WorldWideScience

Sample records for iv reactor iris

  1. Report on the O IV and S IV lines observed by IRIS

    CERN Document Server

    Young, Peter R

    2015-01-01

    The O IV intercombination lines observed by the Interface Region Imaging Spectrograph (IRIS) between 1397 and 1407 A provide useful density diagnostics. This document presents data that address two issues related to these lines: (1) the contribution of S IV to the O IV 1404.8 line; and (2) the range of sensitivity of the O IV 1399.8/1401.2 ratio.

  2. The design and safety features of the IRIS reactor

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, Mario D. E-mail: carellmd@westinghouse.com; Conway, L.E.; Oriani, L.; Petrovic, B.; Lombardi, C.V.; Ricotti, M.E.; Barroso, A.C.O.; Collado, J.M.; Cinotti, L.; Todreas, N.E.; Grgic, D.; Moraes, M.M.; Boroughs, R.D.; Ninokata, H.; Ingersoll, D.T.; Oriolo, F

    2004-05-01

    Salient features of the International Reactor Innovative and Secure (IRIS) are presented here. IRIS, an integral, modular, medium size (335 MWe) PWR, has been under development since the turn of the century by an international consortium led by Westinghouse and including over 20 organizations from nine countries. Described here are the features of the integral design which includes steam generators, pumps and pressurizer inside the vessel, together with the core, control rods, and neutron reflector/shield. A brief summary is provided of the IRIS approach to extended maintenance over a 48-month schedule. The unique IRIS safety-by-design approach is discussed, which, by eliminating accidents, at the design stage, or decreasing their consequences/probabilities when outright elimination is not possible, provides a very powerful first level of defense in depth. The safety-by-design allows a significant reduction and simplification of the passive safety systems, which are presented here, together with an assessment of the IRIS response to transients and postulated accidents.

  3. Density diagnostics derived from the O iv and S iv intercombination lines observed by IRIS

    Science.gov (United States)

    Polito, V.; Del Zanna, G.; Dudík, J.; Mason, H. E.; Giunta, A.; Reeves, K. K.

    2016-10-01

    The intensity of the O iv 2s2 2p 2P-2s2p24P and S iv 3 s2 3p 2P-3s 3p24 P intercombination lines around 1400 Å observed with the Interface Region Imaging Spectrograph (IRIS) provide a useful tool to diagnose the electron number density (Ne) in the solar transition region plasma. We measure the electron number density in a variety of solar features observed by IRIS, including an active region (AR) loop, plage and brightening, and the ribbon of the 22-June-2015 M 6.5 class flare. By using the emissivity ratios of O iv and S iv lines, we find that our observations are consistent with the emitting plasma being near isothermal (logT[K] ≈ 5) and iso-density (Ne ≈ 1010.6 cm-3) in the AR loop. Moreover, high electron number densities (Ne ≈ 1013 cm-3) are obtained during the impulsive phase of the flare by using the S iv line ratio. We note that the S iv lines provide a higher range of density sensitivity than the O iv lines. Finally, we investigate the effects of high densities (Ne ≳ 1011 cm-3) on the ionization balance. In particular, the fractional ion abundances are found to be shifted towards lower temperatures for high densities compared to the low density case. We also explored the effects of a non-Maxwellian electron distribution on our diagnostic method. The movie associated to Fig. 3 is available at http://www.aanda.org

  4. Full core analysis of IRIS reactor by using MCNPX.

    Science.gov (United States)

    Amin, E A; Bashter, I I; Hassan, Nabil M; Mustafa, S S

    2016-07-01

    This paper describes neutronic analysis for fresh fuelled IRIS (International Reactor Innovative and Secure) reactor by MCNPX code. The analysis included criticality calculations, radial power and axial power distribution, nuclear peaking factor and axial offset percent at the beginning of fuel cycle. The effective multiplication factor obtained by MCNPX code is compared with previous calculations by HELIOS/NESTLE, CASMO/SIMULATE, modified CORD-2 nodal calculations and SAS2H/KENO-V code systems. It is found that k-eff value obtained by MCNPX is closer to CORD-2 value. The radial and axial powers are compared with other published results carried out using SAS2H/KENO-V code. Moreover, the WIMS-D5 code is used for studying the effect of enriched boron in form of ZrB2 on the effective multiplication factor (K-eff) of the fuel pin. In this part of calculation, K-eff is calculated at different concentrations of Boron-10 in mg/cm at different stages of burnup of unit cell. The results of this part are compared with published results performed by HELIOS code.

  5. An Iris Mechanism Driven Temperature Control of Solar Thermal Reactors

    OpenAIRE

    Van den Langenbergh, Lode; Ophoff, Cédric; Ozalp, Nesrin

    2015-01-01

    In spite of their attraction for clean production of fuels and commodities; solar thermal reactors are challenged by the transient nature of solar energy. Control of reactor temperature during transient periods is the key factor to maintain solar reactor performance. Currently, there are few techniques that are being used to accommodate the fluctuations of incoming solar radiation. One of the commonly practiced methods is to adjust the mass flow rate of the feedstock which is very simple to i...

  6. IRIS Reactor a Suitable Option to Provide Energy and Water Desalination for the Mexican Northwest Region

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, G.; Ramirez, R.; Gomez, C.; Viais, J.

    2004-10-03

    The Northwest region of Mexico has a deficit of potable water, along this necessity is the region growth, which requires of additional energy capacity. The IRIS reactor offers a very suitable source of energy given its modular size of 300 MWe and it can be coupled with a desalination plant to provide the potable water for human consumption, agriculture and industry. The present paper assess the water and energy requirements for the Northwest region of Mexico and how the deployment of the IRIS reactor can satisfy those necessities. The possible sites for deployment of Nuclear Reactors are considered given the seismic constraints and the closeness of the sea for external cooling. And in the other hand, the size of the desalination plant and the type of desalination process are assessed accordingly with the water deficit of the region.

  7. DESIGN AND LAYOUT CONCEPTS FOR COMPACT, FACTORY-PRODUCED, TRANSPORTABLE, GENERATION IV REACTOR SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Mynatt Fred R.; Townsend, L.W.; Williamson, Martin; Williams, Wesley; Miller, Laurence W.; Khan, M. Khurram; McConn, Joe; Kadak, Andrew C.; Berte, Marc V.; Sawhney, Rapinder; Fife, Jacob; Sedler, Todd L.; Conway, Larry E.; Felde, Dave K.

    2003-11-12

    The purpose of this research project is to develop compact (100 to 400 MWe) Generation IV nuclear power plant design and layout concepts that maximize the benefits of factory-based fabrication and optimal packaging, transportation and siting. The reactor concepts selected were compact designs under development in the 2000 to 2001 period. This interdisciplinary project was comprised of three university-led nuclear engineering teams identified by reactor coolant type (water, gas, and liquid metal) and a fourth Industrial Engineering team. The reactors included a Modular Pebble Bed helium-cooled concept being developed at MIT, the IRIS water-cooled concept being developed by a team led by Westinghouse Electric Company, and a Lead-Bismuth-cooled concept developed by UT. In addition to the design and layout concepts this report includes a section on heat exchanger manufacturing simulations and a section on construction and cost impacts of proposed modular designs.

  8. Dynamic modeling of primary and secondary systems of IRIS reactor for transient analysis using SIMULINK

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Mardson Alencar de Sa; Lira, Carlos Alberto Brayner de Oliveira; Silva, Mario Augusto Bezerra da, E-mail: cabol@ufpe.b [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Lima, Fernando Roberto de Andrade, E-mail: falima@cnen.gov.b [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    The IRIS project has significantly advanced in the last few years in response to a demand for a new generation reactor, that could fulfill the essential requirements for a future nuclear power plant: better economics, safety-by-design, low proliferation risk and environmental sustainability. IRIS reactor is a integral type PWR in which all primary components are arranged inside the pressure vessel. This configuration involves important changes in relation to a conventional PWR. These changes require several studies to comply with the safe operational limits for the reactor. In this paper, a study has been conducted to develop a dynamic model (named MODIRIS) for transient analysis, implemented in the MATLAB'S software SIMULINK, allowing the analysis of IRIS behavior by considering the neutron point kinetics for power production. The methodology is based on generating a set of differential equations of neutronic and thermal-hydraulic balances which describes the dynamics of the primary circuit, as well as a set of differential equations describing the dynamics of secondary circuit. The equations and initialization parameters at full power were into the SIMULINK and the code was validated by the confrontation with RELAP simulations for a transient of feedwater reduction in the steam generators. (author)

  9. The SPES3 Experimental Facility Design for the IRIS Reactor Simulation

    Directory of Open Access Journals (Sweden)

    Mario Carelli

    2009-01-01

    Full Text Available IRIS is an advanced integral pressurized water reactor, developed by an international consortium led by Westinghouse. The licensing process requires the execution of integral and separate effect tests on a properly scaled reactor simulator for reactor concept, safety system verification, and code assessment. Within the framework of an Italian R&D program on Nuclear Fission, managed by ENEA and supported by the Ministry of Economic Development, the SPES3 facility is under design and will be built and operated at SIET laboratories. SPES3 simulates the primary, secondary, and containment systems of IRIS with 1 : 100 volume scale, full elevation, and prototypical thermal-hydraulic conditions. The simulation of the facility with the RELAP5 code and the execution of the tests will provide a reliable tool for data extrapolation and safety analyses of the final IRIS design. This paper summarises the main design steps of the SPES3 integral test facility, underlying choices and phases that lead to the final design.

  10. Fuel burnup analysis for IRIS reactor using MCNPX and WIMS-D5 codes

    Science.gov (United States)

    Amin, E. A.; Bashter, I. I.; Hassan, Nabil M.; Mustafa, S. S.

    2017-02-01

    International Reactor Innovative and Secure (IRIS) reactor is a compact power reactor designed with especial features. It contains Integral Fuel Burnable Absorber (IFBA). The core is heterogeneous both axially and radially. This work provides the full core burn up analysis for IRIS reactor using MCNPX and WIMDS-D5 codes. Criticality calculations, radial and axial power distributions and nuclear peaking factor at the different stages of burnup were studied. Effective multiplication factor values for the core were estimated by coupling MCNPX code with WIMS-D5 code and compared with SAS2H/KENO-V code values at different stages of burnup. The two calculation codes show good agreement and correlation. The values of radial and axial powers for the full core were also compared with published results given by SAS2H/KENO-V code (at the beginning and end of reactor operation). The behavior of both radial and axial power distribution is quiet similar to the other data published by SAS2H/KENO-V code. The peaking factor values estimated in the present work are close to its values calculated by SAS2H/KENO-V code.

  11. Advanced Instrumentation and Control Methods for Small and Medium Reactors with IRIS Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    J. Wesley Hines; Belle R. Upadhyaya; J. Michael Doster; Robert M. Edwards; Kenneth D. Lewis; Paul Turinsky; Jamie Coble

    2011-05-31

    Development and deployment of small-scale nuclear power reactors and their maintenance, monitoring, and control are part of the mission under the Small Modular Reactor (SMR) program. The objectives of this NERI-consortium research project are to investigate, develop, and validate advanced methods for sensing, controlling, monitoring, diagnosis, and prognosis of these reactors, and to demonstrate the methods with application to one of the proposed integral pressurized water reactors (IPWR). For this project, the IPWR design by Westinghouse, the International Reactor Secure and Innovative (IRIS), has been used to demonstrate the techniques developed under this project. The research focuses on three topical areas with the following objectives. Objective 1 - Develop and apply simulation capabilities and sensitivity/uncertainty analysis methods to address sensor deployment analysis and small grid stability issues. Objective 2 - Develop and test an autonomous and fault-tolerant control architecture and apply to the IRIS system and an experimental flow control loop, with extensions to multiple reactor modules, nuclear desalination, and optimal sensor placement strategy. Objective 3 - Develop and test an integrated monitoring, diagnosis, and prognosis system for SMRs using the IRIS as a test platform, and integrate process and equipment monitoring (PEM) and process and equipment prognostics (PEP) toolboxes. The research tasks are focused on meeting the unique needs of reactors that may be deployed to remote locations or to developing countries with limited support infrastructure. These applications will require smaller, robust reactor designs with advanced technologies for sensors, instrumentation, and control. An excellent overview of SMRs is described in an article by Ingersoll (2009). The article refers to these as deliberately small reactors. Most of these have modular characteristics, with multiple units deployed at the same plant site. Additionally, the topics focus

  12. Advanced Instrumentation and Control Methods for Small and Medium Reactors with IRIS Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    J. Wesley Hines; Belle R. Upadhyaya; J. Michael Doster; Robert M. Edwards; Kenneth D. Lewis; Paul Turinsky; Jamie Coble

    2011-05-31

    Development and deployment of small-scale nuclear power reactors and their maintenance, monitoring, and control are part of the mission under the Small Modular Reactor (SMR) program. The objectives of this NERI-consortium research project are to investigate, develop, and validate advanced methods for sensing, controlling, monitoring, diagnosis, and prognosis of these reactors, and to demonstrate the methods with application to one of the proposed integral pressurized water reactors (IPWR). For this project, the IPWR design by Westinghouse, the International Reactor Secure and Innovative (IRIS), has been used to demonstrate the techniques developed under this project. The research focuses on three topical areas with the following objectives. Objective 1 - Develop and apply simulation capabilities and sensitivity/uncertainty analysis methods to address sensor deployment analysis and small grid stability issues. Objective 2 - Develop and test an autonomous and fault-tolerant control architecture and apply to the IRIS system and an experimental flow control loop, with extensions to multiple reactor modules, nuclear desalination, and optimal sensor placement strategy. Objective 3 - Develop and test an integrated monitoring, diagnosis, and prognosis system for SMRs using the IRIS as a test platform, and integrate process and equipment monitoring (PEM) and process and equipment prognostics (PEP) toolboxes. The research tasks are focused on meeting the unique needs of reactors that may be deployed to remote locations or to developing countries with limited support infrastructure. These applications will require smaller, robust reactor designs with advanced technologies for sensors, instrumentation, and control. An excellent overview of SMRs is described in an article by Ingersoll (2009). The article refers to these as deliberately small reactors. Most of these have modular characteristics, with multiple units deployed at the same plant site. Additionally, the topics focus

  13. Nordic Nuclear Materials Forum for Generation IV Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Anghel, C. (Studsvik Nuclear AB, Nykoeping (Sweden)); Penttilae, S. (Technical Research Centre of Finland, VTT (Finland))

    2010-03-15

    A network for material issues for Generation IV nuclear power has been initiated within the Nordic countries. The objectives of the Generation IV Nordic Nuclear Materials Forum (NOMAGE4) are to put the basis of a sustainable forum for Gen IV issues, especially focussing on fuels, cladding, structural materials and coolant interaction. Other issues include reactor physics, dynamics and diagnostics, core and fuel design. The present report summarizes the work performed during the year 2009. The efforts made include identification of organisations involved in Gen IV issues in the Nordic countries, update of the forum website, http://www.studsvik.se/GenerationIV, and investigation of capabilities for research within the area of Gen IV. Within the NOMAGE4 project a seminar on Generation IV Nuclear Energy Systems has been organized during 15-16th of October 2009. The aim of the seminar was to provide a forum for exchange of information, discussion on future research needs and networking of experts on Generation IV reactor concepts. As an outcome of the NOMAGE4, a few collaboration project proposals have been prepared/planned in 2009. The network was welcomed by the European Commission and was mentioned as an exemplary network with representatives from industries, universities, power companies and research institutes. NOMAGE4 has been invited to participate to the 'European Energy Research Alliance, EERA, workshop for nuclear structural materials' http://www.eera-set.eu/index.php?index=41 as external observers. Future plans include a new Nordic application for continuation of NOMAGE4 network. (author)

  14. Generation IV Reactors Integrated Materials Technology Program Plan: Focus on Very High Temperature Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, William R [ORNL; Burchell, Timothy D [ORNL; Katoh, Yutai [ORNL; McGreevy, Timothy E [ORNL; Nanstad, Randy K [ORNL; Ren, Weiju [ORNL; Snead, Lance Lewis [ORNL; Wilson, Dane F [ORNL

    2008-08-01

    Since 2002, the Department of Energy's (DOE's) Generation IV Nuclear Energy Systems (Gen IV) Program has addressed the research and development (R&D) necessary to support next-generation nuclear energy systems. The six most promising systems identified for next-generation nuclear energy are described within this roadmap. Two employ a thermal neutron spectrum with coolants and temperatures that enable hydrogen or electricity production with high efficiency (the Supercritical Water Reactor-SCWR and the Very High Temperature Reactor-VHTR). Three employ a fast neutron spectrum to enable more effective management of actinides through recycling of most components in the discharged fuel (the Gas-cooled Fast Reactor-GFR, the Lead-cooled Fast Reactor-LFR, and the Sodium-cooled Fast Reactor-SFR). The Molten Salt Reactor (MSR) employs a circulating liquid fuel mixture that offers considerable flexibility for recycling actinides and may provide an alternative to accelerator-driven systems. At the inception of DOE's Gen IV program, it was decided to significantly pursue five of the six concepts identified in the Gen IV roadmap to determine which of them was most appropriate to meet the needs of future U.S. nuclear power generation. In particular, evaluation of the highly efficient thermal SCWR and VHTR reactors was initiated primarily for energy production, and evaluation of the three fast reactor concepts, SFR, LFR, and GFR, was begun to assess viability for both energy production and their potential contribution to closing the fuel cycle. Within the Gen IV Program itself, only the VHTR class of reactors was selected for continued development. Hence, this document will address the multiple activities under the Gen IV program that contribute to the development of the VHTR. A few major technologies have been recognized by DOE as necessary to enable the deployment of the next generation of advanced nuclear reactors, including the development and qualification of

  15. An Economic Analysis of Generation IV Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J S; Lamont, A D; Rothwell, G S; Smith, C F; Greenspan, E; Brown, N; Barak, A

    2002-03-01

    This report examines some conditions necessary for Generation IV Small Modular Reactors (SMRs) to be competitive in the world energy market. The key areas that make nuclear reactors an attractive choice for investors are reviewed, and a cost model based on the ideal conditions is developed. Recommendations are then made based on the output of the cost model and on conditions and tactics that have proven successful in other industries. The Encapsulated Nuclear Heat Source (ENHS), a specific SMR design concept, is used to develop the cost model and complete the analysis because information about the ENHS design is readily available from the University of California at Berkeley Nuclear Engineering Department. However, the cost model can be used to analyze any of the current SMR designs being considered. On the basis of our analysis, we determined that the nuclear power industry can benefit from and SMRs can become competitive in the world energy market if a combination of standardization and simplification of orders, configuration, and production are implemented. This would require wholesale changes in the way SMRs are produced, manufactured and regulated, but nothing that other industries have not implemented and proven successful.

  16. Critical Issues on Materials for Gen-IV Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Caro, M; Marian, J; Martinez, E; Erhart, P

    2009-02-27

    Within the LDRD on 'Critical Issues on Materials for Gen-IV Reactors' basic thermodynamics of the Fe-Cr alloy and accurate atomistic modeling were used to help develop the capability to predict hardening, swelling and embrittlement using the paradigm of Multiscale Materials Modeling. Approaches at atomistic and mesoscale levels were linked to build-up the first steps in an integrated modeling platform that seeks to relate in a near-term effort dislocation dynamics to polycrystal plasticity. The requirements originated in the reactor systems under consideration today for future sources of nuclear energy. These requirements are beyond the present day performance of nuclear materials and calls for the development of new, high temperature, radiation resistant materials. Fe-Cr alloys with 9-12% Cr content are the base matrix of advanced ferritic/martensitic (FM) steels envisaged as fuel cladding and structural components of Gen-IV reactors. Predictive tools are needed to calculate structural and mechanical properties of these steels. This project represents a contribution in that direction. The synergy between the continuous progress of parallel computing and the spectacular advances in the theoretical framework that describes materials have lead to a significant advance in our comprehension of materials properties and their mechanical behavior. We took this progress to our advantage and within this LDRD were able to provide a detailed physical understanding of iron-chromium alloys microstructural behavior. By combining ab-initio simulations, many-body interatomic potential development, and mesoscale dislocation dynamics we were able to describe their microstructure evolution. For the first time in the case of Fe-Cr alloys, atomistic and mesoscale were merged and the first steps taken towards incorporating ordering and precipitation effects into dislocation dynamics (DD) simulations. Molecular dynamics (MD) studies of the transport of self

  17. Generation IV Reactors Integrated Materials Technology Program Plan: Focus on Very High Temperature Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, William R [ORNL; Burchell, Timothy D [ORNL; Katoh, Yutai [ORNL; McGreevy, Timothy E [ORNL; Nanstad, Randy K [ORNL; Ren, Weiju [ORNL; Snead, Lance Lewis [ORNL; Wilson, Dane F [ORNL

    2008-08-01

    Since 2002, the Department of Energy's (DOE's) Generation IV Nuclear Energy Systems (Gen IV) Program has addressed the research and development (R&D) necessary to support next-generation nuclear energy systems. The six most promising systems identified for next-generation nuclear energy are described within this roadmap. Two employ a thermal neutron spectrum with coolants and temperatures that enable hydrogen or electricity production with high efficiency (the Supercritical Water Reactor-SCWR and the Very High Temperature Reactor-VHTR). Three employ a fast neutron spectrum to enable more effective management of actinides through recycling of most components in the discharged fuel (the Gas-cooled Fast Reactor-GFR, the Lead-cooled Fast Reactor-LFR, and the Sodium-cooled Fast Reactor-SFR). The Molten Salt Reactor (MSR) employs a circulating liquid fuel mixture that offers considerable flexibility for recycling actinides and may provide an alternative to accelerator-driven systems. At the inception of DOE's Gen IV program, it was decided to significantly pursue five of the six concepts identified in the Gen IV roadmap to determine which of them was most appropriate to meet the needs of future U.S. nuclear power generation. In particular, evaluation of the highly efficient thermal SCWR and VHTR reactors was initiated primarily for energy production, and evaluation of the three fast reactor concepts, SFR, LFR, and GFR, was begun to assess viability for both energy production and their potential contribution to closing the fuel cycle. Within the Gen IV Program itself, only the VHTR class of reactors was selected for continued development. Hence, this document will address the multiple activities under the Gen IV program that contribute to the development of the VHTR. A few major technologies have been recognized by DOE as necessary to enable the deployment of the next generation of advanced nuclear reactors, including the development and qualification of

  18. Modelling of advanced structural materials for GEN IV reactors

    Science.gov (United States)

    Samaras, M.; Hoffelner, W.; Victoria, M.

    2007-09-01

    The choice of suitable materials and the assessment of long-term materials damage are key issues that need to be addressed for the safe and reliable performance of nuclear power plants. Operating conditions such as high temperatures, irradiation and a corrosive environment degrade materials properties, posing the risk of very expensive or even catastrophic plant damage. Materials scientists are faced with the scientific challenge to determine the long-term damage evolution of materials under service exposure in advanced plants. A higher confidence in life-time assessments of these materials requires an understanding of the related physical phenomena on a range of scales from the microscopic level of single defect damage effects all the way up to macroscopic effects. To overcome lengthy and expensive trial-and-error experiments, the multiscale modelling of materials behaviour is a promising tool, bringing new insights into the fundamental understanding of basic mechanisms. This paper presents the multiscale modelling methodology which is taking root internationally to address the issues of advanced structural materials for Gen IV reactors.

  19. IRIS Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    M. D. Carelli

    2003-11-03

    OAK-B135 This NERI project, originally started as the Secure Transportable Autonomous Light Water Reactor (STAR-LW) and currently known as the International Reactor Innovative and Secure (IRIS) project, had the objective of investigating a novel type of water-cooled reactor to satisfy the Generation IV goals: fuel cycle sustainability, enhanced reliability and safety, and improved economics. The research objectives over the three-year (1999-2002) program were as follows: First year: Assess various design alternatives and establish main characteristics of a point design; Second year: Perform feasibility and engineering assessment of the selected design solutions; Third year: Complete reactor design and performance evaluation, including cost assessment These objectives were fully attained and actually they served to launch IRIS as a full fledged project for eventual commercial deployment. The program did not terminate in 2002 at the end of the NERI program, and has just entered in its fifth year. This has been made possible by the IRIS project participants which have grown from the original four member, two-countries team to the current twenty members, nine countries consortium. All the consortium members work under their own funding and it is estimated that the value of their in-kind contributions over the life of the project has been of the order of $30M. Currently, approximately 100 people worldwide are involved in the project. A very important constituency of the IRIS project is the academia: 7 universities from four countries are members of the consortium and five more US universities are associated via parallel NERI programs. To date, 97 students have worked or are working on IRIS; 59 IRIS-related graduate theses have been prepared or are in preparation, and 41 of these students have already graduated with M.S. (33) or Ph.D. (8) degrees. This ''final'' report (final only as far as the NERI program is concerned) summarizes the work performed

  20. Plasma and erythrocyte glutathione peroxidase activity, serum selenium concentration, and plasma total antioxidant capacity in cats with IRIS stages I-IV chronic kidney disease.

    Science.gov (United States)

    Krofič Žel, M; Tozon, N; Nemec Svete, A

    2014-01-01

    Serum selenium concentrations and the activity of plasma glutathione peroxidase (GPx) decrease with the progression of chronic kidney disease (CKD) in human patients. Selenium is considered a limiting factor for plasma GPx synthesis. Plasma total antioxidant capacity (TAC) is decreased in CKD cats in comparison to healthy cats. Serum selenium concentrations and plasma and erythrocyte GPx activity in cats with CKD are lower than in healthy cats. Serum selenium concentrations, the activity of enzymes, and plasma TAC progressively decrease with the progression of kidney disease according to IRIS (International Renal Interest Society) classification. Twenty-six client-owned cats in IRIS stages I-IV of CKD were compared with 19 client-owned healthy cats. A CBC, serum biochemical profile, urinalysis, plasma and erythrocyte GPx activity, serum selenium concentration, and plasma TAC were measured in each cat. Cats in IRIS stage IV CKD had a significantly higher (P = .025) activity of plasma GPx (23.44 ± 6.28 U/mL) than cats in the control group (17.51 ± 3.75 U/mL). There were no significant differences in erythrocyte GPx, serum selenium concentration, and plasma TAC, either among IRIS stages I-IV CKD cats or between CKD cats and healthy cats. Erythrocyte GPx activity, serum selenium concentration, and plasma TAC do not change in CKD cats compared with healthy cats. Selenium is not a limiting factor in feline CKD. Increased plasma GPx activity in cats with stage IV CKD suggests induction of antioxidant defense mechanisms. Antioxidant defense systems might not be exhausted in CKD in cats. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  1. Sargent-IV Project. Development of new methodologies for safety analysis of Generation IV reactors; Proyecto SARGEB-IV. Desarrollo de nuevas metodologias de analisis de seguridad para reactores de Generacion IV

    Energy Technology Data Exchange (ETDEWEB)

    Queral, C.; Gallego, E.; Jimenez, G.

    2013-07-01

    The main result of this paper is the proposal for the addition of new ingredients in the safety analysis methodologies for Generation-IV reactors that integrates the features of probabilistic safety analysis within deterministic. This ensures a higher degree of integration between the classical deterministic and probabilistic methodologies.

  2. Updated Generation IV Reactors Integrated Materials Technology Program Plan, Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, William R [ORNL; Burchell, Timothy D [ORNL; Halsey, William [Lawrence Livermore National Laboratory (LLNL); Hayner, George [Idaho National Laboratory (INL); Katoh, Yutai [ORNL; Klett, James William [ORNL; McGreevy, Timothy E [ORNL; Nanstad, Randy K [ORNL; Ren, Weiju [ORNL; Snead, Lance Lewis [ORNL; Stoller, Roger E [ORNL; Wilson, Dane F [ORNL

    2005-12-01

    The Department of Energy's (DOE's) Generation IV Nuclear Energy Systems Program will address the research and development (R&D) necessary to support next-generation nuclear energy systems. Such R&D will be guided by the technology roadmap developed for the Generation IV International Forum (GIF) over two years with the participation of over 100 experts from the GIF countries. The roadmap evaluated over 100 future systems proposed by researchers around the world. The scope of the R&D described in the roadmap covers the six most promising Generation IV systems. The effort ended in December 2002 with the issue of the final Generation IV Technology Roadmap [1.1]. The six most promising systems identified for next generation nuclear energy are described within the roadmap. Two employ a thermal neutron spectrum with coolants and temperatures that enable hydrogen or electricity production with high efficiency (the Supercritical Water Reactor - SCWR and the Very High Temperature Reactor - VHTR). Three employ a fast neutron spectrum to enable more effective management of actinides through recycling of most components in the discharged fuel (the Gas-cooled Fast Reactor - GFR, the Lead-cooled Fast Reactor - LFR, and the Sodium-cooled Fast Reactor - SFR). The Molten Salt Reactor (MSR) employs a circulating liquid fuel mixture that offers considerable flexibility for recycling actinides, and may provide an alternative to accelerator-driven systems. A few major technologies have been recognized by DOE as necessary to enable the deployment of the next generation of advanced nuclear reactors, including the development and qualification of the structural materials needed to ensure their safe and reliable operation. Accordingly, DOE has identified materials as one of the focus areas for Gen IV technology development.

  3. A Virtual Reality Framework to Optimize Design, Operation and Refueling of GEN-IV Reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Rizwan-uddin; Nick Karancevic; Stefano Markidis; Joel Dixon; Cheng Luo; Jared Reynolds

    2008-04-23

    many GEN-IV candidate designs are currently under investigation. Technical issues related to material, safety and economics are being addressed at research laboratories, industry and in academia. After safety, economic feasibility is likely to be the most important crterion in the success of GEN-IV design(s). Lessons learned from the designers and operators of GEN-II (and GEN-III) reactors must play a vital role in achieving both safety and economic feasibility goals.

  4. Nordic Forum for Generation IV Reactors,Status and activities in 2012

    DEFF Research Database (Denmark)

    Van Nieuwenhove, Rudi; Lauritzen, Bent; Nonbøl, Erik

    The Nordic-Gen4 (continuation from NOMAGE4) seminar was this year hosted by DTU Nutech at Risø, Denmark. The seminar was well attended (49 participants from 12 countries). The presentations covered many as-pects in Gen-IV reactor research and gave a good overview of the activi-ties within this fi...

  5. Structural materials for Gen-IV nuclear reactors: Challenges and opportunities

    Science.gov (United States)

    Murty, K. L.; Charit, I.

    2008-12-01

    Generation-IV reactor design concepts envisioned thus far cater toward a common goal of providing safer, longer lasting, proliferation-resistant and economically viable nuclear power plants. The foremost consideration in the successful development and deployment of Gen-IV reactor systems is the performance and reliability issues involving structural materials for both in-core and out-of-core applications. The structural materials need to endure much higher temperatures, higher neutron doses and extremely corrosive environment, which are beyond the experience of the current nuclear power plants. Materials under active consideration for use in different reactor components include various ferritic/martensitic steels, austenitic stainless steels, nickel-base superalloys, ceramics, composites, etc. This paper presents a summary of various Gen-IV reactor concepts, with emphasis on the structural materials issues depending on the specific application areas. This paper also discusses the challenges involved in using the existing materials under both service and off-normal conditions. Tasks become increasingly complex due to the operation of various fundamental phenomena like radiation-induced segregation, radiation-enhanced diffusion, precipitation, interactions between impurity elements and radiation-produced defects, swelling, helium generation and so forth. Further, high temperature capability (e.g. creep properties) of these materials is a critical, performance-limiting factor. It is demonstrated that novel alloy and microstructural design approaches coupled with new materials processing and fabrication techniques may mitigate the challenges, and the optimum system performance may be achieved under much demanding conditions.

  6. Iris si iv line profiles: An indication for the plasmoid instability during small-scale magnetic reconnection on the sun

    CERN Document Server

    Innes, Davina; Huang, YiMin; Bhattacharjee, Amitava

    2015-01-01

    Our understanding of the process of fast reconnection has undergone a dramatic change in the last 10 years driven, in part, by the availability of high-resolution numerical simulations that have consistently demonstrated the break-up of current sheets into magnetic islands, with reconnection rates that become independent of Lundquist number, challenging the belief that fast magnetic reconnection in flares proceeds via the Petschek mechanism that invokes pairs of slow-mode shocks connected to a compact diffusion region. The reconnection sites are too small to be resolved with images but these reconnection mechanisms, Petschek and the plasmoid instability, have reconnection sites with very different density and velocity structures and so can be distinguished by high-resolution line-profiles observations. Using IRIS spectroscopic observations we obtain a survey of typical line profiles produced by small-scale events thought to be reconnection sites on the Sun. Slit-jaw images are used to investigate the plasma h...

  7. A preliminary safety analysis for the prototype Gen IV Sodium-Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwi Lim; Ha, Kwi Seok; Jeong, Jae Ho; Choi, Chi Woong; Jeong, Tae Kyeong; Ahn, Sang June; Lee, Seung Won; Chang, Won Pyo; Kang, Seok Hun; Yoo, Jae Woon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Korea Atomic Energy Research Institute has been developing a pool-type sodium-cooled fast reactor of the Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR). To assess the effectiveness of the inherent safety features of the PGSFR, the system transients during design basis accidents and design extended conditions are analyzed with MARS-LMR and the subchannel blockage events are analyzed with MATRA-LMR-FB. In addition, the in-vessel source term is calculated based on the super-safe, small, and simple reactor methodology. The results show that the PGSFR meets safety acceptance criteria with a sufficient margin during the events and keeps accidents from deteriorating into more severe accidents.

  8. Contribution of the IV generation fast reactors to the sustainable development; Contribucion de los reactores rapidos de IV Generacion al desarrollo sustentable

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza G, G.; Klapp E, J.L. [ININ, Centro Nuclear ' Dr. Nabor Carrillo Flores' Carretera Mexico Toluca, S/N. 52750 La Marquesa, Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: gmg@nuclear.inin.mx

    2007-07-01

    During the XXI century all the energy forms are necessary for the sustainable development. A balanced energy politics has to use a mixture of energy sources that completes the objective of responding to the increase in the demand and that it uses non emitting gases sources of greenhouse effect like the nuclear one. It is evident the great existent difficulty to turn the objectives of emissions for the coming years without having the nuclear energy. Later on, the process continued outlining serious commitments among the development necessity, the improvement of the level of life and the competitiveness, and the execution from the established environmental requirements to world level. It is very foregone that the energy nuclear become the best energy source to improve the environmental conditions and that new initiatives are determined in those that this energy will have an important paper. The solution is to build a nuclear central of advanced design, using technologies that its help to brake the diffusion of the nuclear weapons. The nucleo electric energy at great scale should be developed on the base of designs of reactors and innovative processes of fuel that can lend technological support to the not nuclear proliferation regime, and that at the same time they contribute to satisfy the electricity demand in the world. In a scenario of increase of energy demand, mainly in the development countries, and of growing interest in the pollutants reduction originated by the use of fossil fuels, the nuclear reactors of IV Generation arise as proposal and challenge. Meanwhile the search of new technologies and innovations become imperative, translating an enormous evolution, not only in the conceptual projects, as well as in the fuel cycle so that, in a scenario of open economy, turn its more competitive. Inside the reactors of fourth generation, the quick reactors are configured as those that more assist to such demands and they will be, without a doubt, the reactors in

  9. A Project Management and Systems Engineering Structure for a Generation IV Very High Temperature Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ed Gorski; Dennis Harrell; Finis Southworth

    2004-09-01

    The Very High Temperature Reactor (VHTR) will be an advanced, very high temperature (approximately 1000o C. coolant outlet temperature), gas cooled nuclear reactor and is the nearest term of six Generation IV reactor technologies for nuclear assisted hydrogen production. In 2001, the Generation IV International Forum (GIF), a ten nation international forum working together with the Department of Energy’s (DOE) Nuclear Energy Research Advisory Committee (NERAC), agreed to proceed with the development of a technology roadmap and identified the next generation of nuclear reactor systems for producing new sources of power. Since a new reactor has not been licensed in the United States since the 1970s, the risks are too large for a single utility to assume in the development of an unprecedented Generation IV reactor. The government must sponsor and invest in the research to resolve major first of a kind (FOAK) issues through a full-scale demonstration prior to industry implementation. DOE’s primary mission for the VHTR is to demonstrate nuclear reactor assisted cogeneration of electricity and hydrogen while meeting the Generation IV goals for safety, sustainability, proliferation resistance and physical security and economics. The successful deployment of the VHTR as a demonstration project will aid in restarting the now atrophied U.S. nuclear power industry infrastructure. It is envisioned that VHTR project participants will include DOE Laboratories, industry partners such as designers, constructors, manufacturers, utilities, and Generation IV international countries. To effectively mange R&D, engineering, procurement, construction, and operation for this multi-organizational and technologically complex project, systems engineering will be used extensively to ensure delivery of the final product. Although the VHTR is an unprecedented FOAK system, the R&D, when assessed using the Office of Science and Technology Gate Model, falls primarily in the 3rd - Exploratory

  10. Mechanical Design Concept of Fuel Assembly for Prototype GEN-IV Sodium-cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K. H.; Lee, C. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The prototype GEN-IV sodium-cooled fast reactor (PGSFR) is an advanced fast reactor plant design that utilizes compact modular pool-type reactors sized to enable factory fabrication and an affordable prototype test for design certification at minimum cost and risk. The design concepts of the fuel assembly (FA) were introduced for a PGSFR. Unlike that for the pressurized water reactor, there is a neutron shielding concept in the FA and recycling metal fuel. The PGSFR core is a heterogeneous, uranium-10% zirconium (U-10Zr) metal alloy fuel design with 112 assemblies: 52 inner core fuel assemblies, 60 outer core fuel assemblies, 6 primary control assemblies, 3 secondary control assemblies, 90 reflector assemblies and 102 B4C shield assemblies. This configuration is shown in Fig. 1. The core is designed to produce 150 MWe with an average temperature rise of 155 .deg. C. The inlet temperature is 390 .deg. C and the bulk outlet temperature is 545 .deg. C. The core height is 900 mm and the gas plenum length is 1,250 mm. A mechanical design of a fuel assembly for a PGSFR was established. The mechanical design concepts are well realized in the design. In addition to this, the analytical and experimental works will be carries out for verifying the design soundness.

  11. Overall system description and safety characteristics of Prototype Gen IV Sodium Cooled Fast Reactor in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jae Woon; Chang, Jin Wook; Lim, Jae Yong; Cheon, Jin Sik; Lee, Tae Ho; Kim, Sung Kyun; Lee, Kwi Lim; Joo, Hyung Kook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The Prototype Gen IV sodium cooled fast reactor (PGSFR) has been developed for the last 4 years, fulfilling the technology demonstration of the burning capability of transuranic elements included in light water reactor spent nuclear fuel. The PGSFR design has been focused on the robustness of safety systems by enhancing inherent safety characteristics of metal fuel and strengthening passive safety features using natural circulation and thermal expansion. The preliminary safety information document as a major outcome of the first design phase of PGSFR development was issued at the end of 2015. The project entered the second design phase at the beginning of 2016. This paper summarizes the overall structures, systems, and components of nuclear steam supply system and safety characteristics of the PGSFR. The research and development activities to demonstrate the safety performance are also briefly introduced in the paper.

  12. Decay Heat Removal in GEN IV Gas-Cooled Fast Reactors

    Directory of Open Access Journals (Sweden)

    Lap-Yan Cheng

    2009-01-01

    Full Text Available The safety goal of the current designs of advanced high-temperature thermal gas-cooled reactors (HTRs is that no core meltdown would occur in a depressurization event with a combination of concurrent safety system failures. This study focused on the analysis of passive decay heat removal (DHR in a GEN IV direct-cycle gas-cooled fast reactor (GFR which is based on the technology developments of the HTRs. Given the different criteria and design characteristics of the GFR, an approach different from that taken for the HTRs for passive DHR would have to be explored. Different design options based on maintaining core flow were evaluated by performing transient analysis of a depressurization accident using the system code RELAP5-3D. The study also reviewed the conceptual design of autonomous systems for shutdown decay heat removal and recommends that future work in this area should be focused on the potential for Brayton cycle DHRs.

  13. Nordic forum for generation IV reactors, status and activities in 2012

    Energy Technology Data Exchange (ETDEWEB)

    Van Nieuwenhove, R. [Institutt for Energiteknikk, OECD Halden Reactor Project, Kjeller (Norway); Lauritzen, B.; Nonboel, E. [Technical Univ. of Denmark. DTU Nutech, Roskilde (Denmark)

    2012-12-15

    The Nordic-Gen4 (continuation from NOMAGE4) seminar was this year hosted by DTU Nutech at Risoe, Denmark. The seminar was well attended (49 participants from 12 countries). The presentations covered many aspects in Gen-IV reactor research and gave a good overview of the activities within this field at the various institutes and universities. The present report contains book of abstracts. The individual Power Point presentations are indexed in INIS and may be found at http://nordic-gen4.org/seminars/nordic-gen4-riso-2012-2/ (LN)

  14. Irradiation effects in oxide dispersion strengthened (ODS) Ni-base alloys for Gen. IV nuclear reactors

    Science.gov (United States)

    Oono, Naoko; Ukai, Shigeharu; Kondo, Sosuke; Hashitomi, Okinobu; Kimura, Akihiko

    2015-10-01

    Oxide particle dispersion strengthened (ODS) Ni-base alloys are irradiated by using simulation technique (Fe/He dual-ion irradiation) to investigate the reliability to Gen. IV high-temperature reactors. The fine oxide particles with less than 10 nm in average size and approximately 8.0 × 1022 m-3 in number density remained after 101 dpa irradiation. The tiny helium bubbles were inside grains, not at grain-boundaries; it is advantageous effect of oxide particles which trap the helium atoms at the particle-matrix interface. Ni-base ODS alloys demonstrated their great ability to overcome He embrittlement.

  15. Thermal stability study for candidate stainless steels of GEN IV reactors

    Science.gov (United States)

    Simeg Veternikova, J.; Degmova, J.; Pekarcikova, M.; Simko, F.; Petriska, M.; Skarba, M.; Mikula, P.; Pupala, M.

    2016-11-01

    Candidate stainless steels for GEN IV reactors were investigated in term of thermal and corrosion stability at high temperatures. New austenitic steel (NF 709), austenitic ODS steel (ODS 316) and two ferritic ODS steels (MA 956 and MA 957) were exposed to around 1000 °C in inert argon atmosphere at pressure of ∼8 MPa. The steels were further studied in a light of vacancy defects presence by positron annihilation spectroscopy and their thermal resistance was confronted to classic AISI steels. The thermal strain supported a creation of oxide layers observed by scanning electron microscopy (SEM).

  16. Metal Fuel Development and Verification for Prototype Generation IV Sodium-Cooled Fast Reactor

    OpenAIRE

    Chan Bock Lee; Jin Sik Cheon; Sung Ho Kim; Jeong-Yong Park; Hyung-Kook Joo

    2016-01-01

    Metal fuel is being developed for the prototype generation-IV sodium-cooled fast reactor (PGSFR) to be built by 2028. U–Zr fuel is a driver for the initial core of the PGSFR, and U–transuranics (TRU)–Zr fuel will gradually replace U–Zr fuel through its qualification in the PGSFR. Based on the vast worldwide experiences of U–Zr fuel, work on U–Zr fuel is focused on fuel design, fabrication of fuel components, and fuel verification tests. U–TRU–Zr fuel uses TRU recovered through pyroelectrochem...

  17. Thermal stability study for candidate stainless steels of GEN IV reactors

    Energy Technology Data Exchange (ETDEWEB)

    Simeg Veternikova, J., E-mail: jana.veternikova@stuba.sk [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Degmova, J. [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Pekarcikova, M. [Institute of Materials Science, Faculty of Materials Science and Technology, Slovak University of Technology, Paulinska 16, 917 24 Trnava (Slovakia); Simko, F. [Department of Molten Salts, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 36 Bratislava (Slovakia); Petriska, M. [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Skarba, M. [Slovak University of Technology, Vazovova 5, 812 43 Bratislava (Slovakia); Mikula, P. [Institute of Nuclear and Physical Engineering, Faculty of Electrical and Information Technology, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Pupala, M. [Department of Molten Salts, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 36 Bratislava (Slovakia)

    2016-11-30

    Highlights: • Thermal resistance of advanced stainless steels were observed at 1000 °C. • GEN IV candidate steels were confronted to classic AISI steels. • ODS AISI 316 has weaker thermal resistance than classic AISI steel. • Ferritic ODS steels and NF 709 has better thermal resistance than AISI steels. - Abstract: Candidate stainless steels for GEN IV reactors were investigated in term of thermal and corrosion stability at high temperatures. New austenitic steel (NF 709), austenitic ODS steel (ODS 316) and two ferritic ODS steels (MA 956 and MA 957) were exposed to around 1000 °C in inert argon atmosphere at pressure of ∼8 MPa. The steels were further studied in a light of vacancy defects presence by positron annihilation spectroscopy and their thermal resistance was confronted to classic AISI steels. The thermal strain supported a creation of oxide layers observed by scanning electron microscopy (SEM).

  18. Assessment of the Technical Maturity of Generation IV Concepts for Test or Demonstration Reactor Applications, Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Gougar, Hans David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-01

    The United States Department of Energy (DOE) commissioned a study the suitability of different advanced reactor concepts to support materials irradiations (i.e. a test reactor) or to demonstrate an advanced power plant/fuel cycle concept (demonstration reactor). As part of the study, an assessment of the technical maturity of the individual concepts was undertaken to see which, if any, can support near-term deployment. A Working Group composed of the authors of this document performed the maturity assessment using the Technical Readiness Levels as defined in DOE’s Technology Readiness Guide . One representative design was selected for assessment from of each of the six Generation-IV reactor types: gas-cooled fast reactor (GFR), lead-cooled fast reactor (LFR), molten salt reactor (MSR), supercritical water-cooled reactor (SCWR), sodium-cooled fast reactor (SFR), and very high temperature reactor (VHTR). Background information was obtained from previous detailed evaluations such as the Generation-IV Roadmap but other technical references were also used including consultations with concept proponents and subject matter experts. Outside of Generation IV activity in which the US is a party, non-U.S. experience or data sources were generally not factored into the evaluations as one cannot assume that this data is easily available or of sufficient quality to be used for licensing a US facility. The Working Group established the scope of the assessment (which systems and subsystems needed to be considered), adapted a specific technology readiness scale, and scored each system through discussions designed to achieve internal consistency across concepts. In general, the Working Group sought to determine which of the reactor options have sufficient maturity to serve either the test or demonstration reactor missions.

  19. Progress reports for Gen IV sodium fast reactor activities FY 2007.

    Energy Technology Data Exchange (ETDEWEB)

    Cahalan, J. E.; Tentner, A. M.; Nuclear Engineering Division

    2007-10-04

    identified as being for prevention of progression into severe accident conditions (prevention of core melting) or for mitigation of severe accident consequences (mitigation of the impact of core melting to protect public health and safety). Because design measures for severe accident prevention and mitigation are beyond the normal design basis, established regulatory guidelines and codes do not provide explicit identification of the design performance requirements for severe accident accommodation. The treatment of severe accidents is one of the key issues of R&D plans for the Gen IV systems in general, and for the Sodium Fast Reactor (SFR) in particular. Despite the lack of an unambiguous definition of safety approach applicable for severe accidents, there is an emerging consensus on the need for their consideration for the design. The US SFR program and Argonne National Laboratory (ANL) in particular have actively studied the potential scenarios and consequences of Hypothetical Core Disruptive Accidents (HCDA) for SFRs with oxide fuel during the Fast Flux Test Facility (FFTF) and Clinch River Breeder Reactor Plant (CRBRP) programs in the 70s and 80s. Later, the focus of the US SFR safety R&D activities shifted to the prevention of all HCDAs through passive safety features of the SFRs with metal fuel in the Integral Fast Reactor (IFR) program, and the study of severe accident consequences was de-emphasized. The goal of this paper is to provide an overview of the current SFR safety approach and the role of severe accidents in Japan and France, in preparation for an expected and more active collaboration in this area between the US, Japan, and France.

  20. Metal fuel development and verification for prototype generation- IV Sodium- Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chan Bock; Cheon, Jin Sik; Kim, Sung Ho; Park, Jeong Yong; Joo, Hyung Kook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Metal fuel is being developed for the prototype generation-IV sodium-cooled fast reactor (PGSFR) to be built by 2028. U-Zr fuel is a driver for the initial core of the PGSFR, and U -transuranics (TRU)-Zr fuel will gradually replace U-Zr fuel through its qualification in the PGSFR. Based on the vast worldwide experiences of U-Zr fuel, work on U-Zr fuel is focused on fuel design, fabrication of fuel components, and fuel verification tests. U-TRU-Zr fuel uses TRU recovered through pyroelectrochemical processing of spent PWR (pressurized water reactor) fuels, which contains highly radioactive minor actinides and chemically active lanthanide or rare earth elements as carryover impurities. An advanced fuel slug casting system, which can prevent vaporization of volatile elements through a control of the atmospheric pressure of the casting chamber and also deal with chemically active lanthanide elements using protective coatings in the casting crucible, was developed. Fuel cladding of the ferritic-martensitic steel FC92, which has higher mechanical strength at a high temperature than conventional HT9 cladding, was developed and fabricated, and is being irradiated in the fast reactor.

  1. Fundamental Understanding of Crack Growth in Structural Components of Generation IV Supercritical Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Iouri I. Balachov; Takao Kobayashi; Francis Tanzella; Indira Jayaweera; Palitha Jayaweera; Petri Kinnunen; Martin Bojinov; Timo Saario

    2004-11-17

    This work contributes to the design of safe and economical Generation-IV Super-Critical Water Reactors (SCWRs) by providing a basis for selecting structural materials to ensure the functionality of in-vessel components during the entire service life. During the second year of the project, we completed electrochemical characterization of the oxide film properties and investigation of crack initiation and propagation for candidate structural materials steels under supercritical conditions. We ranked candidate alloys against their susceptibility to environmentally assisted degradation based on the in situ data measure with an SRI-designed controlled distance electrochemistry (CDE) arrangement. A correlation between measurable oxide film properties and susceptibility of austenitic steels to environmentally assisted degradation was observed experimentally. One of the major practical results of the present work is the experimentally proven ability of the economical CDE technique to supply in situ data for ranking candidate structural materials for Generation-IV SCRs. A potential use of the CDE arrangement developed ar SRI for building in situ sensors monitoring water chemistry in the heat transport circuit of Generation-IV SCWRs was evaluated and proved to be feasible.

  2. A Cylindrical Shielding Design Concept for the Prototype Gen-IV Sodium-cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Sunghwan; Kim, Sang Ji [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In the Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR), a metal fueled, blanket-free, pool type SFR concept is adopted to acquire the inherent safety characteristics and high proliferation-resistance. In the pool type fast reactor, the intermediate heat exchangers (IHXs), which transfer heat from the primary sodium pool to a secondary sodium loop, are placed inside of the reactor vessel. Hence, secondary sodium passing the IHXs can be radioactivated by a {sup 23}Na(n,g){sup 24}Na reaction, and radioactivated secondary sodium causes a significant dose in the Steam Generator Building (SGB). Therefore, a typical core of a pool type fast reactor is usually surrounded by a massive quantity of shields. In addition, the blanket composed of depleted uranium plays a role as superior shielding material; a significant increase in shields is required in the blanket-free pool type SFR. In this paper, a new cylindrical shielding design concept is proposed for a blanket-free pool type SFR. In a conventional shielding design, massive axial shields are required to prevent irradiation of secondary sodium passing IHXs and they should be replaced according to the subassembly replacement in spite of negligible depletion of the shielding material. The proposed shielding design concept minimizes the quantity of shields without their replacement. In this paper, a new cylindrical shielding design concept is proposed for a blanket-free pool type SFR such as a PGSFR. The proposed design concept satisfied the dose limit in the steam generator building successfully without introducing a large quantity of B{sub 4}C shielding inside the subassembly.

  3. Light water reactor fuel analysis code FEMAXI-IV(Ver.2). Detailed structure and user`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Motoe [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Saitou, Hiroaki

    1997-11-01

    A light water reactor fuel behavior analysis code FEMAXI-IV(Ver.2) was developed as an improved version of FEMAXI-IV. Development of FEMAXI-IV has been already finished in 1992, though a detailed structure and input manual of the code have not been open to users yet. Here, the basic theories and structure, the models and numerical solutions applied to FEMAXI-IV(Ver.2), and the material properties adopted in the code are described in detail. In FEMAXI-IV(Ver.2), programming bugs in previous FEMAXI-IV were eliminated, renewal of the pellet thermal conductivity was performed, and a model of thermal-stress restraint on FP gas release was incorporated. For facilitation of effective and wide-ranging application of the code, methods of input/output of the code are also described in detail, and sample output is included. (author)

  4. Generation IV Nuclear Energy Systems Construction Cost Reductions through the Use of Virtual Environments - Task 5 Report: Generation IV Reactor Virtual Mockup Proof-of-Principle Study

    Energy Technology Data Exchange (ETDEWEB)

    Timothy Shaw; Anthony Baratta; Vaughn Whisker

    2005-02-28

    Task 5 report is part of a 3 year DOE NERI-sponsored effort evaluating immersive virtual reality (CAVE) technology for design review, construction planning, and maintenance planning and training for next generation nuclear power plants. Program covers development of full-scale virtual mockups generated from 3D CAD data presented in a CAVE visualization facility. Created a virtual mockup of PBMR reactor cavity and discussed applications of virtual mockup technology to improve Gen IV design review, construction planning, and maintenance planning.

  5. Status of advanced fuel candidates for Sodium Fast Reactor within the Generation IV International Forum

    Science.gov (United States)

    Delage, F.; Carmack, J.; Lee, C. B.; Mizuno, T.; Pelletier, M.; Somers, J.

    2013-10-01

    The main challenge for fuels for future Sodium Fast Reactor systems is the development and qualification of a nuclear fuel sub-assembly which meets the Generation IV International Forum goals. The Advanced Fuel project investigates high burn-up minor actinide bearing fuels as well as claddings and wrappers to withstand high neutron doses and temperatures. The R&D outcome of national and collaborative programs has been collected and shared between the AF project members in order to review the capability of sub-assembly material and fuel candidates, to identify the issues and select the viable options. Based on historical experience and knowledge, both oxide and metal fuels emerge as primary options to meet the performance and the reliability goals of Generation IV SFR systems. There is a significant positive experience on carbide fuels but major issues remain to be overcome: strong in-pile swelling, atmosphere required for fabrication as well as Pu and Am losses. The irradiation performance database for nitride fuels is limited with longer term R&D activities still required. The promising core material candidates are Ferritic/Martensitic (F/M) and Oxide Dispersed Strengthened (ODS) steels.

  6. Simplified Design Criteria for Very High Temperature Applications in Generation IV Reactors

    Energy Technology Data Exchange (ETDEWEB)

    McGreevy, TE

    2004-12-15

    The goal of this activity is to provide simplified criteria which can be used in rapid feasibility assessments of the structural viability of very high temperature components in conceptual and early preliminary design phases for Generation IV reactors. The current criteria in ASME Code Section III, Subsection NH, hereafter referred to as NH, (and Code Case N-201 for core support structures) are difficult and require a complex deconstruction of finite element analysis results for their implementation. Further, and most important, times, temperatures and some materials of interest to the very high temperature Generation IV components are not covered by the current provisions of NH. Future revisions to NH are anticipated that will address very high temperature Generation IV components and materials requirements but, until that occurs interim guidance is required for design activities to proceed. These simplified criteria are for design guidance and are not necessarily in rigorous compliance with NH methodology. Rather, the objective is for criteria which address the early design needs of very high temperature Generation IV components and materials. The intent is to provide simplified but not overly conservative design methods. When more rigorous criteria and methods are incorporated in NH, the degree of conservatism should obviously be reduced. These criteria are based on currently available information. Although engineering judgments have been made in the formulation of these criteria they are not intended to require additional development or testing prior to implementation as a tool for use in conceptual and early preliminary design. Appendices are provided herein that contain useful information. The simplified methods were developed specifically with Alloy 617 in mind; however, they could be applied for the same intended purpose for other materials such as 9Cr-1Mo, Alloy 800H, etc. However, supporting design curves, stress allowables, and isochronous curves may

  7. Reactors

    CERN Document Server

    International Electrotechnical Commission. Geneva

    1988-01-01

    This standard applies to the following types of reactors: shunt reactors, current-limiting reactors including neutral-earthing reactors, damping reactors, tuning (filter) reactors, earthing transformers (neutral couplers), arc-suppression reactors, smoothing reactors, with the exception of the following reactors: small reactors with a rating generally less than 2 kvar single-phase and 10 kvar three-phase, reactors for special purposes such as high-frequency line traps or reactors mounted on rolling stock.

  8. NOMAGE4 activities 2011. Part I, Nordic Nuclear Materials Forum for Generation IV Reactors: Status and activities in 2011

    Energy Technology Data Exchange (ETDEWEB)

    Van Nieuwenhove, R. (Institutt for Energiteknikk, OECD Halden Reactor Project (Norway))

    2012-01-15

    A network for materials issues has been initiated in 2009 within the Nordic countries. The original objectives of the Generation IV Nordic Nuclear Materials Forum (NOMAGE4) were to form the basis of a sustainable forum for Gen-IV issues, especially focusing on fuels, cladding, structural materials and coolant interaction. Over the last years, other issues such as reactor physics, thermal hydraulics, safety and waste have gained in importance (within the network) and therefore the scope of the forum has been enlarged and a more appropriate and more general name, NORDIC-GEN4, has been chosen for the forum. Further, the interaction with non-Nordic countries (such as The Netherlands (JRC, NRG) and Czech Republic (CVR)) will be increased. Within the NOMAGE4 project, a seminar was organized by IFE-Halden during 31 October - 1 November 2011. The seminar attracted 65 participants from 12 countries. The seminar provided a forum for exchange of information, discussion on future research reactor needs and networking of experts on Generation IV reactor concepts. The participants could also visit the Halden reactor site and the workshop. (Author)

  9. Uncertainty Quantification in the Reliability and Risk Assessment of Generation IV Reactors: Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Vierow, Karen; Aldemir, Tunc

    2009-09-10

    The project entitled, “Uncertainty Quantification in the Reliability and Risk Assessment of Generation IV Reactors”, was conducted as a DOE NERI project collaboration between Texas A&M University and The Ohio State University between March 2006 and June 2009. The overall goal of the proposed project was to develop practical approaches and tools by which dynamic reliability and risk assessment techniques can be used to augment the uncertainty quantification process in probabilistic risk assessment (PRA) methods and PRA applications for Generation IV reactors. This report is the Final Scientific/Technical Report summarizing the project.

  10. Development of the Plan for Improvement of the Competitiveness of KALIMER Design against the Competing Reactor Design in Gen IV

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Yoon Sub; Kim, Yeong Il; Hong, Ser Gi (and others)

    2005-11-15

    A fast reactor has a good transmutation capability and it enables breeding of fuel and use of a closed fuel cycle. By these characteristics of a fast reactor, the limited uranium resources of the world can be much more effectively utilized and the nuclear wastes of a high level of radioactivity and toxicity from the current nuclear power reactors of LWRs and HWRs can be drastically reduced in its volume and the management of the wastes can be easily treated. Also electricity can be generated more effectively since a fast reactor has the feature of high operation temperature. These features of a fast reactor makes it inevitable on a long term basis to construct fast reactors in Korea. The domestic fast reactor technology level, however, is at the level of coming out of a beginning stage and needs utilization of international expertise. Recently an international cooperation program called GIF has been formulated and our KALIMER was selected as one of the two reference designs for the international joint R and D works with JSFR of Japan. In the current frame of the GIF program, the two selected reference designs are supposed to be evaluated against each other in future and one design is to be finally selected. To make the international cooperation program directed more useful to our fast reactor technology development, it is required to strengthen the competitiveness of KALIMER so that it can be selected. To meet the necessity, a study was made to enhance the competitiveness of KALIMER. The design characteristics of JSFR was investigated and relatively weak points and strong points of KALIMER were identified. Also the GenIV SFR design requirements were applied to two designs to evaluate the level of requirements satisfaction. Based on these investigation results, a plan for improving the weak features and strengthening the strong points of the KALIMER design has been developed.

  11. IGORR-IV -- Proceedings of the fourth meeting of the International Group on Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbalm, K.F. [comp.

    1995-12-31

    The International Group on Research Reactors was formed to facilitate the sharing of knowledge and experience among those institutions and individuals who are actively working to design, build, and promote new research reactors or to make significant upgrades to existing facilities. Twenty-nine papers were presented in five sessions and written versions of the papers or hard copies of the vugraphs used are published in these proceedings. The five sessions were: (1) Operating Research Reactors and Facility Upgrades; (2) Research Reactors in Design and Construction; (3) ANS Closeout Activities; (4) and (5) Research, Development, and Analysis Results.

  12. SVBR-100 module-type fast reactor of the IV generation for regional power industry

    Science.gov (United States)

    Zrodnikov, A. V.; Toshinsky, G. I.; Komlev, O. G.; Stepanov, V. S.; Klimov, N. N.

    2011-08-01

    In the report the following is presented: basic conceptual provisions of the innovative nuclear power technology (NPT) based on modular fast reactors (FR) SVBR-100, summarized results of calculations of the reactor, analysis of the opportunities of multi-purpose application of such reactor facilities (RF) including export potentials with due account of nonproliferation requirements. The most important features of the proposed NPT analyzed in the report are as follows: (1) integral (monoblock) arrangement of the primary circuit equipment with entire elimination of the primary circuit pipelines and valves that considerably reduces the construction and assembly works period and coupling with high boiling point of lead-bismuth coolant (LBC) deterministically eliminates accidents of the LOCA type, (2) option for 100 MWe power and dimensions of the reactor provide: on the one hand, an opportunity to transport the reactor monoblock in factory-readiness by railway as well as other kinds of transport, on the other hand, core breeding ratio (CBR) exceeds 1 while MOX-fuel is used. The preferable area of application of RF SVBR-100 is regional and small power requiring power-units of electric power in a range of (100-600) MW, which could be used for cogeneration-based district heating while locating them nearby cities as well as for generation of electric power in a mode of load tracking in the regions with low network systems.

  13. Millimeter-Wave Thermal Analysis Development and Application to GEN IV Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Wosko, Paul; Sundram, S. K.

    2012-10-16

    New millimeter-wave thermal analysis instrumentation has been developed and studied for characterization of materials required for diverse fuel and structural needs in high temperature reactor environments such as the Next Generation Nuclear Plant (NGNP). A two-receiver 137 GHz system with orthogonal polarizations for anisotropic resolution of material properties has been implemented at MIT. The system was tested with graphite and silicon carbide specimens at temperatures up to 1300 ºC inside an electric furnace. The analytic and hardware basis for active millimeter-wave radiometry of reactor materials at high temperature has been established. Real-time, non contact measurement sensitivity to anisotropic surface emissivity and submillimeter surface displacement was demonstrated. The 137 GHz emissivity of reactor grade graphite (NBG17) from SGL Group was found to be low, ~ 5 %, in the 500 – 1200 °C range and increases by a factor of 2 to 4 with small linear grooves simulating fracturing. The low graphite emissivity would make millimeter-wave active radiometry a sensitive diagnostic of graphite changes due to environmentally induced stress fracturing, swelling, or corrosion. The silicon carbide tested from Ortek, Inc. was found to have a much higher emissivity at 137 GHz of ~90% Thin coatings of silicon carbide on reactor grade graphite supplied by SGL Group were found to be mostly transparent to millimeter-waves, increasing the 137 GHz emissivity of the coated reactor grade graphite to about ~14% at 1250 ºC.

  14. Eugene P. Wigner’s Visionary Contributions to Generations-I through IV Fission Reactors

    Directory of Open Access Journals (Sweden)

    Carré Frank

    2014-01-01

    Full Text Available Among Europe’s greatest scientists who fled to Britain and America in the 1930s, Eugene P. Wigner made instrumental advances in reactor physics, reactor design and technology, and spent nuclear fuel processing for both purposes of developing atomic weapons during world-war II and nuclear power afterwards. Wigner who had training in chemical engineering and self-education in physics first gained recognition for his remarkable articles and books on applications of Group theory to Quantum mechanics, Solid state physics and other topics that opened new branches of Physics.

  15. Eugene P. Wigner's Visionary Contributions to Generations-I through IV Fission Reactors

    Science.gov (United States)

    Carré, Frank

    2014-09-01

    Among Europe's greatest scientists who fled to Britain and America in the 1930s, Eugene P. Wigner made instrumental advances in reactor physics, reactor design and technology, and spent nuclear fuel processing for both purposes of developing atomic weapons during world-war II and nuclear power afterwards. Wigner who had training in chemical engineering and self-education in physics first gained recognition for his remarkable articles and books on applications of Group theory to Quantum mechanics, Solid state physics and other topics that opened new branches of Physics.

  16. Consistent Multigroup Theory Enabling Accurate Course-Group Simulation of Gen IV Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rahnema, Farzad; Haghighat, Alireza; Ougouag, Abderrafi

    2013-11-29

    The objective of this proposal is the development of a consistent multi-group theory that accurately accounts for the energy-angle coupling associated with collapsed-group cross sections. This will allow for coarse-group transport and diffusion theory calculations that exhibit continuous energy accuracy and implicitly treat cross- section resonances. This is of particular importance when considering the highly heterogeneous and optically thin reactor designs within the Next Generation Nuclear Plant (NGNP) framework. In such reactors, ignoring the influence of anisotropy in the angular flux on the collapsed cross section, especially at the interface between core and reflector near which control rods are located, results in inaccurate estimates of the rod worth, a serious safety concern. The scope of this project will include the development and verification of a new multi-group theory enabling high-fidelity transport and diffusion calculations in coarse groups, as well as a methodology for the implementation of this method in existing codes. This will allow for a higher accuracy solution of reactor problems while using fewer groups and will reduce the computational expense. The proposed research represents a fundamental advancement in the understanding and improvement of multi- group theory for reactor analysis.

  17. SARGEN-IV: Consideration on the possible content of the safety analysis report for innovative ESNII reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ammirabile, L., E-mail: Luca.AMMIRABILE@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, Petten (Netherlands); Tuček, K. [European Commission, Joint Research Centre, Institute for Energy and Transport, Petten (Netherlands); Blanc, D. [Institut de radioprotection et de sûreté nucléaire, Fontenay-aux-Roses (France); Pabarcius, R.; Kaliatka, A. [Lithuanian Energy Institute, Kaunas (Lithuania); Mansani, L. [ANSALDO Nucleare, Genova (Italy); Carluec, B. [AREVA, Lyon (France); Dufour, P. [Commissariat à l’énergie atomique, Cadarache (France); Homann, C. [Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2016-04-15

    Highlights: • We present considerations on the content of the safety analysis report for innovative ESNII reactors. • The innovative ESNII reactor concepts require identification of safety objectives and engineering design requirements. • For innovative plant designs the SAR should clearly address all safety aspects to help the regulatory's safety evaluation. • It is recommended that parts of the SAR be discussed with the regulatory body at an early stage. - Abstract: In view of the potential deployment of demonstrators and prototypes associated with the European Sustainable Nuclear Industrial Initiative (ESNII), the present licensing framework, based on the current Light Water Reactor (LWR) technology, will have to adjust as necessary taking into account to the new safety aspects introduced by these innovative technologies. Within the SARGEN-IV project under the Euratom Framework Programme FP7, an extensive work has been done to review the critical safety features of the reactor concepts developed under ESNII. This review has also been used as a reference to provide guidelines on the structure and content of the Safety Analysis Report (SAR) for the innovative ESNII reactors. Structure and content of a SAR generally differ among countries. The approach followed to give recommendations and guidance was to adopt as far as possible the format of the current practices for LWR based on the US NRC Reg Guide 1.70 together with IAEA publication GS-G-4.1 and to identify those chapters whose subjects need to be adapted to the specific design. Due to the innovative nature of the design, the licensing process for new ESNII concepts may take longer. The early involvement of regulators in defining safety objectives and criteria and acceptable solutions to meet these criteria may be beneficial to shorten this process. Therefore, it is recommended that parts of the SAR should be submitted to the regulatory body at an early stage and in accordance with an agreed

  18. Analysis of supercritical CO{sub 2} cycle control strategies and dynamic response for Generation IV Reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

    2011-04-12

    The analysis of specific control strategies and dynamic behavior of the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle has been extended to the two reactor types selected for continued development under the Generation IV Nuclear Energy Systems Initiative; namely, the Very High Temperature Reactor (VHTR) and the Sodium-Cooled Fast Reactor (SFR). Direct application of the standard S-CO{sub 2} recompression cycle to the VHTR was found to be challenging because of the mismatch in the temperature drop of the He gaseous reactor coolant through the He-to-CO{sub 2} reactor heat exchanger (RHX) versus the temperature rise of the CO{sub 2} through the RHX. The reference VHTR features a large temperature drop of 450 C between the assumed core outlet and inlet temperatures of 850 and 400 C, respectively. This large temperature difference is an essential feature of the VHTR enabling a lower He flow rate reducing the required core velocities and pressure drop. In contrast, the standard recompression S-CO{sub 2} cycle wants to operate with a temperature rise through the RHX of about 150 C reflecting the temperature drop as the CO{sub 2} expands from 20 MPa to 7.4 MPa in the turbine and the fact that the cycle is highly recuperated such that the CO{sub 2} entering the RHX is effectively preheated. Because of this mismatch, direct application of the standard recompression cycle results in a relatively poor cycle efficiency of 44.9%. However, two approaches have been identified by which the S-CO{sub 2} cycle can be successfully adapted to the VHTR and the benefits of the S-CO{sub 2} cycle, especially a significant gain in cycle efficiency, can be realized. The first approach involves the use of three separate cascaded S-CO{sub 2} cycles. Each S-CO{sub 2} cycle is coupled to the VHTR through its own He-to-CO{sub 2} RHX in which the He temperature is reduced by 150 C. The three respective cycles have efficiencies of 54, 50, and 44%, respectively, resulting in a net cycle

  19. Stability analysis of the Korean prototype generation-IV sodium-cooled fast reactor using linear frequency domain approach

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Ji; Ha, Pham Nhu Viet; Lim, Jae Yong; Hahn, Do Hee; Kang, Chang Mu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of). Fast Reactor Development Div.

    2016-03-15

    The Korea Atomic Energy Research Institute (KAERI) has been developing the 150 MWe Prototype Generation-IV Sodium-cooled Fast Reactor (PGSFR). The design concept is highly based on passive safety mechanisms, minimizing the need for engineered safety systems. Presently, it is of primary importance to assure the reactor dynamics and stability against small reactivity disturbances under power operating conditions. KAERI has therefore developed the NuSTAB code for stability analysis of the PGSFR. In NuSTAB, the neutron-kinetic and thermal-hydraulic coupling equations are linearized to form the characteristic equation, which is solved as a generalized eigenvalue problem for determining the decay ratio, an indicator of the system stability. In this paper, the stability of the PGSFR was analyzed by applying the point kinetic and spatial kinetic options in the NuSTAB code. System responses to temperature feedbacks including the Doppler effect, thermal expansion, coolant density change, and overall feedback were studied. The results indicate that the initial U and final TRU cores of the PGSFR are both inherently stable thanks to the temperature feedbacks.

  20. Analysis of supercritical CO{sub 2} cycle control strategies and dynamic response for Generation IV Reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

    2011-04-12

    The analysis of specific control strategies and dynamic behavior of the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle has been extended to the two reactor types selected for continued development under the Generation IV Nuclear Energy Systems Initiative; namely, the Very High Temperature Reactor (VHTR) and the Sodium-Cooled Fast Reactor (SFR). Direct application of the standard S-CO{sub 2} recompression cycle to the VHTR was found to be challenging because of the mismatch in the temperature drop of the He gaseous reactor coolant through the He-to-CO{sub 2} reactor heat exchanger (RHX) versus the temperature rise of the CO{sub 2} through the RHX. The reference VHTR features a large temperature drop of 450 C between the assumed core outlet and inlet temperatures of 850 and 400 C, respectively. This large temperature difference is an essential feature of the VHTR enabling a lower He flow rate reducing the required core velocities and pressure drop. In contrast, the standard recompression S-CO{sub 2} cycle wants to operate with a temperature rise through the RHX of about 150 C reflecting the temperature drop as the CO{sub 2} expands from 20 MPa to 7.4 MPa in the turbine and the fact that the cycle is highly recuperated such that the CO{sub 2} entering the RHX is effectively preheated. Because of this mismatch, direct application of the standard recompression cycle results in a relatively poor cycle efficiency of 44.9%. However, two approaches have been identified by which the S-CO{sub 2} cycle can be successfully adapted to the VHTR and the benefits of the S-CO{sub 2} cycle, especially a significant gain in cycle efficiency, can be realized. The first approach involves the use of three separate cascaded S-CO{sub 2} cycles. Each S-CO{sub 2} cycle is coupled to the VHTR through its own He-to-CO{sub 2} RHX in which the He temperature is reduced by 150 C. The three respective cycles have efficiencies of 54, 50, and 44%, respectively, resulting in a net cycle

  1. Tritium permeation characterization of materials for fusion and generation IV very high temperature reactors

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, S.; Pilatzke, K.; McCrimmon, K.; Castillo, I.; Suppiah, S. [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON (Canada)

    2015-03-15

    The objective of this work is to establish the tritium-permeation properties of structural alloys considered for Fusion systems and very high temperature reactors (VHTR). A description of the work performed to set up an apparatus to measure permeation rates of hydrogen and tritium in 304L stainless steel is presented. Following successful commissioning with hydrogen, the test apparatus was commissioned with tritium. Commissioning tests with tritium suggest the need for a reduction step that is capable of removing the oxide layer from the test sample surfaces before accurate tritium-permeation data can be obtained. Work is also on-going to clearly establish the temperature profile of the sample to correctly estimate the tritium-permeability data.

  2. Iris Recognition Using Wavelet

    Directory of Open Access Journals (Sweden)

    Khaliq Masood

    2013-08-01

    Full Text Available Biometric systems are getting more attention in the present era. Iris recognition is one of the most secure and authentic among the other biometrics and this field demands more authentic, reliable and fast algorithms to implement these biometric systems in real time. In this paper, an efficient localization technique is presented to identify pupil and iris boundaries using histogram of the iris image. Two small portions of iris have been used for polar transformation to reduce computational time and to increase the efficiency of the system. Wavelet transform is used for feature vector generation. Rotation of iris is compensated without shifts in the iris code. System is tested on Multimedia University Iris Database and results show that proposed system has encouraging performance.

  3. An EBSD investigation on flow localization and microstructure evolution of 316L stainless steel for Gen IV reactor applications

    Science.gov (United States)

    Wu, Xianglin; Pan, Xiao; Mabon, James C.; Li, Meimei; Stubbins, James F.

    2007-09-01

    Type 316L stainless steel has been selected as a candidate structural material in a series of current accelerator driven systems and Generation IV reactor conceptual designs. The material is sensitive to irradiation damage in the temperature range of 150-400 °C: even low levels of irradiation exposure, as small as 0.1 dpa, can cause severe loss of ductility during tensile loading. This process, where the plastic flow becomes highly localized resulting in extremely low overall ductility, is referred as flow localization. The process controlling this confined flow is related to the difference between the yield and ultimate tensile strengths such that large irradiation-induced increases in the yield strength result in very limited plastic flow leading to necking after very small levels of uniform elongation. In this study, the microstructural evolution controlling flow localization is examined. It is found that twinning is an important deformation mechanism at lower temperatures since it promotes the strain hardening process. At higher temperatures, twinning becomes energetically impossible since the activation of twinning is determined by the critical twinning stress, which increases rapidly with temperature. Mechanical twinning and dislocation-based planar slip are competing mechanisms for plastic deformation.

  4. Uranium enrichment reduction in the Prototype Gen-IV sodium-cooled fast reactor (PGSFR) with PBO reflector

    Energy Technology Data Exchange (ETDEWEB)

    Hartanto, Donny; Kim, Chi Hyung; Kim, Yong Hee [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of)

    2016-04-15

    The Korean Prototype Gen-IV sodium-cooled fast reactor (PGSFR) is supposed to be loaded with a relatively-costly low-enriched U fuel, while its envisaged transuranic fuels are not available for transmutation. In this work, the U-enrichment reduction by improving the neutron economy is pursued to save the fuel cost. To improve the neutron economy of the core, a new reflector material, PbO, has been introduced to replace the conventional HT9 reflector in the current PGSFR core. Two types of PbO reflectors are considered: one is the conventional pin-type and the other one is an inverted configuration. The inverted PbO reflector design is intended to maximize the PbO volume fraction in the reflector assembly. In addition, the core radial configuration is also modified to maximize the performance of the PbO reflector. For the baseline PGSFR core with several reflector options, the U enrichment requirement has been analyzed and the fuel depletion analysis is performed to derive the equilibrium cycle parameters. The linear reactivity model is used to determine the equilibrium cycle performances of the core. Impacts of the new PbO reflectors are characterized in terms of the cycle length, neutron leakage, radial power distribution, and operational fuel cost.

  5. TAPIOCA MELANOMA OF THE IRIS

    NARCIS (Netherlands)

    DEKEIZER, RJW; OOSTERHUIS, JA; HOUTMAN, WA; DEWOLFFROUENDAAL, D

    Clinical identification of tapioca melanoma of the iris is important because its medical treatment may differ from that of other malignant iris melanomas. The characteristic iris nodules must be differentiated from granulomatous uveitis, metastases, and Lisch nodules (neurofibromatosis). We will

  6. Iris and periocular biometrics

    CERN Document Server

    Rathgeb, Christian

    2017-01-01

    This book provides an overview of scientific fundamentals and principles of iris and periocular biometric recognition. It covers: an introduction to iris and periocular recognition; a selective overview of issues and challenges; soft biometric classification; security aspects; privacy protection and forensics; and future trends.

  7. Evaluation of a sodium-water reaction event caused by steam generator tubes break in the prototype generation IV sodium-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang June; Ha, Kwi Seok; Chang, Won Pyo; Kang, Seok Hun; Lee, Kwi Lim; Choi, Chi Woong; Lee, Seung Won; Yoo, Jin; Jeong, Jae Ho; Jeong, Tae Kyeong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-08-15

    The prototype generation IV sodium-cooled fast reactor (PGSFR) has been developed by the Korea Atomic Energy Research Institute. This reactor uses sodium as a reactor coolant to transfer the core heat energy to the turbine. Sodium has chemical characteristics that allow it to violently react with materials such as a water or steam. When a sodium–water reaction (SWR) occurs due to leakage or breakage of steam generator tubes, high-pressure waves and corrosive reaction products are produced, which threaten the structural integrity of the components of the intermediate heat-transfer system (IHTS) and the safety of the primary heat-transfer system (PHTS). In the PGSFR, SWR events are included in the design-basis event. This event should be analyzed from the viewpoint of the integrities of the IHTS and fuel rods. To evaluate the integrity of the IHTS based on the consequences of the SWR, the behaviors of the generated high-pressure waves are analyzed at the major positions of a failed IHTS loop using a sodium–water advanced analysis method-II code. The integrity of the fuel rods must be consistently maintained below the safety acceptance criteria to avoid the consequences of the SWR. The integrity of the PHTS is evaluated using the multidimensional analysis of reactor safety-liquid metal reactor code to model the whole plant.

  8. Internetwork chromospheric bright grains observed with IRIS

    CERN Document Server

    Martínez-Sykora, Juan; Carlsson, Mats; De Pontieu, Bart; Pereira, Tiago M D; Boerner, Paul; Hurlburt, Neal; Kleint, Lucia; Lemen, James; Tarbell, Ted D; Title, Alan; Wuelser, Jean-Pierre; Hansteen, Viggo H; Golub, Leon; McKillop, Sean; Reeves, Kathy K; Saar, Steven; Testa, Paola; Tian, Hui; Jaeggli, Sarah; Kankelborg, Charles

    2015-01-01

    The Interface Region Imaging Spectrograph (IRIS) reveals small-scale rapid brightenings in the form of bright grains all over coronal holes and the quiet sun. These bright grains are seen with the IRIS 1330 \\AA, 1400 \\AA\\ and 2796 \\AA\\ slit-jaw filters. We combine coordinated observations with IRIS and from the ground with the Swedish 1-m Solar Telescope (SST) which allows us to have chromospheric (Ca II 8542 \\AA, Ca II H 3968 \\AA, H\\alpha, and Mg II k 2796 \\AA), and transition region (C II 1334 \\AA, Si IV 1402) spectral imaging, and single-wavelength Stokes maps in Fe I 6302 \\AA at high spatial (0.33"), temporal and spectral resolution. We conclude that the IRIS slit-jaw grains are the counterpart of so-called acoustic grains, i.e., resulting from chromospheric acoustic waves in a non-magnetic environment. We compare slit-jaw images with spectra from the IRIS spectrograph. We conclude that the grain intensity in the 2796 \\AA\\ slit-jaw filter comes from both the Mg II k core and wings. The signal in the C II ...

  9. Generation IV nuclear energy system initiative. Large GFR core subassemblydesign for the Gas-Cooled Fast Reactor.

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E. A.; Kulak, R. F.; Therios, I. U.; Wei, T. Y. C.

    2006-07-31

    Gas-cooled fast reactor (GFR) designs are being developed to meet Gen IV goals of sustainability, economics, safety and reliability, and proliferation resistance and physical protection as part of an International Generation IV Nuclear Energy System Research Initiative effort. Different organizations are involved in the development of a variety of GFR design concepts. The current analysis has focused on the evaluation of low-pressure drop, pin-core designs with favorable passive cooling properties. Initial evaluation of the passive cooling safety case for the GFR during depressurized decay heat removal accidents with concurrent loss of electric power have resulted in requirements for a reduction of core power density to the 100 w/cc level and a low core pressure drop of 0.5 bars. Additional design constraints and the implementation of their constraints are evaluated in this study to enhance and passive cooling properties of the reactor. Passive cooling is made easier by a flat radial distribution of the decay heat. One goal of this study was to evaluate the radial power distribution and determine to what extent it can be flattened, since the decay heat is nearly proportional to the fission power at shutdown. In line with this investigation of the radial power profile, an assessment was also made of the control rod configuration. The layout provided a large number of control rod locations with a fixed area provided for control rods. The number of control rods was consistent with other fast reactor designs. The adequacy of the available control rod locations was evaluated. Future studies will be needed to optimize the control rod designs and evaluate the shutdown system. The case for low pressure drop core can be improved by the minimization of pressure drop sources such as the number of required fuel spacers in the subassembly design and by the details of the fuel pin design. The fuel pin design is determined by a number of neutronic, thermal-hydraulic (gas dynamics

  10. Study of a fuel assembly for the nuclear reactor of IV generation cooled with supercritical water; Estudio de un ensamble de combustible para el reactor nuclear de generacion IV enfriado con agua supercritica

    Energy Technology Data Exchange (ETDEWEB)

    Barragan M, A.; Martin del Campo M, C.; Francois L, J. L. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Espinosa P, G., E-mail: albrm29@yahoo.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Area de Ingenieria en Recursos Energeticos, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (MX)

    2011-11-15

    In this work a neutron study is presented about a square assembly design of double line of fuel rods, with moderator box to the center of the arrangement, for a nuclear reactor cooled with supercritical water (SCWR). The SCWR reactor was chosen by the characteristics of its design, mainly because is based in light water reactors (PWR and BWR), and the operational experience that has of them allow to use models and similar programs to simulate the fuel and the nucleus of this type of reactors. To develop the necessary models and to carry out the design and analysis of the SCWR reactor, the neutron codes MCNPX and Helios were used. The reason of using both codes, is because the code MCNPX used thoroughly in the neutron simulation of these reactors, it has been our reference code to analyze the results obtained with the Helios code which results are more efficient because its calculation times are minors. In the nucleus design the same parameters for both codes were considered. The results show that the design with Helios is a viable option to simulate these reactors since their values of the neutrons multiplication factor are very similar to those obtained with MCNPX. On the other hand, it could be corroborated that the CASMO-4 code is inadequate to simulate the fuel to the temperature conditions and water pressure in the SCWR. (Author)

  11. Noncooperative Iris Segmentation

    Directory of Open Access Journals (Sweden)

    Elsayed Mostafa

    2012-01-01

    Full Text Available In noncooperative iris recognition one should deal with uncontrolled behavior of the subject as well as uncontrolled lighting conditions. That means eyelids and eyelashes occlusion, non uniform intensities, reflections, imperfect focus, and orientation among the others are to be considered. To cope with this situation a noncooperative iris segmentation algorithm based on numerically stable direct least squares fitting of ellipses model and modified Chan-Vese model (local binary fitting energy with variational level set formulation is to be proposed. The proposed algorithm is tested using CASIA-IrisV3.

  12. IS (Iris Security)

    OpenAIRE

    Iovane, G.; Tortoriello, F. S.

    2003-01-01

    In the paper will be presented a safety system based on iridology. The results suggest a new scenario where the security problem in supervised and unsupervised areas can be treat with the present system and the iris image recognition.

  13. Iris Recognition Technique

    Institute of Scientific and Technical Information of China (English)

    XIE Mei

    2006-01-01

    The demand on security is increasing greatly in these years and biometric recognition gradually becomes a hot field of research. Iris recognition is a new branch of biometric recognition, which is regarded as the most stable, safe and accurate biometric recognition method. In these years, much progress in this field has been made by scholars and experts of different countries. In this paper, some successful iris recognition methods are listed and their performance are compared. Furthermore, the existing problems and challenges are discussed.

  14. A Novel Iris Segmentation Scheme

    Directory of Open Access Journals (Sweden)

    Chen-Chung Liu

    2014-01-01

    Full Text Available One of the key steps in the iris recognition system is the accurate iris segmentation from its surrounding noises including pupil, sclera, eyelashes, and eyebrows of a captured eye-image. This paper presents a novel iris segmentation scheme which utilizes the orientation matching transform to outline the outer and inner iris boundaries initially. It then employs Delogne-Kåsa circle fitting (instead of the traditional Hough transform to further eliminate the outlier points to extract a more precise iris area from an eye-image. In the extracted iris region, the proposed scheme further utilizes the differences in the intensity and positional characteristics of the iris, eyelid, and eyelashes to detect and delete these noises. The scheme is then applied on iris image database, UBIRIS.v1. The experimental results show that the presented scheme provides a more effective and efficient iris segmentation than other conventional methods.

  15. Reactor

    Science.gov (United States)

    Evans, Robert M.

    1976-10-05

    1. A neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch.

  16. Iris - nimi marmortahvlilt / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2003-01-01

    Briti kirjanikust Iris Murdochist pajatava inglise-ameerika mängufilmist "Iris" eesti videolevisse jõudmise puhul. Võrreldakse inglise teatrilavastaja Richard Eyre filmidebüüti Elmo Nüganeni debüütfilmiga "Nimed marmortahvlil"

  17. Iris Recognition using Orthogonal Transforms

    Directory of Open Access Journals (Sweden)

    M.Mani Roja

    2012-12-01

    Full Text Available Iris Recognition is a biometric recognition technique in which features of the iris are used to uniquely identify individuals. Iris recognition has over the years emerged as one of the most accuratebiometric techniques as opposed to other biometric techniques like face, signature and fingerprint. First, the iris image is pre processed using canny edge detector using a Gaussian filter. The iris edge and the pupil edge are extracted using image morphological operation, image opening. After normalization of red, green and blue components of the colour iris using Euclidean distance method, they are combined to form the localized colour iris. For feature vectors extraction, orthogonal transforms like discrete cosine transform, discrete sine transform and discrete Fourier transform have been considered. The proposed iris recognition system is very time efficient and it takes less than 1 second to grant authentication.

  18. The Interface Region Imaging Spectrograph (IRIS)

    CERN Document Server

    De Pontieu, B; Lemen, J; Kushner, G D; Akin, D J; Allard, B; Berger, T; Boerner, P; Cheung, M; Chou, C; Drake, J F; Duncan, D W; Freeland, S; Heyman, G F; Hoffman, C; Hurlburt, N E; Lindgren, R W; Mathur, D; Rehse, R; Sabolish, D; Seguin, R; Schrijver, C J; Tarbell, T D; Wuelser, J -P; Wolfson, C J; Yanari, C; Mudge, J; Nguyen-Phuc, N; Timmons, R; van Bezooijen, R; Weingrod, I; Brookner, R; Butcher, G; Dougherty, B; Eder, J; Knagenhjelm, V; Larsen, S; Mansir, D; Phan, L; Boyle, P; Cheimets, P N; DeLuca, E E; Golub, L; Gates, R; Hertz, E; McKillop, S; Park, S; Perry, T; Podgorski, W A; Reeves, K; Saar, S; Testa, P; Tian, H; Weber, M; Dunn, C; Eccles, S; Jaeggli, S A; Kankelborg, C C; Mashburn, K; Pust, N; Springer, L; Carvalho, R; Kleint, L; Marmie, J; Mazmanian, E; Pereira, T M D; Sawyer, S; Strong, J; Worden, S P; Carlsson, M; Hansteen, V H; Leenaarts, J; Wiesmann, M; Aloise, J; Chu, K -C; Bush, R I; Scherrer, P H; Brekke, P; Martinez-Sykora, J; Lites, B W; McIntosh, S W; Uitenbroek, H; Okamoto, T J; Gummin, M A; Auker, G; Jerram, P; Pool, P; Waltham, N

    2014-01-01

    The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33-0.4 arcsec spatial resolution, 2 s temporal resolution and 1 km/s velocity resolution over a field-of-view of up to 175 arcsec x 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332-1358, 1389-1407 and 2783-2834 Angstrom including bright spectral lines formed in the chromosphere (Mg II h 2803 Angstrom and Mg II k 2796 Angstrom) and transition region (C II 1334/1335 Angstrom and Si IV 1394/1403 Angstrom). Slit-jaw images in four different passbands (C II 1330, Si IV 1400, Mg II k 2796 and Mg II wing 2830 Angstrom) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec x 175 arcsec at a variety of spatial sa...

  19. TAPIOCA MELANOMA OF THE IRIS

    NARCIS (Netherlands)

    DEKEIZER, RJW; OOSTERHUIS, JA; HOUTMAN, WA; DEWOLFFROUENDAAL, D

    1993-01-01

    Clinical identification of tapioca melanoma of the iris is important because its medical treatment may differ from that of other malignant iris melanomas. The characteristic iris nodules must be differentiated from granulomatous uveitis, metastases, and Lisch nodules (neurofibromatosis). We will dis

  20. Acquired iris inclusion cysts

    Institute of Scientific and Technical Information of China (English)

    Aruna; Dharmasena; Priya; Bhatt; Jeffrey; Kwartz

    2014-01-01

    Dear Sir/Madam,The development of epithelial implantation cysts of the iris is rare and they pose a major therapeutic challenge due to the poor overall surgical outcome and high risk of recurrence.Several conservative and invasive treatment strategies such as needle aspiration,viscodissection,endolaser photocoagulation,endodiathermy,cryotherapy,

  1. The Interface Region Imaging Spectrograph (IRIS)

    Science.gov (United States)

    De Pontieu, B.; Title, A. M.; Lemen, J. R.; Kushner, G. D.; Akin, D. J.; Allard, B.; Berger, T.; Boerner, P.; Cheung, M.; Chou, C.; Drake, J. F.; Duncan, D. W.; Freeland, S.; Heyman, G. F.; Hoffman, C.; Hurlburt, N. E.; Lindgren, R. W.; Mathur, D.; Rehse, R.; Sabolish, D.; Seguin, R.; Schrijver, C. J.; Tarbell, T. D.; Wülser, J.-P.; Wolfson, C. J.; Yanari, C.; Mudge, J.; Nguyen-Phuc, N.; Timmons, R.; van Bezooijen, R.; Weingrod, I.; Brookner, R.; Butcher, G.; Dougherty, B.; Eder, J.; Knagenhjelm, V.; Larsen, S.; Mansir, D.; Phan, L.; Boyle, P.; Cheimets, P. N.; DeLuca, E. E.; Golub, L.; Gates, R.; Hertz, E.; McKillop, S.; Park, S.; Perry, T.; Podgorski, W. A.; Reeves, K.; Saar, S.; Testa, P.; Tian, H.; Weber, M.; Dunn, C.; Eccles, S.; Jaeggli, S. A.; Kankelborg, C. C.; Mashburn, K.; Pust, N.; Springer, L.; Carvalho, R.; Kleint, L.; Marmie, J.; Mazmanian, E.; Pereira, T. M. D.; Sawyer, S.; Strong, J.; Worden, S. P.; Carlsson, M.; Hansteen, V. H.; Leenaarts, J.; Wiesmann, M.; Aloise, J.; Chu, K.-C.; Bush, R. I.; Scherrer, P. H.; Brekke, P.; Martinez-Sykora, J.; Lites, B. W.; McIntosh, S. W.; Uitenbroek, H.; Okamoto, T. J.; Gummin, M. A.; Auker, G.; Jerram, P.; Pool, P.; Waltham, N.

    2014-07-01

    The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 - 0.4 arcsec spatial resolution, two-second temporal resolution, and 1 km s-1 velocity resolution over a field-of-view of up to 175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332 - 1358 Å, 1389 - 1407 Å, and 2783 - 2834 Å, including bright spectral lines formed in the chromosphere (Mg ii h 2803 Å and Mg ii k 2796 Å) and transition region (C ii 1334/1335 Å and Si iv 1394/1403 Å). Slit-jaw images in four different passbands (C ii 1330, Si iv 1400, Mg ii k 2796, and Mg ii wing 2830 Å) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec × 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative-MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.

  2. Core physics and safety analysis of Generation-IV Sodium Fast Reactors using existing and newly developed computational tools

    OpenAIRE

    Ochoa Valero, Raquel

    2014-01-01

    El futuro de la energía nuclear de fisión dependerá, entre otros factores, de la capacidad que las nuevas tecnologías demuestren para solventar los principales retos a largo plazo que se plantean. Los principales retos se pueden resumir en los siguientes aspectos: la capacidad de proporcionar una solución final, segura y fiable a los residuos radiactivos; así como dar solución a la limitación de recursos naturales necesarios para alimentar los reactores nucleares; y por último, una mejora rob...

  3. On the safety and performance demonstration tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and validation and verification of computational codes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Bum; Jeong, Ji Young; Lee, Tae Ho; Kim, Sung Kyun; Euh, Dong Jin; Joo, Hyung Kook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V and V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V and V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

  4. Effects of Iris Surface Curvature on Iris Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Joseph T [ORNL; Flynn, Patrick J [ORNL; Bowyer, Kevin W [University of Notre Dame, IN; Santos-Villalobos, Hector J [ORNL

    2013-01-01

    To focus on objects at various distances, the lens of the eye must change shape to adjust its refractive power. This change in lens shape causes a change in the shape of the iris surface which can be measured by examining the curvature of the iris. This work isolates the variable of iris curvature in the recognition process and shows that differences in iris curvature degrade matching ability. To our knowledge, no other work has examined the effects of varying iris curvature on matching ability. To examine this degradation, we conduct a matching experiment across pairs of images with varying degrees of iris curvature differences. The results show a statistically signi cant degradation in matching ability. Finally, the real world impact of these ndings is discussed

  5. An efficient iris segmentation approach

    Science.gov (United States)

    Gomai, Abdu; El-Zaart, A.; Mathkour, H.

    2011-10-01

    Iris recognition system became a reliable system for authentication and verification tasks. It consists of five stages: image acquisition, iris segmentation, iris normalization, feature encoding, and feature matching. Iris segmentation stage is one of the most important stages. It plays an essential role to locate the iris efficiently and accurately. In this paper, we present a new approach for iris segmentation using image processing technique. This approach is composed of four main parts. (1) Eliminating reflections of light on the eye image based on inverting the color of the grayscale image, filling holes in the intensity image, and inverting the color of the intensity image to get the original grayscale image without any reflections. (2) Pupil boundary detection based on dividing an eye image to nine sub-images and finding the minimum value of the mean intensity for each sub-image to get a suitable threshold value of pupil. (3) Enhancing the contrast of outer iris boundary using exponential operator to have sharp variation. (4) Outer iris boundary localization based on applying a gray threshold and morphological operations on the rectangular part of an eye image including the pupil and the outer boundaries of iris to find the small radius of outer iris boundary from the center of pupil. The proposed approach has been tested on CASIA v1.0 iris image database and other collected iris image database. The experimental results show that the approach is able to detect pupil and outer iris boundary with high accuracy results approximately 100% and reduce time consuming.

  6. Research on Iris Region Localization Algorithms

    Directory of Open Access Journals (Sweden)

    Pravin S.Patil

    2014-10-01

    Full Text Available Iris recognition is a biometric technique that offers premium performance. Iris localization is critical to the success of an iris recognition system, since data that is falsely represented as iris pattern data will corrupt the biometric templates generated, resulting in poor recognition rates. So far different algorithms for iris localization having been proposed. This paper explored four efficient methods for iris localization, out of these three methods of iris localization in circular form and one methods of unwrapping the iris in to a flat bed. Experimental results are reported to demonstrate performance evaluation of every implemented algorithms. Conclusion based on comparisons can provide most significant information for further research. A CASIA and UPOL iris databases of iris images has been used for implementation of iris localization General Term Biometrics,Iris Recognition,Iris Localization

  7. Advanced Non-Destructive Assessment Technology to Determine the Aging of Silicon Containing Materials for Generation IV Nuclear Reactors

    Science.gov (United States)

    Koenig, T. W.; Olson, D. L.; Mishra, B.; King, J. C.; Fletcher, J.; Gerstenberger, L.; Lawrence, S.; Martin, A.; Mejia, C.; Meyer, M. K.; Kennedy, R.; Hu, L.; Kohse, G.; Terry, J.

    2011-06-01

    To create an in-situ, real-time method of monitoring neutron damage within a nuclear reactor core, irradiated silicon carbide samples are examined to correlate measurable variations in the material properties with neutron fluence levels experienced by the silicon carbide (SiC) during the irradiation process. The reaction by which phosphorus doping via thermal neutrons occurs in the silicon carbide samples is known to increase electron carrier density. A number of techniques are used to probe the properties of the SiC, including ultrasonic and Hall coefficient measurements, as well as high frequency impedance analysis. Gamma spectroscopy is also used to examine residual radioactivity resulting from irradiation activation of elements in the samples. Hall coefficient measurements produce the expected trend of increasing carrier concentration with higher fluence levels, while high frequency impedance analysis shows an increase in sample impedance with increasing fluence.

  8. System and safety studies of accelerator driven systems and generation IV reactors for transmutation of minor actinides. Annual report 2009

    Energy Technology Data Exchange (ETDEWEB)

    Bergloef, Calle; Fokau, Andrei; Jolkkonen, Mikael; Tesinsky, Milan; Wallenius, Janne; Youpeng Zhang (Div. of Reactor Physics, Royal Institute of Technology, Stockholm (Sweden))

    2010-03-15

    During 2009, the reactor physics division has made a design study of a source efficient ADS with nitride fuel and 15/15Ti cladding, based on the EFIT design made within the EUROTRANS project. It was shown that the source efficiency may be doubled as compared to the reference design with oxide fuel and T91 cladding. Transient analysis of a medium sized sodium cooled reactor with MOX fuel allowed to define criteria in terms of power penalty for americium introduction. It was shown that for each percent of americium added to the fuel, the linear rating must be reduced by 6% in order for the fuel to survive postulated unprotected transients. The Sjoestrand area ratio method for reactivity determination has been evaluated experimentally in the strongly heterogeneous subcritical facility YALINA-Booster. Surprisingly, it has been found that the area ratio reactivity estimates may differ by a factor of two depending on detector position. It is shown that this strong spatial dependence can be explained based on a two-region point kinetics model and rectified by means of correction factors obtained through Monte Carlo simulations. For the purpose of measuring high energy neutron cross sections at the SCANDAL facility in Uppsala, Monte Carlo simulations of neutron to proton conversion efficiencies in CsI detectors have been performed. A uranium fuel fabrication laboratory has been taken into operation at KTH in 2009. Uranium and zirconium nitride powders have been fabricated by hydridation/nitridation of metallic source materials. Sample pellets have been pressed and ZrN discs have been sintered to 93% density by means of spark plasma sintering methods

  9. Are IRIS bombs connected to Ellerman bombs?

    CERN Document Server

    Tian, Hui; He, Jiansen; Madsen, Chad

    2016-01-01

    Recent observations by the Interface Region Imaging Spectrograph (IRIS) have revealed pockets of hot gas ($\\sim$2--8$\\times$10$^{4}$ K) potentially resulting from magnetic reconnection in the partially ionized lower solar atmosphere (IRIS bombs; IBs). Using joint observations between IRIS and the Chinese New Vacuum Solar Telescope, we have identified ten IBs. We find that three are unambiguously and three others are possibly connected to Ellerman bombs (EBs), which show intense brightening of the extended H$_{\\alpha}$ wings without leaving an obvious signature in the H$_{\\alpha}$ core. These bombs generally reveal the following distinct properties: (1) The O~{\\sc{iv}}~1401.156\\AA{} and 1399.774\\AA{} lines are absent or very weak; (2) The Mn~{\\sc{i}}~2795.640\\AA{} line manifests as an absorption feature superimposed on the greatly enhanced Mg~{\\sc{ii}}~k line wing; (3) The Mg~{\\sc{ii}}~k and h lines show intense brightening in the wings and no dramatic enhancement in the cores; (4) Chromospheric absorption lin...

  10. Integrated risk information system (IRIS)

    Energy Technology Data Exchange (ETDEWEB)

    Tuxen, L. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    The Integrated Risk Information System (IRIS) is an electronic information system developed by the US Environmental Protection Agency (EPA) containing information related to health risk assessment. IRIS is the Agency`s primary vehicle for communication of chronic health hazard information that represents Agency consensus following comprehensive review by intra-Agency work groups. The original purpose for developing IRIS was to provide guidance to EPA personnel in making risk management decisions. This original purpose for developing IRIS was to guidance to EPA personnel in making risk management decisions. This role has expanded and evolved with wider access and use of the system. IRIS contains chemical-specific information in summary format for approximately 500 chemicals. IRIS is available to the general public on the National Library of Medicine`s Toxicology Data Network (TOXNET) and on diskettes through the National Technical Information Service (NTIS).

  11. Accurate and Fast Iris Segmentation

    Directory of Open Access Journals (Sweden)

    G. AnnaPoorani,

    2010-06-01

    Full Text Available A novel iris segmentation approach for noisy iris is proposed in this paper. The proposed approach comprises of specular reflection removal, pupil localization, iris localization and eyelid localization. Reflection map computation is devised to get the reflection ROI of eye image using adaptive threshold technique. Bilinear interpolation is used to fill these reflection points in the eye image. Variant of edge-based segmentation technique is adopted to detect the pupil boundary from the eye image. Gradient based heuristic approach is devised to detect the iris boundary from theeye image. Eyelid localization is designed to detect the eyelids using the edge detection and curve fitting. Feature sequence combined into spatial domain segments the iris texture patterns properly. Empirical results show that the proposed approach is effective and suitable to deal with the noisy eye image for iris segmentation.

  12. CFD modeling of the IRIS pressurizer dynamic

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Ronny R.; Montesinos, Maria E.; Garcia, Carlos; Bueno, Elizabeth D.; Mazaira, Leorlen R., E-mail: rsanz@instec.cu, E-mail: mmontesi@instec.cu, E-mail: cgh@instec.cu, E-mail: leored1984@gmail.com [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Bezerra, Jair L.; Lira, Carlos A.B. Oliveira, E-mail: jair.lima@ufpe.br, E-mail: cabol@ufpe.br [Universida Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2015-07-01

    Integral layout of nuclear reactor IRIS makes possible the elimination of the spray system, which is usually used to mitigate in-surge transient and also help to Boron homogenization. The study of transients with deficiencies in the Boron homogenization in this technology is very important, because they can cause disturbances in the reactor power and insert a strong reactivity in the core. The detailed knowledge of the behavior of multiphase multicomponent flows is challenging due to the complex phenomena and interactions at the interface. In this context, the CFD modeling is employed in the design of equipment in the nuclear industry as it allows predicting accidents or predicting their performance in dissimilar applications. The aim of the present research is to model the IRIS pressurizer's dynamic using the commercial CFD code CFX. A symmetric tri dimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The model considers the coexistence of four phases and also takes into account the heat losses. The relationships for interfacial mass, energy, and momentum transport are programmed and incorporated into CFX. Moreover, two subdomains and several additional variables are defined to monitoring the boron dilution sequences and condensation-evaporation rates in different control volumes. For transient states a non - equilibrium stratification in the pressurizer is considered. This paper discusses the model developed and the behavior of the system for representative transients sequences. The results of analyzed transients of IRIS can be applied to the design of pressurizer internal structures and components. (author)

  13. On the Safety and Performance Demonstration Tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and Validation and Verification of Computational Codes

    Directory of Open Access Journals (Sweden)

    Jong-Bum Kim

    2016-10-01

    Full Text Available The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR has been developed and the validation and verification (V&V activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1, produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

  14. Plan for IER-443 Testing of the Y-12 and AWE Criticality Accident Alarm System Detectors at the Godiva IV Burst Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Scorby, J. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hickman, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hudson, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garbett, S. [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Auld, G. [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Horrne, A. [Atomic Weapons Establishment (AWE), Berkshire (United Kingdom); Beller, T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Goda, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haught, C. [Y-12 National Security Complex, Oak Ridge, TN (United States); Woodrow, C. [Y-12 National Security Complex, Oak Ridge, TN (United States); Ward, D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-24

    This document provides the scope and details of the “Plan for Testing the Y-12 and AWE Criticality Accident Alarm System Detectors at the Godiva IV Burst Reactor”. Due to the relative simplicity of the testing goals, scope, and methodology, the NCSP Manager approved execution of the test when ready. No preliminary CED-1 or final design CED-2 reports were required or issued. The test will subject Criticality Accident Alarm System (CAAS) detectors supplied by Y- 12 and AWE to very intense and short duration mixed neutron and gamma radiation fields. The goals of the test will be to (1) substantiate functionality, for both existing and newly acquired Y- 12 CAAS detectors, and (2) the ability of the AWE detectors to provide quality temporal dose information after a hypothetical criticality accident. ANSI/ANS-8.3.1997 states that the “system shall be sufficiently robust as to actuate an alarm signal when exposed to the maximum radiation expected”, which has been defined at Y-12, in Documented Safety Analyses (DSAs), to be a dose rate of 10 Rad/s. ANSI/ANS-8.3.1997 further states that “alarm actuation shall occur as a result of a minimum duration transient” which may be assumed to be 1 msec. The pulse widths and dose rates which will be achieved in this test will exceed these requirements. Pulsed radiation fields will be produced by the Godiva IV fast metal burst reactor at the National Criticality Experimental Research Center (NCERC) at the Nevada National Security Site (NNSS). The magnitude of the pulses and the relative distances to the detectors will be varied to afford a wide range of radiation fluence and pulse widths. The magnitude of the neutron and gamma fields will be determined by reactor temperature rise to fluence and dose conversions which have been previously established through extensive measurements performed under IER-147. The requirements for CAAS systems to detect and alarm under a “minimum accident of concern” as well as other

  15. Iris image segmentation based on phase congruency

    Science.gov (United States)

    Gao, Chao; Jiang, Da-Qin; Guo, Yong-Cai

    2006-09-01

    Iris image segmentation is very important for an iris recognition system. There are always iris noises as eyelash, eyelid, reflection and pupil in iris images. The paper proposes a virtual method of segmentation. By locating and normalizing iris images with Gabor filter, we can acquire information of image texture in a series of frequencies and orientations. Iris noise regions are determined based on phase congruency by a group of Gabor filters whose kernels are suitable for edge detection. These regions are filled according to the characteristics of iris noise. The experimental results show that the proposed method can segment iris images effectively.

  16. Iris image Segmentation Based on Phase Congruency

    Institute of Scientific and Technical Information of China (English)

    GAO Chao; JIANG Da-qin; Guo Yong-cai

    2006-01-01

    @@ Iris image segmentation is very important for an iris recognition system.There are always iris noises as eyelash,eyelid,reflection and pupil in iris images.The paper proposes a virtual method of segmentation.By locating and normalizing iris images with Gabor filter,we can acquire information of image texture in a series of frequencies and orientations.Iris noise regions are determined based on phase congruency by a group of Gabor filters whose kernels are suitable for edge detection.These regions are filled according to the characteristics of iris noise.The experimental results show that the proposed method can segment iris images effectively.

  17. Bartus Iris biometrics

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, R.; Grace, W.

    1996-07-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). We won a 1994 R&D 100 Award for inventing the Bartas Iris Verification System. The system has been delivered to a sponsor and is no longer available to us. This technology can verify the identity of a person for purposes of access control, national security, law enforcement, forensics, counter-terrorism, and medical, financial, or scholastic records. The technique is non-invasive, psychologically acceptable, works in real-time, and obtains more biometric data than any other biometric except DNA analysis. This project sought to develop a new, second-generation prototype instrument.

  18. Micropropagation of Iris sp.

    Science.gov (United States)

    Jevremović, Slađana; Jeknić, Zoran; Subotić, Angelina

    2013-01-01

    Irises are perennial plants widely used as ornamental garden plants or cut flowers. Some species accumulate secondary metabolites, making them highly valuable to the pharmaceutical and perfume industries. Micropropagation of irises has successfully been accomplished by culturing zygotic embryos, different flower parts, and leaf base tissues as starting explants. Plantlets are regenerated via somatic embryogenesis, organogenesis, or both processes at the same time depending on media composition and plant species. A large number of uniform plants are produced by somatic embryogenesis, however, some species have decreased morphogenetic potential overtime. Shoot cultures obtained by organogenesis can be multiplied for many years. Somatic embryogenic tissue can be reestablished from leaf bases of in vitro-grown shoots. The highest number of plants can be obtained by cell suspension cultures. This chapter describes effective in vitro plant regeneration protocols for Iris species from different types of explants by somatic embryogenesis and/or organogenesis suitable for the mass propagation of ornamental and pharmaceutical irises.

  19. Shape Adaptive, Robust Iris Feature Extraction from Noisy Iris Images

    Science.gov (United States)

    Ghodrati, Hamed; Dehghani, Mohammad Javad; Danyali, Habibolah

    2013-01-01

    In the current iris recognition systems, noise removing step is only used to detect noisy parts of the iris region and features extracted from there will be excluded in matching step. Whereas depending on the filter structure used in feature extraction, the noisy parts may influence relevant features. To the best of our knowledge, the effect of noise factors on feature extraction has not been considered in the previous works. This paper investigates the effect of shape adaptive wavelet transform and shape adaptive Gabor-wavelet for feature extraction on the iris recognition performance. In addition, an effective noise-removing approach is proposed in this paper. The contribution is to detect eyelashes and reflections by calculating appropriate thresholds by a procedure called statistical decision making. The eyelids are segmented by parabolic Hough transform in normalized iris image to decrease computational burden through omitting rotation term. The iris is localized by an accurate and fast algorithm based on coarse-to-fine strategy. The principle of mask code generation is to assign the noisy bits in an iris code in order to exclude them in matching step is presented in details. An experimental result shows that by using the shape adaptive Gabor-wavelet technique there is an improvement on the accuracy of recognition rate. PMID:24696801

  20. Are IRIS Bombs Connected to Ellerman Bombs?

    Science.gov (United States)

    Tian, Hui; Xu, Zhi; He, Jiansen; Madsen, Chad

    2016-06-01

    Recent observations by the Interface Region Imaging Spectrograph (IRIS) have revealed pockets of hot gas (˜2-8 × 104 K) potentially resulting from magnetic reconnection in the partially ionized lower solar atmosphere (IRIS bombs; IBs). Using joint observations between IRIS and the Chinese New Vacuum Solar Telescope, we have identified 10 IBs. We find that 3 are unambiguously and 3 others are possibly connected to Ellerman bombs (EBs), which show intense brightening of the extended {{{H}}}α wings without leaving an obvious signature in the {{{H}}}α core. These bombs generally reveal the following distinct properties: (1) the O iv 1401.156 Å and 1399.774 Å lines are absent or very weak; (2) the Mn i 2795.640 Å line manifests as an absorption feature superimposed on the greatly enhanced Mg ii k line wing; (3) the Mg ii k and h lines show intense brightening in the wings and no dramatic enhancement in the cores; (4) chromospheric absorption lines such as Ni ii 1393.330 Å and 1335.203 Å are very strong; and (5) the 1700 Å images obtained with the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory reveal intense and compact brightenings. These properties support the formation of these bombs in the photosphere, demonstrating that EBs can be heated much more efficiently than previously thought. We also demonstrate that the Mg ii k and h lines can be used to investigate EBs similarly to {{{H}}}α , which opens a promising new window for EB studies. The remaining four IBs obviously have no connection to EBs and they do not have the properties mentioned above, suggesting a higher formation layer, possibly in the chromosphere.

  1. Ankeny - Yellow Flag Iris Control

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project aims to inventory and map all existing stands of yellow flag iris within wetland habitats at Ankeny NWR, treat them with herbicide in late spring and...

  2. Iris Murdoch armastusest / Udo uibo

    Index Scriptorium Estoniae

    Uibo, Udo, 1956-

    2010-01-01

    Londoni Kingstoni ülikool omandas 50 000 naesterlingi eest 164 Iris Murdochi kirja prantsuse kirjanikule, keeleeksperimentaatorile Raymond Quenaule, millest selgub Murdochi ühepoolne ning vastamata jäänud tunne Quenau suhtes.

  3. Integrated Risk Information System (IRIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPA?s Integrated Risk Information System (IRIS) is a compilation of electronic reports on specific substances found in the environment and their potential to cause...

  4. Iris Murdoch armastusest / Udo uibo

    Index Scriptorium Estoniae

    Uibo, Udo, 1956-

    2010-01-01

    Londoni Kingstoni ülikool omandas 50 000 naesterlingi eest 164 Iris Murdochi kirja prantsuse kirjanikule, keeleeksperimentaatorile Raymond Quenaule, millest selgub Murdochi ühepoolne ning vastamata jäänud tunne Quenau suhtes.

  5. Academy Distance Learning Tools (IRIS)

    Data.gov (United States)

    Department of Transportation — IRIS is a suite of front-end web applications utilizing a centralized back-end Oracle database. The system fully supports the FAA Academy's Distance Learning Program...

  6. IRI-2016: Description and Introduction

    Science.gov (United States)

    Bilitza, Dieter; Watanabe, Shigeto; Truhlik, Vladimir; Altadill, David

    2016-07-01

    The International Reference Ionosphere (IRI) is recognized as the official standard for the ionosphere (COSPAR, URSI, ISO) and is widely used for a multitude of different applications as evidenced by the many papers in science and engineering journals that acknowledge the use of IRI (e.g., about 11% of all Radio Science papers each year and citations in 21 different journals in 2015). The improvement process of the model is continuing as new data become fully available and new modeling techniques provide a more optimal representation of the observed variation patterns. We will introduce and present the latest version of the IRI model (IRI-2016) and discuss the impact of the various improvements and new additions. Most importantly, two new models will be introduced for the F2 peak height, hmF2, that were developed based on ionosonde measurements and COSMIC radio occultation data, respectively. In addition IRI-2016 includes an improved representation of the ionosphere during the very low solar activities that were reached during the last solar minimum in 2008/2009. A number of other improvements and corrections were implemented in the model and will be discussed in this presentation. We will also report about recent IRI workshops and their findings and plans for the future.

  7. Iris: The VAO SED Application

    CERN Document Server

    Doe, Stephen; Busko, Ivo; D'Abrusco, Raffaele; Cresitello-Dittmar, Mark; Ebert, Richard; Evans, Janet; Laurino, Omar; McDowell, Jonathan; Pevunova, Olga; Refsdal, Brian

    2012-01-01

    We present Iris, the VAO (Virtual Astronomical Observatory) application for analyzing SEDs (spectral energy distributions). Iris is the result of one of the major science initiatives of the VAO, and the first version was released in September 2011. Iris combines key features of several existing software applications to streamline and enhance SED analysis. With Iris, users may read and display SEDs, select data ranges for analysis, fit models to SEDs, and calculate confidence limits on best-fit parameters. SED data may be uploaded into the application from IVOA-compliant VOTable and FITS format files, or retrieved directly from NED. Data written in unsupported formats may be converted using SedImporter, a new application provided with Iris. The components of Iris have been contributed by members of the VAO. Specview, contributed by STScI, provides a GUI for reading, editing, and displaying SEDs, as well as defining models and parameter values. Sherpa, contributed by the Chandra project at SAO, provides a libra...

  8. Improvement of Sodium Neutronic Nuclear Data for the Computation of Generation IV Reactors; Contribution a l'amelioration des donnees nucleaires neutroniques du sodium pour le calcul des reacteurs de generation IV

    Energy Technology Data Exchange (ETDEWEB)

    Archier, P.

    2011-09-14

    The safety criteria to be met for Generation IV sodium fast reactors (SFR) require reduced and mastered uncertainties on neutronic quantities of interest. Part of these uncertainties come from nuclear data and, in the particular case of SFR, from sodium nuclear data, which show significant differences between available international libraries (JEFF-3.1.1, ENDF/B-VII.0, JENDL-4.0). The objective of this work is to improve the knowledge on sodium nuclear data for a better calculation of SFR neutronic parameters and reliable associated uncertainties. After an overview of existing {sup 23}Na data, the impact of the differences is quantified, particularly on sodium void reactivity effects, with both deterministic and stochastic neutronic codes. Results show that it is necessary to completely re-evaluate sodium nuclear data. Several developments have been made in the evaluation code Conrad, to integrate new nuclear reactions models and their associated parameters and to perform adjustments with integral measurements. Following these developments, the analysis of differential data and the experimental uncertainties propagation have been performed with Conrad. The resolved resonances range has been extended up to 2 MeV and the continuum range begins directly beyond this energy. A new {sup 23}Na evaluation and the associated multigroup covariances matrices were generated for future uncertainties calculations. The last part of this work focuses on the sodium void integral data feedback, using methods of integral data assimilation to reduce the uncertainties on sodium cross sections. This work ends with uncertainty calculations for industrial-like SFR, which show an improved prediction of their neutronic parameters with the new evaluation. (author) [French] Les criteres de surete exiges pour les reacteurs rapides au sodium de Generation IV (RNR-Na) se traduisent par la necessite d'incertitudes reduites et maitrisees sur les grandeurs neutroniques d'interet. Une part

  9. ANTIMICROBIAL ACTIVITY OF EXTRACTS OF IRIS HUNGARICA AND IRIS SIBIRICA

    Directory of Open Access Journals (Sweden)

    Kovalev V. M.

    2017-06-01

    Full Text Available Introduction. Referring to the latest data, infectious diseases command a large part of among the total number of pathologies in the world and are an important problem in medicine. The leading role in prevention and treatment of diseases of microbial origin belongs to antibacterial chemotherapeutic agents. Advantages of antibiotics of synthetic origin are the high activity compared to phytogenic drugs. But it is known that microorganisms can release the resistance to synthetic antibiotics, so the use of drugs based on the plant materials is appropriate: phytogenic drugs more rarely induce the formation of resistance of the strains of microorganisms, they have a gentle action, can be used for a long-term, have the low cost. Therefore, it is appropriate to examine the drug plants with the aim of determination their antibacterial activity.Iris hungarica Waldst et Kit. and Iris sibirica L. are the representatives of the family Iridaceae, genus Iris and they have a wide spectrum of the pharmacological activity. Biologically active substances that were recovered from plants of the genus Iris (tectoridin, iristectorigenin B, nigracin, kaempferol, quercetin, etc. exhibited an antitumor, antimicrobial, estrogenic, insecticidal, antiplasmatic, anticholinesterase action, they were the inhibitors of enzymes and exhibited the immunomodulatory properties, which made these plants perspective for the research study. Raw materials Irises are constituent components of more than 9 medicines. Materials and Methods. The objects of the study were the leaves and rhizomes of Iris hungarica and Iris sibirica that were prepared during the growing season in 2014 in the M.M. Gryshko National botanical garden (Kiev, Ukraine. The dry and lipophilic extracts from the leaves and rhizomes of Irises were used to establish the antimicrobial activity. For the study of extracts antimicrobial activity was used agar well diffusion method. According to the WHO recommendations the

  10. Iris reconstruction combined with iris-claw intraocular lens implantation for the management of iris-lens injured patients

    Science.gov (United States)

    Hu, Shufang; Wang, Mingling; Xiao, Tianlin; Zhao, Zhenquan

    2016-01-01

    Aim: To study the efficiency and safety of iris reconstruction combined with iris-claw intraocular lens (IOL) implantation in the patients with iris-lens injuries. Settings and Design: Retrospective, noncomparable consecutive case series study. Materials and Methods: Eleven patients (11 eyes) following iris-lens injuries underwent iris reconstructions combined with iris-claw IOL implantations. Clinical data, such as cause and time of injury, visual acuity (VA), iris and lens injuries, surgical intervention, follow-up period, corneal endothelial cell count, and optical coherence tomography, were collected. Results: Uncorrected VA (UCVA) in all injured eyes before combined surgery was equal to or <20/1000. Within a 1.1–4.2-year follow-up period, a significant increase, equal to or better than 20/66, in UCVA was observed in six (55%) cases, and in best-corrected VA (BCVA) was observed in nine (82%) cases. Postoperative BCVA was 20/40 or better in seven cases (64%). After combined surgery, the iris returned to its natural round shape or smaller pupil, and the iris-claw IOLs in the 11 eyes were well-positioned on the anterior surface of reconstructed iris. No complications occurred in those patients. Conclusions: Iris reconstruction combined with iris-claw IOL implantation is a safe and efficient procedure for an eye with iris-lens injury in the absence of capsular support. PMID:27146932

  11. Phase Correlation Based Iris Image Registration Model

    Institute of Scientific and Technical Information of China (English)

    Jun-Zhou Huang; Tie-Niu Tan; Li Ma; Yun-Hong Wang

    2005-01-01

    Iris recognition is one of the most reliable personal identification methods. In iris recognition systems, image registration is an important component. Accurately registering iris images leads to higher recognition rate for an iris recognition system. This paper proposes a phase correlation based method for iris image registration with sub-pixel accuracy.Compared with existing methods, it is insensitive to image intensity and can compensate to a certain extent the non-linear iris deformation caused by pupil movement. Experimental results show that the proposed algorithm has an encouraging performance.

  12. Computational model for transient studies of IRIS pressurizer behavior; Modelo computacional para el estudio de transitorios en el compensador de presion IRIS

    Energy Technology Data Exchange (ETDEWEB)

    Rives Sanz, R.; Montesino Otero, M.E.; Gonzalez Mantecon, J.; Rojas Mazaira, L., E-mail: mmontesi@instec.cu [Higher Institute of Technology and Applied Science, La Habana (Cuba). Department of Nuclear Engineering; Lira, C.A. Brayner de Oliveira [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2014-07-01

    International Reactor Innovative and Secure (IRIS) excels other Small Modular Reactor (SMR) designs due to its innovative characteristics regarding safety. IRIS integral pressurizer makes the design of larger pressurizer system than the conventional PWR, without any additional cost. The IRIS pressurizer volume of steam can provide enough margins to avoid spray requirement to mitigate in-surge transient. The aim of the present research is to model the IRIS pressurizer's dynamic using the commercial finite volume Computational Fluid Dynamic code CFX 14. A symmetric tridimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The model considers the coexistence of three phases: liquid, steam, and vapor bubbles in liquid volume. Additionally, it takes into account the heat losses between the pressurizer and primary circuit. The relationships for interfacial mass, energy, and momentum transport are programmed and incorporated into CFX by using expressions in CFX Command Language (CCL) format. Moreover, several additional variables are defined for improving the convergence and allow monitoring of boron dilution sequences and condensation-evaporation rate in different control volumes. For transient states a non - equilibrium stratification in the pressurizer is considered. This paper discusses the model developed and the behavior of the system for representative transients sequences such as the in/out-surge transients and boron dilution sequences. The results of analyzed transients of IRIS can be applied to the design of pressurizer internal structures and components. (author)

  13. Quality assessment for online iris images

    CSIR Research Space (South Africa)

    Makinana, S

    2015-01-01

    Full Text Available Iris recognition systems have attracted much attention for their uniqueness, stability and reliability. However, performance of this system depends on quality of iris image. Therefore there is a need to select good quality images before features can...

  14. What Genes Tell about Iris Appearance

    DEFF Research Database (Denmark)

    Harder, Stine; Christoffersen, Susanne R.; Johansen, Peter

    2012-01-01

    are performed supporting that this SNP is very important for eye color expression. With the suggested image characterizations we are able to investigate the correlation between the phenotypic iris appearance and specific SNPs. This has potential for further investigation of the relation between DNA and iris......Predicting phenotypes based on genotypes is generally hard, but has shown good results for prediction of iris color. We propose to correlate the appearance of iris with DNA. Six single-nucleotide polymorphisms (SNPs) have previously been shown to correlate with human iris color, and we demonstrate...... that especially one of the six SNPs are correlated with iris appearance. To perform this analysis we need a method to model the iris appearance, and we suggest an iris characterization based on a bag of visual words, which gives us a similarity measure between images of eyes. We have a dataset of 215 eye images...

  15. Exploring New Directions in Iris Recognition

    CERN Document Server

    Popescu-Bodorin, Nicolaie

    2011-01-01

    A new approach in iris recognition based on Circular Fuzzy Iris Segmentation (CFIS) and Gabor Analytic Iris Texture Binary Encoder (GAITBE) is proposed and tested here. CFIS procedure is designed to guarantee that similar iris segments will be obtained for similar eye images, despite the fact that the degree of occlusion may vary from one image to another. Its result is a circular iris ring (concentric with the pupil) which approximates the actual iris. GAITBE proves better encoding of statistical independence between the iris codes extracted from different irides using Hilbert Transform. Irides from University of Bath Iris Database are binary encoded on two different lengths (768 / 192 bytes) and tested in both single-enrollment and multi-enrollment identification scenarios. All cases illustrate the capacity of the newly proposed methodology to narrow down the distribution of inter-class matching scores, and consequently, to guarantee a steeper descent of the False Accept Rate.

  16. IRIS Toxicological Review of Acrolein (2003 Final)

    Science.gov (United States)

    EPA announced the release of the final report, Toxicological Review of Acrolein: in support of the Integrated Risk Information System (IRIS). The updated Summary for Acrolein and accompanying toxicological review have been added to the IRIS Database.

  17. Automatic quantification of iris color

    DEFF Research Database (Denmark)

    Christoffersen, S.; Harder, Stine; Andersen, J. D.

    2012-01-01

    An automatic algorithm to quantify the eye colour and structural information from standard hi-resolution photos of the human iris has been developed. Initially, the major structures in the eye region are identified including the pupil, iris, sclera, and eyelashes. Based on this segmentation...... regions. The result is a blue-brown ratio for each eye. Furthermore, an image clustering approach has been used with promising results. The approach is based on using a sparse dictionary of feature vectors learned from a training set of iris regions. The feature vectors contain both local structural...... is completely data driven and it can divide a group of eye images into classes based on structure, colour or a combination of the two. The methods have been tested on a large set of photos with promising results....

  18. Eyelid Localization for Iris Identification

    Directory of Open Access Journals (Sweden)

    T. Ea

    2008-12-01

    Full Text Available This article presents a new eyelid localization algorithm based on a parabolic curve fitting. To deal with eyelashes, low contrast or false detection due to iris texture, we propose a two steps algorithm. First, possible edge candidates are selected by applying edge detection on a restricted area inside the iris. Then, a gradient maximization is applied along every parabola, on a larger area, to refine parameters and select the best one. Experiments have been conducted on a database of 151 iris that have been manually segmented. The performance evaluation is carried out by comparing the segmented images obtained by the proposed method with the manual segmentation. The results are satisfactory in more than 90% of the cases.

  19. Iris Identification Technology Based on Multiwavelets

    Institute of Scientific and Technical Information of China (English)

    Wei Lian-xin; Ma Fu-ming; Xu Tao; Li Zhi-hui; Wu Deng-feng

    2005-01-01

    A new method for iris identification based on multiwavelets is proposed. By means of the properties of multiwavelets,such as orthogonality, symmetry, vanishing moments and approximation order, the iris texture can be simply presented. A brief overview of muhiwavelets is presented at first. Iris identification system and iris texture feature presentation and recognition based on multiwavelets are introduced subsequently. And the experiment indicates the validity of this method finally.

  20. Iris mammillations in ocular melanocytosis.

    Science.gov (United States)

    Swann, Peter G

    2001-01-01

    Hyperpigmentation of the ocular tissues and of the skin around the eye is uncommon. In ocular melanosis, the episclera, uveal tract and the angle of the anterior chamber may be involved. Heterochromia iridis may be present, if the iris is affected. In oculodermal melanocytosis or the naevus of Ota, hyperpigmentation of the skin follows the distribution of the first and second divisions of the fifth cranial nerve. This report documents a patient with episcleral pigment, heterochromia iridis and numerous tiny pigmented nodules on the iris (mammillations). The possible significance of these findings is discussed.

  1. Some Refinement on Iris Localization Algorithm

    Directory of Open Access Journals (Sweden)

    Abikoye O.C

    2012-11-01

    Full Text Available Biometrics recognition is a common and reliable way to authenticate the identity of a living person based on physiological or behavioral characteristics. Iris recognition is one of the newer biometric recognition technologies used for personal identification. It is reliable and widely used. In general a typical iris recognition system consists of three basic module which include image acquisition, Iris Localization & pre-processing, Iris texture extraction & signature encoding and lastly Iris signature matching for recognition or verification. One of the most important steps in iris recognition systems is iris localization, which is related to the detection of the exact location and contour of the iris in an image. (i.e it defines the inner and outer boundaries of iris region Obviously, the performance of the identification system is closely related to the precision of the iris localization step. In this study, an efficient algorithm for iris localization is proposed. The algorithm proposed can accurately define both the inner and outer boundaries of the iris irrespective of the geometry it may be (circle or eclipse by capturing the parameters that represents the geometry.

  2. 四代核电技术(高温堆)产业化探讨%Chinese Development of Generation IV Nuclear Power Technology--High Temperature Gas Cooled Reactor

    Institute of Scientific and Technical Information of China (English)

    石磊; 肖国平; 鲁盛会; 张见营; 王芝芬; 李金英

    2015-01-01

    该文综述了四代核电技术(高温堆)的发展现状和技术特点,对中国高温气冷堆的产业化提出了建议,供政府及相关行业集团公司等参考。%The author reviewed the development of generation IV nuclear power technology --Temperature Gas Cooled Reactor(HTR) . Some The advice of industrialization of HTR in China was proposed.The article can give some advice for the government and relevant company.

  3. Automatic quantification of iris color

    DEFF Research Database (Denmark)

    Christoffersen, S.; Harder, Stine; Andersen, J. D.

    2012-01-01

    , the iris is resampled into a standardized quadratic coordinate system, where occluded and invalid regions are masked out. Secondly, a pixel classification approach has been evaluated with good results. It is based on a so-called Markov Random Field spatial classification into dominantly brown and blue...

  4. Texture based iris recognition system

    Science.gov (United States)

    Mehrotra, Hunny; Gupta, Phalguni; Kaushik, Anil K.

    2008-04-01

    The paper proposes an efficient iris recognition algorithm, obtained through the fusion of Haar Wavelet and Circular Mellin operator. The recognition system preprocesses the captured iris image to remove the effect of holes or spot of light lying on the pupillary region which creates problem in pupil localization. The processed image is localized by detecting inner and outer boundaries from the pupil center using maximum value of the spectrum image. Then the eyelids are detected by fitting a 3 rd degree polynomial on the suitable edge segments and removing the region occluded by eyelids from the normalized iris image. The features for the iris pattern are extracted using Haar Wavelet and Circular Mellin operator. The Haar Wavelet decomposition reduces the size of feature vector while Circular Mellin operator is used for rotation and scale invariant feature extraction. The features are compared using Hamming Distance method and the fusion is done at decision level using Conjunction rule. The recognizer is found to be more robust with accuracy level more than 95%.

  5. A giant traumatic iris cyst

    Institute of Scientific and Technical Information of China (English)

    Lott Pooi Wah; Tan Boon Hooi; Leow Sue Ngein; Shuaibah Abdul Ghani; Visvaraja AL Subrayan

    2015-01-01

    A 52 year-old construction worker presented with progressive painful blurring of vision in the left eye associated with redness for past 1 month. There was a history of penetrating injury in the same eye 10 years ago and he underwent primary wound toilet and suturing, lens removal with intraocular lens implantation. Slit lamp examination revealed a corneal scar at 9’oclock, a large transilluminant iris cyst superotemporally and adherent to corneal endothelium. It was extended from angle of the pupil and obstructing the visual axis. The patient underwent excision of an iris cyst through superior limbal incision. Viscodissection was done to separate the cyst from the corneal endothelium and underlying iris stroma. Trypan blue ophthalmic solution was injected into the cyst to stain the cyst capsule. Post operatively 7 days, vision improved to 6/7.5 without complication. There was no recurrence up to 1 year postoperation. Histopathological finding revealed a benign cyst mass lined by simple cuboidal to non-keratinized stratified squamous epithelium. We had achieved a good surgical outcome with no complication to date for our case study. We advocate this modified surgical method to completely remove iris cyst.

  6. Fractional Scaling Analysis for IRIS pressurizer reduced scale experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra da Silva, Mario Augusto, E-mail: mabs500@gmail.co [Departamento de Energia Nuclear - Centro de Tecnologia e Geociencias, Universidade Federal de Pernambuco, Av. Prof. Luiz Freire, 1000, 50740-540 Recife, PE (Brazil); Brayner de Oliveira Lira, Carlos Alberto, E-mail: cabol@ufpe.b [Departamento de Energia Nuclear - Centro de Tecnologia e Geociencias, Universidade Federal de Pernambuco, Av. Prof. Luiz Freire, 1000, 50740-540 Recife, PE (Brazil); Oliveira Barroso, Antonio Carlos de, E-mail: barroso@ipen.b [Instituto de Pesquisas Energeticas e Nucleares - Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes, 2242, 05508-900 Cidade Universitaria, Sao Paulo (Brazil)

    2010-10-15

    About twenty organizations joined in a consortium led by Westinghouse to develop an integral, modular and medium size pressurized water reactor (PWR), known as international reactor innovative and secure (IRIS), which is characterized by having most of its components inside the pressure vessel, eliminating or minimizing the probability of severe accidents. The pressurizer is responsible for pressure control in PWRs. A small continuous flow is maintained by the spray system in conventional pressurizers. This mini-flow allows a mixing between the reactor coolant and the pressurizer water, warranting acceptable limits for occasional differences in boron concentrations. There are neither surge lines nor spray in IRIS pressurizer, but surge and recirculation orifices that promote a circulation flow between primary system and pressurizer, avoiding power transients whether outsurges occur. The construction of models is a routine practice in engineering, being supported by similarity rules. A new method of scaling systems, Fractional Scaling Analysis, has been successfully used to analyze pressure variations, considering the most relevant agents of change. The aim of this analysis is to obtain the initial boron concentration ratio and the volumetric flows that ensure similar behavior for boron dispersion in a prototype and its model.

  7. Study of mixing process in the IRIS downcomer

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Elizabeth; Montesinos, Maria E.; Garcia, Carlos; Rives, Ronny; Rojas, Leorlen Y., E-mail: ciazbueno@instec.cu, E-mail: mmontesi@instec.cu, E-mail: cgh@instec.cu, E-mail: rsanz@instec.cu, E-mail: leored1984@gmail.com [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Bezerra, Jair L.; Lira, Carlos A.B. de Oliveira, E-mail: jairbezerra@gmail.com, E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear

    2015-07-01

    The reactivity of a water cooled reactor is controlled using control rods or boron dilution in water of the primary circuit. The Boron-10 (10B) is an efficient neutron absorber, especially when used in the absorption of thermal neutrons. Transient analysis with disabilities in the homogenization of Boron in PWR reactors becomes important as the boric acid solution is added to the primary circuit coolant in order to help control the fission rate in the reactor core. After reactor shutdown, the Boron present in coolant has the function of maintaining the reactor subcriticality. The aim of this research is to study the Boron homogenization processes in the downcomer of the IRIS nuclear reactor. It was used a test section, which represents a quarter of the interest geometry to harness the domain symmetry. By using the CFX code, the startup and shutdown were simulated in order to analyze the mixing processes in the coolant. It was evaluated the influence in the Boron homogenization of different geometrical configurations such as three different positions of coolant entrance with respect to the core holders and the variation of the dimensions of the DVI lines. This paper also analyze an event of partial loss of coolant because a coolant pump failure. (author)

  8. [A woman with iris heterochromia].

    Science.gov (United States)

    Birker, I L; Boons, L S T M; Luyten, G P M

    2016-01-01

    A 20-year-old woman with congenital iris heterochromia presented with loss of vision of her right eye. We made de diagnosis of a large 'uvea melanoma' and enucleated the eye. Pathological examination showed an underlying oculodermal melanocytosis (ODM). The life-time risk of uveal melanoma in the general population is 0.7:100,000, but 1:400 in patients with ODM. Therefore, annual fundoscopy is recommended in these patients.

  9. Prominence and tornado dynamics observed with IRIS and THEMIS

    Science.gov (United States)

    Schmieder, Brigitte; Levens, Peter; Labrosse, Nicolas; Mein, Pierre; Lopez Ariste, Arturo; Zapior, Maciek

    2017-08-01

    Several prominences were observed during campaigns in September 2013 and July 2014 with the IRIS spectrometer and the vector magnetograph THEMIS (Tenerife). SDO/AIA and IRIS provided images and spectra of prominences and tornadoes corresponding to different physical conditions of the transition region between the cool plasma and the corona. The vector magnetic field was derived from THEMIS observations by using the He D3 depolarisation due to the magnetic field. The inversion code (PCA) takes into account the Hanle and Zeeman effects and allows us to compute the strength and the inclination of the magnetic field which is shown to be mostly horizontal in prominences as well as in tornadoes. Movies from SDO/AIA in 304 A and Hinode/SOT in Ca II show the highly dynamic nature of the fine structures. From spectra in Mg II and Si IV lines provided by IRIS and H-alpha observed by the Multi-channel Subtractive Double Pass (MSDP) spectrograph in the Meudon Solar Tower we derived the Doppler shifts of the fine structures and reconstructed the 3D structure of tornadoes. We conclude that the apparent rotation of AIA tornadoes is due to large-scale quasi-periodic oscillations of the plasma along more or less horizontal magnetic structures.

  10. CDIS: Circle Density Based Iris Segmentation

    Science.gov (United States)

    Gupta, Anand; Kumari, Anita; Kundu, Boris; Agarwal, Isha

    Biometrics is an automated approach of measuring and analysing physical and behavioural characteristics for identity verification. The stability of the Iris texture makes it a robust biometric tool for security and authentication purposes. Reliable Segmentation of Iris is a necessary precondition as an error at this stage will propagate into later stages and requires proper segmentation of non-ideal images having noises like eyelashes, etc. Iris Segmentation work has been done earlier but we feel it lacks in detecting iris in low contrast images, removal of specular reflections, eyelids and eyelashes. Hence, it motivates us to enhance the said parameters. Thus, we advocate a new approach CDIS for Iris segmentation along with new algorithms for removal of eyelashes, eyelids and specular reflections and pupil segmentation. The results obtained have been presented using GAR vs. FAR graphs at the end and have been compared with prior works related to segmentation of iris.

  11. Video-based noncooperative iris image segmentation.

    Science.gov (United States)

    Du, Yingzi; Arslanturk, Emrah; Zhou, Zhi; Belcher, Craig

    2011-02-01

    In this paper, we propose a video-based noncooperative iris image segmentation scheme that incorporates a quality filter to quickly eliminate images without an eye, employs a coarse-to-fine segmentation scheme to improve the overall efficiency, uses a direct least squares fitting of ellipses method to model the deformed pupil and limbic boundaries, and develops a window gradient-based method to remove noise in the iris region. A remote iris acquisition system is set up to collect noncooperative iris video images. An objective method is used to quantitatively evaluate the accuracy of the segmentation results. The experimental results demonstrate the effectiveness of this method. The proposed method would make noncooperative iris recognition or iris surveillance possible.

  12. Biometric Authentication System based on Iris Patterns

    Directory of Open Access Journals (Sweden)

    G. Sathish

    2012-01-01

    Full Text Available In the present age of digital impersonation, biometrictechniques are being used increasingly to prevaricateagainst identity thefts. Iris recognition is a proven,accurate means to identify people. Iris is regarded as themost reliable biometric feature in terms of its uniquenessand robustness. The objective of this work is to present abiometric authentication system for high securityphysical access control based on iris pattern. Theproposed iris recognition with improvement in segmentation and matching stages using Hamming distance provides match for iris pattern if hamming distance is below 0.15. The CASIA IRIS image database of Chinese Academy of Sciences Institute of Automation is used and the system is implemented in MATLAB. The proposed approach found to report higher verification accuracy of 99.2%.

  13. Iris segmentation using variational level set method

    Science.gov (United States)

    Roy, Kaushik; Bhattacharya, Prabir; Suen, Ching Y.

    2011-04-01

    Continuous efforts have been made to process degraded iris images for enhancement of the iris recognition performance in unconstrained situations. Recently, many researchers have focused on developing the iris segmentation techniques, which can deal with iris images in a non-cooperative environment where the probability of acquiring unideal iris images is very high due to gaze deviation, noise, blurring, and occlusion by eyelashes, eyelids, glasses, and hair. Although there have been many iris segmentation methods, most focus primarily on the accurate detection of iris images captured in a closely controlled environment. The novelty of this research effort is that we propose to apply a variational level set-based curve evolution scheme that uses a significantly larger time step to numerically solve the evolution partial differential equation (PDE) for segmentation of an unideal iris image accurately, and thereby, speeding up the curve evolution process drastically. The iris boundary represented by the variational level set may break and merge naturally during evolution, and thus, the topological changes are handled automatically. The proposed variational model is also robust against poor localization and weak iris/sclera boundaries. In order to solve the size irregularities occurring due to arbitrary shapes of the extracted iris/pupil regions, a simple method is applied based on connection of adjacent contour points. Furthermore, to reduce the noise effect, we apply a pixel-wise adaptive 2D Wiener filter. The verification and identification performance of the proposed scheme is validated on three challenging iris image datasets, namely, the ICE 2005, the WVU Unideal, and the UBIRIS Version 1.

  14. Iris analysis for biometric recognition systems

    CERN Document Server

    Bodade, Rajesh M

    2014-01-01

    The book presents three most significant areas in Biometrics and Pattern Recognition. A step-by-step approach for design and implementation of Dual Tree Complex Wavelet Transform (DTCWT) plus Rotated Complex Wavelet Filters (RCWF) is discussed in detail. In addition to the above, the book provides detailed analysis of iris images and two methods of iris segmentation. It also discusses simplified study of some subspace-based methods and distance measures for iris recognition backed by empirical studies and statistical success verifications.

  15. Iris Recognition: The Consequences of Image Compression

    Directory of Open Access Journals (Sweden)

    Bishop DanielA

    2010-01-01

    Full Text Available Iris recognition for human identification is one of the most accurate biometrics, and its employment is expanding globally. The use of portable iris systems, particularly in law enforcement applications, is growing. In many of these applications, the portable device may be required to transmit an iris image or template over a narrow-bandwidth communication channel. Typically, a full resolution image (e.g., VGA is desired to ensure sufficient pixels across the iris to be confident of accurate recognition results. To minimize the time to transmit a large amount of data over a narrow-bandwidth communication channel, image compression can be used to reduce the file size of the iris image. In other applications, such as the Registered Traveler program, an entire iris image is stored on a smart card, but only 4 kB is allowed for the iris image. For this type of application, image compression is also the solution. This paper investigates the effects of image compression on recognition system performance using a commercial version of the Daugman iris2pi algorithm along with JPEG-2000 compression, and links these to image quality. Using the ICE 2005 iris database, we find that even in the face of significant compression, recognition performance is minimally affected.

  16. Iris Recognition: The Consequences of Image Compression

    Science.gov (United States)

    Ives, Robert W.; Bishop, Daniel A.; Du, Yingzi; Belcher, Craig

    2010-12-01

    Iris recognition for human identification is one of the most accurate biometrics, and its employment is expanding globally. The use of portable iris systems, particularly in law enforcement applications, is growing. In many of these applications, the portable device may be required to transmit an iris image or template over a narrow-bandwidth communication channel. Typically, a full resolution image (e.g., VGA) is desired to ensure sufficient pixels across the iris to be confident of accurate recognition results. To minimize the time to transmit a large amount of data over a narrow-bandwidth communication channel, image compression can be used to reduce the file size of the iris image. In other applications, such as the Registered Traveler program, an entire iris image is stored on a smart card, but only 4 kB is allowed for the iris image. For this type of application, image compression is also the solution. This paper investigates the effects of image compression on recognition system performance using a commercial version of the Daugman iris2pi algorithm along with JPEG-2000 compression, and links these to image quality. Using the ICE 2005 iris database, we find that even in the face of significant compression, recognition performance is minimally affected.

  17. Iris Image Quality Assessment for Biometric Application

    Directory of Open Access Journals (Sweden)

    U. M. Chaskar

    2012-05-01

    Full Text Available Image quality assessment plays an important role in the performance of biometric system involving iris images. Data quality assessment is a key issue in order to broaden the applicability of iris biometrics to unconstrained imaging conditions. In this paper, we have proposed the quality factors of individual iris images by assessing their prominent factors by their scores. The work has been carried out for the following databases: CASIA, UBIRIS, UPOL, MMU and our own created COEP Database using HIS 5000 HUVITZ Iris Camera. The comparison is also done with existing databases which in turn will act as a benchmark in increasing the efficiency of further processing.

  18. Exploring the feasibility of iris recognition for visible spectrum iris images obtained using smartphone camera

    Science.gov (United States)

    Trokielewicz, Mateusz; Bartuzi, Ewelina; Michowska, Katarzyna; Andrzejewska, Antonina; Selegrat, Monika

    2015-09-01

    In the age of modern, hyperconnected society that increasingly relies on mobile devices and solutions, implementing a reliable and accurate biometric system employing iris recognition presents new challenges. Typical biometric systems employing iris analysis require expensive and complicated hardware. We therefore explore an alternative way using visible spectrum iris imaging. This paper aims at answering several questions related to applying iris biometrics for images obtained in the visible spectrum using smartphone camera. Can irides be successfully and effortlessly imaged using a smartphone's built-in camera? Can existing iris recognition methods perform well when presented with such images? The main advantage of using near-infrared (NIR) illumination in dedicated iris recognition cameras is good performance almost independent of the iris color and pigmentation. Are the images obtained from smartphone's camera of sufficient quality even for the dark irides? We present experiments incorporating simple image preprocessing to find the best visibility of iris texture, followed by a performance study to assess whether iris recognition methods originally aimed at NIR iris images perform well with visible light images. To our best knowledge this is the first comprehensive analysis of iris recognition performance using a database of high-quality images collected in visible light using the smartphones flashlight together with the application of commercial off-the-shelf (COTS) iris recognition methods.

  19. Simultaneous observation of a hot explosion by NST and IRIS

    Science.gov (United States)

    Kim, Yeon-Han; Yurchyshyn, Vasyl; Bong, Su-Chan; Cho, Il-Hyun; Cho, Kyung-Suk; Lee, Jaejin; Lim, Eun-Kyung; Park, Young-Deuk; Yang, Heesu; Ahn, Kwangsu; Goode, Philip R.; Jang, Bi-Ho

    2015-09-01

    We present the first simultaneous observations of so-called “hot explosions” in the cool atmosphere of the Sun made by the New Solar Telescope (NST) of Big Bear Solar Observatory and the Interface Region Imaging Spectrograph (IRIS) in space. The data were obtained during the joint IRIS-NST observations on 2014 July 30. The explosion of interest started around 19:20 UT and lasted for about 10 minutes. Our findings are as follows: (1) the IRIS brightening was observed in three channels of slit-jaw images, which cover the temperature range from 4000 to 80,000 K; (2) during the brightening, the Si iv emission profile showed a double-peaked shape with highly blue and redshifted components (-40 and 80 km s-1) (3) wing brightening occurred in Hα and Ca ii 8542 Å bands and related surges were observed in both bands of the NST Fast Imaging Solar Spectrograph (FISS) instrument; (4) the elongated granule, seen in NST TiO data, is clear evidence of the emergence of positive flux to trigger the hot explosion; (5) the brightening in Solar Dynamics Observatory/Atmospheric Imaging Assembly 1600 Å images is quite consistent with the IRIS brightening. These observations suggest that our event is a hot explosion that occurred in the cool atmosphere of the Sun. In addition, our event appeared as an Ellerman bomb (EB) in the wing of Hα, although its intensity is weak and the vertical extent of the brightening seems to be relatively high compared with the typical EBs.

  20. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  1. Comparison of open and closed U-Pu equilibrium fuel cycles for Generation-IV fast reactors with the EQL3D procedure

    Energy Technology Data Exchange (ETDEWEB)

    Krepel, Jiri, E-mail: Jiri.Krepel@psi.ch [Laboratory for Reactor Physics and Systems Behaviour, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Pelloni, Sandro; Mikityuk, Konstantin [Laboratory for Reactor Physics and Systems Behaviour, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We analyze open and closed fuel cycle of GFR, SFR, and LFR cores by means of ERANOS based EQL3D procedure. Black-Right-Pointing-Pointer Equilibrium of open and closed fuel cycles were compared in terms of their performance and safety parameters. Black-Right-Pointing-Pointer All three cores act in equilibrium closed cycle as iso-breeder and have similar fuel composition. Black-Right-Pointing-Pointer In spite of the same fuel composition the Dopper constants and void reactivities strongly differ between the cores. Black-Right-Pointing-Pointer All three systems seem capable, from neutronics point of view, for the fuel cycle closure. - Abstract: The advanced fast reactors of the fourth generation should enable an indirect burning of poorly fissile {sup 238}U through {sup 239}Pu breeding and recycling of the actinides from their own spent fuel. The recycling or actually the fuel cycle closure can significantly reduce the amount of long-lived radioactive waste and the {sup 238}U burning can multiply the sustainability of the uranium fueled reactors. Regular periodic operation with the fuel recycling converges to an equilibrium cycle. To enable its simulation a numerical tool named equilibrium fuel cycle procedure for fast reactors (EQL3D) was developed in the FAST group of LRS at Paul Scherrer Institut. The procedure is based on the ERANOS code and can be used to yield the description of two basic situations: the equilibrium of an open fuel cycle and the equilibrium of a closed fuel cycle. The goals of the present study are (i) to apply EQL3D to the Gas-cooled Fast Reactor (GFR), Sodium-cooled Fast Reactor (SFR), and Lead-cooled Fast Reactor (LFR), (ii) to simulate and confirm the GFR, SFR, and LFR neutronics capability for closed fuel cycle, and (iii) to evaluate and compare the equilibrium cycle safety and performance parameters. The EQL3D capability enables to characterize the equilibrium cycle for complex reloading patterns

  2. Feasibility of co-generation of water and electricity by means of the IRIS;Factibilidad de cogeneracion de agua y electricidad mediante el IRIS

    Energy Technology Data Exchange (ETDEWEB)

    Vargas E, S.; Alonso V, G.; Gonzalez, J. A.; Xolocostli, V.; Ramirez S, J. R., E-mail: samuel.vargas@inin.gob.m [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-10-15

    The importance to count with resources that allow the development of a country is an important factor. The electricity and the water are factors that in the future will be crucial for the development of any region of the planet. In this work the economic reliability of use of IRIS reactor like a energy source for the electricity production, as well as for the potable water production through the desalination of sea water. Within this study the requirements of these two outlines for different regions from the country are analyzed, nevertheless, chooses the northwest region of the Mexican republic, because, according to estimations realized for the Energy Secretary and the National Commission of the Water, this would present important water requirements and electricity, due to the population increase that is considered for all the country, mainly the built-up zones. Combined to this one is due to consider that the present water demand in some regions of the country present a worrisome over-exploitation of this liquid appraising. The economic evaluation of co-generation that appears in this work though the IRIS reactor, includes different desalination capacities at the moment, using the three more used techniques, obtaining the even costs of water and electricity, as well as net saleable energy and the construction costs as much for the desalination plant and the IRIS reactor. (Author)

  3. Comparing Haar-Hilbert and Log-Gabor Based Iris Encoders on Bath Iris Image Database

    CERN Document Server

    Popescu-Bodorin, Nicolaie; 10.1109/SOFA.2010.5565599

    2011-01-01

    This papers introduces a new family of iris encoders which use 2-dimensional Haar Wavelet Transform for noise attenuation, and Hilbert Transform to encode the iris texture. In order to prove the usefulness of the newly proposed iris encoding approach, the recognition results obtained by using these new encoders are compared to those obtained using the classical Log- Gabor iris encoder. Twelve tests involving single/multienrollment and conducted on Bath Iris Image Database are presented here. One of these tests achieves an Equal Error Rate comparable to the lowest value reported so far for this database. New Matlab tools for iris image processing are also released together with this paper: a second version of the Circular Fuzzy Iris Segmentator (CFIS2), a fast Log-Gabor encoder and two Haar-Hilbert based encoders.

  4. Feature Vector Construction Method for IRIS Recognition

    Science.gov (United States)

    Odinokikh, G.; Fartukov, A.; Korobkin, M.; Yoo, J.

    2017-05-01

    One of the basic stages of iris recognition pipeline is iris feature vector construction procedure. The procedure represents the extraction of iris texture information relevant to its subsequent comparison. Thorough investigation of feature vectors obtained from iris showed that not all the vector elements are equally relevant. There are two characteristics which determine the vector element utility: fragility and discriminability. Conventional iris feature extraction methods consider the concept of fragility as the feature vector instability without respect to the nature of such instability appearance. This work separates sources of the instability into natural and encodinginduced which helps deeply investigate each source of instability independently. According to the separation concept, a novel approach of iris feature vector construction is proposed. The approach consists of two steps: iris feature extraction using Gabor filtering with optimal parameters and quantization with separated preliminary optimized fragility thresholds. The proposed method has been tested on two different datasets of iris images captured under changing environmental conditions. The testing results show that the proposed method surpasses all the methods considered as a prior art by recognition accuracy on both datasets.

  5. 75 FR 8154 - Advisory Committee on Reactor Safeguards

    Science.gov (United States)

    2010-02-23

    ... NRC staff regarding new advanced reactor designs such as NuScale, Iris, Babcock and Wilcox Modular... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards In accordance with the purposes of Sections 29 and...

  6. Enhanced iris recognition method based on multi-unit iris images

    Science.gov (United States)

    Shin, Kwang Yong; Kim, Yeong Gon; Park, Kang Ryoung

    2013-04-01

    For the purpose of biometric person identification, iris recognition uses the unique characteristics of the patterns of the iris; that is, the eye region between the pupil and the sclera. When obtaining an iris image, the iris's image is frequently rotated because of the user's head roll toward the left or right shoulder. As the rotation of the iris image leads to circular shifting of the iris features, the accuracy of iris recognition is degraded. To solve this problem, conventional iris recognition methods use shifting of the iris feature codes to perform the matching. However, this increases the computational complexity and level of false acceptance error. To solve these problems, we propose a novel iris recognition method based on multi-unit iris images. Our method is novel in the following five ways compared with previous methods. First, to detect both eyes, we use Adaboost and a rapid eye detector (RED) based on the iris shape feature and integral imaging. Both eyes are detected using RED in the approximate candidate region that consists of the binocular region, which is determined by the Adaboost detector. Second, we classify the detected eyes into the left and right eyes, because the iris patterns in the left and right eyes in the same person are different, and they are therefore considered as different classes. We can improve the accuracy of iris recognition using this pre-classification of the left and right eyes. Third, by measuring the angle of head roll using the two center positions of the left and right pupils, detected by two circular edge detectors, we obtain the information of the iris rotation angle. Fourth, in order to reduce the error and processing time of iris recognition, adaptive bit-shifting based on the measured iris rotation angle is used in feature matching. Fifth, the recognition accuracy is enhanced by the score fusion of the left and right irises. Experimental results on the iris open database of low-resolution images showed that the

  7. Correlation of iris biometrics and DNA

    DEFF Research Database (Denmark)

    Harder, Stine; Clemmensen, Line Katrine Harder; Dahl, Anders Bjorholm

    2013-01-01

    The presented work concerns prediction of complex human phenotypes from genotypes. We were interested in correlating iris color and texture with DNA. Our data consist of 212 eye images along with DNA: 32 single-nucleotide polymorphisms (SNPs). We used two types of biometrics to describe the eye...... images: One for iris color and one for iris texture. Both biometrics were high dimensional and a sparse principle component analysis (SPCA) reduced the dimensions and resulted in a representation of data with good interpretability. The correlations between the sparse principal components (SPCs....... The significant canonical variables for color and texture were primarily explained by the first SPC (SPC1). Therefore, we made a visual inspection of the first SPCs. The color based SPC1 explained a blue to brown variation in iris color and the texture based SPC1 gave a general explanation of iris texture...

  8. Iris Localization Based on Edge Searching Strategies

    Institute of Scientific and Technical Information of China (English)

    Wang Yong; Han Jiuqiang

    2005-01-01

    An iris localization scheme based on edge searching strategies is presented. First, the edge detection operator Laplacian-ofGaussian (LoG) is used to iris original image to search its inner boundary. Then, a circle detection operator is introduced to locate the outer boundary and its center, which is invariant of translation, rotation and scale. Finally, the method of curve fitting is developed in localization of eyelid. The performance of the proposed method is tested with 756 iris images from 108 different classes in CASIA Iris Database and compared with the conventional Hough transform method. The experimental results show that without loss of localization accuracy, the proposed iris localization algorithm is apparently faster than Hough transform.

  9. Behaviour of palladium(II), platinum(IV), and rhodium(III) in artificial and natural waters: influence of reactor surface and geochemistry on metal recovery.

    Science.gov (United States)

    Cobelo-Garcia, Antonio; Turner, Andrew; Millward, Geoffrey E; Couceiro, Fay

    2007-03-07

    The recovery of dissolved platinum group elements (PGE: Pd(II), Pt(IV) and Rh(III)) added to Milli-Q water, artificial freshwater and seawater and filtered natural waters has been studied, as a function of pH and PGE concentration, in containers of varying synthetic composition. The least adsorptive and/or precipitative loss was obtained for borosilicate glass under most of the conditions employed, whereas the greatest loss was obtained for low-density polyethylene. Of the polymeric materials tested, the adsorptive and/or precipitative loss of PGE was lowest for fluorinated ethylene propylene (Teflon). The loss of Pd(II) in freshwater was significant due to its affinity for surface adsorption and its relatively low solubility. The presence of natural dissolved organic matter increases the recovery of Pd(II) but enhances the loss of Pt(IV). The loss of Rh(III) in seawater was significant and was mainly due to precipitation, whereas Pd(II) recovery was enhanced, compared to freshwater, because of its complexation with chloride. The results have important implications regarding protocols employed for sample preservation and controlled laboratory experiments used in the study of the speciation and biogeochemical behaviour of PGE.

  10. An iris segmentation algorithm based on edge orientation for off-angle iris recognition

    Science.gov (United States)

    Karakaya, Mahmut; Barstow, Del; Santos-Villalobos, Hector; Boehnen, Christopher

    2013-03-01

    Iris recognition is known as one of the most accurate and reliable biometrics. However, the accuracy of iris recognition systems depends on the quality of data capture and is negatively affected by several factors such as angle, occlusion, and dilation. In this paper, we present a segmentation algorithm for off-angle iris images that uses edge detection, edge elimination, edge classification, and ellipse fitting techniques. In our approach, we first detect all candidate edges in the iris image by using the canny edge detector; this collection contains edges from the iris and pupil boundaries as well as eyelash, eyelids, iris texture etc. Edge orientation is used to eliminate the edges that cannot be part of the iris or pupil. Then, we classify the remaining edge points into two sets as pupil edges and iris edges. Finally, we randomly generate subsets of iris and pupil edge points, fit ellipses for each subset, select ellipses with similar parameters, and average to form the resultant ellipses. Based on the results from real experiments, the proposed method shows effectiveness in segmentation for off-angle iris images.

  11. An Iris Segmentation Algorithm based on Edge Orientation for Off-angle Iris Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Boehnen, Chris Bensing [ORNL

    2013-01-01

    Iris recognition is known as one of the most accurate and reliable biometrics. However, the accuracy of iris recognition systems depends on the quality of data capture and is negatively affected by several factors such as angle, occlusion, and dilation. In this paper, we present a segmentation algorithm for off-angle iris images that uses edge detection, edge elimination, edge classification, and ellipse fitting techniques. In our approach, we first detect all candidate edges in the iris image by using the canny edge detector; this collection contains edges from the iris and pupil boundaries as well as eyelash, eyelids, iris texture etc. Edge orientation is used to eliminate the edges that cannot be part of the iris or pupil. Then, we classify the remaining edge points into two sets as pupil edges and iris edges. Finally, we randomly generate subsets of iris and pupil edge points, fit ellipses for each subset, select ellipses with similar parameters, and average to form the resultant ellipses. Based on the results from real experiments, the proposed method shows effectiveness in segmentation for off-angle iris images.

  12. Fuzzy difference-of-Gaussian-based iris recognition method for noisy iris images

    Science.gov (United States)

    Kang, Byung Jun; Park, Kang Ryoung; Yoo, Jang-Hee; Moon, Kiyoung

    2010-06-01

    Iris recognition is used for information security with a high confidence level because it shows outstanding recognition accuracy by using human iris patterns with high degrees of freedom. However, iris recognition accuracy can be reduced by noisy iris images with optical and motion blurring. We propose a new iris recognition method based on the fuzzy difference-of-Gaussian (DOG) for noisy iris images. This study is novel in three ways compared to previous works: (1) The proposed method extracts iris feature values using the DOG method, which is robust to local variations of illumination and shows fine texture information, including various frequency components. (2) When determining iris binary codes, image noises that cause the quantization error of the feature values are reduced with the fuzzy membership function. (3) The optimal parameters of the DOG filter and the fuzzy membership function are determined in terms of iris recognition accuracy. Experimental results showed that the performance of the proposed method was better than that of previous methods for noisy iris images.

  13. Role of Arbuscular Mycorrhizal Fungi on Iris

    Directory of Open Access Journals (Sweden)

    CHEN Yuan

    2014-06-01

    Full Text Available For efficiency using the amphibious plant iris to restore polluted water, the promoting effect of different arbuscular mycorrhiza fungi(AMFon iris was investigated, by monitoring the plant growth index, the physicochemical properties of the soil and the plant photosynthesis indexes. The result showed that the promoting effects of the AMF on the aboveground part and the underground part of the iris were based on different mechanism. For the underground part of the iris, the AMF stimulated its growth through the nutrient enrichment which was performed by the enormous hypha network. The nitrogen absorbing rate of the G. mosseae and the G. intraradices infected iris increased about 71.75% and 42.55%, and the phosphorous absorbing rate increased 8.36% and 9.5% separately. For the aboveground part of the iris, the AMF strengthened the conductance of the leaves’ stomas to control the balance between the net photosynthesis rate and the transpiration rate, so that the utilization rate of water resources was optimized, the metabolic rate was accelerated and the growth of the plant was promoted eventually. In this study, the promoting effect of the G. mosseae on the photosynthesis rate of the iris was significantly better than that of the G. intraradices(P<0.05.

  14. Iris pigment epithelial cysts in a newborn

    Directory of Open Access Journals (Sweden)

    Zargar, Shabnam

    2016-04-01

    Full Text Available Purpose: We report a case of iris pigment epithelial cysts in a newborn and discuss the importance of an accurate diagnosis for prevention of amblyopia.Methods: We describe a case of an abnormal red reflex seen on a newborn exam.Results: A full-term female born via normal spontaneous vaginal delivery without any complications was seen in the newborn nursery. She was noted to have an abnormal eye exam. Pupils were large with circular dark excrescences of the iris pigment epithelium. She was referred to a pediatric ophthalmologist where she was noted to fixate and follow faces. No afferent pupillary defect was seen. OD red reflex was normal whereas OS red reflex was blocked mostly by dark excrescences. A 2– dark brown lesion was seen in the OD iris and a 3–5 mm dark brown lesion was seen in the OS iris, consistent with a pupillary iris pigment epithelial cyst. Central visual axis was clear OU. Glaucoma was not present and patching was not performed. Observations and clinical photographs were recommended with follow-up in three months.Conclusion: Iris pigment epithelial cysts are uncommonly seen in children. The primary care provider first seeing a newborn must be aware of lesions obscuring a red reflex with appropriate follow-up. Follow-up in three months with IOP measurements is recommended. Iris pigment epithelial cysts in children may be a cause of amblyopia, thus prompt evaluation is important for prognostic purposes and the prevention of amblyopia.

  15. Off-Angle Iris Correction Methods

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Villalobos, Hector J [ORNL; Thompson, Joseph T [ORNL; Karakaya, Mahmut [ORNL; Boehnen, Chris Bensing [ORNL

    2016-01-01

    In many real world iris recognition systems obtaining consistent frontal images is problematic do to inexperienced or uncooperative users, untrained operators, or distracting environments. As a result many collected images are unusable by modern iris matchers. In this chapter we present four methods for correcting off-angle iris images to appear frontal which makes them compatible with existing iris matchers. The methods include an affine correction, a retraced model of the human eye, measured displacements, and a genetic algorithm optimized correction. The affine correction represents a simple way to create an iris image that appears frontal but it does not account for refractive distortions of the cornea. The other method account for refraction. The retraced model simulates the optical properties of the cornea. The other two methods are data driven. The first uses optical flow to measure the displacements of the iris texture when compared to frontal images of the same subject. The second uses a genetic algorithm to learn a mapping that optimizes the Hamming Distance scores between off-angle and frontal images. In this paper we hypothesize that the biological model presented in our earlier work does not adequately account for all variations in eye anatomy and therefore the two data-driven approaches should yield better performance. Results are presented using the commercial VeriEye matcher that show that the genetic algorithm method clearly improves over prior work and makes iris recognition possible up to 50 degrees off-angle.

  16. The voices of Iris: Cinematic representations of the aged woman and Alzheimer's disease in Iris (2001).

    Science.gov (United States)

    Graham, Megan E

    2016-09-01

    Audiences must be critical of film representations of the aged woman living with Alzheimer's disease and of dangerous reinscriptions of stereotypical equations about ageing as deterioration. This paper analyses the representation and decline of the aged woman through the different voices of Iris Murdoch in Richard Eyre's film Iris (2001). Key vocal scenes are considered: On-screen encounters between young and aged Iris, vocal representations of dementia symptoms and silencing Iris as her disease progresses. Further, Iris' recurrent unaccompanied song, "The Lark in the Clear Air," compels audiences to "see" Iris with their ears more than with their eyes, exemplifying the representational power of sound in film. This paper is an appeal for increased debate about sonic representations of aged women, ageing and Alzheimer's disease and dementia in film. The significance of audiences' critical awareness and understanding about the social implications of these representations is discussed. © The Author(s) 2014.

  17. Hough Transform and Active Contour for Enhanced Iris Segmentation

    Directory of Open Access Journals (Sweden)

    Alaa Hilal

    2012-11-01

    Full Text Available Iris segmentation is considered as the most difficult and fundamental step in an iris recognition system. While iris boundaries are largely approximated by two circles or ellipses, other methods define more accurately the iris resulting in better recognition results. In this paper we propose an iris segmentation method using Hough transform and active contour to detect a circular approximation of the outer iris boundary and to accurately segment the inner boundary in its real shape motivated by the fact that richer iris textures are closer to the pupil than to the sclera. Normalization, encoding and matching are implemented according to Daugmans method. The method, tested on CASIA-V3 iris images database is compared to Daugmans iris recognition system. Recognition performance is measured in terms of decidability, accuracy at the equal error rate and ROC curves. Improved recognition performance is obtained using our segmentation model proposing its use for better iris recognition system.

  18. SEGMENTATION AND QUALITY ANALYSIS OF LONG RANGE CAPTURED IRIS IMAGE

    Directory of Open Access Journals (Sweden)

    Anand Deshpande

    2016-05-01

    Full Text Available The iris segmentation plays a major role in an iris recognition system to increase the performance of the system. This paper proposes a novel method for segmentation of iris images to extract the iris part of long range captured eye image and an approach to select best iris frame from the iris polar image sequences by analyzing the quality of iris polar images. The quality of iris image is determined by the frequency components present in the iris polar images. The experiments are carried out on CASIA-long range captured iris image sequences. The proposed segmentation method is compared with Hough transform based segmentation and it has been determined that the proposed method gives higher accuracy for segmentation than Hough transform.

  19. A novel iris localization algorithm using correlation filtering

    Science.gov (United States)

    Pohit, Mausumi; Sharma, Jitu

    2015-06-01

    Fast and efficient segmentation of iris from the eye images is a primary requirement for robust database independent iris recognition. In this paper we have presented a new algorithm for computing the inner and outer boundaries of the iris and locating the pupil centre. Pupil-iris boundary computation is based on correlation filtering approach, whereas iris-sclera boundary is determined through one dimensional intensity mapping. The proposed approach is computationally less extensive when compared with the existing algorithms like Hough transform.

  20. Using multi-matching system based on a simplified deformable model of the human iris for iris recognition

    Institute of Scientific and Technical Information of China (English)

    MING Xing; XU Tao; WANG Zheng-xuan

    2004-01-01

    A new method for iris recognition using a multi-matching system based on a simplified deformable model of the human iris was proposed. The method defined iris feature points and formed the feature space based on a wavelet transform. In the matching stage it worked in a crude manner. Driven by a simplified deformable iris model, the crude matching was refined. By means of such multi-matching system, the task of iris recognition was accomplished. This process can preserve the elastic deformation between an input iris image and a template and improve precision for iris recognition. The experimental results indicate the validity of this method.

  1. EFFICIENT IRIS SEGMENTATION BASED ON EYELID DETECTION

    Directory of Open Access Journals (Sweden)

    ABDULJALIL RADMAN

    2013-08-01

    Full Text Available This paper proposes a computationally efficient eyelid detection algorithm for detecting eyelid boundaries in iris images acquired under less constrained imaging conditions. The proposed eyelid detection algorithm is developed based on the live-wire technique. The major advantage of the proposed algorithm is its computational simplicity as compared to the prior eyelid detection algorithms. The saturation color features of the sclera region of the HSI color space of the iris image are exploited to determine the two intersection points between each eyelid and the outer iris boundary. The strongly connected edges between these two points are detected using the live wire technique that is likely to be the eyelid boundary. The experimental results obtained from UBIRIS.v1 database reveal that the eyelid detection algorithm which proposed in this paper improves the segmentation accuracy for the less constrained iris images.

  2. Internet Renewable energy Information System (IRIS)

    DEFF Research Database (Denmark)

    Bäurle, Britta; Nielsen, Vilhjalmur; Ménard, Lionel

    1999-01-01

    Even though the Internet is now a widely accessible data source, the unorganised flood of information makes a specific request e.g. for renewable energy products inefficient. In addition, existing databases on renewable energies are often old and incomplete. The objective of IRIS has been...... to organise and retrieve renewable energy product information on the Internet instead of collecting it manually. Updating coincides with the self interestself-interest of manufacturers to present their latest renewable energy products on their own HTML documents. IRIS is based on a set of powerful tools...... on biogas systems in order to become part of IRIS. IRIS has been developed in the context of the project „AVALANCHE" which is partly funded under the JOULE programme of the European Commission DGXII.Keywords: Renewable Energy Technologies - Electronic Commerce - Information System - META-tags...

  3. JAERI's contribution to the IAEA coordinated research programme on assuring structural integrity of reactor pressure vessels' (CRP-IV). Final report (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Onizawa, Kunio; Suzuki, Masahide [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-05-01

    According to the Research Agreement No. 9736 between the IAEA and the JAERI, we commenced the test program for the IAEA Coordinated Research Program (CRP) on 'Assuring Structural Integrity of Reactor Pressure Vessels' at JAERI in September 1997. For the program, we received one block of the IAEA reference material JRQ from the IAEA CRP coordinator in June 1997. The test program has been conducted using the JRQ block and additional materials (Steels A and B) from our own program having a similar object with the CRP. The CRP consists of two parts; a mandatory part and an optional part. For the mandatory part of the JAERI program, instrumented Charpy impact tests and fracture toughness tests using precracked Charpy-v (PCCv) specimens were performed. As the optional part, neutron irradiation to specimens of JRQ was conducted at JMTR by using two capsules. In this report, the results of the mandatory part and irradiated Charpy and PCCv specimens of JRQ from capsule No.1 as well as those of Steel A and Steel B were described. The following conclusions were drawn; (1) the data form Charpy impact and fracture toughness tests of JRQ agreed well with the data in the CRP-3, (2) the scatter of fracture toughness of JRQ is relatively large, i. e., the Weibull slope 'b' is less than 3, (3) the reference temperature T{sub 0} from PCCv is in good agreement with T{sub 0} from 1T-Compact Tension (CT) when the tests are performed at the recommended temperature or the data has no invalid data, (4) the reference temperature T{sub 0} after neutron irradiation can be determined with six to eight specimens at the recommended temperature and (5) the shift of the reference temperature T{sub 0} is almost equivalent to the shift of Charpy transition temperature, but affected by the treatment of the highest data and testing temperature. Further studies on the fracture toughness evaluation are necessary concerning the treatment of outlier, temperature dependence after

  4. [Iris movement mediates pupillary membrane regression].

    Science.gov (United States)

    Morizane, Yuki

    2007-11-01

    In the course of mammalian lens development, a transient capillary meshwork called as the pupillary membrane (PM) forms. It is located in the pupil area to nourish the anterior surface of the lens, and then regresses to clear the optical path. Although the involvement of the apoptotic process has been reported in PM regression, the initiating factor remains unknown. We initially found that regression of the PM coincided with the development of iris motility, and that iris movement caused cessation and resumption of blood flow within the PM. Therefore, we investigated whether the development of the capacity of the iris to constrict and dilate can function as an essential signal that induces apoptosis in the PM. Continuous inhibition of iris movement with mydriatic agents suppressed apoptosis of the PM and resulted in the persistence of PM in rats. The distribution of apoptotic cells in the regressing PM was diffuse and showed no apparent localization. These results indicated that iris movement induced regression of the PM by changing the blood flow within it. This study suggests the importance of the physiological interactions between tissues-in this case, the iris and the PM-as a signal to advance vascular regression during organ development.

  5. Deteksi Iris Berdasarkan Metode Black Hole dan Circle Curve Fitting

    Directory of Open Access Journals (Sweden)

    Danny Kurnianto

    2013-11-01

    Full Text Available Sistem pengenalan identitas personal berdasarkan ciri biometrika adalah suatu sistem pengenalan seseorang berdasarkan pada ciri biometrika yang melekat pada orang tersebut. Iris mata merupakan salah satu ciri biometrik yang handal untuk sistem pengenalan identitas personal. Bagian sistem pengenalan identitas personal berdasarkan biometrik iris yang dianggap paling krusial adalah deteksi lokasi iris, karena akurasi deteksi iris berpengaruh pada tingkat akurasi sistem secara keseluruhan. Lokasi iris pada citra mata dibatasi oleh dua buah lingkaran yang memisahkan antara bagian iris  dengan pupil dan sklera. Telah banyak metodemetode yang diusulkan oleh para peneliti untuk menghasilkan deteksi lokasi iris dengan akurat dan cepat. Masalah akurasi, kecepatan waktu eksekusi dan ketahanan terhadap noise merupakan bidang penelitian yang menantang pada deteksi iris. Makalah ini menyajikan metode deteksi iris menggunakan metode black hole dan circle curve fitting. Langkah pertama, mencari batas dalam lingkaran iris yang memisahkan antara daerah iris dan pupil. Dengan metode black hole yang bekerja berdasarkan fakta bahwa lokasi pupil merupakan daerah  lingkaran yang paling hitam dan memiliki distribusi nilai intensitas yang seragam, maka lokasi pupil dapat ditentukan dengan teknik pengambangan. Batas lingkaran pupil dapat ditentukan dengan circle curve fitting dari parameter lingkaran daerah pupil. Langkah kedua,  mencari batas luar lingkaran iris yang memisahkan antara iris dan sklera. Peta tepi citra iris dicari dengan menggunakan deteksi tepi Canny, kemudian diambil satu komponen tepi arah vertikal yang dapat mewakili batas lingkaran luar iris. Dari komponen tepi tersebut, dihitung jari-jari iris yang berpusat di pusat pupil. Dengan jari-jari iris dan pusat iris maka dapat ditentukan batas luar iris menggunakan circle curve fitting

  6. Performance of Personal Identification System Technique Using Iris Biometrics Technology

    Directory of Open Access Journals (Sweden)

    V.K. Narendira Kumar

    2013-04-01

    Full Text Available The Iris identification as one of the significant techniques of biometric identification systems s and iris recognition algorithm is described. Biometric technology advances intellectual properties are wanted by many unauthorized personnel. As a result many researchers have being searching ways for more secure authentication methods for the user access. Iris recognition uses iris patterns for personnel identification. The system steps are capturing iris patterns; determining the location of iris boundaries; converting the iris boundary to the stretched polar coordinate system; extracting iris code based on texture analysis. The system has been implemented and tested using dataset of number of samples of iris data with different contrast quality. The developed algorithm performs satisfactorily on the images, provides 93% accuracy. Experimental results show that the proposed method has an encouraging performance.

  7. IRIS Observation of a Sunspot and the Surrounding Plage Region

    Science.gov (United States)

    TIAN, H.; DeLuca, E. E.; Mcintosh, S. W.; Reeves, K. K.; McKillop, S.; Weber, M.; Saar, S.; Golub, L.; Testa, P.

    2013-12-01

    NASA's IRIS mission is providing high-cadence and high-resolution observations of the solar transition region and chromosphere. We present preliminary results from IRIS observation of a sunspot and the surrounding plage region. The major findings in this observation can be summarized as following: (1) The slit jaw images in the filters of 1400Å and 1330Å reveal the presence of many rapidly evolving fibril-like structures in the transition region for the first time. These thin and long structures mainly reside in the plage region. They could be strands of low-lying cool transition region loops or the transition region counterpart of chromospheric spicules. (2) The C II and Mg II line profiles are almost Gaussian in the sunspot umbra and clearly exhibit a deep reversal at the line center in the plage region, suggesting a greatly reduced opacity in the sunspot atmosphere. (3) Bidirectional jets are frequently occurring mainly in the plage region immediately outside the sunspot throughout the observation. Triple or double Gaussian fit to the line profiles of Si IV suggests a velocity as high as 100 km/s. These velocity values are of the same order of the Alfven speed in the transition region. (4)Three-minute oscillation is clearly present in the sunspot umbra. The oscillation is identified in not only the slit jaw images of 2796Å, 1400Å and 1330Å, but also in spectra of the bright Mg II, C II and Si IV lines. Strong non-linearity is clearly seen in the intensity and Doppler shift oscillations. Interestingly, the obvious increase of the line width only occurs at the times of largest blue shift. The correlated change of the intensity and Doppler shift suggests an upward propagating magneto-acoustic shock wave.

  8. New Iris Localization Method Based on Chaos Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    Jia Dongli; Muhammad Khurram Khan; Zhang Jiashu

    2005-01-01

    This paper present a new method based on Chaos Genetic Algorithm (CGA) to localize the human iris in a given image. First, the iris image is preprocessed to estimate the range of the iris localization, and then CGA is used to extract the boundary of the iris. Simulation results show that the proposed algorithms is efficient and robust, and can achieve sub pixel precision. Because Genetic Algorithms (GAs) can search in a large space, the algorithm does not need accurate estimation of iris center for subsequent localization, and hence can lower the requirement for original iris image processing. On this point, the present localization algirithm is superior to Daugmans algorithm.

  9. Histopathology in the iris-nevus (Cogan-Reese) syndrome.

    Science.gov (United States)

    Radius, R L; Herschler, J

    1980-06-01

    A 23-year-old-woman had iris-nevus (Cogan-Reese) syndrome characterized by unilateral glaucoma with peripheral anterior synechiae, multiple iris nodules, and ectopic Descemet's membrane. A surgical specimen excised from the involved eye was examined by light and electron microscopy. A cuticular membrane covered both the anterior and posterior surfaces of the iris in this specimen. On the anterior surface of the iris, many projections of apparently normal iris stroma pierced or were surrounded by this membrane. On the posterior surface of the iris, this membrane was associated with a monolayer of cuboidal cells.

  10. ORNL Biometric Eye Model for Iris Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Villalobos, Hector J [ORNL; Barstow, Del R [ORNL; Karakaya, Mahmut [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK); Boehnen, Chris Bensing [ORNL

    2012-01-01

    Iris recognition has been proven to be an accurate and reliable biometric. However, the recognition of non-ideal iris images such as off angle images is still an unsolved problem. We propose a new biometric targeted eye model and a method to reconstruct the off-axis eye to its frontal view allowing for recognition using existing methods and algorithms. This allows for existing enterprise level algorithms and approaches to be largely unmodified by using our work as a pre-processor to improve performance. In addition, we describe the `Limbus effect' and its importance for an accurate segmentation of off-axis irides. Our method uses an anatomically accurate human eye model and ray-tracing techniques to compute a transformation function, which reconstructs the iris to its frontal, non-refracted state. Then, the same eye model is used to render a frontal view of the reconstructed iris. The proposed method is fully described and results from synthetic data are shown to establish an upper limit on performance improvement and establish the importance of the proposed approach over traditional linear elliptical unwrapping methods. Our results with synthetic data demonstrate the ability to perform an accurate iris recognition with an image taken as much as 70 degrees off-axis.

  11. Statistical feature extraction based iris recognition system

    Indian Academy of Sciences (India)

    ATUL BANSAL; RAVINDER AGARWAL; R K SHARMA

    2016-05-01

    Iris recognition systems have been proposed by numerous researchers using different feature extraction techniques for accurate and reliable biometric authentication. In this paper, a statistical feature extraction technique based on correlation between adjacent pixels has been proposed and implemented. Hamming distance based metric has been used for matching. Performance of the proposed iris recognition system (IRS) has been measured by recording false acceptance rate (FAR) and false rejection rate (FRR) at differentthresholds in the distance metric. System performance has been evaluated by computing statistical features along two directions, namely, radial direction of circular iris region and angular direction extending from pupil tosclera. Experiments have also been conducted to study the effect of number of statistical parameters on FAR and FRR. Results obtained from the experiments based on different set of statistical features of iris images show thatthere is a significant improvement in equal error rate (EER) when number of statistical parameters for feature extraction is increased from three to six. Further, it has also been found that increasing radial/angular resolution,with normalization in place, improves EER for proposed iris recognition system

  12. A fourier transform quality measure for iris images

    CSIR Research Space (South Africa)

    Makinana, S

    2014-08-01

    Full Text Available Iris recognition systems have attracted much attention for their uniqueness, stability and reliability. However, performance of this system depends on quality of acquired iris sample. This is because in order to obtain reliable features good quality...

  13. Iris recognition: a biometric method after refractive surgery

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Iris recognition, as a biometric method, outperforms others because of its high accuracy. Iris is the visible internal organ of human, so it is stable and very difficult to be altered. But if an eye surgery must be made to some individuals, it may be rejected by iris recognition system as imposters after the surgery, because the iris pattern was altered or damaged somewhat during surgery and cannot match the iris template stored before the surgery. In this paper, we originally discuss whether refractive surgery for vision correction (LASIK surgery) would influence the performance of iris recognition. And experiments are designed and tested on iris images captured especially for this research from patients before and after refractive surgery. Experiments showed that refractive surgery has little influence on iris recognition.

  14. An image segmentation based method for iris feature extraction

    Institute of Scientific and Technical Information of China (English)

    XU Guang-zhu; ZHANG Zai-feng; MA Yi-de

    2008-01-01

    In this article, the local anomalistic blocks such ascrypts, furrows, and so on in the iris are initially used directly asiris features. A novel image segmentation method based onintersecting cortical model (ICM) neural network was introducedto segment these anomalistic blocks. First, the normalized irisimage was put into ICM neural network after enhancement.Second, the iris features were segmented out perfectly and wereoutput in binary image type by the ICM neural network. Finally,the fourth output pulse image produced by ICM neural networkwas chosen as the iris code for the convenience of real timeprocessing. To estimate the performance of the presentedmethod, an iris recognition platform was produced and theHamming Distance between two iris codes was computed tomeasure the dissimilarity between them. The experimentalresults in CASIA vl.0 and Bath iris image databases show thatthe proposed iris feature extraction algorithm has promisingpotential in iris recognition.

  15. Comparison of features response in texture-based iris segmentation

    CSIR Research Space (South Africa)

    Bachoo, A

    2009-03-01

    Full Text Available the Fisher linear discriminant and the iris region of interest is extracted. Four texture description methods are compared for segmenting iris texture using a region based pattern classification approach: Grey Level Co-occurrence Matrix (GLCM), Discrete...

  16. Bilateral acute iris transillumination: Case report

    Directory of Open Access Journals (Sweden)

    Cumali Degirmenci

    2016-04-01

    Full Text Available Bilateral acute iris transillumination (BAIT is a recently defined disease characterized with bilateral acute, severe pigment dispersion of iris and pupil sphincter paralysis. The etiopathogenesis of the disease is unknown, but antibiotics such as moxifloxacin, clarithromycin, viral infections, and fumigation therapies were considered as probable etiologic factors. A 33-year-old female was referred to our clinic for acute iridocyclitis refractory to azathioprine, colchicum and corticosteroid treatments. Ophthalmic examination revealed bilateral pigment dispersion, significant iris transillumination, heavy pigment deposition in iridocorneal angle, and elevated intraocular pressure. Upon systemic evaluation she was found to have bacterial urinary tract infection. BAIT is an important cause of pigment dispersion and clinicians must be vigilant for this condition to avoid unnecessary diagnostic tests and treatment.

  17. [Iris heterochromia in acquired Horner's syndrome].

    Science.gov (United States)

    Beynat, J; Soichot, P; Bidot, S; Dugas, B; Creuzot-Garcher, C; Bron, A

    2007-09-01

    Horner's syndrome (HS) is related to an interruption of the oculosympathetic nerve pathway. The classic clinical findings associated with this condition are ptosis, miosis, and enophthalmos. Heterochromia is typically described in congenital HS, but it is an uncommon finding in acquired HS. We report a case of post-traumatic HS associated with heterochromia. A literature review indicates that this type of heterochromia may be related to a reduction in the number of iris melanocytes. This mechanism may be the same in the physiological iris color modifications in adulthood.

  18. Analysis of different containment models for IRIS small break LOCA, using GOTHIC and RELAP5 codes

    Energy Technology Data Exchange (ETDEWEB)

    Papini, Davide, E-mail: davide.papini@mail.polimi.i [Department of Energy, CeSNEF - Nuclear Engineering Division, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Grgic, Davor [Department of Power Systems, FER, University of Zagreb, Unska 3, 10000 Zagreb (Croatia); Cammi, Antonio; Ricotti, Marco E. [Department of Energy, CeSNEF - Nuclear Engineering Division, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy)

    2011-04-15

    Advanced nuclear water reactors rely on containment behaviour in realization of some of their passive safety functions. Steam condensation on containment walls, where non-condensable gas effects are significant, is an important feature of the new passive containment concepts, like the AP600/1000 ones. In this work the international reactor innovative and secure (IRIS) was taken as reference, and the relevant condensation phenomena involved within its containment were investigated with different computational tools. In particular, IRIS containment response to a small break LOCA (SBLOCA) was calculated with GOTHIC and RELAP5 codes. A simplified model of IRIS containment drywell was implemented with RELAP5 according to a sliced approach, based on the two-pipe-with-junction concept, while it was addressed with GOTHIC using several modelling options, regarding both heat transfer correlations and volume and thermal structure nodalization. The influence on containment behaviour prediction was investigated in terms of drywell temperature and pressure response, heat transfer coefficient (HTC) and steam volume fraction distribution, and internal recirculating mass flow rate. The objective of the paper is to preliminarily compare the capability of the two codes in modelling of the same postulated accident, thus to check the results obtained with RELAP5, when applied in a situation not covered by its validation matrix (comprising SBLOCA and to some extent LBLOCA transients, but not explicitly the modelling of large dry containment volumes). The option to include or not droplets in fluid mass flow discharged to the containment was the most influencing parameter for GOTHIC simulations. Despite some drawbacks, due, e.g. to a marked overestimation of internal natural recirculation, RELAP5 confirmed its capability to satisfactorily model the basic processes in IRIS containment following SBLOCA.

  19. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR BERYLLIUM AND COMPOUNDS

    Science.gov (United States)

    EPA's assessment of the noncancer health effects and carcinogenic potential of Beryllium was added to the IRIS database in 1998. The IRIS program is updating the IRIS assessment for Beryllium. This update will incorporate health effects information published since the last assess...

  20. H Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The H Reactor was the first reactor to be built at Hanford after World War II.It became operational in October of 1949, and represented the fourth nuclear reactor on...

  1. IRIS Toxicological Review and Summary Documents for ...

    Science.gov (United States)

    Carbon tetrachloride is a volatile haloalkane with a wide range of industrial and chemical applications. It is produced commercially from chlorination of a variety of low molecular weight hydrocarbons such as carbon disulfide, methanol, methane, propane, and ethylene dichloride. It is also produced by thermal chlorination in the production of tetrachloroethylene. Major uses of carbon tetrachloride have been in the recovery of tin from tin plating waste, in formulation of petrol additives and refrigerants, in metal degreasing and agricultural fumigants, in chlorination of organic compounds, in the production of semiconductors, in the reduction of fire hazard, as a solvent for rubber cement, and as a catalyst in polymer technology. Its production has been decreasing and it is no longer permitted in products intended for home use. Despite this ban, carbon tetrachloride has been detected at 314 hazardous waste sites. EPA's assessment of noncancer health effects and carcinogenic potential of carbon tetrachloride was last prepared and added to the IRIS database in 1991. The IRIS program is preparing an assessment that will incorporate health effects information available for carbon tetrachloride, and current risk assessment methods. The IRIS assessment for carbon tetrachloride will consist of a Toxicological Review and IRIS Summary. The Toxicological Review is a critical review of the physiochemical and toxicokinetic properties of a chemical, and its toxicity

  2. Iris recognition using the JAVAVis Library

    Directory of Open Access Journals (Sweden)

    L.Martin García

    2008-12-01

    Full Text Available This project has been created to develop a biometric identification system through a man’s iris using a computer to perform the processing of the pictures. To develop this application, and to differentiate the project from others who have already implemented, we have used the image processing library JAVAVis and JAVA as a programming language.

  3. [Intraoperative floppy iris syndrome--a prospective study].

    Science.gov (United States)

    Nicula, Cristina; Nicula, D; Popescu, Raluca

    2013-01-01

    is to evaluate the incidence and typical signs of floppy iris syndrome intraoperatory revealed in patients diagnosed with cataracts. We studied a total of 15 eyes diagnosed with cataracts, belonging to 14 patients who had been treated chronically with Tamsulosin for benign prostatic hyperplasia. In 80% of cases we have seen a preoperative semimidriasis which required iris hooks in 5 eyeballs. On 1 eye preoperative semimidriasis was sufficient for capsulorhexis, but later pupil became miotic, requiring iris hooks. On 4 eye flaccid iris was noticed, that prolabated in corneal incision. floppy iris syndrome occurs in patients treated with Tamsulosin for benign prostatic hyperplasia, generating a series of difficulties during cataract surgery.

  4. Hinode and IRIS Observations of a Prominence-Cavity System

    Science.gov (United States)

    Jibben, Patricia R.; Reeves, Kathy; Su, Yingna

    2016-05-01

    Long-lived solar prominences often have a coronal cavity enclosing the prominence. Within the cavity, hot X-ray emission can persist above the prominence and in the central regions of the cavity. We present the results of an Interface Region Imaging Spectrograph (IRIS) and Hinode coordinated Observation Program (IHOP 264) study of a prominence-cavity system. The X-ray Telescope (XRT) observes an inflow of bright X-ray emission that strikes and envelops the prominence-cavity system causing an eruption of chromospheric plasma near the base of the prominence. During and after the eruption, an increase in X-ray emission forms within the cavity and above the prominence. IRIS and the EUV Imaging Spectrometer (EIS) observe strong blue shifts in both chromosphere and coronal lines during the eruption. The Solar Optical Telescope (SOT) Ca II H-line data show bright emission along the eruption path with complex turbulent plasma motions. The IRIS Si IV 1394 Angstrom spectra along the on-disk portion of the prominence show a region of decreased emission near the base of the prominence, suggesting a magnetic field bald-patch topology along the Polarity Inversion Line (PIL). Combined, these observations imply a cylindrical flux rope best represents the prominence-cavity system. A model of the magnetic structure of the prominence-cavity system comprised of a weakly twisted flux rope can explain the observed loops in the X-ray and EUV data. Observations from the Coronal Multichannel Polarimeter (CoMP) are compared to predicted models and are inconclusive. We find that more sensitive measurements of the magnetic field strength along the line-of-sight are needed to verify this configuration.Patricia Jibben and Kathy Reeves are supported by under contract 80111112705 from Lockheed-Martin to SAO, contract NNM07AB07C from NASA to SAO, grant number NNX12AI30G from NASA to SAO, and contract Z15-12504 from HAO to SAO under a grant from AFOSR. Yingna Su is supported by the Youth Fund of

  5. Checking the new IRI model The bottomside B parameters

    CERN Document Server

    Mosert, M; Ezquer, R; Lazo, B; Miro, G

    2002-01-01

    Electron density profiles obtained at Pruhonice (50.0, 15.0), El Arenosillo (37.1, 353.2) and Havana (23, 278) were used to check the bottom-side B parameters BO (thickness parameter) and B1 (shape parameter) predicted by the new IRI - 2000 version. The electron density profiles were derived from ionograms using the ARP technique. The data base includes daytime and nighttime ionograms recorded under different seasonal and solar activity conditions. Comparisons with IRI predictions were also done. The analysis shows that: a) The parameter B1 given by IRI 2000 reproduces better the observed ARP values than the IRI-90 version and b) The observed BO values are in general well reproduced by both IRI versions: IRI-90 and IRI-2000.

  6. A novel iris segmentation algorithm based on small eigenvalue analysis

    Science.gov (United States)

    Harish, B. S.; Aruna Kumar, S. V.; Guru, D. S.; Ngo, Minh Ngoc

    2015-12-01

    In this paper, a simple and robust algorithm is proposed for iris segmentation. The proposed method consists of two steps. In first step, iris and pupil is segmented using Robust Spatial Kernel FCM (RSKFCM) algorithm. RSKFCM is based on traditional Fuzzy-c-Means (FCM) algorithm, which incorporates spatial information and uses kernel metric as distance measure. In second step, small eigenvalue transformation is applied to localize iris boundary. The transformation is based on statistical and geometrical properties of the small eigenvalue of the covariance matrix of a set of edge pixels. Extensive experimentations are carried out on standard benchmark iris dataset (viz. CASIA-IrisV4 and UBIRIS.v2). We compared our proposed method with existing iris segmentation methods. Our proposed method has the least time complexity of O(n(i+p)) . The result of the experiments emphasizes that the proposed algorithm outperforms the existing iris segmentation methods.

  7. IRDO: Iris Recognition by fusion of DTCWT and OLBP

    Directory of Open Access Journals (Sweden)

    Arunalatha J S

    2015-03-01

    Full Text Available Iris Biometric is a physiological trait of human beings. In this paper, we propose Iris an Recognition using Fusion of Dual Tree Complex Wavelet Transform (DTCWT and Over Lapping Local Binary Pattern (OLBP Features. An eye is preprocessed to extract the iris part and obtain the Region of Interest (ROI area from an iris. The complex wavelet features are extracted for region from the Iris DTCWT. OLBP is further applied on ROI to generate features of magnitude coefficients. The resultant features are generated by fusing DTCWT and OLBP using arithmetic addition. The Euclidean Distance (ED is used to compare test iris with database iris features to identify a person. It is observed that the values of Total Success Rate (TSR and Equal Error Rate (EER are better in the case of proposed IRDO compared to the state-of-the art techniques.

  8. Identity Recognizing using Iris Scan with multiple frames of Video

    Directory of Open Access Journals (Sweden)

    Asha Latha Bandi

    2012-03-01

    Full Text Available The field of iris biometrics has been significant research over the last decade. At this point, iris capture has become a main stream technology with wide acceptance. A general iris recognition systemworks with four different steps. 1. Capturing the image from the eye. 2. Extracting iris from the processed image. 3. Transforming the raw image coordinates into normalized polar coordinates. 4. Finally the iris code is compared with known iris code for identification of a person. Iris performance can be improved by creating a single average image. We prepared two different sets of images called gallery set of images and probe set of images and then compared all gallery set images to all probe set images. This comparison gives better recognition performance.

  9. [Analysis of iris: history and future].

    Science.gov (United States)

    Norn, Mogens

    2003-01-01

    Analysis of the iris has ancient roots, but iridology in its present sense was established by Philippi Meyers in 1670. The discipline was further developed by Ignaz Péczely in 1881 and by Nils Liljequist in 1890. Other studies have been published in Germany, Sweden, Norway, England, France, USA, Australia and elsewhere, and iridology is practiced worldwide. The techniques used are described and the sources of error are mentioned when several photos from the same patient are compared (e.g. the influences of differences in pupil size, magnification and the effect of oblique light). The iris key (irigraphy) and the interpretation of different sights are discussed in some detail; there is little agreement among iridologists. Some iris diagnoses are of little interest to day and some modern diseases are missing in the diagnostic system. Controlled studies reveal that iridology is of no use whatsoever for the detection of cancer and other diseases in the stomach, intestines, kidney, lungs and heart. The reason for the continued popularity of iridology is discussed, and it is concluded that this type of alternative medicine is not harmless.

  10. Computerized ionospheric tomography with the IRI model

    Science.gov (United States)

    Arikan, Orhan; Arikan, Feza; Erol, Cemil B.

    Computerized ionospheric tomography (CIT) is a method to estimate ionospheric electron density distribution by using the global positioning system (GPS) signals recorded by the GPS receivers. Ionospheric electron density is a function of latitude, longitude, height and time. A general approach in CIT is to represent the ionosphere as a linear combination of basis functions. In this study, the model of the ionosphere is obtained from the IRI in latitude and height only. The goal is to determine the best representing basis function from the set of Squeezed Legendre polynomials, truncated Legendre polynomials, Haar Wavelets and singular value decomposition (SVD). The reconstruction algorithms used in this study can be listed as total least squares (TLS), regularized least squares, algebraic reconstruction technique (ART) and a hybrid algorithm where the reconstruction from the TLS algorithm is used as the initial estimate for the ART. The error performance of the reconstruction algorithms are compared with respect to the electron density generated by the IRI-2001 model. In the investigated scenario, the measurements are obtained from the IRI-2001 as the line integral of the electron density profiles, imitating the total electron content estimated from GPS measurements. It has been observed that the minimum error between the reconstructed and model ionospheres depends on both the reconstruction algorithm and the basis functions where the best results have been obtained for the basis functions from the model itself through SVD.

  11. Infrasound product resources at the IRIS DMC

    Science.gov (United States)

    Bahavar, M.; Trabant, C.; Hutko, A. R.; Karstens, R.

    2012-12-01

    In 2011 infrasound sensors were installed at some existing USArray Transportable Array (TA) sites and became a standard component of all new sites. Currently there are over 400 sites with infrasound sensors with an average spacing of 70 kilometers. To promote and facilitate the use of these data the IRIS Data Management Center has developed two new data products: an infrasound reference event database and an infrasound signal detector. The TA Infrasound Reference Event Database (TAIRED) is a user-supported database that contains information on events of interest for which there are associated USArray microbarograph recordings. This database is initially populated with a few events from observations on the USArray infrasound data, event bulletins, news on explosions, meteorological events and rocket launches. As a user-supported resource, we ask users to submit events of interest to be included in the database or submit their alternate solutions to the existing events. The second data product is an infrasound signal detector that regularly scans the USArray broadband infrasound data (BDF channel sampled at 40 Hz) and produces detections that highlight time intervals containing potential signals of interest. The detection product includes two components, standard signal-to-noise ratio based detections and spectral power based detections. No attempt is made to categorize detections or associate them to events. These data products join the growing collection of products produced and managed at the IRIS DMC, for the complete list please visit http://www.iris.edu/dms/products/.

  12. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  13. Iris image recognition wavelet filter-banks based iris feature extraction schemes

    CERN Document Server

    Rahulkar, Amol D

    2014-01-01

    This book provides the new results in wavelet filter banks based feature extraction, and the classifier in the field of iris image recognition. It provides the broad treatment on the design of separable, non-separable wavelets filter banks, and the classifier. The design techniques presented in the book are applied on iris image analysis for person authentication. This book also brings together the three strands of research (wavelets, iris image analysis, and classifier). It compares the performance of the presented techniques with state-of-the-art available schemes. This book contains the compilation of basic material on the design of wavelets that avoids reading many different books. Therefore, it provide an easier path for the new-comers, researchers to master the contents. In addition, the designed filter banks and classifier can also be effectively used than existing filter-banks in many signal processing applications like pattern classification, data-compression, watermarking, denoising etc.  that will...

  14. Efficient iris recognition via ICA feature and SVM classifier

    Institute of Scientific and Technical Information of China (English)

    Wang Yong; Xu Luping

    2007-01-01

    To improve flexibility and reliability of iris recognition algorithm while keeping iris recognition success rate, an iris recognition approach for combining SVM with ICA feature extraction model is presented. SVM is a kind of classifier which has demonstrated high generalization capabilities in the object recognition problem. And ICA is a feature extraction technique which can be considered a generalization of principal component analysis. In this paper, ICA is used to generate a set of subsequences of feature vectors for iris feature extraction. Then each subsequence is classified using support vector machine sequence kernels. Experiments are made on CASIA iris database, the result indicates combination of SVM and ICA can improve iris recognition flexibility and reliability while keeping recognition success rate.

  15. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    1962-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  16. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  17. New Ultrasound Biomicroscopy Iris Findings in Juvenile Xanthogranuloma.

    Science.gov (United States)

    Syed, Zeba A; Chen, Teresa C

    2016-08-01

    We report a case of juvenile xanthogranuloma in a 12-month-old girl presenting with heterochromia, hyphema, and elevated intraocular pressure. This case demonstrates new ultrasound biomicroscopy iris findings of a generalized bumpy iris contour, suggesting diffuse heterogeneous involvement. This imaging finding has not been previously described. Untreated, iris juvenile xanthogranuloma may lead to corneal blood staining, glaucoma, and amblyopia. An understanding of the full range of ultrasound features of juvenile xanthogranuloma expands our appreciation for the clinical findings in this condition.

  18. FUV Continuum in Flare Kernels Observed by IRIS

    Science.gov (United States)

    Daw, Adrian N.; Kowalski, Adam; Allred, Joel C.; Cauzzi, Gianna

    2016-05-01

    Fits to Interface Region Imaging Spectrograph (IRIS) spectra observed from bright kernels during the impulsive phase of solar flares are providing long-sought constraints on the UV/white-light continuum emission. Results of fits of continua plus numerous atomic and molecular emission lines to IRIS far ultraviolet (FUV) spectra of bright kernels are presented. Constraints on beam energy and cross sectional area are provided by cotemporaneous RHESSI, FERMI, ROSA/DST, IRIS slit-jaw and SDO/AIA observations, allowing for comparison of the observed IRIS continuum to calculations of non-thermal electron beam heating using the RADYN radiative-hydrodynamic loop model.

  19. Iris recognition as a biometric method after cataract surgery

    Directory of Open Access Journals (Sweden)

    Roizenblatt Jaime

    2004-01-01

    Full Text Available Abstract Background Biometric methods are security technologies, which use human characteristics for personal identification. Iris recognition systems use iris textures as unique identifiers. This paper presents an analysis of the verification of iris identities after intra-ocular procedures, when individuals were enrolled before the surgery. Methods Fifty-five eyes from fifty-five patients had their irises enrolled before a cataract surgery was performed. They had their irises verified three times before and three times after the procedure, and the Hamming (mathematical distance of each identification trial was determined, in a controlled ideal biometric environment. The mathematical difference between the iris code before and after the surgery was also compared to a subjective evaluation of the iris anatomy alteration by an experienced surgeon. Results A correlation between visible subjective iris texture alteration and mathematical difference was verified. We found only six cases in which the eye was no more recognizable, but these eyes were later reenrolled. The main anatomical changes that were found in the new impostor eyes are described. Conclusions Cataract surgeries change iris textures in such a way that iris recognition systems, which perform mathematical comparisons of textural biometric features, are able to detect these changes and sometimes even discard a pre-enrolled iris considering it an impostor. In our study, re-enrollment proved to be a feasible procedure.

  20. Iris Localization Algorithm Based on Improved Generalized Symmetry Transform

    Institute of Scientific and Technical Information of China (English)

    左坤隆; 刘文耀; 朱昊; 王晓东

    2004-01-01

    Accuracy and fastness of iris localization are very important in automatic iris recognition. A new fast iris localization algorithm based on improved generalized symmetry transform (GST) was proposed by utilizing iris symmetry. GST was improved in three aspects:1) A new distance weight function is defined. The new weight function, which is effective in iris localization, utilized the characteristic of irises that the iris is a circular object and it has one inner boundary and one outer boundary. 2) Each calculation of the symmetry measurement of a pair of symmetry points was performed by taking one point of a pair as the starting point of the transformation. This is the most important reason for fast iris localization,due to which, repetitious computation was largely excluded. 3) A new phase weight function was proposed to adjust GST to locate circle target much better because the inner part of iris is darker than the outer part. The edge map of iris image was acquired and GST was only implemented on the edge point, which decreased computation without loss of accuracy. The modification of distance weight function and phase weight function leads to the accuracy of localization, and other ideas speed up the localization. Experiments show that the average speed of new algorithm is about 7.0-8.5 times as high as traditional ones including integro-differential operator and Hough transform method.

  1. Gabor Weber Local Descriptor for Bovine Iris Recognition

    Directory of Open Access Journals (Sweden)

    Shengnan Sun

    2013-01-01

    Full Text Available Iris recognition is a robust biometric technology. This paper proposes a novel local descriptor for bovine iris recognition, named Gabor Weber local descriptor (GWLD. We first compute the Gabor magnitude maps for the input bovine iris image, and then calculate the differential excitation and orientation for each pixel over each Gabor magnitude map. After that, we use these differential excitations and orientations to construct the GWLD histogram representation. Finally, histogram intersection is adopted to measure the similarity between different GWLD histograms. The experimental results on the SEU bovine iris database verify the representation power of our proposed local descriptor.

  2. Iris Recognition System Using Fractal Dimensions of Haar Patterns

    Directory of Open Access Journals (Sweden)

    Patnala S. R. Chandra Murty

    2009-09-01

    Full Text Available Classification of iris templates based on their texture patterns is one of the most effective methods in iris recognition systems. This paper proposes a novel algorithm for automatic iris classification based on fractal dimensions of Haar wavelet transforms is presented. Fractal dimensions obtained from multiple scale features are used to characterize the textures completely. Haar wavelet is applied in order to extract the multiple scale features at different resolutions from the iris image. Fractal dimensions are estimated from these patterns and a classifier is used to recognize the given image from a data base. Performance comparison was made among different classifiers.

  3. Limbus Impact on Off-angle Iris Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

    2013-01-01

    The accuracy of iris recognition depends on the quality of data capture and is negatively affected by several factors such as angle, occlusion, and dilation. Off-angle iris recognition is a new research focus in biometrics that tries to address several issues including corneal refraction, complex 3D iris texture, and blur. In this paper, we present an additional significant challenge that degrades the performance of the off-angle iris recognition systems, called the limbus effect . The limbus is the region at the border of the cornea where the cornea joins the sclera. The limbus is a semitransparent tissue that occludes a side portion of the iris plane. The amount of occluded iris texture on the side nearest the camera increases as the image acquisition angle increases. Without considering the role of the limbus effect, it is difficult to design an accurate off-angle iris recognition system. To the best of our knowledge, this is the first work that investigates the limbus effect in detail from a biometrics perspective. Based on results from real images and simulated experiments with real iris texture, the limbus effect increases the hamming distance score between frontal and off-angle iris images ranging from 0.05 to 0.2 depending upon the limbus height.

  4. Person Identification System Using Fusion of Matching Score of Iris

    Directory of Open Access Journals (Sweden)

    Yogeshwari Borse

    2012-05-01

    Full Text Available Human iris provides a unique structure suitable for non-invasive biometric assessment. In particular the irises are as distinct as fingerprints even for twins. In this paper a system for person identification is presented that uses a technique of localization, alignment, feature extraction, matching the features of irises and finally the decision regarding the degree of match based on hamming distance. A CASIA iris database of iris images has been used in the implementation of the iris recognition system. The results show that proposed method is quite effective

  5. Phase-only Correlation in Human Iris Database

    Directory of Open Access Journals (Sweden)

    Alin C. Teuşdea

    2009-05-01

    Full Text Available This paper presents human eye-iris registration and matching in an iris database using phase-only correlation techniques. Two modified phase-only correlation techniques with efficient registration results are used: the rectangle band limited phase-only correlation method (BPOC and an elliptic limited phase-only correlation method (EPOC the last one being proposed by the authors. The results of the computer simulations obtained for these two methods are analyzed on the same iris database and the analysis denotes that the proposed method EPOC has better performances than BPOC method for iris matching in the used database.

  6. A Case of Iris Mammillation Associated with Nevus of Ota

    Directory of Open Access Journals (Sweden)

    Onur Polat

    2013-10-01

    Full Text Available Nevus of Ota is characterized by the presence of hyperpigmentation in the skin areas innervated by the first or the second branches of the trigeminal nerve. Women are affected three times as often as men. Although nevus of Ota is a congenital disorder, it can be seen in puberty or adulthood. Herein a case of nevus of Ota was reported accompanying iris heterochromia and rare iris mammillation. Because of the relationship between iris heterochromia and iris mammillation with glaucoma and especially uveal melanoma, all the patients with nevus of Ota should be monitored closely with regular ophthalmologic examination.

  7. Iris Transponder-Communications and Navigation for Deep Space

    Science.gov (United States)

    Duncan, Courtney B.; Smith, Amy E.; Aguirre, Fernando H.

    2014-01-01

    The Jet Propulsion Laboratory has developed the Iris CubeSat compatible deep space transponder for INSPIRE, the first CubeSat to deep space. Iris is 0.4 U, 0.4 kg, consumes 12.8 W, and interoperates with NASA's Deep Space Network (DSN) on X-Band frequencies (7.2 GHz uplink, 8.4 GHz downlink) for command, telemetry, and navigation. This talk discusses the Iris for INSPIRE, it's features and requirements; future developments and improvements underway; deep space and proximity operations applications for Iris; high rate earth orbit variants; and ground requirements, such as are implemented in the DSN, for deep space operations.

  8. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) ...

    Science.gov (United States)

    The IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) was released for external peer review in April 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the ETBE assessment and release a final report of their review. Information regarding the peer review can be found on the SAB website. EPA is conducting an Integrated Risk Information System (IRIS) health assessment for Ethyl Tertiary Butyl Ether (ETBE). The outcome of this project is a Toxicological Review and IRIS Summary for ETBE that will be entered into the IRIS database.

  9. Advanced Computational Thermal Fluid Physics (CTFP) and Its Assessment for Light Water Reactors and Supercritical Reactors

    Energy Technology Data Exchange (ETDEWEB)

    D.M. McEligot; K. G. Condie; G. E. McCreery; H. M. McIlroy; R. J. Pink; L.E. Hochreiter; J.D. Jackson; R.H. Pletcher; B.L. Smith; P. Vukoslavcevic; J.M. Wallace; J.Y. Yoo; J.S. Lee; S.T. Ro; S.O. Park

    2005-10-01

    Background: The ultimate goal of the study is the improvement of predictive methods for safety analyses and design of Generation IV reactor systems such as supercritical water reactors (SCWR) for higher efficiency, improved performance and operation, design simplification, enhanced safety and reduced waste and cost. The objective of this Korean / US / laboratory / university collaboration of coupled fundamental computational and experimental studies is to develop the supporting knowledge needed for improved predictive techniques for use in the technology development of Generation IV reactor concepts and their passive safety systems. The present study emphasizes SCWR concepts in the Generation IV program.

  10. Assessment of IRI and IRI-Plas models over the African equatorial and low-latitude region

    Science.gov (United States)

    Adebiyi, S. J.; Adimula, I. A.; Oladipo, O. A.; Joshua, B. W.

    2016-07-01

    A reliable ionospheric specification by empirical models is important to mitigate the effects of the ionosphere on the operations of satellite-based positioning and navigation systems. This study evaluates the capability of the International Reference Ionosphere (IRI) and IRI extended to the plasmasphere (IRI-Plas) models in predicting the total electron content (TEC) over stations located in the southern hemisphere of the African equatorial and low-latitude region. TEC derived from Global Positioning System (GPS) measurements were compared with TEC predicted by both the IRI-Plas 2015 model and the three topside options of the IRI 2012 model (i.e., NeQuick (NeQ), IRI 2001 corrected factor (IRI-01 Corr), and the IRI 2001(IRI-01)). Generally, the diurnal and the seasonal structures of modeled TEC follow quite well with the observed TEC in all the stations, although with some upward and downward offsets observed during the daytime and nighttime. The prediction errors of both models exhibit latitudinal variation and these showed seasonal trends. The values generally decrease with increase in latitude. The TEC data-model divergence of both models is most significant at stations in the equatorial region during the daytime and nighttime. Conversely, both models demonstrate most pronounced convergence during the nighttime at stations outside the equatorial region. The IRI-Plas model, in general, performed better in months and seasons when the three options of the IRI model underestimate TEC. Factors such as the height limitation of the IRI model, the inaccurate predictions of the bottomside and topside electron density profiles were used to explain the data-model discrepancies.

  11. Intraoperative floppy iris syndrome (IFIS): a practical approach to medical and surgical considerations in cataract extractions

    DEFF Research Database (Denmark)

    Storr-Paulsen, Allan; Nørregaard, Jens Christian; Børme, Kim Kamp;

    2009-01-01

    Abstract. Intraoperative floppy iris syndrome (IFIS) during cataract surgery is characterized by iris fluttering, iris prolapse towards the incisions, and a progressive pupillary constriction leading to high rates of complications. The syndrome has been reported following the treatment of benign...

  12. Reactor Neutrinos

    OpenAIRE

    Soo-Bong Kim; Thierry Lasserre; Yifang Wang

    2013-01-01

    We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very ...

  13. BOILING REACTORS

    Science.gov (United States)

    Untermyer, S.

    1962-04-10

    A boiling reactor having a reactivity which is reduced by an increase in the volume of vaporized coolant therein is described. In this system unvaporized liquid coolant is extracted from the reactor, heat is extracted therefrom, and it is returned to the reactor as sub-cooled liquid coolant. This reduces a portion of the coolant which includes vaporized coolant within the core assembly thereby enhancing the power output of the assembly and rendering the reactor substantially self-regulating. (AEC)

  14. Metallic fuels for advanced reactors

    Science.gov (United States)

    Carmack, W. J.; Porter, D. L.; Chang, Y. I.; Hayes, S. L.; Meyer, M. K.; Burkes, D. E.; Lee, C. B.; Mizuno, T.; Delage, F.; Somers, J.

    2009-07-01

    In the framework of the Generation IV Sodium Fast Reactor Program, the Advanced Fuel Project has conducted an evaluation of the available fuel systems supporting future sodium cooled fast reactors. This paper presents an evaluation of metallic alloy fuels. Early US fast reactor developers originally favored metal alloy fuel due to its high fissile density and compatibility with sodium. The goal of fast reactor fuel development programs is to develop and qualify a nuclear fuel system that performs all of the functions of a conventional fast spectrum nuclear fuel while destroying recycled actinides. This will provide a mechanism for closure of the nuclear fuel cycle. Metal fuels are candidates for this application, based on documented performance of metallic fast reactor fuels and the early results of tests currently being conducted in US and international transmutation fuel development programs.

  15. Effect of tamsulosin on iris vasculature and morphology.

    Science.gov (United States)

    Shtein, Roni M; Hussain, Munira T; Cooney, Theresa M; Elner, Victor M; Hood, Christopher T

    2014-05-01

    To determine whether preoperative iris vasculature and morphology are altered in patients who have taken tamsulosin (Flomax). Academic multispecialty practice. Case series. Patients with current or past tamsulosin use and age- and sex-matched control patients were included. Anterior segment optical coherence tomography (AS-OCT) and iris fluorescein angiography were performed to measure iris vasculature and thickness before cataract surgery. Data collected at surgery included pupil diameter, clinical signs of intraoperative floppy-iris syndrome, and surgical complications. Tamsulosin was currently used by 16 patients and in the past by 4 patients; the control group comprised 10 patients. Pharmacologically dilated pupil diameter was statistically significantly smaller preoperatively and immediately postoperatively in the tamsulosin group than in the control group (P=.009 and P=.003, respectively). There was a statistically significant decrease in pupil size intraoperatively in the tamsulosin group (P=.05) but not in the control group (P=.3). Iris-vasculature parameters, specifically time to first vessel fill and percentage of vessel fill on iris fluorescein angiography, were not significantly different between the 2 groups. The AS-OCT measurements of iris morphology were not statistically significantly different between the groups. No surgical complications occurred. No fluorescein dye leakage, staining, or other vascular anomalies were observed. Although there were differences in pupil measurements and intraoperative iris behavior between patients who had been on tamsulosin and control patients, there were no significant differences in iris vasculature on iris fluorescein angiography or in iris morphology on AS-OCT. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  16. The cellular and molecular biology of the iris, an overlooked tissue: the iris and pseudoexfoliation glaucoma.

    Science.gov (United States)

    Borrás, Terete

    2014-01-01

    Located between the cornea and the lens, the Iris is fully immersed in aqueous humor. During exfoliation syndrome, a disorder of the elastic fibers, an abnormal fibrillar material (XFM) is deposited on the anterior lens capsule underneath the pigment epithelium of the Iris. Release of this material to the aqueous humor reaches the trabecular meshwork where its presence is associated with elevated intraocular pressure. Ultrastructural studies suggest that the XFM material is produced by the lens capsule, lens epithelial and iris pigment epithelial cells (IPE). The involvement of the IPE in pseudoexfoliation glaucoma has not been extensively addressed. Immunohistochemistry studies have shown higher levels of LOXL1 and clusterin in the IPE extracellular space of specimens from exfoliation patients. But studies using IPE cells to understand the formation of the XFM in vitro and/or in vivo are scarce. A focus on the Iris and its IPE cells would be key for the elucidation of XFM and the understanding of the development of pseudoexfoliation glaucoma.

  17. An unusual case of seed dispersal in an invasive aquatic; yellow flag iris (Iris pseudacorus)

    Science.gov (United States)

    Understanding reproductive mode of invasive plants can help managers plan more efficacious control. Invasive aquatics typically reproduce primarily through vegetative means. Yellow flag iris is an invasive plant species often growing as an emergent aquatic. There have been contradictory reports of i...

  18. Asteroids IV

    Science.gov (United States)

    Michel, Patrick; DeMeo, Francesca E.; Bottke, William F.

    . Asteroids, like planets, are driven by a great variety of both dynamical and physical mechanisms. In fact, images sent back by space missions show a collection of small worlds whose characteristics seem designed to overthrow our preconceived notions. Given their wide range of sizes and surface compositions, it is clear that many formed in very different places and at different times within the solar nebula. These characteristics make them an exciting challenge for researchers who crave complex problems. The return of samples from these bodies may ultimately be needed to provide us with solutions. In the book Asteroids IV, the editors and authors have taken major strides in the long journey toward a much deeper understanding of our fascinating planetary ancestors. This book reviews major advances in 43 chapters that have been written and reviewed by a team of more than 200 international authorities in asteroids. It is aimed to be as comprehensive as possible while also remaining accessible to students and researchers who are interested in learning about these small but nonetheless important worlds. We hope this volume will serve as a leading reference on the topic of asteroids for the decade to come. We are deeply indebted to the many authors and referees for their tremendous efforts in helping us create Asteroids IV. We also thank the members of the Asteroids IV scientific organizing committee for helping us shape the structure and content of the book. The conference associated with the book, "Asteroids Comets Meteors 2014" held June 30-July 4, 2014, in Helsinki, Finland, did an outstanding job of demonstrating how much progress we have made in the field over the last decade. We are extremely grateful to our host Karri Muinonnen and his team. The editors are also grateful to the Asteroids IV production staff, namely Renée Dotson and her colleagues at the Lunar and Planetary Institute, for their efforts, their invaluable assistance, and their enthusiasm; they made life as

  19. Conversion from mutual helicity to self-helicity observed with IRIS

    Science.gov (United States)

    Li, L. P.; Peter, H.; Chen, F.; Zhang, J.

    2014-10-01

    Context. In the upper atmosphere of the Sun observations show convincing evidence for crossing and twisted structures, which are interpreted as mutual helicity and self-helicity. Aims: We use observations with the new Interface Region Imaging Spectrograph (IRIS) to show the conversion of mutual helicity into self-helicity in coronal structures on the Sun. Methods: Using far UV spectra and slit-jaw images from IRIS and coronal images and magnetograms from SDO, we investigated the evolution of two crossing loops in an active region, in particular, the properties of the Si IV line profile in cool loops. Results: In the early stage two cool loops cross each other and accordingly have mutual helicity. The Doppler shifts in the loops indicate that they wind around each other. As a consequence, near the crossing point of the loops (interchange) reconnection sets in, which heats the plasma. This is consistent with the observed increase of the line width and of the appearance of the loops at higher temperatures. After this interaction, the two new loops run in parallel, and in one of them shows a clear spectral tilt of the Si IV line profile. This is indicative of a helical (twisting) motion, which is the same as to say that the loop has self-helicity. Conclusions: The high spatial and spectral resolution of IRIS allowed us to see the conversion of mutual helicity to self-helicity in the (interchange) reconnection of two loops. This is observational evidence for earlier theoretical speculations. Movie associated with Fig. 1 and Appendix A are available in electronic form at http://www.aanda.org

  20. Isolated Bilateral Congenital Iris Sphincter Agenesis

    Directory of Open Access Journals (Sweden)

    Aparna Rao

    2011-01-01

    Full Text Available Purpose. We herein report a patient with bilateral congenital total iris sphincter agenesis with no other abnormality detected on systemic examination. Methods. A 24-year-old laborer presented to us for a routine checkup with complaint of photophobia and inability to work under sunlight. Examination revealed bilateral absence of sphincter and 6.5 mm pupil in both eyes in the undilated state. Results. Accommodation was poor in both eyes. Systemic examination was within normal limits. He was prescribed bifocal photochromic glasses for constant wear. Conclusions. Congenital sphincter agenesis can occur in an isolated form without systemic abnormalities which can be managed conservatively.

  1. IRIS Toxicological Review of Acrylamide (External Review ...

    Science.gov (United States)

    EPA has conducted a peer review by EPA’s Science Advisory Board (SAB) of the scientific basis supporting the human health hazard and dose-response assessment of acrylamide that once finalized will appear on the Integrated Risk Information System (IRIS) database. Peer review is meant to ensure that the science is used credibly and appropriately in derivation of the dose-response assessments and toxicological characterization. The draft Toxicological Review of Acrylamide provides scientific support and rationale for the hazard identification and dose-response assessment pertaining to a chronic exposure to acrylamide.

  2. Frontal view reconstruction for iris recognition

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Villalobos, Hector J; Bolme, David S; Boehnen, Chris Bensing

    2015-02-17

    Iris recognition can be accomplished for a wide variety of eye images by correcting input images with an off-angle gaze. A variety of techniques, from limbus modeling, corneal refraction modeling, optical flows, and genetic algorithms can be used. A variety of techniques, including aspherical eye modeling, corneal refraction modeling, ray tracing, and the like can be employed. Precomputed transforms can enhance performance for use in commercial applications. With application of the technologies, images with significantly unfavorable gaze angles can be successfully recognized.

  3. Frontal view reconstruction for iris recognition

    Science.gov (United States)

    Santos-Villalobos, Hector J; Bolme, David S; Boehnen, Chris Bensing

    2015-02-17

    Iris recognition can be accomplished for a wide variety of eye images by correcting input images with an off-angle gaze. A variety of techniques, from limbus modeling, corneal refraction modeling, optical flows, and genetic algorithms can be used. A variety of techniques, including aspherical eye modeling, corneal refraction modeling, ray tracing, and the like can be employed. Precomputed transforms can enhance performance for use in commercial applications. With application of the technologies, images with significantly unfavorable gaze angles can be successfully recognized.

  4. Improving fuel cycle design and safety characteristics of a gas cooled fast reactor

    NARCIS (Netherlands)

    van Rooijen, W.F.G.

    2006-01-01

    This research concerns the fuel cycle and safety aspects of a Gas Cooled Fast Reactor, one of the so-called "Generation IV" nuclear reactor designs. The Generation IV Gas Cooled Fast Reactor uses helium as coolant at high temperature. The goal of the GCFR is to obtain a "closed nuclear fuel cycle",

  5. Improving fuel cycle design and safety characteristics of a gas cooled fast reactor

    NARCIS (Netherlands)

    van Rooijen, W.F.G.

    2006-01-01

    This research concerns the fuel cycle and safety aspects of a Gas Cooled Fast Reactor, one of the so-called "Generation IV" nuclear reactor designs. The Generation IV Gas Cooled Fast Reactor uses helium as coolant at high temperature. The goal of the GCFR is to obtain a "closed nuclear fuel cycle",

  6. Membrane reactor. Membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, Y.; Wakabayashi, K. (National Chemical Laboratory for Industry, Tsukuba (Japan))

    1990-08-05

    Many reaction examples were introduced of membrane reactor, to be on the point of forming a new region in the field of chemical technology. It is a reactor to exhibit excellent function, by its being installed with membrane therein, and is generally classified into catalyst function type and reaction promotion type. What firstly belongs to the former is stabilized zirconia, where oxygen, supplied to the cathodic side of membrane with voltage, impressed thereon, becomes O {sup 2 {minus}} to be diffused through the membrane and supplied, as variously activated oxygenous species, on the anodic side. Examples with many advantages can be given such as methane coupling, propylene oxidation, methanating reaction of carbon dioxide, etc. Apart, palladium film and naphion film also belong to the former. While examples of the latter comprise, among others, decomposition of hydrogen sulfide by porous glass film and dehydrogenation of cyclohexane or palladium alloy film, which are expected to be developed and materialized in the industry. 33 refs., 8 figs.

  7. Solar Transition-Region Lines Observed by the Interface Region Imaging Spectrograph: Diagnostics for the O IV and Si IV Lines

    CERN Document Server

    Dudík, Jaroslav; Dzifčáková, Elena; Mason, Helen E; Golub, Leon

    2013-01-01

    The formation of the transition-region O IV and Si IV lines observable by the Interface Region Imaging Spectrograph (IRIS) is investigated for both Maxwellian and non-Maxellian conditions characterized by a kappa-distribution exhibiting a high-energy tail. The \\ion{Si}{4} lines are formed at lower temperatures than the O IV lines for all kappa. In non-Maxwellian situations with lower kappa, the contribution functions are shifted to lower temperatures. Combined with the slope of the differential emission measure, it is possible for the Si IV lines to be formed at very different regions of solar transition region than the O IV lines; possibly close to solar chromosphere. Such situations might be discernible by IRIS. It is found that photoexcitation can be important for the Si IV lines, but is negligible for the O IV lines. The usefulness of the O IV ratios for density diagnostics independently of kappa is investigated and it is found that the O IV 1404.78A /1399.77A ratio provides a good density diagnostics exc...

  8. TIME DEPENDENT NONEQUILIBRIUM IONIZATION OF TRANSITION REGION LINES OBSERVED WITH IRIS

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Sykora, Juan; Pontieu, Bart De; Hansteen, Viggo H. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States); Gudiksen, Boris, E-mail: j.m.sykora@astro.uio.no [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway)

    2016-01-20

    The properties of nonstatistical equilibrium ionization of silicon and oxygen ions are analyzed in this work. We focus on five solar targets (quiet Sun; coronal hole; plage; quiescent active region, AR; and flaring AR) as observed with the Interface Region Imaging Spectrograph (IRIS). IRIS is best suited for this work owing to the high cadence (up to 0.5 s), high spatial resolution (up to 0.″32), and high signal-to-noise ratios for O iv λ1401 and Si iv λ1402. We find that the observed intensity ratio between lines of three times ionized silicon and oxygen ions depends on their total intensity and that this correlation varies depending on the region observed (quiet Sun, coronal holes, plage, or active regions) and on the specific observational objects present (spicules, dynamic loops, jets, microflares, or umbra). In order to interpret the observations, we compare them with synthetic profiles taken from 2D self-consistent radiative MHD simulations of the solar atmosphere, where the statistical equilibrium or nonequilibrium treatment of silicon and oxygen is applied. These synthetic observations show vaguely similar correlations to those in the observations, i.e., between the intensity ratios and their intensities, but only in the nonequilibrium case do we find that (some of) the observations can be reproduced. We conclude that these lines are formed out of statistical equilibrium. We use our time-dependent nonequilibrium ionization simulations to describe the physical mechanisms behind these observed properties.

  9. Nuclear Systems Enhanced Performance Program, Maintenance Cycle Extension in Advanced Light Water Reactor Design

    Energy Technology Data Exchange (ETDEWEB)

    Professor Neill Todreas

    2001-10-01

    A renewed interest in new nuclear power generation in the US has spurred interest in developing advanced reactors with features which will address the public's concerns regarding nuclear generation. However, it is economic performance which will dictate whether any new orders for these plants will materialize. Economic performance is, to a great extent, improved by maximizing the time that the plant is on-line generating electricity relative to the time spent off-line conducting maintenance and refueling. Indeed, the strategy for the advanced light water reactor plant IRIS (International Reactor, Innovative and Secure) is to utilize an eight year operating cycle. This report describes a formalized strategy to address, during the design phase, the maintenance-related barriers to an extended operating cycle. The top-level objective of this investigation was to develop a methodology for injecting component and system maintainability issues into the reactor plant design process to overcome these barriers. A primary goal was to demonstrate the applicability and utility of the methodology in the context of the IRIS design. The first step in meeting the top-level objective was to determine the types of operating cycle length barriers that the IRIS design team is likely to face. Evaluation of previously identified regulatory and investment protection surveillance program barriers preventing a candidate operating PWR from achieving an extended (48 month) cycle was conducted in the context of the IRIS design. From this analysis, 54 known IRIS operating cycle length barriers were identified. The resolution methodology was applied to each of these barriers to generate design solution alternatives for consideration in the IRIS design. The methodology developed has been demonstrated to narrow the design space to feasible design solutions which enable a desired operating cycle length, yet is general enough to have broad applicability. Feedback from the IRIS design team

  10. The IRIS network site at the Wilcox Solar Observatory

    Science.gov (United States)

    Hoeksema, J. T.; Scherrer, P. H.

    1991-01-01

    The site for the International Research on the Interior of the Sun (IRIS) instrument housed at the Wilcox Solar Observatory at Stanford University (near San Francisco, USA) is described together with the instrument operation procedure. The IRIS instrument, which measures global oscillations of the sun, operates continuously every clear day since it was installed in August 1987.

  11. IRIS Toxicological Review of Methyl Ethyl Ketone (2003 Final)

    Science.gov (United States)

    EPA announced the release of the final report, Toxicological Review of Methyl Ethyl Ketone: in support of the Integrated Risk Information System (IRIS). The updated Summary for Methyl Ethyl Ketone and accompanying toxicological review have been added to the IRIS Database....

  12. Iris Recognition for Partially Occluded Images: Methodology and Sensitivity Analysis

    Science.gov (United States)

    Poursaberi, A.; Araabi, B. N.

    2006-12-01

    Accurate iris detection is a crucial part of an iris recognition system. One of the main issues in iris segmentation is coping with occlusion that happens due to eyelids and eyelashes. In the literature, some various methods have been suggested to solve the occlusion problem. In this paper, two different segmentations of iris are presented. In the first algorithm, a circle is located around the pupil with an appropriate diameter. The iris area encircled by the circular boundary is used for recognition purposes then. In the second method, again a circle is located around the pupil with a larger diameter. This time, however, only the lower part of the encircled iris area is utilized for individual recognition. Wavelet-based texture features are used in the process. Hamming and harmonic mean distance classifiers are exploited as a mixed classifier in suggested algorithm. It is observed that relying on a smaller but more reliable part of the iris, though reducing the net amount of information, improves the overall performance. Experimental results on CASIA database show that our method has a promising performance with an accuracy of 99.31%. The sensitivity of the proposed method is analyzed versus contrast, illumination, and noise as well, where lower sensitivity to all factors is observed when the lower half of the iris is used for recognition.

  13. Iris-based medical analysis by geometric deformation features.

    Science.gov (United States)

    Ma, Lin; Zhang, D; Li, Naimin; Cai, Yan; Zuo, Wangmeng; Wang, Kuanguan

    2013-01-01

    Iris analysis studies the relationship between human health and changes in the anatomy of the iris. Apart from the fact that iris recognition focuses on modeling the overall structure of the iris, iris diagnosis emphasizes the detecting and analyzing of local variations in the characteristics of irises. This paper focuses on studying the geometrical structure changes in irises that are caused by gastrointestinal diseases, and on measuring the observable deformations in the geometrical structures of irises that are related to roundness, diameter and other geometric forms of the pupil and the collarette. Pupil and collarette based features are defined and extracted. A series of experiments are implemented on our experimental pathological iris database, including manual clustering of both normal and pathological iris images, manual classification by non-specialists, manual classification by individuals with a medical background, classification ability verification for the proposed features, and disease recognition by applying the proposed features. The results prove the effectiveness and clinical diagnostic significance of the proposed features and a reliable recognition performance for automatic disease diagnosis. Our research results offer a novel systematic perspective for iridology studies and promote the progress of both theoretical and practical work in iris diagnosis.

  14. The FDSN Archive at the IRIS Data Management Center

    Directory of Open Access Journals (Sweden)

    T. Ahern

    1994-06-01

    Full Text Available In August of 1990, the IRIS Data Management Center (IRIS DMC was designated as the first FDSN Data Center. Since that time the IRIS DMC has also come to be known as the FDSN Archive. As the FDSN Archive, all member networks, through their own local Network Data Centers, routinely send data to the IRIS DMC. At the present time we have received data from seven member networks. These include: CNSN (Canada; CDSN (China; GEOSCOPE (France; Graefenberg (Germany; IRIS GSN (U.S.A.; MEDNET (Italy; POSEIDON (Japan. In addition to acting as the FDSN Archive, the IRIS DMC is responsible for archiving and distributing data from several sources. The Global Seismographie Network (GSN and the Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL and the Joint Seismic Program (JSP are three IRIS programs that presently send data to the IRIS DMS. The DMC also archives data from some regional networks in the United States and in the Former Soviet Union (FSU. The DMC is one component of a larger Data Management System (DMS consisting of several components including two Data Collection Centers (DCCs, one Data Management Center (DMQ, a DMC Host at the University of Washington, a Wave form Quality Center (WQC, and the Moscow Data Analysis Center (MDC in Russia.

  15. Iris Recognition for Partially Occluded Images: Methodology and Sensitivity Analysis

    Directory of Open Access Journals (Sweden)

    A. Poursaberi

    2007-01-01

    Full Text Available Accurate iris detection is a crucial part of an iris recognition system. One of the main issues in iris segmentation is coping with occlusion that happens due to eyelids and eyelashes. In the literature, some various methods have been suggested to solve the occlusion problem. In this paper, two different segmentations of iris are presented. In the first algorithm, a circle is located around the pupil with an appropriate diameter. The iris area encircled by the circular boundary is used for recognition purposes then. In the second method, again a circle is located around the pupil with a larger diameter. This time, however, only the lower part of the encircled iris area is utilized for individual recognition. Wavelet-based texture features are used in the process. Hamming and harmonic mean distance classifiers are exploited as a mixed classifier in suggested algorithm. It is observed that relying on a smaller but more reliable part of the iris, though reducing the net amount of information, improves the overall performance. Experimental results on CASIA database show that our method has a promising performance with an accuracy of 99.31%. The sensitivity of the proposed method is analyzed versus contrast, illumination, and noise as well, where lower sensitivity to all factors is observed when the lower half of the iris is used for recognition.

  16. Unconstrained Iris Acquisition and Recognition Using COTS PTZ Camera

    Directory of Open Access Journals (Sweden)

    Venugopalan Shreyas

    2010-01-01

    Full Text Available Abstract Uniqueness of iris patterns among individuals has resulted in the ubiquity of iris recognition systems in virtual and physical spaces, at high security facilities around the globe. Traditional methods of acquiring iris patterns in commercial systems scan the iris when an individual is at a predetermined location in front of the scanner. Most state-of-the-art techniques for unconstrained iris acquisition in literature use expensive custom equipment and are composed of a multicamera setup, which is bulky, expensive, and requires calibration. This paper investigates a method of unconstrained iris acquisition and recognition using a single commercial off-the-shelf (COTS pan-tilt-zoom (PTZ camera, that is compact and that reduces the cost of the final system, compared to other proposed hierarchical multicomponent systems. We employ state-of-the-art techniques for face detection and a robust eye detection scheme using active shape models for accurate landmark localization. Additionally, our system alleviates the need for any calibration stage prior to its use. We present results using a database of iris images captured using our system, while operating in an unconstrained acquisition mode at 1.5 m standoff, yielding an iris diameter in the 150–200 pixels range.

  17. Eclipse-Free-Time Assessment Tool for IRIS

    Science.gov (United States)

    Eagle, David

    2012-01-01

    IRIS_EFT is a scientific simulation that can be used to perform an Eclipse-Free- Time (EFT) assessment of IRIS (Infrared Imaging Surveyor) mission orbits. EFT is defined to be those time intervals longer than one day during which the IRIS spacecraft is not in the Earth s shadow. Program IRIS_EFT implements a special perturbation of orbital motion to numerically integrate Cowell's form of the system of differential equations. Shadow conditions are predicted by embedding this integrator within Brent s method for finding the root of a nonlinear equation. The IRIS_EFT software models the effects of the following types of orbit perturbations on the long-term evolution and shadow characteristics of IRIS mission orbits. (1) Non-spherical Earth gravity, (2) Atmospheric drag, (3) Point-mass gravity of the Sun, and (4) Point-mass gravity of the Moon. The objective of this effort was to create an in-house computer program that would perform eclipse-free-time analysis. of candidate IRIS spacecraft mission orbits in an accurate and timely fashion. The software is a suite of Fortran subroutines and data files organized as a "computational" engine that is used to accurately predict the long-term orbit evolution of IRIS mission orbits while searching for Earth shadow conditions.

  18. Opening of Iris flowers is regulated by endogenous auxins

    NARCIS (Netherlands)

    Doorn, van W.G.; Dole, I.; Celikel, F.G.; Harkema, H.

    2013-01-01

    Flower opening in Iris (Iris x hollandica) requires elongation of the pedicel and ovary. This moves the floral bud upwards, thereby allowing the tepals to move laterally. Flower opening is requires with elongation of the pedicel and ovary. In cv. Blue Magic, we investigated the possible role of horm

  19. Delay of Iris flower senescence by cytokinins and jasmonates

    NARCIS (Netherlands)

    Doorn, van W.G.; Celikel, F.G.; Pak, C.; Harkema, H.

    2013-01-01

    It is not known whether tepal senescence in Iris flowers is regulated by hormones. We applied hormones and hormone inhibitors to cut flowers and isolated tepals of Iris x hollandica cv. Blue Magic. Treatments with ethylene or ethylene antagonists indicated lack of ethylene involvement. Auxins or aux

  20. A Novel and Efficient Method for Iris Automatic Location

    Institute of Scientific and Technical Information of China (English)

    XU Guang-zhu; ZHANG Zai-feng; MA Yi-de

    2007-01-01

    An efficient and robust iris location algorithm plays a very important role in a real iris recognition system. A novel and efficient iris automatic location method is presented in this study. It includes following two steps mainly: pupil location and iris outer boundary location. A digital eye image was divided into many small rectangular blocks with fixed size in the pupil location, and the block with the smallest average intensity was selected as a reference area. Then image binarization was implemented taking the average intensity of the reference area as a threshold. At last the center coordinates and radius of pupil were estimated by extending the reference area to the pupil's boundaries in the binary iris image. In the iris outer location, two local parts of the eye image were selected and transformed into polar coordinates from Cartesian reference. In order to detect the fainter outer boundary of the iris quickly, a novel edge detector was used to locate boundaries of the two parts. The center coordinates and radius of the iris outer boundary can be estimated using the fusion of the locating results of the two local parts and the location information of the pupil. The algorithm was tested on CASIA v1.0 and MMU v1.0 digital eye image databases and experimental results show that the proposed method has satisfying performance and good robustness.

  1. Delay of Iris flower senescence by cytokinins and jasmonates

    NARCIS (Netherlands)

    Doorn, van W.G.; Celikel, F.G.; Pak, C.; Harkema, H.

    2013-01-01

    It is not known whether tepal senescence in Iris flowers is regulated by hormones. We applied hormones and hormone inhibitors to cut flowers and isolated tepals of Iris x hollandica cv. Blue Magic. Treatments with ethylene or ethylene antagonists indicated lack of ethylene involvement. Auxins or

  2. Iris Matching Based On a Stack Like Structure Graph Approach

    Directory of Open Access Journals (Sweden)

    Roushdi Mohamed FAROUK

    2012-12-01

    Full Text Available In this paper, we present the elastic bunch graph matching as a new approach for iris recognition. The task is difficult because of iris variation in terms of position, size, and partial occlusion. We have used the circular Hough transform to determine the iris boundaries. Individual segmented irises are represented as labeled graphs. We have combined a representative set of individual model graphs into a stack like structure called an iris bunch graph (IBG. Finally, a bunch graph similarity function is proposed to compare a test graph with the IBG. Recognition results are given for galleries of irises from CASIA version and UBIRIS databases. The numerical results show that, the elastic bunch graph matching is an effective technique for iris matching. We also compare our results with previous results and find that, the elastic bunch graph matching is an effective matching performance.

  3. Investigation on Optimization in Segmentation Phase of Iris Recognition

    Directory of Open Access Journals (Sweden)

    Selvamuthukumaran Shanmugam

    2010-01-01

    Full Text Available In a progressively more digital society, the demandfor secure identification has led to amplified development ofbiometric systems. Iris biometric systems are becoming widelyadopted and accepted as one of the most effective ways topositively identify people. In this paper, the Segmentation phasesof Iris recognition has been examined. The performance of theSegmentation phase could be amplified by the proposedoptimization technique- Optimized Iris Segmentation using SobelEdge Detection. By the proposed method, the overall rank-onerecognition rate of 90% is being achieved which is much betterthan reported accuracies for iris recognition in the literature.Also the proposed approach makes the overall iris recognitionsystem performance by the improvement factor of 10 fold as well.

  4. Tuning Iris Recognition for Noisy Images

    Science.gov (United States)

    Ferreira, Artur; Lourenço, André; Pinto, Bárbara; Tendeiro, Jorge

    The use of iris recognition for human authentication has been spreading in the past years. Daugman has proposed a method for iris recognition, composed by four stages: segmentation, normalization, feature extraction, and matching. In this paper we propose some modifications and extensions to Daugman's method to cope with noisy images. These modifications are proposed after a study of images of CASIA and UBIRIS databases. The major modification is on the computationally demanding segmentation stage, for which we propose a faster and equally accurate template matching approach. The extensions on the algorithm address the important issue of pre-processing, that depends on the image database, being mandatory when we have a non infra-red camera, like a typical WebCam. For this scenario, we propose methods for reflection removal and pupil enhancement and isolation. The tests, carried out by our C# application on grayscale CASIA and UBIRIS images, show that the template matching segmentation method is more accurate and faster than the previous one, for noisy images. The proposed algorithms are found to be efficient and necessary when we deal with non infra-red images and non uniform illumination.

  5. Pigment Melanin: Pattern for Iris Recognition

    CERN Document Server

    Hosseini, Mahdi S; Soltanian-Zadeh, Hamid

    2009-01-01

    Recognition of iris based on Visible Light (VL) imaging is a difficult problem because of the light reflection from the cornea. Nonetheless, pigment melanin provides a rich feature source in VL, unavailable in Near-Infrared (NIR) imaging. This is due to biological spectroscopy of eumelanin, a chemical not stimulated in NIR. In this case, a plausible solution to observe such patterns may be provided by an adaptive procedure using a variational technique on the image histogram. To describe the patterns, a shape analysis method is used to derive feature-code for each subject. An important question is how much the melanin patterns, extracted from VL, are independent of iris texture in NIR. With this question in mind, the present investigation proposes fusion of features extracted from NIR and VL to boost the recognition performance. We have collected our own database (UTIRIS) consisting of both NIR and VL images of 158 eyes of 79 individuals. This investigation demonstrates that the proposed algorithm is highly s...

  6. Improvement of the decay heat removal characteristics of the generation IV gas-cooled fast reactor; Amelioration des caracteristiques de la dissipation de la chaleur de decroissance pour les reacteurs a neutrons rapides de quatrieme generation refroidi au gaz

    Energy Technology Data Exchange (ETDEWEB)

    Epiney, A.S.

    2010-09-07

    The main drawback of the GFR is the difficulty to evacuate decay heat following a loss-of-coolant accident (LOCA) due to the low thermal inertia of the core, as well as to the low coolant density. The present doctoral research focuses on the improvement of decay heat removal (DHR) for the Generation-IV GFR. The reference GFR system design considered in the thesis is the 2006 CEA concept, with a power of 2400 MWth. The CEA 2006 DHR strategy foresees, in all accidental cases (independent of the system pressure), that the reactor is shut down. For high pressure events, dedicated DHR loops with blowers and heat exchangers are designed to operate when the power conversion system cannot be used to provide acceptable core temperatures under natural convection conditions. For de-pressurized events, the strategy relies on a dedicated small containment (called the guard containment) providing an intermediate back-up pressure. The DHR blowers, designed to work under these pressure conditions, need to be powered either by the power grid or by batteries for at least 24 hours. The specific contributions of the present research - aimed at achieving enhanced passivity of the DHR system for the GFR - are design and analysis related to (1) the injection of heavy gas into the primary circuit after a LOCA, to enable natural convection cooling at an intermediate-pressure level, and (2) an autonomous Brayton loop to evacuate decay heat at low primary pressure in case of a loss of the guard containment pressure. Both these developments reduce the dependence on blower power availability considerably. First, the thermal-hydraulic codes used in the study - TRACE and CATHARE - are validated for gas cooling. The validation includes benchmark comparisons between the codes, serving to identify the sensitivity of the results to the different modeling assumptions. The parameters found to be the most sensitive in this analysis, such as heat transfer and friction models, are then validated via a

  7. Barumiki antocyjanowe u Iris germanica [Anthocyanin pigments in Iris germanica L.

    Directory of Open Access Journals (Sweden)

    J. Szczepańska

    2015-06-01

    Full Text Available Anthocyanin pigments occurring in the flowers of Iris germanica were investigated in five varieties: Rota, Wedgewood, Empress of India, Deputate Nomblot and Joanna. The relation between the colour of the flower and the amount of the pigment was studied. The pigments were extracted from the dry plant material with 1% hydrochloric acid in methanol. Paper chromatography and colorimetric determinations were used for identification of the pigments and their quantitative determination. The results allow the following conclusions: 1. The varieties investigated were characterized toy the occurrence of delphinidine glycoside; 2. The colour intensity is dependent on the anthocyanin pigments; 3. The colour spectrum of Iris sp. flowersis greatly extended by yellow copigments.

  8. Iris detection based on pupil prospect point and horizontal projections

    Science.gov (United States)

    Shahid, Muhammad; Nawaz, Tabassam

    2010-02-01

    Iris is one of the most discriminating human physiological traits being used for personal human identification. The success of iris based system is highly relied on the accurately captured and precisely segmented iris image. False rejection rate has been a major challenge in the success of such system which primarily results from inaccurate iris segmentation. Most of the presented algorithms on iris segmentation considers pupil as perfect circle. However, according to observation this is not true in all the cases. In addition, a little angular shift in position of subject iris can further deteriorate the performance of algorithms based on circular assumption. To improve the quality of segmentation, an effective algorithm is proposed for iris segmentation which takes into consideration issues related to irregular pupil boundary as well as computation intensive nature of the prevailing algorithms. Contrary to all the previous approaches, the proposed algorithm is based on detection of pupil prospect point within the pupil region and utilizes bi-directional horizontal projections and distance parameters to detect the pupillary as well as limbus boundaries. The processing involved is linear in nature. Simulation of the proposed algorithm is done in Matlab.

  9. A simple shape prior model for iris image segmentation

    Science.gov (United States)

    Bishop, Daniel A.; Yezzi, Anthony, Jr.

    2011-06-01

    In order to make biometric systems faster and more user-friendly, lower-quality images must be accepted. A major hurdle in this task is accurate segmentation of the boundaries of the iris in these images. Quite commonly, circle-fitting is used to approximate the boundaries of the inner (pupil) and outer (limbic) boundaries of the iris, but this assumption does not hold for off-axis or otherwise non-circular boundaries. In this paper we present a novel, foundational method for elliptical segmentation of off-axis iris images. This method uses active contours with constrained flow to achieve a simplified form of shape prior active contours. This is done by calculating a region-based contour evolution and projecting it upon a properly chosen set of vectors to confine it to a class of shapes. In this case, that class of shapes is ellipses. This serves to regularize the contour, simplifying the curve evolution and preventing the development of irregularities that present challenges in iris segmentation. The proposed method is tested using images from the UBIRIS v.1 and CASIA-IrisV3 image data sets, with both near-ideal and off-axis images. Additional testing has been performed using the WVU Off Axis/Angle Iris Dataset, Release 1. By avoiding many of the assumptions commonly used in iris segmentation methods, the proposed method is able to accurately fit elliptical boundaries to off-axis images.

  10. Evaluating the impact of image preprocessing on iris segmentation

    Directory of Open Access Journals (Sweden)

    José F. Valencia-Murillo

    2014-08-01

    Full Text Available Segmentation is one of the most important stages in iris recognition systems. In this paper, image preprocessing algorithms are applied in order to evaluate their impact on successful iris segmentation. The preprocessing algorithms are based on histogram adjustment, Gaussian filters and suppression of specular reflections in human eye images. The segmentation method introduced by Masek is applied on 199 images acquired under unconstrained conditions, belonging to the CASIA-irisV3 database, before and after applying the preprocessing algorithms. Then, the impact of image preprocessing algorithms on the percentage of successful iris segmentation is evaluated by means of a visual inspection of images in order to determine if circumferences of iris and pupil were detected correctly. An increase from 59% to 73% in percentage of successful iris segmentation is obtained with an algorithm that combine elimination of specular reflections, followed by the implementation of a Gaussian filter having a 5x5 kernel. The results highlight the importance of a preprocessing stage as a previous step in order to improve the performance during the edge detection and iris segmentation processes.

  11. Scale Invariant Gabor Descriptor-Based Noncooperative Iris Recognition

    Directory of Open Access Journals (Sweden)

    Du Yingzi

    2010-01-01

    Full Text Available Abstract A new noncooperative iris recognition method is proposed. In this method, the iris features are extracted using a Gabor descriptor. The feature extraction and comparison are scale, deformation, rotation, and contrast-invariant. It works with off-angle and low-resolution iris images. The Gabor wavelet is incorporated with scale-invariant feature transformation (SIFT for feature extraction to better extract the iris features. Both the phase and magnitude of the Gabor wavelet outputs were used in a novel way for local feature point description. Two feature region maps were designed to locally and globally register the feature points and each subregion in the map is locally adjusted to the dilation/contraction/deformation. We also developed a video-based non-cooperative iris recognition system by integrating video-based non-cooperative segmentation, segmentation evaluation, and score fusion units. The proposed method shows good performance for frontal and off-angle iris matching. Video-based recognition methods can improve non-cooperative iris recognition accuracy.

  12. Scale Invariant Gabor Descriptor-based Noncooperative Iris Recognition

    Directory of Open Access Journals (Sweden)

    Zhi Zhou

    2010-01-01

    Full Text Available A new noncooperative iris recognition method is proposed. In this method, the iris features are extracted using a Gabor descriptor. The feature extraction and comparison are scale, deformation, rotation, and contrast-invariant. It works with off-angle and low-resolution iris images. The Gabor wavelet is incorporated with scale-invariant feature transformation (SIFT for feature extraction to better extract the iris features. Both the phase and magnitude of the Gabor wavelet outputs were used in a novel way for local feature point description. Two feature region maps were designed to locally and globally register the feature points and each subregion in the map is locally adjusted to the dilation/contraction/deformation. We also developed a video-based non-cooperative iris recognition system by integrating video-based non-cooperative segmentation, segmentation evaluation, and score fusion units. The proposed method shows good performance for frontal and off-angle iris matching. Video-based recognition methods can improve non-cooperative iris recognition accuracy.

  13. Ultrasound Biomicroscopy of Iris-claw Phakic Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    Ayong Yu; Zhende Lin; Xiaoyu Cai; Xiuqi Chen; Shuke Luo; Yonghua Li

    2006-01-01

    Purpose: To study in situ the intraocular position of iris-claw phakic intraocular lens (ICPIOL) in myopic eyes using ultrasound biomicroscopy (UBM).Methods: UBM echograms of the anterior segment were taken preoperatively and 62to 115 days postoperatively in 6 eyes implanted with the Verisys ICPIOL (AMO). The echograms were assessed for the effect of the ICPIOL on iris tissue.Results: The preoperative distance between the corneal endothelium and the lens ranged from 2.96 to 3.09 mm, and the postoperative distance between the ICPIOL and the corneal endothelium, from 1.86 to 2.03 mm. The distance between the lens and the posterior surface of the ICPIOL ranged from 0.61 to 0.76 mm. The distance between the superior, inferior optic edge and the iris ranged from 0.49 to 1.00 mm,0.21 to 0.51 mm respectively. The shortest distance between the ICPIOL haptics and the angle of anterior chamber ranged from 1.25 to 1.65 mm. The indentation of iris tissue by the ICPIOL haptics without pigmentary dispersion and distortion of posterior curvature of iris was observed.Conclusion: Adequate space is maintained between the Verisyse myopic ICPIOL and the corneal endothelium, angle, and crystalline lens. Haptic indentation of the iris without pigment erosion and distortion of iris curvature is noted. The ICPIOL implanted in phakic eyes is a safe alternative for treatment of high myopia.

  14. Supercritical-pressure light water cooled reactors

    CERN Document Server

    Oka, Yoshiaki

    2014-01-01

    This book focuses on the latest reactor concepts, single pass core and experimental findings in thermal hydraulics, materials, corrosion, and water chemistry. It highlights research on supercritical-pressure light water cooled reactors (SCWRs), one of the Generation IV reactors that are studied around the world. This book includes cladding material development and experimental findings on heat transfer, corrosion and water chemistry. The work presented here will help readers to understand the fundamental elements of reactor design and analysis methods, thermal hydraulics, materials and water

  15. Integrated Microfluidic Reactors.

    Science.gov (United States)

    Lin, Wei-Yu; Wang, Yanju; Wang, Shutao; Tseng, Hsian-Rong

    2009-12-01

    Microfluidic reactors exhibit intrinsic advantages of reduced chemical consumption, safety, high surface-area-to-volume ratios, and improved control over mass and heat transfer superior to the macroscopic reaction setting. In contract to a continuous-flow microfluidic system composed of only a microchannel network, an integrated microfluidic system represents a scalable integration of a microchannel network with functional microfluidic modules, thus enabling the execution and automation of complicated chemical reactions in a single device. In this review, we summarize recent progresses on the development of integrated microfluidics-based chemical reactors for (i) parallel screening of in situ click chemistry libraries, (ii) multistep synthesis of radiolabeled imaging probes for positron emission tomography (PET), (iii) sequential preparation of individually addressable conducting polymer nanowire (CPNW), and (iv) solid-phase synthesis of DNA oligonucleotides. These proof-of-principle demonstrations validate the feasibility and set a solid foundation for exploring a broad application of the integrated microfluidic system.

  16. Iris segmentation using an edge detector based on fuzzy sets theory and cellular learning automata.

    Science.gov (United States)

    Ghanizadeh, Afshin; Abarghouei, Amir Atapour; Sinaie, Saman; Saad, Puteh; Shamsuddin, Siti Mariyam

    2011-07-01

    Iris-based biometric systems identify individuals based on the characteristics of their iris, since they are proven to remain unique for a long time. An iris recognition system includes four phases, the most important of which is preprocessing in which the iris segmentation is performed. The accuracy of an iris biometric system critically depends on the segmentation system. In this paper, an iris segmentation system using edge detection techniques and Hough transforms is presented. The newly proposed edge detection system enhances the performance of the segmentation in a way that it performs much more efficiently than the other conventional iris segmentation methods.

  17. Methylene blue-related corneal edema and iris discoloration.

    Science.gov (United States)

    Timucin, Ozgur Bulent; Karadag, Mehmet Fatih; Aslanci, Mehmet Emin; Baykara, Mehmet

    2016-04-01

    We report the case of a 70-year-old female patient who developed corneal edema and iris discoloration following the inadvertent use of 1% methylene blue instead of 0.025% trypan blue to stain the anterior capsule during cataract phacoemulsification surgery. Copious irrigation was performed upon realization of incorrect dye use. Corneal edema and iris discoloration developed during the early postoperative period and persisted at 24-months follow-up. However, keratoplasty was not required. The intracameral use of 1% methylene blue has a cytotoxic effect on the corneal endothelium and iris epithelium. Copious irrigation for at least 30 min using an anterior chamber maintainer may improve outcomes.

  18. Hardware based segmentation in iris recognition and authentication systems

    Science.gov (United States)

    Ulis, Bradley J.; Broussard, Randy P.; Rakvic, Ryan N.; Ives, Robert W.; Steiner, Neil; Ngo, Hau

    2009-05-01

    Iris recognition algorithms depend on image processing techniques for proper segmentation of the iris. In the Ridge Energy Direction (RED) iris recognition algorithm, the initial step in the segmentation process searches for the pupil by thresholding and using binary morphology functions to rectify artifacts obfuscating the pupil. These functions take substantial processing time in software on the order of a few hundred million operations. Alternatively, a hardware version of the binary morphology functions is implemented to assist in the segmentation process. The hardware binary morphology functions have negligible hardware footprint and power consumption while achieving speed up of 200 times compared to the original software functions.

  19. BRCA1-IRIS overexpression promotes formation of aggressive breast cancers.

    Directory of Open Access Journals (Sweden)

    Yoshiko Shimizu

    Full Text Available INTRODUCTION: Women with HER2(+ or triple negative/basal-like (TN/BL breast cancers succumb to their cancer rapidly due, in part to acquired Herceptin resistance and lack of TN/BL-targeted therapies. BRCA1-IRIS is a recently discovered, 1399 residue, BRCA1 locus alternative product, which while sharing 1365 residues with the full-length product of this tumor suppressor gene, BRCA1/p220, it has oncoprotein-like properties. Here, we examine whether BRCA1-IRIS is a valuable treatment target for HER2(+ and/or TN/BL tumors. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistochemical staining of large cohort of human breast tumor samples using new monoclonal anti-BRCA1-IRIS antibody, followed by correlation of BRCA1-IRIS expression with that of AKT1, AKT2, p-AKT, survivin and BRCA1/p220, tumor status and age at diagnosis. Generation of subcutaneous tumors in SCID mice using human mammary epithelial (HME cells overexpressing TERT/LT/BRCA1-IRIS, followed by comparing AKT, survivin, and BRCA1/p220 expression, tumor status and aggressiveness in these tumors to that in tumors developed using TERT/LT/Ras(V12-overexpressing HME cells. Induction of primary and invasive rat mammary tumors using the carcinogen N-methyl-N-nitrosourea (NMU, followed by analysis of rat BRCA1-IRIS and ERα mRNA levels in these tumors. High BRCA1-IRIS expression was detected in the majority of human breast tumors analyzed, which was positively correlated with that of AKT1-, AKT2-, p-AKT-, survivin, but negatively with BRCA1/p220 expression. BRCA1-IRIS-positivity induced high-grade, early onset and metastatic HER2(+ or TN/BL tumors. TERT/LT/BRCA1-IRIS overexpressing HME cells formed invasive subcutaneous tumors that express high AKT1, AKT2, p-AKT and vimentin, but no CK19, p63 or BRCA1/p220. NMU-induced primary and invasive rat breast cancers expressed high levels of rat BRCA1-IRIS mRNA but low levels of rat ERα mRNA. CONCLUSION/SIGNIFICANCE: BRCA1-IRIS overexpression triggers aggressive

  20. Challenges at different stages of an iris based biometric system

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Singla

    2012-04-01

    Full Text Available Iris recognition has been used for authentication for the past few years and is capable of positive/negative authenticationof an individual without any physical contact or intervention. This technique is being used mainly because of its uniqueness,stability, and reliability but still many challenges are being faced an the iris based recognition system. This paperpresents the difficulties faced in different modules, like the sensor module, preprocessing module, feature extraction module,and matching module of an iris biometric system.

  1. Multifunctional reactors

    NARCIS (Netherlands)

    Westerterp, K.R.

    1992-01-01

    Multifunctional reactors are single pieces of equipment in which, besides the reaction, other functions are carried out simultaneously. The other functions can be a heat, mass or momentum transfer operation and even another reaction. Multifunctional reactors are not new, but they have received much

  2. Trade off between variable and fixed size normalization in orthogonal polynomials based iris recognition system.

    Science.gov (United States)

    Krishnamoorthi, R; Anna Poorani, G

    2016-01-01

    Iris normalization is an important stage in any iris biometric, as it has a propensity to trim down the consequences of iris distortion. To indemnify the variation in size of the iris owing to the action of stretching or enlarging the pupil in iris acquisition process and camera to eyeball distance, two normalization schemes has been proposed in this work. In the first method, the iris region of interest is normalized by converting the iris into the variable size rectangular model in order to avoid the under samples near the limbus border. In the second method, the iris region of interest is normalized by converting the iris region into a fixed size rectangular model in order to avoid the dimensional discrepancies between the eye images. The performance of the proposed normalization methods is evaluated with orthogonal polynomials based iris recognition in terms of FAR, FRR, GAR, CRR and EER.

  3. Evidence for two-loop interaction from IRIS and SDO observations of penumbral brightenings

    Science.gov (United States)

    Alissandrakis, C. E.; Koukras, A.; Patsourakos, S.; Nindos, A.

    2017-07-01

    Aims: We investigate small scale energy release events which can provide clues on the heating mechanism of the solar corona. Methods: We analyzed spectral and imaging data from the Interface Region Imaging Spectrograph (IRIS), images from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatoty (SDO), and magnetograms from the Helioseismic and Magnetic Imager (HMI) aboard SDO. Results: We report observations of small flaring loops in the penumbra of a large sunspot on July 19, 2013. Our main event consisted of a loop spanning 15'', from the umbral-penumbral boundary to an opposite polarity region outside the penumbra. It lasted approximately 10 min with a two minute impulsive peak and was observed in all AIA/SDO channels, while the IRIS slit was located near its penumbral footpoint. Mass motions with an apparent velocity of 100 km s-1 were detected beyond the brightening, starting in the rise phase of the impulsive peak; these were apparently associated with a higher-lying loop. We interpret these motions in terms of two-loop interaction. IRIS spectra in both the C ii and Si iv lines showed very extended wings, up to about 400 km s-1, first in the blue (upflows) and subsequently in the red wing. In addition to the strong lines, emission was detected in the weak lines of Cl i, O i and C i, as well as in the Mg ii triplet lines. Absorption features in the profiles of the C ii doublet, the Si iv doublet and the Mg ii h and k lines indicate the existence of material with a lower source function between the brightening and the observer. We attribute this absorption to the higher loop and this adds further credibility to the two-loop interaction hypothesis. Tilts were detected in the absorption spectra, as well as in the spectra of Cl i, O i, and C i lines, possibly indicating rotational motions from the untwisting of magnetic flux tubes. Conclusions: We conclude that the absorption features in the C ii, Si iv and Mg ii profiles originate in a higher

  4. Review of EPA's Integrated Risk Information System (IRIS) Process

    National Research Council Canada - National Science Library

    Board on Environmental Studies and Toxicology; Division on Earth and Life Studies; National Research Council; National Research Council

    2014-01-01

    ...) that is responsible for developing toxicologic assessments of environmental contaminants. An IRIS assessment contains hazard identifications and dose-response assessments of various chemicals related to cancer and noncancer outcomes...

  5. 8-Valent Fuzzy Logic for Iris Recognition and Biometry

    CERN Document Server

    Popescu-Bodorin, N; Motoc, I M; 10.1109/ISCIII.2011.6069761

    2011-01-01

    This paper shows that maintaining logical consistency of an iris recognition system is a matter of finding a suitable partitioning of the input space in enrollable and unenrollable pairs by negotiating the user comfort and the safety of the biometric system. In other words, consistent enrollment is mandatory in order to preserve system consistency. A fuzzy 3-valued disambiguated model of iris recognition is proposed and analyzed in terms of completeness, consistency, user comfort and biometric safety. It is also shown here that the fuzzy 3-valued model of iris recognition is hosted by an 8-valued Boolean algebra of modulo 8 integers that represents the computational formalization in which a biometric system (a software agent) can achieve the artificial understanding of iris recognition in a logically consistent manner.

  6. IRIS Toxicological Review of Hydrogen Cyanide (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of hydrogen cyanide and cyanide salts that will appear on the Integrated Risk Information System (IRIS) database.

  7. Mid-Columbia - Yellow-flag Iris Eradication 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The project as described was to attempt to eradicate yellow-flag iris from Toppenish, McNary and Columbia National Wildlife Refuges using chemical and, where...

  8. Mid-Columbia - Eradication of Yellow-flag Iris 2013

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The project as described was to attempt to eradicate yellow-flag iris from Toppenish, McNary and Columbia National Wildlife Refuges using chemical and, where...

  9. Peer Review Comments on the IRIS Assessment of Benzene

    Science.gov (United States)

    Attachment to IRIS file for benzene, January 19, 2000, RESPONSE TO THE PEER REVIEW COMMENTS, II. Extrapolation of the Benzene Inhalation Unit Risk Estimate to the Oral Route of Exposure (EPA/NCEA-W-0517, July 1999)

  10. IRIS Toxicological Review of Hydrogen Cyanide (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of hydrogen cyanide and cyanide salts that will appear on the Integrated Risk Information System (IRIS) database.

  11. IRIS Toxicological Review for Acrylamide (Interagency Science Discussion Draft)

    Science.gov (United States)

    EPA is releasing the draft report, Toxicological Review for Acrylamide, that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process<...

  12. Exploratory simulation of an Intelligent Iris Verifier Distributed System

    CERN Document Server

    Popescu-Bodorin, Nicolaie; 10.1109/SACI.2011.5873010

    2011-01-01

    This paper discusses some topics related to the latest trends in the field of evolutionary approaches to iris recognition. It presents the results of an exploratory experimental simulation whose goal was to analyze the possibility of establishing an Interchange Protocol for Digital Identities evolved in different geographic locations interconnected through and into an Intelligent Iris Verifier Distributed System (IIVDS) based on multi-enrollment. Finding a logically consistent model for the Interchange Protocol is the key factor in designing the future large-scale iris biometric networks. Therefore, the logical model of such a protocol is also investigated here. All tests are made on Bath Iris Database and prove that outstanding power of discrimination between the intra- and the inter-class comparisons can be achieved by an IIVDS, even when practicing 52.759.182 inter-class and 10.991.943 intra-class comparisons. Still, the test results confirm that inconsistent enrollment can change the logic of recognition ...

  13. Gabor Filter Optimization Design for Iris Texture Analysis

    Institute of Scientific and Technical Information of China (English)

    Tao Xu; Xing Ming; Xiaoguang Yang

    2004-01-01

    This paper deals with an optimization design method for the Gabor filters based on the analysis of an iris texture model. By means of analyzing the properties of an iris texture image, the energy distribution regularity of the iris texture image measured by the average power spectrum density is exploited, and the theoretical ranges of the efficient valued frequency and orientation parameters can also be deduced. The analysis shows that the energy distribution of the iris texture is generally centralized around lower frequencies in the spatial frequency domain. Accordingly, an iterative algorithm is designed to optimize the Gabor parameter field. The experimental results indicate the validity of the theory and efficiency of the algorithm.

  14. Bilateral acute iris transillumination (BAIT initially misdiagnosed as acute iridocyclitis

    Directory of Open Access Journals (Sweden)

    Saban Gonul

    2015-04-01

    Full Text Available Bilateral acute iris transillumination (BAIT is a relatively new clinical entity characterized by bilateral acute loss of iris pigment epithelium, iris transillumination, pigment dispersion in the anterior chamber, and sphincter paralysis. We report the case of a 30-year-old male who was initially diagnosed with acute iridocyclitis in a different clinic and treated with topical and systemic corticosteroids. He was referred to our clinic to seek another opinion because his symptoms did not improve. An ocular examination revealed bilateral pigment dispersion into the anterior chamber, diffuse iris transillumination, pigment dusting on the anterior lens capsule, atonic and distorted pupils, and increased intraocular pressure, suggesting a diagnosis of BAIT rather than iridocyclitis. Clinicians should be aware of the differential diagnosis of syndromes associated with pigment dispersion from iridocyclitis to avoid aggressive anti-inflammatory therapy and detailed investigation for uveitis.

  15. IRIS TOXICOLOGICAL REVIEW OF TETRACHLOROETHYLENE (PERCHLOROETHYLENE) (INTERAGENCY SCIENCE DISCUSSION DRAFT)

    Science.gov (United States)

    EPA is releasing the draft report, Toxicological Review of Tetrachloroethylene (Perchloroethylene), that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment...

  16. IRIS Toxicological Review for Acrylamide (Interagency Science Discussion Draft)

    Science.gov (United States)

    EPA is releasing the draft report, Toxicological Review for Acrylamide, that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process<...

  17. Iris Recognition Based on LBP and Combined LVQ Classifier

    CERN Document Server

    Shams, M Y; Nomir, O; El-Awady, R M; 10.5121/ijcsit.2011.3506

    2011-01-01

    Iris recognition is considered as one of the best biometric methods used for human identification and verification, this is because of its unique features that differ from one person to another, and its importance in the security field. This paper proposes an algorithm for iris recognition and classification using a system based on Local Binary Pattern and histogram properties as a statistical approaches for feature extraction, and Combined Learning Vector Quantization Classifier as Neural Network approach for classification, in order to build a hybrid model depends on both features. The localization and segmentation techniques are presented using both Canny edge detection and Hough Circular Transform in order to isolate an iris from the whole eye image and for noise detection .Feature vectors results from LBP is applied to a Combined LVQ classifier with different classes to determine the minimum acceptable performance, and the result is based on majority voting among several LVQ classifier. Different iris da...

  18. Mid-Columbia - Yellow-flag Iris Control

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Yellow-flag iris is an escaped ornamental rhizomatous perennial herb that forms dense vegetative mats in riparian and wetland areas. These mats can displace most...

  19. Ethnicity distinctiveness through iris texture features using Gabor filters

    CSIR Research Space (South Africa)

    Mabuza-Hocquet, Gugulethu P

    2017-02-01

    Full Text Available and ethnicity. Researchers have reported that iris texture features contain information that is inclined to human genetics and is highly discriminative between different eyes of different ethnicities. This work applies image processing and machine learning...

  20. IRIS Toxicological Review of Trichloroethylene (TCE) (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroethylene (TCE) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

  1. A bibliography of IRIS-related publications, 2000-2011

    Science.gov (United States)

    Muco, B.

    2012-12-01

    Citations and acknowledgements in scientific journals can be an indicator of the role an organization has on the research of that field. Since its formation and incorporation in May 1984, the IRIS Consortium (Incorporated Research Institutions for Seismology) is mentioned more and more as a valuable source of data, instruments and programs in the literature of earth sciences. As a large organization with more than 100 member domestic institutes and about 40 international affiliates, obviously IRIS has a direct impact on the earth sciences through all its programs, projects, workshops, symposia, and news¬letters and as a lively forum for exchanging ideas. In order to maintain support from National Science Foundation (NSF) and the research community, it is important to document the continued use of IRIS facilities in basic research programs. IRIS maintains a database of articles that are based on the use of IRIS facilities or which reference use of IRIS data and resources. Articles in this database have been either been provided to IRIS by the authors or selected through an annual search of a number of prominent journals. A text version of the full bibliographic database is available on the IRIS website and a version in EndNote format is also provided. To provide a more complete bibliography and a consistent evaluation of temporal tends in publications, a special annual search began in 2000 which focused on a subset of key seismology and Earth science journals: Bulletin of Seismological Society of America, Journal of Geophysical Research, Seismological Research Letters, Geophysical Research Letters, Earth and Planetary Science Letters, Physics of the Earth and Planetary Interiors, Tectonophysics, Geophysical Journal International, Nature, Science, Geology and EOS. Using different search engines as Scirus, ScienceDirect, GeoRef, OCLC First Search, EASI Search, NASA Abstract Service etc. for online journals and publishers' databases, we searched for key words (IRIS

  2. New Materials for NGNP/Gen IV

    Energy Technology Data Exchange (ETDEWEB)

    Robert W. Swindeman; Douglas L. Marriott

    2009-12-18

    The bounding conditions were briefly summarized for the Next Generation Nuclear Plant (NGNP) that is the leading candidate in the Department of Energy Generation IV reactor program. Metallic materials essential to the successful development and proof of concept for the NGNP were identified. The literature bearing on the materials technology for high-temperature gas-cooled reactors was reviewed with emphasis on the needs identified for the NGNP. Several materials were identified for a more thorough study of their databases and behavioral features relative to the requirements ASME Boiler and Pressure Vessel Code, Section III, Division 1, Subsection NH.

  3. Iris Pattern Segmentation using Automatic Segmentation and Window Technique

    OpenAIRE

    Swati Pandey; Prof. Rajeev Gupta

    2013-01-01

    A Biometric system is an automatic identification of an individual based on a unique feature or characteristic. Iris recognition has great advantage such as variability, stability and security. In thispaper, use the two methods for iris segmentation -An automatic segmentation method and Window method. Window method is a novel approach which comprises two steps first finds pupils' center andthen two radial coefficients because sometime pupil is not perfect circle. The second step extract the i...

  4. Reactor vessel

    OpenAIRE

    Makkee, M.; Kapteijn, F.; Moulijn, J.A

    1999-01-01

    A reactor vessel (1) comprises a reactor body (2) through which channels (3) are provided whose surface comprises longitudinal inwardly directed parts (4) and is provided with a catalyst (6), as well as buffer bodies (8, 12) connected to the channels (3) on both sides of the reactor body (2) and comprising connections for supplying (9, 10, 11) and discharging (13, 14, 15) via the channels (3) gases and/or liquids entering into a reaction with each other and substances formed upon this reactio...

  5. Foreign Trip Report MATGEN-IV Sep 24- Oct 26, 2007

    Energy Technology Data Exchange (ETDEWEB)

    de Caro, M S

    2007-10-30

    Gen-IV activities in France, Japan and US focus on the development of new structural materials for Gen-IV nuclear reactors. Oxide dispersion strengthened (ODS) F/M steels have raised considerable interest in nuclear applications. Promising collaborations can be established seeking fundamental knowledge of relevant Gen-IV ODS steel properties (see attached travel report on MATGEN- IV 'Materials for Generation IV Nuclear Reactors'). Major highlights refer to results on future Ferritic/Martensitic steel cladding candidates (relevant to Gen-IV materials properties for LFR Materials Program) and on thermodynamic and mechanic behavior of metallic FeCr binary alloys, base matrix for future candidate steels (for the LLNL-LDRD project on Critical Issues on Materials for Gen-IV Reactors).

  6. SINGLE FRAME SUPER RESOLUTION OF NONCOOPERATIVE IRIS IMAGES

    Directory of Open Access Journals (Sweden)

    Anand Deshpande

    2016-11-01

    Full Text Available Image super-resolution, a process to enhance image resolution, has important applications in biometrics, satellite imaging, high definition television, medical imaging, etc. The long range captured iris identification systems often suffer from low resolution and meager focus of the captured iris images. These degrade the iris recognition performance. This paper proposes enhanced iterated back projection (EIBP method to super resolute the long range captured iris polar images. The performance of proposed method is tested and analyzed on CASIA long range iris database by comparing peak signal to noise ratio (PSNR and structural similarity index (SSIM with state-of-the-art super resolution (SR algorithms. It is further analyzed by increasing the up-sampling factor. Performance analysis shows that the proposed method is superior to state-of-the-art algorithms, the peak signal-to-noise ratio improved about 0.1-1.5 dB. The results demonstrate that the proposed method is well suited to super resolve the iris polar images captured at a long distance

  7. A multi-approach feature extractions for iris recognition

    Science.gov (United States)

    Sanpachai, H.; Settapong, M.

    2014-04-01

    Biometrics is a promising technique that is used to identify individual traits and characteristics. Iris recognition is one of the most reliable biometric methods. As iris texture and color is fully developed within a year of birth, it remains unchanged throughout a person's life. Contrary to fingerprint, which can be altered due to several aspects including accidental damage, dry or oily skin and dust. Although iris recognition has been studied for more than a decade, there are limited commercial products available due to its arduous requirement such as camera resolution, hardware size, expensive equipment and computational complexity. However, at the present time, technology has overcome these obstacles. Iris recognition can be done through several sequential steps which include pre-processing, features extractions, post-processing, and matching stage. In this paper, we adopted the directional high-low pass filter for feature extraction. A box-counting fractal dimension and Iris code have been proposed as feature representations. Our approach has been tested on CASIA Iris Image database and the results are considered successful.

  8. On the Active Region Bright Grains Observed in the Transition Region Imaging Channels of IRIS

    CERN Document Server

    Skogsrud, H; De Pontieu, B

    2015-01-01

    The Interface Region Imaging Spectrograph (IRIS) provides spectroscopy and narrow band slit-jaw (SJI) imaging of the solar chromosphere and transition region at unprecedented spatial and temporal resolution. Combined with high-resolution context spectral imaging of the photosphere and chromosphere as provided by the Swedish 1-m Solar Telescope (SST), we can now effectively trace dynamic phenomena through large parts of the solar atmosphere in both space and time. IRIS SJI 1400 images from active regions, which primarily sample the transition region with the Si IV 1394 and 1403 {\\AA} lines, reveal ubiquitous bright "grains" which are short-lived (2-5 min) bright roundish small patches of sizes 0.5-1.7" that generally move limbward with velocities up to about 30 km s$^{-1}$. In this paper we show that many bright grains are the result of chromospheric shocks impacting the transition region. These shocks are associated with dynamic fibrils (DFs), most commonly observed in H{\\alpha}. We find that the grains show ...

  9. Limb Event Brightenings (LEBs) with fast ejection using IRIS mission Observations

    CERN Document Server

    Tavabi, E; Golub, L

    2015-01-01

    The Interface Region Imaging Spectrograph (IRIS) of the recently commissioned NASA Small Explorer mission provides significantly more complete and higher resolution spectral coverage of the dynamical conditions inside the chromosphere and Transition Region (TR) than has heretofore been available. Near the solar limb high temporal, spatial (0''3) and spectral resolution observations from ultraviolet IRIS spectra reveal high-energy limb event brightenings (LEBs) at low chromospheric height, near 1 Mm height above the limb. They can be characterized as explosive events producing jets. We selected 2 events showing spectra of a confined eruption just off or near the quiet Sun limb, the jet part showing obvious moving material with short duration large Doppler shifts in three directions identified as macro- spicules on slit-jaw (SJ) images in SiIV and HeII 304. The events are analyzed from a sequence of very close rasters taken near the central meridian and the South Pole limb. The processed SJ images and the simul...

  10. Lessons learned from IRIS EPO program evaluations

    Science.gov (United States)

    Taber, J.; Hubenthal, M.

    2012-12-01

    Evaluating the overall impact of EPO programs that include activities ranging from formal education through broad public outreach, is a complex issue. The impact of education activities targeted at narrowly defined audiences is generally easier to quantify than the national impact of outreach activities conducted by a relatively small program. For educational activities, our approach has been to leverage the best-practices identified through research and to continuously assess the individual elements internally with the intention of making improvements based on the data generated and the existing research. By constructing our elements on the best practices identified by the research community we feel that internal formative evaluation is a valid means to determine if an activity is effective, particularly when the results are compared to similar programs. For example, effective practices of professional development are well documented in the literature. As a result, this allows us to shape our programs and our evaluations to monitor elements that have been identified as key by the educational research community. Further, such actions allow us to avoid allocating significant resources with the intention of pinning down direct causal relationships between our programs and consumers, when similar interventions (conducted by others) have already shown such relationships. Ongoing review by an EPO advisory committee also provides regular oversight of program impact. While we find internal and external formative evaluation extremely useful in shaping the program and documenting its impact, we also recognize the value of a summative evaluation process. For example, an external summative evaluation of the IRIS EPO program was conducted in 2009, followed by an external panel review, as part of the regular review of IRIS programs. We found that the most valuable part of the external evaluation was our preparation, including clarifying the goals of each of the elements of the

  11. Chemical Reactors.

    Science.gov (United States)

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  12. Reactor Neutrinos

    Directory of Open Access Journals (Sweden)

    Soo-Bong Kim

    2013-01-01

    Full Text Available We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angle θ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.

  13. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  14. Reactor Engineering

    Science.gov (United States)

    Lema, Juan M.; López, Carmen; Eibes, Gemma; Taboada-Puig, Roberto; Moreira, M. Teresa; Feijoo, Gumersindo

    In this chapter, the engineering aspects of processes catalyzed by peroxidases will be presented. In particular, a discussion of the existing technologies that utilize peroxidases for different purposes, such as the removal of recalcitrant compounds or the synthesis of polymers, is analyzed. In the first section, the essential variables controlling the process will be investigated, not only those that are common in any enzymatic system but also those specific to peroxidative reactions. Next, different reactor configurations and operational modes will be proposed, emphasizing their suitability and unsuitability for different systems. Finally, two specific reactors will be described in detail: enzymatic membrane reactors and biphasic reactors. These configurations are especially valuable for the treatment of xenobiotics with high and poor water solubility, respectively.

  15. Reactor Neutrinos

    OpenAIRE

    Lasserre, T.; Sobel, H.W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrin...

  16. Aqueous humor tyrosinase activity is indicative of iris melanocyte toxicity.

    Science.gov (United States)

    Mahanty, Sarmistha; Kawali, Ankush A; Dakappa, Shruthi Shirur; Mahendradas, Padmamalini; Kurian, Mathew; Kharbanda, Varun; Shetty, Rohit; Setty, Subba Rao Gangi

    2017-09-01

    Antibiotics such as fluoroquinolones (FQLs) are commonly used to treat ocular infections but are also known to cause dermal melanocyte toxicity. The release of dispersed pigments from the iris into the aqueous humor has been considered a possible ocular side effect of the systemic administration of FQLs such as Moxifloxacin, and this condition is known as bilateral acute iris transillumination (BAIT). Bilateral acute depigmentation of iris (BADI) is a similar condition, with iris pigment released into the aqueous, but it has not been reported as a side effect of FQL. Iris pigments are synthesized by the melanogenic enzyme tyrosinase (TYR) and can be detected but not quantified by using slit-lamp biomicroscopy. The correlation between dispersed pigments in the aqueous and the extent of melanocyte toxicity due to topical antibiotics in vivo is not well studied. Here, we aimed to study the effect of topical FQLs on iris tissue, the pigment release in the aqueous humor and the development of clinically evident iris atrophic changes. We evaluated this process by measuring the activity of TYR in the aqueous humor of 82 healthy eyes undergoing cataract surgery following topical application of FQLs such as Moxifloxacin (27 eyes, preservative-free) or Ciprofloxacin (29 eyes, with preservative) or the application of non-FQL Tobramycin (26 eyes, with preservative) as a control. In addition, the patients were questioned and examined for ocular side effects in pre- and post-operative periods. Our data showed a significantly higher mean TYR activity in the aqueous humor of Ciprofloxacin-treated eyes compared to Moxifloxacin- (preservative free, p humor from both Ciprofloxacin- and Moxifloxacin-treated eyes showed the presence of soluble TYR enzyme, thus reflecting its toxicity to iris melanocytes and corresponding to its activity in the aqueous humor. Intriguingly, none of these patients developed any clinically appreciable ocular side effects characteristic of BAIT or BADI

  17. Dynamic iris biometry: a technique for enhanced identification

    Directory of Open Access Journals (Sweden)

    McDowell Douglas R

    2010-07-01

    Full Text Available Abstract Background The iris as a unique identifier is predicated on the assumption that the iris image does not alter. This does not consider the fact that the iris changes in response to certain external factors including medication, disease, surgery as well as longer term ageing changes. It is also part of a dynamic optical system that alters with light level and focussing distance. A means of distinguishing the features that do not alter over time from those that do is needed. This paper applies iris recognition algorithms to a newly acquired database of 186 iris images from four subjects. These images have greater magnification and detail than iris images in existing databases. Iris segmentation methods are tested on the database. A new technique that enhances segmentation is presented and compared to two existing methods. These are also applied to test the effects of pupil dilation in the identification process. Findings Segmentation results from all the images showed that using the proposed algorithm accurately detected pupil boundaries for 96.2% respectively of the images, which was an increase of 88.7% over the most commonly used algorithm. For the images collected, the proposed technique also showed significant improvement in detection of the limbal boundary compared to the detection rates using existing methods. With regard to boundary displacement errors, only slight errors were found with the proposed technique compared to extreme errors made when existing techniques were applied. As the pupil becomes more dilated, the success of identification is increasingly more dependent on the decision criterion used. Conclusions The enhanced segmentation technique described in this paper performs with greater accuracy than existing methods for the higher quality images collected in this study. Implementation of the proposed segmentation enhancement significantly improves pupil boundary detection and therefore overall iris segmentation. Pupil

  18. [Management of intraoperative floppy iris syndrome].

    Science.gov (United States)

    Chiseliţă, D; Cantemir, Alina; Epifanov, Lucia; Huţuleac, Alexandra; Irod, Alexandra

    2012-01-01

    To evaluate the incidence of IFIS in male patients whith alfa 1-AB treatment for benign prostatic hyperplasia (BPH) who underwent cataract surgery and also the pre and intraoperatory management and IFIS profilaxy. Iasi "Sf Spiridon" Emergency Hospital and "Oftaprof" private practice Observational retrospective study that took place over a period of 2 years (july 2009-july 2011) and reviewed 2484 eyes that underwent cataract surgery. A number of 1199 eyes were from 1049 male patients. Out of the 1049 male patients, 139 (13,25%) underwent treatment for BHP using the medication as follows: 119 used tamsulosin (85,6%); 18 used doxazosin, (12,94%); 2 used alfuzosin (1,43%). Out of the 139 men, 32 (23,02%) showed IFIS but only the ones treated with tamsulosin. After introducing a surgical protocol that comprised of the use of large amounts of vascoelastic material (Viscoat), intracamerular fenilefrin (Mezaton), the use of iris retractors and low faco parameters the incidence and severity of IFIS was significantly reduced. Correct evauation before surgery is necessary in order to anticipate the condition as its frequency and severity can be reduced by a proactive behavior which demands experience and adequate endowment.

  19. The influence of neighbouring species on ecological variation of the selected subpopulations of Iris sibirica L.

    Directory of Open Access Journals (Sweden)

    Kostrakiewicz-Gierałt Kinga

    2013-12-01

    Full Text Available Ecological variation of the selected subpopulations of Iris sibirica L. were studied in the years 2011-2012, in the abandoned patches of Molinietum caeruleae dominated by small meadow species (Patch I, macroforbs (Patch II, largetussock grasses (Patch III, shrubs (Patch IV, as well as shrubs and trees (Patch V. The abundance of subpopulations and dimensions of aggregations of ramet clusters increased gradually from Patch I to Patch IV and subsequently declined in Patch V. During the whole study period, all subpopulations showed signs of senility due to the absence of individuals in prereproductive stages. The share of generative ramet clusters diminished, while contribution of senile and fragmentised ramet clusters increased substantially in consecutive patches. The dimensions of ramet clusters increased significantly in successive plots and years. The number and height of generative stems and production of flowers and fruits did not show the temporal variability. The abundance of generative stems was considerably lower in the plots dominated by small meadow species, than in the sites dominated by large-tussock grasses, shrubs or overgrown shrubs and trees. Both the height of flowering stems and production of flowers and fruits increased gradually from Patch I, via Patches II, III and IV, to Patch V. The augmentation of flower production might contribute to better visibility of inflorescences for pollinators, whereas an increase in the production of fruits may increase the chances for successful seed dispersal to new sites.

  20. Examining Computational Assumptions For Godiva IV

    Energy Technology Data Exchange (ETDEWEB)

    Kirkland, Alexander Matthew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jaegers, Peter James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-11

    Over the course of summer 2016, the effects of several computational modeling assumptions with respect to the Godiva IV reactor were examined. The majority of these assumptions pertained to modeling errors existing in the control rods and burst rod. The Monte Carlo neutron transport code, MCNP, was used to investigate these modeling changes, primarily by comparing them to that of the original input deck specifications.

  1. ON THE ACTIVE REGION BRIGHT GRAINS OBSERVED IN THE TRANSITION REGION IMAGING CHANNELS OF IRIS

    Energy Technology Data Exchange (ETDEWEB)

    Skogsrud, H.; Voort, L. Rouppe van der; Pontieu, B. De [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway)

    2016-02-01

    The Interface Region Imaging Spectrograph (IRIS) provides spectroscopy and narrow band slit-jaw (SJI) imaging of the solar chromosphere and transition region at unprecedented spatial and temporal resolutions. Combined with high-resolution context spectral imaging of the photosphere and chromosphere as provided by the Swedish 1 m Solar Telescope (SST), we can now effectively trace dynamic phenomena through large parts of the solar atmosphere in both space and time. IRIS SJI 1400 images from active regions, which primarily sample the transition region with the Si iv 1394 and 1403 Å lines, reveal ubiquitous bright “grains” which are short-lived (two to five minute) bright roundish small patches of sizes 0.″5–1.″7 that generally move limbward with velocities up to about 30 km s{sup −1}. In this paper, we show that many bright grains are the result of chromospheric shocks impacting the transition region. These shocks are associated with dynamic fibrils (DFs), most commonly observed in Hα. We find that the grains show the strongest emission in the ascending phase of the DF, that the emission is strongest toward the top of the DF, and that the grains correspond to a blueshift and broadening of the Si iv lines. We note that the SJI 1400 grains can also be observed in the SJI 1330 channel which is dominated by C ii lines. Our observations show that a significant part of the active region transition region dynamics is driven from the chromosphere below rather than from coronal activity above. We conclude that the shocks that drive DFs also play an important role in the heating of the upper chromosphere and lower transition region.

  2. Explosive events in active region observed by IRIS and SST/CRISP

    Science.gov (United States)

    Huang, Z.; Madjarska, M. S.; Scullion, E. M.; Xia, L.-D.; Doyle, J. G.; Ray, T.

    2017-01-01

    Transition-region explosive events (EEs) are characterized by non-Gaussian line profiles with enhanced wings at Doppler velocities of 50-150 km s-1. They are believed to be the signature of solar phenomena that are one of the main contributors to coronal heating. The aim of this study is to investigate the link of EEs to dynamic phenomena in the transition region and chromosphere in an active region. We analyse observations simultaneously taken by the Interface Region Imaging Spectrograph (IRIS) in the Si IV 1394 Å line and the slit-jaw (SJ) 1400 Å images, and the Swedish 1-m Solar Telescope in the Hα line. In total 24 events were found. They are associated with small-scale loop brightenings in SJ 1400 Å images. Only four events show a counterpart in the Hα-35 km s-1 and Hα+35 km s-1 images. Two of them represent brightenings in the conjunction region of several loops that are also related to a bright region (granular lane) in the Hα-35 km s-1 and Hα+35 km s-1 images. 16 are general loop brightenings that do not show any discernible response in the Hα images. Six EEs appear as propagating loop brightenings, from which two are associated with dark jet-like features clearly seen in the Hα-35 km s-1 images. We found that chromospheric events with jet-like appearance seen in the wings of the Hα line can trigger EEs in the transition region and in this case the IRIS Si IV 1394 Å line profiles are seeded with absorption components resulting from Fe II and Ni II. Our study indicates that EEs occurring in active regions have mostly upper-chromosphere/transition-region origin. We suggest that magnetic reconnection resulting from the braidings of small-scale transition region loops is one of the possible mechanisms of energy release that are responsible for the EEs reported in this paper.

  3. GNSS derived TEC data ingestion into IRI 2012

    Science.gov (United States)

    Migoya-Orué, Yenca; Nava, Bruno; Radicella, Sandro; Alazo-Cuartas, Katy

    2015-04-01

    Experimental vertical total electron content (VTEC) data given by Global Ionospheric Maps (GIM) has been ingested into the IRI version 2012, aiming to obtain grids of effective input parameter values that allow to minimize the difference between the experimental and modeled vertical TEC. Making use of the experience gained with the technique of model adaptation applied to NeQuick (Nava et al., 2005), it has been found possible to compute IRI world grids of effective ionosphere index parameters (IG). The IG grids thus obtained can be interpolated in space and time to calculate with IRI the 3D electron density at any location and also the TEC along any ground-to-satellite ray-path for a given epoch. In this study, the ingestion technique is presented and a posteriori validation, along with an assessment of the capability of the 'ingested' IRI to reproduce the ionosphere day-to-day foF2 variability during disturbed and quiet periods. The foF2 values retrieved are compared with data from about 20 worldwide ionosondes for selected periods of high (year 2000) and moderate to low solar activity (year 2006). It was found that the use of the ingestion scheme enhances the performance of the model when compared with its standard use based on solar activity drivers (R12 and F10.7), especially for high solar activity. As an example, the mean and standard deviation of the differences between experimental and reconstructed F2-peak values for April of year 2000 is 0.09 and 1.28 MHz for ingested IRI, compared to -0.81 and 1.27 MHz (IRI with R12 input) and -0.02 and 1.46 MHz (IRI with F10.7 input).

  4. The iris family (Iridaceae in the flora of eastern Indochina

    Directory of Open Access Journals (Sweden)

    L. V. Averyanov

    2016-03-01

    Full Text Available Iris family in the countries of eastern part of Indochina Peninsula, such as Cambodia, Laos and Viet­nam includes lone native genus – Iris L. with two aboriginal species – I. japonica Thunb. and I. tectorum Maxim. Iris japonica is often cultivated as an outdoor ornamental plant in mountainous regions in the northern Vietnam, where it occasionally naturalizes. Herbarium specimens of I. japonica, collected in central Laos near Nape town, probably represent southernmost locality of the Iris genus in Eurasia. Iris tectorum was discovered in native, primary plant communities of karstic highly eroded limestone in Cao Bang province (Bao Lac district of the northern Vietnam. This species is recorded as new for the flora of the Indochina Peninsula. The report of I. collettii Hook. f. on the territory of peninsular flora does not yet confirmed by herbaria and remains doubtful. Data on taxonomy, authentic specimens, distribution, habitats, phenology, conservation status and biology are provided for all Iris species. The identification key for Iris species is compiled, as well as dotted distribution maps on the territory of countries of eastern Indochina. Other representatives of the family from such genera as Belamcanda Adans. (B. chinensis (L. Redouté, Crocosmia Planch. (C. × crocosmiiflora (G. Nicholson N. E. Br., Eleutherine Herb. (E. bulbosa (Mill. Urb., Freesia Klatt (F. refracta (Jacq. Klatt., Gladiolus L. (numerous horticultural forms и Trimezia Salisb. ex Herb. (T. martinicensis (Jacq. Herb. reported from Indochina are introduced cultivated ornamental plants capable to occasional naturaliza­tion as an adventive element of the Indochinese flora.

  5. Japanese infrared survey mission IRIS (ASTRO-F)

    Science.gov (United States)

    Murakami, Hiroshi

    1998-08-01

    The IR Imaging Survey (IRIS) is the second IR astronomy mission of the Institute of Space and Astronomical Science (ISAS). The IRIS is a 70 cm cooled telescope dedicated for IR sky survey. This project has been approved as ISAS's 21st science mission 'ASTRO-F', and prototype model development has been ongoing since 1997. The IRIS will be launched with ISAS's launch vehicle M-V, into a sun-synchronous polar orbit with an altitude of 750 km. The IRIS telescope has a 70 cm aperture and is cooled to 6K using Stirling-cycle coolers and liquid helium. The primary and secondary mirrors are light-weight mirrors make of silicon carbide. Two focal- plane instruments are installed. One is the far-IR surveyor (FIS) which will survey the entire sky in the wavelength range from 50 to 200 micron with angular resolutions of 30- 50 arcsec. The other focal-plane instrument is the IR camera (IRC). It employs large-format detector arrays and will take deep images of selected sky regions in the near and mid IR range. The field of view of the IRC is 10 arcmin and the spatial resolution is approximately 2 arcsec. The IRIS has much higher sensitivity than that of the IRAS survey. The detection limits are 1-100 micro Jy in the near-MID IR and 10-100 mJy in the far IR. With the IRIS survey, great progress is expected in the research on evolution of galaxies, formation of stars and planets, dark matter and brown dwarfs. The IRIS is now scheduled to be launched in early 2003.

  6. Lessons Learned From Gen I Carbon Dioxide Cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    David E. Shropshire

    2004-04-01

    This paper provides a review of early gas cooled reactors including the Magnox reactors originating in the United Kingdom and the subsequent development of the Advanced Gas-cooled Reactors (AGR). These early gas cooled reactors shared a common coolant medium, namely carbon dioxide (CO2). A framework of information is provided about these early reactors and identifies unique problems/opportunities associated with use of CO2 as a coolant. Reactor designers successfully rose to these challenges. After years of successful use of the CO2 gas cooled reactors in Europe, the succeeding generation of reactors, called the High Temperature Gas Reactors (HTGR), were designed with Helium gas as the coolant. Again, in the 21st century, with the latest reactor designs under investigation in Generation IV, there is a revived interest in developing Gas Cooled Fast Reactors that use CO2 as the reactor coolant. This paper provides a historical perspective on the 52 CO2 reactors and the reactor programs that developed them. The Magnox and AGR design features and safety characteristics were reviewed, as well as the technologies associated with fuel storage, reprocessing, and disposal. Lessons-learned from these programs are noted to benefit the designs of future generations of gas cooled nuclear reactors.

  7. Generation-IV Nuclear Energy Systems

    Science.gov (United States)

    McFarlane, Harold

    2008-05-01

    Nuclear power technology has evolved through roughly three generations of system designs: a first generation of prototypes and first-of-a-kind units implemented during the period 1950 to 1970; a second generation of industrial power plants built from 1970 to the turn of the century, most of which are still in operation today; and a third generation of evolutionary advanced reactors which began being built by the turn of the 20^th century, usually called Generation III or III+, which incorporate technical lessons learned through more than 12,000 reactor-years of operation. The Generation IV International Forum (GIF) is a cooperative international endeavor to develop advanced nuclear energy systems in response to the social, environmental and economic requirements of the 21^st century. Six Generation IV systems under development by GIF promise to enhance the future contribution and benefits of nuclear energy. All Generation IV systems aim at performance improvement, new applications of nuclear energy, and/or more sustainable approaches to the management of nuclear materials. High-temperature systems offer the possibility of efficient process heat applications and eventually hydrogen production. Enhanced sustainability is achieved primarily through adoption of a closed fuel cycle with reprocessing and recycling of plutonium, uranium and minor actinides using fast reactors. This approach provides significant reduction in waste generation and uranium resource requirements.

  8. Gen IV Materials Handbook Implementation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Rittenhouse, P.; Ren, W.

    2005-03-29

    A Gen IV Materials Handbook is being developed to provide an authoritative single source of highly qualified structural materials information and materials properties data for use in design and analyses of all Generation IV Reactor Systems. The Handbook will be responsive to the needs expressed by all of the principal government, national laboratory, and private company stakeholders of Gen IV Reactor Systems. The Gen IV Materials Handbook Implementation Plan provided here addresses the purpose, rationale, attributes, and benefits of the Handbook and will detail its content, format, quality assurance, applicability, and access. Structural materials, both metallic and ceramic, for all Gen IV reactor types currently supported by the Department of Energy (DOE) will be included in the Gen IV Materials Handbook. However, initial emphasis will be on materials for the Very High Temperature Reactor (VHTR). Descriptive information (e.g., chemical composition and applicable technical specifications and codes) will be provided for each material along with an extensive presentation of mechanical and physical property data including consideration of temperature, irradiation, environment, etc. effects on properties. Access to the Gen IV Materials Handbook will be internet-based with appropriate levels of control. Information and data in the Handbook will be configured to allow search by material classes, specific materials, specific information or property class, specific property, data parameters, and individual data points identified with materials parameters, test conditions, and data source. Details on all of these as well as proposed applicability and consideration of data quality classes are provided in the Implementation Plan. Website development for the Handbook is divided into six phases including (1) detailed product analysis and specification, (2) simulation and design, (3) implementation and testing, (4) product release, (5) project/product evaluation, and (6) product

  9. Height formation of bright points observed by IRIS in Mg II line wings during flux emergence

    Science.gov (United States)

    Grubecka, M.; Schmieder, B.; Berlicki, A.; Heinzel, P.; Dalmasse, K.; Mein, P.

    2016-09-01

    Context. A flux emergence in the active region AR 111850 was observed on September 24, 2013 with the Interface Region Imaging Spectrograph (IRIS). Many bright points are associated with the new emerging flux and show enhancement brightening in the UV spectra. Aims: The aim of this work is to compute the altitude formation of the compact bright points (CBs) observed in Mg II lines in the context of searching Ellerman bombs (EBs). Methods: IRIS provided two large dense rasters of spectra in Mg II h and k lines, Mg II triplet, C II and Si IV lines covering all the active region and slit jaws in the two bandpasses (1400 Å and 2796 Å) starting at 11:44 UT and 15:39 UT, and lasting 20 min each. Synthetic profiles of Mg II and Hα lines are computed with non-local thermodynamic equlibrium (NLTE) radiative transfer treatment in 1D solar atmosphere model including a hotspot region defined by three parameters: temperature, altitude, and width. Results: Within the two IRIS rasters, 74 CBs are detected in the far wings of the Mg II lines (at +/-1 Å and 3.5 Å). Around 10% of CBs have a signature in Si IV and CII. NLTE models with a hotspot located in the low atmosphere were found to fit a sample of Mg II profiles in CBs. The Hα profiles computed with these Mg II CB models are consistent with typical EB profiles observed from ground based telescopes e.g. THEMIS. A 2D NLTE modelling of fibrils (canopy) demonstrates that the Mg II line centres can be significantly affected but not the peaks and the wings of Mg II lines. Conclusions: We conclude that the bright points observed in Mg II lines can be formed in an extended domain of altitudes in the photosphere and/or the chromosphere (400 to 750 km). Our results are consistent with the theory of heating by Joule dissipation in the atmosphere produced by magnetic field reconnection during flux emergence.

  10. IRISpy: Analyzing IRIS Data in Python

    Science.gov (United States)

    Ryan, Daniel; Christe, Steven; Mumford, Stuart; Baruah, Ankit; Timothy, Shelbe; Pereira, Tiago; De Pontieu, Bart

    2017-08-01

    IRISpy is a new community-developed open-source software library for analysing IRIS level 2 data. It is written in Python, a free, cross-platform, general-purpose, high-level programming language. A wide array of scientific computing software packages have already been developed in Python, from numerical computation (NumPy, SciPy, etc.), to visualization and plotting (matplotlib), to solar-physics-specific data analysis (SunPy). IRISpy is currently under development as a SunPy-affiliated package which means it depends on the SunPy library, follows similar standards and conventions, and is developed with the support of of the SunPy development team. IRISpy’s has two primary data objects, one for analyzing slit-jaw imager data and another for analyzing spectrograph data. Both objects contain basic slicing, indexing, plotting, and animating functionality to allow users to easily inspect, reduce and analyze the data. As part of this functionality the objects can output SunPy Maps, TimeSeries, Spectra, etc. of relevant data slices for easier inspection and analysis. Work is also ongoing to provide additional data analysis functionality including derivation of systematic measurement errors (e.g. readout noise), exposure time correction, residual wavelength calibration, radiometric calibration, and fine scale pointing corrections. IRISpy’s code base is publicly available through github.com and can be contributed to by anyone. In this poster we demonstrate IRISpy’s functionality and future goals of the project. We also encourage interested users to become involved in further developing IRISpy.

  11. Developmental origin of the posterior pigmented epithelium of iris.

    Science.gov (United States)

    Wang, Xiaobing; Xiong, Kai; Lu, Lei; Gu, Dandan; Wang, Songtao; Chen, Jing; Xiao, Honglei; Zhou, Guomin

    2015-03-01

    Iris epithelium is a double-layered pigmented cuboidal epithelium. According to the current model, the neural retina and the posterior iris pigment epithelium (IPE) are derived from the inner wall of the optic cup, while the retinal pigment epithelium (RPE) and the anterior IPE are derived from the outer wall of the optic cup during development. Our current study shows evidence, contradicting this model of fetal iris development. We demonstrate that human fetal iris expression patterns of Otx2 and Mitf transcription factors are similar, while the expressions of Otx2 and Sox2 are complementary. Furthermore, IPE and RPE exhibit identical morphologic development during the early embryonic period. Our results suggest that the outer layer of the optic cup forms two layers of the iris epithelium, and the posterior IPE is the inward-curling anterior rim of the outer layer of the optic cup. These findings provide a reasonable explanation of how IPE cells can be used as an appropriate substitute for RPE cells.

  12. A Study on Iris Localization and Recognition on Mobile Phones

    Science.gov (United States)

    Park, Kang Ryoung; Park, Hyun-Ae; Kang, Byung Jun; Lee, Eui Chul; Jeong, Dae Sik

    2007-12-01

    A new iris recognition method for mobile phones based on corneal specular reflections (SRs) is discussed. We present the following three novelties over previous research. First, in case of user with glasses, many noncorneal SRs may happen on the surface of glasses and it is very difficult to detect genuine SR on the cornea. To overcome such problems, we propose a successive on/off dual illuminator scheme to detect genuine SRs on the corneas of users with glasses. Second, to detect SRs robustly, we estimated the size, shape, and brightness of the SRs based on eye, camera, and illuminator models. Third, the detected eye (iris) region was verified again using the AdaBoost eye detector. Experimental results with 400 face images captured from 100 persons with a mobile phone camera showed that the rate of correct iris detection was 99.5[InlineEquation not available: see fulltext.] (for images without glasses) and 98.9[InlineEquation not available: see fulltext.] (for images with glasses or contact lenses). The consequent accuracy of iris authentication was 0.05[InlineEquation not available: see fulltext.] of the EER (equal error rate) based on detected iris images.

  13. A Study on Iris Localization and Recognition on Mobile Phones

    Directory of Open Access Journals (Sweden)

    Dae Sik Jeong

    2007-11-01

    Full Text Available A new iris recognition method for mobile phones based on corneal specular reflections (SRs is discussed. We present the following three novelties over previous research. First, in case of user with glasses, many noncorneal SRs may happen on the surface of glasses and it is very difficult to detect genuine SR on the cornea. To overcome such problems, we propose a successive on/off dual illuminator scheme to detect genuine SRs on the corneas of users with glasses. Second, to detect SRs robustly, we estimated the size, shape, and brightness of the SRs based on eye, camera, and illuminator models. Third, the detected eye (iris region was verified again using the AdaBoost eye detector. Experimental results with 400 face images captured from 100 persons with a mobile phone camera showed that the rate of correct iris detection was 99.5% (for images without glasses and 98.9% (for images with glasses or contact lenses. The consequent accuracy of iris authentication was 0.05% of the EER (equal error rate based on detected iris images.

  14. Human identification using correlation metrics of iris images

    Science.gov (United States)

    Celenk, Mehmet; Brown, Michael; Luo, Yi; Kaufman, Jason; Ma, Limin; Zhou, Qiang

    2005-01-01

    This paper presents work done based on second order statistical features including cross- and auto-correlations as well as co-occurrence matrices of iris images in an attempt to extract a simple, yet powerful, set of features of an iris as a biometric. Prior to our work, the most prevalent methods for iris identification include the frontier work based on the use of quadrature 2-D Gabor wavelets with the Hamming Distance-based classification [1,2], circular Gabor filters with a nearest feature line (NFL) classifier [3], dyadic wavelet transform with the zero-cross detectors [4], texture analysis [9] and transient signal [11], and independent component analysis (ICA) [7], and boundary localization [10]. Our method differs significantly from the earlier approaches to iris recognition in that it relies on the wide-sense stationary approximation to the texture and gray-level characteristics of irises, and aims to lend itself for a single-chip hardware implementation. Our preliminary results show that cross- and auto-correlators along with co-occurrence matrix features are highly likely to be prominent iris discriminators.

  15. Mechanism and clinical significance of prostaglandin-induced iris pigmentation.

    Science.gov (United States)

    Stjernschantz, Johan W; Albert, Daniel M; Hu, Dan-Ning; Drago, Filippo; Wistrand, Per J

    2002-08-01

    The new glaucoma drugs latanoprost, isopropyl unoprostone, travoprost, and bimatoprost cause increased pigmentation of the iris in some patients. The purpose of the present article is to survey the available preclinical and clinical data on prostaglandin-induced iris pigmentation and to assess the phenomenon from a clinical perspective. Most of the data have been obtained with latanoprost, and it appears that there is a predisposition to latanoprost-induced iris pigmentation in individuals with hazel or heterochromic eye color. As latanoprost and travoprost are selective agonists for the prostaglandin F(2alpha) receptor, it is likely that the phenomenon is mediated by this receptor. Several studies indicate that latanoprost stimulates melanogenesis in iridial melanocytes, and transcription of the tyrosinase gene is upregulated. The safety aspects of latanoprost-induced iris pigmentation have been addressed in histopathologic studies, and no evidence of harmful consequences of the side effect has been found. Although a final assessment of the clinical significance of prostaglandin-induced iris pigmentation currently is impossible to make, it appears that the only clear-cut disadvantage is a potential heterochromia between the eyes in unilaterally treated patients because the heterochromia is likely to be permanent, or very slowly reversible.

  16. Systemic and Ophthalmologic Findings in Patients with Iris Coloboma

    Directory of Open Access Journals (Sweden)

    Sevda Ertekin

    2013-01-01

    Full Text Available Pur po se: Ocular coloboma is a rare malformation resulting from defective closure of the embryonic optic fissure. It can affect iris, retina, choroid, optic disc or ciliary body. This study reviews the clinical diagnosis and the accompanying ocular and systemic abnormalities in cases of iris coloboma. Ma te ri al and Met hod: Sixteen eyes of ten patients referred to our clinic and diagnosed as iris coloboma were included in the study and were reviewed retrospectively. Re sults: Seven cases were sporadic, and three cases were familial. Isolated iris coloboma was present in only one case, and chorioretinal involvement was present in all the others. Seven cases had involvement of the optic disc. Other ocular anomalies were unilateral microphthalmia in 3 cases, unilateral anophthalmia in 1 case, and unilateral microcornea in one case. Strabismus was present in the familial cases. Dis cus si on: In patients, diagnosed with iris coloboma, routine eye examination should be completed, refractive errors should be corrected, and these patients must be follewed for amblyopia. If strabismus is concominant, surgery can be performed. For potential complications, patients should be checked at regular intervals. (Turk J Ophthalmol 2013; 43: 19-22

  17. Bioconversion reactor

    Science.gov (United States)

    McCarty, Perry L.; Bachmann, Andre

    1992-01-01

    A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

  18. Visual outcome after corneal transplantation for corneal perforation and iris prolapse in 37 horses

    DEFF Research Database (Denmark)

    Henriksen, Michala de Linde; Plummer, C. E.; Mangan, B.;

    2012-01-01

    We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation.......We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation....

  19. Fusion of phase congruency and harris algorithm for extraction of iris corner points

    CSIR Research Space (South Africa)

    Mabuza-Hocquet, G

    2015-12-01

    Full Text Available iris identification systems. Low cost devices used under uncontrolled environments acquire poor iris images with inconsistent illumination and specular reflections. These factors inflict challenges towards the accurate identification and extraction...

  20. Automatic localization of pupil using eccentricity and iris using gradient based method

    Science.gov (United States)

    Khan, Tariq M.; Aurangzeb Khan, M.; Malik, Shahzad A.; Khan, Shahid A.; Bashir, Tariq; Dar, Amir H.

    2011-02-01

    This paper presents a novel approach for the automatic localization of pupil and iris. Pupil and iris are nearly circular regions, which are surrounded by sclera, eyelids and eyelashes. The localization of both pupil and iris is extremely important in any iris recognition system. In the proposed algorithm pupil is localized using Eccentricity based Bisection method which looks for the region that has the highest probability of having pupil. While iris localization is carried out in two steps. In the first step, iris image is directionally segmented and a noise free region (region of interest) is extracted. In the second step, angular lines in the region of interest are extracted and the edge points of iris outer boundary are found through the gradient of these lines. The proposed method is tested on CASIA ver 1.0 and MMU Iris databases. Experimental results show that this method is comparatively accurate.

  1. Ethnicity prediction and classification from iris texture patterns: A survey on recent advances

    CSIR Research Space (South Africa)

    Mabuza-Hocquet, Gugulethu

    2017-03-01

    Full Text Available The prediction and classification of ethnicity based on iris texture patterns using image processing, artificial intelligence and computer vision techniques is still a recent topic in iris biometrics. While the large body of knowledge and research...

  2. Iris recognition using image moments and k-means algorithm.

    Science.gov (United States)

    Khan, Yaser Daanial; Khan, Sher Afzal; Ahmad, Farooq; Islam, Saeed

    2014-01-01

    This paper presents a biometric technique for identification of a person using the iris image. The iris is first segmented from the acquired image of an eye using an edge detection algorithm. The disk shaped area of the iris is transformed into a rectangular form. Described moments are extracted from the grayscale image which yields a feature vector containing scale, rotation, and translation invariant moments. Images are clustered using the k-means algorithm and centroids for each cluster are computed. An arbitrary image is assumed to belong to the cluster whose centroid is the nearest to the feature vector in terms of Euclidean distance computed. The described model exhibits an accuracy of 98.5%.

  3. Texture Feature Extraction and Classification for Iris Diagnosis

    Science.gov (United States)

    Ma, Lin; Li, Naimin

    Appling computer aided techniques in iris image processing, and combining occidental iridology with the traditional Chinese medicine is a challenging research area in digital image processing and artificial intelligence. This paper proposes an iridology model that consists the iris image pre-processing, texture feature analysis and disease classification. To the pre-processing, a 2-step iris localization approach is proposed; a 2-D Gabor filter based texture analysis and a texture fractal dimension estimation method are proposed for pathological feature extraction; and at last support vector machines are constructed to recognize 2 typical diseases such as the alimentary canal disease and the nerve system disease. Experimental results show that the proposed iridology diagnosis model is quite effective and promising for medical diagnosis and health surveillance for both hospital and public use.

  4. Evaluation of the Yellow IRIS. An automated method for urinalysis.

    Science.gov (United States)

    Roe, C E; Carlson, D A; Daigneault, R W; Statland, B E

    1986-11-01

    The authors evaluated the Yellow IRIS automated urinalysis instrument (International Remote Imaging Systems, Chatsworth, CA 91311) in terms of its analytic performance as well as its ease of use. The Yellow IRIS is a system using automated intelligence microscopy (AIM), coupled with a dipstick reader and specific gravity module. The instrument can handle up to 30 specimens per hour in the authors' setting as compared with 10 specimens per hour using a full manual urinalysis coupled with microscopic examination. The authors conclude that the Yellow IRIS performed better than the manual method in terms of precision, linearity, and throughput. In addition, the diagnostic yield using this system in terms of abnormal results was higher than would have been picked up by manual analysis alone.

  5. IRIS: A Generic Three-Dimensional Radiative Transfer Code

    CERN Document Server

    Ibgui, L; Lanz, T; Stehlé, C

    2012-01-01

    We present IRIS, a new generic three-dimensional (3D) spectral radiative transfer code that generates synthetic spectra, or images. It can be used as a diagnostic tool for comparison with astrophysical observations or laboratory astrophysics experiments. We have developed a 3D short-characteristic solver that works with a 3D nonuniform Cartesian grid. We have implemented a piecewise cubic, locally monotonic, interpolation technique that dramatically reduces the numerical diffusion effect. The code takes into account the velocity gradient effect resulting in gradual Doppler shifts of photon frequencies and subsequent alterations of spectral line profiles. It can also handle periodic boundary conditions. This first version of the code assumes Local Thermodynamic Equilibrium (LTE) and no scattering. The opacities and source functions are specified by the user. In the near future, the capabilities of IRIS will be extended to allow for non-LTE and scattering modeling. IRIS has been validated through a number of te...

  6. Avoiding iris trauma from phacoemulsification in eyes with iridoschisis.

    Science.gov (United States)

    Rozenberg, Israel; Seabra, Fabíola P

    2004-04-01

    Iridoschisis is a rare condition frequently associated with age-related cataract. Phacoemulsification can be difficult to perform in these eyes, as the detached iris fibrils that are typically present free float in the anterior chamber and are attracted to the phaco tip and the irrigation/aspiration handpiece port. We describe a technique for performing phacoemulsification in eyes with iridoschisis. In this technique, iris fibrils are held in place by 2 ophthalmic viscosurgical devices (OVDs) that are injected into the inferior portion of the anterior chamber. An elliptical capsulorhexis is made and limited to the superior half of the pupil for additional stability of the anterior chamber during surgery. The nucleus is chopped with a phaco chopper and a bent-tip, 22-gauge needle. Most of the phacoemulsification is performed under the anterior capsule. The iris comes into contact with the OVDs only and has no mechanical trauma.

  7. Analyzing the IAR with IRI During the Recent Solar Minimum

    Science.gov (United States)

    Ivanov, S.; Klenzing, J.; Simoes, F.

    2012-01-01

    The 2008-2009 solar minimum was deeper than any within the past century. As such, the performance of the empirical International Reference Ionosphere (IRI) model was impacted. This impact manifested as a disagreement between predicted and measured characteristic separation in frequency for a wave resonating within an Ionospheric Alfven Resonator (IAR). The predicted value of the characteristic was a factor of three lower than what was measured by the Communication/Navigation Outage Forecast System (C/NOFS). Analyzing the model performance and comparing output with measured ionospheric values showed that more than half of the inaccuracy could be explained by inaccuracies in the output of the model. The 2008-2009 solar minimum was outside of the bounds of the effectiveness of the empirical IRI model. Incorporating recent data measurements and new indices would increase the accuracy of IRI during this period.

  8. Thirty Years of Innovation in Seismology with the IRIS Consortium

    Science.gov (United States)

    Sumy, D. F.; Woodward, R.; Aderhold, K.; Ahern, T. K.; Anderson, K. R.; Busby, R.; Detrick, R. S.; Evers, B.; Frassetto, A.; Hafner, K.; Simpson, D. W.; Sweet, J. R.; Taber, J.

    2015-12-01

    The United States academic seismology community, through the National Science Foundation (NSF)-funded Incorporated Research Institutions for Seismology (IRIS) Consortium, has promoted and encouraged a rich environment of innovation and experimentation in areas such as seismic instrumentation, data processing and analysis, teaching and curriculum development, and academic science. As the science continually evolves, IRIS helps drive the market for new research tools that enable science by establishing a variety of standards and goals. This has often involved working directly with manufacturers to better define the technology required, co-funding key development work or early production prototypes, and purchasing initial production runs. IRIS activities have helped establish de-facto international standards and impacted the commercial sector in areas such as seismic instrumentation, open-access data management, and professional development. Key institutional practices, conducted and refined over IRIS' thirty-year history of operations, have focused on open-access data availability, full retention of maximum-bandwidth, continuous data, and direct community access to state-of-the-art seismological instrumentation and software. These practices have helped to cultivate and support a thriving commercial ecosystem, and have been a key element in the professional development of multiple generations of seismologists who now work in both industry and academia. Looking toward the future, IRIS is increasing its engagement with industry to better enable bi-directional exchange of techniques and technology, and enhancing the development of tomorrow's workforce. In this presentation, we will illustrate how IRIS has promoted innovations grown out of the academic community and spurred technological advances in both academia and industry.

  9. Anterior iris-claw lens implantation with single paracentesis

    Directory of Open Access Journals (Sweden)

    Ahmet Özer

    2011-11-01

    Full Text Available In this study, the technique and results of iris-claw intraocular lens (IOL implantation with corneal incision and single paracentesis were presented. Eighteen eyes of 18 patients who underwent iris-claw implantation surgery with a single paracentesis were included in this prospective study. Iris-claw lens was grasped by its forceps and placed into the anterior chamber through superior corneal opening. While IOL was held by forceps, a blunt enclavation spatula was introduced through inferior paracentesis. Then the spatula was directed toward underneath of iris through pupil and toward sides where iris was entrapped into the claw by gentle push of iris through the slotted center of the lens haptics. Mean age of patients was 54.28±25.21 years (7-76 years. Mean anterior chamber depth was 4.07±0.32 mm and mean keratometric power was 43.01±2.73 D. Preoperative BCVA was 20/63 or better in 8 (44.4% patients. At the first postoperative month BCVA was 20/63 or better in 14 (77.8% patients. Preoperative mean spherical refraction was +11.05±2.62 D, preoperative astigmatism was 2.15±0.85. Postoperative mean spherical refraction was - 0.58±0.25 D and mean astigmatism was - 1.92±0.67 D. The most frequent postoperative complication was mild corneal edema seen in three patients that resolved completely during the first week with medical treatment. Irisclaw IOL implantation can be performed easily with corneal incision and single paracentesis. Single paracentesis does not increase surgical time or cause inconvenience during the procedure.

  10. Computer simulation of the NASA water vapor electrolysis reactor

    Science.gov (United States)

    Bloom, A. M.

    1974-01-01

    The water vapor electrolysis (WVE) reactor is a spacecraft waste reclamation system for extended-mission manned spacecraft. The WVE reactor's raw material is water, its product oxygen. A computer simulation of the WVE operational processes provided the data required for an optimal design of the WVE unit. The simulation process was implemented with the aid of a FORTRAN IV routine.

  11. Sonochemical Reactors.

    Science.gov (United States)

    Gogate, Parag R; Patil, Pankaj N

    2016-10-01

    Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation.

  12. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl ...

    Science.gov (United States)

    EPA released the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from other Federal agencies and White House Offices are provided below with external peer review panel comments. EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of EGBE that will appear on the Integrated Risk Information System (IRIS) database.

  13. Off-Angle Iris Correction using a Biological Model

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Villalobos, Hector J [ORNL; Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Boehnen, Chris Bensing [ORNL

    2013-01-01

    This work implements an eye model to simulate corneal refraction effects. Using this model, ray tracing is performed to calculate transforms to remove refractive effects in off-angle iris images when reprojected to a frontal view. The correction process is used as a preprocessing step for off-angle iris images for input to a commercial matcher. With this method, a match score distribution mean improvement of 11.65% for 30 degree images, 44.94% for 40 degree images, and 146.1% improvement for 50 degree images is observed versus match score distributions with unmodified images.

  14. Off-Angle Iris Correction using a Biological Model

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Joseph T [ORNL; Santos-Villalobos, Hector J [ORNL; Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

    2013-01-01

    This work implements an eye model to simulate corneal refraction effects. Using this model, ray tracing is performed to calculate transforms to remove refractive effects in off-angle iris images when reprojected to a frontal view. The correction process is used as a preprocessing step for off-angle iris images for input to a commercial matcher. With this method, a match score distribution mean improvement of 11.65% for 30 degree images, 44.94% for 40 degree images, and 146.1% improvement for 50 degree images is observed versus match score distributions with unmodi ed images.

  15. Comparisons of IRI global TEC maps with CODE GIMs

    CERN Document Server

    Coisson, P; Radicella, S M

    2002-01-01

    The Global Ionospheric Maps (GIM) produced at CODE are used in this work as experimental reference to evaluate the performance of IRI in predicting global vertical TEC during a period of high solar activity. The analysis has been done for the four seasons of year 2001, comparing monthly median GIMs for 12 different UTs. The attention is focused on the correct reproduction of large scale features like the equatorial anomaly or behavior at high latitudes, to understand where and under which conditions the IRI model could present unexpectable features.

  16. Iris image enhancement for feature recognition and extraction

    CSIR Research Space (South Africa)

    Mabuza, GP

    2012-10-01

    Full Text Available Gonzalez, R.C. and Woods, R.E. 2002. Digital Image Processing 2nd Edition, Instructor?s manual .Englewood Cliffs, Prentice Hall, pp 17-36. Proen?a, H. and Alexandre, L.A. 2007. Toward Noncooperative Iris Recognition: A classification approach using... for performing such tasks and yielding better accuracy (Gonzalez & Woods, 2002). METHODOLOGY The block diagram in Figure 2 demonstrates the processes followed to achieve the results. Figure 2: Methodology flow chart Iris image enhancement for feature...

  17. Minimizing the fissile inventory of the molten salt fast reactor

    OpenAIRE

    Merle-Lucotte, E.; Heuer, D.; Allibert, M.; Doligez, X.; Ghetta, V.

    2009-01-01

    International audience; Molten salt reactors in the configurations presented here, called Molten Salt Fast Reactors (MSFR), have been selected for further studies by the Generation IV International Forum. These reactors may be operated in simplified and safe conditions in the Th/233U fuel cycle with fluoride salts. We present here the concept, before focusing on a possible optimization in term of minimization of the initial fissile inventory. Our studies demonstrate that an inventory of 233U ...

  18. On the oxidation of uraninite from natural reactor cores

    Energy Technology Data Exchange (ETDEWEB)

    Cui, D.; Eriksen, T.; Eklund, U.B.

    1999-07-01

    Natural nuclear reactors provide unique evidence in helping to understand the processes that might occur over long timescales in radioactive waste disposal sites. In the presented work, the extent and kinetics of oxidation of core material from the Oklo-Bangombe natural reactors are investigated. The X-ray powder diffraction analysis shows that the uraninites core samples from the Bangombe Reactor and Oklo Reactor 2, and Oklo Reactor 13 have the same unit-cell parameters as synthetic UO{sub 2.25}. A significant amount of fourmarierite, Pb(UO{sub 2}){sub 4}O{sub 3}(OH){sub 4}.4H{sub 2}O, was identified in the core samples from two shallow reactors Bangombe and Oklo 2, but not in the deeper reactor Oklo 13. The results of U(IV)/U(IV) measurements indicate that the extent of oxidative weathering of shallow reactors (Bangombe and Oklo 2) is greater than for the deeper reactor Oklo 13. Evaporable organic compounds found in the uraninite inclusion containing bitumen at the edge of Okelobondo Reactor (400 C) and in the black shale immediately above the Bangombe Reactor (260 C) may work as a reducing buffer or/and a hydrophobic water shield to depress the oxidative dissolution of the uraninite cores.

  19. [The automatic iris map overlap technology in computer-aided iridiagnosis].

    Science.gov (United States)

    He, Jia-feng; Ye, Hu-nian; Ye, Miao-yuan

    2002-11-01

    In the paper, iridology and computer-aided iridiagnosis technologies are briefly introduced and the extraction method of the collarette contour is then investigated. The iris map can be overlapped on the original iris image based on collarette contour extraction. The research on collarette contour extraction and iris map overlap is of great importance to computer-aided iridiagnosis technologies.

  20. An Analysis on Better Testing than Training Performances on the Iris Dataset

    NARCIS (Netherlands)

    Schutten, Marten; Wiering, Marco

    2016-01-01

    The Iris dataset is a well known dataset containing information on three different types of Iris flowers. A typical and popular method for solving classification problems on datasets such as the Iris set is the support vector machine (SVM). In order to do so the dataset is separated in a set used fo

  1. Expression of defender against apoptotic death (DAD-1) in iris and dianthus petals

    NARCIS (Netherlands)

    Kop, van der D.A.M.; Ruys, G.; Dees, D.; Schoot, van der C.; Boer, de A.D.; Doorn, van W.G.

    2003-01-01

    The gene defender against apoptotic death (DAD-1) prevents programmed cell death in animal cells. We investigated the expression pattern of DAD-1 in petals of iris (Iris x hollandica cv. Blue Magic) and carnation (Dianthus caryophyllus cv. Etarro). DAD-1 expression in Iris petals was strongly reduce

  2. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (Etbe) (Public Comment Draft)

    Science.gov (United States)

    In September 2016, the U.S. Environmental Protection Agency's (USEPA) released the draft Integrated Risk Information System (IRIS) Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE). Consistent with the 2013 IRIS Enhancements, draft IRIS assessments are released prior to e...

  3. Developmental validation of the IrisPlex system: determination of blue and brown iris colour for forensic intelligence.

    Science.gov (United States)

    Walsh, Susan; Lindenbergh, Alexander; Zuniga, Sofia B; Sijen, Titia; de Knijff, Peter; Kayser, Manfred; Ballantyne, Kaye N

    2011-11-01

    The IrisPlex system consists of a highly sensitive multiplex genotyping assay together with a statistical prediction model, providing users with the ability to predict blue and brown human eye colour from DNA samples with over 90% precision. This 'DNA intelligence' system is expected to aid police investigations by providing phenotypic information on unknown individuals when conventional DNA profiling is not informative. Falling within the new area of forensic DNA phenotyping, this paper describes the developmental validation of the IrisPlex assay following the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines for the application of DNA-based eye colour prediction to forensic casework. The IrisPlex assay produces complete SNP genotypes with only 31pg of DNA, approximately six human diploid cell equivalents, and is therefore more sensitive than commercial STR kits currently used in forensics. Species testing revealed human and primate specificity for a complete SNP profile. The assay is capable of producing accurate results from simulated casework samples such as blood, semen, saliva, hair, and trace DNA samples, including extremely low quantity samples. Due to its design, it can also produce full profiles with highly degraded samples often found in forensic casework. Concordance testing between three independent laboratories displayed reproducible results of consistent levels on varying types of simulated casework samples. With such high levels of sensitivity, specificity, consistency and reliability, this genotyping assay, as a core part of the IrisPlex system, operates in accordance with SWGDAM guidelines. Furthermore, as we demonstrated previously, the IrisPlex eye colour prediction system provides reliable results without the need for knowledge on the bio-geographic ancestry of the sample donor. Hence, the IrisPlex system, with its model-based prediction probability estimation of blue and brown human eye colour, represents a useful tool for

  4. Plateau iris Íris em platô

    Directory of Open Access Journals (Sweden)

    Alberto Diniz Filho

    2008-10-01

    Full Text Available The term plateau iris was first coined in 1958 to describe the iris configuration of a patient. Two years later the concept of plateau iris was published. In 1977, the plateau iris configuration was classically defined as presurgical changes of an eye with a relative normal central anterior chamber depth, flat iris by conventional biomicroscopy, but displaying an extremely narrow or closed angle on gonioscopic examination. On the other hand, the plateau iris syndrome was defined as an acute glaucoma crisis in one eye with a relative normal central anterior chamber depth and patent iridotomy on direct examination, presenting angle closure confirmed by gonioscopic examination after mydriasis. In 1992, the anatomic aspects of plateau iris were studied using ultrasound biomicroscopy. Finally, plateau iris has been considered an anatomic variant of iris structure in which the iris periphery angulates sharply forward from its insertion point and then again angulates sharply and centrally backward, along with an anterior positioning of the ciliary processes seen on ultrasound biomicroscopy. The clinical treatment of plateau iris syndrome is carried out with topical use of pilocarpine. However, the definitive treatment should be fulfilled by performing an argon laser peripheral iridoplasty.O termo íris em platô foi primeiramente inventado em 1958 para descrever a configuração da íris de um paciente. Dois anos depois o conceito de íris em platô foi publicado. Em 1977, a configuração de íris em platô foi classicamente definida como alterações pré-cirúrgicas de um olho com uma profundidade de câmara anterior relativamente normal, íris plana pela biomicroscopia convencional, mas mostrando um ângulo extremamente estreito ou fechado pela gonioscopia. Por outro lado, a síndrome de íris em platô foi definida como uma crise de glaucoma agudo em um olho com uma profundidade de câmara anterior relativamente normal e uma iridectomia patente ao

  5. 76 FR 78096 - U.S. Advanced Boiling Water Reactor Aircraft Impact Design Certification Amendment

    Science.gov (United States)

    2011-12-16

    ... COMMISSION 10 CFR Part 52 RIN 3150-AI84 U.S. Advanced Boiling Water Reactor Aircraft Impact Design.... Advanced Boiling Water Reactor (U.S. ABWR) standard plant design to comply with the NRC's aircraft impact...--Design Certification Rule for the U.S. Advanced Boiling Water Reactor IV. Section-by-Section Analysis A...

  6. 76 FR 3540 - U.S. Advanced Boiling Water Reactor Aircraft Impact Design Certification Amendment

    Science.gov (United States)

    2011-01-20

    ... COMMISSION 10 CFR Part 52 RIN 3150-AI84 U.S. Advanced Boiling Water Reactor Aircraft Impact Design... the U.S. Advanced Boiling Water Reactor (ABWR) standard plant design to comply with the NRC's aircraft...--Design Certification Rule for the U.S. Advanced Boiling Water Reactor IV. Section-by-Section Analysis A...

  7. DOE/NNSA perspective safeguard by design: GEN III/III+ light water reactors and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Paul Y [Los Alamos National Laboratory

    2010-12-10

    An overview of key issues relevant to safeguards by design (SBD) for GEN III/IV nuclear reactors is provided. Lessons learned from construction of typical GEN III+ water reactors with respect to SBD are highlighted. Details of SBD for safeguards guidance development for GEN III/III+ light water reactors are developed and reported. This paper also identifies technical challenges to extend SBD including proliferation resistance methodologies to other GEN III/III+ reactors (except HWRs) and GEN IV reactors because of their immaturity in designs.

  8. Heating signatures in the disk counterparts of solar spicules in IRIS observations

    CERN Document Server

    van der Voort, L Rouppe; Pereira, T M D; Carlsson, M; Hansteen, V

    2014-01-01

    We use coordinated observations with the Interface Region Imaging Spectrograph (IRIS) and the Swedish 1-m Solar Telescope (SST) to identify the disk counterpart of type II spicules in upper-chromospheric and transition region (TR) diagnostics. These disk counterparts were earlier identified through short-lived asymmetries in chromospheric spectral lines: rapid blue- or red-shifted excursions (RBEs or RREs). We find clear signatures of RBEs and RREs in Mg II h & k, often with excursions of the central h3 and k3 absorption features in concert with asymmetries in co-temporal and co-spatial H-alpha spectral profiles. We find spectral signatures for RBEs and RREs in C II 1335 and 1336 A and Si IV 1394 and 1403 A spectral lines and interpret this as a sign that type II spicules are heated to at least TR temperatures, supporting other recent work. These C II and Si IV spectral signals are weaker for a smaller network region than for more extended network regions in our data. A number of bright features around ex...

  9. Observation and analysis of ballistic downflows in a M-class flare using IRIS

    Science.gov (United States)

    Brannon, Sean

    2016-05-01

    Despite significant advances in instrumentation, there remain no studies that analyze observations of on-disk flare loop plasma flows covering the entire evolution from chromospheric evaporation, through plasma cooling, to draining downflows. We present results from an imaging and spectroscopic observation from the Interface Region Imaging Spectrograph (IRIS) of the SOL2015-03-12T11:50:00 M-class flare, at high spatial resolution and time cadence. Our analysis of this event reveals initial plasma evaporation at flare temperatures indicated by 100-200 km/s blueshifts in the Fe XXI line. We subsequently observe plasma cooling into chromospheric lines (Si IV and O IV) with ~11 minute delay, followed by loop draining at ~40 km/s as indicated by a ``C''-shaped redshift structure and significant (~60 km/s) non-thermal broadening. We use density sensitive lines to calculate a plasma density for the flare loops, and estimate a theoretical cooling time approximately equal to the observed delay. Finally, we use a simple elliptical free-fall draining model to construct synthetic spectra, and perform what we believe to be the first direct comparison of such synthetic spectra to observations of draining downflows in flare loops.

  10. Delay of Iris flower senescence by protease inhibitors

    NARCIS (Netherlands)

    Pak, C.; Doorn, van W.G.

    2005-01-01

    asterisk inside a circle sign Visible senescence of the flag tepals in Iris x hollandica (cv. Blue Magic) was preceded by a large increase in endoprotease activity. Just before visible senescence about half of total endoprotease activity was apparently due to cysteine proteases, somewhat less than h

  11. Daffodil flower delay senescence in cut Iris flowers

    NARCIS (Netherlands)

    Doorn, van W.G.; Sinz, A.; Tomassen, M.M.M.

    2004-01-01

    Visible symptoms of tepal senescence in cut Iris x hollandica (cv. Blue Magic) flowers were delayed by placing one cut daffodil flower (Narcissus pseudonarcissus, cv. Carlton) in the same vase. Addition of mucilage, exuded by daffodil stems, to the vase water had the same effect as the flowering daf

  12. IRIS Toxicological Review of Acrylamide (External Review Draft)

    Science.gov (United States)

    EPA has conducted a peer review by EPA’s Science Advisory Board (SAB) of the scientific basis supporting the human health hazard and dose-response assessment of acrylamide that once finalized will appear on the Integrated Risk Information System (IRIS) database. Peer review is m...

  13. The Infrared Imaging Spectrograph (IRIS) for TMT: Data Reduction System

    CERN Document Server

    Walth, Gregory; Weiss, Jason; Larkin, James E; Moore, Anna M; Chapin, Edward L; Do, Tuan; Dunn, Jennifer; Ellerbroek, Brent; Gillies, Kim; Hayano, Yutaka; Johnson, Chris; Marshall, Daniel; Riddle, Reed L; Simard, Luc; Sohn, Ji Man; Suzuki, Ryuji; Wincensten, James

    2016-01-01

    IRIS (InfraRed Imaging Spectrograph) is the diffraction-limited first light instrument for the Thirty Meter Telescope (TMT) that consists of a near-infrared (0.84 to 2.4 $\\mu$m) imager and integral field spectrograph (IFS). The IFS makes use of a lenslet array and slicer for spatial sampling, which will be able to operate in 100's of different modes, including a combination of four plate scales from 4 milliarcseconds (mas) to 50 mas with a large range of filters and gratings. The imager will have a field of view of 34$\\times$34 arcsec$^{2}$ with a plate scale of 4 mas with many selectable filters. We present the preliminary design of the data reduction system (DRS) for IRIS that need to address all of these observing modes. Reduction of IRIS data will have unique challenges since it will provide real-time reduction and analysis of the imaging and spectroscopic data during observational sequences, as well as advanced post-processing algorithms. The DRS will support three basic modes of operation of IRIS; reduc...

  14. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    Directory of Open Access Journals (Sweden)

    Garcia-Rojas Leonardo

    2012-10-01

    Full Text Available Abstract Background To assess the efficacy, clinical outcomes, visual acuity (VA, incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%, 20/60 or better in 12 eyes (92%, and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method.

  15. Interface Region Imaging Spectrograph (IRIS) entrance aperture design

    Science.gov (United States)

    Cheimets, P.; Park, S.; Bergner, H.; Chou, C.; Gates, R.; Honsa, M.; Podgorski, W.; Yanari, C.

    2014-07-01

    The Interface Region Imaging Spectrograph (IRIS) is a complementary follow-on to Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO-AIA) and funded as a member of the NASA SMEX program. This paper presents the thermal design of the IRIS telescope front end, with a focus on the IRIS door and entrance aperture assembly. The challenge of the IRIS entrance aperture, including the door design, was to manage the solar flux, both before and after the door was opened. This is especially a problem with instruments that are permanently pointed directly at the sun. Though there is an array of effective flux-rejecting coatings, they are expensive, hard to apply, harder to measure, delicate, prone to unpredictable performance decay with exposure, and very often a source of contamination. This paper presents a thermal control and protection method based on robust, inexpensive coatings and materials, combined to produce high thermal and structural isolation. The end result is a first line of thermal protection whose performance is easy to predict and well isolated from the instrument it is protecting.

  16. Drop-out probabilities of IrisPlex SNP alleles

    DEFF Research Database (Denmark)

    Andersen, Jeppe Dyrberg; Tvedebrink, Torben; Mogensen, Helle Smidt

    2013-01-01

    -out of true alleles is possible. As part of the validation of the IrisPlex assay in our ISO17025 accredited, forensic genetic laboratory, we estimated the probability of drop-out of specific SNP alleles using 29 and 30 PCR cycles and 25, 50 and 100 Single Base Extension (SBE) cycles. We observed no drop...

  17. A Field Study of an Iris Identification System

    Science.gov (United States)

    2008-05-01

    and hygiene problems associated with finger scanning); fast; and highly individualistic (with an estimated 173 bits of entropy in each iris template[4...IEEE, May 3–6 1998. [5] G. Doddington, W. Liggett, A. Martin, M. Przybocki, and D. Reynolds. Sheep, goats, lambs and wolves a statistical analysis of

  18. IRIS Toxicological Review of Tetrachloroethylene (Perchloroethylene) (External Review Draft)

    Science.gov (United States)

    EPA conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of tetrachloroethylene that will appear on the Integrated Risk Information System (IRIS) database. Peer review is meant to ensure that science is used credibly and ...

  19. IRIS Toxicological Review of Ethylene Glycol Mono Butyl ...

    Science.gov (United States)

    EPA has finalized the Toxicological Review of Ethylene Glycol Mono Butyl Ether: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health. N/A

  20. IRIS Toxicological Review of Methanol (External Review Draft, 2013)

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of methanol (non-cancer) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

  1. IRIS Toxicological Review of Methanol (Noncancer) (Interagency Science Discussion Draft)

    Science.gov (United States)

    On May 3, 2013, the Toxicological Review of Methanol (noncancer) (Revised External Review Draft) was posted for public review and comment. Subsequently, the draft Toxicological Review, Appendices, and draft IRIS Summary were reviewed internally by EPA and by other federal agenci...

  2. The infrared imaging spectrograph (IRIS) for TMT: sensitivities and simulations

    CERN Document Server

    Wright, Shelley A; Larkin, James E; Moore, Anna M; Crampton, David; Simard, Luc

    2010-01-01

    We present sensitivity estimates for point and resolved astronomical sources for the current design of the InfraRed Imaging Spectrograph (IRIS) on the future Thirty Meter Telescope (TMT). IRIS, with TMT's adaptive optics system, will achieve unprecedented point source sensitivities in the near-infrared (0.84 - 2.45 {\\mu}m) when compared to systems on current 8-10m ground based telescopes. The IRIS imager, in 5 hours of total integration, will be able to perform a few percent photometry on 26 - 29 magnitude (AB) point sources in the near-infrared broadband filters (Z, Y, J, H, K). The integral field spectrograph, with a range of scales and filters, will achieve good signal-to-noise on 22 - 26 magnitude (AB) point sources with a spectral resolution of R=4,000 in 5 hours of total integration time. We also present simulated 3D IRIS data of resolved high-redshift star forming galaxies (1 < z < 5), illustrating the extraordinary potential of this instrument to probe the dynamics, assembly, and chemical abunda...

  3. IRIS Toxicological Review of Acrylamide (External Review Draft)

    Science.gov (United States)

    EPA has conducted a peer review by EPA’s Science Advisory Board (SAB) of the scientific basis supporting the human health hazard and dose-response assessment of acrylamide that once finalized will appear on the Integrated Risk Information System (IRIS) database. Peer review is m...

  4. Preface: The International Reference Ionosphere (IRI) at equatorial latitudes

    Science.gov (United States)

    Reinisch, Bodo; Bilitza, Dieter

    2017-07-01

    This issue of Advances in Space Research includes papers that report and discuss improvements of the International Reference Ionosphere (IRI). IRI is the international standard for the representation of the plasma in Earth's ionosphere and recognized as such by the Committee on Space Research (COSPAR), the International Union of Radio Science (URSI), the International Telecommunication Union (ITU), and the International Standardization Organization (ISO). As requested, particularly by COSPAR and URSI, IRI is an empirical model relying on most of the available and reliable ground and space observations of the ionosphere. As new data become available and as older data sources are fully exploited the IRI model undergoes improvement cycles to stay as close to the existing data record as possible. The latest episode of this process is documented in the papers included in this issue using data from the worldwide network of ionosondes, from a few of the incoherent scatter radars, from the Alouette and ISIS topside sounders, and from the Global Navigation Satellite Systems (GNSS). The focus of this issue is on the equatorial and low latitude region that is of special importance for ionospheric physics because it includes the largest densities and steep density gradients in the double hump latitudinal structure, the Equatorial Ionization Anomaly (EIA), which is characteristic for this region.

  5. Gene expression during anthesis and senescence in Iris flowers

    NARCIS (Netherlands)

    Doorn, van W.G.; Balk, P.A.; Houwelingen, van A.M.; Hoebrechts, F.A.; Hall, R.D.; Vorst, O.; Schoot, van der C.; Wordragen, van M.F.

    2003-01-01

    We investigated changes in gene expression in Iris hollandicaflowers by microarray technology. Flag tepals were sampled daily, from three days prior to flower opening to the onset of visible senescence symptoms. Gene expression profiles were compared with biochemical data including lipid and protein

  6. Delay of Iris flower senescence by protease inhibitors

    NARCIS (Netherlands)

    Pak, C.; Doorn, van W.G.

    2005-01-01

    asterisk inside a circle sign Visible senescence of the flag tepals in Iris x hollandica (cv. Blue Magic) was preceded by a large increase in endoprotease activity. Just before visible senescence about half of total endoprotease activity was apparently due to cysteine proteases, somewhat less than

  7. IRIS Toxicological Review of Libby Amphibole Asbestos (Final Report)

    Science.gov (United States)

    EPA has finalized the, Toxicological Review of Libby Amphibole Asbestos: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health.

  8. Comparison of ionospheric radio occultation CHAMP data with IRI 2001

    Directory of Open Access Journals (Sweden)

    N. Jakowski

    2004-01-01

    Full Text Available GPS radio occultation measurements on board low Earth orbiting satellites can provide vertical electron density profiles of the ionosphere from satellite orbit heights down to the bottomside. Ionospheric radio occultation (IRO measurements carried out onboard the German CHAMP satellite mission since 11 April 2001 were used to derive vertical electron density profiles (EDP’s on a routine basis. About 150 vertical electron density profiles may be retrieved per day thus providing a huge data basis for testing and developing ionospheric models. Although the validation of the EDP retrievals is not yet completed, the paper addresses a systematic comparison of about 78 000 electron density profiles derived from CHAMP IRO data with the International Reference Ionosphere (IRI 2001. The results are discussed for quite different geophysical conditions, e.g. as a function of latitude, local time and geomagnetic activity. The comparison of IRO data with corresponding IRI data indicates that IRI generally overestimates the upper part of the ionosphere whereas it underestimates the lower part of the ionosphere under high solar activity conditions. In a first order correction this systematic deviation could be compensated by introducing a height dependence correction factor in IRI profiling.

  9. In Vitro Antimicrobial Activity of Iris pseudacorus and Urtica dioica

    Directory of Open Access Journals (Sweden)

    Maryam Ramtin

    2014-03-01

    Full Text Available Background: In this study, the effects of antibacterial activity of Urtica dioica and Iris pseudacorus essential oils, native plant northern of Iran, were investigated for some selected bacteria. Material and Methods: The influence of essential oils was tested by the using of disk diffusion and micro-broth dilution methods against standard strains of the picked out bacteria. Gas Chromatography/Mass Spectroscopy (GC/MS analysis, bioactivity determination, Minimum inhibitory concentrations (MIC and minimum bactericidal concentration (MBC of essential oils were utilized for this goal. Results: This study showed that, Inhibition zone diameter varied from 11 to 19 mm and 9 to 17 mm for Urtica dioica and Iris pseudacorus respectively. In contrast, this figure fluctuated from 19 to 28 mm and 7 to 17 mm for gentamicin and ampicillin separately. By the application of micro-broth dilution technique, MICs for 1% essential oils were 1.8-7.5 μg/ml and 3.75-15 μg/ml for, Urtica dioica and Iris pseudacorus against gram-positive and gram-negative bacteria individually. Furthermore, the MBCs of herbal essences were 1.8-15 μg/ml for, Urtica dioica and 15-30 μg/ml for Iris. Conclusion: The application of essential oils for the bio-control of diseases, as a novel emerging alternative to antimicrobial treatments, lead to safer and more environmental management for infective diseases4T.4T

  10. Design and performance of a cryogenic iris aperture mechanism

    Science.gov (United States)

    de Jonge, C.; Laauwen, W. M.; de Vries, E. A.; Smit, H. P.; Detrain, A.; Eggens, M. J.; Ferrari, L.; Dieleman, P.

    2014-07-01

    A cryogenic iris mechanism is under development as part of the ground calibration source for the SAFARI instrument. The iris mechanism is a variable aperture used as an optical shutter to fine-tune and modulate the absolute power output of the calibration source. It has 4 stainless steel blades that create a near-circular aperture in every position. The operating temperature is 4.5 Kelvin to provide a negligible background to the SAFARI detectors, and `hot spots' above 9K should be prevented. Cryogenic testing proved that the iris works at 4K. It can be used in a broad range of cryogenic optical instruments where optical throughput needs to be controlled. Challenges in the design include the low cooling power available (5mW) and low friction at cryogenic temperatures. The actuator is an `arc-type' rotary voice-coil motor. The use of flexural pivots creates a mono-stable mechanism with a resonance frequency at 26Hz. Accurate and fast position control with disturbance rejection is managed by a PID servo loop using a hall-sensor as input. At 4 Kelvin, the frequency is limited to 4Hz to avoid excess dissipation and heating. In this paper, the design and performance of the iris are discussed. The design was optimized using a thermal, magnetic and mechanical model made with COMSOL Finite Element Analysis software. The dynamical and state-space modeling of the mechanism and the concept of the electrical control are presented. The performance of the iris show good agreement to the analytical and COMSOL modeling.

  11. The Interface Region Imaging Spectrograph (IRIS) NASA SMEX

    Science.gov (United States)

    Lemen, James; Title, A.; De Pontieu, B.; Schrijver, C.; Tarbell, T.; Wuelser, J.; Golub, L.; Kankelborg, C.

    2011-05-01

    The solar chromosphere and transition region (TR) is highly structured, dynamic, and intimately connected to the corona. It requires more than ten times the energy required to heat the corona, and yet it has received far less interest because of the complexity of the required observational and analytical tools. In the TR the density drops by six orders of magnitude and the temperature increases by three orders of magnitude. Hinode observations reveal the importance the magnetic field has on this region of the solar atmosphere that acts as the interface between the photosphere and the corona. The Interface Region Imaging Spectrograph (IRIS) was selected for a NASA SMEX mission in 2009 and is scheduled to launch in December 2012. IRIS addresses critical questions in order to understand the flow of energy and mass through the chromosphere and TR, namely: (1) Which types of non-thermal energy dominate in the chromosphere and beyond? (2) How does the chromosphere regulate mass and energy supply to the corona and heliosphere? (3) How do magnetic flux and matter rise through the lower atmosphere, and what roles dos flux emergence play in flares and mass ejections? These questions are addressed with a high-resolution imaging spectrometer that observes Near- and Far-VU emissions that are formed at temperatures between 5,000K and 1.5 x 106 K. IRIS has a field-of-view of 120 arcsec, a spatial resolution of 0.4 arcsec, and velocity resolution of 0.5 km/s. Members of the IRIS investigation team are developing advanced radiative MHD codes to facilitate comparison with and interpretation of observations. We present the status of the IRIS observatory development, which completed its Critical Design Review in December 2010.

  12. Alpha antagonists and intraoperative floppy iris syndrome: A spectrum

    Directory of Open Access Journals (Sweden)

    Sharif A Issa

    2008-07-01

    Full Text Available Sharif A Issa, Omar H Hadid, Oliver Baylis, Margaret DayanDepartment of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UKBackground: To determine occurrence of features of intraoperative floppy iris syndrome (IFIS during cataract surgery in patients taking systemic alpha-antagonists (AA.Methods: We prospectively studied patients on AA and who underwent phacoemulsification. The following were recorded: pupil diameter preoperatively, iris flaccidity, iris prolapse and peroperative miosis.Results: We studied 40 eyes of 31 subjects. Mean age was 78 years. Overall, 14 eyes (13 patients showed signs of IFIS: 9/13 (69% eyes of patients on tamsulosin, 1/18 (6% eyes in the doxazosin group, 2/2 prazosin patients, 1/4 eyes in the indoramin group, and 1/2 eyes in two patients on a combination of doxazosin and tamsulosin. Most cases (92% had only one or two signs of IFIS. Bilateral cataract surgery was undertaken in 9 patients but only one patient (on tamsulosin had features of IFIS in both eyes, while 4 patients (2 on tamsulosin and 2 on other AA showed signs of IFIS in one eye only, and 4 patients did not show IFIS in either eye.Conclusion: Most AA were associated with IFIS, but it tends to present as a spectrum of signs rather than full triad originally described. Tamsulosin was most likely to be associated with IFIS; however, its intake does not necessarily mean that IFIS will occur. For patients on AA, the behavior of the iris intraoperatively in one eye is a poor predictor of the other eye. Surgeons should anticipate the occurrence of IFIS in any patient on AA.Keywords: alpha blocker, alpha antagonist, cataract surgery, intraoperative floppy iris syndrome, tamsulosin.

  13. Topography of Lymphatic Markers in Human Iris and Ciliary Body.

    Science.gov (United States)

    Kaser-Eichberger, Alexandra; Schrödl, Falk; Trost, Andrea; Strohmaier, Clemens; Bogner, Barbara; Runge, Christian; Motloch, Karolina; Bruckner, Daniela; Laimer, Martin; Schlereth, Simona L; Heindl, Ludwig M; Reitsamer, Herbert A

    2015-07-01

    Reports of lymphatics in the anterior human uvea are contradictory. This might be caused due to a certain topography, which has not been considered yet. Therefore, here we systematically analyze iris and adjacent ciliary body with immunohistochemistry by combining various lymphatic markers. Human iris and ciliary body were obtained from cornea donors and prepared for cryosectioning. Cross sections of tissue blocks at 12/3/6/9 o'clock position and at corresponding intersections (1:30/4:30/7:30/10:30) were processed for immunohistochemistry of LYVE-1, PDPN, PROX1, FOXC2, VEGFR3, and CCL21, and when necessary, these lymphatic markers were combined with CD31, α-smooth muscle-actin, CD68, and 4',6-diamidino-2 phenylindole dihydrochloride (DAPI). Double, triple, and quadruple marker combinations were documented using confocal microscopy. Numerous podoplanin+ cells were mainly located at the anterior border of the iris while LYVE-1+ cells were distributed throughout the nonpigmented part. Both cell populations were PROX1/FOXC2/CCL21/VEGFR3-. Blood vessels, iris smooth muscles, and individual cells were VEGFR3+. While PDPN+ cells were rarely detected posteriorly of the iris root, many LYVE-1+ cells were present within the ciliary body muscle and villi. Within the muscle, occasionally PDPN+ vessel-like structures were detectable, but these were never colocalized with LYVE-1. Similar vessel-like structures were VEGFR3+/PROX1-/CCL21-, but CD31+. Further, ciliary muscle fibers and ciliary epithelium were immunoreactive for VEGFR3/CCL21, but were LYVE-1/PDPN-. A certain topography of structures at the various uvea-positions investigated was not obvious. The majority of LYVE-1+ cells displayed immunoreactivity for CD68. Lymphatic vessels colocalizing for at least two lymphatic markers were not detectable. Therefore, if present, putative lymphatic channels of the anterior uvea might display a different marker panel than generally presumed.

  14. The IRIS Federator: Accessing Seismological Data Across Data Centers

    Science.gov (United States)

    Trabant, C. M.; Van Fossen, M.; Ahern, T. K.; Weekly, R. T.

    2015-12-01

    In 2013 the International Federation of Digital Seismograph Networks (FDSN) approved a specification for web service interfaces for accessing seismological station metadata, time series and event parameters. Since then, a number of seismological data centers have implemented FDSN service interfaces, with more implementations in development. We have developed a new system called the IRIS Federator which leverages this standardization and provides the scientific community with a service for easy discovery and access of seismological data across FDSN data centers. These centers are located throughout the world and this work represents one model of a system for data collection across geographic and political boundaries.The main components of the IRIS Federator are a catalog of time series metadata holdings at each data center and a web service interface for searching the catalog. The service interface is designed to support client­-side federated data access, a model in which the client (software run by the user) queries the catalog and then collects the data from each identified center. By default the results are returned in a format suitable for direct submission to those web services, but could also be formatted in a simple text format for general data discovery purposes. The interface will remove any duplication of time series channels between data centers according to a set of business rules by default, however a user may request results with all duplicate time series entries included. We will demonstrate how client­-side federation is being incorporated into some of the DMC's data access tools. We anticipate further enhancement of the IRIS Federator to improve data discovery in various scenarios and to improve usefulness to communities beyond seismology.Data centers with FDSN web services: http://www.fdsn.org/webservices/The IRIS Federator query interface: http://service.iris.edu/irisws/fedcatalog/1/

  15. First-Year Students' Priorities and Choices in STEM Studies--IRIS Findings from Germany and Austria

    Science.gov (United States)

    Elster, D.

    2014-01-01

    IRIS (Interests and Recruitment in Science; http://iris.fp-7.org/about-iris/) is a European 7th framework project focusing on the challenge that only few young people in general, and women in particular, choose an education and career in science and technology. Project IRIS aims to contribute to the improvement of recruitment, retention and gender…

  16. Sodium fast reactor evaluation: Core materials

    Science.gov (United States)

    Cheon, Jin Sik; Lee, Chan Bock; Lee, Byoung Oon; Raison, J. P.; Mizuno, T.; Delage, F.; Carmack, J.

    2009-07-01

    In the framework of the Generation IV Sodium Fast Reactor (SFR) Program the Advanced Fuel Project has conducted an evaluation of the available fuel systems supporting future sodium cooled fast reactors. In this paper the status of available and developmental materials for SFR core cladding and duct applications is reviewed. To satisfy the Generation IV SFR fuel requirements, an advanced cladding needs to be developed. The candidate cladding materials are austenitic steels, ferritic/martensitic (F/M) steels, and oxide dispersion strengthened (ODS) steels. A large amount of irradiation testing is required, and the compatibility of cladding with TRU-loaded fuel at high temperatures and high burnup must be investigated. The more promising F/M steels (compared to HT9) might be able to meet the dose requirements of over 200 dpa for ducts in the GEN-IV SFR systems.

  17. Iris Segmentation using Gradient Magnitude and Fourier Descriptor for Multimodal Biometric Authentication System

    Directory of Open Access Journals (Sweden)

    Defiana Sulaeman

    2016-12-01

    Full Text Available Perfectly segmenting the area of the iris is one of the most important steps in iris recognition. There are several problematic areas that affect the accuracy of the iris segmentation step, such as eyelids, eyelashes, glasses, pupil (due to less accurate iris segmentation, motion blur, and lighting and specular reflections. To solve these problems, gradient magnitude and Fourier descriptor are employed to do iris segmentation in the proposed Multimodal Biometric Authentication System (MBAS. This approach showed quite promising results, i.e. an accuracy rate of 97%. The result of the iris recognition system was combined with the result of an open-source fingerprint recognition system to develop a multimodal biometrics authentication system. The results of the fusion between iris and fingerprint authentication were 99% accurate. Data from Multimedia Malaysia University (MMUI and our own prepared database, the SGU-MB-1 dataset, were used to test the accuracy of the proposed system.

  18. The Infrared Imaging Spectrograph (IRIS) for TMT: optical design of IRIS imager with "Co-axis double TMA"

    CERN Document Server

    Tsuzuki, Toshihiro; Harakawa, Hiroki; Ikenoue, Bungo; Larkin, James; Moore, Anna; Obuchi, Yoshiyuki; Phillips, Andrew C; Saito, Sakae; Uraguchi, Fumihiro; Wincentsen, James; Wright, Shelley; Hayano, Yutaka

    2016-01-01

    IRIS (InfraRed Imaging Spectrograph) is one of the first-generation instruments for the Thirty Meter Telescope (TMT). IRIS is composed of a combination of near-infrared (0.84--2.4 $\\mu$m) diffraction limited imager and integral field spectrograph. To achieve near-diffraction limited resolutions in the near-infrared wavelength region, IRIS uses the advanced adaptive optics system NFIRAOS (Narrow Field Infrared Adaptive Optics System) and integrated on-instrument wavefront sensors (OIWFS). However, IRIS itself has challenging specifications. First, the overall system wavefront error should be less than 40 nm in Y, z, J, and H-band and 42 nm in K-band over a 34.0 $\\times$ 34.0 arcsecond field of view. Second, the throughput of the imager components should be more than 42 percent. To achieve the extremely low wavefront error and high throughput, all reflective design has been newly proposed. We have adopted a new design policy called "Co-Axis double-TMA", which cancels the asymmetric aberrations generated by "col...

  19. Conceptual design of an integrated information system for safety related analysis of nuclear power plants (IRIS Phase 1)

    Energy Technology Data Exchange (ETDEWEB)

    Hofer, K.; Zehnder, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Galperin, A. [Ben-Gurion Univ. of the Negev, Beersheba (Israel)

    1994-01-01

    This report deals with a conceptual design of an integrated information management system, called PSI-IRIS, as needed to assist the analysts for reactor safety related investigations on Swiss nuclear power plants within the project STARS. Performing complicated engineering analyses of an NPP requires storage and manipulation of a large amount of information, both data and knowledge. This information is characterized by its multi-disciplinary nature, complexity, and diversity. The problems caused by inefficient and lengthy manual operations involving the data flow management within the framework of the safety related analysis of an NPP, can be solved by applying computer aided engineering (CAE) principles. These principles are the basis for the design of the integrated information management system PSI-IRIS presented in this report. The basic idea is to create a computerized environment, which includes both database and functional capabilities. The database of the PSI-IRIS consists of two parts, an NPP generic database (GDB) and a collection of analysis results (CASE{sub L}IB). The GDB includes all technical plant data and information needed to generate input decks for all computer codes utilized within the STARS project. The CASE{sub L}IB storage contains the accumulated knowledge, input decks, and result files of the NPP transient analyses. Considerations and analysis of the data types and the required data manipulation capabilities as well as operational requirements resulted in the choice of an object-oriented database management system (OODBMS) as a development platform for solving the software engineering problems. Several advantages of OODBMS`s over conventional relational database management systems were found of crucial importance, especially providing the necessary flexibility for different data types and the potential for extensibility. (author) 15 figs., tabs., 20 refs.

  20. Simulation of Reactor Transient and Design Criteria of Sodium-cooled Fast Reactors

    OpenAIRE

    Gottfridsson, Filip

    2010-01-01

    The need for energy is growing in the world and the market of nuclear power is now once more expanding. Some issues of the current light-water reactors can be solved by the next generation of nuclear power, Generation IV, where sodium-cooled reactors are one of the candidates. Phénix was a French prototype sodium-cooled reactor, which is seen as a success. Although it did encounter an earlier unexperienced phenomenon, A.U.R.N., in which a negative reactivity transient followed by an oscillati...

  1. Thermochemical investigation of molten fluoride salts for Generation IV nuclear applications - an equilibrium exercise

    NARCIS (Netherlands)

    Meer, J.P.M. van der

    2006-01-01

    The concept of the Molten Salt Reactor, one of the so-called Generation IV future reactors, is that the fuel, a fissile material, which is dissolved in a molten fluoride salt, circulates through a closed circuit. The heat of fission is transferred to a second molten salt coolant loop, the heat of wh

  2. The Infrared Imaging Spectrograph (IRIS) for TMT: optical design of IRIS imager with "co-axis double TMA"

    Science.gov (United States)

    Tsuzuki, Toshihiro; Suzuki, Ryuji; Harakawa, Hiroki; Ikenoue, Bungo; Larkin, James; Moore, Anna; Obuchi, Yoshiyuki; Phillips, Andrew C.; Saito, Sakae; Uraguchi, Fumihiro; Wincentsen, James; Wright, Shelley; Hayano, Yutaka

    2016-08-01

    IRIS (InfraRed Imaging Spectrograph) is one of the first-generation instruments for the Thirty Meter Telescope (TMT). IRIS is composed of a combination of near-infrared (0.84-2.4 μm) diffraction limited imager and integral field spectrograph. To achieve near-diffraction limited resolutions in the near-infrared wavelength region, IRIS uses the advanced adaptive optics system NFIRAOS (Narrow Field Infrared Adaptive Optics System) and integrated on-instrument wavefront sensors (OIWFS). However, IRIS itself has challenging specifications. First, the overall system wavefront error should be less than 40 nm in Y, z, J, and H-band and 42 nm in K-band over a 34.0 × 34.0 arcsecond field of view. Second, the throughput of the imager components should be more than 42 percent. To achieve the extremely low wavefront error and high throughput, all reflective design has been newly proposed. We have adopted a new design policy called "Co-Axis double-TMA", which cancels the asymmetric aberrations generated by "collimator/TMA" and "camera/TMA" efficiently. The latest imager design meets all specifications, and, in particular, the wavefront error is less than 17.3 nm and throughput is more than 50.8 percent. However, to meet the specification of wavefront error and throughput as built performance, the IRIS imager requires both mirrors with low surface irregularity after high-reflection coating in cryogenic and high-level Assembly Integration and Verification (AIV). To deal with these technical challenges, we have done the tolerance analysis and found that total pass rate is almost 99 percent in the case of gauss distribution and more than 90 percent in the case of parabolic distribution using four compensators. We also have made an AIV plan and feasibility check of the optical elements. In this paper, we will present the details of this optical system.

  3. A Novel Edge-Map Creation Approach for Highly Accurate Pupil Localization in Unconstrained Infrared Iris Images

    OpenAIRE

    Vineet Kumar; Abhijit Asati; Anu Gupta

    2016-01-01

    Iris segmentation in the iris recognition systems is a challenging task under noncooperative environments. The iris segmentation is a process of detecting the pupil, iris’s outer boundary, and eyelids in the iris image. In this paper, we propose a pupil localization method for locating the pupils in the non-close-up and frontal-view iris images that are captured under near-infrared (NIR) illuminations and contain the noise, such as specular and lighting reflection spots, eyeglasses, nonunifor...

  4. Real-Time IRI driven by GIRO data

    Science.gov (United States)

    Galkin, Ivan; Huang, Xueqin; Reinisch, Bodo; Bilitza, Dieter; Vesnin, Artem

    Real-time extensions of the empirical International Reference Ionosphere (IRI) model are based on assimilative techniques that preserve the IRI formalism which is optimized for the description of climatological ionospheric features. The Global Ionosphere Radio Observatory (GIRO) team has developed critical parts of an IRI Real Time Assimilative Model (IRTAM) for the global ionospheric plasma distribution using measured data available in real time from ~50 ionosondes of the GIRO network, The current assimilation results present global assimilative maps of foF2 and hmF2 that reproduce available data at the sensor sites and smoothly return to the climatological specifications when and where the data are missing, and are free from artificial sharp gradients and short-lived artifacts when viewed in time progression. Animated real-time maps of foF2 and hmF2 are published with a few minutes latency at http://giro.uml.edu/IRTAM/. Our real-time IRI modeling uses morphing, a technique that transforms the climatological ionospheric specifications to match the observations by iteratively computing corrections to the original coefficients of the diurnal/spatial expansions, used in IRI to map the key ionospheric characteristics, while keeping the IRI expansion basis formalism intact. Computation of the updated coefficient set for a given point in time includes analysis of the latest 24-hour history of observations, which allows the morphing technique to sense evolving ionospheric dynamics even with a sparse sensor network. A Non-linear Error Compensation Technique for Associative Restoration (NECTAR), one of the features in our morphing approach, has been in operation at the Lowell GIRO Data Center since 2013. The cornerstone of NECTAR is a recurrent neural network optimizer that is responsible for smoothing the transitions between the grid cells where observations are available. NECTAR has proved suitable for real-time operations that require the assimilation code to be

  5. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  6. D and DR Reactors

    Data.gov (United States)

    Federal Laboratory Consortium — The world's second full-scale nuclear reactor was the D Reactor at Hanford which was built in the early 1940's and went operational in December of 1944.D Reactor ran...

  7. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  8. EXPLOSIVE EVENTS ON A SUBARCSECOND SCALE IN IRIS OBSERVATIONS: A CASE STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhenghua; Xia, Lidong; Fu, Hui [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, 264209 Shandong (China); Madjarska, Maria S.; Doyle, J. G. [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Galsgaard, Klaus, E-mail: huangzhenghua@gmail.com [Niels Bohr Institute, DK-2100 Copenhagen (Denmark)

    2014-12-20

    We present a study of a typical explosive event (EE) at subarcsecond scale witnessed by strong non-Gaussian profiles with blue- and redshifted emission of up to 150 km s{sup –1} seen in the transition region Si IV 1402.8 Å, and the chromospheric Mg II k 2796.4 Å and C II 1334.5 Å observed by the Interface Region Imaging Spectrograph (IRIS) at unprecedented spatial and spectral resolution. For the first time an EE is found to be associated with very small-scale (∼120 km wide) plasma ejection followed by retraction in the chromosphere. These small-scale jets originate from a compact bright-point-like structure of ∼1.''5 size as seen in the IRIS 1330 Å images. SDO/AIA and SDO/HMI co-observations show that the EE lies in the footpoint of a complex loop-like brightening system. The EE is detected in the higher temperature channels of AIA 171 Å, 193 Å, and 131 Å, suggesting that it reaches a higher temperature of log T = 5.36 ± 0.06 (K). Brightenings observed in the AIA channels with durations 90-120 s are probably caused by the plasma ejections seen in the chromosphere. The wings of the C II line behave in a similar manner to the Si IV'S, indicating close formation temperatures, while the Mg II k wings show additional Doppler-shifted emission. Magnetic convergence or emergence followed by cancellation at a rate of 5 × 10{sup 14} Mx s{sup –1} is associated with the EE region. The combined changes of the locations and the flux of different magnetic patches suggest that magnetic reconnection must have taken place. Our results challenge several theories put forward in the past to explain non-Gaussian line profiles, i.e., EEs. Our case study on its own, however, cannot reject these theories; thus, further in-depth studies on the phenomena producing EEs are required.

  9. Iris color and associated pathological ocular complications:a review of epidemiologic studies

    Directory of Open Access Journals (Sweden)

    Hong-Peng Sun

    2014-10-01

    Full Text Available AIM:To elucidate the associations of iris color with major eye diseases.METHODS:A systematic search on Medline with coverage up to August 2013 was conducted. Assessment of the quality of studies based on their levels of evidence was in accordance with the Centre for Evidence-Based Medicine, Oxford, United Kingdom.RESULTS:A relationship between darker iris color and an increased risk of age-related cataract has been reported from cross-sectional studies and prospective cohort studies. There was no consistent evidence supporting a major role of iris color in the development or progression of age-related macular degeneration. The association of iris color with ocular uveal melanoma has been confirmed by a meta-analysis of observational studies previously. The etiologic synergism between light iris color and environmental exposure such as UV the exposure of UV radiation was found. There were no studies evaluating the refractive associations with iris color but there may be a possible link between iris color and myopia.CONCLUSION:Darker iris color is associated with an increased risk of cataractand a reduced risk ofocular uveal melanoma. The association of iris color with age-related macular degeneration is not confirmed. Ophthalmologists should be aware that the risk of ocular disorders appears to vary by differences in iris color.

  10. A fast and robust iris localization method based on texture segmentation

    Science.gov (United States)

    Cui, Jiali; Wang, Yunhong; Tan, Tieniu; Ma, Li; Sun, Zhenan

    2004-08-01

    With the development of the current networked society, personal identification based on biometrics has received more and more attention. Iris recognition has a satisfying performance due to its high reliability and non-invasion. In an iris recognition system, preprocessing, especially iris localization plays a very important role. The speed and performance of an iris recognition system is crucial and it is limited by the results of iris localization to a great extent. Iris localization includes finding the iris boundaries (inner and outer) and the eyelids (lower and upper). In this paper, we propose an iris localization algorithm based on texture segmentation. First, we use the information of low frequency of wavelet transform of the iris image for pupil segmentation and localize the iris with a differential integral operator. Then the upper eyelid edge is detected after eyelash is segmented. Finally, the lower eyelid is localized using parabolic curve fitting based on gray value segmentation. Extensive experimental results show that the algorithm has satisfying performance and good robustness.

  11. Iris color and associated pathological ocular complications: a review of epidemiologic studies

    Institute of Scientific and Technical Information of China (English)

    Hong-Peng; Sun; Yi; Lin; Chen-Wei; Pan

    2014-01-01

    AIM:To elucidate the associations of iris color with major eye diseases.· METHODS:A systematic search on Medline with coverage up to August 2013 was conducted. Assessment of the quality of studies based on their levels of evidence was in accordance with the Centre for Evidence-Based Medicine, Oxford, United Kingdom.RESULTS:A relationship between darker iris color and an increased risk of age-related cataract has been reported from cross-sectional studies and prospective cohort studies. There was no consistent evidence supporting a major role of iris color in the development or progression of age-related macular degeneration. The association of iris color with ocular uveal melanoma has been confirmed by a meta-analysis of observational studies previously. The etiologic synergism between light iris color and environmental exposure such as UV the exposure of UV radiation was found. There were no studies evaluating the refractive associations with iris color but there may be a possible link between iris color and myopia.CONCLUSION:Darker iris color is associated with an increased risk of cataract and a reduced risk of ocular uveal melanoma. The association of iris color with agerelated macular degeneration is not confirmed.Ophthalmologists should be aware that the risk of ocular disorders appears to vary by differences in iris color.

  12. Improving iris recognition performance using segmentation, quality enhancement, match score fusion, and indexing.

    Science.gov (United States)

    Vatsa, Mayank; Singh, Richa; Noore, Afzel

    2008-08-01

    This paper proposes algorithms for iris segmentation, quality enhancement, match score fusion, and indexing to improve both the accuracy and the speed of iris recognition. A curve evolution approach is proposed to effectively segment a nonideal iris image using the modified Mumford-Shah functional. Different enhancement algorithms are concurrently applied on the segmented iris image to produce multiple enhanced versions of the iris image. A support-vector-machine-based learning algorithm selects locally enhanced regions from each globally enhanced image and combines these good-quality regions to create a single high-quality iris image. Two distinct features are extracted from the high-quality iris image. The global textural feature is extracted using the 1-D log polar Gabor transform, and the local topological feature is extracted using Euler numbers. An intelligent fusion algorithm combines the textural and topological matching scores to further improve the iris recognition performance and reduce the false rejection rate, whereas an indexing algorithm enables fast and accurate iris identification. The verification and identification performance of the proposed algorithms is validated and compared with other algorithms using the CASIA Version 3, ICE 2005, and UBIRIS iris databases.

  13. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2014.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  14. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2016.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  15. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2015.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  16. The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

    CERN Document Server

    Larkin, James E; Barton, Elizabeth J; Bauman, Brian; Bui, Khanh; Canfield, John; Crampton, David; Delacroix, Alex; Fletcher, Murray; Hale, David; Loop, David; Niehaus, Cyndie; Phillips, Andrew C; Reshetov, Vladimir; Simard, Luc; Smith, Roger; Suzuki, Ryuji; Usuda, Tomonori; Wright, Shelley A

    2010-01-01

    We present an overview of the design of IRIS, an infrared (0.85 - 2.5 micron) integral field spectrograph and imaging camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system (NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter aperture. With a primary spectral resolution of 4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a very large vacuum cryogenic system.

  17. The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

    CERN Document Server

    Moore, Anna M; Wright, Shelley A; Bauman, Brian; Dunn, Jennifer; Ellerbroek, Brent; Phillips, Andrew C; Simard, Luc; Suzuki, Ryuji; Zhang, Kai; Aliado, Ted; Brims, George; Canfield, John; Chen, Shaojie; Dekany, Richard; Delacroix, Alex; Do, Tuan; Herriot, Glen; Ikenoue, Bungo; Johnson, Chris; Meyer, Elliot; Obuchi, Yoshiyuki; Pazder, John; Reshetov, Vladimir; Riddle, Reed; Saito, Sakae; Smith, Roger; Sohn, Ji Man; Uraguchi, Fumihiro; Usuda, Tomonori; Wang, Eric; Wang, Lianqi; Weiss, Jason; Wooff, Robert

    2014-01-01

    We present an overview of the design of IRIS, an infrared (0.84 - 2.4 micron) integral field spectrograph and imaging camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system (NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter aperture. With a primary spectral resolution of 4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a very large vacuum cryogenic system.

  18. The Evolution of Transition Region Loops Using IRIS and AIA

    Science.gov (United States)

    Winebarger, Amy R.; DePontieu, Bart

    2014-01-01

    Over the past 50 years, the model for the structure of the solar transition region has evolved from a simple transition layer between the cooler chromosphere to the hotter corona to a complex and diverse region that is dominated by complete loops that never reach coronal temperatures. The IRIS slitjaw images show many complete transition region loops. Several of the "coronal" channels in the SDO AIA instrument include contributions from weak transition region lines. In this work, we combine slitjaw images from IRIS with these channels to determine the evolution of the loops. We develop a simple model for the temperature and density evolution of the loops that can explain the simultaneous observations. Finally, we estimate the percentage of AIA emission that originates in the transition region.

  19. Eye and Iris Detection Using Projection and Radial Symmetry Transform

    Institute of Scientific and Technical Information of China (English)

    XIANG Shu-lan; CAO Cheng; Aishy Amer

    2010-01-01

    This paper presents an eye and iris detection algorithm for human facial images. The authors combine three features of the eye to develop the algorithm: 1) the pixels surrounding the eyes are more variable than other parts of the face; 2) eye pixels are darker than their neighbors; 3) eyes often exhibit radial symmetric properties. Through the first feature, two rough regions of both eyes are detected on the face. Eye masks are then formed based on the second feature, and a fast radial symmetry transform is applied to the two rough regions of both eyes. Finally, accurate iris centers are located by searching the maximum value of the radial symmetry transform results. Using 450 human facial images from the Caltech face database, experiments show that the success rate of the proposed method is 91.7%. The effectiveness of the method was also verified through detection of video frames.

  20. The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

    CERN Document Server

    Larkin, James E; Wright, Shelley A; Wincentsen, James E; Anderson, David; Chisholm, Eric M; Dekany, Richard G; Dunn, Jennifer S; Ellerbroek, Brent L; Hayano, Yutaka; Phillips, Andrew C; Simard, Luc; Smith, Roger; Suzuki, Ryuji; Weber, Robert W; Weiss, Jason L; Zhang, Kai

    2016-01-01

    IRIS is a near-infrared (0.84 to 2.4 microns) integral field spectrograph and wide-field imager being developed for first light with the Thirty Meter (TMT). It mounts to the advanced optics (AO) system NFIRAOS and has integrated on-instrument wavefront sensors (OIWFS) to achieve diffraction-limited spatial resolution at wavelengths longer than 1 micron. With moderate spectral resolution (R ~4,000 - 8,000) and large bandpass over a continuous field of view, IRIS will open new opportunities in virtually every area of astrophysical science. It will be able to resolve surface features tens of kilometers across Titan, while also mapping the distant galaxies at the scale of an individual star forming region. This paper summarizes the entire design and capabilities, and includes the results from the nearly completed preliminary design phase.

  1. Interplanetary Type IV Bursts

    CERN Document Server

    Hillaris, Alexander; Nindos, Alexander

    2016-01-01

    In this work we study the characteristics of moving type IV radio bursts which extend to the hectometric wavelengths (interplanetary type IV or type IV IP bursts) and their relationship with energetic phenomena on the Sun. Our dataset comprised 48 Interplanetary type IV bursts observed by the Wind/WAVES in the 13.825 MHz?20 KHz frequency range. The dynamic spec tra of the RSTN, DAM, ARTEMIS-IV, CULGOORA, Hiraiso and IZMIRAN Radio-spectrographs were used to track the evolution of the events in the low corona; these were supplemented with SXR ?ux recordings from GOES and CME data from LASCO. Positional information for the coronal bursts were obtained by the Nan\\c{c}ay radioheliograph (NRH). We examined the relationship of the type IV events with coronal radio bursts, CMEs and SXR ?ares. The majority of the events (45) were characterized as compact; their duration was on average 106 min. This type of events were, mostly, associated with M and X class ?ares (40 out of 45) and fast CMEs; 32 of these events had CME...

  2. Boimsja togo, tshego ne znajem / Iris Pettai ; interv. Nelli Kuznetsova

    Index Scriptorium Estoniae

    Pettai, Iris, 1947-

    2004-01-01

    Presidendi juures asuva vähemusrahvuste ümarlaua ning poliitikute ja ekspertide kohtumisel esinenud sotsioloogi Iris Pettai hinnangul on riigile ohtlik, kui kaks kogukonda elavad paralleelselt, puutuvad vähe kokku. Mida väiksem on sallivus või tolerantsus põhirahva hulgas, seda rohkem tõukab ta ühiskonnast eemale teistest rahvustest inimesi. Sallivuse viiest arengufaasist

  3. IRIS: a generic three-dimensional radiative transfer code

    Science.gov (United States)

    Ibgui, L.; Hubeny, I.; Lanz, T.; Stehlé, C.

    2013-01-01

    Context. For most astronomical objects, radiation is the only probe of their physical properties. Therefore, it is important to have the most elaborate theoretical tool to interpret observed spectra or images, thus providing invaluable information to build theoretical models of the physical nature, the structure, and the evolution of the studied objects. Aims: We present IRIS, a new generic three-dimensional (3D) spectral radiative transfer code that generates synthetic spectra, or images. It can be used as a diagnostic tool for comparison with astrophysical observations or laboratory astrophysics experiments. Methods: We have developed a 3D short-characteristic solver that works with a 3D nonuniform Cartesian grid. We have implemented a piecewise cubic, locally monotonic, interpolation technique that dramatically reduces the numerical diffusion effect. The code takes into account the velocity gradient effect resulting in gradual Doppler shifts of photon frequencies and subsequent alterations of spectral line profiles. It can also handle periodic boundary conditions. This first version of the code assumes local thermodynamic equilibrium (LTE) and no scattering. The opacities and source functions are specified by the user. In the near future, the capabilities of IRIS will be extended to allow for non-LTE and scattering modeling. Results: IRIS has been validated through a number of tests. We provide the results for the most relevant ones, in particular a searchlight beam test, a comparison with a 1D plane-parallel model, and a test of the velocity gradient effect. Conclusions: IRIS is a generic code to address a wide variety of astrophysical issues applied to different objects or structures, such as accretion shocks, jets in young stellar objects, stellar atmospheres, exoplanet atmospheres, accretion disks, rotating stellar winds, cosmological structures. It can also be applied to model laboratory astrophysics experiments, such as radiative shocks produced with high

  4. Implementation of Reliable Open Source IRIS Recognition System

    Directory of Open Access Journals (Sweden)

    Dhananjay Ikhar

    2013-12-01

    Full Text Available RELIABLE automatic recognition of persons has long been an attractive goal. As in all pattern recognition problems, the key issue is the relation between inter-class and intra-class variability: objects can be reliably classified only if the variability among different instances of a given class is less than the variability between different classes.The objective of this paper is to implement an open-source iris recognition system in order to verify the claimed performance of the technology. The development tool used will be MATLAB, and emphasis will be only on the software for performing recognition and not hardware for capturing an eye image. A reliable application development approach will be employed in order to produce results quickly. MATLAB provides an excellent environment, with its image processing toolbox. To test the system, a database of 756 grayscale eye images courtesy of Chinese Academy of Sciences-Institute of Automation (CASIA is used. The system is to be composed of a number of sub-systems, which correspond to each stage of iris recognition. These stages are- image acquisition, segmentation, normalization and feature encoding. The input to the system will be an eye image, and the output will be an iris template, which will provide a mathematical representation of the iris region. Which conclude the objectives to design recognition system are- study of different biometrics and their features? Study of different recognition systems and their steps, selection of simple and efficient recognition algorithm for implementation, selection of fast and efficient tool for processing, apply the implemented algorithm to different database and find out performance factors.

  5. Assimilation of GIRO Data into a Real-Time IRI

    Science.gov (United States)

    Galkin, I. A.; Reinisch, B. W.; Huang, X.; Bilitza, D.

    2012-01-01

    Increasingly accurate and detailed global 3-D specification of the Earth's space plasma environment is required to further understand its intricate organization and behavior. For a long time space physics and aeronomy research has been data starved due to the great variety of natural time scales involved in the plasma phenomenology. We have started developing a new approach to the global ionospheric specification called Real-Time Assimilative Mapping (RTAM). The IRI-RTAM will use data from the Global Ionospheric Radio Observatory (GIRO) to smoothly transform International Reference Ionosphere's (IRI's) background empirical maps of the ionospheric characteristics to match the observations. Such empirical assimilative modeling will provide a high-resolution, global picture of the ionospheric response to various short-term events observed during periods of storm activity or the impact of gravity waves coupling the ionosphere to the lower atmosphere, including timelines of the vertical restructuring of the plasma distribution. It will also contribute to the challenging task of providing a rapid insight into the temporal and spatial space weather development using the real-time GIRO data streams. The new assimilation technique "updates" the IRI electron density distribution while preserving the overall integrity of IRI s typical ionospheric feature representations. The technique adjusts the coefficients of the spherical/diurnal expansions used by the CCIR and URSI-88 model to obtain the global sub-peak electron density distribution. The set of global corrected coefficients can be generated as frequently as every 15 min and easily disseminated using a single real-time RTAM server operated by GIRO.

  6. The Infrared Imaging Spectrograph (IRIS) for TMT: data reduction system

    Science.gov (United States)

    Walth, Gregory; Wright, Shelley A.; Weiss, Jason; Larkin, James E.; Moore, Anna M.; Chapin, Edward L.; Do, Tuan; Dunn, Jennifer; Ellerbroek, Brent; Gillies, Kim; Hayano, Yutaka; Johnson, Chris; Marshall, Daniel; Riddle, Reed L.; Simard, Luc; Sohn, Ji Man; Suzuki, Ryuji; Wincentsen, James

    2016-08-01

    IRIS (InfraRed Imaging Spectrograph) is the diffraction-limited first light instrument for the Thirty Meter Telescope (TMT) that consists of a near-infrared (0.84 to 2.4 μm) imager and integral field spectrograph (IFS). The IFS makes use of a lenslet array and slicer for spatial sampling, which will be able to operate in 100's of different modes, including a combination of four plate scales from 4 milliarcseconds (mas) to 50 mas with a large range of filters and gratings. The imager will have a field of view of 34×34 arcsec2 with a plate scale of 4 mas with many selectable filters. We present the preliminary design of the data reduction system (DRS) for IRIS that need to address all of these observing modes. Reduction of IRIS data will have unique challenges since it will provide real-time reduction and analysis of the imaging and spectroscopic data during observational sequences, as well as advanced post-processing algorithms. The DRS will support three basic modes of operation of IRIS; reducing data from the imager, the lenslet IFS, and slicer IFS. The DRS will be written in Python, making use of open-source astronomical packages available. In addition to real-time data reduction, the DRS will utilize real-time visualization tools, providing astronomers with up-to-date evaluation of the target acquisition and data quality. The quick look suite will include visualization tools for 1D, 2D, and 3D raw and reduced images. We discuss the overall requirements of the DRS and visualization tools, as well as necessary calibration data to achieve optimal data quality in order to exploit science cases across all cosmic distance scales.

  7. Two new isoflavanoids from the rhizomes of Iris soforana.

    Science.gov (United States)

    Atta-ur-Rahman; Nasim, Shama; Baig, Irfan; Sener, Bilge; Orhan, Ilkay; Ayanoglu, Filiz; Choudhary, M Iqbal

    2004-10-01

    Two new isoflavones 1 and 2 along with eleven known compounds 3-13, have been isolated for the first time from the rhizomes of Iris soforana. The structures of these compounds were determined on the basis of spectroscopic methods and found to be 5,3'-dihydroxy-4'-methoxy-6,7-methylenedioxyisoflavone (1) (Soforanarin A), and 5,7,5'-trimethoxy-6,3',4'-trihydroxyisoflavone (2) (Soforanarin B).

  8. The infrared imaging spectrograph (IRIS) for TMT: spectrograph design

    CERN Document Server

    Moore, Anna M; Barton, Elizabeth J; Crampton, David; Delacroix, Alex; Larkin, James E; Simard, Luc; Suzuki, Ryuji; Wright, Shelley A

    2010-01-01

    The Infra-Red Imaging Spectrograph (IRIS) is one of the three first light instruments for the Thirty Meter Telescope (TMT) and is the only one to directly sample the diffraction limit. The instrument consists of a parallel imager and off-axis Integral Field Spectrograph (IFS) for optimum use of the near infrared (0.84um-2.4um) Adaptive Optics corrected focal surface. We present an overview of the IRIS spectrograph that is designed to probe a range of scientific targets from the dynamics and morphology of high-z galaxies to studying the atmospheres and surfaces of solar system objects, the latter requiring a narrow field and high Strehl performance. The IRIS spectrograph is a hybrid system consisting of two state of the art IFS technologies providing four plate scales (4mas, 9mas, 25mas, 50mas spaxel sizes). We present the design of the unique hybrid system that combines the power of a lenslet spectrograph and image slicer spectrograph in a configuration where major hardware is shared. The result is a powerful...

  9. LDPC and SHA based iris recognition for image authentication

    Directory of Open Access Journals (Sweden)

    K. Seetharaman

    2012-11-01

    Full Text Available We introduce a novel way to authenticate an image using Low Density Parity Check (LDPC and Secure Hash Algorithm (SHA based iris recognition method with reversible watermarking scheme, which is based on Integer Wavelet Transform (IWT and threshold embedding technique. The parity checks and parity matrix of LDPC encoding and cancellable biometrics i.e., hash string of unique iris code from SHA-512 are embedded into an image for authentication purpose using reversible watermarking scheme based on IWT and threshold embedding technique. Simply by reversing the embedding process, the original image, parity checks, parity matrix and SHA-512 hash are extracted back from watermarked-image. For authentication, the new hash string produced by employing SHA-512 on error corrected iris code from live person is compared with hash string extracted from watermarked-image. The LDPC code reduces the hamming distance for genuine comparisons by a larger amount than for the impostor comparisons. This results in better separation between genuine and impostor users which improves the authentication performance. Security of this scheme is very high due to the security complexity of SHA-512, which is 2256 under birthday attack. Experimental results show that this approach can assure more accurate authentication with a low false rejection or false acceptance rate and outperforms the prior arts in terms of PSNR.

  10. Optimal Features Subset Selection and Classification for Iris Recognition

    Directory of Open Access Journals (Sweden)

    Roy Kaushik

    2008-01-01

    Full Text Available Abstract The selection of the optimal features subset and the classification have become an important issue in the field of iris recognition. We propose a feature selection scheme based on the multiobjectives genetic algorithm (MOGA to improve the recognition accuracy and asymmetrical support vector machine for the classification of iris patterns. We also suggest a segmentation scheme based on the collarette area localization. The deterministic feature sequence is extracted from the iris images using the 1D log-Gabor wavelet technique, and the extracted feature sequence is used to train the support vector machine (SVM. The MOGA is applied to optimize the features sequence and to increase the overall performance based on the matching accuracy of the SVM. The parameters of SVM are optimized to improve the overall generalization performance, and the traditional SVM is modified to an asymmetrical SVM to treat the false accept and false reject cases differently and to handle the unbalanced data of a specific class with respect to the other classes. Our experimental results indicate that the performance of SVM as a classifier is better than the performance of the classifiers based on the feedforward neural network, the k-nearest neighbor, and the Hamming and the Mahalanobis distances. The proposed technique is computationally effective with recognition rates of 99.81% and 96.43% on CASIA and ICE datasets, respectively.

  11. Optimal Features Subset Selection and Classification for Iris Recognition

    Directory of Open Access Journals (Sweden)

    Prabir Bhattacharya

    2008-06-01

    Full Text Available The selection of the optimal features subset and the classification have become an important issue in the field of iris recognition. We propose a feature selection scheme based on the multiobjectives genetic algorithm (MOGA to improve the recognition accuracy and asymmetrical support vector machine for the classification of iris patterns. We also suggest a segmentation scheme based on the collarette area localization. The deterministic feature sequence is extracted from the iris images using the 1D log-Gabor wavelet technique, and the extracted feature sequence is used to train the support vector machine (SVM. The MOGA is applied to optimize the features sequence and to increase the overall performance based on the matching accuracy of the SVM. The parameters of SVM are optimized to improve the overall generalization performance, and the traditional SVM is modified to an asymmetrical SVM to treat the false accept and false reject cases differently and to handle the unbalanced data of a specific class with respect to the other classes. Our experimental results indicate that the performance of SVM as a classifier is better than the performance of the classifiers based on the feedforward neural network, the k-nearest neighbor, and the Hamming and the Mahalanobis distances. The proposed technique is computationally effective with recognition rates of 99.81% and 96.43% on CASIA and ICE datasets, respectively.

  12. A bayesian approach to deformed pattern matching of iris images.

    Science.gov (United States)

    Thornton, Jason; Savvides, Marios; Vijaya Kumar, B V K

    2007-04-01

    We describe a general probabilistic framework for matching patterns that experience in-plane nonlinear deformations, such as iris patterns. Given a pair of images, we derive a maximum a posteriori probability (MAP) estimate of the parameters of the relative deformation between them. Our estimation process accomplishes two things simultaneously: It normalizes for pattern warping and it returns a distortion-tolerant similarity metric which can be used for matching two nonlinearly deformed image patterns. The prior probability of the deformation parameters is specific to the pattern-type and, therefore, should result in more accurate matching than an arbitrary general distribution. We show that the proposed method is very well suited for handling iris biometrics, applying it to two databases of iris images which contain real instances of warped patterns. We demonstrate a significant improvement in matching accuracy using the proposed deformed Bayesian matching methodology. We also show that the additional computation required to estimate the deformation is relatively inexpensive, making it suitable for real-time applications.

  13. [Iris heterochromia: variations in form, age changes, sex dimorphism].

    Science.gov (United States)

    Stelzer, O

    1979-06-01

    On a sample of n = 25,346 individuals from Vienna (10,855 males, 14,491 females) the iris pigmentation has been typed by the author. In this sample 65 cases of different types of heterochromia were found. The frequency of the occurrence of the different types of this anomaly could be calculated for the first time. Neglecting age, sex, and type of heterochromia the total frequency amounts to 0.256 (males: 0.157; females: 0.37) %. The variants of heterochromia very from cases of total heterochromia to those of various size; in addition to it a number of special types could be observed. The localization of the heterochrome parts of the iris shows certain variations; mostly, however, it is seen in the lower half of the iris. The nasal part is concerned in only one case; the temporal region never. Thus, the partial heterochromia is characteristic by a marked dependency of its localization. The colour of heterochromia varies from 2 a-14 according to the Martin-Schultz standard set of coloured eyes. However, No. 9 (ca. 50%) and No. 7 (ca. 20%) were the most frequent colours. The age variations are considerable. 5/6 of all heterochromias were found between the age from 2-19 years. Finally, a marked sexual dimorphism was observed, as in females heterochromia is much more frequent than in males.

  14. Design of bipod flexure mounts for the IRIS spectrometer

    Science.gov (United States)

    Weingrod, Isaac; Chou, Catherine Y.; Holmes, Buck; Hom, Craig; Irwin, James Wes; Lindstrom, Obert; Lopez, Frank; Stubbs, David M.; Wüelser, Jean-Pierre

    2013-09-01

    The Interface Region Imaging Spectrograph (IRIS) is a NASA SMall Explorer (SMEX) mission launched onboard a Pegasus™ booster on June 27, 2013. The spacecraft and instrument were designed and built at the Lockheed Martin Space Systems Company. The primary mission goal is to learn how the solar atmosphere is energized. IRIS will obtain high-resolution UV spectra and images in space (0.4 arcsec) and time (1s), focusing on the chromosphere and transition region of our sun, which is a complex interface region between the photosphere and corona. The IRIS instrument uses a Cassegrain telescope to feed a dual spectrograph and slit-jaw imager, which operate in the 133-141 nm and 278-283 nm wavelengths, respectively. Within the spectrograph there are sixteen optics, each requiring subtle mounting features to meet exacting surface figure and stability requirements. This paper covers the opto-mechanical design for the most challenging optic mounts, which include the Collimator, UV Fold Mirrors, and UV Gratings. Although all mounts are unique in size and shape, the fundamental design remains the same. The mounts are highly kinematic, thermally matched, and independent of friction. Their development will be described in detail, starting with the driving requirements and an explanation of the underlying design philosophy.

  15. Outcomes of Sutureless Iris-Claw Lens Implantation

    Science.gov (United States)

    Nowomiejska, Katarzyna; Moneta-Wielgoś, Joanna; Jünemann, Anselm G. M.

    2016-01-01

    Purpose. To evaluate the indications, refraction, and visual and safety outcomes of iris-claw intraocular lens implanted retropupillary with sutureless technique during primary or secondary operation. Methods. Retrospective study of case series. The Haigis formula was used to calculate intraocular lens power. In all cases the wound was closed without suturing. Results. The study comprised 47 eyes. The mean follow-up time was 15.9 months (SD 12.2). The mean preoperative CDVA was 0.25 (SD 0.21). The final mean CDVA was 0.46 (SD 0.27). No hypotony or need for wound suturing was observed postoperatively. Mean postoperative refractive error was −0.27 Dsph (−3.87 Dsph to +2.85 Dsph; median 0.0, SD 1.28). The mean postoperative astigmatism was −1.82 Dcyl (min −0.25, max −5.5; median −1.25, SD 1.07). Postoperative complications were observed in 10 eyes. The most common complication was ovalization of the iris, which was observed in 8 eyes. The mean operation time was 35.9 min (min 11 min, max 79 min; median 34, SD 15.4). Conclusion. Retropupilary iris-claw intraocular lens (IOL) implantation with sutureless wound closing is an easy and fast method, ensuring good refractive outcome and a low risk of complication. The Haigis formula proved to be predictable in postoperative refraction. PMID:27642519

  16. Iris Recognition System Based on Feature Level Fusion

    Directory of Open Access Journals (Sweden)

    Dr. S. R. Ganorkar

    2013-11-01

    Full Text Available Multibiometric systems utilize the evidence presented by multiple biometric sources (e.g., face and fingerprint, multiple fingers of a single user, multiple matchers, etc. in order to determine or verify the identity of an individual. Information from multiple sources can be consolidated in several distinct levels. But fusion of two different biometric traits are difficult due to (i the feature sets of multiple modalities may be incompatible (e.g., minutiae set of fingerprints and eigen-coefficients of face; (ii the relationship between the feature spaces of different biometric systems may not be known; (iii concatenating two feature vectors may result in a feature vector with very large dimensionality leading to the `curse of dimensionality problem, huge storage space and different processing algorithm. Also if we are use multiple images of single biometric trait, then it doesn’t show much variations. So in this paper, we present a efficient technique of feature-based fusion in a multimodal system where left eye and right eye are used as input. Iris recognition basically contains iris location, feature extraction, and identification. This algorithm uses canny edge detection to identify inner and outer boundary of iris. Then this image is feed to Gabor wavelet transform to extract the feature and finally matching is done by using indexing algorithm. The results from the analysis of works indicate that the proposed technique can lead to substantial improvement in performance.

  17. Nuclear reactor neutron shielding

    Energy Technology Data Exchange (ETDEWEB)

    Speaker, Daniel P; Neeley, Gary W; Inman, James B

    2017-09-12

    A nuclear reactor includes a reactor pressure vessel and a nuclear reactor core comprising fissile material disposed in a lower portion of the reactor pressure vessel. The lower portion of the reactor pressure vessel is disposed in a reactor cavity. An annular neutron stop is located at an elevation above the uppermost elevation of the nuclear reactor core. The annular neutron stop comprises neutron absorbing material filling an annular gap between the reactor pressure vessel and the wall of the reactor cavity. The annular neutron stop may comprise an outer neutron stop ring attached to the wall of the reactor cavity, and an inner neutron stop ring attached to the reactor pressure vessel. An excore instrument guide tube penetrates through the annular neutron stop, and a neutron plug comprising neutron absorbing material is disposed in the tube at the penetration through the neutron stop.

  18. Fast reactor safety and related physics. Volume IV. Phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    Separate abstracts are included for 58 papers concerning single-phase flow and sodium boiling; sodium boiling and subassembly flow blockages; transient-overpower and loss-of-flow experiments; fuel and cladding behavior and relocation; fuel and cladding freezing; molten-fuel-coolant interaction; aerosols and fission product release, and post-accident heat removal. Thirteen papers have been perivously abstracted and included in ERA.

  19. Reactor and method of operation

    Science.gov (United States)

    Wheeler, John A.

    1976-08-10

    A nuclear reactor having a flattened reactor activity curve across the reactor includes fuel extending over a lesser portion of the fuel channels in the central portion of the reactor than in the remainder of the reactor.

  20. Uso de la triamcinolona subtenoniana en pacientes con rubeosis del iris Use of intravitreal triamcinolone in patients with iris rubeosis

    Directory of Open Access Journals (Sweden)

    Irene Rojas Rondón

    2008-12-01

    Full Text Available OBJETIVO: Describir el comportamiento de la rubeosis del iris luego de la aplicación de triamcinolona subtenoniana. MÉTODOS: Se realizó un estudio descriptivo de corte longitudinal con 25 pacientes para un total de 32 ojos con diferentes afecciones oculares. Se efectuaron pruebas estadísticas con las variables del estudio y en algunas se utilizó la prueba de los signos de comparación para datos pareados y en otras se aplicó chi cuadrado. Se caracterizaron las variables: edad, sexo, causa de rubeosis del iris y sus estadios, síntomas y tratamiento con láser de panfotocoagulación retiniana. RESULTADOS: La retinopatía diabética proliferativa fue la afección más frecuente en el 76 % de los pacientes, seguida de la oclusión de la vena central retiniana. Del total de pacientes tratados, el 37,5 % evolucionó satisfactoriamente el estado de la rubeosis del iris. Fue mayor el número de pacientes que mejoraron el grado de la rubeosis con tratamiento combinado de láser y triamcinolona subtenoniana, aunque estadísticamente no fue significativo. El estado de la rubeosis mejoró en más de la mitad de los pacientes con tiempo de evolución menor de 6 meses. En aquellos con un tiempo mayor de 6 meses y neovascularización del iris grado III, se pudo estabilizar el glaucoma neovascular. CONCLUSIÓN: Se plantea que la triamcinolona subtenoniana constituye una alternativa para el manejo de este tipo de pacientes.OBJECTIVE: To describe the behaviour of iris rubeosis after using intravitreal triamcinolone. METHODS: A longitudinal descriptive study was performed on 25 patients for a total number of 32 eyes with several ocular diseases. Statistical tests were made with the study variables; sign comparison for paired data and Chi square tests were applied. The variables were age, sex, cause of iris rubeosis and its staging, symptoms and treatment with retinal photocoagulation laser. RESULTS: Proliferative diabetic retinopathy was the most common

  1. Annual Research Technical Report 2004; Informe Tecnico de Investigacion Anual del 2004

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Viais J, J.; Mendoza G, G.; Ramirez S, J. R.; Castillo M, J. A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-09-15

    In this work it plans to be carried out the Probabilistic Safety Analysis level 1 for the Modified Design of the IRIS Reactor. To generate computational tools of calculation of the analysis of the reactors of IV Generation and to optimize the use of nuclear fuel. To elaborate the economic analysis of the IRIS Reactor. (Author)

  2. A New IRIS Normalization Process For Recognition System With Cryptographic Techniques

    CERN Document Server

    Nithyanandam, S; Priyadarshini, P L K

    2011-01-01

    Biometric technologies are the foundation of personal identification systems. It provides an identification based on a unique feature possessed by the individual. This paper provides a walkthrough for image acquisition, segmentation, normalization, feature extraction and matching based on the Human Iris imaging. A Canny Edge Detection scheme and a Circular Hough Transform, is used to detect the iris boundaries in the eye's digital image. The extracted IRIS region was normalized by using Image Registration technique. A phase correlation base method is used for this iris image registration purpose. The features of the iris region is encoded by convolving the normalized iris region with 2D Gabor filter. Hamming distance measurement is used to compare the quantized vectors and authenticate the users. To improve the security, Reed-Solomon technique is employed directly to encrypt and decrypt the data. Experimental results show that our system is quite effective and provides encouraging performance. Keywords: Biome...

  3. A data hiding approach for the self-security of iris recognition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Attacks to biometric data are the primary danger to the self-security of biometrics.To improve the iris feature template data security,a data hiding approach based on bit streams is proposed,in which an iris feature template is embedded into a face image. The proposed approach is applicable to present dominant techniques of iris recognition.With the low computation cost and the zero decoding-error-rate,this data hiding approach,embedding target biometric data into other biometric data for improving the security of target data in identity recognition,data storage and transmission,can deceive attackers more effectively.Furthermore,it does not degrade the iris recognition performances.Experimental results prove that the proposed approach can be used to protect iris feature templates and enhance the security of the iris recognition system itself.

  4. A New IRIS Normalization Process For Recognition System With Cryptographic Techniques

    Directory of Open Access Journals (Sweden)

    S Nithyanandam

    2011-07-01

    Full Text Available Biometric technologies are the foundation of personal identification systems. It provides an identification based on a unique feature possessed by the individual. This paper provides a walkthrough for image acquisition, segmentation, normalization, feature extraction and matching based on the Human Iris imaging. A Canny Edge Detection scheme and a Circular Hough Transform, is used to detect the iris boundaries in the eye's digital image. The extracted IRIS region was normalized by using Image Registration technique. A phase correlation base method is used for this iris image registration purpose. The features of the iris region is encoded by convolving the normalized iris region with 2D Gabor filter. Hamming distance measurement is used to compare the quantized vectors and authenticate the users. To improve the security, Reed-Solomon technique is employed directly to encrypt and decrypt the data. Experimental results show that our system is quite effective and provides encouraging performance.

  5. Analysis of Inter-Moss Loops in the Solar Region with IRIS and SDO AIA: Automatic Event Detection and Characterization

    Science.gov (United States)

    Fayock, Brian; Winebarger, Amy; De Pontieu, Bart; Alexander, Caroline

    2016-01-01

    The Interface Region Imaging Spectrograph (IRIS), launched in the summer of 2013, is designed specifically to observe and investigate the transition region and adjacent layers of the solar atmosphere, obtaining images in high spatial, temporal, and spectral resolution. Our particular work is focused on the evolution of inter-moss loops, which have been detected in the lower corona by the Atmospheric Imaging Assembly (AIA) and the High-Resolution Coronal Imager (Hi- C), but are known to have foot points below the transition region. With the high-resolution capabilities of IRIS and its Si IV pass band, which measures activity in the upper chromosphere, we can study these magnetic loops in detail and compare their characteristic length and time scales to those obtained from several AIA image sets, particularly the 171, 193, and 211 pass bands. By comparing the results between these four data sets, one can potentially establish a measure of the ionization equilibrium for the location in question. To explore this idea, we found a large, sit-and-stare observation within the IRIS database that fit our specifications. This data set contained a number of well-defined inter-moss loops (by visual inspection) with a cadence less than or equal to that of AIA (approximately 12 seconds). This particular data set was recorded on October 23, 2013 at 07:09:30, lasting for 3219 seconds with a field of view of 120.6 by 128.1 arcseconds, centered on -53.9 by 59.1 arcseconds from disk center. For ease of comparison, the AIA data has been interpolated to match the IRIS cadence and resolution. In the main portion of the poster, we demonstrate the detection of events, the information collected, and the immediate results to the right, showing the progress of an event with green as the start, blue as the peak, and red as the end. Below here, we demonstrate how pixels are combined to form groups. The 3D results are shown to the right

  6. Fuel development for gas-cooled fast reactors

    Science.gov (United States)

    Meyer, M. K.; Fielding, R.; Gan, J.

    2007-09-01

    The Generation IV Gas-cooled Fast Reactor (GFR) concept is proposed to combine the advantages of high-temperature gas-cooled reactors (such as efficient direct conversion with a gas turbine and the potential for application of high-temperature process heat), with the sustainability advantages that are possible with a fast-spectrum reactor. The latter include the ability to fission all transuranics and the potential for breeding. The GFR is part of a consistent set of gas-cooled reactors that includes a medium-term Pebble Bed Modular Reactor (PBMR)-like concept, or concepts based on the Gas Turbine Modular Helium Reactor (GT-MHR), and specialized concepts such as the Very High-Temperature Reactor (VHTR), as well as actinide burning concepts [A Technology Roadmap for Generation IV Nuclear Energy Systems, US DOE Nuclear Energy Research Advisory Committee and the Generation IV International Forum, December 2002]. To achieve the necessary high power density and the ability to retain fission gas at high temperature, the primary fuel concept proposed for testing in the United States is dispersion coated fuel particles in a ceramic matrix. Alternative fuel concepts considered in the US and internationally include coated particle beds, ceramic clad fuel pins, and novel ceramic 'honeycomb' structures. Both mixed carbide and mixed nitride-based solid solutions are considered as fuel phases.

  7. Observations of solar flares with IRIS and SDO

    Science.gov (United States)

    Li, D.; Innes, D. E.; Ning, Z. J.

    2016-03-01

    Flare kernels brighten simultaneously in all Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) channels making it difficult to determine their temperature structure. The Interface Region Imaging Spectrograph (IRIS) is able to spectrally resolve Fe xxi emission from cold chromospheric brightenings, so it can be used to infer the amount of Fe xxi emission in the 131 Å AIA channel. We use observations of two small solar flares seen by IRIS and SDO to compare the emission measures (EMs) deduced from the IRIS Fe xxi line and the AIA 131 Å channel to determine the fraction of Fe xxi emission in flare kernels in the 131 Å channel of AIA. Cotemporal and cospatial pseudo-raster AIA images are compared with the IRIS results. We use multi-Gaussian line fitting to separate the blending chromospheric emission so as to derive Fe xxi intensities and Doppler shifts in IRIS spectra. We define loop and kernel regions based on the brightness of the 131 Å and 1600 Å intensities. In the loop regions the Fe xxi EMs are typically 80% of the 131 Å values, and range from 67% to 92%. Much of the scatter is due to small misalignments, but the largest site with low Fe xxi contributions was probably affected by a recent injection of cool plasma into the loop. In flare kernels the contribution of Fe xxi increases from less than 10% at the low-intensity 131 Å sites to 40-80% in the brighter kernels. Here the Fe xxi is superimposed on bright chromospheric emission and the Fe xxi line shows blueshifts, sometimes extending up to the edge of the spectral window, 200 km s-1. The AIA 131 Å emission in flare loops is due to Fe xxi emission with a 10-20% contribution from continuum, Fe xxiii, and cooler background plasma emission. In bright flare kernels up to 52% of the 131 Å is from cooler plasma. The wide range seen in the kernels is caused by significant structure in the kernels, which is seen as sharp gradients in Fe xxi EM at sites of molecular and transition region

  8. Biometric iris image acquisition system with wavefront coding technology

    Science.gov (United States)

    Hsieh, Sheng-Hsun; Yang, Hsi-Wen; Huang, Shao-Hung; Li, Yung-Hui; Tien, Chung-Hao

    2013-09-01

    Biometric signatures for identity recognition have been practiced for centuries. Basically, the personal attributes used for a biometric identification system can be classified into two areas: one is based on physiological attributes, such as DNA, facial features, retinal vasculature, fingerprint, hand geometry, iris texture and so on; the other scenario is dependent on the individual behavioral attributes, such as signature, keystroke, voice and gait style. Among these features, iris recognition is one of the most attractive approaches due to its nature of randomness, texture stability over a life time, high entropy density and non-invasive acquisition. While the performance of iris recognition on high quality image is well investigated, not too many studies addressed that how iris recognition performs subject to non-ideal image data, especially when the data is acquired in challenging conditions, such as long working distance, dynamical movement of subjects, uncontrolled illumination conditions and so on. There are three main contributions in this paper. Firstly, the optical system parameters, such as magnification and field of view, was optimally designed through the first-order optics. Secondly, the irradiance constraints was derived by optical conservation theorem. Through the relationship between the subject and the detector, we could estimate the limitation of working distance when the camera lens and CCD sensor were known. The working distance is set to 3m in our system with pupil diameter 86mm and CCD irradiance 0.3mW/cm2. Finally, We employed a hybrid scheme combining eye tracking with pan and tilt system, wavefront coding technology, filter optimization and post signal recognition to implement a robust iris recognition system in dynamic operation. The blurred image was restored to ensure recognition accuracy over 3m working distance with 400mm focal length and aperture F/6.3 optics. The simulation result as well as experiment validates the proposed code

  9. Comparison of ionospheric characteristic parameters obtained by GPS and ionosonde with IRI model over China

    Indian Academy of Sciences (India)

    Cheng Wang

    2016-06-01

    This paper presents a comparison of ionospheric characteristic parameters obtained by a GPS networkand three ionosondes at Mohe (122.4^◦E, 53.5^◦N, dip angle 70.983^◦N), Zuolingzhen (114.6^◦E, 30.5^◦N, dipangle 46.350^◦N), and Fuke (109.1^◦E, 19.5^◦N, dip angle 27.083^◦N) located in China with an IRI model inthe year 2011. Observed NmF2 and hmF2 values at the three stations are compared with IRI2007 andIRI2012 predictions, respectively. The results show that there are clear linear correlations between theobserved values and the IRI model predicted values. The IRI model gives overestimations at the threestations mostly in 2011. For the NmF2 and hmF2 values, most of the results show that the IRI2012predicted values are closer to the observed values compared with those of IRI2007. Additionally, theGPS TEC values derived from the Crustal Movement Observation Network of China (CMONOC) arecompared with the IRI2012 predictions. From the results, it is evident that the IRI2012 model predictionsfollow the normal trend of diurnal variation of GPS measured TEC monthly means but do not reproducethe measured data well. The IRI2012 model overestimates electron density in the latter part of spring aswell as the first half of autumn and winter and underestimates electron density in early spring and thelatter part of autumn. Referring to GPS TEC, the precision of the IRI2012 model predicted TEC valuesis ∼5 TECU over China. It may also be noted that there are two discontinuities of IRI-TEC monthlymeans appearing in November and December of the year 2011. This brings a bias of ∼3 TECU of TECvalues between two adjacent months.

  10. Perancangan Program Aplikasi Deteksi Iris Mata untuk Absensi Karyawan Menggunakan Metode Gabor Wavelet

    Directory of Open Access Journals (Sweden)

    Zahedi Zahedi

    2011-06-01

    Full Text Available To take the employees’ absences in a company, a variety of invented tools or technologies are and already used, for example, attendance cards, fingerprints attendance tool, and attendance tool that uses facial recognition. Attendance tool with a facial recognition uses iris recognition of those employees. Iris code has many properties that hard to forge. Thus, the detection and iris recognition is one of the most secure and accurate for identification. 

  11. Susceptibility of human iris stromal cells to herpes simplex virus 1 entry.

    Science.gov (United States)

    Baldwin, John; Park, Paul J; Zanotti, Brian; Maus, Erika; Volin, Michael V; Shukla, Deepak; Tiwari, Vaibhav

    2013-04-01

    Ocular herpes simplex virus 1 (HSV-1) infection can lead to multiple complications, including iritis, an inflammation of the iris. Here, we use human iris stroma cells as a novel in vitro model to demonstrate HSV-1 entry and the inflammatory mediators that can damage the iris. The upregulated cytokines observed in this study provide a new understanding of the intrinsic immune mechanisms that can contribute to the onset of iritis.

  12. CHARACTERIZING HABITUATION USING THE TIME-ON-TASK METRIC IN AN IRIS RECOGNITION SYSTEM

    OpenAIRE

    Hasselgren, Jacob A.

    2014-01-01

    This thesis presents a characterization of biometric habituation in an iris recognition study using qualitative analysis of a distributed habituation survey and quantitative analysis of iris images collected in 2010 and 2012. The performed analyses answered the following two questions: a) How consistently does the biometric community define habituation?; and b) Does the time-on-task variable provide enough evidence to indicate the existence of habituation in an iris recognition system? The qu...

  13. Nuclear Data Needs for Generation IV Nuclear Energy Systems

    Science.gov (United States)

    Rullhusen, Peter

    2006-04-01

    Nuclear data needs for generation IV systems. Future of nuclear energy and the role of nuclear data / P. Finck. Nuclear data needs for generation IV nuclear energy systems-summary of U.S. workshop / T. A. Taiwo, H. S. Khalil. Nuclear data needs for the assessment of gen. IV systems / G. Rimpault. Nuclear data needs for generation IV-lessons from benchmarks / S. C. van der Marck, A. Hogenbirk, M. C. Duijvestijn. Core design issues of the supercritical water fast reactor / M. Mori ... [et al.]. GFR core neutronics studies at CEA / J. C. Bosq ... [et al]. Comparative study on different phonon frequency spectra of graphite in GCR / Young-Sik Cho ... [et al.]. Innovative fuel types for minor actinides transmutation / D. Haas, A. Fernandez, J. Somers. The importance of nuclear data in modeling and designing generation IV fast reactors / K. D. Weaver. The GIF and Mexico-"everything is possible" / C. Arrenondo Sánchez -- Benmarks, sensitivity calculations, uncertainties. Sensitivity of advanced reactor and fuel cycle performance parameters to nuclear data uncertainties / G. Aliberti ... [et al.]. Sensitivity and uncertainty study for thermal molten salt reactors / A. Biduad ... [et al.]. Integral reactor physics benchmarks- The International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the International Reactor Physics Experiment Evaluation Project (IRPHEP) / J. B. Briggs, D. W. Nigg, E. Sartori. Computer model of an error propagation through micro-campaign of fast neutron gas cooled nuclear reactor / E. Ivanov. Combining differential and integral experiments on [symbol] for reducing uncertainties in nuclear data applications / T. Kawano ... [et al.]. Sensitivity of activation cross sections of the Hafnium, Tanatalum and Tungsten stable isotopes to nuclear reaction mechanisms / V. Avrigeanu ... [et al.]. Generating covariance data with nuclear models / A. J. Koning. Sensitivity of Candu-SCWR reactors physics calculations to nuclear data files / K. S

  14. Interplanetary Type IV Bursts

    Science.gov (United States)

    Hillaris, A.; Bouratzis, C.; Nindos, A.

    2016-08-01

    We study the characteristics of moving type IV radio bursts that extend to hectometric wavelengths (interplanetary type IV or type {IV}_{{IP}} bursts) and their relationship with energetic phenomena on the Sun. Our dataset comprises 48 interplanetary type IV bursts observed with the Radio and Plasma Wave Investigation (WAVES) instrument onboard Wind in the 13.825 MHz - 20 kHz frequency range. The dynamic spectra of the Radio Solar Telescope Network (RSTN), the Nançay Decametric Array (DAM), the Appareil de Routine pour le Traitement et l' Enregistrement Magnetique de l' Information Spectral (ARTEMIS-IV), the Culgoora, Hiraso, and the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) Radio Spectrographs were used to track the evolution of the events in the low corona. These were supplemented with soft X-ray (SXR) flux-measurements from the Geostationary Operational Environmental Satellite (GOES) and coronal mass ejections (CME) data from the Large Angle and Spectroscopic Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). Positional information of the coronal bursts was obtained by the Nançay Radioheliograph (NRH). We examined the relationship of the type IV events with coronal radio bursts, CMEs, and SXR flares. The majority of the events (45) were characterized as compact, their duration was on average 106 minutes. This type of events was, mostly, associated with M- and X-class flares (40 out of 45) and fast CMEs, 32 of these events had CMEs faster than 1000 km s^{-1}. Furthermore, in 43 compact events the CME was possibly subjected to reduced aerodynamic drag as it was propagating in the wake of a previous CME. A minority (three) of long-lived type {IV}_{{IP}} bursts was detected, with durations from 960 minutes to 115 hours. These events are referred to as extended or long duration and appear to replenish their energetic electron content, possibly from electrons escaping from the corresponding coronal

  15. Observations of an X-shaped Ribbon Flare and Its Three-dimensional Magnetic Reconnection with IRIS and SDO

    Science.gov (United States)

    Li, Ying; Qiu, Jiong; Longcope, Dana; Ding, Mingde

    2016-05-01

    We report evolution of an atypical X-shaped flare ribbon which provides novel observational evidence of three-dimensional (3D) magnetic reconnection at a separator. The flare occurred on 2014 November 9, and high-resolution slit-jaw 1330 images from IRIS reveal four chromospheric flare ribbons that converge and form an X-shape. These four ribbons are located in a quadrupolar magnetic field. Reconstruction of magnetic topology in the active region suggests the presence of a separator connecting to the X-point outlined by the ribbons. The inward motion of flare ribbons, as well as coronal loops observed by the SDO/AIA, indicates 3D magnetic reconnection between two sets of non-coplanar loops that approach laterally, and the reconnection proceeds downward to a very low height. We also study spectra of Si IV, C II, and Mg II observed with the IRIS slit, which cuts across the flare ribbons near the X-point. We have found two distinct types of line profiles. At the flare ribbon, all the lines show evident redshifts with a velocity up to 50 km/s, and the redshifts are well correlated with the line intensity and width. These redshifts suggest chromospheric condensation caused by impulsive energy deposition from the separator reconnection. While right outside the flare ribbon, the lines exhibit unshifted, symmetric, yet broadened profiles; in particular, the Si IV line is significantly broadened at the far wing. The line broadening persists for 20 minutes till after the end of the flare. The distinct spectral features near the X-point indicate different dynamics associated with the separator reconnection.

  16. Lantionpohjan toimintahäiriöt : Fysioterapeuttiset hoitokäytännöt

    OpenAIRE

    Halinen, Erika; Pulkkinen, Sari

    2011-01-01

    Lantionpohjan toimintahäiriöt ovat merkittävä naisten elämänlaatua heikentävä vaiva. Lantionpohjan toimintahäiriöitä ovat virtsaamiseen, ulostamiseen ja seksuaalitoimintoihin liittyvät häiriöt sekä laskeumat ja lantionpohjan alueen kiputilat. Suurimmat riskitekijät toimintahäiriöiden synnylle ovat raskauksien, synnytysten ja ikääntymisen mukanaan tuomat lantionpohjan lihas-, sidekudos- ja hermovauriot tai -muutokset. Lantionpohjan eri rakenteet ja toiminnat ovat läheisessä yhteydessä toisiins...

  17. Iridectomy of the anterior iris stroma using the vitreocutter during phacoemulsification in patients with iridoschisis.

    Science.gov (United States)

    Ghanem, Vinícius Coral; Ghanem, Emir Amin; Ghanem, Ramon Coral

    2003-11-01

    We present a technique to manage iridoschisis. This technique for anterior iridectomy of the affected iris fibers avoids intraoperative obstruction of the phaco tip and prevents postoperative complications such as corneal decompensation and glaucoma. Before the capsulorhexis is created, a vitreocutter is inserted in the anterior chamber and used to cut the iris strands at the site of the iridoschisis, making an anterior sectorial stromal iridectomy and preserving the iris pigment epithelium. Phacoemulsification is then performed. After the pupil is constricted with carbacol, remnants of the loose anterior iris fibers are excised with the vitreocutter and the scleral incision is sutured.

  18. Narrow-line-width UV Bursts in the Transition Region above Sunspots Observed by IRIS

    Science.gov (United States)

    Hou, Zhenyong; Huang, Zhenghua; Xia, Lidong; Li, Bo; Madjarska, Maria S.; Fu, Hui; Mou, Chaozhou; Xie, Haixia

    2016-10-01

    Various small-scale structures abound in the solar atmosphere above active regions, playing an important role in the dynamics and evolution therein. We report on a new class of small-scale transition region structures in active regions, characterized by strong emissions but extremely narrow Si iv line profiles as found in observations taken with the Interface Region Imaging Spectrograph (IRIS). Tentatively named as narrow-line-width UV bursts (NUBs), these structures are located above sunspots and comprise one or multiple compact bright cores at sub-arcsecond scales. We found six NUBs in two data sets (a raster and a sit-and-stare data set). Among these, four events are short-lived with a duration of ∼10 minutes, while two last for more than 36 minutes. All NUBs have Doppler shifts of 15–18 km s‑1, while the NUB found in sit-and-stare data possesses an additional component at ∼50 km s‑1 found only in the C ii and Mg ii lines. Given that these events are found to play a role in the local dynamics, it is important to further investigate the physical mechanisms that generate these phenomena and their role in the mass transport in sunspots.

  19. Explosive events in active region observed by IRIS and SST/CRISP

    CERN Document Server

    Huang, Z; Scullion, E M; Xia, L -D; Doyle, J G; Ray, T

    2016-01-01

    Transition-region explosive events (EEs) are characterized by non-Gaussian line profiles with enhanced wings at Doppler velocities of 50-150 km/s. They are believed to be the signature of solar phenomena that are one of the main contributors to coronal heating. The aim of this study is to investigate the link of EEs to dynamic phenomena in the transition region and chromosphere in an active region. We analyze observations simultaneously taken by the Interface Region Imaging Spectrograph (IRIS) in the Si IV 1394\\AA\\ line and the slit-jaw (SJ) 1400\\AA\\ images, and the Swedish 1-m Solar Telescope (SST) in the H$\\alpha$ line. In total 24 events were found. They are associated with small-scale loop brightenings in SJ 1400\\AA\\ images. Only four events show a counterpart in the H$\\alpha$-35 km/s and H$\\alpha$+35 km/s images. Two of them represent brightenings in the conjunction region of several loops that are also related to a bright region (granular lane) in the H$\\alpha$-35km/s and H$\\alpha$+35 km/s images. Sixte...

  20. Subarcsecond Bright Points and Quasi-periodic Upflows Below a Quiescent Filament Observed by the IRIS

    CERN Document Server

    Li, Ting

    2016-01-01

    Using UV spectra and SJIs from the IRIS, and coronal images and magnetograms from the Solar Dynamics Observatory (SDO), we present the new features in a quiescent filament channel: subarcsecond bright points (BPs) and quasi-periodic upflows. The BPs in the TR have a spatial scale of about 350$-$580 km and lifetime of more than several tens of minutes. They are located at stronger magnetic structures in the filament channel, with magnetic flux of about 10$^{17}$$-$10$^{18}$ Mx. Quasi-periodic brightenings and upflows are observed in the BPs and the period is about 4$-$5 min. The BP and the associated jet-like upflow comprise a "tadpole-shaped" structure. The upflows move along bright filament threads and their directions are almost parallel to the spine of the filament. The upflows initiated from the BPs with opposite polarity magnetic fields have opposite directions. The velocity of the upflows in plane of sky is about 5$-$50 km s$^{-1}$. The emission line of Si IV 1402.77 {\\AA} at the locations of upflows ex...

  1. Narrow-line-width UV bursts in the transition region above Sunspots observed by IRIS

    CERN Document Server

    Hou, Zhenyong; Xia, Lidong; Li, Bo; Madjarska, Maria S; Fu, Hui; Mou, Chaozhou; Xie, Haixia

    2016-01-01

    Various small-scale structures abound in the solar atmosphere above active regions, playing an important role in the dynamics and evolution therein. We report on a new class of small-scale transition region structures in active regions, characterized by strong emissions but extremely narrow Si IV line profiles as found in observations taken with the Interface Region Imaging Spectrograph (IRIS). Tentatively named as Narrow-line-width UV bursts (NUBs), these structures are located above sunspots and comprise of one or multiple compact bright cores at sub-arcsecond scales. We found six NUBs in two datasets (a raster and a sit-and-stare dataset). Among these, four events are short-living with a duration of $\\sim$10 mins while two last for more than 36 mins. All NUBs have Doppler shifts of 15--18 km/s, while the NUB found in sit-and-stare data possesses an additional component at $\\sim$50 km/s found only in the C II and Mg II lines. Given that these events are found to play a role in the local dynamics, it is impo...

  2. IV access in dental practice.

    LENUS (Irish Health Repository)

    Fitzpatrick, J J

    2009-04-01

    Intravenous (IV) access is a valuable skill for dental practitioners in emergency situations and in IV sedation. However, many people feel some apprehension about performing this procedure. This article explains the basic principles behind IV access, and the relevant anatomy and physiology, as well as giving a step-by-step guide to placing an IV cannula.

  3. Hyaluronic acid production and hyaluronidase activity in the newt iris during lens regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Kulyk, W.M.; Zalik, S.E.; Dimitrov, E.

    1987-09-01

    The process of lens regeneration in newts involves the dedifferentiation of pigmented iris epithelial cells and their subsequent conversion into lens fibers. In vivo this cell-type conversion is restricted to the dorsal region of the iris. We have examined the patterns of hyaluronate accumulation and endogenous hyaluronidase activity in the newt iris during the course of lens regeneration in vivo. Accumulation of newly synthesized hyaluronate was estimated from the uptake of (/sup 3/H)glucosamine into cetylpyridinium chloride-precipitable material that was sensitive to Streptomyces hyaluronidase. Endogenous hyaluronidase activity was determined from the quantity of reducing N-acetylhexosamine released upon incubation of iris tissue extract with exogenous hyaluronate substrate. We found that incorporation of label into hyaluronate was consistently higher in the regeneration-activated irises of lentectomized eyes than in control irises from sham-operated eyes. Hyaluronate labeling was higher in the dorsal (lens-forming) region of the iris than in ventral (non-lens-forming) iris tissue during the regeneration process. Label accumulation into hyaluronate was maximum between 10 and 15 days after lentectomy, the period of most pronounced dedifferentiation in the dorsal iris epithelium. Both normal and regenerating irises demonstrated a high level of endogenous hyaluronidase activity with a pH optimum of 3.5-4.0. Hyaluronidase activity was 1.7 to 2 times higher in dorsal iris tissue than in ventral irises both prior to lentectomy and throughout the regeneration process. We suggest that enhanced hyaluronate accumulation may facilitate the dedifferentiation of iris epithelial cells in the dorsal iris and prevent precocious withdrawal from the cell cycle. The high level of hyaluronidase activity in the dorsal iris may promote the turnover and remodeling of extracellular matrix components required for cell-type conversion.

  4. Dibromidodimethyldipyridineplatinum(IV

    Directory of Open Access Journals (Sweden)

    Mairéad E. Kelly

    2008-11-01

    Full Text Available In the title complex, [PtBr2(CH32(C5H5N2], the PtIV metal centre lies on a twofold rotation axis and adopts a slightly distorted octahedral coordination geometry. The structure displays weak intramolecular C—H...Br hydrogen-bonding interactions.

  5. Marketing produktu Karel IV.

    OpenAIRE

    Mikšů, Šárka

    2009-01-01

    Goal of the thesis Marketing of the product Karel IV. is to propose chanels of marketing communication and indicate possibilities of next product's development. Theoretical part is based on marketing plan and it's partition. In the practical part you can find market analysis and competing products analysis, product's evolution description and marketing research.

  6. PLATO IV Accountancy Index.

    Science.gov (United States)

    Pondy, Dorothy, Comp.

    The catalog was compiled to assist instructors in planning community college and university curricula using the 48 computer-assisted accountancy lessons available on PLATO IV (Programmed Logic for Automatic Teaching Operation) for first semester accounting courses. It contains information on lesson access, lists of acceptable abbreviations for…

  7. Virtual Ionosonde Construction by using ITS and IRI-2012 models

    Science.gov (United States)

    Kabasakal, Mehmet; Toker, Cenk

    2016-07-01

    Ionosonde is a kind of radar which is used to examine several properties of the ionosphere, including the electron density and drift velocity. Ionosonde is an expensive device and its installation requires special expertise and a proper area clear of sources of radio interference. In order to overcome the difficulties of installing an ionosonde hardware, the target of this study is to construct a virtual ionosonde based on communication channel models where the model parameters are determined by ray tracing obtained by the PHaRLAP software and the International Reference Ionosphere (IRI-2012) model. Although narrowband high frequency (HF) communication models have been widely used to represent the behaviour of the radio channel, they are applicable to a limited set of actual propagation conditions and wideband models are needed to better understand the HF channel. In 1997, the Institute for Telecommunication Science (ITS) developed a wideband HF ionospheric model, the so-called ITS model, however, it has some restrictions in real life applications. The ITS model parameters are grouped into two parts; the deterministic and the stochastic parameters. The deterministic parameters are the delay time (tau _{c}) of each reflection path based on the penetration frequency (f _{p}), the height (h _{0}) of the maximum electron density and the half thickness (sigma) of the reflective layer. The stochastic parameters, delay spread (sigma _{tau}), delay rise time (sigma _{c}), Doppler spread (sigma _{D}), Doppler shift (f _{s}), are to calculate the impulse response of the channel. These parameters are generally difficult to obtain and are based on the measured data which may not be available in all cases. In order to obtain these parameters, we propose to integrate the PHaRLAP ray tracing toolbox and the IRI-2012 model. When Total Electron Content (TEC) estimates obtained from GNSS measurements are input to IRI-2012, the model generates electron density profiles close to the

  8. Looking for gall bladder disease in the patient's iris.

    OpenAIRE

    Knipschild, P

    1988-01-01

    In alternative health care iridology is used as a diagnostic aid. The diagnosis of gall bladder disease was used to study its validity and interperformer consistency. The presence of an inflamed gall bladder containing gall stones is said to be easily recognised by certain signs in the lower lateral part of the iris of the right eye. Stereo colour slides were made of the right eye. Stereo colour slides were made of the right eye of 39 patients with this disease and 39 control subjects of the ...

  9. Thirty Years Supporting Portable Arrays: The IRIS Passcal Instrument Center

    Science.gov (United States)

    Beaudoin, B. C.; Anderson, K. R.; Bilek, S. L.; Woodward, R.

    2014-12-01

    Thirty years have passed since establishment of the IRIS Program for the Array Seismic Studies of the Continental Lithosphere (PASSCAL). PASSCAL was part of a coordinated plan proposed to the National Science Foundation (NSF) defining the instrumentation, data collection and management structure to support a wide range of research in seismology. The PASSCAL program has surpassed the early goal of 6000 data acquisition channels with a current inventory of instrumentation capable of imaging from the near surface to the inner core. Here we present the evolution of the PASSCAL program from instrument depot to full service community resource. PASSCAL has supported close to 1100 PI driven seismic experiments since its inception. Instruments from PASSCAL have covered the globe and have contributed over 7400 SEED stations and 242 assembled data sets to the IRIS Data Management Center in Seattle. Since the combination in 1998 of the Stanford and Lamont instrument centers into the single PASSCAL Instrument Center (PIC) at New Mexico Tech, the facility has grown in scope by adding the EarthScope Array Operations Facility in 2005, the incorporation of the EarthScope Flexible Array, and a Polar support group in 2006. The polar support group enhances portable seismic experiments in extremely harsh polar environments and also extends to special projects such as the Greenland Ice Sheet Monitoring Network (GLISN) and the recent development effort for Geophysical Earth Observatory for Ice Covered Environments (GEOICE). Through these support efforts the PIC has established itself as a resource for field practices, engineered solutions for autonomous seismic stations, and a pioneer in successful seismic recording in polar environments. We are on the cusp of a new generation of instrumentation driven in part by the academic community's desire to record unaliased wavefields in multiple frequency bands and industry's interest in utilizing lower frequency data. As part of the recently

  10. The Iris biometric feature segmentation using finite element method

    Directory of Open Access Journals (Sweden)

    David Ibitayo LANLEGE

    2015-05-01

    Full Text Available This manuscript presents a method for segmentation of iris images based on a deformable contour (active contour paradigm. The deformable contour is a novel approach in image segmentation. A type of active contour is the Snake. Snake is a parametric curve defined within the domain of the image. Snake properties are specified through a function called energy functional. This means they consist of packets of energy which expressed as partial Differential Equations. The partial Differential Equation is the controlling engine of the active contour since this project, the Finite Element Method (Standard Galerkin Method implementation for deformable model is presented.

  11. Iris sector heterochromia as a marker for neural crest disease.

    Science.gov (United States)

    Brazel, S M; Sullivan, T J; Thorner, P S; Clarke, M P; Hunter, W S; Morin, J D

    1992-02-01

    A 6-month-old female infant with biopsy-proved Hirschsprung's disease had associated sector heterochromia of the irides. The association between sector heterochromia and Hirschsprung's disease has been previously reported and both conditions have been ascribed to neural crest defects. Histologic characteristics of the ocular involvement have not previously been reported, to our knowledge. Histopathologic examination of the globes revealed decreased iris stroma, decreased pigmentation in the anterior stroma, and reduced numbers of pigment-producing cells in the affected areas. Both the ocular and gastrointestinal findings reflect abnormalities in tissues of neural crest origin.

  12. EST and EST-SSR marker resources for Iris

    Directory of Open Access Journals (Sweden)

    Taylor Christopher A

    2009-06-01

    Full Text Available Abstract Background Limited DNA sequence and DNA marker resources have been developed for Iris (Iridaceae, a monocot genus of 200–300 species in the Asparagales, several of which are horticulturally important. We mined an I. brevicaulis-I. fulva EST database for simple sequence repeats (SSRs and developed ortholog-specific EST-SSR markers for genetic mapping and other genotyping applications in Iris. Here, we describe the abundance and other characteristics of SSRs identified in the transcript assembly (EST database and the cross-species utility and polymorphisms of I. brevicaulis-I. fulva EST-SSR markers among wild collected ecotypes and horticulturally important cultivars. Results Collectively, 6,530 ESTs were produced from normalized leaf and root cDNA libraries of I. brevicaulis (IB72 and I. fulva (IF174, and assembled into 4,917 unigenes (1,066 contigs and 3,851 singletons. We identified 1,447 SSRs in 1,162 unigenes and developed 526 EST-SSR markers, each tracing a different unigene. Three-fourths of the EST-SSR markers (399/526 amplified alleles from IB72 and IF174 and 84% (335/399 were polymorphic between IB25 and IF174, the parents of I. brevicaulis × I. fulva mapping populations. Forty EST-SSR markers were screened for polymorphisms among 39 ecotypes or cultivars of seven species – 100% amplified alleles from wild collected ecotypes of Louisiana Iris (I.brevicaulis, I.fulva, I. nelsonii, and I. hexagona, whereas 42–52% amplified alleles from cultivars of three horticulturally important species (I. pseudacorus, I. germanica, and I. sibirica. Ecotypes and cultivars were genetically diverse – the number of alleles/locus ranged from two to 18 and mean heterozygosity was 0.76. Conclusion Nearly 400 ortholog-specific EST-SSR markers were developed for comparative genetic mapping and other genotyping applications in Iris, were highly polymorphic among ecotypes and cultivars, and have broad utility for genotyping applications within

  13. Biofilm Community Dynamics in Bench-Scale Annular Reactors Simulating Arrestment of Chloraminated Drinking Water Nitrification

    Science.gov (United States)

    Annular reactors (ARs) were used to study biofilm community succession and provide an ecological insight during nitrification arrestment through simultaneously increasing monochloramine (NH2Cl) and chlorine to nitrogen mass ratios, resulting in four operational periods (I to IV)....

  14. Control, Co-generation, and Sensor Placement Strategy for Integral Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyaya, Belle-R.; Fan, Li; Hines, J.-Wesley [University of Tennessee, Knoxville (United States); Perillo, Sergio-R. P. [Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil)

    2011-08-15

    The development of Small Modular Reactors (SMR) has multiple applications for electricity generation, process heat, hydrogen production, and others. The results of research, development, and demonstration (RD and D) of load-following control design for multiple modules, nuclear desalination, and sensor placement strategy for enhanced fault detection and isolation, are presented in this paper. The technologies are demonstrated with application to an integral pressurized water reactor (IPWR) such as the IRIS reactor. The outcomes of this RD and D include the development of a complete dynamic model of the IRIS system, load following control under dual-module steam mixing, nuclear desalination with a multi-stage flash (MSF) desalination plant, and automated technique for sensor allocation in a combined reactor and balance-of-plant system. The dynamic performance of a nuclear power station comprised of two IRIS reactor modules, operating simultaneously with a common steam header with steam mixing, was evaluated. The control problem addressed 'load-following' scenarios, such as varying load during the day or reduced consumption during the weekend. To solve this problem, a single-module IRIS MATLAB-Simulink model was developed and used to quantify the responses from both modules. The resulting model was subjected to eight different perturbation cases to analyze its capability of detecting small perturbations, therefore testing its robustness and sensitivity. The prospects of using nuclear energy for seawater desalination on a large scale can be very attractive since desalination is an energy intensive process that can utilize the heat from a nuclear reactor and/or the electricity produced by such plants. Small modular reactors, ranging from 50 MWe to 300 MWe, offer the largest potential as coupling options to nuclear desalination systems. However, coupling a nuclear plant and a desalination plant involves a number of issues that have to be addressed. Among these

  15. Iris Marion Young's Imaginations of Gift Giving: Some Implications for the Teacher and the Student

    Science.gov (United States)

    Galea, Simone

    2006-01-01

    The paper discusses Iris Marion Young's idea of asymmetric reciprocity that rethinks typical understandings of gift giving. Iris Marion Young's proposals for asymmetric ethical relationships have important implications for democratic contexts that seek to take differences seriously. Imagining oneself in the place of the other or expecting from the…

  16. Gaze estimation for off-angle iris recognition based on the biometric eye model

    Science.gov (United States)

    Karakaya, Mahmut; Barstow, Del; Santos-Villalobos, Hector; Thompson, Joseph; Bolme, David; Boehnen, Christopher

    2013-05-01

    Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ORNL biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

  17. Influence of tamsulosin on the iris and its implications for cataract surgery.

    Science.gov (United States)

    Pärssinen, Olavi; Leppänen, Esa; Keski-Rahkonen, Pekka; Mauriala, Timo; Dugué, Benoit; Lehtonen, Marko

    2006-09-01

    To study iris-related complications during cataract surgery in patients on tamsulosin medication. Twenty-one consecutive cataract patients administered tamsulosin and 21 control patients were studied. Characteristics of the iris during surgery were recorded. Pupillary diameters of 16 patients were measured before and after iris dilatation. Tamsulosin concentrations in the aqueous humor and serum were analyzed. In five patients, surgery on the second eye was carried out after a 7- to 28-day pause in tamsulosin medication. Each patient administered tamsulosin had a sluggish hypotonic iris, along with a tendency toward miosis and a tendency for prolapse of the iris into the phaco tunnel or into the side port during cataract surgery. Sluggish irises also often adhered to the phaco tip or to the irrigation-aspiration tip. Despite a pause of 7 to 28 days in the use of tamsulosin, the adverse effects persisted. Tamsulosin concentrations varied between 0.1 and 1.0 ng/mL in the anterior chamber fluid. In three of five cases, tamsulosin remained in detectable amounts the aqueous humor after the 7- to 28-day pause. Preoperative pupillary diameter was smaller in the patients using tamsulosin than in the controls. Tamsulosin has selective alpha1A-adrenoreceptor antagonistic properties and obviously binds for a long period to the postsynaptic nerve endings of the iris dilator muscle, thus affecting iris dilatation and leading to complications in cataract surgery. The iris remained floppy after 7- to 28-day interruption of the tamsulosin regimen.

  18. Iris: Constructing and Analyzing Spectral Energy Distributions with the Virtual Observatory

    Science.gov (United States)

    Laurino, O.; Budynkiewicz, J.; Busko, I.; Cresitello-Dittmar, M.; D'Abrusco, R.; Doe, S.; Evans, J.; Pevunova, O.

    2014-05-01

    We present Iris 2.0, the latest release of the Virtual Astronomical Observatory application for building and analyzing Spectral Energy Distributions (SEDs). With Iris, users may read in and display SEDs inspect and edit any selection of SED data, fit models to SEDs in arbitrary spectral ranges, and calculate confidence limits on best-fit parameters. SED data may be loaded into the application from VOTable and FITS files compliant with the International Virtual Observatoy Alliance interoperable data models, or retrieved directly from NED or the Italian Space Agency Science Data Center; data in non-standard formats may also be converted within the application. Users may seamlessy exchange data between Iris and other Virtual Observatoy tools using the Simple Application Messaging Protocol. Iris 2.0 also provides a tool for redshifting, interpolating, and measuring integratd fluxes, and allows simple aperture corrections for individual points and SED segments. Custom Python functions, template models and template libraries may be imported into Iris for fitting SEDs. Iris may be extended through Java plugins; users can install third-party packages, or develop their own plugin using Iris' Software Development Kit. Iris 2.0 is available for Linux and Mac OS X systems.

  19. Gaze Estimation for Off-Angle Iris Recognition Based on the Biometric Eye Model

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

    2013-01-01

    Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ANONYMIZED biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

  20. A Summary and Perspective of Recent IRIS Assessments and Impact on Planning Environmental Investigations

    Science.gov (United States)

    2011-03-30

    IRIS)  IRIS values also inform regulatory decisions (MCLs etc.) BUILDING STRONG® Emerging Contaminants (ECs)  Are chemicals or materials of...there is an existing health standard, but the standard is evolving or being re-evaluated. 4 Source: “Initiation of Emerging Contaminants Characterization

  1. Membrane degradation and phospholipase D activity during developmental cell death in Iris flowers

    NARCIS (Netherlands)

    Vrije, de T.; Schoot, van der C.; Pak, C.; Doorn, van W.G.

    1996-01-01

    Iris x hollandica (cv. Blue Magic) flowers show the first symptoms of senescence within 4 days after the onset of flower opening. Wilting of the tepals starts at the distal edges, rapidly proceeds to the base, and is followed by total discolouration of the tepal. Senescence of Iris flowers is not

  2. Modular Pebble-Bed Reactor Project: Laboratory-Directed Research and Development Program FY 2002 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Petti, David Andrew; Dolan, Thomas James; Miller, Gregory Kent; Moore, Richard Leroy; Terry, William Knox; Ougouag, Abderrafi Mohammed-El-Ami; Oh, Chang H; Gougar, Hans D

    2002-11-01

    This report documents the results of our research in FY-02 on pebble-bed reactor technology under our Laboratory Directed Research and Development (LDRD) project entitled the Modular Pebble-Bed Reactor. The MPBR is an advanced reactor concept that can meet the energy and environmental needs of future generations under DOE’s Generation IV initiative. Our work is focused in three areas: neutronics, core design and fuel cycle; reactor safety and thermal hydraulics; and fuel performance.

  3. Modular Pebble-Bed Reactor Project: Laboratory-Directed Research and Development Program FY 2002 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Petti, David Andrew; Dolan, Thomas James; Miller, Gregory Kent; Moore, Richard Leroy; Terry, William Knox; Ougouag, Abderrafi Mohammed-El-Ami; Oh, Chang H; Gougar, Hans D

    2002-11-01

    This report documents the results of our research in FY-02 on pebble-bed reactor technology under our Laboratory Directed Research and Development (LDRD) project entitled the Modular Pebble-Bed Reactor. The MPBR is an advanced reactor concept that can meet the energy and environmental needs of future generations under DOE’s Generation IV initiative. Our work is focused in three areas: neutronics, core design and fuel cycle; reactor safety and thermal hydraulics; and fuel performance.

  4. Reactor Physics Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Raedt, C

    2000-07-01

    The Reactor Physics and Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies.

  5. The InfraRed Imaging Spectrograph (IRIS) for TMT: latest science cases and simulations

    CERN Document Server

    Wright, Shelley A; Do, Tuan; Marshall, Daniel; Larkin, James E; Moore, Anna M; Adamkovics, Mate; Andersen, David; Armus, Lee; Barth, Aaron; Cote, Patrick; Cooke, Jeff; Chisholm, Eric M; Davidge, Timothy; Dunn, Jennifer S; Dumas, Christophe; Ellerbroeck, Brent L; Ghez, Andrea M; Hao, Lei; Hayano, Yutaka; Liu, Michael; Lopez-Rodriguez, Enrique; Lu, Jessica R; Mao, Shude; Marois, Christian; Pandey, Shashi B; Philips, Andrew C; Schoeck, Matthias; Subramaniam, Annapurni; Subramanian, Smitha; Suzuki, Ryuji; Tan, Jonathan C; Terai, Tsuyoshi; Treu, Tommaso; Simard, Luc; Weiss, Jason L; Wincensten, James; Wong, Michael; Zhang, Kai

    2016-01-01

    The Thirty Meter Telescope (TMT) first light instrument IRIS (Infrared Imaging Spectrograph) will complete its preliminary design phase in 2016. The IRIS instrument design includes a near-infrared (0.85 - 2.4 micron) integral field spectrograph (IFS) and imager that are able to conduct simultaneous diffraction-limited observations behind the advanced adaptive optics system NFIRAOS. The IRIS science cases have continued to be developed and new science studies have been investigated to aid in technical performance and design requirements. In this development phase, the IRIS science team has paid particular attention to the selection of filters, gratings, sensitivities of the entire system, and science cases that will benefit from the parallel mode of the IFS and imaging camera. We present new science cases for IRIS using the latest end-to-end data simulator on the following topics: Solar System bodies, the Galactic center, active galactic nuclei (AGN), and distant gravitationally-lensed galaxies. We then briefl...

  6. [Use of computer technologies for studying the morphological characteristics of the iris color in anthropology].

    Science.gov (United States)

    Dorofeeva, A A; Khrustalev, A V; Krylov, Iu V; Bocharov, D A; Negasheva, M A

    2010-01-01

    Digital images of the iris were received for study peculiarities of the iris color during the anthropological examination of 578 students aged 16-24 years. Simultaneously with the registration of the digital images, the visual assessment of the eye color was carried out using the traditional scale of Bunak, based on 12 ocular prostheses. Original software for automatic determination of the iris color based on 12 classes scale of Bunak was designed, and computer version of that scale was developed. The software proposed allows to conduct the determination of the iris color with high validity based on numerical evaluation; its application may reduce the bias due to subjective assessment and methodological divergences of the different researchers. The software designed for automatic determination of the iris color may help develop both theoretical and applied anthropology, it may be used in forensic and emergency medicine, sports medicine, medico-genetic counseling and professional selection.

  7. Free-Floating Iris Cyst in a Patient with Recurrent Iritis

    Science.gov (United States)

    Teong, Joanne M.Y.; Adler, Paul A.; Fuzzard, Dujon R.W.

    2015-01-01

    Purpose We describe an unusual clinical finding of a free-floating iris cyst in a patient with recurrent iritis. Method The clinical finding of a free-floating iris cyst was recorded using slit-lamp photography. Results A 39-year-old male with a 5-year history of recurrent right iritis was found to have a small mobile iris cyst within his right anterior chamber, first identified 3 years ago. The patient did not experience any discomfort or visual symptoms resulting from the cyst. Conclusion Surgical removal is not indicated for asymptomatic non-progressive free-floating iris cysts. The significance of a free-floating iris cyst in the setting of recurrent iritis remains unknown. PMID:26120316

  8. Performance evaluation of IRI-2007 at equatorial latitudes and its Matlab version for GNSS applications

    Science.gov (United States)

    Satya Srinivas, V.; Sarma, A. D.; Swamy, K. C. T.; Satyanarayana, K.

    2013-11-01

    International Reference Ionosphere (IRI) model is the widely used empirical model for ionospheric predictions, especially TEC which is an important parameter for radio navigation and communication. The Fortran based IRI-2007 does not support real-time interactive visualization and debugging. Therefore, the source code is converted into Matlab and is validated for the purposes of this study. This facilitates easy representation of results and for near real-time implementation of IRI in the applications including spacecraft launching, now casting, pseudolite based navigation systems etc. In addition, the vertical delay results over the equatorial region derived from IRI and GPS data of three IGS stations namely Libreville (Garbon, Africa), Brasilia (Brazil, South America) and Hyderabad (India, Asia) are compared. As the IRI model does not account for plasmasphere TEC, the vertical delays are underestimated compared to vertical delays of GPS signals. Therefore, the model should be modified accordingly for precise TEC estimation.

  9. A Narrative Methodology to Recognize Iris Patterns By Extracting Features Using Gabor Filters and Wavelets

    Directory of Open Access Journals (Sweden)

    Shristi Jha

    2016-01-01

    Full Text Available Iris pattern Recognition is an automated method of biometric identification that uses mathematical pattern-Recognition techniques on images of one or both of the irises of an individual’s eyes, whose complex random patterns are unique, stable, and can be seen from some distance. Iris recognition uses video camera technology with subtle near infrared illumination to acquire images of the detail-rich, intricate structures of the iris which are visible externally. In this narrative research paper the input image is captured and the success of the iris recognition depends on the quality of the image so the captured image is subjected to the preliminary image preprocessing techniques like localization, segmentation, normalization and noise detection followed by texture and edge feature extraction by using Gabor filters and wavelets then the processed image is matched with templates stored in the database to detect the Iris Patterns.

  10. Twin Layer Iris Certification for Confidential Archive by Conceiving Shares (ICCA-CS

    Directory of Open Access Journals (Sweden)

    R. Sinduja

    2013-02-01

    Full Text Available Iris is one of the most challenging biometric techniques. In many proposed biometric recognition technique, template’s are store in the database for comparison. But there exists a vital problem in storing the template in the database since it can be easily bootlegged. In order to overcome these issues a novel method for person identification by their Iris, through securely storing the template is proposed. Visual Cryptography Encryption (VCE technique is used for securely storing the iris template. By means of VCE, shares are generated for the iris template which is stored in the database instead of storing the entire template. Shares are generated by pixel expansion method. Authentication is provided by comparing the shares. Comparison is done by using Hamming Code. So it is a very effective method of person identification. The proposed method gives an extra security in iris recognition.

  11. Measuring Biometric Sample Quality in terms of Biometric Feature Information in Iris Images

    Directory of Open Access Journals (Sweden)

    R. Youmaran

    2012-01-01

    Full Text Available This paper develops an approach to measure the information content in a biometric feature representation of iris images. In this context, the biometric feature information is calculated using the relative entropy between the intraclass and interclass feature distributions. The collected data is regularized using a Gaussian model of the feature covariances in order to practically measure the biometric information with limited data samples. An example of this method is shown for iris templates processed using Principal-Component Analysis- (PCA- and Independent-Component Analysis- (ICA- based feature decomposition schemes. From this, the biometric feature information is calculated to be approximately 278 bits for PCA and 288 bits for ICA iris features using Masek's iris recognition scheme. This value approximately matches previous estimates of iris information content.

  12. Secure and Robust Iris Recognition Using Random Projections and Sparse Representations.

    Science.gov (United States)

    Pillai, Jaishanker K; Patel, Vishal M; Chellappa, Rama; Ratha, Nalini K

    2011-09-01

    Noncontact biometrics such as face and iris have additional benefits over contact-based biometrics such as fingerprint and hand geometry. However, three important challenges need to be addressed in a noncontact biometrics-based authentication system: ability to handle unconstrained acquisition, robust and accurate matching, and privacy enhancement without compromising security. In this paper, we propose a unified framework based on random projections and sparse representations, that can simultaneously address all three issues mentioned above in relation to iris biometrics. Our proposed quality measure can handle segmentation errors and a wide variety of possible artifacts during iris acquisition. We demonstrate how the proposed approach can be easily extended to handle alignment variations and recognition from iris videos, resulting in a robust and accurate system. The proposed approach includes enhancements to privacy and security by providing ways to create cancelable iris templates. Results on public data sets show significant benefits of the proposed approach.

  13. Free-Floating Iris Cyst in a Patient with Recurrent Iritis

    Directory of Open Access Journals (Sweden)

    Joanne M.Y. Teong

    2015-06-01

    Full Text Available Purpose: We describe an unusual clinical finding of a free-floating iris cyst in a patient with recurrent iritis. Method: The clinical finding of a free-floating iris cyst was recorded using slit-lamp photography. Results: A 39-year-old male with a 5-year history of recurrent right iritis was found to have a small mobile iris cyst within his right anterior chamber, first identified 3 years ago. The patient did not experience any discomfort or visual symptoms resulting from the cyst. Conclusion: Surgical removal is not indicated for asymptomatic non-progressive free-floating iris cysts. The significance of a free-floating iris cyst in the setting of recurrent iritis remains unknown.

  14. TEC Longitude Difference Using GIMS and the IRI Model

    Science.gov (United States)

    Natali, Maria Paula; Meza, Amalia Margarita; Mendoza, Gastón

    2016-07-01

    The main geomagnetic field declination has a global distribution with positive and negative values showing maximum east-west differences over North America and Oceania and minimum differences over America and Asia. Several authors study one or more of these regions using TEC data derived from GNSS observations to describe variations in TEC. They reported a pronounced longitudinal variation respect to zero magnetic declination. One of the important factors that cause the longitude difference at mid-latitude is a combined effect of the longitude variations of magnetic declination and the variations of the zonal thermospheric winds with local time. We propose to study this effect using Global Ionospheric Maps (GIMs) and the respective TEC values generated from the International Reference Ionospheric (IRI) model, during a solar cycle, applying Principal Component Analysis (PCA). Our works is focused over different local times and regions at mid-latitude. PCA involves a mathematical procedure that transforms a number of correlated variables into a number of uncorrelated variables using the data itself. The spatial structure of the ionosphere variability and its temporal evolution, together are called modes, and there are ordered according to their percentage of the variability of data from highest to lowest. In this analysis the first mode has more than the 90 % of the variability, representing the nominal behavior of the ionosphere, and the second and third modes are the more important for our analysis, because they show the strong longitudinal variation in the different regions using either GIMs or the IRI model.

  15. Posterior Iris Fixated Intraocular Lens for Pediatric Traumatic Cataract

    Science.gov (United States)

    Kavitha, V.; Balasubramanian, Preethi; Heralgi, Mallikarjun M.

    2016-01-01

    Purpose: To evaluate the postoperative visual outcomes and complications of posterior iris fixated intraocular lens (IFIOL) implantation for pediatric traumatic cataract. Methods: A retrospective clinical audit was performed of all the pediatric traumatic cataract patients who underwent lens removal and iris fixated lens implantation due to inadequate capsular support with or without corneal tear repair between January 2009 and December 2013. Data were collected and analyzed on the preoperative and postoperative visual outcomes and complications. Results: Twenty-five children (25 eyes; 21 males and 4 females) were enrolled with the mean age of 11 ± 4.0 years. There were 72% of eyes that underwent primary cataract removal with IFIOL implantation. Twenty-eight percent of eyes underwent corneal tear repair prior to intraocular lens (IOL) implantation. Preoperative best corrected visual acuity (BCVA) was hand motion in 32% eyes, counting fingers in 24%, and perception of light in 44%. Postoperative BCVA of 0-0.2 logarithm of minimum angle of resolution was reported in the 64% of eyes. One eye developed secondary glaucoma, one eye underwent re-enclavation, and none developed retinal complications. Conclusion: Posterior IFIOL implantation resulted in an improved visual outcome, low incidence of postoperative complications, and is a good alternative to other IOL, in the cases of pediatric traumatic cataract without adequate capsular support. PMID:27162456

  16. Unilatelaral iris plateau syndrome after the use of ecstasy

    Directory of Open Access Journals (Sweden)

    Jovanović Predrag

    2009-01-01

    Full Text Available Bacground. Courmon street name for 3,4-Methylenedioxymethamphetamine (MDMA is ecstasy. This widely abused 'recreational' drug causes both an increased release of monoamine neurotransmitters, including serotonine and dopamine, and an increased reuptake inhibition of serotonin. As a consequence, mydriasis and increased intraocular pressure (IOP in predisposed patients occur. We present herein a rare case of acute increased IOP after use of ecstasy. Case report. A female patient, aged 38 years, visited doctor complaing of a decreased vision acuity and severe pain in the left eye and in the left part of the head. The initial treatment was urgent antiglaucomatous therapy followed by withdrawal of subjective problems of the patient and improvement of objective finding. History taking procedure reveled that just before the onset of the pain the patient had used ecstasy and had had similar 'experience' 6 years ago after cocaine snorting. She had not been to a doctor although she had experienced sporadic migrenous pain. Previous medical records excavation of revealed optic disk (cup-to-dise C/D=06, Bjerum arcuate scotoma and iris plateau with narrow chamber angle (Scheie II- III so the diagnosis was a rare unilateral iris plateau syndrome of the left eye. Although the patient was given some pieces of information about the dangerous and possible deadly consequences of psychoactive substance abuse, she has not continue the treatment. Conclusion. Ecstasy abuse might cause a complete loss of vision, thus medicametous and surgical treatment are obligatory.

  17. Noninvasive in vivo glucose sensing using an iris based technique

    Science.gov (United States)

    Webb, Anthony J.; Cameron, Brent D.

    2011-03-01

    Physiological glucose monitoring is important aspect in the treatment of individuals afflicted with diabetes mellitus. Although invasive techniques for glucose monitoring are widely available, it would be very beneficial to make such measurements in a noninvasive manner. In this study, a New Zealand White (NZW) rabbit animal model was utilized to evaluate a developed iris-based imaging technique for the in vivo measurement of physiological glucose concentration. The animals were anesthetized with isoflurane and an insulin/dextrose protocol was used to control blood glucose concentration. To further help restrict eye movement, a developed ocular fixation device was used. During the experimental time frame, near infrared illuminated iris images were acquired along with corresponding discrete blood glucose measurements taken with a handheld glucometer. Calibration was performed using an image based Partial Least Squares (PLS) technique. Independent validation was also performed to assess model performance along with Clarke Error Grid Analysis (CEGA). Initial validation results were promising and show that a high percentage of the predicted glucose concentrations are within 20% of the reference values.

  18. RANK LEVEL FUSION USING FINGERPRINT AND IRIS BIOMETRICS

    Directory of Open Access Journals (Sweden)

    N. Radha

    2011-12-01

    Full Text Available Authentication of users is an essential and difficult to achieve in all systems. Shared secrets like Personal Identification Numbers (PIN or Passwords and key devices such as Smart cards are not presently sufficient in few situations. The biometric improves the capability to recognize the persons. A biometric identificationsystem is an automatic recognition system that recognizes a person based on the physiological (e.g., fingerprints,face, retina, iris, ear or behavioral (e.g., gait, signature, voice characteristics. In many real-world applications,unimodal biometric systems often face has significant limitations due to sensitivity to noise, intra classvariability, data quality, non-universality, and other factors. Multimodal biometric systems overcome some of these limitations. Multimodal biometric system provides more accuracy when compared to unimodal biometric system. The main goal of multimodal biometric system is to develop the security system for the areas that require high level of security. The proposed system focused on developing a multimodal biometrics system,which uses biometrics such as fingerprint and iris. Fusion of biometrics is performed by means of rank level fusion. The features from the biometrics are obtained by using the FLD (Fisher Linear Discriminant. The experimental result shows the performance of the proposed multimodal biometrics system. In this paper, the decision is made using rank level fusion and the ranks of individual persons are calculated using the Borda count, and Logistic regression approaches.

  19. Human Iris Recognition System using Wavelet Transform and LVQ

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwan Yong; Lim, Shin Young [Electronics and Telecommunications Research Institute (Korea); Cho, Seong Won [Hongik University (Korea)

    2000-07-01

    The popular methods to check the identity of individuals include passwords and ID cards. These conventional methods for user identification and authentication are not altogether reliable because they can be stolen and forgotten. As an alternative of the existing methods, biometric technology has been paid much attention for the last few decades. In this paper, we propose an efficient system for recognizing the identity of a living person by analyzing iris patterns which have a high level of stability and distinctiveness than other biometric measurements. The proposed system is based on wavelet transform and a competitive neural network with the improved mechanisms. After preprocessing the iris data acquired through a CCD camera, feature vectors are extracted by using Haar wavelet transform. LVQ(Learning Vector Quantization) is exploited to classify these feature vectors. We improve the overall performance of the proposed system by optimizing the size of feature vectors and by introducing an efficient initialization of the weight vectors and a new method for determining the winner in order to increase the recognition accuracy of LVQ. From the experiments, we confirmed that the proposed system has a great potential of being applied to real applications in an efficient and effective way. (author). 14 refs., 13 figs., 7 tabs.

  20. Some Physiological Responses of Chinese Iris to Salt Stress

    Institute of Scientific and Technical Information of China (English)

    BAI Wen-Bo; LI Pin-Fang; LI Bao-Guo; H. FUJIYAMA; FAN Fen-Cheng

    2008-01-01

    Chinese iris (Iris lactea Pall. Var. Chinensis (Fisch) Koidz.), a robust iridaceous plant, is widesprcad in arid and semiarid regions with high salinity. However, the mechanism of its salt tolerance is not well understood. In this study,plant growth, water status, content and distribution of inorganic ions, cell membrane permeability, and proline content of I. Lactea under salt stress were investigated using nutrient solutions with six NaCl concentrations ranging from 0 to 350 mmol L-1. The results indicated that the biomass, height, fresh weight, K+ content, and K+/Na+ and Ca2+/Na+ratios decreased with increasing NaCl stress, whereas plant water deficit and contents of Na+ and Cl- increased with increasing NaCl stress. In all salt treatments, water deficit of shoots was found to be higher than that of roots and had a positive correlation with salt concentration. When the NaCl concentration was less than 280 mmol L-1, the ion absorption selectivity ratio and the transportation selectivity ratio sharply increased with increasing NaCl stress. Under medium salt stress, I. Lactea exhibited a strong K+ selective absorption and the transportation of K+ from roots to shoots increased, whereas Na+ was not transported and was mostly retained in roots. The plants were able to maintain osmotic adjustment through the accumulation of Na+, Cl-, and proline. On the basis of its biomass production under salt stress,I. Lactea could be considered as a facultative halophyte.

  1. Foreign body embedded in the iris after cataract surgery.

    Science.gov (United States)

    Santos-Bueso, E; Jiménez-Santos, M; Díaz-Valle, D; Gegúndez-Fernández, J A; Cuiña-Sardiña, R; Benítez-del-Castillo, J M; García-Sánchez, J

    2016-03-01

    a 75-year old woman who had had cataract surgery in her left eye and showed a visual acuity of 0.8 twenty-four hours post-surgery. Biomicroscopy revealed a foreign body attached to the iris in the nasal sector that coincided with the main incision of the phacoemulsification, which was then removed in a second surgical procedure. It was analysed and described as an inert structure made of plastic. The possible origin of the presence of a fragment of plastic in the postoperative period following cataract surgery is established. In this case, its inert nature did not cause any further intraocular inflammation. Its rigid structure also favoured its attachment to the iris, thus avoiding any other complications. There must be greater preventative measures during cataract surgery, including checking the instruments and accessories before and after the surgical procedure. Copyright © 2015 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  2. The Infrared Imaging Surveyor (Iris) Project: Astro-F

    Science.gov (United States)

    Shibai, H.

    IRIS (Infrared Imaging Surveyor) is the first Japanese satellite dedicated solely to infrared astronomy. The telescope has 70-cm aperture, and is cooled down to 6 K with super-fluid helium assisted by two-stage Stirling cycle coolers. On the focal plane, the two instruments, the InfraRed Camera (IRC) and the Far-Infrared Surveyor (FIS), are mounted. IRC is a near- and mid-infrared camera for deep imaging-surveys in the wavelength region from 2 to 25 microns. FIS is a far-infrared instrument for a whole sky survey in the wavelength region from 50 to 200 microns. The diffraction-limited spatial resolution is achieved except in the shortest waveband. The point source sensitivity and the survey coverage are significantly improved compared to previous missions. The primary scientific objective is to investigate birth and evolution of galaxies in the early universe by surveys of young normal galaxies and starburst galaxies. IRIS is thrown by a Japanese M-V rocket into a sun-synchronous orbit, in which the cooled telescope can avoid huge emissions from the Sun and the Earth. The expected holding time of the super-fluid helium is more than one year. After consumption of the helium, the near-infrared observation can be continued by the mechanical coolers

  3. Comparison of GPS-TEC measurements with IRI-2007 and IRI-2012 modeled TEC at an equatorial latitude station, Bangkok, Thailand

    Science.gov (United States)

    Arunpold, Sanit; Tripathi, Nitin K.; Rajesh Chowdhary, V.; Raju, Durairaju Kumaran

    2014-09-01

    This paper presents the first vertical total electron content (VTEC) data derived from a dual-frequency GPS receiver installed at the Asian Institute of Technology in Bangkok, as part of project SCINDA (Scintillation Network and Decision Aid) with a magnetic dip latitude of 14°N, The diurnal, monthly, and seasonal variation in TEC, measured between August 2010 and July 2012, was compared with values derived from two International Reference Ionosphere (IRI) models: the IRI-2007 and the recently released IRI-2012. The highest diurnal TEC always occurred between 08:00 and 12:00 Universal Time (UT). The diurnal pattern of GPS-TEC reached its maximum values during equinoctial months (March, April, September, and October) and minimum values during solstice months (June, July, December, and January), which can be attributed to the solar extreme ultra-violet ionization coupled with the upward vertical E×B drift. The modeled TEC was underestimated in 2010 and 2011 and overestimated in 2012, especially with the IRI-2007 model. The measured values were better correlated with the IRI-2012 model, especially in 2012. However, neither of the IRI models responded to geomagnetic activity, despite the selection of the “storm” option, generally showing a smooth curve and underestimating TEC during a storm. To verify this phenomenon, the impacts of geomagnetic storms were considered.

  4. Instrumentation Needs for Integral Primary System Reactors (IPSRs) - Task 1 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Storrick; Bojan Petrovic; Luca Oriani; Lawrence E. Conway; Diego Conti

    2005-09-30

    This report presents the results of the Westinghouse work performed under Task 1 of this Financial Assistance Award and satisfies a Level 2 Milestone for the project. While most of the signals required for control of IPSRs are typical of other PWRs, the integral configuration poses some new challenges in the design or deployment of the sensors/instrumentation and, in some cases, requires completely new approaches. In response to this consideration, the overall objective of Task 1 was to establish the instrumentation needs for integral reactors, provide a review of the existing solutions where available, and, identify research and development needs to be addressed to enable successful deployment of IPSRs. The starting point for this study was to review and synthesize general characteristics of integral reactors, and then to focus on a specific design. Due to the maturity of its design and availability of design information to Westinghouse, IRIS (International Reactor Innovative and Secure) was selected for this purpose. The report is organized as follows. Section 1 is an overview. Section 2 provides background information on several representative IPSRs, including IRIS. A review of the IRIS safety features and its protection and control systems is used as a mechanism to ensure that all critical safety-related instrumentation needs are addressed in this study. Additionally, IRIS systems are compared against those of current advanced PWRs. The scope of this study is then limited to those systems where differences exist, since, otherwise, the current technology already provides an acceptable solution. Section 3 provides a detailed discussion on instrumentation needs for the representative IPSR (IRIS) with detailed qualitative and quantitative requirements summarized in the exhaustive table included as Appendix A. Section 3 also provides an evaluation of the current technology and the instrumentation used for measurement of required parameters in current PWRs. Section 4

  5. Enhanced Design Alternative IV

    Energy Technology Data Exchange (ETDEWEB)

    N. E. Kramer

    1999-05-18

    This report evaluates Enhanced Design Alternative (EDA) IV as part of the second phase of the License Application Design Selection (LADS) effort. The EDA IV concept was compared to the VA reference design using criteria from the ''Design Input Request for LADS Phase II EDA Evaluations'' (CRWMS M&O 1999b) and (CRWMS M&O 1999f). Briefly, the EDA IV concept arranges the waste packages close together in an emplacement configuration known as ''line load''. Continuous pre-closure ventilation keeps the waste packages from exceeding the 350 C cladding and 200 C (4.3.13) drift wall temperature limits. This EDA concept keeps relatively high, uniform emplacement drift temperatures (post-closure) to drive water away from the repository and thus dry out the pillars between emplacement drifts. The waste package is shielded to permit human access to emplacement drifts and includes an integral filler inside the package to reduce the amount of water that can contact the waste form. Closure of the repository is desired 50 years after first waste is emplaced. Both backfill and a drip shields will be emplaced at closure to improve post-closure performance.

  6. Attrition reactor system

    Science.gov (United States)

    Scott, Charles D.; Davison, Brian H.

    1993-01-01

    A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur.

  7. Uji Penurunan Kandungan COD, BOD pada Limbah Cair Pewarnaan Batik Menggunakan Scirpus Grossus dan Iris Pseudacorus dengan Sistem Pemaparan Intermittent

    Directory of Open Access Journals (Sweden)

    Bieby Voijant Tangahu

    2016-06-01

    Full Text Available Mostly, batik industrial wastewater is produced from batik coloring process. One of this batik industry is located in Jetis, Sidoarjo since 1675. The wastewater produced from the coloring process in this location is directly dumped to Jetis river or drainage system around the area. One of the effective, efficient, and not costly wastewater treatment is by using phytotreatment process.Plants used in this research are Scirpus grossus and Iris pseudacorus. Both of this plants can grow in polluted environment and suitable to be used in wastewater treatment process. Moreover, both of these plants are semi aquatic plant that can grow in both wet and dry condition. Intermittent exposure system can be applied to increase the efficiency of the phytotreatment process for batik industry wastewater. This system connects plant and wastewater periodically through flood and drain cycle (F/D. This exposure can increase redox condition, so it can increase removal efficiency.The study variables used in this research are species variation of plants Scirpus grossus and Iris pseudacorus (single plant or combined plant and intermittent exposure system variation, which is F/D 2:1 and F/D 1:2. The Primary parameter of this research is the concentration reduction of BOD, COD, and color. The secondary parameter such as plant morphology, wet weight, and dry weight, pH, and temperature.Preliminary research that has been done for this research is plant acclimatization and range finding test to determine the wastewater concentration. Phytotreatment test is conducted for 18 days in intermittent phase. The result shows that the best variable to remove pollutant is combined plant reactor with intermittent exposure of F/D 2:1 is able to remove 89% of COD and 97% of BOD.

  8. Closed Fuel Cycle and Minor Actinide Multirecycling in a Gas-Cooled Fast Reactor

    NARCIS (Netherlands)

    Van Rooijen, W.F.G.; Kloosterman, J.L.

    2009-01-01

    The Generation IV International Forum has identified the Gas-Cooled Fast Reactor (GCFR) as one of the reactor concepts for future deployment. The GCFR targets sustainability, which is achieved by the use of a closed nuclear fuel cycle where only fission products are discharged to a repository; all H

  9. Closed Fuel Cycle and Minor Actinide Multirecycling in a Gas-Cooled Fast Reactor

    NARCIS (Netherlands)

    Van Rooijen, W.F.G.; Kloosterman, J.L.

    2009-01-01

    The Generation IV International Forum has identified the Gas-Cooled Fast Reactor (GCFR) as one of the reactor concepts for future deployment. The GCFR targets sustainability, which is achieved by the use of a closed nuclear fuel cycle where only fission products are discharged to a repository; all

  10. Closed Fuel Cycle and Minor Actinide Multirecycling in a Gas-Cooled Fast Reactor

    NARCIS (Netherlands)

    Van Rooijen, W.F.G.; Kloosterman, J.L.

    2009-01-01

    The Generation IV International Forum has identified the Gas-Cooled Fast Reactor (GCFR) as one of the reactor concepts for future deployment. The GCFR targets sustainability, which is achieved by the use of a closed nuclear fuel cycle where only fission products are discharged to a repository; all H

  11. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hiroto

    1995-02-07

    A reactor container of the present invention has a structure that the reactor container is entirely at the same temperature as that at the inlet of the reactor and, a hot pool is incorporated therein, and the reactor container has is entirely at the same temperature and has substantially uniform temperature follow-up property transiently. Namely, if the temperature at the inlet of the reactor core changes, the temperature of the entire reactor container changes following this change, but no great temperature gradient is caused in the axial direction and no great heat stresses due to axial temperature distribution is caused. Occurrence of thermal stresses caused by the axial temperature distribution can be suppressed to improve the reliability of the reactor container. In addition, since the laying of the reactor inlet pipelines over the inside of the reactor is eliminated, the reactor container is made compact and the heat shielding structures above the reactor and a protection structure of container walls are simplified. Further, secondary coolants are filled to the outside of the reactor container to simplify the shieldings. The combined effects described above can improve economical property and reliability. (N.H.).

  12. Fluid and structure coupling analysis of the interaction between aqueous humor and iris.

    Science.gov (United States)

    Wang, Wenjia; Qian, Xiuqing; Song, Hongfang; Zhang, Mindi; Liu, Zhicheng

    2016-12-28

    Glaucoma is the primary cause of irreversible blindness worldwide associated with high intraocular pressure (IOP). Elevated intraocular pressure will affect the normal aqueous humor outflow, resulting in deformation of iris. However, the deformation ability of iris is closely related to its material properties. Meanwhile, the passive deformation of the iris aggravates the pupillary block and angle closure. The nature of the interaction mechanism of iris deformation and aqueous humor fluid flow has not been fully understood and has been somewhat a controversial issue. The purpose here was to study the effect of IOP, localization, and temperature on the flow of the aqueous humor and the deformation of iris interacted by aqueous humor fluid flow. Based on mechanisms of aqueous physiology and fluid dynamics, 3D model of anterior chamber (AC) was constructed with the human anatomical parameters as a reference. A 3D idealized standard geometry of anterior segment of human eye was performed. Enlarge the size of the idealization geometry model 5 times to create a simulation device by using 3D printing technology. In this paper, particle image velocimetry technology is applied to measure the characteristic of fluid outflow in different inlet velocity based on the device. Numerically calculations were made by using ANSYS 14.0 Finite Element Analysis. Compare of the velocity distributions to confirm the validity of the model. The fluid structure interaction (FSI) analysis was carried out in the valid geometry model to study the aqueous flow and iris change. In this paper, the validity of the model is verified through computation and comparison. The results indicated that changes of gravity direction of model significantly affected the fluid dynamics parameters and the temperature distribution in anterior chamber. Increased pressure and the vertical position increase the velocity of the aqueous humor fluid flow, with the value increased of 0.015 and 0.035 mm/s. The results

  13. Positive Selection of Iris, a Retroviral Envelope-Derived Host Gene in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    2005-10-01

    Full Text Available Eukaryotic genomes can usurp enzymatic functions encoded by mobile elements for their own use. A particularly interesting kind of acquisition involves the domestication of retroviral envelope genes, which confer infectious membrane-fusion ability to retroviruses. So far, these examples have been limited to vertebrate genomes, including primates where the domesticated envelope is under purifying selection to assist placental function. Here, we show that in Drosophila genomes, a previously unannotated gene (CG4715, renamed Iris was domesticated from a novel, active Kanga lineage of insect retroviruses at least 25 million years ago, and has since been maintained as a host gene that is expressed in all adult tissues. Iris and the envelope genes from Kanga retroviruses are homologous to those found in insect baculoviruses and gypsy and roo insect retroviruses. Two separate envelope domestications from the Kanga and roo retroviruses have taken place, in fruit fly and mosquito genomes, respectively. Whereas retroviral envelopes are proteolytically cleaved into the ligand-interaction and membrane-fusion domains, Iris appears to lack this cleavage site. In the takahashii/suzukii species groups of Drosophila, we find that Iris has tandemly duplicated to give rise to two genes (Iris-A and Iris-B. Iris-B has significantly diverged from the Iris-A lineage, primarily because of the "invention" of an intron de novo in what was previously exonic sequence. Unlike domesticated retroviral envelope genes in mammals, we find that Iris has been subject to strong positive selection between Drosophila species. The rapid, adaptive evolution of Iris is sufficient to unambiguously distinguish the phylogenies of three closely related sibling species of Drosophila (D. simulans, D. sechellia, and D. mauritiana, a discriminative power previously described only for a putative "speciation gene." Iris represents the first instance of a retroviral envelope-derived host gene

  14. Effects of Nuclear Energy on Sustainable Development and Energy Security: Sodium-Cooled Fast Reactor Case

    OpenAIRE

    Sungjoo Lee; Byungun Yoon; Juneseuk Shin

    2016-01-01

    We propose a stepwise method of selecting appropriate indicators to measure effects of a specific nuclear energy option on sustainable development and energy security, and also to compare an energy option with another. Focusing on the sodium-cooled fast reactor, one of the highlighted Generation IV reactors, we measure and compare its effects with the standard pressurized water reactor-based nuclear power, and then with coal power. Collecting 36 indicators, five experts select seven key indic...

  15. Determination of the Sensitivity of the Antineutrino Probe for Reactor Core Monitoring

    Science.gov (United States)

    Cormon, S.; Fallot, M.; Bui, V.-M.; Cucoanes, A.; Estienne, M.; Lenoir, M.; Onillon, A.; Shiba, T.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-01

    This paper presents a feasibility study of the use of the detection of reactor-antineutrinos (νbare) for non proliferation purpose. To proceed, we have started to study different reactor designs with our simulation tools. We use a package called MCNP Utility for Reactor Evolution (MURE), initially developed by CNRS/IN2P3 labs to study Generation IV reactors. The MURE package has been coupled to fission product beta decay nuclear databases for studying reactor antineutrino emission. This method is the only one able to predict the antineutrino emission from future reactor cores, which don't use the thermal fission of 235U, 239Pu and 241Pu. It is also the only way to include off-equilibrium effects, due to neutron captures and time evolution of the fission product concentrations during a reactor cycle. We will present here the first predictions of antineutrino energy spectra from innovative reactor designs (Generation IV reactors). We will then discuss a summary of our results of non-proliferation scenarios involving the latter reactor designs, taking into account reactor physics constraints.

  16. Determination of the Sensitivity of the Antineutrino Probe for Reactor Core Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Cormon, S.; Fallot, M., E-mail: fallot@subatech.in2p3.fr; Bui, V.-M.; Cucoanes, A.; Estienne, M.; Lenoir, M.; Onillon, A.; Shiba, T.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-15

    This paper presents a feasibility study of the use of the detection of reactor-antineutrinos (ν{sup ¯}{sub e}) for non proliferation purpose. To proceed, we have started to study different reactor designs with our simulation tools. We use a package called MCNP Utility for Reactor Evolution (MURE), initially developed by CNRS/IN2P3 labs to study Generation IV reactors. The MURE package has been coupled to fission product beta decay nuclear databases for studying reactor antineutrino emission. This method is the only one able to predict the antineutrino emission from future reactor cores, which don't use the thermal fission of {sup 235}U, {sup 239}Pu and {sup 241}Pu. It is also the only way to include off-equilibrium effects, due to neutron captures and time evolution of the fission product concentrations during a reactor cycle. We will present here the first predictions of antineutrino energy spectra from innovative reactor designs (Generation IV reactors). We will then discuss a summary of our results of non-proliferation scenarios involving the latter reactor designs, taking into account reactor physics constraints.

  17. Investigation of materials for fusion power reactors

    Science.gov (United States)

    Bouhaddane, A.; Slugeň, V.; Sojak, S.; Veterníková, J.; Petriska, M.; Bartošová, I.

    2014-06-01

    The possibility of application of nuclear-physical methods to observe radiation damage to structural materials of nuclear facilities is nowadays a very actual topic. The radiation damage to materials of advanced nuclear facilities, caused by extreme radiation stress, is a process, which significantly limits their operational life as well as their safety. In the centre of our interest is the study of the radiation degradation and activation of the metals and alloys for the new nuclear facilities (Generation IV fission reactors, fusion reactors ITER and DEMO). The observation of the microstructure changes in the reactor steels is based on experimental investigation using the method of positron annihilation spectroscopy (PAS). The experimental part of the work contains measurements focused on model reactor alloys and ODS steels. There were 12 model reactor steels and 3 ODS steels. We were investigating the influence of chemical composition on the production of defects in crystal lattice. With application of the LT 9 program, the spectra of specimen have been evaluated and the most convenient samples have been determined.

  18. Computer Models for IRIS Control System Transient Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Storrick; Bojan Petrovic; Luca Oriani

    2007-01-31

    This report presents results of the Westinghouse work performed under Task 3 of this Financial Assistance Award and it satisfies a Level 2 Milestone for the project. Task 3 of the collaborative effort between ORNL, Brazil and Westinghouse for the International Nuclear Energy Research Initiative entitled “Development of Advanced Instrumentation and Control for an Integrated Primary System Reactor” focuses on developing computer models for transient analysis. This report summarizes the work performed under Task 3 on developing control system models. The present state of the IRIS plant design – such as the lack of a detailed secondary system or I&C system designs – makes finalizing models impossible at this time. However, this did not prevent making considerable progress. Westinghouse has several working models in use to further the IRIS design. We expect to continue modifying the models to incorporate the latest design information until the final IRIS unit becomes operational. Section 1.2 outlines the scope of this report. Section 2 describes the approaches we are using for non-safety transient models. It describes the need for non-safety transient analysis and the model characteristics needed to support those analyses. Section 3 presents the RELAP5 model. This is the highest-fidelity model used for benchmark evaluations. However, it is prohibitively slow for routine evaluations and additional lower-fidelity models have been developed. Section 4 discusses the current Matlab/Simulink model. This is a low-fidelity, high-speed model used to quickly evaluate and compare competing control and protection concepts. Section 5 describes the Modelica models developed by POLIMI and Westinghouse. The object-oriented Modelica language provides convenient mechanisms for developing models at several levels of detail. We have used this to develop a high-fidelity model for detailed analyses and a faster-running simplified model to help speed the I&C development process

  19. Results of Iris-Claw Intraocular Lens Implantation in Aphakia

    Directory of Open Access Journals (Sweden)

    Mehmet Tahir Şam

    2014-12-01

    Full Text Available Objectives: To evaluate the visual outcomes and complications of iris-claw intraocular lenses (ICIOL implanted in cases of aphakia or in cataract surgery with insufficient capsule support. Material and Method: In this retrospective study, we reviewed the medical records of 34 eyes of 34 patients who had undergone ICIOL implantation with a minimum follow-up of 12 months in Bucak State Hospital and in a private hospital between November 2007 and November 2012. Results: Twenty-one eyes with complicated cataract accompanied by zonular deficiency, 8 eyes with aphakia, and 5 eyes with dislocated IOL were operated and ICIOL implanted. Mean preoperative BCVA was 1.46±1.05 LogMAR and postoperative BCVA was 0.20±0.21 LogMAR. There was an improvement in visual acuity in 31 eyes of the 34 patients, and 29 of them had a visual acuity better than 6/12 postoperatively. Mean postoperative spherical equivalent (SE was -0.76±0.94 D, and deviation from estimated SE was -0.26±0.94 D. Mean preoperative astigmatism was -1.36±0.77 Cyl D and mean postoperative astigmatism was -0.98±0.82 Cyl D. In second postoperative month, one case had a pupillary block glaucoma due to the closure of peripheral iridotomy, and after ND-YAG laser treatment, intraocular pressure return to normal value. One eye had iris pigment precipitates on the ICIOL in early postoperative period, and in one case, there was a pupillary ovalization. Three months after a cataract surgery, retinal detachment developed in one eye of a patient who had a history of severe ocular trauma; anterior vitrectomy and ICIOL implantation were performed. Visual acuity remained unchanged after a successful pars plana vitrectomy operation. Conclusion: Iris-claw lenses provide fairly good visual outcomes in aphakic eyes without capsular support and in challenging cataract cases with zonular deficiency. They are safe regarding complications when compared to other alternative intraocular lens implantation methods

  20. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate