Sample records for field studies final

  1. Field Water Balance of Landfill Final Covers

    EPA Science Inventory

    Landfill covers are critical to waste containment, yet field performance of specific cover designs has not been well documented and seldom been compared in side-by-side testing. A study was conducted to assess the ability of landfill final covers to control percolation into unde...

  2. Development of interactive hypermedia software for high school biology: A research and development study

    NASA Astrophysics Data System (ADS)

    Alturki, Uthman T.

    The goal of this research was to research, design, and develop a hypertext program for students who study biology. The Ecology Hypertext Program was developed using Research and Development (R&D) methodology. The purpose of this study was to place the final "product", a CD-ROM for learning biology concepts, in the hands of teachers and students to help them in learning and teaching process. The product was created through a cycle of literature review, needs assessment, development, and a cycle of field tests and revisions. I applied the ten steps of R&D process suggested by Borg and Gall (1989) which, consisted of: (1) Literature review, (2) Needs assessment, (3) Planning, (4) Develop preliminary product, (5) Preliminary field-testing, (6) Preliminary revision, (7) Main field-testing, (8) Main revision, (9) Final field-testing, and (10) Final product revision. The literature review and needs assessment provided a support and foundation for designing the preliminary product---the Ecology Hypertext Program. Participants in the needs assessment joined a focus group discussion. They were a group of graduate students in education who suggested the importance for designing this product. For the preliminary field test, the participants were a group of high school students studying biology. They were the potential user of the product. They reviewed the preliminary product and then filled out a questionnaire. Their feedback and suggestions were used to develop and improve the product in a step called preliminary revision. The second round of field tasting was the main field test in which the participants joined a focus group discussion. They were the same group who participated in needs assessment task. They reviewed the revised product and then provided ideas and suggestions to improve the product. Their feedback were categorized and implemented to develop the product as in the main revision task. Finally, a group of science teachers participated in this study by reviewing the product and then filling out the questionnaire. Their suggestions were used to conduct the final step in R&D methodology, the final product revision. The primary result of this study was the Ecology Hypertext Program. It considered a small attempt to give students an opportunity to learn through an interactive hypertext program. In addition, using the R&D methodology was an ideal procedure for designing and developing new educational products and material.

  3. Construction records study : final report.

    DOT National Transportation Integrated Search

    1975-09-01

    The purpose of this study was to determine the extent of change and revision necessary for efficient record keeping and to revise the record keeping process in the field, eliminating irrelevant entries. This study attempted to standardize field recor...

  4. 77 FR 38282 - Final Test Guidelines; OCSPP 850 Series; Notice of Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... conditions. EPA is changing the title of OPPTS 850.4450 ``Aquatic Plants Field Study, Tier III'' test....4300 ``Terrestrial Plants Field Study, Tier III'' test guideline. Public Draft OPPTS 850.4025 ``Target..., OCSPP 850.4300 ``Terrestrial Plants Field Study.'' The target area test guideline covers a special case...

  5. A Field Study in the Application of CONSULT-I to the Problem of Inconsistency in Diagnosis and Treatment of Reading Difficulties. Proffitt Grant Final Report.

    ERIC Educational Resources Information Center

    Newman, Anabel P.; Metz, Elizabeth

    A field study tested the application of the CONSULT-I (R) program, which uses artificial intelligence with statistical pattern recognition in constructing a diagnosis and recommending treatment of reading difficulties. Participants in the field study came from 10 southern and central Indiana school districts, both public and parochial, and one…

  6. Effect of steady and time-harmonic magnetic fields on macrosegragation in alloy solidification

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

    Incropera, F.P.; Prescott, P.J.

    Buoyancy-induced convection during the solidification of alloys can contribute significantly to the redistribution of alloy constituents, thereby creating large composition gradients in the final ingot. Termed macrosegregation, the condition diminishes the quality of the casting and, in the extreme, may require that the casting be remelted. The deleterious effects of buoyancy-driven flows may be suppressed through application of an external magnetic field, and in this study the effects of both steady and time-harmonic fields have been considered. For a steady magnetic field, extremely large field strengths would be required to effectively dampen convection patterns that contribute to macrosegregation. However, bymore » reducing spatial variations in temperature and composition, turbulent mixing induced by a time-harmonic field reduces the number and severity of segregates in the final casting.« less

  7. Facing Finality: Cognitive and Cultural Studies on Death and Dying "Arabic Culture"

    ERIC Educational Resources Information Center

    Al-Meshhedany, Amna A. Hasan; Al-Sammerai, Nabiha S. Mehdi

    2010-01-01

    Semantics is a study of human beings cultural background, has from its beginning as a field of study been concerned with the study of humans understanding of culture. Understanding the meaning of "death" has been of great importance to many of the central theoretical developments in this field, especially as it imposes on studies of…

  8. How to Conduct a Research Field Trip

    ERIC Educational Resources Information Center

    Wacker, David G.

    1974-01-01

    Discusses the three phases of a three-day intensive research study field trip: planning and pre-trip training; actual trip; and post-trip report, research and data organization, and final trip evaluation. Included is a sample program of the limnology field trip taken by the Grafton High School, Wisconsin. (CC)

  9. Alabama warm mix asphalt field study : final report.

    DOT National Transportation Integrated Search

    2010-05-01

    The Alabama Department of Transportation hosted a warm mix asphalt field demonstration in August 2007. The warm mix asphalt technology demonstrated was Evotherm Dispersed Asphalt Technology. The WMA and hot mix asphalt produced for the demonstration ...

  10. Cathodic Protection Field Trials on Prestressed Concrete Components, Final Report

    DOT National Transportation Integrated Search

    1998-01-01

    This is the final report in a study to demonstrate the feasibility of using cathodic protection (CP) on concrete bridge structures containing prestressed steel. The interim report, FHWA-RD-95-032, has more details on the installation of selected CP s...

  11. Ellington Field: A Short History, 1917-1963

    NASA Technical Reports Server (NTRS)

    Carlson, Erik D.

    1999-01-01

    My 1998 NASA/ASEE Summer Faculty Fellowship comprised two separate assignments: one to study the history of Ellington Field, the other to evaluate the Johnson Space Center Oral History Project (JSCOHP). This final report gives a summary of my article-length history of Ellington Field, from it inception as a U.S. Army training base to its present commercial/private status. This final report also presents my assessment of the methodology, administration, and continuing value of the JSCOHP, which is a series of recorded interviews with former and long-time JSC employees begun in 1997 to capture the experience of key participants in the human space program.

  12. Soil stabilization field trial : final report.

    DOT National Transportation Integrated Search

    2006-01-01

    A five-year study was initiated seeking materials/additives and procedures that help to mitigate : crack susceptibility in cement-treated material (CTM). A field test program of six 305-m (1000-ft) test : sections was implemented in August 2000. The ...

  13. 78 FR 33633 - Human Exposure to Radiofrequency Electromagnetic Fields

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ..., and 15, et al. Human Exposure to Radiofrequency Electromagnetic Fields; Reassessment of Exposure to Radiofrequency Electromagnetic Fields Limits and Policies; Final Rule and Proposed Rule #0;#0;Federal Register... Radiofrequency Electromagnetic Fields AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY...

  14. Water quality of flow through cured-in-place pipe (CIPP) : final report.

    DOT National Transportation Integrated Search

    2017-02-01

    Though this study did not include replication, the preponderance of the data from field and simulated-field experiments indicates that Curedin-Place : Pipe (CIPP), with some care in enforcing the Caltrans specification and delaying the reintroduction...

  15. Applying Threshold Concepts Theory to an Unsettled Field: An Exploratory Study in Criminal Justice Education

    ERIC Educational Resources Information Center

    Wimshurst, Kerry

    2011-01-01

    Criminal justice education is a relatively new program in higher education in many countries, and its curriculum and parameters remain unsettled. An exploratory study investigated whether threshold concepts theory provided a useful lens by which to explore student understandings of this multidisciplinary field. Eight high-performing final-year…

  16. Outdoor Education, Junior Biology Field Studies.

    ERIC Educational Resources Information Center

    Aikman, John H.; And Others

    Field studies for grade nine and ten biology students are developed in this teacher and student guide for outdoor education. A small section is devoted to teacher pre-planning and final sections are concerned with equipment, audio-visual resources, and a large booklist. Twenty-three investigations related to earth science and biology topics are…

  17. Mithras Studies of the Boundary Between Open and Closed Field Lines.

    DTIC Science & Technology

    1994-01-31

    I ¸ . . A- : - Final Report • March 1995 MITHRAS STUDIES OF THE BOUNDARY BETWEEN OPEN AND CLOSED FIELD LINES John D. Kelly, Program Manager Richard A...Kelly, Program Manager Richard A. Doe, Research Physicist Geoscience and Engineering Center SRI Project 3245 Prepared for: Department of the Air...characteristic energy, energy flux, and an estimate for upward field-aligned current. On the basis of coordinated radar/optical experiments, Vallance Jones et al

  18. A Field Experimental Approach to the Study of Relevance Assessments in Relation to Document Searching. Final Report to the National Science Foundation. Volume I.

    ERIC Educational Resources Information Center

    Rees, Alan M; Schultz, Douglas G.

    An empirical study of the nature and variability of the relevance judgment process was conducted from July 1, 1965 to September 30, 1967. Volume I of the final report presents a literature review and statement of the theoretical framework of the study, a discussion of the experimental design and a summary of data analyses. The study had two…

  19. Field verification of geogrid properties for base course reinforcement applications : final report.

    DOT National Transportation Integrated Search

    2013-11-01

    The proposed field study is a continuation of a recently concluded, ODOT-funded project titled: Development of ODOT Guidelines for the Use of Geogrids in Aggregate Bases, which is aimed at addressing the need for improved guidelines for base reinforc...

  20. Investigation of improved compaction by rubber-tire rollers : final report.

    DOT National Transportation Integrated Search

    1987-01-01

    The study consisted of a review of the literature and field testing on five projects. The field testing on each project consisted of rolling a conventional section using the contractor's steel-wheel rollers and rolling a test section using a rubber-t...

  1. Field Performance Of Three Compacted Clay Landfill Covers

    EPA Science Inventory

    A study was conducted at sites in subtropical Georgia, seasonal and humid Iowa, and arid southeastern California to evaluate the field hydrology of compacted clay covers for final closure of landfills. Water balance of the covers was monitored with large (10 by 20 m ), instrumen...

  2. Saturn's Internal Magnetic Field Revealed by Cassini Grand Finale

    NASA Astrophysics Data System (ADS)

    Cao, H.; Dougherty, M. K.; Khurana, K. K.; Hunt, G. J.; Provan, G.; Kellock, S.; Burton, M. E.; Burk, T. A.

    2017-12-01

    Saturn's internal magnetic field has been puzzling since the first in-situ measurements during the Pioneer 11 Saturn flyby. Cassini magnetometer measurements prior to the Grand Finale phase established 1) the highly axisymmetric nature of Saturn's internal magnetic field with a dipole tilt smaller than 0.06 degrees, 2) at least an order of magnitude slower secular variation rate compared to that of the current geomagnetic field, and 3) expulsion of magnetic fluxes from the equatorial region towards high latitude. The highly axisymmetric nature of Saturn's intrinsic magnetic field not only challenges dynamo theory but also makes an accurate determination of the interior rotation rate of Saturn extremely difficult. The Cassini spacecraft entered the Grand Finale phase in April 2017, during which time the spacecraft dived through the gap between Saturn's atmosphere and the inner edge of the D-ring 22 times before descending into the deep atmosphere of Saturn. The unprecedented proximity to Saturn (reaching 2500 km above the cloud deck) and the highly inclined nature of the Grand Finale orbits provided an ideal opportunity to decode Saturn's internal magnetic field. The fluxgate magnetometer onboard Cassini made precise vector measurements during the Grand Finale phase. Magnetic signals from the interior of the planet, the magnetospheric ring current, the high-latitude field-aligned current (FAC) modulated by the 10.7 hour planetary period oscillation, and low-latitude FACs were observed during the Grand Finale phase. Here we report the magnetometer measurements during the Cassini Grand Finale phase, new features of Saturn's internal magnetic field revealed by these measurements (e.g., the high degree magnetic moments of Saturn, the level of axisymmetry beyond dipole), and implications for the deep interior of Saturn.

  3. Measuring the impact of complete streets projects : preliminary field testing : final report.

    DOT National Transportation Integrated Search

    2016-12-01

    This report describes a field study that sought to assess the impact of Complete Streets (CS) projects in Buffalo, NY. Multiple data collection tools were deployed to capture a diversity of impacts on 8 street corridors where CS projects have been im...

  4. Reflectivity and Teaching Performance of Novice Teachers: Three Years of Investigation

    ERIC Educational Resources Information Center

    Pultorak, Edward; Barnes, Debbie

    2009-01-01

    The purpose of this 3-year investigation was to determine if a relationship exists between teacher reflectivity and the classroom performance of novice teachers when final evaluations are aligned with national standards. This study included 98 novice teachers enrolled in their final field-based teaching experience. Participants reflected over two…

  5. Field Performance Of A Compacted Clay Landfill Final Cover At A Humid Site

    EPA Science Inventory

    A study was conducted in southern Georgia, USA, to evalaute how the hydraulic properties of the compacted clay barrier layer in a final landfill cover changed over a 4-year service life. The cover was part of a test section constructed in a large drainage lysimeter that allowed ...

  6. Federal Research Action Plan on Recycled Tire Crumb Used ...

    EPA Pesticide Factsheets

    Over the past several years, parents, athletes, schools, and communities have raised concerns about the safety of recycled tire crumb rubber used as infill for playing fields and playgrounds in the United States. The public has expressed concerns that the use of these fields could potentially be related to certain health effects. Studies to date have not shown an elevated health risk from playing on fields with tire crumb rubber, but these studies have limitations and do not comprehensively evaluate the concerns about health risks from exposure to tire crumb rubber. This status report provides a summary of activities to date, including: (1) stakeholder outreach, (2) the tire crumb rubber manufacturing industry, (3) the final peer-reviewed Literature Review/Gaps Analysis (LRGA), (4) progress on the research activities, and (5) next steps and a timeline for completion of the final report. The status report does not include research findings.

  7. NADE Members Respond--Developmental Education Research Agenda: Survey of Field Professionals, Part 2

    ERIC Educational Resources Information Center

    Saxon, D. Patrick; Martirosyan, Nara M.; Wentworth, Rebecca A.; Boylan, Hunter R.

    2015-01-01

    This is the final of a two-part article that provides the results of a qualitative study designed to document ideas and beliefs that professionals have regarding an appropriate research agenda on which the field of developmental education should focus in the near future. The participants of the study were members of the National Association for…

  8. Application of integral equation theory to analyze stability of electric field in multimode microwave heating cavity

    NASA Astrophysics Data System (ADS)

    Tang, Zhengming; Hong, Tao; Chen, Fangyuan; Zhu, Huacheng; Huang, Kama

    2017-10-01

    Microwave heating uniformity is mainly dependent on and affected by electric field. However, little study has paid attention to its stability characteristics in multimode cavity. In this paper, this problem is studied by the theory of Freedholm integral equation. Firstly, Helmholtz equation and the electric dyadic Green's function are used to derive the electric field integral equation. Then, the stability of electric field is demonstrated as the characteristics of solutions to Freedholm integral equation. Finally, the stability characteristics are obtained and verified by finite element calculation. This study not only can provide a comprehensive interpretation of electric field in multimode cavity but also help us make better use of microwave energy.

  9. The Feynman-Vernon Influence Functional Approach in QED

    NASA Astrophysics Data System (ADS)

    Biryukov, Alexander; Shleenkov, Mark

    2016-10-01

    In the path integral approach we describe evolution of interacting electromagnetic and fermionic fields by the use of density matrix formalism. The equation for density matrix and transitions probability for fermionic field is obtained as average of electromagnetic field influence functional. We obtain a formula for electromagnetic field influence functional calculating for its various initial and final state. We derive electromagnetic field influence functional when its initial and final states are vacuum. We present Lagrangian for relativistic fermionic field under influence of electromagnetic field vacuum.

  10. Field application of a thermal-sprayed titanium anode for cathodic protection of reinforcing steel in concrete : final report

    DOT National Transportation Integrated Search

    1999-01-01

    This study provided the first field trial of a catalyzed, thermal-sprayed titanium anode for cathodic protection of steel reinforced concrete structures. Catalyzed titanium as an anode material offers the advantage of long life due to the inherent no...

  11. Development of an improved capability for predicting the response of highway bridges : final report.

    DOT National Transportation Integrated Search

    1986-01-01

    This study compared experimental and analytical stress and deflection response of a simply-supported highway bridge as measured from a field test and as predicted from a finite-element analysis. The field test was conducted on one span of a six-span ...

  12. Modeling and simulation of flow field in giant magnetostrictive pump

    NASA Astrophysics Data System (ADS)

    Zhao, Yapeng; Ren, Shiyong; Lu, Quanguo

    2017-09-01

    Recent years, there has been significant research in the design and analysis of giant magnetostrictive pump. In this paper, the flow field model of giant magnetostrictive pump was established and the relationship between pressure loss and working frequency of piston was studied by numerical simulation method. Then, the influence of different pump chamber height on pressure loss in giant magnetostrictive pump was studied by means of flow field simulation. Finally, the fluid pressure and velocity vector distribution in giant magnetostrictive pump chamber were simulated.

  13. Visibility and Visual Characteristics of the Ivanpah Solar Electric Generating System Power Tower Facility

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

    Sullivan, Robert; Abplanalp, Jennifer M.

    2015-03-01

    This report presents the results of a study conducted to document the visibility and visual characteristics of the Ivanpah Solar Electric Generating System (ISEGS), a utility-scale solar power tower facility located on land administered by the U.S. Department of the Interior Bureau of Land Management in southern California. Study activities consisted of field observations of the ISEGS facility and comparison of the observations made in the field with the visual contrast assessments and visual simulations in the ISEGS Final Environmental Impact Statement (Final EIS) and supporting documents created prior to ISEGS construction. Field observations of ISEGS were made from 19more » locations within 35 mi (56 km) of the facility in the course of one week in September 2014. The study results established that reflected sunlight from the receivers was the primary source of visual contrast from the operating ISEGS facility. The ISEGS facility was found to be a major source of visual contrast for all observations up to 20 mi (32 km), and was easily visible at 35 mi. Glare from individual heliostats was frequently visible, and often brighter than the reflected light from the receivers. Heliostat glare caused discomfort for one or more viewers at distances up to 20 mi. The ISEGS power blocks were brightly lit at night, and were conspicuous at the observation distance of approximately 6 mi (10 km). The facility is substantially brighter and is seen more clearly in the field than in photographs of the facility or in the prepared simulations, which were based on photographs. The simulations of the ISEGS facility in the Final EIS, which were evaluated as part of this study, sometimes lacked spatial accuracy and realism. The evaluated simulations generally under-represented the actual visual contrast from the project, and some of the contrast ratings in the Final EIS predicted substantially lower levels of visual contrast than were actually observed for the operating facility.« less

  14. Chiral symmetry breaking in a semilocalized magnetic field

    NASA Astrophysics Data System (ADS)

    Cao, Gaoqing

    2018-03-01

    In this work, we explore the pattern of chiral symmetry breaking and restoration in a solvable magnetic field configuration within the Nambu-Jona-Lasinio model. The special semilocalized static magnetic field can roughly mimic the realistic situation in peripheral heavy ion collisions; thus, the study is important for the dynamical evolution of quark matter. We find that the magnetic-field-dependent contribution from discrete spectra usually dominates over the contribution from continuum spectra and chiral symmetry breaking is locally catalyzed by both the magnitude and scale of the magnetic field. The study is finally extended to the case with finite temperature or chemical potential.

  15. The stochastic spectator

    NASA Astrophysics Data System (ADS)

    Hardwick, Robert J.; Vennin, Vincent; Byrnes, Christian T.; Torrado, Jesús; Wands, David

    2017-10-01

    We study the stochastic distribution of spectator fields predicted in different slow-roll inflation backgrounds. Spectator fields have a negligible energy density during inflation but may play an important dynamical role later, even giving rise to primordial density perturbations within our observational horizon today. During de-Sitter expansion there is an equilibrium solution for the spectator field which is often used to estimate the stochastic distribution during slow-roll inflation. However slow roll only requires that the Hubble rate varies slowly compared to the Hubble time, while the time taken for the stochastic distribution to evolve to the de-Sitter equilibrium solution can be much longer than a Hubble time. We study both chaotic (monomial) and plateau inflaton potentials, with quadratic, quartic and axionic spectator fields. We give an adiabaticity condition for the spectator field distribution to relax to the de-Sitter equilibrium, and find that the de-Sitter approximation is never a reliable estimate for the typical distribution at the end of inflation for a quadratic spectator during monomial inflation. The existence of an adiabatic regime at early times can erase the dependence on initial conditions of the final distribution of field values. In these cases, spectator fields acquire sub-Planckian expectation values. Otherwise spectator fields may acquire much larger field displacements than suggested by the de-Sitter equilibrium solution. We quantify the information about initial conditions that can be obtained from the final field distribution. Our results may have important consequences for the viability of spectator models for the origin of structure, such as the simplest curvaton models.

  16. Fractional Poisson Fields and Martingales

    NASA Astrophysics Data System (ADS)

    Aletti, Giacomo; Leonenko, Nikolai; Merzbach, Ely

    2018-02-01

    We present new properties for the Fractional Poisson process (FPP) and the Fractional Poisson field on the plane. A martingale characterization for FPPs is given. We extend this result to Fractional Poisson fields, obtaining some other characterizations. The fractional differential equations are studied. We consider a more general Mixed-Fractional Poisson process and show that this process is the stochastic solution of a system of fractional differential-difference equations. Finally, we give some simulations of the Fractional Poisson field on the plane.

  17. Semantic Data And Visualization Techniques Applied To Geologic Field Mapping

    NASA Astrophysics Data System (ADS)

    Houser, P. I. Q.; Royo-Leon, M.; Munoz, R.; Estrada, E.; Villanueva-Rosales, N.; Pennington, D. D.

    2015-12-01

    Geologic field mapping involves the use of technology before, during, and after visiting a site. Geologists utilize hardware such as Global Positioning Systems (GPS) connected to mobile computing platforms such as tablets that include software such as ESRI's ArcPad and other software to produce maps and figures for a final analysis and report. Hand written field notes contain important information and drawings or sketches of specific areas within the field study. Our goal is to collect and geo-tag final and raw field data into a cyber-infrastructure environment with an ontology that allows for large data processing, visualization, sharing, and searching, aiding in connecting field research with prior research in the same area and/or aid with experiment replication. Online searches of a specific field area return results such as weather data from NOAA and QuakeML seismic data from USGS. These results that can then be saved to a field mobile device and searched while in the field where there is no Internet connection. To accomplish this we created the GeoField ontology service using the Web Ontology Language (OWL) and Protégé software. Advanced queries on the dataset can be made using reasoning capabilities can be supported that go beyond a standard database service. These improvements include the automated discovery of data relevant to a specific field site and visualization techniques aimed at enhancing analysis and collaboration while in the field by draping data over mobile views of the site using augmented reality. A case study is being performed at University of Texas at El Paso's Indio Mountains Research Station located near Van Horn, Texas, an active multi-disciplinary field study site. The user can interactively move the camera around the study site and view their data digitally. Geologist's can check their data against the site in real-time and improve collaboration with another person as both parties have the same interactive view of the data.

  18. Entanglement of a quantum field with a dispersive medium.

    PubMed

    Klich, Israel

    2012-08-10

    In this Letter we study the entanglement of a quantum radiation field interacting with a dielectric medium. In particular, we describe the quantum mixed state of a field interacting with a dielectric through plasma and Drude models and show that these generate very different entanglement behavior, as manifested in the entanglement entropy of the field. We also present a formula for a "Casimir" entanglement entropy, i.e., the distance dependence of the field entropy. Finally, we study a toy model of the interaction between two plates. In this model, the field entanglement entropy is divergent; however, as in the Casimir effect, its distance-dependent part is finite, and the field matter entanglement is reduced when the objects are far.

  19. Experimental Study of Impinging Jets Flow-Fields

    DTIC Science & Technology

    2016-07-27

    1 Grant # N000141410830 Experimental Study of Impinging Jet Flow-Fields Final Report for Period: Jun 15, 2014 – Jun 14, 2016 PI: Dennis K...impinging jet model in the absence of any jet heating. The results of the computations had been compared with the experimental data produced in the...of the validity of the computations, and also of the experimental approach. Figure 12a. Initial single

  20. The Effect of Using E-Learning Tools in Online and Campus-Based Classrooms on Student Performance

    ERIC Educational Resources Information Center

    Galy, Edith; Downey, Clara; Johnson, Jennie

    2011-01-01

    Creating an integrative research framework that extends a model frequently used in the Information Systems field, the Technology Acceptance Model, together with variables used in the Education field, this empirical study investigates the factors influencing student performance as reflected by their final course grade. The Technology Acceptance…

  1. Coaxial cable sensors and sensing instrument for crack detection in bridge structures--phase I : field qualification/validation planning : final report.

    DOT National Transportation Integrated Search

    2009-11-06

    The objectives of this study are to pre-test analyze a decommissioned RC bridge that is selected in consultation : with New York State Department of Transportation (NYSDOT), and design and plan the field tests of the bridge : for the performance qual...

  2. Time rate of local scour at complex bridge piers field and laboratory analyses : final report, April 2009.

    DOT National Transportation Integrated Search

    2009-04-01

    A local scour evolution field study was conducted under this contract. One of the piers on the A1A Bridge over the Intracoastal Waterway (ICCW) in Fort Pierce, Florida was selected for the test site. The existing local scour hole was filled with sand...

  3. REBCO tape performance under high magnetic field

    NASA Astrophysics Data System (ADS)

    Benkel, Tara; Miyoshi, Yasuyuki; Chaud, Xavier; Badel, Arnaud; Tixador, Pascal

    2017-08-01

    New improvements in high temperature superconductors (HTS) make them a promising candidate for building the next generation of high field magnets. As the conductors became recently available in long length, new projects such as NOUGAT (new magnet generation to generate Tesla at low cost) were started. This project aims at designing and building an HTS magnet prototype generating 10 T inside a 20 T resistive magnet. In this configuration, severe mechanical stress is applied on the insert and its extremities are subject to a high transverse component of the field. Because the conductor has anisotropic properties, it has to be studied carefully under similar conditions as the final prototype. First, this paper presents both the NOUGAT project and its context. Then, it shows the experimental results on short HTS tapes studied under high magnetic field up to 23 T with varying orientation. These results allow validating the current margin of the prototype. Finally, a first wound prototype is presented with experimental results up to 200 A under 16 T. Contribution to the topical issue "Electrical Engineering Symposium (SGE 2016)", edited by Adel Razek

  4. Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

    DOE PAGES

    Chen, Yue; Cunningham, Gregory; Henderson, Michael

    2016-09-21

    Our study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Furthermore, using a newly developedmore » proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors < ~2°, than those from the three empirical models with averaged errors > ~5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. Finally, this study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.« less

  5. Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

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

    Chen, Yue; Cunningham, Gregory; Henderson, Michael

    Our study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Furthermore, using a newly developedmore » proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors < ~2°, than those from the three empirical models with averaged errors > ~5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. Finally, this study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.« less

  6. Soil-cement study : final report.

    DOT National Transportation Integrated Search

    1973-11-01

    This study consisted of an examination of the compressive strengths of soil-cement mixtures on 15 construction projects from the standpoint of design and actual achievement. The laboratory design test was examined closely along with the present field...

  7. 77 FR 14006 - Record of Decision for the Military Housing Privatization Initiative Hurlburt Field and Eglin Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ... DEPARTMENT OF DEFENSE Department of the Air Force Record of Decision for the Military Housing Privatization Initiative Hurlburt Field and Eglin Air Force Base, Florida, Final Environmental Impact Statement... Field and Eglin Air Force Base, Florida, Final Environmental Impact Statement (FEIS). The MHPI ROD...

  8. Detailed analysis of grid-based molecular docking: A case study of CDOCKER-A CHARMm-based MD docking algorithm.

    PubMed

    Wu, Guosheng; Robertson, Daniel H; Brooks, Charles L; Vieth, Michal

    2003-10-01

    The influence of various factors on the accuracy of protein-ligand docking is examined. The factors investigated include the role of a grid representation of protein-ligand interactions, the initial ligand conformation and orientation, the sampling rate of the energy hyper-surface, and the final minimization. A representative docking method is used to study these factors, namely, CDOCKER, a molecular dynamics (MD) simulated-annealing-based algorithm. A major emphasis in these studies is to compare the relative performance and accuracy of various grid-based approximations to explicit all-atom force field calculations. In these docking studies, the protein is kept rigid while the ligands are treated as fully flexible and a final minimization step is used to refine the docked poses. A docking success rate of 74% is observed when an explicit all-atom representation of the protein (full force field) is used, while a lower accuracy of 66-76% is observed for grid-based methods. All docking experiments considered a 41-member protein-ligand validation set. A significant improvement in accuracy (76 vs. 66%) for the grid-based docking is achieved if the explicit all-atom force field is used in a final minimization step to refine the docking poses. Statistical analysis shows that even lower-accuracy grid-based energy representations can be effectively used when followed with full force field minimization. The results of these grid-based protocols are statistically indistinguishable from the detailed atomic dockings and provide up to a sixfold reduction in computation time. For the test case examined here, improving the docking accuracy did not necessarily enhance the ability to estimate binding affinities using the docked structures. Copyright 2003 Wiley Periodicals, Inc.

  9. 2016 availability and disparity study : final report.

    DOT National Transportation Integrated Search

    2016-07-01

    The study examined whether there was a level playing field for minority- and women-owned firms in the Montana transportation : contracting marketplace and for MDT contracting. This information helps MDT set an overall goal for Disadvantage Business :...

  10. Roadwaste management : field trials : final report.

    DOT National Transportation Integrated Search

    2001-03-01

    The Oregon Department of Transportation is concluding a study on roadwaste management. The first phase of the study provided a thorough regulatory analysis and synthesis of known fact compiled in Roadwaste: Issues and Options. The main emphasis of th...

  11. Genesis field operational test : final evaluation report

    DOT National Transportation Integrated Search

    1997-09-01

    This document is the Final Evaluation Report for the Genesis Advanced Traveler Information System (ATIS) Field Operational Test (FOT). Genesis was one of the early projects sponsored by the US Department of Transportation (USDOT) Intelligent Transpor...

  12. The stochastic spectator

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

    Hardwick, Robert J.; Vennin, Vincent; Wands, David

    We study the stochastic distribution of spectator fields predicted in different slow-roll inflation backgrounds. Spectator fields have a negligible energy density during inflation but may play an important dynamical role later, even giving rise to primordial density perturbations within our observational horizon today. During de-Sitter expansion there is an equilibrium solution for the spectator field which is often used to estimate the stochastic distribution during slow-roll inflation. However slow roll only requires that the Hubble rate varies slowly compared to the Hubble time, while the time taken for the stochastic distribution to evolve to the de-Sitter equilibrium solution can bemore » much longer than a Hubble time. We study both chaotic (monomial) and plateau inflaton potentials, with quadratic, quartic and axionic spectator fields. We give an adiabaticity condition for the spectator field distribution to relax to the de-Sitter equilibrium, and find that the de-Sitter approximation is never a reliable estimate for the typical distribution at the end of inflation for a quadratic spectator during monomial inflation. The existence of an adiabatic regime at early times can erase the dependence on initial conditions of the final distribution of field values. In these cases, spectator fields acquire sub-Planckian expectation values. Otherwise spectator fields may acquire much larger field displacements than suggested by the de-Sitter equilibrium solution. We quantify the information about initial conditions that can be obtained from the final field distribution. Our results may have important consequences for the viability of spectator models for the origin of structure, such as the simplest curvaton models.« less

  13. Numerical study of soap-film flow by nonuniform alternating electric fields

    NASA Astrophysics Data System (ADS)

    Nasiri, M.; Shirsavar, R.; Mollaei, S.; Ramos, A.

    2017-02-01

    Fluid flow of suspended liquid films induced by non-uniform alternating electric fields has been reported. The electric fields were generated by two rod-like electrodes perpendicular to the fluid surface. The observed fluid flow was explained qualitatively by considering a charge induction mechanism, where the electric field actuates on the charge induced on the film surface. In this paper we perform a numerical study of this fluid flow taking into account the charge induction mechanism. The numerical results are compared with experiments and good agreement is found. Finally, we propose the application of the device as a new kind of two dimensional fluid pump.

  14. Numerical study of soap-film flow by nonuniform alternating electric fields.

    PubMed

    Nasiri, M; Shirsavar, R; Mollaei, S; Ramos, A

    2017-02-01

    Fluid flow of suspended liquid films induced by non-uniform alternating electric fields has been reported. The electric fields were generated by two rod-like electrodes perpendicular to the fluid surface. The observed fluid flow was explained qualitatively by considering a charge induction mechanism, where the electric field actuates on the charge induced on the film surface. In this paper we perform a numerical study of this fluid flow taking into account the charge induction mechanism. The numerical results are compared with experiments and good agreement is found. Finally, we propose the application of the device as a new kind of two dimensional fluid pump.

  15. Consumer Education: A Conceptual Structure and Planning Guide for Senior High Schools in Wisconsin.

    ERIC Educational Resources Information Center

    Appleton Public Schools, WI.

    Prepared by junior and senior high teachers, the curriculum guide is an interdisciplinary approach by the business education, home economics, and social studies departments to a consumer education course. The initial development of materials was field tested and revised; a second-year field testing of the revised curriculum and a final analysis…

  16. Embedding Research in a Field-Based Module through Peer Review and Assessment for Learning

    ERIC Educational Resources Information Center

    Nicholson, Dawn T.

    2011-01-01

    A case study is presented of embedding research in a final year undergraduate, field-based, physical geography module. The approach is holistic, whereby research-based learning activities simulate the full life cycle of research from inception through to peer review and publication. The learning, teaching and assessment strategy emphasizes the…

  17. Student Voice Use and Vocal Health during an All-State Chorus Event

    ERIC Educational Resources Information Center

    Daugherty, James F.; Manternach, Jeremy N.; Price, Kathy K.

    2011-01-01

    This field-based case study documented students' (N = 256) voice use and voice health perceptions during a 3-day all-state high school chorus event through daily surveys, phonation duration data, analysis of rehearsal voice use behaviors, and field notes. Among the primary results are the following: (a) First and final day survey comparisons…

  18. The Definition and Measurement of Small Military Unit Team Functions. Final Report, July 1980-October 1981.

    ERIC Educational Resources Information Center

    Shiflett, Samuel; And Others

    A study was undertaken to improve the measurement of small team performance within the Army. A provisional taxonomy of team-level performance functions was field-validated; criteria and measures of the functions were developed; and their reliability was examined. The provisional taxonomy, used for observing Army field training exercises, was used…

  19. On the adiabatic limit of Hadamard states

    NASA Astrophysics Data System (ADS)

    Drago, Nicolò; Gérard, Christian

    2017-08-01

    We consider the adiabatic limit of Hadamard states for free quantum Klein-Gordon fields, when the background metric and the field mass are slowly varied from their initial to final values. If the Klein-Gordon field stays massive, we prove that the adiabatic limit of the initial vacuum state is the (final) vacuum state, by extending to the symplectic framework the adiabatic theorem of Avron-Seiler-Yaffe. In cases when only the field mass is varied, using an abstract version of the mode decomposition method we can also consider the case when the initial or final mass vanishes, and the initial state is either a thermal state or a more general Hadamard state.

  20. A study of girder deflections during bridge deck construction : final report.

    DOT National Transportation Integrated Search

    1971-01-01

    Problems involved in obtaining the desired thickness of bridge decks were investigated. The study, which was limited to decks which were longitudinally screeded during construction, included (1) field measurements of the girder deflections during con...

  1. Field studies of Pan troglodytes reviewed and comprehensively mapped, focussing on Japan's contribution to cultural primatology.

    PubMed

    McGrew, William C

    2017-01-01

    Field studies done over decades of wild chimpanzees in East, Central and West Africa have yielded impressive, cumulative findings in cultural primatology. Japanese primatologists have been involved in this advance from the outset, over a wide variety of topics. Here I review the origins and development of field studies of Pan troglodytes, then assess their progress based on analogy between cultural primatology and cultural anthropology, through four stages: natural history, ethnography, ethnology, and intuition. Then, I focus on six topics that continue to yield informative debate: technology, universals, nuanced variation, archaeology, applied primatology, and ecology. Finally, I offer a map of sites of field study of wild chimpanzees. It is clear that Japanese primatologists have made a significant contribution to East-West scientific exchange, especially at the field sites of Bossou and Mahale.

  2. Quench field sensitivity of two-particle correlation in a Hubbard model

    PubMed Central

    Zhang, X. Z.; Lin, S.; Song, Z.

    2016-01-01

    Short-range interaction can give rise to particle pairing with a short-range correlation, which may be destroyed in the presence of an external field. We study the transition between correlated and uncorrelated particle states in the framework of one- dimensional Hubbard model driven by a field. We show that the long time-scale transfer rate from an initial correlated state to final uncorrelated particle states is sensitive to the quench field strength and exhibits a periodic behavior. This process involves an irreversible energy transfer from the field to particles, leading to a quantum electrothermal effect. PMID:27250080

  3. Field trial of solvent-free emulsion in Oregon : final report.

    DOT National Transportation Integrated Search

    2003-03-01

    This final report summarizes construction, laboratory and performance information gathered by ODOT personnel from a single field trial of solvent-free emulsion mix constructed in June 2001. The solvent-free emulsion mix presented several placement pr...

  4. Dynamics of marginally trapped surfaces in a binary black hole merger: Growth and approach to equilibrium

    NASA Astrophysics Data System (ADS)

    Gupta, Anshu; Krishnan, Badri; Nielsen, Alex B.; Schnetter, Erik

    2018-04-01

    The behavior of quasilocal black hole horizons in a binary black hole merger is studied numerically. We compute the horizon multipole moments, fluxes, and other quantities on black hole horizons throughout the merger. These lead to a better qualitative and quantitative understanding of the coalescence of two black holes: how the final black hole is formed, initially grows, and then settles down to a Kerr black hole. We calculate the rate at which the final black hole approaches equilibrium in a fully nonperturbative situation and identify a time at which the linear ringdown phase begins. Finally, we provide additional support for the conjecture that fields at the horizon are correlated with fields in the wave zone by comparing the in-falling gravitational wave flux at the horizon to the outgoing flux as estimated from the gravitational waveform.

  5. The Topology of Three-Dimensional Symmetric Tensor Fields

    NASA Technical Reports Server (NTRS)

    Lavin, Yingmei; Levy, Yuval; Hesselink, Lambertus

    1994-01-01

    We study the topology of 3-D symmetric tensor fields. The goal is to represent their complex structure by a simple set of carefully chosen points and lines analogous to vector field topology. The basic constituents of tensor topology are the degenerate points, or points where eigenvalues are equal to each other. First, we introduce a new method for locating 3-D degenerate points. We then extract the topological skeletons of the eigenvector fields and use them for a compact, comprehensive description of the tensor field. Finally, we demonstrate the use of tensor field topology for the interpretation of the two-force Boussinesq problem.

  6. Saturn's Magnetic Field from the Cassini Grand Finale orbits

    NASA Astrophysics Data System (ADS)

    Dougherty, M. K.; Cao, H.; Khurana, K. K.; Hunt, G. J.; Provan, G.; Kellock, S.; Burton, M. E.; Burk, T. A.

    2017-12-01

    The fundamental aims of the Cassini magnetometer investigation during the Cassini Grand Finale orbits were determination of Saturn's internal planetary magnetic field and the rotation rate of the deep interior. The unique geometry of the orbits provided an unprecedented opportunity to measure the intrinsic magnetic field at close distances never before encountered. The surprising close alignment of Saturn's magnetic axis with its spin axis, known about since the days of Pioneer 11, has been a focus of the team's analysis since Cassini Saturn Orbit Insertion. However, the varying northern and southern magnetospheric planetary period oscillations, which fill the magnetosphere, has been a factor in masking the field signals from the interior. Here we describe an overview of the magnetometer results from the Grand Finale orbits, including confirmation of the extreme axisymmetric nature of the planetary magnetic field, implications for knowledge of the rotation rate and the behaviour of external magnetic fields (arising from the ring current, field aligned currents both at high and low latitudes and the modulating effect of the planetary period oscillations).

  7. Q-Space Scattering Power Laws and the Interior Fields of Particles

    DTIC Science & Technology

    2016-02-12

    SECURITY CLASSIFICATION OF: This work studied the relationship between light scattered by particles of any shape and the interior field of that...Release; Distribution Unlimited UU UU UU UU 12-02-2016 7-Jul-2014 6-Apr-2015 Final Report: Q-space Scattering Power Laws and the Interior Fields of...the Army position, policy or decision, unless so designated by other documentation. 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS (ES) U.S

  8. Unconventional spin dynamics in the honeycomb-lattice material α - RuCl 3 : High-field electron spin resonance studies

    DOE PAGES

    Ponomaryov, A. N.; Schulze, E.; Wosnitza, J.; ...

    2017-12-19

    Here, we present high-field electron spin resonance (ESR) studies of the honeycomb-lattice material α-RuCl 3, a prime candidate to exhibit Kitaev physics. Two modes of antiferromagnetic resonance were detected in the zigzag ordered phase, with magnetic field applied in the a b plane. A very rich excitation spectrum was observed in the field-induced quantum paramagnetic phase. We compare the data obtained with the results of recent numerical calculations, strongly suggesting a very unconventional multiparticle character of the spin dynamics in α-RuCl 3. Finally, the frequency-field diagram of the lowest-energy ESR mode is found consistent with the behavior of the field-inducedmore » energy gap, revealed by thermodynamic measurements.« less

  9. Unconventional spin dynamics in the honeycomb-lattice material α - RuCl 3 : High-field electron spin resonance studies

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

    Ponomaryov, A. N.; Schulze, E.; Wosnitza, J.

    Here, we present high-field electron spin resonance (ESR) studies of the honeycomb-lattice material α-RuCl 3, a prime candidate to exhibit Kitaev physics. Two modes of antiferromagnetic resonance were detected in the zigzag ordered phase, with magnetic field applied in the a b plane. A very rich excitation spectrum was observed in the field-induced quantum paramagnetic phase. We compare the data obtained with the results of recent numerical calculations, strongly suggesting a very unconventional multiparticle character of the spin dynamics in α-RuCl 3. Finally, the frequency-field diagram of the lowest-energy ESR mode is found consistent with the behavior of the field-inducedmore » energy gap, revealed by thermodynamic measurements.« less

  10. Electric Propulsion Study

    DTIC Science & Technology

    1990-08-01

    DTIC FILE COPY AL-TR-89-040 AD: AD-A227 121 Final Report forteprod Electric Propulsion Study 21 Sep 1988 to 30 Nov 1989 DTIC ’ELECTE0OCT 0c 41990u... Electric Propulsion Study (U) 12. PERSONAL AUTHOR(S) Cravens, Dennis J. 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Month, Day) 15. PAGE...identif bv block number) FIELD GROUP SUB-GROUP Inductive theories, electric propulsion, unified field 21 0- theories, Conservatc!±,n Laws, Dynamic

  11. Computer-aided dispatch--traffic management center field operational test final detailed test plan : WSDOT deployment

    DOT National Transportation Integrated Search

    2003-10-01

    The purpose of this document is to expand upon the evaluation components presented in "Computer-aided dispatch--traffic management center field operational test final evaluation plan : WSDOT deployment". This document defines the objective, approach,...

  12. Computer-aided dispatch--traffic management center field operational test : Washington State final report

    DOT National Transportation Integrated Search

    2006-05-01

    This document provides the final report for the evaluation of the USDOT-sponsored Computer-Aided Dispatch - Traffic Management Center Integration Field Operations Test in the State of Washington. The document discusses evaluation findings in the foll...

  13. Erosion evaluation study : final report.

    DOT National Transportation Integrated Search

    1974-06-01

    This study concerned with attempting to develop a laboratory procedure by which products can be evaluated, as quickly as possible after they appear on the market, in order to screen them so that the best ones can be further tested in the field. : Pri...

  14. Management of Social Incentives in Air Force Technical Training: A Field Experiment. Final Report.

    ERIC Educational Resources Information Center

    Hakel, Milton D.; And Others

    The report is a study of the utility of social reinforcement for improving Air Force training. It was conducted through a field evaluation of social incentive instructional systems which would serve to improve student motivation, classroom performance, and attitudes. The participants included a total of 300 trainees from two Air Force bases; 25…

  15. Development and Field Test of Competency Based Instructional Material for a Career Mobility Program for Licensed Practical Nurses. Final Report.

    ERIC Educational Resources Information Center

    Bergen Community Coll., Paramus, NJ.

    The Associate Degree Nursing Program at Bergen Community College developed and field tested competency-based instructional modules in a program designed to allow licensed practical nurses to qualify to take the certification examination for registered nurses after a year of study. Thirteen licensed practical nurses were enrolled in the first class…

  16. Modeling of microstructure evolution in direct metal laser sintering: A phase field approach

    NASA Astrophysics Data System (ADS)

    Nandy, Jyotirmoy; Sarangi, Hrushikesh; Sahoo, Seshadev

    2017-02-01

    Direct Metal Laser Sintering (DMLS) is a new technology in the field of additive manufacturing, which builds metal parts in a layer by layer fashion directly from the powder bed. The process occurs within a very short time period with rapid solidification rate. Slight variations in the process parameters may cause enormous change in the final build parts. The physical and mechanical properties of the final build parts are dependent on the solidification rate which directly affects the microstructure of the material. Thus, the evolving of microstructure plays a vital role in the process parameters optimization. Nowadays, the increase in computational power allows for direct simulations of microstructures during materials processing for specific manufacturing conditions. In this study, modeling of microstructure evolution of Al-Si-10Mg powder in DMLS process was carried out by using a phase field approach. A MATLAB code was developed to solve the set of phase field equations, where simulation parameters include temperature gradient, laser scan speed and laser power. The effects of temperature gradient on microstructure evolution were studied and found that with increase in temperature gradient, the dendritic tip grows at a faster rate.

  17. Mature vs. Active Deep-Seated Landslides: A Comparison Through Two Case Histories in the Alps

    NASA Astrophysics Data System (ADS)

    Delle Piane, Luca; Perello, Paolo; Baietto, Alessandro; Giorza, Alessandra; Musso, Alessia; Gabriele, Piercarlo; Baster, Ira

    2016-06-01

    Two case histories are presented, concerning the still poorly known alpine deep-seated gravitational slope deformations (DSD) located nearby Lanzada (central Italian Alps), and Sarre (north-western Italian Alps). The Lanzada DSD is a constantly monitored, juvenile, and active phenomenon, partly affecting an existing hydropower plant. Its well-developed landforms allow a precise field characterization of the instability-affected area. The Sarre DSD is a mature, strongly remodeled phenomenon, where the only hazard factor is represented by secondary instability processes at the base of the slope. In this case, the remodeling imposed the adoption of complementary analytical techniques to support the field work. The two presented studies had to be adapted to external factors, namely (a) available information, (b) geological and geomorphological setting, and (c) final scope of the work. The Lanzada case essentially relied upon accurate field work; the Sarre case was mostly based on digital image and DTM processing. In both cases a sound field structural analysis formed the necessary background to understand the mechanisms leading to instability. A back-analysis of the differences between the study methods adopted in the two cases is finally presented, leading to suggestions for further investigations and design.

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

    Paudel, Nava Raj, E-mail: nrpaudel@yahoo.com; Shvydka, Diana; Parsai, E. Ishmael

    Purpose: Gold nanoparticles (GNPs) are known to be effective mediators in microwave hyperthermia. Interaction with an electromagnetic field, large surface to volume ratio, and size quantization of nanoparticles (NPs) can lead to increased cell killing beyond pure heating effects. The purpose of this study is to explore the possibility of free radical generation by GNPs in aqueous media when they are exposed to a microwave field. Methods: A number of samples with 500 mM 5,5-dimethyl-1-pyrroline N-oxide (DMPO) in 20 ppm GNP colloidal suspensions were scanned with an electron paramagnetic resonance (EPR)/electron spin resonance spectrometer to generate and detect free radicals.more » A fixed (9.68 GHz) frequency microwave from the spectrometer has served for both generation and detection of radicals. EPR spectra obtained as first derivatives of intensity with the spectrometer were double integrated to get the free radical signal intensities. Power dependence of radical intensity was studied by applying various levels of microwave power (12.5, 49.7, and 125 mW) while keeping all other scan parameters the same. Free radical signal intensities from initial and final scans, acquired at the same power levels, were compared. Results: Hydroxyl radical (OH⋅) signal was found to be generated due to the exposure of GNP–DMPO colloidal samples to a microwave field. Intensity of OH⋅ signal thus generated at 12.5 mW microwave power for 2.8 min was close to the intensity of OH⋅ signal obtained from a water–DMPO sample exposed to 1.5 Gy ionizing radiation dose. For repeated scans, higher OH⋅ intensities were observed in the final scan for higher power levels applied between the initial and the final scans. Final intensities were higher also for a shorter time interval between the initial and the final scans. Conclusions: Our results observed for the first time demonstrate that GNPs generate OH⋅ radicals in aqueous media when they are exposed to a microwave field. If OH⋅ radicals can be generated close to deoxyribonucleic acid of cells by proper localization of NPs, NP-aided microwave hyperthermia can yield cell killing via both elevated temperature and free radical generation.« less

  19. A novel property of gold nanoparticles: Free radical generation under microwave irradiation.

    PubMed

    Paudel, Nava Raj; Shvydka, Diana; Parsai, E Ishmael

    2016-04-01

    Gold nanoparticles (GNPs) are known to be effective mediators in microwave hyperthermia. Interaction with an electromagnetic field, large surface to volume ratio, and size quantization of nanoparticles (NPs) can lead to increased cell killing beyond pure heating effects. The purpose of this study is to explore the possibility of free radical generation by GNPs in aqueous media when they are exposed to a microwave field. A number of samples with 500 mM 5,5-dimethyl-1-pyrroline N-oxide (DMPO) in 20 ppm GNP colloidal suspensions were scanned with an electron paramagnetic resonance (EPR)/electron spin resonance spectrometer to generate and detect free radicals. A fixed (9.68 GHz) frequency microwave from the spectrometer has served for both generation and detection of radicals. EPR spectra obtained as first derivatives of intensity with the spectrometer were double integrated to get the free radical signal intensities. Power dependence of radical intensity was studied by applying various levels of microwave power (12.5, 49.7, and 125 mW) while keeping all other scan parameters the same. Free radical signal intensities from initial and final scans, acquired at the same power levels, were compared. Hydroxyl radical (OH⋅) signal was found to be generated due to the exposure of GNP-DMPO colloidal samples to a microwave field. Intensity of OH⋅ signal thus generated at 12.5 mW microwave power for 2.8 min was close to the intensity of OH⋅ signal obtained from a water-DMPO sample exposed to 1.5 Gy ionizing radiation dose. For repeated scans, higher OH⋅ intensities were observed in the final scan for higher power levels applied between the initial and the final scans. Final intensities were higher also for a shorter time interval between the initial and the final scans. Our results observed for the first time demonstrate that GNPs generate OH⋅ radicals in aqueous media when they are exposed to a microwave field. If OH⋅ radicals can be generated close to deoxyribonucleic acid of cells by proper localization of NPs, NP-aided microwave hyperthermia can yield cell killing via both elevated temperature and free radical generation.

  20. Computer-aided dispatch--traffic management center field operational test : state of Utah final report

    DOT National Transportation Integrated Search

    2006-07-01

    This document provides the final report for the evaluation of the USDOT-sponsored Computer-Aided Dispatch Traffic Management Center Integration Field Operations Test in the State of Utah. The document discusses evaluation findings in the followin...

  1. Computer-aided dispatch--traffic management center field operational test final test plans : state of Utah

    DOT National Transportation Integrated Search

    2004-01-01

    The purpose of this document is to expand upon the evaluation components presented in "Computer-aided dispatch--traffic management center field operational test final evaluation plan : state of Utah". This document defines the objective, approach, an...

  2. Hazardous material transportation safety and security field operational test final detailed test plans : executive summary

    DOT National Transportation Integrated Search

    2003-09-16

    The objective of this Hazardous Material (HazMat) Transportation Safety and Security Field Operational Test (FOT) Final Detailed Test Plans evaluation is to measure the impact of technology solutions on the safety, security, and operational efficienc...

  3. Monitoring load distribution and fatigue cost estimates of heavy truck loads on Louisiana state bridges : research project capsule.

    DOT National Transportation Integrated Search

    2009-03-01

    Several LTRC funded studies have : evaluated fatigue damage from heavy : truck loads (GVW 100,000 lb.) on : Louisiana Bridges.(1-4) The final : reports for these studies : recommended a field investigation to : verify the theoretical studies. LTRC : ...

  4. Building Assessment Survey and Evaluation Study: Quality Assurance Project Plan

    EPA Pesticide Factsheets

    This supplement describes QA/QC aspects of the implementation of the Office of Radiation and Indoor Air's BASE protocol including: recruitment of study buildings, execution of field studies in each building, and the processing and coordination of each building's ata for final submittal to EPA.

  5. Fast generation of complex modulation video holograms using temporal redundancy compression and hybrid point-source/wave-field approaches

    NASA Astrophysics Data System (ADS)

    Gilles, Antonin; Gioia, Patrick; Cozot, Rémi; Morin, Luce

    2015-09-01

    The hybrid point-source/wave-field method is a newly proposed approach for Computer-Generated Hologram (CGH) calculation, based on the slicing of the scene into several depth layers parallel to the hologram plane. The complex wave scattered by each depth layer is then computed using either a wave-field or a point-source approach according to a threshold criterion on the number of points within the layer. Finally, the complex waves scattered by all the depth layers are summed up in order to obtain the final CGH. Although outperforming both point-source and wave-field methods without producing any visible artifact, this approach has not yet been used for animated holograms, and the possible exploitation of temporal redundancies has not been studied. In this paper, we propose a fast computation of video holograms by taking into account those redundancies. Our algorithm consists of three steps. First, intensity and depth data of the current 3D video frame are extracted and compared with those of the previous frame in order to remove temporally redundant data. Then the CGH pattern for this compressed frame is generated using the hybrid point-source/wave-field approach. The resulting CGH pattern is finally transmitted to the video output and stored in the previous frame buffer. Experimental results reveal that our proposed method is able to produce video holograms at interactive rates without producing any visible artifact.

  6. Concrete probe-strength study : final report.

    DOT National Transportation Integrated Search

    1969-12-01

    The Windsor probe - test system was evaluated for determining compressive strength of concrete by comparing probe strengths against cylinder and core strengths from both laboratory and field-poured concrete. Advantages and disadvantages of this syste...

  7. Settlement study : final report.

    DOT National Transportation Integrated Search

    1982-09-01

    This report covers field observations of several medium and high embankments' settlement along Interstate Highways 12 and 20. The predictive settlements from laboratory tests (consolidation tests) are given in an interim report published in July, 198...

  8. Nonlinear evolution and final fate of (charged) superradiant instability

    NASA Astrophysics Data System (ADS)

    Green, Stephen; Bosch, Pablo; Lehner, Luis

    2016-03-01

    We describe the full nonlinear development of the superradiant instability for a charged massless scalar field, coupled to general relativity and electromagnetism, in the vicinity of a Reissner-Nordstrom-AdS black hole. The presence of the negative cosmological constant provides a natural context for considering perfectly reflecting boundary conditions and studying the dynamics as the scalar field interacts repeateadly with the black hole. At early times, small superradiant perturbations grow as expected from linearized studies. Backreaction then causes the black hole to lose charge and mass until the perturbation becomes nonsuperradiant, with the final state described by a stable hairy black hole. For large gauge coupling, the instability extracts a large amount of charge per unit mass, resulting in greater entropy increase. We discuss the implications of the observed behavior for the general problem of superradiance in black hole spacetimes.

  9. Primordial magnetic fields from a non-singular bouncing cosmology

    NASA Astrophysics Data System (ADS)

    Membiela, Federico Agustín

    2014-08-01

    Although inflation is a natural candidate to generate the lengths of coherence of magnetic fields needed to explain current observations, it needs to break conformal invariance of electromagnetism to obtain significant magnetic amplitudes. Of the simplest realizations are the kinetically-coupled theories f2(ϕ)FμνF (or IFF theories). However, these are known to suffer from electric fields backreaction or the strong coupling problem. In this work we shall confirm that such class of theories are problematic to support magnetogenesis during inflationary cosmology. On the contrary, we show that a bouncing cosmology with a contracting phase dominated by an equation of state with p>-ρ/3 can support magnetogenesis, evading the backreaction/strong-coupling problem. Finally, we study safe magnetogenesis in a particular bouncing model with an ekpyrotic-like contracting phase. In this case we found that f2(ϕ)F2-instabilities might arise during the final kinetic-driven expanding phase for steep ekpyrotic potentials.

  10. Curvature tensors unified field equations on SEXn

    NASA Astrophysics Data System (ADS)

    Chung, Kyung Tae; Lee, Il Young

    1988-09-01

    We study the curvature tensors and field equations in the n-dimensional SE manifold SEXn. We obtain several basic properties of the vectors S λ and U λ and then of the SE curvature tensor and its contractions, such as a generalized Ricci identity, a generalized Bianchi identity, and two variations of the Bianchi identity satisfied by the SE Einstein tensor. Finally, a system of field equations is discussed in SEXn and one of its particular solutions is constructed and displayed.

  11. Quality Controlled Radiosonde Profile from MC3E

    DOE Data Explorer

    Toto, Tami; Jensen, Michael

    2014-11-13

    The sonde-adjust VAP produces data that corrects documented biases in radiosonde humidity measurements. Unique fields contained within this datastream include smoothed original relative humidity, dry bias corrected relative humidity, and final corrected relative humidity. The smoothed RH field refines the relative humidity from integers - the resolution of the instrument - to fractions of a percent. This profile is then used to calculate the dry bias corrected field. The final correction fixes a time-lag problem and uses the dry-bias field as input into the algorithm. In addition to dry bias, solar heating is another correction that is encompassed in the final corrected relative humidity field. Additional corrections were made to soundings at the extended facility sites (S0*) as necessary: Corrected erroneous surface elevation (and up through rest of height of sounding), for S03, S04 and S05. Corrected erroneous surface pressure at Chanute (S02).

  12. Health psychology in Ghana: A review of the multidisciplinary origins of a young sub-field and its future prospects.

    PubMed

    de-Graft Aikins, Ama

    2018-03-01

    This article presents a historical overview of psychology applied to health and health psychology in Ghana. A brief history of health, illness and healthcare in Ghana is introduced. Then, the history of psychology in Ghana is presented, with signposts of the major turns in the field in relation to psychology and other disciplines applied to health and the emergence of health psychology as a sub-field. Selected health psychology studies are reviewed to highlight ideological trends in the field. Finally, future prospects are considered in terms of how the sub-field can transition into an established critical field with unique contributions to make to global health psychology.

  13. Choosing a Field: How Graduate Student Choices of Field Sites Reflect Different Ideas of "Real" Anthropology in Colombia and the United States

    ERIC Educational Resources Information Center

    Macia, Laura

    2012-01-01

    This paper examines the decisions and motivations of graduate students in cultural anthropology when defining the field sites and topics of their final projects. The decisions among students at the Universidad de los Andes in Colombia are contrasted with those at the University of Pittsburgh in the United States. A review of recent final projects…

  14. Optical Near-Field Plates

    DTIC Science & Technology

    2015-04-08

    AFRL-OSR-VA-TR-2015-0085 OPTICAL NEAR-FILED PLATES Roberto Merlin UNIVERSITY OF MICHIGAN Final Report 04/08/2015 DISTRIBUTION A: Distribution...03-2015 Final 09/01/2009-12/31/2014 Optical Near-Field Plates FA9550-09-1-0636 erlin, Roberto, D. The University of Michigan Ann Arbor, MI 48109...distribution unlimited Optical near-field plates were designed using antisymmetric plasmon modes to generate abrupt phase changes within a fraction of a

  15. Analysis of a Field Study: Programs, Services, and Approaches Toward the Reduction of Adolescent Pregnancy. Final Report.

    ERIC Educational Resources Information Center

    Moore, Audrey

    This field survey relative to adolescent pregnancy was undertaken through site visits and interviews. Data indicated that: (1) while many people are carrying out excellent programs and activities, the numbers are small compared to the need; (2) in some types of services the old tried-and-found-wanting approaches are perpetuated; (3) in some,…

  16. A Field-Based Aquatic Life Benchmark for Conductivity in Central Appalachian Streams (Final Report)

    EPA Science Inventory

    EPA announced the availability of the final report, A Field-Based Aquatic Life Benchmark for Conductivity in Central Appalachian Streams. This report describes a method to characterize the relationship between the extirpation (the effective extinction) of invertebrate g...

  17. Experienced Teacher Fellowship Program. Final Report.

    ERIC Educational Resources Information Center

    Wolansky, William D.; Cochran, Leslie H.

    The Industrial Arts Fellowship Program provides an opportunity for 24 experienced teachers to pursue graduate study related to two occupational clusters: industrial materials and processes or energy and propulsion systems. As part of their studies, students developed, field tested, and evaluated curriculum materials which applied these evolving…

  18. Field testing of hand-held infrared thermography, phase II TPF-5(247) : final report.

    DOT National Transportation Integrated Search

    2016-05-01

    This report is the second of two volumes that document results from the pooled fund study TPF-5 (247), Development of : Handheld Infrared Thermography, Phase II. The interim report (volume I) studied the implementation of handheld thermography : by p...

  19. Paving block study : final report.

    DOT National Transportation Integrated Search

    1971-10-01

    The Louisiana Department of Highways has conducted field tests with an experimental revetment consisting of cellular concrete revetment blocks used in conjunction with plastic filter cloth and/or vegetation such as grass or vines. The precast blocks ...

  20. Use of psi(alpha)-ETOs in the unified treatment of electronic attraction, electric field and electric field gradient multicenter integrals of screened Coulomb potentials over Slater orbitals.

    PubMed

    Guseinov, Israfil

    2004-02-01

    In this study, using complete orthonormal sets of Psi(alpha)-ETOs (where alpha=1, 0, -1, -2, ...) introduced by the author, a large number of series expansion formulae for the multicenter electronic attraction (EA), electric field (EF) and electric field gradient (EFG) integrals of the Yukawa-like screened Coulomb potentials (SCPs) is presented through the new central and noncentral potentials and the overlap integrals with the same screening constants. The final results obtained are valid for arbitrary locations of STOs and their parameters.

  1. Effects of high voltage transmission lines on honeybees: a feasibility study. Final report

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

    Greenberg, B.

    1977-07-01

    Methodology is described for the investigation of the effects of electric fields generated by high-tension power lines on honeybees (Apis mellifera L.). The parameters to be measured include colony population, honey stores, amount of acoustical noise generated by the bees, in-hive temperature, incidence of queen cell production, and tendency to swarm. Accompanying dosimetric support includes in-hive electric field measurements, development of shielding to eliminate the electric field from selected colonies, analysis of the acoustical data, and periodic checks on the ambient electric field present under the line and at the control site.

  2. Investigation of consolidation kinetics and microstructure evolution of Al alloys in direct metal laser sintering using phase field simulation

    NASA Astrophysics Data System (ADS)

    Bimal Satpathy, Bubloom; Nandy, Jyotirmoy; Sahoo, Seshadev

    2018-03-01

    Direct metal laser sintering is one of the very efficient processes which comes under the field of additive manufacturing and is capable of producing products of good mechanical and physical properties. The process parameters affect the physical and mechanical properties of the final products. Rapid solidification plays an important role in the consolidation kinetics as the powdered material sinters and forms a polycrystalline structure. In the recent times, the enormous use of computational modeling has helped in examining the utility of final products in a wide range of applications. In this study, a phase field model has been implemented to foresee the consolidation kinetics during the liquid state sintering. Temperature profiles have been used to study the densification behavior and neck growth which is caused by the surface diffusion of particles at initial stage. Later, importance of grain boundary and the volume diffusion during densification process is analyzed. It is also found that with rise in temperature, neck growth also increases rapidly due to the interaction of adjacent grains through grain boundary diffusion and stabilization of grain growth.

  3. Simulation study of spheroidal dust gains charging: Applicable to dust grain alignment

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

    Zahed, H.; Sobhanian, S.; Mahmoodi, J.

    2006-09-15

    The charging process of nonspherical dust grains in an unmagnetized plasma as well as in the presence of a magnetic field is studied. It is shown that unlike the spherical dust grain, due to nonhomogeneity of charge distribution on the spheroidal dust surface, the resultant electric forces on electrons and ions are different. This process produces some surface charge density gradient on the nonspherical grain surface. Effects of a magnetic field and other plasma parameters on the properties of the dust particulate are studied. It has been shown that the alignment direction could be changed or even reversed with themore » magnetic field and plasma parameters. Finally, the charge distribution on the spheroidal grain surface is studied for different ambient parameters including plasma temperature, neutral collision frequency, and the magnitude of the magnetic field.« less

  4. Towards timelike singularity via AdS dual

    NASA Astrophysics Data System (ADS)

    Bhowmick, Samrat; Chatterjee, Soumyabrata

    2017-07-01

    It is well known that Kasner geometry with spacelike singularity can be extended to bulk AdS-like geometry, furthermore, one can study field theory on this Kasner space via its gravity dual. In this paper, we show that there exists a Kasner-like geometry with timelike singularity for which one can construct a dual gravity description. We then study various extremal surfaces including spacelike geodesics in the dual gravity description. Finally, we compute correlators of highly massive operators in the boundary field theory with a geodesic approximation.

  5. Transgenic miR156 switchgrass in the field: growth, recalcitrance and rust susceptibility

    DOE PAGES

    Baxter, Holly L.; Mazarei, Mitra; Dumitrache, Alexandru; ...

    2017-04-24

    Sustainable utilization of lignocellulosic perennial grass feedstocks will be enabled by high biomass production and optimized cell wall chemistry for efficient conversion into biofuels. MicroRNAs are regulatory elements that modulate the expression of genes involved in various biological functions in plants, including growth and development. In greenhouse studies, overexpressing a microRNA (miR156) gene in switchgrass had dramatic effects on plant architecture and flowering, which appeared to be driven by transgene expression levels. High expressing lines were extremely dwarfed, whereas low and moderate-expressing lines had higher biomass yields, improved sugar release and delayed flowering. Four lines with moderate or low miR156more » overexpression from the prior greenhouse study were selected for a field experiment to assess the relationship between miR156 expression and biomass production over three years. We also analysed important bioenergy feedstock traits such as flowering, disease resistance, cell wall chemistry and biofuel production. Phenotypes of the transgenic lines were inconsistent between the greenhouse and the field as well as among different field growing seasons. One low expressing transgenic line consistently produced more biomass (25%–56%) than the control across all three seasons, which translated to the production of 30% more biofuel per plant during the final season. The other three transgenic lines produced less biomass than the control by the final season, and the two lines with moderate expression levels also exhibited altered disease susceptibilities. Results of this study emphasize the importance of performing multiyear field studies for plants with altered regulatory transgenes that target plant growth and development.« less

  6. Transgenic miR156 switchgrass in the field: growth, recalcitrance and rust susceptibility

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

    Baxter, Holly L.; Mazarei, Mitra; Dumitrache, Alexandru

    Sustainable utilization of lignocellulosic perennial grass feedstocks will be enabled by high biomass production and optimized cell wall chemistry for efficient conversion into biofuels. MicroRNAs are regulatory elements that modulate the expression of genes involved in various biological functions in plants, including growth and development. In greenhouse studies, overexpressing a microRNA (miR156) gene in switchgrass had dramatic effects on plant architecture and flowering, which appeared to be driven by transgene expression levels. High expressing lines were extremely dwarfed, whereas low and moderate-expressing lines had higher biomass yields, improved sugar release and delayed flowering. Four lines with moderate or low miR156more » overexpression from the prior greenhouse study were selected for a field experiment to assess the relationship between miR156 expression and biomass production over three years. We also analysed important bioenergy feedstock traits such as flowering, disease resistance, cell wall chemistry and biofuel production. Phenotypes of the transgenic lines were inconsistent between the greenhouse and the field as well as among different field growing seasons. One low expressing transgenic line consistently produced more biomass (25%–56%) than the control across all three seasons, which translated to the production of 30% more biofuel per plant during the final season. The other three transgenic lines produced less biomass than the control by the final season, and the two lines with moderate expression levels also exhibited altered disease susceptibilities. Results of this study emphasize the importance of performing multiyear field studies for plants with altered regulatory transgenes that target plant growth and development.« less

  7. Market-Based Adult Lifelong Learning Performance Measures for Public Libraries Serving Lower Income and Majority-Minority Markets. Final Performance Report. September 1, 1996-August 31, 1999.

    ERIC Educational Resources Information Center

    Koontz, Christine; Jue, Dean K.; Lance, Keith Curry

    This document is the final performance report for a Field Initiated Studies (FIS) project that addressed the need for a better assessment of public library services for adult lifelong learning in majority-minority and lower income library market areas. After stating the major educational problem addressed by the FIS project, the report lists the…

  8. An Investigation into Quantifying Micron-G Changes in a Gravitational Field of 1G

    NASA Technical Reports Server (NTRS)

    Gauthier, Richard R.; Gilbert, John A.

    1997-01-01

    This project called for the development of an accelerometer designed to be used in conjunction with gravity shielding experiments. The device had to measure local gravitational changes on the order of a few micro-G's (micron-G) with a spatial resolution greater than one measurement per ten square centimeters. Measurements had to be made at a minimum rate of two per second. Tasks included the design, development and demonstration of a prototype. The deliverable consisted of three copies of this final report. The study resulted in the development of a Transversely Suspended Accelerometer (TSA) which met all of the technical specifications. Different generations of the device were demonstrated to NASA/MSFC personnel as they were developed. The final prototype is available for further demonstration and future use. The study draws attention to the fact that the magnetic fields required to produce gravitational shielding may result in apparent decreases in the weights of suspended objects on the order of those attributed to the effect itself. This observation reinforces the need to quantify the influences of the magnetic field on any measurement device used to study gravitational shielding. This task was accomplished for the TSA.

  9. Magnetohydrodynamical Effects on Nuclear Deflagration Fronts in Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Hristov, Boyan; Collins, David C.; Hoeflich, Peter; Weatherford, Charles A.; Diamond, Tiara R.

    2018-05-01

    This article presents a study of the effects of magnetic fields on non-distributed nuclear burning fronts as a possible solution to a fundamental problem for the thermonuclear explosion of a Chandrasekhar mass ({M}Ch}) white dwarf (WD), the currently favored scenario for the majority of Type Ia SNe. All existing 3D hydrodynamical simulations predict strong global mixing of the burning products due to Rayleigh–Taylor (RT) instabilities, which contradicts observations. As a first step toward studying the flame physics, we present a set of computational magnet-hydrodynamic models in rectangular flux tubes, resembling a small inner region of a WD. We consider initial magnetic fields up to {10}12 {{G}} of various orientations. We find an increasing suppression of RT instabilities starting at about {10}9 {{G}}. The front speed tends to decrease with increasing magnitude up to about {10}11 {{G}}. For even higher fields new small-scale, finger-like structures develop, which increase the burning speed by a factor of 3 to 4 above the field-free RT-dominated regime. We suggest that the new instability may provide sufficiently accelerated energy production during the distributed burning regime to go over the Chapman–Jougey limit and trigger a detonation. Finally, we discuss the possible origins of high magnetic fields during the final stage of the progenitor evolution or the explosion.

  10. Note: An approach to 1000 T using the electro-magnetic flux compression.

    PubMed

    Nakamura, D; Sawabe, H; Takeyama, S

    2018-01-01

    The maximum magnetic field obtained by the electro-magnetic flux compression technique was investigated with respect to the initial seed magnetic field. It was found that the reduction in the seed magnetic field from 3.8 T to 3.0 T led to a substantial increase in the final peak magnetic field. The optical Faraday rotation method with a minimal size probe evades disturbances from electromagnetic noise and shockwave effects to detect such final peak fields in a reduced space of an inner wall of the imploding liner. The Faraday rotation signal recorded the maximum magnetic field increased significantly to the highest magnetic field of 985 T approaching 1000 T, ever achieved by the electro-magnetic flux compression technique as an indoor experiment.

  11. The 100 most cited articles in metastatic spine disease.

    PubMed

    Cohen, Jonathan; Alan, Nima; Zhou, James; Kojo Hamilton, D

    2016-08-01

    OBJECTIVE Despite the growing neurosurgical literature, a subset of pioneering studies have significantly impacted the field of metastatic spine disease. The purpose of this study was to identify and analyze the 100 most frequently cited articles in the field. METHODS A keyword search using the Thomson Reuters Web of Science was conducted to identify articles relevant to the field of metastatic spine disease. The results were filtered based on title and abstract analysis to identify the 100 most cited articles. Statistical analysis was used to characterize journal frequency, past and current citations, citation distribution over time, and author frequency. RESULTS The total number of citations for the final 100 articles ranged from 74 to 1169. Articles selected for the final list were published between 1940 and 2009. The years in which the greatest numbers of top-100 studies were published were 1990 and 2005, and the greatest number of citations occurred in 2012. The majority of articles were published in the journals Spine (15), Cancer (11), and the Journal of Neurosurgery (9). Forty-four individuals were listed as authors on 2 articles, 9 were listed as authors on 3 articles, and 2 were listed as authors on 4 articles in the top 100 list. The most cited article was the work by Batson (1169 citations) that was published in 1940 and described the role of the vertebral veins in the spread of metastases. The second most cited article was Patchell's 2005 study (594 citations) discussing decompressive resection of spinal cord metastases. The third most cited article was the 1978 study by Gilbert that evaluated treatment of epidural spinal cord compression due to metastatic tumor (560 citations). CONCLUSIONS The field of metastatic spine disease has witnessed numerous milestones and so it is increasingly important to recognize studies that have influenced the field. In this bibliographic study the authors identified and analyzed the most influential articles in the field of metastatic spine disease.

  12. Contrasting effects of nitrogenous pollution on fitness and swimming performance of Iberian waterfrog, Pelophylax perezi (Seoane, 1885), larvae in mesocosms and field enclosures.

    PubMed

    Egea-Serrano, A; Tejedo, M

    2014-01-01

    Amphibians are declining worldwide and pollutants have been implicated as a major contributor to these declines. To understand these declines, many studies have assessed the impact of pollutants on amphibian behaviour. However, information regarding their effect on locomotor abilities, as well as the intra-specific variation of the tolerance to pollutants, is extremely rare. Further, the majority of studies examining the impact of pollutants on amphibians have been conducted in simplified laboratory settings. Given the complexity of natural systems, determining whether amphibian responses in laboratory studies can be generalized to more realistic natural scenarios is critical. Towards this goal, this study assessed the impact of nitrogenous pollution on survival and fitness-related larval traits (growth, mass and swimming performance) for three populations of the frog Pelophylax perezi, exposed to different degrees of eutrophication in two different and complementary experiments: (1) pond mesocosms, with NH4Cl isolated or combined with NaNO2 and NaNO3, and (2) field enclosures placed in natural streams differing in their degree of pollution. For both mesocosm and field enclosure experiments, larval mortality was unaffected by nitrogenous pollution. However, in the mesocosm experiment, exposure to nitrogenous compounds reduced final larvae mass and growth. In contrast, in the enclosure experiment, polluted locations facilitated final mass and growth of surviving tadpoles. Population-level variation in the effect of pollution was observed for final larval mass in the mesocosm but not in the field enclosure experiment. In addition, although nitrogenous compounds in both mesocosm and natural conditions had no direct effect on absolute larval swimming performance, they may impact the viability of larvae by affecting the relationships between growth and the swimming abilities. The differential pattern found in the impacts of nitrogenous compounds on larvae of P. perezi when raised in different experimental venues (mesocosms and field conditions) points to the convenience of considering more realistic natural scenarios in assessing the impact of pollutants on amphibians. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Views from the Field on Needs in Precollege Science, Mathematics, and Social Studies Education.

    ERIC Educational Resources Information Center

    Buccino, Alphonse; Evans, Paul L.

    1981-01-01

    Summarizes the findings reported in the final volume of an eight-volume series sponsored by the National Science Foundation that deal with the key elements responsible for influencing and shaping science, mathematics, and social studies education at the precollege level. (CS)

  14. J. Robert Schrieffer and the BCS Theory of Superconductivity

    Science.gov Websites

    and a chief scientist at the National High Magnetic Field Laboratory before his retirement in 2006 Theoretical Studies of Magnetic Systems. Final Report, August 1, 1994 - November 30, 1997, DOE Technical

  15. Field study of an integral backwall bridge : final report.

    DOT National Transportation Integrated Search

    1996-01-01

    Integral bridges offer reduced maintenance expenditures, primarily due to the elimination of deck expansion joints. The design of an integral bridge, however, is complicated by the soil-structure interaction associated with thermal movements. It has ...

  16. Nonlinear Evolution and Final Fate of Charged Anti-de Sitter Black Hole Superradiant Instability

    NASA Astrophysics Data System (ADS)

    Bosch, Pablo; Green, Stephen R.; Lehner, Luis

    2016-04-01

    We describe the full nonlinear development of the superradiant instability for a charged massless scalar field coupled to general relativity and electromagnetism, in the vicinity of a Reissner-Nordström-anti-de Sitter black hole. The presence of the negative cosmological constant provides a natural context for considering perfectly reflecting boundary conditions and studying the dynamics as the scalar field interacts repeatedly with the black hole. At early times, small superradiant perturbations grow as expected from linearized studies. Backreaction then causes the black hole to lose charge and mass until the perturbation becomes nonsuperradiant, with the final state described by a stable hairy black hole. For large gauge coupling, the instability extracts a large amount of charge per unit mass, resulting in greater entropy increase. We discuss the implications of the observed behavior for the general problem of superradiance in black hole spacetimes.

  17. Nonlinear Evolution and Final Fate of Charged Anti-de Sitter Black Hole Superradiant Instability.

    PubMed

    Bosch, Pablo; Green, Stephen R; Lehner, Luis

    2016-04-08

    We describe the full nonlinear development of the superradiant instability for a charged massless scalar field coupled to general relativity and electromagnetism, in the vicinity of a Reissner-Nordström-anti-de Sitter black hole. The presence of the negative cosmological constant provides a natural context for considering perfectly reflecting boundary conditions and studying the dynamics as the scalar field interacts repeatedly with the black hole. At early times, small superradiant perturbations grow as expected from linearized studies. Backreaction then causes the black hole to lose charge and mass until the perturbation becomes nonsuperradiant, with the final state described by a stable hairy black hole. For large gauge coupling, the instability extracts a large amount of charge per unit mass, resulting in greater entropy increase. We discuss the implications of the observed behavior for the general problem of superradiance in black hole spacetimes.

  18. Diffusion of Magnetic Field and Removal of Magnetic Flux from Clouds Via Turbulent Reconnection

    NASA Astrophysics Data System (ADS)

    Santos-Lima, R.; Lazarian, A.; de Gouveia Dal Pino, E. M.; Cho, J.

    2010-05-01

    The diffusion of astrophysical magnetic fields in conducting fluids in the presence of turbulence depends on whether magnetic fields can change their topology via reconnection in highly conducting media. Recent progress in understanding fast magnetic reconnection in the presence of turbulence reassures that the magnetic field behavior in computer simulations and turbulent astrophysical environments is similar, as far as magnetic reconnection is concerned. This makes it meaningful to perform MHD simulations of turbulent flows in order to understand the diffusion of magnetic field in astrophysical environments. Our studies of magnetic field diffusion in turbulent medium reveal interesting new phenomena. First of all, our three-dimensional MHD simulations initiated with anti-correlating magnetic field and gaseous density exhibit at later times a de-correlation of the magnetic field and density, which corresponds well to the observations of the interstellar media. While earlier studies stressed the role of either ambipolar diffusion or time-dependent turbulent fluctuations for de-correlating magnetic field and density, we get the effect of permanent de-correlation with one fluid code, i.e., without invoking ambipolar diffusion. In addition, in the presence of gravity and turbulence, our three-dimensional simulations show the decrease of the magnetic flux-to-mass ratio as the gaseous density at the center of the gravitational potential increases. We observe this effect both in the situations when we start with equilibrium distributions of gas and magnetic field and when we follow the evolution of collapsing dynamically unstable configurations. Thus, the process of turbulent magnetic field removal should be applicable both to quasi-static subcritical molecular clouds and cores and violently collapsing supercritical entities. The increase of the gravitational potential as well as the magnetization of the gas increases the segregation of the mass and magnetic flux in the saturated final state of the simulations, supporting the notion that the reconnection-enabled diffusivity relaxes the magnetic field + gas system in the gravitational field to its minimal energy state. This effect is expected to play an important role in star formation, from its initial stages of concentrating interstellar gas to the final stages of the accretion to the forming protostar. In addition, we benchmark our codes by studying the heat transfer in magnetized compressible fluids and confirm the high rates of turbulent advection of heat obtained in an earlier study.

  19. A new method for indirectly estimating infiltration of paddy fields in situ

    NASA Astrophysics Data System (ADS)

    Xu, Yunqiang; Su, Baolin; Wang, Hongqi; He, Jingyi

    2018-06-01

    Infiltration is one of the major procedures in water balance research and pollution load estimation in paddy fields. In this study, a new method for indirectly estimating infiltration of paddy fields in situ was proposed and implemented in Taihu Lake basin. Since when there were no rainfall, irrigation and artificial drainage, the water depth variation process of a paddy field is only influenced by evapotranspiration and infiltration (E + F). Firstly, (E + F) was estimated by deciding the steady decreasing rate of water depth; then the evapotranspiration (ET) of the paddy field was calculated by using the crop coefficient method with the recommended FAO-56 Penman-Monteith equation; finally, the infiltration of the paddy field was obtained by subtracting ET from (E + F). Results show that the mean infiltration of the studied paddy field during rice jointing-booting period was 7.41 mm day-1, and the mean vertical infiltration and lateral seepage of the paddy field were 5.46 and 1.95 mm day-1 respectively.

  20. 77 FR 76477 - Notice of Availability of the Final Environmental Impact Statement for the Quartzsite Solar...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-28

    ... traditional steam turbine generators. The Project would contain the central receiver or tower, a solar field... the Final Environmental Impact Statement for the Quartzsite Solar Energy Project and the Yuma Field...: Notice of Availability. SUMMARY: Quartzsite Solar Energy (QSE) has requested to interconnect the...

  1. Cosmology of a covariant Galilean field.

    PubMed

    De Felice, Antonio; Tsujikawa, Shinji

    2010-09-10

    We study the cosmology of a covariant scalar field respecting a Galilean symmetry in flat space-time. We show the existence of a tracker solution that finally approaches a de Sitter fixed point responsible for cosmic acceleration today. The viable region of model parameters is clarified by deriving conditions under which ghosts and Laplacian instabilities of scalar and tensor perturbations are absent. The field equation of state exhibits a peculiar phantomlike behavior along the tracker, which allows a possibility to observationally distinguish the Galileon gravity from the cold dark matter model with a cosmological constant.

  2. Measuring Plasma Formation Field Strength and Current Loss in Pulsed Power Diodes

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

    Johnston, Mark D.; Patel, Sonal G.; Falcon, Ross Edward

    This LDRD investigated plasma formation, field strength, and current loss in pulsed power diodes. In particular the Self-Magnetic Pinch (SMP) e-beam diode was studied on the RITS-6 accelerator. Magnetic fields of a few Tesla and electric fields of several MV/cm were measured using visible spectroscopy techniques. The magnetic field measurements were then used to determine the current distribution in the diode. This distribution showed that significant beam current extends radially beyond the few millimeter x-ray focal spot diameter. Additionally, shielding of the magnetic field due to dense electrode surface plasmas was observed, quantified, and found to be consistent with themore » calculated Spitzer resistivity. In addition to the work on RITS, measurements were also made on the Z-machine looking to quantify plasmas within the power flow regions. Measurements were taken in the post-hole convolute and final feed gap regions on Z. Dopants were applied to power flow surfaces and measured spectroscopically. These measurements gave species and density/temperature estimates. Preliminary B-field measurements in the load region were attempted as well. Finally, simulation work using the EMPHASIS, electromagnetic particle in cell code, was conducted using the Z MITL conditions. The purpose of these simulations was to investigate several surface plasma generations models under Z conditions for comparison with experimental data.« less

  3. Final report on a cold climate permeable interlocking concrete pavement test facility at the University of New Hampshire Stormwater Center.

    DOT National Transportation Integrated Search

    2013-05-01

    University of New Hampshire Stormwater Center (UNHSC) completed a two year field verification study of a permeable interlocking concrete pavement (PICP) stormwater management system. The purpose of this study was to evaluate the cold climate function...

  4. Field evaluation of viscosity and penetration-graded asphalt cements : asphalt cement consistency study : final report.

    DOT National Transportation Integrated Search

    1977-04-01

    The major objectives of this study were three-fold and can be listed as follows in their order of importance: : (1) To seek data relative to the changes that occur with time in the physical characteristics of penetration and viscosity graded-asphalt ...

  5. Laser velocimetry in highly three-dimensional and vortical flows

    NASA Technical Reports Server (NTRS)

    Novak, C. J.; Huie, C. R.; Cornelius, K. C.

    1986-01-01

    The need for experimentally determined 3-D velocity information is crucial to the understanding of highly 3-dimensional and vortical flow fields. In addition to gaining an understanding of the physics of flow fields, a correlation of velocity data is needed for advanced computational modelling. A double pass method for acquiring 3-D flow field information using a 2-D laser velocimeter (LV) is described. The design and implementation of a 3-D LV with expanded capabilities to acquire real-time 3-D flow field information are also described. Finally, the use of such an instrument in a wind tunnel study of a generic fighter configuration is described. The results of the wind tunnel study highlight the complexities of 3-D flow fields, particularly when the vortex behavior is examined over a range of angles of attack.

  6. Evacuation dynamics with smoking diffusion in three dimension based on an extended Floor-Field model

    NASA Astrophysics Data System (ADS)

    Zheng, Ying; Li, Xingang; Zhu, Nuo; Jia, Bin; Jiang, Rui

    2018-10-01

    This paper proposes an extended Floor-Field (FF) model to study the pedestrian evacuation dynamics under the influence of smoke diffusing in three-dimension (3D). In addition to static and dynamic fields, the extended model adopts the smoke and herding fields to reflect pedestrian's smoke-avoiding behavior and herding behavior. The impact of smoke on pedestrians' health is also considered. The smoke will reduce the pedestrians' health point and finally impact their moving ability. Numerical simulations were carried out to study the evacuation dynamics. The influence of the smoke particles producing rate, the initial health point, the critical smoke concentration value, and the herding field on evacuation dynamics were analyzed in detail. Those results could bring some guidance to make the evacuation strategy in the smoke diffusing environment.

  7. Breast density quantification using magnetic resonance imaging (MRI) with bias field correction: A postmortem study

    PubMed Central

    Ding, Huanjun; Johnson, Travis; Lin, Muqing; Le, Huy Q.; Ducote, Justin L.; Su, Min-Ying; Molloi, Sabee

    2013-01-01

    Purpose: Quantification of breast density based on three-dimensional breast MRI may provide useful information for the early detection of breast cancer. However, the field inhomogeneity can severely challenge the computerized image segmentation process. In this work, the effect of the bias field in breast density quantification has been investigated with a postmortem study. Methods: T1-weighted images of 20 pairs of postmortem breasts were acquired on a 1.5 T breast MRI scanner. Two computer-assisted algorithms were used to quantify the volumetric breast density. First, standard fuzzy c-means (FCM) clustering was used on raw images with the bias field present. Then, the coherent local intensity clustering (CLIC) method estimated and corrected the bias field during the iterative tissue segmentation process. Finally, FCM clustering was performed on the bias-field-corrected images produced by CLIC method. The left–right correlation for breasts in the same pair was studied for both segmentation algorithms to evaluate the precision of the tissue classification. Finally, the breast densities measured with the three methods were compared to the gold standard tissue compositions obtained from chemical analysis. The linear correlation coefficient, Pearson's r, was used to evaluate the two image segmentation algorithms and the effect of bias field. Results: The CLIC method successfully corrected the intensity inhomogeneity induced by the bias field. In left–right comparisons, the CLIC method significantly improved the slope and the correlation coefficient of the linear fitting for the glandular volume estimation. The left–right breast density correlation was also increased from 0.93 to 0.98. When compared with the percent fibroglandular volume (%FGV) from chemical analysis, results after bias field correction from both the CLIC the FCM algorithms showed improved linear correlation. As a result, the Pearson's r increased from 0.86 to 0.92 with the bias field correction. Conclusions: The investigated CLIC method significantly increased the precision and accuracy of breast density quantification using breast MRI images by effectively correcting the bias field. It is expected that a fully automated computerized algorithm for breast density quantification may have great potential in clinical MRI applications. PMID:24320536

  8. Breast density quantification using magnetic resonance imaging (MRI) with bias field correction: a postmortem study.

    PubMed

    Ding, Huanjun; Johnson, Travis; Lin, Muqing; Le, Huy Q; Ducote, Justin L; Su, Min-Ying; Molloi, Sabee

    2013-12-01

    Quantification of breast density based on three-dimensional breast MRI may provide useful information for the early detection of breast cancer. However, the field inhomogeneity can severely challenge the computerized image segmentation process. In this work, the effect of the bias field in breast density quantification has been investigated with a postmortem study. T1-weighted images of 20 pairs of postmortem breasts were acquired on a 1.5 T breast MRI scanner. Two computer-assisted algorithms were used to quantify the volumetric breast density. First, standard fuzzy c-means (FCM) clustering was used on raw images with the bias field present. Then, the coherent local intensity clustering (CLIC) method estimated and corrected the bias field during the iterative tissue segmentation process. Finally, FCM clustering was performed on the bias-field-corrected images produced by CLIC method. The left-right correlation for breasts in the same pair was studied for both segmentation algorithms to evaluate the precision of the tissue classification. Finally, the breast densities measured with the three methods were compared to the gold standard tissue compositions obtained from chemical analysis. The linear correlation coefficient, Pearson's r, was used to evaluate the two image segmentation algorithms and the effect of bias field. The CLIC method successfully corrected the intensity inhomogeneity induced by the bias field. In left-right comparisons, the CLIC method significantly improved the slope and the correlation coefficient of the linear fitting for the glandular volume estimation. The left-right breast density correlation was also increased from 0.93 to 0.98. When compared with the percent fibroglandular volume (%FGV) from chemical analysis, results after bias field correction from both the CLIC the FCM algorithms showed improved linear correlation. As a result, the Pearson's r increased from 0.86 to 0.92 with the bias field correction. The investigated CLIC method significantly increased the precision and accuracy of breast density quantification using breast MRI images by effectively correcting the bias field. It is expected that a fully automated computerized algorithm for breast density quantification may have great potential in clinical MRI applications.

  9. Tissue interactions with nonionizing electromagnetic fields. Final report, March 1979-February 1986

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

    Adey, W.R.; Bawin, S.M.; Byus, C.V.

    1986-08-01

    This report provides an overview of this research program focused on basic research in nervous system responses to electric fields at 60 Hz. The emphasis in this project was to determine the fundamental mechanisms underlying some phenomena of electric field interactions in neural systems. The five studies of the initial program were tests of behavioral responses in the rat based upon the hypothesis that electric field detection might follow psychophysical rules known from prior research with light, sound and other stimuli; tests of electrophysiological responses to ''normal'' forms of stimulation in rat brain tissue exposed in vitro to electric fields,more » based on the hypothesis that the excitability of brain tissue might be affected by fields in the extracellular environment; tests of electrophysiological responses of spontaneously active pacemaker neurons of the Aplysia abdominal ganglion, based on the hypothesis that electric field interactions at the cell membrane might affect the balance among the several membrane-related processes that govern pacemaker activity; studies of mechanisms of low frequency electromagnetic field interactions with bone cells in the context of field therapy of ununited fractures; and manipulation of cell surface receptor proteins in studies of their mobility during EM field exposure.« less

  10. Tachyon and quintessence in brane worlds

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

    Chimento, Luis P.; Forte, Monica; Richarte, Martin G.

    2009-04-15

    Using tachyon or quintessence fields along with a barotropic fluid on the brane we examine the different cosmological stages in a Friedmann-Robertson-Walker universe, from the first radiation scenario to the later era dominated by cosmic string networks. We introduce a new algorithm to generalize previous works on exact solutions and apply it to study tachyon and quintessence fields localized on the brane. We also explore the low and high energy regimes of the solutions. Besides, we show that the tachyon and quintessence fields are driven by an inverse power law potential. Finally, we find several simple exacts solutions for tachyonmore » and/or quintessence fields.« less

  11. On Finsler spacetimes with a timelike Killing vector field

    NASA Astrophysics Data System (ADS)

    Caponio, Erasmo; Stancarone, Giuseppe

    2018-04-01

    We study Finsler spacetimes and Killing vector fields taking care of the fact that the generalised metric tensor associated to the Lorentz–Finsler function L is in general well defined only on a subset of the slit tangent bundle. We then introduce a new class of Finsler spacetimes endowed with a timelike Killing vector field that we call stationary splitting Finsler spacetimes. We characterize when a Finsler spacetime with a timelike Killing vector field is locally a stationary splitting. Finally, we show that the causal structure of a stationary splitting is the same of one of two Finslerian static spacetimes naturally associated to the stationary splitting.

  12. The Dynamics of a Five-level (Double Λ)-type Atom Interacting with Two-mode Field in a Cross Kerr-like Medium

    NASA Astrophysics Data System (ADS)

    Obada, A.-S. F.; Ahmed, M. M. A.; Farouk, Ahmed M.

    2018-04-01

    In this paper, we propose a new transition scheme (Double Λ) for the interaction between a five-level atom and an electromagnetic field and study its dynamics in the presence of a cross Kerr-like medium in the exact-resonance case. The wave function is derived when the atom is initially prepared in its upper most state, and the field is initially prepared in the coherent state. We studied the atomic population inversion, the coherence degree by studying the second-order correlation function, Cauchy-Schwartz inequality (CSI) and the relation with P-function. Finally, we investigate the effect of Kerr-like medium on the evolution of Husimi Q-function of the considered system.

  13. Speckle evolution with multiple steps of least-squares phase removal

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

    Chen Mingzhou; Dainty, Chris; Roux, Filippus S.

    2011-08-15

    We study numerically the evolution of speckle fields due to the annihilation of optical vortices after the least-squares phase has been removed. A process with multiple steps of least-squares phase removal is carried out to minimize both vortex density and scintillation index. Statistical results show that almost all the optical vortices can be removed from a speckle field, which finally decays into a quasiplane wave after such an iterative process.

  14. Validating electromagnetic walking stick rail surface crack measuring systems : final report.

    DOT National Transportation Integrated Search

    2016-06-01

    A series of field studies were undertaken to evaluate electromagnetic walking stick systems and their ability to measure the depth : of damage from surface breaking cracks. In total, four railroads, and four suppliers participated in the project. The...

  15. Final report : mobile surveillance and wireless communication systems field operational test. Volume 1, Executive summary

    DOT National Transportation Integrated Search

    1999-03-01

    This study focused on assessing the application of traffic monitoring and management systems which use transportable surveillance and ramp meter trailers, video image processors, and wireless communications. The mobile surveillance and wireless commu...

  16. A Study of the Effects of Microteaching Experiences Upon the Classroom Behavior of Social Studies Student Teachers.

    ERIC Educational Resources Information Center

    Limbacher, Philip C.

    The hypotheses of this field study, conducted in connection with the Teaching Techniques Laboratory at the University of Illinois, were that student teachers who had participated in a supervised, laboratory, microteaching experience would: 1) receive more favorable pupil evaluations of an initial and final teaching effort on the Teacher…

  17. Experimental Studies on the Effects of Thermal Bumps in the Flow-Field around a Flat Plate using a Hypersonic Wind Tunnel

    DTIC Science & Technology

    2012-07-01

    Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the...PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 12 July 2012 2. REPORT TYPE Final Report 3. DATES COVERED...From – To) 1 October 2008 – 31 January 2012 4. TITLE AND SUBTITLE Experimental Studies on the Effects of Thermal Bumps in the Flow-Field around a

  18. The Width of a Solar Coronal Mass Ejection and the Source of the Driving Magnetic Explosion: A Test of the Standard Scenario for CME Production

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.; Suess, Steven T.

    2007-01-01

    We show that the strength (B(sub F1are)) of the magnetic field in the area covered by the flare arcade following a CME-producing ejective solar eruption can be estimated from the final angular width (Final Theta(sub CME)) of the CME in the outer corona and the final angular width (Theta(sub Flare)) of the flare arcade: B(sub Flare) approx. equals 1.4[(Final Theta(sub CME)/Theta(sub Flare)] (exp 2)G. We assume (1) the flux-rope plasmoid ejected from the flare site becomes the interior of the CME plasmoid; (2) in the outer corona (R > 2 (solar radius)) the CME is roughly a "spherical plasmoid with legs" shaped like a lightbulb; and (3) beyond some height in or below the outer corona the CME plasmoid is in lateral pressure balance with the surrounding magnetic field. The strength of the nearly radial magnetic field in the outer corona is estimated from the radial component of the interplanetary magnetic field measured by Ulysses. We apply this model to three well-observed CMEs that exploded from flare regions of extremely different size and magnetic setting. One of these CMEs was an over-and-out CME, that is, in the outer corona the CME was laterally far offset from the flare-marked source of the driving magnetic explosion. In each event, the estimated source-region field strength is appropriate for the magnetic setting of the flare. This agreement (1) indicates that CMEs are propelled by the magnetic field of the CME plasmoid pushing against the surrounding magnetic field; (2) supports the magnetic-arch-blowout scenario for over-and-out CMEs; and (3) shows that a CME's final angular width in the outer corona can be estimated from the amount of magnetic flux covered by the source-region flare arcade.

  19. Field instrumentation and testing to study set-up phenomenon of piles driven into Louisiana clayey soils : final report.

    DOT National Transportation Integrated Search

    2016-07-01

    This research study aims to investigate the pile set-up phenomenon for clayey soils and develop empirical models to predict pile set-up : resistance at certain time after end of driving (EOD). To fulfill the objective, a total number of twelve prestr...

  20. The effects of transverse magnetic field and local electronic interaction on thermoelectric properties of monolayer graphene

    NASA Astrophysics Data System (ADS)

    Rezania, Hamed; Azizi, Farshad

    2018-02-01

    We study the effects of a transverse magnetic field and electron doping on the thermoelectric properties of monolayer graphene in the context of Hubbard model at the antiferromagnetic sector. In particular, the temperature dependence of thermal conductivity and Seebeck coefficient has been investigated. Mean field approximation has been employed in order to obtain the electronic spectrum of the system in the presence of local electron-electron interaction. Our results show the peak in thermal conductivity moves to higher temperatures with increase of both chemical potential and Hubbard parameter. Moreover the increase of magnetic field leads to shift of peak in temperature dependence of thermal conductivity to higher temperatures. Finally the behavior of Seebeck coefficient in terms of temperature has been studied and the effects of magnetic field and Hubbard parameter on this coefficient have been investigated in details.

  1. Field emission properties of different forms of carbon

    NASA Astrophysics Data System (ADS)

    Merkulov, Vladimir I.; Lowndes, Douglas H.; Baylor, Larry R.; Kang, Sukill

    2001-06-01

    The results of field emission (FE) studies are reported for three different forms of carbon: smooth amorphous carbon (a-C) films with both low and high sp 3 content prepared by pulsed-laser deposition (PLD), nanostructured carbon prepared by hot-filament chemical-vapor deposition (HFCVD), and vertically aligned carbon nanofibers (VACNFs). The studies reveal that smooth PLD carbon films are poor field emitters regardless of their sp 3 content. Conditioning of the films, which resulted in films' modification, was required to draw FE current and the emission turn-on fields were relatively high. In contrast, HFCVD carbon films exhibit very good FE properties, including low-emission turn-on fields, relatively high emission site density, and excellent durability. Finally, VACNFs also were found to possess quite promising FE properties that compete with those of HFCVD films. We believe that the latter two forms of carbon are among the most promising candidates for use as cold cathodes in commercial devices.

  2. Diffusion of magnetic field via turbulent reconnection

    NASA Astrophysics Data System (ADS)

    Santos de Lima, Reinaldo; Lazarian, Alexander; de Gouveia Dal Pino, Elisabete M.; Cho, Jungyeon

    2010-05-01

    The diffusion of astrophysical magnetic fields in conducting fluids in the presence of turbulence depends on whether magnetic fields can change their topology via reconnection in highly conducting media. Recent progress in understanding fast magnetic reconnection in the presence of turbulence is reassuring that the magnetic field behavior in computer simulations and turbulent astrophysical environments is similar, as far as magnetic reconnection is concerned. This makes it meaningful to perform MHD simulations of turbulent flows in order to understand the diffusion of magnetic field in astrophysical environments. Our studies of magnetic field diffusion in turbulent medium reveal interesting new phenomena. First of all, our 3D MHD simulations initiated with anti-correlating magnetic field and gaseous density exhibit at later times a de-correlation of the magnetic field and density, which corresponds well to the observations of the interstellar media. While earlier studies stressed the role of either ambipolar diffusion or time-dependent turbulent fluctuations for de-correlating magnetic field and density, we get the effect of permanent de-correlation with one fluid code, i.e. without invoking ambipolar diffusion. In addition, in the presence of gravity and turbulence, our 3D simulations show the decrease of the magnetic flux-to-mass ratio as the gaseous density at the center of the gravitational potential increases. We observe this effect both in the situations when we start with equilibrium distributions of gas and magnetic field and when we follow the evolution of collapsing dynamically unstable configurations. Thus the process of turbulent magnetic field removal should be applicable both to quasi-static subcritical molecular clouds and cores and violently collapsing supercritical entities. The increase of the gravitational potential as well as the magnetization of the gas increases the segregation of the mass and magnetic flux in the saturated final state of the simulations, supporting the notion that the reconnection-enabled diffusivity relaxes the magnetic field + gas system in the gravitational field to its minimal energy state. This effect is expected to play an important role in star formation, from its initial stages of concentrating interstellar gas to the final stages of the accretion to the forming protostar.

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

    Kavet, R.; Tell, R.A.

    As the use of video display terminals (VDTs) has expanded, questions have been raised as to whether working at a VDT affects the risk of adverse pregnancy outcome. A particular focus for these questions has been the very low frequency (VLF) magnetic field produced by a VDT's horizontal deflection coil. VDTs also produce VLF electric fields, extremely low frequency (ELF) electric and magnetic fields, and static electric fields, Ten studies of pregnancy outcome in VDT operators have been conducted in six countries, and with one exception, none has concluded that magnetic fields from VDTs may predispose pregnant operators to spontaneousmore » abortion or congenital malformation. The epidemiologic studies conducted thus far do not provide a basis for concluding that VDT work and adverse pregnancy outcome are associated. Studies of fetal resorptions and malformations in rodents exposed to VLF magnetic fields have produced inconsistent findings. Two laboratories in Sweden that studied mice have reported positive results, one laboratory showing field-related malformations (but not resorptions) and the other showing field-related resorptions (but not malformations). Two Canadian laboratories have reported negative results in rats and mice. Studies of avian embryos have also yielded inconsistent results, but lacking a maternal-fetal placental interface, avian embryos are a questionable model for evaluating human reproductive risks. Finally, VLF electric and magnetic fields measured at the operator position are in compliance with field strength standards and guidelines that have been established around the world. 55 refs.« less

  4. Magnetic field effects on charge structure factors of gapped graphene structure

    NASA Astrophysics Data System (ADS)

    Rezania, Hamed; Tawoose, Nasrin

    2018-02-01

    We present the behaviors of dynamical and static charge susceptibilities of undoped gapped graphene using the Green's function approach in the context of tight binding model Hamiltonian. Specially, the effects of magnetic field on the plasmon modes of gapped graphene structure are investigated via calculating correlation function of charge density operators. Our results show the increase of magnetic field leads to disappear high frequency plasmon mode for gapped case. We also show that low frequency plasmon mode has not affected by increase of magnetic field and chemical potential. Finally the temperature dependence of static charge structure factor of gapp graphene structure is studied. The effects of both magnetic field and gap parameter on the static structure factor are discusses in details.

  5. Photoionization of water molecules by a train of attosecond pulses assisted by a near-infrared laser: delay and polarization control

    NASA Astrophysics Data System (ADS)

    Martini, Lara; Boll, Diego I. R.; Fojón, Omar A.

    2017-08-01

    Basic reactions involving water molecules are essential to understand the interaction between radiation and the biological tissue because living cells are composed mostly by water. Therefore, the knowledge of ionization of the latter is crucial in many domains of Biology and Physics. So, we study theoretically the photoionization of water molecules by extreme ultraviolet attopulse trains assisted by lasers in the near-infrared range. We use a separable Coulomb-Volkov model in which the temporal evolution of the system can be divided into three stages allowing spatial and temporal separation for the Coulomb and Volkov final state wavefunctions. First, we analyze photoelectron angular distributions for different delays between the attopulse train and the assistant laser field. We compare our results for water and Ne atoms as they belong to the same isoelectronic series. Moreover, we contrast our calculations with previous theoretical and experimental work for Ar atoms due to the similarities of the orbitals involved in the reaction. Second, we study the effect of varying the relative orientations of the attopulse and laser field polarizations and we compare our predictions with other theories and experiments. We expect these studies contribute to the improvement of polarization experiments and the development of the attopulse trains and assistant laser fields technologies. Finally, we hope our work promote progress on the control of the chemical reactivity of water molecules since this could be useful in different fields such as radiobiology and medical physics.

  6. Field evaluation of the myrtle creek advanced curve warning system : final report.

    DOT National Transportation Integrated Search

    2006-06-01

    As part of a larger study focusing on determining optimum countermeasures for speed related crashes, this report presents the results of a quantitative and qualitative before and after evaluation of a dynamic curve warning system deployed at one site...

  7. Transport of Energetic Ions in the Ring Current During Geomagnetic Storms

    NASA Technical Reports Server (NTRS)

    Kistler, Lynn M.; Kaufmann, Richard

    2001-01-01

    In the final year (plus no-cost extentions) of this grant, we have: Used the particle tracing code to perform a systematic study of the expected energy spectra over the full range of local times in the ring current using a variety of electric and magnetic field models. Shown that the Weimer electric field is superior to the Volland-Stern electric field in reproducing the observed energy spectra on the AMPTE CCE spacecraft. Redone our analysis of the pitch angle spectra of energetic ions during storms in the magnetosphere, using a larger data set, and a more reliable classification technique.

  8. Execution of deep dipole geoelectrical soundings in areas of geothermal interest. Final report

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

    Patella, D.

    It is suggested that deep geoelectrical problems may be resolved by carrying out dipole soundings in the field and applying a quantitative interpretation in the Schlumberger domain. The 'transformation' of original field dipole sounding curves into equivalent Schlumberger curves is outlined for the cases of layered structures and arbitrary underground structures. Theoretical apparent resistivity curves are derived for soundings over bidimensional structures. Following a summary of the geological features of the Travale-Radicondoli geothermal area of Italy, the dipole sounding method employed for this field study and the means of collecting and analyzing the data, are outlined.

  9. Performance of field-emitting resonating carbon nanotubes as radio-frequency demodulators

    NASA Astrophysics Data System (ADS)

    Vincent, P.; Poncharal, P.; Barois, T.; Perisanu, S.; Gouttenoire, V.; Frachon, H.; Lazarus, A.; de Langre, E.; Minoux, E.; Charles, M.; Ziaei, A.; Guillot, D.; Choueib, M.; Ayari, A.; Purcell, S. T.

    2011-04-01

    We report on a systematic study of the use of resonating nanotubes in a field emission (FE) configuration to demodulate radio frequency signals. We particularly concentrate on how the demodulation depends on the variation of the field amplification factor during resonance. Analytical formulas describing the demodulation are derived as functions of the system parameters. Experiments using AM and FM demodulations in a transmission electron microscope are also presented with a determination of all the pertinent experimental parameters. Finally we discuss the use of CNTs undergoing FE as nanoantennae and the different geometries that could be used for optimization and implementation.

  10. Long-time predictability in disordered spin systems following a deep quench

    NASA Astrophysics Data System (ADS)

    Ye, J.; Gheissari, R.; Machta, J.; Newman, C. M.; Stein, D. L.

    2017-04-01

    We study the problem of predictability, or "nature vs nurture," in several disordered Ising spin systems evolving at zero temperature from a random initial state: How much does the final state depend on the information contained in the initial state, and how much depends on the detailed history of the system? Our numerical studies of the "dynamical order parameter" in Edwards-Anderson Ising spin glasses and random ferromagnets indicate that the influence of the initial state decays as dimension increases. Similarly, this same order parameter for the Sherrington-Kirkpatrick infinite-range spin glass indicates that this information decays as the number of spins increases. Based on these results, we conjecture that the influence of the initial state on the final state decays to zero in finite-dimensional random-bond spin systems as dimension goes to infinity, regardless of the presence of frustration. We also study the rate at which spins "freeze out" to a final state as a function of dimensionality and number of spins; here the results indicate that the number of "active" spins at long times increases with dimension (for short-range systems) or number of spins (for infinite-range systems). We provide theoretical arguments to support these conjectures, and also study analytically several mean-field models: the random energy model, the uniform Curie-Weiss ferromagnet, and the disordered Curie-Weiss ferromagnet. We find that for these models, the information contained in the initial state does not decay in the thermodynamic limit—in fact, it fully determines the final state. Unlike in short-range models, the presence of frustration in mean-field models dramatically alters the dynamical behavior with respect to the issue of predictability.

  11. Long-time predictability in disordered spin systems following a deep quench.

    PubMed

    Ye, J; Gheissari, R; Machta, J; Newman, C M; Stein, D L

    2017-04-01

    We study the problem of predictability, or "nature vs nurture," in several disordered Ising spin systems evolving at zero temperature from a random initial state: How much does the final state depend on the information contained in the initial state, and how much depends on the detailed history of the system? Our numerical studies of the "dynamical order parameter" in Edwards-Anderson Ising spin glasses and random ferromagnets indicate that the influence of the initial state decays as dimension increases. Similarly, this same order parameter for the Sherrington-Kirkpatrick infinite-range spin glass indicates that this information decays as the number of spins increases. Based on these results, we conjecture that the influence of the initial state on the final state decays to zero in finite-dimensional random-bond spin systems as dimension goes to infinity, regardless of the presence of frustration. We also study the rate at which spins "freeze out" to a final state as a function of dimensionality and number of spins; here the results indicate that the number of "active" spins at long times increases with dimension (for short-range systems) or number of spins (for infinite-range systems). We provide theoretical arguments to support these conjectures, and also study analytically several mean-field models: the random energy model, the uniform Curie-Weiss ferromagnet, and the disordered Curie-Weiss ferromagnet. We find that for these models, the information contained in the initial state does not decay in the thermodynamic limit-in fact, it fully determines the final state. Unlike in short-range models, the presence of frustration in mean-field models dramatically alters the dynamical behavior with respect to the issue of predictability.

  12. Magnetization of InAs parabolic quantum dot: An exact diagonalization approach

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

    Aswathy, K. M., E-mail: aswathykm20@gmail.com; Sanjeev Kumar, D.

    2016-04-13

    The magnetization of two electron InAs quantum dot has been studied as a function of magnetic field. The electron-electron interaction has been taken into account by using exact diagonalization method numerically. The magnetization at zero external magnetic field is zero and increases in the negative direction. There is also a paramagnetic peak where the energy levels cross from singlet state to triplet state. Finally, the magnetization falls again to even negative values and saturates.

  13. Perceptions of final-year nursing students on the facilities, resources and quality of education provided by schools in Turkey.

    PubMed

    Güner, Perihan

    2015-01-01

    The purpose of this study is to determine the perceptions of final-year nursing students regarding the adequacy of education, resources and internships in preparation for graduation. The study design was a descriptive cross-sectional study of nursing students (n: 1804) in their final year of education and questionnaires were used to collect data. Information related to student-to-instructor ratios and internships was obtained from each institution. Most students reported receiving instruction or supervision by lecturers and clinicians who did not specialise in the field. Overall, students did not find the facilities, educational or technological resources and the quality of education offered by their respective schools adequate. The proportion of students who found the level of theoretical education, clinical practice and instructor support adequate was higher in state university colleges of nursing/faculties of health sciences than in state university schools of health sciences.

  14. A qualitative and quantitative laser-based computer-aided flow visualization method. M.S. Thesis, 1992 Final Report

    NASA Technical Reports Server (NTRS)

    Canacci, Victor A.; Braun, M. Jack

    1994-01-01

    The experimental approach presented here offers a nonintrusive, qualitative and quantitative evaluation of full field flow patterns applicable in various geometries in a variety of fluids. This Full Flow Field Tracking (FFFT) Particle Image Velocimetry (PIV) technique, by means of particle tracers illuminated by a laser light sheet, offers an alternative to Laser Doppler Velocimetry (LDV), and intrusive systems such as Hot Wire/Film Anemometry. The method makes obtainable the flow patterns, and allows quantitative determination of the velocities, accelerations, and mass flows of an entire flow field. The method uses a computer based digitizing system attached through an imaging board to a low luminosity camera. A customized optical train allows the system to become a long distance microscope (LDM), allowing magnifications of areas of interest ranging up to 100 times. Presented in addition to the method itself, are studies in which the flow patterns and velocities were observed and evaluated in three distinct geometries, with three different working fluids. The first study involved pressure and flow analysis of a brush seal in oil. The next application involved studying the velocity and flow patterns in a cowl lip cooling passage of an air breathing aircraft engine using water as the working fluid. Finally, the method was extended to a study in air to examine the flows in a staggered pin arrangement located on one side of a branched duct.

  15. Massive Black Hole Mergers: Can We "See" what LISA will "Hear"?

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2010-01-01

    The final merger of massive black holes produces strong gravitational radiation that can be detected by the space-borne LISA. If the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We will review current efforts to simulate these systems, and discuss possibilities for observing the electromagnetic signals they produce.

  16. Light field reconstruction robust to signal dependent noise

    NASA Astrophysics Data System (ADS)

    Ren, Kun; Bian, Liheng; Suo, Jinli; Dai, Qionghai

    2014-11-01

    Capturing four dimensional light field data sequentially using a coded aperture camera is an effective approach but suffers from low signal noise ratio. Although multiplexing can help raise the acquisition quality, noise is still a big issue especially for fast acquisition. To address this problem, this paper proposes a noise robust light field reconstruction method. Firstly, scene dependent noise model is studied and incorporated into the light field reconstruction framework. Then, we derive an optimization algorithm for the final reconstruction. We build a prototype by hacking an off-the-shelf camera for data capturing and prove the concept. The effectiveness of this method is validated with experiments on the real captured data.

  17. On Alfvenic Waves and Stochastic Ion Heating with 1Re Observations of Strong Field-aligned Currents, Electric Fields, and O+ ions

    NASA Technical Reports Server (NTRS)

    Coffey, Victoria; Chandler, Michael; Singh, Nagendra

    2008-01-01

    The role that the cleft/cusp has in ionosphere/magnetosphere coupling makes it a very dynamic region having similar fundamental processes to those within the auroral regions. With Polar passing through the cusp at 1 Re in the Spring of 1996, we observe a strong correlation between ion heating and broadband ELF (BBELF) emissions. This commonly observed relationship led to the study of the coupling of large field-aligned currents, burst electric fields, and the thermal O+ ions. We demonstrate the role of these measurements to Alfvenic waves and stochastic ion heating. Finally we will show the properties of the resulting density cavities.

  18. An optimized workflow for building 3D models from balanced sections and potential field geophysics: a study case in NE Spain.

    NASA Astrophysics Data System (ADS)

    Ayala, Conxi; Izquierdo-Llavall, Esther; Pueyo, Emilio Luis; Rubio, Félix; Rodríguez-Pintó, Adriana; María Casas, Antonio; Oliva-Urcía, Belén; Rey-Moral, Carmen

    2015-04-01

    Obtaining an accurate 3D image of the geometry and physical properties of geological structures in depth is a challenge regardless the scale and the aim of the investigation. In this framework, assessing the origin of the uncertainties and reducing them is a key issue when building a 3D reconstruction of a target area. Usually, this process involves an interdisciplinary approach and also the use of different software whose inputs and outputs have to be interoperable. We have designed a new workflow for 2.5D and 3D geological and potential field modelling, especially useful in areas where no seismic data is available. The final aim is to obtain a 3D geological model, at a regional or local scale, with the smaller uncertainty as possible. Once the study area and the working scale are is decided, the first obvious step is to compile all preexisting data and to determine its uncertainties. If necessary, a survey will be carried out to acquire additional data (e.g., gravity, magnetic or petrophysical data) to have an appropriated coverage of information and rock samples. A thorough study of the petrophysical properties is made to determine the density, magnetic susceptibility and remanence that will be assigned to each lithology, together with its corresponding uncertainty. Finally, the modelling process is started, and it includes a feedback between geology and potential fields in order to progressively refine the model until it fits all the existing data. The procedure starts with the construction of balanced geological cross sections from field work, available geological maps as well as data from stratigraphic columns, boreholes, etc. These geological cross sections are exported and imported in GMSYS software to carry out the 2.5D potential field modelling. The model improves and its uncertainty is reduced through the feedback between the geologists and the geophysicists. Once the potential field anomalies are well adjusted, the cross sections are exported into 3DMove (Midland Valley) to construct a preliminary balanced 3D model. Inversion of the potential field data in GeoModeller is the final step to obtain a 3D model consistent with the input data and with the minimum possible uncertainty. Our case study is a 3D model from the Linking Zone between the Iberian Range and the Catalonian Costal ones (NE Spain, an extension of 11,325 km2). No seismic data was available, so we carried out several surveys to acquire new gravity data and rock samples to complete the data from IGME petrophysical databases. A total of 1470 samples have been used to define the physical properties for the modelled lithologies. The gravity data consists of 2902 stations. The initial model is based on the surface geology, eleven boreholes and 8 balanced geological cross sections built in the frame of this research. The final model resulted from gravimetric inversion has allowed us to define the geometry of the top of the basement as well as to identify two structures (anticlines) as potential CO2 reservoirs.

  19. Cergop-2, A Multipurpose and Interdisciplinary Sensor Array For Environmental Research In Central Europe

    NASA Astrophysics Data System (ADS)

    Pesec, P.

    The project CERGOP-2 (second phase of the Central Europe Regional Geodynamics Project)was initiated 1998, as a successor of CERGOP 1993/1998. During the follow- ing 3 years a new concept was worked out which finally was submitted for EU-support under the Sub-Programme Environment and Sustainable Development (5. FP) Octo- ber 2001. In the meanwhile the proposal received a "go" which implies a ranking in the final set of proposals forseen for eventual financial support. 14 contractors out of 13 countries contributed to the formulation of the proposal, the planned actions comprize the consolidation of the GPS-network,which covers about 15 % of the European territory, the final aim being the establishment of a velocity field which allows for the derivation of strain-fields and the monitoring of energy transfer for geodynamic studies and hazard mitigation. This paper will give an overview of the required actions and the expected results, paying special attention to near real-time information and regional geodynamic inves- tigations of seismic active regions.

  20. Inflation with a smooth constant-roll to constant-roll era transition

    NASA Astrophysics Data System (ADS)

    Odintsov, S. D.; Oikonomou, V. K.

    2017-07-01

    In this paper, we study canonical scalar field models, with a varying second slow-roll parameter, that allow transitions between constant-roll eras. In the models with two constant-roll eras, it is possible to avoid fine-tunings in the initial conditions of the scalar field. We mainly focus on the stability of the resulting solutions, and we also investigate if these solutions are attractors of the cosmological system. We shall calculate the resulting scalar potential and, by using a numerical approach, we examine the stability and attractor properties of the solutions. As we show, the first constant-roll era is dynamically unstable towards linear perturbations, and the cosmological system is driven by the attractor solution to the final constant-roll era. As we demonstrate, it is possible to have a nearly scale-invariant power spectrum of primordial curvature perturbations in some cases; however, this is strongly model dependent and depends on the rate of the final constant-roll era. Finally, we present, in brief, the essential features of a model that allows oscillations between constant-roll eras.

  1. Estimation of frequency based flood peaks for an ungauged watershed using field calibration : final report.

    DOT National Transportation Integrated Search

    1997-06-01

    The present study has been conducted to evaluate eight flood prediction models for an ungauged small watershed. These models are either frequently used by or were developed by Louisiana Department of Transportation and Development (LADOTD). The eight...

  2. Field evaluation of fly ash in aggregate shoulder materials : final report.

    DOT National Transportation Integrated Search

    1985-06-01

    This study consisted of an evaluation of self-hardening fly ash (Class C) used as an additive in the treatment of shoulders surfaced with sand clay gravel and/or shell (oyster). This was accomplished through construction of fly ash treated aggregate ...

  3. Tailgate test kit for determining appropriate sediment reducing chemicals and dose rates : final report.

    DOT National Transportation Integrated Search

    2017-07-01

    This study develops a Tailgate Test Kit to be used in the field to test flocculants for reducing turbidity in construction stormwater discharge. Turbidity of stormwater runoff at construction sites varies depending on which site soils are exposed to ...

  4. Characterization of time-dependent changes in strength and stiffness of Florida base materials : final report, October 2008.

    DOT National Transportation Integrated Search

    2008-10-01

    Resilient modulus and Youngs modulus are parameters increasingly used to fundamentally characterize the behavior : of pavement materials both in the laboratory and in the field. This study documents the small-strain Youngs modulus : and larger-...

  5. Estimating plant distance in maize using Unmanned Aerial Vehicle (UAV).

    PubMed

    Zhang, Jinshui; Basso, Bruno; Price, Richard F; Putman, Gregory; Shuai, Guanyuan

    2018-01-01

    Distance between rows and plants are essential parameters that affect the final grain yield in row crops. This paper presents the results of research intended to develop a novel method to quantify the distance between maize plants at field scale using an Unmanned Aerial Vehicle (UAV). Using this method, we can recognize maize plants as objects and calculate the distance between plants. We initially developed our method by training an algorithm in an indoor facility with plastic corn plants. Then, the method was scaled up and tested in a farmer's field with maize plant spacing that exhibited natural variation. The results of this study demonstrate that it is possible to precisely quantify the distance between maize plants. We found that accuracy of the measurement of the distance between maize plants depended on the height above ground level at which UAV imagery was taken. This study provides an innovative approach to quantify plant-to-plant variability and, thereby final crop yield estimates.

  6. A Social Studies Curriculum for a Modern World. The Marin Social Studies Project. Final Report.

    ERIC Educational Resources Information Center

    Lester, G. Sidney; And Others

    The major portion of this report provides a narrative summary and description of the work of the project, its context, evaluation, and recommendations. The major objectives of this three-year project were to: 1) field test and evaluate new K-12 social studies curriculum project materials, and 2) design a new K-12 social studies framework based on…

  7. Global magnetic field modelling with archeomagnetic and historical data

    NASA Astrophysics Data System (ADS)

    Senftleben, Robin; Korte, Monika; Finlay, Chris

    2016-04-01

    Global geomagnetic field models on different time scales are useful tools to study the field evolution and gain insights into underlying processes in the Earth's outer core. However, historical full vector field data are only available from 1840 on, and millennial scale field models based on archeo- and paleomagnetic data have, in general, rather low temporal and spatial resolution. This study complements the high resolution data of historical sources with archeomagnetic data in order to expand the time range back to 1000 AD and add total magnetic field informations in the times from 1590 AD to 1840 AD. This makes it possible to constrain the axial dipole moment with actual observations unlike the gufm1 model, which does so through linear extrapolation (Jackson et al. 2000). The resulting model is compared against new paleomagnetic data from the island Fogo of Cap Verde. The age of the sampled volcanic flows spans between 1600 AD and 1900 AD. The final objective of this study is to use this model to uncover details of the decaying behaviour of the dipole moment and the development of the South Atlantic Anomaly.

  8. FY95 limited energy study. Area B nitric acid production facilities, Holston Army Ammunition Plant, Kingsport, Tennessee. Final report

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

    NONE

    1996-04-02

    In June 1995, Affiliated Engineers SE, Inc. (AESE) was retained by the Mobile District U.S. Army Corps of Engineers to perform a Limited Energy Study for Holston Army Ammunition Plant, Kingsport, Tennessee. The field survey of existing conditions was completed in July 1995. The results of this field survey were subsequently tabulated and used to generate single line process flow diagrams on Autocad. A subsequent one day field survey was conducted in August 1995. This report summarizes the results obtained from field investigation and the analysis of various alternative Energy Conservation Opportunities (ECO`s). ECO`s were analyzed for suitability for themore » Energy Conservation Investment Program (ECIP) using the government`s software package called Life Cycle Cost in Design (LCCID).« less

  9. De Sitter and scaling solutions in a higher-order modified teleparallel theory

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

    Paliathanasis, Andronikos, E-mail: anpaliat@phys.uoa.gr

    The existence and the stability conditions for some exact relativistic solutions of special interest are studied in a higher-order modified teleparallel gravitational theory. The theory with the use of a Lagrange multiplier is equivalent with that of General Relativity with a minimally coupled noncanonical field. The conditions for the existence of de Sitter solutions and ideal gas solutions in the case of vacuum are studied as also the stability criteria. Furthermore, in the presence of matter the behaviour of scaling solutions is given. Finally, we discuss the degrees of freedom of the field equations and we reduce the field equationsmore » in an algebraic equation, where in order to demonstrate our result we show how this noncanonical scalar field can reproduce the Hubble function of Λ-cosmology.« less

  10. Pacing in Olympic track races: competitive tactics versus best performance strategy.

    PubMed

    Thiel, Christian; Foster, Carl; Banzer, Winfried; De Koning, Jos

    2012-01-01

    The purpose of this study was to describe pacing strategies in the 800 to 10,000-m Olympic finals. We asked 1) if Olympic finals differed from World Records, 2) how variable the pace was, 3) whether runners faced catastrophic events, and 4) for the winning strategy. Publically available data from the Beijing 2008 Olympic Games gathered by four transponder antennae under the 400-m track were analysed to extract descriptors of pacing strategies. Individual pacing patterns of 133 finalists were visualised using speed by distance plots. Six of eight plots differed from the patterns reported for World Records. The coefficient of running speed variation was 3.6-11.4%. In the long distance finals, runners varied their pace every 100 m by a mean 1.6-2.7%. Runners who were 'dropped' from the field achieved a stable running speed and displayed an endspurt. Top contenders used variable pacing strategies to separate themselves from the field. All races were decided during the final lap. Olympic track finalists employ pacing strategies which are different from World Record patterns. The observed micro- and macro-variations of pace may have implications for training programmes. Dropping off the pace of the leading group is an active step, and the result of interactive psychophysiological decision making.

  11. Correlation of DCPI with deformation under proof roller loading to assess soft subgrade stabilization criterion : addendum to NCDOT final report 2011-05, entitled : "Field verification of undercut criteria and alternatives for subgrade stabilization in th

    DOT National Transportation Integrated Search

    2016-11-21

    Work presented herein is an addendum to the final report for NCDOT Project 2011-05 entitled : Field Verification of Undercut Criteria and Alternatives for Subgrade Stabilization in the : Piedmont Area. The objective of the addendum work is to p...

  12. IMP-I spacecraft final magnetic tests

    NASA Technical Reports Server (NTRS)

    Harris, C. A.

    1972-01-01

    The increased IMP-I spacecraft spin axis moment resulting from excessive field exposures during environmental testing substantiated the need for a final pre-launch magnetic deperm and measurement. By performing a dc rotation deperm it was possible to reduce this moment below the previous initial test post deperm magnitude. In addition, the magnetic field disturbance at the flight magnetometer diminished to below 0.1 nanotesla (gamma) in all directions.

  13. Carryover negligibility and relevance in bioequivalence studies.

    PubMed

    Ocaña, Jordi; Sanchez O, Maria P; Carrasco, Josep L

    2015-01-01

    The carryover effect is a recurring issue in the pharmaceutical field. It may strongly influence the final outcome of an average bioequivalence study. Testing a null hypothesis of zero carryover is useless: not rejecting it does not guarantee the non-existence of carryover, and rejecting it is not informative of the true degree of carryover and its influence on the validity of the final outcome of the bioequivalence study. We propose a more consistent approach: even if some carryover is present, is it enough to seriously distort the study conclusions or is it negligible? This is the central aim of this paper, which focuses on average bioequivalence studies based on 2 × 2 crossover designs and on the main problem associated with carryover: type I error inflation. We propose an equivalence testing approach to these questions and suggest reasonable negligibility or relevance limits for carryover. Finally, we illustrate this approach on some real datasets. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Description of the supporting factors of final project in Mathematics and Natural Sciences Faculty of Syiah Kuala University with multiple correspondence analysis

    NASA Astrophysics Data System (ADS)

    Rusyana, Asep; Nurhasanah; Maulizasari

    2018-05-01

    Syiah Kuala University (Unsyiah) is hoped to have graduates who are qualified for working or creating a field of work. A final project course implementation process must be effective. This research uses data from the evaluation conducted by Mathematics and Natural Sciences Faculty (FMIPA) of Unsyiah. Some of the factors that support the completion of the final project are duration, guidance, the final project seminars, facility, public impact, and quality. This research aims to know the factors that have a relationship with the completion of the final project and identify similarities among variables. The factors that support the completion of the final project at every study program in FMIPA are (1) duration, (2) guidance and (3) facilities. These factors are examined for the correlations by chi-square test. After that, the variables are analyzed with multiple correspondence analysis. Based on the plot of correspondence, the activities of the guidance and facilities in Informatics Study Program are included in the fair category, while the guidance and facilities in the Chemistry are included in the best category. Besides that, students in Physics can finish the final project with the fastest completion duration, while students in Pharmacy finish for the longest time.

  15. Inquiring into Pre-Service Content Area Teachers' Development of Literacy Practices and Pedagogical Content Knowledge

    ERIC Educational Resources Information Center

    Mitton Kukner, Jennifer; Murray Orr, Anne

    2015-01-01

    The focus of this qualitative multi-year case study is on preservice teachers' experiences related to the development of their literacy practices in teaching high school science, math, social studies and other content area courses during their final field placement in a teacher education program. Results indicate tangible indicators of overall…

  16. Workplace Education Efforts in Small Business: Learning from the Field. Final Report.

    ERIC Educational Resources Information Center

    Vencill, Mary P.; And Others

    A study identified and conducted onsite case studies of 18 different education programs conducted by small companies. Two-thirds of them were conducted by manufacturing companies; the remainder were in health services, construction, or transportation companies. Most of the programs served fewer than 25 workers and had been in operation for less…

  17. A Hermeneutic Phenomenological Study of Pre-Service Physical Educators' Perceptions of Their Professional Preparedness

    ERIC Educational Resources Information Center

    Hampson, Geoffrey Martin

    2017-01-01

    The purpose of this hermeneutic phenomenological study was to capture the essence of the perceptions of 11 pre-service physical educators in the final field placement and clinical practices of their undergraduate degree program at the University of Redbank, the University of Peters, and Ina University where they prepared to become professional…

  18. Epilepsy Genetics—Past, Present, and Future

    PubMed Central

    Poduri, Annapurna; Lowenstein, Daniel

    2014-01-01

    Human epilepsy is a common and heterogeneous condition in which genetics play an important etiological role. We begin by reviewing the past history of epilepsy genetics, a field that has traditionally included studies of pedigrees with epilepsy caused by defects in ion channels and neurotransmitters. We highlight important recent discoveries that have expanded the field beyond the realm of channels and neurotransmitters and that have challenged the notion that single genes produce single disorders. Finally, we project toward an exciting future for epilepsy genetics as large-scale collaborative phenotyping studies come face to face with new technologies in genomic medicine. PMID:21277190

  19. The Dirac equation in Schwarzschild black hole coupled to a stationary electromagnetic field

    NASA Astrophysics Data System (ADS)

    Al-Badawi, A.; Owaidat, M. Q.

    2017-08-01

    We study the Dirac equation in a spacetime that represents the nonlinear superposition of the Schwarzschild solution to an external, stationary electromagnetic field. The set of equations representing the uncharged Dirac particle in the Newman-Penrose formalism is decoupled into a radial and an angular parts. We obtain exact analytical solutions of the angular equations. We manage to obtain the radial wave equations with effective potentials. Finally, we study the potentials by plotting them as a function of radial distance and examine the effect of the twisting parameter and the frequencies on the potentials.

  20. Cost Modeling and Design of Field-Reversed Configuration Fusion Power Plants

    NASA Astrophysics Data System (ADS)

    Kirtley, David; Slough, John; Helion Team

    2017-10-01

    The Inductively Driven Liner (IDL) fusion concept uses the magnetically driven implosion of thin (0.5-1 mm) Aluminum hoops to magnetically compress a merged Field-Reversed Configuration (FRC) plasma to fusion conditions. Both the driver and the target have been studied experimentally and theoretically by researchers at Helion Energy, MSNW, and the University of Washington, demonstrating compression fields greater than 100 T and suitable fusion targets. In the presented study, a notional power plant facility using this approach will be described. In addition, a full cost study based on the LLNL Z-IFE and HYLIFE-II studies, the ARIES Tokamak concept, and RAND power plant studies will be described. Finally, the expected capital costs, development requirements, and LCOE for 50 and 500 MW power plants will be given. This analysis includes core FRC plant scaling, metallic liner recycling, radiation shielding, operations, and facilities capital requirements.

  1. Environmental Impact Analysis Process. Final Environmental Impact Statement. Part 2. Proposed High Frequency Active Auroral Research Program.

    DTIC Science & Technology

    1993-07-01

    there are any. The recent set of articles in gcience (1) on the effects of Electromagnetic Fields (EDF) states quite clearly and accurately that we...gone into the explanation of how the HAARP will impact the areas most closely related to the study subject, associated electromagnetic fields and...during break-up each year. page 4-90. Exposure to Humans . This first paragraph is terrible. Concerned citizens will be looking here first to learn if

  2. Strong gravitational lensing—a probe for extra dimensions and Kalb-Ramond field

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

    Chakraborty, Sumanta; SenGupta, Soumitra, E-mail: sumantac.physics@gmail.com, E-mail: tpssg@iacs.res.in

    2017-07-01

    Strong field gravitational lensing in the context of both higher spacetime dimensions and in presence of Kalb-Ramond field have been studied. After developing proper analytical tools to analyze the problem we consider gravitational lensing in three distinct black hole spacetimes—(a) four dimensional black hole in presence of Kalb-Ramond field, (b) brane world black holes with Kalb-Ramond field and finally (c) black hole solution in f ( T ) gravity. In all the three situations we have depicted the behavior of three observables: the asymptotic position approached by the relativistic images, the angular separation and magnitude difference between the outermost imagesmore » with others packed inner ones, both numerically and analytically. Difference between these scenarios have also been discussed along with possible observational signatures.« less

  3. An Introduction to Magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Davidson, P. A.

    2001-03-01

    Magnetic fields are routinely used in industry to heat, pump, stir and levitate liquid metals. There is the terrestrial magnetic field that is maintained by fluid motion in the earth's core, the solar magnetic field, which generates sunspots and solar flares, and the galactic field that influences the formation of stars. This introductory text on magnetohydrodynamics (MHD) (the study of the interaction of magnetic fields and conducting fluids) is intended to serve as an introductory text for advanced undergraduates and graduate students in physics, applied mathematics and engineering. The material in the text is heavily weighted toward incompressible flows and to terrestrial (as distinct from astrophysical) applications. The final sections of the text, which outline the latest advances in the metallurgical applications of MHD, make the book of interest to professional researchers in applied mathematics, engineering and metallurgy.

  4. Soap-film flow induced by electric fields in asymmetric frames

    NASA Astrophysics Data System (ADS)

    Mollaei, S.; Nasiri, M.; Soltanmohammadi, N.; Shirsavar, R.; Ramos, A.; Amjadi, A.

    2018-04-01

    Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

  5. Soap-film flow induced by electric fields in asymmetric frames.

    PubMed

    Mollaei, S; Nasiri, M; Soltanmohammadi, N; Shirsavar, R; Ramos, A; Amjadi, A

    2018-04-01

    Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

  6. Methane Hydrate Field Program: Development of a Scientific Plan for a Methane Hydrate-Focused Marine Drilling, Logging and Coring Program

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

    Myers, Greg

    This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report: Historical Methane Hydrate Projectmore » Review Report; Methane Hydrate Workshop Report; Topical Report: Marine Methane Hydrate Field Research Plan; and Final Scientific/Technical Report.« less

  7. Development of safety performance functions and other decision support tools to assess pedestrian and bicycle safety : final report.

    DOT National Transportation Integrated Search

    2016-09-30

    field study was performed at 40 uncontrolled midblock crosswalks and 26 signalized intersections on low-speed roadways selected from the areas surrounding three major urban college campuses across lower Michigan. An array of existing traffic control ...

  8. Study of the potential impacts of highway construction on selected birds with emphasis on the golden-cheeked warbler : final report 2008-2011.

    DOT National Transportation Integrated Search

    2012-07-01

    This report summarizes the 20082011 field seasons for the Highway 71 impact assessment of : highway construction noise and activity on golden-cheeked warblers (Setophaga chrysoparia). Researchers : examined if construction activity and noise alter...

  9. Field evaluation of a new aluminum alloy as a sacrificial anode for steel embedded in concrete

    DOT National Transportation Integrated Search

    1998-04-01

    This is the final report for a study to evaluate the use of sacrificial cathodic protection for reinforced and prestressed concrete bridge members. Cathodic protection (CP) using impressed current is an accepted and common method used to provide corr...

  10. Field Control and Performance of Asphalt Mixtures Containing Greater than 25 Percent Reclaimed Asphalt Pavement : Draft Final Report

    DOT National Transportation Integrated Search

    2018-02-02

    The Alabama Department of Transportation (ALDOT) and other highway agencies are interested in utilization of higher percentages of reclaimed asphalt pavement (RAP) in asphalt mixtures. There are a number of research studies at both state and national...

  11. SECURING CONTAINERIZED HAZARDOUS WASTES WITH WELDED POLYETHYLENE ENCAPSULATES

    EPA Science Inventory

    Full-scale encapsulation of 208-liter (55-gal) drums was studied as a means for managing corroding containers of hazardous wastes in the field and rendering them suitable for transport and safe deposit within a final disposal site such as a landfill. Polyethylene (PE) receivers w...

  12. EVALUATION OF ANEUPLOIDY AND DNA DAMAGE IN HUMAN SPERMATOZOA: APPLICATION IN FIELD STUDIES (R827019)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. Research on Mathematical Techniques in Psychology. Final Report.

    ERIC Educational Resources Information Center

    Gulliksen, Harold

    Mathematical techniques are developed for studying psychological problems in three fields: (1) psychological scaling, (2) learning and concept formation, and (3) mental measurement. Psychological scaling procedures are demonstrated to be useful in many areas, ranging from sensory discrimination of physical stimuli, such as colors, sounds, etc.,…

  14. Field testing and implementation of dilemma zone protection and signal coordination at closely-spaced high-speed intersections : final report, May 19, 2005.

    DOT National Transportation Integrated Search

    2005-05-01

    The report presents the details of a study carried out to test and implement a dilemma zone protection technique at three high-speed closely-spaced intersections on Roosevelt Blvd in Middletown, Ohio.

  15. Mentoring Student Teachers: A Conceptual Model.

    ERIC Educational Resources Information Center

    Stahlhut, Richard G.; Hawkes, Richard R.

    This study sought to determine how student teachers perceived their cooperating teacher's leadership practices. The Leader Behavior Description Questionnaire Form was completed during the final week of clinical field experience by 212 student teachers. The questionnaire was based on four identified leadership styles used by mentors: (1)…

  16. Final Report: The Influence of Novel Behavioral Strategies in Promoting the Diffusion of Solar Energy

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

    Gillingham, Kenneth; Bollinger, Bryan

    This is the final report for a systematic, evidence-based project using an unprecedented series of large-scale field experiments to examine the effectiveness and cost-effectiveness of novel approaches to reduce the soft costs of solar residential photovoltaics. The approaches were based around grassroots marketing campaigns called ‘Solarize’ campaigns, that were designed to lower costs and increase adoption of solar technology. This study quantified the effectiveness and cost-effectiveness of the Solarize programs and tested new approaches to further improve the model.

  17. Study of rainfall-induced landslide: a review

    NASA Astrophysics Data System (ADS)

    Tohari, A.

    2018-02-01

    Rainfall-induced landslides pose a substantial risk to people and infrastructure. For this reason, there have been numerous studies to understand the landslide mechanism. Most of them were performed on the numerical analysis and laboratory experiment. This paper presents a review of existing research on field hydrological condition of soil slopes leading to the initiation of rainfall-induced landslide. Existing methods to study field hydrological response of slopes are first reviewed, emphasizing their limitations and suitability of application. The typical hydrological response profiles in the slope are then discussed. Subsequently, some significant findings on hydrological condition leading to rainfall-induced landslides are summarized and discussed. Finally, several research topics are recommended for future study.

  18. NTP Studies of Magnetic Field Promotion (DMBA Initiation) in Female Sprague-Dawley Rats (Whole-body Exposure/Gavage Studies).

    PubMed

    1999-08-01

    Electric and magnetic fields are associated with the production, transmission, and use of electricity; thus, the potential for human exposure is high. These elec-tric and magnetic fields are predominantly of low fre-quency (60 Hz in the United States and 50 Hz in Europe) and generally of low intensity. Because some epidemiology studies and initiation/promotion studies in rats have suggested a potential for increased breast cancer rates with increasing magnetic field exposure, the ability of 50- and 60-Hz magnetic fields to pro-mote mammary gland tumors initiated by the administration of 7,12-dimethylbenz(a)anthracene (DMBA) was examined in female Sprague-Dawley rats in 13- and 26-week whole-body exposure studies. Additional animals were evaluated for changes in pineal gland and serum melatonin concentrations. FIRST 13-WEEK STUDY: Groups of 100 female Sprague-Dawley rats were ad-ministered 20 mg DMBA (four weekly gavage doses of 5 mg in sesame oil) and exposed to 1 G 50-Hz, 5 G 50-Hz, or 1 G 60-Hz magnetic fields for 18.5 hours per day, 7 days per week, for 13 weeks. A group of 100 rats administered 20 mg DMBA served as DMBA controls. A group of 100 vehicle control rats was administered only sesame oil on the same schedule. Additional groups of 10 rats receiving similar treatment were evaluated for pineal gland and serum melatonin concentrations at 4, 8, or 12 weeks. All vehicle control rats survived to the end of the study. Of the animals administered 20 mg DMBA, 6 rats in the DMBA control group, 13 in the DMBA/1 G 50-Hz group, eight in the DMBA/5 G 50-Hz group, and five in the DMBA/1 G 60-Hz group died or were removed from the study prior to the final necropsy. Final mean body weights and body weight gains of the DMBA/1 G 50-Hz and DMBA/1 G 60-Hz groups and the mean body weight gain of the DMBA/5 G 50-Hz group were slightly greater than those of the DMBA control group. Clinical findings including torso masses and ulcers (on the mammary masses) were attributed to DMBA administration. The numbers of palpable mammary gland tumors, tumor sizes, and total tumor areas in DMBA/magnetic field groups were similar to those in the DMBA control group. Relative to the DMBA control group, exposure to magnetic fields did not significantly affect overall incidences of mammary gland neoplasms or nonneoplastic lesions in the DMBA/magnetic field groups. SECOND 13-WEEK STUDY: Groups of 100 female Sprague-Dawley rats were ad-ministered 8 mg DMBA (four weekly gavage doses of 2 mg in sesame oil) and exposed to 1 G 50-Hz or 5 G 50-Hz magnetic fields for 18.5 hours per day, 7 days per week, for 13 weeks. A group of 100 female rats administered 8 mg DMBA served as DMBA controls. Additional groups of 10 rats receiving similar treatment were evaluated for pineal gland and serum melatonin concentrations at 4, 8, or 12 weeks. Except for one rat in the DMBA/5 G 50-Hz group, all rats survived until the end of the study. Final mean body weights of DMBA/magnetic field groups were similar to those of the DMBA control group. Clinical findings including torso masses and ulcers were attributed to DMBA administration. The numbers of palpable mammary gland tumors, tumor sizes, and total tumor areas in DMBA/magnetic field groups were similar to those in the DMBA control group. Relative to the DMBA control group, exposure to magnetic fields did not significantly affect overall incidences of mammary gland neoplasms or nonneoplastic lesions in the DMBA/magnetic field groups. 26-WEEK STUDY: Groups of 100 female Sprague-Dawley rats were administered 10 mg DMBA (in sesame oil) by gavage followed by exposure to 1 G 50-Hz, 5 G 50-Hz, or 1 G 60-Hz magnetic fields for 18.5 hours per day, 7 days per week, for 26 weeks. A group of 100 female rats administered 10 mg DMBA served as DMBA controls. Another 100 vehicle control rats were administered only sesame oil. Additional groups of 10 rats receiving similar treatment were evaluated for pineal gland and serum melatonin concentrations at 4, 8, or 12 weeks. All rats in the vehicle control group survived until the end of the study. Twelve rats in the DMBA control group, 15 in the DMBA/1 G 50-Hz group, 9 in the DMBA/5 G 50-Hz group, and six in the DMBA/1 G 60-Hz group died or were removed during the study. The final mean body weights and body weight gains of the DMBA/1 G 50-Hz and DMBA/5 G 50-Hz groups were significantly greater than those of the DMBA control group. Clinical findings including torso masses, abscesses, and ulcers were attributed to DMBA administration. The pineal gland melatonin concentrations of DMBA/5 G 50-Hz and DMBA/1 G 60-Hz rats were significantly greater than that of the DMBA controls at week 12; however, these data were highly variable between individual animals within each group. The numbers of palpable mammary gland tumors, tumor sizes, and total tumor areas in DMBA/magnetic field groups were similar to those in the DMBA controls. The incidences of mammary gland carci-noma (including multiple) in the DMBA/1 G 60-Hz group were significantly decreased relative to the DMBA control group. CONCLUSIONS: In an initiation/promotion study in which female Sprague-Dawley rats were initiated by four weekly doses of 5 mg DMBA per rat beginning at 50 days of age and exposed to 50-Hz magnetic fields at 1 or 5 G field intensities or to 1 G 60-Hz magnetic fields for 13 weeks, there was no evidence that magnetic fields promoted the development of mammary gland neoplasms. The prevalence and multiplicity of mammary gland carcinomas in all DMBA groups limited the ability of this assay to detect a promoting effect of magnetic fields. In an initiation/promotion study in which female Sprague-Dawley rats were initiated by four weekly doses of 2 mg DMBA per rat beginning at 50 days of age and exposed to 50-Hz magnetic fields at 1 or 5 G field intensities for 13 weeks, there was no evidence that magnetic fields promoted the development of mammary gland neoplasms. In an initiation/promotion study in which female Sprague-Dawley rats were initiated by a single 10 mg DMBA dose at 50 days of age and then exposed to 50-Hz magnetic fields at 1 or 5 G field intensities or to 1 G 60-Hz magnetic fields for 26 weeks, there was no evidence that magnetic fields promoted the development of mammary gland neoplasms.

  19. Unsteady magnetohydrodynamic free convection flow of a second grade fluid in a porous medium with ramped wall temperature.

    PubMed

    Samiulhaq; Ahmad, Sohail; Vieru, Dumitru; Khan, Ilyas; Shafie, Sharidan

    2014-01-01

    Magnetic field influence on unsteady free convection flow of a second grade fluid near an infinite vertical flat plate with ramped wall temperature embedded in a porous medium is studied. It has been observed that magnitude of velocity as well as skin friction in case of ramped temperature is quite less than the isothermal temperature. Some special cases namely: (i) second grade fluid in the absence of magnetic field and porous medium and (ii) Newtonian fluid in the presence of magnetic field and porous medium, performing the same motion are obtained. Finally, the influence of various parameters is graphically shown.

  20. Leptogenesis and reheating in complex hybrid inflation

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

    Martinez-Prieto, Carlos; Delepine, David; Urena-Lopez, L. Arturo

    2010-02-01

    We study the transformation into a baryon asymmetry of a charge initially stored in a complex (waterfall) scalar field at the end of a hybrid inflation phase as described by Delepine, Martinez, and Urena-Lopez [Phys. Rev. Lett. 98, 161302 (2007)]. The waterfall field is coupled to right-handed neutrinos, and is also responsible for their Majorana masses. The charge is finally transferred to the leptons of the standard model through the decay of the right-handed neutrinos without introducing new CP violating interactions. Other needed processes, like the decay of the inflaton field and the reheating of the Universe, are also discussedmore » in detail.« less

  1. Initialization of soil-water content in regional-scale atmospheric prediction models

    NASA Technical Reports Server (NTRS)

    Smith, Christopher B.; Lakhtakia, Mercedes; Capehart, William J.; Carlson, Toby N.

    1994-01-01

    The purpose of this study is to demonstrate the feasibility of determining the soil-water content fields required as initial conditions for land surface components within atmospheric prediction models. This is done using a model of the hydrologic balance and conventional meteorological observations, land cover, and soils information. A discussion is presented of the subgrid-scale effects, the integration time, and the choice of vegetation type on the soil-water content patterns. Finally, comparisons are made between two The Pennsylvania State University/National Center for Atmospheric Research mesoscale model simulations, one using climatological fields and the other one using the soil-moisture fields produced by this new method.

  2. Cassini's Grand Finale Science Highlights

    NASA Astrophysics Data System (ADS)

    Spilker, Linda

    2017-10-01

    After 13 years in orbit, the Cassini-Huygens Mission to Saturn ended in a science-rich blaze of glory. Cassini returned its final bits of unique science data on September 15, 2017, as it plunged into Saturn's atmosphere satisfying planetary protection requirements. Cassini's Grand Finale covered a period of roughly five months and ended with the first time exploration of the region between the rings and planet.The final close flyby of Titan in late April 2017 propelled Cassini across Saturn’s main rings and into its Grand Finale orbits; 22 orbits that repeatedly dove between Saturn’s innermost rings and upper atmosphere making Cassini the first spacecraft to explore this region. The last orbit turned the spacecraft into the first Saturn upper atmospheric probe.The Grand Finale orbits provided highest resolution observations of both the rings and Saturn, and in-situ sampling of the ring particle composition, Saturn's atmosphere, plasma, and innermost radiation belts. The gravitational field was measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the deeper atmosphere, and mass of the rings. The magnetic field provided insight into the physical nature of the magnetic dynamo and structure of the internal magnetic field. The ion and neutral mass spectrometer sampled the upper atmosphere for molecules that escape the atmosphere in addition to molecules originating from the rings. The cosmic dust analyzer directly sampled the composition from different parts of the main rings for the first time. Fields and particles instruments directly measured the plasma environment between the rings and planet.Science highlights and new mysteries gleaned to date from the Grand Finale orbits will be discussed.The research described in this paper was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2017 California Institute of Technology. Government sponsorship is acknowledged.

  3. Simulation of Temperature Field Distribution for Cutting the Temperated Glass by Ultraviolet Laser

    NASA Astrophysics Data System (ADS)

    Yang, B. J.; He, Y. C.; Dai, F.; Lin, X. C.

    2017-03-01

    The finite element software ANSYS was adopted to simulate the temperature field distribution for laser cutting tempered glass, and the influence of different process parameters, including laser power, glass thickness and cutting speed, on temperature field distribution was studied in detail. The results show that the laser power has a greater influence on temperature field distribution than other paremeters, and when the laser power gets to 60W, the highest temperature reaches 749°C, which is higher than the glass softening temperature. It reflects the material near the laser spot is melted and the molten slag is removed by the high-energy water beam quickly. Finally, through the water guided laser cutting tempered glass experiment the FEM theoretical analysis was verified.

  4. Distribution and specificity of S-cone ("blue cone") signals in subcortical visual pathways.

    PubMed

    Martin, Paul R; Lee, Barry B

    2014-03-01

    We review here the distribution of S-cone signals and properties of S-cone recipient receptive fields in subcortical pathways. Nearly everything we know about S-cone signals in the subcortical visual system comes from the study of visual systems in cats and primates (monkeys); in this review, we concentrate on results from macaque and marmoset monkeys. We discuss segregation of S-cone recipient (blue-on and blue-off) receptive fields in the dorsal lateral geniculate nucleus and describe their receptive field properties. We treat in some detail the question of detecting weak S-cone signals as an introduction for newcomers to the field. Finally, we briefly consider the question on how S-cone signals are distributed among nongeniculate targets.

  5. Field and lab evaluation of the use of lime fly ash to replace soil cement as a base course : final report.

    DOT National Transportation Integrated Search

    1997-09-01

    This study evaluates the performance of lime/fly ash stabilized base as an alternative to soil cement stabilized base for flexible pavement systems on reconstructed highways in Louisiana. Louisiana has historically used soil cement for most flexible ...

  6. Lime utilization in the laboratory, field, and design of pavement layers : final report.

    DOT National Transportation Integrated Search

    2017-01-01

    The objective of this study was to review and report the best practices of using lime (i.e., granulated lime, hydrated lime, and slurry lime) to dry soil, in working tables, and in pavement applications. The project also reviewed and documented the i...

  7. Development of a wireless MEMS multifunction sensor system and field demonstration of embedded sensors for monitoring concrete pavements, volume II

    DOT National Transportation Integrated Search

    2016-08-01

    This two-pronged study evaluated the performance of commercial off-the-shelf (COTS) micro-electromechanical sensors and systems (MEMS) embedded in concrete pavement (Final Report Volume I) and developed a wireless MEMS multifunctional sensor system f...

  8. 48 CFR 801.690-5 - Requirements for contracting authority.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Education. (1) The 24 business-related college credits shall be in any combination of the following fields of study at an accredited college or university: accounting, business, finance, law, contracts.... (2) The HCA will make the final determination whether a course is accepted as business-related for...

  9. 48 CFR 801.690-5 - Requirements for contracting authority.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Education. (1) The 24 business-related college credits shall be in any combination of the following fields of study at an accredited college or university: accounting, business, finance, law, contracts.... (2) The HCA will make the final determination whether a course is accepted as business-related for...

  10. 48 CFR 801.690-5 - Requirements for contracting authority.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Education. (1) The 24 business-related college credits shall be in any combination of the following fields of study at an accredited college or university: accounting, business, finance, law, contracts.... (2) The HCA will make the final determination whether a course is accepted as business-related for...

  11. 48 CFR 801.690-5 - Requirements for contracting authority.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Education. (1) The 24 business-related college credits shall be in any combination of the following fields of study at an accredited college or university: accounting, business, finance, law, contracts.... (2) The HCA will make the final determination whether a course is accepted as business-related for...

  12. A Model for Producing and Sharing Instructional Materials in Veterinary Medicine. Final Report.

    ERIC Educational Resources Information Center

    Ward, Billy C.; Niec, Alphonsus P.

    This report describes a study of factors which appear to influence the "shareability" of audiovisual materials in the field of veterinary medicine. Specific factors addressed are content quality, instructional effectiveness, technical quality, institutional support, organization, logistics, and personal attitudes toward audiovisuals. (Author/CO)

  13. Field Study on Environmental Dredging Residuals: Ashtabula River; Volume I. Final Report

    EPA Science Inventory

    A partnership was formed in 2006 between the National Risk Management Research Laboratory (NRMRL) and the National Exposure Research Laboratory (NERL) of the U.S. Environmental Protection Agency's (U.S. EPA's) Office of Research and Development (ORD) and U.S. EPA's Great Lakes Na...

  14. Field Study on the Efficacy of the New Restart Provision for Hours of Service

    DOT National Transportation Integrated Search

    2014-01-01

    The objective of this research project was to examine the efficacy of the new restart rule promulgated as partof the Hours of Service of Drivers Final Rule, published on December 27, 2011, with a compliance date of July 1, 2013. Under the new restart...

  15. The Psychology of Life Construction

    ERIC Educational Resources Information Center

    Duarte, Maria Eduarda

    2009-01-01

    The present article analyzes, from a historical perspective, the object of the study in the fields of vocational guidance and career management. It then considers the contemporary need to view workers as collaborators within organizations. Finally, in the third part, it presents tentative principles for the construction of a new paradigm called…

  16. THE USE OF BREATH CONDENSATE AS A NONINVASIVE MEASURE OF AIRWAY INFLAMMATION IN FIELD STUDIES. (R827355C002)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  17. ECOLOGICAL CORRELATES OF ANURAN SPECIES RICHNESS IN TEMPORARY POOLS: A FIELD STUDY IN SOUTH CAROLINA, USA. (R825795)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  18. Studies in Group Upbringing. Final Report.

    ERIC Educational Resources Information Center

    Bronfenbrenner, Urie

    Four years of an ongoing research project designed to investigate the joint impact of family, peers, teacher, and professional upbringers on the socialization of children in Israel are reported. Data are gathered on child behavior and socialization practices from fifth, sixth, and seventh graders. Settings in the two major waves of field work…

  19. The University of Texas Institute for Geophysics Marine Geology and Geophysics Field Course

    NASA Astrophysics Data System (ADS)

    Davis, M. B.; Gulick, S. P.; Allison, M. A.; Goff, J. A.; Duncan, D. D.; Saustrup, S.

    2010-12-01

    During the spring-summer intersession, we annually offer an intensive three-week field course designed to provide hands-on instruction and training for graduate and upper-level undergraduate students in the acquisition, processing, interpretation, and visualization of marine geological and geophysical data. Now in year four, the course covers high-resolution air gun and streamer seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples (e.g., core description, grain size analysis, x-radiography, etc.). Students first participate in three days of classroom instruction designed to provide theoretical and technical background on each field method and impart geologic context of the study area. Students then travel to the Gulf Coast for a week of at-sea field work. In the field, students rotate between two small research vessels: one vessel, the 22’ aluminum-hulled R/V Lake Itasca, owned and operated by UTIG, is used for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA’s R/V Manta or the R/V Acadiana, operated by the Louisiana Universities Marine Consortium, is used for high-resolution seismic reflection, CHIRP sub-bottom profiling, gravity coring, and vibracoring. Students assist with survey design, learn systems setup and acquisition parameters, and safe instrument deployment and retrieval techniques. Students also perform on-shore sedimentology lab work, data quality control, data processing and visualization using industry-standard software such as Focus, Landmark, Caris, and Fledermaus. During the course’s final week, students return to the classroom where, collaborating in teams of three, they integrate and interpret data in a final project which examines the geologic history and/or sedimentary processes as typified by the Gulf Coast continental shelf. The course culminates in a series of professional-level final presentations and discussions. Following the course, students report a greater understanding of marine geology and geophysics via the course’s intensive, hands-on, team approach, and low instructor to student ratio. This course satisfies field experience requirements for some degree programs and thus provides a unique alternative to land-based field courses.

  20. Radiotherapy quality assurance report from children's oncology group AHOD0031

    PubMed Central

    Dharmarajan, Kavita V.; Friedman, Debra L.; FitzGerald, T.J.; McCarten, Kathleen M.; Constine, Louis S.; Chen, Lu; Kessel, Sandy K.; Iandoli, Matt; Laurie, Fran; Schwartz, Cindy L.; Wolden, Suzanne L.

    2016-01-01

    Purpose A phase III trial assessing response-based therapy in intermediate-risk Hodgkin lymphoma, mandated real-time central review of involved field radiotherapy and imaging records by a centralized review center to maximize protocol compliance. We report the impact of centralized radiotherapy review upon protocol compliance. Methods Review of simulation films, port films, and dosimetry records was required pre-treatment and after treatment completion. Records were reviewed by study-affiliated or review center-affiliated radiation oncologists. A 6–10% deviation from protocol-specified dose was scored as “minor”; >10% was “major”. A volume deviation was scored as “minor” if margins were less than specified, or “major” if fields transected disease-bearing areas. Interventional review and final compliance review scores were assigned to each radiotherapy case and compared. Results Of 1712 patients enrolled, 1173 underwent IFRT at 256 institutions in 7 countries. An interventional review was performed in 88% and a final review in 98%. Overall, minor and major deviations were found in 12% and 6%, respectively. Among the cases for which ≥ 1 pre-IFRT modification was requested by QARC and subsequently made by the treating institution, 100% were made compliant on final review. In contrast, among the cases for which ≥ 1 modification was requested but not made by the treating institution, 10% were deemed compliant on final review. Conclusion In a large trial with complex treatment pathways and heterogeneous radiotherapy fields, central review was performed in a large percentage of cases pre-IFRT and identified frequent potential deviations in a timely manner. When suggested modifications were performed by the institutions, deviations were almost eliminated. PMID:25670539

  1. Inverse method predicting spinning modes radiated by a ducted fan from free-field measurements.

    PubMed

    Lewy, Serge

    2005-02-01

    In the study the inverse problem of deducing the modal structure of the acoustic field generated by a ducted turbofan is addressed using conventional farfield directivity measurements. The final objective is to make input data available for predicting noise radiation in other configurations that would not have been tested. The present paper is devoted to the analytical part of that study. The proposed method is based on the equations governing ducted sound propagation and free-field radiation. It leads to fast computations checked on Rolls-Royce tests made in the framework of previous European projects. Results seem to be reliable although the system of equations to be solved is generally underdetermined (more propagating modes than acoustic measurements). A limited number of modes are thus selected according to any a priori knowledge of the sources. A first guess of the source amplitudes is obtained by adjusting the calculated maximum of radiation of each mode to the measured sound pressure level at the same angle. A least squares fitting gives the final solution. A simple correction can be made to take account of the mean flow velocity inside the nacelle which shifts the directivity patterns. It consists of modifying the actual frequency to keep the cut-off ratios unchanged.

  2. Standardization of Course Plan and Design of Objective Structured Field Examination (OSFE) for the Assessment of Pharm.D. Student’s Community Pharmacy Clerkship Skills

    PubMed Central

    Monajjemzadeh, Farnaz; Shokri, Javad; Mohajel Nayebi, Ali Reza; Nemati, Mahboob; Azarmi, Yadollah; Charkhpour, Mohammad; Najafi, Moslem

    2014-01-01

    Purpose: This study was aimed to design Objective Structured Field Examination (OSFE) and also standardize the course plan of community pharmacy clerkship at Pharmacy Faculty of Tabriz University of Medical Sciences (Iran). Methods: The study was composed of several stages including; evaluation of the old program, standardization and implementation of the new course plan, design and implementation of OSFE, and finally results evaluation. Results: Lack of a fair final assessment protocol and proper organized educating system in various fields of community pharmacy clerkship skills were assigned as the main weaknesses of the old program. Educational priorities were determined and student’s feedback was assessed to design the new curriculum consisting of sessions to fulfill a 60-hour training course. More than 70% of the students were satisfied and successfulness and efficiency of the new clerkship program was significantly greater than the old program (P<0.05). In addition, they believed that OSFE was a suitable testing method. Conclusion: The defined course plan was successfully improved different skills of the students and OSFE was concluded as a proper performance based assessment method. This is easily adoptable by pharmacy faculties to improve the educational outcomes of the clerkship course. PMID:24511477

  3. Drag and Lift Forces Between a Rotating Conductive Sphere and a Cylindrical Magnet

    NASA Technical Reports Server (NTRS)

    Nurge, Mark A.; Youngquist, Robert C.

    2017-01-01

    Modeling the interaction between a non-uniform magnetic field and a rotating conductive object allows study of the drag force which is used in applications such as eddy current braking and linear induction motors as well as the transition to a repulsive force that is the basis for magnetic levitation systems. Here, we study the interaction between a non-uniform field generated by a cylindrical magnet and a rotating conductive sphere. Each eddy current in the sphere generates a magnetic field which in turn generates another eddy current, eventually feeding back on itself. A two step mathematics process is developed to find a closed form solution in terms of only two eddy currents. However, the complete solution requires decomposition of the magnetic field into a summation of spherical harmonics, making it more suitable for a graduate level electromagnetism lecture or lab. Finally, the forces associated with these currents are calculated and then verified experimentally.

  4. An investigation into possible quantum chaos in the H2 molecule under intense laser fields via Ehrenfest phase space (EPS) trajectories.

    PubMed

    Sadhukhan, Mainak; Deb, B M

    2018-06-21

    By employing the Ehrenfest "phase space" trajectory method for studying quantum chaos, developed in our laboratory, the present study reveals that the H 2 molecule under intense laser fields of three different intensities, I = 1 × 10 14  W/cm 2 , 5 × 10 14  W/cm 2 , and 1 × 10 15  W/cm 2 , does not show quantum chaos. A similar conclusion is also reached through the Loschmidt echo (also called quantum fidelity) calculations reported here for the first time for a real molecule under intense laser fields. Thus, a long-standing conjecture about the possible existence of quantum chaos in atoms and molecules under intense laser fields has finally been tested and not found to be valid in the present case.

  5. A Trans-National Study of Formal Education: Its Relationship to the Social System and Its Consequences. Final Report.

    ERIC Educational Resources Information Center

    Cohen, Yehudi A.

    In a comparison of the educational systems of Israel and the United States, extensive observations are reported from field studies of representative samples of elementary and secondary schools in the two countries. Special attention is given to provisions made by each of the educational systems for education of subgroups within the respective…

  6. BIOGEOCHEMISTRY OF MERCURY IN VERMONT AND NEW HAMPSHIRE LAKES: AN ASSESSMENT OF MERCURY IN WATER, SEDIMENT, AND BIOTA OF VERMONT AND NEW HAMPSHIRE LAKES - COMPREHENSIVE FINAL PROJECT REPORT

    EPA Science Inventory

    This report summarizes findings of a three-year field study of mercury in freshwater lakes of Vermont and New Hampshire. The study was undertaken jointly by the Vermont Department of Environmental Conservation, New Hampshire Department of Environmental Services, and Syracuse Univ...

  7. A Study to Formulate Quantitative Guidelines for the Audio-Visual Communications Field. Final Report.

    ERIC Educational Resources Information Center

    Faris, Gene; Sherman, Mendel

    Quantitative guidelines for use in determining the audiovisual (AV) needs of educational institutions were developed by the Octobe r 14-16, 1965 Seminar of the NDEA (National Defense Education Act), Faris-Sherman study. The guidelines that emerged were based in part on a review of past efforts and existing standards but primarily reflected the…

  8. The American Government Information Unit: A Pilot Program to Improve Information Flow Between Research and Development and Practice in Education. Final Report.

    ERIC Educational Resources Information Center

    Adelson, Nancy C.; And Others

    The Laboratory staff reported the unit development and field test activities in their effort to collect, analyze, synthesize, and disseminate new curriculum developments in secondary level social studies to school curriculum decision makers. The audience consisted primarily of social studies teachers and department chairmen. To further refine and…

  9. Estuarine and Riverine Areas Final Programmatic Environmental Assessment

    DTIC Science & Technology

    2004-06-25

    sources in the study area include WWTP spray field runoff, urban and agricultural runoff, septic tank leachate , landfill leachate , silviculture...overland sheet flow. Urban and agricultural runoff are sources of fecal and total coliform and fecal streptococcus bacteria. Septic tank leachate and...in leachate from experiments using sand showed the greatest mobility of tungsten. Outdoor exposures and accelerated aging tests studied the

  10. Limb Dominance Results from Asymmetries in Predictive and Impedance Control Mechanisms

    PubMed Central

    Yadav, Vivek; Sainburg, Robert L.

    2014-01-01

    Handedness is a pronounced feature of human motor behavior, yet the underlying neural mechanisms remain unclear. We hypothesize that motor lateralization results from asymmetries in predictive control of task dynamics and in control of limb impedance. To test this hypothesis, we present an experiment with two different force field environments, a field with a predictable magnitude that varies with the square of velocity, and a field with a less predictable magnitude that varies linearly with velocity. These fields were designed to be compatible with controllers that are specialized in predicting limb and task dynamics, and modulating position and velocity dependent impedance, respectively. Because the velocity square field does not change the form of the equations of motion for the reaching arm, we reasoned that a forward dynamic-type controller should perform well in this field, while control of linear damping and stiffness terms should be less effective. In contrast, the unpredictable linear field should be most compatible with impedance control, but incompatible with predictive dynamics control. We measured steady state final position accuracy and 3 trajectory features during exposure to these fields: Mean squared jerk, Straightness, and Movement time. Our results confirmed that each arm made straighter, smoother, and quicker movements in its compatible field. Both arms showed similar final position accuracies, which were achieved using more extensive corrective sub-movements when either arm performed in its incompatible field. Finally, each arm showed limited adaptation to its incompatible field. Analysis of the dependence of trajectory errors on field magnitude suggested that dominant arm adaptation occurred by prediction of the mean field, thus exploiting predictive mechanisms for adaptation to the unpredictable field. Overall, our results support the hypothesis that motor lateralization reflects asymmetries in specific motor control mechanisms associated with predictive control of limb and task dynamics, and modulation of limb impedance. PMID:24695543

  11. Geomorphology in context: Dispatches from the field

    NASA Astrophysics Data System (ADS)

    Harden, Carol P.

    2013-10-01

    Field research enables a researcher to view geomorphic systems in broader contexts than those envisioned while at a desk and can yield unanticipated insights that change the course of an investigation or affect the interpretation of results. Geomorphological field research often produces 'aha!' moments, epiphanies that enhance understanding and lead toward more complete explanation of the processes and landforms under study. This paper uses examples from 'aha!' moments in the field to demonstrate the importance of field observation as a way of gaining information about the broader contexts of research sites, especially in process geomorphology. Spatial contexts include the scales of processes and features, linkages between a study site and its surroundings, and information observed in the field about other processes, anthropogenic activities, or unexpected factors that might affect a study. Temporal contexts, not as evident in the field, place a research site in a longer term history of changes and adjustments. Finally, exploring an abstract set of mental contexts reveals reasons that expectations differ from the realities encountered in the field—constraints and biases that a researcher may not have noted—and the possibility that the unexpected can potentially advance geomorphic research. Time spent in the field complements scientific reductionism and provides opportunities to appreciate the richness and complexity of Earth surface systems.

  12. Effect of magnetic field on seed germination and seedling growth of sunflower

    NASA Astrophysics Data System (ADS)

    Matwijczuk, A.; Kornarzyński, K.; Pietruszewski, S.

    2012-07-01

    The impact of a variable magnetic field, magnetically treated water and a combination of both these factors on the germination of seeds and the final mass at the initial stage of growth sunflower plants was presented. Investigations were carried out in pots filled with sand, tin an air-conditioned plant house with no access to daylight using fluorescent light as illumination. A statistical significance positive impact was achieved for the samples subjected to the interaction of both stimulating factors simultaneously, the magnetic field and the impact of treated water several times on the speed of seed germination and final plant mass. Negative impacts were obtained for the majority of the test cases, for the magnetically treated water, the short duration of activity of the magnetic field and for the connection of the magnetic field and low-flow times.

  13. Analysis of an Adjustable Field Permanent Magnet Solenoid

    DOE PAGES

    Burris-Mog, Trevor John; Burns, Michael James; Chavez, Mark Anthony; ...

    2017-07-12

    A feasibility study has been performed on an adjustable-field permanent magnet (PM) solenoid concept in an effort to reduce the dependence that linear induction accelerators have on large direct current power supplies and associated cooling systems. The concept relies on the ability to reorient sections of the PMs and thus redirect their magnetization vector to either add to or subtract from the on-axis magnetic field. This study concentrated on the focal strengths and emittance growths for two different designs, both with 19 cm bore diameters extending 53 cm in length. The first design is expected to produce peak magnetic fieldsmore » ranging from 260 to 900 G (0.026 to 0.09 T) while the second design is expected to produce peak magnetic fields ranging from 580 to 2100 G (0.058 to 0.21 T). Finally, although the PM configuration generates a variable magnetic field and the torques acting on PMs within the assembly appear manageable, the emittance growth is larger than that of a DC solenoid.« less

  14. The stability of nonlinear dynamos and the limited role of kinematic growth rates

    NASA Astrophysics Data System (ADS)

    Brandenburg, A.; Krause, F.; Meinel, R.; Moss, D.; Tuominen, I.

    1989-04-01

    The growth rate behavior of several kinematic dynamo models was investigated in the context of the observation that, as a rule, a magnetic field of a single symmetry dominates in the sun and other cosmic objects. For all dynamo models considered, it is shown that, as the dynamo numbers increase, the kinematic growth rates of fields of different parities are asymptotically equal, indicating that growth rates do not dominate the final state of the field. The possibility that the stability of different solutions of nonlinear dynamos determines the final state was then investigated. Dynamo models in spherical geometry were found in which both symmetric and antisymmetric solutions are stable. The kind of symmetry finally established depends in these cases on the initial conditions, i.e., on the history of the object. It is noted that the basic mechanism stabilizing or destabilizing different solutions is not well understood.

  15. Intense transient electric field sensor based on the electro-optic effect of LiNbO{sub 3}

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

    Yang, Qing, E-mail: yangqing@cqu.edu.cn; Sun, Shangpeng; Han, Rui

    2015-10-15

    Intense transient electric field measurements are widely applied in various research areas. An optical intense E-field sensor for time-domain measurements, based on the electro-optic effect of lithium niobate, has been studied in detail. Principles and key issues in the design of the sensor are presented. The sensor is insulated, small in size (65 mm × 15 mm × 15 mm), and suitable for high-intensity (<801 kV/m) electric field measurements over a wide frequency band (10 Hz–10 MHz). The input/output characteristics of the sensor were obtained and the sensor calibrated. Finally, an application using this sensor in testing laboratory lightning impulsesmore » and in measuring transient electric fields during switch-on of a disconnector confirmed that the sensor is expected to find widespread use in transient intense electric field measurement applications.« less

  16. Intense transient electric field sensor based on the electro-optic effect of LiNbO3

    NASA Astrophysics Data System (ADS)

    Yang, Qing; Sun, Shangpeng; Han, Rui; Sima, Wenxia; Liu, Tong

    2015-10-01

    Intense transient electric field measurements are widely applied in various research areas. An optical intense E-field sensor for time-domain measurements, based on the electro-optic effect of lithium niobate, has been studied in detail. Principles and key issues in the design of the sensor are presented. The sensor is insulated, small in size (65 mm × 15 mm × 15 mm), and suitable for high-intensity (<801 kV/m) electric field measurements over a wide frequency band (10 Hz-10 MHz). The input/output characteristics of the sensor were obtained and the sensor calibrated. Finally, an application using this sensor in testing laboratory lightning impulses and in measuring transient electric fields during switch-on of a disconnector confirmed that the sensor is expected to find widespread use in transient intense electric field measurement applications.

  17. Ion Beam Neutralization Using FEAs and Mirror Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Nicolaescu, Dan; Sakai, Shigeki; Gotoh, Yasuhito; Ishikawa, Junzo

    2011-01-01

    Advanced implantation systems used for semiconductor processing require transportation of ion beams which are quasi-parallel and have low energy, such as (11B+,31P+,75As+) with energy in the range Eion = 200-1000 eV. Compensation of ion beam divergence may be obtained through electron injection and confinement in regions of non-uniform magnetic fields. Field emitter arrays with special properties are used as electron sources. The present study shows that electron confinement takes place in regions of gradient magnetic field, such as nearby analyzing, collimator and final energy magnets of the ion beam line. Modeling results have been obtained using Opera3D/Tosca/Scala. In regions of gradient magnetic field, electrons have helical trajectories which are confined like a cloud inside curved "magnetic bottles". An optimal range of positions with respect to the magnet for placing electron sources in gradient magnetic field has been shown to exist.

  18. Influence of spatiotemporally distributed irradiance data input on temperature evolution in parabolic trough solar field simulations

    NASA Astrophysics Data System (ADS)

    Bubolz, K.; Schenk, H.; Hirsch, T.

    2016-05-01

    Concentrating solar field operation is affected by shadowing through cloud movement. For line focusing systems the impact of varying irradiance has been studied before by several authors with simulations of relevant thermodynamics assuming spatially homogeneous irradiance or using artificial test signals. While today's simulation capabilities allow more and more a higher spatiotemporal resolution of plant processes there are only few studies on influence of spatially distributed irradiance due to lack of available data. Based on recent work on generating real irradiance maps with high spatial resolution this paper demonstrates their influence on solar field thermodynamics. For a case study an irradiance time series is chosen. One solar field section with several loops and collecting header is modeled for simulation purpose of parabolic trough collectors and oil as heat transfer medium. Assuming homogeneous mass flow distribution among all loops we observe spatially varying temperature characteristics. They are analysed without and with mass flow control and their impact on solar field control design is discussed. Finally, the potential of distributed irradiance data is outlined.

  19. A New Self-Consistent Field Model of Polymer/Nanoparticle Mixture

    NASA Astrophysics Data System (ADS)

    Chen, Kang; Li, Hui-Shu; Zhang, Bo-Kai; Li, Jian; Tian, Wen-De

    2016-02-01

    Field-theoretical method is efficient in predicting assembling structures of polymeric systems. However, it’s challenging to generalize this method to study the polymer/nanoparticle mixture due to its multi-scale nature. Here, we develop a new field-based model which unifies the nanoparticle description with the polymer field within the self-consistent field theory. Instead of being “ensemble-averaged” continuous distribution, the particle density in the final morphology can represent individual particles located at preferred positions. The discreteness of particle density allows our model to properly address the polymer-particle interface and the excluded-volume interaction. We use this model to study the simplest system of nanoparticles immersed in the dense homopolymer solution. The flexibility of tuning the interfacial details allows our model to capture the rich phenomena such as bridging aggregation and depletion attraction. Insights are obtained on the enthalpic and/or entropic origin of the structural variation due to the competition between depletion and interfacial interaction. This approach is readily extendable to the study of more complex polymer-based nanocomposites or biology-related systems, such as dendrimer/drug encapsulation and membrane/particle assembly.

  20. The WFIRST Interim Design Reference Mission: Capabilities, Constraints, and Open Questions

    NASA Technical Reports Server (NTRS)

    Kruk, Jeffrey W.

    2012-01-01

    The Project Office and Science Definition Team for the Wide-Field Infrared Survey Telescope (WFIRST) are in the midst of a pre-Phase A study to establish a Design Reference Mission (DRM). An Interim report was released in June 2011, with a final report due later in 2012. The predicted performance of the Interim DRM Observatory will be described, including optical quality, observing efficiency, and sensitivity for representative observing scenarios. Observing constraints and other limitations on performance will also be presented, with an emphasis on potential Guest Observer programs. Finally, a brief status update will be provided on open trade studies of interest to the scientific community. The final DRM may differ from the Interim DRM presented here. However, the underlying requirements of the scientific programs are not expected to change, hence the capabilities of the IDRM are likely to be maintained even if the implementation changes in significant ways.

  1. On the global well-posedness theory for a class of PDE models for criminal activity

    NASA Astrophysics Data System (ADS)

    Rodríguez, N.

    2013-10-01

    We study a class of ‘reaction-advection-diffusion’ system of partial differential equations, which can be taken as basic models for criminal activity. This class of models are based on routine activity theory and other theories, such as the ‘repeat and near-repeat victimization effect’ and were first introduced in Short et al. (2008) [11]. In these models the criminal density is advected by a velocity field that depends on a scalar field, which measures the appeal to commit a crime. We refer to this scalar field as the attractiveness field. We prove local well-posedness of solutions for the general class of models. Furthermore, we prove global well-posedness of solutions to a fully-parabolic system with a velocity field that depends logarithmically on the attractiveness field. Our final result is the global well-posedness of solutions the fully-parabolic system with velocity field that depends linearly on the attractiveness field for small initial mass.

  2. Relation between residential magnetic fields, light-at-night, and nocturnal urine melatonin levels in women: Volume 2 -- Magnetic field exposure analysis. Final report

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

    Kaune, W.; Davis, S.; Stevens, R.

    Scientists have postulated a link between exposure to magnetic fields and reduced blood melatonin levels. This EPRI study was designed to supplement a National Cancer Institute study (NCI-BC) of magnetic fields, light-at-night, and the risk of breast cancer. By expanding the exposure assessment of the NCI-BC and collecting data on urine melatonin levels, this project provides new insight into a possible magnetic field-melatonin link. It has been proposed that exposure to 60-Hz (power frequency) magnetic fields may increase the risk of breast cancer by suppressing the normal nocturnal rise in melatonin production in the pineal gland. It remains unknown whethermore » the human pineal gland is reproducibly responsive or sensitive to magnetic field exposure, and whether such exposures could alter elements of the endogenous hormonal environment in women that might be important in the etiology of breast cancer. The objective of this research was to investigate whether exposure to power-frequency magnetic fields and/or light-at-night is associated with levels of the primary urinary melatonin metabolite in women without a history of breast cancer.« less

  3. Dynamical system analysis for DBI dark energy interacting with dark matter

    NASA Astrophysics Data System (ADS)

    Mahata, Nilanjana; Chakraborty, Subenoy

    2015-01-01

    A dynamical system analysis related to Dirac-Born-Infeld (DBI) cosmological model has been investigated in this present work. For spatially flat FRW spacetime, the Einstein field equation for DBI scenario has been used to study the dynamics of DBI dark energy interacting with dark matter. The DBI dark energy model is considered as a scalar field with a nonstandard kinetic energy term. An interaction between the DBI dark energy and dark matter is considered through a phenomenological interaction between DBI scalar field and the dark matter fluid. The field equations are reduced to an autonomous dynamical system by a suitable redefinition of the basic variables. The potential of the DBI scalar field is assumed to be exponential. Finally, critical points are determined, their nature have been analyzed and corresponding cosmological scenario has been discussed.

  4. Determination of the space-charge field amplitude in polymeric photorefractive polymers.

    PubMed

    Hwang, Ui-Jung; Choi, Chil-Sung; Vuong, Nguyen Quoc; Kim, Nakjoong

    2005-12-22

    The space-charge field built in a polymeric photorefractive polymer was calculated by a simple method based on the oriented gas model. When anisotropic chromophores in a photorefractive polymer were exposed to an external field, they oriented preferentially to exhibit a birefringence. Then, under illumination of two coherent beams and an external field, they reoriented to form a photorefractive grating. During the formation of the grating, the chromophores were reoriented by the space-charge field as well as by the external applied field. The birefringence induced in the material by an external electric field was determined by measuring the transmittance of the sample which is placed between crossed polarizers, where birefringence depicts the orientation of the chromophores. By measuring the diffraction efficiency with a modified degenerate four-wave mixing setup, the index amplitude of the grating was determined. Finally, the space-charge field was determined by comparing the diffraction efficiency with the birefringence with respect to the applied electric field. In our study, the space-charge field was about 20% of the external applied field, which coincided with previous results obtained from our laboratory.

  5. Community Background Reports: Blackfeet Indian Reservation, Browning, Montana. National Study of American Indian Education, Series I, No. 7, Final Report.

    ERIC Educational Resources Information Center

    Humphrey, Theodore R.

    A 4-man field team from the University of Colorado, under the auspices of the National Study of American Indian Education, spent 6 weeks in the Blackfeet Indian Reservation, Montana, in the fall of 1968. The team studied the public school system of Browning, Montana, the major town on the reservation and reported on educational facilities,…

  6. Electric and magnetic fields and tumor progression. Final report

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

    Keng, P.C.; Grota, L.J.; Michaelson, S.

    This laboratory study has rigorously investigated two previously reported biological effects of 60-Hz electric and magnetic fields. The first effect involves nighttime suppression of melatonin synthesis in the pineal glands of rats exposed to high electric fields. The second concerns the increase in colony forming ability of human colon cancer cells exposed to 1.4-G magnetic fields. Neither effect was detected in the present study. A series of published laboratory studies on rats reported that 60-Hz electric fields at various field levels up to 130 kV/m suppress the nighttime synthesis of melatonin, a hormone produced by the pineal gland. Since melatoninmore » is known to modulate the immune system and may inhibit cancer cell activity, changes in physiological levels of melatonin may have significant health consequences. In the repeat experiments, field exposure did not alter nighttime levels of melatonin or enzyme activities in the pineal gland. A small but statistically significant reduction of about 20% in serum melatonin was seen in exposed animals. Pineal melatonin was also unaffected by the presence of red light as a cofactor with field exposure or by time-shifting the daily field exposure period. Another study reported that 60-Hz magnetic fields can affect the colony forming ability of human cancer cells after exposure in a culture medium. In the repeat experiments, field exposure did not alter the colony forming ability of human Colo 205 cells in two different cell concentrations at plating or in two different incubation conditions. Field exposure also did not affect cell cycling in any of the four cell lines tested.« less

  7. [Application of an Adaptive Inertia Weight Particle Swarm Algorithm in the Magnetic Resonance Bias Field Correction].

    PubMed

    Wang, Chang; Qin, Xin; Liu, Yan; Zhang, Wenchao

    2016-06-01

    An adaptive inertia weight particle swarm algorithm is proposed in this study to solve the local optimal problem with the method of traditional particle swarm optimization in the process of estimating magnetic resonance(MR)image bias field.An indicator measuring the degree of premature convergence was designed for the defect of traditional particle swarm optimization algorithm.The inertia weight was adjusted adaptively based on this indicator to ensure particle swarm to be optimized globally and to avoid it from falling into local optimum.The Legendre polynomial was used to fit bias field,the polynomial parameters were optimized globally,and finally the bias field was estimated and corrected.Compared to those with the improved entropy minimum algorithm,the entropy of corrected image was smaller and the estimated bias field was more accurate in this study.Then the corrected image was segmented and the segmentation accuracy obtained in this research was 10% higher than that with improved entropy minimum algorithm.This algorithm can be applied to the correction of MR image bias field.

  8. Electromechanical properties of Na0.5Bi0.5TiO3-SrTiO3-PbTiO3 solid solutions

    NASA Astrophysics Data System (ADS)

    Svirskas, Šarūnas; Dunce, Marija; Birks, Eriks; Sternberg, Andris; Banys, Jūras

    2018-03-01

    Thorough studies of electric field-induced strain are presented in 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3 (NBT-ST-PT) ternary solid solutions. The increase of concentration of lead x induces crossover from relaxor to ferroelectric. Strain in a relaxor state can be described by electrostrictive behavior. The electrostrictive coefficients correspond to other well-known relaxor ferroelectrics. The concentration region with a stable ferroelectric phase revealed that the polarization dependence of strain does not exhibit nonlinearity, although they are inherent to the electric field dependence of strain. In this case, electric field dependence of strain is described in terms of the Rayleigh law and the role of domain wall contribution is extracted. Finally, the character of strain at the electric field-induced phase transition between the nonpolar and the ferroelectric states is studied. The data shows that in the vicinity of the electric field induced phase transition the strain vs. electric field displays electrostrictive character.

  9. 76 FR 33342 - Final Supplementary Rules for Public Lands Managed by the California Desert District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [L12200000.NO0000.LLCAD00000] Final Supplementary Rules for Public Lands Managed by the California Desert District AGENCY: Bureau of Land Management... Land Management (BLM), CDD office and the five field offices within the CDD, are issuing Final...

  10. 76 FR 2705 - Notice of Availability of the Final Supplemental Environmental Impact Statement for the Cortez...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ... amended, the Bureau of Land Management (BLM), Battle Mountain District, Mount Lewis Field Office, Battle Mountain, Nevada, has prepared a Final Supplemental Environmental Impact Statement (EIS) for the Cortez... Final Supplemental EIS are available for public inspection at the Battle Mountain District Office, 50...

  11. Beam dynamics validation of the Halbach Technology FFAG Cell for Cornell-BNL Energy Recovery Linac

    NASA Astrophysics Data System (ADS)

    Méot, F.; Tsoupas, N.; Brooks, S.; Trbojevic, D.

    2018-07-01

    The Cornell-BNL Electron Test Accelerator (CBETA), a 150 MeV energy recovery linac (ERL) now in construction at Cornell, employs a fixed-field alternating gradient optics return loop: a single beam line comprised of FFAG cells, which accepts four recirculated energies. CBETA FFAG cell uses Halbach permanent magnet technology, its design studies have covered an extended period of time supported by extensive particle dynamics simulations using computed 3-D field map models. This approach is discussed, and illustrated here, based on the final stage in these beam dynamics studies, namely the validation of a ultimate, optimized design of the Halbach cell.

  12. Project Atlas Field Definitions | NOAA Gulf Spill Restoration

    Science.gov Websites

    Archive Home Project Atlas Field Definitions Project Atlas Field Definitions Field Definition Project Title The Project Title as listed in the Final Early Restoration Plan and Environmental Assessment (FERP /EA). General Information: Project Description Narrative description of the project. General

  13. Evaluation of hydrothermal resources of North Dakota. Phase II. Final technical report

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

    Harris, K.L.; Howell, F.L.; Winczewski, L.M.

    1981-06-01

    This evaluation of the hydrothermal resources of North Dakota is based on existing data on file with the North Dakota Geological Survey (NDGS) and other state and federal agencies, and field and laboratory studies conducted. The principal sources of data used during the Phase II study were WELLFILE, the computer library of oil and gas well data developed during the Phase I study, and WATERCAT, a computer library system of water well data assembled during the Phase II study. A field survey of the shallow geothermal gradients present in selected groundwater observation holes was conducted. Laboratory determinations of the thermalmore » conductivity of core samples is being done to facilitate heat-flow calculations on those hole-of-convenience cased.« less

  14. Evaluation of hydrothermal resources of North Dakota. Phase III final technical report

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

    Harris, K.L.; Howell, F.L.; Wartman, B.L.

    1982-08-01

    The hydrothermal resources of North Dakota were evaluated. This evaluation was based on existing data on file with the North Dakota Geological Survey (NDGS) and other state and federal agencies, and field and laboratory studies conducted. The principal sources of data used during the study were WELLFILE, the computer library of oil and gas well data developed during the Phase I study, and WATERCAT, a computer library system of water well data assembled during the Phase II study. A field survey of the shallow geothermal gradients present in selected groundwater observation holes was conducted. Laboratory determinations of the thermal conductivitymore » of core samples were done to facilitate heat-flow calculations on those holes-of-convenience cased.« less

  15. Women Facing the Multiple Role Challenge. Adult Women Studying Social Work and Adult Education in Canada: A Study of Their Multiple Role Experiences and of Supports Available to Them. Final Report.

    ERIC Educational Resources Information Center

    Home, Alice M.

    A study examined the multiple role experiences of 20 adult women studying social work and adult education in 7 programs throughout Canada and the supports available to the women. Also interviewed during the study were two professors and the department head from each program, a field instructor, several program coordinators, and five employers.…

  16. Magnetism and the interior of the moon

    NASA Technical Reports Server (NTRS)

    Dyal, P.; Parkin, C. W.; Daily, W. D.

    1974-01-01

    The application of lunar magnetic field measurements to the study of properties of the lunar crust and deep interior is reviewed. Following a brief description of lunar magnetometers and the lunar magnetic environment, measurements of lunar remanent fields and their interaction with the solar plasma are discussed. The magnetization induction mode is considered with reference to lunar magnetic permeability and iron abundance calculations. Finally, electrical conductivity and temperature calculations from analyses of poloidal induction, for data taken in both the solar wind and in the geomagnetic tail, are reviewed.

  17. Enhancing Productivity Through Feedback and Goal Setting. Final Report.

    ERIC Educational Resources Information Center

    Pritchard, Robert D.; And Others

    A field test was conducted to research the effects of feedback and goal-setting techniques on increasing productivity. Subjects were regular employees of two autonomous clerical-type units in a credit card and payment processing center of a Southwestern oil company. The study desiqn had three phases--baseline period and two experimental conditions…

  18. Project: Ways to Improve Education in Desegregated Schools (WIEDS). [Appendices for Final Report.

    ERIC Educational Resources Information Center

    Roberson, Don R.; And Others

    This document consists of a literature review and the description of a field study undertaken as part of a pilot research project focusing on improving education in desegregated public schools. The review documents the organization and successful programmatic strategies of school integration. Findings are presented in terms of administrative and…

  19. Visual Tools for Eliciting Connections and Cohesiveness in Mixed Methods Research

    ERIC Educational Resources Information Center

    Murawska, Jaclyn M.; Walker, David A.

    2017-01-01

    In this commentary, we offer a set of visual tools that can assist education researchers, especially those in the field of mathematics, in developing cohesiveness from a mixed methods perspective, commencing at a study's research questions and literature review, through its data collection and analysis, and finally to its results. This expounds…

  20. Determining Performance Levels of Competencies for Job Entry. Final Report. Marketing and Retail Sales Programs.

    ERIC Educational Resources Information Center

    Hillmer, Warren; And Others

    To provide input for curriculum evaluation, a study to identify basic competencies required for entry-level positions in the marketing/merchandising field was conducted in Wisconsin vocational education districts. Marketing and merchandising graduates and their employers were surveyed by mailed questionnaire to determine the degree of performance…

  1. Distribution of end bearing, tip shear and rotation on drilled shafts with combined loading in Florida limestone : final report, May 2008.

    DOT National Transportation Integrated Search

    2008-05-01

    The study investigated the behavior of large diameter drilled shafts embedded short distances in Florida Limestone (i.e. L/D=1 &3). The work was performed via laboratory (centrifuge) tests and at two field sites (17th Street and Fuller Warren Bridges...

  2. Research Handbook on Children's Language Learning. Preliminary Edition. Final Report.

    ERIC Educational Resources Information Center

    Dato, Daniel P.

    This handbook serves as an introduction to the study of children's language development and as a supplementary aid in the training of research workers in the field of children's language learning. As a teaching aid, it is suggested this work be used with a film entitled "Psycholinquistic Research Techniques: Children's Language." Major chapters…

  3. Revised Planning Methodology For Signalized Intersections And Operational Analysis Of Exclusive Left-Turn Lanes, A Simulation-Based Method, Part - I: Literature Review (Final Report)

    DOT National Transportation Integrated Search

    1996-04-01

    THE STUDY INVESTIGATES THE APPLICATION OF SIMULATION ALONG WITH FIELD OBSERVATIONS FOR ESTIMATION OF EXCLUSIVE LEFT-TURN SATURATION FLOW RATE AND CAPACITY. THE ENTIRE RESEARCH HAS COVERED THE FOLLOWING PRINCIPAL SUBJECTS: (1) A SATURATION FLOW MODEL ...

  4. Evaluation of several types of curing and protective materials for concrete : final report on part I : laboratory and outdoor exposure studies preliminary to field trials.

    DOT National Transportation Integrated Search

    1970-01-01

    Concern for improving the durability of concrete has focused renewed attention on all aspects of concrete technology. Numerous proprietary products which are claimed to improve durability have been marketed as protective coatings, curing agents or co...

  5. Experimental Investigation of Free Field and Shock-Initiated Implosion of Composite Structures

    DTIC Science & Technology

    2017-02-06

    From- To) 06 - 02 - 2017 Final Report Nov . 2013 - De c . 2016 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Experimental I nvestigation of Free Fie l d...of experimental studies is perfor med to study the implos i on behavior of a variety of different composite structures under varying loading...Introduction Materials Experimental Procedure DIC Technique Collapse Pressure Predictions Specific and Total Impulse

  6. SOLERAS - Solar Controlled Environment Agriculture Project. Final report, Volume 4. Saudi Engineering Solar Energy Applications System Design Study

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

    Not Available

    1985-01-01

    Literature summarizing a study on the Saudi Arabian solar controlled environment agriculture system is presented. Specifications and performance requirements for the system components are revealed. Detailed performance and cost analyses are used to determine the optimum design. A preliminary design of an engineering field test is included. Some weather data are provided for Riyadh, Saudi Arabia. (BCS)

  7. Trends in Connectivity Technologies and Their Socioeconomic Impacts. Final Report of the Study: Policy Options for the Ubiquitous Internet Society. Technical Report

    ERIC Educational Resources Information Center

    Cave, Jonathan; van Oranje-Nassau, Constantijn; Schindler, Helen Rebecca; Shehabi, Ala'a; Brutscher, Philipp-Bastian; Robinson, Neil

    2009-01-01

    This report is intended to inform the European Commission's DG Information Society and Media in developing its policies for the period 2010-2020. It is targeted to policymakers with expert knowledge of the field. The report summarises the work conducted in the study: "Policy Options for the Ubiquitous Internet Society". It builds on…

  8. The Education of Indian Children and Youth. National Study of American Indian Education, Series 4, No. 6, Summary Report and Recommendations.

    ERIC Educational Resources Information Center

    Havighurst, Robert J.

    As a part of the Final Report of the National Study of American Indian Education, this document contains the summary report and recommendations regarding education of Indian children and youth. The document summarizes results of field research made in 30 Indian communities and contains recommendations for action to improve the education of…

  9. A combined approach based on MAF analysis and AHP method to fault detection mapping: A case study from a gas field, southwest of Iran

    NASA Astrophysics Data System (ADS)

    Shakiba, Sima; Asghari, Omid; Khah, Nasser Keshavarz Faraj

    2018-01-01

    A combined geostatitical methodology based on Min/Max Auto-correlation Factor (MAF) analysis and Analytical Hierarchy Process (AHP) is presented to generate a suitable Fault Detection Map (FDM) through seismic attributes. Five seismic attributes derived from a 2D time slice obtained from data related to a gas field located in southwest of Iran are used including instantaneous amplitude, similarity, energy, frequency, and Fault Enhancement Filter (FEF). The MAF analysis is implemented to reduce dimension of input variables, and then AHP method is applied on three obtained de-correlated MAF factors as evidential layer. Three Decision Makers (DMs) are used to construct PCMs for determining weights of selected evidential layer. Finally, weights obtained by AHP were multiplied in normalized valued of each alternative (MAF layers) and the concluded weighted layers were integrated in order to prepare final FDM. Results proved that applying algorithm proposed in this study generate a map more acceptable than the each individual attribute and sharpen the non-surface discontinuities as well as enhancing continuity of detected faults.

  10. Investigation of thermal protection systems effects on viscid and inviscid flow fields for manned entry systems

    NASA Technical Reports Server (NTRS)

    Bartlett, E. P.; Morse, H. L.; Tong, H.

    1971-01-01

    Procedures and methods for predicting aerothermodynamic heating to delta orbiter shuttle vehicles were reviewed. A number of approximate methods were found to be adequate for large scale parameter studies, but are considered inadequate for final design calculations. It is recommended that final design calculations be based on a computer code which accounts for nonequilibrium chemistry, streamline spreading, entropy swallowing, and turbulence. It is further recommended that this code be developed with the intent that it can be directly coupled with an exact inviscid flow field calculation when the latter becomes available. A nonsimilar, equilibrium chemistry computer code (BLIMP) was used to evaluate the effects of entropy swallowing, turbulence, and various three dimensional approximations. These solutions were compared with available wind tunnel data. It was found study that, for wind tunnel conditions, the effect of entropy swallowing and three dimensionality are small for laminar boundary layers but entropy swallowing causes a significant increase in turbulent heat transfer. However, it is noted that even small effects (say, 10-20%) may be important for the shuttle reusability concept.

  11. Partial Return Yoke for MICE Step IV and Final Step

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

    Witte, Holger; Plate, Stephen; Berg, J.Scott

    2015-06-01

    This paper reports on the progress of the design and construction of a retro-fitted return yoke for the international Muon Ionization Cooling Experiment (MICE). MICE is a proof-of-principle experiment aiming to demonstrate ionization cooling experimentally. In earlier studies we outlined how a partial return yoke can be used to mitigate stray magnetic field in the experimental hall; we report on the progress of the construction of the partial return yoke for MICE Step IV. We also discuss an extension of the Partial Return Yoke for the final step of MICE; we show simulation results of the expected performance.

  12. Partial return yoke for MICE step IV and final step

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

    Witte, H.; Plate, S.; Berg, J. S.

    2015-05-03

    This paper reports on the progress of the design and construction of a retro-fitted return yoke for the international Muon Ionization Cooling Experiment (MICE). MICE is a proof-of-principle experiment aiming to demonstrate ionization cooling experimentally. In earlier studies we outlined how a partial return yoke can be used to mitigate stray magnetic field in the experimental hall; we report on the progress of the construction of the partial return yoke for MICE Step IV. We also discuss an extension of the Partial Return Yoke for the final step of MICE; we show simulation results of the expected performance.

  13. Human melatonin in magnetic fields: Second study. Final report

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

    Graham, C.; Cook, M.R.; Cohen, H.D.

    1995-11-01

    Melatonin (MLT) is a hormone secreted primarily at night by the pineal gland in the brain. A number of studies suggest it is part of the body`s natural defenses against cancer. This hormone is reported to stimulate immune function and has been implicated in the control of cell proliferation, the growth of transplanted tumors, and the promotion and/or co-promotion of mammary tumors. MLT also plays a key role in the regulation of reproductive hormones implicated in a number of carcinogenic processes. Studies with rodents, although not always consistent, suggest that nocturnal MLT levels may be suppressed by electric or magneticmore » field (EMF) exposure. This relationship has been proposed as a possible biological mechanism to account for epidemiological reports linking chronic EMF exposure and increased cancer risk. Research was needed to determine if a similar suppression of MLT occurs when humans are exposed to magnetic fields at night.« less

  14. Diffusive processes in a stochastic magnetic field

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

    Wang, H.; Vlad, M.; Vanden Eijnden, E.

    1995-05-01

    The statistical representation of a fluctuating (stochastic) magnetic field configuration is studied in detail. The Eulerian correlation functions of the magnetic field are determined, taking into account all geometrical constraints: these objects form a nondiagonal matrix. The Lagrangian correlations, within the reasonable Corrsin approximation, are reduced to a single scalar function, determined by an integral equation. The mean square perpendicular deviation of a geometrical point moving along a perturbed field line is determined by a nonlinear second-order differential equation. The separation of neighboring field lines in a stochastic magnetic field is studied. We find exponentiation lengths of both signs describing,more » in particular, a decay (on the average) of any initial anisotropy. The vanishing sum of these exponentiation lengths ensures the existence of an invariant which was overlooked in previous works. Next, the separation of a particle`s trajectory from the magnetic field line to which it was initially attached is studied by a similar method. Here too an initial phase of exponential separation appears. Assuming the existence of a final diffusive phase, anomalous diffusion coefficients are found for both weakly and strongly collisional limits. The latter is identical to the well known Rechester-Rosenbluth coefficient, which is obtained here by a more quantitative (though not entirely deductive) treatment than in earlier works.« less

  15. Unsupervised segmentation of lung fields in chest radiographs using multiresolution fractal feature vector and deformable models.

    PubMed

    Lee, Wen-Li; Chang, Koyin; Hsieh, Kai-Sheng

    2016-09-01

    Segmenting lung fields in a chest radiograph is essential for automatically analyzing an image. We present an unsupervised method based on multiresolution fractal feature vector. The feature vector characterizes the lung field region effectively. A fuzzy c-means clustering algorithm is then applied to obtain a satisfactory initial contour. The final contour is obtained by deformable models. The results show the feasibility and high performance of the proposed method. Furthermore, based on the segmentation of lung fields, the cardiothoracic ratio (CTR) can be measured. The CTR is a simple index for evaluating cardiac hypertrophy. After identifying a suspicious symptom based on the estimated CTR, a physician can suggest that the patient undergoes additional extensive tests before a treatment plan is finalized.

  16. Non-minimally coupled scalar field cosmology with torsion

    NASA Astrophysics Data System (ADS)

    Cid, Antonella; Izaurieta, Fernando; Leon, Genly; Medina, Perla; Narbona, Daniela

    2018-04-01

    In this work we present a generalized Brans-Dicke lagrangian including a non-minimally coupled Gauss-Bonnet term without imposing the vanishing torsion condition. In the resulting field equations, the torsion is closely related to the dynamics of the scalar field, i.e., if non-minimally coupled terms are present in the theory, then the torsion must be present. For the studied lagrangian we analyze the cosmological consequences of an effective torsional fluid and we show that this fluid can be responsible for the current acceleration of the universe. Finally, we perform a detailed dynamical system analysis to describe the qualitative features of the model, we find that accelerated stages are a generic feature of this scenario.

  17. A type N radiation field solution with Λ <0 in a curved space-time and closed time-like curves

    NASA Astrophysics Data System (ADS)

    Ahmed, Faizuddin

    2018-05-01

    An anti-de Sitter background four-dimensional type N solution of the Einstein's field equations, is presented. The matter-energy content pure radiation field satisfies the null energy condition (NEC), and the metric is free-from curvature divergence. In addition, the metric admits a non-expanding, non-twisting and shear-free geodesic null congruence which is not covariantly constant. The space-time admits closed time-like curves which appear after a certain instant of time in a causally well-behaved manner. Finally, the physical interpretation of the solution, based on the study of the equation of the geodesics deviation, is analyzed.

  18. An analysis of temperature effect in a finite journal bearing with spatial tilt and viscous dissipation

    NASA Technical Reports Server (NTRS)

    Braun, M. J.; Mullen, R. L.; Hendricks, R. C.

    1984-01-01

    The analysis presented herein deals with the evaluation of the pressure, velocity, and temperature profiles in a finite-length plane journal bearing. The geometry of the case under study consists of a spatially tilted shaft. The two-dimensional Reynolds equation accounts for the variation of the clearance gap h with x and z and is used to model the pressure field. The latter is solved for a variety of shaft tilt angles and then used to calculate the two-dimensional flow field. Finally, the flow field is used in the energy equation to solve for the film temperature profile, when the effect of viscous dissipation is taken into account.

  19. VizieR Online Data Catalog: Candidate clusters in 4 CFHTLS T0007 Wide fields (Sarron+, 2018)

    NASA Astrophysics Data System (ADS)

    Sarron, F.; Martinet, N.; Durret, F.; Adami, C.

    2018-06-01

    We have updated the Adami & MAzure Cluster FInder (AMACFI, Mazure et al., 2007A&A...467...49M) and applied it to the CFHTLS final data release T0007 photometric redshift (hereafter photo-z, symbol zphot) catalogues. The original AMACFI algorithm was already applied to the CFHTLS in previous studies: Mazure et al. (2007A&A...467...49M) for the Deep1 field, Adami et al. (2010, Cat. J/A+A/509/A81) for the T0004 data release, and Durret et al. (2011, Cat. J/A+A/535/A65) for the Wide fields of the T0006 data release. (2 data files).

  20. Topological and statistical properties of nonlinear force-free fields

    NASA Astrophysics Data System (ADS)

    Mangalam, A.; Prasad, A.

    2018-01-01

    We use our semi-analytic solution of the nonlinear force-free field equation to construct three-dimensional magnetic fields that are applicable to the solar corona and study their statistical properties for estimating the degree of braiding exhibited by these fields. We present a new formula for calculating the winding number and compare it with the formula for the crossing number. The comparison is shown for a toy model of two helices and for realistic cases of nonlinear force-free fields; conceptually the formulae are nearly the same but the resulting distributions calculated for a given topology can be different. We also calculate linkages, which are useful topological quantities that are independent measures of the contribution of magnetic braiding to the total free energy and relative helicity of the field. Finally, we derive new analytical bounds for the free energy and relative helicity for the field configurations in terms of the linking number. These bounds will be of utility in estimating the braided energy available for nano-flares or for eruptions.

  1. Dynamically flavored description of holographic QCD in the presence of a magnetic field

    NASA Astrophysics Data System (ADS)

    Li, Si-wen; Jia, Tuo

    2017-09-01

    We construct the gravitational solution of the Witten-Sakai-Sugimoto model by introducing a magnetic field on the flavor brane. Taking into account their backreaction, we re-solve type IIA supergravity in the presence of a magnetic field. Our calculation shows that the gravitational solutions are magnetically dependent and analytic both in the bubble (confined) and black brane (deconfined) case. We study the dual field theory at the leading order in the ratio of the number of flavors and colors, and also in the Veneziano limit. Some physical properties related to the hadronic physics in an external magnetic field are discussed by using our confined backreaction solution holographically. We also investigate the thermodynamics and holographic renormalization of this model in both phases by our solution. Since the backreaction of the magnetic field is considered in our gravitational solution, it allows us to study the Hawking-Page transition with flavors and colors of this model in the presence of the magnetic field. Finally we therefore obtain the holographic phase diagram with the contributions from the flavors and the magnetic field. Our holographic phase diagram is in qualitative agreement with the lattice QCD result, which thus can be interpreted as the inhibition of confinement or chirally broken symmetry by the magnetic field.

  2. Relation between residential magnetic fields, light-at-night, and nocturnal urine melatonin levels in women: Volume 1 -- Background and purpose, methods, results, discussion. Final report

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

    Kaune, W.; Davis, S.; Stevens, R.

    Scientists have postulated a link between exposure to magnetic fields and reduced blood melatonin levels. This EPRI study was designed to supplement a National Cancer Institute study (NCI-BC) of magnetic fields, light-at-night, and the risk of breast cancer. By expanding the exposure assessment of the NCI-BC and collecting data on urine melatonin levels, this project provides new insight into a possible magnetic field-melatonin link. It has been proposed that exposure to 60-Hz (power frequency) magnetic fields may increase the risk of breast cancer by suppressing the normal nocturnal rise in melatonin production in the pineal gland. It remains unknown whethermore » the human pineal gland is reproducibly responsive or sensitive to magnetic field exposure, and whether such exposures could alter elements of the endogenous hormonal environment in women that might be important in the etiology of breast cancer. The objective of this research was to investigate whether exposure to power-frequency magnetic fields and/or light-at-night is associated with levels of the primary urinary melatonin metabolite in women without a history of breast cancer.« less

  3. Collapse scenarios in magnetized star-forming regions

    NASA Astrophysics Data System (ADS)

    Juarez, Carmen

    2017-04-01

    Turbulence, magnetic fields and gravity driven flows are important for the formation of new stars. Although magnetic fields have been proven to be important in the formation of stars, only a few works have been done combining magnetic field and kinematic information. Such studies are important to analyze both gravity and gas dynamics and be able to compare them with the magnetic field. In this thesis we will combine dust polarization studies with kinematic analysis towards different star-forming regions. We aim to study the physical properties at core scales (<0.1 pc) from molecular line and dust emission, and study the role of the magnetic field in their dynamic evolution. For this, we will use millimeter and submillimeter observational data taken towards low- and high- mass star-forming regions in different environments and evolutionary states. The first project is the study of the physical, chemical and magnetic properties of the pre-stellar core FeSt1-457 in the Pipe nebula. We studied the emission of the molecular line N2H+(1-0) which is a good tracer of dense gas and therefore describes well the structure of the core. In addition, we detected more than 15 molecular lines and found a clear chemical spatial differentiation for molecules with nitrogen, oxygen and sulfur. Using the ARTIST radiative transfer code (Brinch & Hogerheijde 2010, Padovani et al., 2011, 2012, Jørgensen et al., 2014), we simulated the emission of the different molecules detected and estimated their abundance. In addition, we estimated the magnetic field properties of the core (using the Chandrasekhar-Fermi approximation) from polarization data previously obtained by Alves et al., (2014). Finally, we found interesting correlations between the polarization properties and the chemistry in the region. The second project is the study of a high-mass star-forming region called NGC6334V. NGC6334V is in a more advanced evolutionary state and in an environment surrounded by other massive star-forming regions. During the project we studied the magnetic field from the polarized emission of the dust and also the kinematics of the gas from the molecular line emission of the different tracers of dense gas. From the molecular emission of the gas tracing the envelope of the dense core, we see two different velocity structures separated by 2 km/s and converging towards the potential well in the region. In addition, the magnetic field also presents a bimodal pattern following the distribution of the two velocity structures. Finally, we compared the observational results with 3D magnetohydrodynamic simulations of star-forming regions dominated by gravity. The last project is the study of a lower-mass star-forming region, L1287. From the data obtained with the SMA, the dust continuum structure shows six main dense cores with masses between 0.4 and 4 solar masses. The dense gas tracer DCN(3- 2) shows two velocity structures separated by 2-3 km/s, converging towards the highest-density region, the young stellar object IRAS 00338+6312, in a similar scenario to the one observed in the higher-mass case of NGC6334V. Finally, the studies of the pre-stellar core FeSt1-457 and the massive region NGC6334V, show how the magnetic field has been overcome by gravity and is not enough to avoid the gravitational collapse. In addition, NGC6334V and the lower- mass region L1287 present very similar scenarios with the material converging from large scales ( 0.1 pc) to the potential wells of both regions at smaller scales ( 0.02 pc) through two dense gas flows separated by 2-3 km/s. In a similar scenario, FeSt1-457 is located just in the region where two dense gas structures separated by 3 km/s appear to converge.

  4. Artificial magnetic-field quenches in synthetic dimensions

    NASA Astrophysics Data System (ADS)

    Yılmaz, F.; Oktel, M. Ö.

    2018-02-01

    Recent cold atom experiments have realized models where each hyperfine state at an optical lattice site can be regarded as a separate site in a synthetic dimension. In such synthetic ribbon configurations, manipulation of the transitions between the hyperfine levels provide direct control of the hopping in the synthetic dimension. This effect was used to simulate a magnetic field through the ribbon. Precise control over the hopping matrix elements in the synthetic dimension makes it possible to change this artificial magnetic field much faster than the time scales associated with atomic motion in the lattice. In this paper, we consider such a magnetic-flux quench scenario in synthetic dimensions. Sudden changes have not been considered for real magnetic fields as such changes in a conducting system would result in large induced currents. Hence we first study the difference between a time varying real magnetic field and an artificial magnetic field using a minimal six-site model. This minimal model clearly shows the connection between gauge dependence and the lack of on-site induced scalar potential terms. We then investigate the dynamics of a wave packet in an infinite two- or three-leg ladder following a flux quench and find that the gauge choice has a dramatic effect on the packet dynamics. Specifically, a wave packet splits into a number of smaller packets moving with different velocities. Both the weights and the number of packets depend on the implemented gauge. If an initial packet, prepared under zero flux in an n -leg ladder, is quenched to Hamiltonian with a vector potential parallel to the ladder, it splits into at most n smaller wave packets. The same initial wave packet splits into up to n2 packets if the vector potential is implemented to be along the rungs. Even a trivial difference in the gauge choice such as the addition of a constant to the vector potential produces observable effects. We also calculate the packet weights for arbitrary initial and final fluxes. Finally, we show that edge states in a thick ribbon are robust under the quench only when the same gap supports an edge state for the final Hamiltonian.

  5. Quantum to classical transition in quantum field theory

    NASA Astrophysics Data System (ADS)

    Lombardo, Fernando C.

    1998-12-01

    We study the quatum to classical transition process in the context of quantum field theory. Extending the influence functional formalism of Feynman and Vernon, we study the decoherence process for self-interacting quantum fields in flat space. We also use this formalism for arbitrary geometries to analyze the quantum to classical transition in quantum gravity. After summarizing the main results known for the quantum Brownian motion, we consider a self-interacting field theory in Minkowski spacetime. We compute a coarse grained effective action by integrating out the field modes with wavelength shorter than a critical value. From this effective action we obtain the evolution equation for the reduced density matrix (master equation). We compute the diffusion coefficients for this equation and analyze the decoherence induced on the long-wavelength modes. We generalize the results to the case of a conformally coupled scalar field in de Sitter spacetime. We show that the decoherence is effective as long as the critical wavelength is taken to be not shorter than the Hubble radius. On the other hand, we study the classical limit for scalar-tensorial models in two dimensions. We consider different couplings between the dilaton and the scalar field. We discuss the Hawking radiation process and, from an exact evaluation of the influence functional, we study the conditions by which decoherence ensures the validity of the semiclassical approximation in cosmological metrics. Finally we consider four dimensional models with massive scalar fields, arbitrary coupled to the geometry. We compute the Einstein-Langevin equations in order to study the effect of the fluctuations induced by the quantum fields on the classical geometry.

  6. Fluctuations of the partition function in the generalized random energy model with external field

    NASA Astrophysics Data System (ADS)

    Bovier, Anton; Klimovsky, Anton

    2008-12-01

    We study Derrida's generalized random energy model (GREM) in the presence of uniform external field. We compute the fluctuations of the ground state and of the partition function in the thermodynamic limit for all admissible values of parameters. We find that the fluctuations are described by a hierarchical structure which is obtained by a certain coarse graining of the initial hierarchical structure of the GREM with external field. We provide an explicit formula for the free energy of the model. We also derive some large deviation results providing an expression for the free energy in a class of models with Gaussian Hamiltonians and external field. Finally, we prove that the coarse-grained parts of the system emerging in the thermodynamic limit tend to have a certain optimal magnetization, as prescribed by the strength of the external field and by parameters of the GREM.

  7. Skyrmion states in thin confined polygonal nanostructures

    NASA Astrophysics Data System (ADS)

    Pepper, Ryan Alexander; Beg, Marijan; Cortés-Ortuño, David; Kluyver, Thomas; Bisotti, Marc-Antonio; Carey, Rebecca; Vousden, Mark; Albert, Maximilian; Wang, Weiwei; Hovorka, Ondrej; Fangohr, Hans

    2018-03-01

    Recent studies have demonstrated that skyrmionic states can be the ground state in thin-film FeGe disk nanostructures in the absence of a stabilising applied magnetic field. In this work, we advance this understanding by investigating to what extent this stabilisation of skyrmionic structures through confinement exists in geometries that do not match the cylindrical symmetry of the skyrmion—such as squares and triangles. Using simulation, we show that skyrmionic states can form the ground state for a range of system sizes in both triangular and square-shaped FeGe nanostructures of 10 nm thickness in the absence of an applied field. We further provide data to assist in the experimental verification of our prediction; to imitate an experiment where the system is saturated with a strong applied field before the field is removed, we compute the time evolution and show the final equilibrium configuration of magnetization fields, starting from a uniform alignment.

  8. L2F and LDV velocimetry measurement and analysis of the 3-D flow field in a centrifugal compressor

    NASA Technical Reports Server (NTRS)

    Fagan, John R., Jr.; Fleeter, Sanford

    1989-01-01

    The flow field in the Purdue Research Centrifugal Compressor is studied using a laser two-focus (L2F) velocimeter. L2F data are obtained which quantify: (1) the compressor inlet flow field; (2) the steady-state velocity field in the impeller blade passages; and (3) the flow field in the radial diffuser. The L2F data are compared with both laser Doppler velocimetry (LDV) data and predictions from three-dimensional inviscid and viscous flow models. In addition, a model is developed to calculate the effect on the measurement volume geometry of refraction by curved windows. Finally, the advantages and disadvantages of using the L2F for turbomachinery measurements is discussed in terms of measurement accuracy, ease of use, including sample time per correlated event and the ability to make measurements in regions of high noise due to stray radiation from wall reflections.

  9. Cloud morphology and dynamics in Saturn's northern polar region

    NASA Astrophysics Data System (ADS)

    Antuñano, Arrate; del Río-Gaztelurrutia, Teresa; Sánchez-Lavega, Agustín; Rodríguez-Aseguinolaza, Javier

    2018-01-01

    We present a study of the cloud morphology and motions in the north polar region of Saturn, from latitude ∼ 70°N to the pole based on Cassini ISS images obtained between January 2009 and November 2014. This region shows a variety of dynamical structures: the permanent hexagon wave and its intense eastward jet, a large field of permanent ;puffy; clouds with scales from 10 - 500 km, probably of convective origin, local cyclone and anticyclones vortices with sizes of ∼1,000 km embedded in this field, and finally the intense cyclonic polar vortex. We report changes in the albedo of the clouds that delineate rings of circulation around the polar vortex and the presence of ;plume-like; activity in the hexagon jet, in both cases not accompanied with significant variations in the corresponding jets. No meridional migration is observed in the clouds forming and merging in the field of puffy clouds, suggesting that their mergers do not contribute to the maintenance of the polar vortex. Finally, we analyze the dominant growing modes for barotropic and baroclinic instabilities in the hexagon jet, showing that a mode 6 barotropic instability is dominant at the latitude of the hexagon.

  10. Applications of magnetohydrodynamics in biological systems-a review on the numerical studies

    NASA Astrophysics Data System (ADS)

    Rashidi, Saman; Esfahani, Javad Abolfazli; Maskaniyan, Mahla

    2017-10-01

    Magnetohydrodynamic (MHD) fluid flow in different geometries relevant to human body parts is an interesting and important scientific area due to its applications in medical sciences. This article performs a comprehensive review on the applications of MHD and their numerical modelling in biological systems. Applications of MHD in medical sciences are classified into four categories in this paper. Applications of MHD in simple flow, peristaltic flow, pulsatile flow, and drag delivery are these categories. The numerical researches performed for these categories are reviewed and summarized separately. Finally, some conclusions and suggestions for future works based on the literature review are presented. The results indicated that during a surgery when it is necessary to drop blood flow or reduce tissue temperature, it may be achieved by using a magnetic field. Moreover, the review showed that the trapping is an important phenomenon in peristaltic flows that causes the formation of thrombus in blood and the movement of food bolus in gastrointestinal tract. This phenomenon may be disappeared by using a proper magnetic field. Finally, the concentration of particles that are delivered to the target region increases with an increase in the magnetic field intensity.

  11. Bias Field Inconsistency Correction of Motion-Scattered Multislice MRI for Improved 3D Image Reconstruction

    PubMed Central

    Kim, Kio; Habas, Piotr A.; Rajagopalan, Vidya; Scott, Julia A.; Corbett-Detig, James M.; Rousseau, Francois; Barkovich, A. James; Glenn, Orit A.; Studholme, Colin

    2012-01-01

    A common solution to clinical MR imaging in the presence of large anatomical motion is to use fast multi-slice 2D studies to reduce slice acquisition time and provide clinically usable slice data. Recently, techniques have been developed which retrospectively correct large scale 3D motion between individual slices allowing the formation of a geometrically correct 3D volume from the multiple slice stacks. One challenge, however, in the final reconstruction process is the possibility of varying intensity bias in the slice data, typically due to the motion of the anatomy relative to imaging coils. As a result, slices which cover the same region of anatomy at different times may exhibit different sensitivity. This bias field inconsistency can induce artifacts in the final 3D reconstruction that can impact both clinical interpretation of key tissue boundaries and the automated analysis of the data. Here we describe a framework to estimate and correct the bias field inconsistency in each slice collectively across all motion corrupted image slices. Experiments using synthetic and clinical data show that the proposed method reduces intensity variability in tissues and improves the distinction between key tissue types. PMID:21511561

  12. Bias field inconsistency correction of motion-scattered multislice MRI for improved 3D image reconstruction.

    PubMed

    Kim, Kio; Habas, Piotr A; Rajagopalan, Vidya; Scott, Julia A; Corbett-Detig, James M; Rousseau, Francois; Barkovich, A James; Glenn, Orit A; Studholme, Colin

    2011-09-01

    A common solution to clinical MR imaging in the presence of large anatomical motion is to use fast multislice 2D studies to reduce slice acquisition time and provide clinically usable slice data. Recently, techniques have been developed which retrospectively correct large scale 3D motion between individual slices allowing the formation of a geometrically correct 3D volume from the multiple slice stacks. One challenge, however, in the final reconstruction process is the possibility of varying intensity bias in the slice data, typically due to the motion of the anatomy relative to imaging coils. As a result, slices which cover the same region of anatomy at different times may exhibit different sensitivity. This bias field inconsistency can induce artifacts in the final 3D reconstruction that can impact both clinical interpretation of key tissue boundaries and the automated analysis of the data. Here we describe a framework to estimate and correct the bias field inconsistency in each slice collectively across all motion corrupted image slices. Experiments using synthetic and clinical data show that the proposed method reduces intensity variability in tissues and improves the distinction between key tissue types.

  13. The timing and targeting of treatment in influenza pandemics influences the emergence of resistance in structured populations.

    PubMed

    Althouse, Benjamin M; Patterson-Lomba, Oscar; Goerg, Georg M; Hébert-Dufresne, Laurent

    2013-01-01

    Antiviral resistance in influenza is rampant and has the possibility of causing major morbidity and mortality. Previous models have identified treatment regimes to minimize total infections and keep resistance low. However, the bulk of these studies have ignored stochasticity and heterogeneous contact structures. Here we develop a network model of influenza transmission with treatment and resistance, and present both standard mean-field approximations as well as simulated dynamics. We find differences in the final epidemic sizes for identical transmission parameters (bistability) leading to different optimal treatment timing depending on the number initially infected. We also find, contrary to previous results, that treatment targeted by number of contacts per individual (node degree) gives rise to more resistance at lower levels of treatment than non-targeted treatment. Finally we highlight important differences between the two methods of analysis (mean-field versus stochastic simulations), and show where traditional mean-field approximations fail. Our results have important implications not only for the timing and distribution of influenza chemotherapy, but also for mathematical epidemiological modeling in general. Antiviral resistance in influenza may carry large consequences for pandemic mitigation efforts, and models ignoring contact heterogeneity and stochasticity may provide misleading policy recommendations.

  14. Concept analysis of moral courage in nursing: A hybrid model.

    PubMed

    Sadooghiasl, Afsaneh; Parvizy, Soroor; Ebadi, Abbas

    2018-02-01

    Moral courage is one of the most fundamental virtues in the nursing profession, however, little attention has been paid to it. As a result, no exact and clear definition of moral courage has ever been accessible. This study is carried out for the purposes of defining and clarifying its concept in the nursing profession. This study used a hybrid model of concept analysis comprising three phases, namely, a theoretical phase, field work phase, and a final analysis phase. To find relevant literature, electronic search of valid databases was utilized using keywords related to the concept of courage. Field work data were collected over an 11 months' time period from 2013 to 2014. In the field work phase, in-depth interviews were performed with 10 nurses. The conventional content analysis was used in two theoretical and field work phases using Graneheim and Lundman stages, and the results were combined in the final analysis phase. Ethical consideration: Permission for this study was obtained from the ethics committee of Tehran University of Medical Sciences. Oral and written informed consent was received from the participants. From the sum of 750 gained titles in theoretical phase, 26 texts were analyzed. The analysis resulted in 494 codes in text analysis and 226 codes in interview analysis. The literature review in the theoretical phase revealed two features of inherent-transcendental characteristics, two of which possessed a difficult nature. Working in the field phase added moral self-actualization characteristic, rationalism, spiritual beliefs, and scientific-professional qualifications to the feature of the concept. Moral courage is a pure and prominent characteristic of human beings. The antecedents of moral courage include model orientation, model acceptance, rationalism, individual excellence, acquiring academic and professional qualification, spiritual beliefs, organizational support, organizational repression, and internal and external personal barriers. Professional excellence resulting from moral courage can be crystallized in the form of provision of professional care, creating peace of mind, and the nurse's decision making and proper functioning.

  15. Cassini's Grand Finale Overview

    NASA Astrophysics Data System (ADS)

    Spilker, L. J.

    2017-12-01

    After 13 years in orbit, the Cassini-Huygens Mission to Saturn ended in a science-rich blaze of glory. Cassini sent back its final bits of unique science data on September 15, 2017, as it plunged into Saturn's atmosphere, vaporizing and satisfying planetary protection requirements. Cassini's final phase covered roughly ten months and ended with the first time exploration of the region between the rings and planet. In late 2016 Cassini transitioned to a series of 20 Ring Grazing orbits with peripases just outside Saturn's F ring, providing close flybys of tiny ring moons, including Pan, Daphnis and Atlas, and high-resolution views of Saturn's A and F rings. A final Titan flyby in late April 2017 propelled Cassini across Saturn's main rings and into its Grand Finale orbits. Comprised of 22 orbits, Cassini repeatedly dove between Saturn's innermost rings and upper atmosphere to answer fundamental questions unattainable earlier in the mission. The last orbit turned the spacecraft into the first Saturn atmosphere probe. The Grand Finale orbits provided highest resolution observations of both the rings and Saturn, and in-situ sampling of the ring particle composition, Saturn's atmosphere, plasma, and innermost radiation belts. The gravitational field was measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the deeper atmosphere, and mass of the rings. The magnetic field provided insight into the physical nature of the magnetic dynamo and structure of the internal magnetic field. The ion and neutral mass spectrometer sampled the upper atmosphere for molecules that escape the atmosphere in addition to molecules originating from the rings. The cosmic dust analyzer directly sampled the composition from different parts of the main rings for the first time. Fields and particles instruments directly measured the plasma environment between the rings and planet. Science highlights and new mysteries collected in the Grand Finale orbits will be discussed. The research described in this paper was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2017 California Institute of Technology. Government sponsorship is acknowledged.

  16. Radiation fluxes at the FIFE site. Final report, 1 January 1991-31 July 1992

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

    Walter-Shea, E.A.; Blad, B.L.; Zara, P.

    1993-01-01

    The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions'. The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1987-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used tomore » quantify surface processes. Our last report (Walter-Shea et al.) focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989. We report here on the final analysis of the slope data as well as results from thermal radiation studies conducted during the FIFE experiment. The specific areas reported are the following: (1) analysis of slope effects on measured reflectance values and estimates of surface albedo; (2) using remotely-measured surface temperatures as a means of estimating sensible heat flux from the Konza Prairie; (3) extracting canopy temperatures from remotely-measured composite surface temperatures; (4) modeling the measured composite temperature of partially vegetated surfaces; and (5) estimating gap distribution in partially vegetated surfaces from reflectance measurements.« less

  17. Bioethical and Other Philosophical Considerations in Positive Psychiatry.

    PubMed

    Singh, Ajai R; Singh, Shakuntala A

    2016-01-01

    The paper begins by asserting the need for bioethical and related philosophical considerations in the emerging subspecialty Positive Psychiatry. Further discussion proceeds after offering operational definitions of the concepts fundamental to the field - Bioethics, Positive Psychology, Positive Psychiatry and Positive Mental Health - with their conceptual analysis to show their areas of connect and disconnect. It then studies the implications of positive and negative findings in the field, and presents the Positive Psychosocial Factors (PPSFs) like Resilience, Optimism, Personal Mastery, Wisdom, Religion/Spirituality, Social relationships and support, Engagement in pleasant events etc. It then evaluates them on the basis of the 4-principled bioethical model of Beneficence, Non-malfeasance, Autonomy and Justice (Beauchamp and Childress, 2009[5], 2013[6]), first offering a brief clarification of these principles and then their bioethical analysis based on the concepts of 'Common Morality', 'Specific Morality', 'Specification', 'Balancing' and 'Double Effects'. The paper then looks into the further development of the branch by studying the connectivity, synergy and possible antagonism of the various Positive Psychosocial Factors, and presents technical terms in place of common terms so that they carry least baggage. It also takes note of the salient points of caution and alarm that many incisive analysts have presented about further development in the related field of Positive Mental Health. Finally, the paper looks at where, and how, the field is headed, and why, if at all, it is proper it is headed there, based on Aristotle's concept of the four causes - Material, Efficient, Formal and Final. Suitable case vignettes are presented all through the write-up to clarify concepts.

  18. Explosion and Final State of an Unstable Reissner-Nordström Black Hole.

    PubMed

    Sanchis-Gual, Nicolas; Degollado, Juan Carlos; Montero, Pedro J; Font, José A; Herdeiro, Carlos

    2016-04-08

    A Reissner-Nordström black hole (BH) is superradiantly unstable against spherical perturbations of a charged scalar field enclosed in a cavity, with a frequency lower than a critical value. We use numerical relativity techniques to follow the development of this unstable system-dubbed a charged BH bomb-into the nonlinear regime, solving the full Einstein-Maxwell-Klein-Gordon equations, in spherical symmetry. We show that (i) the process stops before all the charge is extracted from the BH, and (ii) the system settles down into a hairy BH: a charged horizon in equilibrium with a scalar field condensate, whose phase is oscillating at the (final) critical frequency. For a low scalar field charge q, the final state is approached smoothly and monotonically. For large q, however, the energy extraction overshoots, and an explosive phenomenon, akin to a bosenova, pushes some energy back into the BH. The charge extraction, by contrast, does not reverse.

  19. de Sitter limit analysis for dark energy and modified gravity models

    NASA Astrophysics Data System (ADS)

    De Felice, Antonio; Frusciante, Noemi; Papadomanolakis, Georgios

    2017-07-01

    The effective field theory of dark energy and modified gravity is supposed to well describe, at low energies, the behavior of the gravity modifications due to one extra scalar degree of freedom. The usual curvature perturbation is very useful when studying the conditions for the avoidance of ghost instabilities as well as the positivity of the squared speeds of propagation for both the scalar and tensor modes, or the Stückelberg field performs perfectly when investigating the evolution of linear perturbations. We show that the viable parameter space identified by requiring no-ghost instabilities and positive squared speeds of propagation does not change by performing a field redefinition, while the requirement of the avoidance of tachyonic instability might instead be different. Therefore, we find it interesting to associate to the general modified gravity theory described in the effective field theory framework, a perturbation field which will inherit all of the properties of the theory. In the present paper we address the following questions: (1) how can we define such a field? and (2) what is the mass of such a field as the background approaches a final de Sitter state? We define a gauge-invariant quantity which identifies the density of the dark energy perturbation field valid for any background. We derive the mass associated to the gauge-invariant dark energy field on a de Sitter background, which we retain to be still a good approximation also at very low redshift (z ≃0 ). On this background we also investigate the value of the speed of propagation and we find that there exist classes of theories which admit a nonvanishing speed of propagation, even in the Horndeski model, for which a zero speed of sound has previously been found in the literature. We finally apply our results to specific well-known models.

  20. Factors affecting interest in orthopedics among female medical students: a prospective analysis.

    PubMed

    Baldwin, Keith; Namdari, Surena; Bowers, Andrea; Keenan, Mary Ann; Levin, L Scott; Ahn, Jaimo

    2011-12-06

    The field of orthopedics has a limited ability to recruit high-quality female applicants. The purpose of this study was to determine whether early exposure to the field affects a woman's decision to pursue orthopedics. We performed a prospective, nonrandomized cohort study between academic years 2005 and 2009 and compared interest in orthopedic surgery among female (n=271) and male (n=71) medical students at 2 urban teaching institutions. Elective lectures and orthopedic literature were distributed via e-mail to the study participants. These materials included articles published in the medical literature, materials produced and distributed by the American Academy of Orthopaedic Surgeons, and Web sites providing educational materials. The primary outcome was the likelihood of application for orthopedic residency. We studied the influence of demographics, exposure, and attitudes on interest in pursuing an orthopedic career. Men had a significantly higher baseline level of interest in orthopedic surgery than women (P=.005). Younger age (P<.001) and personal (P<.001), independent (P<.001), and school (P=.023) exposures to orthopedics were significantly related to interest among women. At final follow-up, total personal exposures (P=.003) and total independent exposures (P<.001) in the form of our literature and lectures were correlated with final interest in women. Female interest was decreased by the long hours, physical demands, and predominantly male nature of the field. Early exposure to orthopedic educational resources may be useful in generating female interest. Perceptions and attitudes regarding orthopedic surgery must to be changed to attract the best and brightest minds, regardless of sex. Copyright © 2011, SLACK Incorporated.

  1. Social Structures, Ideologies, and Culture Codes in Occupational Development of Puerto Rican Youths. Volume 1 of Final Report, Anthropological Study of Disability From Educational Problems of Puerto Rican Youths.

    ERIC Educational Resources Information Center

    Burnett, Jacquetta Hill

    The question of how educational failures lead to or contribute to occupational disability was studied in a youthful Puerto Rican population in an economically poor neighborhood and school district of Chicago. Anthropological field research techniques, supplemented by scheduled interviews and questionnaires, were used to collect qualitative and…

  2. Medical sociology as a heuristic instrument for medical tourism and cross-border healthcare

    PubMed Central

    Mainil, Tomas

    2015-01-01

    In this commentary, we establish a relationship between medical sociology and the study of medical tourism and cross-border healthcare by introducing Ronald Andersen’s behavioral model of healthcare use, and linking this model to the recent empirical study of Kovacs et al. on patients travelling to Hungary for orthopedic treatment. Finally, we plead for more measurement in the field of patient mobility. PMID:25844386

  3. TELEVISION AND THE CONTINUING EDUCATION OF TEACHERS, A FEASIBILITY STUDY OF THE POTENTIAL OF NETWORK TELEVISION FOR DISSEMINATION OF EDUCATIONAL RESEARCH INFORMATION. FINAL REPORT.

    ERIC Educational Resources Information Center

    CRESHKOFF, LAWRENCE

    THIS 3-PHASE STUDY SOUGHT TO BRIDGE THE GAP BETWEEN THE PRODUCER OF NEW EDUCATIONAL IDEAS AND THE PRACTITIONER, OR TEACHER, BY EFFECTIVE USE OF NETWORK TELEVISION. PHASE I, DATA GATHERING, INCLUDED REVIEW OF THE LITERATURE, AND IDENTIFICATION OF INNOVATIONAL PROJECTS BY CONSULTATION, FIELD VISITS, AND A QUESTIONNAIRE SENT TO MEMBERS OF 2 NATIONAL…

  4. The mobility and diffusion of ions in gases

    NASA Technical Reports Server (NTRS)

    Mcdaniel, E. W.; Mason, E. A.

    1973-01-01

    Experimental and theoretical aspects of the mobility and diffusion of ions in gases are studied in detail. Some of the subjects discussed include ion-ion interaction, boundary condition and ion and electron behavior. Also discussed in separate chapters are the problems of the diffusion coefficients and the afterglow techniques. Finally, a special chapter studies the kinetic theory of diffusion and mobility, stressing the low-, medium- and high-field theory.

  5. Hydrodynamic cavitation for sonochemical effects.

    PubMed

    Moholkar, V S; Kumar, P S; Pandit, A B

    1999-03-01

    A comparative study of hydrodynamic and acoustic cavitation has been made on the basis of numerical solutions of the Rayleigh-Plesset equation. The bubble/cavity behaviour has been studied under both acoustic and hydrodynamic cavitation conditions. The effect of varying pressure fields on the collapse of the cavity (sinusoidal for acoustic and linear for hydrodynamic) and also on the latter's dynamic behaviour has been studied. The variations of parameters such as initial cavity size, intensity of the acoustic field and irradiation frequency in the case of acoustic cavitation, and initial cavity size, final recovery pressure and time for pressure recovery in the case of hydrodynamic cavitation, have been found to have significant effects on cavity/bubble dynamics. The simulations reveal that the bubble/cavity collapsing behaviour in the case of hydrodynamic cavitation is accompanied by a large number of pressure pulses of relatively smaller magnitude, compared with just one or two pulses under acoustic cavitation. It has been shown that hydrodynamic cavitation offers greater control over operating parameters and the resultant cavitation intensity. Finally, a brief summary of the experimental results on the oxidation of aqueous KI solution with a hydrodynamic cavitation set-up is given which supports the conclusion of this numerical study. The methodology presented allows one to manipulate and optimise of specific process, either physical or chemical.

  6. Conjugated ionomers for photovoltaic applications: electric field driven charge separation in organic photovoltaics. Final Technical report

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

    Lonergan, Mark

    Final technical report for Conjugated ionomers for photovoltaic applications, electric field driven charge separation in organic photovoltaics. The central goal of the work we completed was been to understand the photochemical and photovoltaic properties of ionically functionalized conjugated polymers (conjugated ionomers or polyelectrolytes) and energy conversion systems based on them. We primarily studied two classes of conjugated polymer interfaces that we developed based either upon undoped conjugated polymers with an asymmetry in ionic composition (the ionic junction) or doped conjugated polymers with an asymmetry in doping type (the p-n junction). The materials used for these studies have primarily been themore » polyacetylene ionomers. We completed a detailed study of p-n junctions with systematically varying dopant density, photochemical creation of doped junctions, and experimental and theoretical work on charge transport and injection in polyacetylene ionomers. We have also completed related work on the use of conjugated ionomers as interlayers that improve the efficiency or organic photovoltaic systems and studied several important aspects of the chemistry of ionically functionalized semiconductors, including mechanisms of so-called "anion-doping", the formation of charge transfer complexes with oxygen, and the synthesis of new polyfluorene polyelectrolytes. We also worked worked with the Haley group at the University of Oregon on new indenofluorene-based organic acceptors.« less

  7. Final report on the maintenance asset management project : phase II.

    DOT National Transportation Integrated Search

    2013-07-01

    Iowa Department of Transportation (IA DOT) is finalizing research to streamline field inventory/inspection of culverts by Maintenance and Construction staff while maximizing the use of tablet technologies. The project began in 2011 to develop some ne...

  8. The Geneva Conference--A Summary

    ERIC Educational Resources Information Center

    American Indian Journal, 1977

    1977-01-01

    The "Final Resolution" of the International Non-Governmental Organizations Conference on Discrimination Against Indigenous Populations (1977) is detailed in this article which describes the program of action for the legal field and the sociocultural field. (JC)

  9. Future healthcare professionals’ knowledge about the Argentinean abortion law

    PubMed Central

    Oizerovich, Silvia; Stray-Pedersen, Babill

    2016-01-01

    Objectives We assessed healthcare students’ knowledge and opinions on Argentinian abortion law and identified differences between first- and final-year healthcare students. Methods In this cross-sectional study, self-administered anonymous questionnaires were administered to 760 first- and 695 final-year students from different fields of study (medicine, midwifery, nursing, radiology, nutrition, speech therapy, and physiotherapy) of the School of Medicine at the University of Buenos Aires, in 2011-2013. Results Compared to first-year students, a higher percentage of final-year students knew that abortion is legally restricted in Argentina (p < 0.001). A significantly higher percentage of final-year students could correctly identify the circumstances in which abortion is legal: woman´s life risk (87.4% last vs. 79.1% first year), rape of a woman with developmental disability (66.2% first vs. 85.4% last-year; p < 0.001). More final-year students chose severe foetal malformations (37.3% first year vs. 57.3% final year) despite its being illegal. Conclusions Although most final-year students knew that abortion is legally restricted in Argentina, misconceptions regarding circumstances of legal abortion were observed; this may be due to the fact that abortion is inadequately covered in the medical curricula. Medical schools should ensure that sexual and reproductive health topics are an integral part of their curricula. Healthcare providers who are aware of the legality of abortion are more likely to provide the public with sound information and ensure abortions are appropriately performed. PMID:27018552

  10. The Social Basis of Math Teaching and Learning. Final Report.

    ERIC Educational Resources Information Center

    Orvik, James M.; Van Veldhuizen, Philip A.

    This study was designed to identify a set of research questions and testable hypothesis to aid in planning long-range research. Five mathematics teachers were selected. These instructors enrolled in a special project-related seminar, video-taped sessions of their own mathematics classes, and kept field journals. The group met once a week to…

  11. Flow Visualization Studies in the Novacor Left Ventricular Assist System CRADA PC91-002, Final Report

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

    Borovetz, H.S.; Shaffer, F.; Schaub, R.

    This paper discusses a series of experiments to visualize and measure flow fields in the Novacor left ventricular assist system (LVAS). The experiments utilize a multiple exposure, optical imaging technique called fluorescent image tracking velocimetry (FITV) to hack the motion of small, neutrally-buoyant particles in a flowing fluid.

  12. Knowledge Surveys in General Chemistry: Confidence, Overconfidence, and Performance

    ERIC Educational Resources Information Center

    Bell, Priscilla; Volckmann, David

    2011-01-01

    Knowledge surveys have been used in a number of fields to assess changes in students' understanding of their own learning and to assist students in review. This study compares metacognitive confidence ratings of students faced with problems on the surveys with their actual knowledge as shown on the final exams in two courses of general chemistry…

  13. "Something He Could Do without Being Taught": Honors, Play, and "Harry Potter"

    ERIC Educational Resources Information Center

    Yager, Susan

    2015-01-01

    Years after the publication of its seventh and final volume in 2007 and the completion of the film series in 2011, the "Harry Potter" series is still studied and cited by professionals in fields ranging from science and economics to law and theology (for recent examples see Gierzynski and Eddy; Reagin; Bassham). Its continuing popularity…

  14. Innovations: The Social Consequences of Science and Technology. Final Evaluation Report.

    ERIC Educational Resources Information Center

    Tolman, Richard R.

    The Biological Sciences Curriculum Study designed, developed, and field-tested a series of nine curriculum resource units for a semester program called "Innovations: The Social Consequences of Science and Technology (IST)." The units were designed for use by students and teachers in the 11th and 12th grades and at the junior college…

  15. NASA KEPLER OPENS THE STUDY OF THE GALAXY’S PLANET POPULATION

    NASA Image and Video Library

    2017-06-20

    NASA's Kepler mission released its eighth Kepler Candidate Catalog, which contains the best measured and most reliable planet candidates from the space telescope's final survey of the Cygnus Field. In the data are 219 new planet candidates, of which 10 are less than twice the size of the Earth and orbit in the habitable zone.

  16. Final Report; Arsenic Fate, Transport and Stability Study; Groundwater, Surface Water, Soil And Sediment Investigation, Fort Devens Superfund Site, Devens, Massachusetts

    EPA Science Inventory

    This document presents results from the Fiscal Years 2006-2008 field investigation at the Fort Devens Superfund Site, Operable Unit 1 (Shepley's Hill Landfill) to fulfill the research objectives outlined in the proposal entitled, 'Fate and Transport of Arsenic in an Urban, Milita...

  17. Design and Implementation of BusinessApp, a MALL Application to Make Successful Business Presentations

    ERIC Educational Resources Information Center

    Calle-Martínez, Cristina; Yanes, Lourdes Pomposo; Pareja-Lora, Antonio

    2016-01-01

    Little by little, (or, simply, MALL) is taking force in the field of education, as it supports language blended learning and language learning ubiquity. The study presented here belongs in the Social Ontology-based Cognitively Augmented Language Learning Mobile Environment (SO-CALL-ME) research project, whose final aim is to design and create…

  18. Academic Control and Action Control in the Achievement of College Students: A Longitudinal Field Study.

    ERIC Educational Resources Information Center

    Perry, Raymond P.; Hladkyj, Steven; Pekrun, Reinhard H.; Pelletier, Sarah T.

    2001-01-01

    Two measures, perceived academic control and action control (i.e., preoccupation with failure), were administered to college students. Achievement-related cognitions, emotions, motivation, and final grades were measured at the end of the course. Of note, high-control, high-failure-preoccupied students outperformed the other groups by one to two…

  19. A Study To Identify the Appropriate Vocational Education Related Competencies Needed for Graduation by Handicapped Students. Final Report.

    ERIC Educational Resources Information Center

    North Texas Univ., Denton.

    A project developed competency profiles identifying entry-level skills and employability skills to be acquired by handicapped students before graduation. Research literature was reviewed to identify generalizable skills, employability skills, self-help skills, and job skills. Feedback was obtained from practitioners in the field regarding rating…

  20. TECHNOLOGY TRANSFER OF AN INNOVATIVE REMEDIATION TECHNOLOGY FROM THE LABORATORY TO THE FIELD: A CASE STUDY OF IN SITU AEROBIC COMETABOLIC BIOREMEDIATION. (R825689C067)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. FORTRAN programs to process Magsat data for lithospheric, external field, and residual core components

    NASA Technical Reports Server (NTRS)

    Alsdorf, Douglas E.; Vonfrese, Ralph R. B.

    1994-01-01

    The FORTRAN programs supplied in this document provide a complete processing package for statistically extracting residual core, external field and lithospheric components in Magsat observations. To process the individual passes: (1) orbits are separated into dawn and dusk local times and by altitude, (2) passes are selected based on the variance of the magnetic field observations after a least-squares fit of the core field is removed from each pass over the study area, and (3) spatially adjacent passes are processed with a Fourier correlation coefficient filter to separate coherent and non-coherent features between neighboring tracks. In the second state of map processing: (1) data from the passes are normalized to a common altitude and gridded into dawn and dusk maps with least squares collocation, (2) dawn and dusk maps are correlated with a Fourier correlation efficient filter to separate coherent and non-coherent features; the coherent features are averaged to produce a total field grid, (3) total field grids from all altitudes are continued to a common altitude, correlation filtered for coherent anomaly features, and subsequently averaged to produce the final total field grid for the study region, and (4) the total field map is differentially reduced to the pole.

  2. Gravity field and shape of Ceres from Dawn

    NASA Astrophysics Data System (ADS)

    Park, Ryan; Konopliv, Alexander; Vaughan, Andrew; Bills, Bruce; Castillo-Rogez, Julie; Ermakov, Anton; Fu, Roger; Raymond, Carol; Russell, Chris; Zuber, Maria

    2017-04-01

    The Dawn gravity science investigation utilizes the DSN radio tracking of the spacecraft and on-board framing camera images to determine the gravity field and global shape of Ceres. The gravity science data collected during Approach, Survey, High-Altitude Mapping Orbit, and Low-Altitude Mapping Orbit phases were processed. The final gravity science solution yielded a degree and order 18 gravity field, called CERES18C, which is globally accurate to degree and order 14. Also, the final Ceres shape using the stereo-photoclinometry method is available with the height uncertainty better than 30 meters. The degree-2 gravity harmonics show that the rotation of Ceres is very nearly about a principal axis. Combining the gravity field and topography gives the bulk density of 2162.6±2.0 kg/m3. The estimated spin pole vector yields RA=(291.42744±0.00022)° and Dec=(66.76065±0.00022)° with the prime meridian and rotation rate of (170.374±0.012)° and (952.1532638±0.0000019)°/day, respectively. The low Bouguer gravity at high topographic areas, and vice versa, indicates that the topography of Ceres is compensated, which can be explained by a low-viscosity layer at depth. Further studies on Ceres interior show that low gravity-topography admittances are consistent with Airy isostasy and finite-element modeling require a decrease of viscosity with depth.

  3. Evaluation of depleted uranium in the environment at Aberdeen Proving Grounds, Maryland and Yuma Proving Grounds, Arizona. Final report

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

    Kennedy, P.L.; Clements, W.H.; Myers, O.B.

    1995-01-01

    This report represents an evaluation of depleted uranium (DU) introduced into the environment at the Aberdeen Proving Grounds (APG), Maryland and Yuma Proving Grounds (YPG) Arizona. This was a cooperative project between the Environmental Sciences and Statistical Analyses Groups at LANL and with the Department of Fishery and Wildlife Biology at Colorado State University. The project represents a unique approach to assessing the environmental impact of DU in two dissimilar ecosystems. Ecological exposure models were created for each ecosystem and sensitivity/uncertainty analyses were conducted to identify exposure pathways which were most influential in the fate and transport of DU inmore » the environment. Research included field sampling, field exposure experiment, and laboratory experiments. The first section addresses DU at the APG site. Chapter topics include bioenergetics-based food web model; field exposure experiments; bioconcentration by phytoplankton and the toxicity of U to zooplankton; physical processes governing the desorption of uranium from sediment to water; transfer of uranium from sediment to benthic invertebrates; spead of adsorpion by benthic invertebrates; uptake of uranium by fish. The final section of the report addresses DU at the YPG site. Chapters include the following information: Du transport processes and pathway model; field studies of performance of exposure model; uptake and elimination rates for kangaroo rates; chemical toxicity in kangaroo rat kidneys.« less

  4. The sensitivity of aquatic insects to divalent metals: a comparative analysis of laboratory and field data.

    PubMed

    Brix, Kevin V; DeForest, David K; Adams, William J

    2011-09-15

    Laboratory studies have traditionally indicated that aquatic insects are relatively insensitive to metals while field studies have suggested them to be among the most sensitive aquatic invertebrate taxa. We reviewed and synthesized available studies in the literature to critically assess why this discrepancy exists. Despite the intense effort to study the effects of metals on aquatic biota over the past several decades, we found studies specific to insects to still be relatively limited. In general, the discrepancy between laboratory and field studies continues with few efforts having been made to elucidate the ecological and physiological mechanisms that underlie the relative sensitivity (or insensitivity) of aquatic insects to metals. However, given the limited data available, it appears that aquatic insects are indeed relatively insensitive to acute metal exposures. In contrast, we suggest that some aquatic insect taxa may be quite sensitive to chronic metal exposure and in some cases may not be protected by existing water quality criteria for metals. The discrepancy between laboratory and field studies with respect to chronic sensitivity appears to largely be driven by the relatively short exposure periods in laboratory studies as compared to field studies. It also appears that, in some cases, the sensitivity of aquatic insects in field studies may be the result of direct effects on primary producers, which lead to indirect effects via the food chain on aquatic insects. Finally, available evidence suggests that diet is an important source of metal accumulation in insects, but to date there have been no conclusive studies evaluating whether dietary metal accumulation causes toxicity. There is a clear need for developing a more mechanistic understanding of aquatic insect sensitivity to metals in long-term laboratory and field studies. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Bridging Class and Field: Field Instructors' and Liaisons' Reactions to Information about Students' Baseline Performance Derived from Simulated Interviews

    ERIC Educational Resources Information Center

    Bogo, Marion; Lee, Barbara; McKee, Eileen; Ramjattan, Roxanne; Baird, Stephanie L.

    2017-01-01

    To strengthen students' preparation for engaging in field learning, an innovation was implemented to teach and assess foundation-year students' performance prior to entering field education. An Objective Structured Clinical Examination informed the final evaluation of students' performance in two companion courses on practice theory and skills.…

  6. Random Fields and Collective Effects in Molecular Magnets

    DTIC Science & Technology

    2018-01-29

    longitudinal fields the final state consists of only partially reversed spins. Further, we measured the front speed as a function of applied magnetic...field. The theory of magnetic deflagration, together with a modification that takes into account the partial spin reversal, fits the transverse field...Conference Paper or Presentation Conference Name: APS March Meeting 2016 Conference Location: Baltimore, Paper Title: Time-resolved Measurements

  7. Magnetic hyperthermia with hard-magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Kashevsky, Bronislav E.; Kashevsky, Sergey B.; Korenkov, Victor S.; Istomin, Yuri P.; Terpinskaya, Tatyana I.; Ulashchik, Vladimir S.

    2015-04-01

    Recent clinical trials of magnetic hyperthermia have proved, and even hardened, the Ankinson-Brezovich restriction as upon magnetic field conditions applicable to any site of human body. Subject to this restriction, which is harshly violated in numerous laboratory and small animal studies, magnetic hyperthermia can relay on rather moderate heat source, so that optimization of the whole hyperthermia system remains, after all, the basic problem predetermining its clinical perspectives. We present short account of our complex (theoretical, laboratory and small animal) studies to demonstrate that such perspectives should be related with the hyperthermia system based on hard-magnetic (Stoner-Wohlfarth type) nanoparticles and strong low-frequency fields rather than with superparamagnetic (Brownian or Neél) nanoparticles and weak high-frequency fields. This conclusion is backed by an analytical evaluation of the maximum absorption rates possible under the field restriction in the ideal hard-magnetic (Stoner-Wohlarth) and the ideal superparamagnetic (single relaxation time) systems, by theoretical and experimental studies of the dynamic magnetic hysteresis in suspensions of movable hard-magnetic particles, by producing nanoparticles with adjusted coercivity and suspensions of such particles capable of effective energy absorption and intratumoral penetration, and finally, by successful treatment of a mice model tumor under field conditions acceptable for whole human body.

  8. Front dynamics and entanglement in the XXZ chain with a gradient

    NASA Astrophysics Data System (ADS)

    Eisler, Viktor; Bauernfeind, Daniel

    2017-11-01

    We consider the XXZ spin chain with a magnetic field gradient and study the profiles of the magnetization as well as the entanglement entropy. For a slowly varying field, it is shown that, by means of a local density approximation, the ground-state magnetization profile can be obtained with standard Bethe ansatz techniques. Furthermore, it is argued that the low-energy description of the theory is given by a Luttinger liquid with slowly varying parameters. This allows us to obtain a very good approximation of the entanglement profile using a recently introduced technique of conformal field theory in curved spacetime. Finally, the front dynamics is also studied after the gradient field has been switched off, following arguments of generalized hydrodynamics for integrable systems. While for the XX chain the hydrodynamic solution can be found analytically, the XXZ case appears to be more complicated and the magnetization profiles are recovered only around the edge of the front via an approximate numerical solution.

  9. Field induced spontaneous quasiparticle decay and renormalization of quasiparticle dispersion in a quantum antiferromagnet

    DOE PAGES

    Hong, Tao; Qiu, Y.; Matsumoto, M.; ...

    2017-05-05

    The notion of a quasiparticle, such as a phonon, a roton or a magnon, is used in modern condensed matter physics to describe an elementary collective excitation. The intrinsic zero-temperature magnon damping in quantum spin systems can be driven by the interaction of the one-magnon states and multi-magnon continuum. However, detailed experimental studies on this quantum many-body effect induced by an applied magnetic field are rare. Here we present a high-resolution neutron scattering study in high fields on an S=1/2 antiferromagnet C 9H 18N 2CuBr 4. Finally, compared with the non-interacting linear spin–wave theory, our results demonstrate a variety ofmore » phenomena including field-induced renormalization of one-magnon dispersion, spontaneous magnon decay observed via intrinsic linewidth broadening, unusual non-Lorentzian two-peak structure in the excitation spectra and a dramatic shift of spectral weight from one-magnon state to the two-magnon continuum.« less

  10. A comparison of top and middle level women administrators in social work, nursing, and education: career supports and barriers.

    PubMed

    Collins, S K

    1984-01-01

    Presented in this article are findings from a descriptive study of a national stratified random sample of 259 women administrators in social work, nursing, and education. Subjects responded to a 54 item, mailed questionnaire about their career experiences. The author explores career support from parents and persons within their work organizations. Barriers of sex discrimination and difficulties balancing career and family responsibilities are included. Finally, the extent to which the women administrators provided career assistance to other women is discussed. Comparisons between the three fields and between top and middle management levels are emphasized. Recommendations are made for increasing women's opportunities for career achievement within the fields studied.

  11. Beam dynamics validation of the Halbach Technology FFAG Cell for Cornell-BNL Energy Recovery Linac

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

    Meot, Francois; Tsoupas, N.; Brooks, S.

    The Cornell-BNL Electron Test Accelerator (CBETA), a 150 MeV energy recovery linac (ERL) now in construction at Cornell, employs a fixed-field alternating gradient optics return loop: a single beam line comprised of FFAG cells, which accepts four recirculated energies. CBETA FFAG cell uses Halbach permanent magnet technology, its design studies have covered an extended period of time supported by extensive particle dynamics simulations using computed 3-D field map models. As a result, this approach is discussed, and illustrated here, based on the final stage in these beam dynamics studies, namely the validation of a ultimate, optimized design of the Halbachmore » cell.« less

  12. Impact of Dynamic Specimen Shape Evolution on the Atom Probe Tomography Results of Doped Epitaxial Oxide Multilayers: Comparison of Experiment and Simulation

    DOE PAGES

    Madaan, Nitesh; Bao, Jie; Nandasiri, Manjula I.; ...

    2015-08-31

    The experimental atom probe tomography results from two different specimen orientations (top-down and side-ways) of a high oxygen ion conducting Samaria-doped-ceria/Scandia-stabilized-zirconia multilayer thin film solid oxide fuel cell electrolyte was correlated with level-set method based field evaporation simulations for the same specimen orientations. This experiment-theory correlation explains the dynamic specimen shape evolution and ion trajectory aberrations that can induce density artifacts in final reconstruction leading to inaccurate estimation of interfacial intermixing. This study highlights the need and importance of correlating experimental results with field evaporation simulations when using atom probe tomography for studying oxide heterostructure interfaces.

  13. Beam dynamics validation of the Halbach Technology FFAG Cell for Cornell-BNL Energy Recovery Linac

    DOE PAGES

    Meot, Francois; Tsoupas, N.; Brooks, S.; ...

    2018-04-16

    The Cornell-BNL Electron Test Accelerator (CBETA), a 150 MeV energy recovery linac (ERL) now in construction at Cornell, employs a fixed-field alternating gradient optics return loop: a single beam line comprised of FFAG cells, which accepts four recirculated energies. CBETA FFAG cell uses Halbach permanent magnet technology, its design studies have covered an extended period of time supported by extensive particle dynamics simulations using computed 3-D field map models. As a result, this approach is discussed, and illustrated here, based on the final stage in these beam dynamics studies, namely the validation of a ultimate, optimized design of the Halbachmore » cell.« less

  14. A Collaborative Problem-solving Process Through Environmental Field Studies

    NASA Astrophysics Data System (ADS)

    Kim, Mijung; Teck Tan, Hoe

    2013-02-01

    This study explored and documented students' responses to opportunities for collective knowledge building and collaboration in a problem-solving process within complex environmental challenges and pressing issues with various dimensions of knowledge and skills. Middle-school students (n = 16; age 14) and high-school students (n = 16; age 17) from two Singapore public institutions participated in an environmental science field study to experience knowledge integration and a decision-making process. Students worked on six research topics to understand the characteristics of an organic farm and plan for building an ecological village. Students collected and analysed data from the field and shared their findings. Their field work and discussions were video-recorded, and their reflective notes and final reports were collected for data coding and interpretation. The results revealed that throughout the study, students experienced the needs and development of integrated knowledge, encountered the challenges of knowledge sharing and communication during their collaboration, and learned how to cope with the difficulties. Based on research findings, this study further discusses students' learning through a collaborative problem-solving process, including the interdependence of knowledge and the development of mutual relationships such as respect and care for others' knowledge and learning.

  15. Role of structural relaxations and chemical substitutions on piezoelectric fields and potential lineup in GaN/Al junctions

    NASA Astrophysics Data System (ADS)

    Picozzi, S.; Profeta, G.; Continenza, A.; Massidda, S.; Freeman, A. J.

    2002-04-01

    First-principles full-potential linearized augmented plane wave calculations are performed to clarify the role of the interface geometry on piezoelectric fields and potential lineups in [0001] wurtzite and [111]-zincblende GaN/Al junctions. The electric field (polarity and magnitude) is found to be strongly affected by atomic relaxations in the interface region. A procedure is used to evaluate the Schottky-barrier height in the presence of electric fields, showing that their effect is relatively small (a few tenths of an eV). These calculations assess the rectifying behavior of the GaN/Al contact, in agreement with experimental values for the barrier. We disentangle chemical and structural effects on the relevant properties (such as the potential discontinuity and the electric field) by studying unrelaxed ideal nitride/metal systems. Using simple electronegativity arguments, we outline the leading mechanisms that define the values of the electric field and Schottky barrier in these ideal systems. Finally, the transitivity rule is proved to be well satisfied.

  16. Lymphocyte Electrotaxis in vitro and in vivo

    PubMed Central

    Lin, Francis; Baldessari, Fabio; Gyenge, Christina Crenguta; Sato, Tohru; Chambers, Robert D.; Santiago, Juan G.; Butcher, Eugene C.

    2008-01-01

    Electric fields are generated in vivo in a variety of physiologic and pathologic settings, including penetrating injury to epithelial barriers. An applied electric field with strength within the physiologic range can induce directional cell migration (i.e. electrotaxis) of epithelial cells, endothelial cells, fibroblasts, and neutrophils suggesting a potential role in cell positioning during wound healing. In the present study, we investigated the ability of lymphocytes to respond to applied direct current (DC) electric fields. Using a modified transwell assay and a simple microfluidic device, we show that human peripheral blood lymphocytes migrate toward the cathode in physiologically relevant DC electric fields. Additionally, electrical stimulation activates intracellular kinase signaling pathways shared with chemotactic stimuli. Finally, video microscopic tracing of GFP-tagged immunocytes in the skin of mouse ears reveals that motile cutaneous T cells actively migrate toward the cathode of an applied DC electric field. Lymphocyte positioning within tissues can thus be manipulated by externally applied electric fields, and may be influenced by endogenous electrical potential gradients as well. PMID:18684937

  17. Lymphocyte electrotaxis in vitro and in vivo.

    PubMed

    Lin, Francis; Baldessari, Fabio; Gyenge, Christina Crenguta; Sato, Tohru; Chambers, Robert D; Santiago, Juan G; Butcher, Eugene C

    2008-08-15

    Electric fields are generated in vivo in a variety of physiologic and pathologic settings, including penetrating injury to epithelial barriers. An applied electric field with strength within the physiologic range can induce directional cell migration (i.e., electrotaxis) of epithelial cells, endothelial cells, fibroblasts, and neutrophils suggesting a potential role in cell positioning during wound healing. In the present study, we investigated the ability of lymphocytes to respond to applied direct current (DC) electric fields. Using a modified Transwell assay and a simple microfluidic device, we show that human PBLs migrate toward the cathode in physiologically relevant DC electric fields. Additionally, electrical stimulation activates intracellular kinase signaling pathways shared with chemotactic stimuli. Finally, video microscopic tracing of GFP-tagged immunocytes in the skin of mouse ears reveals that motile cutaneous T cells actively migrate toward the cathode of an applied DC electric field. Lymphocyte positioning within tissues can thus be manipulated by externally applied electric fields, and may be influenced by endogenous electrical potential gradients as well.

  18. The Design and Implementation of Indoor Localization System Using Magnetic Field Based on Smartphone

    NASA Astrophysics Data System (ADS)

    Liu, J.; Jiang, C.; Shi, Z.

    2017-09-01

    Sufficient signal nodes are mostly required to implement indoor localization in mainstream research. Magnetic field take advantage of high precision, stable and reliability, and the reception of magnetic field signals is reliable and uncomplicated, it could be realized by geomagnetic sensor on smartphone, without external device. After the study of indoor positioning technologies, choose the geomagnetic field data as fingerprints to design an indoor localization system based on smartphone. A localization algorithm that appropriate geomagnetic matching is designed, and present filtering algorithm and algorithm for coordinate conversion. With the implement of plot geomagnetic fingerprints, the indoor positioning of smartphone without depending on external devices can be achieved. Finally, an indoor positioning system which is based on Android platform is successfully designed, through the experiments, proved the capability and effectiveness of indoor localization algorithm.

  19. The calculation of steady non-linear transonic flow over finite wings with linear theory aerodynamics

    NASA Technical Reports Server (NTRS)

    Cunningham, A. M., Jr.

    1976-01-01

    The feasibility of calculating steady mean flow solutions for nonlinear transonic flow over finite wings with a linear theory aerodynamic computer program is studied. The methodology is based on independent solutions for upper and lower surface pressures that are coupled through the external flow fields. Two approaches for coupling the solutions are investigated which include the diaphragm and the edge singularity method. The final method is a combination of both where a line source along the wing leading edge is used to account for blunt nose airfoil effects; and the upper and lower surface flow fields are coupled through a diaphragm in the plane of the wing. An iterative solution is used to arrive at the nonuniform flow solution for both nonlifting and lifting cases. Final results for a swept tapered wing in subcritical flow show that the method converges in three iterations and gives excellent agreement with experiment at alpha = 0 deg and 2 deg. Recommendations are made for development of a procedure for routine application.

  20. Flight Integral Field Spectrograph (IFS) Optical Design for WFIRST Coronagraphic Exoplanet Demonstration

    NASA Technical Reports Server (NTRS)

    Gong, Qian; Groff, Tyler D.; Zimmerman, Neil; Mandell, Avi; McElwain, Michael; Rizzo, Maxime; Saxena, Prabal

    2017-01-01

    Based on the experience from Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) for WFIRST, we have moved to the flight instrument design phase. The specifications for flight IFS have similarities and differences from the prototype. This paper starts with the science and system requirement, discusses a number of critical trade-offs: such as IFS type selection, lenslet array shape and layout versus detector pixel accuracy, how to accommodate the larger Field Of View (FOV) and wider wavelength band for a potential add-on StarShade occulter. Finally, the traditional geometric optical design is also investigated and traded: reflective versus refractive, telecentric versus non-telecentric relay. The relay before the lenslet array controls the chief angle distribution on the lenslet array. Our previous paper has addressed how the relay design combined with lenslet arraypinhole mask can further compress the residual star light and increase the contrast. Finally, a complete phase A IFS optical design is presented.

  1. Pharmaceutical aspects of salt and cocrystal forms of APIs and characterization challenges.

    PubMed

    Cerreia Vioglio, Paolo; Chierotti, Michele R; Gobetto, Roberto

    2017-08-01

    In recent years many efforts have been devoted to the screening and the study of new solid-state forms of old active pharmaceutical ingredients (APIs) with salification or co-crystallization processes, thus modulating final properties without changing the pharmacological nature. Salts, hydrates/solvates, and cocrystals are the common solid-state forms employed. They offer the intriguing possibility of exploring different pharmaceutical properties for a single API in the quest of enhancing the final drug product. New synthetic strategies and advanced characterization techniques have been recently proposed in this hot topic for pharmaceutical companies. This paper reviews the recent progresses in the field particularly focusing on the characterization challenges encountered when the nature of the solid-state form must be determined. The aim of this article is to offer the state-of-the-art on this subject in order to develop new insights and to promote cooperative efforts in the fascinating field of API salt and cocrystal forms. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Bacterial growth rates are influenced by cellular characteristics of individual species when immersed in electromagnetic fields.

    PubMed

    Tessaro, Lucas W E; Murugan, Nirosha J; Persinger, Michael A

    2015-03-01

    Previous studies have shown that exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) have negative effects on the rate of growth of bacteria. In the present study, two Gram-positive and two Gram-negative species were exposed to six magnetic field conditions in broth cultures. Three variations of the 'Thomas' pulsed frequency-modulated pattern; a strong-static "puck" magnet upwards of 5000G in intensity; a pair of these magnets rotating opposite one another at ∼30rpm; and finally a strong dynamic magnetic field generator termed the 'Resonator' with an average intensity of 250μT were used. Growth rate was discerned by optical density (OD) measurements every hour at 600nm. ELF-EMF conditions significantly affected the rates of growth of the bacterial cultures, while the two static magnetic field conditions were not statistically significant. Most interestingly, the 'Resonator' dynamic magnetic field increased the rates of growth of three species (Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli), while slowing the growth of one (Serratia marcescens). We suggest that these effects are due to individual biophysical characteristics of the bacterial species. Copyright © 2015 Elsevier GmbH. All rights reserved.

  3. Glassy phases and driven response of the phase-field-crystal model with random pinning.

    PubMed

    Granato, E; Ramos, J A P; Achim, C V; Lehikoinen, J; Ying, S C; Ala-Nissila, T; Elder, K R

    2011-09-01

    We study the structural correlations and the nonlinear response to a driving force of a two-dimensional phase-field-crystal model with random pinning. The model provides an effective continuous description of lattice systems in the presence of disordered external pinning centers, allowing for both elastic and plastic deformations. We find that the phase-field crystal with disorder assumes an amorphous glassy ground state, with only short-ranged positional and orientational correlations, even in the limit of weak disorder. Under increasing driving force, the pinned amorphous-glass phase evolves into a moving plastic-flow phase and then, finally, a moving smectic phase. The transverse response of the moving smectic phase shows a vanishing transverse critical force for increasing system sizes.

  4. Local White Matter Geometry from Diffusion Tensor Gradients

    PubMed Central

    Savadjiev, Peter; Kindlmann, Gordon L.; Bouix, Sylvain; Shenton, Martha E.; Westin, Carl-Fredrik

    2009-01-01

    We introduce a mathematical framework for computing geometrical properties of white matter fibres directly from diffusion tensor fields. The key idea is to isolate the portion of the gradient of the tensor field corresponding to local variation in tensor orientation, and to project it onto a coordinate frame of tensor eigenvectors. The resulting eigenframe-centered representation then makes it possible to define scalar indices (or measures) that describe the local white matter geometry directly from the diffusion tensor field and its gradient, without requiring prior tractography. We derive new scalar indices of (1) fibre dispersion and (2) fibre curving, and we demonstrate them on synthetic and in vivo data. Finally, we illustrate their applicability to a group study on schizophrenia. PMID:19896542

  5. Local White Matter Geometry from Diffusion Tensor Gradients

    PubMed Central

    Savadjiev, Peter; Kindlmann, Gordon L.; Bouix, Sylvain; Shenton, Martha E.; Westin, Carl-Fredrik

    2010-01-01

    We introduce a mathematical framework for computing geometrical properties of white matter fibres directly from diffusion tensor fields. The key idea is to isolate the portion of the gradient of the tensor field corresponding to local variation in tensor orientation, and to project it onto a coordinate frame of tensor eigenvectors. The resulting eigenframe-centered representation then makes it possible to define scalar indices (or measures) that describe the local white matter geometry directly from the diffusion tensor field and its gradient, without requiring prior tractography. We derive new scalar indices of (1) fibre dispersion and (2) fibre curving, and we demonstrate them on synthetic and in vivo data. Finally, we illustrate their applicability to a group study on schizophrenia. PMID:20426006

  6. Ultra-fast magnetic vortex core reversal by a local field pulse

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

    Rückriem, R.; Albrecht, M., E-mail: manfred.albrecht@physik.uni-augsburg.de; Schrefl, T.

    2014-02-03

    Magnetic vortex core reversal of a 20-nm-thick permalloy disk with a diameter of 100 nm was studied by micromagnetic simulations. By applying a global out-of-plane magnetic field pulse, it turned out that the final core polarity is very sensitive to pulse width and amplitude, which makes it hard to control. The reason for this phenomenon is the excitation of radial spin waves, which dominate the reversal process. The excitation of spin waves can be strongly suppressed by applying a local field pulse within a small area at the core center. With this approach, ultra-short reversal times of about 15 ps weremore » achieved, which are ten times faster compared to a global pulse.« less

  7. [Microdose clinical trial--impact of PET molecular imaging].

    PubMed

    Yano, Tsuneo; Watanabe, Yasuyoshi

    2010-10-01

    Microdose (MD) clinical trial and exploratory IND study including sub-therapeutic dose and therapeutic dose which are higher than microdoses are expected to bring about innovations in drug development. The outlines of guidances for microdose clinical trial and ICH-M3 (R2) issued by the MHLW in June, 2008, and February, 2010, are first explained, respectively, and some examples of their application to clinical developments of therapeutic drugs in the infection and cancer fields are introduced. Especially, thanks to the progress of molecular imaging research, a new field of drug development is explored by using imaging biomarkers for efficacy or safety evaluation which visualize biomarkers by PET imaging agents. Finally, the roadmap for drug development in infection and cancer fields utilizing PET molecular imaging is discussed.

  8. Electromagnetic fields and their impacts

    NASA Astrophysics Data System (ADS)

    Prša, M. A.; Kasaš-Lažetić, K. K.

    2018-01-01

    The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.

  9. Low Temperature and Neutron Physics Studies: Final Progress Report, March 1, 1986--May 31, 1987

    DOE R&D Accomplishments Database

    Shull, C.G.

    1989-07-27

    A search for a novel coupling interaction between the Pendelloesung periodicity which is formed in a diffracting crystal and the Larmor precession of neutrons in a magnetic field has been carried out. This interaction is expected to exhibit a resonant behavior when the two spatial periodicities become matched upon scanning the magnetic field being applied to the crystal. Observations on a diffracting, perfect crystal of silicon with neutrons of wavelength 1 Angstrom show the expected resonant action but some discrepancy between the observed magnitude of the resonance effects remains for interpretation.

  10. Phase-field-crystal model for magnetocrystalline interactions in isotropic ferromagnetic solids

    NASA Astrophysics Data System (ADS)

    Faghihi, Niloufar; Provatas, Nikolas; Elder, K. R.; Grant, Martin; Karttunen, Mikko

    2013-09-01

    An isotropic magnetoelastic phase-field-crystal model to study the relation between morphological structure and magnetic properties of pure ferromagnetic solids is introduced. Analytic calculations in two dimensions were used to determine the phase diagram and obtain the relationship between elastic strains and magnetization. Time-dependent numerical simulations in two dimensions were used to demonstrate the effect of grain boundaries on the formation of magnetic domains. It was shown that the grain boundaries act as nucleating sites for domains of reverse magnetization. Finally, we derive a relation for coercivity versus grain misorientation in the isotropic limit.

  11. The Evolution of Spiral Disks

    NASA Astrophysics Data System (ADS)

    Bershady, Matthew A.; Andersen, David R.

    We report on aspects of an observational study to probe the mass assembly of large galaxy disks. In this contribution we focus on a new survey of integral-field Hα velocity-maps of nearby, face on disks. Preliminary results yield disk asymmetry amplitudes consistent with estimates based on the scatter in the local Tully-Fisher relation. We also show how the high quality of integral-field echelle spectroscopy enables determinations of kinematic inclinations to i ~20 °. This holds the promise that nearly-face-on galaxies can be included in the Tully-Fisher relation. Finally, we discuss the prospects for measuring dynamical asymmetries of distant galaxies.

  12. Design and prototype fabrication of a 30 tesla cryogenic magnet

    NASA Technical Reports Server (NTRS)

    Prok, G. M.; Swanson, M. C.; Brown, G. V.

    1977-01-01

    A liquid-neon-cooled magnet has been designed to produce 30 teslas in steady operation. Its feasibility was established by a previously reported parametric study. To ensure the correctness of the heat transfer relationships used, supercritical neon heat transfer tests were made. Other tests made before the final design included tests on the effect of the magnetic field on pump motors; tensile-shear tests on the cryogenic adhesives; and simulated flow studies for the coolant. The magnet will be made of two pairs of coils, cooled by forced convection of supercritical neon. Heat from the supercritical neon will be rejected through heat exchangers which are made of roll-bonded copper panels and are submerged in a pool of saturated liquid neon. A partial mock-up coil was wound to identify the tooling required to wind the magnet. This was followed by winding a prototype pair of coils. The prototype winding established procedures for fabricating the final magnet and revealed slight changes needed in the final design.

  13. Evaluation method for in situ electric field in standardized human brain for different transcranial magnetic stimulation coils

    NASA Astrophysics Data System (ADS)

    Iwahashi, Masahiro; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa

    2017-03-01

    This study proposes a method to evaluate the electric field induced in the brain by transcranial magnetic stimulation (TMS) to realize focal stimulation in the target area considering the inter-subject difference of the brain anatomy. The TMS is a non-invasive technique used for treatment/diagnosis, and it works by inducing an electric field in a specific area of the brain via a coil-induced magnetic field. Recent studies that report on the electric field distribution in the brain induced by TMS coils have been limited to simplified human brain models or a small number of detailed human brain models. Until now, no method has been developed that appropriately evaluates the coil performance for a group of subjects. In this study, we first compare the magnetic field and the magnetic vector potential distributions to determine if they can be used as predictors of the TMS focality derived from the electric field distribution. Next, the hotspots of the electric field on the brain surface of ten subjects using six coils are compared. Further, decisive physical factors affecting the focality of the induced electric field by different coils are discussed by registering the computed electric field in a standard brain space for the first time, so as to evaluate coil characteristics for a large population of subjects. The computational results suggest that the induced electric field in the target area cannot be generalized without considering the morphological variability of the human brain. Moreover, there was no remarkable difference between the various coils, although focality could be improved to a certain extent by modifying the coil design (e.g., coil radius). Finally, the focality estimated by the electric field was more correlated with the magnetic vector potential than the magnetic field in a homogeneous sphere.

  14. Water liquid-vapor interface subjected to various electric fields: A molecular dynamics study.

    PubMed

    Nikzad, Mohammadreza; Azimian, Ahmad Reza; Rezaei, Majid; Nikzad, Safoora

    2017-11-28

    Investigation of the effects of E-fields on the liquid-vapor interface is essential for the study of floating water bridge and wetting phenomena. The present study employs the molecular dynamics method to investigate the effects of parallel and perpendicular E-fields on the water liquid-vapor interface. For this purpose, density distribution, number of hydrogen bonds, molecular orientation, and surface tension are examined to gain a better understanding of the interface structure. Results indicate enhancements in parallel E-field decrease the interface width and number of hydrogen bonds, while the opposite holds true in the case of perpendicular E-fields. Moreover, perpendicular fields disturb the water structure at the interface. Given that water molecules tend to be parallel to the interface plane, it is observed that perpendicular E-fields fail to realign water molecules in the field direction while the parallel ones easily do so. It is also shown that surface tension rises with increasing strength of parallel E-fields, while it reduces in the case of perpendicular E-fields. Enhancement of surface tension in the parallel field direction demonstrates how the floating water bridge forms between the beakers. Finally, it is found that application of external E-fields to the liquid-vapor interface does not lead to uniform changes in surface tension and that the liquid-vapor interfacial tension term in Young's equation should be calculated near the triple-line of the droplet. This is attributed to the multi-directional nature of the droplet surface, indicating that no constant value can be assigned to a droplet's surface tension in the presence of large electric fields.

  15. Evaluation method for in situ electric field in standardized human brain for different transcranial magnetic stimulation coils.

    PubMed

    Iwahashi, Masahiro; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa

    2017-03-21

    This study proposes a method to evaluate the electric field induced in the brain by transcranial magnetic stimulation (TMS) to realize focal stimulation in the target area considering the inter-subject difference of the brain anatomy. The TMS is a non-invasive technique used for treatment/diagnosis, and it works by inducing an electric field in a specific area of the brain via a coil-induced magnetic field. Recent studies that report on the electric field distribution in the brain induced by TMS coils have been limited to simplified human brain models or a small number of detailed human brain models. Until now, no method has been developed that appropriately evaluates the coil performance for a group of subjects. In this study, we first compare the magnetic field and the magnetic vector potential distributions to determine if they can be used as predictors of the TMS focality derived from the electric field distribution. Next, the hotspots of the electric field on the brain surface of ten subjects using six coils are compared. Further, decisive physical factors affecting the focality of the induced electric field by different coils are discussed by registering the computed electric field in a standard brain space for the first time, so as to evaluate coil characteristics for a large population of subjects. The computational results suggest that the induced electric field in the target area cannot be generalized without considering the morphological variability of the human brain. Moreover, there was no remarkable difference between the various coils, although focality could be improved to a certain extent by modifying the coil design (e.g., coil radius). Finally, the focality estimated by the electric field was more correlated with the magnetic vector potential than the magnetic field in a homogeneous sphere.

  16. Influence of beam incidence and irradiation parameters on stray neutron doses to healthy organs of pediatric patients treated for an intracranial tumor with passive scattering proton therapy.

    PubMed

    Bonfrate, A; Farah, J; De Marzi, L; Delacroix, S; Hérault, J; Sayah, R; Lee, C; Bolch, W E; Clairand, I

    2016-04-01

    In scattering proton therapy, the beam incidence, i.e. the patient's orientation with respect to the beam axis, can significantly influence stray neutron doses although it is almost not documented in the literature. MCNPX calculations were carried out to estimate stray neutron doses to 25 healthy organs of a 10-year-old female phantom treated for an intracranial tumor. Two beam incidences were considered in this article, namely a superior (SUP) field and a right lateral (RLAT) field. For both fields, a parametric study was performed varying proton beam energy, modulation width, collimator aperture and thickness, compensator thickness and air gap size. Using a standard beam line configuration for a craniopharyngioma treatment, neutron absorbed doses per therapeutic dose of 63μGyGy(-1) and 149μGyGy(-1) were found at the heart for the SUP and the RLAT fields, respectively. This dose discrepancy was explained by the different patient's orientations leading to changes in the distance between organs and the final collimator where external neutrons are mainly produced. Moreover, investigations on neutron spectral fluence at the heart showed that the number of neutrons was 2.5times higher for the RLAT field compared against the SUP field. Finally, the influence of some irradiation parameters on neutron doses was found to be different according to the beam incidence. Beam incidence was thus found to induce large variations in stray neutron doses, proving that this parameter could be optimized to enhance the radiation protection of the patient. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  17. Report of final results regarding brain and heart tumors in Sprague-Dawley rats exposed from prenatal life until natural death to mobile phone radiofrequency field representative of a 1.8 GHz GSM base station environmental emission.

    PubMed

    Falcioni, L; Bua, L; Tibaldi, E; Lauriola, M; De Angelis, L; Gnudi, F; Mandrioli, D; Manservigi, M; Manservisi, F; Manzoli, I; Menghetti, I; Montella, R; Panzacchi, S; Sgargi, D; Strollo, V; Vornoli, A; Belpoggi, F

    2018-08-01

    In 2011, IARC classified radiofrequency radiation (RFR) as possible human carcinogen (Group 2B). According to IARC, animals studies, as well as epidemiological ones, showed limited evidence of carcinogenicity. In 2016, the NTP published the first results of its long-term bioassays on near field RFR, reporting increased incidence of malignant glial tumors of the brain and heart Schwannoma in rats exposed to GSM - and CDMA - modulated cell phone RFR. The tumors observed in the NTP study are of the type similar to the ones observed in some epidemiological studies of cell phone users. The Ramazzini Institute (RI) performed a life-span carcinogenic study on Sprague-Dawley rats to evaluate the carcinogenic effects of RFR in the situation of far field, reproducing the environmental exposure to RFR generated by 1.8 GHz GSM antenna of the radio base stations of mobile phone. This is the largest long-term study ever performed in rats on the health effects of RFR, including 2448 animals. In this article, we reported the final results regarding brain and heart tumors. Male and female Sprague-Dawley rats were exposed from prenatal life until natural death to a 1.8 GHz GSM far field of 0, 5, 25, 50 V/m with a whole-body exposure for 19 h/day. A statistically significant increase in the incidence of heart Schwannomas was observed in treated male rats at the highest dose (50 V/m). Furthermore, an increase in the incidence of heart Schwann cells hyperplasia was observed in treated male and female rats at the highest dose (50 V/m), although this was not statistically significant. An increase in the incidence of malignant glial tumors was observed in treated female rats at the highest dose (50 V/m), although not statistically significant. The RI findings on far field exposure to RFR are consistent with and reinforce the results of the NTP study on near field exposure, as both reported an increase in the incidence of tumors of the brain and heart in RFR-exposed Sprague-Dawley rats. These tumors are of the same histotype of those observed in some epidemiological studies on cell phone users. These experimental studies provide sufficient evidence to call for the re-evaluation of IARC conclusions regarding the carcinogenic potential of RFR in humans. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Final height in elite male artistic gymnasts.

    PubMed

    Georgopoulos, Neoklis A; Theodoropoulou, Anastasia; Roupas, Nikolaos D; Armeni, Anastasia K; Koukkou, Eftychia; Leglise, Michel; Markou, Kostas B

    2012-01-01

    Elite male artistic gymnasts (AG) are exposed to high levels of physical and psychological stress during adolescence and experience a significant late maturation in both linear growth and pubertal development. The aim of the present study was to determine the impact of intensive physical training on the adult final height in elite male AG. This study is unique in character, as all variables were measured on the field of competition. The study was prospective and longitudinal; however, the current analysis of data is cross-sectional. Data from 86 elite male AG were obtained during the gymnastics competitions of European and World Championships. Clinical evaluation included height and weight measurements, as well as assessment of pubic hair and genital development according to Tanner's stages of pubertal development. The laboratory investigation included determination of skeletal maturation. All athletes completed a questionnaire that included questions on personal (onset and intensity of training, number of competitions per year) and family data (paternal and maternal heights). Male AG were below the 50th percentile for both final height and weight. Elite male AG had final height standard deviation score (SDS) lower than their genetic predisposition. Final height SDS was correlated positively with target height SDS (r = 0.430, p < 0.001) and weight SDS (r = 0.477, p < 0.001) and negatively to the intensity of training (r = -0.252, p = 0.022). The main factors influencing final height, by multiple regression analysis were weight SDS (p < 0.001) and target height SDS (p = 0.003). In elite maleAG, final height falls short of genetic predisposition, still well within normal limits. Considering medical and psychological risks in general, and based on the results of this research project, the International Federation of Gymnastics has increased the age limit for participants in international gymnastics competitions by 1 year.

  19. 76 FR 28664 - Method 301-Field Validation of Pollutant Measurement Methods From Various Waste Media

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 63 [OAR-2004-0080, FRL-9306-8] RIN 2060-AF00 Method 301--Field Validation of Pollutant Measurement Methods From Various Waste Media AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This action amends EPA's Method 301, Field Validation...

  20. Final Report on the Airborne Field Mill Project (ABFM) 2000-2001 Field Campaign

    NASA Technical Reports Server (NTRS)

    Dye, James E.; Lewis, Sharon; Bateman, Monte, G.; Mach, Douglas M.; Merceret, Francis J.; Ward, Jennifer G.; Grainger, Cedric A.

    2004-01-01

    The Airborne Field Mill (ABFM) research program conducted under the direction of the John F. Kennedy Space Center during 2000 and 2001 is described. The purpose, methodology and initial results from the program are presented. Extensive appendices detailing the instrumentation used to collect the data are provided.

  1. Multibar sawless lint cleaner: fiber quality analysis after 3rd year of field testing

    USDA-ARS?s Scientific Manuscript database

    After two years of field testing a prototype spiked-tooth lint cleaner, the Multibar Sawless Lint Cleaner (MBSLC), a final year of field evaluation was conducted at commercial cotton gin in West Texas located approximately 30 miles Southwest of Lubbock, Texas.The cotton lint cleaner was tested in a ...

  2. Folding Digital Mapping into a Traditional Field Camp Program

    NASA Astrophysics Data System (ADS)

    Kelley, D. F.

    2011-12-01

    Louisiana State University runs a field camp with a permanent fixed-base which has continually operated since 1928 in the Front Range just to the south of Colorado Springs, CO. The field camp program which offers a 6-credit hour course in Field Geology follows a very traditional structure. The first week is spent collecting data for the construction of a detailed stratigraphic column of the local geology. The second week is spent learning the skills of geologic mapping, while the third applies these skills to a more geologically complicated mapping area. The final three weeks of the field camp program are spent studying and mapping igneous and metamorphic rocks as well as conducting a regional stratigraphic correlation exercise. Historically there has been a lack of technology involved in this program. All mapping has been done in the field without the use of any digital equipment and all products have been made in the office without the use of computers. In the summer of 2011 the use of GPS units, and GIS software were introduced to the program. The exercise that was chosen for this incorporation of technology was one in which metamorphic rocks are mapped within Golden Gate Canyon State Park in Colorado. This same mapping exercise was carried out during the 2010 field camp session with no GPS or GIS use. The students in both groups had the similar geologic backgrounds, similar grade point averages, and similar overall performances at field camp. However, the group that used digital mapping techniques mapped the field area more quickly and reportedly with greater ease. Additionally, the students who used GPS and GIS included more detailed rock descriptions with their final maps indicating that they spent less time in the field focusing on mapping contacts between units. The outcome was a better overall product. The use of GPS units also indirectly caused the students to produce better field maps. In addition to greater ease in mapping, the use of GIS software to create maps was rewarding to the students and gave them mapping experience that is in line with industry standards.

  3. Field Emission Cold Cathode Devices Based on Eutectic Systems

    DTIC Science & Technology

    1981-07-01

    8217RADC-TR-811-170 ’,Final Technical Report July 1981 FIELD EMISSION COLD CATHODE DEVICES BASED ON EUTECTIC SYSTEMS Fulmer Research Institute Ltd...and identify by block numrber) Field Emission Eutectic Systems Cold Cathode Rod Eutectics Electron Emitter Array Directionally Solidified Eutectics...Identify by block number) A survey has been made of the performance as field emission cold cathodes of selected refractory materials fabricated as

  4. A Competency Based, Field Centered, Systems Approach to Elementary Teacher Education. Volume I: Overview and Specifications. Final Report.

    ERIC Educational Resources Information Center

    Schalock, H. Del, Ed.; Hale, James R., Ed.

    This main volume (SP 002 155-SP 002 180 comprise the appendixes to this volume) explains the ComField (competency based, field centered) Model--a systems approach to the education of elementary school teachers which entails specifications (1) for instruction and (2) for management of the instructional program. In an overview, the ComField Model is…

  5. Study on a liquid-moderator-based neutron spectrometer for BNCT-Development and experimental test of the prototype spectrometer

    NASA Astrophysics Data System (ADS)

    Tamaki, S.; Sato, F.; Murata, I.

    2017-10-01

    Boron neutron capture therapy (BNCT) is known to be an effective radiation cancer therapy that requires neutron irradiation. A neutron field generated by an accelerator-based neutron source has various energy spectra, and it is necessary to evaluate the neutron spectrum in the treatment field. However, the method used to measure the neutron spectrum in the treatment field is not well established, and many researchers are making efforts to improve the spectrometers used. In the present study, we developed a prototype of a new neutron spectrometer that can measure the neutron spectra more accurately and precisely. The spectrometer is based on the same theory as that of the Bonner sphere spectrometer, and it uses a liquid moderator and an absorber. By carrying out an experimental test of the developed spectrometer, we finally revealed the problems and necessary conditions of the prototype detector.

  6. The study of stereo vision technique for the autonomous vehicle

    NASA Astrophysics Data System (ADS)

    Li, Pei; Wang, Xi; Wang, Jiang-feng

    2015-08-01

    The stereo vision technology by two or more cameras could recovery 3D information of the field of view. This technology can effectively help the autonomous navigation system of unmanned vehicle to judge the pavement conditions within the field of view, and to measure the obstacles on the road. In this paper, the stereo vision technology in measuring the avoidance of the autonomous vehicle is studied and the key techniques are analyzed and discussed. The system hardware of the system is built and the software is debugged, and finally the measurement effect is explained by the measured data. Experiments show that the 3D reconstruction, within the field of view, can be rebuilt by the stereo vision technology effectively, and provide the basis for pavement condition judgment. Compared with unmanned vehicle navigation radar used in measuring system, the stereo vision system has the advantages of low cost, distance and so on, it has a good application prospect.

  7. Studies on in situ magnetic alignment of bonded anisotropic Nd-Fe-B alloy powders

    DOE PAGES

    Nlebedim, I. C.; Ucar, Huseyin; Hatter, Christine B.; ...

    2016-08-30

    We presented some considerations for achieving high degree of alignment in polymer bonded permanent magnets via the results of a study on in situ magnetic alignment of anisotropic Nd-Fe-B magnet powders. Contributions from effect of the alignment temperature, alignment magnetic field and the properties of the polymer on the hard magnetic properties of the bonded magnet were considered. Moreover, the thermo-rheological properties of the polymer and the response of the magnet powders to the applied magnetic field indicate that hard magnetic properties were optimized at an alignment temperature just above the melting temperature of the EVA co-polymer. This agrees withmore » an observed correlation between the change in magnetization due to improved magnetic alignment of the anisotropic powders and the change in viscosity of the binder. Finally, manufacturing cost can be minimized by identifying optimum alignment temperatures and magnetic field strengths.« less

  8. Astrophysically Relevant Dipole Studies at WiPAL

    NASA Astrophysics Data System (ADS)

    Endrizzi, Douglass; Forest, Cary; Wallace, John; WiPAL Team

    2015-11-01

    A novel terrella experiment is being developed to immerse a dipole magnetic field in the large, unmagnetized, and fully ionized background plasma of WiPAL (Wisconsin Plasma Astrophysics Lab). This allows for a series of related experiments motivated by astrophysical processes, including (1) inward transport of plasma into a magnetosphere with focus on development of Kelvin-Helmholtz instabilities from boundary shear flow; (2) helicity injection and simulation of solar eruptive events via electrical breakdown along dipole field lines; (3) interaction of Coronal Mass Ejection-like flows with a target magnetosphere and dependence on background plasma pressure; (4) production of a centrifugally driven wind to study how dipolar magnetic topology changes as closed field lines open. A prototype has been developed and preliminary results will be presented. An overview of the final design and construction progress will be given. This material is based upon work supported by the NSF Graduate Research Fellowship Program.

  9. Comparative Theoretical Analysis Between Parallel and Perpendicular Geomotries for 2D Particle Patterning in Photovoltaic Ferroelectric Substrates

    NASA Astrophysics Data System (ADS)

    Arregui, C.; Ramiro, J. B.; Alcázar, A.; Méndez, A.; Muñoz-Martínez, J. F.; Carrascosa, M.

    2015-05-01

    This paper describes the dielectrophoretic potential created by the evanescent electric field acting on a particle near a photovoltaic crystalsurface depending on the crystal cut. This electric field is obtained from the steady state solution of the Kukhtarev equations for thephotovoltaic effect, where the diffusion term has been disregarded. First, the space charge field generated by a small, square, light spotwhere d << l (being d a side of the square and l the crystal thickness) is studied. The surface charge density generated in both geometriesis calculated and compared as their relation determines the different properties of the dielectrophoretic potential for both cuts. The shapeof the dielectrophoretic potential is obtained and compared for several distances to the sample. Afterwards other light patterns are studiedby the superposition of square spots, and the resulting trapping profiles are analysed. Finally the surface charge densities and trappingprofiles for different d/l relations are studied.

  10. Construction and Application of a Terahertz Scanning Near-Field Microscope for Study of Correlated Electron Materials at Cryogenic Temperatures and Nanometer Length Scales

    NASA Astrophysics Data System (ADS)

    Stinson, Harry Theodore, III

    This dissertation describes the design and construction of the world's first cryogenic apertureless near-field microscope designed for terahertz sources and detectors. I first provide motivation for the creation of this instrument in the context of spectroscopy of correlated electron materials, and background information on the two techniques that the instrument combines, scanning near-field optical microscopy and terahertz time-domain spectroscopy. I then detail key components of the instrument design, including proof-of-principle results obtained at room and cryogenic temperatures. Following this, I discuss an imaging experiment performed with this instrument on vanadium dioxide, an insulator-metal transition material, which sheds new light on the nature of the phase transition and provides support for a new model Hamiltonian for the system. Finally, I discuss a theoretical proposal for the study of cuprate superconductors using this instrument.

  11. Short range ferromagnetic, magneto-electric, and magneto-dielectric effect in ceramic Co{sub 3}TeO{sub 6}

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

    Singh, Harishchandra, E-mail: singh85harish@gmail.com, E-mail: singh85harish@rrcat.gov.in; Ghosh, Haranath; Indus Synchrotrons Utilization Division, Raja Ramanna Center for Advanced Technology, Indore 452013

    2016-01-28

    We report observation of magneto-electric and magneto-dielectric couplings along with short range ferromagnetic order in ceramic Cobalt Tellurate (Co{sub 3}TeO{sub 6}, CTO) using magnetic, structural, dielectric, pyroelectric, and polarization studies. DC magnetization along with dielectric constant measurements indicate a coupling between magnetic order and electrical polarization. A strong anomaly in the dielectric constant at ∼17.4 K in zero magnetic field indicates spontaneous electric polarization, consistent with a recent neutron diffraction study. Observation of weak short range ferromagnetic order at lower temperatures is attributed to the Griffiths-like ferromagnetism. Furthermore, magnetic field dependence of the ferroelectric transition follows earlier theoretical predictions, applicable tomore » single crystal CTO. Finally, combined dielectric, pyroelectric, and polarization measurements suggest that the ground state of CTO may possess spontaneous symmetry breaking in the absence of magnetic field.« less

  12. Uncertainty quantification of environmental performance metrics in heterogeneous aquifers with long-range correlations

    NASA Astrophysics Data System (ADS)

    Moslehi, Mahsa; de Barros, Felipe P. J.

    2017-01-01

    We investigate how the uncertainty stemming from disordered porous media that display long-range correlation in the hydraulic conductivity (K) field propagates to predictions of environmental performance metrics (EPMs). In this study, the EPMs are quantities that are of relevance to risk analysis and remediation, such as peak flux-averaged concentration, early and late arrival times among others. By using stochastic simulations, we quantify the uncertainty associated with the EPMs for a given disordered spatial structure of the K-field and identify the probability distribution function (PDF) model that best captures the statistics of the EPMs of interest. Results indicate that the probabilistic distribution of the EPMs considered in this study follows lognormal PDF. Finally, through the use of information theory, we reveal how the persistent/anti-persistent correlation structure of the K-field influences the EPMs and corresponding uncertainties.

  13. Canted-Cosine-Theta Superconducting Accelerator Magnets for High Energy Physics and Ion Beam Cancer Therapy

    NASA Astrophysics Data System (ADS)

    Brouwer, Lucas Nathan

    Advances in superconducting magnet technology have historically enabled the construction of new, higher energy hadron colliders. Looking forward to the needs of a potential future collider, a significant increase in magnet field and performance is required. Such a task requires an open mind to the investigation of new design concepts for high field magnets. Part I of this thesis will present an investigation of the Canted-Cosine-Theta (CCT) design for high field Nb3Sn magnets. New analytic and finite element methods for analysis of CCT magnets will be given, along with a discussion on optimization of the design for high field. The design, fabrication, and successful test of the 2.5 T NbTi dipole CCT1 will be presented as a proof-of-principle step towards a high field Nb3Sn magnet. Finally, the design and initial steps in the fabrication of the 16 T Nb3Sn dipole CCT2 will be described. Part II of this thesis will investigate the CCT concept extended to a curved magnet for use in an ion beam therapy gantry. The introduction of superconducting technology in this field shows promise to reduce the weight and cost of gantries, as well as open the door to new beam optics solutions with high energy acceptance. An analytic approach developed for modeling curved CCT magnets will be presented, followed by a design study of a superconducting magnet for a proton therapy gantry. Finally, a new magnet concept called the "Alternating Gradient CCT" (AG-CCT) will be introduced. This concept will be shown to be a practical magnet solution for achieving the alternating quadrupole fields desired for an achromatic gantry, allowing for the consideration of treatment with minimal field changes in the superconducting magnets. The primary motivation of this thesis is to share new developments for Canted-Cosine-Theta superconducting magnets, with the hope this design will improve technology for high energy physics and ion beam cancer therapy.

  14. Field evaluation of skid resistant surfaces : final report : part I.

    DOT National Transportation Integrated Search

    1970-06-01

    This project was undertaken to establish a thin bituminous surface course that would possess good skid resistant qualities as well as, being both economical and durable. : This is the final report on the evaluation of skid resistant surfaces which wa...

  15. Competency-Based Curriculum for Articulated Programs in Nursing Occupations. A Study for the Articulation of Competency-Based Curricula for the Coordination of Vocational-Technical Education Programs in Louisiana. Final Report. Volume V.

    ERIC Educational Resources Information Center

    Louisiana State Dept. of Education, Baton Rouge. Div. of Vocational Education.

    The curriculum guide for nursing occupations is one of five guides written and field tested in a project to develop statewide articulated competency-based curricula in selected vocational education programs. Following an introductory section giving the philosophy, background, and recommendations for nursing education, the 82 study units are…

  16. Computerizing Audit Studies

    PubMed Central

    Lahey, Joanna N.; Beasley, Ryan A.

    2014-01-01

    This paper briefly discusses the history, benefits, and shortcomings of traditional audit field experiments to study market discrimination. Specifically it identifies template bias and experimenter bias as major concerns in the traditional audit method, and demonstrates through an empirical example that computerization of a resume or correspondence audit can efficiently increase sample size and greatly mitigate these concerns. Finally, it presents a useful meta-tool that future researchers can use to create their own resume audits. PMID:24904189

  17. Field trial of solvent-free emulsion in Oregon : appendices.

    DOT National Transportation Integrated Search

    2003-03-01

    This final report summarizes construction, laboratory and performance information gathered by ODOT personnel from a single field trial of solvent-free emulsion mix constructed in June 2001. The solvent-free emulsion mix presented several placement pr...

  18. Marine Geology and Geophysics Field Course Offered by The University of Texas Institute for Geophysics

    NASA Astrophysics Data System (ADS)

    Duncan, D.; Davis, M. B.; Allison, M. A.; Gulick, S. P.; Goff, J. A.; Saustrup, S.

    2012-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers an intensive three-week marine geology and geophysics field course during the spring-summer intersession. Now in year six, the course provides hands-on instruction and training for graduate and upper-level undergraduate students in data acquisition, processing, interpretation, and visualization. Techniques covered include high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples (e.g., core description, grain size analysis, x-radiography, etc.). Students participate in an initial period of classroom instruction designed to communicate geological context of the field area (which changes each year) along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. Our field sites at Port Aransas and Galveston, Texas, and Grand Isle, Louisiana, have provided ideal locations for students to investigate coastal and sedimentary processes of the Gulf Coast and continental shelf through application of geophysical techniques. In the field, students rotate between two research vessels: one vessel, the 22' aluminum-hulled R/V Lake Itasca, owned and operated by UTIG, is used principally for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA's R/V Manta or the R/V Acadiana, operated by the Louisiana Universities Marine Consortium, and is used primarily for high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, gravity coring, and vibrocoring. While at sea, students assist with survey design, learn instrumentation set up, acquisition parameters, data quality control, and safe instrument deployment and retrieval. In teams of three, students work in onshore field labs preparing sediment samples for particle size analysis and initial post-processing of geophysical data. During the course's final week, teams return to the classroom where they integrate, interpret, and visualize data in a final project using industry-standard software such as Focus, Landmark, Caris, and Fledermaus. The course concludes with a series of professional-level final presentations and discussions with academic and industry supporters in which students examine the geologic history and sedimentary processes of the studied area of the Gulf Coast continental shelf. After completion, students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and low instructor to student ratio (12 students, three faculty, and three teaching assistants). This course satisfies field experience requirements for some degree programs and thus provides a unique alternative to land-based field courses.

  19. Magnetic inhibition of convection and the fundamental properties of low-mass stars. I. Stars with a radiative core

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

    Feiden, Gregory A.; Chaboyer, Brian, E-mail: gregory.a.feiden.gr@dartmouth.edu, E-mail: brian.chaboyer@dartmouth.edu

    2013-12-20

    Magnetic fields are hypothesized to inflate the radii of low-mass stars—defined as less massive than 0.8 M {sub ☉}—in detached eclipsing binaries (DEBs). We investigate this hypothesis using the recently introduced magnetic Dartmouth stellar evolution code. In particular, we focus on stars thought to have a radiative core and convective outer envelope by studying in detail three individual DEBs: UV Psc, YY Gem, and CU Cnc. Our results suggest that the stabilization of thermal convection by a magnetic field is a plausible explanation for the observed model-radius discrepancies. However, surface magnetic field strengths required by the models are significantly strongermore » than those estimated from observed coronal X-ray emission. Agreement between model predicted surface magnetic field strengths and those inferred from X-ray observations can be found by assuming that the magnetic field sources its energy from convection. This approach makes the transport of heat by convection less efficient and is akin to reduced convective mixing length methods used in other studies. Predictions for the metallicity and magnetic field strengths of the aforementioned systems are reported. We also develop an expression relating a reduction in the convective mixing length to a magnetic field strength in units of the equipartition value. Our results are compared with those from previous investigations to incorporate magnetic fields to explain the low-mass DEB radius inflation. Finally, we explore how the effects of magnetic fields might affect mass determinations using asteroseismic data and the implication of magnetic fields on exoplanet studies.« less

  20. The Width of a Solar Coronal Mass Ejection and the Source of the Driving Magnetic Explosion

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.; Suess, Steven T.

    2007-01-01

    We show that the strength of the magnetic field in the area covered by the flare arcade following a CME-producing ejective solar eruption can be estimated from the final angular width of the CME in the outer corona and the final angular width of the flare arcade. We assume (1) the flux-rope plasmoid ejected from the flare site becomes the interior of the CME plasmoid, (2) in the outer corona (R greater than 2R(sub Sun)) the CME is roughly a spherical plasmoid with legs shaped like a light bulb, and (3) beyond some height in or below the outer corona the CME plasmoid is in lateral pressure balance with the surrounding magnetic field. The strength of the nearly radial magnetic field in the outer corona is estimated from the radial component of the interplanetary magnetic field measured by Ulysses. We apply this model to three well-observed CMEs that exploded from flare regions of extremely different size and magnetic setting. One of these CMEs is an over-and-out CME that exploded from a laterally far offset compact ejective flare. In each event, the estimated source-region field strength is appropriate for the magnetic setting of the flare. This agreement (1) indicates that CMEs are propelled by the magnetic field of the CME plasmoid pushing against the surrounding magnetic field, (2) supports the magnetic-arch-blowout scenario for over-and-out CMEs, and (3) shows that a CME s final angular width in the outer corona can be estimated from the amount of magnetic flux covered by the source-region flare arcade.

  1. Magnetic field dependent dynamics and field-driven metal-to-insulator transition of the half-filled Hubbard model: A DMFT+DMRG study

    DOE PAGES

    Zhu, Wei; Sheng, D. N.; Zhu, Jian -Xin

    2017-08-14

    Here, we study the magnetic field-driven metal-to-insulator transition in half-filled Hubbard model on the Bethe lattice, using the dynamical mean-field theory by solving the quantum impurity problem with density-matrix renormalization group algorithm. The method enables us to obtain a high-resolution spectral densities in the presence of a magnetic field. It is found that the Kondo resonance at the Fermi level splits at relatively high magnetic field: the spin-up and -down components move away from the Fermi level and finally form a spin-polarized band insulator. By calculating the magnetization and spin susceptibility, we clarify that an applied magnetic field drives amore » transition from a paramagnetic metallic phase to a band insulating phase. In the weak interaction regime, the nature of the transition is continuous and captured by the Stoner's description, while in the strong interaction regime the transition is very likely to be metamagnetic, evidenced by the hysteresis curve. Furthermore, we determine the phase boundary by tracking the kink in the magnetic susceptibility, and the steplike change of the entanglement entropy and the entanglement gap closing. Interestingly, the phase boundaries determined from these two different ways are largely consistent with each other.« less

  2. Magnetic field dependent dynamics and field-driven metal-to-insulator transition of the half-filled Hubbard model: A DMFT+DMRG study

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

    Zhu, Wei; Sheng, D. N.; Zhu, Jian -Xin

    Here, we study the magnetic field-driven metal-to-insulator transition in half-filled Hubbard model on the Bethe lattice, using the dynamical mean-field theory by solving the quantum impurity problem with density-matrix renormalization group algorithm. The method enables us to obtain a high-resolution spectral densities in the presence of a magnetic field. It is found that the Kondo resonance at the Fermi level splits at relatively high magnetic field: the spin-up and -down components move away from the Fermi level and finally form a spin-polarized band insulator. By calculating the magnetization and spin susceptibility, we clarify that an applied magnetic field drives amore » transition from a paramagnetic metallic phase to a band insulating phase. In the weak interaction regime, the nature of the transition is continuous and captured by the Stoner's description, while in the strong interaction regime the transition is very likely to be metamagnetic, evidenced by the hysteresis curve. Furthermore, we determine the phase boundary by tracking the kink in the magnetic susceptibility, and the steplike change of the entanglement entropy and the entanglement gap closing. Interestingly, the phase boundaries determined from these two different ways are largely consistent with each other.« less

  3. Development of Guidelines and Resource Materials on Latin America for Use in Grades 1-12. Final Report.

    ERIC Educational Resources Information Center

    Gill, Clark C.; Conroy, William B.

    The Latin America Project (1966-69) consisted of two phases: (1) completion of background studies and (2) preparation, field testing, and evaluation of instructional materials. Five background bulletins were prepared and distributed (See ED 012 832, ED 012 833, ED 012 365, ED 013 342, ED 022 781) and instructional materials organized around…

  4. Design of a Model Management Information System (MIS) for California's Regional Occupational Centers and Programs. Final Report.

    ERIC Educational Resources Information Center

    Dick, James C.; And Others

    The management information system (MIS) development project for California's Regional Occupational Centers and Programs (ROC/Ps) was conducted in 3 phases over a 12-month period. Phase I involved a literature review and field study to match MIS design features and development strategy with existing conditions in ROC/Ps. A decision support system…

  5. A Memory-Process Model of Symbolic Assimilation

    DTIC Science & Technology

    1974-04-01

    Systems: Final Report of a Study Group, published for Artificial Intellegence by North-Holland/Amorican...contribution of the methods is answered by evaluating the same program in the context of the field of artificial intelligence. The remainder of the...been widely demonstrated on a diversity of tasks in tha history of artificial intelligence. See [r.71], chapter 2. Given a particular task to be

  6. Becoming Teachers: Examining How Preservice Elementary Teachers Use Language to Construct Professional Identities, Learn within Relationships, and Take Risks in the Classroom

    ERIC Educational Resources Information Center

    Ticknor, Anne Swenson

    2010-01-01

    This longitudinal qualitative study examined how four preservice elementary teachers used language to construct professional identities, learn within relationships, and take risks in the classroom during their final three semesters in teacher education coursework and field experiences. My female participants were former students of mine in the…

  7. Evaluation of the National Science Foundation's Integrative Graduate Education and Research Traineeship Program (IGERT): Follow-Up Study of IGERT Graduates. Final Report

    ERIC Educational Resources Information Center

    Carney, Jennifer; Martinez, Alina; Dreier, John; Neishi, Kristen; Parsad, Amanda

    2011-01-01

    The National Science Foundation's Integrative Graduate Education and Research Traineeship (IGERT) program supports students in science, technology, engineering, and mathematics (STEM) fields who participate in university-developed interdisciplinary graduate training experiences. Faculty members at each IGERT site develop a series of education…

  8. Planning the Development of Measurement and Evaluation Services for Use in Occupational Programs at Postsecondary Institutions. Final Report.

    ERIC Educational Resources Information Center

    Sharon, Amiel T.; And Others

    The purpose of this study was to obtain information that will make it possible to plan for the development of occupational competency assessment procedures in a rational manner, based on the expressed needs of occupational educators and employers. Eight fields were selected for scrutiny: Accounting, Agribusiness, Data Processing, Day Care,…

  9. Scientific and Technical Manpower Requirements of Selected Segments of the Atomic Energy Field. Final Report.

    ERIC Educational Resources Information Center

    Voight, Keith L.

    The primary purpose of the study was to develop a supply/demand ratio for nuclear degree scientists and engineers from July 1969 through 1973. The need by private industry and electric utilities for scientists and engineers with degrees in disciplines other than nuclear science or engineering, as well as for technicians, nuclear reactor operators,…

  10. A periodic table for black hole orbits

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

    Levin, Janna; Institute for Strings, Cosmology and Astroparticle Physics, Columbia University, New York, New York 10027; Perez-Giz, Gabe

    2008-05-15

    Understanding the dynamics around rotating black holes is imperative to the success of future gravitational wave observatories. Although integrable in principle, test-particle orbits in the Kerr spacetime can also be elaborate, and while they have been studied extensively, classifying their general properties has been a challenge. This is the first in a series of papers that adopts a dynamical systems approach to the study of Kerr orbits, beginning with equatorial orbits. We define a taxonomy of orbits that hinges on a correspondence between periodic orbits and rational numbers. The taxonomy defines the entire dynamics, including aperiodic motion, since every orbitmore » is in or near the periodic set. A remarkable implication of this periodic orbit taxonomy is that the simple precessing ellipse familiar from planetary orbits is not allowed in the strong-field regime. Instead, eccentric orbits trace out precessions of multileaf clovers in the final stages of inspiral. Furthermore, for any black hole, there is some point in the strong-field regime past which zoom-whirl behavior becomes unavoidable. Finally, we sketch the potential application of the taxonomy to problems of astrophysical interest, in particular its utility for computationally intensive gravitational wave calculations.« less

  11. Characterization of oil and gas reservoir heterogeneity; Final report, November 1, 1989--June 30, 1993

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

    Sharma, G.D.

    1993-09-01

    The Alaskan North Slope comprises one of the Nation`s and the world`s most prolific oil province. Original oil in place (OOIP) is estimated at nearly 70 BBL (Kamath and Sharma, 1986). Generalized reservoir descriptions have been completed by the University of Alaska`s Petroleum Development Laboratory over North Slope`s major fields. These fields include West Sak (20 BBL OOIP), Ugnu (15 BBL OOIP), Prudhoe Bay (23 BBL OOIP), Kuparuk (5.5 BBL OOIP), Milne Point (3 BBL OOIP), and Endicott (1 BBL OOIP). Reservoir description has included the acquisition of open hole log data from the Alaska Oil and Gas Conservation Commissionmore » (AOGCC), computerized well log analysis using state-of-the-art computers, and integration of geologic and logging data. The studies pertaining to fluid characterization described in this report include: experimental study of asphaltene precipitation for enriched gases, CO{sup 2} and West Sak crude system, modeling of asphaltene equilibria including homogeneous as well as polydispersed thermodynamic models, effect of asphaltene deposition on rock-fluid properties, fluid properties of some Alaskan north slope reservoirs. Finally, the last chapter summarizes the reservoir heterogeneity classification system for TORIS and TORIS database.« less

  12. Wilson Prize Talk

    NASA Astrophysics Data System (ADS)

    Symon, Keith R.

    2005-04-01

    In the late 1950's and the 1960's the MURA (Midwestern Universities Research Association) working group developed fixed field alternating gradient (FFAG) particle accelerators. FFAG accelerators are a natural corollary of the invention of alternating gradient focusing. The fixed guide field accommodates all orbits from the injection to the final energy. For this reason, the transverse motion in the guide field is nearly decoupled from the longitudinal acceleration. This allows a wide variety of acceleration schemes, using betatron or rf accelerating fields, beam stacking, bucket lifts, phase displacement, etc. It also simplifies theoretical and experimental studies of accelerators. Theoretical studies included an extensive analysis of rf acceleration processes, nonlinear orbit dynamics, and collective instabilities. Two FFAG designs, radial sector and spiral sector, were invented. The MURA team built small electron models of each type, and used them to study orbit dynamics, acceleration processes, orbit instabilities, and space charge limits. A practical result of these studies was the invention of the spiral sector cyclotron. Another was beam stacking, which led to the first practical way of achieving colliding beams. A 50 MeV two-way radial sector model was built in which it proved possible to stack a beam of over 10 amperes of electrons.

  13. The 3D Kasteleyn transition in dipolar spin ice: a numerical study with the conserved monopoles algorithm

    NASA Astrophysics Data System (ADS)

    Baez, M. L.; Borzi, R. A.

    2017-02-01

    We study the three-dimensional Kasteleyn transition in both nearest neighbours and dipolar spin ice models using an algorithm that conserves the number of excitations. We first limit the interactions range to nearest neighbours to test the method in the presence of a field applied along ≤ft[1 0 0\\right] , and then focus on the dipolar spin ice model. The effect of dipolar interactions, which is known to be greatly self screened at zero field, is particularly strong near full polarization. It shifts the Kasteleyn transition to lower temperatures, which decreases  ≈0.4 K for the parameters corresponding to the best known spin ice materials, \\text{D}{{\\text{y}}2}\\text{T}{{\\text{i}}2}{{\\text{O}}7} and \\text{H}{{\\text{o}}2}\\text{T}{{\\text{i}}2}{{\\text{O}}7} . This shift implies effective dipolar fields as big as 0.05 T opposing the applied field, and thus favouring the creation of ‘strings’ of reversed spins. We compare the reduction in the transition temperature with results in previous experiments, and study the phenomenon quantitatively using a simple molecular field approach. Finally, we relate the presence of the effective residual field to the appearance of string-ordered phases at low fields and temperatures, and we check numerically that for fields applied along ≤ft[1 0 0\\right] there are only three different stable phases at zero temperature.

  14. Comparison of the effectiveness of real and virtual field trips in biology and ecology classes in lower secondary school based on the example of the Maribor island natural educational trail

    NASA Astrophysics Data System (ADS)

    Puhek, Miro

    The present doctoral thesis presents a case study within the scope of which real and virtual field trips have been compared. The emphasis of the study was on determining the levels of knowledge gain effectiveness in the fields of biology and ecology in the final triad (third) of lower secondary school education. The analysis included students completing various tasks along the Maribor Island natural education trail, which had been digitized and inserted into Geopedia. The study was conducted in autumn of 2011 and included 464 students (enrolled in grades from 6 to 9) from 11 lower secondary schools located in the Maribor area. The results have generally shown minute differences between the levels of knowledge acquisition effectiveness between both field trips. During the real field trip, the majority of the students included in the study achieved better results particularly at tasks where they were able to benefit from first-hand experience. During the virtual field trip, individual students were more successful at tasks where they were allowed to access a computer in order to obtain additional information. Within the scope of the study, we had also surveyed lower secondary and secondary school teachers on the frequency of including field trips in the curriculum, on the obstacles that the teachers faced with regard to including field work in it, and on their views on real and virtual field trips. The survey included a total of 386 teachers, the majority whom were teaching the subjects of biology, geography, and natural science. The results have shown that the surveyed teachers regard field trips as a very important educational method that particularly encourages experience-based learning in nature. The views of the teachers on virtual field trips were generally positive, but only when regarded and applied as a supplemental teaching tool and not as a substitute for real field trips.

  15. The impact of the Morgantown power plant on the Potomac estuary: an interpretive summary of the 1972-1973 investigations. Final interpretive report

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

    Bongers, L.H.; Polgar, T.T.; Lippson, A.J.

    1975-12-01

    This report summarizes and interprets the findings of aquatic field studies conducted at PEPCO's Morgantown generating station. The purpose of this investigation was to determine if power plant operations would adversely affect the aquatic ecosystem of the Potomac River. The field studies, conducted in 1972 and 1973, include investigations of physical effects and of biological responses to heat, chlorination, and passage through the plants cooling system. Key cooling system operation characteristics were systematically varied while measurements were conducted. On the basis of these entrainment and site investigations, it was possible to arrive at value judgments on the significance of observedmore » plant effects. Both impingement and entrainment effects were considered in these studies.« less

  16. Alaska OCS social and economic studies program. Technical report Number 94. Diapir field Anchorage impacts analysis. Final technical report

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

    Not Available

    1984-03-01

    The purpose of the study is threefold: (1) to update earlier baseline descriptions of Anchorage region; (2) to revise the community impact-assessment methodology to be applied to the Anchorage region; and (3) to assess the community impacts on the Anchorage region through the year 2010 of a base-case growth forecast and of a scenario for production of 3.0 billion barrels of crude oil from the Diapir Field OCS Sale no.87. Some results of the study are that the Anchorage region, historically and currently, has demonstrated a very resilient capacity to accommodate rapid economic and population growth; and that State expendituremore » of petroleum revenues accounts for much of the region's recent growth.« less

  17. Analysis of magnetic field levels at KSC

    NASA Technical Reports Server (NTRS)

    Christodoulou, Christos G.

    1994-01-01

    The scope of this work is to evaluate the magnetic field levels of distribution systems and other equipment at Kennedy Space Center (KSC). Magnetic fields levels in several operational areas and various facilities are investigated. Three dimensional mappings and contour are provided along with the measured data. Furthermore, the portion of magnetic fields generated by the 60 Hz fundamental frequency and the portion generated by harmonics are examined. Finally, possible mitigation techniques for attenuating fields from electric panels are discussed.

  18. Thermalization of Wightman functions in AdS/CFT and quasinormal modes

    NASA Astrophysics Data System (ADS)

    Keränen, Ville; Kleinert, Philipp

    2016-07-01

    We study the time evolution of Wightman two-point functions of scalar fields in AdS3 -Vaidya, a spacetime undergoing gravitational collapse. In the boundary field theory, the collapse corresponds to a quench process where the dual 1 +1 -dimensional CFT is taken out of equilibrium and subsequently thermalizes. From the two-point function, we extract an effective occupation number in the boundary theory and study how it approaches the thermal Bose-Einstein distribution. We find that the Wightman functions, as well as the effective occupation numbers, thermalize with a rate set by the lowest quasinormal mode of the scalar field in the BTZ black hole background. We give a heuristic argument for the quasinormal decay, which is expected to apply to more general Vaidya spacetimes also in higher dimensions. This suggests a unified picture in which thermalization times of one- and two-point functions are determined by the lowest quasinormal mode. Finally, we study how these results compare to previous calculations of two-point functions based on the geodesic approximation.

  19. Effective Lesson Planning: Field Trips in the Science Curriculum

    NASA Astrophysics Data System (ADS)

    Rieger, C. R.

    2010-10-01

    Science field trips can positively impact and motivate students. However, if a field trip is not executed properly, with appropriate preparation and follow-up reinforcement, it can result in a loss of valuable educational time and promote misconceptions in the students. This study was undertaken to determine if a classroom lesson before an out-of-the-classroom activity would affect learner gain more or less than a lesson after the activity. The study was based on the immersive theater movie ``Earth's Wild Ride'' coupled with a teacher-led Power Point lesson. The participants in the study were students in a sixth grade physical science class. The order of lessons showed no detectable effect on final learner outcomes. Based on pre- and post-testing, improvement in mean learning gain came from the teacher-led lesson independent of the movie. The visit to the immersive theater, however, had significant positive effects that did not show up in the quantitative results of the testing.

  20. Advanced Electron Holography Applied to Electromagnetic Field Study in Materials Science.

    PubMed

    Shindo, Daisuke; Tanigaki, Toshiaki; Park, Hyun Soon

    2017-07-01

    Advances and applications of electron holography to the study of electromagnetic fields in various functional materials are presented. In particular, the development of split-illumination electron holography, which introduces a biprism in the illumination system of a holography electron microscope, enables highly accurate observations of electromagnetic fields and the expansion of the observable area. First, the charge distributions on insulating materials were studied by using split-illumination electron holography and including a mask in the illumination system. Second, the three-dimensional spin configurations of skyrmion lattices in a helimagnet were visualized by using a high-voltage holography electron microscope. Third, the pinning of the magnetic flux lines in a high-temperature superconductor YBa 2 Cu 3 O 7-y was analyzed by combining electron holography and scanning ion microscopy. Finally, the dynamic accumulation and collective motions of electrons around insulating biomaterial surfaces were observed by utilizing the amplitude reconstruction processes of electron holography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. SMART operational field test evaluation : dispatchers survey report : final report

    DOT National Transportation Integrated Search

    1997-06-01

    The Suburban Mobility Authority for Regional Transportation (SMART) has installed an automaticscheduling and dispatch system (ASD) in Southeast Michigan in accordance with their plans toimplement ITS as a site for an operational field test. The purpo...

  2. Bioethical and Other Philosophical Considerations in Positive Psychiatry

    PubMed Central

    Singh, Ajai R.; Singh, Shakuntala A.

    2016-01-01

    The paper begins by asserting the need for bioethical and related philosophical considerations in the emerging subspecialty Positive Psychiatry. Further discussion proceeds after offering operational definitions of the concepts fundamental to the field – Bioethics, Positive Psychology, Positive Psychiatry and Positive Mental Health - with their conceptual analysis to show their areas of connect and disconnect. It then studies the implications of positive and negative findings in the field, and presents the Positive Psychosocial Factors (PPSFs) like Resilience, Optimism, Personal Mastery, Wisdom, Religion/Spirituality, Social relationships and support, Engagement in pleasant events etc. It then evaluates them on the basis of the 4-principled bioethical model of Beneficence, Non-malfeasance, Autonomy and Justice (Beauchamp and Childress, 2009[5], 2013[6]), first offering a brief clarification of these principles and then their bioethical analysis based on the concepts of ‘Common Morality’, ‘Specific Morality’, ‘Specification’, ‘Balancing’ and ‘Double Effects’. The paper then looks into the further development of the branch by studying the connectivity, synergy and possible antagonism of the various Positive Psychosocial Factors, and presents technical terms in place of common terms so that they carry least baggage. It also takes note of the salient points of caution and alarm that many incisive analysts have presented about further development in the related field of Positive Mental Health. Finally, the paper looks at where, and how, the field is headed, and why, if at all, it is proper it is headed there, based on Aristotle's concept of the four causes - Material, Efficient, Formal and Final. Suitable case vignettes are presented all through the write-up to clarify concepts. PMID:28031624

  3. Impact of online visual feedback on motor acquisition and retention when learning to reach in a force field.

    PubMed

    Batcho, C S; Gagné, M; Bouyer, L J; Roy, J S; Mercier, C

    2016-11-19

    When subjects learn a novel motor task, several sources of feedback (proprioceptive, visual or auditory) contribute to the performance. Over the past few years, several studies have investigated the role of visual feedback in motor learning, yet evidence remains conflicting. The aim of this study was therefore to investigate the role of online visual feedback (VFb) on the acquisition and retention stages of motor learning associated with training in a reaching task. Thirty healthy subjects made ballistic reaching movements with their dominant arm toward two targets, on 2 consecutive days using a robotized exoskeleton (KINARM). They were randomly assigned to a group with (VFb) or without (NoVFb) VFb of index position during movement. On day 1, the task was performed before (baseline) and during the application of a velocity-dependent resistive force field (adaptation). To assess retention, participants repeated the task with the force field on day 2. Motor learning was characterized by: (1) the final endpoint error (movement accuracy) and (2) the initial angle (iANG) of deviation (motor planning). Even though both groups showed motor adaptation, the NoVFb-group exhibited slower learning and higher final endpoint error than the VFb-group. In some condition, subjects trained without visual feedback used more curved initial trajectories to anticipate for the perturbation. This observation suggests that learning to reach targets in a velocity-dependent resistive force field is possible even when feedback is limited. However, the absence of VFb leads to different strategies that were only apparent when reaching toward the most challenging target. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. The European DISABKIDS project: development of seven condition-specific modules to measure health related quality of life in children and adolescents

    PubMed Central

    Baars, Rolanda M; Atherton, Clare I; Koopman, Hendrik M; Bullinger, Monika; Power, Mick

    2005-01-01

    Background The European DISABKIDS project aims to enhance the Health Related Quality of Life (HRQoL) of children and adolescents with chronic medical conditions and their families. We describe the development of the seven cross-nationally tested condition-specific modules of the European DISABKIDS HRQoL instrument in a population of children and adolescents. The condition-specific modules are intended for use in conjunction with the DISABKIDS chronic generic module. Methods Focus groups were used to construct the pilot version of the DISABKIDS condition-specific HRQoL modules for asthma, juvenile idiopathic arthritis, atopic dermatitis, cerebral palsy, cystic fibrosis, diabetes and epilepsy. Analyses were conducted on pilot test data in order to construct field test versions of the modules. A series of factor analyses were run, first, to determine potential structures for each condition-specific module, and, secondly, to select a reduced number of items from the pilot test to be included in the field test. Post-field test analyses were conducted to retest the domain structure for the final DISABKIDS condition-specific modules. Results The DISABKIDS condition-specific modules were tested in a pilot study of 360 respondents, and subsequently in a field test of 1152 respondents in 7 European countries. The final condition-specific modules consist of an 'Impact' domain and an additional domain (e.g. worry, stigma, treatment) with between 10 to 12 items in total. The Cronbach's alpha of the final domains was found to vary from 0.71 to 0.90. Conclusion The condition-specific modules of the DISABKIDS instrument were developed through a step-by-step process including cognitive interview, clinical expertise, factor analysis, correlations and internal consistency. A cross-national pilot and field test were necessary to collect these data. In general, the internal consistency of the domains was satisfactory to high. In future, the DISABKIDS instrument may serve as a useful tool with which to assess HRQoL in children and adolescents with a chronic condition. The condition-specific modules can be used in conjunction with the DISABKIDS chronic generic module. PMID:16283947

  5. The European DISABKIDS project: development of seven condition-specific modules to measure health related quality of life in children and adolescents.

    PubMed

    Baars, Rolanda M; Atherton, Clare I; Koopman, Hendrik M; Bullinger, Monika; Power, Mick

    2005-11-13

    The European DISABKIDS project aims to enhance the Health Related Quality of Life (HRQoL) of children and adolescents with chronic medical conditions and their families. We describe the development of the seven cross-nationally tested condition-specific modules of the European DISABKIDS HRQoL instrument in a population of children and adolescents. The condition-specific modules are intended for use in conjunction with the DISABKIDS chronic generic module. Focus groups were used to construct the pilot version of the DISABKIDS condition-specific HRQoL modules for asthma, juvenile idiopathic arthritis, atopic dermatitis, cerebral palsy, cystic fibrosis, diabetes and epilepsy. Analyses were conducted on pilot test data in order to construct field test versions of the modules. A series of factor analyses were run, first, to determine potential structures for each condition-specific module, and, secondly, to select a reduced number of items from the pilot test to be included in the field test. Post-field test analyses were conducted to retest the domain structure for the final DISABKIDS condition-specific modules. The DISABKIDS condition-specific modules were tested in a pilot study of 360 respondents, and subsequently in a field test of 1152 respondents in 7 European countries. The final condition-specific modules consist of an 'Impact' domain and an additional domain (e.g. worry, stigma, treatment) with between 10 to 12 items in total. The Cronbach's alpha of the final domains was found to vary from 0.71 to 0.90. The condition-specific modules of the DISABKIDS instrument were developed through a step-by-step process including cognitive interview, clinical expertise, factor analysis, correlations and internal consistency. A cross-national pilot and field test were necessary to collect these data. In general, the internal consistency of the domains was satisfactory to high. In future, the DISABKIDS instrument may serve as a useful tool with which to assess HRQoL in children and adolescents with a chronic condition. The condition-specific modules can be used in conjunction with the DISABKIDS chronic generic module.

  6. Final Environmental Assessment for Jacksonville Aviation Authority Launch Site Operator License at Cecil Field, Florida

    DTIC Science & Technology

    2009-07-01

    eligible areas near Cecil Field – Branan Field Mitigation Park Wildlife and Environmental Area , Cecil Field Conservation Corridor, and Sal Taylor... Environmental Health Risks and Safety Risks (April 21, 1997), Federal agencies are directed to make it a high priority to identify and assess ... Environmental Protection 3900 Commonwealth Blvd. Mail Station 47 Tallahassee, FL 32399-3000 Dear Ms. Milligan: RE: Environmental Assessment

  7. Reflections on international medical law.

    PubMed

    Wattad, Mohammed S; Hrevtsova, Radmyla Yu

    2011-12-01

    Does international medical law exist, in the first place, as an independent area of study? If so, is it urgently required in an era of comparative studies? Namely, to what extent, if at all, international studies differ from comparative ones? Besides, what are the particular characteristics of such international discipline? Namely, what are the particular features of this field that elaborate on our legal and scientific understanding in sketching possible definition for this notion of "international medical law?" In addition, how does international medical law correlate with health, ethics and health policies in our globalized world? And finally, what are the challenges that might face the international community, once the concept of "international medical law" is acknowledged? This papers aims at establishing the conceptual grounds for these questions, thus calling for the acknowledgment of a new field of study described as "international medical law".

  8. 24 CFR 203.677 - Decision to approve or deny a request.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... the date of HUD's notice. The appeal must be addressed to the Field Office Manager and be in writing.... This final decision will be made by the HUD Field Office Manager or a representative of the Field Office Manager (other than the Chief, Property Disposition). If the decision is to deny the occupant's...

  9. 24 CFR 203.677 - Decision to approve or deny a request.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... the date of HUD's notice. The appeal must be addressed to the Field Office Manager and be in writing.... This final decision will be made by the HUD Field Office Manager or a representative of the Field Office Manager (other than the Chief, Property Disposition). If the decision is to deny the occupant's...

  10. 24 CFR 203.677 - Decision to approve or deny a request.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the date of HUD's notice. The appeal must be addressed to the Field Office Manager and be in writing.... This final decision will be made by the HUD Field Office Manager or a representative of the Field Office Manager (other than the Chief, Property Disposition). If the decision is to deny the occupant's...

  11. 24 CFR 203.677 - Decision to approve or deny a request.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... the date of HUD's notice. The appeal must be addressed to the Field Office Manager and be in writing.... This final decision will be made by the HUD Field Office Manager or a representative of the Field Office Manager (other than the Chief, Property Disposition). If the decision is to deny the occupant's...

  12. 24 CFR 203.677 - Decision to approve or deny a request.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the date of HUD's notice. The appeal must be addressed to the Field Office Manager and be in writing.... This final decision will be made by the HUD Field Office Manager or a representative of the Field Office Manager (other than the Chief, Property Disposition). If the decision is to deny the occupant's...

  13. 75 FR 55603 - Meeting of the California Desert District Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-13

    ..., October 2, 2010, from 8 a.m. to 4:30 p.m. at the BLM Needles Field Office, 1303 S Highway 95, Needles, CA 92363. Agenda topics will include updates by Council members and reports from the BLM District Manager and five field office managers. Final agenda items, including details of the field tour, will be...

  14. Insights on the origin of the Tb5Ge4 magnetocaloric effect

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

    Belo, J. H.; Barbosa, M. B.; Pires, A. L.

    2017-05-01

    In this report the magnetic, atomic structures and spin-lattice coupling have been thoroughly studied through high magnetic field magnetometry, Synchrotron X-ray diffraction under applied magnetic field and magnetostriction measurements in the Tb5Ge4 compounds. A field induced phase transition from an antiferromagnetic towards a ferromagnetic ordering was confirmed but with absence of structural transformation. This absence has been confirmed experimentally through synchrotron x-ray diffraction under applied field (up to 30 T). Moreover, this absence was explained via a thermodynamic free energy model: first principles calculations determined a large energy gap (ΔE=0.65 eV) between the two possible structures, O(I) and O(II). Frommore » magnetic and structural properties, a H-T phase diagram has been proposed for Tb5Ge4. Finally it was observed a large magnetostriction (up to 600 ppm) induced by ΔH=7 T.« less

  15. The monitoring and managing application of cloud computing based on Internet of Things.

    PubMed

    Luo, Shiliang; Ren, Bin

    2016-07-01

    Cloud computing and the Internet of Things are the two hot points in the Internet application field. The application of the two new technologies is in hot discussion and research, but quite less on the field of medical monitoring and managing application. Thus, in this paper, we study and analyze the application of cloud computing and the Internet of Things on the medical field. And we manage to make a combination of the two techniques in the medical monitoring and managing field. The model architecture for remote monitoring cloud platform of healthcare information (RMCPHI) was established firstly. Then the RMCPHI architecture was analyzed. Finally an efficient PSOSAA algorithm was proposed for the medical monitoring and managing application of cloud computing. Simulation results showed that our proposed scheme can improve the efficiency about 50%. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Numerical simulation of turbulent jet noise, part 2

    NASA Technical Reports Server (NTRS)

    Metcalfe, R. W.; Orszag, S. A.

    1976-01-01

    Results on the numerical simulation of jet flow fields were used to study the radiated sound field, and in addition, to extend and test the capabilities of the turbulent jet simulation codes. The principal result of the investigation was the computation of the radiated sound field from a turbulent jet. In addition, the computer codes were extended to account for the effects of compressibility and eddy viscosity, and the treatment of the nonlinear terms of the Navier-Stokes equations was modified so that they can be computed in a semi-implicit way. A summary of the flow model and a description of the numerical methods used for its solution are presented. Calculations of the radiated sound field are reported. In addition, the extensions that were made to the fundamental dynamical codes are described. Finally, the current state-of-the-art for computer simulation of turbulent jet noise is summarized.

  17. Attosecond control of electron beams at dielectric and absorbing membranes

    NASA Astrophysics Data System (ADS)

    Morimoto, Yuya; Baum, Peter

    2018-03-01

    Ultrashort electron pulses are crucial for time-resolved electron diffraction and microscopy of the fundamental light-matter interaction. In this work, we study experimentally and theoretically the generation and characterization of attosecond electron pulses by optical-field-driven compression and streaking at dielectric or absorbing interaction elements. The achievable acceleration and deflection gradient depends on the laser-electron angle, the laser's electric and magnetic field directions, and the foil orientation. Electric and magnetic fields have similar contributions to the final effect and both need to be considered. Experiments and theory agree well and reveal the optimum conditions for highly efficient, velocity-matched electron-field interactions in the longitudinal or transverse direction. We find that metallic membranes are optimum for light-electron control at mid-infrared or terahertz wavelengths, but dielectric membranes are excellent in the visible and near-infrared regimes and are therefore ideal for the formation of attosecond electron pulses.

  18. Actuated rheology of magnetic micro-swimmers suspensions: Emergence of motor and brake states

    NASA Astrophysics Data System (ADS)

    Vincenti, Benoit; Douarche, Carine; Clement, Eric

    2018-03-01

    We study the effect of magnetic field on the rheology of magnetic micro-swimmers suspensions. We use a model of a dilute suspension under simple shear and subjected to a constant magnetic field. Particle shear stress is obtained for both pusher and puller types of micro-swimmers. In the limit of low shear rate, the rheology exhibits a constant shear stress, called actuated stress, which only depends on the swimming activity of the particles. This stress is induced by the magnetic field and can be positive (brake state) or negative (motor state). In the limit of low magnetic fields, a scaling relation of the motor-brake effect is derived as a function of the dimensionless parameters of the model. In this case, the shear stress is an affine function of the shear rate. The possibilities offered by such an active system to control the rheological response of a fluid are finally discussed.

  19. Drag and lift forces between a rotating conductive sphere and a cylindrical magnet

    NASA Astrophysics Data System (ADS)

    Nurge, Mark A.; Youngquist, Robert C.; Starr, Stanley O.

    2018-06-01

    Modeling the interaction between a non-uniform magnetic field and a rotating conductive object provides insight into the drag force, which is used in applications such as eddy current braking and linear induction motors, as well as the transition to a repulsive force, which is the basis for magnetic levitation systems. Here, we study the interaction between a non-uniform field generated by a cylindrical magnet and a rotating conductive sphere. Each eddy current in the sphere generates a magnetic field which in turn generates another eddy current, eventually feeding back on itself. A two-step mathematical process is developed to find a closed-form solution in terms of only three eddy currents. However, the complete solution requires decomposition of the magnetic field into a summation of spherical harmonics, making it more suitable for a graduate-level electromagnetism lecture or lab. Finally, the forces associated with these currents are calculated and then verified experimentally.

  20. Single-Case Design Research: Building the Evidence-Base in the Field of Education of Deaf and Hard of Hearing Students.

    PubMed

    Cannon, Joanna E; Guardino, Caroline; Antia, Shirin D; Luckner, John L

    2016-01-01

    The field of education of deaf and hard of hearing (DHH) students has a paucity of evidence-based practices (EBPs) to guide instruction. The authors discussed how the research methodology of single-case design (SCD) can be used to build EBPs through direct and systematic replication of studies. An overview of SCD research methods is presented, including an explanation of how internal and external validity issues are addressed, and why SCD is appropriate for intervention research with DHH children. The authors then examine the SCD research in the field according to quality indicators (QIs; at the individual level and as a body of evidence) to determine the existing evidence base. Finally, future replication areas are recommended to fill the gaps in SCD research with students who are DHH in order to add to the evidence base in the field.

  1. Influence of magnetic field on chemically reactive blood flow through stenosed bifurcated arteries

    NASA Astrophysics Data System (ADS)

    Hossain, Khan Enaet; Haque, Md. Mohidul

    2017-06-01

    Dynamic response of mass transfer in chemically reactive blood flow through bifurcated arteries under the stenotic condition is numerically studied in the present of a uniform magnetic field. The blood flowing through the artery is assumed an incompressible, fully developed and Newtonian. The nonlinear unsteady flow phenomena are governed by the Navier-Stokes and concentration equations. All these equations together with the appropriate boundary conditions describing the present biomechanical problem are transformed by using a radial transformation and the numerical results are obtained using a finite difference technique. Effects of stenosed bifurcation and externally applied magnetic field on the blood flow with chemical reaction are discussed with the help of graph. All the flow characteristics are found to be affected by the presence of chemical reaction and exposure of magnetic field of different intensities. Finally some important findings of the problem are concluded in this work.

  2. Idiopathic scoliosis, growth zones, magnetic therapy.

    PubMed

    Arsenev, A; Dudin, M; Lednev, V; Belova, N; Mikhailov, V; Sokolov, G

    2012-01-01

    The study has been performed to investigate the influence of pulsed magnetic field on the bone growth plates to get new grounds of magneto therapy in AIS treatment. Were used methods of "strong" and "weak" pulsed magnetic fields influence. Application of pulsed magnetic field causes an authentic inhibition of chondrocytes' active proliferation processes, decreases the index of labeled nuclei, indicating the suppression of DNA synthesis, takes place an increase in the unit weight of the more "mature" differentiated chondrocytes. The final result of these effects is the accelerated synostosis of bones' growth plates. Regardless of the reasons that cause growth infringements, the operating organ in the chain is the body's growth plate. Therefore, the appliance of magnetic fields in AIS treatment can be considered as a perspective one concerning growth plates' functional activity local management. To our point of view, the potential of magneto therapy methods in child's orthopedic treatment is significantly higher compared with modern practice.

  3. Performance of PZT stacks under high-field electric cycling at various temperatures in heavy-duty diesel engine fuel injectors

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

    Wang, Hong; Lin, Hua-Tay; Stafford, Mr Randy

    2016-01-01

    Testing and characterization of large prototype lead zirconate titanate (PZT) stacks present substantial technical challenges to electronic systems. The work in this study shows that an alternative approach can be pursued by using subunits extracted from prototype stacks. Piezoelectric and dielectric integrity was maintained even though the PZT plate specimens experienced an additional loading process involved with the extraction after factory poling. Extracted 10-layer plate specimens were studied by an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles, both at room temperature (22 C) and at 50 C. The elevated temperature had amore » defined impact on the fatigue of PZT stacks. About 48 and 28% reductions were observed in the piezoelectric and dielectric coefficients, respectively, after 108 cycles at 50 C, compared with reductions of 25 and 15% in the respective coefficients at 22 C. At the same time, the loss tangent varied to a limited extent. The evolution of PZT electrode interfacial layers or nearby dielectric layers should account for the difference in the fatigue rates of piezoelectric and dielectric coefficients. But the basic contribution to observed fatigue may result from the buildup of a bias field that finally suppressed the motion of the domain walls. Finally, monitoring of dielectric coefficients can be an effective tool for on-line lifetime prediction of PZT stacks in service if a failure criterion is defined properly.« less

  4. Performance of PZT stacks under high-field electric cycling at various temperatures in heavy-duty diesel engine fuel injectors

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Lee, Sung-Min; Lin, Hua-Tay; Stafford, Randy

    2016-04-01

    Testing and characterization of large prototype lead zirconate titanate (PZT) stacks present substantial technical challenges to electronic systems. The work in this study shows that an alternative approach can be pursued by using subunits extracted from prototype stacks. Piezoelectric and dielectric integrity was maintained even though the PZT plate specimens experienced an additional loading process involved with the extraction after factory poling. Extracted 10-layer plate specimens were studied by an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles, both at room temperature (22°C) and at 50°C. The elevated temperature had a defined impact on the fatigue of PZT stacks. About 48 and 28% reductions were observed in the piezoelectric and dielectric coefficients, respectively, after 108 cycles at 50°C, compared with reductions of 25 and 15% in the respective coefficients at 22°C. At the same time, the loss tangent varied to a limited extent. The evolution of PZT-electrode interfacial layers or nearby dielectric layers should account for the difference in the fatigue rates of piezoelectric and dielectric coefficients. But the basic contribution to observed fatigue may result from the buildup of a bias field that finally suppressed the motion of the domain walls. Finally, monitoring of dielectric coefficients can be an effective tool for on-line lifetime prediction of PZT stacks in service if a failure criterion is defined properly.

  5. Investigation of the multiplet features of SrTiO 3 in X-ray absorption spectra based on configuration interaction calculations

    DOE PAGES

    Wu, M.; Xin, Houlin L.; Wang, J. O.; ...

    2018-04-24

    Synchrotron-based L 2,3-edge absorption spectra show strong sensitivities to the local electronic structure and chemical environment. However, detailed physical information cannot be extracted easily without computational aids. Here in this study using the experimental Ti L 2,3-edges absorption spectrum of SrTiO 3as a fingerprint and considering full multiplet effects, calculations yield different energy parameters characterizing local ground state properties. The peak splitting and intensity ratios of the L 3 and L 2 set of peaks are carefully analyzed quantitatively, giving rise to a small hybridization energy around 1.2 eV, and the different hybridization energy values reported in the literature aremore » further addressed. Finally, absorption spectra with different linearly polarized photons under various tetragonal crystal fields are investigated, revealing a non-linear orbital–lattice interaction, and a theoretical guidance for material engineering of SrTiO 3-based thin films and heterostructures is offered. Finally, detailed analysis of spectrum shifts with different tetragonal crystal fields suggests that the e g crystal field splitting is a necessary parameter for a thorough analysis of the spectra, even though it is not relevant for the ground state properties.« less

  6. Investigation of the multiplet features of SrTiO 3 in X-ray absorption spectra based on configuration interaction calculations

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

    Wu, M.; Xin, Houlin L.; Wang, J. O.

    Synchrotron-based L 2,3-edge absorption spectra show strong sensitivities to the local electronic structure and chemical environment. However, detailed physical information cannot be extracted easily without computational aids. Here in this study using the experimental Ti L 2,3-edges absorption spectrum of SrTiO 3as a fingerprint and considering full multiplet effects, calculations yield different energy parameters characterizing local ground state properties. The peak splitting and intensity ratios of the L 3 and L 2 set of peaks are carefully analyzed quantitatively, giving rise to a small hybridization energy around 1.2 eV, and the different hybridization energy values reported in the literature aremore » further addressed. Finally, absorption spectra with different linearly polarized photons under various tetragonal crystal fields are investigated, revealing a non-linear orbital–lattice interaction, and a theoretical guidance for material engineering of SrTiO 3-based thin films and heterostructures is offered. Finally, detailed analysis of spectrum shifts with different tetragonal crystal fields suggests that the e g crystal field splitting is a necessary parameter for a thorough analysis of the spectra, even though it is not relevant for the ground state properties.« less

  7. Neural Plasticity following Abacus Training in Humans: A Review and Future Directions

    PubMed Central

    Li, Yongxin; Chen, Feiyan; Huang, Wenhua

    2016-01-01

    The human brain has an enormous capacity to adapt to a broad variety of environmental demands. Previous studies in the field of abacus training have shown that this training can induce specific changes in the brain. However, the neural mechanism underlying these changes remains elusive. Here, we reviewed the behavioral and imaging findings of comparisons between abacus experts and average control subjects and focused on changes in activation patterns and changes in brain structure. Finally, we noted the limitations and the future directions of this field. We concluded that although current studies have provided us with information about the mechanisms of abacus training, more research on abacus training is needed to understand its neural impact. PMID:26881089

  8. A duality web in condensed matter systems

    NASA Astrophysics Data System (ADS)

    Ma, Chen-Te

    2018-03-01

    We study various dualities in condensed matter systems. The dualities in three dimensions can be derived from a conjecture of a duality between a Dirac fermion theory and an interacting scalar field theory at a Wilson-Fisher fixed point and zero temperature in three dimensions. We show that the dualities are not affected by non-trivial holonomy, use a mean-field method to study the dualities, and discuss the dualities at a finite temperature. Finally, we combine a bulk theory, which is an Abelian p-form theory with a theta term in 2 p + 2 dimensions, and a boundary theory, which is a 2 p + 1 dimensional theory, to discuss constraints and difficulties of a 2 p + 1 dimensional duality web.

  9. Flux cutting in high- T c superconductors

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

    Vlasko-Vlasov, V.; Koshelev, A.; Glatz, A.

    We performed magneto-optical study of flux distributions in a YBCO crystal under various applied crossed- field orientations to elucidate the complex nature of magnetic flux cutting in superconductors. Our study reveals unusual vortex patterns induced by the interplay between flux-cutting and vortex pinning. We observe strong flux penetration anisotropy of the normal flux B⊥ in the presence of an in-plane field H|| and associate the modified flux dynamics with staircase structure of tilted vortices in YBCO and the flux-cutting process. We demonstrate that flux-cutting can effectively delay vortex entry in the direction transverse to H||. Finally, we elucidate details ofmore » the vortex-cutting and reconnection process using time-dependent Ginzburg-Landau simulations.« less

  10. Spatial Interpolation of Fine Particulate Matter Concentrations Using the Shortest Wind-Field Path Distance

    PubMed Central

    Li, Longxiang; Gong, Jianhua; Zhou, Jieping

    2014-01-01

    Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW) with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the wind-flow effect, both of which are of great importance for the assessment of the effects of pollutants on human health. PMID:24798197

  11. Spatial interpolation of fine particulate matter concentrations using the shortest wind-field path distance.

    PubMed

    Li, Longxiang; Gong, Jianhua; Zhou, Jieping

    2014-01-01

    Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW) with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the wind-flow effect, both of which are of great importance for the assessment of the effects of pollutants on human health.

  12. Origin and Properties of Striatal Local Field Potential Responses to Cortical Stimulation: Temporal Regulation by Fast Inhibitory Connections

    PubMed Central

    Galiñanes, Gregorio L.; Braz, Barbara Y.; Murer, Mario Gustavo

    2011-01-01

    Evoked striatal field potentials are seldom used to study corticostriatal communication in vivo because little is known about their origin and significance. Here we show that striatal field responses evoked by stimulating the prelimbic cortex in mice are reduced by more than 90% after infusing the AMPA receptor antagonist CNQX close to the recording electrode. Moreover, the amplitude of local field responses and dPSPs recorded in striatal medium spiny neurons increase in parallel with increasing stimulating current intensity. Finally, the evoked striatal fields show several of the basic known properties of corticostriatal transmission, including paired pulse facilitation and topographical organization. As a case study, we characterized the effect of local GABAA receptor blockade on striatal field and multiunitary action potential responses to prelimbic cortex stimulation. Striatal activity was recorded through a 24 channel silicon probe at about 600 µm from a microdialysis probe. Intrastriatal administration of the GABAA receptor antagonist bicuculline increased by 65±7% the duration of the evoked field responses. Moreover, the associated action potential responses were markedly enhanced during bicuculline infusion. Bicuculline enhancement took place at all the striatal sites that showed a response to cortical stimulation before drug infusion, but sites showing no field response before bicuculline remained unresponsive during GABAA receptor blockade. Thus, the data demonstrate that fast inhibitory connections exert a marked temporal regulation of input-output transformations within spatially delimited striatal networks responding to a cortical input. Overall, we propose that evoked striatal fields may be a useful tool to study corticostriatal synaptic connectivity in relation to behavior. PMID:22163020

  13. Evidence of circular Rydberg states in beam-foil experiments: Role of the surface wake field

    NASA Astrophysics Data System (ADS)

    Sharma, Gaurav; Puri, Nitin K.; Kumar, Pravin; Nandi, T.

    2017-12-01

    We have employed the concept of the surface wake field to model the formation of the circular Rydberg states in the beam-foil experiments. The experimental studies of atomic excitation processes show the formation of circular Rydberg states either in the bulk of the foil or at the exit surface, and the mechanism is explained by several controversial theories. The present model is based on the interesting fact that the charge state fraction as well as the surface wake field depend on the foil thickness and it resolves a long-standing discrepancy on the mechanism of the formation of circular Rydberg states. The influence of exit layers is twofold. Initially, the high angular momentum Rydberg states are produced in the last layers of the foil by the Stark switching due to the bulk wake field and finally, they are transferred to the circular Rydberg states as a single multiphoton process due to the influence of the surface wake field.

  14. Investigation of wing crack formation with a combined phase-field and experimental approach

    NASA Astrophysics Data System (ADS)

    Lee, Sanghyun; Reber, Jacqueline E.; Hayman, Nicholas W.; Wheeler, Mary F.

    2016-08-01

    Fractures that propagate off of weak slip planes are known as wing cracks and often play important roles in both tectonic deformation and fluid flow across reservoir seals. Previous numerical models have produced the basic kinematics of wing crack openings but generally have not been able to capture fracture geometries seen in nature. Here we present both a phase-field modeling approach and a physical experiment using gelatin for a wing crack formation. By treating the fracture surfaces as diffusive zones instead of as discontinuities, the phase-field model does not require consideration of unpredictable rock properties or stress inhomogeneities around crack tips. It is shown by benchmarking the models with physical experiments that the numerical assumptions in the phase-field approach do not affect the final model predictions of wing crack nucleation and growth. With this study, we demonstrate that it is feasible to implement the formation of wing cracks in large scale phase-field reservoir models.

  15. Strain fields induced by kink band propagation in Cu-Nb nanolaminate composites

    DOE PAGES

    Nizolek, T. J.; Begley, M. R.; McCabe, R. J.; ...

    2017-07-01

    Kink band formation is a common deformation mode for anisotropic materials and has been observed in polymer matrix fiber composites, single crystals, geological formations, and recently in metallic nanolaminates. While numerous studies have been devoted to kink band formation, the majority do not consider the often rapid and unstable process of kink band propagation. In this paper, we take advantage of stable kink band formation in Cu-Nb nanolaminates to quantitatively map the local strain fields surrounding a propagating kink band during uniaxial compression. Kink bands are observed to initiate at specimen edges, propagate across the sample during a rising globalmore » stress, and induce extended strain fields in the non-kinked material surrounding the propagating kink band. Finally, it is proposed that these stress/strain fields significantly contribute to the total energy dissipated during kinking and, analogous to crack tip stress/strain fields, influence the direction of kink propagation and therefore the kink band inclination angle.« less

  16. Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO

    NASA Astrophysics Data System (ADS)

    Yver Kwok, C.; Laurent, O.; Guemri, A.; Philippon, C.; Wastine, B.; Rella, C. W.; Vuillemin, C.; Truong, F.; Delmotte, M.; Kazan, V.; Darding, M.; Lebègue, B.; Kaiser, C.; Xueref-Rémy, I.; Ramonet, M.

    2015-09-01

    To develop an accurate measurement network of greenhouse gases, instruments in the field need to be stable and precise and thus require infrequent calibrations and a low consumption of consumables. For about 10 years, cavity ring-down spectroscopy (CRDS) analyzers have been available that meet these stringent requirements for precision and stability. Here, we present the results of tests of CRDS instruments in the laboratory (47 instruments) and in the field (15 instruments). The precision and stability of the measurements are studied. We demonstrate that, thanks to rigorous testing, newer models generally perform better than older models, especially in terms of reproducibility between instruments. In the field, we see the importance of individual diagnostics during the installation phase, and we show the value of calibration and target gases that assess the quality of the data. Finally, we formulate recommendations for use of these analyzers in the field.

  17. Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO

    NASA Astrophysics Data System (ADS)

    Yver Kwok, C.; Laurent, O.; Guemri, A.; Philippon, C.; Wastine, B.; Rella, C. W.; Vuillemin, C.; Truong, F.; Delmotte, M.; Kazan, V.; Darding, M.; Lebègue, B.; Kaiser, C.; Ramonet, M.

    2015-04-01

    To develop an accurate measurement network of greenhouse gases, instruments in the field need to be stable and precise and thus require infrequent calibrations and a low consumption of consumables. For about ten years, cavity ring-down spectroscopy (CRDS) analyzers have been available that meet these stringent requirements for precision and stability. Here, we present the results of tests of CRDS instruments in the laboratory (47 instruments) and in the field (15 instruments). The precision and stability of the measurements are studied. We demonstrate that, thanks to rigorous testing, newer models generally perform better than older models, especially in terms of reproducibility between instruments. In the field, we see the importance of individual diagnostics during the installation phase, and we show the value of calibration and target gases that assess the quality of the data. Finally, we formulate recommendations for use of these analyzers in the field.

  18. History and conceptual developments in vascular biology and angiogenesis research: a personal view.

    PubMed

    Bikfalvi, Andreas

    2017-11-01

    Vascular biology is an important scientific domain that has gradually penetrated many medical and scientific fields. Scientists are most often focused on present problems in their daily scientific work and lack awareness regarding the evolution of their domain throughout history and of how philosophical issues are related to their research field. In this article, I provide a personal view with an attempt to conceptualize vascular development research that articulates lessons taken from history, philosophy, biology and medicine. I discuss selected aspects related to the history and the philosophy of sciences that can be extracted from the study of vascular development and how conceptual progress in this research field has been made. I will analyze paradigm shifts, cross-fertilization of different fields, technological advances and its impact on angiogenesis and discuss issues related to evolutionary biology, proximity of different molecular systems and scientific methodologies. Finally, I discuss briefly my views where the field is heading in the future.

  19. The Use of Handheld X-Ray Fluorescence (XRF) Technology in Unraveling the Eruptive History of the San Francisco Volcanic Field, Arizona

    NASA Technical Reports Server (NTRS)

    Young, Kelsey E.; Evans, C. A.; Hodges, K. V.

    2012-01-01

    While traditional geologic mapping includes the examination of structural relationships between rock units in the field, more advanced technology now enables us to simultaneously collect and combine analytical datasets with field observations. Information about tectonomagmatic processes can be gleaned from these combined data products. Historically, construction of multi-layered field maps that include sample data has been accomplished serially (first map and collect samples, analyze samples, combine data, and finally, readjust maps and conclusions about geologic history based on combined data sets). New instruments that can be used in the field, such as a handheld xray fluorescence (XRF) unit, are now available. Targeted use of such instruments enables geologists to collect preliminary geochemical data while in the field so that they can optimize scientific data return from each field traverse. Our study tests the application of this technology and projects the benefits gained by real-time geochemical data in the field. The integrated data set produces a richer geologic map and facilitates a stronger contextual picture for field geologists when collecting field observations and samples for future laboratory work. Real-time geochemical data on samples also provide valuable insight regarding sampling decisions by the field geologist

  20. Evaluation of TravInfo field operational test

    DOT National Transportation Integrated Search

    2000-04-25

    This document constitutes the final report of the evaluation of the TravInfo field operational test. TravInfo is a regional traveler information system in operation in the San Francisco Bay Area. The focus of the evaluation was on three areas: instit...

  1. Herald : field operational test evaluation final report

    DOT National Transportation Integrated Search

    2000-09-01

    The Herald Field Operational Test (FOT) tested AM radio as a low-cost way to broadcast traveler information in rural areas. It tested the feasibility of broadcasting data on the inaudible portion of an existing AM broadcast. Two systems were tested, ...

  2. Herald Field Operation Test Evaluation : Final Report

    DOT National Transportation Integrated Search

    2000-09-01

    The Herald Field Operational Test (FOT) tested AM radio as a low-cost way to broadcast traveler information in rural areas. It tested the feasibility of broadcasting data on the inaudible portion of an existing AM broadcast. Two systems were tested, ...

  3. SMART operational field test evaluation : scheduler survey report : final report

    DOT National Transportation Integrated Search

    1997-06-01

    The Suburban Mobility Authority for Regional Transportation (SMART) has installed an automatic scheduling and dispatch system (ASD) in Southeast Michigan in accordance with their plans to implement ITS as a site for an operational field test. The pur...

  4. Art and Culture in the Space Age

    NASA Astrophysics Data System (ADS)

    Guidi, A.; de Chiara, V.

    2002-01-01

    The relation between culture and science it is a key point for understanding of our changing world. The relation between Art and Science needs to be analyzed more deeply and some specific field have to be studied with the help of people who really work in these field. One of the selected field will be certainly "theatre" one of the most ancient form of art and especially of communication. Since the Greek culture theatre contributed to diffuse culture, not only in the same community, but even in different one. Actors and their play were always travelling around. With the help of a director and of an actor in the paper will be described the argument from them point of view. Another fundamental art form is "Architecture". There is in the last period a strong changing in this field, the architecture is the form of art which is more related to technology. It can be said that Architecture can be considered as a "bridge" between Art and Technology. Finally even all the visual arts are strongly influenced by the nowadays technology. Different kind of visual arts will be considered, and impressions from people working on them will be analysed. An other aspect of our changing world is the evolution of the communication and the diffusion of culture, through century. This aspect and the nowadays level of "communication technology" is another key point who will be further analyzed. Conclusion is identified in opening the door to a wider variety of experiments on the International Space Station (ISS). A type of experiments devoted to involve a wider number of people in space technology. A type of experiments which will also bring the space age closer to a public that has least interest in technical fields. This increase of public support will bring to the space technology an increase in development. The more public interest there is in a certain technology, the larger it is its development. Finally this type of experiments would also open sociological and psychological study.

  5. Migrant Child Welfare: A State of the Field Study of Child Welfare Services for Migrant Children and Their Families Who Are In-Stream, Home Based, Or Settled-Out. Final Report, June 1977.

    ERIC Educational Resources Information Center

    Cavenaugh, David N.; And Others

    The five parts of this report present the findings and recommendations of the Migrant Child Welfare study. Part I briefly summarizes the impact of the child welfare services and the family interview results, and reviews the organizational structure of program delivery at the state and local levels. Part II synthesizes the information obtained from…

  6. Modeling Flows Around Merging Black Hole Binaries

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2008-01-01

    Coalescing massive black hole binaries are produced by the merger of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases in which the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a first step towards this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We report on the results of these initial simulations and discuss their likely importance for future hydrodynamical simulations.

  7. Simulations of Cold Electroweak Baryogenesis: quench from portal coupling to new singlet field

    NASA Astrophysics Data System (ADS)

    Mou, Zong-Gang; Saffin, Paul M.; Tranberg, Anders

    2018-01-01

    We compute the baryon asymmetry generated from Cold Electroweak Baryogenesis, when a dynamical Beyond-the-Standard-Model scalar singlet field triggers the spinodal transition. Using a simple potential for this additional field, we match the speed of the quench to earlier simulations with a "by-hand" mass flip. We find that for the parameter subspace most similar to a by-hand transition, the final baryon asymmetry shows a similar dependence on quench time and is of the same magnitude. For more general parameter choices the Higgs-singlet dynamics can be very complicated, resulting in an enhancement of the final baryon asymmetry. Our results validate and generalise results of simulations in the literature and open up the Cold Electroweak Baryogenesis scenario to further model building.

  8. Flow Field Investigations of a Simulated Weapons Cavity at Mach 3.

    DTIC Science & Technology

    1981-12-01

    AD-Alll 843 ARMO" ENGINEERING. DEVELOPMENT CENTER ARNOLD AFS TN F/9 14/2 FLOW FIELD INVESTIGATIONS OF A SIMULATED WEAPONS CAVITY AT MACN--ETC(U) DEC...TEST CHART .. AEDC-TSR-81-V37 FLOW FIELD INVESTIGATIONS OF A _____SIMULATED WEAPONS CAVITY AT MACH 3 _~W. A. Crosby Calspan Field Services, Inc...TYPE OF REPORT & PERIOD COVERED Final Report FLOW FIELD INVESTIGATIONS OF A SIMULATED WEAPONS 27 October 1981 CAVITY AT MACH 3 6. PERFORMING O1G

  9. Compact toroid generation, lifetime, and stability studies in linear reversed-field theta pinch geometries, (TRX-1): Second annual and final report, June 1981-March 1983

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

    Hoffman, A.L.; Slough, J.T.

    1983-09-01

    Four major areas have been investigated in the triggered reconnection experiment (TRX) program. These areas are flux trapping; formation (reconnection and axial dynamics); stability; and lifetime. This report describes the progress in each of these areas. Flux trapping for relatively slow field reversal rates due to the formation of a wall sheath has been accomplished and techniques have been developed for both triggered and programmed reconnection and the formation process has been optimized for maximum flux retention. Rotational n=2 instability has been controlled through the use of octopole barrier fields and long particle lifetimes have been achieved through optimization ofmore » the formation process. 46 refs., 63 figs., 4 tabs. (FI)« less

  10. Generation of three wide frequency bands within a single white-light cavity

    NASA Astrophysics Data System (ADS)

    Othman, Anas; Yevick, David; Al-Amri, M.

    2018-04-01

    We theoretically investigate the double-Λ scheme inside a Fabry-Pérot cavity employing a weak probe beam and two strong driving fields together with an incoherent pumping mechanism. By generating analytical expressions for the susceptibility and applying the white-light cavity conditions, we devise a procedure that reaches the white-light condition at a smaller gas density than the values typically cited in similar previous studies. Further, when the intensities of the two driving fields are equal, a single giant white band is obtained, while for unequal driving fields three white bands can be present in the cavity. Two additional techniques are then advanced for generating three white bands and a method is described for displacing the center frequency of the bands. Finally, some potential applications are suggested.

  11. Design and modeling of energy generated magneto rheological damper

    NASA Astrophysics Data System (ADS)

    Ahamed, Raju; Rashid, Muhammad Mahbubur; Ferdaus, Md Meftahul; Yusof, Hazlina Md.

    2016-02-01

    In this paper an energy generated mono tube MR damper model has been developed for vehicle suspension systems. A 3D model of energy generated MR damper is developed in Solid Works electromagnetic simulator (EMS) where it is analyzed extensively by finite element method. This dynamic simulation clearly illustrates the power generation ability of the damper. Two magnetic fields are induced inside this damper. One is in the outer coil of the power generator and another is in the piston head coils. The complete magnetic isolation between these two fields is accomplished here, which can be seen in the finite element analysis. The induced magnetic flux densities, magnetic field intensities of this damper are analyzed for characterizing the damper's power generation ability. Finally, the proposed MR damper's energy generation ability was studied experimentally.

  12. Cartan symmetries and global dynamical systems analysis in a higher-order modified teleparallel theory

    NASA Astrophysics Data System (ADS)

    Karpathopoulos, L.; Basilakos, S.; Leon, G.; Paliathanasis, A.; Tsamparlis, M.

    2018-07-01

    In a higher-order modified teleparallel theory cosmological we present analytical cosmological solutions. In particular we determine forms of the unknown potential which drives the scalar field such that the field equations form a Liouville integrable system. For the determination of the conservation laws we apply the Cartan symmetries. Furthermore, inspired from our solutions, a toy model is studied and it is shown that it can describe the Supernova data, while at the same time introduces dark matter components in the Hubble function. When the extra matter source is a stiff fluid then we show how analytical solutions for Bianchi I universes can be constructed from our analysis. Finally, we perform a global dynamical analysis of the field equations by using variables different from that of the Hubble-normalization.

  13. Design and prototype fabrication of a 30 tesla cryogenic magnet

    NASA Technical Reports Server (NTRS)

    Prok, G. M.; Swanson, M. C.; Brown, G. V.

    1977-01-01

    A liquid neon cooled magnet was designed to produce 30 teslas in steady operation. To ensure the correctness of the heat transfer relationships used, supercritical neon heat transfer tests were made. Other tests made before the final design included tests on the effect of the magnetic field on pump motors, tensile shear tests on the cryogenic adhesives, and simulated flow studies for the coolant. The magnet will consist of two pairs of coils, cooled by forced convection of supercritical neon. Heat from the supercritical neon will be rejected through heat exchangers which are made of roll bonded copper panels and are submerged in a pool of saturated liquid neon. A partial mock up coil was wound to identify the tooling required to wind the magnet. This was followed by winding a prototype pair of coils. The prototype winding established procedures for fabricating the final magnet and revealed slight changes needed in the final design.

  14. Final states in Si and GaAs via RF μSR spectroscopy

    NASA Astrophysics Data System (ADS)

    Kreitzman, S. R.; Pfiz, T.; Sun-Mack, S.; Riseman, T. M.; Brewer, J. H.; Williams, D. Ll.; Estle, T. L.

    1991-02-01

    The ionization of muonium centers in Si and GaAs have been studied using radio frequency (RF) resonant techniques. In Si all three muonic centers are detectable by RF. No evidence was found for delayed Mu and Mu* states at any temperature. However, our results on the diamagnetic final state (μ{f/+}) show that it is composed of prompt fractions (as seen by conventional μSR) and delayed fractions arising from the ionization of Mu* and Mu. We observe a full μ{f/+} fraction at 317 K when the Mu relaxation rate is above 10 μs-1. GaAs differs from the situation in Si in that we observed only a partial conversion of Mu* and Mu to a μ+ final state up to 310 K in spite of the fact that the transverse field relaxation rates become very high at 150 and 250 K respectively.

  15. Supersymmetric QCD on the lattice: An exploratory study

    NASA Astrophysics Data System (ADS)

    Costa, M.; Panagopoulos, H.

    2017-08-01

    We perform a pilot study of the perturbative renormalization of a supersymmetric gauge theory with matter fields on the lattice. As a specific example, we consider supersymmetric N =1 QCD (SQCD). We study the self-energies of all particles which appear in this theory, as well as the renormalization of the coupling constant. To this end we compute, perturbatively to one-loop, the relevant two-point and three-point Green's functions using both dimensional and lattice regularizations. Our lattice formulation involves the Wilson discretization for the gluino and quark fields; for gluons we employ the Wilson gauge action; for scalar fields (squarks) we use naïve discretization. The gauge group that we consider is S U (Nc), while the number of colors, Nc, the number of flavors, Nf, and the gauge parameter, α , are left unspecified. We obtain analytic expressions for the renormalization factors of the coupling constant (Zg) and of the quark (Zψ), gluon (Zu), gluino (Zλ), squark (ZA ±), and ghost (Zc) fields on the lattice. We also compute the critical values of the gluino, quark and squark masses. Finally, we address the mixing which occurs among squark degrees of freedom beyond tree level: we calculate the corresponding mixing matrix which is necessary in order to disentangle the components of the squark field via an additional finite renormalization.

  16. Stability analysis of magnetized neutron stars - a semi-analytic approach

    NASA Astrophysics Data System (ADS)

    Herbrik, Marlene; Kokkotas, Kostas D.

    2017-04-01

    We implement a semi-analytic approach for stability analysis, addressing the ongoing uncertainty about stability and structure of neutron star magnetic fields. Applying the energy variational principle, a model system is displaced from its equilibrium state. The related energy density variation is set up analytically, whereas its volume integration is carried out numerically. This facilitates the consideration of more realistic neutron star characteristics within the model compared to analytical treatments. At the same time, our method retains the possibility to yield general information about neutron star magnetic field and composition structures that are likely to be stable. In contrast to numerical studies, classes of parametrized systems can be studied at once, finally constraining realistic configurations for interior neutron star magnetic fields. We apply the stability analysis scheme on polytropic and non-barotropic neutron stars with toroidal, poloidal and mixed fields testing their stability in a Newtonian framework. Furthermore, we provide the analytical scheme for dropping the Cowling approximation in an axisymmetric system and investigate its impact. Our results confirm the instability of simple magnetized neutron star models as well as a stabilization tendency in the case of mixed fields and stratification. These findings agree with analytical studies whose spectrum of model systems we extend by lifting former simplifications.

  17. Clinical Case Studies in Psychoanalytic and Psychodynamic Treatment

    PubMed Central

    Willemsen, Jochem; Della Rosa, Elena; Kegerreis, Sue

    2017-01-01

    This manuscript provides a review of the clinical case study within the field of psychoanalytic and psychodynamic treatment. The method has been contested for methodological reasons and because it would contribute to theoretical pluralism in the field. We summarize how the case study method is being applied in different schools of psychoanalysis, and we clarify the unique strengths of this method and areas for improvement. Finally, based on the literature and on our own experience with case study research, we come to formulate nine guidelines for future case study authors: (1) basic information to include, (2) clarification of the motivation to select a particular patient, (3) information about informed consent and disguise, (4) patient background and context of referral or self-referral, (5) patient's narrative, therapist's observations and interpretations, (6) interpretative heuristics, (7) reflexivity and counter-transference, (8) leaving room for interpretation, and (9) answering the research question, and comparison with other cases. PMID:28210235

  18. Cardiac fluid dynamics meets deformation imaging.

    PubMed

    Dal Ferro, Matteo; Stolfo, Davide; De Paris, Valerio; Lesizza, Pierluigi; Korcova, Renata; Collia, Dario; Tonti, Giovanni; Sinagra, Gianfranco; Pedrizzetti, Gianni

    2018-02-20

    Cardiac function is about creating and sustaining blood in motion. This is achieved through a proper sequence of myocardial deformation whose final goal is that of creating flow. Deformation imaging provided valuable contributions to understanding cardiac mechanics; more recently, several studies evidenced the existence of an intimate relationship between cardiac function and intra-ventricular fluid dynamics. This paper summarizes the recent advances in cardiac flow evaluations, highlighting its relationship with heart wall mechanics assessed through the newest techniques of deformation imaging and finally providing an opinion of the most promising clinical perspectives of this emerging field. It will be shown how fluid dynamics can integrate volumetric and deformation assessments to provide a further level of knowledge of cardiac mechanics.

  19. Robustness of inflation to inhomogeneous initial conditions

    NASA Astrophysics Data System (ADS)

    Clough, Katy; Lim, Eugene A.; DiNunno, Brandon S.; Fischler, Willy; Flauger, Raphael; Paban, Sonia

    2017-09-01

    We consider the effects of inhomogeneous initial conditions in both the scalar field profile and the extrinsic curvature on different inflationary models. In particular, we compare the robustness of small field inflation to that of large field inflation, using numerical simulations with Einstein gravity in 3+1 dimensions. We find that small field inflation can fail in the presence of subdominant gradient energies, suggesting that it is much less robust to inhomogeneities than large field inflation, which withstands dominant gradient energies. However, we also show that small field inflation can be successful even if some regions of spacetime start out in the region of the potential that does not support inflation. In the large field case, we confirm previous results that inflation is robust if the inflaton occupies the inflationary part of the potential. Furthermore, we show that increasing initial scalar gradients will not form sufficiently massive inflation-ending black holes if the initial hypersurface is approximately flat. Finally, we consider the large field case with a varying extrinsic curvature K, such that some regions are initially collapsing. We find that this may again lead to local black holes, but overall the spacetime remains inflationary if the spacetime is open, which confirms previous theoretical studies.

  20. Applying TM-polarization geoelectric exploration for study of low-contrast three-dimensional targets

    NASA Astrophysics Data System (ADS)

    Zlobinskiy, Arkadiy; Mogilatov, Vladimir; Shishmarev, Roman

    2018-03-01

    With using new field and theoretical data, it has been shown that applying the electromagnetic field of transverse magnetic (TM) polarization will give new opportunities for electrical prospecting by the method of transient processes. Only applying a pure field of the TM polarization permits poor three-dimensional objects (required metalliferous deposits) to be revealed in a host horizontally-layered medium. This position has good theoretical grounds. There is given the description of the transient electromagnetic method, that uses only the TM polarization field. The pure TM mode is excited by a special source, which is termed as a circular electric dipole (CED). The results of three-dimensional simulation (by the method of finite elements) are discussed for three real geological situations for which applying electromagnetic fields of transverse electric (TE) and transverse magnetic (TM) polarizations are compared. It has been shown that applying the TE mode gives no positive results, while applying the TM polarization field permits the problem to be tackled. Finally, the results of field works are offered, which showed inefficiency of application of the classical TEM method, whereas in contrast, applying the field of TM polarization makes it easy to identify the target.

  1. Spin- and valley-dependent electronic band structure and electronic heat capacity of ferromagnetic silicene in the presence of strain, exchange field and Rashba spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Hoi, Bui Dinh; Yarmohammadi, Mohsen; Kazzaz, Houshang Araghi

    2017-10-01

    We studied how the strain, induced exchange field and extrinsic Rashba spin-orbit coupling (RSOC) enhance the electronic band structure (EBS) and electronic heat capacity (EHC) of ferromagnetic silicene in presence of external electric field (EF) by using the Kane-Mele Hamiltonian, Dirac cone approximation and the Green's function approach. Particular attention is paid to investigate the EHC of spin-up and spin-down bands at Dirac K and K‧ points. We have varied the EF, strain, exchange field and RSOC to tune the energy of inter-band transitions and consequently EHC, leading to very promising features for future applications. Evaluation of EF exhibits three phases: Topological insulator (TI), valley-spin polarized metal (VSPM) and band insulator (BI) at given aforementioned parameters. As a new finding, we have found a quantum anomalous Hall phase in BI regime at strong RSOCs. Interestingly, the effective mass of carriers changes with strain, resulting in EHC behaviors. Here, exchange field has the same behavior with EF. Finally, we have confirmed the reported and expected symmetry results for both Dirac points and spins with the study of valley-dependent EHC.

  2. Controllable spin polarization and spin filtering in a zigzag silicene nanoribbon

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

    Farokhnezhad, Mohsen, E-mail: Mohsen-farokhnezhad@physics.iust.ac.ir; Esmaeilzadeh, Mahdi, E-mail: mahdi@iust.ac.ir; Pournaghavi, Nezhat

    2015-05-07

    Using non-equilibrium Green's function, we study the spin-dependent electron transport properties in a zigzag silicene nanoribbon. To produce and control spin polarization, it is assumed that two ferromagnetic strips are deposited on the both edges of the silicene nanoribbon and an electric field is perpendicularly applied to the nanoribbon plane. The spin polarization is studied for both parallel and anti-parallel configurations of exchange magnetic fields induced by the ferromagnetic strips. We find that complete spin polarization can take place in the presence of perpendicular electric field for anti-parallel configuration and the nanoribbon can work as a perfect spin filter. Themore » spin direction of transmitted electrons can be easily changed from up to down and vice versa by reversing the electric field direction. For parallel configuration, perfect spin filtering can occur even in the absence of electric field. In this case, the spin direction can be changed by changing the electron energy. Finally, we investigate the effects of nonmagnetic Anderson disorder on spin dependent conductance and find that the perfect spin filtering properties of nanoribbon are destroyed by strong disorder, but the nanoribbon retains these properties in the presence of weak disorder.« less

  3. The Model for Final Stage of Gravitational Collapse Massless Scalar Field

    NASA Astrophysics Data System (ADS)

    Gladush, V. D.; Mironin, D. V.

    It is known that in General relativity, for some spherically symmetric initial conditions, the massless scalar field (SF) experience the gravitational collapse (Choptuik, 1989), and arise a black hole (BH). According Bekenstein, a BH has no "hair scalar", so the SF is completely under the horizon. Thus, the study of the final stage for the gravitational collapse of a SF is reduced to the construction of a solution of Einstein's equations describing the evolution of a SF inside the BH. In this work, we build the Lagrangian for scalar and gravitationalfields in the spherically symmetric case, when the metric coefficients and SF depends only on the time. In this case, it is convenient to use the methods of classical mechanics. Since the metric allows an arbitrary transformation of time, then the corresponding field variable (g00) is included in the Lagrangian without time derivative. It is a non-dynamic variable, and is included in the Lagrangian as a Lagrange multiplier. A variation of the action on this variable gives the constraint. It turns out that Hamiltonian is proportional to the constraint, and so it is zero. The corresponding Hamilton-Jacobi equation easily integrated. Hence, we find the relation between the SF and the metric. To restore of time dependence we using an equation dL / dq' = dS / dq After using a gauge condition, it allows us to find solution. Thus, we find the evolution of the SF inside the BH, which describes the final stage of the gravitational collapse of a SF. It turns out that the mass BH associated with a scalar charge G of the corresponding SF inside the BH ratio M = G/(2√ κ).

  4. BESTNET: Binational English & Spanish Telecommunications Network. Final FIPSE Report.

    ERIC Educational Resources Information Center

    Arias, Armando A., Jr.; Bellman, Beryl L.

    The final evaluation of BESTNET (the Binational English and Spanish Telecommunications Network) is described. Undertaken as a collaborative effort to experiment with new telecommunications media in distance education and to attract Hispanic students into the science and engineering fields, the project involved the development of a number of…

  5. Navy Career Education Diffusion Project: State of Oregon. Final Report.

    ERIC Educational Resources Information Center

    McDermott, Michael M.

    The final report describes a project to research, develop, and field test Navy occupational information for inclusion into the Oregon Career Information System (CIS), a computer-assisted career education program. Five sections include: (1) introductory information; (2) a discussion of the preparation of Navy occupational information and reviewing…

  6. President's Task Force on Communications Policy. Final Report.

    ERIC Educational Resources Information Center

    Rostow, Eugene V.

    The final report of the President's Task Force on Communications Policy recommends strengthened federal powers to form public policy in telecommunications. Such planned policy would enable the private sector to reach its full capacities in the field by improving regulation when it is necessary and removing unnecessary regulation. Monopoly of…

  7. Reactions of the nervous system to magnetic fields

    NASA Technical Reports Server (NTRS)

    Kholodov, Y. A.

    1974-01-01

    This magnetobiological survey considers sensory, nervous, stress and genetic effects of magnetic fields on man and animals. It is shown that the nervous system plays an important role in the reactions of the organism to magnetic fields; the final biological effect is a function of the strength of the magnetic fields, the gradient, direction of the lines of force, duration and location of the action, and the functional status of the organism.

  8. Melt-processing high-T{sub c} superconductors under an elevated magnetic field [Final report no. 2

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

    John B. Vander Sande

    2001-09-05

    This report presents models for crystallographic texture development for high temperature superconducting oxides processed in the absence of a magnetic field and in the presence of a high magnetic field. The results of the models are confirmed through critical experiments. Processing thick films and tapes of high temperature superconducting oxides under a high magnetic field (5-10T) improves the critical current density exhibited.

  9. Magnetic Field Applications in Semiconductor Crystal Growth and Metallurgy

    NASA Technical Reports Server (NTRS)

    Mazuruk, Konstantin; Ramachandran, Narayanan; Grugel, Richard; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    The Traveling Magnetic Field (TMF) technique, recently proposed to control meridional flow in electrically conducting melts, is reviewed. In particular, the natural convection damping capability of this technique has been numerically demonstrated with the implication of significantly improving crystal quality. Advantages of the traveling magnetic field, in comparison to the more mature rotating magnetic field method, are discussed. Finally, results of experiments with mixing metallic alloys in long ampoules using TMF is presented

  10. Fires Readiness: The State of US Army Fires in Support of Combined Arms Maneuver at the Division Level

    DTIC Science & Technology

    2016-06-10

    proficiency in their core competencies. 15. SUBJECT TERMS Fires, Fire Support, DIVARTY, FAB , Combined Arms Maneuver, DOTMLPF 16. SECURITY...FAA Functional Area Analysis FAB Field Artillery Brigade FER Final Exercise Report FFA HQ Force Field Artillery Headquarters FM Field Manual FNA...function. This provided me the opportunity to work with several Division Artillerys (DIVARTYs) and Field Artillery Brigades ( FABs ). During this time

  11. International Joint Seminar on Geographical and Occupational Mobility of Manpower (Castelfusano, November 19-22, 1963). Final Report. International Seminars 1963.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France). Social Affairs Div.

    Representatives of employers' and workers' organizations from 16 member countries met to analyze the problems of facilitating adjustment to geographical and occupational changes, to discuss their experience, and to study the type of overall program needed in this field. The report contains (1) an introduction to the Seminar by Solomon Barkin, (2)…

  12. Attrition/Retention of Urban Special Education Teachers: Multi-Faceted Research and Strategic Action Planning. Final Performance Report, Volume 1. [Chapter Three and Chapter Four].

    ERIC Educational Resources Information Center

    Morvant, Martha; Gersten, Russell

    This paper reports on a study investigating the issues that most significantly influence urban special education teachers' decisions to leave the field voluntarily or transfer to a different type of educational position. First, it presents the results of post-attrition interviews with 17 special educators who left their positions during or…

  13. Developing a Validated Instrument to Measure Preservice Teachers' ICT Competencies: Meeting the Demands of the 21st Century

    ERIC Educational Resources Information Center

    Tondeur, Jo; Aesaert, Koen; Pynoo, Bram; van Braak, Johan; Fraeyman, Norbert; Erstad, Ola

    2017-01-01

    The main objective of this study is to develop a self-report instrument to measure preservice teachers' ICT competencies in education. The questionnaire items of this instrument are based on an existing comprehensive framework and were created with input from experts in the field. The data were collected from a sample of 931 final-year preservice…

  14. The theory of spin noise spectroscopy: a review

    DOE PAGES

    Sinitsyn, Nikolai A.; Pershin, Yuriy V.

    2016-09-12

    Direct measurements of spin fluctuations are becoming the mainstream approach for studies of complex condensed matter, molecular, nuclear, and atomic systems. Our review covers recent progress in the field of optical spin noise spectroscopy (SNS) with an additional goal to establish an introduction into its theoretical foundations. Finally we used various theoretical techniques recently to interpret results of SNS measurements are explained alongside examples of their applications.

  15. Japan 1945-1989: Re-Creating a Modern Nation. A Humanities Approach to Japanese History, Part IV.

    ERIC Educational Resources Information Center

    Parisi, Lynn; Masalski, Kathleen Woods

    This curriculum unit is the final volume of a four-part series. Noting that the humanities reveal the values and beliefs that underlie social, political, and economic institutions, the unit contends that the study of other countries and their histories may be greatly enriched by a humanities approach that draws on the fields of literature,…

  16. Readability Levels of the Reading Passages in the ITED: Final Report. Iowa Testing Programs Research Report. Number 6.

    ERIC Educational Resources Information Center

    Forsyth, Robert

    The readability level of passages from three subtests of the Iowa Tests of Educational Development (ITED), Forms X-6 and Y-6, were compared with the readability level of passages selected from the Des Moines Resister, Reader's Digest, Time, Newsweek, Saturday Review, and 18 high school textbooks from the fields of social studies, science, and…

  17. Report on Development and Evaluation of a Self-Study Course for Adult Four-H Leaders.

    ERIC Educational Resources Information Center

    Neidt, Charles O.

    This programed instruction project for adult Four-H leaders was undertaken to develop a ten unit manuscript covering basic Four H concepts; to prepare four versions thereof differing in response mode; to field test all four on a national sample of leaders; and to prepare a final research edition of the course based on the response mode proving…

  18. Bioengineering of Artificial Lymphoid Organs.

    PubMed

    Nosenko, M A; Drutskaya, M S; Moisenovich, M M; Nedospasov, S A

    2016-01-01

    This review addresses the issue of bioengineering of artificial lymphoid organs.Progress in this field may help to better understand the nature of the structure-function relations that exist in immune organs. Artifical lymphoid organs may also be advantageous in the therapy or correction of immunodefficiencies, autoimmune diseases, and cancer. The structural organization, development, and function of lymphoid tissue are analyzed with a focus on the role of intercellular contacts and on the cytokine signaling pathways regulating these processes. We describe various polymeric materials, as scaffolds, for artificial tissue engineering. Finally, published studies in which artificial lymphoid organs were generated are reviewed and possible future directions in the field are discussed.

  19. Bioengineering of Artificial Lymphoid Organs

    PubMed Central

    Nosenko, M. A.; Drutskaya, M. S.; Moisenovich, M. M.; Nedospasov, S. A.

    2016-01-01

    This review addresses the issue of bioengineering of artificial lymphoid organs.Progress in this field may help to better understand the nature of the structure-function relations that exist in immune organs. Artifical lymphoid organs may also be advantageous in the therapy or correction of immunodefficiencies, autoimmune diseases, and cancer. The structural organization, development, and function of lymphoid tissue are analyzed with a focus on the role of intercellular contacts and on the cytokine signaling pathways regulating these processes. We describe various polymeric materials, as scaffolds, for artificial tissue engineering. Finally, published studies in which artificial lymphoid organs were generated are reviewed and possible future directions in the field are discussed. PMID:27437136

  20. Tachyon warm inflation with the effects of loop quantum cosmology in the light of Planck 2015

    NASA Astrophysics Data System (ADS)

    Kamali, Vahid; Basilakos, Spyros; Mehrabi, Ahmad; Motaharfar, Meysam; Massaeli, Erfan

    We investigate the observational signatures of quantum cosmology in the Cosmic Microwave Background data provided by Planck collaboration. We apply the warm inflationary paradigm with a tachyon scalar field to the loop quantum cosmology. In this context, we first provide the basic cosmological functions in terms of the tachyon field. We then obtain the slow-roll parameters and the power spectrum of scalar and tensor fluctuations, respectively. Finally, we study the performance of various warm inflationary scenarios against the latest Planck data and we find a family of models which are in agreement with the observations.

  1. Entanglement of two blocks of spins in the critical Ising model

    NASA Astrophysics Data System (ADS)

    Facchi, P.; Florio, G.; Invernizzi, C.; Pascazio, S.

    2008-11-01

    We compute the entropy of entanglement of two blocks of L spins at a distance d in the ground state of an Ising chain in an external transverse magnetic field. We numerically study the von Neumann entropy for different values of the transverse field. At the critical point we obtain analytical results for blocks of size L=1 and 2. In the general case, the critical entropy is shown to be additive when d→∞ . Finally, based on simple arguments, we derive an expression for the entropy at the critical point as a function of both L and d . This formula is in excellent agreement with numerical results.

  2. Conduction quantization in monolayer MoS2

    NASA Astrophysics Data System (ADS)

    Li, T. S.

    2016-10-01

    We study the ballistic conduction of a monolayer MoS2 subject to a spatially modulated magnetic field by using the Landauer-Buttiker formalism. The band structure depends sensitively on the field strength, and its change has profound influence on the electron conduction. The conductance is found to demonstrate multi-step behavior due to the discrete number of conduction channels. The sharp peak and rectangular structures of the conductance are stretched out as temperature increases, due to the thermal broadening of the derivative of the Fermi-Dirac distribution function. Finally, quantum behavior in the conductance of MoS2 can be observed at temperatures below 10 K.

  3. Geologic interpretation of HCMM and aircraft thermal data

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Progress on the Heat Capacity Mapping Mission (HCMM) follow-on study is reported. Numerous image products for geologic interpretation of both HCMM and aircraft thermal data were produced. These include, among others, various combinations of the thermal data with LANDSAT and SEASAT data. The combined data sets were displayed using simple color composites, principal component color composites and black and white images, and hue, saturation intensity color composites. Algorithms for incorporating both atmospheric and elevation data simultaneously into the digital processing for creation of quantitatively correct thermal inertia images, are in the final development stage. A field trip to Death Valley was undertaken to field check the aircraft and HCMM data.

  4. Nonlinear electromagnetic interactions in energetic materials

    DOE PAGES

    Wood, Mitchell Anthony; Dalvit, Diego Alejandro; Moore, David Steven

    2016-01-12

    We study the scattering of electromagnetic waves in anisotropic energetic materials. Nonlinear light-matter interactions in molecular crystals result in frequency-conversion and polarization changes. Applied electromagnetic fields of moderate intensity can induce these nonlinear effects without triggering chemical decomposition, offering a mechanism for the nonionizing identification of explosives. We use molecular-dynamics simulations to compute such two-dimensional THz spectra for planar slabs made of pentaerythritol tetranitrate and ammonium nitrate. Finally, we discuss third-harmonic generation and polarization-conversion processes in such materials. These observed far-field spectral features of the reflected or transmitted light may serve as an alternative tool for standoff explosive detection.

  5. A telescope with augmented reality functions

    NASA Astrophysics Data System (ADS)

    Hou, Qichao; Cheng, Dewen; Wang, Qiwei; Wang, Yongtian

    2016-10-01

    This study introduces a telescope with virtual reality (VR) and augmented reality (AR) functions. In this telescope, information on the micro-display screen is integrated to the reticule of telescope through a beam splitter and is then received by the observer. The design and analysis of telescope optical system with AR and VR ability is accomplished and the opto-mechanical structure is designed. Finally, a proof-of-concept prototype is fabricated and demonstrated. The telescope has an exit pupil diameter of 6 mm at an eye relief of 19 mm, 6° field of view, 5 to 8 times visual magnification , and a 30° field of view of the virtual image.

  6. Untangling Autophagy Measurements: All Fluxed Up

    PubMed Central

    Gottlieb, Roberta A.; Andres, Allen M.; Sin, Jon; Taylor, David

    2015-01-01

    Autophagy is an important physiological process in the heart, and alterations in autophagic activity can exacerbate or mitigate injury during various pathological processes. Methods to assess autophagy have changed rapidly as the field of research has expanded. As with any new field, methods and standards for data analysis and interpretation evolve as investigators acquire experience and insight. The purpose of this review is to summarize current methods to measure autophagy, selective mitochondrial autophagy (mitophagy), and autophagic flux. We will examine several published studies where confusion arose in in data interpretation, in order to illustrate the challenges. Finally we will discuss methods to assess autophagy in vivo and in patients. PMID:25634973

  7. Alliance for Computational Science Collaboration, HBCU Partnership at Alabama A&M University Final Performance Technical Report

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

    Deng, Z.T.

    2001-11-15

    The objective of this project was to conduct high-performance computing research and teaching at AAMU, and to train African-American and other minority students and scientists in the computational science field for eventual employment with DOE. During the project period, eight tasks were accomplished. Student Research Assistant, Work Study, Summer Interns, Scholarship were proved to be one of the best ways for us to attract top-quality minority students. Under the support of DOE, through research, summer interns, collaborations, scholarships programs, AAMU has successfully provided research and educational opportunities to minority students in the field related to computational science.

  8. Magneto-optical effects in semimetallic Bi 1–xSb x (x=0.015)

    DOE PAGES

    Dordevic, S. V.; Wolf, M. S.; Stojilovic, N.; ...

    2012-09-12

    We report the results of infrared and magneto-optical spectroscopy study on electrodynamic response of bismuth doped with 1.5% of antimony. The spectra are presented for temperatures down to 4.2 K, and in magnetic fields as high as 18 T. The results reveal strong magneto-optical activity, similar to pure bismuth, however there are some differences introduced by antimony doping. Analysis of optical functions reveals that the two type of charge carriers respond differently to external magnetic field. Finally, when the system enters the extreme quantum regime, both the inter- and intraband Landau Level transition are observed in the spectra.

  9. A GIS-BASED MULTI-CRITERIA EVALUATION SYSTEM FOR SELECTION OF LANDFILL SITES: a case study from Abu Dhabi, United Arab Emirates

    NASA Astrophysics Data System (ADS)

    Issa, S. M.; Shehhi, B. Al

    2012-07-01

    Landfill sites receive 92% of total annual solid waste produced by municipalities in the emirate of Abu Dhabi. In this study, candidate sites for an appropriate landfill location for the Abu Dhabi municipal area are determined by integrating geographic information systems (GIS) and multi-criteria evaluation (MCE) analysis. To identify appropriate landfill sites, eight input map layers including proximity to urban areas, proximity to wells and water table depth, geology and topography, proximity to touristic and archeological sites, distance from roads network, distance from drainage networks, and land slope are used in constraint mapping. A final map was generated which identified potential areas showing suitability for the location of the landfill site. Results revealed that 30% of the study area was identified as highly suitable, 25% as suitable, and 45% as unsuitable. The selection of the final landfill site, however, requires further field research.

  10. A plane-polar approach for far-field construction from near-field measurements. [of large space-craft antennas

    NASA Technical Reports Server (NTRS)

    Rahmat-Samii, Y.; Galindo-Israel, V.; Mittra, R.

    1980-01-01

    The planar configuration with a probe scanning a polar geometry is discussed with reference to its usefulness in the determination of a far field from near-field measurements. The accuracy of the method is verified numerically, using the concept of probe compensation as a vector deconvolution. Advantages of the Jacobi-Bessel series over the fast Fourier transforms for the plane-polar geometry are demonstrated. Finally, the far-field pattern of the Viking high gain antenna is constructed from the plane-polar near-field measured data and compared with the previously measured far-field pattern.

  11. Evaluation of the Mack Intelligent Vehicle Field Operational Test: September 2006

    DOT National Transportation Integrated Search

    2006-09-01

    This report presents the final results of an independent evaluation of the U.S. Department of Transportation (USDOT) Mack Intelligent Vehicle Initiative (IVI) Field Operational Test (FOT). The IVI is a cooperative effort to conduct FOTs of advanced i...

  12. Microsiemens or Milligrams: Measures of Ionic Mixtures

    EPA Science Inventory

    In December of 2016, EPA released the Draft Field-Based Methods for Developing Aquatic Life Criteria for Specific Conductivity for public comment. Once final, states and authorized tribes may use these methods to derive field-based ecoregional ambient Aquatic Life Ambient Water Q...

  13. Integrated vehicle-based safety systems field operational test final program report.

    DOT National Transportation Integrated Search

    2011-06-01

    "This document presents results from the light-vehicle and heavy-truck field operational tests performed as part of the Integrated Vehicle-Based Safety Systems (IVBSS) program. The findings are the result of analyses performed by the University of Mi...

  14. Integrated Vehicle-Based Safety Systems Field Operational Test : Final Program Report

    DOT National Transportation Integrated Search

    2011-06-01

    This document presents results from the light-vehicle and heavy-truck field operational tests performed as part of the Integrated Vehicle-Based Safety Systems (IVBSS) program. The findings are the result of analyses performed by the University of Mic...

  15. Field validation of a drive-by bridge inspection system with wireless BWIM + NDE devices : final report.

    DOT National Transportation Integrated Search

    2016-09-01

    In this project, researchers developed and performed field validation of a wireless structural sensing system for a variety of bridge response measurements, including strain, acceleration, and displacement. The research team used the wireless strain ...

  16. Research in the Theory of Condensed Matter and Elementary Particles: Final Report, September 1, 1984 - November 30, 1987

    DOE R&D Accomplishments Database

    Friedan, D.; Kadanoff, L.; Nambu, Y.; Shenker, S.

    1988-04-01

    Progress is reported in the field of condensed matter physics in the area of two-dimensional critical phenomena, specifically results allowing complete classification of all possible two-dimensional critical phenomena in a certain domain. In the field of high energy physics, progress is reported in string and conformal field theory, and supersymmetry.

  17. Design and characterization of microstrip based E-field sensor for GSM and UMTS frequency bands

    NASA Astrophysics Data System (ADS)

    Narang, N.; Dubey, S. K.; Negi, P. S.; Ojha, V. N.

    2016-12-01

    An Electric (E-) field sensor based on coplanar waveguide-fed microstrip antenna to measure E-field strength for dual-band operation at 914 MHz and 2.1 GHz is proposed, designed, and characterized. The parametric optimization of the design has been performed to obtain resonance at global system for mobile communication and universal mobile telecommunication system frequency band. Low return loss (-17 dB and -19 dB), appropriate gain (0.50 dB and 1.55 dB), and isotropic behaviour (directivity ˜ 1 dB), respectively, at 914 MHz and 2.1 GHz, are obtained for probing application. Antenna factor (AF) is used as an important parameter to characterize the performance of the E-field sensor. The AF measurement is explained in detail and results are reported. Finally, using the designed E-field sensor, the E-field strength measurements are carried out in a transverse electromagnetic cell. The key sources of uncertainties in the measurement are identified, evaluated, and incorporated into the final results. The measurement results are compared with theoretical values, which are found in good agreement. For comparative validation, the results are evaluated with reference to an already calibrated commercially available isotropic probe.

  18. Design and characterization of microstrip based E-field sensor for GSM and UMTS frequency bands.

    PubMed

    Narang, N; Dubey, S K; Negi, P S; Ojha, V N

    2016-12-01

    An Electric (E-) field sensor based on coplanar waveguide-fed microstrip antenna to measure E-field strength for dual-band operation at 914 MHz and 2.1 GHz is proposed, designed, and characterized. The parametric optimization of the design has been performed to obtain resonance at global system for mobile communication and universal mobile telecommunication system frequency band. Low return loss (-17 dB and -19 dB), appropriate gain (0.50 dB and 1.55 dB), and isotropic behaviour (directivity ∼ 1 dB), respectively, at 914 MHz and 2.1 GHz, are obtained for probing application. Antenna factor (AF) is used as an important parameter to characterize the performance of the E-field sensor. The AF measurement is explained in detail and results are reported. Finally, using the designed E-field sensor, the E-field strength measurements are carried out in a transverse electromagnetic cell. The key sources of uncertainties in the measurement are identified, evaluated, and incorporated into the final results. The measurement results are compared with theoretical values, which are found in good agreement. For comparative validation, the results are evaluated with reference to an already calibrated commercially available isotropic probe.

  19. Maximal near-field radiative heat transfer between two plates

    NASA Astrophysics Data System (ADS)

    Nefzaoui, Elyes; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

    2013-09-01

    Near-field radiative transfer is a promising way to significantly and simultaneously enhance both thermo-photovoltaic (TPV) devices power densities and efficiencies. A parametric study of Drude and Lorentz models performances in maximizing near-field radiative heat transfer between two semi-infinite planes separated by nanometric distances at room temperature is presented in this paper. Optimal parameters of these models that provide optical properties maximizing the radiative heat flux are reported and compared to real materials usually considered in similar studies, silicon carbide and heavily doped silicon in this case. Results are obtained by exact and approximate (in the extreme near-field regime and the electrostatic limit hypothesis) calculations. The two methods are compared in terms of accuracy and CPU resources consumption. Their differences are explained according to a mesoscopic description of nearfield radiative heat transfer. Finally, the frequently assumed hypothesis which states a maximal radiative heat transfer when the two semi-infinite planes are of identical materials is numerically confirmed. Its subsequent practical constraints are then discussed. Presented results enlighten relevant paths to follow in order to choose or design materials maximizing nano-TPV devices performances.

  20. Autonomous dynamic obstacle avoidance for bacteria-powered microrobots (BPMs) with modified vector field histogram

    PubMed Central

    Kim, Hoyeon; Cheang, U. Kei

    2017-01-01

    In order to broaden the use of microrobots in practical fields, autonomous control algorithms such as obstacle avoidance must be further developed. However, most previous studies of microrobots used manual motion control to navigate past tight spaces and obstacles while very few studies demonstrated the use of autonomous motion. In this paper, we demonstrated a dynamic obstacle avoidance algorithm for bacteria-powered microrobots (BPMs) using electric field in fluidic environments. A BPM consists of an artificial body, which is made of SU-8, and a high dense layer of harnessed bacteria. BPMs can be controlled using externally applied electric fields due to the electrokinetic property of bacteria. For developing dynamic obstacle avoidance for BPMs, a kinematic model of BPMs was utilized to prevent collision and a finite element model was used to characteristic the deformation of an electric field near the obstacle walls. In order to avoid fast moving obstacles, we modified our previously static obstacle avoidance approach using a modified vector field histogram (VFH) method. To validate the advanced algorithm in experiments, magnetically controlled moving obstacles were used to intercept the BPMs as the BPMs move from the initial position to final position. The algorithm was able to successfully guide the BPMs to reach their respective goal positions while avoiding the dynamic obstacles. PMID:29020016

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