinear particle simulations which have accelerated progress in understanding the nature of plasma turbulence in magnetically-confined high temperature plasmas. These calculations, which typically utilized billions of particles for thousands of time-steps, would not have been possible without access to powerful present generation MPP computers and the associated diagnostic and visualization capabilities. In general, results from advanced simulations provide great encouragement for being able to include increasingly realistic dynamics to enable deeper physics insights into plasmas in both natural and laboratory environments. The associated scientific excitement should serve to stimulate improved cross-cutting collaborations with other fields and also to help attract bright young talent to the computational science area.

A multi-physics analysis for the actuation of the SSS in opal reactor

NASA Astrophysics Data System (ADS)

Ferraro, Diego; Alberto, Patricio; Villarino, Eduardo; Doval, Alicia

2018-05-01

OPAL is a 20 MWth multi-purpose open-pool type Research Reactor located at Lucas Heights, Australia. It was designed, built and commissioned by INVAP between 2000 and 2006 and it has been operated by the Australia Nuclear Science and Technology Organization (ANSTO) showing a very good overall performance. On November 2016, OPAL reached 10 years of continuous operation, becoming one of the most reliable and available in its kind worldwide, with an unbeaten record of being fully operational 307 days a year. One of the enhanced safety features present in this state-of-art reactor is the availability of an independent, diverse and redundant Second Shutdown System (SSS), which consists in the drainage of the heavy water reflector contained in the Reflector Vessel. As far as high quality experimental data is available from reactor commissioning and operation stages and even from early component design validation stages, several models both regarding neutronic and thermo-hydraulic approaches have been developed during recent years using advanced calculations tools and the novel capabilities to couple them. These advanced models were developed in order to assess the capability of such codes to simulate and predict complex behaviours and develop highly detail analysis. In this framework, INVAP developed a three-dimensional CFD model that represents the detailed hydraulic behaviour of the Second Shutdown System for an actuation scenario, where the heavy water drainage 3D temporal profiles inside the Reflector Vessel can be obtained. This model was validated, comparing the computational results with experimental measurements performed in a real-size physical model built by INVAP during early OPAL design engineering stages. Furthermore, detailed 3D Serpent Monte Carlo models are also available, which have been already validated with experimental data from reactor commissioning and operating cycles. In the present work the neutronic and thermohydraulic models, available for OPAL reactor, are coupled by means of a shared unstructured mesh geometry definition of relevant zones inside the Reflector Vessel. Several scenarios, both regarding coupled and uncoupled neutronic & thermohydraulic behavior, are presented and analyzed, showing the capabilities to develop and manage advanced modelling that allows to predict multi-physics variables observed when an in-depth performance analysis of a Research Reactor like OPAL is carried out.

Advances in Medical Physics: 2010.

PubMed

2011-07-01

Advances in Medical Physics: 2010., Wolbarst Anthony B., Karellas Andrew, Krupinski Elizabeth A., Hendee William R., Medical Physics Publishing, Madison, WI, 2010, 368 pp (hardcover). Price: $140.00. ISBN: 978-1-93052-450-7. © 2011 American Association of Physicists in Medicine.

WE-F-211-01: The Evolving Landscape of Scientific Publishing.

PubMed

Armato, S; Hendee, W; Marshall, C; Curran, B

2012-06-01

The dissemination of scientific advances has changed little since the first peer-reviewed journal was published in 1665 - that is, until this past decade. The print journal, delivered by mail and stored on office shelves and in library reading rooms around the world, has been transformed by immediate, on-demand access to scientific discovery in electronic form. At the same time, the producers and consumers of that scientific content have greatly increased in number, and the balance between supply and demand has required innovations in the world of scientific publishing. In light of technological advances and societal expectations, the dissemination of scientific knowledge has assumed a new form, one that is dynamic and rapidly changing. The academic medical physicist must understand this evolution to ensure that appropriate decisions are made with regard to journal submission strategies and that relevant information on new findings is obtained in a timely manner. Medical Physics is adapting to these changes in substantive ways. This new scientific publishing landscape has implications for subscription models, targeted access through semantic enrichment, user interactivity with content, customized content delivery, and advertising opportunities. Many organizations, including the AAPM, depend on scientific publishing as a significant source of revenue, but web-based delivery raises the expectation that access should be free and threatens this model. The purpose of this symposium is to explore the factors that have contributed to the current state of scientific publishing, to anticipate future directions in this arena, and to convey how medical physicists may benefit from the expanded opportunities, both as authors and as readers. 1. To appreciate the importance of scientific and clinical practice communication for the advancement of the medical physics field 2. To understand the roles of the Editorial Board and the Journal Business Management Committee in the promotion and advancement of Medical Physics 3. To explore technology-driven content delivery mechanisms and their role in facilitating content access and driving content usage 4. To understand the potential benefits and pitfalls of various economic and editorial models of scientific publications and the recent shifts away from the traditional role of libraries. © 2012 American Association of Physicists in Medicine.

Stereotype Threat? Male and Female Students in Advanced High School Courses

NASA Astrophysics Data System (ADS)

Corra, Mamadi

Propositions of stereotype threat theory imply that the social consequences of academic distinction in advanced quantitative areas (such as math and the physical sciences) for women may promote the under representation of female students in advanced quantitative academic courses. The hypothesis that female students will be underrepresented in advanced quantitative (honors and advanced placement math and physical science) courses is tested using academic performance and enrollment data for high school students in a "Student/Parent Informed Choice" (open registration) school district in North Carolina. Results show female students to be overrepresented in both advanced verbal/writing intensive (honors and advanced placement English, foreign language, and social science) and advanced quantitative (honors and advanced placement math and physical science) courses compared to their proportion of the student body. More surprisingly, results also indicate female students (compared to male students) to be overrepresented in advanced courses compared to their proportion of high-performing students. Furthermore, as with patterns observed at the district level, additional analysis of enrollment data for the entire state reveals similar results. Taken together, the findings call into question the prevailing presumption that female students continue to be underrepresented in math and physical science courses. Instead, the changing social context within which females and males experience schooling may provide an explanation for the findings.

Los Alamos NEP research in advanced plasma thrusters

NASA Technical Reports Server (NTRS)

Schoenberg, Kurt; Gerwin, Richard

1991-01-01

Research was initiated in advanced plasma thrusters that capitalizes on lab capabilities in plasma science and technology. The goal of the program was to examine the scaling issues of magnetoplasmadynamic (MPD) thruster performance in support of NASA's MPD thruster development program. The objective was to address multi-megawatt, large scale, quasi-steady state MPD thruster performance. Results to date include a new quasi-steady state operating regime which was obtained at space exploration initiative relevant power levels, that enables direct coaxial gun-MPD comparisons of thruster physics and performance. The radiative losses are neglible. Operation with an applied axial magnetic field shows the same operational stability and exhaust plume uniformity benefits seen in MPD thrusters. Observed gun impedance is in close agreement with the magnetic Bernoulli model predictions. Spatial and temporal measurements of magnetic field, electric field, plasma density, electron temperature, and ion/neutral energy distribution are underway. Model applications to advanced mission logistics are also underway.

What Factors Determine the Uptake of A-level Physics?

NASA Astrophysics Data System (ADS)

Gill, Tim; Bell, John F.

2013-03-01

There has been much concern recently in the UK about the decline in the number of students studying physics beyond age 16. To investigate why this might be we used data from a national database of student qualifications and a multilevel modelling technique to investigate which factors had the greatest impact on the uptake of physics at Advanced Level (A-level) in a particular year. Each factor of interest was entered into a separate model, while accounting for prior attainment and gender (both well-known predictors of A-level uptake). We found that factors associated with greater probability of uptake included better attainment in physics (or combined science) and maths qualifications at age 16 in comparison to other subjects, and (for girls only) attending an independent or grammar school. While it is difficult to address these factors directly, the results imply that more needs to be done to improve relative performance at General Certificate of Secondary Education, perhaps by increasing the supply of specialist physics teachers at this level and to overcome the perception (especially among girls) that physics is a particularly difficult subject.

Predicted Infiltration for Sodic/Saline Soils from Reclaimed Coastal Areas: Sensitivity to Model Parameters

PubMed Central

She, Dongli; Yu, Shuang'en; Shao, Guangcheng

2014-01-01

This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm3. A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related parameters was tested. The model well simulated the measured data. The results revealed that soil compaction notably affected the water retention of both soils. Model simulations showed that increasing the ponded water depth had little effect on the infiltration process, since the increases in cumulative infiltration and wetting front advancement rate were small. However, the wetting front advancement rate increased and the cumulative infiltration decreased to a greater extent when θ 0 was increased. Soil physical quality was described better by the S parameter than by the saturated hydraulic conductivity since the latter was also affected by the physical chemical effects on clay swelling occurring in the presence of different levels of electrolytes in the soil solutions of the two soils. PMID:25197699

Predicted infiltration for sodic/saline soils from reclaimed coastal areas: sensitivity to model parameters.

PubMed

Liu, Dongdong; She, Dongli; Yu, Shuang'en; Shao, Guangcheng; Chen, Dan

2014-01-01

This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm(3). A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related parameters was tested. The model well simulated the measured data. The results revealed that soil compaction notably affected the water retention of both soils. Model simulations showed that increasing the ponded water depth had little effect on the infiltration process, since the increases in cumulative infiltration and wetting front advancement rate were small. However, the wetting front advancement rate increased and the cumulative infiltration decreased to a greater extent when θ₀ was increased. Soil physical quality was described better by the S parameter than by the saturated hydraulic conductivity since the latter was also affected by the physical chemical effects on clay swelling occurring in the presence of different levels of electrolytes in the soil solutions of the two soils.

The Physics and Chemistry of Marine Aerosols

NASA Astrophysics Data System (ADS)

Russell, Lynn M.

Understanding the physics and chemistry of the marine atmosphere requires both predicting the evolution of its gas and aerosol phases and making observations that reflect the processes in that evolution. This work presents a model of the most fundamental physical and chemical processes important in the marine atmosphere, and discusses the current uncertainties in our theoretical understanding of those processes. Backing up these predictions with observations requires improved instrumentation for field measurements of aerosol. One important advance in this instrumentation is described for accelerating the speed of size distribution measurements. Observations of aerosols in the marine boundary layer during the Atlantic Stratocumulus Transition Experiment (ASTEX) provide an illustration of the impact of cloud processing in marine stratus. More advanced measurements aboard aircraft were enabled by redesigning the design of the system for separating particles by differential mobility and counting them by condensational growth. With this instrumentation, observations made during the Monterey Area Ship Tracks (MAST) Experiment have illustrated the role of aerosol emissions of ships in forming tracks in clouds. High-resolution gas chromatography and mass spectrometry was used with samples extracted by supercritical fluid extraction in order to identify the role of combustion organics in forming ship tracks. The results illustrate the need both for more sophisticated models incorporating organic species in cloud activation and for more extensive boundary layer observations.

Advances in water resources research in the Upper Blue Nile basin and the way forward: A review

NASA Astrophysics Data System (ADS)

Dile, Yihun Taddele; Tekleab, Sirak; Ayana, Essayas K.; Gebrehiwot, Solomon G.; Worqlul, Abeyou W.; Bayabil, Haimanote K.; Yimam, Yohannes T.; Tilahun, Seifu A.; Daggupati, Prasad; Karlberg, Louise; Srinivasan, Raghavan

2018-05-01

The Upper Blue Nile basin is considered as the lifeline for ∼250 million people and contributes ∼50 Gm3/year of water to the Nile River. Poor land management practices in the Ethiopian highlands have caused a significant amount of soil erosion, thereby threatening the productivity of the Ethiopian agricultural system, degrading the health of the aquatic ecosystem, and shortening the life of downstream reservoirs. The Upper Blue Nile basin, because of limited research and availability of data, has been considered as the "great unknown." In the recent past, however, more research has been published. Nonetheless, there is no state-of-the-art review that presents research achievements, gaps and future directions. Hence, this paper aims to bridge this gap by reviewing the advances in water resources research in the basin while highlighting research needs and future directions. We report that there have been several research projects that try to understand the biogeochemical processes by collecting information on runoff, groundwater recharge, sediment transport, and tracers. Different types of hydrological models have been applied. Most of the earlier research used simple conceptual and statistical approaches for trend analysis and water balance estimations, mainly using rainfall and evapotranspiration data. More recent research has been using advanced semi-physically/physically based distributed hydrological models using high-resolution temporal and spatial data for diverse applications. We identified several research gaps and provided recommendations to address them. While we have witnessed advances in water resources research in the basin, we also foresee opportunities for further advancement. Incorporating the research findings into policy and practice will significantly benefit the development and transformation agenda of the Ethiopian government.

Advancing Cyberinfrastructure to support high resolution water resources modeling

NASA Astrophysics Data System (ADS)

Tarboton, D. G.; Ogden, F. L.; Jones, N.; Horsburgh, J. S.

2012-12-01

Addressing the problem of how the availability and quality of water resources at large scales are sensitive to climate variability, watershed alterations and management activities requires computational resources that combine data from multiple sources and support integrated modeling. Related cyberinfrastructure challenges include: 1) how can we best structure data and computer models to address this scientific problem through the use of high-performance and data-intensive computing, and 2) how can we do this in a way that discipline scientists without extensive computational and algorithmic knowledge and experience can take advantage of advances in cyberinfrastructure? This presentation will describe a new system called CI-WATER that is being developed to address these challenges and advance high resolution water resources modeling in the Western U.S. We are building on existing tools that enable collaboration to develop model and data interfaces that link integrated system models running within an HPC environment to multiple data sources. Our goal is to enhance the use of computational simulation and data-intensive modeling to better understand water resources. Addressing water resource problems in the Western U.S. requires simulation of natural and engineered systems, as well as representation of legal (water rights) and institutional constraints alongside the representation of physical processes. We are establishing data services to represent the engineered infrastructure and legal and institutional systems in a way that they can be used with high resolution multi-physics watershed modeling at high spatial resolution. These services will enable incorporation of location-specific information on water management infrastructure and systems into the assessment of regional water availability in the face of growing demands, uncertain future meteorological forcings, and existing prior-appropriations water rights. This presentation will discuss the informatics challenges involved with data management and easy-to-use access to high performance computing being tackled in this project.

Testing a self-determination theory model of children’s physical activity motivation: a cross-sectional study

PubMed Central

2013-01-01

Background Understanding children’s physical activity motivation, its antecedents and associations with behavior is important and can be advanced by using self-determination theory. However, research among youth is largely restricted to adolescents and studies of motivation within certain contexts (e.g., physical education). There are no measures of self-determination theory constructs (physical activity motivation or psychological need satisfaction) for use among children and no previous studies have tested a self-determination theory-based model of children’s physical activity motivation. The purpose of this study was to test the reliability and validity of scores derived from scales adapted to measure self-determination theory constructs among children and test a motivational model predicting accelerometer-derived physical activity. Methods Cross-sectional data from 462 children aged 7 to 11 years from 20 primary schools in Bristol, UK were analysed. Confirmatory factor analysis was used to examine the construct validity of adapted behavioral regulation and psychological need satisfaction scales. Structural equation modelling was used to test cross-sectional associations between psychological need satisfaction, motivation types and physical activity assessed by accelerometer. Results The construct validity and reliability of the motivation and psychological need satisfaction measures were supported. Structural equation modelling provided evidence for a motivational model in which psychological need satisfaction was positively associated with intrinsic and identified motivation types and intrinsic motivation was positively associated with children’s minutes in moderate-to-vigorous physical activity. Conclusions The study provides evidence for the psychometric properties of measures of motivation aligned with self-determination theory among children. Children’s motivation that is based on enjoyment and inherent satisfaction of physical activity is associated with their objectively-assessed physical activity and such motivation is positively associated with perceptions of psychological need satisfaction. These psychological factors represent potential malleable targets for interventions to increase children’s physical activity. PMID:24067078

SHARP User Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Y. Q.; Shemon, E. R.; Thomas, J. W.

SHARP is an advanced modeling and simulation toolkit for the analysis of nuclear reactors. It is comprised of several components including physical modeling tools, tools to integrate the physics codes for multi-physics analyses, and a set of tools to couple the codes within the MOAB framework. Physics modules currently include the neutronics code PROTEUS, the thermal-hydraulics code Nek5000, and the structural mechanics code Diablo. This manual focuses on performing multi-physics calculations with the SHARP ToolKit. Manuals for the three individual physics modules are available with the SHARP distribution to help the user to either carry out the primary multi-physics calculationmore » with basic knowledge or perform further advanced development with in-depth knowledge of these codes. This manual provides step-by-step instructions on employing SHARP, including how to download and install the code, how to build the drivers for a test case, how to perform a calculation and how to visualize the results. Since SHARP has some specific library and environment dependencies, it is highly recommended that the user read this manual prior to installing SHARP. Verification tests cases are included to check proper installation of each module. It is suggested that the new user should first follow the step-by-step instructions provided for a test problem in this manual to understand the basic procedure of using SHARP before using SHARP for his/her own analysis. Both reference output and scripts are provided along with the test cases in order to verify correct installation and execution of the SHARP package. At the end of this manual, detailed instructions are provided on how to create a new test case so that user can perform novel multi-physics calculations with SHARP. Frequently asked questions are listed at the end of this manual to help the user to troubleshoot issues.« less

PREFACE: Physics and Mathematics of Nonlinear Phenomena 2013 (PMNP2013)

NASA Astrophysics Data System (ADS)

Konopelchenko, B. G.; Landolfi, G.; Martina, L.; Vitolo, R.

2014-03-01

Modern theory of nonlinear integrable equations is nowdays an important and effective tool of study for numerous nonlinear phenomena in various branches of physics from hydrodynamics and optics to quantum filed theory and gravity. It includes the study of nonlinear partial differential and discrete equations, regular and singular behaviour of their solutions, Hamitonian and bi- Hamitonian structures, their symmetries, associated deformations of algebraic and geometrical structures with applications to various models in physics and mathematics. The PMNP 2013 conference focused on recent advances and developments in Continuous and discrete, classical and quantum integrable systems Hamiltonian, critical and geometric structures of nonlinear integrable equations Integrable systems in quantum field theory and matrix models Models of nonlinear phenomena in physics Applications of nonlinear integrable systems in physics The Scientific Committee of the conference was formed by Francesco Calogero (University of Rome `La Sapienza', Italy) Boris A Dubrovin (SISSA, Italy) Yuji Kodama (Ohio State University, USA) Franco Magri (University of Milan `Bicocca', Italy) Vladimir E Zakharov (University of Arizona, USA, and Landau Institute for Theoretical Physics, Russia) The Organizing Committee: Boris G Konopelchenko, Giulio Landolfi, Luigi Martina, Department of Mathematics and Physics `E De Giorgi' and the Istituto Nazionale di Fisica Nucleare, and Raffaele Vitolo, Department of Mathematics and Physics `E De Giorgi'. A list of sponsors, speakers, talks, participants and the conference photograph are given in the PDF. Conference photograph

Modeling and simulation challenges pursued by the Consortium for Advanced Simulation of Light Water Reactors (CASL)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turinsky, Paul J., E-mail: turinsky@ncsu.edu; Kothe, Douglas B., E-mail: kothe@ornl.gov

The Consortium for the Advanced Simulation of Light Water Reactors (CASL), the first Energy Innovation Hub of the Department of Energy, was established in 2010 with the goal of providing modeling and simulation (M&S) capabilities that support and accelerate the improvement of nuclear energy's economic competitiveness and the reduction of spent nuclear fuel volume per unit energy, and all while assuring nuclear safety. To accomplish this requires advances in M&S capabilities in radiation transport, thermal-hydraulics, fuel performance and corrosion chemistry. To focus CASL's R&D, industry challenge problems have been defined, which equate with long standing issues of the nuclear powermore » industry that M&S can assist in addressing. To date CASL has developed a multi-physics “core simulator” based upon pin-resolved radiation transport and subchannel (within fuel assembly) thermal-hydraulics, capitalizing on the capabilities of high performance computing. CASL's fuel performance M&S capability can also be optionally integrated into the core simulator, yielding a coupled multi-physics capability with untapped predictive potential. Material models have been developed to enhance predictive capabilities of fuel clad creep and growth, along with deeper understanding of zirconium alloy clad oxidation and hydrogen pickup. Understanding of corrosion chemistry (e.g., CRUD formation) has evolved at all scales: micro, meso and macro. CFD R&D has focused on improvement in closure models for subcooled boiling and bubbly flow, and the formulation of robust numerical solution algorithms. For multiphysics integration, several iterative acceleration methods have been assessed, illuminating areas where further research is needed. Finally, uncertainty quantification and data assimilation techniques, based upon sampling approaches, have been made more feasible for practicing nuclear engineers via R&D on dimensional reduction and biased sampling. Industry adoption of CASL's evolving M&S capabilities, which is in progress, will assist in addressing long-standing and future operational and safety challenges of the nuclear industry. - Highlights: • Complexity of physics based modeling of light water reactor cores being addressed. • Capability developed to help address problems that have challenged the nuclear power industry. • Simulation capabilities that take advantage of high performance computing developed.« less

Physics-based distributed snow models in the operational arena: Current and future challenges

NASA Astrophysics Data System (ADS)

Winstral, A. H.; Jonas, T.; Schirmer, M.; Helbig, N.

2017-12-01

The demand for modeling tools robust to climate change and weather extremes along with coincident increases in computational capabilities have led to an increase in the use of physics-based snow models in operational applications. Current operational applications include the WSL-SLF's across Switzerland, ASO's in California, and USDA-ARS's in Idaho. While the physics-based approaches offer many advantages there remain limitations and modeling challenges. The most evident limitation remains computation times that often limit forecasters to a single, deterministic model run. Other limitations however remain less conspicuous amidst the assumptions that these models require little to no calibration based on their foundation on physical principles. Yet all energy balance snow models seemingly contain parameterizations or simplifications of processes where validation data are scarce or present understanding is limited. At the research-basin scale where many of these models were developed these modeling elements may prove adequate. However when applied over large areas, spatially invariable parameterizations of snow albedo, roughness lengths and atmospheric exchange coefficients - all vital to determining the snowcover energy balance - become problematic. Moreover as we apply models over larger grid cells, the representation of sub-grid variability such as the snow-covered fraction adds to the challenges. Here, we will demonstrate some of the major sensitivities of distributed energy balance snow models to particular model constructs, the need for advanced and spatially flexible methods and parameterizations, and prompt the community for open dialogue and future collaborations to further modeling capabilities.

The effects of smoking and physical inactivity on advancing mortality in U.S. adults.

PubMed

Borrell, Luisa N

2014-06-01

The aim of the study was to calculate the rate advancement period (RAP) by which deaths for all-cause and cardiovascular disease (CVD)-specific mortality is advanced by smoking and physical inactivity among U.S. adults aged 18 years or more who participated in the Third National Health and Nutrition Examination Survey and were followed to December 31, 2006. Mortality status was determined using the underlying cause of death. Cox regression was used to calculate the advanced time of deaths for all-cause and CVD-specific mortality among exposed adults relative to their nonexposed counterparts. Deaths for all-cause and CVD-specific mortality were advanced by 7.9 and 5.1 years among current smoker adults. For physically inactive adults, the RAPs for all-cause and CVD-specific mortality were 4.0 and 2.4 years, respectively. The joint effects of current smoking, physical inactivity, and obesity resulted in early all-cause and CVD-specific deaths of 14.2 and 12.2 years. For current smokers, physically inactive, and overweight adults, the RAPs for all-cause and CVD-specific deaths were 7.9 and 8.9 years, respectively. Our findings suggest that smoking and physical inactivity could significantly advance the time of death associated with all-cause and CVD-specific mortality by at least 2.4 years among U.S. adults. Moreover, the advancement death period for the joint effects of smoking, physical inactivity, and overweight or obesity could be at least 7.9 years. Copyright © 2014 Elsevier Inc. All rights reserved.

Optimizing zonal advection of the Advanced Research WRF (ARW) dynamics for Intel MIC

NASA Astrophysics Data System (ADS)

Mielikainen, Jarno; Huang, Bormin; Huang, Allen H.

2014-10-01

The Weather Research and Forecast (WRF) model is the most widely used community weather forecast and research model in the world. There are two distinct varieties of WRF. The Advanced Research WRF (ARW) is an experimental, advanced research version featuring very high resolution. The WRF Nonhydrostatic Mesoscale Model (WRF-NMM) has been designed for forecasting operations. WRF consists of dynamics code and several physics modules. The WRF-ARW core is based on an Eulerian solver for the fully compressible nonhydrostatic equations. In the paper, we will use Intel Intel Many Integrated Core (MIC) architecture to substantially increase the performance of a zonal advection subroutine for optimization. It is of the most time consuming routines in the ARW dynamics core. Advection advances the explicit perturbation horizontal momentum equations by adding in the large-timestep tendency along with the small timestep pressure gradient tendency. We will describe the challenges we met during the development of a high-speed dynamics code subroutine for MIC architecture. Furthermore, lessons learned from the code optimization process will be discussed. The results show that the optimizations improved performance of the original code on Xeon Phi 5110P by a factor of 2.4x.

Optimizing meridional advection of the Advanced Research WRF (ARW) dynamics for Intel Xeon Phi coprocessor

NASA Astrophysics Data System (ADS)

Mielikainen, Jarno; Huang, Bormin; Huang, Allen H.-L.

2015-05-01

The most widely used community weather forecast and research model in the world is the Weather Research and Forecast (WRF) model. Two distinct varieties of WRF exist. The one we are interested is the Advanced Research WRF (ARW) is an experimental, advanced research version featuring very high resolution. The WRF Nonhydrostatic Mesoscale Model (WRF-NMM) has been designed for forecasting operations. WRF consists of dynamics code and several physics modules. The WRF-ARW core is based on an Eulerian solver for the fully compressible nonhydrostatic equations. In the paper, we optimize a meridional (north-south direction) advection subroutine for Intel Xeon Phi coprocessor. Advection is of the most time consuming routines in the ARW dynamics core. It advances the explicit perturbation horizontal momentum equations by adding in the large-timestep tendency along with the small timestep pressure gradient tendency. We will describe the challenges we met during the development of a high-speed dynamics code subroutine for MIC architecture. Furthermore, lessons learned from the code optimization process will be discussed. The results show that the optimizations improved performance of the original code on Xeon Phi 7120P by a factor of 1.2x.

Experimental Validation of Various Temperature Modells for Semi-Physical Tyre Model Approaches

NASA Astrophysics Data System (ADS)

Hackl, Andreas; Scherndl, Christoph; Hirschberg, Wolfgang; Lex, Cornelia

2017-10-01

With increasing level of complexity and automation in the area of automotive engineering, the simulation of safety relevant Advanced Driver Assistance Systems (ADAS) leads to increasing accuracy demands in the description of tyre contact forces. In recent years, with improvement in tyre simulation, the needs for coping with tyre temperatures and the resulting changes in tyre characteristics are rising significantly. Therefore, experimental validation of three different temperature model approaches is carried out, discussed and compared in the scope of this article. To investigate or rather evaluate the range of application of the presented approaches in combination with respect of further implementation in semi-physical tyre models, the main focus lies on the a physical parameterisation. Aside from good modelling accuracy, focus is held on computational time and complexity of the parameterisation process. To evaluate this process and discuss the results, measurements from a Hoosier racing tyre 6.0 / 18.0 10 LCO C2000 from an industrial flat test bench are used. Finally the simulation results are compared with the measurement data.

Motivating and Facilitating Advancements in Space Weather Real-Time Data Availability: Factors, Data, and Access Methods

NASA Astrophysics Data System (ADS)

Pankratz, C. K.; Baker, D. N.; Jaynes, A. N.; Elkington, S. R.; Baltzer, T.; Sanchez, F.

2017-12-01

Society's growing reliance on complex and highly interconnected technological systems makes us increasingly vulnerable to the effects of space weather events - maybe more than for any other natural hazard. An extreme solar storm today could conceivably impact hundreds of the more than 1400 operating Earth satellites. Such an extreme storm could cause collapse of the electrical grid on continental scales. The effects on navigation, communication, and remote sensing of our home planet could be devastating to our social functioning. Thus, it is imperative that the scientific community address the question of just how severe events might become. At least as importantly, it is crucial that policy makers and public safety officials be informed by the facts on what might happen during extreme conditions. This requires essentially real-time alerts, warnings, and also forecasts of severe space weather events, which in turn demands measurements, models, and associated data products to be available via the most effective data discovery and access methods possible. Similarly, advancement in the fundamental scientific understanding of space weather processes is also vital, requiring that researchers have convenient and effective access to a wide variety of data sets and models from multiple sources. The space weather research community, as with many scientific communities, must access data from dispersed and often uncoordinated data repositories to acquire the data necessary for the analysis and modeling efforts that advance our understanding of solar influences and space physics on the Earth's environment. The Laboratory for Atmospheric and Space Physics (LASP), as a leading institution in both producing data products and advancing the state of scientific understanding of space weather processes, is well positioned to address many of these issues. In this presentation, we will outline the motivating factors for effective space weather data access, summarize the various data and models that are available, and present methods for meeting the data management and access needs of the disparate communities who require low-latency space weather data and information.

Physics Literacy for All Students

NASA Astrophysics Data System (ADS)

Hobson, Art

2010-03-01

Physics teachers must broaden their focus from physics for scientists to physics for all. The reason, as the American Association for the Advancement of Science puts it, is: ``Without a scientifically literate population, the outlook for a better world is not promising.'' Physics for all (including the first course for scientists) should be conceptual, not technical. It should describe the universe as we understand it today, including special and general relativity, quantum physics, modern cosmology, the standard model, and quantum fields. Many science writers have shown this is possible. It should include physics-related social topics such as global warming and nuclear weapons, because citizens need to vote on these issues. Above all, it should emphasize the scientific process and the difference between science and nonsense. Science is based not on beliefs but rather on evidence and reason. We should constantly ask ``How do we know?'' and ``What is the evidence?''

Constitutive Modeling and Testing of Polymer Matrix Composites Incorporating Physical Aging at Elevated Temperatures

NASA Technical Reports Server (NTRS)

Veazie, David R.

1998-01-01

Advanced polymer matrix composites (PMC's) are desirable for structural materials in diverse applications such as aircraft, civil infrastructure and biomedical implants because of their improved strength-to-weight and stiffness-to-weight ratios. For example, the next generation military and commercial aircraft requires applications for high strength, low weight structural components subjected to elevated temperatures. A possible disadvantage of polymer-based composites is that the physical and mechanical properties of the matrix often change significantly over time due to the exposure of elevated temperatures and environmental factors. For design, long term exposure (i.e. aging) of PMC's must be accounted for through constitutive models in order to accurately assess the effects of aging on performance, crack initiation and remaining life. One particular aspect of this aging process, physical aging, is considered in this research.

Development of an advanced undergraduate course in acoustics

NASA Astrophysics Data System (ADS)

Gee, Kent L.; Neilsen, Tracianne B.; Sommerfeldt, Scott D.

2016-03-01

Within many physics undergraduate programs, acoustics is given only a cursory treatment, usually within an introductory course. Because acoustics is a natural vehicle for students to develop intuition about wave phenomena, an advanced undergraduate acoustics course has been developed at Brigham Young University. Although it remains an elective course, enrollment has increased steadily since its inception. The course has been taken by students in physics, applied physics, physics teaching, and mechanical and electrical engineering. In addition to providing training for students motivated by interest in undergraduate research, internship, employment, and graduate schooling opportunities in acoustics, the course facilitates connections between various areas of physics. Explicit connections are made to mechanics, electricity and magnetism, thermodynamics, optics, quantum mechanics, and experimental and computational laboratory courses. Active learning is emphasized through Just-in-Time-Teaching and course structure. Homework exercises are both theoretical and practical and often require making and interpreting of graphs. For example, students may model traffic noise as a series of uncorrelated monopoles or examine highway barrier effectiveness using Fresnel diffraction techniques. Additionally, students participate in resumé-building measurements and learn to report their results in the form of technical memoranda. Course evaluations and post-graduation student surveys rate it among the most valuable undergraduate student courses offered.

Cognitive predictors of skilled performance with an advanced upper limb multifunction prosthesis: a preliminary analysis.

PubMed

Hancock, Laura; Correia, Stephen; Ahern, David; Barredo, Jennifer; Resnik, Linda

2017-07-01

Purpose The objectives were to 1) identify major cognitive domains involved in learning to use the DEKA Arm; 2) specify cognitive domain-specific skills associated with basic versus advanced users; and 3) examine whether baseline memory and executive function predicted learning. Method Sample included 35 persons with upper limb amputation. Subjects were administered a brief neuropsychological test battery prior to start of DEKA Arm training, as well as physical performance measures at the onset of, and following training. Multiple regression models controlling for age and including neuropsychological tests were developed to predict physical performance scores. Prosthetic performance scores were divided into quartiles and independent samples t-tests compared neuropsychological test scores of advanced scorers and basic scorers. Baseline neuropsychological test scores were used to predict change in scores on physical performance measures across time. Results Cognitive domains of attention and processing speed were statistically significantly related to proficiency of DEKA Arm use and predicted level of proficiency. Conclusions Results support use of neuropsychological tests to predict learning and use of a multifunctional prosthesis. Assessment of cognitive status at the outset of training may help set expectations for the duration and outcomes of treatment. Implications for Rehabilitation Cognitive domains of attention and processing speed were significantly related to level of proficiencyof an advanced multifunctional prosthesis (the DEKA Arm) after training. Results provide initial support for the use of neuropsychological tests to predict advanced learningand use of a multifunctional prosthesis in upper-limb amputees. Results suggest that assessment of patients' cognitive status at the outset of upper limb prosthetictraining may, in the future, help patients, their families and therapists set expectations for theduration and intensity of training and may help set reasonable proficiency goals.

Advanced computations in plasma physics

NASA Astrophysics Data System (ADS)

Tang, W. M.

2002-05-01

Scientific simulation in tandem with theory and experiment is an essential tool for understanding complex plasma behavior. In this paper we review recent progress and future directions for advanced simulations in magnetically confined plasmas with illustrative examples chosen from magnetic confinement research areas such as microturbulence, magnetohydrodynamics, magnetic reconnection, and others. Significant recent progress has been made in both particle and fluid simulations of fine-scale turbulence and large-scale dynamics, giving increasingly good agreement between experimental observations and computational modeling. This was made possible by innovative advances in analytic and computational methods for developing reduced descriptions of physics phenomena spanning widely disparate temporal and spatial scales together with access to powerful new computational resources. In particular, the fusion energy science community has made excellent progress in developing advanced codes for which computer run-time and problem size scale well with the number of processors on massively parallel machines (MPP's). A good example is the effective usage of the full power of multi-teraflop (multi-trillion floating point computations per second) MPP's to produce three-dimensional, general geometry, nonlinear particle simulations which have accelerated progress in understanding the nature of turbulence self-regulation by zonal flows. It should be emphasized that these calculations, which typically utilized billions of particles for thousands of time-steps, would not have been possible without access to powerful present generation MPP computers and the associated diagnostic and visualization capabilities. In general, results from advanced simulations provide great encouragement for being able to include increasingly realistic dynamics to enable deeper physics insights into plasmas in both natural and laboratory environments. The associated scientific excitement should serve to stimulate improved cross-cutting collaborations with other fields and also to help attract bright young talent to plasma science.

Advanced Computation in Plasma Physics

NASA Astrophysics Data System (ADS)

Tang, William

2001-10-01

Scientific simulation in tandem with theory and experiment is an essential tool for understanding complex plasma behavior. This talk will review recent progress and future directions for advanced simulations in magnetically-confined plasmas with illustrative examples chosen from areas such as microturbulence, magnetohydrodynamics, magnetic reconnection, and others. Significant recent progress has been made in both particle and fluid simulations of fine-scale turbulence and large-scale dynamics, giving increasingly good agreement between experimental observations and computational modeling. This was made possible by innovative advances in analytic and computational methods for developing reduced descriptions of physics phenomena spanning widely disparate temporal and spatial scales together with access to powerful new computational resources. In particular, the fusion energy science community has made excellent progress in developing advanced codes for which computer run-time and problem size scale well with the number of processors on massively parallel machines (MPP's). A good example is the effective usage of the full power of multi-teraflop MPP's to produce 3-dimensional, general geometry, nonlinear particle simulations which have accelerated progress in understanding the nature of turbulence self-regulation by zonal flows. It should be emphasized that these calculations, which typically utilized billions of particles for tens of thousands time-steps, would not have been possible without access to powerful present generation MPP computers and the associated diagnostic and visualization capabilities. In general, results from advanced simulations provide great encouragement for being able to include increasingly realistic dynamics to enable deeper physics insights into plasmas in both natural and laboratory environments. The associated scientific excitement should serve to stimulate improved cross-cutting collaborations with other fields and also to help attract bright young talent to plasma science.

Reliability Quantification of Advanced Stirling Convertor (ASC) Components

NASA Technical Reports Server (NTRS)

Shah, Ashwin R.; Korovaichuk, Igor; Zampino, Edward

2010-01-01

The Advanced Stirling Convertor, is intended to provide power for an unmanned planetary spacecraft and has an operational life requirement of 17 years. Over this 17 year mission, the ASC must provide power with desired performance and efficiency and require no corrective maintenance. Reliability demonstration testing for the ASC was found to be very limited due to schedule and resource constraints. Reliability demonstration must involve the application of analysis, system and component level testing, and simulation models, taken collectively. Therefore, computer simulation with limited test data verification is a viable approach to assess the reliability of ASC components. This approach is based on physics-of-failure mechanisms and involves the relationship among the design variables based on physics, mechanics, material behavior models, interaction of different components and their respective disciplines such as structures, materials, fluid, thermal, mechanical, electrical, etc. In addition, these models are based on the available test data, which can be updated, and analysis refined as more data and information becomes available. The failure mechanisms and causes of failure are included in the analysis, especially in light of the new information, in order to develop guidelines to improve design reliability and better operating controls to reduce the probability of failure. Quantified reliability assessment based on fundamental physical behavior of components and their relationship with other components has demonstrated itself to be a superior technique to conventional reliability approaches based on utilizing failure rates derived from similar equipment or simply expert judgment.

A Trial of Physics Education for Liberal Arts Students Using the Advancing Physics

NASA Astrophysics Data System (ADS)

Ochi, Nobuaki

A new approach to physics education for liberal arts students was performed in a Japanese university. The Advancing Physics, a modern textbook developed by the Institute of Physics, was employed as the base of this approach. The textbook includes a variety of modern topics about science and technology with beautiful pictures, while the use of math is kept to a minimum. From results of the questionnaire after one-semester lectures, it turned out that students' interest in science and technology rose substantially. On the other hand, there were some difficulties in lecturing, mathematical techniques in particular, which should be modified by the next trial. This result is an indication of a potential of the Advancing Physics for liberal arts education.

Quantum Sensing for High Energy Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

van Bibber, Karl; Boshier, Malcolm; Demarteau, Marcel

The Coordinating Panel for Advanced Detectors (CPAD) of the APS Division of Particles and Fields organized a first workshop on Quantum Sensing for High Energy Physics (HEP) in early December 2017 at Argonne National Laboratory. Participants from universities and national labs were drawn from the intersecting fields of Quantum Information Science (QIS), high energy physics, atomic, molecular and optical physics, condensed matter physics, nuclear physics and materials science. Quantum-enabled science and technology has seen rapid technical advances and growing national interest and investments over the last few years. The goal of the workshop was to bring the various communities togethermore » to investigate pathways to integrate the expertise of these two disciplines to accelerate the mutual advancement of scientific progress.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Curtis L.; Prescott, Steven; Coleman, Justin

This report describes the current progress and status related to the Industry Application #2 focusing on External Hazards. For this industry application within the Light Water Reactor Sustainability (LWRS) Program Risk-Informed Safety Margin Characterization (RISMC) R&D Pathway, we will create the Risk-Informed Margin Management (RIMM) approach to represent meaningful (i.e., realistic facility representation) event scenarios and consequences by using an advanced 3D facility representation that will evaluate external hazards such as flooding and earthquakes in order to identify, model and analyze the appropriate physics that needs to be included to determine plant vulnerabilities related to external events; manage the communicationmore » and interactions between different physics modeling and analysis technologies; and develop the computational infrastructure through tools related to plant representation, scenario depiction, and physics prediction. One of the unique aspects of the RISMC approach is how it couples probabilistic approaches (the scenario) with mechanistic phenomena representation (the physics) through simulation. This simulation-based modeling allows decision makers to focus on a variety of safety, performance, or economic metrics. In this report, we describe the evaluation of various physics toolkits related to flooding representation. Ultimately, we will be coupling the flooding representation with other events such as earthquakes in order to provide coupled physics analysis for scenarios where interactions exist.« less

Machine learning of network metrics in ATLAS Distributed Data Management

NASA Astrophysics Data System (ADS)

Lassnig, Mario; Toler, Wesley; Vamosi, Ralf; Bogado, Joaquin; ATLAS Collaboration

2017-10-01

The increasing volume of physics data poses a critical challenge to the ATLAS experiment. In anticipation of high luminosity physics, automation of everyday data management tasks has become necessary. Previously many of these tasks required human decision-making and operation. Recent advances in hardware and software have made it possible to entrust more complicated duties to automated systems using models trained by machine learning algorithms. In this contribution we show results from one of our ongoing automation efforts that focuses on network metrics. First, we describe our machine learning framework built atop the ATLAS Analytics Platform. This framework can automatically extract and aggregate data, train models with various machine learning algorithms, and eventually score the resulting models and parameters. Second, we use these models to forecast metrics relevant for networkaware job scheduling and data brokering. We show the characteristics of the data and evaluate the forecasting accuracy of our models.

Physical and mathematical modeling of antimicrobial photodynamic therapy

NASA Astrophysics Data System (ADS)

Bürgermeister, Lisa; López, Fernando Romero; Schulz, Wolfgang

2014-07-01

Antimicrobial photodynamic therapy (aPDT) is a promising method to treat local bacterial infections. The therapy is painless and does not cause bacterial resistances. However, there are gaps in understanding the dynamics of the processes, especially in periodontal treatment. This work describes the advances in fundamental physical and mathematical modeling of aPDT used for interpretation of experimental evidence. The result is a two-dimensional model of aPDT in a dental pocket phantom model. In this model, the propagation of laser light and the kinetics of the chemical reactions are described as coupled processes. The laser light induces the chemical processes depending on its intensity. As a consequence of the chemical processes, the local optical properties and distribution of laser light change as well as the reaction rates. The mathematical description of these coupled processes will help to develop treatment protocols and is the first step toward an inline feedback system for aPDT users.

Health Behavior and Behavioral Economics: Economic Preferences and Physical Activity Stages of Change in a Low-Income African American Community

PubMed Central

Leonard, Tammy; Shuval, Kerem; de Oliveira, Angela; Skinner, Celette Sugg; Eckel, Catherine; Murdoch, James C.

2014-01-01

Purpose To examine the relationship between physical activity stages of change and preferences for financial risk and time. Design A cross-sectional, community-based study. Setting A low-income, urban, African American neighborhood. Subjects 169 adults Measures Self-reported physical activity stages of change—precontemplation to maintenance, objectively measured BMI and waist circumference, and economic preferences for time and risk measured via incentivized economic experiments. Analysis Multivariable ordered logistic regression models were used to examine the association between physical activity stages of change and economic preferences while controlling for demographic characteristics of the individuals. Results Individuals who are more tolerant of financial risks (OR=1.31, p<0.05) and whose time preferences indicate more patience (OR=1.68, p<0.01) are more likely to be in a more advanced physical activity stage (e.g. from preparation to action). The likelihood of being in the maintenance stage increases by 5.6 and 10.9 percentage points for each 1 unit increase in financial risk tolerance or 1 unit increase in the time preference measure, respectively. Conclusions Greater tolerance of financial risk and more patient time preferences among this low-income ethnic minority population are associated with a more advanced physical activity stage. Further exploration is clearly warranted in larger and more representative samples. PMID:23448410

iPSC-based drug screening for Huntington's disease.

PubMed

Zhang, Ningzhe; Bailus, Barbara J; Ring, Karen L; Ellerby, Lisa M

2016-05-01

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder, caused by an expansion of the CAG repeat in exon 1 of the huntingtin gene. The disease generally manifests in middle age with both physical and mental symptoms. There are no effective treatments or cures and death usually occurs 10-20 years after initial symptoms. Since the original identification of the Huntington disease associated gene, in 1993, a variety of models have been created and used to advance our understanding of HD. The most recent advances have utilized stem cell models derived from HD-patient induced pluripotent stem cells (iPSCs) offering a variety of screening and model options that were not previously available. The discovery and advancement of technology to make human iPSCs has allowed for a more thorough characterization of human HD on a cellular and developmental level. The interaction between the genome editing and the stem cell fields promises to further expand the variety of HD cellular models available for researchers. In this review, we will discuss the history of Huntington's disease models, common screening assays, currently available models and future directions for modeling HD using iPSCs-derived from HD patients. This article is part of a Special Issue entitled SI: PSC and the brain. Copyright © 2015 Elsevier B.V. All rights reserved.

A Physics-Based Engineering Approach to Predict the Cross Section for Advanced SRAMs

NASA Astrophysics Data System (ADS)

Li, Lei; Zhou, Wanting; Liu, Huihua

2012-12-01

This paper presents a physics-based engineering approach to estimate the heavy ion induced upset cross section for 6T SRAM cells from layout and technology parameters. The new approach calculates the effects of radiation with junction photocurrent, which is derived based on device physics. The new and simple approach handles the problem by using simple SPICE simulations. At first, the approach uses a standard SPICE program on a typical PC to predict the SPICE-simulated curve of the collected charge vs. its affected distance from the drain-body junction with the derived junction photocurrent. And then, the SPICE-simulated curve is used to calculate the heavy ion induced upset cross section with a simple model, which considers that the SEU cross section of a SRAM cell is more related to a “radius of influence” around a heavy ion strike than to the physical size of a diffusion node in the layout for advanced SRAMs in nano-scale process technologies. The calculated upset cross section based on this method is in good agreement with the test results for 6T SRAM cells processed using 90 nm process technology.

The New APS Topical Group on the Physics of Climate: History, Objectives and Panel Discussion

NASA Astrophysics Data System (ADS)

Brasseur, James; Behringer, Robert

2013-03-01

The GPC Chair will introduce the new APS Topical Group on the Physics of Climate (GPC), describe its history and objectives, and introduce the current GPC leadership before opening the floor to a panel discussion. The GPC resulted from two petitions that emerged from the controversy that followed the APS Statement on Climate Change (see APS website). The two proposals were merged and an organization committee formed by the APS leadership. After a long organizational period in 2011, the GPC bylaws were finalized with the following key objective: The objective of the GPC shall be to promote the advancement and diffusion of knowledge concerning the physics, measurement, and modeling of climate processes, within the domain of natural science and outside the domains of societal impact and policy, legislation and broader societal issues. The objective includes the integration of scientific knowledge and analysis methods across disciplines to address the dynamical complexities and uncertainties of climate physics. The GPC Invited and Focus Sessions at this March meeting are the inaugural GPC events. The Program Committee Chair will moderate a panel between the attending GPC leadership and audience to solicit suggestions for potential future GPC events that advance the GPC objectives.

TerraFERMA: Harnessing Advanced Computational Libraries in Earth Science

NASA Astrophysics Data System (ADS)

Wilson, C. R.; Spiegelman, M.; van Keken, P.

2012-12-01

Many important problems in Earth sciences can be described by non-linear coupled systems of partial differential equations. These "multi-physics" problems include thermo-chemical convection in Earth and planetary interiors, interactions of fluids and magmas with the Earth's mantle and crust and coupled flow of water and ice. These problems are of interest to a large community of researchers but are complicated to model and understand. Much of this complexity stems from the nature of multi-physics where small changes in the coupling between variables or constitutive relations can lead to radical changes in behavior, which in turn affect critical computational choices such as discretizations, solvers and preconditioners. To make progress in understanding such coupled systems requires a computational framework where multi-physics problems can be described at a high-level while maintaining the flexibility to easily modify the solution algorithm. Fortunately, recent advances in computational science provide a basis for implementing such a framework. Here we present the Transparent Finite Element Rapid Model Assembler (TerraFERMA), which leverages several advanced open-source libraries for core functionality. FEniCS (fenicsproject.org) provides a high level language for describing the weak forms of coupled systems of equations, and an automatic code generator that produces finite element assembly code. PETSc (www.mcs.anl.gov/petsc) provides a wide range of scalable linear and non-linear solvers that can be composed into effective multi-physics preconditioners. SPuD (amcg.ese.ic.ac.uk/Spud) is an application neutral options system that provides both human and machine-readable interfaces based on a single xml schema. Our software integrates these libraries and provides the user with a framework for exploring multi-physics problems. A single options file fully describes the problem, including all equations, coefficients and solver options. Custom compiled applications are generated from this file but share an infrastructure for services common to all models, e.g. diagnostics, checkpointing and global non-linear convergence monitoring. This maximizes code reusability, reliability and longevity ensuring that scientific results and the methods used to acquire them are transparent and reproducible. TerraFERMA has been tested against many published geodynamic benchmarks including 2D/3D thermal convection problems, the subduction zone benchmarks and benchmarks for magmatic solitary waves. It is currently being used in the investigation of reactive cracking phenomena with applications to carbon sequestration, but we will principally discuss its use in modeling the migration of fluids in subduction zones. Subduction zones require an understanding of the highly nonlinear interactions of fluids with solids and thus provide an excellent scientific driver for the development of multi-physics software.

Undergraduate Teaching of Ideal and Real Fluid Flows: The Value of Real-World Experimental Projects

ERIC Educational Resources Information Center

Baldock, Tom E.; Chanson, Hubert

2006-01-01

This paper describes the pedagogical impact of real-world experimental projects undertaken as part of an advanced undergraduate fluid mechanics subject at an Australian university. The projects have been organized to complement traditional lectures and introduce students to the challenges of professional design, physical modelling, data collection…

Modeling and Validation of Power-split and P2 Parallel Hybrid Electric Vehicles SAE 2013-01-1470)

EPA Science Inventory

The Advanced Light-Duty Powertrain and Hybrid Analysis tool was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles. It is a physics-based, forward-looking, full vehicle computer simulator capable of analyzing various vehicle types combined ...

A Noted Physicist's Contrarian View of Global Warming

ERIC Educational Resources Information Center

Goldstein, Evan R., Comp.

2008-01-01

According to Freeman Dyson, an emeritus professor of physics at the Institute for Advanced Study, the debate about global warming has become too narrow and opinions have become too entrenched. Relying on a computer model designed by the Yale University economist William D. Nordhaus, Dyson compared the effectiveness and economic feasibility of…

Center for Advanced Power and Energy Research (CAPEC)

DTIC Science & Technology

2015-01-01

discharge (DCD). A glow discharge at a low ambient density becomes Corona discharge at the elevated ambient pressure condition. The thermal plasma actuator...Elisson and Kogelschlatz [9] has identified that the discharge consists of two distinct positive Corona streamers and diffusion modes. Enloe et al...4 2.3 Physics-Base Discharge Modeling

A Model of Online Education Effecting Holistic Student Formation Appropriate for Global Cross-Cultural Contexts

ERIC Educational Resources Information Center

Hannaford, Ronald Geoffrey

2012-01-01

Factors associated with globalization and unprecedented technological advancement have facilitated the opportunity to take education beyond the boundaries of the physical classroom and geographical borders to serve a global context. While this exponential growth has resulted in more convenient access to learning, increased possibilities for…

Sizing up the Solar System

ERIC Educational Resources Information Center

Wiebke, Heidi; Rogers, Meredith Park; Nargund-Joshi, Vanashri

2011-01-01

The American Association for the Advancement of Science (AAAS 1993) states that by the end of fifth grade, students should understand that a model, such as those depicting the solar system, is a smaller version of the real product, making it easier to physically work with and therefore learn from. However, for students and even adults,…

atlant: Advanced Three Level Approximation for Numerical Treatment of Cosmological Recombination

NASA Astrophysics Data System (ADS)

Kholupenko, E. E.; Ivanchik, A. V.; Balashev, S. A.; Varshalovich, D. A.

2011-10-01

atlant is a public numerical code for fast calculations of cosmological recombination of primordial hydrogen-helium plasma is presented. This code is based on the three-level approximation (TLA) model of recombination and allows us to take into account some "fine" physical effects of cosmological recombination simultaneously with using fudge factors.

Development and Testing of an Automatic Transmission Shift Schedule Algorithm for Vehicle Simulation (SAE Paper 2015-01-1142)

EPA Science Inventory

The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) modeling tool was created by EPA to estimate greenhouse gas (GHG) emissions of light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle type...

Collective cell migration: a physics perspective

NASA Astrophysics Data System (ADS)

Hakim, Vincent; Silberzan, Pascal

2017-07-01

Cells have traditionally been viewed either as independently moving entities or as somewhat static parts of tissues. However, it is now clear that in many cases, multiple cells coordinate their motions and move as collective entities. Well-studied examples comprise development events, as well as physiological and pathological situations. Different ex vivo model systems have also been investigated. Several recent advances have taken place at the interface between biology and physics, and have benefitted from progress in imaging and microscopy, from the use of microfabrication techniques, as well as from the introduction of quantitative tools and models. We review these interesting developments in quantitative cell biology that also provide rich examples of collective out-of-equilibrium motion.

Refining Low Physical Activity Measurement Improves Frailty Assessment in Advanced Lung Disease and Survivors of Critical Illness.

PubMed

Baldwin, Matthew R; Singer, Jonathan P; Huang, Debbie; Sell, Jessica; Gonzalez, Wendy C; Pollack, Lauren R; Maurer, Mathew S; D'Ovidio, Frank F; Bacchetta, Matthew; Sonett, Joshua R; Arcasoy, Selim M; Shah, Lori; Robbins, Hilary; Hays, Steven R; Kukreja, Jasleen; Greenland, John R; Shah, Rupal J; Leard, Lorriana; Morrell, Matthew; Gries, Cynthia; Katz, Patricia P; Christie, Jason D; Diamond, Joshua M; Lederer, David J

2017-08-01

The frail phenotype has gained popularity as a clinically relevant measure in adults with advanced lung disease and in critical illness survivors. Because respiratory disease and chronic illness can greatly limit physical activity, the measurement of participation in traditional leisure time activities as a frailty component may lead to substantial misclassification of frailty in pulmonary and critical care patients. To test and validate substituting the Duke Activity Status Index (DASI), a simple 12-item questionnaire, for the Minnesota Leisure Time Physical Activity (MLTA) questionnaire, a detailed questionnaire covering 18 leisure time activities, as the measure of low activity in the Fried frailty phenotype (FFP) instrument. In separate multicenter prospective cohort studies of adults with advanced lung disease who were candidates for lung transplant and older survivors of acute respiratory failure, we assessed the FFP using either the MLTA or the DASI. For both the DASI and MLTA, we evaluated content validity by testing floor effects and construct validity through comparisons with conceptually related factors. We tested the predictive validity of substituting the DASI for the MLTA in the FFP assessment using Cox models to estimate associations between the FFP and delisting/death before transplant in those with advanced lung disease and 6-month mortality in older intensive care unit (ICU) survivors. Among 618 adults with advanced lung disease and 130 older ICU survivors, the MLTA had a substantially greater floor effect than the DASI (42% vs. 1%, and 49% vs. 12%, respectively). The DASI correlated more strongly with strength and function measures than did the MLTA in both cohorts. In models adjusting for age, sex, comorbidities, and illness severity, substitution of the DASI for the MLTA led to stronger associations of the FFP with delisting/death in lung transplant candidates (FFP-MLTA hazard ratio [HR], 1.42; 95% confidence interval [CI], 0.55-3.65; FFP-DASI HR, 2.99; 95% CI, 1.03-8.65) and with mortality in older ICU survivors (FFP-MLTA HR, 2.68; 95% CI, 0.62-11.6; FFP-DASI HR, 5.71; 95% CI, 1.34-24.3). The DASI improves the construct and predictive validity of frailty assessment in adults with advanced lung disease or recent critical illness. This simple questionnaire should replace the more complex MLTA in assessing the frailty phenotype in these populations.

Probing students’ conceptions at the classical-quantum interface

NASA Astrophysics Data System (ADS)

Chhabra, Mahima; Das, Ritwick

2018-03-01

Quantum mechanics (QM) is one of the core subject areas in the undergraduate physics curriculum and many of the advanced level physics courses involve direct or indirect application of the concepts and ideas taught in QM. On the other hand, proper understanding of QM interpretations requires an optimum level of understanding of fundamental concepts in classical physics such as energy, momentum, force and their role in determining motion of the particle. This study is an attempt to explore a group of undergraduate students’ mental models regarding fundamental concepts in classical physics which are actually the stepping stone for understanding and visualisation of QM. The data and analysis presented here elucidate the challenges students face to understand the classical ideas and how that affects their understanding of QM.

Logistic regression models for predicting physical and mental health-related quality of life in rheumatoid arthritis patients.

PubMed

Alishiri, Gholam Hossein; Bayat, Noushin; Fathi Ashtiani, Ali; Tavallaii, Seyed Abbas; Assari, Shervin; Moharamzad, Yashar

2008-01-01

The aim of this work was to develop two logistic regression models capable of predicting physical and mental health related quality of life (HRQOL) among rheumatoid arthritis (RA) patients. In this cross-sectional study which was conducted during 2006 in the outpatient rheumatology clinic of our university hospital, Short Form 36 (SF-36) was used for HRQOL measurements in 411 RA patients. A cutoff point to define poor versus good HRQOL was calculated using the first quartiles of SF-36 physical and mental component scores (33.4 and 36.8, respectively). Two distinct logistic regression models were used to derive predictive variables including demographic, clinical, and psychological factors. The sensitivity, specificity, and accuracy of each model were calculated. Poor physical HRQOL was positively associated with pain score, disease duration, monthly family income below 300 US$, comorbidity, patient global assessment of disease activity or PGA, and depression (odds ratios: 1.1; 1.004; 15.5; 1.1; 1.02; 2.08, respectively). The variables that entered into the poor mental HRQOL prediction model were monthly family income below 300 US$, comorbidity, PGA, and bodily pain (odds ratios: 6.7; 1.1; 1.01; 1.01, respectively). Optimal sensitivity and specificity were achieved at a cutoff point of 0.39 for the estimated probability of poor physical HRQOL and 0.18 for mental HRQOL. Sensitivity, specificity, and accuracy of the physical and mental models were 73.8, 87, 83.7% and 90.38, 70.36, 75.43%, respectively. The results show that the suggested models can be used to predict poor physical and mental HRQOL separately among RA patients using simple variables with acceptable accuracy. These models can be of use in the clinical decision-making of RA patients and to recognize patients with poor physical or mental HRQOL in advance, for better management.

Images as drivers of progress in cardiac computational modelling

PubMed Central

Lamata, Pablo; Casero, Ramón; Carapella, Valentina; Niederer, Steve A.; Bishop, Martin J.; Schneider, Jürgen E.; Kohl, Peter; Grau, Vicente

2014-01-01

Computational models have become a fundamental tool in cardiac research. Models are evolving to cover multiple scales and physical mechanisms. They are moving towards mechanistic descriptions of personalised structure and function, including effects of natural variability. These developments are underpinned to a large extent by advances in imaging technologies. This article reviews how novel imaging technologies, or the innovative use and extension of established ones, integrate with computational models and drive novel insights into cardiac biophysics. In terms of structural characterization, we discuss how imaging is allowing a wide range of scales to be considered, from cellular levels to whole organs. We analyse how the evolution from structural to functional imaging is opening new avenues for computational models, and in this respect we review methods for measurement of electrical activity, mechanics and flow. Finally, we consider ways in which combined imaging and modelling research is likely to continue advancing cardiac research, and identify some of the main challenges that remain to be solved. PMID:25117497

Advanced Cell Culture Techniques for Cancer Drug Discovery

PubMed Central

Lovitt, Carrie J.; Shelper, Todd B.; Avery, Vicky M.

2014-01-01

Human cancer cell lines are an integral part of drug discovery practices. However, modeling the complexity of cancer utilizing these cell lines on standard plastic substrata, does not accurately represent the tumor microenvironment. Research into developing advanced tumor cell culture models in a three-dimensional (3D) architecture that more prescisely characterizes the disease state have been undertaken by a number of laboratories around the world. These 3D cell culture models are particularly beneficial for investigating mechanistic processes and drug resistance in tumor cells. In addition, a range of molecular mechanisms deconstructed by studying cancer cells in 3D models suggest that tumor cells cultured in two-dimensional monolayer conditions do not respond to cancer therapeutics/compounds in a similar manner. Recent studies have demonstrated the potential of utilizing 3D cell culture models in drug discovery programs; however, it is evident that further research is required for the development of more complex models that incorporate the majority of the cellular and physical properties of a tumor. PMID:24887773

Advanced cell culture techniques for cancer drug discovery.

PubMed

Lovitt, Carrie J; Shelper, Todd B; Avery, Vicky M

2014-05-30

Human cancer cell lines are an integral part of drug discovery practices. However, modeling the complexity of cancer utilizing these cell lines on standard plastic substrata, does not accurately represent the tumor microenvironment. Research into developing advanced tumor cell culture models in a three-dimensional (3D) architecture that more prescisely characterizes the disease state have been undertaken by a number of laboratories around the world. These 3D cell culture models are particularly beneficial for investigating mechanistic processes and drug resistance in tumor cells. In addition, a range of molecular mechanisms deconstructed by studying cancer cells in 3D models suggest that tumor cells cultured in two-dimensional monolayer conditions do not respond to cancer therapeutics/compounds in a similar manner. Recent studies have demonstrated the potential of utilizing 3D cell culture models in drug discovery programs; however, it is evident that further research is required for the development of more complex models that incorporate the majority of the cellular and physical properties of a tumor.

Fuel Performance Experiments and Modeling: Fission Gas Bubble Nucleation and Growth in Alloy Nuclear Fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDeavitt, Sean; Shao, Lin; Tsvetkov, Pavel

2014-04-07

Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. Many mechanistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, research, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development suchmore » that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.« less

Recent numerical and algorithmic advances within the volume tracking framework for modeling interfacial flows

DOE PAGES

François, Marianne M.

2015-05-28

A review of recent advances made in numerical methods and algorithms within the volume tracking framework is presented. The volume tracking method, also known as the volume-of-fluid method has become an established numerical approach to model and simulate interfacial flows. Its advantage is its strict mass conservation. However, because the interface is not explicitly tracked but captured via the material volume fraction on a fixed mesh, accurate estimation of the interface position, its geometric properties and modeling of interfacial physics in the volume tracking framework remain difficult. Several improvements have been made over the last decade to address these challenges.more » In this study, the multimaterial interface reconstruction method via power diagram, curvature estimation via heights and mean values and the balanced-force algorithm for surface tension are highlighted.« less

Does availability of physical activity and food outlets differ by race and income? Findings from an enumeration study in a health disparate region.

PubMed

Hill, Jennie L; Chau, Clarice; Luebbering, Candice R; Kolivras, Korine K; Zoellner, Jamie

2012-09-06

Low-income, ethnic/racial minorities and rural populations are at increased risk for obesity and related chronic health conditions when compared to white, urban and higher-socio-economic status (SES) peers. Recent systematic reviews highlight the influence of the built environment on obesity, yet very few of these studies consider rural areas or populations. Utilizing a CBPR process, this study advances community-driven causal models to address obesity by exploring the difference in resources for physical activity and food outlets by block group race and income in a small regional city that anchors a rural health disparate region. To guide this inquiry we hypothesized that lower income and racially diverse block groups would have fewer food outlets, including fewer grocery stores and fewer physical activity outlets. We further hypothesized that walkability, as defined by a computed walkability index, would be lower in the lower income block groups. Using census data and GIS, base maps of the region were created and block groups categorized by income and race. All food outlets and physical activity resources were enumerated and geocoded and a walkability index computed. Analyses included one-way MANOVA and spatial autocorrelation. In total, 49 stores, 160 restaurants and 79 physical activity outlets were enumerated. There were no differences in the number of outlets by block group income or race. Further, spatial analyses suggest that the distribution of outlets is dispersed across all block groups. Under the larger CPBR process, this enumeration study advances the causal models set forth by the community members to address obesity by providing an overview of the food and physical activity environment in this region. This data reflects the food and physical activity resources available to residents in the region and will aid many of the community-academic partners as they pursue intervention strategies targeting obesity.

Nonequilibrium radiative hypersonic flow simulation

NASA Astrophysics Data System (ADS)

Shang, J. S.; Surzhikov, S. T.

2012-08-01

Nearly all the required scientific disciplines for computational hypersonic flow simulation have been developed on the framework of gas kinetic theory. However when high-temperature physical phenomena occur beneath the molecular and atomic scales, the knowledge of quantum physics and quantum chemical-physics becomes essential. Therefore the most challenging topics in computational simulation probably can be identified as the chemical-physical models for a high-temperature gaseous medium. The thermal radiation is also associated with quantum transitions of molecular and electronic states. The radiative energy exchange is characterized by the mechanisms of emission, absorption, and scattering. In developing a simulation capability for nonequilibrium radiation, an efficient numerical procedure is equally important both for solving the radiative transfer equation and for generating the required optical data via the ab-initio approach. In computational simulation, the initial values and boundary conditions are paramount for physical fidelity. Precise information at the material interface of ablating environment requires more than just a balance of the fluxes across the interface but must also consider the boundary deformation. The foundation of this theoretic development shall be built on the eigenvalue structure of the governing equations which can be described by Reynolds' transport theorem. Recent innovations for possible aerospace vehicle performance enhancement via an electromagnetic effect appear to be very attractive. The effectiveness of this mechanism is dependent strongly on the degree of ionization of the flow medium, the consecutive interactions of fluid dynamics and electrodynamics, as well as an externally applied magnetic field. Some verified research results in this area will be highlighted. An assessment of all these most recent advancements in nonequilibrium modeling of chemical kinetics, chemical-physics kinetics, ablation, radiative exchange, computational algorithms, and the aerodynamic-electromagnetic interaction are summarized and delineated. The critical basic research areas for physic-based hypersonic flow simulation should become self-evident through the present discussion. Nevertheless intensive basic research efforts must be sustained in these areas for fundamental knowledge and future technology advancement.

Rad4 recognition-at-a-distance: Physical basis of conformation-specific anomalous diffusion of DNA repair proteins.

PubMed

Kong, Muwen; Van Houten, Bennett

2017-08-01

Since Robert Brown's first observations of random walks by pollen particles suspended in solution, the concept of diffusion has been subject to countless theoretical and experimental studies in diverse fields from finance and social sciences, to physics and biology. Diffusive transport of macromolecules in cells is intimately linked to essential cellular functions including nutrient uptake, signal transduction, gene expression, as well as DNA replication and repair. Advancement in experimental techniques has allowed precise measurements of these diffusion processes. Mathematical and physical descriptions and computer simulations have been applied to model complicated biological systems in which anomalous diffusion, in addition to simple Brownian motion, was observed. The purpose of this review is to provide an overview of the major physical models of anomalous diffusion and corresponding experimental evidence on the target search problem faced by DNA-binding proteins, with an emphasis on DNA repair proteins and the role of anomalous diffusion in DNA target recognition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Advancement of CMOS Doping Technology in an External Development Framework

NASA Astrophysics Data System (ADS)

Jain, Amitabh; Chambers, James J.; Shaw, Judy B.

2011-01-01

The consumer appetite for a rich multimedia experience drives technology development for mobile hand-held devices and the infrastructure to support them. Enhancements in functionality, speed, and user experience are derived from advancements in CMOS technology. The technical challenges in developing each successive CMOS technology node to support these enhancements have become increasingly difficult. These trends have motivated the CMOS business towards a collaborative approach based on strategic partnerships. This paper describes our model and experience of CMOS development, based on multi-dimensional industrial and academic partnerships. We provide to our process equipment, materials, and simulation partners, as well as to our silicon foundry partners, the detailed requirements for future integrated circuit products. This is done very early in the development cycle to ensure that these requirements can be met. In order to determine these fundamental requirements, we rely on a strategy that requires strong interaction between process and device simulation, physical and chemical analytical methods, and research at academic institutions. This learning is shared with each project partner to address integration and manufacturing issues encountered during CMOS technology development from its inception through product ramp. We utilize TI's core strengths in physical analysis, unit processes and integration, yield ramp, reliability, and product engineering to support this technological development. Finally, this paper presents examples of the advancement of CMOS doping technology for the 28 nm node and beyond through this development model.

Using Recent Planetary Science Data to Develop Advanced Undergraduate Physics and Astronomy Activities

NASA Astrophysics Data System (ADS)

Steckloff, Jordan; Lindell, Rebecca

2016-10-01

Teaching science by having students manipulate real data is a popular trend in astronomy and planetary science education. However, many existing activities simply couple this data with traditional "cookbook" style verification labs. As with most topics within science, this instructional technique does not enhance the average students' understanding of the phenomena being studied. Here we present a methodology for developing "science by doing" activities that incorporate the latest discoveries in planetary science with up-to-date constructivist pedagogy to teach advanced concepts in Physics and Astronomy. In our methodology, students are first guided to understand, analyze, and plot real raw scientific data; develop and test physical and computational models to understand and interpret the data; finally use their models to make predictions about the topic being studied and test it with real data.To date, two activities have been developed according to this methodology: Understanding Asteroids through their Light Curves (hereafter "Asteroid Activity"), and Understanding Exoplanetary Systems through Simple Harmonic Motion (hereafter "Exoplanet Activity"). The Asteroid Activity allows students to explore light curves available on the Asteroid Light Curve Database (ALCDB) to discover general properties of asteroids, including their internal structure, strength, and mechanism of asteroid moon formation. The Exoplanet Activity allows students to investigate the masses and semi-major axes of exoplanets in a system by comparing the radial velocity motion of their host star to that of a coupled simple harmonic oscillator. Students then explore how noncircular orbits lead to deviations from simple harmonic motion. These activities will be field tested during the Fall 2016 semester in an advanced undergraduate mechanics and astronomy courses at a large Midwestern STEM-focused university. We will present the development methodologies for these activities, description of the activities, and results from the pre-tests.

Introducing Seismic Tomography with Computational Modeling

NASA Astrophysics Data System (ADS)

Neves, R.; Neves, M. L.; Teodoro, V.

2011-12-01

Learning seismic tomography principles and techniques involves advanced physical and computational knowledge. In depth learning of such computational skills is a difficult cognitive process that requires a strong background in physics, mathematics and computer programming. The corresponding learning environments and pedagogic methodologies should then involve sets of computational modelling activities with computer software systems which allow students the possibility to improve their mathematical or programming knowledge and simultaneously focus on the learning of seismic wave propagation and inverse theory. To reduce the level of cognitive opacity associated with mathematical or programming knowledge, several computer modelling systems have already been developed (Neves & Teodoro, 2010). Among such systems, Modellus is particularly well suited to achieve this goal because it is a domain general environment for explorative and expressive modelling with the following main advantages: 1) an easy and intuitive creation of mathematical models using just standard mathematical notation; 2) the simultaneous exploration of images, tables, graphs and object animations; 3) the attribution of mathematical properties expressed in the models to animated objects; and finally 4) the computation and display of mathematical quantities obtained from the analysis of images and graphs. Here we describe virtual simulations and educational exercises which enable students an easy grasp of the fundamental of seismic tomography. The simulations make the lecture more interactive and allow students the possibility to overcome their lack of advanced mathematical or programming knowledge and focus on the learning of seismological concepts and processes taking advantage of basic scientific computation methods and tools.

A Global Data Assimilation System for Atmospheric Aerosol

NASA Technical Reports Server (NTRS)

daSilva, Arlindo

1999-01-01

We will give an overview of an aerosol data assimilation system which combines advances in remote sensing of atmospheric aerosols, aerosol modeling and data assimilation methodology to produce high spatial and temporal resolution 3D aerosol fields. Initially, the Goddard Aerosol Assimilation System (GAAS) will assimilate TOMS, AVHRR and AERONET observations; later we will include MODIS and MISR. This data assimilation capability will allows us to integrate complementing aerosol observations from these platforms, enabling the development of an assimilated aerosol climatology as well as a global aerosol forecasting system in support of field campaigns. Furthermore, this system provides an interactive retrieval framework for each aerosol observing satellites, in particular TOMS and AVHRR. The Goddard Aerosol Assimilation System (GAAS) takes advantage of recent advances in constituent data assimilation at DAO, including flow dependent parameterizations of error covariances and the proper consideration of model bias. For its prognostic transport model, GAAS will utilize the Goddard Ozone, Chemistry, Aerosol, Radiation and Transport (GOCART) model developed at NASA/GSFC Codes 916 and 910.3. GOCART includes the Lin-Rood flux-form, semi-Langrangian transport model with parameterized aerosol chemistry and physical processes for absorbing (dust and black carbon) and non-absorbing aerosols (sulfate and organic carbon). Observations and model fields are combined using a constituent version of DAO's Physical-space Statistical Analysis System (PSAS), including its adaptive quality control system. In this talk we describe the main components of this assimilation system and present preliminary results obtained by assimilating TOMS data.

Study of the effects of multimodal exercise program on physical fitness and health perception in community-living Hungarian older adults.

PubMed

Virág, Anikó; Harkányi, Izabella; Karóczi, Csilla K; Vass, Zsolt; Kovács, Éva

2018-05-01

The aim of this study was to investigate the effects on fitness indicators and subjective health-perception of a multimodal exercise program provided by a district in Budapest among community-living seniors. Sixty community-living older adults aged over 60 years formed beginner group (who were at the beginning of the exercise program), advanced group (who had been in the programme for 3-6 months), active group (who had been participating in the exercise program for at least 6 months, in addition to Nordic walking program) and a physically inactive control group. Balance, functional mobility, lower and upper limb strength, lower and upper body flexibility, aerobic endurance and self-reported health perception were measured at baseline, and after a 12-week follow-up period. The beginner group and the advanced group improved in upper body flexibility (beginner Δ=1.2; d=0.83; advanced: Δ=1.7; d=1.39), lower body flexibility (beginner: Δ=1.7, d=0.484; advanced: Δ=1.9; d=1.55), lower limb strength (beginner: Δ=1.47; d=0.84; advanced: Δ=1.57; d=0.72), and functional mobility (beginner: Δ=-0.6; d=0.54; advanced: Δ=-0.4; d=0.90). There were also improvements in aerobic endurance (Δ=11.06; d=0.96) and balance (Δ=1.6; d=0.62) of beginner group. These indicators declined in the control group. Indicators of the active group did not change. The self-perceived health status declined (Δ=-13.9; d=0.73) in the control group but did not change in any exercising groups. This multimodal exercise program can be effective among community-living older adults, even in Hungary, a country where geriatric physical activity is not widespread. Therefore, it would be useful to extend this model program to other settlements as well.

An Overview of Numerical Weather Prediction on Various Scales

NASA Astrophysics Data System (ADS)

Bao, J.-W.

2009-04-01

The increasing public need for detailed weather forecasts, along with the advances in computer technology, has motivated many research institutes and national weather forecasting centers to develop and run global as well as regional numerical weather prediction (NWP) models at high resolutions (i.e., with horizontal resolutions of ~10 km or higher for global models and 1 km or higher for regional models, and with ~60 vertical levels or higher). The need for running NWP models at high horizontal and vertical resolutions requires the implementation of non-hydrostatic dynamic core with a choice of horizontal grid configurations and vertical coordinates that are appropriate for high resolutions. Development of advanced numerics will also be needed for high resolution global and regional models, in particular, when the models are applied to transport problems and air quality applications. In addition to the challenges in numerics, the NWP community is also facing the challenges of developing physics parameterizations that are well suited for high-resolution NWP models. For example, when NWP models are run at resolutions of ~5 km or higher, the use of much more detailed microphysics parameterizations than those currently used in NWP model will become important. Another example is that regional NWP models at ~1 km or higher only partially resolve convective energy containing eddies in the lower troposphere. Parameterizations to account for the subgrid diffusion associated with unresolved turbulence still need to be developed. Further, physically sound parameterizations for air-sea interaction will be a critical component for tropical NWP models, particularly for hurricane predictions models. In this review presentation, the above issues will be elaborated on and the approaches to address them will be discussed.

Revealing physical interaction networks from statistics of collective dynamics

PubMed Central

Nitzan, Mor; Casadiego, Jose; Timme, Marc

2017-01-01

Revealing physical interactions in complex systems from observed collective dynamics constitutes a fundamental inverse problem in science. Current reconstruction methods require access to a system’s model or dynamical data at a level of detail often not available. We exploit changes in invariant measures, in particular distributions of sampled states of the system in response to driving signals, and use compressed sensing to reveal physical interaction networks. Dynamical observations following driving suffice to infer physical connectivity even if they are temporally disordered, are acquired at large sampling intervals, and stem from different experiments. Testing various nonlinear dynamic processes emerging on artificial and real network topologies indicates high reconstruction quality for existence as well as type of interactions. These results advance our ability to reveal physical interaction networks in complex synthetic and natural systems. PMID:28246630

Tuning and predicting the wetting of nanoengineered material surface

NASA Astrophysics Data System (ADS)

Ramiasa-MacGregor, M.; Mierczynska, A.; Sedev, R.; Vasilev, K.

2016-02-01

The wetting of a material can be tuned by changing the roughness on its surface. Recent advances in the field of nanotechnology open exciting opportunities to control macroscopic wetting behaviour. Yet, the benchmark theories used to describe the wettability of macroscopically rough surfaces fail to fully describe the wetting behaviour of systems with topographical features at the nanoscale. To shed light on the events occurring at the nanoscale we have utilised model gradient substrata where surface nanotopography was tailored in a controlled and robust manner. The intrinsic wettability of the coatings was varied from hydrophilic to hydrophobic. The measured water contact angle could not be described by the classical theories. We developed an empirical model that effectively captures the experimental data, and further enables us to predict the wetting of surfaces with nanoscale roughness by considering the physical and chemical properties of the material. The fundamental insights presented here are important for the rational design of advanced materials having tailored surface nanotopography with predictable wettability.The wetting of a material can be tuned by changing the roughness on its surface. Recent advances in the field of nanotechnology open exciting opportunities to control macroscopic wetting behaviour. Yet, the benchmark theories used to describe the wettability of macroscopically rough surfaces fail to fully describe the wetting behaviour of systems with topographical features at the nanoscale. To shed light on the events occurring at the nanoscale we have utilised model gradient substrata where surface nanotopography was tailored in a controlled and robust manner. The intrinsic wettability of the coatings was varied from hydrophilic to hydrophobic. The measured water contact angle could not be described by the classical theories. We developed an empirical model that effectively captures the experimental data, and further enables us to predict the wetting of surfaces with nanoscale roughness by considering the physical and chemical properties of the material. The fundamental insights presented here are important for the rational design of advanced materials having tailored surface nanotopography with predictable wettability. Electronic supplementary information (ESI) available: Detailed characterization of the nanorough substrates and model derivation. See DOI: 10.1039/c5nr08329j

Advanced teaching labs in physics - celebrating progress; challenges ahead

NASA Astrophysics Data System (ADS)

Peterson, Richard

A few examples of optical physics experiments may help us first reflect on significant progress on how advanced lab initiatives may now be more effectively developed, discussed, and disseminated - as opposed to only 10 or 15 years back. Many cooperative developments of the last decade are having profound impacts on advanced lab workers and students. Central to these changes are the programs of the Advanced Laboratory Physics Association (ALPhA) (Immersions, BFY conferences), AAPT (advlab-l server, ComPADRE, apparatus competitions, summer workshops/sessions), APS (Reichert Award, FEd activities and sessions), and the Jonathan F. Reichert Foundation (ALPhA support and institution matched equipment grants for Immersion participants). Broad NSF support has helped undergird several of these initiatives. Two of the most significant challenges before this new advanced lab community are (a) to somehow enhance funding opportunities for teaching equipment and apparatus in an era of minimal NSF equipment support, and (b) to help develop a more complementary relationship between research-based advanced lab pedagogies and the development of fresh physics experiments that help enable the mentoring and experimental challenge of our students.

Millimeter-wave imaging of magnetic fusion plasmas: technology innovations advancing physics understanding

NASA Astrophysics Data System (ADS)

Wang, Y.; Tobias, B.; Chang, Y.-T.; Yu, J.-H.; Li, M.; Hu, F.; Chen, M.; Mamidanna, M.; Phan, T.; Pham, A.-V.; Gu, J.; Liu, X.; Zhu, Y.; Domier, C. W.; Shi, L.; Valeo, E.; Kramer, G. J.; Kuwahara, D.; Nagayama, Y.; Mase, A.; Luhmann, N. C., Jr.

2017-07-01

Electron cyclotron emission (ECE) imaging is a passive radiometric technique that measures electron temperature fluctuations; and microwave imaging reflectometry (MIR) is an active radar imaging technique that measures electron density fluctuations. Microwave imaging diagnostic instruments employing these techniques have made important contributions to fusion science and have been adopted at major fusion facilities worldwide including DIII-D, EAST, ASDEX Upgrade, HL-2A, KSTAR, LHD, and J-TEXT. In this paper, we describe the development status of three major technological advancements: custom mm-wave integrated circuits (ICs), digital beamforming (DBF), and synthetic diagnostic modeling (SDM). These have the potential to greatly advance microwave fusion plasma imaging, enabling compact and low-noise transceiver systems with real-time, fast tracking ability to address critical fusion physics issues, including ELM suppression and disruptions in the ITER baseline scenario, naturally ELM-free states such as QH-mode, and energetic particle confinement (i.e. Alfvén eigenmode stability) in high-performance regimes that include steady-state and advanced tokamak scenarios. Furthermore, these systems are fully compatible with today’s most challenging non-inductive heating and current drive systems and capable of operating in harsh environments, making them the ideal approach for diagnosing long-pulse and steady-state tokamaks.

Millimeter-wave imaging of magnetic fusion plasmas: technology innovations advancing physics understanding

DOE PAGES

Wang, Y.; Tobias, B.; Chang, Y. -T.; ...

2017-03-14

Electron cyclotron emission (ECE) imaging is a passive radiometric technique that measures electron temperature fluctuations; and microwave imaging reflectometry (MIR) is an active radar imaging technique that measures electron density fluctuations. The microwave imaging diagnostic instruments employing these techniques have made important contributions to fusion science and have been adopted at major fusion facilities worldwide including DIII-D, EAST, ASDEX Upgrade, HL-2A, KSTAR, LHD, and J-TEXT. In this paper, we describe the development status of three major technological advancements: custom mm-wave integrated circuits (ICs), digital beamforming (DBF), and synthetic diagnostic modeling (SDM). These also have the potential to greatly advance microwavemore » fusion plasma imaging, enabling compact and low-noise transceiver systems with real-time, fast tracking ability to address critical fusion physics issues, including ELM suppression and disruptions in the ITER baseline scenario, naturally ELM-free states such as QH-mode, and energetic particle confinement (i.e. Alfven eigenmode stability) in high-performance regimes that include steady-state and advanced tokamak scenarios. Furthermore, these systems are fully compatible with today's most challenging non-inductive heating and current drive systems and capable of operating in harsh environments, making them the ideal approach for diagnosing long-pulse and steady-state tokamaks.« less

DRS: Derivational Reasoning System

NASA Technical Reports Server (NTRS)

Bose, Bhaskar

1995-01-01

The high reliability requirements for airborne systems requires fault-tolerant architectures to address failures in the presence of physical faults, and the elimination of design flaws during the specification and validation phase of the design cycle. Although much progress has been made in developing methods to address physical faults, design flaws remain a serious problem. Formal methods provides a mathematical basis for removing design flaws from digital systems. DRS (Derivational Reasoning System) is a formal design tool based on advanced research in mathematical modeling and formal synthesis. The system implements a basic design algebra for synthesizing digital circuit descriptions from high level functional specifications. DRS incorporates an executable specification language, a set of correctness preserving transformations, verification interface, and a logic synthesis interface, making it a powerful tool for realizing hardware from abstract specifications. DRS integrates recent advances in transformational reasoning, automated theorem proving and high-level CAD synthesis systems in order to provide enhanced reliability in designs with reduced time and cost.

Interdisciplinary cantilever physics: Elasticity of carrot, celery, and plasticware

NASA Astrophysics Data System (ADS)

Pestka, Kenneth A.

2014-05-01

This article presents several simple cantilever-based experiments using common household items (celery, carrot, and a plastic spoon) that are appropriate for introductory undergraduate laboratories or independent student projects. By applying Hooke's law and Euler beam theory, students are able to determine Young's modulus, fracture stress, yield stress, strain energy, and sound speed of these apparently disparate materials. In addition, a cellular foam elastic model is introduced—applicable to biologic materials as well as an essential component in the development of advanced engineering composites—that provides a mechanism to determine Young's modulus of the cell wall material found in celery and carrot. These experiments are designed to promote exploration of the similarities and differences between common inorganic and organic materials, fill a void in the typical undergraduate curriculum, and provide a foundation for more advanced material science pursuits within biology, botany, and food science as well as physics and engineering.

Advanced life support study

NASA Technical Reports Server (NTRS)

1991-01-01

Summary reports on each of the eight tasks undertaken by this contract are given. Discussed here is an evaluation of a Closed Ecological Life Support System (CELSS), including modeling and analysis of Physical/Chemical Closed Loop Life Support (P/C CLLS); the Environmental Control and Life Support Systems (ECLSS) evolution - Intermodule Ventilation study; advanced technologies interface requirements relative to ECLSS; an ECLSS resupply analysis; the ECLSS module addition relocation systems engineering analysis; an ECLSS cost/benefit analysis to identify rack-level interface requirements of the alternate technologies evaluated in the ventilation study, with a comparison of these with the rack level interface requirements for the baseline technologies; advanced instrumentation - technology database enhancement; and a clean room survey and assessment of various ECLSS evaluation options for different growth scenarios.

MODEST: A Tool for Geodesy and Astronomy

NASA Technical Reports Server (NTRS)

Sovers, Ojars J.; Jacobs, Christopher S.; Lanyi, Gabor E.

2004-01-01

Features of the JPL VLBI modeling and estimation software "MODEST" are reviewed. Its main advantages include thoroughly documented model physics, portability, and detailed error modeling. Two unique models are included: modeling of source structure and modeling of both spatial and temporal correlations in tropospheric delay noise. History of the code parallels the development of the astrometric and geodetic VLBI technique and the software retains many of the models implemented during its advancement. The code has been traceably maintained since the early 1980s, and will continue to be updated with recent IERS standards. Scripts are being developed to facilitate user-friendly data processing in the era of e-VLBI.

Challenging the standard model by high-precision comparisons of the fundamental properties of protons and antiprotons

NASA Astrophysics Data System (ADS)

Ulmer, S.; Mooser, A.; Nagahama, H.; Sellner, S.; Smorra, C.

2018-03-01

The BASE collaboration investigates the fundamental properties of protons and antiprotons, such as charge-to-mass ratios and magnetic moments, using advanced cryogenic Penning trap systems. In recent years, we performed the most precise measurement of the magnetic moments of both the proton and the antiproton, and conducted the most precise comparison of the proton-to-antiproton charge-to-mass ratio. In addition, we have set the most stringent constraint on directly measured antiproton lifetime, based on a unique reservoir trap technique. Our matter/antimatter comparison experiments provide stringent tests of the fundamental charge-parity-time invariance, which is one of the fundamental symmetries of the standard model of particle physics. This article reviews the recent achievements of BASE and gives an outlook to our physics programme in the ELENA era. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

Challenging the standard model by high-precision comparisons of the fundamental properties of protons and antiprotons.

PubMed

Ulmer, S; Mooser, A; Nagahama, H; Sellner, S; Smorra, C

2018-03-28

The BASE collaboration investigates the fundamental properties of protons and antiprotons, such as charge-to-mass ratios and magnetic moments, using advanced cryogenic Penning trap systems. In recent years, we performed the most precise measurement of the magnetic moments of both the proton and the antiproton, and conducted the most precise comparison of the proton-to-antiproton charge-to-mass ratio. In addition, we have set the most stringent constraint on directly measured antiproton lifetime, based on a unique reservoir trap technique. Our matter/antimatter comparison experiments provide stringent tests of the fundamental charge-parity-time invariance, which is one of the fundamental symmetries of the standard model of particle physics. This article reviews the recent achievements of BASE and gives an outlook to our physics programme in the ELENA era.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Authors.

The need to advance nutrition education in the training of health care professionals and recommended research to evaluate implementation and effectiveness1234

PubMed Central

Kris-Etherton, Penny M; Akabas, Sharon R; Bales, Connie W; Bistrian, Bruce; Braun, Lynne; Edwards, Marilyn S; Laur, Celia; Lenders, Carine M; Levy, Matthew D; Palmer, Carole A; Pratt, Charlotte A; Ray, Sumantra; Rock, Cheryl L; Saltzman, Edward; Seidner, Douglas L; Van Horn, Linda

2014-01-01

Nutrition is a recognized determinant in 3 (ie, diseases of the heart, malignant neoplasms, cerebrovascular diseases) of the top 4 leading causes of death in the United States. However, many health care providers are not adequately trained to address lifestyle recommendations that include nutrition and physical activity behaviors in a manner that could mitigate disease development or progression. This contributes to a compelling need to markedly improve nutrition education for health care professionals and to establish curricular standards and requisite nutrition and physical activity competencies in the education, training, and continuing education for health care professionals. This article reports the present status of nutrition and physical activity education for health care professionals, evaluates the current pedagogic models, and underscores the urgent need to realign and synergize these models to reflect evidence-based and outcomes-focused education. PMID:24717343

Challenging the standard model by high-precision comparisons of the fundamental properties of protons and antiprotons

PubMed Central

Mooser, A.; Nagahama, H.; Sellner, S.; Smorra, C.

2018-01-01

The BASE collaboration investigates the fundamental properties of protons and antiprotons, such as charge-to-mass ratios and magnetic moments, using advanced cryogenic Penning trap systems. In recent years, we performed the most precise measurement of the magnetic moments of both the proton and the antiproton, and conducted the most precise comparison of the proton-to-antiproton charge-to-mass ratio. In addition, we have set the most stringent constraint on directly measured antiproton lifetime, based on a unique reservoir trap technique. Our matter/antimatter comparison experiments provide stringent tests of the fundamental charge–parity–time invariance, which is one of the fundamental symmetries of the standard model of particle physics. This article reviews the recent achievements of BASE and gives an outlook to our physics programme in the ELENA era. This article is part of the Theo Murphy meeting issue ‘Antiproton physics in the ELENA era’. PMID:29459414

Perspectives on Physical Activity Among People with Multiple Sclerosis Who Are Wheelchair Users

PubMed Central

Learmonth, Yvonne C.; Rice, Ian M.; Ostler, Teresa; Rice, Laura A.

2015-01-01

Background: People with advanced multiple sclerosis (MS) are less physically active than those with milder forms of the disease, and wheelchair use has a negative association with physical activity participation. Thus, wheelchair users with MS are doubly disadvantaged for accruing the benefits of physical activity and exercise. Appropriate physical activity and exercise interventions are needed for this population. Methods: We undertook a qualitative study to explore the meanings, motivations, and outcomes of physical activity in wheelchair users with MS. We sought to understand daily opportunities to accumulate physical activity and exercise, and to identify perceived barriers, facilitators, and benefits that might inform the design of future interventions. Results: We interviewed 15 wheelchair users (mean age, 52 ± 8.8 years; n = 12 women). Data were transcribed and analyzed to identify and explore common themes. Our first theme was the reduced opportunity to participate in physical activity due to participants' dependence on mobility devices, environmental adaptations, and tangible support. Our second theme was the importance of incorporating physical activity and exercise into the everyday environment, highlighting the need for adaptive exercise and accessible environments. This indicated the need to incorporate behavior change modulators into physical activity and exercise interventions for those with advanced MS. Health-care professionals played an important role in promoting increased physical activity and exercise participation in those with advanced MS. Conclusions: Our findings may inform future interventions to increase initiation and maintenance of physical activity and exercise among people with advanced MS. PMID:26052256

Higher-order chromatin structure: bridging physics and biology.

PubMed

Fudenberg, Geoffrey; Mirny, Leonid A

2012-04-01

Advances in microscopy and genomic techniques have provided new insight into spatial chromatin organization inside of the nucleus. In particular, chromosome conformation capture data has highlighted the relevance of polymer physics for high-order chromatin organization. In this context, we review basic polymer states, discuss how an appropriate polymer model can be determined from experimental data, and examine the success and limitations of various polymer models of higher-order interphase chromatin organization. By taking into account topological constraints acting on the chromatin fiber, recently developed polymer models of interphase chromatin can reproduce the observed scaling of distances between genomic loci, chromosomal territories, and probabilities of contacts between loci measured by chromosome conformation capture methods. Polymer models provide a framework for the interpretation of experimental data as ensembles of conformations rather than collections of loops, and will be crucial for untangling functional implications of chromosomal organization. Copyright © 2012 Elsevier Ltd. All rights reserved.

Higher order chromatin structure: bridging physics and biology

PubMed Central

Fudenberg, Geoffrey; Mirny, Leonid A.

2012-01-01

Recent advances in microscopy and genomic techniques have provided new insight into spatial chromatin organization inside of the nucleus. In particular, chromosome conformation capture data has highlighted the relevance of polymer physics for high-order chromatin organization. In this context, we review basic polymer states, discuss how an appropriate polymer model can be determined from experimental data, and examine the success and limitations of various polymer models of high-order interphase chromatin organization. By taking into account topological constraints acting on the chromatin fiber, recently-developed polymer models of interphase chromatin can reproduce the observed scaling of distances between genomic loci, chromosomal territories, and probabilities of contacts between loci measured by chromosome conformation capture methods. Polymer models provide a framework for the interpretation of experimental data as ensembles of conformations rather than collections of loops, and will be crucial for untangling functional implications of chromosomal organization. PMID:22360992

Computational Cosmology: From the Early Universe to the Large Scale Structure.

PubMed

Anninos, Peter

2001-01-01

In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations (and numerical methods applied to specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

Computational Cosmology: from the Early Universe to the Large Scale Structure.

PubMed

Anninos, Peter

1998-01-01

In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

Validating a Model for Welding Induced Residual Stress Using High-Energy X-ray Diffraction

NASA Astrophysics Data System (ADS)

Mach, J. C.; Budrow, C. J.; Pagan, D. C.; Ruff, J. P. C.; Park, J.-S.; Okasinski, J.; Beaudoin, A. J.; Miller, M. P.

2017-05-01

Integrated computational materials engineering (ICME) provides a pathway to advance performance in structures through the use of physically-based models to better understand how manufacturing processes influence product performance. As one particular challenge, consider that residual stresses induced in fabrication are pervasive and directly impact the life of structures. For ICME to be an effective strategy, it is essential that predictive capability be developed in conjunction with critical experiments. In the present work, simulation results from a multi-physics model for gas metal arc welding are evaluated through x-ray diffraction using synchrotron radiation. A test component was designed with intent to develop significant gradients in residual stress, be representative of real-world engineering application, yet remain tractable for finely spaced strain measurements with positioning equipment available at synchrotron facilities. The experimental validation lends confidence to model predictions, facilitating the explicit consideration of residual stress distribution in prediction of fatigue life.

Sleep Quality Prediction From Wearable Data Using Deep Learning.

PubMed

Sathyanarayana, Aarti; Joty, Shafiq; Fernandez-Luque, Luis; Ofli, Ferda; Srivastava, Jaideep; Elmagarmid, Ahmed; Arora, Teresa; Taheri, Shahrad

2016-11-04

The importance of sleep is paramount to health. Insufficient sleep can reduce physical, emotional, and mental well-being and can lead to a multitude of health complications among people with chronic conditions. Physical activity and sleep are highly interrelated health behaviors. Our physical activity during the day (ie, awake time) influences our quality of sleep, and vice versa. The current popularity of wearables for tracking physical activity and sleep, including actigraphy devices, can foster the development of new advanced data analytics. This can help to develop new electronic health (eHealth) applications and provide more insights into sleep science. The objective of this study was to evaluate the feasibility of predicting sleep quality (ie, poor or adequate sleep efficiency) given the physical activity wearable data during awake time. In this study, we focused on predicting good or poor sleep efficiency as an indicator of sleep quality. Actigraphy sensors are wearable medical devices used to study sleep and physical activity patterns. The dataset used in our experiments contained the complete actigraphy data from a subset of 92 adolescents over 1 full week. Physical activity data during awake time was used to create predictive models for sleep quality, in particular, poor or good sleep efficiency. The physical activity data from sleep time was used for the evaluation. We compared the predictive performance of traditional logistic regression with more advanced deep learning methods: multilayer perceptron (MLP), convolutional neural network (CNN), simple Elman-type recurrent neural network (RNN), long short-term memory (LSTM-RNN), and a time-batched version of LSTM-RNN (TB-LSTM). Deep learning models were able to predict the quality of sleep (ie, poor or good sleep efficiency) based on wearable data from awake periods. More specifically, the deep learning methods performed better than traditional logistic regression. “CNN had the highest specificity and sensitivity, and an overall area under the receiver operating characteristic (ROC) curve (AUC) of 0.9449, which was 46% better as compared with traditional logistic regression (0.6463). Deep learning methods can predict the quality of sleep based on actigraphy data from awake periods. These predictive models can be an important tool for sleep research and to improve eHealth solutions for sleep. ©Aarti Sathyanarayana, Shafiq Joty, Luis Fernandez-Luque, Ferda Ofli, Jaideep Srivastava, Ahmed Elmagarmid, Teresa Arora, Shahrad Taheri. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 04.11.2016.

Sleep Quality Prediction From Wearable Data Using Deep Learning

PubMed Central

Sathyanarayana, Aarti; Joty, Shafiq; Ofli, Ferda; Srivastava, Jaideep; Elmagarmid, Ahmed; Arora, Teresa; Taheri, Shahrad

2016-01-01

Background The importance of sleep is paramount to health. Insufficient sleep can reduce physical, emotional, and mental well-being and can lead to a multitude of health complications among people with chronic conditions. Physical activity and sleep are highly interrelated health behaviors. Our physical activity during the day (ie, awake time) influences our quality of sleep, and vice versa. The current popularity of wearables for tracking physical activity and sleep, including actigraphy devices, can foster the development of new advanced data analytics. This can help to develop new electronic health (eHealth) applications and provide more insights into sleep science. Objective The objective of this study was to evaluate the feasibility of predicting sleep quality (ie, poor or adequate sleep efficiency) given the physical activity wearable data during awake time. In this study, we focused on predicting good or poor sleep efficiency as an indicator of sleep quality. Methods Actigraphy sensors are wearable medical devices used to study sleep and physical activity patterns. The dataset used in our experiments contained the complete actigraphy data from a subset of 92 adolescents over 1 full week. Physical activity data during awake time was used to create predictive models for sleep quality, in particular, poor or good sleep efficiency. The physical activity data from sleep time was used for the evaluation. We compared the predictive performance of traditional logistic regression with more advanced deep learning methods: multilayer perceptron (MLP), convolutional neural network (CNN), simple Elman-type recurrent neural network (RNN), long short-term memory (LSTM-RNN), and a time-batched version of LSTM-RNN (TB-LSTM). Results Deep learning models were able to predict the quality of sleep (ie, poor or good sleep efficiency) based on wearable data from awake periods. More specifically, the deep learning methods performed better than traditional linear regression. CNN had the highest specificity and sensitivity, and an overall area under the receiver operating characteristic (ROC) curve (AUC) of 0.9449, which was 46% better as compared with traditional linear regression (0.6463). Conclusions Deep learning methods can predict the quality of sleep based on actigraphy data from awake periods. These predictive models can be an important tool for sleep research and to improve eHealth solutions for sleep. PMID:27815231

Advanced Electronics

DTIC Science & Technology

2017-07-21

Technology Branch (RVSW) is conducting a first time experimental and theoretical investigation focused on evaluating new physical phenomena in the quasi ...bandgap energy, are formulated in our microscopic model for explaining the experimentally observed enhancements in both conduction- and valence... experimental and theoretical study on the nature of carrier transport, of both electrons and holes, through narrow constricted crystalline Si “wall

Laser Measurement of Optical Errors of the Eye

ERIC Educational Resources Information Center

Colicchia, Giuseppe; Wiesner, Hartmut

2006-01-01

One way to motivate students' interest in physics is to teach it in the context of medicine. Optics, for example, can be taught with examples from the eye. For many years simple optics of lenses has been taught using a model of the eye. However, recent advances in using lasers for ophthalmological (ocular) examinations can be used to increase…

Use of Advanced Spectroscopic Techniques for Predicting the Mechanical Properties of Wood Composites

Treesearch

Timothy G. Rials; Stephen S. Kelley; Chi-Leung So

2002-01-01

Near infrared (NIR) spectroscopy was used to characterize a set of medium-density fiberboard (MDF) samples. This spectroscopic technique, in combination with projection to latent structures (PLS) modeling, effectively predicted the mechanical strength of MDF samples with a wide range of physical properties. The stiffness, strength, and internal bond properties of the...

A Child Constructs an Understanding of a Water Wheel in Five Media.

ERIC Educational Resources Information Center

Forman, George

1996-01-01

Presents case study of a child trying to represent and understand the water wheel as an example of knowledge construction from the constructivism perspective. Focuses on how his understanding of physical perspective taking advances through conflicts in the use of different media (telling, drawing, paper, clay, or wood model) and how the Reggio…

Innovation in prediction planning for anterior open bite correction.

PubMed

Almuzian, Mohammed; Almukhtar, Anas; O'Neil, Michael; Benington, Philip; Al Anezi, Thamer; Ayoub, Ashraf

2015-05-01

This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical correction of a case.

Near-earth orbital guidance and remote sensing

NASA Technical Reports Server (NTRS)

Powers, W. F.

1972-01-01

The curriculum of a short course in remote sensing and parameter optimization is presented. The subjects discussed are: (1) basics of remote sensing and the user community, (2) multivariant spectral analysis, (3) advanced mathematics and physics of remote sensing, (4) the atmospheric environment, (5) imaging sensing, and (6)nonimaging sensing. Mathematical models of optimization techniques are developed.

Advances in modeling aerodynamic decelerator dynamics.

NASA Technical Reports Server (NTRS)

Whitlock, C. H.

1973-01-01

The Viking entry vehicle uses a lines-first type of deployment in which the parachute, packed in a deployment bag, gets ejected rearward from the vehicle by a mortar. As the bag moves rearward, first the lines are unfurled and then the canopy. An analysis of the unfurling process is conducted, giving attention to longitudinal and rotational dynamics. It is shown that analytical modeling of aerodynamic systems provides significant information for a better understanding of the physics of the deployment process.

Where the girls aren't: High school girls and advanced placement physics enrollment

NASA Astrophysics Data System (ADS)

Barton, Susan O'brien

During the high school years, when many students first have some choice in course selection, research indicates that girls choose to enroll in more math and science courses, take more advanced placement courses, and take more honors courses in English, biology, chemistry, mathematics, and foreign languages than ever before. Yet, not only are boys more likely to take all of the three core science courses (biology, chemistry, and physics), boys enroll in advanced placement physics approximately three times as often as do girls. This study examines the perceptions, attitudes, and aspirations of thirty high school girls enrolled in senior-level science electives in an attempt to understand their high school science course choices, and what factors were influencing them. This is a qualitative investigation employing constructivist grounded theory methods. There are two main contributions of this study. First, it presents a new conceptual and analytical framework to investigate the problem of why some high school girls do not enroll in physics coursework. This framework is grounded in the data and is comprised of three existing feminist perspectives along the liberal/radical continuum of feminist thought. Second, this study illuminates a complex set of reasons why participants avoided high school physics (particularly advanced placement physics) coursework. These reasons emerged as three broad categories related to: (a) a lack of connectedness with physics curriculum and instruction; (b) prior negative experiences with physics and math classroom climates; and (c) future academic goals and career aspirations. Taken together, the findings of this study indicate that the problem of high school girls and physics enrollment---particularly advanced placement physics enrollment---is a problem that cannot be evaluated or considered from one perspective.

Artificial heart development program. Volume I. System development. Phase III summary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1977-01-01

The report documents efforts and results in the development of the power system portions of a calf implantable model of nuclear-powered artificial heart. The primary objective in developing the implantable model was to solve the packaging problems for total system implantation. The power systems portion is physically that portion of the implantable model between the Pu-238 heat sources and the blood pump ventricles. The work performed had two parallel themes. The first of these was the development of an integrated implantable model for bench and animal experiments plus design effort on a more advanced model. The second was research andmore » development on components of the system done in conjunction with the development of the implantable model and to provide technology for incorporation into advanced models plus support to implantations, at the University of Utah, of the systems blood pumping elements when driven by electric motor. The efforts and results of implantable model development are covered, mainly, in the text of the report. The research and development efforts and results are reported, primarily, in the appendices (Vol. 2).« less

Advances in Computational Capabilities for Hypersonic Flows

NASA Technical Reports Server (NTRS)

Kumar, Ajay; Gnoffo, Peter A.; Moss, James N.; Drummond, J. Philip

1997-01-01

The paper reviews the growth and advances in computational capabilities for hypersonic applications over the period from the mid-1980's to the present day. The current status of the code development issues such as surface and field grid generation, algorithms, physical and chemical modeling, and validation is provided. A brief description of some of the major codes being used at NASA Langley Research Center for hypersonic continuum and rarefied flows is provided, along with their capabilities and deficiencies. A number of application examples are presented, and future areas of research to enhance accuracy, reliability, efficiency, and robustness of computational codes are discussed.

Optimization of Ballast Design: A Case Study of the Physics Entrepreneurship Program

NASA Astrophysics Data System (ADS)

Ding, Jun; Cheng, Norman; Lamouri, Abbas; Sulcs, Juris; Brown, Robert; Taylor, Cyrus

2001-10-01

This talk presents a typical internship project for students in the Physics Entrepreneurship Program at Case Western Reserve University. As part of their overall strategy, Advanced Lighting International (ADLT) is involved in the production of magnetic ballasts for metal halide lamps. The systems in which these ballasts function is undergoing rapid evolution, leading to the question of how the design of the ballasts can be optimized in order to deliver superior performance for lower cost. Addressing this question requires a full understanding of a variety of issues ranging from the basic modeling of the physics of the magnetic ballasts to questions of overall market strategy, manufacturing considerations, and the competitive environment.

Physics-based scoring of protein-ligand interactions: explicit polarizability, quantum mechanics and free energies.

PubMed

Bryce, Richard A

2011-04-01

The ability to accurately predict the interaction of a ligand with its receptor is a key limitation in computer-aided drug design approaches such as virtual screening and de novo design. In this article, we examine current strategies for a physics-based approach to scoring of protein-ligand affinity, as well as outlining recent developments in force fields and quantum chemical techniques. We also consider advances in the development and application of simulation-based free energy methods to study protein-ligand interactions. Fuelled by recent advances in computational algorithms and hardware, there is the opportunity for increased integration of physics-based scoring approaches at earlier stages in computationally guided drug discovery. Specifically, we envisage increased use of implicit solvent models and simulation-based scoring methods as tools for computing the affinities of large virtual ligand libraries. Approaches based on end point simulations and reference potentials allow the application of more advanced potential energy functions to prediction of protein-ligand binding affinities. Comprehensive evaluation of polarizable force fields and quantum mechanical (QM)/molecular mechanical and QM methods in scoring of protein-ligand interactions is required, particularly in their ability to address challenging targets such as metalloproteins and other proteins that make highly polar interactions. Finally, we anticipate increasingly quantitative free energy perturbation and thermodynamic integration methods that are practical for optimization of hits obtained from screened ligand libraries.

Probabilistic short-term forecasting of eruption rate at Kīlauea Volcano using a physics-based model

NASA Astrophysics Data System (ADS)

Anderson, K. R.

2016-12-01

Deterministic models of volcanic eruptions yield predictions of future activity conditioned on uncertainty in the current state of the system. Physics-based eruption models are well-suited for deterministic forecasting as they can relate magma physics with a wide range of observations. Yet, physics-based eruption forecasting is strongly limited by an inadequate understanding of volcanic systems, and the need for eruption models to be computationally tractable. At Kīlauea Volcano, Hawaii, episodic depressurization-pressurization cycles of the magma system generate correlated, quasi-exponential variations in ground deformation and surface height of the active summit lava lake. Deflations are associated with reductions in eruption rate, or even brief eruptive pauses, and thus partly control lava flow advance rates and associated hazard. Because of the relatively well-understood nature of Kīlauea's shallow magma plumbing system, and because more than 600 of these events have been recorded to date, they offer a unique opportunity to refine a physics-based effusive eruption forecasting approach and apply it to lava eruption rates over short (hours to days) time periods. A simple physical model of the volcano ascribes observed data to temporary reductions in magma supply to an elastic reservoir filled with compressible magma. This model can be used to predict the evolution of an ongoing event, but because the mechanism that triggers events is unknown, event durations are modeled stochastically from previous observations. A Bayesian approach incorporates diverse data sets and prior information to simultaneously estimate uncertain model parameters and future states of the system. Forecasts take the form of probability distributions for eruption rate or cumulative erupted volume at some future time. Results demonstrate the significant uncertainties that still remain even for short-term eruption forecasting at a well-monitored volcano - but also the value of a physics-based, mixed deterministic-probabilistic eruption forecasting approach in reducing and quantifying these uncertainties.

Project T.E.A.M. (Technical Education Advancement Modules). Introduction to Industrial Physics.

ERIC Educational Resources Information Center

Whisenhunt, James E.

This instructional guide, one of a series developed by the Technical Education Advancement Modules (TEAM) project, is a 20-hour introduction to industrial physics that explains and demonstrates to industrial maintenance mechanics the direct relationship of physics to machinery. Project TEAM is intended to upgrade basic technical competencies of…

America COMPETES Act and the FY2010 Budget

DTIC Science & Technology

2009-06-29

Outstanding Junior Investigator, Fusion Energy Sciences Plasma Physics Junior Faculty Development; Advanced Scientific Computing Research Early Career...the Fusion Energy Sciences Graduate Fellowships.2 If members of Congress agree with this contention, these America COMPETES Act programs were...Physics Outstanding Junior Investigator, Fusion Energy Sciences Plasma Physics Junior Faculty Development; Advanced Scientific Computing Research Early

Model-assisted probability of detection of flaws in aluminum blocks using polynomial chaos expansions

NASA Astrophysics Data System (ADS)

Du, Xiaosong; Leifsson, Leifur; Grandin, Robert; Meeker, William; Roberts, Ronald; Song, Jiming

2018-04-01

Probability of detection (POD) is widely used for measuring reliability of nondestructive testing (NDT) systems. Typically, POD is determined experimentally, while it can be enhanced by utilizing physics-based computational models in combination with model-assisted POD (MAPOD) methods. With the development of advanced physics-based methods, such as ultrasonic NDT testing, the empirical information, needed for POD methods, can be reduced. However, performing accurate numerical simulations can be prohibitively time-consuming, especially as part of stochastic analysis. In this work, stochastic surrogate models for computational physics-based measurement simulations are developed for cost savings of MAPOD methods while simultaneously ensuring sufficient accuracy. The stochastic surrogate is used to propagate the random input variables through the physics-based simulation model to obtain the joint probability distribution of the output. The POD curves are then generated based on those results. Here, the stochastic surrogates are constructed using non-intrusive polynomial chaos (NIPC) expansions. In particular, the NIPC methods used are the quadrature, ordinary least-squares (OLS), and least-angle regression sparse (LARS) techniques. The proposed approach is demonstrated on the ultrasonic testing simulation of a flat bottom hole flaw in an aluminum block. The results show that the stochastic surrogates have at least two orders of magnitude faster convergence on the statistics than direct Monte Carlo sampling (MCS). Moreover, the evaluation of the stochastic surrogate models is over three orders of magnitude faster than the underlying simulation model for this case, which is the UTSim2 model.

Formulating physical processes in a full-range model of soil water retention

NASA Astrophysics Data System (ADS)

Nimmo, J. R.

2016-12-01

Currently-used water retention models vary in how much their formulas correspond to controlling physical processes such as capillarity, adsorption, and air-trapping. In model development, realistic correspondence to physical processes has often been a lower priority than ease of use and compatibility with other models. For example, the wettest range is normally represented simplistically, as by a straight line of zero slope, or by default using the same formulation as for the middle range. The new model presented here recognizes dominant processes within three segments of the range from oven-dryness to saturation. The adsorption-dominated dry range is represented by a logarithmic relation used in earlier models. The middle range of capillary advance/retreat and Haines jumps is represented by a new adaptation of the lognormal distribution function. In the wet range, the expansion of trapped air in response to matric pressure change is important because (1) it displaces water, and (2) it triggers additional volume-adjusting processes such as the collapse of liquid bridges between air pockets. For this range, the model incorporates the Boyles' law inverse-proportionality of trapped air volume and pressure, amplified by an empirical factor to account for the additional processes. With their basis in processes, the model's parameters have a strong physical interpretation, and in many cases can be assigned values from knowledge of fundamental relationships or individual measurements. An advantage of the physically-plausible treatment of the wet range is that it avoids such problems as the blowing-up of derivatives on approach to saturation, enhancing the model's utility for important but challenging wet-range phenomena such as domain exchange between preferential flow paths and soil matrix. Further development might be able to accommodate hysteresis by a systematic adjustment of the relation between the wet and middle ranges.

Challenges to modeling the Sun-Earth System: A Workshop Summary

NASA Technical Reports Server (NTRS)

Spann, James F.

2006-01-01

This special issue of the Journal of' Atmospheric and Solar-Terrestrial Physics is a compilation of 23 papers presented at The 2004 Huntsville Modeling Workshop: Challenges to Modeling thc San-Earth System held in Huntsville, AB on October 18-22, 2004. The title of the workshop appropriately captures the theme of what was presented and discussed by the 120 participants. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA living with a star (LWS) programs. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales inn time and space. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress

Fast neural network surrogates for very high dimensional physics-based models in computational oceanography.

PubMed

van der Merwe, Rudolph; Leen, Todd K; Lu, Zhengdong; Frolov, Sergey; Baptista, Antonio M

2007-05-01

We present neural network surrogates that provide extremely fast and accurate emulation of a large-scale circulation model for the coupled Columbia River, its estuary and near ocean regions. The circulation model has O(10(7)) degrees of freedom, is highly nonlinear and is driven by ocean, atmospheric and river influences at its boundaries. The surrogates provide accurate emulation of the full circulation code and run over 1000 times faster. Such fast dynamic surrogates will enable significant advances in ensemble forecasts in oceanography and weather.

Extinct radioactivities - A three-phase mixing model. [for early solar system abundances

NASA Technical Reports Server (NTRS)

Clayton, D. D.

1983-01-01

A new class of models is advanced for interpreting the relationship of radioactive abundances in the early solar system to their average concentration in the interstellar medium. The model assumes that fresh radioactivities are ejected from supernovae into the hot interstellar medium, and that the time scales for changes of phase into molecular clouds determine how much survives for formation therein of the solar system. A more realistic and physically motivated understanding of the low observed concentrations of I-129, Pu-244, and Pd-107 may result.

Nowcasting recreational water quality

USGS Publications Warehouse

Boehm, Alexandria B.; Whitman, Richard L.; Nevers, Meredith; Hou, Deyi; Weisberg, Stephen B.

2007-01-01

Advances in molecular techniques may soon provide new opportunities to provide more timely information on whether recreational beaches are free from fecal contamination. However, an alternative approach is the use of predictive models. This chapter presents a summary of these developing efforts. First, we describe documented physical, chemical, and biological factors that have been demonstrated by researchers to affect bacterial concentrations at beaches and thus represent logical parameters for inclusion in a model. Then, we illustrate how various types of models can be applied to predict water quality at freshwater and marine beaches.

Slow Solar Wind: Observations and Modeling

NASA Technical Reports Server (NTRS)

Abbo, L.; Ofman, L.; Antiochos, S. K.; Hansteen, V. H.; Harra, L.; Ko, Y.-K.; Lapenta, G.; Li, B.; Riley, P.; Strachan, L.;

Advanced analytical modeling of double-gate Tunnel-FETs - A performance evaluation

NASA Astrophysics Data System (ADS)

Graef, Michael; Hosenfeld, Fabian; Horst, Fabian; Farokhnejad, Atieh; Hain, Franziska; Iñíguez, Benjamín; Kloes, Alexander

2018-03-01

The Tunnel-FET is one of the most promising devices to be the successor of the standard MOSFET due to its alternative current transport mechanism, which allows a smaller subthreshold slope than the physically limited 60 mV/dec of the MOSFET. Recently fabricated devices show smaller slopes already but mostly not over multiple decades of the current transfer characteristics. In this paper the performance limiting effects, occurring during the fabrication process of the device, such as doping profiles and midgap traps are analyzed by physics-based analytical models and their performance limiting abilities are determined. Additionally, performance enhancing possibilities, such as hetero-structures and ambipolarity improvements are introduced and discussed. An extensive double-gate n-Tunnel-FET model is presented, which meets the versatile device requirements and shows a good fit with TCAD simulations and measurement data.

Numerical Ergonomics Analysis in Operation Environment of CNC Machine

NASA Astrophysics Data System (ADS)

Wong, S. F.; Yang, Z. X.

2010-05-01

The performance of operator will be affected by different operation environments [1]. Moreover, poor operation environment may cause health problems of the operator [2]. Physical and psychological considerations are two main factors that will affect the performance of operator under different conditions of operation environment. In this paper, applying scientific and systematic methods find out the pivot elements in the field of physical and psychological factors. There are five main factors including light, temperature, noise, air flow and space that are analyzed. A numerical ergonomics model has been built up regarding the analysis results which can support to advance the design of operation environment. Moreover, the output of numerical ergonomic model can provide the safe, comfortable, more productive conditions for the operator.

Radiation Oncology Physics and Medical Physics Education

NASA Astrophysics Data System (ADS)

Bourland, Dan

2011-10-01

Medical physics, an applied field of physics, is the applications of physics in medicine. Medical physicists are essential professionals in contemporary healthcare, contributing primarily to the diagnosis and treatment of diseases through numerous inventions, advances, and improvements in medical imaging and cancer treatment. Clinical service, research, and teaching by medical physicists benefits thousands of patients and other individuals every day. This talk will cover three main topics. First, exciting current research and development areas in the medical physics sub-specialty of radiation oncology physics will be described, including advanced oncology imaging for treatment simulation, image-guided radiation therapy, and biologically-optimized radiation treatment. Challenges in patient safety in high-technology radiation treatments will be briefly reviewed. Second, the educational path to becoming a medical physicist will be reviewed, including undergraduate foundations, graduate training, residency, board certification, and career opportunities. Third, I will introduce the American Association of Physicists in Medicine (AAPM), which is the professional society that represents, advocates, and advances the field of medical physics (www.aapm.org).

Advances in modelling of condensation phenomena

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, W.S.; Zaltsgendler, E.; Hanna, B.

1997-07-01

The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUFmore » are described.« less

Physical activity in advanced cancer patients: a systematic review protocol.

PubMed

Lowe, Sonya S; Tan, Maria; Faily, Joan; Watanabe, Sharon M; Courneya, Kerry S

2016-03-11

Progressive, incurable cancer is associated with increased fatigue, increased muscle weakness, and reduced physical functioning, all of which negatively impact quality of life. Physical activity has demonstrated benefits on cancer-related fatigue and physical functioning in early-stage cancer patients; however, its impact on these outcomes in end-stage cancer has not been established. The aim of this systematic review is to determine the potential benefits, harms, and effects of physical activity interventions on quality of life outcomes in advanced cancer patients. A systematic review of peer-reviewed literature on physical activity in advanced cancer patients will be undertaken. Empirical quantitative studies will be considered for inclusion if they present interventional or observational data on physical activity in advanced cancer patients. Searches will be conducted in the following electronic databases: CINAHL; CIRRIE Database of International Rehabilitation Research; Cochrane Database of Systematic Reviews (CDSR); Database of Abstracts of Reviews of Effects (DARE); Cochrane Central Register of Controlled Trials (CENTRAL); EMBASE; MEDLINE; PEDro: the Physiotherapy Evidence Database; PQDT; PsycInfo; PubMed; REHABDATA; Scopus; SPORTDiscus; and Web of Science, to identify relevant studies of interest. Additional strategies to identify relevant studies will include citation searches and evaluation of reference lists of included articles. Titles, abstracts, and keywords of identified studies from the search strategies will be screened for inclusion criteria. Two independent reviewers will conduct quality appraisal using the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies (EPHPP) and the Cochrane risk of bias tool. A descriptive summary of included studies will describe the study designs, participant and activity characteristics, and objective and patient-reported outcomes. This systematic review will summarize the current evidence base on physical activity interventions in advanced cancer patients. The findings from this systematic review will identify gaps to be explored by future research studies and inform future practice guideline development of physical activity interventions in advanced cancer patients. PROSPERO CRD42015026281.

The isotopic and chemical evolution of planets: Mars as a missing link

NASA Technical Reports Server (NTRS)

Depaolo, D. J.

1988-01-01

The study of planetary bodies has advanced to a stage where it is possible to contemplate general models for the chemical and physical evolution of planetary interiors, which might be referred to as UMPES (Unified Models of Planetary Evolution and Structure). UMPES would be able to predict the internal evolution and structure of a planet given certain input parameters such as mass, distance from the sun, and a time scale for accretion. Such models are highly dependent on natural observations because the basic material properties of planetary interiors, and the processes that take place during the evolution of planets are imperfectly understood. The idea of UMPES was particularly unrealistic when the only information available was from the earth. However, advances have been made in the understanding of the general aspects of planetary evolution now that there is geochemical and petrological data available for the moon and for meteorites.

Advanced diffusion MRI and biomarkers in the central nervous system: a new approach.

PubMed

Martín Noguerol, T; Martínez Barbero, J P

The introduction of diffusion-weighted sequences has revolutionized the detection and characterization of central nervous system (CNS) disease. Nevertheless, the assessment of diffusion studies of the CNS is often limited to qualitative estimation. Moreover, the pathophysiological complexity of the different entities that affect the CNS cannot always be correctly explained through classical models. The development of new models for the analysis of diffusion sequences provides numerous parameters that enable a quantitative approach to both diagnosis and prognosis as well as to monitoring the response to treatment; these parameters can be considered potential biomarkers of health and disease. In this update, we review the physical bases underlying diffusion studies and diffusion tensor imaging, advanced models for their analysis (intravoxel coherent motion and kurtosis), and the biological significance of the parameters derived. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Getting quantitative about consequences of cross-ecosystem resource subsidies on recipient consumers

USGS Publications Warehouse

Richardson, John S.; Wipfli, Mark S.

2016-01-01

Most studies of cross-ecosystem resource subsidies have demonstrated positive effects on recipient consumer populations, often with very large effect sizes. However, it is important to move beyond these initial addition–exclusion experiments to consider the quantitative consequences for populations across gradients in the rates and quality of resource inputs. In our introduction to this special issue, we describe at least four potential models that describe functional relationships between subsidy input rates and consumer responses, most of them asymptotic. Here we aim to advance our quantitative understanding of how subsidy inputs influence recipient consumers and their communities. In the papers following, fish were either the recipient consumers or the subsidy as carcasses of anadromous species. Advancing general, predictive models will enable us to further consider what other factors are potentially co-limiting (e.g., nutrients, other population interactions, physical habitat, etc.) and better integrate resource subsidies into consumer–resource, biophysical dynamics models.

Large Eddy Simulation of High Reynolds Number Complex Flows

NASA Astrophysics Data System (ADS)

Verma, Aman

Marine configurations are subject to a variety of complex hydrodynamic phenomena affecting the overall performance of the vessel. The turbulent flow affects the hydrodynamic drag, propulsor performance and structural integrity, control-surface effectiveness, and acoustic signature of the marine vessel. Due to advances in massively parallel computers and numerical techniques, an unsteady numerical simulation methodology such as Large Eddy Simulation (LES) is well suited to study such complex turbulent flows whose Reynolds numbers (Re) are typically on the order of 10. 6. LES also promises increasedaccuracy over RANS based methods in predicting unsteady phenomena such as cavitation and noise production. This dissertation develops the capability to enable LES of high Re flows in complex geometries (e.g. a marine vessel) on unstructured grids and provide physical insight into the turbulent flow. LES is performed to investigate the geometry induced separated flow past a marine propeller attached to a hull, in an off-design condition called crashback. LES shows good quantitative agreement with experiments and provides a physical mechanism to explain the increase in side-force on the propeller blades below an advance ratio of J=-0.7. Fundamental developments in the dynamic subgrid-scale model for LES are pursued to improve the LES predictions, especially for complex flows on unstructured grids. A dynamic procedure is proposed to estimate a Lagrangian time scale based on a surrogate correlation without any adjustable parameter. The proposed model is applied to turbulent channel, cylinder and marine propeller flows and predicts improved results over other model variants due to a physically consistent Lagrangian time scale. A wall model is proposed for application to LES of high Reynolds number wall-bounded flows. The wall model is formulated as the minimization of a generalized constraint in the dynamic model for LES and applied to LES of turbulent channel flow at various Reynolds numbers up to Reτ=10000 and coarse grid resolutions to obtain significant improvement.

Averaging Theory for Description of Environmental Problems: What Have We Learned?

PubMed Central

Miller, Cass T.; Schrefler, Bernhard A.

2012-01-01

Advances in Water Resources has been a prime archival source for implementation of averaging theories in changing the scale at which processes of importance in environmental modeling are described. Thus in celebration of the 35th year of this journal, it seems appropriate to assess what has been learned about these theories and about their utility in describing systems of interest. We review advances in understanding and use of averaging theories to describe porous medium flow and transport at the macroscale, an averaged scale that models spatial variability, and at the megascale, an integral scale that only considers time variation of system properties. We detail physical insights gained from the development and application of averaging theory for flow through porous medium systems and for the behavior of solids at the macroscale. We show the relationship between standard models that are typically applied and more rigorous models that are derived using modern averaging theory. We discuss how the results derived from averaging theory that are available can be built upon and applied broadly within the community. We highlight opportunities and needs that exist for collaborations among theorists, numerical analysts, and experimentalists to advance the new classes of models that have been derived. Lastly, we comment on averaging developments for rivers, estuaries, and watersheds. PMID:23393409

Modeling North Atlantic Nor'easters With Modern Wave Forecast Models

NASA Astrophysics Data System (ADS)

Perrie, Will; Toulany, Bechara; Roland, Aron; Dutour-Sikiric, Mathieu; Chen, Changsheng; Beardsley, Robert C.; Qi, Jianhua; Hu, Yongcun; Casey, Michael P.; Shen, Hui

2018-01-01

Three state-of-the-art operational wave forecast model systems are implemented on fine-resolution grids for the Northwest Atlantic. These models are: (1) a composite model system consisting of SWAN implemented within WAVEWATCHIII® (the latter is hereafter, WW3) on a nested system of traditional structured grids, (2) an unstructured grid finite-volume wave model denoted "SWAVE," using SWAN physics, and (3) an unstructured grid finite element wind wave model denoted as "WWM" (for "wind wave model") which uses WW3 physics. Models are implemented on grid systems that include relatively large domains to capture the wave energy generated by the storms, as well as including fine-resolution nearshore regions of the southern Gulf of Maine with resolution on the scale of 25 m to simulate areas where inundation and coastal damage have occurred, due to the storms. Storm cases include three intense midlatitude cases: a spring Nor'easter storm in May 2005, the Patriot's Day storm in 2007, and the Boxing Day storm in 2010. Although these wave model systems have comparable overall properties in terms of their performance and skill, it is found that there are differences. Models that use more advanced physics, as presented in recent versions of WW3, tuned to regional characteristics, as in the Gulf of Maine and the Northwest Atlantic, can give enhanced results.

Discovering the nature of advanced nursing practice in high dependency care: a critical care nurse consultant's experience.

PubMed

Fairley, Debra

2005-06-01

This paper describes how a critical care nurse consultant's clinical role has evolved within a surgical high dependency unit (SHDU) in a large teaching hospitals trust. In order to provide some background to role development, an overview of the research exploring the nature of advanced nursing practice in the context of critical care will be presented. From the outset, advanced nursing practice was not perceived as the acquisition and application of technical procedures usually undertaken by doctors, but possibly an integration of medicine and nursing where holistic nursing assessment is combined with symptom-focused physical examination. A reflective account of practical problems encountered relating to role integration, professional autonomy, legal and consent issues, non-medical prescribing, and role evaluation will be presented. A model of working that can be applied to high dependency units, integrating the role of the advanced nurse practitioner within the clinical team, will be described.

Model-Based Diagnostics for Propellant Loading Systems

NASA Technical Reports Server (NTRS)

Daigle, Matthew John; Foygel, Michael; Smelyanskiy, Vadim N.

2011-01-01

The loading of spacecraft propellants is a complex, risky operation. Therefore, diagnostic solutions are necessary to quickly identify when a fault occurs, so that recovery actions can be taken or an abort procedure can be initiated. Model-based diagnosis solutions, established using an in-depth analysis and understanding of the underlying physical processes, offer the advanced capability to quickly detect and isolate faults, identify their severity, and predict their effects on system performance. We develop a physics-based model of a cryogenic propellant loading system, which describes the complex dynamics of liquid hydrogen filling from a storage tank to an external vehicle tank, as well as the influence of different faults on this process. The model takes into account the main physical processes such as highly nonequilibrium condensation and evaporation of the hydrogen vapor, pressurization, and also the dynamics of liquid hydrogen and vapor flows inside the system in the presence of helium gas. Since the model incorporates multiple faults in the system, it provides a suitable framework for model-based diagnostics and prognostics algorithms. Using this model, we analyze the effects of faults on the system, derive symbolic fault signatures for the purposes of fault isolation, and perform fault identification using a particle filter approach. We demonstrate the detection, isolation, and identification of a number of faults using simulation-based experiments.

Leading institutional change: Implementing Studio in physics and beyond

NASA Astrophysics Data System (ADS)

Kohl, Patrick; Kuo, H. Vincent

2013-04-01

The Colorado School of Mines (CSM) teaches its first-year calculus-based introductory physics courses (Physics I and Physics II) using a hybrid of lecture and Studio physics. This model was first implemented in Physics I in 1997, and was established in Physics II in the fall of 2007. In this talk, we highlight the stages of the transformation from traditional to Studio, highlighting what has worked and what has not, and describing methods for assessment and evaluation. Results suggest that Studio has increased student performance and satisfaction despite an aggressive expansion of class sizes in the past few years. Gains have been concentrated mostly in problem-solving skills and exam performance (as opposed to conceptual survey gains), in contrast to what has sometimes been seen in other studies. Most recently, we as a department have been capitalizing on our successes with Studio physics to take a leadership role in disseminating advanced educational methods throughout CSM, both vertically (into upper division physics courses) and horizontally (into various departments outside of physics). We will briefly describe progress so far.

Introduction: Cardiovascular physics

NASA Astrophysics Data System (ADS)

Wessel, Niels; Kurths, Jürgen; Ditto, William; Bauernschmitt, Robert

2007-03-01

The number of patients suffering from cardiovascular diseases increases unproportionally high with the increase of the human population and aging, leading to very high expenses in the public health system. Therefore, the challenge of cardiovascular physics is to develop high-sophisticated methods which are able to, on the one hand, supplement and replace expensive medical devices and, on the other hand, improve the medical diagnostics with decreasing the patient's risk. Cardiovascular physics-which interconnects medicine, physics, biology, engineering, and mathematics-is based on interdisciplinary collaboration of specialists from the above scientific fields and attempts to gain deeper insights into pathophysiology and treatment options. This paper summarizes advances in cardiovascular physics with emphasis on a workshop held in Bad Honnef, Germany, in May 2005. The meeting attracted an interdisciplinary audience and led to a number of papers covering the main research fields of cardiovascular physics, including data analysis, modeling, and medical application. The variety of problems addressed by this issue underlines the complexity of the cardiovascular system. It could be demonstrated in this Focus Issue, that data analyses and modeling methods from cardiovascular physics have the ability to lead to significant improvements in different medical fields. Consequently, this Focus Issue of Chaos is a status report that may invite all interested readers to join the community and find competent discussion and cooperation partners.

Physical Analytics: An emerging field with real-world applications and impact

NASA Astrophysics Data System (ADS)

Hamann, Hendrik

2015-03-01

In the past most information on the internet has been originated by humans or computers. However with the emergence of cyber-physical systems, vast amount of data is now being created by sensors from devices, machines etc digitizing the physical world. While cyber-physical systems are subject to active research around the world, the vast amount of actual data generated from the physical world has attracted so far little attention from the engineering and physics community. In this presentation we use examples to highlight the opportunities in this new subject of ``Physical Analytics'' for highly inter-disciplinary research (including physics, engineering and computer science), which aims understanding real-world physical systems by leveraging cyber-physical technologies. More specifically, the convergence of the physical world with the digital domain allows applying physical principles to everyday problems in a much more effective and informed way than what was possible in the past. Very much like traditional applied physics and engineering has made enormous advances and changed our lives by making detailed measurements to understand the physics of an engineered device, we can now apply the same rigor and principles to understand large-scale physical systems. In the talk we first present a set of ``configurable'' enabling technologies for Physical Analytics including ultralow power sensing and communication technologies, physical big data management technologies, numerical modeling for physical systems, machine learning based physical model blending, and physical analytics based automation and control. Then we discuss in detail several concrete applications of Physical Analytics ranging from energy management in buildings and data centers, environmental sensing and controls, precision agriculture to renewable energy forecasting and management.

The Use of 3D Printing Technology in the Ilizarov Method Treatment: Pilot Study.

PubMed

Burzyńska, Karolina; Morasiewicz, Piotr; Filipiak, Jarosław

2016-01-01

Significant developments in additive manufacturing technology have occurred in recent years. 3D printing techniques can also be helpful in the Ilizarov method treatment. The aim of this study was to evaluate the usefulness of 3D printing technology in the Ilizarov method treatment. Physical models of bones used to plan the spatial design of Ilizarov external fixator were manufactured by FDM (Fused Deposition Modeling) spatial printing technology. Bone models were made of poly(L-lactide) (PLA). Printed 3D models of both lower leg bones allow doctors to prepare in advance for the Ilizarov method treatment: detailed consideration of the spatial configuration of the external fixation, experimental assembly of the Ilizarov external fixator onto the physical models of bones prior to surgery, planning individual osteotomy level and Kirschner wires introduction sites. Printed 3D bone models allow for accurate preparation of the Ilizarov apparatus spatially matched to the size of the bones and prospective bone distortion. Employment of the printed 3D models of bone will enable a more precise design of the apparatus, which is especially useful in multiplanar distortion and in the treatment of axis distortion and limb length discrepancy in young children. In the course of planning the use of physical models manufactured with additive technology, attention should be paid to certain technical aspects of model printing that have an impact on the accuracy of mapping of the geometry and physical properties of the model. 3D printing technique is very useful in 3D planning of the Ilizarov method treatment.

Recent advances in non-LTE stellar atmosphere models

NASA Astrophysics Data System (ADS)

Sander, Andreas A. C.

2017-11-01

In the last decades, stellar atmosphere models have become a key tool in understanding massive stars. Applied for spectroscopic analysis, these models provide quantitative information on stellar wind properties as well as fundamental stellar parameters. The intricate non-LTE conditions in stellar winds dictate the development of adequate sophisticated model atmosphere codes. The increase in both, the computational power and our understanding of physical processes in stellar atmospheres, led to an increasing complexity in the models. As a result, codes emerged that can tackle a wide range of stellar and wind parameters. After a brief address of the fundamentals of stellar atmosphere modeling, the current stage of clumped and line-blanketed model atmospheres will be discussed. Finally, the path for the next generation of stellar atmosphere models will be outlined. Apart from discussing multi-dimensional approaches, I will emphasize on the coupling of hydrodynamics with a sophisticated treatment of the radiative transfer. This next generation of models will be able to predict wind parameters from first principles, which could open new doors for our understanding of the various facets of massive star physics, evolution, and death.

Bridging Empirical and Physical Approaches for Landslide Monitoring and Early Warning

NASA Technical Reports Server (NTRS)

Kirschbaum, Dalia; Peters-Lidard, Christa; Adler, Robert; Kumar, Sujay; Harrison, Ken

2011-01-01

Rainfall-triggered landslides typically occur and are evaluated at local scales, using slope-stability models to calculate coincident changes in driving and resisting forces at the hillslope level in order to anticipate slope failures. Over larger areas, detailed high resolution landslide modeling is often infeasible due to difficulties in quantifying the complex interaction between rainfall infiltration and surface materials as well as the dearth of available in situ soil and rainfall estimates and accurate landslide validation data. This presentation will discuss how satellite precipitation and surface information can be applied within a landslide hazard assessment framework to improve landslide monitoring and early warning by considering two disparate approaches to landslide hazard assessment: an empirical landslide forecasting algorithm and a physical slope-stability model. The goal of this research is to advance near real-time landslide hazard assessment and early warning at larger spatial scales. This is done by employing high resolution surface and precipitation information within a probabilistic framework to provide more physically-based grounding to empirical landslide triggering thresholds. The empirical landslide forecasting tool, running in near real-time at http://trmm.nasa.gov, considers potential landslide activity at the global scale and relies on Tropical Rainfall Measuring Mission (TRMM) precipitation data and surface products to provide a near real-time picture of where landslides may be triggered. The physical approach considers how rainfall infiltration on a hillslope affects the in situ hydro-mechanical processes that may lead to slope failure. Evaluation of these empirical and physical approaches are performed within the Land Information System (LIS), a high performance land surface model processing and data assimilation system developed within the Hydrological Sciences Branch at NASA's Goddard Space Flight Center. LIS provides the capabilities to quantify uncertainty from model inputs and calculate probabilistic estimates for slope failures. Results indicate that remote sensing data can provide many of the spatiotemporal requirements for accurate landslide monitoring and early warning; however, higher resolution precipitation inputs will help to better identify small-scale precipitation forcings that contribute to significant landslide triggering. Future missions, such as the Global Precipitation Measurement (GPM) mission will provide more frequent and extensive estimates of precipitation at the global scale, which will serve as key inputs to significantly advance the accuracy of landslide hazard assessment, particularly over larger spatial scales.

IAEA Coordinated Research Project on HTGR Reactor Physics, Thermal-hydraulics and Depletion Uncertainty Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strydom, Gerhard; Bostelmann, F.

The continued development of High Temperature Gas Cooled Reactors (HTGRs) requires verification of HTGR design and safety features with reliable high fidelity physics models and robust, efficient, and accurate codes. The predictive capability of coupled neutronics/thermal-hydraulics and depletion simulations for reactor design and safety analysis can be assessed with sensitivity analysis (SA) and uncertainty analysis (UA) methods. Uncertainty originates from errors in physical data, manufacturing uncertainties, modelling and computational algorithms. (The interested reader is referred to the large body of published SA and UA literature for a more complete overview of the various types of uncertainties, methodologies and results obtained).more » SA is helpful for ranking the various sources of uncertainty and error in the results of core analyses. SA and UA are required to address cost, safety, and licensing needs and should be applied to all aspects of reactor multi-physics simulation. SA and UA can guide experimental, modelling, and algorithm research and development. Current SA and UA rely either on derivative-based methods such as stochastic sampling methods or on generalized perturbation theory to obtain sensitivity coefficients. Neither approach addresses all needs. In order to benefit from recent advances in modelling and simulation and the availability of new covariance data (nuclear data uncertainties) extensive sensitivity and uncertainty studies are needed for quantification of the impact of different sources of uncertainties on the design and safety parameters of HTGRs. Only a parallel effort in advanced simulation and in nuclear data improvement will be able to provide designers with more robust and well validated calculation tools to meet design target accuracies. In February 2009, the Technical Working Group on Gas-Cooled Reactors (TWG-GCR) of the International Atomic Energy Agency (IAEA) recommended that the proposed Coordinated Research Program (CRP) on the HTGR Uncertainty Analysis in Modelling (UAM) be implemented. This CRP is a continuation of the previous IAEA and Organization for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA) international activities on Verification and Validation (V&V) of available analytical capabilities for HTGR simulation for design and safety evaluations. Within the framework of these activities different numerical and experimental benchmark problems were performed and insight was gained about specific physics phenomena and the adequacy of analysis methods.« less

Accelerating advances in continental domain hydrologic modeling

USGS Publications Warehouse

Archfield, Stacey A.; Clark, Martyn; Arheimer, Berit; Hay, Lauren E.; McMillan, Hilary; Kiang, Julie E.; Seibert, Jan; Hakala, Kirsti; Bock, Andrew R.; Wagener, Thorsten; Farmer, William H.; Andreassian, Vazken; Attinger, Sabine; Viglione, Alberto; Knight, Rodney; Markstrom, Steven; Over, Thomas M.

2015-01-01

In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

PHYSICS OF ECLIPSING BINARIES. II. TOWARD THE INCREASED MODEL FIDELITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prša, A.; Conroy, K. E.; Horvat, M.

The precision of photometric and spectroscopic observations has been systematically improved in the last decade, mostly thanks to space-borne photometric missions and ground-based spectrographs dedicated to finding exoplanets. The field of eclipsing binary stars strongly benefited from this development. Eclipsing binaries serve as critical tools for determining fundamental stellar properties (masses, radii, temperatures, and luminosities), yet the models are not capable of reproducing observed data well, either because of the missing physics or because of insufficient precision. This led to a predicament where radiative and dynamical effects, insofar buried in noise, started showing up routinely in the data, but weremore » not accounted for in the models. PHOEBE (PHysics Of Eclipsing BinariEs; http://phoebe-project.org) is an open source modeling code for computing theoretical light and radial velocity curves that addresses both problems by incorporating missing physics and by increasing the computational fidelity. In particular, we discuss triangulation as a superior surface discretization algorithm, meshing of rotating single stars, light travel time effects, advanced phase computation, volume conservation in eccentric orbits, and improved computation of local intensity across the stellar surfaces that includes the photon-weighted mode, the enhanced limb darkening treatment, the better reflection treatment, and Doppler boosting. Here we present the concepts on which PHOEBE is built and proofs of concept that demonstrate the increased model fidelity.« less

A 1-D Model of the 4 Bed Molecular Sieve of the Carbon Dioxide Removal Assembly

NASA Technical Reports Server (NTRS)

Coker, Robert; Knox, Jim

2015-01-01

Developments to improve system efficiency and reliability for water and carbon dioxide separation systems on crewed vehicles combine sub-scale systems testing and multi-physics simulations. This paper describes the development of COMSOL simulations in support of the Life Support Systems (LSS) project within NASA's Advanced Exploration Systems (AES) program. Specifically, we model the 4 Bed Molecular Sieve (4BMS) of the Carbon Dioxide Removal Assembly (CDRA) operating on the International Space Station (ISS).

MODELING MICROBUBBLE DYNAMICS IN BIOMEDICAL APPLICATIONS*

PubMed Central

CHAHINE, Georges L.; HSIAO, Chao-Tsung

2012-01-01

Controlling microbubble dynamics to produce desirable biomedical outcomes when and where necessary and avoid deleterious effects requires advanced knowledge, which can be achieved only through a combination of experimental and numerical/analytical techniques. The present communication presents a multi-physics approach to study the dynamics combining viscous- in-viscid effects, liquid and structure dynamics, and multi bubble interaction. While complex numerical tools are developed and used, the study aims at identifying the key parameters influencing the dynamics, which need to be included in simpler models. PMID:22833696

Probability for Weather and Climate

NASA Astrophysics Data System (ADS)

Smith, L. A.

2013-12-01

Over the last 60 years, the availability of large-scale electronic computers has stimulated rapid and significant advances both in meteorology and in our understanding of the Earth System as a whole. The speed of these advances was due, in large part, to the sudden ability to explore nonlinear systems of equations. The computer allows the meteorologist to carry a physical argument to its conclusion; the time scales of weather phenomena then allow the refinement of physical theory, numerical approximation or both in light of new observations. Prior to this extension, as Charney noted, the practicing meteorologist could ignore the results of theory with good conscience. Today, neither the practicing meteorologist nor the practicing climatologist can do so, but to what extent, and in what contexts, should they place the insights of theory above quantitative simulation? And in what circumstances can one confidently estimate the probability of events in the world from model-based simulations? Despite solid advances of theory and insight made possible by the computer, the fidelity of our models of climate differs in kind from the fidelity of models of weather. While all prediction is extrapolation in time, weather resembles interpolation in state space, while climate change is fundamentally an extrapolation. The trichotomy of simulation, observation and theory which has proven essential in meteorology will remain incomplete in climate science. Operationally, the roles of probability, indeed the kinds of probability one has access too, are different in operational weather forecasting and climate services. Significant barriers to forming probability forecasts (which can be used rationally as probabilities) are identified. Monte Carlo ensembles can explore sensitivity, diversity, and (sometimes) the likely impact of measurement uncertainty and structural model error. The aims of different ensemble strategies, and fundamental differences in ensemble design to support of decision making versus advance science, are noted. It is argued that, just as no point forecast is complete without an estimate of its accuracy, no model-based probability forecast is complete without an estimate of its own irrelevance. The same nonlinearities that made the electronic computer so valuable links the selection and assimilation of observations, the formation of ensembles, the evolution of models, the casting of model simulations back into observables, and the presentation of this information to those who use it to take action or to advance science. Timescales of interest exceed the lifetime of a climate model and the career of a climate scientist, disarming the trichotomy that lead to swift advances in weather forecasting. Providing credible, informative climate services is a more difficult task. In this context, the value of comparing the forecasts of simulation models not only with each other but also with the performance of simple empirical models, whenever possible, is stressed. The credibility of meteorology is based on its ability to forecast and explain the weather. The credibility of climatology will always be based on flimsier stuff. Solid insights of climate science may be obscured if the severe limits on our ability to see the details of the future even probabilistically are not communicated clearly.

Three-Dimensional Printing of X-Ray Computed Tomography Datasets with Multiple Materials Using Open-Source Data Processing

ERIC Educational Resources Information Center

Sander, Ian M.; McGoldrick, Matthew T.; Helms, My N.; Betts, Aislinn; van Avermaete, Anthony; Owers, Elizabeth; Doney, Evan; Liepert, Taimi; Niebur, Glen; Liepert, Douglas; Leevy, W. Matthew

2017-01-01

Advances in three-dimensional (3D) printing allow for digital files to be turned into a "printed" physical product. For example, complex anatomical models derived from clinical or pre-clinical X-ray computed tomography (CT) data of patients or research specimens can be constructed using various printable materials. Although 3D printing…

Advanced Physical Models and Numerical Methods for High Enthalpy and Plasma Flows Applied to Hypersonics

DTIC Science & Technology

2011-07-28

4874–48??, 1970. [16] R. O. Jung , J. B. Boffard, L. W. Anderson, and C. C. Lin. Electron-impact excitation cross sections from the xenon j = 2...Journal of Quantitative Spectroscopy and Radiative Transfer, 5(2):503– 510, 1965. [35] O. Zatsarinny and K. Bartschat. B -spline Breit- Pauli R-matrix

A contact angle hysteresis model based on the fractal structure of contact line.

PubMed

Wu, Shuai; Ma, Ming

2017-11-01

Contact angle is one of the most popular concept used in fields such as wetting, transport and microfludics. In practice, different contact angles such as equilibrium, receding and advancing contact angles are observed due to hysteresis. The connection among these contact angles is important in revealing the chemical and physical properties of surfaces related to wetting. Inspired by the fractal structure of contact line, we propose a single parameter model depicting the connection of the three angles. This parameter is decided by the fractal structure of the contact line. The results of this model agree with experimental observations. In certain cases, it can be reduced to other existing models. It also provides a new point of view in understanding the physical nature of the contact angle hysteresis. Interestingly, some counter-intuitive phenomena, such as the binary receding angles, are indicated in this model, which are waited to be validated by experiments. Copyright © 2017 Elsevier Inc. All rights reserved.

Advanced solar irradiances applied to satellite and ionospheric operational systems

NASA Astrophysics Data System (ADS)

Tobiska, W. Kent; Schunk, Robert; Eccles, Vince; Bouwer, Dave

Satellite and ionospheric operational systems require solar irradiances in a variety of time scales and spectral formats. We describe the development of a system using operational grade solar irradiances that are applied to empirical thermospheric density models and physics-based ionospheric models used by operational systems that require a space weather characterization. The SOLAR2000 (S2K) and SOLARFLARE (SFLR) models developed by Space Environment Technologies (SET) provide solar irradiances from the soft X-rays (XUV) through the Far Ultraviolet (FUV) spectrum. The irradiances are provided as integrated indices for the JB2006 empirical atmosphere density models and as line/band spectral irradiances for the physics-based Ionosphere Forecast Model (IFM) developed by the Space Environment Corporation (SEC). We describe the integration of these irradiances in historical, current epoch, and forecast modes through the Communication Alert and Prediction System (CAPS). CAPS provides real-time and forecast HF radio availability for global and regional users and global total electron content (TEC) conditions.

Data Assimilation - Advances and Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Brian J.

2014-07-30

This presentation provides an overview of data assimilation (model calibration) for complex computer experiments. Calibration refers to the process of probabilistically constraining uncertain physics/engineering model inputs to be consistent with observed experimental data. An initial probability distribution for these parameters is updated using the experimental information. Utilization of surrogate models and empirical adjustment for model form error in code calibration form the basis for the statistical methodology considered. The role of probabilistic code calibration in supporting code validation is discussed. Incorporation of model form uncertainty in rigorous uncertainty quantification (UQ) analyses is also addressed. Design criteria used within a batchmore » sequential design algorithm are introduced for efficiently achieving predictive maturity and improved code calibration. Predictive maturity refers to obtaining stable predictive inference with calibrated computer codes. These approaches allow for augmentation of initial experiment designs for collecting new physical data. A standard framework for data assimilation is presented and techniques for updating the posterior distribution of the state variables based on particle filtering and the ensemble Kalman filter are introduced.« less

The role of data fusion in predictive maintenance using digital twin

NASA Astrophysics Data System (ADS)

Liu, Zheng; Meyendorf, Norbert; Mrad, Nezih

2018-04-01

Modern aerospace industry is migrating from reactive to proactive and predictive maintenance to increase platform operational availability and efficiency, extend its useful life cycle and reduce its life cycle cost. Multiphysics modeling together with data-driven analytics generate a new paradigm called "Digital Twin." The digital twin is actually a living model of the physical asset or system, which continually adapts to operational changes based on the collected online data and information, and can forecast the future of the corresponding physical counterpart. This paper reviews the overall framework to develop a digital twin coupled with the industrial Internet of Things technology to advance aerospace platforms autonomy. Data fusion techniques particularly play a significant role in the digital twin framework. The flow of information from raw data to high-level decision making is propelled by sensor-to-sensor, sensor-to-model, and model-to-model fusion. This paper further discusses and identifies the role of data fusion in the digital twin framework for aircraft predictive maintenance.

Recent theoretical advances on superradiant phase transitions

NASA Astrophysics Data System (ADS)

Baksic, Alexandre; Nataf, Pierre; Ciuti, Cristiano

2013-03-01

The Dicke model describing a single-mode boson field coupled to two-level systems is an important paradigm in quantum optics. In particular, the physics of ``superradiant phase transitions'' in the ultrastrong coupling regime is the subject of a vigorous research activity in both cavity and circuit QED. Recently, we explored the rich physics of two interesting generalizations of the Dicke model: (i) A model describing the coupling of a boson mode to two independent chains A and B of two-level systems, where chain A is coupled to one quadrature of the boson field and chain B to the orthogonal quadrature. This original model leads to a quantum phase transition with a double symmetry breaking and a fourfold ground state degeneracy. (ii) A generalized Dicke model with three-level systems including the diamagnetic term. In contrast to the case of two-level atoms for which no-go theorems exist, in the case of three-level system we prove that the Thomas-Reich-Kuhn sum rule does not always prevent a superradiant phase transition.

Inferential control -- Part 1: Crude unit advanced controls pass accuracy and repeatability tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

San, Y.P.; Landells, K.C.; Mackay, D.C.

1994-11-28

An inferential model is one that provides a quality for which an analyzer is not available. This type of model uses readily available physical measurements -- such as temperatures, pressures, and flow rates -- to infer a quality such as kerosine flash point. The No. 2 crude distillation unit (CDU-2) at Singapore Refining Co. Pte. Ltd.'s Pulau Merlimau refinery has a nominal 130,000 b/d capacity. It produces naphtha, kerosine, diesel, and residue products from a wide range of crude blends. Over the past 12 months, extensive advanced control applications have been implemented on the unit. This first of two articlesmore » will describe the control system and its implementation. The second will outline the project's achievements, including reduced quality giveaway and increased profits. The paper describes background of the company and unit, the process, project implementation, the Infer model, model tuning, closed-loop control, feed rate maximization, and economic monitoring.« less

Canopy structural complexity predicts forest canopy light absorption at continental scales

NASA Astrophysics Data System (ADS)

Atkins, J. W.; Fahey, R. T.; Hardiman, B. S.; Gough, C. M.

2017-12-01

Understanding how the physical structure of forest canopies influence light acquisition is a long-standing area of inquiry fundamental to advancing understanding of many areas of the physical sciences, including the modeling and interpretation of biogeochemical cycles. Conventional measures of forest canopy structure employed in earth system models are often limited to leaf area index (LAI)—a measure of the quantity of leaves in the canopy. However, more novel multi-dimensional measures of canopy structural complexity (CSC) that describe the arrangement of vegetation are now possible because of technological advances, and may improve modeled estimates of canopy light absorption. During 2016 and 2017, we surveyed forests at sites from across the eastern, southern, and midwestern United States using portable canopy LiDAR (PCL). This survey included 14 National Ecological Observation Network (NEON), Long-Term Ecological Research Network (LTER,) Ameriflux, and University affiliated sites. Our findings show that a composite model including CSC parameters and LAI explains 96.8% of the variance in light acquisition, measured as the fraction of photosynthetically absorbed radiation (fPAR) at the continental scale, and improvement of 12% over an LAI only model. Under high light sky conditions, measures of CSC are more strongly coupled with light acquisition than under low light, possibly because light scattering partially decouples CSC from canopy light absorption under low, predominately diffuse light conditions. We conclude that scalable estimates of CSC metrics may improve continent-wide estimates of canopy light absorption and, therefore, carbon uptake, with implications for remote sensing and earth system modeling.

a Dosimetry Assessment for the Core Restraint of AN Advanced Gas Cooled Reactor

NASA Astrophysics Data System (ADS)

Thornton, D. A.; Allen, D. A.; Tyrrell, R. J.; Meese, T. C.; Huggon, A. P.; Whiley, G. S.; Mossop, J. R.

2009-08-01

This paper describes calculations of neutron damage rates within the core restraint structures of Advanced Gas Cooled Reactors (AGRs). Using advanced features of the Monte Carlo radiation transport code MCBEND, and neutron source data from core follow calculations performed with the reactor physics code PANTHER, a detailed model of the reactor cores of two of British Energy's AGR power plants has been developed for this purpose. Because there are no relevant neutron fluence measurements directly supporting this assessment, results of benchmark comparisons and successful validation of MCBEND for Magnox reactors have been used to estimate systematic and random uncertainties on the predictions. In particular, it has been necessary to address the known under-prediction of lower energy fast neutron responses associated with the penetration of large thicknesses of graphite.

Advances in modelling of biomimetic fluid flow at different scales

PubMed Central

2011-01-01

The biomimetic flow at different scales has been discussed at length. The need of looking into the biological surfaces and morphologies and both geometrical and physical similarities to imitate the technological products and processes has been emphasized. The complex fluid flow and heat transfer problems, the fluid-interface and the physics involved at multiscale and macro-, meso-, micro- and nano-scales have been discussed. The flow and heat transfer simulation is done by various CFD solvers including Navier-Stokes and energy equations, lattice Boltzmann method and molecular dynamics method. Combined continuum-molecular dynamics method is also reviewed. PMID:21711847

Some highlights in few-body nuclear physics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holt, R. J.

2000-12-07

During the past five years, there have been tremendous advances in both experiments and theoretical calculations in few-body nuclear systems. Advances in technology have permitted experiments of unprecedented accuracy. Jefferson Laboratory has begun operation and the first round of experimental results have become available. New polarization techniques have been exploited at a number of laboratories, in particular, at Jefferson Lab, IUCF, RIKEN, NIKHEF, Mainz, MIT-Bates and HERMES. Some of these results will be shown here. In addition, there have been tremendous advances in few-body theory. Five modern two-nucleon potentials have which describe the nucleon-nucleon data extremely well have become available.more » A standard model of nuclear physics based on these two nucleon potentials as well as modern three-nucleon forces has emerged. This standard model has enjoyed tremendous success in the few body systems. Exact three-body calculations have been extended into the continuum in order to take full advantage of scattering data in advancing our understanding of the the few-nucleon system. In addition, the application of chiral symmetry has become an important constraint on nucleon-nucleon as well as three-nucleon forces. As a result of all these efforts, we have seen rapid developments in the three-body force. Despite these advances, there remain some extremely important open issues: (1) What is the role of quarks and gluons in nuclear structure; (2) Can we distinguish meson exchange from quark interchange; (3) Is few-body theory sufficient to describe simultaneously the mass 2, 3 and 4 form factors; (4) What is the isospin and spin dependence of the three-body force; (5) Are there medium modifications for nucleons and mesons in nuclei; (6) Is there an enhancement of antiquarks or pions in nuclei related to the binding; and (7) Are short range correlations observable in nuclei? In this paper the author summarizes the status of our understanding of these issues.« less

Modeling Patient-Specific Deformable Mitral Valves.

PubMed

Ginty, Olivia; Moore, John; Peters, Terry; Bainbridge, Daniel

2018-06-01

Medical imaging has advanced enormously over the last few decades, revolutionizing patient diagnostics and care. At the same time, additive manufacturing has emerged as a means of reproducing physical shapes and models previously not possible. In combination, they have given rise to 3-dimensional (3D) modeling, an entirely new technology for physicians. In an era in which 3D imaging has become a standard for aiding in the diagnosis and treatment of cardiac disease, this visualization now can be taken further by bringing the patient's anatomy into physical reality as a model. The authors describe the generalized process of creating a model of cardiac anatomy from patient images and their experience creating patient-specific dynamic mitral valve models. This involves a combination of image processing software and 3D printing technology. In this article, the complexity of 3D modeling is described and the decision-making process for cardiac anesthesiologists is summarized. The management of cardiac disease has been altered with the emergence of 3D echocardiography, and 3D modeling represents the next paradigm shift. Copyright © 2017 Elsevier Inc. All rights reserved.

A stochastic vision-based model inspired by zebrafish collective behaviour in heterogeneous environments

PubMed Central

Collignon, Bertrand; Séguret, Axel; Halloy, José

2016-01-01

Collective motion is one of the most ubiquitous behaviours displayed by social organisms and has led to the development of numerous models. Recent advances in the understanding of sensory system and information processing by animals impels one to revise classical assumptions made in decisional algorithms. In this context, we present a model describing the three-dimensional visual sensory system of fish that adjust their trajectory according to their perception field. Furthermore, we introduce a stochastic process based on a probability distribution function to move in targeted directions rather than on a summation of influential vectors as is classically assumed by most models. In parallel, we present experimental results of zebrafish (alone or in group of 10) swimming in both homogeneous and heterogeneous environments. We use these experimental data to set the parameter values of our model and show that this perception-based approach can simulate the collective motion of species showing cohesive behaviour in heterogeneous environments. Finally, we discuss the advances of this multilayer model and its possible outcomes in biological, physical and robotic sciences. PMID:26909173

Experimental equipment for an advanced ISOL facility[Isotope Separation On-Line Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baktash, C.; Lee, I.Y.; Rehm, K.E.

This report summarizes the proceedings and recommendations of the Workshop on the Experimental Equipment for an Advanced ISOL Facility which was held at Lawrence Berkeley National Laboratory on July 22--25, 1998. The purpose of this workshop was to discuss the performance requirements, manpower and cost estimates, as well as a schedule of the experimental equipment needed to fully exploit the new physics which can be studied at an advanced ISOL facility. An overview of the new physics opportunities that would be provided by such a facility has been presented in the White Paper that was issued following the Columbus Meeting.more » The reactions and experimental techniques discussed in the Columbus White Paper served as a guideline for the formulation of the detector needs at the Berkeley Workshop. As outlined a new ISOL facility with intense, high-quality beams of radioactive nuclei would provide exciting new research opportunities in the areas of: the nature of nucleonic matter; the origin of the elements; and tests of the Standard Model. After an introductory section, the following equipment is discussed: gamma-ray detectors; recoil separators; magnetic spectrographs; particle detectors; targets; and apparatus using non-accelerated beams.« less

Dynamic Initiator Imaging at the Advanced Photon Source: Understanding the early stages of initiator function and subsequent explosive interactions

NASA Astrophysics Data System (ADS)

Sanchez, Nate; Neal, Will; Jensen, Brian; Gibson, John; Martinez, Mike; Jaramillo, Dennis; Iverson, Adam; Carlson, Carl

2017-06-01

Recent advances in diagnostics coupled with synchrotron sources have allowed the in-situ investigation of exploding foil initiators (EFI) during flight. We present the first images of EFIs during flight utilizing x-ray phase contrast imaging at the Advanced Photon Source (APS) located in Argonne National Laboratory. These images have provided the DOE/DoD community with unprecedented images resolving details on the micron scale of the flyer formation, plasma instabilities and in flight characteristics along with the subsequent interaction with high explosives on the nanosecond time scale. Phase contrast imaging has allowed the ability to make dynamic measurements on the length and time scale necessary to resolve initiator function and provide insight to key design parameters. These efforts have also probed the fundamental physics at ``burst'' to better understand what burst means in a physical sense, rather than the traditional understanding of burst as a peak in voltage and increase in resistance. This fundamental understanding has led to increased knowledge on the mechanisms of burst and has allowed us to improve our predictive capability through magnetohydrodnamic modeling. Results will be presented from several EFI designs along with a look to the future for upcoming work.

Development of Foundational Movement Skills: A Conceptual Model for Physical Activity Across the Lifespan.

PubMed

Hulteen, Ryan M; Morgan, Philip J; Barnett, Lisa M; Stodden, David F; Lubans, David R

2018-03-09

Evidence supports a positive association between competence in fundamental movement skills (e.g., kicking, jumping) and physical activity in young people. Whilst important, fundamental movement skills do not reflect the broad diversity of skills utilized in physical activity pursuits across the lifespan. Debate surrounds the question of what are the most salient skills to be learned which facilitate physical activity participation across the lifespan. In this paper, it is proposed that the term 'fundamental movement skills' be replaced with 'foundational movement skills'. The term 'foundational movement skills' better reflects the broad range of movement forms that increase in complexity and specificity and can be applied in a variety of settings. Thus, 'foundational movement skills' includes both traditionally conceptualized 'fundamental' movement skills and other skills (e.g., bodyweight squat, cycling, swimming strokes) that support physical activity engagement across the lifespan. A proposed conceptual model outlines how foundational movement skill competency can provide a direct or indirect pathway, via specialized movement skills, to a lifetime of physical activity. Foundational movement skill development is hypothesized to vary according to culture and/or geographical location. Further, skill development may be hindered or enhanced by physical (i.e., fitness, weight status) and psychological (i.e., perceived competence, self-efficacy) attributes. This conceptual model may advance the application of motor development principles within the public health domain. Additionally, it promotes the continued development of human movement in the context of how it leads to skillful performance and how movement skill development supports and maintains a lifetime of physical activity engagement.

Displaying Computer Simulations Of Physical Phenomena

NASA Technical Reports Server (NTRS)

Watson, Val

1991-01-01

Paper discusses computer simulation as means of experiencing and learning to understand physical phenomena. Covers both present simulation capabilities and major advances expected in near future. Visual, aural, tactile, and kinesthetic effects used to teach such physical sciences as dynamics of fluids. Recommends classrooms in universities, government, and industry be linked to advanced computing centers so computer simulations integrated into education process.

Hybrid Physical Vapor Deposition Instrument for Advanced Functional Multilayers and Materials

DTIC Science & Technology

2016-04-27

Hybrid Physical Vapor Deposition Instrument for Advanced Functional Multilayers and Materials PI Maria received support to construct a physical...vapor deposition (PVD) system that combines electron beam (e- beam) evaporation, magnetron sputtering, pulsed laser ablation, and ion-assisted deposition ...The instrumentation enables clean, uniform, and rapid deposition of a wide variety of metallic, semiconducting, and ceramic thin films with

A transfer function type of simplified electrochemical model with modified boundary conditions and Padé approximation for Li-ion battery: Part 1. lithium concentration estimation

NASA Astrophysics Data System (ADS)

Yuan, Shifei; Jiang, Lei; Yin, Chengliang; Wu, Hongjie; Zhang, Xi

2017-06-01

To guarantee the safety, high efficiency and long lifetime for lithium-ion battery, an advanced battery management system requires a physics-meaningful yet computationally efficient battery model. The pseudo-two dimensional (P2D) electrochemical model can provide physical information about the lithium concentration and potential distributions across the cell dimension. However, the extensive computation burden caused by the temporal and spatial discretization limits its real-time application. In this research, we propose a new simplified electrochemical model (SEM) by modifying the boundary conditions for electrolyte diffusion equations, which significantly facilitates the analytical solving process. Then to obtain a reduced order transfer function, the Padé approximation method is adopted to simplify the derived transcendental impedance solution. The proposed model with the reduced order transfer function can be briefly computable and preserve physical meanings through the presence of parameters such as the solid/electrolyte diffusion coefficients (Ds&De) and particle radius. The simulation illustrates that the proposed simplified model maintains high accuracy for electrolyte phase concentration (Ce) predictions, saying 0.8% and 0.24% modeling error respectively, when compared to the rigorous model under 1C-rate pulse charge/discharge and urban dynamometer driving schedule (UDDS) profiles. Meanwhile, this simplified model yields significantly reduced computational burden, which benefits its real-time application.

Physical activity in patients with advanced-stage cancer: a systematic review of the literature.

PubMed

Albrecht, Tara A; Taylor, Ann Gill

2012-06-01

The importance of physical activity for chronic disease prevention and management has become generally well accepted. The number of research interventions and publications examining the benefits of physical activity for patients with cancer has been rising steadily. However, much of that research has focused on the impact of physical activity either prior to or early in the cancer diagnosis, treatment, and survivorship process. Research focusing on the effects of physical activity, specifically for patients with advanced-stage cancer and poorer prognostic outcomes, has been addressed only recently. The purpose of this article is to examine the state of the science for physical activity in the advanced-stage disease subset of the cancer population. Exercise in a variety of intensities and forms, including yoga, walking, biking, and swimming, has many health benefits for people, including those diagnosed with cancer. Research has shown that, for people with cancer (including advanced-stage cancer), exercise can decrease anxiety, stress, and depression while improving levels of pain, fatigue, shortness of breath, constipation, and insomnia. People diagnosed with cancer should discuss with their oncologist safe, easy ways they can incorporate exercise into their daily lives.

Physics basis for an advanced physics and advanced technology tokamak power plant configuration: ARIES-ACT1

DOE PAGES

Kessel, C. E.; Poli, F. M.; Ghantous, K.; ...

2015-01-01

Here, the advanced physics and advanced technology tokamak power plant ARIES-ACT1 has a major radius of 6.25 m at an aspect ratio of 4.0, toroidal field of 6.0 T, strong shaping with elongation of 2.2, and triangularity of 0.63. The broadest pressure cases reached wall-stabilized β N ~ 5.75, limited by n = 3 external kink mode requiring a conducting shell at b/a = 0.3, requiring plasma rotation, feedback, and/or kinetic stabilization. The medium pressure peaking case reaches β N = 5.28 with B T = 6.75, while the peaked pressure case reaches β N < 5.15. Fast particle magnetohydrodynamicmore » stability shows that the alpha particles are unstable, but this leads to redistribution to larger minor radius rather than loss from the plasma. Edge and divertor plasma modeling shows that 75% of the power to the divertor can be radiated with an ITER-like divertor geometry, while >95% can be radiated in a stable detached mode with an orthogonal target and wide slot geometry. The bootstrap current fraction is 91% with a q95 of 4.5, requiring ~1.1 MA of external current drive. This current is supplied with 5 MW of ion cyclotron radio frequency/fast wave and 40 MW of lower hybrid current drive. Electron cyclotron is most effective for safety factor control over ρ~0.2 to 0.6 with 20 MW. The pedestal density is ~0.9×10 20/m 3, and the temperature is ~4.4 keV. The H98 factor is 1.65, n/n Gr = 1.0, and the ratio of net power to threshold power is 2.8 to 3.0 in the flattop.« less

Her physics, his physics: gender issues in Israeli advanced placement physics classes

NASA Astrophysics Data System (ADS)

Zohar, Anat

2003-02-01

Gender gaps in physics in favour of boys are more prominent in Israel than in other countries. The main research question is to find out what gender issues are at play in Israeli advanced placement physics classes. Matriculation exam scores from approximately 400 high schools were analysed across 12 years. In addition, semi-constructed interviews were conducted with 50 advanced placement physics students (25 girls and 25 boys). In terms of participation, it was found that the ratio of girls to boys has been unchanged from 1988 to 2000 and is roughly 1:3. In terms of performance, it was found that the final matriculation scores of boys and girls are similar. However, breaking up the final scores into its two components - teachers' given grades and matriculation test scores - showed that boy's test scores are usually higher than girls' test scores, while girls' teachers' given grades are usually higher than boys'. Results from semi-constructed interviews pointed to two factors that are especially unfavourable to many girls: excessive competitiveness and lack of teaching for understanding. Girls' yearning for deep understanding is seen as a form of questing for connected knowledge. It is suggested that instructional methods that foster students' understanding while decreasing competitiveness in physics classes might contribute to girls' participation and performance in advanced physics classes while also supporting the learning of many boys.

Top-down models in biology: explanation and control of complex living systems above the molecular level.

PubMed

Pezzulo, Giovanni; Levin, Michael

2016-11-01

It is widely assumed in developmental biology and bioengineering that optimal understanding and control of complex living systems follows from models of molecular events. The success of reductionism has overshadowed attempts at top-down models and control policies in biological systems. However, other fields, including physics, engineering and neuroscience, have successfully used the explanations and models at higher levels of organization, including least-action principles in physics and control-theoretic models in computational neuroscience. Exploiting the dynamic regulation of pattern formation in embryogenesis and regeneration requires new approaches to understand how cells cooperate towards large-scale anatomical goal states. Here, we argue that top-down models of pattern homeostasis serve as proof of principle for extending the current paradigm beyond emergence and molecule-level rules. We define top-down control in a biological context, discuss the examples of how cognitive neuroscience and physics exploit these strategies, and illustrate areas in which they may offer significant advantages as complements to the mainstream paradigm. By targeting system controls at multiple levels of organization and demystifying goal-directed (cybernetic) processes, top-down strategies represent a roadmap for using the deep insights of other fields for transformative advances in regenerative medicine and systems bioengineering. © 2016 The Author(s).

Top-down models in biology: explanation and control of complex living systems above the molecular level

PubMed Central

2016-01-01

It is widely assumed in developmental biology and bioengineering that optimal understanding and control of complex living systems follows from models of molecular events. The success of reductionism has overshadowed attempts at top-down models and control policies in biological systems. However, other fields, including physics, engineering and neuroscience, have successfully used the explanations and models at higher levels of organization, including least-action principles in physics and control-theoretic models in computational neuroscience. Exploiting the dynamic regulation of pattern formation in embryogenesis and regeneration requires new approaches to understand how cells cooperate towards large-scale anatomical goal states. Here, we argue that top-down models of pattern homeostasis serve as proof of principle for extending the current paradigm beyond emergence and molecule-level rules. We define top-down control in a biological context, discuss the examples of how cognitive neuroscience and physics exploit these strategies, and illustrate areas in which they may offer significant advantages as complements to the mainstream paradigm. By targeting system controls at multiple levels of organization and demystifying goal-directed (cybernetic) processes, top-down strategies represent a roadmap for using the deep insights of other fields for transformative advances in regenerative medicine and systems bioengineering. PMID:27807271

Randomized Clinical Trial of the Effectiveness of a Home-Based Advanced Practice Psychiatric Nurse Intervention: Outcomes for Individuals with Serious Mental Illness and HIV

PubMed Central

Hanrahan, Nancy P.; Wu, Evan; Kelly, Deena; Aiken, Linda H.; Blank, Michael B.

2011-01-01

Individuals with serious mental illness have greater risk for contracting HIV, multiple morbidities, and die 25 years younger than the general population. This high need and high cost subgroup face unique barriers to accessing required health care in the current health care system. The effectiveness of an advanced practice nurse model of care management was assessed in a four-year random controlled trial. Results are reported in this paper. In a four-year random controlled trial, a total of 238 community-dwelling individuals with HIV and serious mental illness (SMI) were randomly assigned to an intervention group (n=128) or to a control group (n=110). Over 12 months, the intervention group received care management from advanced practice psychiatric nurse, and the control group received usual care. The intervention group showed significant improvement in depression (P=.012) and the physical component of health-related quality of life (P=.03) from baseline to 12 months. The advanced practice psychiatric nurse intervention is a model of care that holds promise for a higher quality of care and outcomes for this vulnerable population. PMID:21935499

FY17 Status Report on the Micromechanical Finite Element Modeling of Creep Fracture of Grade 91 Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Messner, M. C.; Truster, T. J.; Cochran, K. B.

Advanced reactors designed to operate at higher temperatures than current light water reactors require structural materials with high creep strength and creep-fatigue resistance to achieve long design lives. Grade 91 is a ferritic/martensitic steel designed for long creep life at elevated temperatures. It has been selected as a candidate material for sodium fast reactor intermediate heat exchangers and other advanced reactor structural components. This report focuses on the creep deformation and rupture life of Grade 91 steel. The time required to complete an experiment limits the availability of long-life creep data for Grade 91 and other structural materials. Design methodsmore » often extrapolate the available shorter-term experimental data to longer design lives. However, extrapolation methods tacitly assume the underlying material mechanisms causing creep for long-life/low-stress conditions are the same as the mechanisms controlling creep in the short-life/high-stress experiments. A change in mechanism for long-term creep could cause design methods based on extrapolation to be non-conservative. The goal for physically-based microstructural models is to accurately predict material response in experimentally-inaccessible regions of design space. An accurate physically-based model for creep represents all the material mechanisms that contribute to creep deformation and damage and predicts the relative influence of each mechanism, which changes with loading conditions. Ideally, the individual mechanism models adhere to the material physics and not an empirical calibration to experimental data and so the model remains predictive for a wider range of loading conditions. This report describes such a physically-based microstructural model for Grade 91 at 600° C. The model explicitly represents competing dislocation and diffusional mechanisms in both the grain bulk and grain boundaries. The model accurately recovers the available experimental creep curves at higher stresses and the limited experimental data at lower stresses, predominately primary creep rates. The current model considers only one temperature. However, because the model parameters are, for the most part, directly related to the physics of fundamental material processes, the temperature dependence of the properties are known. Therefore, temperature dependence can be included in the model with limited additional effort. The model predicts a mechanism shift for 600° C at approximately 100 MPa from a dislocation- dominated regime at higher stress to a diffusion-dominated regime at lower stress. This mechanism shift impacts the creep life, notch-sensitivity, and, likely, creep ductility of Grade 91. In particular, the model predicts existing extrapolation methods for creep life may be non-conservative when attempting to extrapolate data for higher stress creep tests to low stress, long-life conditions. Furthermore, the model predicts a transition from notchstrengthening behavior at high stress to notch-weakening behavior at lower stresses. Both behaviors may affect the conservatism of existing design methods.« less

Physical therapy mandates by Medicare administrative contractors: effective or wasteful?

PubMed

Fehring, Thomas K; Fehring, Keith; Odum, Susan M; Halsey, David

2013-10-01

Documentation of medical necessity for arthroplasty has come under scrutiny by Medicare. In some jurisdictions three months of physical therapy prior to arthroplasty has been mandated. The purpose of this study was to determine the efficacy and cost of this policy to treat advanced osteoarthritis. A systematic review was performed to assimilate efficacy data for physical therapy in patients with advanced osteoarthritis. The number of arthroplasties performed annually was obtained to calculate cost. Evidence-based studies documenting the efficacy of physical therapy in treating advanced arthritis are lacking with a potential cost of 36-68 million dollars. Physical therapy mandates by administrative contractors are not only ineffective but are costly without patient benefit. Medical necessity documentation should be driven by orthopedists not retroactively by Medicare contractors. Copyright © 2013 Elsevier Inc. All rights reserved.

Developing model-making and model-breaking skills using direct measurement video-based activities

NASA Astrophysics Data System (ADS)

Vonk, Matthew; Bohacek, Peter; Militello, Cheryl; Iverson, Ellen

2017-12-01

This study focuses on student development of two important laboratory skills in the context of introductory college-level physics. The first skill, which we call model making, is the ability to analyze a phenomenon in a way that produces a quantitative multimodal model. The second skill, which we call model breaking, is the ability to critically evaluate if the behavior of a system is consistent with a given model. This study involved 116 introductory physics students in four different sections, each taught by a different instructor. All of the students within a given class section participated in the same instruction (including labs) with the exception of five activities performed throughout the semester. For those five activities, each class section was split into two groups; one group was scaffolded to focus on model-making skills and the other was scaffolded to focus on model-breaking skills. Both conditions involved direct measurement videos. In some cases, students could vary important experimental parameters within the video like mass, frequency, and tension. Data collected at the end of the semester indicate that students in the model-making treatment group significantly outperformed the other group on the model-making skill despite the fact that both groups shared a common physical lab experience. Likewise, the model-breaking treatment group significantly outperformed the other group on the model-breaking skill. This is important because it shows that direct measurement video-based instruction can help students acquire science-process skills, which are critical for scientists, and which are a key part of current science education approaches such as the Next Generation Science Standards and the Advanced Placement Physics 1 course.

Advanced physical-chemical life support systems research

NASA Technical Reports Server (NTRS)

Evanich, Peggy L.

1988-01-01

A proposed NASA space research and technology development program will provide adequate data for designing closed loop life support systems for long-duration manned space missions. This program, referred to as the Pathfinder Physical-Chemical Closed Loop Life Support Program, is to identify and develop critical chemical engineering technologies for the closure of air and water loops within the spacecraft, surface habitats or mobility devices. Computerized simulation can be used both as a research and management tool. Validated models will guide the selection of the best known applicable processes and in the development of new processes. For the integration of the habitat system, a biological subsystem would be introduced to provide food production and to enhance the physical-chemical life support functions on an ever-increasing basis.

Trends in Nuclear Explosion Monitoring Research & Development - A Physics Perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maceira, Monica; Blom, Philip Stephen; MacCarthy, Jonathan K.

This document entitled “Trends in Nuclear Explosion Monitoring Research and Development – A Physics Perspective” reviews the accessible literature, as it relates to nuclear explosion monitoring and the Comprehensive Nuclear-Test-Ban Treaty (CTBT, 1996), for four research areas: source physics (understanding signal generation), signal propagation (accounting for changes through physical media), sensors (recording the signals), and signal analysis (processing the signal). Over 40 trends are addressed, such as moving from 1D to 3D earth models, from pick-based seismic event processing to full waveform processing, and from separate treatment of mechanical waves in different media to combined analyses. Highlighted in the documentmore » for each trend are the value and benefit to the monitoring mission, key papers that advanced the science, and promising research and development for the future.« less

Integrating 3D geological information with a national physically-based hydrological modelling system

NASA Astrophysics Data System (ADS)

Lewis, Elizabeth; Parkin, Geoff; Kessler, Holger; Whiteman, Mark

2016-04-01

Robust numerical models are an essential tool for informing flood and water management and policy around the world. Physically-based hydrological models have traditionally not been used for such applications due to prohibitively large data, time and computational resource requirements. Given recent advances in computing power and data availability, a robust, physically-based hydrological modelling system for Great Britain using the SHETRAN model and national datasets has been created. Such a model has several advantages over less complex systems. Firstly, compared with conceptual models, a national physically-based model is more readily applicable to ungauged catchments, in which hydrological predictions are also required. Secondly, the results of a physically-based system may be more robust under changing conditions such as climate and land cover, as physical processes and relationships are explicitly accounted for. Finally, a fully integrated surface and subsurface model such as SHETRAN offers a wider range of applications compared with simpler schemes, such as assessments of groundwater resources, sediment and nutrient transport and flooding from multiple sources. As such, SHETRAN provides a robust means of simulating numerous terrestrial system processes which will add physical realism when coupled to the JULES land surface model. 306 catchments spanning Great Britain have been modelled using this system. The standard configuration of this system performs satisfactorily (NSE > 0.5) for 72% of catchments and well (NSE > 0.7) for 48%. Many of the remaining 28% of catchments that performed relatively poorly (NSE < 0.5) are located in the chalk in the south east of England. As such, the British Geological Survey 3D geology model for Great Britain (GB3D) has been incorporated, for the first time in any hydrological model, to pave the way for improvements to be made to simulations of catchments with important groundwater regimes. This coupling has involved development of software to allow for easy incorporation of geological information into SHETRAN for any model setup. The addition of more realistic subsurface representation following this approach is shown to greatly improve model performance in areas dominated by groundwater processes. The resulting modelling system has great potential to be used as a resource at national, regional and local scales in an array of different applications, including climate change impact assessments, land cover change studies and integrated assessments of groundwater and surface water resources.

The Standard Model: how far can it go and how can we tell?

PubMed

Butterworth, J M

2016-08-28

The Standard Model of particle physics encapsulates our current best understanding of physics at the smallest distances and highest energies. It incorporates quantum electrodynamics (the quantized version of Maxwell's electromagnetism) and the weak and strong interactions, and has survived unmodified for decades, save for the inclusion of non-zero neutrino masses after the observation of neutrino oscillations in the late 1990s. It describes a vast array of data over a wide range of energy scales. I review a selection of these successes, including the remarkably successful prediction of a new scalar boson, a qualitatively new kind of object observed in 2012 at the Large Hadron Collider. New calculational techniques and experimental advances challenge the Standard Model across an ever-wider range of phenomena, now extending significantly above the electroweak symmetry breaking scale. I will outline some of the consequences of these new challenges, and briefly discuss what is still to be found.This article is part of the themed issue 'Unifying physics and technology in light of Maxwell's equations'. © 2016 The Author(s).

Application of physics engines in virtual worlds

NASA Astrophysics Data System (ADS)

Norman, Mark; Taylor, Tim

2002-03-01

Dynamic virtual worlds potentially can provide a much richer and more enjoyable experience than static ones. To realize such worlds, three approaches are commonly used. The first of these, and still widely applied, involves importing traditional animations from a modeling system such as 3D Studio Max. This approach is therefore limited to predefined animation scripts or combinations/blends thereof. The second approach involves the integration of some specific-purpose simulation code, such as car dynamics, and is thus generally limited to one (class of) application(s). The third approach involves the use of general-purpose physics engines, which promise to enable a range of compelling dynamic virtual worlds and to considerably speed up development. By far the largest market today for real-time simulation is computer games, revenues exceeding those of the movie industry. Traditionally, the simulation is produced by game developers in-house for specific titles. However, off-the-shelf middleware physics engines are now available for use in games and related domains. In this paper, we report on our experiences of using middleware physics engines to create a virtual world as an interactive experience, and an advanced scenario where artificial life techniques generate controllers for physically modeled characters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahesh, M; Borras, C; Frey, G

This workshop is jointly organized by the AAPM, the Spanish (SEFM) and the Russian (AMPR) Medical Physics Societies, as part of formal educational exchange agreements signed by the AAPM with each one of these two societies.With the rapid technological advances in radiation therapy both for treatment and imaging, it is challenging how physics is taught to medical physicists practicing in radiation therapy. The main Objectives: of this workshop is to bring forth current status, challenges and issues related to education of radiation therapy physicists here in the US, Spain and Russia. Medical physicists from each one of these countries willmore » present educational requirements of international recommendations and directives and analyze their impact on national legislations. Current and future educational models and plans for harmonization will be described. The role of universities, professional societies and examination boards, such as the American Board of Radiology, will be discussed. Minimum standards will be agreed upon. Learning Objectives: Review medical physics educational models supported by AAPM, SEFM, and AMPR. Discuss the role of governmental and non-governmental organizations in elaborating and adopting medical physics syllabi. Debate minimum educational standards for medical physics education based on country-specific resources.« less

Teaching Physics with Basketball

NASA Astrophysics Data System (ADS)

Chanpichai, N.; Wattanakasiwich, P.

2010-07-01

Recently, technologies and computer takes important roles in learning and teaching, including physics. Advance in technologies can help us better relating physics taught in the classroom to the real world. In this study, we developed a module on teaching a projectile motion through shooting a basketball. Students learned about physics of projectile motion, and then they took videos of their classmates shooting a basketball by using the high speed camera. Then they analyzed videos by using Tracker, a video analysis and modeling tool. While working with Tracker, students learned about the relationships between three kinematics graphs. Moreover, they learned about a real projectile motion (with an air resistance) through modeling tools. Students' abilities to interpret kinematics graphs were investigated before and after the instruction by using the Test of Understanding Graphs in Kinematics (TUG-K). The maximum normalized gain or is 0.77, which indicated students' improvement in determining displacement from the velocity-time graph. The minimum is 0.20, which indicated that most students still have difficulties interpreting the change in velocity from the acceleration-time graph. Results from evaluation questionnaires revealed that students also satisfied with the instructions that related physics contents to shooting basketball.

Spiro K. Antiochos Receives 2013 John Adam Fleming Medal: Citation

NASA Astrophysics Data System (ADS)

Klimchuk, James A.

2014-01-01

The John Adam Fleming Medal is awarded for "original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and related sciences." Originality and technical leadership are exactly the characteristics that distinguish the research of Spiro K. Antiochos. Spiro possesses a truly unique combination of physical insight, creativity, and mastery of the concepts and mathematical and numerical tools of space physics. These talents have allowed him to develop completely original theories for major observational problems and to test and refine those theories using sophisticated numerical simulation codes that he himself helped to develop. Spiro's physical insight is especially impressive. He has an uncanny ability to identify the fundamental aspects of complex problems and to see physical connections where others do not. This can sometimes involve ideas that may initially seem counterintuitive to those with less creativity. Many of Spiro's revolutionary advances have opened up whole new areas of study and shaped the course of space physics. Examples include the breakout model for coronal mass ejections (CMEs), the S-web model for the slow solar wind, and the thermal nonequilibrium model for solar prominences. The breakout model is of special significance to AGU as it strives to promote science for the betterment of humanity. CMEs are enormous explosions on the Sun that can have major "space weather" impacts here on Earth. They affect technologies ranging from communication and navigation systems to electrical power grids. Breakout is the leading theory for why CMEs occur and may one day be the foundation for more accurate space weather forecasting.

Mixed convective peristaltic flow of carbon nanotubes submerged in water using different thermal conductivity models.

PubMed

Hayat, T; Ahmed, Bilal; Abbasi, F M; Ahmad, B

2016-10-01

Single Walled Carbon Nanotubes (SWCNTs) are the advanced product of nanotechnology having notable mechanical and physical properties. Peristalsis of SWCNTs suspended in water through an asymmetric channel is examined. Such mechanism is studied in the presence of viscous dissipation, velocity slip, mixed convection, temperature jump and heat generation/absorption. Mathematical modeling is carried out under the low Reynolds number and long wavelength approximation. Resulting nonlinear system is solved using the perturbation technique for small Brinkman's number. Physical analysis and comparison of the results in light of three different thermal conductivity models is also provided. It is reported that the heat transfer rate at the boundary increases with an increase in the nanotubes volume fraction. The addition of nanotubes affects the pressure gradient during the peristaltic flow. Moreover, the maximum velocity of the fluid decreases due to addition of the nanotubes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Parabolic discounting of monetary rewards by physical effort.

PubMed

Hartmann, Matthias N; Hager, Oliver M; Tobler, Philippe N; Kaiser, Stefan

2013-11-01

When humans and other animals make decisions in their natural environments prospective rewards have to be weighed against costs. It is well established that increasing costs lead to devaluation or discounting of reward. While our knowledge about discount functions for time and probability costs is quite advanced, little is known about how physical effort discounts reward. In the present study we compared three different models in a binary choice task in which human participants had to squeeze a handgrip to earn monetary rewards: a linear, a hyperbolic, and a parabolic model. On the group as well as the individual level, the concave parabolic model explained most variance of the choice data, thus contrasting with the typical hyperbolic discounting of reward value by delay. Research on effort discounting is not only important to basic science but also holds the potential to quantify aberrant motivational states in neuropsychiatric disorders. Copyright © 2013 Elsevier B.V. All rights reserved.

Jonathan F. Reichert and Barbara Wolff-Reichert Award for Excellence in Advanced Laboratory Instruction: Advanced Instructional Labs: Why Bother?

NASA Astrophysics Data System (ADS)

Bistrow, Van

What aren't we teaching about physics in the traditional lecture course? Plenty! By offering the Advanced Laboratory Course, we hope to shed light on the following questions: How do we develop a systematic process of doing experiments? How do we record procedures and results? How should we interpret theoretical concepts in the real world? What experimental and computational techniques are available for producing and analyzing data? With what degree of confidence can we trust our measurements and interpretations? How well does a theory represent physical reality? How do we collaborate with experimental partners? How do we best communicate our findings to others?These questions are of fundamental importance to experimental physics, yet are not generally addressed by reading textbooks, attending lectures or doing homework problems. Thus, to provide a more complete understanding of physics, we offer laboratory exercises as a supplement to the other modes of learning. The speaker will describe some examples of experiments, and outline the history, structure and student impressions of the Advanced Lab course at the University of Chicago Department of Physics.

Increasing Specificity of Correlate Research: Exploring Correlates of Children’s Lunchtime and After-School Physical Activity

PubMed Central

Stanley, Rebecca M.; Ridley, Kate; Olds, Timothy S.; Dollman, James

2014-01-01

Background The lunchtime and after-school contexts are critical windows in a school day for children to be physically active. While numerous studies have investigated correlates of children’s habitual physical activity, few have explored correlates of physical activity occurring at lunchtime and after-school from a social-ecological perspective. Exploring correlates that influence physical activity occurring in specific contexts can potentially improve the prediction and understanding of physical activity. Using a context-specific approach, this study investigated correlates of children’s lunchtime and after-school physical activity. Methods Cross-sectional data were collected from 423 South Australian children aged 10.0–13.9 years (200 boys; 223 girls) attending 10 different schools. Lunchtime and after-school physical activity was assessed using accelerometers. Correlates were assessed using purposely developed context-specific questionnaires. Correlated Component Regression analysis was conducted to derive correlates of context-specific physical activity and determine the variance explained by prediction equations. Results The model of boys’ lunchtime physical activity contained 6 correlates and explained 25% of the variance. For girls, the model explained 17% variance from 9 correlates. Enjoyment of walking during lunchtime was the strongest correlate for both boys and girls. Boys’ and girls’ after-school physical activity models explained 20% variance from 14 correlates and 7% variance from the single item correlate, “I do an organised sport or activity after-school because it gets you fit”, respectively. Conclusions Increasing specificity of correlate research has enabled the identification of unique features of, and a more in-depth interpretation of, lunchtime and after-school physical activity behaviour and is a potential strategy for advancing the physical activity correlate research field. The findings of this study could be used to inform and tailor gender-specific public health messages and interventions for promoting lunchtime and after-school physical activity in children. PMID:24809440

Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH) program

NASA Astrophysics Data System (ADS)

Fayette, Daniel F.; Speicher, Patricia; Stoklosa, Mark J.; Evans, Jillian V.; Evans, John W.; Gentile, Mike; Pagel, Chuck A.; Hakim, Edward

1993-08-01

A joint military-commercial effort to evaluate multichip module (MCM) structures is discussed. The program, Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH), has been designed to identify the failure mechanisms that are possible in MCM structures. The RELTECH test vehicles, technical assessment task, product evaluation plan, reliability modeling task, accelerated and environmental testing, and post-test physical analysis and failure analysis are described. The information obtained through RELTECH can be used to address standardization issues, through development of cost effective qualification and appropriate screening criteria, for inclusion into a commercial specification and the MIL-H-38534 general specification for hybrid microcircuits.

Microbiome Tools for Forensic Science.

PubMed

Metcalf, Jessica L; Xu, Zhenjiang Z; Bouslimani, Amina; Dorrestein, Pieter; Carter, David O; Knight, Rob

2017-09-01

Microbes are present at every crime scene and have been used as physical evidence for over a century. Advances in DNA sequencing and computational approaches have led to recent breakthroughs in the use of microbiome approaches for forensic science, particularly in the areas of estimating postmortem intervals (PMIs), locating clandestine graves, and obtaining soil and skin trace evidence. Low-cost, high-throughput technologies allow us to accumulate molecular data quickly and to apply sophisticated machine-learning algorithms, building generalizable predictive models that will be useful in the criminal justice system. In particular, integrating microbiome and metabolomic data has excellent potential to advance microbial forensics. Copyright © 2017. Published by Elsevier Ltd.

Energy geotechnics: Advances in subsurface energy recovery, storage, exchange, and waste management

DOE PAGES

McCartney, John S.; Sanchez, Marcelo; Tomac, Ingrid

2016-02-17

Energy geotechnics involves the use of geotechnical principles to understand and engineer the coupled thermo-hydro-chemo-mechanical processes encountered in collecting, exchanging, storing, and protecting energy resources in the subsurface. In addition to research on these fundamental coupled processes and characterization of relevant material properties, applied research is being performed to develop analytical tools for the design and analysis of different geo-energy applications. In conclusion, the aims of this paper are to discuss the fundamental physics and constitutive models that are common to these different applications, and to summarize recent advances in the development of relevant analytical tools.

Energy geotechnics: Advances in subsurface energy recovery, storage, exchange, and waste management

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCartney, John S.; Sanchez, Marcelo; Tomac, Ingrid

Energy geotechnics involves the use of geotechnical principles to understand and engineer the coupled thermo-hydro-chemo-mechanical processes encountered in collecting, exchanging, storing, and protecting energy resources in the subsurface. In addition to research on these fundamental coupled processes and characterization of relevant material properties, applied research is being performed to develop analytical tools for the design and analysis of different geo-energy applications. In conclusion, the aims of this paper are to discuss the fundamental physics and constitutive models that are common to these different applications, and to summarize recent advances in the development of relevant analytical tools.

Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH) program

NASA Technical Reports Server (NTRS)

Fayette, Daniel F.; Speicher, Patricia; Stoklosa, Mark J.; Evans, Jillian V.; Evans, John W.; Gentile, Mike; Pagel, Chuck A.; Hakim, Edward

1993-01-01

A joint military-commercial effort to evaluate multichip module (MCM) structures is discussed. The program, Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH), has been designed to identify the failure mechanisms that are possible in MCM structures. The RELTECH test vehicles, technical assessment task, product evaluation plan, reliability modeling task, accelerated and environmental testing, and post-test physical analysis and failure analysis are described. The information obtained through RELTECH can be used to address standardization issues, through development of cost effective qualification and appropriate screening criteria, for inclusion into a commercial specification and the MIL-H-38534 general specification for hybrid microcircuits.

Advances in simulation of wave interactions with extended MHD phenomena

NASA Astrophysics Data System (ADS)

Batchelor, D.; Abla, G.; D'Azevedo, E.; Bateman, G.; Bernholdt, D. E.; Berry, L.; Bonoli, P.; Bramley, R.; Breslau, J.; Chance, M.; Chen, J.; Choi, M.; Elwasif, W.; Foley, S.; Fu, G.; Harvey, R.; Jaeger, E.; Jardin, S.; Jenkins, T.; Keyes, D.; Klasky, S.; Kruger, S.; Ku, L.; Lynch, V.; McCune, D.; Ramos, J.; Schissel, D.; Schnack, D.; Wright, J.

2009-07-01

The Integrated Plasma Simulator (IPS) provides a framework within which some of the most advanced, massively-parallel fusion modeling codes can be interoperated to provide a detailed picture of the multi-physics processes involved in fusion experiments. The presentation will cover four topics: 1) recent improvements to the IPS, 2) application of the IPS for very high resolution simulations of ITER scenarios, 3) studies of resistive and ideal MHD stability in tokamk discharges using IPS facilities, and 4) the application of RF power in the electron cyclotron range of frequencies to control slowly growing MHD modes in tokamaks and initial evaluations of optimized location for RF power deposition.

Improving Simulated Soil Moisture Fields Through Assimilation of AMSR-E Soil Moisture Retrievals with an Ensemble Kalman Filter and a Mass Conservation Constraint

NASA Technical Reports Server (NTRS)

Li, Bailing; Toll, David; Zhan, Xiwu; Cosgrove, Brian

2011-01-01

Model simulated soil moisture fields are often biased due to errors in input parameters and deficiencies in model physics. Satellite derived soil moisture estimates, if retrieved appropriately, represent the spatial mean of soil moisture in a footprint area, and can be used to reduce model bias (at locations near the surface) through data assimilation techniques. While assimilating the retrievals can reduce model bias, it can also destroy the mass balance enforced by the model governing equation because water is removed from or added to the soil by the assimilation algorithm. In addition, studies have shown that assimilation of surface observations can adversely impact soil moisture estimates in the lower soil layers due to imperfect model physics, even though the bias near the surface is decreased. In this study, an ensemble Kalman filter (EnKF) with a mass conservation updating scheme was developed to assimilate the actual value of Advanced Microwave Scanning Radiometer (AMSR-E) soil moisture retrievals to improve the mean of simulated soil moisture fields by the Noah land surface model. Assimilation results using the conventional and the mass conservation updating scheme in the Little Washita watershed of Oklahoma showed that, while both updating schemes reduced the bias in the shallow root zone, the mass conservation scheme provided better estimates in the deeper profile. The mass conservation scheme also yielded physically consistent estimates of fluxes and maintained the water budget. Impacts of model physics on the assimilation results are discussed.

Are Current Physical Match Performance Metrics in Elite Soccer Fit for Purpose or is the Adoption of an Integrated Approach Needed?

PubMed

Bradley, Paul S; Ade, Jack D

2018-01-18

Time-motion analysis is a valuable data-collection technique used to quantify the physical match performance of elite soccer players. For over 40 years researchers have adopted a 'traditional' approach when evaluating match demands by simply reporting the distance covered or time spent along a motion continuum of walking through to sprinting. This methodology quantifies physical metrics in isolation without integrating other factors and this ultimately leads to a one-dimensional insight into match performance. Thus, this commentary proposes a novel 'integrated' approach that focuses on a sensitive physical metric such as high-intensity running but contextualizes this in relation to key tactical activities for each position and collectively for the team. In the example presented, the 'integrated' model clearly unveils the unique high-intensity profile that exists due to distinct tactical roles, rather than one-dimensional 'blind' distances produced by 'traditional' models. Intuitively this innovative concept may aid the coaches understanding of the physical performance in relation to the tactical roles and instructions given to the players. Additionally, it will enable practitioners to more effectively translate match metrics into training and testing protocols. This innovative model may well aid advances in other team sports that incorporate similar intermittent movements with tactical purpose. Evidence of the merits and application of this new concept are needed before the scientific community accepts this model as it may well add complexity to an area that conceivably needs simplicity.

Wind-US Code Physical Modeling Improvements to Complement Hypersonic Testing and Evaluation

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.; Yoder, Dennis A.; Towne, Charles S.; Engblom, William A.; Bhagwandin, Vishal A.; Power, Greg D.; Lankford, Dennis W.; Nelson, Christopher C.

2009-01-01

This report gives an overview of physical modeling enhancements to the Wind-US flow solver which were made to improve the capabilities for simulation of hypersonic flows and the reliability of computations to complement hypersonic testing. The improvements include advanced turbulence models, a bypass transition model, a conjugate (or closely coupled to vehicle structure) conduction-convection heat transfer capability, and an upgraded high-speed combustion solver. A Mach 5 shock-wave boundary layer interaction problem is used to investigate the benefits of k- s and k-w based explicit algebraic stress turbulence models relative to linear two-equation models. The bypass transition model is validated using data from experiments for incompressible boundary layers and a Mach 7.9 cone flow. The conjugate heat transfer method is validated for a test case involving reacting H2-O2 rocket exhaust over cooled calorimeter panels. A dual-mode scramjet configuration is investigated using both a simplified 1-step kinetics mechanism and an 8-step mechanism. Additionally, variations in the turbulent Prandtl and Schmidt numbers are considered for this scramjet configuration.

Lattice Anharmonicity and Thermal Conductivity from Compressive Sensing of First-Principles Calculations

DOE PAGES

Zhou, Fei; Nielson, Weston; Xia, Yi; ...

2014-10-27

First-principles prediction of lattice thermal conductivity K L of strongly anharmonic crystals is a long-standing challenge in solid state physics. Using recent advances in information science, we propose a systematic and rigorous approach to this problem, compressive sensing lattice dynamics (CSLD). Compressive sensing is used to select the physically important terms in the lattice dynamics model and determine their values in one shot. Non-intuitively, high accuracy is achieved when the model is trained on first-principles forces in quasi-random atomic configurations. The method is demonstrated for Si, NaCl, and Cu 12Sb 4S 13, an earth-abundant thermoelectric with strong phononphonon interactions thatmore » limit the room-temperature K L to values near the amorphous limit.« less

Grain Flow at High Stresses

NASA Astrophysics Data System (ADS)

McSaveney, M. J.

2015-12-01

The transport mechanism of rapid long-runout rock avalanches was a hotly debated topic when I came on the scene in 1967. So how come it is still debated today? My explanation is that it is the expected outcome of peer review, poor comprehension, and technological advances outpacing intellectual advances. Why think about the problem when we can model it! So let us think about the problem. Shreve thought that rock avalanches fell upon and trapped a layer of air. What physics was he thinking about? It is how feathers and tissue papers fall. When my rock avalanches fly, they fly like unlubricated bricks using the physics of projectiles and ballistics. But the main transport mechanism is not flight. The dominant impression from watching a rock avalanche in motion is of fluid flow, as Heim described it in 1882. A rock avalanche is a very large grain flow. Bagnold studied dispersive grain flows, but why should one assume that rock avalanches are dispersive grain flows as many do. The more common grain flow type is a dense grain flow and rock avalanches are dense grain flows in which the weight can and does generate very high stresses at grain contacts. Brittle rock deforms elastically up to its compressive strength, whereupon it breaks, releasing elastic strain as transient elastic strain (seismic energy to a seismologist, acoustic energy to a physicist). Melosh and others have shown that acoustic energy can fluidize a grain mass. There is no exotic physics behind grain flow at high stress. When grains break, the released elastic strain has to go somewhere, and it goes somewhere principally by transmission though grain contacts. Depending on the state of stress at the grain contact, the contact will pass the stress or will slip at conventional values of Coulomb friction. Enough thinking! A physical model of the entire process is too big for any laboratory. So whose numerical model will do it?

Coupling biology and oceanography in models.

PubMed

Fennel, W; Neumann, T

2001-08-01

The dynamics of marine ecosystems, i.e. the changes of observable chemical-biological quantities in space and time, are driven by biological and physical processes. Predictions of future developments of marine systems need a theoretical framework, i.e. models, solidly based on research and understanding of the different processes involved. The natural way to describe marine systems theoretically seems to be the embedding of chemical-biological models into circulation models. However, while circulation models are relatively advanced the quantitative theoretical description of chemical-biological processes lags behind. This paper discusses some of the approaches and problems in the development of consistent theories and indicates the beneficial potential of the coupling of marine biology and oceanography in models.

The Shale Hills Sensorium for Embedded Sensors, Simulation, & Visualization: A Prototype for Land-Vegetation-Atmosphere Interactions

NASA Astrophysics Data System (ADS)

Duffy, C.

2008-12-01

The future of environmental observing systems will utilize embedded sensor networks with continuous real- time measurement of hydrologic, atmospheric, biogeochemical, and ecological variables across diverse terrestrial environments. Embedded environmental sensors, benefitting from advances in information sciences, networking technology, materials science, computing capacity, and data synthesis methods, are undergoing revolutionary change. It is now possible to field spatially-distributed, multi-node sensor networks that provide density and spatial coverage previously accessible only via numerical simulation. At the same time, computational tools are advancing rapidly to the point where it is now possible to simulate the physical processes controlling individual parcels of water and solutes through the complete terrestrial water cycle. Our goal for the Penn State Critical Zone Observatory is to apply environmental sensor arrays, integrated hydrologic models, and state-of-the-art visualization deployed and coordinated at a testbed within the Penn State Experimental Forest. The Shale Hills Hydro_Sensorium prototype proposed here is designed to observe land-atmosphere interactions in four-dimensional (space and time). The term Hydro_Sensorium implies the totality of physical sensors, models and visualization tools that allow us to perceive the detailed space and time complexities of the water and energy cycle for a watershed or river basin for all physical states and fluxes (groundwater, soil moisture, temperature, streamflow, latent heat, snowmelt, chemistry, isotopes etc.). This research will ultimately catalyze the study of complex interactions between the land surface, subsurface, biological and atmospheric systems over a broad range of scales. The sensor array would be real-time and fully controllable by remote users for "computational steering" and data fusion. Presently fully-coupled physical models are being developed that link the atmosphere-land-vegetation-subsurface system into a fully-coupled distributed system. During the last 5 years the Penn State Integrated Hydrologic Modeling System has been under development as an open-source community modeling project funded by NSF EAR/GEO and NSF CBET/ENG. PIHM represents a strategy for the formulation and solution of fully-coupled process equations at the watershed and river basin scales, and includes a tightly coupled GIS tool for data handling, domain decomposition, optimal unstructured grid generation, and model parameterization. The sensor and simulation system has the following elements: 1) extensive, spatially-distributed, non- invasive, smart sensor networks to gather massive geologic, hydrologic, and geochemical data; 2) stochastic information fusion methods; 3) spatially-explicit multiphysics models/solutions of the land-vegetation- atmosphere system; and 4) asynchronous, parallel/distributed, adaptive algorithms for rapidly simulating the states of a basin at high resolution, 5) signal processing tools for data mining and parameter estimation, and 6) visualization tools. The prototype proposed sensor array and simulation system proposed here will offer a coherent new approach to environmental predictions with a fully integrated observing system design. We expect that the Shale Hills Hydro_Sensorium may provide the needed synthesis of information and conceptualization necessary to advance predictive understanding in complex hydrologic systems.

Time-efficient simulations of tight-binding electronic structures with Intel Xeon PhiTM many-core processors

NASA Astrophysics Data System (ADS)

Ryu, Hoon; Jeong, Yosang; Kang, Ji-Hoon; Cho, Kyu Nam

2016-12-01

Modelling of multi-million atomic semiconductor structures is important as it not only predicts properties of physically realizable novel materials, but can accelerate advanced device designs. This work elaborates a new Technology-Computer-Aided-Design (TCAD) tool for nanoelectronics modelling, which uses a sp3d5s∗ tight-binding approach to describe multi-million atomic structures, and simulate electronic structures with high performance computing (HPC), including atomic effects such as alloy and dopant disorders. Being named as Quantum simulation tool for Advanced Nanoscale Devices (Q-AND), the tool shows nice scalability on traditional multi-core HPC clusters implying the strong capability of large-scale electronic structure simulations, particularly with remarkable performance enhancement on latest clusters of Intel Xeon PhiTM coprocessors. A review of the recent modelling study conducted to understand an experimental work of highly phosphorus-doped silicon nanowires, is presented to demonstrate the utility of Q-AND. Having been developed via Intel Parallel Computing Center project, Q-AND will be open to public to establish a sound framework of nanoelectronics modelling with advanced HPC clusters of a many-core base. With details of the development methodology and exemplary study of dopant electronics, this work will present a practical guideline for TCAD development to researchers in the field of computational nanoelectronics.

To Advance and Diffuse the Knowledge of Physics...

NASA Astrophysics Data System (ADS)

Lustig, Harry

1999-10-01

: On May 20th,1899, thirty-six physicists founded the American Physical Society. A hundred years later, 11,239 scientists - the Society had by then 41,786 members, - gathered to mark both a century of physics and the Centennial of the Society. Selected tales from the author's comprehensive account of how the APS came about and developed and how it pusued its mission - the advancement and diffusion of the knowledge of physics - through its meetings, journals, and pulic activities, will be the subject of this talk.

Virtual Observation System for Earth System Model: An Application to ACME Land Model Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dali; Yuan, Fengming; Hernandez, Benjamin

Investigating and evaluating physical-chemical-biological processes within an Earth system model (EMS) can be very challenging due to the complexity of both model design and software implementation. A virtual observation system (VOS) is presented to enable interactive observation of these processes during system simulation. Based on advance computing technologies, such as compiler-based software analysis, automatic code instrumentation, and high-performance data transport, the VOS provides run-time observation capability, in-situ data analytics for Earth system model simulation, model behavior adjustment opportunities through simulation steering. A VOS for a terrestrial land model simulation within the Accelerated Climate Modeling for Energy model is also presentedmore » to demonstrate the implementation details and system innovations.« less

Virtual Observation System for Earth System Model: An Application to ACME Land Model Simulations

DOE PAGES

Wang, Dali; Yuan, Fengming; Hernandez, Benjamin; ...

2017-01-01

Investigating and evaluating physical-chemical-biological processes within an Earth system model (EMS) can be very challenging due to the complexity of both model design and software implementation. A virtual observation system (VOS) is presented to enable interactive observation of these processes during system simulation. Based on advance computing technologies, such as compiler-based software analysis, automatic code instrumentation, and high-performance data transport, the VOS provides run-time observation capability, in-situ data analytics for Earth system model simulation, model behavior adjustment opportunities through simulation steering. A VOS for a terrestrial land model simulation within the Accelerated Climate Modeling for Energy model is also presentedmore » to demonstrate the implementation details and system innovations.« less

A Future State for NASA Laboratories - Working in the 21st Century

NASA Technical Reports Server (NTRS)

Kegelman, Jerome T.; Harris, Charles E.; Antcliff, Richard R.; Bushnell, Dennis M.; Dwoyer, Douglas L.

2009-01-01

The name "21 st Century Laboratory" is an emerging concept of how NASA (and the world) will conduct research in the very near future. Our approach is to carefully plan for significant technological changes in products, organization, and society. The NASA mission can be the beneficiary of these changes, provided the Agency prepares for the role of 21st Century laboratories in research and technology development and its deployment in this new age. It has been clear for some time now that the technology revolutions, technology "mega-trends" that we are in the midst of now, all have a common element centered around advanced computational modeling of small scale physics. Whether it is nano technology, bio technology or advanced computational technology, all of these megatrends are converging on science at the very small scale where it is profoundly important to consider the quantum effects at play with physics at that scale. Whether it is the bio-technology creation of "nanites" designed to mimic our immune system or the creation of nanoscale infotechnology devices, allowing an order of magnitude increase in computational capability, all involve quantum physics that serves as the heart of these revolutionary changes.

Optimization and Control of Cyber-Physical Vehicle Systems

PubMed Central

Bradley, Justin M.; Atkins, Ella M.

2015-01-01

A cyber-physical system (CPS) is composed of tightly-integrated computation, communication and physical elements. Medical devices, buildings, mobile devices, robots, transportation and energy systems can benefit from CPS co-design and optimization techniques. Cyber-physical vehicle systems (CPVSs) are rapidly advancing due to progress in real-time computing, control and artificial intelligence. Multidisciplinary or multi-objective design optimization maximizes CPS efficiency, capability and safety, while online regulation enables the vehicle to be responsive to disturbances, modeling errors and uncertainties. CPVS optimization occurs at design-time and at run-time. This paper surveys the run-time cooperative optimization or co-optimization of cyber and physical systems, which have historically been considered separately. A run-time CPVS is also cooperatively regulated or co-regulated when cyber and physical resources are utilized in a manner that is responsive to both cyber and physical system requirements. This paper surveys research that considers both cyber and physical resources in co-optimization and co-regulation schemes with applications to mobile robotic and vehicle systems. Time-varying sampling patterns, sensor scheduling, anytime control, feedback scheduling, task and motion planning and resource sharing are examined. PMID:26378541

Optimization and Control of Cyber-Physical Vehicle Systems.

PubMed

Bradley, Justin M; Atkins, Ella M

2015-09-11

A cyber-physical system (CPS) is composed of tightly-integrated computation, communication and physical elements. Medical devices, buildings, mobile devices, robots, transportation and energy systems can benefit from CPS co-design and optimization techniques. Cyber-physical vehicle systems (CPVSs) are rapidly advancing due to progress in real-time computing, control and artificial intelligence. Multidisciplinary or multi-objective design optimization maximizes CPS efficiency, capability and safety, while online regulation enables the vehicle to be responsive to disturbances, modeling errors and uncertainties. CPVS optimization occurs at design-time and at run-time. This paper surveys the run-time cooperative optimization or co-optimization of cyber and physical systems, which have historically been considered separately. A run-time CPVS is also cooperatively regulated or co-regulated when cyber and physical resources are utilized in a manner that is responsive to both cyber and physical system requirements. This paper surveys research that considers both cyber and physical resources in co-optimization and co-regulation schemes with applications to mobile robotic and vehicle systems. Time-varying sampling patterns, sensor scheduling, anytime control, feedback scheduling, task and motion planning and resource sharing are examined.

Developing a predictive model for the chemical composition of soot nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Violi, Angela; Michelsen, Hope; Hansen, Nils

In order to provide the scientific foundation to enable technology breakthroughs in transportation fuel, it is important to develop a combustion modeling capability to optimize the operation and design of evolving fuels in advanced engines for transportation applications. The goal of this proposal is to develop a validated predictive model to describe the chemical composition of soot nanoparticles in premixed and diffusion flames. Atomistic studies in conjunction with state-of-the-art experiments are the distinguishing characteristics of this unique interdisciplinary effort. The modeling effort has been conducted at the University of Michigan by Prof. A. Violi. The experimental work has entailed amore » series of studies using different techniques to analyze gas-phase soot precursor chemistry and soot particle production in premixed and diffusion flames. Measurements have provided spatial distributions of polycyclic aromatic hydrocarbons and other gas-phase species and size and composition of incipient soot nanoparticles for comparison with model results. The experimental team includes Dr. N. Hansen and H. Michelsen at Sandia National Labs' Combustion Research Facility, and Dr. K. Wilson as collaborator at Lawrence Berkeley National Lab's Advanced Light Source. Our results show that the chemical and physical properties of nanoparticles affect the coagulation behavior in soot formation, and our results on an experimentally validated, predictive model for the chemical composition of soot nanoparticles will not only enhance our understanding of soot formation since but will also allow the prediction of particle size distributions under combustion conditions. These results provide a novel description of soot formation based on physical and chemical properties of the particles for use in the next generation of soot models and an enhanced capability for facilitating the design of alternative fuels and the engines they will power.« less

An Overview of ARPA-E

NASA Astrophysics Data System (ADS)

Rohlfing, Eric

2015-04-01

In less than six years, the Advanced Research Projects Agency - Energy (ARPA-E) has developed and implemented a unique model for the support of energy research and development. ARPA-E funds R&D on high-potential, high-impact energy technologies that are too early for private-sector investment. The agency focuses on technologies that can be meaningfully advanced with a modest investment over a defined period of time in order to catalyze the translation from scientific discovery to early-stage technology. The fundamental question asked of every ARPA-E program and project is: ``If it works, will it matter?'' This talk will discuss the ARPA-E model, including the development of focused technology programs and the active management of projects for technical and market success. Highlights of programs and projects of particular interest to the physics community will be given.

Integrating Levels of Analysis in Systems and Cognitive Neurosciences: Selective Attention as a Case Study.

PubMed

Itthipuripat, Sirawaj; Serences, John T

2016-06-01

Neuroscience is inherently interdisciplinary, rapidly expanding beyond its roots in biological sciences to many areas of the social and physical sciences. This expansion has led to more sophisticated ways of thinking about the links between brains and behavior and has inspired the development of increasingly advanced tools to characterize the activity of large populations of neurons. However, along with these advances comes a heightened risk of fostering confusion unless efforts are made to better integrate findings across different model systems and to develop a better understanding about how different measurement techniques provide mutually constraining information. Here we use selective visuospatial attention as a case study to highlight the importance of these issues, and we suggest that exploiting multiple measures can better constrain models that relate neural activity to animal behavior. © The Author(s) 2015.

Advanced statistical energy analysis

NASA Astrophysics Data System (ADS)

Heron, K. H.

1994-09-01

A high-frequency theory (advanced statistical energy analysis (ASEA)) is developed which takes account of the mechanism of tunnelling and uses a ray theory approach to track the power flowing around a plate or a beam network and then uses statistical energy analysis (SEA) to take care of any residual power. ASEA divides the energy of each sub-system into energy that is freely available for transfer to other sub-systems and energy that is fixed within the sub-systems that are physically separate and can be interpreted as a series of mathematical models, the first of which is identical to standard SEA and subsequent higher order models are convergent on an accurate prediction. Using a structural assembly of six rods as an example, ASEA is shown to converge onto the exact results while SEA is shown to overpredict by up to 60 dB.

Book Review: Dolores Knipp’s Understanding Space Weather and the Physics Behind It

NASA Astrophysics Data System (ADS)

Moldwin, Mark

2012-08-01

Delores Knipp's textbook Understanding Space Weather and the Physics Behind It provides a comprehensive resource for space physicists teaching in a variety of academic departments to introduce space weather to advanced undergraduates. The book benefits from Knipp's extensive experience teaching introductory and advanced undergraduate physics courses at the U.S. Air Force Academy. The fundamental physics concepts are clearly explained and are connected directly to the space physics concepts being discussed. To expand upon the relevant basic physics, current research areas and new observations are highlighted, with many of the chapters including contributions from a number of leading space physicists.

Numerical modeling of late Glacial Laurentide advance of ice across Hudson Strait: Insights into terrestrial and marine geology, mass balance, and calving flux

USGS Publications Warehouse

Pfeffer, W.T.; Dyurgerov, M.; Kaplan, M.; Dwyer, J.; Sassolas, C.; Jennings, A.; Raup, B.; Manley, W.

1997-01-01

A time-dependent finite element model was used to reconstruct the advance of ice from a late Glacial dome on northern Quebec/Labrador across Hudson Strait to Meta Incognita Peninsula (Baffin Island) and subsequently to the 9.9-9.6 ka 14C Gold Cove position on Hall Peninsula. Terrestrial geological and geophysical information from Quebec and Labrador was used to constrain initial and boundary conditions, and the model results are compared with terrestrial geological information from Baffin Island and considered in the context of the marine event DC-0 and the Younger Dryas cooling. We conclude that advance across Hudson Strait from Ungava Bay to Baffin Island is possible using realistic glacier physics under a variety of reasonable boundary conditions. Production of ice flux from a dome centered on northeastern Quebec and Labrador sufficient to deliver geologically inferred ice thickness at Gold Cove (Hall Peninsula) appears to require extensive penetration of sliding south from Ungava Bay. The discharge of ice into the ocean associated with advance and retreat across Hudson Strait does not peak at a time coincident with the start of the Younger Dryas and is less than minimum values proposed to influence North Atlantic thermohaline circulation; nevertheless, a significant fraction of freshwater input to the North Atlantic may have been provided abruptly and at a critical time by this event.

Animal models of post-traumatic stress disorder: face validity

PubMed Central

Goswami, Sonal; Rodríguez-Sierra, Olga; Cascardi, Michele; Paré, Denis

2013-01-01

Post-traumatic stress disorder (PTSD) is a debilitating condition that develops in a proportion of individuals following a traumatic event. Despite recent advances, ethical limitations associated with human research impede progress in understanding PTSD. Fortunately, much effort has focused on developing animal models to help study the pathophysiology of PTSD. Here, we provide an overview of animal PTSD models where a variety of stressors (physical, psychosocial, or psychogenic) are used to examine the long-term effects of severe trauma. We emphasize models involving predator threat because they reproduce human individual differences in susceptibility to, and in the long-term consequences of, psychological trauma. PMID:23754973

NuSTEC1 White Paper: Status and challenges of neutrino-nucleus scattering

NASA Astrophysics Data System (ADS)

Alvarez-Ruso, L.; Sajjad Athar, M.; Barbaro, M. B.; Cherdack, D.; Christy, M. E.; Coloma, P.; Donnelly, T. W.; Dytman, S.; de Gouvêa, A.; Hill, R. J.; Huber, P.; Jachowicz, N.; Katori, T.; Kronfeld, A. S.; Mahn, K.; Martini, M.; Morfín, J. G.; Nieves, J.; Perdue, G. N.; Petti, R.; Richards, D. G.; Sánchez, F.; Sato, T.; Sobczyk, J. T.; Zeller, G. P.

2018-05-01

The precise measurement of neutrino properties is among the highest priorities in fundamental particle physics, involving many experiments worldwide. Since the experiments rely on the interactions of neutrinos with bound nucleons inside atomic nuclei, the planned advances in the scope and precision of these experiments require a commensurate effort in the understanding and modeling of the hadronic and nuclear physics of these interactions, which is incorporated as a nuclear model in neutrino event generators. This model is essential to every phase of experimental analyses and its theoretical uncertainties play an important role in interpreting every result. In this White Paper we discuss in detail the impact of neutrino-nucleus interactions, especially the nuclear effects, on the measurement of neutrino properties using the determination of oscillation parameters as a central example. After an Executive Summary and a concise Overview of the issues, we explain how the neutrino event generators work, what can be learned from electron-nucleus interactions and how each underlying physics process - from quasi-elastic to deep inelastic scattering - is understood today. We then emphasize how our understanding must improve to meet the demands of future experiments. With every topic we find that the challenges can be met only with the active support and collaboration among specialists in strong interactions and electroweak physics that include theorists and experimentalists from both the nuclear and high energy physics communities.

NuSTEC White Paper: Status and Challenges of Neutrino-Nucleus Scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvarez-Ruso, L.; et al.

The precise measurement of neutrino properties is among the highest priorities in fundamental particle physics, involving many experiments worldwide. Since the experiments rely on the interactions of neutrinos with bound nucleons inside atomic nuclei, the planned advances in the scope and precision of these experiments requires a commensurate effort in the understanding and modeling of the hadronic and nuclear physics of these interactions, which is incorporated as a nuclear model in neutrino event generators. This model is essential to every phase of experimental analyses and its theoretical uncertainties play an important role in interpreting every result. In this White Papermore » we discuss in detail the impact of neutrino-nucleus interactions, especially the nuclear effects, on the measurement of neutrino properties using the determination of oscillation parameters as a central example. After an Executive Summary and a concise Overview of the issues, we explain how the neutrino event generators work, what can be learned from electron-nucleus interactions and how each underlying physics process - from quasi-elastic to deep inelastic scattering - is understood today. We then emphasize how our understanding must improve to meet the demands of future experiments. With every topic we find that the challenges can be met only with the active support and collaboration among specialists in strong interactions and electroweak physics that include theorists and experimentalists from both the nuclear and high energy physics communities.« less

Investigation of resistance switching in SiO x RRAM cells using a 3D multi-scale kinetic Monte Carlo simulator

NASA Astrophysics Data System (ADS)

Sadi, Toufik; Mehonic, Adnan; Montesi, Luca; Buckwell, Mark; Kenyon, Anthony; Asenov, Asen

2018-02-01

We employ an advanced three-dimensional (3D) electro-thermal simulator to explore the physics and potential of oxide-based resistive random-access memory (RRAM) cells. The physical simulation model has been developed recently, and couples a kinetic Monte Carlo study of electron and ionic transport to the self-heating phenomenon while accounting carefully for the physics of vacancy generation and recombination, and trapping mechanisms. The simulation framework successfully captures resistance switching, including the electroforming, set and reset processes, by modeling the dynamics of conductive filaments in the 3D space. This work focuses on the promising yet less studied RRAM structures based on silicon-rich silica (SiO x ) RRAMs. We explain the intrinsic nature of resistance switching of the SiO x layer, analyze the effect of self-heating on device performance, highlight the role of the initial vacancy distributions acting as precursors for switching, and also stress the importance of using 3D physics-based models to capture accurately the switching processes. The simulation work is backed by experimental studies. The simulator is useful for improving our understanding of the little-known physics of SiO x resistive memory devices, as well as other oxide-based RRAM systems (e.g. transition metal oxide RRAMs), offering design and optimization capabilities with regard to the reliability and variability of memory cells.

Introducing Enabling Computational Tools to the Climate Sciences: Multi-Resolution Climate Modeling with Adaptive Cubed-Sphere Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jablonowski, Christiane

The research investigates and advances strategies how to bridge the scale discrepancies between local, regional and global phenomena in climate models without the prohibitive computational costs of global cloud-resolving simulations. In particular, the research explores new frontiers in computational geoscience by introducing high-order Adaptive Mesh Refinement (AMR) techniques into climate research. AMR and statically-adapted variable-resolution approaches represent an emerging trend for atmospheric models and are likely to become the new norm in future-generation weather and climate models. The research advances the understanding of multi-scale interactions in the climate system and showcases a pathway how to model these interactions effectively withmore » advanced computational tools, like the Chombo AMR library developed at the Lawrence Berkeley National Laboratory. The research is interdisciplinary and combines applied mathematics, scientific computing and the atmospheric sciences. In this research project, a hierarchy of high-order atmospheric models on cubed-sphere computational grids have been developed that serve as an algorithmic prototype for the finite-volume solution-adaptive Chombo-AMR approach. The foci of the investigations have lied on the characteristics of both static mesh adaptations and dynamically-adaptive grids that can capture flow fields of interest like tropical cyclones. Six research themes have been chosen. These are (1) the introduction of adaptive mesh refinement techniques into the climate sciences, (2) advanced algorithms for nonhydrostatic atmospheric dynamical cores, (3) an assessment of the interplay between resolved-scale dynamical motions and subgrid-scale physical parameterizations, (4) evaluation techniques for atmospheric model hierarchies, (5) the comparison of AMR refinement strategies and (6) tropical cyclone studies with a focus on multi-scale interactions and variable-resolution modeling. The results of this research project demonstrate significant advances in all six research areas. The major conclusions are that statically-adaptive variable-resolution modeling is currently becoming mature in the climate sciences, and that AMR holds outstanding promise for future-generation weather and climate models on high-performance computing architectures.« less

Advanced spacecraft: What will they look like and why

NASA Technical Reports Server (NTRS)

Price, Humphrey W.

1990-01-01

The next century of spaceflight will witness an expansion in the physical scale of spacecraft, from the extreme of the microspacecraft to the very large megaspacecraft. This will respectively spawn advances in highly integrated and miniaturized components, and also advances in lightweight structures, space fabrication, and exotic control systems. Challenges are also presented by the advent of advanced propulsion systems, many of which require controlling and directing hot plasma, dissipating large amounts of waste heat, and handling very high radiation sources. Vehicle configuration studies for a number of theses types of advanced spacecraft were performed, and some of them are presented along with the rationale for their physical layouts.

Army Logistician. Volume 39, Issue 1, January-February 2007

DTIC Science & Technology

2007-02-01

of electronic systems using statistical methods. P& C , however, requires advanced prognostic capabilities not only to detect the early onset of...patterns. Entities operating in a P& C -enabled environment will sense and understand contextual meaning , communicate their state and mission, and act to...accessing of historical and simulation patterns; on- board prognostics capabilities; physics of failure analyses; and predictive modeling. P& C also

RESEARCH AREA 7.1: Exploring the Systematics of Controlling Quantum Phenomena

DTIC Science & Technology

2016-10-05

the bottom to the top of the landscape. Computational analyses for simple model quantum systems are performed to ascertain the relative abundance of...SECURITY CLASSIFICATION OF: This research is concerned with the theoretical and experimental control quantum dynamics phenomena. Advances include new...algorithms to accelerate quantum control as well as provide physical insights into the controlled dynamics. The latter research includes the

Toward a closer integration of magnetospheric research: Magnetospheric currents inferred from ground-based magnetic data

NASA Astrophysics Data System (ADS)

Akasofu, S.-I.; Kamide, Y.

1998-07-01

A new approach is needed to advance magnetospheric physics in the future to achieve a much closer integration than in the past among satellite-based researchers, ground-based researchers, and theorists/modelers. Specifically, we must find efficient ways to combine two-dimensional ground-based data and single points satellite-based data to infer three-dimensional aspects of magnetospheric disturbances. For this particular integration purpose, we propose a new project. It is designed to determine the currents on the magnetospheric equatorial plane from the ionospheric current distribution which has become available by inverting ground-based magnetic data from an extensive, systematic network of observations, combined with ground-based radar measurements of ionospheric parameters, and satellite observations of auroras, electric fields, and currents. The inversion method is based on the KRM/AMIE algorithms. In the first part of the paper, we extensively review the reliability and accuracy of the KRM and AMIE algorithms and conclude that the ionospheric quantities thus obtained are accurate enough for the next step. In the second part, the ionospheric current distribution thus obtained is projected onto the equatorial plane. This process requires a close cooperation with modelers in determining an accurate configuration of the magnetospheric field lines. If we succeed in this projection, we should be able to study the changing distribution of the currents in a vast region of the magnetospheric equatorial plane for extended periods with a time resolution of about 5 min. This process requires a model of the magnetosphere for the different phases of the magnetospheric substorm. Satellite-based observations are needed to calibrate the projection results. Agreements and disagreements thus obtained will be crucial for theoretical studies of magnetospheric plasma convection and dynamics, particularly in studying substorms. Nothing is easy in these procedures. However, unless we can overcome the associated difficulties, we may not be able to make distinct progresses. We believe that the proposed project is one way to draw the three groups closer together in advancing magnetospheric physics in the future. It is important to note that the proposed project has become possible because ground-based space physics has made a major advance during the last decade.

Improving atomic displacement and replacement calculations with physically realistic damage models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nordlund, Kai; Zinkle, Steven J.; Sand, Andrea E.

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett-Robinson-Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations. In particular, the number of radiation defects produced in energetic cascades in metals is only ~1/3 the NRT-dpa prediction, while the number of atoms involved in atomic mixing is about a factor ofmore » 30 larger than the dpa value. Here we propose two new complementary displacement production estimators (athermal recombination corrected dpa, arc-dpa) and atomic mixing (replacements per atom, rpa) functions that extend the NRT-dpa by providing more physically realistic descriptions of primary defect creation in materials and may become additional standard measures for radiation damage quantification.« less

Improving atomic displacement and replacement calculations with physically realistic damage models

DOE PAGES

Nordlund, Kai; Zinkle, Steven J.; Sand, Andrea E.; ...

2018-03-14

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett-Robinson-Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations. In particular, the number of radiation defects produced in energetic cascades in metals is only ~1/3 the NRT-dpa prediction, while the number of atoms involved in atomic mixing is about a factor ofmore » 30 larger than the dpa value. Here we propose two new complementary displacement production estimators (athermal recombination corrected dpa, arc-dpa) and atomic mixing (replacements per atom, rpa) functions that extend the NRT-dpa by providing more physically realistic descriptions of primary defect creation in materials and may become additional standard measures for radiation damage quantification.« less

Improving atomic displacement and replacement calculations with physically realistic damage models.

PubMed

Nordlund, Kai; Zinkle, Steven J; Sand, Andrea E; Granberg, Fredric; Averback, Robert S; Stoller, Roger; Suzudo, Tomoaki; Malerba, Lorenzo; Banhart, Florian; Weber, William J; Willaime, Francois; Dudarev, Sergei L; Simeone, David

2018-03-14

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett-Robinson-Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations. In particular, the number of radiation defects produced in energetic cascades in metals is only ~1/3 the NRT-dpa prediction, while the number of atoms involved in atomic mixing is about a factor of 30 larger than the dpa value. Here we propose two new complementary displacement production estimators (athermal recombination corrected dpa, arc-dpa) and atomic mixing (replacements per atom, rpa) functions that extend the NRT-dpa by providing more physically realistic descriptions of primary defect creation in materials and may become additional standard measures for radiation damage quantification.

The physicist’s guide to one of biotechnology’s hottest new topics: CRISPR-Cas

NASA Astrophysics Data System (ADS)

Bonomo, Melia E.; Deem, Michael W.

2018-07-01

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas) constitute a multi-functional, constantly evolving immune system in bacteria and archaea cells. A heritable, molecular memory is generated of phage, plasmids, or other mobile genetic elements that attempt to attack the cell. This memory is used to recognize and interfere with subsequent invasions from the same genetic elements. This versatile prokaryotic tool has also been used to advance applications in biotechnology. Here we review a large body of CRISPR-Cas research to explore themes of evolution and selection, population dynamics, horizontal gene transfer, specific and cross-reactive interactions, cost and regulation, non-immunological CRISPR functions that boost host cell robustness, as well as applicable mechanisms for efficient and specific genetic engineering. We offer future directions that can be addressed by the physics community. Physical understanding of the CRISPR-Cas system will advance uses in biotechnology, such as developing cell lines and animal models, cell labeling and information storage, combatting antibiotic resistance, and human therapeutics.

Analytical fuel property effects--small combustors

NASA Technical Reports Server (NTRS)

Sutton, R. D.; Troth, D. L.; Miles, G. A.

1984-01-01

The consequences of using broad-property fuels in both conventional and advanced state-of-the-art small gas turbine combustors are assessed. Eight combustor concepts were selected for initial screening, of these, four final combustor concepts were chosen for further detailed analysis. These included the dual orifice injector baseline combustor (a current production 250-C30 engine combustor) two baseline airblast injected modifications, short and piloted prechamber combustors, and an advanced airblast injected, variable geometry air staged combustor. Final predictions employed the use of the STAC-I computer code. This quasi 2-D model includes real fuel properties, effects of injector type on atomization, detailed droplet dynamics, and multistep chemical kinetics. In general, fuel property effects on various combustor concepts can be classified as chemical or physical in nature. Predictions indicate that fuel chemistry has a significant effect on flame radiation, liner wall temperature, and smoke emission. Fuel physical properties that govern atomization quality and evaporation rates are predicted to affect ignition and lean-blowout limits, combustion efficiency, unburned hydrocarbon, and carbon monoxide emissions.

The physicist's guide to one of biotechnology's hottest new topics: CRISPR-Cas.

PubMed

Bonomo, Melia E; Deem, Michael W

2018-04-30

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas) constitute a multi-functional, constantly evolving immune system in bacteria and archaea cells. A heritable, molecular memory is generated of phage, plasmids, or other mobile genetic elements that attempt to attack the cell. This memory is used to recognize and interfere with subsequent invasions from the same genetic elements. This versatile prokaryotic tool has also been used to advance applications in biotechnology. Here we review a large body of CRISPR-Cas research to explore themes of evolution and selection, population dynamics, horizontal gene transfer, specific and cross-reactive interactions, cost and regulation, non-immunological CRISPR functions that boost host cell robustness, as well as applicable mechanisms for efficient and specific genetic engineering. We offer future directions that can be addressed by the physics community. Physical understanding of the CRISPR-Cas system will advance uses in biotechnology, such as developing cell lines and animal models, cell labeling and information storage, combatting antibiotic resistance, and human therapeutics.

Validating a Model for Welding Induced Residual Stress Using High-Energy X-ray Diffraction

DOE PAGES

Mach, J. C.; Budrow, C. J.; Pagan, D. C.; ...

2017-03-15

Integrated computational materials engineering (ICME) provides a pathway to advance performance in structures through the use of physically-based models to better understand how manufacturing processes influence product performance. As one particular challenge, consider that residual stresses induced in fabrication are pervasive and directly impact the life of structures. For ICME to be an effective strategy, it is essential that predictive capability be developed in conjunction with critical experiments. In the present paper, simulation results from a multi-physics model for gas metal arc welding are evaluated through x-ray diffraction using synchrotron radiation. A test component was designed with intent to developmore » significant gradients in residual stress, be representative of real-world engineering application, yet remain tractable for finely spaced strain measurements with positioning equipment available at synchrotron facilities. Finally, the experimental validation lends confidence to model predictions, facilitating the explicit consideration of residual stress distribution in prediction of fatigue life.« less

Validating a Model for Welding Induced Residual Stress Using High-Energy X-ray Diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mach, J. C.; Budrow, C. J.; Pagan, D. C.

Integrated computational materials engineering (ICME) provides a pathway to advance performance in structures through the use of physically-based models to better understand how manufacturing processes influence product performance. As one particular challenge, consider that residual stresses induced in fabrication are pervasive and directly impact the life of structures. For ICME to be an effective strategy, it is essential that predictive capability be developed in conjunction with critical experiments. In the present paper, simulation results from a multi-physics model for gas metal arc welding are evaluated through x-ray diffraction using synchrotron radiation. A test component was designed with intent to developmore » significant gradients in residual stress, be representative of real-world engineering application, yet remain tractable for finely spaced strain measurements with positioning equipment available at synchrotron facilities. Finally, the experimental validation lends confidence to model predictions, facilitating the explicit consideration of residual stress distribution in prediction of fatigue life.« less

Development of the Joint NASA/NCAR General Circulation Model

NASA Technical Reports Server (NTRS)

Lin, S.-J.; Rood, R. B.

1999-01-01

The Data Assimilation Office at NASA/Goddard Space Flight Center is collaborating with NCAR/CGD in an ambitious proposal for the development of a unified climate, numerical weather prediction, and chemistry transport model which is suitable for global data assimilation of the physical and chemical state of the Earth's atmosphere. A prototype model based on the NCAR CCM3 physics and the NASA finite-volume dynamical core has been built. A unique feature of the NASA finite-volume dynamical core is its advanced tracer transport algorithm on the floating Lagrangian control-volume coordinate. The model currently has a highly idealized ozone production/loss chemistry derived from the observed 2D (latitude-height) climatology of the recent decades. Nevertheless, the simulated horizontal wave structure of the total ozone is in good qualitative agreement with the observed (TOMS). Long term climate simulations and NWP experiments have been carried out. Current up to date status and futur! e plan will be discussed in the conference.

Phenomenology of the N = 3 Lee-Wick Standard Model

NASA Astrophysics Data System (ADS)

TerBeek, Russell Henry

With the discovery of the Higgs Boson in 2012, particle physics has decidedly moved beyond the Standard Model into a new epoch. Though the Standard Model particle content is now completely accounted for, there remain many theoretical issues about the structure of the theory in need of resolution. Among these is the hierarchy problem: since the renormalized Higgs mass receives quadratic corrections from a higher cutoff scale, what keeps the Higgs boson light? Many possible solutions to this problem have been advanced, such as supersymmetry, Randall-Sundrum models, or sub-millimeter corrections to gravity. One such solution has been advanced by the Lee-Wick Standard Model. In this theory, higher-derivative operators are added to the Lagrangian for each Standard Model field, which result in propagators that possess two physical poles and fall off more rapidly in the ultraviolet regime. It can be shown by an auxiliary field transformation that the higher-derivative theory is identical to positing a second, manifestly renormalizable theory in which new fields with opposite-sign kinetic and mass terms are found. These so-called Lee-Wick fields have opposite-sign propagators, and famously cancel off the quadratic divergences that plague the renormalized Higgs mass. The states in the Hilbert space corresponding to Lee-Wick particles have negative norm, and implications for causality and unitarity are examined. This dissertation explores a variant of the theory called the N = 3 Lee-Wick Standard Model. The Lagrangian of this theory features a yet-higher derivative operator, which produces a propagator with three physical poles and possesses even better high-energy behavior than the minimal Lee-Wick theory. An analogous auxiliary field transformation takes this higher-derivative theory into a renormalizable theory with states of alternating positive, negative, and positive norm. The phenomenology of this theory is examined in detail, with particular emphasis on the collider signatures of Lee-Wick particles, electroweak precision constraints on the masses that the new particles can take on, and scenarios in early-universe cosmology in which Lee-Wick particles can play a significant role.

Modeling Plasma Turbulence and Flows in LAPD using BOUT++

NASA Astrophysics Data System (ADS)

Friedman, B.; Carter, T. A.; Schaffner, D.; Popovich, P.; Umansky, M. V.; Dudson, B.

2010-11-01

A Braginskii fluid model of plasma turbulence in the BOUT code has recently been applied to LAPD at UCLA [1]. While these initial simulations with a reduced model and periodic axial boundary conditions have shown good agreement with measurements (e.g. power spectrum, correlation lengths), these simulations have lacked physics essential for modeling self-consistent, quantitatively correct flows. In particular, the model did not contain parallel plasma flow induced by sheath boundary conditions, and the axisymmetric radial electric field was not consistent with experiment. This work addresses these issues by extending the simulation model in the BOUT++ code [2], a more advanced version of BOUT. Specifically, end-plate sheath boundary conditions are added, as well as equations to evolve electron temperature and parallel ion velocity. Finally, various techniques are used to attempt to match the experimental electric potential profile, including fixing an equilibrium profile, fixing the radial boundaries, and adding an angular momentum source. [4pt] [1] Popovich et al., http://arxiv.org/abs/1005.2418 (2010).[0pt] [2] Dudson et al., Computer Physics Communications 180 (2009).

Two-dimensional habitat modeling in the Yellowstone/Upper Missouri River system

USGS Publications Warehouse

Waddle, T. J.; Bovee, K.D.; Bowen, Z.H.

1997-01-01

This study is being conducted to provide the aquatic biology component of a decision support system being developed by the U.S. Bureau of Reclamation. In an attempt to capture the habitat needs of Great Plains fish communities we are looking beyond previous habitat modeling methods. Traditional habitat modeling approaches have relied on one-dimensional hydraulic models and lumped compositional habitat metrics to describe aquatic habitat. A broader range of habitat descriptors is available when both composition and configuration of habitats is considered. Habitat metrics that consider both composition and configuration can be adapted from terrestrial biology. These metrics are most conveniently accessed with spatially explicit descriptors of the physical variables driving habitat composition. Two-dimensional hydrodynamic models have advanced to the point that they may provide the spatially explicit description of physical parameters needed to address this problem. This paper reports progress to date on applying two-dimensional hydraulic and habitat models on the Yellowstone and Missouri Rivers and uses examples from the Yellowstone River to illustrate the configurational metrics as a new tool for assessing riverine habitats.

3D Printing of Biomolecular Models for Research and Pedagogy

PubMed Central

Da Veiga Beltrame, Eduardo; Tyrwhitt-Drake, James; Roy, Ian; Shalaby, Raed; Suckale, Jakob; Pomeranz Krummel, Daniel

2017-01-01

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology. PMID:28362403

Proceedings of the 1992 topical meeting on advances in reactor physics. Volume 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-04-01

This document, Volume 2, presents proceedings of the 1992 Topical Meeting on Advances in Reactor Physics on March 8--11, 1992 at Charleston, SC. Session topics were as follows: Transport Theory; Fast Reactors; Plant Analyzers; Integral Experiments/Measurements & Analysis; Core Computational Systems; Reactor Physics; Monte Carlo; Safety Aspects of Heavy Water Reactors; and Space-Time Core Kinetics. The individual reports have been cataloged separately. (FI)

Modeling and simulation challenges pursued by the Consortium for Advanced Simulation of Light Water Reactors (CASL)

NASA Astrophysics Data System (ADS)

Turinsky, Paul J.; Kothe, Douglas B.

2016-05-01

The Consortium for the Advanced Simulation of Light Water Reactors (CASL), the first Energy Innovation Hub of the Department of Energy, was established in 2010 with the goal of providing modeling and simulation (M&S) capabilities that support and accelerate the improvement of nuclear energy's economic competitiveness and the reduction of spent nuclear fuel volume per unit energy, and all while assuring nuclear safety. To accomplish this requires advances in M&S capabilities in radiation transport, thermal-hydraulics, fuel performance and corrosion chemistry. To focus CASL's R&D, industry challenge problems have been defined, which equate with long standing issues of the nuclear power industry that M&S can assist in addressing. To date CASL has developed a multi-physics ;core simulator; based upon pin-resolved radiation transport and subchannel (within fuel assembly) thermal-hydraulics, capitalizing on the capabilities of high performance computing. CASL's fuel performance M&S capability can also be optionally integrated into the core simulator, yielding a coupled multi-physics capability with untapped predictive potential. Material models have been developed to enhance predictive capabilities of fuel clad creep and growth, along with deeper understanding of zirconium alloy clad oxidation and hydrogen pickup. Understanding of corrosion chemistry (e.g., CRUD formation) has evolved at all scales: micro, meso and macro. CFD R&D has focused on improvement in closure models for subcooled boiling and bubbly flow, and the formulation of robust numerical solution algorithms. For multiphysics integration, several iterative acceleration methods have been assessed, illuminating areas where further research is needed. Finally, uncertainty quantification and data assimilation techniques, based upon sampling approaches, have been made more feasible for practicing nuclear engineers via R&D on dimensional reduction and biased sampling. Industry adoption of CASL's evolving M&S capabilities, which is in progress, will assist in addressing long-standing and future operational and safety challenges of the nuclear industry.

MO-A-9A-01: Innovation in Medical Physics Practice: 3D Printing Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ehler, E; Perks, J; Rasmussen, K

2014-06-15

3D printing, also called additive manufacturing, has great potential to advance the field of medicine. Many medical uses have been exhibited from facial reconstruction to the repair of pulmonary obstructions. The strength of 3D printing is to quickly convert a 3D computer model into a physical object. Medical use of 3D models is already ubiquitous with technologies such as computed tomography and magnetic resonance imaging. Thus tailoring 3D printing technology to medical functions has the potential to impact patient care. This session will discuss applications to the field of Medical Physics. Topics discussed will include introduction to 3D printing methodsmore » as well as examples of real-world uses of 3D printing spanning clinical and research practice in diagnostic imaging and radiation therapy. The session will also compare 3D printing to other manufacturing processes and discuss a variety of uses of 3D printing technology outside the field of Medical Physics. Learning Objectives: Understand the technologies available for 3D Printing Understand methods to generate 3D models Identify the benefits and drawbacks to rapid prototyping / 3D Printing Understand the potential issues related to clinical use of 3D Printing.« less

Ordering, thermal excitations and phase transitions in dipolar coupled mono-domain magnet arrays

NASA Astrophysics Data System (ADS)

Kapaklis, Vassilios

2015-03-01

Magnetism has provided a fertile test bed for physical models, such as the Heisenberg and Ising models. Most of these investigations have focused on solid materials and relate to their atomic properties such as the atomic magnetic moments and their interactions. Recently, advances in nanotechnology have enabled the controlled patterning of nano-sized magnetic particles, which can be arranged in extended lattices. Tailoring the geometry and the magnetic material of these lattices, the magnetic interactions and magnetization reversal energy barriers can be tuned. This enables interesting interaction schemes to be examined on adjustable length and energy scales. As a result such nano-magnetic systems represent an ideal playground for the study of physical model systems, being facilitated by direct magnetic imaging techniques. One particularly interesting case is that of systems exhibiting frustration, where competing interactions cannot be simultaneously satisfied. This results in a degeneracy of the ground state and intricate thermodynamic properties. An archetypical frustrated physical system is water ice. Similar physics can be mirrored in nano-magnetic arrays, by tuning the arrangement of neighboring magnetic islands, referred to as artificial spin ice. Thermal excitations in such systems resemble magnetic monopoles. In this presentation key concepts related to nano-magnetism and artificial spin ice will be introduced and discussed, along with recent experimental and theoretical developments.

Numerical modelling of river morphodynamics: Latest developments and remaining challenges

NASA Astrophysics Data System (ADS)

Siviglia, Annunziato; Crosato, Alessandra

2016-07-01

Numerical morphodynamic models provide scientific frameworks for advancing our understanding of river systems. The research on involved topics is an important and socially relevant undertaking regarding our environment. Nowadays numerical models are used for different purposes, from answering questions about basic morphodynamic research to managing complex river engineering problems. Due to increasing computer power and the development of advanced numerical techniques, morphodynamic models are now more and more used to predict the bed patterns evolution to a broad spectrum of spatial and temporal scales. The development and the success of application of such models are based upon a wide range of disciplines from applied mathematics for the numerical solution of the equations to geomorphology for the physical interpretation of the results. In this light we organized this special issue (SI) soliciting multidisciplinary contributions which encompass any aspect needed for the development and applications of such models. Most of the papers in the SI stem from contributions to session HS9.5/GM7.11 on numerical modelling and experiments in river morphodynamics at the European Geosciences Union (EGU) General Assembly held in Vienna, April 27th to May 2nd 2014.

Special issue on Econophysics

NASA Astrophysics Data System (ADS)

Richmond, P.; Ausloos, M.; Dacorogna, M.

2002-05-01

The area of research described as “econophysics" is renewing a kinship between physicists and economists and financial practitioners, that has been lost since the 19th century when scientists such as Pascal and Halley made groundbreaking advances in the area. Now, new meetings are revealing new research opportunities outside the established pathways traditionally explored within economics and finance. In December 2001, around 100 researchers from across the world attended the EPS meeting “Applications of Physics to Financial Analysis” (APFA3). This was held in the Museum of London Conference Centre which was chosen for its proximity to the City of London and its trading centres. The meeting was especially useful in bringing together roughly equal numbers of physicists, mathematicians and financial practitioners. Taking part in the conference we had the impression that, whilst the relation between physics and applied finance may still be at an early stage, it is evolving very quickly. As in nature, a sign of evolution is the emergence of different and specialised branches, each w ith their own specific character. Papers covered a range of topics, including: market modelling, risk management, agent-based modelling, hedging in incomplete markets, benchmarking, performance measurement, foreign exchange markets, time series analysis and prediction, efficient market hypothesis, equilibrium and non-equilibrium markets, economic a nd financial networks, the valuation of derivatives, growth and bankruptcy. The meeting was sponsored by the European Physical Society and the UK Institute of Physics. The invited speakers were J.Ph. Bouchaud, J.F. Muzy, K. Sneppen, G. Iori and S. Solomon. Articles outlining some of the more interesting advances in this fie ld have been selected by the Guest Editors, from amongst the submitted articles, and after having been refereed, they are presented here in this edition of EPJ B. APFA3 closed on a positive note. There was a feeling that links between academia and industry are healthy and that these new interactions between Physics and Finance are producing valuable scientific and economic results.

The AAPT Advanced Laboratory Task Force Report

NASA Astrophysics Data System (ADS)

Dunham, Jeffrey

2008-04-01

In late 2005, the American Association of Physics Teachers (AAPT) assembled a seven-member Advanced Laboratory Task Force^ to recommend ways that AAPT could increase the degree and effectiveness of its interactions with physics teachers of upper-division physics laboratories, with the ultimate goal of improving the teaching of advanced laboratories. The task force completed its work during the first half of 2006 and its recommendations were presented to the AAPT Executive Committee in July 2006. This talk will present the recommendations of the task force and actions taken by AAPT in response to them. The curricular goals of the advanced laboratory course at various institutions will also be discussed. The talk will conclude with an appeal to the APS membership to support ongoing efforts to revitalize advanced laboratory course instruction. ^Members of the Advanced Laboratory Task Force: Van Bistrow, University of Chicago; Bob DeSerio, University of Florida; Jeff Dunham, Middlebury College (Chair); Elizabeth George, Wittenburg University; Daryl Preston, California State University, East Bay; Patricia Sparks, Harvey Mudd College; Gerald Taylor, James Madison University; and David Van Baak, Calvin College.