WorldWideScience

Sample records for vhtr phenomena identification

  1. Development Of An Experiment For Measuring Flow Phenomena Occurring In A Lower Plenum For VHTR CFD Assessment

    Energy Technology Data Exchange (ETDEWEB)

    D. M. McEligot; K.G. Condie; G. E. Mc Creery; H. M. Mc Ilroy

    2005-09-01

    The objective of the present report is to document the design of our first experiment to measure generic flow phenomena expected to occur in the lower plenum of a typical prismatic VHTR (Very High Temperature Reactor) concept. In the process, fabrication sketches are provided for the use of CFD (computational fluid dynamics) analysts wishing to employ the data for assessment of their proposed codes. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/systems code calculations for the same geometry. One aspect of the complex flow in a prismatic VHTR is being addressed: flow and thermal mixing in the lower plenum ("hot streaking" issue). Current prismatic VHTR concepts were examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses were applied to determine key non-dimensional parameters and their magnitudes over this operating range. The flow in the lower plenum can locally be considered to be a situation of multiple jets into a confined crossflow -- with obstructions. Flow is expected to be turbulent with momentum-dominated turbulent jets entering; buoyancy influences are estimated to be negligible in normal full power operation. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments available are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls - with near stagnant surroundings at one extreme and significant crossflow at the other.

  2. A Preliminary Investigation of Rapid Depressurization Phenomena Following a Sudden DLOFC in a VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Richard C. Martineau; Ray A. Berry; Dana A. Knoll

    2009-03-01

    Air ingress has been identified as a potential threat for Very High Temperature gas-cooled Reactors (VHTR). Reactor components constructed of graphite will, at high temperatures, produce exothermic reactions in the presence of oxygen. The danger lies in the possibility of fuel element damage and core structural failure. Previous investigations of air ingress mechanisms have focused on thermal and molecular diffusion, density-driven stratified flow, and natural convection. Here, we investigate the possibility of a rapid ingress of air due to a Taylor wave expansion after a hypothetical sudden loss of coolant accident (LOCA) scenario in a VHTR. Our analysis starts with a one-dimensional shock tube simulation to simply illustrate the development of a Taylor wave with resulting reentrant flow. Then, a simulation is performed of an idealized two-dimensional axisymmetric representation of the lower plenum of General Atomics GT-MHR subjected to a hypothetical catastrophic break of the hot duct. Analysis shows the potential for significant and rapid air ingress into the reactor vessel in the case of a large break in the cooling system.

  3. Prioritization of VHTR system modeling needs based on phenomena identification, ranking and sensitivity studies.

    Energy Technology Data Exchange (ETDEWEB)

    Vilim, R. B.; Pointer, W. D.; Wei, T. Y. C.; Nuclear Engineering Division

    2006-04-30

    Quantification of uncertainty is a key requirement for the design of a nuclear power plant and the assurance of its safety. Historically the procedure has been to perform the required uncertainty assessment through comparison of the analytical predictions with experimental simulations. The issue with this historical approach has always been that the simulations through experiments could not be at full scale for the practical reasons of cost and scheduling. Invariably, only parts of the system were tested separately or if integral testing was performed for the complete system, the size or scale of the experimental apparatus was significantly smaller than the actual plant configuration.

  4. Investigation of Abnormal Heat Transfer and Flow in a VHTR Reactor Core

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    Kawaji, Masahiro [City College of New York, NY (United States); Valentin, Francisco I. [City College of New York, NY (United States); Artoun, Narbeh [City College of New York, NY (United States); Banerjee, Sanjoy [City College of New York, NY (United States); Sohal, Manohar [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schultz, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States); McEligot, Donald M. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-12-21

    The main objective of this project was to identify and characterize the conditions under which abnormal heat transfer phenomena would occur in a Very High Temperature Reactor (VHTR) with a prismatic core. High pressure/high temperature experiments have been conducted to obtain data that could be used for validation of VHTR design and safety analysis codes. The focus of these experiments was on the generation of benchmark data for design and off-design heat transfer for forced, mixed and natural circulation in a VHTR core. In particular, a flow laminarization phenomenon was intensely investigated since it could give rise to hot spots in the VHTR core.

  5. Strategy of VHTR Realization

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jonghwa [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    High temperature gas cooled reactor has been developed since 1956. Fundamental idea of a gas cooled reactor is to achieve high temperature which is suitable for high efficiency application such as electricity generation. The core is composed of ceramics, graphite blocks which are mechanical stable up to very high temperature. Fuel is ceramics, TRISO ( tri-isotropic coated micro particle) whose dense coating layers work as small radioactivity containment. Coolant is inert gas, helium, which is stable chemically, neutronically, and thermal hydraulically. Several test reactors such as DRE, PB-1, FSV, AVR, THTR, HTTR, HTR-10 were built and demonstrated their safety. Large GA-HTR, RSA-PBMR projects are canceled and US-NGNP project is idling. Only Chinese HTR-PM demonstrator is under construction. HTGR has long history of development. For realization and market penetration, VHTR community should look at niche market such as carbon free energy supply to industry complex, electric power for small grid, carbon free hydrogen production, power source for space colony. Technology Readiness Level should be advanced to get proper investment from industry. For this, cooperation between international R and D institutions is required. Clearly divided role between universities, research institutions, and industries will reduce complication and shorten VHTR realization day.

  6. Prismatic VHTR neutronic benchmark problems

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    Connolly, Kevin John, E-mail: connolly@gatech.edu [Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School, Georgia Institute of Technology, Atlanta, GA (United States); Rahnema, Farzad, E-mail: farzad@gatech.edu [Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School, Georgia Institute of Technology, Atlanta, GA (United States); Tsvetkov, Pavel V. [Department of Nuclear Engineering, Texas A& M University, College Station, TX (United States)

    2015-04-15

    Highlights: • High temperature gas-cooled reactor neutronics benchmark problems. • Description of a whole prismatic VHTR core in its full heterogeneity. • Modeled using continuous energy nuclear data at a representative hot operating temperature. • Benchmark results for core eigenvalue, block-averaged power, and some selected pin fission density results. - Abstract: This paper aims to fill an apparent scarcity of benchmarks based on high temperature gas-cooled reactors. Within is a description of a whole prismatic VHTR core in its full heterogeneity and modeling using continuous energy nuclear data at a representative hot operating temperature. Also included is a core which has been simplified for ease in modeling while attempting to preserve as faithfully as possible the neutron physics of the core. Fuel and absorber pins have been homogenized from the particle level, however, the blocks which construct the core remain strongly heterogeneous. A six group multigroup (discrete energy) cross section set has been developed via Monte Carlo using the original heterogeneous core as a basis. Several configurations of the core have been solved using these two cross section sets; eigenvalue results, block-averaged power results, and some selected pin fission density results are presented in this paper, along with the six-group cross section data, so that method developers may use these problems as a standard reference point.

  7. Development of essential technology for VHTR

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    Hong, Sung Deok; Kang, G. H.; Koo, G. H.; Kim, Y. W.; Kim, D. H.; Kim, D. Jong; Kim, D. O.; Kim, D. Jin; Kim, M. C.; Kim, M. C.

    2012-04-15

    The research tasks performed in this project can be classified into five categories; high temperature material of VHTR reactor and components for hydrogen production, the nuclear graphite for the core material, the essential technologies for VHTR components, Process Heat Exchanger (PHE) fabrication, and gas loop for PHE verification tests. Research tasks on high temperature materials of VHTR reactor and components include creep properties of super alloy for high temperature components, properties of a modified 9Cr-1Mo alloy, fabrication and properties of in-core ceramic composites, and corrosion properties of the materials for the sulfuric acid decomposer. The echnologies of graphitization evaluation, nondestructive defect detection, and impurity analysis were developed in field of nuclear graphites. The properties of graphites were evaluated by tests using small specimen test. The abroad status of graphite machining was reviewed. Review about the status of VHTR components, structural sizing and analysis for hot gas duct, thermal sizing of IHX were performed in the field of the essential technologies for VHTR components. The surface modification process with ion beam mixing was optimized and evaluated for the fabrication of process heat exchanger (PHE). The secondary sulfuric acid loop was designed and constructed in the gas loop. The lab-scale PHE test was performed in the gas loop.

  8. Initial VHTR accident scenario classification: models and data.

    Energy Technology Data Exchange (ETDEWEB)

    Vilim, R. B.; Feldman, E. E.; Pointer, W. D.; Wei, T. Y. C.; Nuclear Engineering Division

    2005-09-30

    Nuclear systems codes are being prepared for use as computational tools for conducting performance/safety analyses of the Very High Temperature Reactor. The thermal-hydraulic codes are RELAP5/ATHENA for one-dimensional systems modeling and FLUENT and/or Star-CD for three-dimensional modeling. We describe a formal qualification framework, the development of Phenomena Identification and Ranking Tables (PIRTs), the initial filtering of the experiment databases, and a preliminary screening of these codes for use in the performance/safety analyses. In the second year of this project we focused on development of PIRTS. Two events that result in maximum fuel and vessel temperatures, the Pressurized Conduction Cooldown (PCC) event and the Depressurized Conduction Cooldown (DCC) event, were selected for PIRT generation. A third event that may result in significant thermal stresses, the Load Change event, is also selected for PIRT generation. Gas reactor design experience and engineering judgment were used to identify the important phenomena in the primary system for these events. Sensitivity calculations performed with the RELAP5 code were used as an aid to rank the phenomena in order of importance with respect to the approach of plant response to safety limits. The overall code qualification methodology was illustrated by focusing on the Reactor Cavity Cooling System (RCCS). The mixed convection mode of heat transfer and pressure drop is identified as an important phenomenon for Reactor Cavity Cooling System (RCCS) operation. Scaling studies showed that the mixed convection mode is likely to occur in the RCCS air duct during normal operation and during conduction cooldown events. The RELAP5/ATHENA code was found to not adequately treat the mixed convection regime. Readying the code will require adding models for the turbulent mixed convection regime while possibly performing new experiments for the laminar mixed convection regime. Candidate correlations for the turbulent

  9. Development of a preliminary PIRT (Phenomena Identification and Ranking Table) of thermal-hydraulic phenomena for SMART

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    Chung, Bub Dong; Lee, Won Jae; Kim, Hee Cheol; Song, Jin Ho; Sim, Suk Ku [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    The work reported in this paper identifies the thermal-hydraulic phenomena that are expected to occur during a number of key transients in SMART (System-integrated Modular Advanced ReacTor) which is under development at KAERI. The result of this effort is based on the current design concept of SMART integral reactor. Although the design is still evolving, the preliminary Phenomena Identification and Ranking Table (PIRT) has been developed based on the experts` knowledge and experience. The preliminary PIRT has been developed by consensus of KAERI expert panelists and AHP (Analytical Hierarchy Process). Preliminary PIRT developed in this paper is intended to be used to identify and integrate development areas of further experimental tests needed, thermal hydraulic models and correlations and code improvements for the safety analysis of the SMART. 8 refs., 4 tabs (Author)

  10. Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 1: Main Report

    Energy Technology Data Exchange (ETDEWEB)

    Ball, Sydney J [ORNL

    2008-03-01

    A phenomena identification and ranking table (PIRT) process was conducted for the Next Generation Nuclear Plant (NGNP) design. This design (in the conceptual stage) is a modular high-temperature gas-cooled reactor (HTGR) that generates both electricity and process heat for hydrogen production. Expert panels identified safety-relevant phenomena, ranked their importance, and assessed the knowledge levels in the areas of accidents and thermal fluids, fission-product transport and dose, high-temperature materials, graphite, and process heat for hydrogen production. This main report summarizes and documents the process and scope of the reviews, noting the major activities and conclusions. The identified phenomena, analyses, rationales, and associated ratings of the phenomena, plus a summary of each panel's findings, are presented. Individual panel reports for these areas are provided as attached volumes to this main report and provide considerably more detail about each panel's deliberations as well as a more complete listing of the phenomena that were evaluated.

  11. Final report, BWR drywell debris transport Phenomena Identification and Ranking Tables (PIRTs)

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.E. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); Boyack, B.E. [Los Alamos National Lab., NM (United States); Leonard, M.T.; Williams, K.A.; Wolf, L.T.

    1997-09-01

    The Nuclear Regulatory Commission has issued a Regulatory Bulletin and accompanying Regulatory Guide (1.82, Rev. 2) which requires licensees of boiling water reactors to develop a specific plan of action (including hardware backfits, if necessary) to preclude the possibility of early emergency core cooling system strainer blockage following a postulated loss-of-coolant-accident. The postulated mechanism for strainer blockage is destruction of piping insulation in the vicinity of the break and subsequent transport of fragmented insulation to the wetwell. In the absence of more definitive information, the Regulatory Guide recommends that licensees assume a drywell debris transport fraction of 1.0. Accordingly, the Nuclear Regulatory Commission initiated research focused toward developing a technical basis to provide insights useful to regulatory oversight of licensee submittals associated with resolution of the postulated strainer blockage issue. Part of this program was directed towards experimental and analytical research leading to a more realistic specification of the debris transport through the drywell to the wetwell. To help focus this development into a cost effective effort, a panel, with broad based knowledge and experience, was formed to address the relative importance of the various phenomena that can be expected in plant response to postulated accidents that may produce strainer blockage. The resulting phenomena identification and ranking tables reported herein were used to help guide research. The phenomena occurring in boiling water reactors drywells was the specific focus of the panel, although supporting experimental data and calculations of debris transport fractions were considered.

  12. Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 5: Graphite PIRTs

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, Timothy D [ORNL; Bratton, Rob [Idaho National Laboratory (INL); Marsden, Barry [University of Manchester, UK; Srinivasan, Makuteswara [U.S. Nuclear Regulatory Commission; Penfield, Scott [Technology Insights; Mitchell, Mark [PBMR (Pty) Ltd.; Windes, Will [Idaho National Laboratory (INL)

    2008-03-01

    Here we report the outcome of the application of the Nuclear Regulatory Commission (NRC) Phenomena Identification and Ranking Table (PIRT) process to the issue of nuclear-grade graphite for the moderator and structural components of a next generation nuclear plant (NGNP), considering both routine (normal operation) and postulated accident conditions for the NGNP. The NGNP is assumed to be a modular high-temperature gas-cooled reactor (HTGR), either a gas-turbine modular helium reactor (GTMHR) version [a prismatic-core modular reactor (PMR)] or a pebble-bed modular reactor (PBMR) version [a pebble bed reactor (PBR)] design, with either a direct- or indirect-cycle gas turbine (Brayton cycle) system for electric power production, and an indirect-cycle component for hydrogen production. NGNP design options with a high-pressure steam generator (Rankine cycle) in the primary loop are not considered in this PIRT. This graphite PIRT was conducted in parallel with four other NRC PIRT activities, taking advantage of the relationships and overlaps in subject matter. The graphite PIRT panel identified numerous phenomena, five of which were ranked high importance-low knowledge. A further nine were ranked with high importance and medium knowledge rank. Two phenomena were ranked with medium importance and low knowledge, and a further 14 were ranked medium importance and medium knowledge rank. The last 12 phenomena were ranked with low importance and high knowledge rank (or similar combinations suggesting they have low priority). The ranking/scoring rationale for the reported graphite phenomena is discussed. Much has been learned about the behavior of graphite in reactor environments in the 60-plus years since the first graphite rectors went into service. The extensive list of references in the Bibliography is plainly testament to this fact. Our current knowledge base is well developed. Although data are lacking for the specific grades being considered for Generation IV (Gen IV

  13. Manufacturing Phenomena or Preserving Phenomena? Core Issues in the Identification of Peer Social Groups with Social Cognitive Mapping Procedures

    Science.gov (United States)

    Farmer, Thomas W.; Xie, Hongling

    2013-01-01

    In this commentary on the "Multiple Meanings of Peer Groups in Social Cognitive Mapping," Thomas W. Farmer and Hongling Xie discuss core issues in the identification of peer social groups in natural settings using the social cognitive mapping (SCM) procedures. Farmer and Xie applaud the authors for their efforts to advance the study of…

  14. Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang Ho Oh; Eung Soo Kim; Hee Cheon No; Nam Zin Cho

    2008-12-01

    The US Department of Energy is performing research and development (R&D) that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP) Program / GEN-IV Very High Temperature Reactor (VHTR). Phenomena identification and ranking studies (PIRT) to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Schultz et al., 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) are very high priority for the NGNP program. Following a loss of coolant and system depressurization, air will enter the core through the break. Air ingress leads to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heat-up of the bottom reflector and the reactor core and will cause the release of fission products eventually. The potential collapse of the bottom reflector because of burn-off and the release of CO lead to serious safety problems. For estimation of the proper safety margin we need experimental data and tools, including accurate multi-dimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. We also need to develop effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods R&D project. This project is focused on (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the bottom reflector, (d) structural tests of the burnt-off bottom reflector, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i

  15. FINAL REPORT on Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim; Hee C. NO; Nam Z. Cho

    2011-01-01

    The U.S. Department of Energy is performing research and development that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Generation IV very high temperature reactor (VHTR). Phenomena Identification and Ranking studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important. Consequently, the development of advanced air ingress-related models and verification & validation are of very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air ingress will occur through the break, leading to oxidation of the in-core graphite structure and fuel. This study indicates that depending on the location and the size of the pipe break, the air ingress phenomena are different. In an effort to estimate the proper safety margin, experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model are required. It will also require effective strategies to mitigate the effects of oxidation, eventually. This 3-year project (FY 2008–FY 2010) is focused on various issues related to the VHTR air-ingress accident, including (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the core bottom structures, (d) structural tests of the oxidized core bottom structures, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i) verification and validation of the coupled models.

  16. Evaluation of the DRAGON code for VHTR design analysis.

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    Taiwo, T. A.; Kim, T. K.; Nuclear Engineering Division

    2006-01-12

    This letter report summarizes three activities that were undertaken in FY 2005 to gather information on the DRAGON code and to perform limited evaluations of the code performance when used in the analysis of the Very High Temperature Reactor (VHTR) designs. These activities include: (1) Use of the code to model the fuel elements of the helium-cooled and liquid-salt-cooled VHTR designs. Results were compared to those from another deterministic lattice code (WIMS8) and a Monte Carlo code (MCNP). (2) The preliminary assessment of the nuclear data library currently used with the code and libraries that have been provided by the IAEA WIMS-D4 Library Update Project (WLUP). (3) DRAGON workshop held to discuss the code capabilities for modeling the VHTR.

  17. Identification and correction of previously unreported spatial phenomena using raw Illumina BeadArray data

    Directory of Open Access Journals (Sweden)

    Tavaré Simon

    2010-04-01

    Full Text Available Abstract Background A key stage for all microarray analyses is the extraction of feature-intensities from an image. If this step goes wrong, then subsequent preprocessing and processing stages will stand little chance of rectifying the matter. Illumina employ random construction of their BeadArrays, making feature-intensity extraction even more important for the Illumina platform than for other technologies. In this paper we show that using raw Illumina data it is possible to identify, control, and perhaps correct for a range of spatial-related phenomena that affect feature-intensity extraction. Results We note that feature intensities can be unnaturally high when in the proximity of a number of phenomena relating either to the images themselves or to the layout of the beads on an array. Additionally we note that beads neighbour beads of the same type more often than one might expect, which may cause concern in some models of hybridization. We highlight issues in the identification of a bead's location, and in particular how this both affects and is affected by its intensity. Finally we show that beads can be wrongly identified in the image on either a local or array-wide scale, with obvious implications for data quality. Conclusions The image processing issues identified will often pass unnoticed by an analysis of the standard data returned from an experiment. We detail some simple diagnostics that can be implemented to identify problems of this nature, and outline approaches to correcting for such problems. These approaches require access to the raw data from the arrays, not just the summarized data usually returned, making the acquisition of such raw data highly desirable.

  18. 850/sup 0/C VHTR plant technical description

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    This report describes the conceptual design of an 842-MW(t) process heat very high temperature reactor (VHTR) plant having a core outlet temperature of 850/sup 0/C (1562/sup 0/F). The reactor is a variation of the high-temperature gas-cooled reactor (HTGR) power plant concept. The report includes a description of the nuclear heat source (NHS) and of the balance of reactor plant (BORP) requirements. The design of the associated chemical process plant is not covered in this report. The reactor design is similar to a previously reported VHTR design having a 950/sup 0/C (1742/sup 0/F) core outlet temperature.

  19. VHTR Construction Ripple Effect using Inter-Industry Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T. H.; Lee, K. Y.; Shin, Y. J. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    As a part of a VHTR economic analysis, we have studied the VHTR construction cost and operation and maintenance cost. However, it is somewhat difficult to expect the exact cost due to insufficient reference data and experience. As a result, we propose quantitative analysis techniques for ripple effects such as the production inducement effect, added value inducement effect, and employment inducement effect for VHTR 600MWt x 4 module construction and operation ripple effect based on NOAK. This paper presents a new method for the ripple effect and preliminary ripple effect consequence. We proposed a ripple effect analysis method using a time series and inter-industry table. As a result, we can predict that a 600MWth x 4 module VHTR reactor construction will bring about a 43771 employment effect, 24160 billion KRW production effect, and 4472 billion added value effect for 22 years. It is necessary to use the sub-account values of an inter-industry table to obtain a more precise effect result. However, the methodology can be applied with minor modification to another reactor type.

  20. VHTR, ADS, and PWR spent nuclear fuel analysis

    Energy Technology Data Exchange (ETDEWEB)

    Salome, J.A.D.; Cardoso, F.; Velasquez, C.E.; Pereira, F.; Pereira, C. [Departamento de Engenharia Nuclear - Escola de Engenharia Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, Belo Horizonte MG, CEP: 31270-901 (Brazil); Instituto Nacional de Ciencias e Tecnologia de Reatores Nucleares Inovadores - CNPq, Rio de Janeiro (Brazil); Barros, G.P. [Comissao Nacional de Energia Nuclear - CNEN, Rua General Severiano 82, Botafogo, Rio de Janeiro, RJ, CEP: 22290-040 (Brazil)

    2016-07-01

    The aim of this study is to analyze and compare the discharged-spent fuel of 3 types of nuclear systems: a Very High-Temperature Gas Reactor (VHTR), a lead-cooled Accelerator-Driven System (ADS) and a standard Pressurized Water Reactor (PWR). The two first systems, VHTR, and ADS were designed to use reprocessed fuels. UREX+ and GANEX techniques were used for the reprocessing processes respectively. The fuel burnup simulated for the systems in other works have been used to obtain the final composition of the spent fuel discharged. After discharge, the radioactivity, the radiotoxicity, and the decay heat were evaluated through the ORIGEN 2.1 code until 10{sup 7} years and compared to the literature. The spent nuclear waste (SNF) coming from reprocessing techniques and burned up in advanced reactors show that the radiotoxicity decreases below a conventional SNF from a typical PWR for the time studied. The VHTR and ADs have higher values of radioactivity, radiotoxicity and decay heat, because of the greater concentrations of plutonium and curium in these reactors than in the PWR. Fission products have the greatest contribution for the first 25 years over the parameters studied for a PWR. The most harmful fission products are: Ba{sup 137m}, Tc{sup 99}, I{sup 129} and Nb{sup 93m} and for actinides is the plutonium and curium.

  1. Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 2: Accident and Thermal Fluids Analysis PIRTs

    Energy Technology Data Exchange (ETDEWEB)

    Ball, Sydney J [ORNL; Corradini, M. [University of Wisconsin; Fisher, Stephen Eugene [ORNL; Gauntt, R. [Sandia National Laboratories (SNL); Geffraye, G. [CEA, France; Gehin, Jess C [ORNL; Hassan, Y. [Texas A& M University; Moses, David Lewis [ORNL; Renier, John-Paul [ORNL; Schultz, R. [Idaho National Laboratory (INL); Wei, T. [Argonne National Laboratory (ANL)

    2008-03-01

    An accident, thermal fluids, and reactor physics phenomena identification and ranking process was conducted by a panel of experts on the next generation nuclear plant (NGNP) design (consideration given to both pebble-bed and prismatic gas-cooled reactor configurations). Safety-relevant phenomena, importance, and knowledge base were assessed for the following event classes: (1) normal operation (including some reactor physics aspects), (2) general loss of forced circulation (G-LOFC), (3) pressurized loss-of-forced circulation (P-LOFC), (4) depressurized loss-of-forced circulation (D-LOFC), (5) air ingress (following D-LOFC), (6) reactivity transients - including anticipated transients without scram (ATWS), (7) processes coupled via intermediate heat exchanger (IHX) (IHX failure with molten salt), and (8) steam/water ingress. The panel's judgment of the importance ranking of a given phenomenon (or process) was based on the effect it had on one or more figures of merit or evaluation criteria. These included public and worker dose, fuel failure, and primary (and other safety) system integrity. The major phenomena of concern that were identified and categorized as high importance combined with medium to low knowledge follow: (1) core coolant bypass flows (normal operation), (2) power/flux profiles (normal operation), (3) outlet plenum flows (normal operation), (4) reactivity-temperature feedback coefficients for high-plutonium-content cores (normal operation and accidents), (5) fission product release related to the transport of silver (normal operation), (6)emissivity aspects for the vessel and reactor cavity cooling system (G-LOFC), (7) reactor vessel cavity air circulation and heat transfer (G-LOFC), and (8)convection/radiation heating of upper vessel area (P-LOFC).

  2. Designing a TAC thermometer from a VHTR graphite structure

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    Smith, James A., E-mail: James.Smith@INL.gov; Kotter, Dale, E-mail: James.Smith@INL.gov [Fuel Performance and Design, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Garrett, Steven L.; Ali, Randall A. [Graduate Program in Acoustics, Penn State University, State College, PA (United States)

    2015-03-31

    The interior of a nuclear reactor presents a particularly harsh and challenging environment for both sensors and telemetry due to high temperatures and high fluxes of energetic and ionizing particles among the radioactive decay products. Very High Temperature Reactors are pushing the in core temperatures even higher. A unique sensing approach will be discussed to address the necessary high temperature measurements. Thermoacoustic thermometry exploits high temperatures and uses materials that are immune to the effects of ionizing radiation to create a temperature sensor that is self-powered and wireless. In addition, the form-factor for the Thermoacoustic Thermometer (TACT) can be designed to be integrated within common in-pile structures. There are no physical moving parts required for TACT and the sensor is self-powered, as it uses the nuclear fuel for its heat source. TACT data will be presented from a laboratory prototype mimicking the design necessary for a VHTR graphite structure.

  3. Topical report : NSTF facilities plan for water-cooled VHTR RCCS : normal operational tests.

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, M. T.; Kilsdonk, D. J.; Tzanos, C. P.; Lomperski, S.; Aeschlimann, R. W.; Nuclear Engineering Division

    2006-09-01

    As part of the Department of Energy (DOE) Generation IV roadmapping activity, the gas-cooled Very High Temperature Reactor (VHTR) has been selected as the principal concept for hydrogen production and other process-heat applications such as district heating and potable water production. On this basis, the DOE has selected the VHTR for additional R&D with the ultimate goal of demonstrating emission-free electricity and hydrogen production with this advanced reactor concept.

  4. FY-09 Report: Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2009-12-01

    The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Gen-IV very high temperature reactor (VHTR). Phenomena Identification and Ranking Studies to date have identified that an air ingress event following on the heels of a VHTR depressurization is a very important incident. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air will enter the core through the break, leading to oxidation of the in-core graphite structure and fuel. If this accident occurs, the oxidation will accelerate heat-up of the bottom reflector and the reactor core and will eventually cause the release of fission products. The potential collapse of the core bottom structures causing the release of CO and fission products is one of the concerns. Therefore, experimental validation with the analytical model and computational fluid dynamic (CFD) model developed in this study is very important. Estimating the proper safety margin will require experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. It will also require effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods Research and Development project. The second year of this three-year project (FY-08 to FY-10) was focused on (a) the analytical, CFD, and experimental study of air ingress caused by density-driven, stratified, countercurrent flow; (b) advanced graphite oxidation experiments and modeling; (c) experimental study of burn-off in the core bottom structures, (d) implementation of advanced

  5. Numerical investigation of the High Temperature Reactor (VHTR) using computational fluid dynamics; Investigacao numerica do Reator de Alta Temperatura (VHTR) utilizando fluidodinamica computacional

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Joao Pedro C.T.A.; Santos, Andre A. Campagnole dos; Mesquita, Amir Z., E-mail: jpctap@cdtn.br, E-mail: aacs@cdtn.br, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG),Belo Horizonte, MG (Brazil). Lab. de Termo-Hidraulica

    2013-07-01

    This work consists to evaluate and continue the study that is being developed in the Laboratory of Thermo-Hydraulics of the CNEN/CDTN (Centro de Desenvolvimento da Tecnologia Nuclear), aiming to validate the methods and procedures used in the numerical calculations of fluid flow in fuel elements of the core of the VHTR.

  6. TRISO fuel thermal simulations in the LS-VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Mario C.; Scari, Maria E.; Costa, Antonella L.; Pereira, Claubia; Veloso, Maria A.F., E-mail: marc5663@gmail.com, E-mail: melizabethscari@yahoo.com, E-mail: antonella@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Instituto Nacional de Ciência e Tecnologia de Reatores Nucleares Inovadores/CNPq (Brazil)

    2017-07-01

    The liquid-salt-cooled very high-temperature reactor (LS-VHTR) is a reactor that presents very good characteristics in terms of energy production and safety aspects. It uses as fuel the TRISO particles immersed in a graphite matrix with a cylindrical shape called fuel compact, as moderator graphite and as coolant liquid salt Li{sub 2}BeF{sub 4} called Flibe. This work evaluates the thermal hydraulic performance of the heat removal system and the reactor core by performing different simplifications to represent the reactor core and the fuel compact under steady-state conditions, starting the modeling from a single fuel element, until complete the studies with the entire core model developed in the RELAP5-3D code. Two models were considered for representation of the fuel compact, homogeneous and non-homogeneous models, as well as different geometries of the heat structures was considered. The aim to develop several models was to compare the thermal hydraulic characteristics resulting from the construction of a more economical and less discretized model with much more refined models that can lead to more complexes analyzes to representing TRISO effect particles in the fuel compact. The different results found, mainly, for the core temperature distributions are presented and discussed. (author)

  7. WAVE PROPAGATION in the HOT DUCT of VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Richard Schultz; Jim C. P. Liou

    2013-07-01

    In VHTR, helium from the reactor vessel is conveyed to a power conversion unit through a hot duct. In a hypothesized Depressurized Conduction Cooldown event where a rupture of the hot duct occurs, pressure waves will be initiated and reverberate in the hot duct. A numerical model is developed to quantify the transients and the helium mass flux through the rupture for such events. The flow path of the helium forms a closed loop but only the hot duct is modeled in this study. The lower plum of the reactor vessel and the steam generator are treated as specified pressure and/or temperature boundary to the hot duct. The model is based on the conservation principles of mass, momentum and energy, and on the equations of state for helium. The numerical solution is based on the method of characteristics with specified time intervals with a predictor and corrector algorithm. The rupture sub-model gives reasonable results. Transients induced by ruptures with break area equaling 20%, 10%, and 5% of the duct cross-sectional area are described.

  8. Very High Temperature Reactor (VHTR) Survey of Materials Research and Development Needs to Support Early Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Eric Shaber; G. Baccaglini; S. Ball; T. Burchell; B. Corwin; T. Fewell; M. Labar; P. MacDonald; P. Rittenhouse; Russ Vollam; F. Southworth

    2003-01-01

    The VHTR reference concept is a helium-cooled, graphite moderated, thermal neutron spectrum reactor with an outlet temperature of 1000 C or higher. It is expected that the VHTR will be purchased in the future as either an electricity producing plant with a direct cycle gas turbine or a hydrogen producing (or other process heat application) plant. The process heat version of the VHTR will require that an intermediate heat exchanger (IHX) and primary gas circulator be located in an adjoining power conversion vessel. A third VHTR mission - actinide burning - can be accomplished with either the hydrogen-production or gas turbine designs. The first ''demonstration'' VHTR will produce both electricity and hydrogen using the IHX to transfer the heat to either a hydrogen production plant or the gas turbine. The plant size, reactor thermal power, and core configuration will be designed to assure passive decay heat removal without fuel damage during accidents. The fuel cycle will be a once-through very high burnup low-enriched uranium fuel cycle. The purpose of this report is to identify the materials research and development needs for the VHTR. To do this, we focused on the plant design described in Section 2, which is similar to the GT-MHR plant design (850 C core outlet temperature). For system or component designs that present significant material challenges (or far greater expense) there may be some viable design alternatives or options that can reduce development needs or allow use of available (cheaper) materials. Nevertheless, we were not able to assess those alternatives in the time allotted for this report and, to move forward with this material research and development assessment, the authors of this report felt that it was necessary to use a GT-MHR type design as the baseline design.

  9. Paranormal phenomena

    Science.gov (United States)

    Gaina, Alex

    1996-08-01

    Critical analysis is given of some paranormal phenomena events (UFO, healers, psychokinesis (telekinesis))reported in Moldova. It is argued that correct analysis of paranormal phenomena should be made in the framework of electromagnetism.

  10. Liquid Salt Heat Exchanger Technology for VHTR Based Applications

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark; Sridhara, Kumar; Allen, Todd; Peterson, Per

    2012-10-11

    The objective of this research is to evaluate performance of liquid salt fluids for use as a heat carrier for transferring high-temperature process heat from the very high-temperature reactor (VHTR) to chemical process plants. Currently, helium is being considered as the heat transfer fluid; however, the tube size requirements and the power associated with pumping helium may not be economical. Recent work on liquid salts has shown tremendous potential to transport high-temperature heat efficiently at low pressures over long distances. This project has two broad objectives: To investigate the compatibility of Incoloy 617 and coated and uncoated SiC ceramic composite with MgCl2-KCl molten salt to determine component lifetimes and aid in the design of heat exchangers and piping; and, To conduct the necessary research on the development of metallic and ceramic heat exchangers, which are needed for both the helium-to-salt side and salt-to-process side, with the goal of making these heat exchangers technologically viable. The research will consist of three separate tasks. The first task deals with material compatibility issues with liquid salt and the development of techniques for on-line measurement of corrosion products, which can be used to measure material loss in heat exchangers. Researchers will examine static corrosion of candidate materials in specific high-temperature heat transfer salt systems and develop an in situ electrochemical probe to measure metallic species concentrations dissolved in the liquid salt. The second task deals with the design of both the intermediate and process side heat exchanger systems. Researchers will optimize heat exchanger design and study issues related to corrosion, fabrication, and thermal stresses using commercial and in-house codes. The third task focuses integral testing of flowing liquid salts in a heat transfer/materials loop to determine potential issues of using the salts and to capture realistic behavior of the salts in a

  11. A preliminary neutronic evaluation and depletion study of VHTR and LS-VHTR reactors using the codes: WIMSD5 and MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fabiano C.; Pereira, Claubia; Costa, Antonella Lombardi; Veloso, Maria Auxiliadora Fortini [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2009-07-01

    It is expected that, in the future, besides electricity generation, reactors should also develop secondary activities, such as hydrogen generation and seawater desalinization. Generation IV reactors are expected to possess special characteristics, like high safety, minimization of radioactive rejects amount and ability to use reprocessed fuel with non-proliferating projects in their cycles. Among the projects of IV generation reactors available nowadays, the (High Temperature Reactors) HTR, are highlighted due to these desirable characteristics. Under such circumstances, such reactor may be able to have significant higher thermal power ratings to be used for hydrogen production, without loose of safety, even in an emergency. For this work, we have chosen two HTR concepts of a prismatic reactor: (Very High Temperature Reactor) VHTR and the (Liquid Salted -Very High Temperature Reactor) LS-VHTR. The principal difference between them is the coolant. The VHTR uses helium gas as a coolant and have a burnup of 101,661 MWd/THM while the LS-VHTR uses low-pressure liquid coolant molten fluoride salt with a boiling point near 1500 de C working at 155,946 MWd/THM. The ultimate power output is limited by the capacity of the passive decay system; this capacity is limited by the reactor vessel temperature. The goal was to evaluate the neutronic behavior and fuel composition during the burnup using the codes (Winfrith Improved Multi-Group Scheme) WIMSD5 and the MCNPX2.6. The first, deterministic and the second, stochastic. For both reactors, burned fuel type 'C' coming from Angra-I nuclear plant, in Brazil, was used with 3.1% of initial enrichment, burnup to 33,000 MWd/THM using the ORIGEN2.1 code, divided in three steps of 11,000 MWd/THM, with an average density power of 37.75 MWd/THM and 5 years of cooling in pool. Finally, the fuel was reprocessed by Purex technique extracting 99.9% of Pu, and the desired amount of fissile material (15%) to achieve the final mixed

  12. Emissivity of Candidate Materials for VHTR Applicationbs: Role of Oxidation and Surface Modification Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Anderson, Mark; Cao, Guoping; Kulcinski, Gerald

    2011-07-25

    The Generation IV (GEN IV) Nuclear Energy Systems Initiative was instituted by the Department of Energy (DOE) with the goal of researching and developing technologies and materials necessary for various types of future reactors. These GEN IV reactors will employ advanced fuel cycles, passive safety systems, and other innovative systems, leading to significant differences between these future reactors and current water-cooled reactors. The leading candidate for the Next Generation Nuclear Plant (NGNP) to be built at Idaho National Lab (INL) in the United States is the Very High Temperature Reactor (VHTR). Due to the high operating temperatures of the VHTR, the Reactor Pressure Vessel (RPV) will partially rely on heat transfer by radiation for cooling. Heat expulsion by radiation will become all the more important during high temperature excursions during off-normal accident scenarios. Radiant power is dictated by emissivity, a material property. The NGNP Materials Research and Development Program Plan [1] has identified emissivity and the effects of high temperature oxide formation on emissivity as an area of research towards the development of the VHTR.

  13. Failure Predictions for VHTR Core Components using a Probabilistic Contiuum Damage Mechanics Model

    Energy Technology Data Exchange (ETDEWEB)

    Fok, Alex

    2013-10-30

    The proposed work addresses the key research need for the development of constitutive models and overall failure models for graphite and high temperature structural materials, with the long-term goal being to maximize the design life of the Next Generation Nuclear Plant (NGNP). To this end, the capability of a Continuum Damage Mechanics (CDM) model, which has been used successfully for modeling fracture of virgin graphite, will be extended as a predictive and design tool for the core components of the very high- temperature reactor (VHTR). Specifically, irradiation and environmental effects pertinent to the VHTR will be incorporated into the model to allow fracture of graphite and ceramic components under in-reactor conditions to be modeled explicitly using the finite element method. The model uses a combined stress-based and fracture mechanics-based failure criterion, so it can simulate both the initiation and propagation of cracks. Modern imaging techniques, such as x-ray computed tomography and digital image correlation, will be used during material testing to help define the baseline material damage parameters. Monte Carlo analysis will be performed to address inherent variations in material properties, the aim being to reduce the arbitrariness and uncertainties associated with the current statistical approach. The results can potentially contribute to the current development of American Society of Mechanical Engineers (ASME) codes for the design and construction of VHTR core components.

  14. Three-dimensional NDE of VHTR core components via simulation-based testing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Guzina, Bojan [Univ. of Minnesota, Minneapolis, MN (United States); Kunerth, Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-30

    A next generation, simulation-driven-and-enabled testing platform is developed for the 3D detection and characterization of defects and damage in nuclear graphite and composite structures in Very High Temperature Reactors (VHTRs). The proposed work addresses the critical need for the development of high-fidelity Non-Destructive Examination (NDE) technologies for as-manufactured and replaceable in-service VHTR components. Centered around the novel use of elastic (sonic and ultrasonic) waves, this project deploys a robust, non-iterative inverse solution for the 3D defect reconstruction together with a non-contact, laser-based approach to the measurement of experimental waveforms in VHTR core components. In particular, this research (1) deploys three-dimensional Scanning Laser Doppler Vibrometry (3D SLDV) as a means to accurately and remotely measure 3D displacement waveforms over the accessible surface of a VHTR core component excited by mechanical vibratory source; (2) implements a powerful new inverse technique, based on the concept of Topological Sensitivity (TS), for non-iterative elastic waveform tomography of internal defects - that permits robust 3D detection, reconstruction and characterization of discrete damage (e.g. holes and fractures) in nuclear graphite from limited-aperture NDE measurements; (3) implements state-of-the art computational (finite element) model that caters for accurately simulating elastic wave propagation in 3D blocks of nuclear graphite; (4) integrates the SLDV testing methodology with the TS imaging algorithm into a non-contact, high-fidelity NDE platform for the 3D reconstruction and characterization of defects and damage in VHTR core components; and (5) applies the proposed methodology to VHTR core component samples (both two- and three-dimensional) with a priori induced, discrete damage in the form of holes and fractures. Overall, the newly established SLDV-TS testing platform represents a next-generation NDE tool that surpasses

  15. Design considerations and experimental observations for the TAMU air-cooled reactor cavity cooling system for the VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Sulaiman, S. A., E-mail: shamsulamri@tamu.edu; Dominguez-Ontiveros, E. E., E-mail: elvisdom@tamu.edu; Alhashimi, T., E-mail: jbudd123@tamu.edu; Budd, J. L., E-mail: dubaiboy@tamu.edu; Matos, M. D., E-mail: mailgoeshere@gmail.com; Hassan, Y. A., E-mail: yhasssan@tamu.edu [Department of Nuclear Engineering, Texas A and M University, College Station, TX, 77843-3133 (United States)

    2015-04-29

    The Reactor Cavity Cooling System (RCCS) is a promising passive decay heat removal system for the Very High Temperature Reactor (VHTR) to ensure reliability of the transfer of the core residual and decay heat to the environment under all off-normal circumstances. A small scale experimental test facility was constructed at Texas A and M University (TAMU) to study pertinent multifaceted thermal hydraulic phenomena in the air-cooled reactor cavity cooling system (RCCS) design based on the General Atomics (GA) concept for the Modular High Temperature Gas-Cooled Reactor (MHTGR). The TAMU Air-Cooled Experimental Test Facility is ⅛ scale from the proposed GA-MHTGR design. Groundwork for experimental investigations focusing into the complex turbulence mixing flow behavior inside the upper plenum is currently underway. The following paper illustrates some of the chief design considerations used in construction of the experimental test facility, complete with an outline of the planned instrumentation and data acquisition methods. Computational Fluid Dynamics (CFD) simulations were carried out to furnish some insights on the overall behavior of the air flow in the system. CFD simulations assisted the placement of the flow measurement sensors location. Preliminary experimental observations of experiments at 120oC inlet temperature suggested the presence of flow reversal for cases involving single active riser at both 5 m/s and 2.25 m/s, respectively and four active risers at 2.25 m/s. Flow reversal may lead to thermal stratification inside the upper plenum by means of steady state temperature measurements. A Particle Image Velocimetry (PIV) experiment was carried out to furnish some insight on flow patterns and directions.

  16. Design considerations and experimental observations for the TAMU air-cooled reactor cavity cooling system for the VHTR

    Science.gov (United States)

    Sulaiman, S. A.; Dominguez-Ontiveros, E. E.; Alhashimi, T.; Budd, J. L.; Matos, M. D.; Hassan, Y. A.

    2015-04-01

    The Reactor Cavity Cooling System (RCCS) is a promising passive decay heat removal system for the Very High Temperature Reactor (VHTR) to ensure reliability of the transfer of the core residual and decay heat to the environment under all off-normal circumstances. A small scale experimental test facility was constructed at Texas A&M University (TAMU) to study pertinent multifaceted thermal hydraulic phenomena in the air-cooled reactor cavity cooling system (RCCS) design based on the General Atomics (GA) concept for the Modular High Temperature Gas-Cooled Reactor (MHTGR). The TAMU Air-Cooled Experimental Test Facility is ⅛ scale from the proposed GA-MHTGR design. Groundwork for experimental investigations focusing into the complex turbulence mixing flow behavior inside the upper plenum is currently underway. The following paper illustrates some of the chief design considerations used in construction of the experimental test facility, complete with an outline of the planned instrumentation and data acquisition methods. Computational Fluid Dynamics (CFD) simulations were carried out to furnish some insights on the overall behavior of the air flow in the system. CFD simulations assisted the placement of the flow measurement sensors location. Preliminary experimental observations of experiments at 120oC inlet temperature suggested the presence of flow reversal for cases involving single active riser at both 5 m/s and 2.25 m/s, respectively and four active risers at 2.25 m/s. Flow reversal may lead to thermal stratification inside the upper plenum by means of steady state temperature measurements. A Particle Image Velocimetry (PIV) experiment was carried out to furnish some insight on flow patterns and directions.

  17. Dynamic Simulation of Temperature Transition on the Secondary Helium Loop of a VHTR-SI Hydrogen Production System

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ji Woon; Shin, Young Joon; Lee, Tae Hoon; Lee, Ki Young; Kim, Yong Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Youn, Cheong [Chungnam National University, Daejeon (Korea, Republic of)

    2011-10-15

    A sulfur.iodine (SI) cycle coupled to a Very High Temperature Gas Cooled Reactor (VHTR) is one of the leading candidates of thermochemical cycles for hydrogen production. The SI cycle can be divided into three sections based on the chemical reactions: a Bunsen reaction (Section 1), sulfuric acid concentration and decomposition (Section 2), and a hydrogen iodine concentration and decomposition (Section 3). The heat required in the SI cycle can be supplied through an intermediate heat exchanger (IHX) by the VHTR. On the other hand, helium is used as a high-temperature energy carrier gas between the VHTR and the IHX or IHX and the SI cycle. In the SI cycle, the chemical reactors that receive thermal energy from the helium are a sulfuric acid vaporizer, sulfuric acid decomposer, sulfuric trioxide decomposer, and hydriodic acid decomposer including a pre-heating part. To simulate the dynamic behavior of the VHTR-SI cycle, the Korea Atomic Energy Research Institute -Dynamic Simulation Code (KAERI-DySCo) based on the Visual C++ has been prepared by the KAERI research group in 2010. KAERI-DySCo is integration application software, which includes several code modules that can solve the dynamic problem of the seven chemical reactors in the VHTR-SI cycle. In this paper, the dynamic behavior of the temperature transition on the secondary helium loop of the SI cycle has been simulated using KAERI-DySCo

  18. The Past, Present and Future of the Meteorological Phenomena Identification Near the Ground (mPING) Project

    Science.gov (United States)

    Elmore, K. L.

    2016-12-01

    The Metorological Phenomemna Identification NeartheGround (mPING) project is an example of a crowd-sourced, citizen science effort to gather data of sufficeint quality and quantity needed by new post processing methods that use machine learning. Transportation and infrastructure are particularly sensitive to precipitation type in winter weather. We extract attributes from operational numerical forecast models and use them in a random forest to generate forecast winter precipitation types. We find that random forests applied to forecast soundings are effective at generating skillful forecasts of surface ptype with consideralbly more skill than the current algorithms, especuially for ice pellets and freezing rain. We also find that three very different forecast models yuield similar overall results, showing that random forests are able to extract essentially equivalent information from different forecast models. We also show that the random forest for each model, and each profile type is unique to the particular forecast model and that the random forests developed using a particular model suffer significant degradation when given attributes derived from a different model. This implies that no single algorithm can perform well across all forecast models. Clearly, random forests extract information unavailable to "physically based" methods because the physical information in the models does not appear as we expect. One intersting result is that results from the classic "warm nose" sounding profile are, by far, the most sensitive to the particular forecast model, but this profile is also the one for which random forests are most skillful. Finally, a method for calibrarting probabilties for each different ptype using multinomial logistic regression is shown.

  19. Development of Advanced Suite of Deterministic Codes for VHTR Physics Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Seog; Cho, J. Y.; Lee, K. H. (and others)

    2007-07-15

    Advanced Suites of deterministic codes for VHTR physics analysis has been developed for detailed analysis of current and advanced reactor designs as part of a US-ROK collaborative I-NERI project. These code suites include the conventional 2-step procedure in which a few group constants are generated by a transport lattice calculation, and the reactor physics analysis is performed by a 3-dimensional diffusion calculation, and a whole core transport code that can model local heterogeneities directly at the core level. Particular modeling issues in physics analysis of the gas-cooled VHTRs were resolved, which include a double heterogeneity of the coated fuel particles, a neutron streaming in the coolant channels, a strong core-reflector interaction, and large spectrum shifts due to changes of the surrounding environment, temperature and burnup. And the geometry handling capability of the DeCART code were extended to deal with the hexagonal fuel elements of the VHTR core. The developed code suites were validated and verified by comparing the computational results with those of the Monte Carlo calculations for the benchmark problems.

  20. Development of the HELIOS/MASTER 2-Step Procedure for the Prismatic VHTR Physics Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Seog; Cho, Jin Young; Noh, Jae Man

    2007-05-15

    A new physics analysis procedure has been developed for a prismatic very high temperature gas-cooled reactor based on a conventional two-step procedure for the PWR physics analysis. The HELIOS and MASTER codes were employed to generate the coarse group cross sections through a transport lattice calculation, and to perform the 3-dimensional core physics analysis by a nodal diffusion calculation, respectively. Physics analysis of the prismatic VHTRs involves particular modeling issues such as a double heterogeneity of the coated fuel particles, a neutron streaming in the coolant channels, a strong core-reflector interaction, and large spectrum shifts due to changes of the surrounding environment and state parameters. Double heterogeneity effect was considered by using a recently developed reactivity equivalent physical transformation method. Neutron streaming effect was quantified through 3-dimensional Monte Carlo transport calculations by using the MCNP code. Strong core-reflector interaction could be handled by applying an equivalence theory to the generation of the reflector cross sections. The effects of a spectrum shift could be covered by optimizing the coarse energy group structure. A two-step analysis procedure was established for the prismatic VHTR physics analysis by combining all the methodologies described above. The applicability of our code system was tested against core benchmark problems. The results of these benchmark tests show that our code system is very accurate and practical for a prismatic VHTR physics analysis.

  1. Scoping Analyses on Tritium Permeation to VHTR Integarted Industrial Application Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2011-03-01

    Tritium permeation is a very important current issue in the very high temperature reactor (VHTR) because tritium is easily permeated through high temperature metallic surfaces. Tritium permeations in the VHTR-integrated systems were investigated in this study using the tritium permeation analysis code (TPAC) that was developed by Idaho National Laboratory (INL). The INL TPAC is a numerical tool that is based on the mass balance equations of tritium containing species and hydrogen (i.e. HT, H2, HTO, HTSO4, TI) coupled with a variety of tritium sources, sink, and permeation models. In the TPAC, ternary fission and thermal neutron caption reactions with 6Li, 7Li 10B, 3He were taken into considerations as tritium sources. Purification and leakage models were implemented as main tritium sinks. Permeation of tritium and H2 through pipes, vessels, and heat exchangers were considered as main tritium transport paths. In addition, electroyzer and isotope exchange models were developed for analyzing hydrogen production systems including high temperature electrolysis (HTSE) and sulfur-iodine processes.

  2. Computer Program for Equipment Sizing on the Secondary Helium Loop of a VHTR-SI Hydrogen Production System

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ji Woon; Kim, Ji Hwan; Shin, Young Joon; Lee, Tae Hoon; Lee, Ki Young; Kim, Yong Wan; Chang, Jong Hwa [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Youn, Cheong [Chungnam National University, Daejeon (Korea, Republic of)

    2010-10-15

    The Sulfur-Iodine (SI) process coupled to a very high temperature gas-cooled reactor (VHTR) is well known as a feasible technology to produce hydrogen. The SI process can be divided into three sections based on the chemical reactions a Bunsen reaction (Section 1), a Sulfur acid concentration and decomposition (Section 2) and a hydrogen iodine concentration and decomposition (Section 3). The heat required in the SI process can be supplied through an intermediate heat exchanger (IHX) by the VHTR. On the other hand, Helium is used as a high temperature energy carrier gas between the VHTR and the IHX or the IHX and the SI process. In the SI process, chemical reactors that receive thermal energy from the helium are: A sulfuric acid vaporizer, a sulfuric acid decomposer, a sulfuric trioxide decomposer, and a hydriodic acid decomposer including pre-heating par. The sizing of such chemical reactors is essentially required for dynamic simulation of the VHTR-SI process. In this paper, a sizing program which can calculate the sizing of each chemical reactor to satisfy mass and energy balance at a given operation condition has been introduced. A graphic user interface (GUI) to visualize calculated sizing results of the chemical reactors has been added for the effective program operation

  3. Heat Exchanger Design Options and Tritium Transport Study for the VHTR System

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2008-09-01

    This report presents the results of a study conducted to consider heat exchanger options and tritium transport in a very high temperature reactor (VHTR) system for the Next Generation Nuclear Plant Project. The heat exchanger options include types, arrangements, channel patterns in printed circuit heat exchangers (PCHE), coolant flow direction, and pipe configuration in shell-and-tube designs. Study considerations include: three types of heat exchanger designs (PCHE, shell-and-tube, and helical coil); single- and two-stage unit arrangements; counter-current and cross flow configurations; and straight pipes and U-tube designs in shell-and-tube type heat exchangers. Thermal designs and simple stress analyses were performed to estimate the heat exchanger options, and the Finite Element Method was applied for more detailed calculations, especially for PCHE designs. Results of the options study show that the PCHE design has the smallest volume and heat transfer area, resulting in the least tritium permeation and greatest cost savings. It is theoretically the most reliable mechanically, leading to a longer lifetime. The two-stage heat exchanger arrangement appears to be safer and more cost effective. The recommended separation temperature between first and second stages in a serial configuration is 800oC, at which the high temperature unit is about one-half the size of the total heat exchanger core volume. Based on simplified stress analyses, the high temperature unit will need to be replaced two or three times during the plant’s lifetime. Stress analysis results recommend the off-set channel pattern configuration for the PCHE because stress reduction was estimated at up to 50% in this configuration, resulting in a longer lifetime. The tritium transport study resulted in the development of a tritium behavior analysis code using the MATLAB Simulink code. In parallel, the THYTAN code, previously performed by Ohashi and Sherman (2007) on the Peach Bottom data, was revived

  4. Development of Barrier Layers for the Protection of Candidate Alloys in the VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Carlos G. [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States); Jones, J. Wayne [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States); Pollock, Tresa M. [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States); Was, Gary S. [Battelle Energy Alliance, LLC, Idaho Falls, ID (United States)

    2015-01-22

    The objective of this project was to develop concepts for barrier layers that enable leading candi- date Ni alloys to meet the longer term operating temperature and durability requirements of the VHTR. The concepts were based on alpha alumina as a primary surface barrier, underlay by one or more chemically distinct alloy layers that would promote and sustain the formation of the pro- tective scale. The surface layers must possess stable microstructures that provide resistance to oxidation, de-carburization and/or carburization, as well as durability against relevant forms of thermo-mechanical cycling. The system must also have a self-healing ability to allow endurance for long exposure times at temperatures up to 1000°C.

  5. VHTR-based Nuclear Hydrogen Plant Analysis for Hydrogen Production with SI, HyS, and HTSE Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Youngjoon; Lee, Taehoon; Lee, Kiyoung; Kim, Minhwan [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this paper, analyses of material and heat balances on the SI, HyS, and HTSE processes coupled to a Very High Temperature gas-cooled Reactor (VHTR) were performed. The hydrogen production efficiency including the thermal to electric energy ratio demanded from each process is found and the normalized evaluation results obtained from three processes are compared to each other. The currently technological issues to maintain the long term continuous operation of each process will be discussed at the conference site. VHTR-based nuclear hydrogen plant analysis for hydrogen production with SI, HyS, and HTSE facilities has been carried out to determine the thermal efficiency. It is evident that the thermal to electrical energy ratio demanded from each hydrogen production process is an important parameter to select the adequate process for hydrogen production. To improve the hydrogen production efficiency in the SI process coupled to the VHTR without electrical power generation, the demand of electrical energy in the SI process should be minimized by eliminating an electrodialysis step to break through the azeotrope of the HI/I{sub 2}/H{sub 2}O ternary aqueous solution.

  6. Very High-Temperature Reactor (VHTR) Proliferation Resistance and Physical Protection (PR&PP)

    Energy Technology Data Exchange (ETDEWEB)

    Moses, David Lewis [ORNL

    2011-10-01

    This report documents the detailed background information that has been compiled to support the preparation of a much shorter white paper on the design features and fuel cycles of Very High-Temperature Reactors (VHTRs), including the proposed Next-Generation Nuclear Plant (NGNP), to identify the important proliferation resistance and physical protection (PR&PP) aspects of the proposed concepts. The shorter white paper derived from the information in this report was prepared for the Department of Energy Office of Nuclear Science and Technology for the Generation IV International Forum (GIF) VHTR Systems Steering Committee (SSC) as input to the GIF Proliferation Resistance and Physical Protection Working Group (PR&PPWG) (http://www.gen-4.org/Technology/horizontal/proliferation.htm). The short white paper was edited by the GIF VHTR SCC to address their concerns and thus may differ from the information presented in this supporting report. The GIF PR&PPWG will use the derived white paper based on this report along with other white papers on the six alternative Generation IV design concepts (http://www.gen-4.org/Technology/systems/index.htm) to employ an evaluation methodology that can be applied and will evolve from the earliest stages of design. This methodology will guide system designers, program policy makers, and external stakeholders in evaluating the response of each system, to determine each system's resistance to proliferation threats and robustness against sabotage and terrorism threats, and thereby guide future international cooperation on ensuring safeguards in the deployment of the Generation IV systems. The format and content of this report is that specified in a template prepared by the GIF PR&PPWG. Other than the level of detail, the key exception to the specified template format is the addition of Appendix C to document the history and status of coated-particle fuel reprocessing technologies, which fuel reprocessing technologies have yet to be

  7. Numerical and experimental investigation on labyrinth seal mechanism for bypass flow reduction in prismatic VHTR core

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Su-Jong, E-mail: paper80@snu.ac.r [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Lee, Jeong-Hun [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Lee, Sang-Moon [Department of Mechanical Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Incheon 402-751 (Korea, Republic of); Tak, Nam-il; Kim, Min-Hwan [Korea Atomic Energy Research Institute, 150-1 Deokjin-Dong, 1045 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Kwang-Yong [Department of Mechanical Engineering, Inha University, 253 Yonghyun-Dong, Nam-Gu, Incheon 402-751 (Korea, Republic of); Park, Goon-Cherl [Department of Nuclear Engineering, Seoul National University, San 56-1, Daehak-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of)

    2013-09-15

    Highlights: • Bypass flow reduction method was developed by applying labyrinth seal mechanism. • Grooves on side walls of replaceable reflector block were made. • Design of the grooved wall of the reflector block was optimized by the RSA method. • The flow resistance of the bypass gap rose from 18.04 to 26.24 by the optimization. • The bypass ratios at the inlet and outlet were reduced by 36.19% and 14.66%, respectively. -- Abstract: Core bypass flow in block type very high temperature reactor (VHTR) occurs due to the inevitable gaps between the hexagonal core blocks for the block installation and refueling. Since the core bypass flow affects the reactor safety and efficiency, it should be minimized to enhance the core thermal margin. In this regard, the core bypass flow reduction method applying the labyrinth seal mechanism was developed and optimized by using the single-objective shape optimization method. Response surface approximation (RSA) method was adopted as the optimization method. Side wall of the replaceable reflector block was redesigned and response surface approximate model was adopted to optimize the shape of the reflector wall. Computational fluid dynamics (CFD) analyses were carried out not only to assess the limitation of existing method of bypass flow reduction, but also to optimize the design of a newly developed reduction method. The experiment with Seoul National University (SNU) multi-block experimental facility was performed to demonstrate the performance of the reduction method. It was found that the effect of the existing bypass flow reduction method by sealing the bypass gap exit was restricted nearby the lower region of the core. However, the flow resistance factor of the bypass gap increased from 18.04 to 26.24 by the optimized reduction method. The results of the performance test showed that the bypass flow distribution was reduced throughout the entire core regions. The bypass flow ratios at the inlet and the outlet were

  8. A Research Status on High-Temperature Creep of Alloy 617 for Use in VHTR System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woo-Gon; Park, Jae-Young; Kim, Eung-Seon; Kim, Yong-Wan; Kim, Min-Hwan [KAERI, Daejeon (Korea, Republic of); Kim, Seon-Jin [Pukyong National Univ., Busan (Korea, Republic of)

    2016-05-15

    In this study, a research status on creep works of Alloy 617 conducting at KAERI was introduced and summarized. Various experimental creep data and creep constants obtained in the air/helium environments and base/weld metals were presented and discussed using various creep equations and parameters. The draft Code Case is a modification from ASME Section III Subsection NH that was put forth by a special task force of the ASME subgroup that deals with elevated temperature design. The primary intended application of the draft Code Case is a VHTR. Presently, various creep data for Alloy 617 are being accumulated through Generation-IV forum (GIF) Material Handbook Database of a next-generation nuclear plant research and development. As per this, a new Alloy 617 Code Case is planned to be approved by 2017. However, to do so, various creep data and creep constants in air/helium environments, and base/weld metals etc. should be obtained to help draft the new Code Case, and creep behavior should be investigated through systematic analysis of a wide range of creep temperature and stress conditions. Using various creep equations and parameters, the creep constants were determined for design use of Alloy 617. The stress of the He environment was more reduced than that of the air one. As the stress increases, the creep rate of WM was significantly lower than that of BM. The reason for this was that the rupture elongation of WM was largely reduced compared with that of BM.

  9. Analysis of Creep Crack Growth Behavior of Alloy 617 for Use in a VHTR System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woo-Gon; Kim, Min-Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jae-Young; Ekaputra, I. M. W.; Kim, Seon-Jin [Pukyong National University, Busan (Korea, Republic of)

    2015-05-15

    Alloy 617 is a major candidate material for the IHX component. The design of the component, which will operate well into the creep range, will require a good understanding of creep crack growth deformation. Efforts are now being undertaken in the Gen-IV program to provide data needed for the design and licensing of the nuclear plants, and with this goal in mind, to meet the needs of the conceptual designers of the VHTR system, 'Gen-IV Materials Handbook' is being established through an international collaboration program of GIF (Gen-IV Forum) countries. To logically obtain the B and q values in the CCGR equation, three methods in terms of LSFM, MVM, and PDM were adopted. The PDM was most useful. Both the B and q coefficients followed a lognormal distribution. Using a lognormal distribution in the PDM, a number of random variables were generated by Monte Carlo Simulation, and the CCGR lines could be successfully predicted from the viewpoint of reliability.

  10. CEA and AREVA R and D on V/HTR fuel fabrication with the CAPRI experimental manufacturing line

    Energy Technology Data Exchange (ETDEWEB)

    Charollais, Francois; Fonquernie, Sophie; Perrais, Christophe [DEN/CAD/DEC/SPUA, CEA, Centre de Cadarache, F-13108 Saint Paul lez Durance (France); Perez, Marc [DRT/GRE/DTEN/S3ME, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France); Cellier, Francois [FRAMATOME ANP, 10, rue Juliette Recamier, F-69456 Lyon cedex (France); Vitali, Marie-Pierre [CERCA Romans, FRAMATOME ANP, 10, rue Juliette Recamier, F-69456 Lyon cedex (France)

    2006-07-01

    In the framework of the French V/HTR fuel development and qualification program, the Commissariat a l'Energie Atomique (CEA) and AREVA through its program called ANTARES (Areva New Technology for Advanced Reactor Energy Supply) conduct R and D projects covering the mastering of UO{sub 2} coated particle and fuel compact fabrication technology. To fulfill this task, a review of past knowledge, of existing technologies and a preliminary laboratory scale work program have been conducted with the aim of retrieving the know-how on HTR coated particle and compact manufacture: - The different stages of UO{sub 2} kernel fabrication GSP Sol-Gel process have been reviewed, reproduced and improved; - The experimental conditions for the chemical vapour deposition (CVD) of coatings have been defined on dummy kernels and development of innovative characterization methods has been carried out; - Former CERCA compacting process has been reviewed and updated. In parallel, an experimental manufacturing line for coated particles, named GAIA, and a compacting line based on former CERCA compacting experience have been designed, constructed and are in operation since early 2005 at CEA Cadarache and CERCA Romans, respectively. These two facilities constitute the CAPRI line (CEA and AREVA PRoduction Integrated line). The major objectives of the CAPRI line are: - to recover and validate past knowledge; - to permit the optimisation of reference fabrication processes for kernels and coatings and the investigation of alternative and innovative fuel design (UCO kernel, ZrC coating); - to test alternative compact process options; - to fabricate and characterize fuel required for irradiation and qualification purpose; - to specify needs for the fabrication of representative V/HTR TRISO fuel meeting industrial standards. This paper presents the progress status of the R and D conducted on V/HTR fuel particle and compact manufacture by mid 2005. (authors)

  11. Parametric Study on the Tensile Properties of Ni-Based Alloy for a VHTR

    Science.gov (United States)

    Kim, Dong-Jin; Jung, Su Jin; Mun, Byung Hak; Kim, Sung Woo; Lim, Yun Soo

    2015-01-01

    A very high-temperature reactor (VHTR) has been studied among generation IV nuclear power plants owing to its many advantages such as high-electric efficiency and massive hydrogen production. The material used for the heat exchanger should sustain structural integrity for its life even though the material is exposed to a harsh environment at 1223 K (950 °C) in an impure helium coolant. Therefore, an enhancement of the material performance at high temperature gives a margin in determining the operating temperature and life time. This work is an effort to find an optimum combination of alloying elements and processing parameters to improve the material performance. The tensile property and microstructure for nickel-based alloys fabricated in a laboratory were evaluated as a function of the heat treatment, cold working, and grain boundary strengthener using a tension test at 1223 K (950 °C), scanning electron microscopy, and transmission electron microscopy. Elongation to rupture was increased by additional heat treatment and cold working, followed by additional heat treatment in the temperature range from 1293 K to 1383 K (1020 °C to 1110 °C) implying that the intergranular carbide contributes to grain boundary strengthening. The temperature at which the grain boundary is improved by carbide decoration was higher for a cold-worked specimen, which was described by the difference in carbide stability and carbide formation kinetics between no cold-worked and cold-worked specimens. Zr and Hf played a scavenging effect of harmful elements causing an increase in ductility.

  12. CFD analysis of the VHTR prismatic core with variation of geometry parameters

    Energy Technology Data Exchange (ETDEWEB)

    Lira, Carlos A.B.O.; Paiva, Pedro P.D.S., E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear

    2017-11-01

    The Very High Temperature Reactor is a thermal, graphite moderated and helium cooled nuclear reactor. The purpose of this work is to study the behavior of the VHTR by means of parametric analysis, altering the energy generation profile in the fuel blocks and the influence of modifications in the geometry itself. The coolant flow through the coolant channels and by-pass channels were analyzed in a 1/12{sup th} section of a fuel block column. Geometry was used with by-pass channels of different dimensions, besides one that had only the cooling channels, without by-pass channel. It has been found that the existence of a by-pass flow induces an increase in the temperature gradient in the fuel block. Comparative studies were performed between the results obtained in simulations carried out with different profiles of thermal energy generation (uniform and sinusoidal) in the fuel channels. It was verified that when there is the same total thermal energy generation in the fuel block, the maximum temperature observed in each of the materials is smaller for the generation with sinusoidal profile. Computer simulations were performed using a geometry with a central channel with the same diameter as the others to verify the hypothesis that the existence of a temperature gradient in the fuel block, with the highest temperature at the center and the lowest temperature being at the periphery of this block, is due to the smaller dimension of the coolant channel located in the center of this block. The results obtained confirm the hypothesis. (author)

  13. Computational fluid dynamics analysis of the initial stages of a VHTR air-ingress accident using a scaled-down model

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Tae K., E-mail: taekyu8@gmail.com [Nuclear Engineering Program, The Ohio State University, Columbus, OH 43210 (United States); Arcilesi, David J., E-mail: arcilesi.1@osu.edu [Nuclear Engineering Program, The Ohio State University, Columbus, OH 43210 (United States); Kim, In H., E-mail: ihkim0730@gmail.com [Nuclear Engineering Program, The Ohio State University, Columbus, OH 43210 (United States); Sun, Xiaodong, E-mail: sun.200@osu.edu [Nuclear Engineering Program, The Ohio State University, Columbus, OH 43210 (United States); Christensen, Richard N., E-mail: rchristensen@uidaho.edu [Nuclear Engineering Program, The Ohio State University, Columbus, OH 43210 (United States); Oh, Chang H. [Idaho National Laboratory, Idaho Falls, ID 83402 (United States); Kim, Eung S., E-mail: kes7741@snu.ac.kr [Idaho National Laboratory, Idaho Falls, ID 83402 (United States)

    2016-04-15

    Highlights: • Uncertainty quantification and benchmark study are performed to validate an ANSYS FLUENT computer model for a depressurization process in a high-temperature gas-cooled reactor. • An ANSYS FLUENT computer model of a 1/8th scaled-down geometry of a VHTR hot exit plenum is presented, which is similar to the experimental test facility that has been constructed at The Ohio State University. • Using the computer model of the scaled-down geometry, the effects of the depressurization process and flow oscillations on the subsequent density-driven stratified flow phenomenology are examined computationally. • The effects of the scaled-down hot exit plenum internal structure temperature on the density-driven stratified flow phenomenology are investigated numerically. - Abstract: An air-ingress accident is considered to be one of the design basis accidents of a very high-temperature gas-cooled reactor (VHTR). The air-ingress accident is initiated, in its worst-case scenario, by a complete break of the hot duct in what is referred to as a double-ended guillotine break. This leads to an initial loss of the primary helium coolant via depressurization. Following the depressurization process, the air–helium mixture in the reactor cavity could enter the reactor core via the hot duct and hot exit plenum. In the event that air ingresses into the reactor vessel, the high-temperature graphite structures in the reactor core and hot plenum will chemically react with the air, which could lead to damage of in-core graphite structures and fuel, release of carbon monoxide and carbon dioxide, core heat up, failure of the structural integrity of the system, and eventually the release of radionuclides to the environment. Studies in the available literature focus on the phenomena of the air ingress accident that occur after the termination of the depressurization, such as density-driven stratified flow, molecular diffusion, and natural circulation. However, a recent study

  14. Evaluation of the heat transfer in a geological repository concept containing PWR, VHTR and hybrid ads-fission spent fuels

    Energy Technology Data Exchange (ETDEWEB)

    Jonusan, Raoni A.S.; Pereira, Fernando; Velasquez, Carlos E.; Salome, Jean A.D.; Cardoso, Fabiano; Pereira, Claubia; Fortini, Angela, E-mail: claubia@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-11-01

    The investigation of the thermal behavior of spent fuel (SF) materials is essential to determining appropriate potential sites to accommodate geological repositories as well as the design of canisters, considering their potential risk to people health and of environmental contamination. This work presents studies of the temperature in a canister containing spent fuels discharged from Pressurized Water Reactor (PWR), Very High-Temperature Reactor (VHTR) and Accelerator-Driven Subcritical Reactor System (ADS) reactor systems in a geological repository concept. The thermal analyses were performed with the software ANSYS, which is widely used to solve engineering problems through the Finite Element Method. The ANSYS Transient Thermal module was used. The spent nuclear fuels were set as heat sources using data of previous studies derived from decay heat curves. The studies were based on comparison of the mean temperature on a canister surface along the time under geological disposal conditions, for a same amount of each type of spent nuclear fuel evaluated. The results conclude that fuels from VHTR and ADS systems are inappropriate to be disposed in a standardized PWR canister, demanding new studies to determine the optimal amount of spent fuel and new internal canister geometries. It is also possible to conclude that the hypothetical situation of a single type of canister being used to accommodate different types of spent nuclear fuels is not technically feasible. (author)

  15. Initial Comparison of Baseline Physical and Mechanical Properties for the VHTR Candidate Graphite Grades

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Mark C. [Idaho National Lab. (INL), Idaho Falls, ID (United States). VHTR Program

    2014-09-01

    High-purity graphite is the core structural material of choice in the Very High Temperature Reactor (VHTR) design, a graphite-moderated, helium-cooled configuration capable of producing thermal energy for power generation as well as process heat for industrial applications that require temperatures higher than the outlet temperatures of present nuclear reactors. The Baseline Graphite Characterization Program is establishing accurate as-manufactured mechanical and physical property distributions in nuclear-grade graphites by providing comprehensive data that captures the level of variation in measured values. In addition to providing a thorough comparison between these values in different graphite grades, the program is also carefully tracking individual specimen source, position, and orientation information in order to provide comparisons both in specific properties and in the associated variability between different lots, different billets, and different positions from within a single billet. This report is a preliminary comparison between each of the grades of graphite that are considered “candidate” grades from four major international graphite producers. These particular grades (NBG-18, NBG-17, PCEA, IG-110, and 2114) are the major focus of the evaluations presently underway on irradiated graphite properties through the series of Advanced Graphite Creep (AGC) experiments. NBG-18, a medium-grain pitch coke graphite from SGL from which billets are formed via vibration molding, was the favored structural material in the pebble-bed configuration. NBG-17 graphite from SGL is essentially NBG-18 with the grain size reduced by a factor of two. PCEA, petroleum coke graphite from GrafTech with a similar grain size to NBG-17, is formed via an extrusion process and was initially considered the favored grade for the prismatic layout. IG-110 and 2114, from Toyo Tanso and Mersen (formerly Carbone Lorraine), respectively, are fine-grain grades produced via an isomolding

  16. Materials for the very high temperature reactor (VHTR): a versatile nuclear power station for combined cycle electricity and heat production

    Energy Technology Data Exchange (ETDEWEB)

    Hoffelner, W

    2005-07-01

    The International Generation IV Initiative provides a research platform for the development of advanced nuclear plants which are able to produce electricity and heat in a combined cycle. Very high-temperature gas-cooled reactors are considered as near-term deployable plants meeting these requirements. They build on high-temperature gas-cooled reactors which are already in operation. The main parts of such an advanced plant are: reactor pressure vessel, core and close-to-core components, gas turbine, intermediate heat exchanger, and hydrogen production unit. The paper discusses the VHTR concept, materials, fuel and hydrogen production based on discussions on research and development projects addressed within the generation IV community. It is shown that material limitations might restrict the outlet temperature of near-term deployable VHTRs to about 950 {sup o}C. The impact of the high temperatures on fuel development is also discussed. Current status of combined cycle hydrogen production is elaborated on. (author)

  17. Nonequilibrium Phenomena in Plasmas

    CERN Document Server

    Sharma, A Surjalal

    2005-01-01

    The complexity of plasmas arises mainly from their inherent nonlinearity and far from equilibrium nature. The nonequilibrium behavior of plasmas is evident in the natural settings, for example, in the Earth's magnetosphere. Similarly, laboratory plasmas such as fusion bottles also have their fair share of complex behavior. Nonequilibrium phenomena are intimately connected with statistical dynamics and form one of the growing research areas in modern nonlinear physics. These studies encompass the ideas of self-organization, phase transition, critical phenomena, self-organized criticality and turbulence. This book presents studies of complexity in the context of nonequilibrium phenomena using theory, modeling, simulations, and experiments, both in the laboratory and in nature.

  18. Nonlinear surface electromagnetic phenomena

    CERN Document Server

    Ponath, H-E

    1991-01-01

    In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are

  19. Science and Paranormal Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Noyes, H. Pierre

    1999-06-03

    In order to ground my approach to the study of paranormal phenomena, I first explain my operational approach to physics, and to the ''historical'' sciences of cosmic, biological, human, social and political evolution. I then indicate why I believe that ''paranormal phenomena'' might-but need not- fit into this framework. I endorse the need for a new theoretical framework for the investigation of this field presented by Etter and Shoup at this meeting. I close with a short discussion of Ted Bastin's contention that paranormal phenomena should be defined as contradicting physics.

  20. Ultrashort Laser Pulse Phenomena

    CERN Document Server

    Diels, Jean-Claude

    2006-01-01

    Ultrashort Laser Pulse Phenomena, 2e serves as an introduction to the phenomena of ultra short laser pulses and describes how this technology can be used to examine problems in areas such as electromagnetism, optics, and quantum mechanics. Ultrashort Laser Pulse Phenomena combines theoretical backgrounds and experimental techniques and will serve as a manual on designing and constructing femtosecond (""faster than electronics"") systems or experiments from scratch. Beyond the simple optical system, the various sources of ultrashort pulses are presented, again with emphasis on the basic

  1. Dropout Phenomena at Universities

    DEFF Research Database (Denmark)

    Larsen, Michael Søgaard; Kornbeck, Kasper Pihl; Kristensen, Rune

    Dropout from university studies comprises a number of complex phenomena with serious complex consequences and profound political attention. Further analysis of the field is, therefore, warranted. Such an analysis is offered here as a systematic review which gives answers based on the best possible...... evidence found in the research field comprised by the three review questions to be addressed. The aims of this systematic review can, thus, be summarized like this: Which answers can be offered from research in relation to the following questions: What is dropout from university studies? Why do...... such dropout phenomena occur at universities? What can be done by the universities to prevent or reduce such dropout phenomena?...

  2. Interfacial transport phenomena

    CERN Document Server

    Slattery, John C; Oh, Eun-Suok

    2007-01-01

    Revised and updated extensively from the previous editionDiscusses transport phenomena at common lines or three-phase lines of contactProvides a comprehensive summary about the extensions of continuum mechanics to the nanoscale.

  3. Application of the identification methods from Hilbert and Prony to the study of oscillatory phenomena in electrical power systems; Aplicacion de los metodos de identificacion de Hilbert y Prony al estudio de fenomenos oscilatorios en sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Andrade Soto, Manuel Antonio

    2002-10-15

    In the present thesis work the application of identification techniques is investigated based on methods of spectral analysis to the study of the instantaneous characteristics of signals obtained by means of digital simulation of the dynamic behavior of the power system. The study focuses on the perspectives developed from two different approaches of analysis: the use of lineal methods of spectral analysis and the use of methods of non-lineal analysis, based on the concept of an analytical signal. The developed tools are applied to the study of two phenomena of electromechanical origin of different characteristics in complex power systems. A comparison between the results obtained is performed for these techniques and the possibility of its application is discussed for the problem of on-line identification in power systems. [Spanish] En el presente trabajo de tesis se investiga la aplicacion de tecnicas de identificacion basadas en metodos de analisis espectral al estudio de las caracteristicas instantaneas de senales obtenidas mediante simulacion digital del comportamiento dinamico del sistema de potencia. El estudio se centra en las aproximaciones desarrolladas desde dos enfoques distintos de analisis: la utilizacion de metodos lineales de analisis espectral y la utilizacion de metodos de analisis no lineal, basados en el concepto de una senal analitica. Las herramientas desarrolladas se aplican al estudio de dos fenomenos de origen electromecanico de caracteristicas distintas en sistemas complejos de potencia. Se hace una comparacion entre los resultados obtenidos por estas tecnicas y se discute la posibilidad de su aplicacion al problema de identificacion en linea en sistemas de potencia.

  4. Ion exchange phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  5. Rheological phenomena in focus

    CERN Document Server

    Boger, DV

    1993-01-01

    More than possibly any other scientific discipline, rheology is easily visualized and the relevant literature contains many excellent photographs of unusual and often bizarre phenomena. The present book brings together these photographs for the first time. They are supported by a full explanatory text. Rheological Phenomena in Focus will be an indispensable support manual to all those who teach rheology or have to convince colleagues of the practical relevance of the subject within an industrial setting. For those who teach fluid mechanics, the book clearly illustrates the difference be

  6. Bioelectrochemistry II membrane phenomena

    CERN Document Server

    Blank, M

    1987-01-01

    This book contains the lectures of the second course devoted to bioelectro­ chemistry, held within the framework of the International School of Biophysics. In this course another very large field of bioelectrochemistry, i. e. the field of Membrane Phenomena, was considered, which itself consists of several different, but yet related subfields. Here again, it can be easily stated that it is impossible to give a complete and detailed picture of all membrane phenomena of biological interest in a short course of about one and half week. Therefore the same philosophy, as the one of the first course, was followed, to select a series of lectures at postgraduate level, giving a synthesis of several membrane phenomena chosen among the most'important ones. These lectures should show the large variety of membrane-regulated events occurring in living bodies, and serve as sound interdisciplinary basis to start a special­ ized study of biological phenomena, for which the investigation using the dual approach, physico-che...

  7. Fundamentals of wave phenomena

    CERN Document Server

    Hirose, Akira

    2010-01-01

    This textbook provides a unified treatment of waves that either occur naturally or can be excited and propagated in various media. This includes both longitudinal and transverse waves. The book covers both mechanical and electrical waves, which are normally covered separately due to their differences in physical phenomena.

  8. Status of Physics and Safety Analyses for the Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR)

    Energy Technology Data Exchange (ETDEWEB)

    Ingersoll, DT

    2005-12-15

    A study has been completed to develop a new baseline core design for the liquid-salt-cooled very high-temperature reactor (LS-VHTR) that is better optimized for liquid coolant and that satisfies the top-level operational and safety targets, including strong passive safety performance, acceptable fuel cycle parameters, and favorable core reactivity response to coolant voiding. Three organizations participated in the study: Oak Ridge National Laboratory (ORNL), Idaho National Laboratory (INL), and Argonne National Laboratory (ANL). Although the intent was to generate a new reference LS-VHTR core design, the emphasis was on performing parametric studies of the many variables that constitute a design. The results of the parametric studies not only provide the basis for choosing the optimum balance of design options, they also provide a valuable understanding of the fundamental behavior of the core, which will be the basis of future design trade-off studies. A new 2400-MW(t) baseline design was established that consists of a cylindrical, nonannular core cooled by liquid {sup 7}Li{sub 2}BeF{sub 4} (Flibe) salt. The inlet and outlet coolant temperatures were decreased by 50 C, and the coolant channel diameter was increased to help lower the maximum fuel and vessel temperatures. An 18-month fuel cycle length with 156 GWD/t burnup was achieved with a two-batch shuffling scheme, while maintaining a core power density of 10 MW/m{sup 3} using graphite-coated uranium oxicarbide particle fuel enriched to 15% {sup 235}U and assuming a 25 vol-% packing of the coated particles in the fuel compacts. The revised design appears to have excellent steady-state and transient performance. The previous concern regarding the core's response to coolant voiding has been resolved for the case of Flibe coolant by increasing the coolant channel diameter and the fuel loading. Also, the LSVHTR has a strong decay heat removal performance and appears capable of surviving a loss of forced

  9. Foot Morphometric Phenomena

    OpenAIRE

    Agić, Ante

    2007-01-01

    Knowledge of the foot morphometry is important for proper foot structure and function. Foot structure as a vital part of human body is important for many reasons. The foot anthropometric and morphology phenomena are analyzed together with hidden biomechanical descriptors in order to fully characterize foot functionality. For Croatian student population the scatter data of the individual foot variables were interpolated by multivariate statistics. Foot morphometric descriptors are ...

  10. Transport phenomena II essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena II covers forced convention, temperature distribution, free convection, diffusitivity and the mechanism of mass transfer, convective mass transfer, concentration

  11. Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving VHTR Efficiency and Testing Material Compatibility - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh

    2006-06-01

    Generation IV reactors will need to be intrinsically safe, having a proliferation-resistant fuel cycle and several advantages relative to existing light water reactor (LWR). They, however, must still overcome certain technical issues and the cost barrier before it can be built in the U.S. The establishment of a nuclear power cost goal of 3.3 cents/kWh is desirable in order to compete with fossil combined-cycle, gas turbine power generation. This goal requires approximately a 30 percent reduction in power cost for stateof-the-art nuclear plants. It has been demonstrated that this large cost differential can be overcome only by technology improvements that lead to a combination of better efficiency and more compatible reactor materials. The objectives of this research are (1) to develop a supercritical carbon dioxide Brayton cycle in the secondary power conversion side that can be applied to the Very-High-Temperature Gas-Cooled Reactor (VHTR), (2) to improve the plant net efficiency by using the carbon dioxide Brayton cycle, and (3) to test material compatibility at high temperatures and pressures. The reduced volumetric flow rate of carbon dioxide due to higher density compared to helium will reduce compression work, which eventually increase plant net efficiency.

  12. Paramutation phenomena in plants.

    Science.gov (United States)

    Pilu, Roberto

    2015-08-01

    Paramutation is a particular epigenetic phenomenon discovered in Zea mays by Alexander Brink in the 1950s, and then also found in other plants and animals. Brink coined the term paramutation (from the Greek syllable "para" meaning beside, near, beyond, aside) in 1958, with the aim to differentiate paramutation from mutation. The peculiarity of paramutation with respect to other gene silencing phenomena consists in the ability of the silenced allele (named paramutagenic) to silence the other allele (paramutable) present in trans. The newly silenced (paramutated) allele remains stable in the next generations even after segregation from the paramutagenic allele and acquires paramutagenic ability itself. The inheritance behaviour of these epialleles permits a fast diffusion of a particular gene expression level/phenotype in a population even in the absence of other evolutionary influences, thus breaking the Hardy-Weinberg law. As with other gene silencing phenomena such as quelling in the fungus Neurospora crassa, transvection in Drosophila, co-suppression and virus-induced gene silencing (VIGS) described in transgenic plants and RNA interference (RNAi) in the nematode Caenorhabditis elegans, paramutation occurs without changes in the DNA sequence. So far the molecular basis of paramutation remains not fully understood, although many studies point to the involvement of RNA causing changes in DNA methylation and chromatin structure of the silenced genes. In this review I summarize all paramutation phenomena described in plants, focusing on the similarities and differences between them. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Phenomena based Methodology for Process Synthesis incorporating Process Intensification

    DEFF Research Database (Denmark)

    Lutze, Philip; Babi, Deenesh Kavi; Woodley, John

    2013-01-01

    Process intensification (PI) has the potential to improve existing as well as conceptual processes, in order to achieve a more sustainable production. PI can be achieved at different levels. That is, the unit operations, functional and/or phenomena level. The highest impact is expected by looking...... at processes at the lowest level of aggregation which is the phenomena level. In this paper, a phenomena based synthesis/design methodology incorporating process intensification is presented. Using this methodology, a systematic identification of necessary and desirable (integrated) phenomena as well...

  14. Transport phenomena I essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena I includes viscosity, flow of Newtonian fluids, velocity distribution in laminar flow, velocity distributions with more than one independent variable, thermal con

  15. Solid state phenomena

    CERN Document Server

    Lawrance, R

    1972-01-01

    Solid State Phenomena explores the fundamentals of the structure and their influence on the properties of solids. This book is composed of five chapters that focus on the electrical and thermal conductivities of crystalline solids. Chapter 1 describes the nature of solids, particularly metals and crystalline materials. This chapter also presents a model to evaluate crystal structure, the forces between atom pairs, and the mechanism of plastic and elastic deformation. Chapter 2 demonstrates random vibrations of atoms in a solid using a one-dimensional array, while Chapter 3 examines the resista

  16. Natural Circulation Patterns in the VHTR Air-Ingress Accident and Related Issues

    Energy Technology Data Exchange (ETDEWEB)

    Chang Ho Oh; Eung Soo Kim; Hyung Seok Kang

    2010-10-01

    A natural circulation pattern in a Very High Gas-Cooled Reactor during a hypothetical air-ingress accident has been investigated using computational fluid dynamic (CFD) methods in order to compare with the previous 1-D flow path model for the air-ingress analyses. The GT-MHR 600 MWt reactor was selected to be the reference design and modeled by a half symmetric 3-D geometry using FLUENT 6.3, a commercial CFD code. The simulation was carried out as steady-state calculations, and the boundary conditions were either assumed or provided from the 1-D GAMMA code results. Totally, 12 different cases have been estimated, and many notable findings and results have been obtained in this study. According to the simulations, the natural circulation pattern in the reactor was quite different from the previous 1-D assumptions. A large re-circulation flow with thermal stratification phenomena was clearly observed in the hot-leg and the lower plenum in the 3-D model. This re-circulation flow provided approximately an order faster air-ingress speed (0.46 m/s in superficial velocity) than previously predicted values by 1-D modeling (0.02~0.03 m/s). It indicates that the 1-D air-ingress modeling may significantly distort the air-ingress scenario and consequences. In addition, the complicated natural circulation pattern is eventually expected to lead to very complex graphite oxidations and corrosion patterns.

  17. MULTISCALE PHENOMENA IN MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    A. BISHOP

    2000-09-01

    This project developed and supported a technology base in nonequilibrium phenomena underpinning fundamental issues in condensed matter and materials science, and applied this technology to selected problems. In this way the increasingly sophisticated synthesis and characterization available for classes of complex electronic and structural materials provided a testbed for nonlinear science, while nonlinear and nonequilibrium techniques helped advance our understanding of the scientific principles underlying the control of material microstructure, their evolution, fundamental to macroscopic functionalities. The project focused on overlapping areas of emerging thrusts and programs in the Los Alamos materials community for which nonlinear and nonequilibrium approaches will have decisive roles and where productive teamwork among elements of modeling, simulations, synthesis, characterization and applications could be anticipated--particularly multiscale and nonequilibrium phenomena, and complex matter in and between fields of soft, hard and biomimetic materials. Principal topics were: (i) Complex organic and inorganic electronic materials, including hard, soft and biomimetic materials, self-assembly processes and photophysics; (ii) Microstructure and evolution in multiscale and hierarchical materials, including dynamic fracture and friction, dislocation and large-scale deformation, metastability, and inhomogeneity; and (iii) Equilibrium and nonequilibrium phases and phase transformations, emphasizing competing interactions, frustration, landscapes, glassy and stochastic dynamics, and energy focusing.

  18. New experimental device for VHTR structural material testing and helium coolant chemistry investigation - High Temperature Helium Loop in NRI Rez

    Energy Technology Data Exchange (ETDEWEB)

    Berka, Jan, E-mail: bej@cvrez.cz [Research Centre Rez, Ltd, Husinec-Rez 130, 25068 Rez (Czech Republic); Institute of Chemical Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic); Matecha, Josef, E-mail: josef.matecha@ujv.cz [Nuclear Research Institute Rez plc., Husinec-Rez 130, 25068 Rez (Czech Republic); Cerny, Michal [Institute of Chemical Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic); Viden, Ivan, E-mail: ivan.viden@vscht.cz [Institute of Chemical Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic); Sus, Frantisek [Research Centre Rez, Ltd, Husinec-Rez 130, 25068 Rez (Czech Republic); Nuclear Research Institute Rez plc., Husinec-Rez 130, 25068 Rez (Czech Republic); Hajek, Petr [Nuclear Research Institute Rez plc., Husinec-Rez 130, 25068 Rez (Czech Republic)

    2012-10-15

    The High Temperature Helium Loop (HTHL) is an experimental device for simulation of VHTR helium coolant conditions. The purpose of the HTHL is structural materials testing and helium coolant chemistry investigation. In the HTHL pure helium will be used as working medium and its main physical parameters are 7 MPa, max. temperature in the test section 900 Degree-Sign C and flow rate 37.8 kg/h. The HTHL consists of an active channel, the helium purification system, the system of impurities dosage (e.g. CO, CO{sub 2}, H{sub 2}, H{sub 2}O, O{sub 2}, N{sub 2}, and CH{sub 4}) and the helium chemistry monitoring system (sampling and on-line analysis and determination of impurities in the helium flow). The active channel is planned to be placed into the core of the experimental reactor LVR-15 which will serve as a neutron flux source (max. 2.5 Multiplication-Sign 10{sup 18} n/m{sup 2} s for fast neutrons). The HTHL is now under construction. Some of its main parts are finished, some are still being produced (active channel internals, etc.), some should be improved to work correctly (the helium circulatory compressor); certain sub-systems are planned to be integrated to the loop (systems for the determination of moisture and other impurities in helium, etc.). The start of the HTHL operation is expected during 2011 and the integration of the active channel into the LVR-15 core during 2012.

  19. Workshop on Interface Phenomena

    CERN Document Server

    Kreuzer, Hans

    1987-01-01

    This book contains the proceedings of the first Workshop on Interface Phenomena, organized jointly by the surface science groups at Dalhousie University and the University of Maine. It was our intention to concentrate on just three topics related to the kinetics of interface reactions which, in our opinion, were frequently obscured unnecessarily in the literature and whose fundamental nature warranted an extensive discussion to help clarify the issues, very much in the spirit of the Discussions of the Faraday Society. Each session (day) saw two principal speakers expounding the different views; the session chairmen were asked to summarize the ensuing discussions. To understand the complexity of interface reactions, paradigms must be formulated to provide a framework for the interpretation of experimen­ tal data and for the construction of theoretical models. Phenomenological approaches have been based on a small number of rate equations for the concentrations or mole numbers of the various species involved i...

  20. Advanced diffusion processes and phenomena

    CERN Document Server

    Öchsner, Andreas; Belova, Irina

    2014-01-01

    This topical volume on Advanced Diffusion Processes and Phenomena addresses diffusion in a wider sense of not only mass diffusion but also heat diffusion in fluids and solids. Both diffusion phenomena play an important role in the characterization of engineering materials and corresponding structures. Understanding these different transport phenomena at many levels, from atomistic to macro, has therefore long attracted the attention of many researchers in materials science and engineering and related disciplines. The present topical volume captures a representative cross-section of some of the

  1. Critical Phenomena in Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    Gundlach Carsten

    1999-01-01

    Full Text Available As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term 'critical phenomena'. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. This review gives an introduction to the phenomena, tries to summarize the essential features of what is happening, and then presents extensions and applications of this basic scenario. Critical phenomena are of interest particularly for creating surprising structure from simple equations, and for the light they throw on cosmic censorship and the generic dynamics of general relativity.

  2. Undergraduates' understanding of cardiovascular phenomena.

    Science.gov (United States)

    Michael, Joel A; Wenderoth, Mary Pat; Modell, Harold I; Cliff, William; Horwitz, Barbara; McHale, Philip; Richardson, Daniel; Silverthorn, Dee; Williams, Stephen; Whitescarver, Shirley

    2002-12-01

    Undergraduates students in 12 courses at 8 different institutions were surveyed to determine the prevalence of 13 different misconceptions (conceptual difficulties) about cardiovascular function. The prevalence of these misconceptions ranged from 20 to 81% and, for each misconception, was consistent across the different student populations. We also obtained explanations for the students' answers either as free responses or with follow-up multiple-choice questions. These results suggest that students have a number of underlying conceptual difficulties about cardiovascular phenomena. One possible source of some misconceptions is the students' inability to apply simple general models to specific cardiovascular phenomena. Some implications of these results for teachers of physiology are discussed.

  3. Whistlers and related ionospheric phenomena

    CERN Document Server

    Helliwell, Robert A

    2006-01-01

    The investigation of whistlers and related phenomena is a key element in studies of very-low-frequency propagation, satellite communication, the outer ionosphere, and solar-terrestrial relationships. This comprehensive text presents a history of the study of the phenomena and includes all the elements necessary for the calculation of the characteristics of whistlers and whistler-mode signals.An introduction and brief history are followed by a summary of the theory of whistlers and a detailed explanation of the calculation of their characteristics. Succeeding chapters offer a complete atlas of

  4. Transport phenomena in particulate systems

    CERN Document Server

    Freire, José Teixeira; Ferreira, Maria do Carmo

    2012-01-01

    This volume spans 10 chapters covering different aspects of transport phenomena including fixed and fluidized systems, spouted beds, electrochemical and wastewater treatment reactors. This e-book will be valuable for students, engineers and researchers aiming to keep updated on the latest developments on particulate systems.

  5. Nursing phenomena in inpatient psychiatry

    NARCIS (Netherlands)

    Frauenfelder, F.; Muller-Staub, M.; Needham, I.; Achterberg, T. van

    2011-01-01

    Little is known about the question if the nursing diagnosis classification of North American Nursing Association-International (NANDA-I) describes the adult inpatient psychiatric nursing care. The present study aimed to identify nursing phenomena mentioned in journal articles about the psychiatric

  6. A Course on Surface Phenomena.

    Science.gov (United States)

    Woods, Donald R.

    1983-01-01

    Describes a graduate or senior elective course combining fundamentals of surface phenomena with practical problem-solving structured around a series of case problems. Discusses topics covered and their development through acquiring new knowledge applied to the case problem, practical calculations of solutions, and applications to additional…

  7. Discovery potential for new phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, S. [Carleton Univ., Ottawa, Ontario (Canada). Ottawa Carleton Inst. for Physics; Hewett, J.L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Price, L.E. [Argonne National Lab., IL (United States). High Energy Physics Div.

    1997-03-01

    The authors examine the ability of future facilities to discover and interpret non-supersymmetric new phenomena. The authors first explore explicit manifestations of new physics, including extended gauge sectors, leptoquarks, exotic fermions, and technicolor models. They then take a more general approach where new physics only reveals itself through the existence of effective interactions at lower energy scales.

  8. Collective Phenomena in Kidney Autoregulation

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Sosnovtseva, Olga; Holstein-Rathlou, N.-H.

    2004-01-01

    , the nephron. However, a variety of cooperative phenomena arising through interactions between the nephrons may also be important. We prescut experimental evidence for a coupling between nephrons that are connected via a common piece of afferent arteriole. We also develop a mathematical model that call account...

  9. Astronomical phenomena in Dresden codex

    Directory of Open Access Journals (Sweden)

    Böhm V.

    2013-01-01

    Full Text Available The relationship between Maya and our calendar is expressed by a coefficient known as ‘correlation’ which is a number of days that we have to add to the Mayan Long Count date to get Julian Date used in astronomy. There is surprisingly large uncertainty in the value of the correlation, yielding a shift between both calendars (and thus between the history of Maya and of our world to typically several hundred years. There are more than 50 diverse values of the correlation, some of them derived from historical, other by astronomical data. We test here (among others the well established Goodman-Martínez-Thompson correlation (GMT, based on historical data, and the Böhms’ one (B&B, based on astronomical data decoded from the Dresden Codex (DC; this correlation differs by about +104 years from the GMT. In our previous works we used several astronomical phenomena as recorded in the DC for a check. We clearly demonstrated that (i the GMT was not capable to predict these phenomena that really happened in nature and (ii that the GMT predicts them on the days when they did not occur. The phenomena used till now in the test are, however, short-periodic and the test then may suffer from ambiguity. Therefore, we add long-periodic astronomical phenomena, decoded successfully from the DC, to the testing. These are (i a synchrony of Venusian heliacal risings with the solar eclipses, (ii a synchrony of Venus and Mars conjunctions with the eclipses, (iii conjunctions of Jupiter and Saturn repeated in a rare way, and (iv a synchrony of synodic and sideric periods of Mercury with the tropical year. Based on our analysis, we find that the B&B correlation yields the best agreement with the astronomical phenomena observed by the Maya. Therefore we recommend to reject the GMT and support the B&B correlation.

  10. Thermodynamic constraints on fluctuation phenomena

    Science.gov (United States)

    Maroney, O. J. E.

    2009-12-01

    The relationships among reversible Carnot cycles, the absence of perpetual motion machines, and the existence of a nondecreasing globally unique entropy function form the starting point of many textbook presentations of the foundations of thermodynamics. However, the thermal fluctuation phenomena associated with statistical mechanics has been argued to restrict the domain of validity of this basis of the second law of thermodynamics. Here we demonstrate that fluctuation phenomena can be incorporated into the traditional presentation, extending rather than restricting the domain of validity of the phenomenologically motivated second law. Consistency conditions lead to constraints upon the possible spectrum of thermal fluctuations. In a special case this uniquely selects the Gibbs canonical distribution and more generally incorporates the Tsallis distributions. No particular model of microscopic dynamics need be assumed.

  11. Solar Neutrons and Related Phenomena

    CERN Document Server

    Dorman, Lev

    2010-01-01

    This book presents the first comprehensive compilation and review of the extensive body of experimental and theoretical material on solar neutrons and related phenomena published in the scientific literature over the last sixty years. Phenomena related to solar neutrons are more specifically: the decay products of solar neutrons solar gamma rays generated in processes like nuclear reactions between solar energetic charged particles and matter of the solar atmosphere, as well as by the capture of solar neutrons by hydrogen atoms in the solar atmosphere the propagation of solar neutrons, solar gamma rays and other secondary particles through the solar photosphere, chromosphere and corona, as well as through interplanetary space and through the Earth's atmosphere. Models and simulations of particle acceleration, interactions, and propagation processes show that observations of solar neutrons and gamma rays in space and in the Earth's atmosphere yield essential and unique information on the source function of ene...

  12. Transport phenomena in multiphase flows

    CERN Document Server

    Mauri, Roberto

    2015-01-01

    This textbook provides a thorough presentation of the phenomena related to the transport of mass, momentum and energy.  It lays all the basic physical principles, then for the more advanced readers, it offers an in-depth treatment with advanced mathematical derivations and ends with some useful applications of the models and equations in specific settings. The important idea behind the book is to unify all types of transport phenomena, describing them within a common framework in terms of cause and effect, respectively represented by the driving force and the flux of the transported quantity. The approach and presentation are original in that the book starts with a general description of transport processes, providing the macroscopic balance relations of fluid dynamics and heat and mass transfer, before diving into the mathematical realm of continuum mechanics to derive the microscopic governing equations at the microscopic level. The book is a modular teaching tool and can be used either for an introductory...

  13. New phenomena searches at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Soha, Aron; /UC, Davis

    2006-04-01

    The authors report on recent results from the Collider Detector at Fermilab (CDF) experiment, which is accumulating data from proton-antiproton collisions with {radical}s = 1.96 TeV at Run II of the Fermilab Tevatron. The new phenomena being explored include Higgs, Supersymmetry, and large extra dimensions. They also present the latest results of searches for heavy objects, which would indicate physics beyond the Standard Model.

  14. Foot Anthropometry and Morphology Phenomena

    OpenAIRE

    Agić, Ante; Nikolić, Vasilije; Mijović, Budimir

    2006-01-01

    Foot structure description is important for many reasons. The foot anthropometric morphology phenomena are analyzed together with hidden biomechanical functionality in order to fully characterize foot structure and function. For younger Croatian population the scatter data of the individual foot variables were interpolated by multivariate statistics. Foot structure descriptors are influenced by many factors, as a style of life, race, climate, and things of the great importance in ...

  15. Mathematical Modeling of Diverse Phenomena

    Science.gov (United States)

    Howard, J. C.

    1979-01-01

    Tensor calculus is applied to the formulation of mathematical models of diverse phenomena. Aeronautics, fluid dynamics, and cosmology are among the areas of application. The feasibility of combining tensor methods and computer capability to formulate problems is demonstrated. The techniques described are an attempt to simplify the formulation of mathematical models by reducing the modeling process to a series of routine operations, which can be performed either manually or by computer.

  16. Innovative and Advanced Coupled Neutron Transport and Thermal Hydraulic Method (Tool) for the Design, Analysis and Optimization of VHTR/NGNP Prismatic Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rahnema, Farzad; Garimeela, Srinivas; Ougouag, Abderrafi; Zhang, Dingkang

    2013-11-29

    This project will develop a 3D, advanced coarse mesh transport method (COMET-Hex) for steady- state and transient analyses in advanced very high-temperature reactors (VHTRs). The project will lead to a coupled neutronics and thermal hydraulic (T/H) core simulation tool with fuel depletion capability. The computational tool will be developed in hexagonal geometry, based solely on transport theory without (spatial) homogenization in complicated 3D geometries. In addition to the hexagonal geometry extension, collaborators will concurrently develop three additional capabilities to increase the code’s versatility as an advanced and robust core simulator for VHTRs. First, the project team will develop and implement a depletion method within the core simulator. Second, the team will develop an elementary (proof-of-concept) 1D time-dependent transport method for efficient transient analyses. The third capability will be a thermal hydraulic method coupled to the neutronics transport module for VHTRs. Current advancements in reactor core design are pushing VHTRs toward greater core and fuel heterogeneity to pursue higher burn-ups, efficiently transmute used fuel, maximize energy production, and improve plant economics and safety. As a result, an accurate and efficient neutron transport, with capabilities to treat heterogeneous burnable poison effects, is highly desirable for predicting VHTR neutronics performance. This research project’s primary objective is to advance the state of the art for reactor analysis.

  17. Transport phenomena in porous media

    Science.gov (United States)

    Bear, Jacob; Corapcioglu, M. Yavuz

    The Advanced Study Institute on Fundamentals of Transport Phenomena in Porous Media, held July 14-23, 1985 in Newark, Del. and directed by Jacob Bear (Israel Institute of Technology, Haifa) and M. Yavuz Corapcioglu (City College of New York), under the auspices of NATO, was a sequel to the NATO Advanced Study Institute (ASI) held in 1982 (proceedings published as Fundamentals of Transport Phenomena in Porous Media, J. Bear, and M.Y. Corapcioglu (Ed.), Martinus Nijhoff, Dordrecht, the Netherlands, 1984). The meeting was attended by 106 participants and lecturers from 21 countries.As in the first NATO/ASI, the objective of this meeting—which was a combination of a conference of experts and a teaching institute— was to present and discuss selected topics of transport in porous media. In selecting topics and lecturers, an attempt was made to bridge the gap that sometimes exists between research and practice. An effort was also made to demonstrate the unified approach to the transport of mass of a fluid phase, components of a fluid phase, momentum, and heat in a porous medium domain. The void space may be occupied by a single fluid phase or by a number of such phases; each fluid may constitute a multicomponent system; the solid matrix may be deformable; and the whole process of transport in the system may take place under nonisothermal conditions, with or without phase changes. Such phenomena are encountered in a variety of disciplines, e.g., petroleum engineering, civil engineering (in connection with groundwater flow and contamination), soil mechanics, and chemical engineering. One of the goals of the 1985 NATO/ASI, as in the 1982 institute, was to bring together experts from all these disciplines and enhance communication among them.

  18. Phase transitions and critical phenomena

    CERN Document Server

    Domb, Cyril

    2001-01-01

    The field of phase transitions and critical phenomena continues to be active in research, producing a steady stream of interesting and fruitful results. It has moved into a central place in condensed matter studies.Statistical physics, and more specifically, the theory of transitions between states of matter, more or less defines what we know about 'everyday' matter and its transformations.The major aim of this serial is to provide review articles that can serve as standard references for research workers in the field, and for graduate students and others wishing to obtain reliable in

  19. Nonlinear Dynamic Phenomena in Mechanics

    CERN Document Server

    Warminski, Jerzy; Cartmell, Matthew P

    2012-01-01

    Nonlinear phenomena should play a crucial role in the design and control of engineering systems and structures as they can drastically change the prevailing dynamical responses. This book covers theoretical and applications-based problems of nonlinear dynamics concerned with both discrete and continuous systems of interest in civil and mechanical engineering. They include pendulum-like systems, slender footbridges, shape memory alloys, sagged elastic cables and non-smooth problems. Pendulums can be used as a dynamic absorber mounted in high buildings, bridges or chimneys. Geometrical nonlinear

  20. Violent phenomena in the Universe

    CERN Document Server

    Narlikar, Jayant V

    2007-01-01

    The serenity of a clear night sky belies the evidence-gathered by balloons, rockets, satellites, and telescopes-that the universe contains centers of furious activity that pour out vast amounts of energy, some in regular cycles and some in gigantic bursts. This reader-friendly book, acclaimed by Nature as ""excellent and uncompromising,"" traces the development of modern astrophysics and its explanations of these startling celestial fireworks.This lively narrative ranges from the gravitational theories of Newton and Einstein to recent exciting discoveries of such violent phenomena as supernova

  1. Phase transitions and critical phenomena

    CERN Document Server

    Domb, Cyril

    2000-01-01

    The field of phase transitions and critical phenomena continues to be active in research, producing a steady stream of interesting and fruitful results. No longer an area of specialist interest, it has acquired a central focus in condensed matter studies. The major aim of this serial is to provide review articles that can serve as standard references for research workers in the field, and for graduate students and others wishing to obtain reliable information on important recent developments.The two review articles in this volume complement each other in a remarkable way. Both deal with what m

  2. Quantum theory of collective phenomena

    CERN Document Server

    Sewell, G L

    2014-01-01

    ""An excellent and competent introduction to the field … [and] … a source of information for the expert."" - Physics Today""This a book of major importance…. I trust that this book will be used as a basis for the teaching of a balanced, modern and rigorous course on statistical mechanics in all universities."" - Bulletin of the London Mathematical Society""This is one of the best introductions to the subject, and it is strongly recommended to anyone interested in collective phenomena."" - Physics Bulletin ""The book may be recommended for students as a well-balanced introduction to this rich s

  3. Phenomena and Diosignes of Aratous

    Science.gov (United States)

    Avgoloupis, S. I.

    2013-01-01

    Aratous (305-240B.C.) was a singular intellectual, writer and poet which engage himself to compose a very interesting astronomical poet, using the "Dactylous sixstage' style, the formal style of the ancient Greek Epic poetry. This astronomic poem of Aratous "Phenomena and Diosignes" became very favorite reading during the Alexandrine, the Romman and the Byzandin eras as well and had received many praises from significant poets and particularly from Hipparchous and from Theonas from Alexandria, an astronomer of 4rth century A.C.(in Greeks)

  4. Uranium Pyrophoricity Phenomena and Prediction

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN, D.R.

    2000-04-20

    We have compiled a topical reference on the phenomena, experiences, experiments, and prediction of uranium pyrophoricity for the Hanford Spent Nuclear Fuel Project (SNFP) with specific applications to SNFP process and situations. The purpose of the compilation is to create a reference to integrate and preserve this knowledge. Decades ago, uranium and zirconium fires were commonplace at Atomic Energy Commission facilities, and good documentation of experiences is surprisingly sparse. Today, these phenomena are important to site remediation and analysis of packaging, transportation, and processing of unirradiated metal scrap and spent nuclear fuel. Our document, bearing the same title as this paper, will soon be available in the Hanford document system [Plys, et al., 2000]. This paper explains general content of our topical reference and provides examples useful throughout the DOE complex. Moreover, the methods described here can be applied to analysis of potentially pyrophoric plutonium, metal, or metal hydride compounds provided that kinetic data are available. A key feature of this paper is a set of straightforward equations and values that are immediately applicable to safety analysis.

  5. Functional theories of thermoelectric phenomena

    Science.gov (United States)

    Eich, F. G.; Di Ventra, M.; Vignale, G.

    2017-02-01

    We review the progress that has been recently made in the application of time-dependent density functional theory to thermoelectric phenomena. As the field is very young, we emphasize open problems and fundamental issues. We begin by introducing the formal structure of thermal density functional theory, a density functional theory with two basic variables—the density and the energy density—and two conjugate fields—the ordinary scalar potential and Luttinger’s thermomechanical potential. The static version of this theory is contrasted with the familiar finite-temperature density functional theory, in which only the density is a variable. We then proceed to constructing the full time-dependent non equilibrium theory, including the practically important Kohn-Sham equations that go with it. The theory is shown to recover standard results of the Landauer theory for thermal transport in the steady state, while showing greater flexibility by allowing a description of fast thermal response, temperature oscillations and related phenomena. Several results are presented here for the first time, i.e. the proof of invertibility of the thermal response function in the linear regime, the full expression of the thermal currents in the presence of Luttinger’s thermomechanical potential, an explicit prescription for the evaluation of the Kohn-Sham potentials in the adiabatic local density approximation, a detailed discussion of the leading dissipative corrections to the adiabatic local density approximation and the thermal corrections to the resistivity that follow from it.

  6. Natural phenomena hazards, Hanford Site, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Conrads, T.J.

    1998-09-29

    This document presents the natural phenomena hazard loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, and supports development of double-shell tank systems specifications at the Hanford Site in south-central Washington State. The natural phenomena covered are seismic, flood, wind, volcanic ash, lightning, snow, temperature, solar radiation, suspended sediment, and relative humidity.

  7. Emergent Phenomena at Oxide Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, H.Y.

    2012-02-16

    Transition metal oxides (TMOs) are an ideal arena for the study of electronic correlations because the s-electrons of the transition metal ions are removed and transferred to oxygen ions, and hence the strongly correlated d-electrons determine their physical properties such as electrical transport, magnetism, optical response, thermal conductivity, and superconductivity. These electron correlations prohibit the double occupancy of metal sites and induce a local entanglement of charge, spin, and orbital degrees of freedom. This gives rise to a variety of phenomena, e.g., Mott insulators, various charge/spin/orbital orderings, metal-insulator transitions, multiferroics, and superconductivity. In recent years, there has been a burst of activity to manipulate these phenomena, as well as create new ones, using oxide heterostructures. Most fundamental to understanding the physical properties of TMOs is the concept of symmetry of the order parameter. As Landau recognized, the essence of phase transitions is the change of the symmetry. For example, ferromagnetic ordering breaks the rotational symmetry in spin space, i.e., the ordered phase has lower symmetry than the Hamiltonian of the system. There are three most important symmetries to be considered here. (i) Spatial inversion (I), defined as r {yields} -r. In the case of an insulator, breaking this symmetry can lead to spontaneous electric polarization, i.e. ferroelectricity, or pyroelectricity once the point group belongs to polar group symmetry. (ii) Time-reversal symmetry (T) defined as t {yields} -t. In quantum mechanics, the time-evolution of the wave-function {Psi} is given by the phase factor e{sup -iEt/{h_bar}} with E being the energy, and hence time-reversal basically corresponds to taking the complex conjugate of the wave-function. Also the spin, which is induced by the 'spinning' of the particle, is reversed by time-reversal. Broken T-symmetry is most naturally associated with magnetism, since the

  8. Earthquake prediction with electromagnetic phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Masashi, E-mail: hayakawa@hi-seismo-em.jp [Hayakawa Institute of Seismo Electomagnetics, Co. Ltd., University of Electro-Communications (UEC) Incubation Center, 1-5-1 Chofugaoka, Chofu Tokyo, 182-8585 (Japan); Advanced Wireless & Communications Research Center, UEC, Chofu Tokyo (Japan); Earthquake Analysis Laboratory, Information Systems Inc., 4-8-15, Minami-aoyama, Minato-ku, Tokyo, 107-0062 (Japan); Fuji Security Systems. Co. Ltd., Iwato-cho 1, Shinjyuku-ku, Tokyo (Japan)

    2016-02-01

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.

  9. Transport phenomena in porous media

    CERN Document Server

    Ingham, Derek B

    1998-01-01

    Research into thermal convection in porous media has substantially increased during recent years due to its numerous practical applications. These problems have attracted the attention of industrialists, engineers and scientists from many very diversified disciplines, such as applied mathematics, chemical, civil, environmental, mechanical and nuclear engineering, geothermal physics and food science. Thus, there is a wealth of information now available on convective processes in porous media and it is therefore appropriate and timely to undertake a new critical evaluation of this contemporary information. Transport Phenomena in Porous Media contains 17 chapters and represents the collective work of 27 of the world's leading experts, from 12 countries, in heat transfer in porous media. The recent intensive research in this area has substantially raised the expectations for numerous new practical applications and this makes the book a most timely addition to the existing literature. It includes recent major deve...

  10. Critical Phenomena in Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    Martín-García José M.

    2007-12-01

    Full Text Available As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term “critical phenomena”. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. Critical phenomena give a natural route from smooth initial data to arbitrarily large curvatures visible from infinity, and are therefore likely to be relevant for cosmic censorship, quantum gravity, astrophysics, and our general understanding of the dynamics of general relativity.

  11. Remote sensing of natural phenomena

    Directory of Open Access Journals (Sweden)

    Miodrag D. Regodić

    2014-06-01

    Full Text Available There has always been a need to directly perceive and study the events whose extent is beyond people's possibilities. In order to get new data and to make observations and studying much more objective in comparison with past syntheses - a new method of examination called remote sensing has been adopted. The paper deals with the principles and elements of remote sensing, as well as with the basic aspects of using remote research in examining meteorological (weather parameters and the conditions of the atmosphere. The usage of satellite images is possible in all phases of the global and systematic research of different natural phenomena when airplane and satellite images of different characteristics are used and their analysis and interpretation is carried out by viewing and computer added procedures. Introduction Remote sensing of the Earth enables observing and studying global and local events that occur on it. Satellite images are nowadays used in geology, agriculture, forestry, geodesy, meteorology, spatial and urbanism planning, designing of infrastructure and other objects, protection from natural and technological catastrophes, etc. It it possible to use satellite images in all phases of global and systematic research of different natural phenomena. Basics of remote sensing Remote sensing is a method of the acquisition and interpretation of information about remote objects without making a physical contact with them. The term Daljinska detekcija is a literal translation of the English term Remote Sensing. In French it isTeledetection, in German - Fernerkundung, in Russian - дистанционие иследования. We also use terms such as: remote survailance, remote research, teledetection, remote methods, and distance research. The basic elements included in Remote Sensing are: object, electromagnetic energy, sensor, platform, image, analysis, interpretation and the information (data, fact. Usage of satellite remote research in

  12. EDITORIAL: Quantum phenomena in Nanotechnology Quantum phenomena in Nanotechnology

    Science.gov (United States)

    Loss, Daniel

    2009-10-01

    Twenty years ago the Institute of Physics launched the journal Nanotechnology from its publishing house based in the home town of Paul Dirac, a legendary figure in the development of quantum mechanics at the turn of the last century. At the beginning of the 20th century, the adoption of quantum mechanical descriptions of events transformed the existing deterministic world view. But in many ways it also revolutionised the progress of research itself. For the first time since the 17th century when Francis Bacon established inductive reasoning as the means of advancing science from fact to axiom to law, theory was progressing ahead of experiments instead of providing explanations for observations that had already been made. Dirac's postulation of antimatter through purely theoretical investigation before its observation is the archetypal example of theory leading the way for experiment. The progress of nanotechnology and the development of tools and techniques that enabled the investigation of systems at the nanoscale brought with them many fascinating observations of phenomena that could only be explained through quantum mechanics, first theoretically deduced decades previously. At the nanoscale, quantum confinement effects dominate the electrical and optical properties of systems. They also render new opportunities for manipulating the response of systems. For example, a better understanding of these systems has enabled the rapid development of quantum dots with precisely determined properties, which can be exploited in a range of applications from medical imaging and photovoltaic solar cells to quantum computation, a radically new information technology being currently developed in many labs worldwide. As the first ever academic journal in nanotechnology, {\\it Nanotechnology} has been the forum for papers detailing progress of the science through extremely exciting times. In the early years of the journal, the investigation of electron spin led to the formulation

  13. Understanding empathy and related phenomena.

    Science.gov (United States)

    Shamasundar, C

    1999-01-01

    Over a period of time, the author arrived at a few tentative postulates concerning empathy and related processes based on some of his experiences and observations. The central theme of these postulates is, firstly, that interpersonal interaction is an interaction of the personal-space fields. Secondly, empathy, therapeutic benefit, and the professional stress are all related to the same process of interpersonal interaction. This interaction takes place as an enmeshment of personal spaces of the interacting individuals, and involves transfer of a wide range of information in the affective, cognitive, and other areas. This is because the personal spaces have fieldlike qualities analogous to what Kurt Lewin described. Thus, such phenomena as empathy, therapeutic benefit, professional stress are all consequences of the same process. It is possible to substantiate these postulates by diverse evidences in the published literature. The natural consequences of such an interpersonal interaction are empathic understanding, transfer of mood states (like hope, distress or expectancy), affective states (like anxiety, sadness, anger or hostility), ideas, images and even attitudes and values, etc. This phenomenon of transfer can explain such processes as therapeutic benefit in individual and group settings, professional stress, shared delusions, and even experimenter bias. Whether one becomes aware of such transferred information or not depends upon the intent and sensitivity of the participants.

  14. Critical Phenomena in Population Coding

    Science.gov (United States)

    Berkowitz, John; Sharpee, Tatyana

    2014-03-01

    Populations of neurons that code for sensory stimuli are often modeled as having sigmoidal tuning curves where the midpoint and slope of the curve represent, respectively, an intrinsic firing threshold and noise level. Recent studies have shown for two subpopulations of neurons that states below a critical noise level are associated with symmetry breaking between the populations' thresholds. In this work we consider the case of up to seven distinct subpopulations encoding a common gaussian stimulus. We optimized the mutual information between output patterns and stimuli by adjusting the thresholds for a fixed noise level. In the high-noise regime the optimal thresholds are fully redundant whereas the low noise limit predicts distinct threshold values that achieve histogram equalization of the input signal. Between the two limits, the thresholds exhibit a complex branching process that occur at successive values of the noise level. Each branch corresponds to a critical point of a continuous phase transition. The behavior of the system in the limit of a large number of subpopulations is also investigated, and critical phenomena are also present in the distribution of thresholds in this limit.

  15. Sketching Biological Phenomena and Mechanisms.

    Science.gov (United States)

    Sheredos, Benjamin; Bechtel, William

    2017-10-01

    In many fields of biology, both the phenomena to be explained and the mechanisms proposed to explain them are commonly presented in diagrams. Our interest is in how scientists construct such diagrams. Researchers begin with evidence, typically developed experimentally and presented in data graphs. To arrive at a robust diagram of the phenomenon or the mechanism, they must integrate a variety of data to construct a single, coherent representation. This process often begins as the researchers create a first sketch, and it continues over an extended period as they revise the sketch until they arrive at a diagram they find acceptable. We illustrate this process by examining the sketches developed in the course of two research projects directed at understanding the generation of circadian rhythms in cyanobacteria. One identified a new aspect of the phenomenon itself, whereas the other aimed to develop a new mechanistic account. In both cases, the research resulted in a paper in which the conclusion was presented in a diagram that the authors deemed adequate to convey it. These diagrams violate some of the normative "cognitive design principles" advanced by cognitive scientists as constraints on successful visual communication. We suggest that scientists' sketching is instead governed by norms of success that are broadly explanatory: conveying the phenomenon or mechanism. Copyright © 2017 Cognitive Science Society, Inc.

  16. Mixed Fluid Conditions: Capillary Phenomena

    KAUST Repository

    Santamarina, Carlos

    2017-07-06

    Mixed fluid phenomena in porous media have profound implications on soil-atmosphere interaction, energy geotechnology, environmental engineering and infrastructure design. Surface tension varies with pressure, temperature, solute concentration, and surfactant concentration; on the other hand, the contact angle responds to interfacial tensions, surface topography, invasion velocity, and chemical interactions. Interfaces are not isolated but interact through the fluid pressure and respond to external fields. Jumps, snap-offs and percolating wetting liquids along edges and crevices are ubiquitous in real, non-cylindrical porous networks. Pore- and macroscale instabilities together with pore structure variability-and-correlation favor fluid trapping and hinder recovery efficiency. The saturation-pressure characteristic curve is affected by the saturation-history, flow-rate, the mechanical response of the porous medium, and time-dependent reactive and diffusive processes; in addition, there are salient differences between unsaturation by internal gas nucleation and gas invasion. Capillary forces add to other skeletal forces in the porous medium and can generate open-mode discontinuities when the capillary entry pressure is high relative to the effective stress. Time emerges as an important variable in mixed-fluid conditions and common quasi-static analyses may fail to capture the system response.

  17. Observation of Celestial Phenomena in Ancient China

    Science.gov (United States)

    Sun, Xiaochun

    Because of the need for calendar-making and portent astrology, the Chinese were diligent and meticulous observers of celestial phenomena. China has maintained the longest continuous historical records of celestial phenomena in the world. Extraordinary or abnormal celestial events were particularly noted because of their astrological significance. The historical records cover various types of celestial phenomena, which include solar and lunar eclipses, sunspots, "guest stars" (novae or supernovae as we understand today), comets and meteors, and all kinds of planetary phenomena. These records provide valuable historical data for astronomical studies today.

  18. Exponential analysis in physical phenomena

    Science.gov (United States)

    Istratov, Andrei A.; Vyvenko, Oleg F.

    1999-02-01

    Many physical phenomena are described by first-order differential equations whose solution is an exponential decay. Determining the time constants and amplitudes of exponential decays from the experimental data is a common task in semiconductor physics (deep level transient spectroscopy), biophysics (fluorescence decay analysis), nuclear physics and chemistry (radioactive decays, nuclear magnetic resonance), chemistry and electrochemistry (reaction kinetics) and medical imaging. This review article discusses the fundamental mathematical limitations of exponential analysis, outlines the critical aspects of acquisition of exponential transients for subsequent analysis, and gives a comprehensive overview of numerical algorithms used in exponential analysis. In the first part of the article the resolution of exponential analysis as a function of noise in input decays is discussed. It is shown that two exponential decays can be resolved in a transient only if the ratio of their time constants is greater than the resolution limit, which can be explicitly calculated from the signal-to-noise ratio in the transient. Although the signal-to-noise ratio is generally limited by the sensitivity of the equipment, it is shown that digitalization of the decays may be a major source of noise. The requirements for type of analog-to-digital converter, number of digitized data points and duration of digitized transients, which must be met to obtain the theoretical resolution limit and to improve stability of the exponential analysis, are formulated. The second part of the review article gives an overview and comparison of major numerical techniques of exponential analysis, such as the nonlinear least squares fit, the Prony method, the method of modulating functions, the method of moments, the Laplace-Padé approximation, the Tikhonov regularization method, the Gardner transformation, the method of maximum entropy and others.

  19. Millisecond phenomena in mass accreting neutron stars

    NARCIS (Netherlands)

    van der Klis, M.; Cohen, L.

    2007-01-01

    The past twelve years have seen the discovery, with NASA's Rossi X-ray Timing Explorer (RXTE), of several long-predicted phenomena associated with the accretion of matter onto a neutron star in a binary (double) star system. These phenomena are observed in the strong X-ray emission produced by these

  20. Autogenous Phenomena in Cement-Based Materials

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    This thesis has been written to obtain the Danish doctoral degree in technology, Dr.Techn. It addresses autogenous phenomena in cement-based materials - primarily deformation and change of the relative humidity (RH). In the thesis it is explained how the importance of these phenomena was identified...

  1. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Mateiu, Ramona Valentina; Yu, Liyun; Skov, Anne Ladegaard

    2017-01-01

    years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we investigate the electrical breakdown phenomena of various types of permittivity-enhanced silicone elastomers. Two types...

  2. A Connection between Transport Phenomena and Thermodynamics

    Science.gov (United States)

    Swaney, Ross; Bird, R. Byron

    2017-01-01

    Although students take courses in transport phenomena and thermodynamics, they probably do not ask whether these two subjects are related. Here we give an answer to that question. Specifically we give relationships between the equations of change for total energy, internal energy, and entropy of transport phenomena and key equations of equilibrium…

  3. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    Science.gov (United States)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    Back in 1967, Clifford Gardner, John Greene, Martin Kruskal and Robert Miura published a seminal paper in Physical Review Letters which was to become a cornerstone in the theory of integrable systems. In 2006, the authors of this paper received the AMS Steele Prize. In this award the AMS pointed out that `In applications of mathematics, solitons and their descendants (kinks, anti-kinks, instantons, and breathers) have entered and changed such diverse fields as nonlinear optics, plasma physics, and ocean, atmospheric, and planetary sciences. Nonlinearity has undergone a revolution: from a nuisance to be eliminated, to a new tool to be exploited.' From this discovery the modern theory of integrability bloomed, leading scientists to a deep understanding of many nonlinear phenomena which is by no means reachable by perturbation methods or other previous tools from linear theories. Nonlinear phenomena appear everywhere in nature, their description and understanding is therefore of great interest both from the theoretical and applicative point of view. If a nonlinear phenomenon can be represented by an integrable system then we have at our disposal a variety of tools to achieve a better mathematical description of the phenomenon. This special issue is largely dedicated to investigations of nonlinear phenomena which are related to the concept of integrability, either involving integrable systems themselves or because they use techniques from the theory of integrability. The idea of this special issue originated during the 18th edition of the Nonlinear Evolution Equations and Dynamical Systems (NEEDS) workshop, held at Isola Rossa, Sardinia, Italy, 16-23 May 2009 (http://needs-conferences.net/2009/). The issue benefits from the occasion offered by the meeting, in particular by its mini-workshops programme, and contains invited review papers and contributed papers. It is worth pointing out that there was an open call for papers and all contributions were peer reviewed

  4. Understanding the Physics of changing mass phenomena

    Science.gov (United States)

    Ellermeijer, A. L.

    2008-05-01

    Changing mass phenomena, like a falling chain or a bungee jumper, might give surprising results, even for experienced physicists. They have resulted in hot discussions in journals, in which for instance Physics professors claim the impossibility of an acceleration larger then g in case of a bungee jumper. These phenomena are also interesting as topics for challenging student projects, and used as such by Dutch high school students. I will take these phenomena as the context in which I like to demonstrate the possibilities of ICT in the learning process of physics. Especially dynamical modeling enables us to describe these phenomena in an elegant way and with knowledge of high school mathematics. Furthermore tools for video-analysis and data from measurements with sensors allow us to study the phenomena in experiments. This example demonstrates the level of implementation of ICT in Physics Education in The Netherlands [1].

  5. Precedent Phenomena in Quebecois Linguistic World View

    Directory of Open Access Journals (Sweden)

    Ксения Эдуардовна Болотина

    2016-12-01

    Full Text Available This article is devoted to the linguocultural analysis of precedent phenomena as parts of Quebecois’ cognitive base. Precedent phenomena being cultural facts are one of the key issues in modern linguistic and cognitive studies. By precedent phenomena we mean, according to Y.E. Prohorov, such entities when verbalized in discourse that refer to a certain cultural fact behind them. In the article the precedent phenomena such as precedent text, precedent situation, precedent utterance, and precedent name are analyzed. The main theses of the precedence theory given in the article (Y.N. Karaulov, Y.E. Prohorov, V.V. Krasnyh, D.B. Gudkov are at the heart of precedence studies on the basis of different languages. However, a complex analysis of precedent phenomena in the Quebec national variant of French is new to Russian linguistics. The study of precedent phenomena enables us to elicit features of their functioning in ethnospecific discourse and determine cultural dominants existing in Quebecois’ linguistic world view. Given the fact that the size of the article is limited, we undertooke the analysis of eight phenomena precedent of the bearers of Quebec linguoculture. The choice of phenomena is determined by the frequency of their use in discourse. The facts analyzed are of national character, i.e. known to all members of the linguocultural community. A certain cultural fact is at the very core of each precedent phenomenon given in the article. To get the whole picture we analysed historic, political, and cultural context connected to the precedent phenomena in question. The study enables us to elicit distinctive features that are at the core of each phenomenon. The results are backed with the supportive material drawn from analysis of different types of discourse. The analysis of precedent phenomena undertaken in this article allows us to reconstruct, to a certain extent, Quebec cultural space and is a stepping stone to the reconstruction of the

  6. Fourteenth International Conference on Ultrafast Phenomena

    CERN Document Server

    Kobayashi, Takayoshi; Kobayashi, Tetsuro; Nelson, Keith A; Silvestri, Sandro; Ultrafast Phenomena XIV

    2005-01-01

    Ultrafast Phenomena XIV presents the latest advances in ultrafast science, including ultrafast laser and measurement technology as well as studies of ultrafast phenomena. Pico-, femto-, and atosecond processes relevant in physics, chemistry, biology and engineering are presented. Ultrafast technology is now having a profound impact within a wide range of applications, among them imaging, material diagnostics, and transformation and high-speed optoelectronics. This book summarizes results presented at the 14th Ultrafast Phenomena Conference and reviews the state of the art in this important and rapidly advancing field.

  7. Transient phenomena in electrical power systems

    CERN Document Server

    Venikov, V A; Higinbotham, W

    1964-01-01

    Electronics and Instrumentation, Volume 24: Transient Phenomena in Electrical Power Systems presents the methods for calculating the stability and the transient behavior of systems with forced excitation control. This book provides information pertinent to the analysis of transient phenomena in electro-mechanical systems.Organized into five chapters, this volume begins with an overview of the principal requirements in an excitation system. This text then explains the electromagnetic and electro-mechanical phenomena, taking into account the mutual action between the components of the system. Ot

  8. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    Kristensen, Niels Rode; Madsen, Henrik; Jørgensen, Sten Bay

    2003-01-01

    unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance......A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  9. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance......A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  10. Nonlinear Photonics and Novel Optical Phenomena

    CERN Document Server

    Morandotti, Roberto

    2012-01-01

    Nonlinear Photonics and Novel Optical Phenomena contains contributed chapters from leading experts in nonlinear optics and photonics, and provides a comprehensive survey of fundamental concepts as well as hot topics in current research on nonlinear optical waves and related novel phenomena. The book covers self-accelerating airy beams, integrated photonics based on high index doped-silica glass, linear and nonlinear spatial beam dynamics in photonic lattices and waveguide arrays, polariton solitons and localized structures in semiconductor microcavities, terahertz waves, and other novel phenomena in different nanophotonic and optical systems.

  11. Periglacial phenomena affecting nuclear waste disposal

    Directory of Open Access Journals (Sweden)

    Niini, H.

    1997-12-01

    Full Text Available Slow future changes in astronomic phenomena seem to make it likely that Finland nll suffer several cold periods during the next 100,000 years. The paper analyses the characteristics of the periglacial factors that are most likely to influence the long-term safety of high-level radioactive waste disposed of in bedrock. These factors and their influences have been divided into two categories, natural and human. It is concluded that the basically natural phenomena are theoretically better understood than the complicated phenomena caused by man. It is therefore important in future research into periglacial phenomena, as well as of the disposal problem, to emphasize not only the proper applications of the results of natural sciences, but especially the effects and control of mankind's own present and future activities.

  12. Classifying prion and prion-like phenomena.

    Science.gov (United States)

    Harbi, Djamel; Harrison, Paul M

    2014-01-01

    The universe of prion and prion-like phenomena has expanded significantly in the past several years. Here, we overview the challenges in classifying this data informatically, given that terms such as "prion-like", "prion-related" or "prion-forming" do not have a stable meaning in the scientific literature. We examine the spectrum of proteins that have been described in the literature as forming prions, and discuss how "prion" can have a range of meaning, with a strict definition being for demonstration of infection with in vitro-derived recombinant prions. We suggest that although prion/prion-like phenomena can largely be apportioned into a small number of broad groups dependent on the type of transmissibility evidence for them, as new phenomena are discovered in the coming years, a detailed ontological approach might be necessary that allows for subtle definition of different "flavors" of prion / prion-like phenomena.

  13. High Temperature Phenomena in Shock Waves

    CERN Document Server

    2012-01-01

    The high temperatures generated in gases by shock waves give rise to physical and chemical phenomena such as molecular vibrational excitation, dissociation, ionization, chemical reactions and inherently related radiation. In continuum regime, these processes start from the wave front, so that generally the gaseous media behind shock waves may be in a thermodynamic and chemical non-equilibrium state. This book presents the state of knowledge of these phenomena. Thus, the thermodynamic properties of high temperature gases, including the plasma state are described, as well as the kinetics of the various chemical phenomena cited above. Numerous results of measurement and computation of vibrational relaxation times, dissociation and reaction rate constants are given, and various ionization and radiative mechanisms and processes are presented. The coupling between these different phenomena is taken into account as well as their interaction with the flow-field. Particular points such as the case of rarefied flows an...

  14. Transport phenomena an introduction to advanced topics

    CERN Document Server

    Glasgow, Larry A

    2010-01-01

    Enables readers to apply transport phenomena principles to solve advanced problems in all areas of engineering and science This book helps readers elevate their understanding of, and their ability to apply, transport phenomena by introducing a broad range of advanced topics as well as analytical and numerical solution techniques. Readers gain the ability to solve complex problems generally not addressed in undergraduate-level courses, including nonlinear, multidimensional transport, and transient molecular and convective transport scenarios. Avoiding rote memorization, the author em

  15. Evidence on Dropout Phenomena at Universities

    DEFF Research Database (Denmark)

    Larsen, Malene Rode; Sommersel, Hanna Bjørnøy; Larsen, Michael Søgaard

    This publication is an excerpt from the full technical report ‘Dropout Phenomena at Universities: What is Dropout? Why does Dropout Occur? What Can be Done by the Universities to Prevent or Reduce it? A systematic review’, which was completed in April 2013. The purpose of this excerpt is to present...... the knowledge we have on dropout phenomena at European universities in a short, precise and comprehensible form to allow readers to orient themselves on the subject in a more readable manner....

  16. ARISK PHENOMENA IN THE SILVANIA MOUNTAINS, INTUITIVE AND GENETIC REFLEXES

    Directory of Open Access Journals (Sweden)

    CAMELIA BOGDAN

    2014-05-01

    and on the other hand, between the latter and the Oradea hills (Plopiș Mountains. The Silvania Mountains are located in the Southwest of Sălaj County, on an area of tectonic fragmentation, which involves the risk of production of some natural and anthropic risk phenomena. We consider appropriate the elaboration of an assessment and identification strategy of these risks considering the qualitative criteria (ZERMOS which refer to three categories of risks: high, average and low and on this basis we have focused on four risk regions within the Silvania Mountains.

  17. Spooky Phenomena in Two-Photon Processes

    Science.gov (United States)

    Li, Ming-Chiang

    2006-05-01

    A spooky phenomenon in two-photon coherent atomic absorption was discussed in 1980 [M. C. Li, Phys. Rev. A 22 (1980) 1323]. The absorption was initiated by two different laser sources. Classically, it is impossible for atoms to transit coherently in the absorption process, but quantum mechanically it is. This is one of the spooky phenomena in quantum mechanic. Around1990, there were very active experimental pursuits on a spooky phenomenon of two photons emitted from crystal parametric down conversion. The two-photon coherent atomic absorption process contained all basic ingredients as that in crystal parametric down conversion. However, the former arises from two different laser sources. The atom entangles two photons together and becomes a correlatior. The latter arises from a single laser source and two photons are entangled with each other at emission. These two spooky phenomena have been considered as disjointed. The present talk will review two spooky phenomena, and point out their similarities. The investigation on quantum spooky phenomena has led to quantum computing and quantum encryption. It is a hope that the present will stimulate the interest on bring in these two disjointed phenomena together and provide clues in advancing quantum computing and quantum encryption.

  18. Theories of dynamical phenomena in sunspots

    Science.gov (United States)

    Thomas, J. H.

    Attempts that have been made to understand and explain observed dynamical phenomena in sunspots within the framework of magnetohydrodynamic theory are surveyed. The qualitative aspects of the theory and physical arguments are emphasized, with mathematical details generally avoided. The dynamical phenomena in sunspots are divided into two categories: aperiodic (quasi-steady) and oscillatory. For each phenomenon discussed, the salient observational features that any theory should explain are summarized. The two contending theoretical models that can account for the fine structure of the Evershed motion, namely the convective roll model and the siphon flow model, are described. With regard to oscillatory phenomena, attention is given to overstability and oscillatory convection, umbral oscillations and flashes. penumbral waves, five-minute oscillations in sunspots, and the wave cooling of sunspots.

  19. The making of extraordinary psychological phenomena.

    Science.gov (United States)

    Lamont, Peter

    2012-01-01

    This article considers the extraordinary phenomena that have been central to unorthodox areas of psychological knowledge. It shows how even the agreed facts relating to mesmerism, spiritualism, psychical research, and parapsychology have been framed as evidence both for and against the reality of the phenomena. It argues that these disputes can be seen as a means through which beliefs have been formulated and maintained in the face of potentially challenging evidence. It also shows how these disputes appealed to different forms of expertise, and that both sides appealed to belief in various ways as part of the ongoing dispute about both the facts and expertise. Finally, it shows how, when a formal Psychology of paranormal belief emerged in the twentieth century, it took two different forms, each reflecting one side of the ongoing dispute about the reality of the phenomena. © 2012 Wiley Periodicals, Inc.

  20. Nonlinear phenomena in contemporary vocal music.

    Science.gov (United States)

    Neubauer, Jürgen; Edgerton, Michael; Herzel, Hanspeter

    2004-03-01

    Complex and multiphonic voice signals of vocal improvisors are analyzed within the framework of nonlinear dynamics. Evidence is given that nonlinear phenomena are extensively used by performers associated with contemporary music. Narrow-band spectrograms of complex vocalizations are used to visualize the appearance of nonlinear phenomena (spectral bifurcation diagrams). Possible production mechanisms are discussed in connection with previous research, personal performance and pedagogical experience. Examples for period doubling, biphonation and irregular aperiodic phonation in vocal sonorities of contemporary vocal improvisors are given, and glottal whistle production encompassed with biphonation and triphonation is shown. Furthermore, coincidences of harmonics-formant matching associated with abrupt transitions to subharmonics and biphonation in the vocal output are provided. This also shows the recurrent use of nonlinear phenomena by performers. It is argued that mechanisms such as source-tract coupling or vocal fold desynchronization due to asymmetry are used in a reproducible way for musical tasks.

  1. Stability and Restoration phenomena in Competitive Systems

    CERN Document Server

    Uechi, Lisa

    2012-01-01

    A conservation law and stability, recovering phenomena and characteristic patterns of a nonlinear dynamical system have been studied and applied to biological and ecological systems. In our previous study, we proposed a system of symmetric 2n-dimensional conserved nonlinear differential equations with external perturbations. In this paper, competitive systems described by 2-dimensional nonlinear dynamical (ND) model with external perturbations are applied to population cycles and recovering phenomena of systems from microbes to mammals. The famous 10-year cycle of population density of Canadian lynx and snowshoe hare is numerically analyzed. We find that a nonlinear dynamical system with a conservation law is stable and generates a characteristic rhythm (cycle) of population density, which we call the {\\it standard rhythm} of a nonlinear dynamical system. The stability and restoration phenomena are strongly related to a conservation law and balance of a system. The {\\it standard rhythm} of population density ...

  2. Current-driven phenomena in nanoelectronics

    CERN Document Server

    Seideman, Tamar

    2010-01-01

    Consisting of ten chapters written by some of the world's leaders in the field, this book combines experimental, theoretical and numerical studies of current-driven phenomena in the nanoscale. The topics covered range from single-molecule, site-specific nanochemistry induced by a scanning tunneling microscope, through inelastic tunneling spectroscopy and current-induced heating, to current-triggered molecular machines. The various chapters focus on experimental and numerical method development, the description of specific systems, and new ideas and novel phenomena.

  3. Dissipative phenomena in condensed matter some applications

    CERN Document Server

    Dattagupta, Sushanta

    2004-01-01

    From the field of nonequilibrium statistical physics, this graduate- and research-level volume treats the modeling and characterization of dissipative phenomena. A variety of examples from diverse disciplines like condensed matter physics, materials science, metallurgy, chemical physics etc. are discussed. Dattagupta employs the broad framework of stochastic processes and master equation techniques to obtain models for a wide range of experimentally relevant phenomena such as classical and quantum Brownian motion, spin dynamics, kinetics of phase ordering, relaxation in glasses, dissipative tunneling. It provides a pedagogical exposition of current research material and will be useful to experimentalists, computational physicists and theorists.

  4. Temporal Phenomena in the Korean Conjunctive Constructions

    Science.gov (United States)

    Kim, Dongmin

    2015-01-01

    The goal of this study is to characterize the temporal phenomena in the Korean conjunctive constructions. These constructions consist of three components: a verbal stem, a clause medial temporal suffix, and a clause terminal suffix. This study focuses on both the temporality of the terminal connective suffixes and the grammatical meanings of the…

  5. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Abstract. Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical ...

  6. Modelling of flow phenomena during DC casting

    NARCIS (Netherlands)

    Zuidema, J.

    2005-01-01

    Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an

  7. Simple classical approach to spin resonance phenomena

    DEFF Research Database (Denmark)

    Gordon, R A

    1977-01-01

    A simple classical method of describing spin resonance in terms of the average power absorbed by a spin system is discussed. The method has several advantages over more conventional treatments, and a number of important spin resonance phenomena, not normally considered at the introductory level...

  8. Quantum phenomena in magnetic nano clusters

    Indian Academy of Sciences (India)

    Unknown

    Quantum phenomena in magnetic nano clusters. 461. Figure 3. Schematic exchange interactions in a V15 cluster. There is no direct exchange interaction amongst the triangle spins. Interactions not shown explicitly can be generated from the C3 symmetry of the system. simplify the calculations, the strongly coupled ...

  9. Quantum phenomena in magnetic nano clusters

    Indian Academy of Sciences (India)

    While semiconductor structures have provided paradigms of nanosystems from the stand point of electronic phenomena, the synthesis of high nuclearity transition metal complexes have provided examples of nano magnets. The range and diversity of the properties exhibited by these systems rivals its electronic counterparts ...

  10. Hyperchaotic phenomena in dynamic decision making

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Mosekilde, Erik; Sterman, John David

    1992-01-01

    of this article is to show how the decision making behavior of real people in simulated corporate environments can lead to chaotic, hyperchaotic and higher-order hyperchaotic phenomena. Characteristics features of these complicated forms of behavior are analyzed with particular emphasis on an interesting form...

  11. Novel experimentally observed phenomena in soft matter

    Indian Academy of Sciences (India)

    Experiments that report a spectrum of novel phenomena exhibited by these materials, such as turbulent drag reduction, elastic turbulence, the formation of shear bands and the existence of rheological chaos, flow-induced birefringence and the unusual rheology of soft glassy materials, are reviewed. The focus then shifts to ...

  12. Interfacial phenomena and the ocular surface.

    Science.gov (United States)

    Yañez-Soto, Bernardo; Mannis, Mark J; Schwab, Ivan R; Li, Jennifer Y; Leonard, Brian C; Abbott, Nicholas L; Murphy, Christopher J

    2014-07-01

    Ocular surface disorders, such as dry eye disease, ocular rosacea, and allergic conjunctivitis, are a heterogeneous group of diseases that require an interdisciplinary approach to establish underlying causes and develop effective therapeutic strategies. These diverse disorders share a common thread in that they involve direct changes in ocular surface chemistry as well as the rheological properties of the tear film and topographical attributes of the cellular elements of the ocular surface. Knowledge of these properties is crucial to understand the formation and stability of the preocular tear film. The study of interfacial phenomena of the ocular surface flourished during the 1970s and 1980s, but after a series of lively debates in the literature concerning distinctions between the epithelial and the glandular origin of ocular surface disorders during the 1990s, research into this important topic has declined. In the meantime, new tools and techniques for the characterization and functionalization of biological surfaces have been developed. This review summarizes the available literature regarding the physicochemical attributes of the ocular surface, analyzes the role of interfacial phenomena in the pathobiology of ocular surface disease, identifies critical knowledge gaps concerning interfacial phenomena of the ocular surface, and discusses the opportunities for the exploitation of these phenomena to develop improved therapeutics for the treatment of ocular surface disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Reflection equations and surface critical phenomena

    OpenAIRE

    Batchelor, M. T.

    1996-01-01

    A brief review is given of recent developments in the study of surface critical phenomena from the viewpoint of exactly solved lattice models. These developments include exact results for the polymer adsorption transition and the surface critical exponents of the eight-vertex model.

  14. Some Phenomena on Negative Inversion Constructions

    Science.gov (United States)

    Sung, Tae-Soo

    2013-01-01

    We examine the characteristics of NDI (negative degree inversion) and its relation with other inversion phenomena such as SVI (subject-verb inversion) and SAI (subject-auxiliary inversion). The negative element in the NDI construction may be" not," a negative adverbial, or a negative verb. In this respect, NDI has similar licensing…

  15. Fourier Series The Mathematics of Periodic Phenomena

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 10. Fourier Series The Mathematics of Periodic Phenomena. S Thangavelu ... Author Affiliations. S Thangavelu1. Department of Mathematics and Statistics, University of New Mexico, Humanities Building 419, Albuquerque, NM 87131-1141, USA ...

  16. Coherent topological phenomena in protein folding

    DEFF Research Database (Denmark)

    Bohr, Henrik; Brunak, Søren; Bohr, Jakob

    1997-01-01

    A theory is presented for coherent topological phenomena in protein dynamics with implications for protein folding and stability. We discuss the relationship to the writhing number used in knot diagrams of DNA. The winding state defines a long-range order along the backbone of a protein with long...

  17. Intervention in Biological Phenomena via Feedback Linearization.

    Science.gov (United States)

    Fnaiech, Mohamed Amine; Nounou, Hazem; Nounou, Mohamed; Datta, Aniruddha

    2012-01-01

    The problems of modeling and intervention of biological phenomena have captured the interest of many researchers in the past few decades. The aim of the therapeutic intervention strategies is to move an undesirable state of a diseased network towards a more desirable one. Such an objective can be achieved by the application of drugs to act on some genes/metabolites that experience the undesirable behavior. For the purpose of design and analysis of intervention strategies, mathematical models that can capture the complex dynamics of the biological systems are needed. S-systems, which offer a good compromise between accuracy and mathematical flexibility, are a promising framework for modeling the dynamical behavior of biological phenomena. Due to the complex nonlinear dynamics of the biological phenomena represented by S-systems, nonlinear intervention schemes are needed to cope with the complexity of the nonlinear S-system models. Here, we present an intervention technique based on feedback linearization for biological phenomena modeled by S-systems. This technique is based on perfect knowledge of the S-system model. The proposed intervention technique is applied to the glycolytic-glycogenolytic pathway, and simulation results presented demonstrate the effectiveness of the proposed technique.

  18. Intervention in Biological Phenomena via Feedback Linearization

    Directory of Open Access Journals (Sweden)

    Mohamed Amine Fnaiech

    2012-01-01

    Full Text Available The problems of modeling and intervention of biological phenomena have captured the interest of many researchers in the past few decades. The aim of the therapeutic intervention strategies is to move an undesirable state of a diseased network towards a more desirable one. Such an objective can be achieved by the application of drugs to act on some genes/metabolites that experience the undesirable behavior. For the purpose of design and analysis of intervention strategies, mathematical models that can capture the complex dynamics of the biological systems are needed. S-systems, which offer a good compromise between accuracy and mathematical flexibility, are a promising framework for modeling the dynamical behavior of biological phenomena. Due to the complex nonlinear dynamics of the biological phenomena represented by S-systems, nonlinear intervention schemes are needed to cope with the complexity of the nonlinear S-system models. Here, we present an intervention technique based on feedback linearization for biological phenomena modeled by S-systems. This technique is based on perfect knowledge of the S-system model. The proposed intervention technique is applied to the glycolytic-glycogenolytic pathway, and simulation results presented demonstrate the effectiveness of the proposed technique.

  19. Analysis of extreme hydrological phenomena in southern Italy (Calabria region)

    Science.gov (United States)

    Caloiero, Tommaso; Aceto, Luigi; Aurora Pasqua, A.; Petrucci, Olga

    2017-04-01

    Calabria (southern Italy) is a region exposed to the effects of contrasting climatic and hydrological phenomena. In fact, due to its oblong shape, to its position in the middle of the Mediterranean Basin, and for its mountainous nature, Calabria shows a high spatial variability of the climatic features and of related phenomena such as floods and drought. The present paper is based on the historical database ASICal (Historically flooded areas in Calabria), a catalogue of effects of floods and rain-related landslides that occurred in the region since the XIX Century. The catalogue has been built using the typical historical data sources as chronicles, diaries, historical books, local and regional agencies, press archives, scientific papers, and documents of civil protection offices. From these sources, we selected information on damage caused by rain related phenomena at a municipal scale and chronologically sorted by year, month and day. The analysis of the entire catalogue allows highlighting the regional Damaging Hydrogeological Events (DHE), defined as periods of intense rain causing damage on regional sectors conventionally selected as larger than 30% of the entire regional territory. For each event, as a measure of the magnitude of rainfall, the return period of the daily rainfall recorded during the event has been evaluated. In addition, we recently carried out a similar historical research to identify the main drought events affecting the region. In this case, due to the spatial and temporal characteristics of drought, data are collected both at municipal and regional scale, and the temporal scale is generally monthly or annual. For each event, we used as climatic descriptors a drought index for monitoring drought phenomena. Among drought indices, we used the Standardized Precipitation Index (SPI) which can be considered the most robust and effective, since it can be calculated for different time-scales and can be used to analyse different drought categories

  20. System Identification

    NARCIS (Netherlands)

    Keesman, K.J.

    2011-01-01

    Summary System Identification Introduction.- Part I: Data-based Identification.- System Response Methods.- Frequency Response Methods.- Correlation Methods.- Part II: Time-invariant Systems Identification.- Static Systems Identification.- Dynamic Systems Identification.- Part III: Time-varying

  1. Tunable caustic phenomena in electron wavefields

    Energy Technology Data Exchange (ETDEWEB)

    Tavabi, Amir Hossein, E-mail: a.tavabi@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Migunov, Vadim; Dwyer, Christian; Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Pozzi, Giulio [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute (PGI), Forschungszentrum Jülich, D-52425 Jülich (Germany); Department of Physics and Astronomy, University of Bologna, Viale B. Pichat 6/2, 40127 Bologna (Italy)

    2015-10-15

    Novel caustic phenomena, which contain fold, butterfly and elliptic umbilic catastrophes, are observed in defocused images of two approximately collinear oppositely biased metallic tips in a transmission electron microscope. The observed patterns depend sensitively on defocus, on the applied voltage between the tips and on their separation and lateral offset. Their main features are interpreted on the basis of a projected electrostatic potential model for the electron-optical phase shift. - Highlights: • Electron-optical caustics are observed in defocused images of biased metallic tips. • The caustics depend on defocus, on the bias between the tips and on their separation. • The setup offers the flexibility to study a wide variety of caustic phenomena.

  2. Ordering phenomena in ABA triblock copolymer gels

    DEFF Research Database (Denmark)

    Reynders, K.; Mischenko, N.; Kleppinger, R.

    1997-01-01

    Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network). The lat......Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network...... crystalline lattice with close-packed spheres or with cubic (presumably BCC) equilibrium morphology. The appearance of the latter is never detected in the gels with a stretched conformation of the midblock....

  3. Basic transport phenomena in materials engineering

    CERN Document Server

    Iguchi, Manabu

    2014-01-01

    This book presents the basic theory and experimental techniques of transport phenomena in materials processing operations. Such fundamental knowledge is highly useful for researchers and engineers in the field to improve the efficiency of conventional processes or develop novel technology. Divided into four parts, the book comprises 11 chapters describing the principles of momentum transfer, heat transfer, and mass transfer in single phase and multiphase systems. Each chapter includes examples with solutions and exercises to facilitate students’ learning. Diagnostic problems are also provided at the end of each part to assess students’ comprehension of the material.  The book is aimed primarily at students in materials science and engineering. However, it can also serve as a useful reference text in chemical engineering as well as an introductory transport phenomena text in mechanical engineering. In addition, researchers and engineers engaged in materials processing operations will find the material use...

  4. Transport phenomena in strongly correlated Fermi liquids

    CERN Document Server

    Kontani, Hiroshi

    2013-01-01

    In conventional metals, various transport coefficients are scaled according to the quasiparticle relaxation time, \\tau, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems, reflecting their unique electronic states. The most famous example would be cuprate high-Tc superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. To better understand the origin of this discrepancy, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. Near the magnetic quantum critical point, the current vertex correction (CVC), which describes the electron-electron scattering beyond the relaxation time approximation, gives rise to various anomalous transport phenomena. We explain anomalous transport phenomena in cuprate HTSCs and other metals near their magnetic or orbital quantum critical poi...

  5. Natural phenomena hazards site characterization criteria

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    The criteria and recommendations in this standard shall apply to site characterization for the purpose of mitigating Natural Phenomena Hazards (wind, floods, landslide, earthquake, volcano, etc.) in all DOE facilities covered by DOE Order 5480.28. Criteria for site characterization not related to NPH are not included unless necessary for clarification. General and detailed site characterization requirements are provided in areas of meteorology, hydrology, geology, seismology, and geotechnical studies.

  6. Workshop on Nonlinear Phenomena in Complex Systems

    CERN Document Server

    1989-01-01

    This book contains a thorough treatment of neural networks, cellular-automata and synergetics, in an attempt to provide three different approaches to nonlinear phenomena in complex systems. These topics are of major interest to physicists active in the fields of statistical mechanics and dynamical systems. They have been developed with a high degree of sophistication and include the refinements necessary to work with the complexity of real systems as well as the more recent research developments in these areas.

  7. AC Electrokinetic Phenomena Generated by Microelectrode Structures

    Science.gov (United States)

    Hart, Robert; Oh, Jonghyun; Capurro, Jorge; Noh, Hongseok (Moses)

    2008-01-01

    The field of AC electrokinetics is rapidly growing due to its ability to perform dynamic fluid and particle manipulation on the micro- and nano-scale, which is essential for Lab-on-a-Chip applications. AC electrokinetic phenomena use electric fields to generate forces that act on fluids or suspended particles (including those made of dielectric or biological material) and cause them to move in astonishing ways1, 2. Within a single channel, AC electrokinetics can accomplish many essential on-chip operations such as active micro-mixing, particle separation, particle positioning and micro-pattering. A single device may accomplish several of those operations by simply adjusting operating parameters such as frequency or amplitude of the applied voltage. Suitable electric fields can be readily created by micro-electrodes integrated into microchannels. It is clear from the tremendous growth in this field that AC electrokinetics will likely have a profound effect on healthcare diagnostics3-5, environmental monitoring6 and homeland security7. In general, there are three AC Electrokinetic phenomena (AC electroosmosis, dielectrophoresis and AC electrothermal effect) each with unique dependencies on the operating parameters. A change in these operating parameters can cause one phenomena to become dominant over another, thus changing the particle or fluid behavior. It is difficult to predict the behavior of particles and fluids due to the complicated physics that underlie AC electrokinetics. It is the goal of this publication to explain the physics and elucidate particle and fluid behavior. Our analysis also covers how to fabricate the electrode structures that generate them, and how to interpret a wide number of experimental observations using several popular device designs. This video article will help scientists and engineers understand these phenomena and may encourage them to start using AC Electrokinetics in their research. PMID:19066515

  8. Bridge windshield design to avoid aeroelastic phenomena

    OpenAIRE

    Ogueta Gutiérrez, Mikel; Franchini Longhi, Sebastian Nicolas

    2014-01-01

    Since in 1940 the Tacoma Narrows Bridge was destroyed by the wind, aeroelastic instabilities have been recognized as one of the most challenging aspects of bridge design. They can produce long-term fatigue failure through vortex induced vibrations, or sudden collapse through self-excited flutter. These vibrations may also cause discomfort for the users and temporary closure of the bridge. Wind tunnel studies are a very helpful tool to understand these phenomena. By means of them, the critical...

  9. Corporate Strategy And The Social Networking Phenomena

    OpenAIRE

    Johnson, Robert L.

    2011-01-01

    The Social Networking (SN) phenomena has developed relatively overnight and is continuing to develop at an exponential pace. It allows for innovative new methods of disseminating and collecting information in ways never before dreamed possible by corporate executives. The rise of Social Networking is becoming a disruptive technology for traditional marketing and advertising medium such as radio, television, web page, and print media, creating new business opportunities for the entrepreneur w...

  10. Duality in Liouville theory and moonshine phenomena

    OpenAIRE

    Eguchi, Tohru; Sugawara, Yuji

    2016-01-01

    We consider the Liouville theory by varying the linear dilaton coupling constant . It is known that, at two different values of coupling constant , the system exhibits two different small superconformal symmetries with central charge and , respectively. In the context of string theory these two theories are considered to describe the Coulomb and Higgs branches of the theory and are expected to be dual to each other. We study the Mathieu and umbral moonshine phenomena in these two theories and...

  11. Bion and Tustin: the autistic phenomena.

    Science.gov (United States)

    Korbivcher, Celia Fix

    2013-08-01

    This article examines the implications of the proposal of autistic transformations within the general context of Bion's theory of Transformations. The aim is to confirm the coherence of this proposal of autistic transformations within the overall structure of Bion's theory of Transformations. She examines the relation between emotional links and their negatives, particularly -K. She questions in which of the dimensions of the mind the autistic phenomena are located, the relation between autistic phenomena and beta elements, and where to place them in the Grid. The author tries to form metapsychological support for the incorporation of the autistic area in Bion's theory of Transformations. She argues that, despite the incongruence and imprecision of this incorporation, such autistic phenomena cannot be excluded from the complexus of the human mind and should therefore be accounted for in Bion's transformations. She discusses the idea that the theory of transformations includes the field of the neurosis and psychosis and deals with emotions, whereas the autistic area is dominated by sensations. The author asks how to add the autistic area to Bion's theory. Clinical material of a child for whom the non-psychotic part of the personality predominates and who presents autistic nuclei provides material for the discussion. Copyright © 2013 Institute of Psychoanalysis.

  12. Quantum Chess: Making Quantum Phenomena Accessible

    Science.gov (United States)

    Cantwell, Christopher

    Quantum phenomena have remained largely inaccessible to the general public. There tends to be a scare factor associated with the word ``Quantum''. This is in large part due to the alien nature of phenomena such as superposition and entanglement. However, Quantum Computing is a very active area of research and one day we will have games that run on those quantum computers. Quantum phenomena such as superposition and entanglement will seem as normal as gravity. Is it possible to create such games today? Can we make games that are built on top of a realistic quantum simulation and introduce players of any background to quantum concepts in a fun and mentally stimulating way? One of the difficulties with any quantum simulation run on a classical computer is that the Hilbert space grows exponentially, making simulations of an appreciable size physically impossible due largely to memory restrictions. Here we will discuss the conception and development of Quantum Chess, and how to overcome some of the difficulties faced. We can then ask the question, ``What's next?'' What are some of the difficulties Quantum Chess still faces, and what is the future of quantum games?

  13. Studies of Novel Quantum Phenomena in Ruthenates

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Zhiqiang

    2011-04-08

    Strongly correlated oxides have been the subject of intense study in contemporary condensed matter physics, and perovskite ruthenates (Sr,Ca)n+1RunO3n+1 have become a new focus in this field. One of important characteristics of ruthenates is that both lattice and orbital degrees of freedom are active and are strongly coupled to charge and spin degrees of freedom. Such a complex interplay of multiple degrees of freedom causes the properties of ruthenates to exhibit a gigantic response to external stimuli under certain circumstances. Magnetic field, pressure, and chemical composition all have been demonstrated to be effective in inducing electronic/magnetic phase transitions in ruthenates. Therefore, ruthenates are ideal candidates for searching for novel quantum phenomena through controlling external parameters. The objective of this project is to search for novel quantum phenomena in ruthenate materials using high-quality single crystals grown by the floating-zone technique, and investigate the underlying physics. The following summarizes our accomplishments. We have focused on trilayered Sr4Ru3O10 and bilayered (Ca1-xSrx)3Ru2O7. We have succeeded in growing high-quality single crystals of these materials using the floating-zone technique and performed systematic studies on their electronic and magnetic properties through a variety of measurements, including resistivity, Hall coefficient, angle-resolved magnetoresistivity, Hall probe microscopy, and specific heat. We have also studied microscopic magnetic properties for some of these materials using neutron scattering in collaboration with Los Alamos National Laboratory. We have observed a number of unusual exotic quantum phenomena through these studies, such as an orbital selective metamagnetic transition, bulk spin valve effect, and a heavy-mass nearly ferromagnetic state with a surprisingly large Wilson ratio. Our work has also revealed underlying physics of these exotic phenomena. Exotic phenomena of correlated

  14. Rod Driven Frequency Entrainment and Resonance Phenomena

    Directory of Open Access Journals (Sweden)

    Christina Salchow

    2016-08-01

    Full Text Available A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α of each volunteer in the range from 0.40–2.30*α. 306-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90–1.10*α and half of the alpha frequency (0.40–0.55*α. No signs of resonance and frequency entrainment phenomena were revealed around 2.00*α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30–2.30*α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex.

  15. Results on large transverse momentum phenomena

    CERN Document Server

    Büsser, F W; Blumenfeld, B; Camilleri, L L; Cool, R L; Di Lella, L; Gladding, G; Lederman, Leon Max; Litt, L; Placci, A; Pope, B G; Segler, S L; Smith, A M; Yoh, J K; Zavattini, E

    1973-01-01

    Preliminary results of an experiment on large transverse momentum phenomena performed at the CERN-ISR at centre-of-mass energies of 52.7 and 44.8 GeV are presented. The topics studied were the inclusive reaction p+p to pi /sup 0/+'anything', where the pi /sup 0/ was emitted around 90 degrees in the centre- of-mass system, ( pi /sup 0/ pi /sup 0/) correlations, and the charged multiplicity associated with large transverse momentum pi /sup 0/'s. In addition, results of a search for electrons and electron pairs are included. (4 refs).

  16. Modeling in transport phenomena a conceptual approach

    CERN Document Server

    Tosun, Ismail

    2007-01-01

    Modeling in Transport Phenomena, Second Edition presents and clearly explains with example problems the basic concepts and their applications to fluid flow, heat transfer, mass transfer, chemical reaction engineering and thermodynamics. A balanced approach is presented between analysis and synthesis, students will understand how to use the solution in engineering analysis. Systematic derivations of the equations and the physical significance of each term are given in detail, for students to easily understand and follow up the material. There is a strong incentive in science and engineering to

  17. Micro- and nanoscale phenomena in tribology

    CERN Document Server

    Chung, Yip-Wah

    2011-01-01

    Drawn from presentations at a recent National Science Foundation Summer Institute on Nanomechanics, Nanomaterials, and Micro/Nanomanufacturing, Micro- and Nanoscale Phenomena in Tribology explores the convergence of the multiple science and engineering disciplines involved in tribology and the connection from the macro to nano world. Written by specialists from computation, materials science, mechanical engineering, surface physics, and chemistry, each chapter provides up-to-date coverage of both basic and advanced topics and includes extensive references for further study.After discussing the

  18. Cooperative phenomena in flows; Poster abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Loekseth, Trine (ed.)

    2011-05-15

    The objective of this 'Geilo School' was to bring together researchers with various interests and background including theoretical experimental physicists, material scientists and molecular biologists to identify and discuss areas where synergism between these disciplines may be most fruitfully applied to the study of various aspects of 'Cooperative phenomena in flows'. There were altogether 21 lecturers at the School with about 80 participants from 19 countries. This was the 21. Geilo School held biannually since the first one in I971. Reference to the earlier Geilo Schools 1971-2009 may be found here: http://www.ife.no/departments/physics/projects/geilo (Author)

  19. Nanoscale and microscale phenomena fundamentals and applications

    CERN Document Server

    Khandekar, Sameer

    2015-01-01

    The book is an outcome of research work in the areas of nanotechnology, interfacial science, nano- and micro-fluidics and manufacturing, soft matter, and transport phenomena at nano- and micro-scales. The contributing authors represent prominent research groups from Indian Institute of Technology Bombay, Indian Institute of Technology Kanpur and Indian Institute of Science, Bangalore. The book has 13 chapters and the entire work presented in the chapters is based on research carried out over past three years. The chapters are designed with number of coloured illustrations, figures and tables. The book will be highly beneficial to academicians as well as industrial professionals working in the mentioned areas.

  20. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Yu, Liyun; Mateiu, Ramona Valentina; Skov, Anne Ladegaard

    years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we focus on the chloro propyl functionalized silicone elastomers prepared in Madsen et al[2] and we investigate the electrical...... breakdown patterns of two similar chloro propyl functionalized silicone elastomers which break down electrically in a rather different way as well as we compare them to a silicone based reference. Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS) are used to evaluate...... the elastomers after electrical breakdown....

  1. Chalcogenides Metastability and Phase Change Phenomena

    CERN Document Server

    Kolobov, Alexander V

    2012-01-01

    A state-of-the-art description of metastability observed in chalcogenide alloys is presented with the accent on the underlying physics. A comparison is made between sulphur(selenium)-based chalcogenide glasses, where numerous photo-induced phenomena take place entirely within the amorphous phase, and tellurides where a reversible crystal-to-amorphous phase-change transformation is a major effect. Applications of metastability in devices¿optical memories and nonvolatile electronic phase-change random-access memories among others are discussed, including the latest trends. Background material essential for understanding current research in the field is also provided.

  2. Whither the Future of Controlling Quantum Phenomena?

    Science.gov (United States)

    Rabitz, Herschel; de Vivie-Riedle, Regina; Motzkus, Marcus; Kompa, Karl

    2000-05-01

    This review puts into perspective the present state and prospects for controlling quantum phenomena in atoms and molecules. The topics considered include the nature of physical and chemical control objectives, the development of possible quantum control rules of thumb, the theoretical design of controls and their laboratory realization, quantum learning and feedback control in the laboratory, bulk media influences, and the ability to utilize coherent quantum manipulation as a means for extracting microscopic information. The preview of the field presented here suggests that important advances in the control of molecules and the capability of learning about molecular interactions may be reached through the application of emerging theoretical concepts and laboratory technologies.

  3. Heavenly Bodies and Phenomena in Petroglyphs

    Science.gov (United States)

    Tokhatyan, Karen

    2016-12-01

    In Armenian culture are amply reflected realities connected with Universe. Their figurative expressions are also petroglyphs in which there are representations of solar signs, swastika, Moon crescend, planets, stars, star groups, constellations, Milky Way, Earth. Among heavenly and atmospheric phenomena are: eclipce, meteor, comet, ligthning, cloud, rain and rainbow. There are many products of scientific thinking: stellar maps, calendars, compasses, astronomical records, Zodiac signs and ideograms. Thousands of the Armenian petroglyphs that were created millennia ago by an indigenous ethnos - Armenians, point to the significant place of celestial bodies and luminaries, especially the Sun, stars, and stellar constellations in our ancestors' cosmological perceptions.

  4. Highly energetic phenomena in water electrolysis

    OpenAIRE

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; V. B. Svetovoy

    2016-01-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is gr...

  5. Advances in modelling of condensation phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.S.; Zaltsgendler, E. [Ontario Hydro Nuclear, Toronto (Canada); Hanna, B. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

    1997-07-01

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

  6. Syntactic Idioms and Precedent Phenomena: Intersection Zones

    Directory of Open Access Journals (Sweden)

    Hanna Sytar

    2016-08-01

    Full Text Available Background: One examined mainly structural and semantic features of syntactic idioms so far. The pragmatic dimension of these original units that are on the verge of syntax and phraseology, has not been highlighted properly in the scientific literature, so it needs theoretical understanding. The combination of syntactic idiom and phraseological phenomenon refers to the communication techniques impacting on message recipient. Purpose: to analyze the intersection zones of syntactic idioms and precedent phenomena. Results: Analysis of the collected factual material allows to distinguish two areas of interpenetration of syntactic idioms and precedent units: 1 construction of expression according to the phraseologized model, within which the position of variable component is filled by the precedent name or precedent expression; 2 the model of sentence itself is precedent, and lexical content does not comply with generally known one that does not affect on understanding of model content by recipient. With a combination of syntactic idiom and precedent phenomena speakers provide drawing of recipients’ attention, carry out a hidden influence on them, express their own attitude to the realities, so that perform phatic, manipulative and expressive-evaluative functions. The modifications and transformations of precedent expressions and names appeared to be regular in such interpenetrations. Discussion: The obtained results reflect the general trend towards transform (transformation, modification, variation, etc. of precedent, as well as phraseological units, and can be used for the analysis of patterns of their formation and modifications. Further research phase implies tracing patterns of syntactic idioms combination with other means of expressive syntax.

  7. WHC natural phenomena hazards mitigation implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    Conrads, T.J.

    1996-09-11

    Natural phenomena hazards (NPH) are unexpected acts of nature which pose a threat or danger to workers, the public or to the environment. Earthquakes, extreme winds (hurricane and tornado),snow, flooding, volcanic ashfall, and lightning strike are examples of NPH at Hanford. It is the policy of U.S. Department of Energy (DOE) to design, construct and operate DOE facilitiesso that workers, the public and the environment are protected from NPH and other hazards. During 1993 DOE, Richland Operations Office (RL) transmitted DOE Order 5480.28, ``Natural Phenomena Hazards Mitigation,`` to Westinghouse Hanford COmpany (WHC) for compliance. The Order includes rigorous new NPH criteria for the design of new DOE facilities as well as for the evaluation and upgrade of existing DOE facilities. In 1995 DOE issued Order 420.1, ``Facility Safety`` which contains the same NPH requirements and invokes the same applicable standards as Order 5480.28. It will supersede Order 5480.28 when an in-force date for Order 420.1 is established through contract revision. Activities will be planned and accomplished in four phases: Mobilization; Prioritization; Evaluation; and Upgrade. The basis for the graded approach is the designation of facilities/structures into one of five performance categories based upon safety function, mission and cost. This Implementation Plan develops the program for the Prioritization Phase, as well as an overall strategy for the implemention of DOE Order 5480.2B.

  8. Shock Wave Diffraction Phenomena around Slotted Splitters

    Directory of Open Access Journals (Sweden)

    Francesca Gnani

    2015-01-01

    Full Text Available In the field of aerospace engineering, the study of the characteristics of vortical flows and their unsteady phenomena finds numerous engineering applications related to improvements in the design of tip devices, enhancement of combustor performance, and control of noise generation. A large amount of work has been carried out in the analysis of the shock wave diffraction around conventional geometries such as sharp and rounded corners, but the employment of splitters with lateral variation has hardly attracted the attention of researchers. The investigation of this phenomenon around two-dimensional wedges has allowed the understanding of the basic physical principles of the flow features. On the other hand, important aspects that appear in the third dimension due to the turbulent nature of the vortices are omitted. The lack of studies that use three-dimensional geometries has motivated the current work to experimentally investigate the evolution of the shock wave diffraction around two splitters with spike-shaped structures for Mach numbers of 1.31 and 1.59. Schlieren photography was used to obtain an insight into the sequential diffraction processes that take place in different planes. Interacting among them, these phenomena generate a complicated turbulent cloud with a vortical arrangement.

  9. Uncommon corrosion phenomena of archaeological bronze alloys

    Science.gov (United States)

    Ingo, G. M.; de Caro, T.; Riccucci, C.; Khosroff, S.

    2006-06-01

    In the framework of the EFESTUS project (funded by the European Commission, contract No. ICA3-CT-2002-10030) the corrosion products of a large number of archaeological bronze artefacts are investigated by means of the combined use of scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and optical microscopy (OM) and tentative correlation of their nature with the chemical composition of the artefacts and the burial context is proposed. The results provide good insight into the corrosion layers and evidence in some bronze Roman coins and artefacts; the occurrence of uncommon corrosion phenomena that give rise to the formation of a yellowish-green complex chlorine-phosphate of lead (pyromorphite, (PbCl)Pb4(PO4)3) and of a gold-like thick layer of an iron and copper sulphide (chalcopyrite, CuFeS2). The micro-chemical and micro-structural results show that the coins were buried in a soil enriched in phosphorus for the accidental presence of a large amount of decomposing fragments of bones or in an anaerobic and humus rich soil where the chalcopyrite layer has been produced via the interaction between the iron of the soil, the copper of the coin and the sulphur produced by the decomposition of organic matter in an almost oxygen free environment. Finally, some unusual periodic corrosion phenomena occurring in high tin bronze mirrors found at Zama (Tunisia) are described.

  10. Microgravity Transport Phenomena Experiment (MTPE) Overview

    Science.gov (United States)

    Mason, Larry W.

    1999-01-01

    The Microgravity Transport Phenomena Experiment (MTPE) is a fluids experiment supported by the Fundamentals in Biotechnology program in association with the Human Exploration and Development of Space (BEDS) initiative. The MTP Experiment will investigate fluid transport phenomena both in ground based experiments and in the microgravity environment. Many fluid transport processes are affected by gravity. Osmotic flux kinetics in planar membrane systems have been shown to be influenced by gravimetric orientation, either through convective mixing caused by unstably stratified fluid layers, or through a stable fluid boundary layer structure that forms in association with the membrane. Coupled transport phenomena also show gravity related effects. Coefficients associated with coupled transport processes are defined in terms of a steady state condition. Buoyancy (gravity) driven convection interferes with the attainment of steady state, and the measurement of coupled processes. The MTP Experiment measures the kinetics of molecular migration that occurs in fluids, in response to the application of various driving potentials. Three separate driving potentials may be applied to the MTP Experiment fluids, either singly or in combination. The driving potentials include chemical potential, thermal potential, and electrical potential. Two separate fluid arrangements are used to study membrane mediated and bulk fluid transport phenomena. Transport processes of interest in membrane mediated systems include diffusion, osmosis, and streaming potential. Bulk fluid processes of interest include coupled phenomena such as the Soret Effect, Dufour Effect, Donnan Effect, and thermal diffusion potential. MTP Experiments are performed in the Microgravity Transport Apparatus (MTA), an instrument that has been developed specifically for precision measurement of transport processes. Experiment fluids are contained within the MTA fluid cells, designed to create a one dimensional flow geometry

  11. Mathematical methods of studying physical phenomena

    Science.gov (United States)

    Man'ko, Margarita A.

    2013-03-01

    In recent decades, substantial theoretical and experimental progress was achieved in understanding the quantum nature of physical phenomena that serves as the foundation of present and future quantum technologies. Quantum correlations like the entanglement of the states of composite systems, the phenomenon of quantum discord, which captures other aspects of quantum correlations, quantum contextuality and, connected with these phenomena, uncertainty relations for conjugate variables and entropies, like Shannon and Rényi entropies, and the inequalities for spin states, like Bell inequalities, reflect the recently understood quantum properties of micro and macro systems. The mathematical methods needed to describe all quantum phenomena mentioned above were also the subject of intense studies in the end of the last, and beginning of the new, century. In this section of CAMOP 'Mathematical Methods of Studying Physical Phenomena' new results and new trends in the rapidly developing domain of quantum (and classical) physics are presented. Among the particular topics under discussion there are some reviews on the problems of dynamical invariants and their relations with symmetries of the physical systems. In fact, this is a very old problem of both classical and quantum systems, e.g. the systems of parametric oscillators with time-dependent parameters, like Ermakov systems, which have specific constants of motion depending linearly or quadratically on the oscillator positions and momenta. Such dynamical invariants play an important role in studying the dynamical Casimir effect, the essence of the effect being the creation of photons from the vacuum in a cavity with moving boundaries due to the presence of purely quantum fluctuations of the electromagnetic field in the vacuum. It is remarkable that this effect was recently observed experimentally. The other new direction in developing the mathematical approach in physics is quantum tomography that provides a new vision of

  12. Multiscale Modeling of Mesoscale and Interfacial Phenomena

    Science.gov (United States)

    Petsev, Nikolai Dimitrov

    With rapidly emerging technologies that feature interfaces modified at the nanoscale, traditional macroscopic models are pushed to their limits to explain phenomena where molecular processes can play a key role. Often, such problems appear to defy explanation when treated with coarse-grained continuum models alone, yet remain prohibitively expensive from a molecular simulation perspective. A prominent example is surface nanobubbles: nanoscopic gaseous domains typically found on hydrophobic surfaces that have puzzled researchers for over two decades due to their unusually long lifetimes. We show how an entirely macroscopic, non-equilibrium model explains many of their anomalous properties, including their stability and abnormally small gas-side contact angles. From this purely transport perspective, we investigate how factors such as temperature and saturation affect nanobubbles, providing numerous experimentally testable predictions. However, recent work also emphasizes the relevance of molecular-scale phenomena that cannot be described in terms of bulk phases or pristine interfaces. This is true for nanobubbles as well, whose nanoscale heights may require molecular detail to capture the relevant physics, in particular near the bubble three-phase contact line. Therefore, there is a clear need for general ways to link molecular granularity and behavior with large-scale continuum models in the treatment of many interfacial problems. In light of this, we have developed a general set of simulation strategies that couple mesoscale particle-based continuum models to molecular regions simulated through conventional molecular dynamics (MD). In addition, we derived a transport model for binary mixtures that opens the possibility for a wide range of applications in biological and drug delivery problems, and is readily reconciled with our hybrid MD-continuum techniques. Approaches that couple multiple length scales for fluid mixtures are largely absent in the literature, and

  13. Physical Simulation: Testing the PHYSICALITY of Phenomena

    Science.gov (United States)

    Srivastava, Jagdish

    2004-05-01

    Theories of Quantum Mechanics in which `consciousness' plays a role have been around for decades. For example, Wheeler maintains that no phenomenon is a real phenomenon unless it has been observed. Also, the von Neumann chain, where the wave function is said to collapse when the chain reaches the mind of a conscious observer, is well known. The author's theory of Quantum Reality (denoted by TK) goes a bit further, saying that at the fundamental levels, all phenomena are logical-mathematical objects only, and the experience of their `physicality' is due to the consciousness of the observer. This paper addresses the question, as to how TK (and, the other related theories) could be tested. A procedure for this, termed `Physical Simulation' is proposed. The idea is to create logical-mathematical objects through a computer. Various aspects of this methodology are discussed.

  14. Localization Phenomena in Disordered Tantalum Films

    Directory of Open Access Journals (Sweden)

    Natalia Kovaleva

    2017-07-01

    Full Text Available Using dc transport and wide-band spectroscopic ellipsometry techniques we study localization phenomena in highly disordered metallic β -Ta films grown by rf sputtering deposition. The dc transport study implies non-metallic behavior (d ρ /dT < 0, with negative temperature coefficient of resistivity (TCR. We found that as the absolute TCR value increased, specifying an elevated degree of disorder, the free charge carrier Drude response decreases, indicating the enhanced charge carrier localization. Moreover, we found that the pronounced changes occur at the extended spectral range, involving not only the Drude resonance, but also the higher-energy Lorentz bands, in evidence of the attendant electronic correlations. We propose that the charge carrier localization, or delocalization, is accompanied by the pronounced electronic band structure reconstruction due to many-body effects, which may be the key feature for understanding the physics of highly disordered metals.

  15. Noise-driven phenomena in hysteretic systems

    CERN Document Server

    Dimian, Mihai

    2014-01-01

    Noise-Driven Phenomena in Hysteretic Systems provides a general approach to nonlinear systems with hysteresis driven by noisy inputs, which leads to a unitary framework for the analysis of various stochastic aspects of hysteresis. This book includes integral, differential and algebraic models that are used to describe scalar and vector hysteretic nonlinearities originating from various areas of science and engineering. The universality of the authors approach is also reflected by the diversity of the models used to portray the input noise, from the classical Gaussian white noise to its impulsive forms, often encountered in economics and biological systems, and pink noise, ubiquitous in multi-stable electronic systems. The book is accompanied by HysterSoft© - a robust simulation environment designed to perform complex hysteresis modeling – that can be used by the reader to reproduce many of the results presented in the book as well as to research both disruptive and constructive effects of noise in hysteret...

  16. Heat Transfer Phenomena of Supercritical Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Krau, Carmen Isabella; Kuhn, Dietmar; Schulenberg, Thomas [Forschungszentrum Karlsruhe, Institute for Nuclear and Energy Technologies, 76021 Karlsruhe (Germany)

    2008-07-01

    In concepts for supercritical water cooled reactors, the reactor core is cooled and moderated by water at supercritical pressures. The significant temperature dependence of the fluid properties of water requires an exact knowledge of the heat transfer mechanism to avoid fuel pin damages. Near the pseudo-critical point a deterioration of heat transfer might happen. Processes, that take place in this case, are not fully understood and are due to be examined systematically. In this paper a general overview on the properties of supercritical water is given, experimental observations of different authors will be reviewed in order to identify heat transfer phenomena and onset of occurrence. The conceptional design of a test rig to investigate heat transfer in the boundary layer will be discussed. Both, water and carbon dioxide, may serve as operating fluids. The loop, including instrumentation and safety devices, is shown and suitable measuring methods are described. (authors)

  17. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

    The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

  18. Stochastic phenomena in a fiber Raman amplifier

    CERN Document Server

    Kalashnikov, Vladimir; Ania-Castanón, Juan Diego; Jacobsen, Gunnar; Popov, Sergei

    2016-01-01

    The interplay of such cornerstones of modern nonlinear fiber optics as a nonlinearity, stochasticity and polarization leads to variety of the noise induced instabilities including polarization attraction and escape phenomena harnessing of which is a key to unlocking the fiber optic systems specifications required in high resolution spectroscopy, metrology, biomedicine and telecommunications. Here, by using direct stochastic modeling, the mapping of interplay of the Raman scattering-based nonlinearity, the random birefringence of a fiber, and the pump-to-signal intensity noise transfer has been done in terms of the fiber Raman amplifier parameters, namely polarization mode dispersion, the relative intensity noise of the pump laser, fiber length, and the signal power. The obtained results reveal conditions for emergence of the random birefringence-induced resonance-like enhancement of the gain fluctuations (stochastic anti-resonance) accompanied by pulse broadening and rare events in the form of low power outpu...

  19. Autistic phenomena in The Adventures of Pinocchio.

    Science.gov (United States)

    Smith, Adrian

    2017-04-01

    This paper seeks to demonstrate that the protagonist of Carlo Collodi's The Adventures of Pinocchio illustrates numerous autistic phenomena such as communication difficulties, sensory and perceptual distortions and mindblindness. While Pinocchio is viewed as a literary construct with contraindications of autism, it will be argued that his autistic traits are sufficient to suggest the possibility that Collodi had a partial intuition of the syndrome 60 years before it was identified by Leo Kanner. Approaching Collodi's text in this manner is taken as an opportunity to survey and reflect upon the psychoanalytic literature on autism and to position it in relation to contemporary theories from cognitive neuroscience. © 2017, The Society of Analytical Psychology.

  20. Nonlinear dynamic phenomena in the beer model

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Laugesen, Jakob Lund

    2007-01-01

    present a formal bifurcation analysis to analyse the complex dynamics produced by the model. Consistent with the rules of the game, the model constitutes a piecewise-linear map with nonlinearities arising from non-negativity constraints. The bifurcations that occur in piecewise-linear systems......The production-distribution system or "beer game" is one of the most well-known system dynamics models. Notorious for the complex dynamics it produces, the beer game has been used for nearly five decades to illustrate how structure generates behavior and to explore human decision making. Here we...... are distinctly different from those observed in smooth systems. We show how the model displays abrupt Hopf and period-doubling bifurcations, truncated bifurcation cascades, and various border-collision bifurcations. The latter allow direct transitions from periodic to chaotic dynamics. Bifurcation phenomena...

  1. Discrete computational mechanics for stiff phenomena

    KAUST Repository

    Michels, Dominik L.

    2016-11-28

    Many natural phenomena which occur in the realm of visual computing and computational physics, like the dynamics of cloth, fibers, fluids, and solids as well as collision scenarios are described by stiff Hamiltonian equations of motion, i.e. differential equations whose solution spectra simultaneously contain extremely high and low frequencies. This usually impedes the development of physically accurate and at the same time efficient integration algorithms. We present a straightforward computationally oriented introduction to advanced concepts from classical mechanics. We provide an easy to understand step-by-step introduction from variational principles over the Euler-Lagrange formalism and the Legendre transformation to Hamiltonian mechanics. Based on such solid theoretical foundations, we study the underlying geometric structure of Hamiltonian systems as well as their discrete counterparts in order to develop sophisticated structure preserving integration algorithms to efficiently perform high fidelity simulations.

  2. Modeling electrical dispersion phenomena in Earth materials

    Directory of Open Access Journals (Sweden)

    D. Patella

    2008-06-01

    Full Text Available It is illustrated that IP phenomena in rocks can be described using conductivity dispersion models deduced as solutions to a 2nd-order linear differential equation describing the motion of a charged particle immersed in an external electrical field. Five dispersion laws are discussed, namely: the non-resonant positive IP model, which leads to the classical Debye-type dispersion law and by extension to the Cole-Cole model, largely used in current practice; the non-resonant negative IP model, which allows negative chargeability values, known in metals at high frequencies, to be explained as an intrinsic physical property of earth materials in specific field cases; the resonant flat, positive or negative IP models, which can explain the presence of peak effects at specific frequencies superimposed on flat, positive or negative dispersion spectra.

  3. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Yu, Liyun; Mateiu, Ramona Valentina; Skov, Anne Ladegaard

    years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we focus on the chloro propyl functionalized silicone elastomers prepared in Madsen et al[2] and we investigate the electrical...... breakdown patterns of two similar chloro propyl functionalized silicone elastomers which break down electrically in a rather different way as well as we compare them to a silicone based reference. Thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) are used to evaluate the elastomers...... before and after electrical breakdown. It was shown the chemically very similar silicone elastomers broke down electrically in very different ways. These observations emphasize that the modification of the silicone backbone may open up for completely new possibilities for stabilizing the silicone...

  4. Peridynamic Formulation for Coupled Thermoelectric Phenomena

    Directory of Open Access Journals (Sweden)

    Migbar Assefa

    2017-01-01

    Full Text Available Modeling of heat and electrical current flow simultaneously in thermoelectric convertor using classical theories do not consider the influence of defects in the material. This is because traditional methods are developed based on partial differential equations (PDEs and lead to infinite fluxes at the discontinuities. The usual way of solving such PDEs is by using numerical technique, like Finite Element Method (FEM. Although FEM is robust and versatile, it is not suitable to model evolving discontinuities. To avoid such shortcomings, we propose the concept of peridynamic theory to derive the balance of energy and charge equations in the coupled thermoelectric phenomena. Therefore, this paper presents the transport of heat and charge in thermoelectric material in the framework of peridynamic (PD theory. To illustrate the reliability of the PD formulation, numerical examples are presented and results are compared with those from literature, analytical solutions, or finite element solutions.

  5. Social phenomena from data analysis to models

    CERN Document Server

    Perra, Nicola

    2015-01-01

    This book focuses on the new possibilities and approaches to social modeling currently being made possible by an unprecedented variety of datasets generated by our interactions with modern technologies. This area has witnessed a veritable explosion of activity over the last few years, yielding many interesting and useful results. Our aim is to provide an overview of the state of the art in this area of research, merging an extremely heterogeneous array of datasets and models. Social Phenomena: From Data Analysis to Models is divided into two parts. Part I deals with modeling social behavior under normal conditions: How we live, travel, collaborate and interact with each other in our daily lives. Part II deals with societal behavior under exceptional conditions: Protests, armed insurgencies, terrorist attacks, and reactions to infectious diseases. This book offers an overview of one of the most fertile emerging fields bringing together practitioners from scientific communities as diverse as social sciences, p...

  6. Characterizing critical phenomena via the Purcell effect

    Science.gov (United States)

    Silva Neto, M. B.; Szilard, D.; Rosa, F. S. S.; Farina, C.; Pinheiro, F. A.

    2017-12-01

    We investigate the role of phase transitions into the spontaneous-emission rate of a single quantum emitter embedded in a critical medium. Using a Landau-Ginzburg approach, we find that in the broken symmetry phase, the emission rate is reduced, or even suppressed, due to the photon mass generated by the Higgs mechanism. Remarkably, its sensitivity to the critical exponents of the phase transition allows for an optical determination of universality classes. When applied to the cases of superconductivity and superfluidity, we show that the Purcell effect also provides valuable information on spectroscopic and thermodynamic quantities, such as the size of the superconducting gap and the discontinuity in the specific heat at the transition. By unveiling that a deeper connection between the Purcell effect and phase transitions exists, we demonstrate that the former is an efficient optical probe of distinct critical phenomena and their associated observables.

  7. Quantum field theory and critical phenomena

    CERN Document Server

    Zinn-Justin, Jean

    1996-01-01

    Over the last twenty years quantum field theory has become not only the framework for the discussion of all fundamental interactions except gravity, but also for the understanding of second-order phase transitions in statistical mechanics. This advanced text is based on graduate courses and summer schools given by the author over a number of years. It approaches the subject in terms of path and functional intergrals, adopting a Euclidean metric and using the language of partition and correlation functions. Renormalization and the renormalization group are examined, as are critical phenomena and the role of instantons. Changes for this edition 1. Extensive revision to eliminate a few bugs that had survived the second edition and (mainly) to improve the pedagogical presentation, as a result of experience gathered by lecturing. 2. Additional new topics; holomorphic or coherent state path integral; functional integral and representation of the field theory S-matrix in the holomorphic formalis; non-relativistic li...

  8. Understanding protein adsorption phenomena at solid surfaces.

    Science.gov (United States)

    Rabe, Michael; Verdes, Dorinel; Seeger, Stefan

    2011-02-17

    Protein adsorption at solid surfaces plays a key role in many natural processes and has therefore promoted a widespread interest in many research areas. Despite considerable progress in this field there are still widely differing and even contradictive opinions on how to explain the frequently observed phenomena such as structural rearrangements, cooperative adsorption, overshooting adsorption kinetics, or protein aggregation. In this review recent achievements and new perspectives on protein adsorption processes are comprehensively discussed. The main focus is put on commonly postulated mechanistic aspects and their translation into mathematical concepts and model descriptions. Relevant experimental and computational strategies to practically approach the field of protein adsorption mechanisms and their impact on current successes are outlined. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Meteorological phenomena in Western classical orchestral music

    Science.gov (United States)

    Williams, P. D.; Aplin, K. L.

    2012-12-01

    The creative output of composers, writers, and artists is often influenced by their surroundings. To give a literary example, it has been claimed recently that some of the characters in Oliver Twist and A Christmas Carol were based on real-life people who lived near Charles Dickens in London. Of course, an important part of what we see and hear is not only the people with whom we interact, but also our geophysical surroundings. Of all the geophysical phenomena to influence us, the weather is arguably the most significant, because we are exposed to it directly and daily. The weather was a great source of inspiration for Monet, Constable, and Turner, who are known for their scientifically accurate paintings of the skies. But to what extent does weather inspire composers? The authors of this presentation, who are atmospheric scientists by day but amateur classical musicians by night, have been contemplating this question. We have built a systematic musical database, which has allowed us to catalogue and analyze the frequencies with which weather is depicted in a sample of classical orchestral music. The depictions vary from explicit mimicry using traditional and specialized orchestral instruments, through to subtle suggestions. We have found that composers are generally influenced by their own environment in the type of weather they choose to represent. As befits the national stereotype, British composers seem disproportionately keen to depict the UK's variable weather patterns and stormy coastline. Reference: Aplin KL and Williams PD (2011) Meteorological phenomena in Western classical orchestral music. Weather, 66(11), pp 300-306. doi:10.1002/wea.765

  10. APRI-6. Accident Phenomena of Risk Importance

    Energy Technology Data Exchange (ETDEWEB)

    Garis, Ninos; Ljung, J (eds.) (Swedish Radiation Safety Authority, Stockholm (Sweden)); Agrenius, Lennart (ed.) (Agrenius Ingenjoersbyraa AB, Stockholm (Sweden))

    2009-06-15

    Since the early 1980s, nuclear power utilities in Sweden and the Swedish Radiation Safety Authority (SSM) collaborate on the research in severe reactor accidents. In the beginning focus was mostly on strengthening protection against environmental impacts after a severe reactor accident, for example by develop systems for the filtered relief of the reactor containment. Since the early 90s, this focus has shifted to the phenomenological issues of risk-dominant significance. During the years 2006-2008, the partnership continued in the research project APRI-6. The aim was to show whether the solutions adopted in the Swedish strategy for incident management provides adequate protection for the environment. This is done by studying important phenomena in the core melt estimating the amount of radioactivity that can be released to the atmosphere in a severe accident. To achieve these objectives the research has included monitoring of international research on severe accidents and evaluation of results and continued support for research of severe accidents at the Royal Inst. of Technology (KTH) and Chalmers University. The follow-up of international research has promoted the exchange of knowledge and experience and has given access to a wealth of information on various phenomena relevant to events in severe accidents. The continued support to KTH has provided increased knowledge about the possibility of cooling the molten core in the reactor tank and the processes associated with coolability in the confinement and about steam explosions. Support for Chalmers has increased knowledge of the accident chemistry, mainly the behavior of iodine and ruthenium in the containment after an accident.

  11. Simulation of Magnetic Phenomena at Realistic Interfaces

    KAUST Repository

    Grytsyuk, Sergiy

    2016-02-04

    In modern technology exciting developments are related to the ability to understand and control interfaces. Particularly, magnetic interfaces revealing spindependent electron transport are of great interest for modern spintronic devices, such as random access memories and logic devices. From the technological point of view, spintronic devices based on magnetic interfaces enable manipulation of the magnetism via an electric field. Such ability is a result of the different quantum effects arising from the magnetic interfaces (for example, spin transfer torque or spin-orbit torque) and it can reduce the energy consumption as compared to the traditional semiconductor electronic devices. Despite many appealing characteristics of these materials, fundamental understanding of their microscopic properties and related phenomena needs to be established by thorough investigation. In this work we implement first principles calculations in order to study the structural, electric, and magnetic properties as well as related phenomena of two types of interfaces with large potential in spintronic applications: 1) interfaces between antiferromagnetic 3d-metal-oxides and ferromagnetic 3d-metals and 2) interfaces between non-magnetic 5d(4d)- and ferromagnetic 3d-metals. A major difficulty in studying such interfaces theoretically is the typically large lattice mismatch. By employing supercells with Moir e patterns, we eliminate the artificial strain that leads to doubtful results and are able to describe the dependence of the atomic density at the interfaces on the component materials and their thicknesses. After establishing understanding about the interface structures, we investigate the electronic and magnetic properties. A Moir e supercell with transition layer is found to reproduce the main experimental findings and thus turns out to be the appropriate model for simulating magnetic misfit interfaces. In addition, we systematically study the magnetic anisotropy and Rashba band

  12. Pathways toward understanding Macroscopic Quantum Phenomena

    Science.gov (United States)

    Hu, B. L.; Subaşi, Y.

    2013-06-01

    Macroscopic quantum phenomena refer to quantum features in objects of 'large' sizes, systems with many components or degrees of freedom, organized in some ways where they can be identified as macroscopic objects. This emerging field is ushered in by several categories of definitive experiments in superconductivity, electromechanical systems, Bose-Einstein condensates and others. Yet this new field which is rich in open issues at the foundation of quantum and statistical physics remains little explored theoretically (with the important exception of the work of A J Leggett [1], while touched upon or implied by several groups of authors represented in this conference. Our attitude differs in that we believe in the full validity of quantum mechanics stretching from the testable micro to meso scales, with no need for the introduction of new laws of physics.) This talk summarizes our thoughts in attempting a systematic investigation into some key foundational issues of quantum macroscopic phenomena, with the goal of ultimately revealing or building a viable theoretical framework. Three major themes discussed in three intended essays are the large N expansion [2], the correlation hierarchy [3] and quantum entanglement [4]. We give a sketch of the first two themes and then discuss several key issues in the consideration of macro and quantum, namely, a) recognition that there exist many levels of structure in a composite body and only by judicious choice of an appropriate set of collective variables can one give the best description of the dynamics of a specific level of structure. Capturing the quantum features of a macroscopic object is greatly facilitated by the existence and functioning of these collective variables; b) quantum entanglement, an exclusively quantum feature [5], is known to persist to high temperatures [6] and large scales [7] under certain conditions, and may actually decrease with increased connectivity in a quantum network [8]. We use entanglement as a

  13. Acoustic Emission Signal Processing Technique to Characterize Reactor In-Pile Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Vivek Agarwal; Magdy Samy Tawfik; James A Smith

    2014-07-01

    Existing and developing advanced sensor technologies and instrumentation will allow non-intrusive in-pile measurement of temperature, extension, and fission gases when coupled with advanced signal processing algorithms. The transmitted measured sensor signals from inside to the outside of containment structure are corrupted by noise and are attenuated, thereby reducing the signal strength and signal-to-noise ratio. Identification and extraction of actual signal (representative of an in-pile phenomenon) is a challenging and complicated process. In this paper, empirical mode decomposition technique is proposed to reconstruct actual sensor signal by partially combining intrinsic mode functions. Reconstructed signal corresponds to phenomena and/or failure modes occurring inside the reactor. In addition, it allows accurate non-intrusive monitoring and trending of in-pile phenomena.

  14. Multivariate data analysis as a fast tool in evaluation of solid state phenomena

    DEFF Research Database (Denmark)

    Jørgensen, Anna Cecilia; Miroshnyk, Inna; Karjalainen, Milja

    2006-01-01

    of information generated can be overwhelming and the need for more effective data analysis tools is well recognized. The aim of this study was to investigate the use of multivariate data analysis, in particular principal component analysis (PCA), for fast analysis of solid state information. The data sets...... analyzed covered dehydration phenomena of a set of hydrates followed by variable temperature X-ray powder diffractometry and Raman spectroscopy and the crystallization of amorphous lactose monitored by Raman spectroscopy. Identification of different transitional states upon the dehydration enabled...... the molecular level interpretation of the structural changes related to the loss of water, as well as interpretation of the phenomena related to the crystallization. The critical temperatures or critical time points were identified easily using the principal component analysis. The variables (diffraction angles...

  15. Detonation wave phenomena in bubbled liquid

    Science.gov (United States)

    Gülhan, A.; Beylich, A. E.

    1990-07-01

    Shock wave propagation was investigated in two phase media consisting of diluted glycerin (85%) and reactive gas bubbles. To understand these complex phenomena, we first performed a numerical analysis and experimental studies of single bubbles containing a reactive gas-mixture. For the two-phase mixtures, a needle matrix bubble-generator enabled us to produce a homogeneous bubble distribution with a size dispersion less than 5%. The void fraction β0 was varied over one order of magnitude, β0=0.2-2%. It was found that there exists a critical value of shock strength above which bubble explosion starts. Once a bubble explodes, it stimulates the adjacent bubbles to explode due to emission of a blast wave; this process is followed by a series of similar events. A steady detonationlike wave propagates as a precurser with a constant velocity which is much higher than that of the first wave. To study the structure of the detonation wave the measured pressured profiles were averaged by superimposing 50 shots.

  16. Dictionary of astronomy, space, and atmospheric phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Tver, D.F.; Motz, L.; Hartmann, W.K.

    1979-01-01

    This concise and up-to-date compendium features descriptions and definitions of terms, techniques and equipment relating to celestial phenomena. It explains the latest concepts in space exploration, planetary research, stellar astronomy, and meteorological science. The authors explore the general configurations of star groups, galaxy types, stars, and other small bodies in the solar system, including such important facts as magnitude of each and distance from Earth. They describe the brightest stars one by one. Vital data provided by the Viking, Mariner, and Pioneer space probes, the Voyager flights past Jupiter and its moons, and the Apollo landings are clearly presented and explained. New concepts in stellar astronomy such as quasars, neutron stars (pulsars), and black holes are precisely defined. Also included are discussions of meteor showers and the important rock types found on each planet; definitions of meteorological terms, ad astronomical equipment including telescopes, eyepieces and their accessories, the Golay cell, canopus sensor, filar micrometer, and more. Charts aid in identifying and locating stars and planets, and helpful reference tables list the location of the major celestial bodies - asteroids, constellations, the nearest stars, the brightest stars, interesting double and variable stars and cluters. Also included is the Meisser catalog of the coordinates and magnitudes for more than 100 celestial objects.

  17. Phantom black holes and critical phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Aïnou, Mustapha [Engineering Faculty, Başkent University, Bağlıca Campus, Ankara (Turkey); Marques, Glauber T. [Universidade Federal Rural da Amazônia ICIBE-LASIC, Av. Presidente Tancredo Neves 2501, CEP 66077-901—Belém/PA (Brazil); Rodrigues, Manuel E., E-mail: azreg@baskent.edu.tr, E-mail: gtadaiesky@hotmail.com, E-mail: esialg@gmail.com [Faculdade de Ciências Exatas e Tecnologia, Universidade Federal do Pará, Campus Universitário de Abaetetuba, CEP 68440-000, Abaetetuba, Pará (Brazil)

    2014-07-01

    We consider the two classes cosh and sinh of normal and phantom black holes of Einstein-Maxwell-dilaton theory. The thermodynamics of these holes is characterized by heat capacities that may have both signs depending on the parameters of the theory. Leaving aside the normal Reissner-Nordström black hole, it is shown that only some phantom black holes of both classes exhibit critical phenomena. The two classes share a nonextremality, but special, critical point where the transition is continuous and the heat capacity, at constant charge, changes sign with an infinite discontinuity. This point yields a classification scheme for critical points. It is concluded that the two unstable and stable phases coexist on one side of the criticality state and disappear on the other side, that is, there is no configuration where only one phase exists. The sinh class has an extremality critical point where the entropy diverges. The transition from extremality to nonextremality with the charge held constant is accompanied by a loss of mass and an increase in the temperature. A special case of this transition is when the hole is isolated (microcanonical ensemble), it will evolve by emission of energy, which results in a decrease of its mass, to the final state of minimum mass and vanishing heat capacity. The Ehrenfest scheme of classification is inaccurate in this case but the generalized one due to Hilfer leads to conclude that the transition is of order less than unity. Fluctuations near criticality are also investigated.

  18. Some novel phenomena at high density

    Science.gov (United States)

    Berkowitz, Evan Scott

    Astrophysical environments probe matter in ways impossible on Earth. In particular, matter in compact objects are extraordinarily dense. In this thesis we discuss two phenomena that may occur at high density. First, we study toroidal topological solitons called vortons, which can occur in the kaon-condensed color-flavor-locked phase of high-density quark matter, a candidate phase for the core of some neutron stars. We show that vortons have a large radius compared to their thickness if their electrical charge is on the order of 104 times the fundamental charge. We show that shielding of electric fields by electrons dramatically reduces the size of a vorton. Second, we study an unusual phase of degenerate electrons and nonrelativistic Bose-condensed helium nuclei that may exist in helium white dwarfs. We show that this phase supports a previously-unknown gapless mode, known as the half-sound, that radically alters the material's specific heat, and can annihilate into neutrinos. We provide evidence that this neutrino radiation is negligible compared to the star's surface photoemission.

  19. Interface-induced phenomena in magnetism

    Science.gov (United States)

    Hellman, Frances; Hoffmann, Axel; Tserkovnyak, Yaroslav; Beach, Geoffrey S. D.; Fullerton, Eric E.; Leighton, Chris; MacDonald, Allan H.; Ralph, Daniel C.; Arena, Dario A.; Dürr, Hermann A.; Fischer, Peter; Grollier, Julie; Heremans, Joseph P.; Jungwirth, Tomas; Kimel, Alexey V.; Koopmans, Bert; Krivorotov, Ilya N.; May, Steven J.; Petford-Long, Amanda K.; Rondinelli, James M.; Samarth, Nitin; Schuller, Ivan K.; Slavin, Andrei N.; Stiles, Mark D.; Tchernyshyov, Oleg; Thiaville, André; Zink, Barry L.

    2017-04-01

    This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on recent progress, identifying the most exciting new scientific results and pointing to promising future research directions. It starts with an introduction and overview of how basic magnetic properties are affected by interfaces, then turns to a discussion of charge and spin transport through and near interfaces and how these can be used to control the properties of the magnetic layer. Important concepts include spin accumulation, spin currents, spin-transfer torque, and spin pumping. An overview is provided to the current state of knowledge and existing review literature on interfacial effects such as exchange bias, exchange-spring magnets, the spin Hall effect, oxide heterostructures, and topological insulators. The article highlights recent discoveries of interface-induced magnetism and noncollinear spin textures, nonlinear dynamics including spin-transfer torque and magnetization reversal induced by interfaces, and interfacial effects in ultrafast magnetization processes.

  20. [Stochastic phenomena and the tumoral process].

    Science.gov (United States)

    Capp, Jean-Pascal

    2014-01-01

    In the reductionist perspective, genetic modifications are considered to initiate cancer. Their appearance is a stochastic phenomenon, but there are some biases linked to DNA sequence or exposure to mutagenic agents for instance. Cancer genome sequencing has shown a high inter- and intra-tumoral heterogeneity, sometimes questioning the genetic origin of cancer. Other stochastic processes are also studied in cancer, especially epigenetic modifications. They have a major role in diversifying phenotypes among cancer cells in the progression steps, but might also provide an alternative to genetic theories of cancer initiation. Nevertheless, the reductionist framework remains dominant here. Finally, stochastic cell-to-cell variations in gene expression constitute a third class of stochastic phenomena that can be considered as causal factors in cancer. Highlighting the role of high gene expression variability due to disruption of cellular interactions and communications allows avoiding reductionism by considering the interplay between genetic and tissue levels at every step of the disease. No organization level is privileged in this alternative theory. © 2014 médecine/sciences – Inserm.

  1. Interface-Induced Phenomena in Magnetism.

    Science.gov (United States)

    Hellman, Frances; Hoffmann, Axel; Tserkovnyak, Yaroslav; Beach, Geoffrey S D; Fullerton, Eric E; Leighton, Chris; MacDonald, Allan H; Ralph, Daniel C; Arena, Dario A; Dürr, Hermann A; Fischer, Peter; Grollier, Julie; Heremans, Joseph P; Jungwirth, Tomas; Kimel, Alexey V; Koopmans, Bert; Krivorotov, Ilya N; May, Steven J; Petford-Long, Amanda K; Rondinelli, James M; Samarth, Nitin; Schuller, Ivan K; Slavin, Andrei N; Stiles, Mark D; Tchernyshyov, Oleg; Thiaville, André; Zink, Barry L

    2017-01-01

    This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially-driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on recent progress, identifying the most exciting new scientific results and pointing to promising future research directions. It starts with an introduction and overview of how basic magnetic properties are affected by interfaces, then turns to a discussion of charge and spin transport through and near interfaces and how these can be used to control the properties of the magnetic layer. Important concepts include spin accumulation, spin currents, spin transfer torque, and spin pumping. An overview is provided to the current state of knowledge and existing review literature on interfacial effects such as exchange bias, exchange spring magnets, spin Hall effect, oxide heterostructures, and topological insulators. The article highlights recent discoveries of interface-induced magnetism and non-collinear spin textures, non-linear dynamics including spin torque transfer and magnetization reversal induced by interfaces, and interfacial effects in ultrafast magnetization processes.

  2. Chemical Phenomena of Atomic Force Microscopy Scanning.

    Science.gov (United States)

    Ievlev, Anton V; Brown, Chance; Burch, Matthew J; Agar, Joshua C; Velarde, Gabriel A; Martin, Lane W; Maksymovych, Petro; Kalinin, Sergei V; Ovchinnikova, Olga S

    2018-02-12

    Atomic force microscopy is widely used for nanoscale characterization of materials by scientists worldwide. The long-held belief of ambient AFM is that the tip is generally chemically inert but can be functionalized with respect to the studied sample. This implies that basic imaging and scanning procedures do not affect surface and bulk chemistry of the studied sample. However, an in-depth study of the confined chemical processes taking place at the tip-surface junction and the associated chemical changes to the material surface have been missing as of now. Here, we used a hybrid system that combines time-of-flight secondary ion mass spectrometry with an atomic force microscopy to investigate the chemical interactions that take place at the tip-surface junction. Investigations showed that even basic contact mode AFM scanning is able to modify the surface of the studied sample. In particular, we found that the silicone oils deposited from the AFM tip into the scanned regions and spread to distances exceeding 15 μm from the tip. These oils were determined to come from standard gel boxes used for the storage of the tips. The explored phenomena are important for interpreting and understanding results of AFM mechanical and electrical studies relying on the state of the tip-surface junction.

  3. Viscous theory of surface noise interaction phenomena

    Science.gov (United States)

    Yates, J. E.

    1980-01-01

    A viscous linear surface noise interaction problem is formulated that includes noise production by an oscillating surface, turbulent or vortical interaction with a surface, and scattering of sound by a surface. The importance of viscosity in establishing uniqueness of solution and partitioning of energy into acoustic and vortical modes is discussed. The results of inviscid two dimensional airfoil theory are used to examine the interactive noise problem in the limit of high reduced frequency and small Helmholtz number. It is shown that in the case of vortex interaction with a surface, the noise produced with the full Kutta condition is 3 dB less than the no Kutta condition result. The results of a study of an airfoil oscillating in a medium at rest are discussed. It is concluded that viscosity can be a controlling factor in analyses and experiments of surface noise interaction phenomena and that the effect of edge bluntness as well as viscosity must be included in the problem formulation to correctly calculate the interactive noise.

  4. Highly energetic phenomena in water electrolysis.

    Science.gov (United States)

    Postnikov, A V; Uvarov, I V; Lokhanin, M V; Svetovoy, V B

    2016-12-16

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

  5. Highly energetic phenomena in water electrolysis

    Science.gov (United States)

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

    2016-12-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

  6. Attractors, bifurcations, & chaos nonlinear phenomena in economics

    CERN Document Server

    Puu, Tönu

    2003-01-01

    The present book relies on various editions of my earlier book "Nonlinear Economic Dynamics", first published in 1989 in the Springer series "Lecture Notes in Economics and Mathematical Systems", and republished in three more, successively revised and expanded editions, as a Springer monograph, in 1991, 1993, and 1997, and in a Russian translation as "Nelineynaia Economicheskaia Dinamica". The first three editions were focused on applications. The last was differ­ ent, as it also included some chapters with mathematical background mate­ rial -ordinary differential equations and iterated maps -so as to make the book self-contained and suitable as a textbook for economics students of dynamical systems. To the same pedagogical purpose, the number of illus­ trations were expanded. The book published in 2000, with the title "A ttractors, Bifurcations, and Chaos -Nonlinear Phenomena in Economics", was so much changed, that the author felt it reasonable to give it a new title. There were two new math­ ematics ch...

  7. Stochastic phenomena in a fiber Raman amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Kalashnikov, Vladimir [Aston Institute of Photonic Technologies, Aston University, Birmingham (United Kingdom); Institute of Photonics, Vienna University of Technology (Austria); Sergeyev, Sergey V. [Aston Institute of Photonic Technologies, Aston University, Birmingham (United Kingdom); Ania-Castanon, Juan Diego [Instituto de Optica CSIC, Madrid (Spain); Jacobsen, Gunnar [Acreo, Kista (Sweden); Popov, Sergei [Royal Institute of Technology (KTH), Stockholm (Sweden)

    2017-01-15

    The interplay of such cornerstones of modern nonlinear fiber optics as a nonlinearity, stochasticity and polarization leads to variety of the noise induced instabilities including polarization attraction and escape phenomena harnessing of which is a key to unlocking the fiber optic systems specifications required in high resolution spectroscopy, metrology, biomedicine and telecommunications. Here, by using direct stochastic modeling, the mapping of interplay of the Raman scattering-based nonlinearity, the random birefringence of a fiber, and the pump-to-signal intensity noise transfer has been done in terms of the fiber Raman amplifier parameters, namely polarization mode dispersion, the relative intensity noise of the pump laser, fiber length, and the signal power. The obtained results reveal conditions for emergence of the random birefringence-induced resonance-like enhancement of the gain fluctuations (stochastic anti-resonance) accompanied by pulse broadening and rare events in the form of low power output signals having probability heavily deviated from the Gaussian distribution. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Natural phenomena hazards, Hanford Site, south central Washington

    Energy Technology Data Exchange (ETDEWEB)

    Tallman, A.M.

    1996-04-16

    This document presents the natural phenomena hazard (NPH) loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, at the Hanford Site in south-central Washington State. The purpose of this document is twofold: (1) summarize the NPH that are important to the design and evaluation of structures, systems, and components at the Hanford Site; (2) develop the appropriate natural phenomena loads for use in the implementation of DOE Order 5480.28. The supporting standards, DOE-STD-1020-94, Natural Phenomena Hazards Design and Evaluation Criteria for Department of Energy Facilities (DOE 1994a); DOE-STD-1022-94, Natural Phenomena Hazards Site Characteristics Criteria (DOE 1994b); and DOE-STD-1023-95, Natural Phenomena Hazards Assessment Criteria (DOE 1995) are the basis for developing the NPH loads.

  9. The role of family phenomena in posttraumatic stress in youth.

    Science.gov (United States)

    McDonald, Catherine C; Deatrick, Janet A

    2011-02-01

    Youth face trauma that can cause posttraumatic stress (PTS). (1) To identify the family phenomena used in youth PTS research; and(2) to critically examine the research findings regarding the relationship between family phenomena and youth PTS. Systematic literature review in PsycInfo, PILOTS, CINAHL, and MEDLINE. Twenty-six empirical articles met inclusion criteria. Measurement of family phenomena included family functioning,support, environment, expressiveness, relationships, cohesion, communication, satisfaction, life events related to family, parental style of influence, and parental bonding. Few studies gave clear conceptualization of family or family phenomena. Empirical findings from the 26 studies indicate inconsistent empirical relationships between family phenomena and youth PTS, although a majority of the prospective studies support a relationship between family phenomena and youth PTS. Future directions for leadership by psychiatric nurses in this area of research and practice are recommended.

  10. Statistical trend analysis methods for temporal phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Lehtinen, E.; Pulkkinen, U. [VTT Automation, (Finland); Poern, K. [Poern Consulting, Nykoeping (Sweden)

    1997-04-01

    We consider point events occurring in a random way in time. In many applications the pattern of occurrence is of intrinsic interest as indicating a trend or some other systematic feature in the rate of occurrence. The purpose of this report is to survey briefly different statistical trend analysis methods and illustrate their applicability to temporal phenomena in particular. The trend testing of point events is usually seen as the testing of the hypotheses concerning the intensity of the occurrence of events. When the intensity function is parametrized, the testing of trend is a typical parametric testing problem. In industrial applications the operational experience generally does not suggest any specified model and method in advance. Therefore, and particularly, if the Poisson process assumption is very questionable, it is desirable to apply tests that are valid for a wide variety of possible processes. The alternative approach for trend testing is to use some non-parametric procedure. In this report we have presented four non-parametric tests: The Cox-Stuart test, the Wilcoxon signed ranks test, the Mann test, and the exponential ordered scores test. In addition to the classical parametric and non-parametric approaches we have also considered the Bayesian trend analysis. First we discuss a Bayesian model, which is based on a power law intensity model. The Bayesian statistical inferences are based on the analysis of the posterior distribution of the trend parameters, and the probability of trend is immediately seen from these distributions. We applied some of the methods discussed in an example case. It should be noted, that this report is a feasibility study rather than a scientific evaluation of statistical methods, and the examples can only be seen as demonstrations of the methods. 14 refs, 10 figs.

  11. Testing the potential paradoxes in "retrocausal" phenomena

    Science.gov (United States)

    Jolij, Jacob; Bierman, Dick J.

    2017-05-01

    Discussions with regard to potential paradoxes arising from "retrocausal" phenomena have been purely theoretical because so far no empirical effects had been established that allowed for empirical exploration of these potential paradoxes. In this article we describe three human experiments that showed clear "retrocausal" effects. In these neuropsychological, so-called, face-detection experiments, consisting of hundreds of trials per participant, we use brain signals to predict an upcoming random stimulus. The binary random decision, corresponding to showing a noisy cartoon face or showing only noise on a display with equal probability is taken after the brain signals have been measured. The prediction accuracy ranges from 50.5-56.5% for the 3 experiments where chance performance would be 50%. The prediction algorithm is based on a template constructed out of all the pre-stimulus brain signals obtained in other trials of that particular participant. This approach thus controls for individual difference in brain functioning. Subsequently we describe an experiment based upon these findings where the predictive information is used in part of the trials to determine the stimulus rather than randomly select that stimulus. In those trials we analyze what the brain signals tell us what the future stimulus would be and then we reverse the actual future that is presented on the display. This is a `bilking' condition. We analyze what the consequence of the introduction of this bilking condition is on the accuracy of the remaining (normal) trials and, following a suggestion inferred from Thorne et al, we also check what the effect is on the random decision to either bilk or not bilk the specific trial. The bilking experiment is in progress and the results so far do not allow for conclusions and are presented only as an illustration.

  12. Feasibility study for use of the natural convection shutdown heat removal test facility (NSTF) for VHTR water-cooled RCCS shutdown.

    Energy Technology Data Exchange (ETDEWEB)

    Tzanos, C.P.; Farmer, M.T.; Nuclear Engineering Division

    2007-08-31

    In summary, a scaling analysis of a water-cooled Reactor Cavity Cooling System (RCCS) system was performed based on generic information on the RCCS design of PBMR. The analysis demonstrates that the water-cooled RCCS can be simulated at the ANL NSTF facility at a prototypic scale in the lateral direction and about half scale in the vertical direction. Because, by necessity, the scaling is based on a number of approximations, and because no analytical information is available on the performance of a reference water-cooled RCCS, the scaling analysis presented here needs to be 'validated' by analysis of the steady state and transient performance of a reference water-cooled RCCS design. The analysis of the RCCS performance by CFD and system codes presents a number of challenges including: strong 3-D effects in the cavity and the RCCS tubes; simulation of turbulence in flows characterized by natural circulation, high Rayleigh numbers and low Reynolds numbers; validity of heat transfer correlations for system codes for heat transfer in the cavity and the annulus of the RCCS tubes; the potential of nucleate boiling in the tubes; water flashing in the upper section of the RCCS return line (during limiting transient); and two-phase flow phenomena in the water tanks. The limited simulation of heat transfer in cavities presented in Section 4.0, strongly underscores the need of experimental work to validate CFD codes, and heat transfer correlations for system codes, and to support the analysis and design of the RCCS. Based on the conclusions of the scaling analysis, a schematic that illustrates key attributes of the experiment system is shown in Fig. 4. This system contains the same physical elements as the PBMR RCCS, plus additional equipment to facilitate data gathering to support code validation. In particular, the prototype consists of a series of oval standpipes surrounding the reactor vessel to provide cooling of the reactor cavity during both normal and off

  13. The phenomenology of life phenomena--in a nursing context.

    Science.gov (United States)

    Delmar, Charlotte

    2006-10-01

    The purpose of this article is to describe and develop knowledge about life phenomena in a life-philosophical and nursing context. Knowledge about life phenomena is part of a care-ethical understanding with a focus on relations. Life phenomena are to be understood as a generalized label for the various phenomena which are given with human existence. The Danish life philosophical tradition with the perspective of life as experienced has something to say in relation to a further refinement of the phenomenology of life phenomena. The refinement will be described as an ethical and existential understanding of the phenomena of nursing. The first part of the article takes a philosophical approach to the phenomenology of life phenomena. It attempts to locate life phenomena in relation to, respectively, needs, senses, and feelings. In order to maintain an overview, the attempt is made to separate needs, senses, and feelings, although in real life these are closely interwoven. The article also describes philosophy and life phenomena in relation to nursing as an empirical field. In nursing there is a risk that life phenomena become invisible to those whose task is to help the ill person adjust to a new life situation. For the nurse, it will be a continuing task, never completed, to develop a sensory-based, situation-determined attention to the patient. And the nurse must be continually aware of whether mere 'need-oriented' nursing is controlling her professional actions as a nurse. Taking a point of departure in the nurse's sensory, situationally determined attention, the last part of the article focuses on needs, senses, and feelings in connection with the nurse being able to direct her attention to the patient's life phenomena.

  14. Saving the Phenomena in Medieval Astronomy

    Science.gov (United States)

    Seeskin, K.

    2011-06-01

    Aristotle's theory of motion is based on two principles: (1) all motion to either from the midpoint of the Earth, toward it, or around it, and (2) circular motion must proceed around an immovable point. On this view, the heavenly bodies are individual points of light carried around by a series of concentric spheres rotating at a constant pace around the midpoint of the Earth. But even in Aristotle's day, it was known that this theory had a great deal of difficulty accounting for planetary motion. Ptolemy's alternative was to introduce epicycles and eccentric orbits, thus denying Aristotle's view of natural motion. There was no doubt that Ptolemy's predictions were far better than Aristotle's. But for the medievals, Aristotle's theory made better intuitive sense. Moreover, Ptolemy's theory raised the question of how one sphere could pass through another. What to do? The solution of Moses Maimonides (1138-1204) was to say that it is not the job of the astronomer to tell us how things actually are but merely to propose a series of hypotheses that allow us to explain the relevant data. This view had obvious theological implications. If astronomy could explain planetary motion in an acceptable way, there was reason to believe that the order or structure of the heavens is what it is by necessity. This suggests that God did not exercise any degree of choice in making it that way. But if astronomy cannot explain planetary motion, the most reasonable explanation is that we are dealing with contingent phenomena rather than necessary ones. If there is contingency, there is reason to think God did exercise a degree of choice in making the heavens the way they are. A God who exercises choice is much closer to the God of Scripture. Although Galileo changed all of this, and paved the way for a vastly different view of astronomy, the answer to one set of questions raises a whole different set. In short, the heavenly motion still poses ultimate questions about God, existence, and

  15. Positive muscle phenomena-diagnosis, pathogenesis and associated disorders

    NARCIS (Netherlands)

    Kortman, Hans G.; Veldink, Jan H.; Drost, Gea

    Positive muscle phenomena arise owing to various forms of spontaneous muscle hyperactivity originating in motor neurons or in the muscle itself. Although they are common in a wide range of neurological and non-neurological diseases, clinical and scientific data on these phenomena are limited, and

  16. Electrokinetic Phenomena in Pencil Lead-Based Microfluidics

    Directory of Open Access Journals (Sweden)

    Yashar Bashirzadeh

    2016-12-01

    Full Text Available Fabrication of microchannels and associated electrodes to generate electrokinetic phenomena often involves costly materials and considerable effort. In this study, we used graphite pencil-leads as low cost, disposable 3D electrodes to investigate various electrokinetic phenomena in straight cylindrical microchannels, which were themselves fabricated by using a graphite rod as the microchannel mold. Individual pencil-leads were employed as the micro-electrodes arranged along the side walls of the microchannel. Efficient electrokinetic phenomena provided by the 3D electrodes, including alternating current electroosmosis (ACEO, induced-charge electroosmosis (ICEO, and dielectrophoresis (DEP, were demonstrated by the introduced pencil-lead based microfluidic devices. The electrokinetic phenomena were characterized by micro-particle image velocimetry (micro-PIV measurements and microscopy imaging. Highly efficient electrokinetic phenomena using 3D pencil-lead electrodes showed the affordability and ease of this technique to fabricate microfluidic devices embedded with electrodes for electrokinetic fluid and particle manipulations.

  17. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    Directory of Open Access Journals (Sweden)

    Seppo E. Iso-Ahola

    2017-06-01

    Full Text Available Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1 scientific method itself is seriously limited (i.e., it can never prove a negative; (2 non-existence of phenomena would require a complete absence of both logical (theoretical and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3 statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4 psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only “temporary winners” and no “final truths” in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size are poor indicators of the theoretical importance and relevance of phenomena (cf. “deliberate practice” vs. “talent” in expert performance, not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested.

  18. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    Science.gov (United States)

    Iso-Ahola, Seppo E

    2017-01-01

    Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1) scientific method itself is seriously limited (i.e., it can never prove a negative); (2) non-existence of phenomena would require a complete absence of both logical (theoretical) and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3) statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4) psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only "temporary winners" and no "final truths" in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size) are poor indicators of the theoretical importance and relevance of phenomena (cf. "deliberate practice" vs. "talent" in expert performance), not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested.

  19. Side Channel Authenticity Discriminant Analysis for Device Class Identification

    Science.gov (United States)

    2016-03-31

    Side Channel Authenticity Discriminant Analysis for Device Class Identification Eric Koziel, Kate...include additional identification components. We instead propose Side Channel Authenticity Discriminant Analysis (SICADA) to leverage physical phenomena... analysis results. All variants were measured at the average, slow-slow, and fast-fast process technology corners (Table 1). We collected 1000 iterations

  20. Separation phenomena in Liquids and Gases

    Energy Technology Data Exchange (ETDEWEB)

    Louvet, P.; Dr Soubbaramayer [CEA Saclay, Dept. des Lasers et de la Physico-Chimie, DESICP/DLPC/SPP, 91 - Gif-sur-Yvette (France); Noe, P

    1989-07-01

    technology was up to the task but the programme was shelved mainly because of lack of demand. Finally, seven papers deal with laser processes. Two of them review the AVLIS program in the UK and one paper gives the status of the MLIS project in West Germany. One communication from China and three papers by French authors deal with specific problems currently met in AVLIS studies, on the vapour beam and the ion extraction. A number of phenomena observed in AVLIS needs satisfactory explanations: the high value of the vapour velocity, the low value of metastables in the vapour beam, the extraction of ions at high density, etc. Session 1: plasma separation (review of isotopic plasma separation processes; production of depleted zirconium using a plasma centrifuge; measurements of isotope separation in a vacuum arc centrifuge). Session 2: plasma separation and centrifugation (recent developments in stable isotope separation by ionic cyclotron resonance; some aspects of the separation of multi-isotope mixtures with gas centrifuges; review paper on centrifuge technology and status of the URENCO centrifuge project; solution of the two-fluid equations for flow in a centrifuge; influence of stationary poles in the central region of gas centrifuges; extension of the analytic sixth order theory; applications of different analytic solutions for the centrifuge flow). Sessions 4 and 5: rotating flows (convection flows driven by centrifugal buoyancy in rapidly rotating systems; experimental investigation of the flow in a rotating pie-shaped cylinder; temperature distribution on rotating spherical shells; centrifugal separation of a suspension in a rotating vessel; spin-up from rest of a suspension - preliminary insight). Session 6: particle fluid mixture (modelling, simulation and comprehension of the flow field of a particles-fluid mixture; the effect of shear and lift on particle-gas separation; on the hydrodynamics of electrolytic refining of metals). Session 7 (calculation of condensation

  1. Astrophysical phenomena related to supermassive black holes

    Science.gov (United States)

    Pott, Jörg-Uwe

    2006-12-01

    The thesis contains the results of my recent projects in astrophysical research. All projects aim at pushing the limits of our knowledge about the interaction between a galaxy, the fundamental building block of today's universe, and a supermassive black hole (SMBH) at its center. Over the past years a lot of observational evidence has been gathered for the current understanding, that at least a major part of the galaxies with a stellar bulge contain central SMBHs. The typical extragalactic approach consists of searching for the spectroscopic pattern of Keplerian rotation, produced by stars and gas, when orbiting a central dark mass (Kormendy & Richstone 1995). It suggests that a significant fraction of large galaxies host in their very nucleus a SMBH of millions to billions of solar masses (Kormendy & Gebhardt 2001). In the closest case, the center of our Milky Way, the most central stars, which can be imaged, were shown to move on orbits with circulation times of a few decades only, evidencing a mass and compactness of the dark counter part of the Keplerian motion, which can only be explained by a SMBH (Eckart & Genzel 1996; Ghez et al. 2000; Schödel et al. 2002). Having acknowledged the widespread existence of SMBHs the obvious next step is investigating the interaction with their environment. Although the basic property of a SMBH, which is concentrating a huge amount of mass in a ludicrously small volume defined by the Schwarzschild radius, only creates a deep gravitational trough, its existence evokes much more phenomena than simply attracting the surrounding matter. It can trigger or exacerbate star formation via tidal forces (Morris 1993). It shapes the distribution of its surrounding matter to accretion discs, which themselves release gravitational potential energy as radiation, possibly due to magnetic friction (Blandford 1995). The radiation efficiency of such active galactic nuclei (AGN) can become roughly 100 times more efficient than atomic nuclear

  2. Electron impact phenomena and the properties of gaseous ions

    CERN Document Server

    Field, F H; Massey, H S W; Brueckner, Keith A

    1970-01-01

    Electron Impact Phenomena and the Properties of Gaseous Ions, Revised Edition deals with data pertaining to electron impact and to molecular gaseous ionic phenomena. This book discusses electron impact phenomena in gases at low pressure that involve low-energy electrons, which result in ion formation. The text also describes the use of mass spectrometers in electron impact studies and the degree of accuracy obtained when measuring electron impact energies. This book also reviews relatively low speed electrons and the transitions that result in the ionization of the atomic system. This text the

  3. Time-Variable Phenomena in the Jovian System

    Science.gov (United States)

    Belton, Michael J. S. (Editor); West, Robert A. (Editor); Rahe, Jurgen (Editor); Pereyda, Margarita

    1989-01-01

    The current state of knowledge of dynamic processes in the Jovian system is assessed and summaries are provided of both theoretical and observational foundations upon which future research might be based. There are three sections: satellite phenomena and rings; magnetospheric phenomena, Io's torus, and aurorae; and atmospheric phenomena. Each chapter discusses time dependent theoretical framework for understanding and interpreting what is observed; others describe the evidence and nature of observed changes or their absence. A few chapters provide historical perspective and attempt to present a comprehensive synthesis of the current state of knowledge.

  4. Inverse Analysis of Cavitation Impact Phenomena on Structures

    National Research Council Canada - National Science Library

    Lambrakos, S. G; Tran, N. E

    2007-01-01

    A general methodology is presented for in situ detection of cavitation impact phenomena on structures based on inverse analysis of luminescent emissions resulting from the collapsing of bubbles onto surfaces...

  5. Explaining the Prevalence, Scaling and Variance of Urban Phenomena

    CERN Document Server

    Gomez-Lievano, Andres; Hausmann, Ricardo

    2016-01-01

    The prevalence of many urban phenomena changes systematically with population size. We propose a theory that unifies models of economic complexity and cultural evolution to derive urban scaling. The theory accounts for the difference in scaling exponents and average prevalence across phenomena, as well as the difference in the variance within phenomena across cities of similar size. The central ideas are that a number of necessary complementary factors must be simultaneously present for a phenomenon to occur, and that the diversity of factors is logarithmically related to population size. The model reveals that phenomena that require more factors will be less prevalent, scale more superlinearly and show larger variance across cities of similar size. The theory applies to data on education, employment, innovation, disease and crime, and it entails the ability to predict the prevalence of a phenomenon across cities, given information about the prevalence in a single city.

  6. Nonlinear structural mechanics theory, dynamical phenomena and modeling

    CERN Document Server

    Lacarbonara, Walter

    2013-01-01

    Nonlinear Structural Mechanics: Theory, Dynamical Phenomena and Modeling offers a concise, coherent presentation of the theoretical framework of nonlinear structural mechanics, computational methods, applications, parametric investigations of nonlinear phenomena and their mechanical interpretation towards design. The theoretical and computational tools that enable the formulation, solution, and interpretation of nonlinear structures are presented in a systematic fashion so as to gradually attain an increasing level of complexity of structural behaviors, under the prevailing assumptions on the geometry of deformation, the constitutive aspects and the loading scenarios. Readers will find a treatment of the foundations of nonlinear structural mechanics towards advanced reduced models, unified with modern computational tools in the framework of the prominent nonlinear structural dynamic phenomena while tackling both the mathematical and applied sciences. Nonlinear Structural Mechanics: Theory, Dynamical Phenomena...

  7. High-speed imaging of dynamic shock wave reflection phenomena

    CSIR Research Space (South Africa)

    Naidoo, K

    2010-09-01

    Full Text Available Dynamic shock wave reflection generated by a rapidly pitching wedge in a steady supersonic free stream has been studied with numerical simulation previously. An experimental facility was developed for the investigation of these dynamic phenomena...

  8. ­Classifying prion and prion-like phenomena

    Science.gov (United States)

    Harbi, Djamel; Harrison, Paul M

    2014-01-01

    The universe of prion and prion-like phenomena has expanded significantly in the past several years. Here, we overview the challenges in classifying this data informatically, given that terms such as “prion-like”, “prion-related” or “prion-forming” do not have a stable meaning in the scientific literature. We examine the spectrum of proteins that have been described in the literature as forming prions, and discuss how “prion” can have a range of meaning, with a strict definition being for demonstration of infection with in vitro-derived recombinant prions. We suggest that although prion/prion-like phenomena can largely be apportioned into a small number of broad groups dependent on the type of transmissibility evidence for them, as new phenomena are discovered in the coming years, a detailed ontological approach might be necessary that allows for subtle definition of different “flavors” of prion / prion-like phenomena. PMID:24549098

  9. Ambroise August Liébeault and psychic phenomena.

    Science.gov (United States)

    Alvarado, Carlos S

    2009-10-01

    Some nineteenth-century hypnosis researchers did not limit their interest to the study of the conventional psychological and behavioral aspects of hypnosis, but also studied and wrote about psychic phenomena such as mental suggestion and clairvoyance. One example, and the topic of this paper, was French physician Ambroise August Liébeault (1823-1904), who influenced the Nancy school of hypnosis. Liébeault wrote about mental suggestion, clairvoyance, mediumship, and even so-called poltergeists. Some of his writings provide conventional explanations of the phenomena. Still of interest today, Liébeault's writings about psychic phenomena illustrate the overlap that existed during the nineteenth-century between hypnosis and psychic phenomena--an overlap related to the potentials of the mind and its subconscious activity.

  10. Unilateral autoscopic phenomena as a lateralizing sign in focal epilepsy.

    Science.gov (United States)

    Hoepner, Robert; Labudda, Kirsten; Hoppe, Matthias; Schoendienst, Martin; Schulz, Reinhard; Tomka-Hoffmeister, Maria; Woermann, Friedrich G; Ebner, Alois; Bien, Christian G; Brandt, Christian

    2012-03-01

    Positive autoscopic phenomena - autoscopy, heautoscopy and out-of-body experience - may occur in a variety of diseases and also in physiological conditions. They are a rare but probably underreported phenomenon in focal epilepsies. Here, we investigate whether ictal lateralized autoscopic phenomena give lateralizing information about the underlying epileptic focus. We present the cases of seven patients from our center who experienced ictal lateralized autoscopic phenomena and analyzed their focus lateralization and localization of the underlying brain lesion. In addition, we reviewed seven cases published in German and English language literature. In the total group of 14 patients with ictal lateralized autoscopic phenomena, 12 (85.7%) of them had a well-defined epileptic focus contralateral to the side of the autoscopic appearance. Therefore, the data point to an association between ictal lateralized autoscopy and contralateral epileptic focus. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. An introduction to macroscopic quantum phenomena and quantum dissipation

    CERN Document Server

    Caldeira, Amir O

    2014-01-01

    Reviewing macroscopic quantum phenomena and quantum dissipation, from the phenomenology of magnetism and superconductivity to the presentation of alternative models for quantum dissipation, this book develops the basic material necessary to understand the quantum dynamics of macroscopic variables. Macroscopic quantum phenomena are presented through several examples in magnetism and superconductivity, developed from general phenomenological approaches to each area. Dissipation naturally plays an important role in these phenomena, and therefore semi-empirical models for quantum dissipation are introduced and applied to the study of a few important quantum mechanical effects. The book also discusses the relevance of macroscopic quantum phenomena to the control of meso- or nanoscopic devices, particularly those with potential applications in quantum computation or quantum information. It is ideal for graduate students and researchers.

  12. Classification of debris flow phenomena in the Faroe Islands

    DEFF Research Database (Denmark)

    Dahl, Mads-Peter Jakob; E. Mortensen, Lis; Jensen, Niels H.

    2012-01-01

    a multidisciplinary study involving geomorphological fieldwork and qualitative collection of indigenous landslide knowledge, presents physical characteristics to classify debris flow phenomena into groups named with Faroese terms. The following landslide definitions are proposed. Brekku-skriðulop (English translation...

  13. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    OpenAIRE

    Iso-Ahola, Seppo E.

    2017-01-01

    Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1) scientific method itself is seriously limited (i.e., it can never prove a negative); (2) non-existence of phenomena would require a complete absence of both logical (theoretical) and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3) statistical data are only one piece of evidence and cann...

  14. On Process Modelling Using Physical Oriented And Phenomena Based Principles

    Directory of Open Access Journals (Sweden)

    Mihai Culea

    2000-12-01

    Full Text Available This work presents a modelling framework based on phenomena description of the process. The approach is taken to easy understand and construct process model in heterogeneous possible distributed modelling and simulation environments. A simplified case study of a heat exchanger is considered and Modelica modelling language to check the proposed concept. The partial results are promising and the research effort will be extended in a computer aided modelling environment based on phenomena.

  15. Comprehensive Study of Plasma-Wall Sheath Transport Phenomena

    Science.gov (United States)

    2016-10-26

    approved for public release. 1 Comprehensive Study of Plasma-Wall Sheath Transport Phenomena Final Report 2016 Prof. Mitchell L. R. Walker Georgia...interaction and how both the sheath and the wall material affect the plasma as a whole. The research aims to determine the fundamental transport properties...AFRL-AFOSR-VA-TR-2016-0346 Comprehensive Study of Plasma-Wall Sheath Transport Phenomena MITCHELL WALKER GEORGIA TECH RESEARCH CORPORATION Final

  16. PREFACE: Transport phenomena in proton conducting media Transport phenomena in proton conducting media

    Science.gov (United States)

    Eikerling, Michael

    2011-06-01

    Proton transport phenomena are of paramount importance for acid-base chemistry, energy transduction in biological organisms, corrosion processes, and energy conversion in electrochemical systems such as polymer electrolyte fuel cells. The relevance for such a plethora of materials and systems, and the ever-lasting fascination with the highly concerted nature of underlying processes drive research across disciplines in chemistry, biology, physics and chemical engineering. A proton never travels alone. Proton motion is strongly correlated with its environment, usually comprised of an electrolyte and a solid or soft host material. For the transport in nature's most benign proton solvent and shuttle, water that is, insights from ab initio simulations, matured over the last 15 years, have furnished molecular details of the structural diffusion mechanism of protons. Excess proton movement in water consists of sequences of Eigen-Zundel-Eigen transitions, triggered by hydrogen bond breaking and making in the surrounding water network. Nowadays, there is little debate about the validity of this mechanism in water, which bears a stunning resemblance to the basic mechanistic picture put forward by de Grotthuss in 1806. While strong coupling of an excess proton with degrees of freedom of solvent and host materials facilitates proton motion, this coupling also creates negative synergies. In general, proton mobility in biomaterials and electrochemical proton conducting media is highly sensitive to the abundance and structure of the proton solvent. In polymer electrolyte membranes, in which protons are bound to move in nano-sized water-channels, evaporation of water or local membrane dehydration due to electro-osmotic coupling are well-known phenomena that could dramatically diminish proton conductivity. Contributions in this special issue address various vital aspects of the concerted nature of proton motion and they elucidate important structural and dynamic effects of solvent

  17. Comprehending emergent systems phenomena through direct-manipulation animation

    Science.gov (United States)

    Aguirre, Priscilla Abel

    This study seeks to understand the type of interaction mode that best supports learning and comprehension of emergent systems phenomena. Given that the literature has established that students hold robust misconceptions of such phenomena, this study investigates the influence of using three types of interaction; speed-manipulation animation (SMN), post-manipulation animation (PMA) and direct-manipulation animation (DMA) for increasing comprehension and testing transfer of the phenomena, by looking at the effect of simultaneous interaction of haptic and visual channels on long term and working memories when seeking to comprehend emergent phenomena. The questions asked were: (1) Does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool (i.e., SMA, PMA or DMA), improve students' mental model construction of systems, thus increasing comprehension of this scientific concept? And (2) does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool, give the students the necessary complex cognitive skill which can then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios? In an empirical study undergraduate and graduate students were asked to participate in one of three experimental conditions: SMA, PMA, or DMA. The results of the study found that it was the participants of the SMA treatment condition that had the most improvement in post-test scores. Students' understanding of the phenomena increased most when they used a dynamic model with few interactive elements (i.e., start, stop, and speed) that allowed for real time visualization of one's interaction on the phenomena. Furthermore, no indication was found that the learning of emergent phenomena, with the aid of a dynamic interactive modeling tool, gave the students the necessary complex cognitive skill which could then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios

  18. Semiology of subtle motor phenomena in critically ill patients.

    Science.gov (United States)

    Florea, Bogdan; Beniczky, Simona Alexandra; Demény, Helga; Beniczky, Sándor

    2017-05-01

    to investigate the semiology of subtle motor phenomena in critically ill patients, with- versus without nonconvulsive status epilepticus (NCSE). 60 consecutive comatose patients, in whom subtle motor phenomena were observed in the intensive care unit (ICU), were analysed prospectively. The semiology of the subtle phenomena was described from video-recordings, blinded to all other data. For each patient, the type, location and occurrence-pattern/duration were described. EEGs recorded in the ICU were classified using the Salzburg criteria for NCSE. only 23% (14/60) of the patients had NCSE confirmed by EEG. None of the semiological features could distinguish between patients with NCSE and those without. In both groups, the following phenomena were most common: discrete myoclonic muscle twitching and discrete tonic muscle activation. Besides these, automatisms and eye deviation were observed in both groups. subtle motor phenomena in critically ill patients can raise the suspicion of NCSE. Nevertheless, EEG is needed to confirm the diagnosis, since none of the semiological features are specific. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  19. Modeling and simulation of transport phenomena in ionic gels

    Science.gov (United States)

    Leichsenring, Peter; Wallmersperger, Thomas

    2015-04-01

    Ionic hydrogels belong to the class of polyelectrolyte gels or ionic gels. Their ability to swell or shrink under different environmental conditions such as change of pH, ion concentration or temperature make them promising materials, e.g. for microsensoric or microactuatoric devices. The hydrogel swelling exhibits nonlinear effects due to the occurrence of different interacting transport phenomena. Numerical simulations are an essential part in the ongoing development of microsensors and microactuators. In order to determine transport effects due to diffusion, migration and convection a multiphase mesoscale model based on the Theory of Porous Media is applied. The governing field equations are solved in the transient regime by applying the Finite Element Method. By means of the derived numerical framework a detailed investigation of the different transport phenomena is carried out. Numerical experiments are performed to characterize the dominating transfer phenomena for ionic gels under chemical stimulation.

  20. Diffusion phenomena of cells and biomolecules in microfluidic devices.

    Science.gov (United States)

    Yildiz-Ozturk, Ece; Yesil-Celiktas, Ozlem

    2015-09-01

    Biomicrofluidics is an emerging field at the cross roads of microfluidics and life sciences which requires intensive research efforts in terms of introducing appropriate designs, production techniques, and analysis. The ultimate goal is to deliver innovative and cost-effective microfluidic devices to biotech, biomedical, and pharmaceutical industries. Therefore, creating an in-depth understanding of the transport phenomena of cells and biomolecules becomes vital and concurrently poses significant challenges. The present article outlines the recent advancements in diffusion phenomena of cells and biomolecules by highlighting transport principles from an engineering perspective, cell responses in microfluidic devices with emphases on diffusion- and flow-based microfluidic gradient platforms, macroscopic and microscopic approaches for investigating the diffusion phenomena of biomolecules, microfluidic platforms for the delivery of these molecules, as well as the state of the art in biological applications of mammalian cell responses and diffusion of biomolecules.

  1. Nonlinear Magnetic Phenomena in Highly Polarized Target Materials

    CERN Document Server

    Kiselev, Yu F

    2007-01-01

    The report introduces and surveys nonlinear magnetic phenomena which have been observed at high nuclear polarizations in polarized targets of the SMC and of the COMPASS collaborations at CERN. Some of these phenomena, namely the frequency modulation eect and the distortion of the NMR line shape, promote the development of the polarized target technique. Others, as the spin-spin cross-relaxation between spin subsystems can be used for the development of quantum statistical physics. New findings bear on an electromagnetic noise and the spectrally resolved radiation from LiD with negatively polarized nuclei detected by low temperature bolometers. These nonlinear phenomena need to be taken into account for achieving the ultimate polarizations.

  2. Emergence of Architectural Phenomena in the Human Habitation of Space

    Science.gov (United States)

    Collen, Arne

    Considering the impact on human beings and human activities of architectural decisions in the design of space for human habitation, this chapter discusses the increasingly evident and necessary confluence in contemporary times of many disciplines and human-oriented sciences, with architecture being the meeting ground to know emergent phenomena of human habitation. As both a general rubric and a specific phenomenon, architectural emergence is the chosen focus of discussion and other phenomena are related to it. Attention is given to the phenomena of architectural induction, emergence, and convergence as having strategic and explanatory value in understanding tensions between two competing mentalities, the global domineering nature-for-humans attitude, in opposition to the lesser practiced humans-for-nature attitude.

  3. Biomedical Signals and Sensors I Linking Physiological Phenomena and Biosignals

    CERN Document Server

    Kaniusas, Eugenijus

    2012-01-01

    This two-volume set focuses on the interface between physiologic mechanisms and diagnostic human engineering. Today numerous biomedical sensors are commonplace in clinical practice. The registered biosignals reflect mostly vital physiologic phenomena. In order to adequately apply biomedical sensors and reasonably interpret the corresponding biosignals, a proper understanding of the involved physiologic phenomena, their influence on the registered biosignals, and the technology behind the sensors is necessary. The first volume is devoted to the interface between physiologic mechanisms and arising biosignals, whereas the second volume is focussed on the interface between biosignals and biomedical sensors. The physiologic mechanisms behind the biosignals are described from the basic cellular level up to their advanced mutual coordination level during sleep. The arising biosignals are discussed within the scope of vital physiologic phenomena to foster their understanding and comprehensive analysis.

  4. Random phenomena fundamentals of probability and statistics for engineers

    CERN Document Server

    Ogunnaike, Babatunde A

    2009-01-01

    PreludeApproach PhilosophyFour Basic PrinciplesI FoundationsTwo Motivating ExamplesYield Improvement in a Chemical ProcessQuality Assurance in a Glass Sheet Manufacturing ProcessOutline of a Systematic ApproachRandom Phenomena, Variability, and UncertaintyTwo Extreme Idealizations of Natural PhenomenaRandom Mass PhenomenaIntroducing ProbabilityThe Probabilistic FrameworkII ProbabilityFundamentals of Probability TheoryBuilding BlocksOperationsProbabilityConditional ProbabilityIndependenceRandom Variables and DistributionsDistributionsMathematical ExpectationCharacterizing DistributionsSpecial Derived Probability FunctionsMultidimensional Random VariablesDistributions of Several Random VariablesDistributional Characteristics of Jointly Distributed Random VariablesRandom Variable TransformationsSingle Variable TransformationsBivariate TransformationsGeneral Multivariate TransformationsApplication Case Studies I: ProbabilityMendel and HeredityWorld War II Warship Tactical Response Under AttackIII DistributionsIde...

  5. Time in powers of ten natural phenomena and their timescales

    CERN Document Server

    't Hooft, Gerard

    2014-01-01

    In this richly illustrated book, Nobel Laureate Gerard 't Hooft and Theoretical Physicist Stefan Vandoren describe the enormous diversity of natural phenomena that take place at different time scales. In the tradition of the bestseller Powers of Ten , the authors zoom in and out in time, each step with a factor of ten. Starting from one second, time scales are enlarged until processes are reached that take much longer than the age of the universe. After the largest possible eternities, the reader is treated to the shortest and fastest phenomena known. Then the authors increase with powers of t

  6. Critical phenomena experiments in space. [for fluid phase-equilibrium

    Science.gov (United States)

    Sengers, J. V.; Moldover, M. R.

    1978-01-01

    The paper analyzes several types of critical phenomena in fluids, shows how they are affected by the presence of gravity, and describes how experiments conducted in an orbiting laboratory under low gravity conditions could extend the range of measurements needed to study critical phenomena. Future experiments are proposed. One would be a careful measurement of the dielectric constant in a low gravity environment. Two basic problems that can benefit especially from space experiments are the specific heat near the critical point and the shear viscosity at the gas-liquid critical point.

  7. Transport phenomena in Newtonian fluids a concise primer

    CERN Document Server

    Olsson, Per

    2013-01-01

    This short primer provides a concise and tutorial-style introduction to transport phenomena in Newtonian fluids , in particular the transport of mass, energy and momentum.  The reader will find detailed derivations of the transport equations for these phenomena, as well as selected analytical solutions to the transport equations in some simple geometries. After a brief introduction to the basic mathematics used in the text, Chapter 2, which deals with momentum transport, presents a derivation of the Navier-Stokes-Duhem equation describing the basic flow in a Newtonian fluid.  Also provided at

  8. Thermionic phenomena the collected works of Irving Langmuir

    CERN Document Server

    Suits, C Guy

    1961-01-01

    Thermionic Phenomena is the third volume of the series entitled The Collected Works of Irving Langmuir. This volume compiles articles written during the 1920's and early 1930's, the period when the science of thermionics is beginning to be of importance. This text is divided into two parts. The first part discusses vacuum pumps, specifically examining the effect of space charge and residual gases on thermionic currents in high vacuum. This part also explains fundamental phenomena in electron tubes having tungsten cathodes and the use of high-power vacuum tubes. The second part of this text loo

  9. Simulation of water hammer phenomena using the system code ATHLET

    Energy Technology Data Exchange (ETDEWEB)

    Bratfisch, Christoph; Koch, Marco K. [Bochum Univ. (Germany). Reactor Simulation and Safety Group

    2017-07-15

    Water Hammer Phenomena can endanger the integrity of structures leading to a possible failure of pipes in nuclear power plants as well as in many industrial applications. These phenomena can arise in nuclear power plants in the course of transients and accidents induced by the start-up of auxiliary feed water systems or emergency core cooling systems in combination with rapid acting valves and pumps. To contribute to further development and validation of the code ATHLET (Analysis of Thermalhydraulics of Leaks and Transients), an experiment performed in the test facility Pilot Plant Pipework (PPP) at Fraunhofer UMSICHT is simulated using the code version ATHLET 3.0A.

  10. Psychosocial Aspects of Dental Anxiety and Clinical Pain Phenomena

    DEFF Research Database (Denmark)

    Moore, Rod

    This Danish Doctoral Dissertation in the science of Odontology contains 7 chapters: 1) Introduction to a social perspective on dental treatment, anxiety and pain throughout time, 2) research models and methods to study dental anxiety and clinical pain phenomena, 3) the fear of dental treatment...... .. what it is and what it is not and how many have it, 4) clinical pain treatment, psychosocial aspects in relation to anxiety, 4) patients and dentists' roles, pain perception and anxiety, 6) psychosocial aspects of managing anxiety and pain phenomena, and 7) Conclusions and proposals for the future...

  11. Understanding the Physical Optics Phenomena by Using a Digital Application for Light Propagation

    Energy Technology Data Exchange (ETDEWEB)

    Sierra-Sosa, Daniel-Esteban; Angel-Toro, Luciano, E-mail: dsierras@eafit.edu.co, E-mail: langel@eafit.edu.co [Grupo de Optica Aplicada, Universidad EAFIT, 1 Medellin (Colombia)

    2011-01-01

    Understanding the light propagation on the basis of the Huygens-Fresnel principle stands for a fundamental factor for deeper comprehension of different physical optics related phenomena like diffraction, self-imaging, image formation, Fourier analysis and spatial filtering. This constitutes the physical approach of the Fourier optics whose principles and applications have been developed since the 1950's. Both for analytical and digital applications purposes, light propagation can be formulated in terms of the Fresnel Integral Transform. In this work, a digital optics application based on the implementation of the Discrete Fresnel Transform (DFT), and addressed to serve as a tool for applications in didactics of optics is presented. This tool allows, at a basic and intermediate learning level, exercising with the identification of basic phenomena, and observing changes associated with modifications of physical parameters. This is achieved by using a friendly graphic user interface (GUI). It also assists the user in the development of his capacity for abstracting and predicting the characteristics of more complicated phenomena. At an upper level of learning, the application could be used to favor a deeper comprehension of involved physics and models, and experimenting with new models and configurations. To achieve this, two characteristics of the didactic tool were taken into account when designing it. First, all physical operations, ranging from simple diffraction experiments to digital holography and interferometry, were developed on the basis of the more fundamental concept of light propagation. Second, the algorithm was conceived to be easily upgradable due its modular architecture based in MATLAB (registered) software environment. Typical results are presented and briefly discussed in connection with didactics of optics.

  12. First applications of structural pattern recognition methods to the investigation of specific physical phenomena at JET

    Energy Technology Data Exchange (ETDEWEB)

    Ratta, G.A. [Asociacion EURATOM/CIEMAT para Fusion (Spain)], E-mail: giuseppe.ratta@ciemat.es; Vega, J.; Pereira, A.; Portas, A.; Luna, E. de la [Asociacion EURATOM/CIEMAT para Fusion (Spain); Dormido-Canto, S.; Farias, G.; Dormido, R.; Sanchez, J.; Duro, N.; Vargas, H. [Dpto. Informatica y Automatica-UNED, 28040 Madrid (Spain); Santos, M.; Pajares, G. [Dpto. Arquitectura de Computadores y Automatica-UCM, 28040 Madrid (Spain); Murari, A. [Consorzio RFX-Associazione EURATOM ENEA per la Fusione, Padua (Italy)

    2008-04-15

    Structural pattern recognition techniques allow the identification of plasma behaviours. Physical properties are encoded in the morphological structure of signals. Intelligent access methods have been applied to JET databases to retrieve data according to physical criteria. On the one hand, the structural form of signals has been used to develop general purpose data retrieval systems to search for both similar entire waveforms and similar structural shapes inside waveforms. On the other hand, domain dependent knowledge was added to the structural information of signals to create particular data retrieval methods for specific physical phenomena. The inclusion of explicit knowledge assists in data analysis. The latter has been applied in JET to look for first, cut-offs in ECE heterodyne radiometer signals and, second, L-H transitions.

  13. A Novel Multi-Phase Stochastic Model for Lithium-Ion Batteries’ Degradation with Regeneration Phenomena

    Directory of Open Access Journals (Sweden)

    Jianxun Zhang

    2017-10-01

    Full Text Available A lithium-Ion battery is a typical degradation product, and its performance will deteriorate over time. In its degradation process, regeneration phenomena have been frequently encountered, which affect both the degradation state and rate. In this paper, we focus on how to build the degradation model and estimate the lifetime. Toward this end, we first propose a multi-phase stochastic degradation model with random jumps based on the Wiener process, where the multi-phase model and random jumps at the changing point are used to describe the variation of degradation rate and state caused by regeneration phenomena accordingly. Owing to the complex structure and random variables, the traditional Maximum Likelihood Estimation (MLE is not suitable for the proposed model. In this case, we treat these random variables as latent parameters, and then develop an approach for model identification based on expectation conditional maximum (ECM algorithm. Moreover, depending on the proposed model, how to estimate the lifetime with fixed changing point is presented via the time-space transformation technique, and the approximate analytical solution is derived. Finally, a numerical simulation and a practical case are provided for illustration.

  14. X-ray spectroscopic study of charge exchange phenomena in plasma-wall interaction

    Directory of Open Access Journals (Sweden)

    Renner O.

    2013-11-01

    Full Text Available Jets of energetic ions launched at laser-burnt-through foils represent an efficient tool for investigation of plasma interaction with solid surfaces (plasma-wall interaction, PWI and for description of transient phenomena occurring close to the walls. Highly charged ions approaching the secondary target interpenetrate the near surface layer, collide with the counter-propagating matter and capture a large number of electrons. This results in a creation of atoms in highly excited Rydberg states or hollow ions with multiple inner vacancies; plasma jet and target ions may also undergo charge exchange (CE processes. We report PWI experiments with Al/Si(PMMA and Al/C targets irradiated at normal or oblique laser incidence. The distinct dip structures observed in red wings of Al Lyγ self-emission is interpreted in terms of CE between C6+ and Al12+ in the near-wall zone. The spectroscopic identification of CE phenomena is supported by results of analytical and numerical calculations.

  15. EDITORIAL: Spin-transfer-torque-induced phenomena Spin-transfer-torque-induced phenomena

    Science.gov (United States)

    Hirohata, Atsufumi

    2011-09-01

    This cluster, consisting of five invited articles on spin-transfer torque, offers the very first review covering both magnetization reversal and domain-wall displacement induced by a spin-polarized current. Since the first theoretical proposal on spin-transfer torque—reported by Berger and Slonczewski independently—spin-transfer torque has been experimentally demonstrated in both vertical magnetoresistive nano-pillars and lateral ferromagnetic nano-wires. In the former structures, an electrical current flowing vertically in the nano-pillar exerts spin torque onto the thinner ferromagnetic layer and reverses its magnetization, i.e., current-induced magnetization switching. In the latter structures, an electrical current flowing laterally in the nano-wire exerts torque onto a domain wall and moves its position by rotating local magnetic moments within the wall, i.e., domain wall displacement. Even though both phenomena are induced by spin-transfer torque, each phenomenon has been investigated separately. In order to understand the physical meaning of spin torque in a broader context, this cluster overviews both cases from theoretical modellings to experimental demonstrations. The earlier articles in this cluster focus on current-induced magnetization switching. The magnetization dynamics during the reversal has been calculated by Kim et al using the conventional Landau--Lifshitz-Gilbert (LLG) equation, adding a spin-torque term. This model can explain the dynamics in both spin-valves and magnetic tunnel junctions in a nano-pillar form. This phenomenon has been experimentally measured in these junctions consisting of conventional ferromagnets. In the following experimental part, the nano-pillar junctions with perpendicularly magnetized FePt and half-metallic Heusler alloys are discussed from the viewpoint of efficient magnetization reversal due to a high degree of spin polarization of the current induced by the intrinsic nature of these alloys. Such switching can

  16. Coupled electric and transport phenomena in porous media

    NARCIS (Netherlands)

    Li, Shuai

    2014-01-01

    The coupled electrical and transport properties of clay-containing porous media are the topics of interest in this study. Both experimental and numerical (pore network modeling) techniques are employed to gain insight into the macro-scale interaction between electrical and solute transport phenomena

  17. Unipolar arcing phenomena observed in laboratory and nature

    Energy Technology Data Exchange (ETDEWEB)

    Sanduloviciu, M. [Al. I. Cuza Univ. (Romania)

    1995-12-31

    Unipolar arcing phenomena observed as coherent {open_quotes}plasma{close_quotes} balls operating on a surface of constant potential are explained in the frame of a new already proposed self-organisation mechanism considered at the origin of the formation and stability of extended coherent structures observed in plasma devices.

  18. Metallurgical applications of shock wave and high strain rate phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Murr, L.E.; Staudhammer, K.P.; Meyers, M.A.

    1986-01-01

    This book presents the papers given at a conference on the impact testing of metals. Topics considered at the conference included dynamic consolidation, the analysis of dislocation kinetics across shocks, high-strain-rate deformation, adiabatic shear band phenomena, dynamic fracture, explosive metal working, shock synthesis and the property modification of materials, and novel concepts and applications of high pressure.

  19. Maxwell Prize Talk: Scaling Laws for the Dynamical Plasma Phenomena

    Science.gov (United States)

    Ryutov, Livermore, Ca 94550, Usa, D. D.

    2017-10-01

    The scaling and similarity technique is a powerful tool for developing and testing reduced models of complex phenomena, including plasma phenomena. The technique has been successfully used in identifying appropriate simplified models of transport in quasistationary plasmas. In this talk, the similarity and scaling arguments will be applied to highly dynamical systems, in which temporal evolution of the plasma leads to a significant change of plasma dimensions, shapes, densities, and other parameters with respect to initial state. The scaling and similarity techniques for dynamical plasma systems will be presented as a set of case studies of problems from various domains of the plasma physics, beginning with collisonless plasmas, through intermediate collisionalities, to highly collisional plasmas describable by the single-fluid MHD. Basic concepts of the similarity theory will be introduced along the way. Among the results discussed are: self-similarity of Langmuir turbulence driven by a hot electron cloud expanding into a cold background plasma; generation of particle beams in disrupting pinches; interference between collisionless and collisional phenomena in the shock physics; similarity for liner-imploded plasmas; MHD similarities with an emphasis on the effect of small-scale (turbulent) structures on global dynamics. Relations between astrophysical phenomena and scaled laboratory experiments will be discussed.

  20. Non-Grammatical Reflexive Binding Phenomena: The Case of Japanese.

    Science.gov (United States)

    Sakakibara, Sonoko

    Two non-syntactic phenomena of Japanese reflexive binding by "zibun" ("self") are analyzed with respect to a pragmatic use condition on "zibun," a culture-specific condition, and the Maxim of Politeness (Fukada 1986). The first phenomenon is the tendency by native speakers of Japanese to avoid referring to an honored…

  1. Investigating Dissolution and Precipitation Phenomena with a Smartphone Microscope

    Science.gov (United States)

    Lumetta, Gregg J.; Arcia, Edgar

    2016-01-01

    A novel smartphone microscope can be used to observe the dissolution and crystallization of sodium chloride at a microscopic level. Observation of these seemingly simple phenomena through the microscope at 100× magnification can actually reveal some surprising behavior. These experiments offer the opportunity to discuss some basic concepts such as…

  2. The Effects of Globalization Phenomena on Educational Concepts

    Science.gov (United States)

    Schrottner, Barbara Theresia

    2010-01-01

    It is becoming more and more apparent that globalization processes represent, theoretically as well as practically, a challenge for educational sciences and therefore, it must be addressed within the sphere of education. Accordingly, educational conceptions have to adapt to globalization phenomena and focus more on alternative and innovative…

  3. Dielectric relaxation phenomena of rigid polar liquid molecules ...

    Indian Academy of Sciences (India)

    The dielectric relaxation phenomena of rigid polar liquid molecules chloral and ethyltrichloroacetate () in benzene, -hexane and -heptane () under 4.2, 9.8 and 24.6 GHz electric fields at 30°C are studied to show the possible existence of double relaxation times 2 and 1 for rotations of the whole and the flexible ...

  4. The Simulation Of Residual Tidal Phenomena In The White Sea

    Science.gov (United States)

    May, R. I.

    2004-12-01

    Residual tidal phenomena (residual tidal circulation and residual tidal level) in the White Sea play a significant role in energy contribution to the formation of the hydrological regime. Non-linear residual tidal currents and sea level due to energy exchanges from the basic harmonics to the high frequency part of the spectrum have been poorly investigated in the White Sea until now. But residual tidal phenomena play an important role in the general circulation, which affects the temperature distribution and the drift of ice, plankton, pollution and other conservative tracers. We carried out numerical experiments with a non-linear hydrodynamic model to estimate the contributions of (shallow, friction and convective) nonlinearities to the residual tidal phenomena of White Sea's, using a `consecutive realisation' technique. The model grid's spatio-temporal resolution is more detailed than before: the Earth's geoid is approximated by the Krasovskiy rotation ellipsoid. A residual tidal level is observed in the low frequency part of spectrum of model results. In the linear approximation, the spectral density has a dominant peak at the frequencies of the basic harmonics in all parts of the sea, and the residual level was absent; overtones were not expressed. The experiments revealed that the residual circulation was defined by the convective non-linearity. The Earth's rotation does not change the current structure: only the circulation intensity decreases. These results will enhance the knowledge of tidal phenomena in the White Sea, and can be used for navigation, ecology and fisheries research.

  5. Explosive phenomena in heavily irradiated NaCl

    NARCIS (Netherlands)

    denHartog, HW; Vainshtein, DI; Matthews, GE; Williams, RT

    1997-01-01

    In heavily irradiated NaCl crystals explosive phenomena can be initiated during irradiation or afterwards when samples are heated to temperatures between 100 and 250 degrees C. During irradiation of NaCl Na and Cl-2 precipitates and void structures are produced along with the accumulation of stored

  6. On the purposes of phonological phenomena: phonetics, parsing ...

    African Journals Online (AJOL)

    The first part of this paper investigates two hypotheses that have been put forward about the purpose of phonological phenomena, namely the mainstream view that the properties of the articulatory or auditory system motivate the phonology (the Phonetic Hypothesis), and Kaye's proposal that the phonology helps the hearer ...

  7. Electrostatic phenomena in organic semiconductors: fundamentals and implications for photovoltaics.

    Science.gov (United States)

    D'Avino, Gabriele; Muccioli, Luca; Castet, Frédéric; Poelking, Carl; Andrienko, Denis; Soos, Zoltán G; Cornil, Jérôme; Beljonne, David

    2016-11-02

    This review summarizes the current understanding of electrostatic phenomena in ordered and disordered organic semiconductors, outlines numerical schemes developed for quantitative evaluation of electrostatic and induction contributions to ionization potentials and electron affinities of organic molecules in a solid state, and illustrates two applications of these techniques: interpretation of photoelectron spectroscopy of thin films and energetics of heterointerfaces in organic solar cells.

  8. Two Oils, Same Phenomena: Historicizing Exclusion, Poverty and ...

    African Journals Online (AJOL)

    Delta communities in the vortex of European imperialism, which suppressed the growth of a viable class of indigenous accumulators and entrepreneurs in the palm oil economy. It demonstrated that contemporary trends and phenomena only heightened when the crude oil economy penetrated and reconfigured Niger Delta ...

  9. The Role of Linguistic Phenomena in Retrieval Performance.

    Science.gov (United States)

    Gillaspie, Deborah L.

    1995-01-01

    This progress report presents findings from a failure analysis of two full-text computer-assisted legal research systems, Lexis and Westlaw. Linguistic analyses of unretrieved documents and false drops are discussed, and examples of natural language phenomena that affect Boolean retrieval system performance are examined. (Author/LRW)

  10. An Initial Investigation of the Psychedelic Drug Flashback Phenomena

    Science.gov (United States)

    Matefy, Robert E.; Krall, Roger G.

    1974-01-01

    This study investigated some characteristics of persons experiencing "flashbacks," and provides systematic descriptions of the flashback phenomena. The drug user showed no significant differences in psychopathological characteristics as measured by the MMPI, nor significant differences in attentional processes as measured by the Embedded Figures…

  11. Towards an event-based corpuscular model for optical phenomena

    NARCIS (Netherlands)

    De Raedt, H.; Jin, F.; Michielsen, K.; Roychoudhuri, C; Khrennikov, AY; Kracklauer, AF

    2011-01-01

    We discuss an event-based corpuscular model of optical phenomena that does not require the knowledge of the solution of a wave equation of the whole system and reproduces the results of Maxwell's theory through a series of cause-and-effect processes, starting with the emission and ending with the

  12. Eighty Phenomena About the Self: Representation, Evaluation, Regulation, and Change

    Directory of Open Access Journals (Sweden)

    Paul eThagard

    2015-03-01

    Full Text Available We propose a new approach for examining self-related aspects and phenomena. The approach includes (1 a taxonomy and (2 an emphasis on multiple levels of mechanisms. The taxonomy categorizes approximately eighty self-related phenomena according to three primary functions involving the self: representing, effecting, and changing. The representing self encompasses the ways in which people depict themselves, either to themselves or to others (e.g., self-concepts, self-presentation. The effecting self concerns ways in which people facilitate or limit their own traits and behaviors (e.g., self-enhancement, self-regulation. The changing self is less time-limited than the regulating self; it concerns phenomena that involve lasting alterations in how people represent and control themselves (e.g., self-expansion, self-development. Each self-related phenomenon within these three categories may be examined at four levels of interacting mechanisms (social, individual, neural, and molecular. We illustrate our approach by focusing on seven self-related phenomena.

  13. Density operator description of geometric phenomena in the ray space

    Indian Academy of Sciences (India)

    Density operator description of geometric phenomena in the ray space. APOORVA G WAGH£ and VEER CHAND RAKHECHAЭ. Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. Email: * nintsspd@magnum.barc.ernet.in; t vcr@apsara.barc.ernet.in. Abstract. A general gauge-invariant ...

  14. Clear and fuzzy fractal models of spreading dangerous environmental phenomena

    Directory of Open Access Journals (Sweden)

    A.E. Guy

    2006-04-01

    Full Text Available  This article is devoted to investigation of possibility of widening models of spreading dangerous environmental phenomena, in particular Grassberger’s models, on the base of notion of fuzzy fractal sets introduced by one of the authors. Basic concepts from the theory of fuzzy fractals are considered.

  15. On some phenomena concerning pregnancy and parturition of the Cetacea

    NARCIS (Netherlands)

    Slijper, E.J.

    1949-01-01

    1. A review is given of some phenomena concerning pregnancy and parturition of the Cetacea, depending on data in literature and on observations made in Antarctic Blue and Fin Whales on board the f.f. “Willem Barendsz” (1946—1947). 2. In Mystacoceti the frequency of twins appears to be less than in

  16. All basic condensed matter physics phenomena and notions mirror ...

    Indian Academy of Sciences (India)

    A few billion years of evolutionary time and the complex process of 'selection' has given biology an opportunity to explore a variety of condensed matter phenomena and situations, some of which have been discovered by humans in the laboratory, that too only in extreme non-biological conditions such as low temperatures, ...

  17. Binding Phenomena within a Reductionist Theory of Grammatical Dependencies

    Science.gov (United States)

    Drummond, Alex

    2011-01-01

    This thesis investigates the implications of binding phenomena for the development of a reductionist theory of grammatical dependencies. The starting point is the analysis of binding and control in Hornstein (2001, 2009). A number of revisions are made to this framework in order to develop a simpler and empirically more successful account of…

  18. Condensation phenomena and frost problems in the air heat recuperators

    Directory of Open Access Journals (Sweden)

    Adamski Mariusz

    2014-01-01

    Full Text Available Investigation results of condensation phenomena and frost problems in the ventilation heat recuperators are presented. The experiments have been conducted for typical value of indoor temperature 20°C and a large range of humidity values from 20 to 75% and more of an exhausted air. The heat exchanger worked in the real conditions of the winter climate in Bialystok.

  19. Coastal Sand Dune Plant Ecology: Field Phenomena and Interpretation

    Science.gov (United States)

    McDonald, K.

    1973-01-01

    Discusses the advantages and disadvantages of selecting coastal sand dunes as the location for field ecology studies. Presents a descriptive zonal model for seaboard sand dune plant communities, suggestions concerning possible observations and activities relevant to interpreting phenomena associated with these forms of vegetation, and additional…

  20. Nuclear phenomena in low-energy nuclear reaction research.

    Science.gov (United States)

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  1. Higher twist, heavy quark, and coherent phenomena in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1984-09-01

    Scaling violations in QCD arise in two basic ways: (1) logarithmic corrections, associated with the variation of the running coupling constant and the radiative corrections which produce structure- and fragmentation-function evolution; and (2) power-law corrections, due to finite mass effects, multiparticle scattering processes, coherent wavefunction effects, and other non-perturbative phenomena. Aspects are briefly discussed.

  2. Undergraduate Laboratory Experiment Modules for Probing Gold Nanoparticle Interfacial Phenomena

    Science.gov (United States)

    Karunanayake, Akila G.; Gunatilake, Sameera R.; Ameer, Fathima S.; Gadogbe, Manuel; Smith, Laura; Mlsna, Deb; Zhang, Dongmao

    2015-01-01

    Three gold-nanoparticle (AuNP) undergraduate experiment modules that are focused on nanoparticles interfacial phenomena have been developed. Modules 1 and 2 explore the synthesis and characterization of AuNPs of different sizes but with the same total gold mass. These experiments enable students to determine how particle size affects the AuNP…

  3. Searches for phenomena beyond the Standard Model at the Large ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 79; Issue 4. Searches for phenomena beyond the Standard Model at the Large Hadron Collider with the ATLAS and CMS detectors. Henri Bachacou on behalf of the ATLAS and CMS Collaborations. Beyond Standard Model Physics Volume 79 Issue 4 October 2012 ...

  4. Extreme wave phenomena in down-stream running modulated waves

    NARCIS (Netherlands)

    Andonowati, A.; Karjanto, N.; van Groesen, Embrecht W.C.

    Modulational, Benjamin-Feir, instability is studied for the down-stream evolution of surface gravity waves. An explicit solution, the soliton on finite background, of the NLS equation in physical space is used to study various phenomena in detail. It is shown that for sufficiently long modulation

  5. Modelling of transport phenomena and defects in crystal growth ...

    Indian Academy of Sciences (India)

    ... transport and defect phenomena involoved in the growth process with the ultimate aim of integrating them into a comprehensive numerical model. The sources of dislocation nucleation in the growing crystal are discussed, and the propagation and multiplication of these under the action of thermal stresses is discussed.

  6. Seasonality of alcohol-related phenomena in Estonia

    Science.gov (United States)

    Silm, Siiri; Ahas, Rein

    2005-03-01

    We studied alcohol consumption and its consequences as a seasonal phenomenon in Estonia and analysed the social and environmental factors that may cause its seasonal rhythm. There are two important questions when researching the seasonality of human activities: (1) whether it is caused by natural or social factors, and (2) whether the impact of the factors is direct or indirect. Often the seasonality of social phenomena is caused by social factors, but the triggering mechanisms are related to environmental factors like temperature, precipitation, and radiation via the circannual calendar. The indicators of alcohol consumption in the current paper are grouped as: (1) pre-consumption phenomena, i.e. production, tax and excise, sales (beer, wine and vodka are analysed separately), and (2) post-consumption phenomena, i.e. alcohol-related crime and traffic accidents and the number of people detained in lockups and admitted to alcohol treatment clinics. In addition, seasonal variability in the amount of alcohol advertising has been studied, and a survey has been carried out among 87 students of Tartu University. The analysis shows that different phenomena related to alcohol have a clear seasonal rhythm in Estonia. The peak period of phenomena related to beer is in the summer, from June to August and the low point is during the first months of the year. Beer consumption correlates well with air temperature. The consumption of vodka increases sharply at the end of the year and in June; the production of vodka does not have a significant correlation with negative temperatures. The consumption of wine increases during summer and in December. The consequences of alcohol consumption, expressed as the rate of traffic accidents or the frequency of medical treatment, also show seasonal variability. Seasonal variability of alcohol consumption in Estonia is influenced by natural factors (temperature, humidity, etc.) and by social factors (celebrations, vacations, etc.). However

  7. Isotope Identification

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-18

    The objective of this training modules is to examine the process of using gamma spectroscopy for radionuclide identification; apply pattern recognition to gamma spectra; identify methods of verifying energy calibration; and discuss potential causes of isotope misidentification.

  8. Autoscopic phenomena and one's own body representation in dreams.

    Science.gov (United States)

    Occhionero, Miranda; Cicogna, Piera Carla

    2011-12-01

    Autoscopic phenomena (AP) are complex experiences that include the visual illusory reduplication of one's own body. From a phenomenological point of view, we can distinguish three conditions: autoscopic hallucinations, heautoscopy, and out-of-body experiences. The dysfunctional pattern involves multisensory disintegration of personal and extrapersonal space perception. The etiology, generally either neurological or psychiatric, is different. Also, the hallucination of Self and own body image is present during dreams and differs according to sleep stage. Specifically, the representation of the Self in REM dreams is frequently similar to the perception of Self in wakefulness, whereas in NREM dreams, a greater polymorphism of Self and own body representation is observed. The parallels between autoscopic phenomena in pathological cases and the Self-hallucination in dreams will be discussed to further the understanding of the particular states of self awareness, especially the complex integration of different memory sources in Self and body representation. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Musical obsessions: a comprehensive review of neglected clinical phenomena.

    Science.gov (United States)

    Taylor, Steven; McKay, Dean; Miguel, Euripedes C; De Mathis, Maria Alice; Andrade, Chittaranjan; Ahuja, Niraj; Sookman, Debbie; Kwon, Jun Soo; Huh, Min Jung; Riemann, Bradley C; Cottraux, Jean; O'Connor, Kieron; Hale, Lisa R; Abramowitz, Jonathan S; Fontenelle, Leonardo F; Storch, Eric A

    2014-08-01

    Intrusive musical imagery (IMI) consists of involuntarily recalled, short, looping fragments of melodies. Musical obsessions are distressing, impairing forms of IMI that merit investigation in their own right and, more generally, research into these phenomena may broaden our understanding of obsessive-compulsive disorder (OCD), which is phenomenologically and etiologically heterogeneous. We present the first comprehensive review of musical obsessions, based on the largest set of case descriptions ever assembled (N=96). Characteristics of musical obsessions are described and compared with normal IMI, musical hallucinations, and visual obsessional imagery. Assessment, differential diagnosis, comorbidity, etiologic hypotheses, and treatments are described. Musical obsessions may be under-diagnosed because they are not adequately assessed by current measures of OCD. Musical obsessions have been misdiagnosed as psychotic phenomena, which has led to ineffective treatment. Accurate diagnosis is important for appropriate treatment. Musical obsessions may respond to treatments that are not recommended for prototypic OCD symptoms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Charged dust and shock phenomena in the Solar System

    Directory of Open Access Journals (Sweden)

    S. I. Popel

    2006-01-01

    Full Text Available The results on shock phenomena in dusty plasmas of the Solar System are reviewed. The problems of dust ion acoustic bow shock in interaction of the solar wind with dusty cometary coma and formation of transient atmospheres of atmosphereless cosmic bodies such as Moon, Mercury, asteroids and comets are considered. The latter assumes the evolution of meteoroid impact plumes and production of charged dust grains due to the condensation of both the plume substance and the vapor thrown from the crater and the surrounding regolith layer. Physical phenomena occurring during large meteoroid impacts can be modeled with the aid of active rocket experiments, which involve the release of some gaseous substance in near-Earth space. New vistas in investigation of shock processes in natural dusty plasmas are determined.

  11. Stokes phenomena in discrete Painlevé II.

    Science.gov (United States)

    Joshi, N; Lustri, C J; Luu, S

    2017-02-01

    We consider the asymptotic behaviour of the second discrete Painlevé equation in the limit as the independent variable becomes large. Using asymptotic power series, we find solutions that are asymptotically pole-free within some region of the complex plane. These asymptotic solutions exhibit Stokes phenomena, which is typically invisible to classical power series methods. We subsequently apply exponential asymptotic techniques to investigate such phenomena, and obtain mathematical descriptions of the rapid switching behaviour associated with Stokes curves. Through this analysis, we determine the regions of the complex plane in which the asymptotic behaviour is described by a power series expression, and find that the behaviour of these asymptotic solutions shares a number of features with the tronquée and tri-tronquée solutions of the second continuous Painlevé equation.

  12. Computational transport phenomena of fluid-particle systems

    CERN Document Server

    Arastoopour, Hamid; Abbasi, Emad

    2017-01-01

    This book concerns the most up-to-date advances in computational transport phenomena (CTP), an emerging tool for the design of gas-solid processes such as fluidized bed systems. The authors examine recent work in kinetic theory and CTP and illustrate gas-solid processes’ many applications in the energy, chemical, pharmaceutical, and food industries. They also discuss the kinetic theory approach in developing constitutive equations for gas-solid flow systems and how it has advanced over the last decade as well as the possibility of obtaining innovative designs for multiphase reactors, such as those needed to capture CO2 from flue gases. Suitable as a concise reference and a textbook supplement for graduate courses, Computational Transport Phenomena of Gas-Solid Systems is ideal for practitioners in industries involved with the design and operation of processes based on fluid/particle mixtures, such as the energy, chemicals, pharmaceuticals, and food processing. Explains how to couple the population balance e...

  13. Preface: MHD wave phenomena in the solar interior and atmosphere

    Science.gov (United States)

    Fedun, Viktor; Srivastava, A. K.

    2018-01-01

    The Sun is our nearest star and this star produces various plasma wave processes and energetic events. These phenomena strongly influence interplanetary plasma dynamics and contribute to space-weather. The understanding of solar atmospheric dynamics requires hi-resolution modern observations which, in turn, further advances theoretical models of physical processes in the solar interior and atmosphere. In particular, it is essential to connect the magnetohydrodynamic (MHD) wave processes with the small and large-scale solar phenomena vis-a-vis transport of energy and mass. With the advent of currently available and upcoming high-resolution space (e.g., IRIS, SDO, Hinode, Aditya-L1, Solar-C, Solar Orbiter), and ground-based (e.g., SST, ROSA, NLST, Hi-C, DKIST, EST, COSMO) observations, solar physicists are able to explore exclusive wave processes in various solar magnetic structures at different spatio-temporal scales.

  14. IUTAM Symposium on Fracture Phenomena in Nature and Technology

    CERN Document Server

    Carini, Angelo; Gei, Massimiliano; Salvadori, Alberto

    2014-01-01

    This book contains contributions presented at the IUTAM Symposium "Fracture Phenomena in Nature and Technology" held in Brescia, Italy, 1-5 July, 2012.The objective of the Symposium was fracture research, interpreted broadly to include new engineering and structural mechanics treatments of damage development and crack growth, and also large-scale failure processes as exemplified by earthquake or landslide failures, ice shelf break-up, and hydraulic fracturing (natural, or for resource extraction or CO2 sequestration), as well as small-scale rupture phenomena in materials physics including, e.g., inception of shear banding, void growth, adhesion and decohesion in contact and friction, crystal dislocation processes, and atomic/electronic scale treatment of brittle crack tips and fundamental cohesive properties.Special emphasis was given to multiscale fracture description and new scale-bridging formulations capable to substantiate recent experiments and tailored to become the basis for innovative computationa...

  15. A Retrospection of Chaotic Phenomena in Electrical Systems

    Directory of Open Access Journals (Sweden)

    Umesh Kumar

    1998-01-01

    Full Text Available In the last decade new phenomena have been observed in all areas of non linear dynamics, principal among these being ‘Chaotic phenomena’. Chaos has been reported virtually from every scientific discipline. This paper summarizes a study of the chaotic phenomena in electrical systems and attempts to translate the mathematical ideas and techniques into language that engineers and applied scientists can use to study ‘Chaos’. Towards this end, the paper has summarized the study of chaos in several examples like Chua’s circuit family; Folded Torus circuit; non-autonomous circuits; switched capacitor circuits and hyper-chaos circuits. As observed in power systems, control systems and digital filters, chaos has been exhibited and shown on examples.

  16. Femtosecond laser induced phenomena in transparent solid materials

    DEFF Research Database (Denmark)

    Tan, D.Z.; Sharafudeen, K.N.; Yue, Yuanzheng

    2016-01-01

    parameters influencing the femtosecond laser interaction with transparent materials, and a brief description of various energy transfer processes in materials during femtosecond laser irradiation. The second part will give an account on various phenomena such as multiphoton excited upconversion luminescence......The interaction of intense femtosecond laser pulses with transparent materials is a topic that has caused great interest of scientists over the past two decades. It will continue to be a fascinating field in the coming years. This is because many challenging fundamental problems have not been......–matter interaction, and fabricate various integrated micro-devices. In recent years we have witnessed exciting development in understanding and applying femtosecond laser induced phenomena in transparent materials. The interaction of femtosecond laser pulses with transparent materials relies on non...

  17. On the fluctuation spectra of seismo-electromagnetic phenomena

    Directory of Open Access Journals (Sweden)

    M. Hayakawa

    2011-02-01

    Full Text Available In order to increase the credibility on the presence of electromagnetic phenomena associated with an earthquake, we have suggested the importance of the modulation (or fluctuation seen in the time-series data of any seismogenic effects. This paper reviews the fluctuation spectra of seismogenic phenomena in order to indicate the modulation mechanisms in the lithosphere, atmosphere and ionosphere/magnetosphere. Especially, the effect of Earth's tides in the lithosphere and the modulation in the atmosphere (acoustic and atmospheric gravity waves are discussed and this kind of fluctuation spectra would further provide essential information on the generation mechanisms of different seismogenic effects. Furthermore, the important role of the slope of fluctuation spectra is suggested in order to investigate the self-organized criticality before the lithospheric rupture and its associated effects in different regions such as the ionosphere.

  18. Autoscopic phenomena: case report and review of literature

    Directory of Open Access Journals (Sweden)

    Thomas Astrid

    2011-01-01

    Full Text Available Abstract Background Autoscopic phenomena are psychic illusory visual experiences consisting of the perception of the image of one's own body or face within space, either from an internal point of view, as in a mirror or from an external point of view. Descriptions based on phenomenological criteria distinguish six types of autoscopic experiences: autoscopic hallucination, he-autoscopy or heautoscopic proper, feeling of a presence, out of body experience, negative and inner forms of autoscopy. Methods and results We report a case of a patient with he-autoscopic seizures. EEG recordings during the autoscopic experience showed a right parietal epileptic focus. This finding confirms the involvement of the temporo-parietal junction in the abnormal body perception during autoscopic phenomena. We discuss and review previous literature on the topic, as different localization of cortical areas are reported suggesting that out of body experience is generated in the right hemisphere while he-autoscopy involves left hemisphere structures.

  19. Visible and invisible the wonders of light phenomena

    CERN Document Server

    Bisi, Olmes

    2015-01-01

    Light phenomena have intrigued humankind since prehistory. Think of the rainbow, a sunset on the sea, a game of shadows. Humans have always used light for their own needs, from cooking food to illuminating a room. However, light is not only limited to what we can see with our eyes. The invisible part of the electromagnetic spectrum is broad and dynamic. This book outlines the mysteries and wonders of electromagnetism, heat, and light. It also covers the history of our scientific understanding of light. The dark as well as the bright sides of light are fully explored in these pages, from their impact on our world to their use in cutting-edge technologies in a variety of fields. Numerous full-color images and drawings complement the text, and light phenomena are explained in a simple and engaging way.

  20. Exploiting transient phenomena for imaging with breath figures

    Science.gov (United States)

    Sasikumar, Harish; Varma, Manoj M.

    2017-02-01

    Breath figures refer to the patterns formed when vapor condenses into the liquid phase on a surface, revealing heterogeneities in topography or chemical composition. These figures are composed of micro-droplets, which scatter light and produce optical contrast. Differences in hydrophobicity imposed by surface features or contaminants result in a difference in micro-droplet densities, which has been used in applications such as substrate independent optical visualization of single layer graphene flakes. Here, we show that transient phenomena, such as the pinning transition of micro-droplets condensed over a polymer surface, can be used to enhance the optical contrast even when the time averaged difference in micro-droplet densities is not substantial. Thus, this work opens a new way of visualizing surface heterogeneities using transient phenomena occurring during condensation or evaporation of micro-droplets as opposed to only using time averaged differences in wettability due to the surface features.

  1. Introduction to symmetry-breaking phenomena in physics

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2001-01-01

    The notion of broken symmetries started slowly to emerge in the 19th century. The early studies of Pasteur on the parity asymmetry of life, the studies of Curie on piezoelectricity and on the symmetries of effects versus the symmetry of causes ( which clearly excluded spontaneous symmetry breaking), are important historical landmarks. However the possibility of spontaneous symmetry breaking within the usual principles of statistical mechanics, waited for the work of Peierls and Onsager. The whole theory of phase transitions and critical phenomena, as well as the construction of field theoretic models as long distance limit of yet unknown physics, relies nowadays on the concept of criticality associated to spontaneous symmetry breaking. The phenomena of Goldstone bosons, of Meissner-Higgs effects, are central to the theory of condensed matter as well as to particle physics. In cosmology as well, the various inflationary scenarios begin similarly with this same concept. The three lectures will provide a simple ...

  2. Navy Tactical Applications Guide. Volume 2. Environmental Phenomena and Effects

    Science.gov (United States)

    1979-01-01

    recorded nearly 1000 n mi to the south, at the Galapogos Islands (Hurd, op. cit.). Note that cloud lines and cloud patches can be seen on the east and west...continental and island barriers. Volume 2 shifts the emphasis from basic image analysis to a study of those phenomena and effects of particular...Pacific, in the vicinity of the Hawaiian Islands , is shown in Fig. IA-4a. Just south of Hawaii, a long band of cirrus with closely spaced transverse

  3. Transport Phenomena and Interfacial Kinetics in Multiphase Combustion Systems

    Science.gov (United States)

    1991-02-01

    Transport phenomena involving the motion of small (mass-)loaded aerosol systems, the literature of this particles suspended in gaseous media and theit depo...flowing nonisothermal gaseous would expect S k to have a similar influence on the media , simultaneously including for the first time the convective...is in the tihermal BL and its infuence on the total much larger than the characteristic time re- deposition rate is taken into account. Since the im

  4. Investigating paranormal phenomena: Functional brain imaging of telepathy

    OpenAIRE

    Venkatasubramanian Ganesan; Jayakumar Peruvumba; Nagendra Hongasandra; Nagaraja Dindagur; Deeptha R; Gangadhar Bangalore

    2008-01-01

    Aim: "Telepathy" is defined as "the communication of impressions of any kind from one mind to another, independently of the recognized channels of sense". Meta-analyses of "ganzfield" studies as well as "card-guessing task" studies provide compelling evidence for the existence of telepathic phenomena. The aim of this study was to elucidate the neural basis of telepathy by examining an individual with this special ability. Materials and Methods: Using functional MRI, we examined a famous "m...

  5. Emergence of dynamical order synchronization phenomena in complex systems

    CERN Document Server

    Manrubia, Susanna C; Zanette, Damián H

    2004-01-01

    Synchronization processes bring about dynamical order and lead tospontaneous development of structural organization in complex systemsof various origins, from chemical oscillators and biological cells tohuman societies and the brain. This book provides a review and adetailed theoretical analysis of synchronization phenomena in complexsystems with different architectures, composed of elements withperiodic or chaotic individual dynamics. Special attention is paid tostatistical concepts, such as nonequilibrium phase transitions, orderparameters and dynamical glasses.

  6. Ecological momentary assessment (EMA) of depression-related phenomena

    OpenAIRE

    Armey, Michael F.; SCHATTEN, HEATHER T.; Haradhvala, Natasha; Miller, Ivan W.

    2015-01-01

    Ecological momentary assessment (EMA) is one research method increasingly employed to better understand the processes that underpin depression and related phenomena. In particular, EMA is well suited to the study of affect (e.g., positive and negative affect), affective responses to stress (e.g., emotion reactivity), and behaviors (e.g., activity level, sleep) that are associated with depression. Additionally, EMA can provide insights into self-harm behavior (i.e. suicide and non-suicidal sel...

  7. Life and the Homeostatic Organization View of Biological Phenomena

    Directory of Open Access Journals (Sweden)

    Robert Arp

    2008-10-01

    Full Text Available p style="text-indent: 0cm; line-height: normal" class="MsoBodyTextIndent3"span style="font-size: 11pt"In this paper, I argue that starting with the organelles that constitute a cellmdash;and continuing up the hierarchy of components in processes and subsystems of an organismmdash;there exist clear instances of emergent biological phenomena that can be considered ldquo;livingrdquo; entities.spannbsp; /spanThese components and their attending processes are living emergent phenomena because of the way in which the components are organized to maintain homeostasis of the organism at the various levels in the hierarchy.spannbsp; /spanI call this view the emhomeostatic organization view/em (HOV of biological phenomena, and, as is shown, it comports well with the standard philosophical accounts of nomological (metaphysical emergence and representational (epistemological emergence.spannbsp; /spanTo proffer HOV, I describe properties of biological entities that include internal-hierarchical data exchange, data selectivity, informational integration, and environmental-organismic information exchange.spannbsp; /spanFurther, a distinction is drawn between particularized homeostasis and generalized homeostasis, and I argue that because the various processes and subsystems of an organism are functioning properly in their internal environments (particularized homeostasis, the organism is able to exist as a hierarchically-organized entity in some environment external to it (generalized homeostasis.spannbsp; /spanStated simply: that components of biological phenomena are organized to perform some function resulting in homeostasis marks them out to be living emergent entities distinguishable, in description and in reality, from the very physico-chemical processes of which they are composed./span/p p style="text-indent: 0cm; line-height: normal" class="MsoBodyTextIndent3"span style="font-size: 11pt"nbsp;/span/p

  8. Investigating Dissolution and Precipitation Phenomena with a Smartphone Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Arcia, Edgar

    2016-10-11

    A novel smartphone microscope can be used to observe the dissolution and crystallization of sodium chloride at a microscopic level. Observation of these seemingly simple phenomena through the microscope at 100× magnification can actually reveal some surprising behavior. These experiments offer the opportunity to discuss some basic concepts such as how the morphological features of the crystals dictates how the dissolution process proceeds, and how materials can be purified by re-crystallization techniques.

  9. Search for collective phenomena in relativistic nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Gutbrod, H.H.

    1980-06-01

    After some general introductory material, the weakness of the fireball/fire streak model is illustrated, and it is indicated that more complex models are both necessary and available. The single-particle spectra of nucleons, clusters, and pions are discussed, and then attention is focused on the fate of the target nucleus and possible evidence of collective phenomena. Finally, data on central collisions that reflect the nature of the energy flux in the target nucleus are discussed. 26 figures. (RWR)

  10. On slip flow and interfacial phenomena within superhydrophobic microchannels

    OpenAIRE

    O'Keeffe, Niall

    2012-01-01

    peer-reviewed The unique wetting properties of superhydrophobic (SH) surfaces have attracted a considerable interest in recent years. Their ability to repel liquids produces some remarkable characteristics such as spherical droplet formations with enhanced mobility, self cleaning properties, anti-sticking abilities and reduced drag on liquid flows. These wetting phenomena are directly attributed to the Cassie-Baxter wetting condition, where a SH surface supports a fluid on t...

  11. Fourth DOE Natural Phenomena Hazards Mitigation Conference: Proceedings. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    This conference allowed an interchange in the natural phenomena area among designers, safety professionals, and managers. The papers presented in Volume I of the proceedings are from sessions I - VIII which cover the general topics of: DOE standards, lessons learned and walkdowns, wind, waste tanks, ground motion, testing and materials, probabilistic seismic hazards, risk assessment, base isolation and energy dissipation, and lifelines and floods. Individual papers are indexed separately. (GH)

  12. Cross-Platform Programming Through System Identification

    OpenAIRE

    Kyriacou, T.; Nehmzow, U.; Igelsiais, R.; Billings, S. A.

    2005-01-01

    In this paper we present the Robot MODIC procedure (robot modelling, identification and characterisation) as a process which lets us identify the robot's motion through a nonlinear polynomial function (NARMAX). This procedure represents an important step towards a science of mobile robots, because the Narmax function can be analysed to understand the underlying phenomena governing the robot's behaviour and it also can be used to subsequently control the movement of the robot.\\ud As we'll see ...

  13. Neuropsychiatric phenomena in the medieval text Cantigas de Santa Maria.

    Science.gov (United States)

    Gondim, Francisco De Assis Aquino; Griesbach, Sarah H; Thomas, Florian P

    2015-05-12

    To discuss the neuropsychiatric phenomena described in Cantigas de Santa Maria (Canticles of St. Mary [CSM]). CSM is a collection of 427 canticles composed in Galician-Portuguese between 1252 and 1284 at the Court of King Alfonso X the Wise of Spain (1221-1284). The canticles (of which 9 are repeated) include devotional and liturgical poems and 353 narrative stories consisting mainly of depictions of Marian miracles. Most are set to music and many are illustrated. We reviewed the canticles for description of miracles and other neuropsychiatric phenomena. Two neurologists reached a consensus about the descriptions. Of the 353 miracles, 279 medically relevant facts (from 187 canticles) and 25 instances of resurrection were reported. Possible neuropsychiatric conditions were described in 98 canticles. Physicians were mentioned in 16 narratives. The most common neurologic conditions detailed were blindness (n = 17), dystonia, weakness, and deformities (n = 20). Other common conditions included psychosis (n = 15), speech disorder/deaf-mutism (n = 12), infections (n = 15), sexual dysfunction/infertility/obstetrical-gynecologic issues (n = 18), head trauma (n = 5), ergotism/St. Anthony's fire (n = 7), and others. There were 9 instances of prodromic mystical experiences/hallucinations heralding death. While limited by retrospection and interpretation of neuropsychiatric phenomena in the medieval context, these short accounts are among the first descriptions of neuropsychiatric conditions in early Portuguese/Galician. They reflect how medieval societies used rational and irrational approaches to understand occurrences in their lives. © 2015 American Academy of Neurology.

  14. 8th International symposium on transport phenomena in combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The 8th International Symposium on Transport Phenomena in Combustion will be held in San Francisco, California, U.S.A., July 16-20, 1995, under the auspices of the Pacific Center of Thermal-Fluids Engineering. The purpose of the Symposium is to provide a forum for researchers and practitioners from around the world to present new developments and discuss the state of the art and future directions and priorities in the areas of transport phenomena in combustion. The Symposium is the eighth in a series; previous venues were Honolulu 1985, Tokyo 1987, Taipei 1988, Sydney 1991, Beijing 1992, Seoul 1993 and Acapulco 1994, with emphasis on various aspects of transport phenomena. The current Symposium theme is combustion. The Symposium has assembled a balanced program with topics ranging from fundamental research to contemporary applications of combustion theory. Invited keynote lecturers will provide extensive reviews of topics of great interest in combustion. Colloquia will stress recent advances and innovations in fire spread and suppression, and in low NO{sub x} burners, furnaces, boilers, internal combustion engines, and other practical combustion systems. Finally, numerous papers will contribute to the fundamental understanding of complex processes in combustion. This document contains abstracts of papers to be presented at the Symposium.

  15. Toward a CFD-grade database addressing LWR containment phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Paladino, Domenico, E-mail: domenico.paladino@psi.ch [Laboratory for Thermal-Hydraulics, Nuclear Energy and Safety Department, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Andreani, Michele; Zboray, Robert; Dreier, Joerg [Laboratory for Thermal-Hydraulics, Nuclear Energy and Safety Department, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The SETH-2 PANDA tests have supplied data with CFD-grade on plumes and jets at large-scale. Black-Right-Pointing-Pointer The PANDA tests have contributed to the understanding of phenomena with high safety relevance for LWRs. Black-Right-Pointing-Pointer The analytical activities related increased confidence in the use of various computational tools for safety analysis. - Abstract: The large-scale, multi-compartment PANDA facility (located at PSI in Switzerland) is one of the state-of-the-art facilities which is continuously upgraded to progressively match the requirements of CFD-grade experiments. Within the OECD/SETH projects, the PANDA facility has been used for the creation of an experimental database on basic containment phenomena e.g. gas mixing, transport, stratification, condensation. In the PANDA tests, these phenomena are driven by large scale plumes or jets. In the paper is presented a selection of the SETH PANDA experimental results. Examples of analytical activities performed at PSI using the GOTHIC, CFX-4 and CFX-5 codes will be used to illustrate how the spatial and temporal resolutions of the measurement grid in PANDA tests are adequate for CFD code (and advanced containment codes) assessment and validation purposes.

  16. Visual and somatosensory phenomena following cerebral venous infarction.

    Science.gov (United States)

    Loster-Niewińska, Aleksandra; Dziadkowiak, Edyta; Chojdak-Łukasiewicz, Justyna; Zimny, Anna; Paradowski, Bogusław

    2017-07-14

    The most frequent clinical presentation of occipital or visual tract lesion is hemianopsia or quadrantanopsia. However, damage to the primary or secondary visual cortex can also manifest as visual hallucinations (photopsiae or complex phenomena). We report visual and somatosensory phenomena following cerebral venous infarction based on a study of a patient with a history of recent head injury. We report a 61-year-old man with a history of recent head injury presented with a headache of two weeks duration. He was complaining of transient visual abnormalities, which he described as impaired ability to recognize faces, dark spots moving in the visual field and distorted contours of an objects. Clinical examination showed a balance disorder with no evidence of visual deficit. During further observation the patient started to experience more complex visual and sensory phenomena of: waving of the ceiling, clouds that he could form and feel, he had an impression of incorrect sizes of given objects, he could see a nonexistent pack of cigarettes and the character from the arcade game Pac-Man "eating" an existing drip stand. The patient mentioned above possessing simple and complex visual and somatosensory hallucinations and illusions in the course of venous stroke. A possible mechanism involves irritation of cortical centers responsible for visual processing. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  17. Transport phenomena and drying of solids and particulate materials

    CERN Document Server

    Lima, AG

    2014-01-01

    The purpose of this book, Transport Phenomena and Drying of Solids and Particulate Materials, is to provide a collection of recent contributions in the field of heat and mass transfer, transport phenomena, drying and wetting of solids and particulate materials. The main benefit of the book is that it discusses some of the most important topics related to the heat and mass transfer in solids and particulate materials. It includes a set of new developments in the field of basic and applied research work on the physical and chemical aspects of heat and mass transfer phenomena, drying and wetting processes, namely, innovations and trends in drying science and technology, drying mechanism and theory, equipment, advanced modelling, complex simulation and experimentation. At the same time, these topics will be going to the encounter of a variety of scientific and engineering disciplines. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional c...

  18. Superfluous neuroscience information makes explanations of psychological phenomena more appealing.

    Science.gov (United States)

    Fernandez-Duque, Diego; Evans, Jessica; Christian, Colton; Hodges, Sara D

    2015-05-01

    Does the presence of irrelevant neuroscience information make explanations of psychological phenomena more appealing? Do fMRI pictures further increase that allure? To help answer these questions, 385 college students in four experiments read brief descriptions of psychological phenomena, each one accompanied by an explanation of varying quality (good vs. circular) and followed by superfluous information of various types. Ancillary measures assessed participants' analytical thinking, beliefs on dualism and free will, and admiration for different sciences. In Experiment 1, superfluous neuroscience information increased the judged quality of the argument for both good and bad explanations, whereas accompanying fMRI pictures had no impact above and beyond the neuroscience text, suggesting a bias that is conceptual rather than pictorial. Superfluous neuroscience information was more alluring than social science information (Experiment 2) and more alluring than information from prestigious "hard sciences" (Experiments 3 and 4). Analytical thinking did not protect against the neuroscience bias, nor did a belief in dualism or free will. We conclude that the "allure of neuroscience" bias is conceptual, specific to neuroscience, and not easily accounted for by the prestige of the discipline. It may stem from the lay belief that the brain is the best explanans for mental phenomena.

  19. Cognition and belief in paranormal phenomena: gestalt/feature-intensive processing theory and tendencies toward ADHD, depression, and dissociation.

    Science.gov (United States)

    Sharps, Matthew J; Matthews, Justin; Asten, Janet

    2006-11-01

    Belief in paranormal phenomena and cryptids--unknown animals such as Bigfoot--may predispose individuals to interpret real-world objects and events in the same way that eyewitness identification can be biased by unrelated information (P. James and N. Thorpe, 1999). Psychological tendencies toward attention deficit hyperactivity disorder (ADHD), dissociation, and depression, even at subclinical levels, may be associated systematically with particular paranormal or cryptozoological beliefs. The authors evaluated these psychological tendencies using the Conners Adult ADHD Rating Scales (C. K. Conners, D. Erhardt, and E. Sparrow, 1999), the Dissociative Experiences Scale (L. Coleman & J. Clark, 1999), and the Beck Depression Inventory-II (A. T. Beck, 1996). They performed regression analyses against beliefs in ghosts, unidentified flying objects (UFOs), extrasensory perception (ESP), astrology, and cryptids. ADHD, dissociation, and depression were associated with enhanced tendencies toward paranormal and cryptozoological beliefs, although participants who believed in each of the phenomena differed from one another in predictable and psychologically distinguishable ways. Cognitively biasing influences of preexisting psychological tendencies may predispose individuals to specific perceptual and cognitive errors during confrontation of real-world phenomena.

  20. Identification device

    Science.gov (United States)

    Lin, Jian-Shian; Su, Chih-Chieh; Chou, Ta-Hsin; Wu, Mount-Learn; Lai, Chieh-Lung; Hsu, Che-Lung; Lan, Hsiao-Chin; Huang, Hung-I.; Liu, Yung-Chih; Tu, Zong-Ru; Lee, Chien-Chieh; Chang, Jenq-Yang

    2007-09-01

    In this Letter, the identification device disclosed in the present invention is comprised of: a carrier and a plurality of pseudo-pixels; wherein each of the plural pseudo-pixels is formed on the carrier and is further comprised of at least a light grating composed of a plurality of light grids. In a preferred aspect, each of the plural light grids is formed on the carrier while spacing from each other by an interval ranged between 50nm and 900nm. As the aforesaid identification device can present specific colors and patterns while it is being viewed by naked eye with respect to a specific viewing angle, the identification device is preferred for security and anti-counterfeit applications since the specific colors and patterns will become invisible when it is viewed while deviating from the specific viewing angle.

  1. Modelling transport phenomena in a multi-physics context

    Energy Technology Data Exchange (ETDEWEB)

    Marra, Francesco [Dipartimento di Ingegneria Chimica e Alimentare - Università degli studi di Salerno Via Ponte Don Melillo - 84084 Fisciano SA (Italy)

    2015-01-22

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

  2. Switching Phenomena in a System with No Switches

    Science.gov (United States)

    Preis, Tobias; Stanley, H. Eugene

    2010-02-01

    It is widely believed that switching phenomena require switches, but this is actually not true. For an intriguing variety of switching phenomena in nature, the underlying complex system abruptly changes from one state to another in a highly discontinuous fashion. For example, financial market fluctuations are characterized by many abrupt switchings creating increasing trends ("bubble formation") and decreasing trends ("financial collapse"). Such switching occurs on time scales ranging from macroscopic bubbles persisting for hundreds of days to microscopic bubbles persisting only for a few seconds. We analyze a database containing 13,991,275 German DAX Future transactions recorded with a time resolution of 10 msec. For comparison, a database providing 2,592,531 of all S&P500 daily closing prices is used. We ask whether these ubiquitous switching phenomena have quantifiable features independent of the time horizon studied. We find striking scale-free behavior of the volatility after each switching occurs. We interpret our findings as being consistent with time-dependent collective behavior of financial market participants. We test the possible universality of our result by performing a parallel analysis of fluctuations in transaction volume and time intervals between trades. We show that these financial market switching processes have properties similar to those of phase transitions. We suggest that the well-known catastrophic bubbles that occur on large time scales—such as the most recent financial crisis—are no outliers but single dramatic representatives caused by the switching between upward and downward trends on time scales varying over nine orders of magnitude from very large (≈102 days) down to very small (≈10 ms).

  3. Nanophenomena at surfaces fundamentals of exotic condensed matter phenomena

    CERN Document Server

    Michailov, Michail

    2011-01-01

    This book presents the state of the art in nanoscale surface physics. It outlines contemporary trends in the field covering a wide range of topical areas: atomic structure of surfaces and interfaces, molecular films and polymer adsorption, biologically inspired nanophysics, surface design and pattern formation, and computer modeling of interfacial phenomena. Bridging 'classical' and 'nano' concepts, the present volume brings attention to the physical background of exotic condensed-matter properties. The book is devoted to Iwan Stranski and Rostislaw Kaischew, remarkable scientists, who played

  4. Fundamentals of Cryobiology Physical Phenomena and Mathematical Models

    CERN Document Server

    Zhmakin, Alexander I

    2009-01-01

    The book gives a summary of the state-of-the-art of cryobiology and its applications. The accent is on the underlying physical phenomena, which are common in such opposite applications as cryosurgery and cryoconservation, and the corresponding mathematical models, including numerical ones. The treatment of some more special issues is moved to the appendices. The glossary contains definitions and explanations of the major entities. All the topics considered are well referenced. The book is useful to both biologists and physicits of different level including practioners and graduate students.

  5. Searches for New Phenomena with the ATLAS detector

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2017-01-01

    Many theories beyond the Standard Model (BSM) predict new phenomena accessible by the LHC which prevent the need of fine-tuning of the Higgs Boson mass or expand the gauge sectors of the SM to name a few. Searches for new physics models are performed using the ATLAS experiment at the LHC focusing on exotic signatures that can be realized in serval BSM theories. The results reported do not touch on Dark Matter signatures and use the pp collision data sample collected in 2015 and 2016 by the ATLAS detector at the LHC with a centre-of-mass energy of 13 TeV.

  6. Imaging episodic memory: implications for cognitive theories and phenomena.

    Science.gov (United States)

    Nyberg, L

    1999-01-01

    Functional neuroimaging studies are beginning to identify neuroanatomical correlates of various cognitive functions. This paper presents results relevant to several theories and phenomena of episodic memory, including component processes of episodic retrieval, encoding specificity, inhibition, item versus source memory, encoding-retrieval overlap, and the picture-superiority effect. Overall, by revealing specific activation patterns, the results provide support for existing theoretical views and they add some unique information which may be important to consider in future attempts to develop cognitive theories of episodic memory.

  7. Introduction to wave scattering, localization, and mesoscopic phenomena

    CERN Document Server

    Sheng, Ping

    1995-01-01

    This book gives readers a coherent picture of waves in disordered media, including multiple scattered waves. The book is intended to be self-contained, with illustrated problems and solutions at the end of each chapter to serve the double purpose of filling out the technical and mathematical details and giving the students exercises if used as a course textbook.The study of wave behavior in disordered media has applications in:Condensed matter physics (semi and superconductor nanostructures and mesoscopic phenomena)Materials science/analytical chemistry (analysis of composite and crystalline structures and properties)Optics and electronics (microelectronic and optoelectronic devices)Geology (seismic exploration of Earths subsurface)

  8. Non-Abelian phenomena on D-branes

    CERN Document Server

    Myers, R

    2003-01-01

    A remarkable feature of D-branes is the appearance of a non-Abelian gauge theory in the description of several (nearly) coincident branes. This non-Abelian structure plays an important role in realizing various geometric effects with D-branes. In particular, the branes' transverse displacements are described by matrix-valued scalar fields and so noncommutative geometry naturally appears in this framework. I review the action governing this non-Abelian theory, as well as various related physical phenomena such as the dielectric effect, giant gravitons and fuzzy funnels.

  9. Adhesion and Disintegration Phenomena on Fractal Agar Gel Surfaces.

    Science.gov (United States)

    Kudo, Ayano; Sato, Marika; Sawaguchi, Haruna; Hotta, Jun-Ichi; Mayama, Hiroyuki; Nonomura, Yoshimune

    2016-11-01

    In the present study, mechanical phenomena on fractal agar gel were analyzed to understand the interfacial properties of hydrophilic biosurfaces. The evaluation of adhesion strength between the fractal agar gel surfaces showed that the fractal structure inhibits the adhesion between the agar gel surfaces. In addition, when the disintegration behavior of an agar gel block was observed between fractal agar gel substrates, the rough structure prevented the sliding of an agar gel block. These findings are useful for understanding the biological significance of rough structure on the biological surfaces.

  10. Analyzing simple pendulum phenomena with a smartphone acceleration sensor

    Science.gov (United States)

    Vogt, Patrik; Kuhn, Jochen

    2012-10-01

    This paper describes a further experiment using the acceleration sensor of a smartphone. For a previous column on this topic, including the description of the operation and use of the acceleration sensor, see Ref. 1. In this contribution we focus on analyzing simple pendulum phenomena. A smartphone is used as a pendulum bob, and SPARKvue2 software is used in conjunction with an iPhone or an iPod touch, or the Accelogger3 app for an Android device. As described in Ref. 1, the values measured by the smartphone are subsequently exported to a spreadsheet application (e.g., MS Excel) for analysis.

  11. Interfacial jetting phenomena induced by focused surface vibrations.

    Science.gov (United States)

    Tan, Ming K; Friend, James R; Yeo, Leslie Y

    2009-07-10

    We exploit large accelerations associated with surface acoustic waves to drive an extraordinary fluid jetting phenomena. Laterally focusing the acoustic energy to a small region beneath a drop placed on the surface causes rapid interfacial destabilization. Above a critical Weber number We, an elongated jet forms for drops with dimensions greater than the fluid sound wavelength. Further increases in We lead to single droplet pinch-off and subsequent axisymmetric breakup to form multiple droplets. A simple equation based on a momentum balance is derived to predict the jet velocity.

  12. Investigation of surface tension phenomena using the KC-135 aircraft

    Science.gov (United States)

    Alter, W. S.

    1982-01-01

    The microgravity environment of the KC-135 aircraft was utilized in three experiments designed to determine the following: (1) the feasibility of measuring critical wetting temperatures; (2) the effectiveness of surface tension as a means of keeping the cushioning heat transfer liquid in the furnace during ampoule translation; and (3) whether a non-wetting fluid would separate from the ampoule wall under low gravity conditions. This trio of investigations concerning surface phenomena demonstrates the effectiveness of the KC-135 as a microgravity research environment for small-scale, hand-held experiments.

  13. Movements of molecular motors: Ratchets, random walks and traffic phenomena

    Science.gov (United States)

    Klumpp, Stefan; Nieuwenhuizen, Theo M.; Lipowsky, Reinhard

    2005-10-01

    Processive molecular motors which drive the traffic of organelles in cells move in a directed way along cytoskeletal filaments. On large time scales, they perform motor walks, i.e., peculiar random walks which arise from the repeated unbinding from and rebinding to filaments. Unbound motors perform Brownian motion in the surrounding fluid. In addition, the traffic of molecular motors exhibits many cooperative phenomena. In particular, it faces similar problems as the traffic on streets such as the occurrence of traffic jams and the coordination of (two-way) traffic. These issues are studied here theoretically using lattice models.

  14. Subspace Identification

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2002-01-01

    Subspace identification algorithms are user friendly, numerical fast and stable and they provide a good consistent estimate of the deterministic part of a system. The weak point is the stochastic part. The uncertainty on this part is discussed below and methods to reduce it is derived....

  15. Subspace Identification

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2001-01-01

    Subspace identification algorithms are user friendly, numerical fast and stable and they provide a good consistent estimate of the deterministic part of a system. The weak point is the stochastic part. The uncertainty on this part is discussed below and methods to reduce it is derived....

  16. 78 FR 8202 - Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy...

    Science.gov (United States)

    2013-02-05

    ... Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels; Notice of Meeting The Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels will hold a meeting on...

  17. Spooky Phenomena in Two-Photon Coherent Atomic Absorption

    Science.gov (United States)

    Li, Ming-Chiang

    2006-03-01

    Physical processes on two-photon coherent atomic absorption of multiple laser beams were discussed more than twenty five years ago. These processes can be divided into two distinct groups. In the first group, laser beams are from a single source^1,2, and in the second group laser beams are from two different sources^3. Several experiments in the first group were carried out and have led to the 2005 Nobel Prize in physics. The second group is more interesting. Atoms are in random motion and two photons are from different sources. Classically, it is impossible for atoms to transit coherently in the absorption process, but quantum mechanically, such a transition is possible and that is one of the spooky phenomena in quantum mechanic. To assure the coherent transition, each photon as absorbed by the atom must have two possible paths of choices. If one photon has the choice and other one is not, then the atomic transitions cannot be coherent. The present talk will review various spooky phenomena associated with two-photon coherent atomic absorption, and will clarify some theoretical misunderstandings regarding these interesting transitions. Reference: *M. C. Li, Nuovo Cimento 39B (1977) 165. *M. C. Li, Phys. Rev. A 16 (1977) 2480. *M. C. Li, Phys. Rev. A 22 (1980) 1323.

  18. Impact of measurable physical phenomena on contact thermal comfort

    Directory of Open Access Journals (Sweden)

    Fojtlín Miloš

    2017-01-01

    Full Text Available Cabin HVAC (Heating Ventilation and Air-conditioning systems have become an essential part of personal vehicles as demands for comfortable transport are still rising. In fact, 85 % of the car trips in Europe are shorter than 18 km and last only up to 30 minutes. Under such conditions, the HVAC unit cannot often ensure desired cabin environment and passengers are prone to experience thermal stress. For this reason, additional comfort systems, such as heated or ventilated seats, are available on the market. However, there is no straightforward method to evaluate thermal comfort at the contact surfaces nowadays. The aim of this work is to summarise information about heated and ventilated seats. These technologies use electrical heating and fan driven air to contact area in order to achieve enhanced comfort. It is also expected, that such measures may contribute to lower energy consumption. Yet, in real conditions it is almost impossible to measure the airflow through the ventilated seat directly. Therefore, there is a need for an approach that would correlate measurable physical phenomena with thermal comfort. For this reason, a method that exploits a measurement of temperatures and humidity at the contact area is proposed. Preliminary results that correlate comfort with measurable physical phenomena are demonstrated.

  19. Dynamic phenomena and human activity in an artificial society

    Science.gov (United States)

    Grabowski, A.; Kruszewska, N.; Kosiński, R. A.

    2008-12-01

    We study dynamic phenomena in a large social network of nearly 3×104 individuals who interact in the large virtual world of a massive multiplayer online role playing game. On the basis of a database received from the online game server, we examine the structure of the friendship network and human dynamics. To investigate the relation between networks of acquaintances in virtual and real worlds, we carried out a survey among the players. We show that, even though the virtual network did not develop as a growing graph of an underlying network of social acquaintances in the real world, it influences it. Furthermore we find very interesting scaling laws concerning human dynamics. Our research shows how long people are interested in a single task and how much time they devote to it. Surprisingly, exponent values in both cases are close to -1 . We calculate the activity of individuals, i.e., the relative time daily devoted to interactions with others in the artificial society. Our research shows that the distribution of activity is not uniform and is highly correlated with the degree of the node, and that such human activity has a significant influence on dynamic phenomena, e.g., epidemic spreading and rumor propagation, in complex networks. We find that spreading is accelerated (an epidemic) or decelerated (a rumor) as a result of superspreaders’ various behavior.

  20. Selected social phenomena following the extraction of mineral resources

    Directory of Open Access Journals (Sweden)

    Kocoń Paweł

    2014-12-01

    Full Text Available The author, due to the didactic needs and seeing a small gap in the way of presenting scientific data on the area of social science, have decided to present this work hoping that it will influence on widening both the social science and geography knowledge of the recipients, having connected the development and creation of certain social phenomena with particular economic activity, that is, the extraction of mineral resources. The aim of the hereby text is to present such social phenomena like organizational culture, discourse and social capital. The notions mentioned above ought to concern not only students, but also the specialists and scientists dealing with any of those two fields, as it seems prudent to follow the path of closely connecting two major issues emerging from two distinctively separate areas of science if that may help to better understand how such mixture influence people’s behaviour and allows to draw conclusion on the effect such actions may have on community or society. Moreover, such fact was prior for the author to decide to work on the problem of protests for mining in the future. On the other hand, the article may help in organizing the process of exploitation of mineral resources in the different organizations involved in this type of activity.

  1. Different Selection Pressures Give Rise to Distinct Ethnic Phenomena

    Science.gov (United States)

    Moya, Cristina; Boyd, Robert

    2015-01-01

    Many accounts of ethnic phenomena imply that processes such as stereotyping, essentialism, ethnocentrism, and intergroup hostility stem from a unitary adaptation for reasoning about groups. This is partly justified by the phenomena’s co-occurrence in correlational studies. Here we argue that these behaviors are better modeled as functionally independent adaptations that arose in response to different selection pressures throughout human evolution. As such, different mechanisms may be triggered by different group boundaries within a single society. We illustrate this functionalist framework using ethnographic work from the Quechua-Aymara language boundary in the Peruvian Altiplano. We show that different group boundaries motivate different ethnic phenomena. For example, people have strong stereotypes about socioeconomic categories, which are not cooperative units, whereas they hold fewer stereotypes about communities, which are the primary focus of cooperative activity. We also show that, despite the cross-cultural importance of ethnolinguistic boundaries, the Quechua-Aymara linguistic distinction does not strongly motivate any of these intergroup processes. PMID:25731969

  2. Resonant and secular phenomena in the libration of the Moon

    Science.gov (United States)

    Barkin, Yu. V.

    1993-10-01

    Principal and subtle regularities, resonant and secular phenomena in the rotational motion of the Moon are investigated on the basis of the analytical solution of a model problem, in which the Moon and the Earth are considered as absolute rigid nonspherical bodies, and the Sun and the other planets are treated as material points. The orbital motion of all these bodies are considered as known and described by analytical theories. An analytical solution of the problem has been built on the basis of the canonical equations of the rotational motion of the Moon in the Andoyer's variables using the method of constructing conditionlly-periodic solutions of an Hamiltonian system depending upon a small parameter, and researching general solutions in their neighbourhood. The solution so constructed is used for analyzing the principal and subtle regularities, resonance phenomena in the rotational motion of the Moon, i.e. for studying the principal departure from the Cassini's laws in the rotational motion of the Moon due to the long periodic orbital perturbations of Moon and Sun.

  3. Emergent ultrafast phenomena in correlated oxides and heterostructures

    Science.gov (United States)

    Gandolfi, M.; Celardo, G. L.; Borgonovi, F.; Ferrini, G.; Avella, A.; Banfi, F.; Giannetti, C.

    2017-03-01

    The possibility of investigating the dynamics of solids on timescales faster than the thermalization of the internal degrees of freedom has disclosed novel non-equilibrium phenomena that have no counterpart at equilibrium. Transition metal oxides (TMOs) provide an interesting playground in which the correlations among the charges in the metal d-orbitals give rise to a wealth of intriguing electronic and thermodynamic properties involving the spin, charge, lattice and orbital orders. Furthermore, the physical properties of TMOs can be engineered at the atomic level, thus providing the platform to investigate the transport phenomena on timescales of the order of the intrinsic decoherence time of the charge excitations. Here, we review and discuss three paradigmatic examples of transient emerging properties that are expected to open new fields of research: (i) the creation of non-thermal magnetic states in spin-orbit Mott insulators; (ii) the possible exploitation of quantum paths for the transport and collection of charge excitations in heterostructures; (iii) the transient wave-like behavior of the temperature field in strongly anisotropic TMOs.

  4. Impact of measurable physical phenomena on contact thermal comfort

    Science.gov (United States)

    Fojtlín, Miloš; Pokorný, Jan; Fišer, Jan; Toma, Róbert; Tuhovčák, Ján

    Cabin HVAC (Heating Ventilation and Air-conditioning) systems have become an essential part of personal vehicles as demands for comfortable transport are still rising. In fact, 85 % of the car trips in Europe are shorter than 18 km and last only up to 30 minutes. Under such conditions, the HVAC unit cannot often ensure desired cabin environment and passengers are prone to experience thermal stress. For this reason, additional comfort systems, such as heated or ventilated seats, are available on the market. However, there is no straightforward method to evaluate thermal comfort at the contact surfaces nowadays. The aim of this work is to summarise information about heated and ventilated seats. These technologies use electrical heating and fan driven air to contact area in order to achieve enhanced comfort. It is also expected, that such measures may contribute to lower energy consumption. Yet, in real conditions it is almost impossible to measure the airflow through the ventilated seat directly. Therefore, there is a need for an approach that would correlate measurable physical phenomena with thermal comfort. For this reason, a method that exploits a measurement of temperatures and humidity at the contact area is proposed. Preliminary results that correlate comfort with measurable physical phenomena are demonstrated.

  5. Modeling as an Anchoring Scientific Practice for Explaining Friction Phenomena

    Science.gov (United States)

    Neilson, Drew; Campbell, Todd

    2017-12-01

    Through examining the day-to-day work of scientists, researchers in science studies have revealed how models are a central sense-making practice of scientists as they construct and critique explanations about how the universe works. Additionally, they allow predictions to be made using the tenets of the model. Given this, alongside research suggesting that engaging students in developing and using models can have a positive effect on learning in science classrooms, the recent national standards documents in science education have identified developing and using models as an important practice students should engage in as they apply and refine their ideas with peers and teachers in explaining phenomena or solving problems in classrooms. This article details how students can be engaged in developing and using models to help them make sense of friction phenomena in a high school conceptual physics classroom in ways that align with visions for teaching and learning outlined in the Next Generation Science Standards. This particular unit has been refined over several years to build on what was initially an inquiry-based unit we have described previously. In this latest iteration of the friction unit, students developed and refined models through engaging in small group and whole class discussions and investigations.

  6. Towards an understanding of flows in avalanche transport phenomena

    Science.gov (United States)

    Jin, Suying; Ramadan, Nikolas; van Compernolle, Bart; Poulos, Matt J.; Morales, George J.

    2017-10-01

    Recent heat transport experiments conducted in the Large Plasma Device (LAPD) at UCLA, studying avalanche phenomena at steep cross-magnetic field pressure gradients, suggest that flows play a critical role in the evolution of transport phenomena, motivating further characterization. A ring shaped electron beam source injects sub-ionization energy electrons along the strong background magnetic field within a larger quiescent plasma, creating a hollow, high pressure filament. Two distinct regimes are observed as the density decays; the first characterized by multiple small avalanches producing sudden relaxations of the pressure profile which then recovers under continued heating, and the second signaled by a permanent collapse of the density profile after a global avalanche event, then dominated by drift-Alfven waves. The source is modified from previous experiments to gain active control of the flows by controlling the bias between the emitting ring and surrounding carbon masks. The results of flow measurements obtained using a Mach probe and Langmuir/emissive probe are here presented and compared. An analytical model for the behavior of the electron beam source is also in development. Sponsored by NSF Grant 1619505 and by DOE/NSF at BaPSF.

  7. GLASS MELTING PHENOMENA, THEIR ORDERING AND MELTING SPACE UTILISATION

    Directory of Open Access Journals (Sweden)

    Němec L.

    2013-12-01

    Full Text Available Four aspects of effective glass melting have been defined – namely the fast kinetics of partial melting phenomena, a consideration of the melting phenomena ordering, high utilisation of the melting space, and effective utilisation of the supplied energy. The relations were defined for the specific melting performance and specific energy consumption of the glass melting process which involve the four mentioned aspects of the process and indicate the potentials of effective melting. The quantity “space utilisation” has been treated in more detail as an aspect not considered in practice till this time. The space utilisation was quantitatively defined and its values have been determined for the industrial melting facility by mathematical modelling. The definitions of the specific melting performance and specific energy consumption have been used for assessment of the potential impact of a controlled melt flow and high space utilisation on the melting process efficiency on the industrial scale. The results have shown that even the partial control of the melt flow, leading to the partial increase of the space utilisation, may considerably increase the melting performance, whereas a decrease of the specific energy consumption was determined to be between 10 - 15 %.

  8. Patterns of Work Identification

    Science.gov (United States)

    Hebden, J. E.

    1975-01-01

    The paper examines ways in which the concept of work identification may provide a useful means of delineating the boundaries of occupational groups. Two kinds of identification are discussed: identification with employing organizations and identification with occupation.

  9. Micro ball lightning and its accelerator proposed to control natural phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Taka-aki [Hokkaido Univ., Sapporo (Japan)

    2002-09-01

    Micro Ball Lightning (BL) was recently discovered in laboratory. It was also observed during natural phenomena such as volcanic eruption and earthquake. This paper described a brief review of micro BL observed in laboratory as well as during two natural phenomena. Being based on a hypothesis of that those natural phenomena could have been caused by explosive reactions of micro BL, a potential accelerator of micro BL was proposed to control the natural phenomena. (author)

  10. Micro ball lightning and its accelerator proposed to control natural phenomena

    CERN Document Server

    Matsumoto, T A

    2002-01-01

    Micro Ball Lightning (BL) was recently discovered in laboratory. It was also observed during natural phenomena such as volcanic eruption and earthquake. This paper described a brief review of micro BL observed in laboratory as well as during two natural phenomena. Being based on a hypothesis of that those natural phenomena could have been caused by explosive reactions of micro BL, a potential accelerator of micro BL was proposed to control the natural phenomena. (author)

  11. The Role of Perspective Taking in How Children Connect Reference Frames When Explaining Astronomical Phenomena

    Science.gov (United States)

    Plummer, Julia D.; Bower, Corinne A.; Liben, Lynn S.

    2016-01-01

    This study investigates the role of perspective-taking skills in how children explain spatially complex astronomical phenomena. Explaining many astronomical phenomena, especially those studied in elementary and middle school, requires shifting between an Earth-based description of the phenomena and a space-based reference frame. We studied 7- to…

  12. Local probe investigation of emergent phenomena in complex oxide heterointerfaces

    Science.gov (United States)

    Huang, Mengchen

    Complex oxide heterointerfaces exhibit rich physics as well as many veiled puzzles. LaAlO3/SrTiO3 (LAO/STO) is one of the prototype of such heterointerfaces. In 2004, Ohtomo and Hwang first reported a conducing interface emerged between perovskite oxide insulators LaAlO3 and SrTiO3. Following this seminal discovery, many emergent phenomena like metal-insulator transition, piezoresponse, superconductivity, magnetism, strong spin-orbit coupling and coexistence of superconductivity and magnetism were reported in the fascinating LAO/STO system. However, the origin of the conducting interface is still the subject of intense debate, and the physics behind these emergent phenomena remains a wild space to be explored. My Ph.D. study focused on the emergent phenomena in LAO/STO by using "local probes" -- nanostructures created by conductive atomic force microscope (c-AFM) lithography and the AFM itself. I used piezoresponse force microscope (PFM) to study the electromechanical response in LAO/STO and developed a high-resolution, non-destructive PFM imaging technique to visualize nanostructures at LAO/STO interface. The results indicate that the PFM signal is related to a carrier density mediated interfacial lattice distortion, and surface adsorbates can affect the PFM signal via coupling to the electrons at the interface. I integrated graphene on LAO/STO, created field-effect devices in graphene/LAO/STO and collaborated with Dr. Giriraj Jnawali to investigate the transport properties. The high quality single layer graphene on LAO/STO exhibited the half-integer quantum Hall effect and room temperature weak antilocalization behavior. I performed transport measurements in (110)-oriented LAO/STO to investigate anisotropic quasi one-dimensional superconductivity in nanowires. Based on the results I proposed a plausible explanation related to the Lifshitz transition and anisotropic band structures of nanowires in (110)-oriented LAO/STO. Co-worked with Dr. Keith Brown, I studied

  13. The Fragility of Interdependency: Coupled Networks Switching Phenomena

    Science.gov (United States)

    Stanley, H. Eugene

    2013-03-01

    Recent disasters ranging from abrupt financial ``flash crashes'' and large-scale power outages to sudden death among the elderly dramatically exemplify the fact that the most dangerous vulnerability is hiding in the many interdependencies among different networks. In the past year, we have quantified failures in model of interconnected networks, and demonstrated the need to consider mutually dependent network properties in designing resilient systems. Specifically, we have uncovered new laws governing the nature of switching phenomena in coupled networks, and found that phenomena that are continuous ``second order'' phase transitions in isolated networks become discontinuous abrupt ``first order'' transitions in interdependent networks [S. V. Buldyrev, R. Parshani, G. Paul, H. E. Stanley, and S. Havlin, ``Catastrophic Cascade of Failures in Interdependent Networks,'' Nature 464, 1025 (2010); J. Gao, S. V. Buldyrev, H. E. Stanley, and S. Havlin, ``Novel Behavior of Networks Formed from Interdependent Networks,'' Nature Physics 8, 40 (2012). We conclude by discussing the network basis for understanding sudden death in the elderly, and the possibility that financial ``flash crashes'' are not unlike the catastrophic first-order failure incidents occurring in coupled networks. Specifically, we study the coupled networks that are responsible for financial fluctuations. It appears that ``trend switching phenomena'' that we uncover are remarkably independent of the scale over which they are analyzed. For example, we find that the same laws governing the formation and bursting of the largest financial bubbles also govern the tiniest finance bubbles, over a factor of 1,000,000,000 in time scale [T. Preis, J. Schneider, and H. E. Stanley, ``Switching Processes in Financial Markets,'' Proc. Natl. Acad. Sci. USA 108, 7674 (2011); T. Preis and H. E. Stanley, ``Bubble Trouble: Can a Law Describe Bubbles and Crashes in Financial Markets?'' Physics World 24, No. 5, 29 (May 2011

  14. Resilience skills as emergent phenomena: A study of emergency departments in Brazil and the United States.

    Science.gov (United States)

    Wachs, Priscila; Saurin, Tarcisio Abreu; Righi, Angela Weber; Wears, Robert Lewis

    2016-09-01

    Although the use of resilience skills (RSs) by emergency department (ED) front-line staff is ubiquitous, the nature and origin of these skills tend to be taken for granted. This study investigates the research question "where do RSs come from"? Case studies in two EDs were undertaken in order to answer the research question: one in Brazil and the other in the United States. The case studies adopted the same data collection and analysis procedures, involving interviews, questionnaires, observations, and analysis of documents. A model for describing RSs as emergent phenomena is proposed. The model indicates that RSs arise from interactions between: work constraints, hidden curriculum, gaps in standardized operating procedures, organizational support for resilience, and RSs themselves. An instantiation of the model is illustrated by a critical event identified from the American ED. The model allows the identification of leverage points for influencing the development of RSs, instead of leaving their evolution purely to chance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Prioritization of natural phenomena hazards evaluations for CHG facilities

    CERN Document Server

    Graves, C E

    2001-01-01

    Natural phenomena hazards (NPH) are unexpected acts of nature that pose a threat or danger to workers, the public or to the environment by potential damage to structures, systems and components (SSCs). Earthquakes, extreme winds (hurricane and tornado), flood, volcanic eruption, lightning strike, or extreme cold or heat are examples of NPH. This document outlines the method used to prioritize buildings for inspection following an NPH event and contains the priority list for CH2M HILL Hanford Group, Inc. (CHG) buildings. Once an NPH event occurs and the Hanford Emergency Operations Center (EOC) is activated, this document will be used by the EOC to assign building inspections for the trained evaluators, barring any information from the field.

  16. Supernatural/Paranormal Phenomena: A Passionate Closer Look

    Science.gov (United States)

    Hameed, S.; Robinson, G.; Maulton, J.

    2003-05-01

    A collaboration between a psychologist, a philosopher, and an astronomer resulted in an inter-term (January) course, titled "Supernatural/Paranormal Phenomena: A Passionate Closer Look" at Smith College. The main purpose of the course was to provide students with the tools to evaluate the pseudo-sciences that are so enticing in today's complex and stressful world. We examined some of the reasons why people are attracted to New-Age enterprises that claim to: provide personal insight and social guidance from stars and planets; communicate with the dead; predict the future; prove contact with extraterrestrial beings. The course provided us with an opportunity to introduce the methodology of science and compare it with the claims made by the defenders of pseudo-sciences. We also conducted a survey of paranormal beliefs of enrolled students before and after our inter-term class.

  17. Quasi-quantum phenomena: the key to understanding homeopathy.

    Science.gov (United States)

    Molski, Marcin

    2010-04-01

    On the basis of the first- and second-order Gompertzian kinetics it has been proved that the crystallization and its reciprocal process of dissolution belong to the class of quasi-quantum non-local coherent phenomena. Hence, there exists a direct link to homeopathy: molecules of the remedy prepared in the process of dilution of the active substance are non-locally interconnected at-a-distance. The results obtained provide strong arguments justifying formulated ad hoc macroscopic versions of quantum non-locality, entanglement and coherence employed in interpretation of the homeopathic remedies activity and effectiveness. In particular they are consistent with the predictions of the weak quantum theory developed by Atmanspacher and coworkers.

  18. Role of insulin hormone in modulation of inflammatory phenomena

    Directory of Open Access Journals (Sweden)

    Antonio Di Petta

    2011-09-01

    Full Text Available Evidence demonstrates the involvement of hormones in thedevelopment of inflammatory response. Inflammation evokes markedstructural alterations of microvasculature, besides migration ofleukocytes from microcirculation to the site of lesion. These alterations are caused primarily by release or activation of endogenous mediators, in which hormones play an integral role in this regulatory system. Binding sites for many hormones may be characterized by vascular structures and hematogenous cells involved with the inflammatory response. Quantitative alterations of inflammatory events involving the decrease in microvascular response to inflammatory mediators, deficiency in the leukocyte-endothelium interaction, reduction of cell concentration in the inflammatory exudate, and failure of the phagocyte function of mononuclear cells were observed in insulindeficient states. Therefore, inflammation is not merely a local response, but rather a process controlled by hormones in which insulin plays an essential role in modulation of these phenomena, and assures tissue repair and remodeling within the limits of normality.

  19. Macroscopic Modeling of Transport Phenomena in Direct Methanol Fuel Cells

    DEFF Research Database (Denmark)

    Olesen, Anders Christian

    An increasing need for energy efficiency and high energy density has sparked a growing interest in direct methanol fuel cells for portable power applications. This type of fuel cell directly generates electricity from a fuel mixture consisting of methanol and water. Although this technology...... for studying their transport. In this PhD dissertation the macroscopic transport phenomena governing direct methanol fuel cell operation are analyzed, discussed and modeled using the two-fluid approach in the computational fluid dynamics framework of CFX 14. The overall objective of this work is to extend...... the present fundamental understanding of direct methanol fuel cell operation by developing a three-dimensional, two-phase, multi-component, non-isotherm mathematical model including detailed non-ideal thermodynamics, non-equilibrium phase change and non-equilibrium sorption-desorption of methanol and water...

  20. Diffusion phenomena in coatings for high temperature service

    Energy Technology Data Exchange (ETDEWEB)

    Zambon, A.; Ramous, E.

    1987-04-01

    The chemical composition modifications of Ni-Co-Cr-Al-Y coatings obtained by physical vapour deposition on the nickel-based superalloy Udimet 520 has been studied and related to soaking times ranging from 500 to 2000 h. The local compositions of both the coating and the base material are continuously changing because of diffusion phenomena, the growth of precipitates and surface oxidation. Electron microscopy examination and X-ray diffraction analysis showed that the zone near the interface tends to become sigma phase prone, thus affecting structural stability in a negative way. The shapes of the concentration profile show the reactive diffusion takes place after a period of high temperature exposure. Diffusion coefficients seem to depend on local concentration values and decrease with increasing soaking time.

  1. Surface Phenomena at Silver Nanoparticles in the Context of Toxicology

    DEFF Research Database (Denmark)

    Miclaus, Teodora

    2015-01-01

    of nanotoxicology. The main aim of this PhD research is to investigate these phenomena at the surface of silver nanoparticles under conditions that are relevant for in vitro studies in order to understand their implications for nano-silver toxicity. Upon contact with biological fluids, particles get coated......Nanoparticle research and applications are rapidly expanding areas and large scale production and use of nanomaterials has prompted concern regarding their safety for humans and the environment. Nanotoxicology aims to offer answers to issues that may arise in regards to potential harmful effects...... associated with engineered nanomaterials. Among these materials, silver nanoparticles are some of the most widely employed and thus represent a major point of focus in nanotoxicology and the topic of this PhD thesis. While nanoparticles have, upon synthesis, well-defined characteristics, specific...

  2. Collisions of fast clusters with solids and related phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Brunelle, A.; Della-Negra, S.; Depauw, J.; Jacquet, D.; Le Beyec, Y.; Pautrat, M.; Schoppmann, Ch.

    1996-12-01

    Fast polyatomic projectiles allow to deposit very high energy densities (at the surface and in the bulk) well beyond that being possible with any single ion impact. As a result, new and unexpected phenomena are observed which will be discussed: large non linear emission of ions and cluster ions, very high sputtering yields, production of giant tracks and craters in various irradiated materials including metals. When entering the solid, the atomic constituents of the projectile remain in a close proximity for a certain distance, and induce collective effects. Secondary ion emission experiments, performed with various carbon cluster beams delivered by the Tandem accelerator in Orsay, aim to determine this depth of spatial correlation by probing these collective effects inside the solid. The influence of the proximity of the cluster constituents on some of their properties such as their charge state distributions inside the solid has been studied. (author). 28 refs.

  3. Investigating paranormal phenomena: Functional brain imaging of telepathy.

    Science.gov (United States)

    Venkatasubramanian, Ganesan; Jayakumar, Peruvumba N; Nagendra, Hongasandra R; Nagaraja, Dindagur; Deeptha, R; Gangadhar, Bangalore N

    2008-07-01

    "Telepathy" is defined as "the communication of impressions of any kind from one mind to another, independently of the recognized channels of sense". Meta-analyses of "ganzfield" studies as well as "card-guessing task" studies provide compelling evidence for the existence of telepathic phenomena. The aim of this study was to elucidate the neural basis of telepathy by examining an individual with this special ability. Using functional MRI, we examined a famous "mentalist" while he was performing a telepathic task in a 1.5 T scanner. A matched control subject without this special ability was also examined under similar conditions. The mentalist demonstrated significant activation of the right parahippocampal gyrus after successful performance of a telepathic task. The comparison subject, who did not show any telepathic ability, demonstrated significant activation of the left inferior frontal gyrus. The findings of this study are suggestive of a limbic basis for telepathy and warrant further systematic research.

  4. A Unified Model of High-Energy Astrophysical phenomena

    CERN Document Server

    De Rújula, Alvaro

    2005-01-01

    I outline a unified model of high-energy astrophysics, in which the gamma background radiation, cluster "cooling flows", gamma-ray bursts, X-ray flashes and cosmic-ray electrons and nuclei of all energies -share a common origin. The mechanism underlying these phenomena is the emission of relativistic "cannonballs" by ordinary supernovae, analogous to the observed ejection of plasmoids by quasars and microquasars. I concentrate on Cosmic Rays: the longest-lasting conundrum in astrophysics. The distribution of Cosmic Rays in the Galaxy, their total "luminosity", the broken power-law spectra with their observed slopes, the position of the knee(s) and ankle(s), and the alleged variations of composition with energy are all explained in terms of simple and "standard" physics. The model is only lacking a satisfactory theoretical understanding of the "cannon" that emits the cannonballs in catastrophic episodes of accretion onto a compact object.

  5. Electrostrictive Effect in Cancer Cell Reflected in Capacitance Relaxation Phenomena

    Directory of Open Access Journals (Sweden)

    Tapas Kumar Basak

    2008-12-01

    Full Text Available The present paper has focus on the composite dielectric property of the cancer cell on concomitant with the capacitance relaxation phenomena. In this respect it has been found from MAT lab simulation the electrostrictive process in cancer cell is a complex one for which the electrostatic surfaces surrounding the cell changes with the incremental changes in the capacitance present in the capacitance relaxation curve. From these incremental changes in capacitance it is also possible to find out the electrostrictive energy of the cancer cell. It is interesting to note that the electrostrictive energy corresponding to the cell incremental changes in the capacitance is more in the first order system than that present in the second order system representing the equivalent configuration of the composite dielectric associated with the cell membrane. This is due the fact that during the process DNA synthesis and cell division the change in capacitance of the membrane for the first order system is relatively slow.

  6. Magnetotransport phenomena in layered conductors under magnetic breakdown

    Science.gov (United States)

    Galbova, O.; Peschansky, V. G.; Stepanenko, D. I.

    2017-06-01

    We study the transport phenomena in layered conductors with rather general electron energy spectrum placed in a high magnetic field H, under conditions when the distance between various sheets of the Fermi surface (FS) may become small under the external effects, such as hydrostatic pressure or impurity atom doping, and electrons can transfer from one sheet of the FS to another due to magnetic breakdown. We calculate the dependence of the in-plane electrical conductivity and magnetoresistance on magnetic field and probability of magnetic breakdown and show that the field-induced quadratic increase of the in-plane resistance in the absence of magnetic breakdown is changed by a linear dependence on H. With a further reduction of the energy gap between FS sheets, the in-plane resistance is saturated.

  7. An overview of photocatalysis phenomena applied to NOx abatement.

    Science.gov (United States)

    Ângelo, Joana; Andrade, Luísa; Madeira, Luís M; Mendes, Adélio

    2013-11-15

    This review provides a short introduction to photocatalysis technology in terms of the present environmental remediation paradigm and, in particular, NOx photoabatement. The fundamentals of photoelectrochemical devices and the photocatalysis phenomena are reviewed, highlighting the main reaction mechanisms. The critical historical developments on heterogeneous photocatalysis are briefly discussed, giving particular emphasis to the pioneer works in this field. The third part of this work focus mainly on NOx removal technology considering topics such as: TiO2 photochemistry; effect of the operating conditions on the photocatalysis process; Langmuir-Hinshelwood modeling; TiO2 photocatalytic immobilization approaches; and their applications. The last section of the paper presents the main conclusions and perspectives on the opportunities related to this technology. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Comments on the measurements of multiple muon phenomena

    Science.gov (United States)

    Sato, T.; Takahashi, T.; Higashi, S.

    1985-01-01

    The extensive air showers in the energy around 10 to the 15th power eV include those initiated by astrophysical primary gamma-rays. The observations need a precise measurement on the directions of primary particles. It is one of the methods to measure the directions of high-energy muons in air showers. The accuracy in measuring the direction, by calculating the cosmic-ray phenomena in the atmosphere at very high energy was investgated. The results calculated by Monte Carlo method suggest that one may determine the direction of primary cosmic-rays within errors of 10/3 rad in observing muons of above 100 GeV at sea level.

  9. Weak chain link breakdown phenomena of multigrade insulation materials

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, J.; McClung, L.B.

    1982-07-01

    Several failures of multigrade insulation systems have been experienced in metal clad, metal enclosed switchgear, and miniature isolated phase busduct systems. The failure sequence of the series insulation system appeared to originate from a point farthest away from the ground plane and not from the insulation in contact with the ground plane. However, in actuality, the ground plane was periodically elevated in relationship to the insulated busbar due to the presence of moisture created by load and ambient temperature cycling and adverse weather conditions. The insulation material in contact with the ground plane, being a high quality track resistant material, did not exhibit permanent deterioration. However the weakest insulation material degraded with time, weakening the overall insulation path to a point that an elevated ground plane condition resulted in failures of the series insulation system. The phenomena experienced in a specific application and the alternatives considered to correct the situation are described.

  10. Ultrafast phenomena in molecular sciences femtosecond physics and chemistry

    CERN Document Server

    Bañares, Luis

    2014-01-01

    This book presents the latest developments in Femtosecond Chemistry and Physics for the study of ultrafast photo-induced molecular processes. Molecular systems, from the simplest H2 molecule to polymers or biological macromolecules, constitute central objects of interest for Physics, Chemistry and Biology, and despite the broad range of phenomena that they exhibit, they share some common behaviors. One of the most significant of those is that many of the processes involving chemical transformation (nuclear reorganization, bond breaking, bond making) take place in an extraordinarily short time, in or around the femtosecond temporal scale (1 fs = 10-15 s). A number of experimental approaches - very particularly the developments in the generation and manipulation of ultrashort laser pulses - coupled with theoretical progress, provide the ultrafast scientist with powerful tools to understand matter and its interaction with light, at this spatial and temporal scale. This book is an attempt to reunite some of the ...

  11. Bifurcation phenomena in internal dynamics of gear systems

    Directory of Open Access Journals (Sweden)

    Hortel M.

    2007-10-01

    Full Text Available The impact effects in gear mesh represent specific phenomena in the dynamic investigation of highspeed light transmission systems with kinematic couplings. They are caused of greater dynamic than static elastic deformations in meshing gear profiles. In term of internal dynamics they are influenced among others by time heteronomous stiffness functions in gear mesh and resonance tuning of stiffness level. The damping in gear mesh and in gear system is concerned significantly in the amplitude progress, greatness and phase shift of relative motion towards stiffness function alternatively towards its modify form in gear mesh. In consequence of these and another actions rise above resonance characteristics certain singular locations with jump amplitude course.

  12. Constrained basin stability for studying transient phenomena in dynamical systems

    Science.gov (United States)

    van Kan, Adrian; Jegminat, Jannes; Donges, Jonathan F.; Kurths, Jürgen

    2016-04-01

    Transient dynamics are of large interest in many areas of science. Here, a generalization of basin stability (BS) is presented: constrained basin stability (CBS) that is sensitive to various different types of transients arising from finite size perturbations. CBS is applied to the paradigmatic Lorenz system for uncovering nonlinear precursory phenomena of a boundary crisis bifurcation. Further, CBS is used in a model of the Earth's carbon cycle as a return time-dependent stability measure of the system's global attractor. Both case studies illustrate how CBS's sensitivity to transients complements BS in its function as an early warning signal and as a stability measure. CBS is broadly applicable in systems where transients matter, from physics and engineering to sustainability science. Thus CBS complements stability analysis with BS as well as classical linear stability analysis and will be a useful tool for many applications.

  13. Stochastic Dynamics and Critical Phenomena in Permafrost Models

    Science.gov (United States)

    Sudakov, I.

    2016-12-01

    There is an estimated 400 PgC of CH4 stored as frozen gas hydrates under boreal permafrost, and it is thought that permafrost melting could release a considerable amount of CH4 to the atmosphere. Methane emissions from tundra permafrost lakes are a significant positive feedback to the atmosphere in a changing climate. The evolution of tundra lakes on the surface of boreal permafrost is a complex stochastic process that is important in climate modeling. We propose a model (based on the Fokker-Planck equation) describing the stochastic dynamics of tundra lakes. We use this model to compute the methane emission generated by tundra permafrost lakes. This model facilitates investigation of critical phenomena in Earth's cryosphere, and methane emission from permafrost in particular.

  14. Kinetic Modifications to MHD Phenomena in Toroidal Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    C.Z. Cheng; N.N. Gorelenkov; G.J. Kramer; E. Fredrickson

    2004-09-03

    Particle kinetic effects involving small spatial and fast temporal scales can strongly affect MHD phenomena and the long time behavior of plasmas. In particular, kinetic effects such as finite ion gyroradii, trapped particle dynamics, and wave-particle resonances have been shown to greatly modify the stability of MHD modes. Here, the kinetic effects of trapped electron dynamics and finite ion gyroradii are shown to have a large stabilizing effect on kinetic ballooning modes in low aspect ratio toroidal plasmas such as NSTX [National Spherical Torus Experiment]. We also present the analysis of Toroidicity-induced Alfven Eigenmodes (TAEs) destabilized by fast neutral-beam injected ions in NSTX experiments and TAE stability in ITER due to alpha-particles and MeV negatively charged neutral beam injected ions.

  15. Hyperchromatic lens for recording time-resolved phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Frayer, Daniel K.

    2017-07-11

    A method and apparatus for the capture of a high number of quasi-continuous effective frames of 2-D data from an event at very short time scales (from less than 10.sup.-12 to more than 10.sup.-8 seconds) is disclosed which allows for short recording windows and effective number of frames. Active illumination, from a chirped laser pulse directed to the event creates a reflection where wavelength is dependent upon time and spatial position is utilized to encode temporal phenomena onto wavelength. A hyperchromatic lens system receives the reflection and maps wavelength onto axial position. An image capture device, such as holography or plenoptic imaging device, captures the resultant focal stack from the hyperchromatic lens system in both spatial (imaging) and longitudinal (temporal) axes. The hyperchromatic lens system incorporates a combination of diffractive and refractive components to maximally separate focal position as a function of wavelength.

  16. Transport phenomena in biomedical engineering principles and practices

    CERN Document Server

    Peattie, Robert A; Bronzino, Joseph D

    2012-01-01

    Biomimetic Systems: Concepts, Design, and Emulation, Robert J. FisherTransport/Reaction Processes in Biology and Medicine, E. N. LightfootMicrovascular Heat Transfer, James W. BaishFluid Dynamics for Bio Systems: Fundamentals and Model Analysis, Robert A. Peattie and Robert J. FisherAnimal Surrogate Systems, Michael L. Shuler, Sarina G. Harris, Xinran Li, and Mandy B. EschArterial Wall Mass Transport: The Possible Role of Blood Phase Resistance in the Localization of Arterial Disease, John M. Tarbell and Yuchen QiuTransport Phenomena and the Microenvironment, Robert J. Fisher and Robert A. PeattieTransport and Drug Delivery through the Blood-Brain Barrier and Cerebrospinal Fluid, Bingmei M. FuInterstitial Transport in the Brain: Principles for Local Drug Delivery, W. Mark SaltzmanSurfactant Transport and Fluid-Structure Interactions during Pulmonary Airway Reopening, David Martin, Anne-Marie Jacob, and Donald P. Gaver IIIIndex.

  17. Stokes phenomena in discrete Painlevé I.

    Science.gov (United States)

    Joshi, N; Lustri, C J

    2015-05-08

    In this study, we consider the asymptotic behaviour of the first discrete Painlevé equation in the limit as the independent variable becomes large. Using an asymptotic series expansion, we identify two types of solutions which are pole-free within some sector of the complex plane containing the positive real axis. Using exponential asymptotic techniques, we determine Stokes phenomena effects present within these solutions, and hence the regions in which the asymptotic series expression is valid. From a careful analysis of the switching behaviour across Stokes lines, we find that the first type of solution is uniquely defined, while the second type contains two free parameters, and that the region of validity may be extended for appropriate choice of these parameters.

  18. Nonlinear thermokinetic phenomena due to the Seebeck effect.

    Science.gov (United States)

    Sugioka, Hideyuki

    2014-07-22

    We propose a novel mechanism to produce nonlinear thermokinetic vortex flows around a circular cylinder with ideally high thermal conductivity in an electrolyte. That is, the nonlinear thermokinetic slip velocity, which is proportional to the square of the temperature gradient [∇(T)0(2)], is derived based on the electrolyte Seebeck effect, heat conduction equation, and Helmholtz–Smoluchowski formula. Different from conventional linear thermokinetic theory, our theory predicts that the inversion of the temperature gradient does not change the direction of the thermokinetic flows and thus a Janus particle using this phenomenon can move to the both hotter and colder regions in a temperature gradient field by changing the direction of its dielectric end. Our findings bridge the gap between the electro- and thermo-kinetic phenomena and provide an integrated physical viewpoint for the interface science.

  19. 2nd Workshop on Laser Interaction and Related Plasma Phenomena

    CERN Document Server

    Hora, Heinrich

    1972-01-01

    Paul Harteck Rensselaer Polytechnic Institute Troy, New York When the Maser and the Laser Were discovered, people were speculating if this was the beginning of a new page, or even a new chapter, in the Book of Physics. The Second Workshop on "Laser Interaction and Related Plasma Phenomena" held in Hartford made it clear that the perspective had changed, that people now question if the consequences of these discoveries constitute a new chapter, or possibly a new era in Physics. While the papers presented were all stimulating and of out­ standing quality, of special interest were the experiments which demonstrated that triggering of thermonuclear fusion by Laser techniques is indeed in the realm of the possible. Along these lines, I enjoy recalling an anecdote concerning the late F. G. Houtermans. I think that all who knew him will agree that he was an unusual genius and at the same time a very amusing colleague.

  20. Experimental study on dynamic buckling phenomena for supercavitating underwater vehicle

    Directory of Open Access Journals (Sweden)

    Minho Chung

    2012-09-01

    Full Text Available Dynamic buckling, also known as parametric resonance, is one of the dynamic instability phenomena which may lead to catastrophic failure of structures. It occurs when compressive dynamic loading is applied to the structures. Therefore it is essential to establish a reliable procedure to test and evaluate the dynamic buckling behaviors of structures, especially when the structure is designed to be utilized in compressive dynamic loading environment, such as supercavitating underwater vehicle. In the line of thought, a dynamic buckling test system is designed in this work. Using the test system, dynamic buckling tests including beam, plate, and stiffened plate are carried out, and the dynamic buckling characteristics of considered structures are investigated experimentally as well as theoretically and numerically.

  1. Some optical and dynamical phenomena in the Rindler model

    CERN Document Server

    Birsin, E

    2014-01-01

    In Rindler's model of a uniformly accelerated reference frame we analyze the apparent shape of rods and marked light rays for the case that the observers as well as the rods and the sources of light are at rest with respect to the Rindler observers. Contrary to the expectation suggested by the strong principle of equivalence, there is no apparent "bending down" of a light ray with direction transversal to the direction of acceleration, but a straight rod oriented orthogonal to the direction of acceleration appears bended "upwards". These optical phenomena are in accordance with the dynamical experience of observers guided by a straight track or a track curved in the same way as the marked light ray, respectively: While the former observer feels a centrifugal force directed "downwards", the centrifugal force for the latter vanishes. The properties of gyroscope transport along such tracks are correspondingly.

  2. Are Critical Phenomena Relevant to Large-Scale Evolution?

    Science.gov (United States)

    Sole, Ricard V.; Bascompte, Jordi

    1996-02-01

    Recent theoretical studies, based on the theory of self-organized critical systems, seem to suggest that the dynamical patterns of macroevolution could belong to such class of critical phenomena. Two basic approaches have been proposed: the Kauffman-Johnsen model (based on the use of coupled fitness landscapes) and the Bak-Sneppen model. Both are reviewed here. These models are oversimplified pictures of biological evolution, but the (possible) validity of them is based on the concept of universality, i.e. that apparently very different systems sharing some few common properties should also behave in a very similar way. In this paper we explore the current evidence from the fossil record, showing that some properties that are suggestive of critical dynamics would also be the result of random phenomema. Some general properties of the large-scale pattern of evolution, which should be reproduced by these models, are discussed.

  3. PREFACE: XI Latin American Workshop on Nonlinear Phenomena

    Science.gov (United States)

    Anteneodo, Celia; da Luz, Marcos G. E.

    2010-09-01

    The XI Latin American Workshop on Nonlinear Phenomena (LAWNP) has been held in Búzios-RJ, Brazil, from 5-9 October 2009. This international conference is one in a series that have gathered biennially, over the past 21 years, physicists and other scientists who direct their work towards several aspects of nonlinear phenomena and complex systems. The main purpose of LAWNP meetings is to create a friendly and motivating environment, such that researchers from Latin America and from other parts of the globe can discuss not only their own latest results but also the trends and perspectives in this very interdisciplinary field of investigation. Hence, it constitutes a forum for promoting scientific collaboration and fomenting the emergence of new ideas, helping to advance the field. The XI edition (LAWNP'09) has gathered more than 230 scientists and students (most from Latin America), covering all of the world (27 different countries from North and South America, Asia, Europe, and Oceania). In total there were 18 plenary lectures, 80 parallel talks, and 140 poster contributions. A stimulating round-table discussion also took place devoted to the present and future of the Latin American Institutions in Complex Phenomena (a summary can be found at http://lawnp09.fis.puc-rio.br, in the Round-Table report link). The 2009 workshop was devoted to a wide scope of themes and points of view, pursuing to include the latest trends and developments in the science of nonlinearity. In this way, we have a great pleasure in publishing this Proceedings volume based on the high quality scientific works presented at LAWNP'09, covering already established methods as well as new approaches, discussing both theoretical and practical aspects, and addressing paradigmatic systems and also completely new problems, in nonlinearity and complexity. In fact, the present volume may be a very valuable reference for those interested in an overview on how nonlinear interactions can affect different

  4. Magnetic phenomena in holographic superconductivity with Lifshitz scaling

    Directory of Open Access Journals (Sweden)

    Aldo Dector

    2015-09-01

    Full Text Available We investigate the effects of Lifshitz dynamical critical exponent z on a family of minimal D=4+1 holographic superconducting models, with a particular focus on magnetic phenomena. We see that it is possible to have a consistent Ginzburg–Landau approach to holographic superconductivity in a Lifshitz background. By following this phenomenological approach we are able to compute a wide array of physical quantities. We also calculate the Ginzburg–Landau parameter for different condensates, and conclude that in systems with higher dynamical critical exponent, vortex formation is more strongly unfavored energetically and exhibits a stronger Type I behavior. Finally, following the perturbative approach proposed by Maeda, Natsuume and Okamura, we calculate the critical magnetic field of our models for different values of z.

  5. Chaos and non-linear phenomena in renal vascular control

    DEFF Research Database (Denmark)

    Yip, K P; Holstein-Rathlou, N H

    1996-01-01

    condition for the interaction is that the nephrons derive their blood supply from the same cortical radial artery. Development of hypertension is associated with a shift from periodic oscillations of tubular pressure to random-like fluctuations. Numerical analyses indicate that these fluctuations...... a variety of non-linear phenomena. In halothane-anesthetized, normotensive rats the TGF system oscillates regularly at 2-3 cycles/min because of the non-linearities and the time delays within the feedback system. Oscillations are present in single nephron blood flow, tubular pressure and flow......, and in the tubular solute concentrations. Nephrons deriving their afferent arteriole from the same cortical radial artery are entrained, and consequently oscillate at the same frequency. Experimental studies have shown that the synchronization is due to an interaction of the TGF between nephrons. A necessary...

  6. Contribution of cellular automata to the understanding of corrosion phenomena

    Directory of Open Access Journals (Sweden)

    M. Zenkri

    2017-09-01

    Full Text Available We present a stochastic CA modelling approach of corrosion based on spatially separated electrochemical half-reactions, diffusion, acido-basic neutralization in solution and passive properties of the oxide layers. Starting from different initial conditions, a single framework allows one to describe generalised corrosion, localised corrosion, reactive and passive surfaces, including occluded corrosion phenomena as well. Spontaneous spatial separation of anodic and cathodic zones is associated with bare metal and passivated metal on the surface. This separation is also related to local acidification of the solution. This spontaneous change is associated with a much faster corrosion rate. Material morphology is closely related to corrosion kinetics, which can be used for technological applications.

  7. Phenomena and mechanisms of crack propagation in glass-ceramics.

    Science.gov (United States)

    Apel, E; Deubener, J; Bernard, A; Höland, M; Müller, R; Kappert, H; Rheinberger, V; Höland, W

    2008-10-01

    Lithium disilicate, leucite and apatite glass-ceramics have become state-of-the-art framework materials in the fabrication of all-ceramic dental restorative materials. The goal of this study was to examine the crack propagation behaviour of these three known glass-ceramic materials after they have been subjected to Vickers indentation and to characterize their crack opening profiles (delta(meas) vs. (a-r)). For this purpose, various methods of optical examination were employed. Optical microscopy investigations were performed to examine the crack phenomena at a macroscopic level, while high-resolution techniques, such as scanning electron microscopy (SEM) and atomic force microscopy (AFM), were employed to investigate the crack phenomena at a microscopic level. The crack patterns of the three glass-ceramics vary from fairly straightforward to more complex, depending on the amount of residual glass matrix present in the material. The high-strength lithium disilicate crystals feature a high degree of crosslinking, thereby preventing crack propagation. In this material, the crack propagates only through the residual glass phase, which constitutes 30%-40% by volume. Having a high glass content of more than 65% by volume, the leucite and apatite glass-ceramics show far more complex crack patterns. Cracks in the leucite glass-ceramic propagate through both the glass and crystal phase. The apatite glass-ceramic shows a similar crack behaviour as an inorganic-organic composite material containing nanoscale fillers, which are pulled out in the surroundings of the crack tip. The observed crack behaviour and the calculated K(tip) values of the three types of glass-ceramics were compared to the K(IC) values determined according to the SEVNB method.

  8. Experimental studies of light emission phenomena in superconducting RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Delayen, J.R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Center for Accelerator Science, Old Dominion University, Norfolk, VA, 23529 (United States); Fryberger, D., E-mail: fryberger@slac.stanford.ed [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Goree, W.S. [2G Enterprises, Pacific Grove, CA 93950 (United States); Mammosser, J. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Szalata, Z.M.; Weisend, J.G. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

    2009-12-21

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from approx1/2 to approx2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW-controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects <=1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  9. A kinetic-MHD model for low frequency phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, C.Z.

    1991-07-01

    A hybrid kinetic-MHD model for describing low-frequency phenomena in high beta anisotropic plasmas that consist of two components: a low energy core component and an energetic component with low density. The kinetic-MHD model treats the low energy core component by magnetohydrodynamic (MHD) description, the energetic component by kinetic approach such as the gyrokinetic equation, and the coupling between the dynamics of these two components through plasma pressure in the momentum equation. The kinetic-MHD model optimizes both the physics contents and the theoretical efforts in studying low frequency MHD waves and transport phenomena in general magnetic field geometries, and can be easily modified to include the core plasma kinetic effects if necessary. It is applicable to any magnetized collisionless plasma system where the parallel electric field effects are negligibly small. In the linearized limit two coupled eigenmode equations for describing the coupling between the transverse Alfven type and the compressional Alfven type waves are derived. The eigenmode equations are identical to those derived from the full gyrokinetic equation in the low frequency limit and were previously analyzed both analytically nd numerically to obtain the eigenmode structure of the drift mirror instability which explains successfully the multi-satellite observation of antisymmetric field-aligned structure of the compressional magnetic field of Pc 5 waves in the magnetospheric ring current plasma. Finally, a quadratic form is derived to demonstrate the stability of the low-frequency transverse and compressional Alfven type instabilities in terms of the pressure anisotropy parameter {tau} and the magnetic field curvature-pressure gradient parameter. A procedure for determining the stability of a marginally stable MHD wave due to wave-particle resonances is also presented.

  10. Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L.; /SLAC; Delayen, J.R.; /Jefferson Lab; Fryberger, D.; /SLAC; Goree, W.S.; Mammosser, J.; /Jefferson Lab /SNS Project, Oak Ridge; Szalata, Z.M.; II, J.G.Weisend /SLAC

    2009-08-04

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  11. New phenomena in non-equilibrium quantum physics

    Science.gov (United States)

    Kitagawa, Takuya

    From its beginning in the early 20th century, quantum theory has become progressively more important especially due to its contributions to the development of technologies. Quantum mechanics is crucial for current technology such as semiconductors, and also holds promise for future technologies such as superconductors and quantum computing. Despite of the success of quantum theory, its applications have been mostly limited to equilibrium or static systems due to 1. lack of experimental controllability of non-equilibrium quantum systems 2. lack of theoretical frameworks to understand non-equilibrium dynamics. Consequently, physicists have not yet discovered too many interesting phenomena in non-equilibrium quantum systems from both theoretical and experimental point of view and thus, non-equilibrium quantum physics did not attract too much attentions. The situation has recently changed due to the rapid development of experimental techniques in condensed matter as well as cold atom systems, which now enables a better control of non-equilibrium quantum systems. Motivated by this experimental progress, we constructed theoretical frameworks to study three different non-equilibrium regimes of transient dynamics, steady states and periodically drives. These frameworks provide new perspectives for dynamical quantum process, and help to discover new phenomena in these systems. In this thesis, we describe these frameworks through explicit examples and demonstrate their versatility. Some of these theoretical proposals have been realized in experiments, confirming the applicability of the theories to realistic experimental situations. These studies have led to not only the improved fundamental understanding of non-equilibrium processes in quantum systems, but also suggested entirely different venues for developing quantum technologies.

  12. Macroscopic quantum phenomena from the large N perspective

    Energy Technology Data Exchange (ETDEWEB)

    Chou, C H [department of Physics, National Cheng Kung University, Tainan, Taiwan 701 (China) and National Center for Theoretical Sciences (South), Tainan, Taiwan 701 (China); Hu, B L; Subasi, Y, E-mail: hubeilok@gmail.com [Joint Quantum Institute and Maryland Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States)

    2011-07-08

    Macroscopic quantum phenomena (MQP) is a relatively new research venue, with exciting ongoing experiments and bright prospects, yet with surprisingly little theoretical activity. What makes MQP intellectually stimulating is because it is counterpoised against the traditional view that macroscopic means classical. This simplistic and hitherto rarely challenged view need be scrutinized anew, perhaps with much of the conventional wisdoms repealed. In this series of papers we report on a systematic investigation into some key foundational issues of MQP, with the hope of constructing a viable theoretical framework for this new endeavour. The three major themes discussed in these three essays are the large N expansion, the correlation hierarchy and quantum entanglement for systems of 'large' sizes, with many components or degrees of freedom. In this paper we use different theories in a variety of contexts to examine the conditions or criteria whereby a macroscopic quantum system may take on classical attributes, and, more interestingly, that it keeps some of its quantum features. The theories we consider here are, the O(N) quantum mechanical model, semiclassical stochastic gravity and gauge / string theories; the contexts include that of a 'quantum roll' in inflationary cosmology, entropy generation in quantum Vlasov equation for plasmas, the leading order and next-to-leading order large N behaviour, and hydrodynamic / thermodynamic limits. The criteria for classicality in our consideration include the use of uncertainty relations, the correlation between classical canonical variables, randomization of quantum phase, environment-induced decoherence, decoherent history of hydrodynamic variables, etc. All this exercise is to ask only one simple question: Is it really so surprising that quantum features can appear in macroscopic objects? By examining different representative systems where detailed theoretical analysis has been carried out, we find that

  13. Quantitative phase-field modeling for wetting phenomena.

    Science.gov (United States)

    Badillo, Arnoldo

    2015-03-01

    A new phase-field model is developed for studying partial wetting. The introduction of a third phase representing a solid wall allows for the derivation of a new surface tension force that accounts for energy changes at the contact line. In contrast to other multi-phase-field formulations, the present model does not need the introduction of surface energies for the fluid-wall interactions. Instead, all wetting properties are included in a unique parameter known as the equilibrium contact angle θeq. The model requires the solution of a single elliptic phase-field equation, which, coupled to conservation laws for mass and linear momentum, admits the existence of steady and unsteady compact solutions (compactons). The representation of the wall by an additional phase field allows for the study of wetting phenomena on flat, rough, or patterned surfaces in a straightforward manner. The model contains only two free parameters, a measure of interface thickness W and β, which is used in the definition of the mixture viscosity μ=μlϕl+μvϕv+βμlϕw. The former controls the convergence towards the sharp interface limit and the latter the energy dissipation at the contact line. Simulations on rough surfaces show that by taking values for β higher than 1, the model can reproduce, on average, the effects of pinning events of the contact line during its dynamic motion. The model is able to capture, in good agreement with experimental observations, many physical phenomena fundamental to wetting science, such as the wetting transition on micro-structured surfaces and droplet dynamics on solid substrates.

  14. Shock Tube Ignition Delay Data Affected by Localized Ignition Phenomena

    KAUST Repository

    Javed, Tamour

    2016-12-29

    Shock tubes have conventionally been used for measuring high-temperature ignition delay times ~ O(1 ms). In the last decade or so, the operating regime of shock tubes has been extended to lower temperatures by accessing longer observation times. Such measurements may potentially be affected by some non-ideal phenomena. The purpose of this work is to measure long ignition delay times for fuels exhibiting negative temperature coefficient (NTC) and to assess the impact of shock tube non-idealities on ignition delay data. Ignition delay times of n-heptane and n-hexane were measured over the temperature range of 650 – 1250 K and pressures near 1.5 atm. Driver gas tailoring and long length of shock tube driver section were utilized to measure ignition delay times as long as 32 ms. Measured ignition delay times agree with chemical kinetic models at high (> 1100 K) and low (< 700 K) temperatures. In the intermediate temperature range (700 – 1100 K), however, significant discrepancies are observed between the measurements and homogeneous ignition delay simulations. It is postulated, based on experimental observations, that localized ignition kernels could affect the ignition delay times at the intermediate temperatures, which lead to compression (and heating) of the bulk gas and result in expediting the overall ignition event. The postulate is validated through simple representative computational fluid dynamic simulations of post-shock gas mixtures which exhibit ignition advancement via a hot spot. The results of the current work show that ignition delay times measured by shock tubes may be affected by non-ideal phenomena for certain conditions of temperature, pressure and fuel reactivity. Care must, therefore, be exercised in using such data for chemical kinetic model development and validation.

  15. Ground subsidence phenomena in Frakadona, West Thessaly, Greece

    Science.gov (United States)

    Tsangaratos, Paraskevas; Loupasakis, Constantinos; Ilia, Ioanna

    2017-09-01

    Ground subsidence is considered among the most frequent geological hazard that usually occurs as a consequence of a number of phenomena, namely: natural compaction of unconsolidated fine - grained deposits, groundwater over - exploitation, peat - oxidation and collapse of underground cavities. The main objective of the present study was to investigate the spatio - temporal patterns of ground deformation in the wider area of Farkadona Municipality in the north-eastern Trikala regional unit, Thessaly, Greece. A set of Synthetic Aperture Radar images, acquired in 1992-2003 by the European Space Agency satellites ERS1 and ERS2 and processed with the Persistent Scatterer Interferometry technique, along with geotechnical data from nearby exploratory boreholes, were used in order to explain the observed deformation. Increasing subsidence rates are observed at almost the entire area within the city complex of Farkadona, which is covered by loose Quaternary sediments of considerable depth. In most cases, the increased deformation rates have caused damages in the form of tensile cracks, mainly along the road network and adjacent buildings. The results of the performed analysis concluded that the geotechnical conditions of the loose deposits occupying the site and also the intensive exploitation of the aquifers are the two main causal factors of the land subsidence phenomena. Additionally, a clear correlation between the subsidence deformation rate and the thickness of the loose deposits has been detected. Besides the geological information, this study made clear that Persistent Scatterer Interferometry could be considered as a valuable tool and cost-efficient method for validating subsidence mechanisms and could serve as an alternative to ground-based measurements.

  16. [Psychiatric doppelganger phenomena with special consideration of the Capgras syndrome] .

    Science.gov (United States)

    Arenz, D

    2000-11-01

    The present paper classifies and analyzes the experience of the "double" in depth. Main focus is on the Capgras experience--certainly the best known phenomenon of the double--and its possible etiology is examined. Moreover, a few other delusional experiences of mis-identification of person are also considered, such as the Frégoli phenomenon, the syndrome of subjective doubles, intermetamorphosis as well as other variants described in the literature.

  17. Whale Identification

    Science.gov (United States)

    1991-01-01

    R:BASE for DOS, a computer program developed under NASA contract, has been adapted by the National Marine Mammal Laboratory and the College of the Atlantic to provide and advanced computerized photo matching technique for identification of humpback whales. The program compares photos with stored digitized descriptions, enabling researchers to track and determine distribution and migration patterns. R:BASE is a spinoff of RIM (Relational Information Manager), which was used to store data for analyzing heat shielding tiles on the Space Shuttle Orbiter. It is now the world's second largest selling line of microcomputer database management software.

  18. Persistent Currents and Quantum Critical Phenomena in Mesoscopic Physics

    Science.gov (United States)

    Zelyak, Oleksandr

    In this thesis, we study persistent currents and quantum critical phenomena in the systems of mesoscopic physics. As an introduction in Chapter 1 we familiarize the reader with the area of mesoscopic physics. We explain how mesoscopic systems are different from quantum systems of single atoms and molecules and bulk systems with an Avogadro number of elements. We also describe some important mesoscopic phenomena. One of the mathematical tools that we extensively use in our studies is Random Matrix Theorty. This theory is not a part of standard physics courses and for educational purposes we provide the basics of Random Matrix Theory in Chapter 2. In Chapter 3 we study the persistent current of noninteracting electrons in quantum billiards. We consider simply connected chaotic Robnik-Berry quantum billiard and its annular analog. The electrons move in the presence of a point-like magnetic flux at the center of the billiard. For the simply connected billiard, we find a large diamagnetic contribution to the persistent current at small flux, which is independent of the flux and is proportional to the number of electrons (or equivalently the density since we keep the area fixed). The size of this diamagnetic contribution is much larger than the previously studied mesoscopic fluctuations in the persistent current in the simply connected billiard. This behavior of persistent current can ultimately be traced to the response of the angular-momentum l = 0 levels (neglected in semiclassical expansions) on the unit disk to a point-like flux at its center. We observe the same behavior for the annular billiard when the inner radius is much smaller than the outer one. We also find that the usual fluctuating persistent current and Anderson-like localization due to boundary scattering are seen when the annulus tends to a one-dimensional ring. We explore the conditions for the observability of this phenomenon. In Chapter 4 we study quantum critical phenomena in a system of two

  19. FOREWORD: Electromagnetic Phenomena and Health - A Continuing Controversy?

    Science.gov (United States)

    Jamieson, Isaac A.; Holdstock, Paul

    2010-05-01

    A variety of natural electromagnetic phenomena - from electrostatic and magnetostatic fields to radiowaves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma radiation - may influence human health and wellbeing (by their presence, intensity or absence) in a number of diverse ways. Some artificially created electromagnetic phenomena may also directly and/or indirectly influence biological functioning, though the levels and extent to which they may do so is still to a large extent open to debate and further investigation. Since the deployment, use and types of technology and materials that can alter the electromagnetic nature of environments to which individuals are exposed are growing at an ever increasing rate; it is necessary to consider and rigorously access the possible biological effects (both beneficial and detrimental) that they may cause, or be instrumental in causing, so that appropriate safety and best practice measures can be introduced/adhered to if and where appropriate. As demonstrated by the papers in these conference proceedings, there is presently a very widespread range of opinions from experts on the best ways to proceed over such matters, indicating that further dialogue is necessary in a way that can satisfactorily address these issues whilst enhancing technological innovation in a sustainable manner and suitably addressing possible health related concerns. It appears that by constructively encouraging dialogue between experts and other stakeholders and the development of 'Win-Win' scenarios and mindsets, where solutions and constructive progress are sought (instead of highlighting problems and differences in opinion - as has often occurred in the past in electromagnetic field (EMF) discourse) - much can be achieved to the benefit of all. It also appears much may be achieved if the possible beneficial health effects of particular types of electromagnetic phenomena, exposure regimes and related factors are investigated more

  20. Magmatic versus sedimentary volcanism: similarities of two different geological phenomena

    Science.gov (United States)

    Mazzini, Adriano

    2015-04-01

    Sedimentary volcanoes (or more commonly called mud volcanoes) are geological phenomena that are present in sedimentary basins of passive and active margins. At these localities gas and water related to hydrocarbon diagenetic and catagenetic production generate overpressure facilitating the rise of mobile and ductily deformable materials that breach through the denser overlying rocks. The results are surface powerful manifestations of mud eruptions that strikingly resemble to those of magmatic volcanoes. Magmatic and sedimentary volcanoes share many other similarities. Initially both systems are essentially gas driven and the subsurface plumbing systems are characterized by intrusions and a complex system of fractures and conduits that bifurcate from a central feeder channel that manifest in the surface as numerous satellite seeps and vents. In both cases are inferred secondary shallower chambers where reactions take place. Comparable structural morphologies (e.g. conical, elongated, pie-shaped, multicrater, swap-like, caldera collapse, subsiding flanks, plateau-like) and/or alteration of the original shape are in both cases related to e.g. density and viscosity of the erupted solids, to the gas content, to the frequency of the eruptions, and to the action of meteoric factors (e.g. strong erosion by rain, wind, temperature changes etc. etc.). Like for magmatic volcanoes, the periodicity of the eruptive activity is related to the time required to charge the system and create new overpressure, as well as how the structure seals during periods of dormancy. Earthquakes are documented to be a powerful trigger capable to activate faults (often hosting magmatic and sedimentary volcanoes) and/or facilitating the breaching of the upper layers, and allowing the rise of deeper charged fluids. Finally, both systems significantly contribute as active source for CH4 (sedimentary) and CO2 (magmatic) resulting of great importance for global budget estimates of sensitive gasses. The

  1. Understanding Complexity: Pattern Recognitions, Emergent Phenomena and Causal Coupling

    Science.gov (United States)

    Raia, F.

    2010-12-01

    In teaching and learning complex systems we face a fundamental issue: Simultaneity of causal interactions -where effects are at the same time causes of systems’ behavior. Complex systems’ behavior and evolution are controlled by negative and positive feedback processes, continually changing boundary conditions and complex interaction between systems levels (emergence). These processes cannot be described and understood in a mechanistic framework where causality is conceived of being mostly of cause-effect nature or a linear chain of causes and effects. Mechanist causality by definition is characterized by the assumption that an earlier phenomenon A has a causal effect on the development of a phenomenon B. Since this concept also assumes unidirectional time, B cannot have an effect on A. Since students study science mostly in the lingering mechanistic framework, they have problems understanding complex systems. Specifically, our research on students understanding of complexity indicates that our students seem to have great difficulties in explaining mechanisms underlying natural processes within the current paradigm. Students tend to utilize simple linear model of causality and establish a one-to-one correspondence between cause and effect describing phenomena such as emergence and self-organization as being mechanistically caused. Contrary to experts, when presented with data distribution -spatial and/or temporal-, students first consider or search for a unique cause without describing the distribution or a recognized pattern. Our research suggests that students do not consider a pattern observed as an emergent phenomenon and therefore a causal determinant influencing and controlling the evolution of the system. Changes in reasoning have been observed when students 1) are iteratively asked to recognize and describe patterns in data distribution and 2) subsequently learn to identify these patterns as emergent phenomena and as fundamental causal controls over

  2. New High-Energy Phenomena in Aircraft Triggered Lightning

    Science.gov (United States)

    Kochkin, P.; Van Deursen, A.; de Boer, A.; Bardet, M.; Boissin, J. F.

    2016-12-01

    High-energy phenomena associated with lighting have been proposed in the twenties, observed for the first time in the sixties, and further investigated more recently by e.g. rocket triggered lightning. Similarly, x-rays have been detected in meter-long discharges in air at standard atmospheric conditions. Questions came up whether lightning triggered by aircraft would also generate hard radiation in-flight, its timing with respect to lightning current, its intensity and spectrum. In an earlier project, we developed a system ILDAS (http://ildas.nlr.nl) to determine the lightning current and its pattern over the aircraft with high accuracy and time-resolution. Later we added two x-ray detectors fore and aft in the aircraft.In many flights X-rays were detected indeed associated with lightning strikes. Up to now we could attribute the observed x-rays to the lightning discharge initiation, first due to leader steps in the attachment phase of the lightning channel which lasts several milliseconds, and secondly during several microseconds before the recoil current pulses. Mostly the x-rays appeared to originate from the cathode spot on the aircraft. The required fast electrons are accelerated in the high electric fields in air just before the current starts.In recent flights we observed a new phenomenon, a series of x-rays pulses lasting 8 microseconds, synchronous with the recoil current maximum of about 20 kA. From the current pattern and the relative intensity observed on both detectors, we again concluded that the x-ray originated somewhere in a region near the cathode, which was in this case the tail of the aircraft. The association with the current maximum is remarkable since an arc usually does not go with large electric fields. Arc jumps are a less likely because of the limited aircraft displacement. An alternative explanation is discharge initiation in the vicinity where the aircraft is not a part of that discharge current.In the presentation we will address such

  3. Compensatory recombination phenomena of neurological functions in central dysphagia patients

    Directory of Open Access Journals (Sweden)

    Xiao-dong Yuan

    2015-01-01

    Full Text Available We speculate that cortical reactions evoked by swallowing activity may be abnormal in patients with central infarction with dysphagia. The present study aimed to detect functional imaging features of cerebral cortex in central dysphagia patients by using blood oxygen level-dependent functional magnetic resonance imaging techniques. The results showed that when normal controls swallowed, primary motor cortex (BA4, insula (BA13, premotor cortex (BA6/8, supramarginal gyrus (BA40, and anterior cingulate cortex (BA24/32 were activated, and that the size of the activated areas were larger in the left hemisphere compared with the right. In recurrent cerebral infarction patients with central dysphagia, BA4, BA13, BA40 and BA6/8 areas were activated, while the degree of activation in BA24/32 was decreased. Additionally, more areas were activated, including posterior cingulate cortex (BA23/31, visual association cortex (BA18/19, primary auditory cortex (BA41 and parahippocampal cortex (BA36. Somatosensory association cortex (BA7 and left cerebellum in patients with recurrent cerebral infarction with central dysphagia were also activated. Experimental findings suggest that the cerebral cortex has obvious hemisphere lateralization in response to swallowing, and patients with recurrent cerebral infarction with central dysphagia show compensatory recombination phenomena of neurological functions. In rehabilitative treatment, using the favorite food of patients can stimulate swallowing through visual, auditory, and other nerve conduction pathways, thus promoting compensatory recombination of the central cortex functions.

  4. Mathematical approaches to bone reformation phenomena and numerical simulations

    Science.gov (United States)

    Matsuura, Yoshinori; Oharu, Shinnosuke; Takata, Takashi; Tamura, Akio

    2003-09-01

    Bone remodeling is metabolism of the bone through repetition of the resorption by osteoclasts and formation by osteoblasts. Osteoblasts produce inorganic calcium phosphate, which is converted to hydroxyapatite, and organic matrix consisting mainly of type I collagen, and then they deposit new bone to the part of the bone resorbed by osteoclasts. Osteoclasts dissociate calcium by secreting acid and degrade organic components by releasing lysosomal enzymes. Moreover, osteocytes in the bone play an important role in sensing various physical loads and conveying signals to activate osteoblasts. These three kinds of cells are linked to each other and perform the bone remodeling. Appropriate parameters representing the states of the bone and marrow are introduced and a mathematical model describing the bone remodeling phenomena is presented. The model involves an interface equation which determines the surface of the bone. The associated discrete model is formulated and its stable solvability is verified. Results of numerical simulations on a computer aided design system are visualized and then compared to clinical bone data. This work may be applied to medical science and in particular to dentistry.

  5. Discrete Particle Method for Simulating Hypervelocity Impact Phenomena

    Directory of Open Access Journals (Sweden)

    Erkai Watson

    2017-04-01

    Full Text Available In this paper, we introduce a computational model for the simulation of hypervelocity impact (HVI phenomena which is based on the Discrete Element Method (DEM. Our paper constitutes the first application of DEM to the modeling and simulating of impact events for velocities beyond 5 kms-1. We present here the results of a systematic numerical study on HVI of solids. For modeling the solids, we use discrete spherical particles that interact with each other via potentials. In our numerical investigations we are particularly interested in the dynamics of material fragmentation upon impact. We model a typical HVI experiment configuration where a sphere strikes a thin plate and investigate the properties of the resulting debris cloud. We provide a quantitative computational analysis of the resulting debris cloud caused by impact and a comprehensive parameter study by varying key parameters of our model. We compare our findings from the simulations with recent HVI experiments performed at our institute. Our findings are that the DEM method leads to very stable, energy–conserving simulations of HVI scenarios that map the experimental setup where a sphere strikes a thin plate at hypervelocity speed. Our chosen interaction model works particularly well in the velocity range where the local stresses caused by impact shock waves markedly exceed the ultimate material strength.

  6. Discrete Particle Method for Simulating Hypervelocity Impact Phenomena.

    Science.gov (United States)

    Watson, Erkai; Steinhauser, Martin O

    2017-04-02

    In this paper, we introduce a computational model for the simulation of hypervelocity impact (HVI) phenomena which is based on the Discrete Element Method (DEM). Our paper constitutes the first application of DEM to the modeling and simulating of impact events for velocities beyond 5 kms-1. We present here the results of a systematic numerical study on HVI of solids. For modeling the solids, we use discrete spherical particles that interact with each other via potentials. In our numerical investigations we are particularly interested in the dynamics of material fragmentation upon impact. We model a typical HVI experiment configuration where a sphere strikes a thin plate and investigate the properties of the resulting debris cloud. We provide a quantitative computational analysis of the resulting debris cloud caused by impact and a comprehensive parameter study by varying key parameters of our model. We compare our findings from the simulations with recent HVI experiments performed at our institute. Our findings are that the DEM method leads to very stable, energy-conserving simulations of HVI scenarios that map the experimental setup where a sphere strikes a thin plate at hypervelocity speed. Our chosen interaction model works particularly well in the velocity range where the local stresses caused by impact shock waves markedly exceed the ultimate material strength.

  7. Prediction and analysis of basic gravitational microlensing phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Nemiroff, R.J.

    1987-01-01

    The phenomena of gravitational microlensing are described, and predictions are made about its possible future detection. A mathematical formalism developed exploits gravitational lensing effects in terms of photometric-measuring capability. This formalism is then used to outline the most-probable places to look for microlensing. Basic microlensing-induced light curves are calculated for a variety of possible lens-source configurations. These configurations include both a single star and a double star acting as the lens. The light-curve signatures of the double-star lens are themselves indicators of the microlensing phenomenon. Light-curve signatures for a single star acting on a uniform extended source are presented. Analysis is described listing methods by which parameters taken from this light curve could be used to recover both lens and source information. The effect of microlensing on the shape of the spectral lines originating in the broad-line emission region (BLR) of an active galactic nucleus (AGN) is analyzed. A sample finding list of QSO's is presented for observers. For the assumption of galaxies made up entirely of compact objects, calculations are presented for each QSO on the list.

  8. Vortex phenomena in sidewall aneurysm hemodynamics: experiment and numerical simulation.

    Science.gov (United States)

    Le, Trung B; Troolin, Daniel R; Amatya, Devesh; Longmire, Ellen K; Sotiropoulos, Fotis

    2013-10-01

    We carry out high-resolution laboratory experiments and numerical simulations to investigate the dynamics of unsteady vortex formation across the neck of an anatomic in vitro model of an intracranial aneurysm. A transparent acrylic replica of the aneurysm is manufactured and attached to a pulse duplicator system in the laboratory. Time-resolved three-dimensional three-component velocity measurements are obtained inside the aneurysm sac under physiologic pulsatile conditions. High-resolution numerical simulations are also carried out under conditions replicating as closely as possible those of the laboratory experiment. Comparison of the measured and computed flow fields shows very good agreement in terms of instantaneous velocity fields and three-dimensional coherent structures. Both experiments and numerical simulations show that a well-defined vortical structure is formed near the proximal neck at early systole. This vortical structure is advected by the flow across the aneurysm neck and impinges on the distal wall. The results underscore the complexity of aneurysm hemodynamics and point to the need for integrating high-resolution, time-resolved three-dimensional experimental and computational techniques. The current work emphasizes the importance of vortex formation phenomena at aneurysmal necks and reinforces the findings of previous computational work and recent clinical studies pointing to links between flow pulsatility and aneurysm growth and rupture.

  9. FDTD modeling of anisotropic nonlinear optical phenomena in silicon waveguides.

    Science.gov (United States)

    Dissanayake, Chethiya M; Premaratne, Malin; Rukhlenko, Ivan D; Agrawal, Govind P

    2010-09-27

    A deep insight into the inherent anisotropic optical properties of silicon is required to improve the performance of silicon-waveguide-based photonic devices. It may also lead to novel device concepts and substantially extend the capabilities of silicon photonics in the future. In this paper, for the first time to the best of our knowledge, we present a three-dimensional finite-difference time-domain (FDTD) method for modeling optical phenomena in silicon waveguides, which takes into account fully the anisotropy of the third-order electronic and Raman susceptibilities. We show that, under certain realistic conditions that prevent generation of the longitudinal optical field inside the waveguide, this model is considerably simplified and can be represented by a computationally efficient algorithm, suitable for numerical analysis of complex polarization effects. To demonstrate the versatility of our model, we study polarization dependence for several nonlinear effects, including self-phase modulation, cross-phase modulation, and stimulated Raman scattering. Our FDTD model provides a basis for a full-blown numerical simulator that is restricted neither by the single-mode assumption nor by the slowly varying envelope approximation.

  10. On New Phenomena of Photon from Modified Double Slit Experiment

    Science.gov (United States)

    Liu, Haisheng

    2011-03-01

    A modified double slit experiment of light was implemented. In the experiment, a spatial shape filter is used to manipulate the shape of cross section of laser beam. When this modified laser beam was shined on the double slit, the intensity distribution of laser beam on double slit is asymmetrical. In this way, the laser light was directed to pass through only one or two slits of double slit in different sections. So the which-way information is predetermined before the photons pass through the slits. At the same time, the visible interference pattern can be observed on a monitor screen after the double slit. A couple of new phenomena had been observed from this experiment. The results of this experiment raise questions about Wave-Particle Duality model of quantum theory, which is the foundation for the Copenhagen explanation that is generally regarded as the principal interpretation of quantum theory. As the observed properties from this experiment cannot be fully explained using the quantum theory, especially the Copenhagen explanation, a new model of photon is proposed. The new model for photon should be also applicable to all other micro entities, according to L. de Broglie assumption.

  11. A variational approach to fracture and other inelastic phenomena

    CERN Document Server

    Piero, Gianpietro

    2014-01-01

    This book exposes a number of mathematical models for fracture of growing difficulty. All models are treated in a unified way, based on incremental energy minimization. They differ from each other by the assumptions made on the inelastic part of the total energy, here called the "cohesive energy". Each model describes a specific aspect of material response, and particular care is devoted to underline the correspondence of each model to the experiments.  The content of the book is  a re-elaboration of the lectures delivered at the First Sperlonga Summer School on Mechanics and Engineering Sciences in September 2011. In the year and a half elapsed after the course, the material has been revised and enriched with new and partially unpublished results. Significant additions have been introduced in the occasion of the course "The variational approach to fracture and other inelastic phenomena", delivered at SISSA, Trieste, in March 2013.  The Notes reflect a research line carried on by the writer over the yea...

  12. Hydration Phenomena of Functionalized Carbon Nanotubes (CNT/Cement Composites

    Directory of Open Access Journals (Sweden)

    Bhuvaneshwari Balasubramaniam

    2017-10-01

    Full Text Available The exciting features of carbon nanotubes (CNTs, such as high elastic modulus, high thermal and electrical conductivities, robustness, and nanoscopic surface properties make them attractive candidates for the cement industry. They have the potential to significantly enhanceengineering properties. CNTs play an important and critical role as nano-anchors in concrete, which enhance the strength by bridging pores in the composite matrix, thereby ensuring robust mechanical strength. The diameter, dispersion, aspect ratio, and interfacial surface interaction of CNTs affect the physical and mechanical properties of concrete, if due care is not taken. In this paper, the usable amount of CNT is scaled down considerably from 0.5% to 0.025% by weight of the cement and the fluctuation caused by these phenomena is assessed. It is observed that the properties and exact quantities of incorporated CNTs influence the hydration and consistency of the composites. In order to address these issues, the surface functionalization of CNTs and rheological studies of the composites are performed. The hydration products and functional groups are carefully optimized and characterized by using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, and a Zeta potential analyzer. For Mixes 6 and 7, the compressive and tensile strength of CNTs incorporated in mortar specimens caused77% and 48% increases in split tensile strength, respectively, and 17% and 35% increases in compressive strength, respectively, after 28 days of curing and compared withthe control Mix.

  13. Investigating paranormal phenomena: Functional brain imaging of telepathy

    Directory of Open Access Journals (Sweden)

    Venkatasubramanian Ganesan

    2008-01-01

    Full Text Available Aim: "Telepathy" is defined as "the communication of impressions of any kind from one mind to another, independently of the recognized channels of sense". Meta-analyses of "ganzfield" studies as well as "card-guessing task" studies provide compelling evidence for the existence of telepathic phenomena. The aim of this study was to elucidate the neural basis of telepathy by examining an individual with this special ability. Materials and Methods: Using functional MRI, we examined a famous "mentalist" while he was performing a telepathic task in a 1.5 T scanner. A matched control subject without this special ability was also examined under similar conditions. Results: The mentalist demonstrated significant activation of the right parahippocampal gyrus after successful performance of a telepathic task. The comparison subject, who did not show any telepathic ability, demonstrated significant activation of the left inferior frontal gyrus. Conclusions: The findings of this study are suggestive of a limbic basis for telepathy and warrant further systematic research.

  14. Some Aspects of Interfacial Phenomena in Steelmaking and Refining

    Science.gov (United States)

    Wang, L. J.; Viswanathan, N. N.; Muhmood, L.; Kapilashrami, E.; Seetharaman, S.

    2016-08-01

    Unique experiments were designed to study the surface phenomena in steelmaking reactions. The concept of surface sulfide capacities and an understanding of the surface accumulation of surface-active species, based on experimental results, are presented. In order to understand the flow phenomenon at slag/metal interface, experiments were designed to measure the interfacial velocity of S on the surface of an iron drop immersed in an aluminosilicate slag using the X-ray sessile drop method. The oscillation of the iron drop in the slag due to the change in the surface concentration of sulfur at the slag-metal interface was monitored by X-ray imaging. From the observations, the interfacial velocity of sulfur was evaluated. Similar experiments were performed to measure the interfacial velocity of oxygen at the interface as well as the impact of oxygen potential on the interfacial velocity of sulfur. The interfacial shear viscosity and the dilatational modulus were also evaluated. In a study of the wetting of alumina base by iron drop at constant oxygen pressure under isothermal condition, the contact angle was found to be decreased with the progress of the reaction leading to the formation of hercynite as an intermediate layer creating non-wetting conditions. In the case of silica substrate, an intermediate liquid fayalite layer was formed.

  15. RISK WEATHER PHENOMENA IN CLUJ COUNTY IN JUNE 2010

    Directory of Open Access Journals (Sweden)

    IRINA BLAGA

    2011-03-01

    Full Text Available Risk weather phenomena in Cluj county in June 2010. June, in the Cluj county area, has been a month of extremes, in both heat and precipitation. The beginning of the month debuted with daily maximum temperatures close to the normal heat period product and then gradually heating the air occurred, the maximum temperatures increasing from day to day, reaching very high values, up 34 °C, by the middle of the month, when the temperature-humidity index (ITU reached and exceeded, in relatively large areas, the critical level of 80. In the second part of June, the target area was characterized by atmospheric instability that fostered the development of strong convective structures, which led to the recording of large amounts of rain from showers and heavy rain, that were associated with floods and strong winds, which turned into storms with hail and lightning. For the second half of the month, a particular case dated 06/21/2010 was analyzed, the day in which the most destructive effects of the floods, seen as phenomenon hazardous weather reported by the Inspectorate for Emergency Situations (ISU in Cluj County: the death of a person in the Morlaca area, 250 homes flooded in the cities of Huedin, Morlaca, Sâncraiu, Săcuieu, Călata, Poeni. There have also been floods in the cities of Turda, Copaceni and Martinesti. Landslides were recorded in Domosu and Horlacea.

  16. A comparison of thermoelectric phenomena in diverse alloy systems

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Bruce [Iowa State Univ., Ames, IA (United States)

    1999-01-01

    The study of thermoelectric phenomena in solids provides a wealth of opportunity for exploration of the complex interrelationships between structure, processing, and properties of materials. As thermoelectricity implies some type of coupled thermal and electrical behavior, it is expected that a basic understanding of transport behavior in materials is the goal of such a study. However, transport properties such as electrical resistivity and thermal diffusivity cannot be fully understood and interpreted without first developing an understanding of the material's preparation and its underlying structure. It is the objective of this dissertation to critically examine a number of diverse systems in order to develop a broad perspective on how structure-processing-property relationships differ from system to system, and to discover the common parameters upon which any good thermoelectric material is based. The alloy systems examined in this work include silicon-germanium, zinc oxide, complex intermetallic compounds such as the half-Heusler MNiSn, where M = Ti, Zr, or Hf, and rare earth chalcogenides.

  17. Comparative phenomena about phraseology in the animal theme field

    Directory of Open Access Journals (Sweden)

    Lindita Çifçi

    2016-07-01

    Full Text Available Every language has its own history and structure of development and it is in a gradual and continuous process of change moving in an unconscious way from one kind to another, so in different languages we distinguish analogical development. Saphir (1912 was one of the first linguistics and anthropologists who developed the linguistic discipline and in an interlingual comparison he identified that languages differ from one another, but some differ more than others. Phraseological units deriving from a certain language do not remain isolated within the same language. They travel from one language to another due to relationships between people and languages. This happens because during these centennial relationships, people have exchanged not only goods, but even cultural values. As a result in our first steps of research there is a need to know and decide on phraseological types in each language, as well as comparison with other languages, to find out what is common and what is special among them. One of the main reasons of analogies in phraseology stays on similar or approximate concepts of objects and features of everyday life. Having into consideration the fact that the main source of phraseological units is the material world with a great variety and a wide range of clothes, tools, domestic animals, parts of human body, food and cooking, weapons and hunting objects, tribal relationships, job processes etc. we are going to analyse in this manuscript this phraseological phenomena.

  18. Thermal Aging Phenomena in Cast Duplex Stainless Steels

    Science.gov (United States)

    Byun, T. S.; Yang, Y.; Overman, N. R.; Busby, J. T.

    2016-02-01

    Cast stainless steels (CASSs) have been extensively used for the large components of light water reactor (LWR) power plants such as primary coolant piping and pump casing. The thermal embrittlement of CASS components is one of the most serious concerns related to the extended-term operation of nuclear power plants. Many past researches have concluded that the formation of Cr-rich α'-phase by Spinodal decomposition of δ-ferrite phase is the primary mechanism for the thermal embrittlement. Cracking mechanism in the thermally-embrittled duplex stainless steels consists of the formation of cleavage at ferrite and its propagation via separation of ferrite-austenite interphase. This article intends to provide an introductory overview on the thermal aging phenomena in LWR-relevant conditions. Firstly, the thermal aging effect on toughness is discussed in terms of the cause of embrittlement and influential parameters. An approximate analysis of thermal reaction using Arrhenius equation was carried out to scope the aging temperatures for the accelerated aging experiments to simulate the 60 and 80 years of services. Further, an equilibrium precipitation calculation was performed for model CASS alloys using the CALPHAD program, and the results are used to describe the precipitation behaviors in duplex stainless steels. These results are also to be used to guide an on-going research aiming to provide knowledge-based conclusive prediction for the integrity of the CASS components of LWR power plants during the service life extended up to and beyond 60 years.

  19. Thermal dynamics of thermoelectric phenomena from frequency resolved methods

    Directory of Open Access Journals (Sweden)

    J. García-Cañadas

    2016-03-01

    Full Text Available Understanding the dynamics of thermoelectric (TE phenomena is important for the detailed knowledge of the operation of TE materials and devices. By analyzing the impedance response of both a single TE element and a TE device under suspended conditions, we provide new insights into the thermal dynamics of these systems. The analysis is performed employing parameters such as the thermal penetration depth, the characteristic thermal diffusion frequency and the thermal diffusion time. It is shown that in both systems the dynamics of the thermoelectric response is governed by how the Peltier heat production/absorption at the junctions evolves. In a single thermoelement, at high frequencies the thermal waves diffuse semi-infinitely from the junctions towards the half-length. When the frequency is reduced, the thermal waves can penetrate further and eventually reach the half-length where they start to cancel each other and further penetration is blocked. In the case of a TE module, semi-infinite thermal diffusion along the thickness of the ceramic layers occurs at the highest frequencies. As the frequency is decreased, heat storage in the ceramics becomes dominant and starts to compete with the diffusion of the thermal waves towards the half-length of the thermoelements. Finally, the cancellation of the waves occurs at the lowest frequencies. It is demonstrated that the analysis is able to identify and separate the different physical processes and to provide a detailed understanding of the dynamics of different thermoelectric effects.

  20. Analytical Study on Transient Direct Contact Melting Phenomena

    Science.gov (United States)

    Saito, Akio; Kumano, Hiroyuki; Okawa, Seiji; Yamashita, Kazuya

    In this research, the investigation on the characteristics of the unsteady state phenomenon of the direct contact melting at the initial stage was carried out analytically, where the system starts to form a liquid film between the solid surface and the heating plate. Three types of heating conditions were examined. One was to have a constant heat flux at the top surface of the heating plate, the next was to have the constant heat flux at bottom surface of the heating plate, and the last was to have the constant heat transfer coefficient at the bottom surface of the heating plate. The difference in phenomena under three conditions were pointed out. Furthermore, various parameters such as the size of the heating plate, the thermal physical properties of the heating plate, the size and the thermal physical properties of the PCM, were varied for each condition, and the effect of each parameter was investigated. The results were summarized qualitatively at two points: one was the melting speed at the steady state, and the other was the time required to approach the steady state.

  1. An experimental investigation of iso-octane ignition phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Walton, S.M.; He, X.; Zigler, B.T.; Wooldridge, M.S.; Atreya, A. [Department of Mechanical Engineering, University of Michigan, 2350 Hayward St., Ann Arbor, MI 48109-2125 (United States)

    2007-08-15

    High-speed digital imaging has been used in rapid compression facility (RCF) studies to investigate ignition phenomena of iso-octane/air mixtures. Sequential images were captured for each experiment. The results indicate the existence of two ignition regimes. In one domain, ignition is rapid, typically less than 76 {mu}s, and ignition occurs simultaneously throughout the test volume. In the other domain, reaction fronts form and propagate within the test volume prior to volumetric ignition. The data span equivalence ratios from {phi}=0.20 to 1.98, with inert/O{sub 2} gas ratios from 1.38 to 5.89, pressures from 8.7 to 16.6 atm, and temperatures from 903 to 1020 K. The transition between the two regimes is discussed in the context of the mixture composition and experimental conditions. The analysis shows that the fuel mole fraction is a key parameter dictating the boundary between the modes of ignition. Below a critical mole fraction limit, volumetric ignition is observed; above the critical limit, reaction fronts are consistently present prior to volumetric ignition. The ignition delay times for both ignition regimes are well reproduced using a homogeneous simulation with detailed reaction chemistry, when the state conditions are modified to account for the presence of the reaction fronts. The results are discussed in terms of proposed reaction chemistry, ignition theory, and previous studies of iso-octane ignition. (author)

  2. Collective phenomena in volume and surface barrier discharges

    Science.gov (United States)

    Kogelschatz, U.

    2010-11-01

    Barrier discharges are increasingly used as a cost-effective configuration to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without significant heating of the background gas. In most applications the barrier is made of dielectric material. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are devoted to biomedical applications and to plasma actuators for flow control. Sinusoidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or diffuse, laterally homogeneous discharges. The physical effects leading to collective phenomena in volume and surface barrier discharges are discussed in detail. Special attention is paid to self-organization of current filaments and pattern formation. Major similarities of the two types of barrier discharges are elaborated.

  3. Transport Phenomena of Water in Molecular Fluidic Channels

    Science.gov (United States)

    Vo, Truong Quoc; Kim, Bohung

    2016-09-01

    In molecular-level fluidic transport, where the discrete characteristics of a molecular system are not negligible (in contrast to a continuum description), the response of the molecular water system might still be similar to the continuum description if the time and ensemble averages satisfy the ergodic hypothesis and the scale of the average is enough to recover the classical thermodynamic properties. However, even in such cases, the continuum description breaks down on the material interfaces. In short, molecular-level liquid flows exhibit substantially different physics from classical fluid transport theories because of (i) the interface/surface force field, (ii) thermal/velocity slip, (iii) the discreteness of fluid molecules at the interface and (iv) local viscosity. Therefore, in this study, we present the result of our investigations using molecular dynamics (MD) simulations with continuum-based energy equations and check the validity and limitations of the continuum hypothesis. Our study shows that when the continuum description is subjected to the proper treatment of the interface effects via modified boundary conditions, the so-called continuum-based modified-analytical solutions, they can adequately predict nanoscale fluid transport phenomena. The findings in this work have broad effects in overcoming current limitations in modeling/predicting the fluid behaviors of molecular fluidic devices.

  4. Can Transient Phenomena Help Improving Time Resolution in Scintillators?

    CERN Document Server

    Lecoq, P; Vasiliev, A

    2014-01-01

    The time resolution of a scintillator-based detector is directly driven by the density of photoelectrons generated in the photodetector at the detection threshold. At the scintillator level it is related to the intrinsic light yield, the pulse shape (rise time and decay time) and the light transport from the gamma-ray conversion point to the photodetector. When aiming at 10 ps time resolution, fluctuations in the thermalization and relaxation time of hot electrons and holes generated by the interaction of ionization radiation with the crystal become important. These processes last for up to a few tens of ps and are followed by a complex trapping-detrapping process, Poole-Frenkel effect, Auger ionization of traps and electron-hole recombination, which can last for a few ns with very large fluctuations. This paper will review the different processes at work and evaluate if some of the transient phenomena taking place during the fast thermalization phase can be exploited to extract a time tag with a precision in...

  5. Optical luminosity of the transient luminous phenomena in Hessdalen, Norway

    Science.gov (United States)

    Gitle Hauge, Bjørn; Kjøniksen, Anna-Lena; Petter Strand, Erling

    2017-04-01

    Transient luminous phenomena has been observed in the low atmosphere over Hessdalen valley for several decades, first report is claimed to be 200 years old. The area is scattered with old copper, zinc, sulphur and iron mines. The river Hesja divides the valley, running south to north. The river descends from 800 m altitude to 600m. In the middle of the valley, an old copper and sulphur mine feeds the river with its acidic sulphur pollution. Eyewitnesses have reported lights emerging from the river, but most reports are of lights suddenly emerging in low altitudes over the valley, 1000m - 2000m altitude. Common colours are white, yellow, orange and blue. Green is absent. The optical spectrum of the white lights has been obtained several times, indicating a continuous spectrum. The luminosity of the Hessdalen lights has been debated, some speculating that the phenomenońs radiant power reaches up to 1MW. A more moderate calculation done by Teodorani in 2004 suggests 19KW. The cause of the huge difference is due to uncertainty in establishing correct distance to the phenomenon. Recent discoveries done by this team, indicates that the radiant power is usually much lower. For the first time in Hessdalen, pictures with optical spectrums was obtained at a distance not more than 500m. Two similar observations were done from the same position, indicating a possible birthplace. Atmospheric data and spectrum analysis was also coinciding. Data from this short distance observation will be presented.

  6. Eletromagnetivity: the mainspring for the understanding of all the phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Clessio Alves [Universidade Estadual de Santa Cruz - UESC, Ilheus, BA (Brazil)

    2013-07-01

    Full text: In the present article, we present the unification of the four fundamental forces (strong force, electroweak, electromagnetic and gravitational) of Nature; demonstrating that, three of them, are just different manifestations of the intensity of a single force - Gravity. Done that, through the unified force, it is explained the mechanism of cohesion of the atomic nucleus, the cause of the Pioneer anomaly, the origin of inertia, the mechanism of the red shift because of a gravitational field and it is demonstrated, through the formula of centrifugal force the reality of the Machs Principle. Moreover, the cause of phenomena already known are explained; such as the superfluidity of helium II, the nature of the escape velocity, the nature of matter and dark energy, the formation mechanism of black holes in the galactic center, the mechanism of gravitational interaction, the variation of energy that must be added to the terms of the total mechanical energy of a system and the retrograde motion of Venus. Furthermore, by the present theory, it is unified the general relativity to the quantum mechanics into a single theoretical body; after establishing the ratio between small and large scales in the universe, proving the applicability of the same physical laws in both situations. (author)

  7. Investigations of corrosion phenomena on gold coins with SIMS

    Science.gov (United States)

    Mayerhofer, K. E.; Piplits, K.; Traum, R.; Griesser, M.; Hutter, H.

    2005-09-01

    In order to establish a new handling procedure for contaminated coins, the Coin Cabinet and the Conservation Science Department of the Kunsthistorisches Museum, Vienna, initiated a research project on corrosion effects of gold coins. By now, investigations on historic and contemporary coins included optical microscopy, scanning electron microscopy (SEM), Auger electron microscopy (AES), X-ray photoelectron microscopy (XPS), and electrochemical methods showing the distribution of pollutants. This work focuses on secondary ion mass spectrometry (SIMS) investigations merely showing the distribution of electronegative elements, such as sulfur, oxygen, and chlorine on the surface. Sulfur is highly suspected of causing the observed corrosion phenomena, and is indeed enriched near polluting splints. Since SIMS is a destructive method, the investigated samples are test coins with intentionally added impurities. These coins were manufactured in cooperation with the Austrian Mint. They were treated with potassium polysulfide (K 2S x) for 8 h gaining a rapid corrosion of the surface. SIMS mass spectra, depth profiles, and images were done (a) at non-polluted areas, (b) near polluted areas with slight coloring, and (c) directly at polluting stains showing enrichments of sulfur and chlorine. Due to the success of these investigations further studies on historic coins are intended.

  8. Investigation of some galactic and extragalactic gravitational phenomena

    Directory of Open Access Journals (Sweden)

    Jovanović P.

    2012-01-01

    Full Text Available Here we present a short overview of the most important results of our investigations of the following galactic and extragalactic gravitational phenomena: supermassive black holes in centers of galaxies and quasars, supermassive black hole binaries, gravitational lenses and dark matter. For the purpose of these investigations, we developed a model of a relativistic accretion disk around a supermassive black hole, based on the ray-tracing method in the Kerr metric, a model of a bright spot in an accretion disk and three different models of gravitational microlenses. All these models enabled us to study physics, spacetime geometry and effects of strong gravity in the vicinity of supermassive black holes, variability of some active galaxies and quasars, different effects in the lensed quasars with multiple images, as well as the dark matter fraction in the Universe. We also found an observational evidence for the first spectroscopically resolved sub-parsec orbit of a supermassive black hole binary system in the core of active galaxy NGC 4151. Besides, we studied applications of one potential alternative to dark matter in the form of a modified theory of gravity on Galactic scales, to explain the recently observed orbital precession of some S-stars, which are orbiting around a massive black hole at the Galactic center. [Projekat Ministarstva nauke Republike Srbije, br. 176003: Gravitation and the Large Scale Structure of the Universe

  9. In search of new phenomena using polarization. HERA and ILC

    Energy Technology Data Exchange (ETDEWEB)

    Helebrant, Christian

    2009-12-15

    The longitudinal polarization of leptons can be used as an important tool in the search for new phenomena at particle colliders. In the first part of this thesis a search for first generation leptoquarks at the H1 experiment is presented. During the HERA-2 runperiod polarized lepton beams were used. The analysis presented herein utilizes this fact in order to enhance the sensitivity to these chirally coupling leptoquarks. Since no evidence for their existence is found, exclusion limits depending on the mass and Yukawa coupling are calculated. This analysis can exclude leptoquarks coupling at electromagnetic strength up to masses of 280-300 GeV, depending on the leptoquark quantum numbers. A new domain of physics is expected to be open to the planned electron positron linear collider ILC, where polarized lepton beams will play an important role. In order to fully exploit its physics potential, the polarization will have to be measured with an as yet unequaled precision of 0.25%, which is expected to be limited by systematic effects, like the nonlinearity of the photodetectors employed. In the second part of this thesis several methods are tested with respect to their capability to resolve photodetector nonlinearities at the permille level, and checked for their long term stability. With some of the methods presented herein it will be possible to measure and correct photodetector nonlinearities at a running ILC experiment with the accuracy required in order to achieve the aimed precision of the polarization measurement. (orig.)

  10. Quantum phenomena modelled by interactions between many classical worlds

    Science.gov (United States)

    Wiseman, Howard; Hall, Michael; Deckert, Dirk-Andre

    2015-03-01

    We investigate how quantum theory can be understood as the continuum limit of a mechanical theory, in which there is a huge, but countable, number of classical ``worlds,'' and quantum effects arise solely from a universal interaction between these worlds, without reference to any wave function. Here a ``world'' means an entire universe with well-defined properties, determined by the classical configuration of its particles and fields. In our approach each world evolves deterministically; probabilities arise due to ignorance as to which world a given observer occupies; and we argue that in the limit of infinitely many worlds the wave function can be recovered (as a secondary object) from the motion of these worlds. We introduce a simple model of such a ``many interacting worlds'' approach and show that it can reproduce some generic quantum phenomena-such as Ehrenfest's theorem, wavepacket spreading, barrier tunneling and zero point energy-as a direct consequence of mutual repulsion between worlds. Finally, we perform numerical simulations using our approach. We demonstrate, first, that it can be used to calculate quantum ground states, and second, that it is capable of reproducing, at least qualitatively, the double-slit interference phenomenon.

  11. Fluid models and simulations of biological cell phenomena

    Science.gov (United States)

    Greenspan, H. P.

    1982-01-01

    The dynamics of coated droplets are examined within the context of biofluids. Of specific interest is the manner in which the shape of a droplet, the motion within it as well as that of aggregates of droplets can be controlled by the modulation of surface properties and the extent to which such fluid phenomena are an intrinsic part of cellular processes. From the standpoint of biology, an objective is to elucidate some of the general dynamical features that affect the disposition of an entire cell, cell colonies and tissues. Conventionally averaged field variables of continuum mechanics are used to describe the overall global effects which result from the myriad of small scale molecular interactions. An attempt is made to establish cause and effect relationships from correct dynamical laws of motion rather than by what may have been unnecessary invocation of metabolic or life processes. Several topics are discussed where there are strong analogies droplets and cells including: encapsulated droplets/cell membranes; droplet shape/cell shape; adhesion and spread of a droplet/cell motility and adhesion; and oams and multiphase flows/cell aggregates and tissues. Evidence is presented to show that certain concepts of continuum theory such as suface tension, surface free energy, contact angle, bending moments, etc. are relevant and applicable to the study of cell biology.

  12. Archaeoastronomy as a Tool for Understanding Celestial Phenomena

    Science.gov (United States)

    Koufos, S.; Chatzichristou, E.

    2017-09-01

    To key feature of the wise and Modern Man was, is and will be the observation of the sky. The acquisition of knowledge by observing the majesty of the sky and studying these phenomena (stars, planets, sun, moon, comets, asteroids, meteors, orbits, seasons, etc.). decisively influenced all human cultures. Therefore the research on the astronomical knowledge and their usefulness for each culture may reveal important anthropological data. With this scientific article the ARCHAEOASTRONOMY engaged in a global dimension. With common ground among even distant peoples. The purpose of the speech is both the externalization of ARCHAEOASTRONOMY secondly the education and students interested in astronomy in a simple manner and methodology as used by our ancestors in order to better understand the basic rules of the celestial dome. Applied methods with the participation of students from local schools and experiments in ancient monuments in Rhodes existed before with great success since the beginning of 2000 and continues today enriching the resources and people of all ages, the island where noted and considered the "father" astronomy of Hipparchus, the island where construction probably the "Antikythera mechanism"

  13. Nonlinear stochastic systems with network-induced phenomena recursive filtering and sliding-mode design

    CERN Document Server

    Hu, Jun; Gao, Huijun

    2014-01-01

    This monograph introduces methods for handling filtering and control problems in nonlinear stochastic systems arising from network-induced phenomena consequent on limited communication capacity. Such phenomena include communication delay, packet dropout, signal quantization or saturation, randomly occurring nonlinearities and randomly occurring uncertainties.The text is self-contained, beginning with an introduction to nonlinear stochastic systems, network-induced phenomena and filtering and control, moving through a collection of the latest research results which focuses on the three aspects

  14. Equilibrium and Non-Equilibrium Condensation Phenomena in Tuneable 3D and 2D Bose Gases

    Science.gov (United States)

    2016-04-01

    AFRL-AFOSR-UK-TR-2016-0009 Equilibrium and non- equilibrium condensation phenomena in tuneable 3D and 2D Bose gases Zoran Hadzibabic THE CHANCELLOR...31-Aug-2015 4. TITLE AND SUBTITLE Equilibrium and non- equilibrium condensation phenomena in tuneable 3D and 2D Bose gases 5a. CONTRACT NUMBER... equilibrium and non- equilibrium many-body phenomena, trapping ultracold atomic gases in different geometries including both 3 and 2 spatial dimensions

  15. Coronal and heliospheric imagers for solar wind phenomena

    Science.gov (United States)

    Middleton, Kevin F.; Bourdelle, Anthony; Davies, Jackie A.; Eyles, Chris J.; Griffin, Doug K.; Harrison, Richard A.; Richards, Tony R.; Rogers, J. Kevin; Tappin, S. James; Tosh, Ian A. J.; Waltham, Nick R.

    2015-09-01

    RAL Space is enhancing its program to lead the development of European capabilities in space-based visible-light coronal and heliospheric imaging instrumentation in the light of emerging opportunities such as the European Space Agency's Space Situational Awareness program and recent S2 small-mission call. Visible-light coronal and heliospheric imaging of solar wind phenomena, such as coronal mass ejections and interaction regions, is of critical importance to space weather studies, both operationally and in terms of enabling the underpinning science. This work draws on heritage from scientific instruments such as LASCO (Large Angle and Spectrometric Coronagraph) on the SOHO spacecraft, SMEI (Solar Mass Ejection Imager) on the Coriolis spacecraft and the HI (Heliospheric Imager) instruments on STEREO. Such visible-light observation of solar wind structures relies on the detection of sunlight that has been Thomson-scattered by electrons (the so-called K-corona). The Thomson-scattered signal must be extracted from other signals that can be many orders of magnitude greater (such as that from the F-corona and the solar disc itself) and this places stringent constraints on stray-light rejection, as well as pointing stability and accuracy. We discuss the determination of instrument requirements, key design trade-offs and the evolution of base-line designs for the coronal and heliospheric regimes. We explain how the next generation of instruments will build on this heritage while also, in some cases, meeting the challenges on resources imposed on operational space weather imagers. In particular, we discuss the optical engineering challenges involved in the design of these instruments.

  16. Field- and irradiation-induced phenomena in memristive nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Mikhaylov, A.N.; Gryaznov, E.G.; Belov, A.I.; Korolev, D.S.; Sharapov, A.N.; Guseinov, D.V.; Tetelbaum, D.I.; Tikhov, S.V.; Malekhonova, N.V.; Bobrov, A.I.; Pavlov, D.A.; Gerasimova, S.A.; Kazantsev, V.B.; Agudov, N.V.; Dubkov, A.A. [Lobachevsky University, Nizhny Novgorod (Russian Federation); Rosario, C.M.M.; Sobolev, N.A. [Departamento de Fisica and I3N, Universidade de Aveiro (Portugal); Spagnolo, B. [Dipartimento di Fisica e Chimica, Universita di Palermo, Group of Interdisciplinary Theoretical Physics (Italy); CNISM, Unita di Palermo (Italy)

    2016-12-15

    The breakthrough in electronics and information technology is anticipated by the development of emerging memory and logic devices, artificial neural networks and brain-inspired systems on the basis of memristive nanomaterials represented, in a particular case, by a simple 'metal-insulator-metal' (MIM) thin-film structure. The present article is focused on the comparative analysis of MIM devices based on oxides with dominating ionic (ZrO{sub x}, HfO{sub x}) and covalent (SiO{sub x}, GeO{sub x}) bonding of various composition and geometry deposited by magnetron sputtering. The studied memristive devices demonstrate reproducible change in their resistance (resistive switching - RS) originated from the formation and rupture of conductive pathways (filaments) in oxide films due to the electric-field-driven migration of oxygen vacancies and / or mobile oxygen ions. It is shown that, for both ionic and covalent oxides under study, the RS behaviour depends only weakly on the oxide film composition and thickness, device geometry (down to a device size of about 20 x 20 μm{sup 2}). The devices under study are found to be tolerant to ion irradiation that reproduces the effect of extreme fluences of high-energy protons and fast neutrons. This common behaviour of RS is explained by the localized nature of the redox processes in a nanoscale switching oxide volume. Adaptive (synaptic) change of resistive states of memristive devices is demonstrated under the action of single or repeated electrical pulses, as well as in a simple model of coupled (synchronized) neuron-like generators. It is concluded that the noise-induced phenomena cannot be neglected in the consideration of a memristive device as a nonlinear system. The dynamic response of a memristive device to periodic signals of complex waveform can be predicted and tailored from the viewpoint of stochastic resonance concept. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Freezing in porous media: Phase behavior, dynamics and transport phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Wettlaufer, John S. [Yale Univ., New Haven, CT (United States)

    2012-12-21

    This research was focused on developing the underlying framework for the mechanisms that control the nature of the solidification of a broad range of porous media. To encompass the scope of porous media under consideration we considered material ranging from a dilute colloidal suspension to a highly packed saturated host matrix with a known geometry. The basic physical processes that occur when the interstitial liquid phase solidifies revealed a host of surprises with a broad range of implications from geophysics to materials science and engineering. We now understand that ostensibly microscopic films of unfrozen liquid control both the equilibrium and transport properties of a highly packed saturated host matrix as well as a rather dilute colloidal suspension. However, our description of the effective medium behavior in these settings is rather different and this sets the stage for the future research based on our past results. Once the liquid phase of a saturated relatively densely packed material is frozen, there is a rich dynamical behavior of particles for example due to the directed motion driven by thermomolecular pressure gradients or the confined Brownian motion of the particles. In quite striking contrast, when one freezes a dilute suspension the behavior can be rather more like that of a binary alloy with the particles playing the role of a ``solute''. We probed such systems quantitatively by (i) using X ray photon correlation spectroscopy (XPCS) and Small Angle X-ray Scattering (SAXS) at the Advanced Photon Source at Argonne (ii) studying the Argonne cell in the laboratory using optical microscopy and imagery (because it is not directly visible while in the vacuum can). (3) analyzed the general transport phenomena within the framework of both irreversible thermodynamics and alloy solidification and (4) applied the results to the study of the redistribution of solid particles in a frozen interstitial material. This research has gone a long way

  18. Wave phenomena preceding and during a beam-plasma discharge

    Energy Technology Data Exchange (ETDEWEB)

    Boswell, R.W.; Morey, I.J.; Porteous, R.K. (Australian National Univ., Canberra, Australian Capital Territory (Australia))

    1989-03-01

    The waves and associated phenomena which are generated prior to and during the beam-plasma discharge (BPD) in the waves on magnetized beams and turbulence (WOMBAT) apparatus are described. These range in frequency from below the ion gyrofrequency of a few kilohertz to strong harmonics of the electron plasma frequency above 1 GHz. The low-frequency ion waves appear to be driven by E {times} B forces arising from the nonneutrality of the electron beam-plasma column at low beam currents (I{sub b}) or low gas pressures (P). As I{sub b} increases, the motion becomes chaotic after a sequence of wave period doublings resulting in the generation of subharmonies. Windows of coherent motion are observed within the chaotic regions. Further increases in I{sub b} lead to increases in ionizing collisions and when the background plasma density becomes sufficiently high, waves around the electron plasma frequency can be generated. Initially, these waves are modulated by the gross density perturbations of the large-amplitude ion waves, but subsequently they also increase to large amplitudes: e{phi}/kT {approximately} 1. This is sufficient to accelerate the background electrons to ionizing energies and produce the BPD. At low pressures this occurs for f{sub pe}/f{sub ce} {approximately} 0.5 (BPD1) with the process occurring in short bursts ({approximately} 100{tau}{sub pe}). Increasing I{sub b} produces a sudden jump in the frequency to {approximately} 1.5 f{sub ce} and a further increase in the plasma density and luminosity, which the authors term BPD2.

  19. Liquid radiation detectors based on nanosilver surface plasmon resonance phenomena.

    Science.gov (United States)

    Puiso, Judita; Laurikaitiene, Jurgita; Adliene, Diana; Prosycevas, Igoris

    2010-01-01

    The rapid development of micro- and nanostructures containing silver nanoparticles is based on their unique physical properties. Despite the new applications of silver nanoparticles in nanomedicine are under heavy discussions, silver nanoparticles could be used in liquid radiation detectors thanks to the irradiation-induced surface plasmon resonance (SPR) phenomena observed in the colloidal solutions. Silver nitrate (1 mM AgNO(3)) and sodium citrate (1 wt% and 5 wt% C(6)H(5)O(7)Na(3)) were used as precursors for the fabrication of colloidal solutions. Prepared solutions were exposed to gamma-rays from a (60)Co gamma therapy unit 'Rokus-M' to varying absorbed doses, from 2 to 250 Gy. A UV/VIS/NIR spectrometer (Avantes-2048) was used for the measurement of the optical properties (absorbance) of the silver solutions. It was found that an initial absorbed dose of 2 Gy induced the formation of spherical silver nanoparticles as it was indicated in the absorbance spectrum of the solution, which had a well-pronounced absorption maximum at the wavelength of 410 nm. There is a potential to measure absorbed doses down to around 20 mGy. The SPR peaks at the wavelengths of 500-700 nm were found at the highest investigated doses >100 Gy, indicating the presence of silver nanorods. The colour of colloidal solutions ranged from pale yellow to green and was dependent on the absorbed dose. The investigation has shown that density, size and shape of synthesised silver nanoparticles are dependent on the absorbed dose and that shape transformations of the particles due to irradiation are possible. Application of colloidal solutions containing silver nanoparticles for dosimetric purposes is discussed on the basis of the obtained results.

  20. Hysteretic phenomena in GFET: Comprehensive theory and experiment

    Science.gov (United States)

    Kurchak, Anatolii I.; Morozovska, Anna N.; Strikha, Maksym V.

    2017-07-01

    We propose a comprehensive analytical theory for the description of versatile hysteretic phenomena in a graphene field effect transistor (GFET). Our theory account for the existence of the three most important rival factors, such as external dipoles on graphene free surface, localized states at the graphene-substrate interface, and the bound polarization charge coming from a ferroelectric substrate. In particular, we demonstrated that the absorbed dipole molecules (e.g., dissociated or highly polarized water molecules) can cause hysteretic form of carrier concentration as a function of gate voltage and corresponding dependence of graphene conductivity in GFET on the substrate of different types, including the most common SiO2 and ferroelectric ones. It was shown that the increase in the gate voltage sweeping rate leads to the complete vanishing of hysteresis for GFET on SiO2 substrate as well as for GFET on ferroelectric substrate for applied electric fields E less than the critical value Ec. For E > Ec, the cross-over from the anti-hysteresis to hysteresis take place. The carriers' trapping from the graphene channel by the interface states describes the "anti-hysteresis" in GFET on PZT substrate well enough. These results well correlate with the available experimental data up to the quantitative agreement. So, the obtained analytical results predict new and clarify existing effects in GFET. They describe quantitatively the physical principles of GFET operation and can become the first necessary step to transform the state-of-art from almost empirical to analytical level, because they can be directly applied to describe the basic characteristics of advanced non-volatile ultra-fast memory devices using GFET on versatile substrates.

  1. GASP. I. Gas Stripping Phenomena in Galaxies with MUSE

    Science.gov (United States)

    Poggianti, Bianca M.; Moretti, Alessia; Gullieuszik, Marco; Fritz, Jacopo; Jaffé, Yara; Bettoni, Daniela; Fasano, Giovanni; Bellhouse, Callum; Hau, George; Vulcani, Benedetta; Biviano, Andrea; Omizzolo, Alessandro; Paccagnella, Angela; D'Onofrio, Mauro; Cava, Antonio; Sheen, Y.-K.; Couch, Warrick; Owers, Matt

    2017-07-01

    GAs Stripping Phenomena in galaxies with MUSE (GASP) is a new integral-field spectroscopic survey with MUSE at the VLT aimed at studying gas removal processes in galaxies. We present an overview of the survey and show a first example of a galaxy undergoing strong gas stripping. GASP is obtaining deep MUSE data for 114 galaxies at z = 0.04-0.07 with stellar masses in the range {10}9.2{--}{10}11.5 {M}⊙ in different environments (galaxy clusters and groups over more than four orders of magnitude in halo mass). GASP targets galaxies with optical signatures of unilateral debris or tails reminiscent of gas-stripping processes (“jellyfish galaxies”), as well as a control sample of disk galaxies with no morphological anomalies. GASP is the only existing integral field unit (IFU) survey covering both the main galaxy body and the outskirts and surroundings, where the IFU data can reveal the presence and origin of the outer gas. To demonstrate GASP’s ability to probe the physics of gas and stars, we show the complete analysis of a textbook case of a jellyfish galaxy, JO206. This is a massive galaxy (9× {10}10 {M}⊙ ) in a low-mass cluster (σ ˜ 500 {km} {{{s}}}-1) at a small projected clustercentric radius and a high relative velocity, with ≥90 kpc long tentacles of ionized gas stripped away by ram pressure. We present the spatially resolved kinematics and physical properties of the gas and stars and depict the evolutionary history of this galaxy.

  2. Karstic Phenomena Susceptibility Map of MÉXICO

    Science.gov (United States)

    Espinasa-Pereña, R.

    2013-05-01

    Approximately 20% of the territory of México is underlain by karstifiable rocks, mostly limestones and in lesser proportions gypsum. The majority of these rocks are distributed along the eastern and southern Sierra Madre, the state of Chiapas and the Yucatán peninsula. Differences in geological structure, climate and geomorphic history have resulted in a great variety of karstic landscapes and types of forms. Several important population centers, including large cities with several million inhabitants and numerous smaller towns are built on karstic terrains and obtain their water supplies from karstic aquifers and/or dispose of their waste products on this type of terrain. Severe problems of waste disposal and aquifer contamination have occurred. Additionally, numerous instances of catastrophic collapse and formation of karstic sinkholes have been registered in the Mexican territory, which have affected many communities, roads and other infrastructure, and have even cost several lives. Lack of knowledge of the special characteristics of karstic terrains and their distribution has compounded these problems. As a first approach to these issues, the existing map of Mexican karst (Espinasa-Pereña, 2007) was modified according to the geotechnical classification proposed by Waltham & Fookes (2003). An important consideration taken into account is the difference in speed of development of karstic features depending on lithology, which makes karst developed in gypsum much more hazardous than limestone karst, and also the degree of soil coverage and the types of sinkholes developed on the cover. Also taken in consideration are the differences between karst developed in the Sierra Madre, with rocks highly deformed and fractured, and karst developed on the Yucatán peninsula with almost negligible deformation of the rocks. The resulting map will be useful to Civil Protection authorities as a tool in prognosticating possible affectations due to karstic phenomena. References

  3. Defect Engineering and Interface Phenomena in Tin Oxide

    KAUST Repository

    Albar, Arwa

    2017-04-05

    The advance in transparent electronics requires high-performance transparent conducting oxide materials. The microscopic properties of these materials are sensitive to the presence of defects and interfaces and thus fundamental understanding is required for materials engineering. In this thesis, first principles density functional theory is used to investigate the possibility of tuning the structural, electronic and magnetic properties of tin oxide by means of defects and interfaces. Our aim is to reveal unique properties and the parameters to control them as well as to explain the origin of unique phenomena in oxide materials. The stability of native defect in tin monoxide (SnO) under strain is investigated using formation energy calculations. We find that the conductivity (which is controlled by native defects) can be switched from p-type to either n-type or undoped semiconducting by means of applied pressure. We then target inducing magnetism in SnO by 3d transition metal doping. We propose that V doping is efficient to realize spin polarization at high temperature. We discuss different tin oxide interfaces. Metallic states are found to form at the SnO/SnO2 interface with electronic properties that depend on the interface terminations. The origin of these states is explained in terms of charge transfer caused by chemical bonding and band alignment. For the SnO/SnO2 heterostructure, we observe the formation of a two dimensional hole gas at the interface, which is surprising as it cannot be explained by the standard polar catastrophe model. Thus, we propose a charge density discontinuity model to explain our results. The model can be generalized to other polar-polar interfaces. Motivated by technological applications, the electronic and structural properties of the MgO (100)/SnO2 (110) interface are investigated. Depending on the interface termination, we observe the formation of a two dimensional electron gas or spin polarized hole gas. Aiming to identify further

  4. Uranium Pyrophoricity Phenomena and Prediction (FAI/00-39)

    Energy Technology Data Exchange (ETDEWEB)

    PLYS, M.G.

    2000-10-10

    The purpose of this report is to provide a topical reference on the phenomena and prediction of uranium pyrophoricity for the Hanford Spent Nuclear Fuel (SNF) Project with specific applications to SNF Project processes and situations. Spent metallic uranium nuclear fuel is currently stored underwater at the K basins in the Hanford 100 area, and planned processing steps include: (1) At the basins, cleaning and placing fuel elements and scrap into stainless steel multi-canister overpacks (MCOs) holding about 6 MT of fuel apiece; (2) At nearby cold vacuum drying (CVD) stations, draining, vacuum drying, and mechanically sealing the MCOs; (3) Shipping the MCOs to the Canister Storage Building (CSB) on the 200 Area plateau; and (4) Welding shut and placing the MCOs for interim (40 year) dry storage in closed CSB storage tubes cooled by natural air circulation through the surrounding vault. Damaged fuel elements have exposed and corroded fuel surfaces, which can exothermically react with water vapor and oxygen during normal process steps and in off-normal situations, A key process safety concern is the rate of reaction of damaged fuel and the potential for self-sustaining or runaway reactions, also known as uranium fires or fuel ignition. Uranium metal and one of its corrosion products, uranium hydride, are potentially pyrophoric materials. Dangers of pyrophoricity of uranium and its hydride have long been known in the U.S. Department of Energy (Atomic Energy Commission/DOE) complex and will be discussed more below; it is sufficient here to note that there are numerous documented instances of uranium fires during normal operations. The motivation for this work is to place the safety of the present process in proper perspective given past operational experience. Steps in development of such a perspective are: (1) Description of underlying physical causes for runaway reactions, (2) Modeling physical processes to explain runaway reactions, (3) Validation of the method

  5. Numerical modeling transport phenomena in proton exchange membrane fuel cells

    Science.gov (United States)

    Suh, DongMyung

    To study the coupled phenomena occurring in proton exchange membrane fuel cells, a two-phase, one-dimensional, non-isothermal model is developed in the chapter 1. The model includes water phase change, proton transport in the membrane and electro-osmotic effect. The thinnest, but most complex layer in the membrane electrode assembly, catalyst layer, is considered an interfacial boundary between the gas diffusion layer and the membrane. Mass and heat transfer and electro-chemical reaction through the catalyst layer are formulated into equations, which are applied to boundary conditions for the gas diffusion layer and the membrane. Detail accounts of the boundary equations and the numerical solving procedure used in this work are given. The polarization curve is calculated at different oxygen pressures and compared with the experimental results. When the operating condition is changed along the polarization curve, the change of physicochemical variables in the membrane electrode assembly is studied. In particular, the over-potential diagram presents the usage of the electrochemical energy at each layer of the membrane electrode assembly. Humidity in supplying gases is one of the most important factors to consider for improving the performance of PEMFE. Both high and low humidity conditions can result in a deteriorating cell performance. The effect of humidity on the cell performance is studied in the chapter 2. First, a numerical model based on computational fluid dynamics is developed. Second, the cell performances are simulated, when the relative humidity is changed from 0% to 100% in the anode and the cathode channel. The simulation results show how humidity in the reactant gases affects the water content distribution in the membrane, the over-potential at the catalyst layers and eventually the cell performance. In particular, the rapid enhancement in the cell performance caused by self-hydrating membrane is captured by the simulation. Fully humidifying either H2

  6. Three-Dimensional Visualization of Interfacial Phenomena Using Confocal Microscopy

    Science.gov (United States)

    Shieh, Ian C.

    Surfactants play an integral role in numerous functions ranging from stabilizing the emulsion in a favorite salad dressing to organizing the cellular components that make life possible. We are interested in lung surfactant, which is a mixture of lipids and proteins essential for normal respiration because it modulates the surface tension of the air-liquid interface of the thin fluid lining in the lungs. Through this surface tension modulation, lung surfactant ensures effortless lung expansion and prevents lung collapse during exhalation, thereby effecting proper oxygenation of the bloodstream. The function of lung surfactant, as well as numerous interfacial lipid systems, is not solely dictated by the behavior of materials confined to the two-dimensional interface. Rather, the distributions of materials in the liquid subphase also greatly influence the performance of interfacial films of lung surfactant. Therefore, to better understand the behavior of lung surfactant and other interfacial lipid systems, we require a three-dimensional characterization technique. In this dissertation, we have developed a novel confocal microscopy methodology for investigating the interfacial phenomena of surfactants at the air-liquid interface of a Langmuir trough. Confocal microscopy provides the excellent combination of in situ, fast, three-dimensional visualization of multiple components of the lung surfactant system that other characterization techniques lack. We detail the solutions to the numerous challenges encountered when imaging a dynamic air-liquid interface with a high-resolution technique like confocal microscopy. We then use confocal microscopy to elucidate the distinct mechanisms by which a polyelectrolyte (chitosan) and nonadsorbing polymer (polyethylene glycol) restore the function of lung surfactant under inhibitory conditions mimicking the effects of lung trauma. Beyond this physiological model, we also investigate several one- and two-component interfacial films

  7. Quantitative phase-field modeling for boiling phenomena.

    Science.gov (United States)

    Badillo, Arnoldo

    2012-10-01

    A phase-field model is developed for quantitative simulation of bubble growth in the diffusion-controlled regime. The model accounts for phase change and surface tension effects at the liquid-vapor interface of pure substances with large property contrast. The derivation of the model follows a two-fluid approach, where the diffuse interface is assumed to have an internal microstructure, defined by a sharp interface. Despite the fact that phases within the diffuse interface are considered to have their own velocities and pressures, an averaging procedure at the atomic scale, allows for expressing all the constitutive equations in terms of mixture quantities. From the averaging procedure and asymptotic analysis of the model, nonconventional terms appear in the energy and phase-field equations to compensate for the variation of the properties across the diffuse interface. Without these new terms, no convergence towards the sharp-interface model can be attained. The asymptotic analysis also revealed a very small thermal capillary length for real fluids, such as water, that makes impossible for conventional phase-field models to capture bubble growth in the millimeter range size. For instance, important phenomena such as bubble growth and detachment from a hot surface could not be simulated due to the large number of grids points required to resolve all the scales. Since the shape of the liquid-vapor interface is primarily controlled by the effects of an isotropic surface energy (surface tension), a solution involving the elimination of the curvature from the phase-field equation is devised. The elimination of the curvature from the phase-field equation changes the length scale dominating the phase change from the thermal capillary length to the thickness of the thermal boundary layer, which is several orders of magnitude larger. A detailed analysis of the phase-field equation revealed that a split of this equation into two independent parts is possible for system sizes

  8. Shrug ambivalence and disagreement; search commonalities in psychiatric phenomena(**).

    Science.gov (United States)

    Singh, Ajai R

    2014-01-01

    Holistic understanding is necessary to study intimate nuances of psychological/psychopathological processes; also, individual manifestations and individual approach are laudable goals in treatment and approach. But we cannot forget that major therapeutic advances result when we are able to delineate commonalities and stable symptom clusters that cut across geo-cultural boundaries and are amenable to study and intervention. Even though the purpose and approach of psychiatry, as of all medicine, has to be humane and caring, major therapeutic advancements and aetiologic understandings result only from a scientific methodology that stresses and figures out the commonalities of psychopathological phenomena. It is a mistake to stress individuality so much that commonalities are obliterated. Although stress on the individual's needs has helped psychiatry at times become more humane, it has hurt the task enormously by making some very bright minds question the very scientific basis of psychiatry and its status as a medical discipline. Hence, even as it is necessary to promote holistic and individualistic caring, it is equally necessary to shrug ambivalence and crippling disagreements that can result if individualism in therapy is carried beyond limits. Psychiatry's tradition, and field, will always allow for diversity in its practice, even in its theorising. For, psychopathology has both a personal, deep inner dimension - due to biogenetic and personality factors - and social, manifest/unmanifest, outer dimension - due to the environment. And the practice, and theory, of both are likely to be different, although we do try to amalgamate them in our 'bio-psycho-social' model. Such differences are only manifestations of an intricate network of influences that make for the human condition in health and disease. Psychiatry is the one branch which realises this diversity the most, but equally important for it is to stress its unity: Of purpose - that of reducing individual and

  9. D SQUID Detection of New Magnetic Resonance Phenomena.

    Science.gov (United States)

    Sleator, Tycho

    A dc Superconducting QUantum Interference Device (SQUID) was used as a tuned radio-frequency amplifier at liquid helium temperatures to detect very low signal magnetic resonance phenomena. Three experiments were performed. In the first experiment a dc SQUID was used to detect pulsed nuclear quadrupole resonance at about 30 MHz. At a bath temperature of 4.2K, a total system noise temperature of 6 +/- 1K has been achieved, with a quality factor Q of 2,500. A novel Q-spoiler, consisting of a series array of Josephson tunnel junctions, reduced the ring-down time of the tuned circuit after each pulse. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse was about 2times 10^{16} in a bandwidth of 10 kHz. In the second experiment a sample of nuclear spins was placed in the inductor of a tuned LCR circuit and the spectral density of current fluctuations in the circuit was measured using a dc SQUID as an rf amplifier. The measurements were made in liquid helium at 1.5K on samples of NaClO_ 3 and KClO_ 3, each of which exhibit a ^ {35 }Cl NQR transition at about 30 MHz. The spectral density of the current fluctuations was measured over the bandwidth of the circuit, which was tuned to the spin resonance frequency, by connecting the output of the SQUID to a spectrum analyzer. When the spin system was in thermal equilibrium with the bath (T_ {rm spin} = T_ {rm bath}), a dip was observed in the spectral density at the resonance frequency. For zero spin polarization (T_ {rm spin}=infty), on the other hand, a bump in the spectral density was observed. This bump is due to temperature-independent fluctuations in the transverse component of magnetization, and represents spontaneous emission from the spins into the circuit. In the third experiment precessing nuclear quadrupole moments were observed to induce oscillating electric dipole moments in neighboring atoms. The ^ {35 }Cl nuclei of a single crystal of NaClO _ 3 placed

  10. A core eating network and its modulations underlie diverse eating phenomena

    NARCIS (Netherlands)

    Chen, Jing|info:eu-repo/dai/nl/411887548; Papies, Esther K.|info:eu-repo/dai/nl/304832766; Barsalou, Lawrence W.

    2016-01-01

    We propose that a core eating network and its modulations account for much of what is currently known about the neural activity underlying a wide range of eating phenomena in humans (excluding homeostasis and related phenomena). The core eating network is closely adapted from a network that Kaye,

  11. Enhanced transport phenomena in CO2 sequestration and CO2 EOR

    NARCIS (Netherlands)

    Farajzadeh, R.

    2009-01-01

    The results of this thesis give insight into the (mass)-transfer during flow of gases, especially CO2, in various gas-liquid systems. A number of experiments was performed to investigate the transport phenomena through interfaces with and without surfactant monolayers. The observed phenomena have

  12. The Prevalence of Suicidal Phenomena in Adolescents: A Systematic Review of Population-Based Studies

    Science.gov (United States)

    Evans, Emma; Hawton, Keith; Rodham, Karen; Deeks, Jonathan

    2005-01-01

    The results of a systematic review of the international literature on the prevalence of suicidal phenomena in adolescents, including the influence of survey method, gender, and ethnicity are reported. The literature was searched using six electronic databases to identify all population-based studies of self-reported suicidal phenomena; 128 studies…

  13. An Undergraduate Experiment for the Measurement of the Speed of Sound in Air: Phenomena and Discussion

    Science.gov (United States)

    Yang, Hujiang; Zhao, Xiaohong; Wang, Xin; Xiao, Jinghua

    2012-01-01

    In this paper, we present and discuss some phenomena in an undergraduate experiment for the measurement of the speed of sound in air. A square wave distorts when connected to a piezoelectric transducer. Moreover, the amplitude of the receiving signal varies with the driving frequency. Comparing with the Gibbs phenomenon, these phenomena can be…

  14. Interplay of Internal and External Representations: Students' Drawings and Textual Explanations about Shadow Phenomena

    Science.gov (United States)

    Valanides, Nicos; Efthymiou, Irene; Angeli, Charoula

    2013-01-01

    Fifty-six third-year kindergarten student teachers (KTS) were presented with an experimental setting for investigating shadow phenomena. Prior to performing any specific experiment, KTS were asked to externalize their ideas about shadow phenomena corresponding to different configurations of the experimental setting through the use of drawings…

  15. Towards an Understanding of Flow and Other Positive Experience Phenomena within Outdoor and Adventurous Activities.

    Science.gov (United States)

    Boniface, Margaret R.

    2000-01-01

    People involved in adventurous activities frequently experience positive phenomena termed peak experience, peak performance, and "flow." Characteristics of these phenomena are compared, along with factors influencing the ability to experience such peak moments. Csikszentmihalyi's flow models are examined with regard to perceived levels…

  16. Artificially Structured Semiconductors to Model Novel Quantum Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Pinczuk, Aron [Columbia Univ., New York, NY (United States). Dept. of Applied Physics and Applied Mathematics; Wind, Shalom J. [Columbia Univ., New York, NY (United States). Dept. of Applied Physics and Applied Mathematics

    2018-01-13

    Award Period: September 1st, 2013 through February 15th, 2017 Submitted to the USDOE Office of Basic Energy Sciences By Aron Pinczuk and Shalom J. Wind Department of Applied Physics and Applied Mathematics Columbia University New York, NY 10027 January 2017 Award # DE-SC0010695 ABSTRACT Research in this project seeks to design, create and study a class of tunable artificial quantum structures in order to extend the range and scope of new and exciting physical phenomena and to explore the potential for new applications. Advanced nanofabrication was used to create an external potential landscape that acts as a lattice of confinement sites for electrons (and/or holes) in a two-dimensional electron gas in a high perfection semiconductor in such a manner that quantum interactions between different sites dictate the significant physics. Our current focus is on ‘artificial graphene’ (AG) in which a set of quantum dots (or sites) are patterned in a honeycomb lattice. The combination of leading edge nanofabrication with ultra-pure semiconductor materials in this project extends the frontier for small period, low-disorder AG systems, enabling the exploration of graphene physics in a semiconductor platform. TECHNICAL DESCRIPTION Contemporary condensed matter science has entered an era of discovery of new low-dimensional materials, such as graphene and other atomically thin materials, that exhibit exciting new physical phenomena that were previously inaccessible. Concurrent with the discovery and development of these new materials are impressive advancements in nanofabrication, which offer an ever-expanding toolbox for creating a myriad of high quality patterns at nanoscale dimensions. This project started about four years ago. Among its major achievements are the realizations of very small period artificial lattices with honeycomb topology in GaAs quantum wells. In our most recent work the periods of the ‘artificial graphene’ (AG) lattices extend down to 40 nm. These

  17. Large X Hadron Physics and Correlations with Central Region Phenomena

    CERN Multimedia

    2002-01-01

    The experiment uses a forward double-septum magnetic spectrometer with acceptance of @+~150~mrad to study the production of multiparticle systems. The system of mini-drift MWPC's has a processor which enables real-time selection of different multiplicities. The 32-cell Cherenkov counters along with the T.O.F. system allow the identification and separation of @p's, K's and p's over a large momentum range. A 3~m~x~3~m shower counter is installed to measure @p|0's and @g's traversing the spectrometer. \\\\ \\\\ A magnetic spectrometer installed at 90|0 measures identified single particles (T.O.F. and aerogel Cherenkov counters) and permits the measurement of flavour correlations with the forward spectrometer. Momentum selection of the 90|0 particles is incorporated in the trigger. .in +3 The experiment is data taking and studying such topics as 1) Production of @L^c|+ @A @L@p|+@p|+@p|- @A pK|-@p|+ 2) Glueball search in diffractive production of p @A pK|0^sK@+@p, pK|0^sK|0^s, p@L@L, etc... 3) p@*, pp comparison inclu...

  18. Individualization of the anisotropic phenomena of the imbalanced Nature

    Science.gov (United States)

    Shlafman, L. M.; Kontar, V. A.

    2013-05-01

    What is an individual phenomenon of Nature? Where are the boundaries? Why it is considered as an individual phenomenon? etc. People cannot directly detect the "something isotropic." Sometimes we notice that there is a "black box." But on closer inspection, especially with new methods, the "black box" began to lighten. It seems that his "blackness" is the result of imperfect human sensors and interpretations, but not a phenomenon of Nature. Really people can identify only the anisotropic phenomena of Nature, but with the significant errors. Let's take a look at our home planet Earth. Where are the borders of our planet? It is may seem as the very simple question. People walk on the land and swim on the seas. This is the border on the surface of land and water. But what is about the dust? The dust is a part of the land, which is in the air. Weight of dust is very small compared to the weight of the planet. But it is the dust has formed valleys. Dust can rise very high above the planet's surface and even fly into the space. A similar situation is with the water. The bulk of the liquid water is in surface and underground waters. Water vapor is in the atmosphere. Atmospheric water is much less than on the earth and under the earth. But atmospheric water plays a huge role in the world and even extends into the space. Without a full accounting of dust and water impossible correctly describe the planet. But with considering the dust and water the planet is not solid-liquid ball. It is like "fuzzy blowball" with the boundaries that go to infinity. This "fuzziness" refers to gravity. The gravitational field does not end in the Lagrange points. This "fuzziness" illustrated by the electro-magnetic fields, etc. Our planet can be seen as a multidimensional anisotropic phenomenon of Nature. The anisotropy precisely is, and therefore is the gradient and movement. This phenomenon is clearly imbalanced because nothing ever repeats itself exactly, etc. The borders of any anisotropic

  19. Spin-Dependent Transport Phenomena in Ferromagnet/Semiconductor Heterostructures

    Science.gov (United States)

    Geppert, Chad Christopher

    This dissertation examines several aspects of spin-dependent transport phenomena in epitaxially grown ferromagnet/n-GaAs heterostructures. Further maturation of the field of semiconductor-based spintronics is hindered by difficulties in evaluating device performance across materials systems. Using Fe/n-GaAs and Co2MnSi/n-GaAs heterostructures as a test case, the main goal of this work is to demonstrate how such difficulties may be overcome by (1) specifying a more quantitative framework for evaluating transport parameters and (2) the introduction of a new spin-to-charge conversion phenomenon which may be parameterized by bulk semiconductor parameters. In the introductory chapter, this work is placed in the broader context of developing improved methods for the generation, modulation, and detection of spins. The lateral spin-valve geometry is presented as a concrete example of the typical measurement procedures employed. Chapter 2 presents the charge-based transport properties of these samples and establishes the notation and calculation techniques to be employed in subsequent chapters. In particular, we examine in detail the calculation of the electrochemical potential for a given carrier concentration. Chapter 3 provides a full derivation of the equations governing spin-dependent transport in the large polarization regime. This is applied to the case of extracting spin lifetimes and diffusion rates, demonstrating how quantitative agreement with theoretical predictions may be obtained upon properly accounting for both device geometry and material parameters. Further examination of the boundary conditions applicable to the heterojunctions of these samples demonstrates to what extent device performance may be parameterized across materials systems. Chapter 4 presents experimental observations of a new spin-to-charge conversion phenomenon using a non-magnetic probe. In the presence of a large non-equilibrium spin accumulation, the combination of a non-constant density

  20. Impact of Disorder on Spin Dependent Transport Phenomena

    KAUST Repository

    Saidaoui, Hamed

    2016-07-03

    The impact of the spin degree of freedom on the transport properties of electrons traveling through magnetic materials has been known since the pioneer work of Mott [1]. Since then it has been demonstrated that the spin angular momentum plays a key role in the scattering process of electrons in magnetic multilayers. This role has been emphasized by the discovery of the Giant Magnetoresistance in 1988 by Fert and Grunberg [2, 3]. Among the numerous applications and effects that emerged in mesoscopic devices two mechanisms have attracted our attention during the course of this thesis: the spin transfer torque and the spin Hall effects. The former consists in the transfer of the spin angular momentum from itinerant carriers to local magnetic moments [4]. This mechanism results in the current-driven magnetization switching and excitations, which has potential application in terms of magnetic data storage and non-volatile memories. The latter, spin Hall effect, is considered as well to be one of the most fascinating mechanisms in condensed matter physics due to its ability of generating non-equilibrium spin currents without the need for any magnetic materials. In fact the spin Hall effect relies only on the presence of the spin-orbit interaction in order to create an imbalance between the majority and minority spins. The objective of this thesis is to investigate the impact of disorder on spin dependent transport phenomena. To do so, we identified three classes of systems on which such disorder may have a dramatic influence: (i) antiferromagnetic materials, (ii) impurity-driven spin-orbit coupled systems and (iii) two dimensional semiconducting electron gases with Rashba spin-orbit coupling. Antiferromagnetic materials - We showed that in antiferromagnetic spin-valves, spin transfer torque is highly sensitive to disorder, which prevents its experimental observation. To solve this issue, we proposed to use either a tunnel barrier as a spacer or a local spin torque using

  1. Identification of a new lactone contributing to overripe orange aroma in Bordeaux dessert wines via perceptual interaction phenomena.

    Science.gov (United States)

    Stamatopoulos, Panagiotis; Frérot, Eric; Tempère, Sophie; Pons, Alexandre; Darriet, Philippe

    2014-03-26

    Recent studies have demonstrated the existence of a typical sensory concept for Bordeaux dessert wines, including the world famous wines of Sauternes. Volatile compounds from several chemical families (thiols, aldehydes, and lactones) were identified and correlated with aromatic typicality in these wines. However, these studies were unable to indicate "key" aromas of overripe fruits, especially overripe orange. The alternative strategy developed in this research combined both analytical and sensory studies of fractions of dessert wine extracts obtained by semipreparative high-performance liquid chromatography (HPLC). Multidimensional gas chromatography coupled to olfactometry and mass spectrometry (MDGC-O/MS) was applied to some of the HPLC fractions recalling "overripe fruit", and a new lactone, 2-nonen-4-olide, was identified. Reconstitution and omission tests using the HPLC fractions highlighted the importance of specific compounds, particularly 2-nonen-4-olide, in the expression of overripe orange notes. Although this lactone presents minty and fruity odors, its key contribution to the typical aroma of orange in Bordeaux dessert wines was revealed through perceptual blending.

  2. "Did You Climax or Are You Just Laughing at Me?" Rare Phenomena Associated With Orgasm.

    Science.gov (United States)

    Reinert, Anna E; Simon, James A

    2017-07-01

    The study of the human orgasm has shown a core set of physiologic and psychological symptoms experienced by most individuals. The study of normal sheds light on the abnormal and has spotlighted rare physical and psychological symptoms experienced by some individuals in association with orgasm. These phenomena are rare and, as is typical of rare phenomena, their documentation in the medical literature is largely confined to case studies. To identify peri-orgasmic phenomena, defined as unusual physical or psychological symptoms subjectively experienced by some individuals as part of the orgasm response, distinct from the usual or normal orgasm response. A list of peri-orgasmic phenomena was made with help from sexual health colleagues and, using this list as a foundation, a literature search was performed of articles published in English. Publications included in this review report on physical or psychological phenomena at the time of orgasm that are distinct from psychological, whole-body, and genito-pelvic sensations commonly experienced at the time of orgasm. Cases of physical symptoms related to the physiology of sexual intercourse and not specifically to orgasm were excluded. Case studies of peri-orgasmic phenomena were reviewed, including cases describing cataplexy (weakness), crying, dysorgasmia, dysphoria, facial and/or ear pain, foot pain, headache, pruritus, laughter, panic attack, post-orgasm illness syndrome, seizures, and sneezing. The literature review confirms the existence of diverse and frequently replicated peri-orgasmic phenomena. The value of case studies is in the collection and recording of observations so that hypotheses can be formed about the observed phenomena. Accordingly, this review could inspire further research on the neurophysiologic mechanisms of orgasm. Reinert AE, Simon JA. "Did You Climax or Are You Just Laughing at Me?" Rare Phenomena Associated With Orgasm. Sex Med Rev 2017;5:275-281. Copyright © 2017 International Society for

  3. Studying the Kinematic Behavior of Coronal Mass Ejections and Other Solar Phenomena using the Time-Convolution Mapping Method

    Science.gov (United States)

    Hess Webber, Shea A.; Thompson, Barbara J.; Kwon, Ryun Young; Ireland, Jack

    2018-01-01

    An improved understanding of the kinematic properties of CMEs and CME-associated phenomena has several impacts: 1) a less ambiguous method of mapping propagating structures into their inner coronal manifestations, 2) a clearer view of the relationship between the “main” CME and CME-associated brightenings, and 3) an improved identification of the heliospheric sources of shocks, Type II bursts, and SEPs. We present the results of a mapping technique that facilitates the separation of CMEs and CME-associated brightenings (such as shocks) from background corona. The Time Convolution Mapping Method (TCMM) segments coronagraph data to identify the time history of coronal evolution, the advantage being that the spatiotemporal evolution profiles allow users to separate features with different propagation characteristics. For example, separating “main” CME mass from CME-associated brightenings or shocks is a well-known obstacle, which the TCMM aids in differentiating. A TCMM CME map is made by first recording the maximum value each individual pixel in the image reaches during the traversal of the CME. Then the maximum value is convolved with an index to indicate the time that the pixel reached that value. The TCMM user is then able to identify continuous “kinematic profiles,” indicating related kinematic behavior, and also identify breaks in the profiles that indicate a discontinuity in kinematic history (i.e. different structures or different propagation characteristics). The maps obtained from multiple spacecraft viewpoints (i.e., STEREO and SOHO) can then be fit with advanced structural models to obtain the 3D properties of the evolving phenomena. We will also comment on the TCMM's further applicability toward the tracking of prominences, coronal hole boundaries and coronal cavities.

  4. Electronic Phenomena in Two-Dimensional Topological Insulators

    Science.gov (United States)

    Hart, Sean

    In recent years, two-dimensional electron systems have played an integral role at the forefront of discoveries in condensed matter physics. These include the integer and fractional quantum Hall effects, massless electron physics in graphene, the quantum spin and quantum anomalous Hall effects, and many more. Investigation of these fascinating states of matter brings with it surprising new results, challenges us to understand new physical phenomena, and pushes us toward new technological capabilities. In this thesis, we describe a set of experiments aimed at elucidating the behavior of two such two-dimensional systems: the quantum Hall effect, and the quantum spin Hall effect. The first experiment examines electronic behavior at the edge of a two-dimensional electron system formed in a GaAs/AlGaAs heterostructure, under the application of a strong perpendicular magnetic field. When the ratio between the number of electrons and flux quanta in the system is tuned near certain integer or fractional values, the electrons in the system can form states which are respectively known as the integer and fractional quantum Hall effects. These states are insulators in the bulk, but carry gapless excitations at the edge. Remarkably, in certain fractional quantum Hall states, it was predicted that even as charge is carried downstream along an edge, heat can be carried upstream in a neutral edge channel. By placing quantum dots along a quantum Hall edge, we are able to locally monitor the edge temperature. Using a quantum point contact, we can locally heat the edge and use the quantum dot thermometers to detect heat carried both downstream and upstream. We find that heat can be carried upstream when the edge contains structure related to the nu = 2/3 fractional quantum Hall state. We further find that this fractional edge physics can even be present when the bulk is tuned to the nu = 1integer quantum Hall state. Our experiments also demonstrate that the nature of this fractional

  5. Application of digital image processing techniques to faint solar flare phenomena

    Science.gov (United States)

    Glackin, D. L.; Martin, S. F.

    1980-01-01

    Digital image processing of eight solar flare events was performed using the Video Information Communication and Retrieval language in order to study moving emission fronts, flare halos, and Moreton waves. The techniques used include contrast enhancement, isointensity contouring, the differencing of images, spatial filtering, and geometrical registration. The spatial extent and temporal behavior of the faint phenomena is examined along with the relation of the three types of phenomena to one another. The image processing techniques make possible the detailed study of the history of the phenomena and provide clues to their physical nature.

  6. Review of Natural Phenomena Hazard (NPH) Assessments for the DOE Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Robert L.; Ross, Steven B.

    2011-09-15

    The purpose of this review is to assess the need for updating Natural Phenomena Hazard (NPH) assessments for the DOE's Hanford Site, as required by DOE Order 420.1B Chapter IV, Natural Phenomena Hazards Mitigation, based on significant changes in state-of-the-art NPH assessment methodology or site-specific information. This review is an update and expansion to the September 2010 review of PNNL-19751, Review of Natural Phenomena Hazard (NPH) Assessments for the Hanford 200 Areas (Non-Seismic).

  7. The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

    CERN Document Server

    Lagowski, J J

    1976-01-01

    The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

  8. Vibro-acoustic modulation–based damage identification in a composite skin–stiffener structure

    NARCIS (Netherlands)

    Ooijevaar, T.H.; Rogge, M.D.; Loendersloot, Richard; Warnet, Laurent; Akkerman, Remko; Tinga, Tiedo

    2016-01-01

    Vibro-acoustic modulation–based damage identification relies on the modulation of a high-frequency carrier signal by an intenser low-frequency vibration signal due to damage-induced structural nonlinearities. A time domain analysis of the vibro-acoustic modulation phenomena was presented at multiple

  9. HOTEL MANAGERS’ PERCEPTIONS OF THE IMPACT OF SOME GLOBAL PHENOMENA ON TOURISM. CASE STUDY ROMANIA - ITALY

    National Research Council Canada - National Science Library

    Stefanica, Mirela; Butnaru, Gina Ionela

    2014-01-01

    ... activity in the areas where they are produced. The present work emphasises the perception of Romanian and Italian hotel managers of these phenomena that have an impact on tourism, using a comparative approach...

  10. Three-dimensional flow phenomena in a wire-wrapped 37-pin fuel bundle for SFR

    National Research Council Canada - National Science Library

    Jeong, Jae-Ho; Yoo, Jin; Lee, Kwi-Lim; Ha, Kwi-Seok

    2015-01-01

    Three-dimensional flow phenomena in a wire-wrapped 37-pin fuel assembly mock-up of a Japanese loop-type sodium-cooled fast reactor, Monju, were investigated with a numerical analysis using a general...

  11. A Photochemical Reactor for the Study of Kinetics and Adsorption Phenomena

    Science.gov (United States)

    Poce-Fatou, J. A.; Gil, M. L. A.; Alcantara, R.; Botella, C.; Martin, J.

    2004-01-01

    The interaction between light and matter is examined with the help of a photochemical experiment. This experiment is useful for the investigation of heterogeneous catalysis, semiconductor properties and adsorption phenomena.

  12. The physics of nanoelectronics transport and fluctuation phenomena at low temperatures

    CERN Document Server

    Heikkila, Tero T

    2013-01-01

    Advances in nanotechnology have allowed physicists and engineers to miniaturize electronic structures to the limit where finite-size related phenomena start to impact their properties. This book discusses such phenomena and models made for their description. The book starts from the semiclassical description of nonequilibrium effects, details the scattering theory used for quantum transport calculations, and explains the main interference effects. It also describes how to treat fluctuations and correlations, how interactions affect transport through small islands, and how superconductivity modifies these effects. The last two chapters describe new emerging fields related with graphene and nanoelectromechanics. The focus of the book is on the phenomena rather than formalism, but the book still explains in detail the main models constructed for these phenomena. It also introduces a number of electronic devices, including the single-electron transistor, the superconducting tunnel junction refrigerator, and the s...

  13. Fusion arrest and collapse phenomena due to Kerr-nonlinearity in quadratic media

    DEFF Research Database (Denmark)

    Johansen, Steffen Kjær; Bang, Ole; Sørensen, Mads Peter

    2000-01-01

    Emphasizing collapse phenomena it is investigated to what extend the always present cubic nonlinearity affects the properties of soliton interaction in quadratic bulk media. An effective particle approach is applied and verified by numerical simulations....

  14. How typical are 'typical' tremor characteristics? : Sensitivity and specificity of five tremor phenomena

    NARCIS (Netherlands)

    van der Stouwe, A. M. M.; Elting, J. W.; van der Hoeven, J. H.; van Laar, T.; Leenders, K. L.; Maurits, N. M.; Tijssen, M. Aj.

    Introduction: Distinguishing between different tremor disorders can be challenging. Some tremor disorders are thought to have typical tremor characteristics: the current study aims to provide sensitivity and specificity for five 'typical' tremor phenomena. Methods: Retrospectively, we examined 210

  15. Design, development, and fabrication of a prototype ice pack heat sink subsystem. Flight experiment physical phenomena experiment chest

    Science.gov (United States)

    Roebelen, G. J., Jr.; Dean, W. C., II

    1975-01-01

    The concept of a flight experiment physical phenomena experiment chest, to be used eventually for investigating and demonstrating ice pack heat sink subsystem physical phenomena during a zero gravity flight experiment, is described.

  16. A STUDY OF NONLINEAR PHENOMENA IN THE PROPAGATION OF ELECTROMAGNETIC WAVES IN A WEAKLY IONIZED GAS.

    Science.gov (United States)

    This paper is a study of nonlinear phenomena in the propagation of electromagnetic waves in a weakly ionized gas externally biased with a magneto...static field. The present study is restricted to the nonlinear phenomena arising from the interaction of electromagnetic waves in the ionized gas. The...the propagation of electromagnetic waves in the ionized gas, and also on the reflection of waves from an ionized gas semi-infinite extent. (Author)

  17. Analysis and Predictions of Social Phenomena via social media using Social Physics method

    OpenAIRE

    Ishii, Akira

    2017-01-01

    As a method of analyzing and predicting social phenomena using social media as data, we propose a method using a mathematical model of hit phenomenon which is the theory of social physics. I could explain the transition of the number of social media written in movies, TV dramas, Music Concerts, Pokemon GO and proposed a method that can be used for analysis and prediction of social phenomena.

  18. FEARS AND PHOBIAS IN THE PERSON’S «ANXIETY ROW» PHENOMENA STRUCTURE

    Directory of Open Access Journals (Sweden)

    I. V. Astakhova

    2012-01-01

    Full Text Available Fear is determined as part of a sequence of so-called «number of anxiety» phenomena (fright – alarm – fear – horror – panics. Phobia isdetermined as alarming upsetting. The origin and development of fears and phobias are examined from the social viewpoint in terms of theinfluence of the «alarm raw» phenomena on the development of both an individual and the whole society.

  19. Searches for other non-SUSY new phenomena at the LHC

    CERN Document Server

    Kajomovitz, E

    2015-01-01

    The ATLAS and CMS collaborations collected datasets of approximately $20 fb^{-1}$ of $pp$ collisions at $\\sqrt{s}$ = 8 TeV produced by the LHC during the Run-1 period. The collaborations performed a thorough analysis of these datasets searching for physics phenomena beyond the Standard Model. These conference proceedings summarize the results of a selection of searches targeting non-Supersymmetry phenomena.

  20. Development of the fuel HTR/VHTR at the CEA; Developpement du combustible HTR/VHTR au CEA

    Energy Technology Data Exchange (ETDEWEB)

    Phelip, M.; Charollais, F.; Lambert, Th

    2005-07-01

    This presentation brings together the slides presented during the conference of the SESC/SPUA the 28 January 2005. The first part is devoted to the fuel behavior under irradiation, the second one to the main objectives of the program and the last part to the international collaboration. It provides information on the fuel behavior under irradiation, the fuel fabrication and performance, the SIROCCO program, the european contacts and the simulation programs. (A.L.B.)