Sample records for reactor structural components

  1. Structural integrity and management of aging in internal components of BWR reactors; Integridad estructural y manejo del envejecimiento en componentes internos de reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Arganis J, C.R. [Instituto Nacional de Investigaciones Nucleares, Km 36.5 Carretera Mexico, Toluca Salazar Edo. de Mexico (Mexico)]. E-mail:


    Presently work the bases to apply structural integrity and the handling of the aging of internal components of the pressure vessel of boiling water reactors of water are revised and is carried out an example of structural integrity in the horizontal welding H4 of the encircling one of the core of a reactor, taking data reported in the literature. It is also revised what is required to carry out the handling program or conduct of the aging (AMP). (Author)

  2. Profiling a reactor component using ultrasonics

    Energy Technology Data Exchange (ETDEWEB)

    Pathak, L.; Seshadri, V.R.; Kumaravadivelu, C.; Sreenivasan, G.; Raghunathan, V.S. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)


    Nuclear reactors have many components within the reactor vessel. During the life of a reactor it is possible for these components to be displaced or deformed because of the thermal cycles to which they are subject. Also, these components in situ therefore becomes important for the upkeep of the reactor. However, high radiation levels make it difficult to monitor using optical methods. This paper describes an ultrasonic method which was successfully employed in profiling a deformed guide tube of a reactor. The method uses the well-known ultrasonic ranging technique. However, the specialty of the method is the use of air transducers at 40 kHz to overcome the inherent divergence problems and the difficulties associated with high temperatures inherent in a sodium cooled reactor.

  3. Proposed and existing passive and inherent safety-related structures, systems, and components (building blocks) for advanced light-water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Moses, D.L.; Lewis, E.B.; Gibson, R.; Pearson, R.; Reich, W.J.; Murphy, G.A.; Staunton, R.H.; Kohn, W.E.


    A nuclear power plant is composed of many structures, systems, and components (SSCs). Examples include emergency core cooling systems, feedwater systems, and electrical systems. The design of a reactor consists of combining various SSCs (building blocks) into an integrated plant design. A new reactor design is the result of combining old SSCs in new ways or use of new SSCs. This report identifies, describes, and characterizes SSCs with passive and inherent features that can be used to assure safety in light-water reactors. Existing, proposed, and speculative technologies are described. The following approaches were used to identify the technologies: world technical literature searches, world patent searches, and discussions with universities, national laboratories and industrial vendors. 214 refs., 105 figs., 26 tabs.

  4. Heavy Water Components Test Reactor Decommissioning - Major Component Removal

    Energy Technology Data Exchange (ETDEWEB)

    Austin, W.; Brinkley, D.


    The Heavy Water Components Test Reactor (HWCTR) facility (Figure 1) was built in 1961, operated from 1962 to 1964, and is located in the northwest quadrant of the Savannah River Site (SRS) approximately three miles from the site boundary. The HWCTR facility is on high, well-drained ground, about 30 meters above the water table. The HWCTR was a pressurized heavy water test reactor used to develop candidate fuel designs for heavy water power reactors. It was not a defense-related facility like the materials production reactors at SRS. The reactor was moderated with heavy water and was rated at 50 megawatts thermal power. In December of 1964, operations were terminated and the facility was placed in a standby condition as a result of the decision by the U.S. Atomic Energy Commission to redirect research and development work on heavy water power reactors to reactors cooled with organic materials. For about one year, site personnel maintained the facility in a standby status, and then retired the reactor in place. In 1965, fuel assemblies were removed, systems that contained heavy water were drained, fluid piping systems were drained, deenergized and disconnected and the spent fuel basin was drained and dried. The doors of the reactor facility were shut and it wasn't until 10 years later that decommissioning plans were considered and ultimately postponed due to budget constraints. In the early 1990s, DOE began planning to decommission HWCTR again. Yet, in the face of new budget constraints, DOE deferred dismantlement and placed HWCTR in an extended surveillance and maintenance mode. The doors of the reactor facility were welded shut to protect workers and discourage intruders. The $1.6 billion allocation from the American Recovery and Reinvestment Act to SRS for site clean up at SRS has opened the doors to the HWCTR again - this time for final decommissioning. During the lifetime of HWCTR, 36 different fuel assemblies were tested in the facility. Ten of these


    Energy Technology Data Exchange (ETDEWEB)

    Austin, W.; Brinkley, D.


    The Heavy Water Components Test Reactor (HWCTR) Decommissioning Project was initiated in 2009 as a Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Removal Action with funding from the American Recovery and Reinvestment Act (ARRA). This paper summarizes the history prior to 2009, the major D&D activities, and final end state of the facility at completion of decommissioning in June 2011. The HWCTR facility was built in 1961, operated from 1962 to 1964, and is located in the northwest quadrant of the Savannah River Site (SRS) approximately three miles from the site boundary. The HWCTR was a pressurized heavy water test reactor used to develop candidate fuel designs for heavy water power reactors. In December of 1964, operations were terminated and the facility was placed in a standby condition as a result of the decision by the U.S. Atomic Energy Commission to redirect research and development work on heavy water power reactors to reactors cooled with organic materials. For about one year, site personnel maintained the facility in a standby status, and then retired the reactor in place. In the early 1990s, DOE began planning to decommission HWCTR. Yet, in the face of new budget constraints, DOE deferred dismantlement and placed HWCTR in an extended surveillance and maintenance mode. The doors of the reactor facility were welded shut to protect workers and discourage intruders. In 2009 the $1.6 billion allocation from the ARRA to SRS for site footprint reduction at SRS reopened the doors to HWCTR - this time for final decommissioning. Alternative studies concluded that the most environmentally safe, cost effective option for final decommissioning was to remove the reactor vessel, both steam generators, and all equipment above grade including the dome. The transfer coffin, originally above grade, was to be placed in the cavity vacated by the reactor vessel and the remaining below grade spaces would be grouted. Once all above equipment

  6. Neutronic Reactor Structure (United States)

    Vernon, H. C.; Weinberg, A. M.


    The neutronic reactor is comprised of a core consisting of natural uranium and heavy water with a K-factor greater than unity. The core is surrounded by a reflector consisting of natural uranium and ordinary water with a Kfactor less than unity. (AEC)

  7. Verification of Remote Inspection Techniques for Reactor Internal Structures of Liquid Metal Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Lee, Jae Han


    The reactor internal structures and components of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection as major in-service inspection (ISI) methods of reactor internal structures and components. Reactor internals of LMR can not be visually examined due to opaque liquid sodium. The under-sodium viewing techniques using an ultrasonic wave should be applied for the visual inspection of reactor internals. Recently, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium inspection. In this study, visualization technique, ranging technique and monitoring technique have been suggested for the remote inspection of reactor internals by using the waveguide sensor. The feasibility of these remote inspection techniques using ultrasonic waveguide sensor has been evaluated by an experimental verification.

  8. Ageing investigation and upgrading of components/systems of Kartini research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Syarip; Widi Setiawan [Yogyakarta Nuclear Research Centre, Yogyakarta (Indonesia)


    Kartini research reactor has been operated in good condition and has demonstrated successful operation for the past 18 years, utilized for: reactor kinetic and control studies, instrumentation tests, neutronic and thermohydraulic studies, routine neutron activation analysis, reactor safety studies, training for research reactor operators and supervisors, and reactor physics experiments. Several components of Kartini reactor use components from the abandoned IRT-2000 Project at Serpong and from Bandung Reactor Centre such as: reactor tank, reactor core, heat exchanger, motor blower for ventilation system, fuel elements, etc. To maintain a good operating performance and also for aging investigation purposes, the component failure data collection has been done. The method used is based on the Manual on Reliability Data Collection For Research Reactor PSAs, IAEA TECDOC 636, and analyzed by using Data Entry System (DES) computer code. Analysis result shows that the components/systems failure rate of Kartini reactor is around 1,5.10{sup -4} up to 2,8.10{sup -4} per hour, these values are within the ranges of the values indicated in IAEA TECDOC 478. Whereas from the analysis of irradiation history shows that the neutron fluence of fuel element with highest burn-up (2,05 gram U-235 in average) is around 1.04.10{sup 16} n Cm{sup -2} and this value is still far below its limiting value. Some reactor components/systems have been replaced and upgraded such as heat exchanger, instrumentation and control system (ICS), etc. The new reactor ICS was installed in 1994 which is designed as a distributed structure by using microprocessor based systems and bus system technology. The characteristic and operating performance of the new reactor ICS, as well as the operation history and improvement of the Kartini research reactor is presented. (J.P.N.)

  9. Designed porosity materials in nuclear reactor components (United States)

    Yacout, A. M.; Pellin, Michael J.; Stan, Marius


    A nuclear fuel pellet with a porous substrate, such as a carbon or tungsten aerogel, on which at least one layer of a fuel containing material is deposited via atomic layer deposition, and wherein the layer deposition is controlled to prevent agglomeration of defects. Further, a method of fabricating a nuclear fuel pellet, wherein the method features the steps of selecting a porous substrate, depositing at least one layer of a fuel containing material, and terminating the deposition when the desired porosity is achieved. Also provided is a nuclear reactor fuel cladding made of a porous substrate, such as silicon carbide aerogel or silicon carbide cloth, upon which layers of silicon carbide are deposited.

  10. Development and verification test of integral reactor major components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. I.; Kim, Y. W.; Kim, J. H. and others


    The conceptual designs for SG, MCP, CEDM to be installed in the integral reactor SMART were developed. Three-dimensional CAD models for the major components were developed to visualize the design concepts. Once-through helical steam generator was conceptually designed for SMART. Canned motor pump was adopted in the conceptual design of MCP. Linear pulse motor type and ballscrew type CEDM, which have fine control capabilities were studied for adoption in SMART. In parallel with the structural design, the electro-magnetic design was performed for the sizing motors and electro-magnet. Prototypes for the CEDM and MCP sub-assemblies were developed and tested to verify the performance. The impeller design procedure and the computer program to analyze the dynamic characteristics of MCP rotor shaft were developed. The design concepts of SG, MCP, CEDM were also invetigated for the fabricability.

  11. Fabrication of nuclear ship reactor MRX model and study on inspection and maintenance of components

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Yoshiyuki [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Nakazawa, Toshio; Kusunoki, Tsuyoshi; Takahashi, Hiroki; Yoritsune, Tsutomu


    The MRX (Marine Reactor X) is an integral type small reactor adopting passive safety systems. As for an integral type reactor, primary system components are installed in the reactor vessel. It is therefor important to establish the appropriate procedure for construction, inspection and maintenance, dismauntling, etc., for all components in the reactor vessel as well as in the reactor containment, because inspection space is limited. To study these subjects, a one-fifth model of the MRX was fabricated and operation capabilities were studied. As a result of studies, the following results are obtained. (1) Manufacturing and installing problems of the reactor pressure vessel, the containment vessel and internal components are basically not abserved. (2) Heat transfer tube structures of the steam generator and the heat exchangers of emergency decay heat removal system and containment water cooler were not seen of any problem for fabrication. However, due consideration is required in the detailed design of supports of heat transfer tubes. (3) Further studies should be needed for designs of flange penetrations and leak countermeasures for pipes instrument cables. (4) Arrangements of equipments in the containment should be taken in consideration in detail because the space is narrow. (5) Further discussion is required for installation methods of instruments and cables. (author)

  12. Diffusion bonding as joining technique for fusion reactor components

    Energy Technology Data Exchange (ETDEWEB)

    Ceccotti, G.C.; Magnoli, L.


    The development of joining techniques for fusion reactor divertors has been undertaken at ENEA (Italian Agency for Energy, New Technologies and the Environment) IFEC Saluggia. Joints were made by the diffusion bonding technique between graphite composite material with DS copper and with molybdenum TZM alloy, respectively. The inter-layers, when necessary, were obtained by metallization with an electronic gun. The same technique is employed in joining Be/SS, DS copper/Be, TZM/Be and graphite/Be for the first wall or plasma facing components of fusion reactors. In this case, a suitable inter-layer material can avoid the problems occuring with the more traditional brazing processes.

  13. Structures and Materials of Reactor Internals for PWR in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. W.; Kim, W. S.; Kwon, S. C.; Kwon, J. H.; Kim, Y. S.; Kim, H. P.; Yoo, C. S.; Lee, S. R.; Jung, M. K.; Hwang, S. S


    Nuclear reactor types in Korea are PWR type reactor (Westinghouse, Combustion Engineering, Farmatome type) and CANDU type reactor. Structures and Materials for reactor internal of PWR type were investigated. Reactor internal was composed of lower core support structure, upper core support assembly, incore instrumentation support structure. Lower core support structure of these structures is the most important. The major material for the reactor internal is type 304 and 316 stainless steel and radial support clevis bolts are made of Inconel. The main damage mechanism for reactor internal was IASCC and the effect of IASCC on reactor internal was investigated. The accident for reactor internal was also investigate.

  14. Thermal Shield and Reactor Structure Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Collier, A.R.


    The purpose of this report is to present reactor structure and thermal shield temperature data taken during P-3 and P-5 cycles and compare them with design calculations in order to predict temperatures at higher power levels.

  15. 77 FR 16270 - Updated Aging Management Criteria for Reactor Vessel Internal Components of Pressurized Water... (United States)


    ... COMMISSION Updated Aging Management Criteria for Reactor Vessel Internal Components of Pressurized Water... license renewal interim staff guidance (LR-ISG), LR-ISG-2011-04, ``Updated Aging Management Criteria for... Aging Lessons Learned (GALL) Report for the aging management of stainless steel structures and...

  16. Nuclear reactor spacer grid and ductless core component (United States)

    Christiansen, David W.; Karnesky, Richard A.


    The invention relates to a nuclear reactor spacer grid member for use in a liquid cooled nuclear reactor and to a ductless core component employing a plurality of these spacer grid members. The spacer grid member is of the egg-shell type and is constructed so that the walls of the cell members of the grid member are formed of a single thickness of metal to avoid tolerance problems. Within each cell member is a hydraulic spring which laterally constrains the nuclear material bearing rod which passes through each cell member against a hardstop in response to coolant flow through the cell member. This hydraulic spring is also suitable for use in a water cooled nuclear reactor. A core component constructed of, among other components, a plurality of these spacer grid members, avoids the use of a full length duct by providing spacer sleeves about the sodium tubes passing through the spacer grid members at locations between the grid members, thereby maintaining a predetermined space between adjacent grid members.

  17. Conditioning of waste from the dismantling of reactor pressure vessel components and of core components

    Energy Technology Data Exchange (ETDEWEB)

    Cleve, R.; Oldiges, O.; Splittler, U.


    When power reactors are shut down, the treatment of the core components and of the reactor pressure vessel components constitutes a particular task. Due to its special radiological characteristics, this waste must basically be handled using remote-control equipment with regard to the treatment. For its conditioning in a manner appropriate for the final storage, the waste must be dried and packed into suitable packing drums. The solution implemented by GNS and DSD in order to treat this waste from the Wuergassen nuclear power plant is described in the present contribution. (orig.)

  18. Study on radiation damage to high energy accelerator components by irradiation in a nuclear reactor

    CERN Document Server

    Schönbacher, Helmut; Casta, J; Van de Voorde, M H


    The structural and other components used in high energy accelerators are continuously exposed to a wide spectrum of high energy particles and electromagnetic radiation. The resulting radiation damage may severely influence the functional capability of accelerator facilities. In order to arrive at an estimate of the service life of various materials in the radiation field, simulating experiments have to be carried out in a nuclear reactor. A large number of organic and inorganic materials, electronic components, metals, etc., intended specifically for use in 400 GeV proton synchrotron of CERN near Geneva, were irradiated in the ASTRA reactor in Seibersdorf near Vienna. The paper reports on the irradiation facilities available in this reactor for this purpose, on the dosimetry methods used, on the most important materials irradiated and on the results obtained in these experiments. (14 refs).

  19. 77 FR 39521 - Application for a License To Export Nuclear Reactor Major Components and Equipment (United States)


    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Application for a License To Export Nuclear Reactor Major Components and Equipment Pursuant to 10... Reactor internals, Components and For use in Braka nuclear power Company LLC reactor coolant equipment for...

  20. 76 FR 68514 - Request for a License To Export Reactor Components (United States)


    ... COMMISSION Request for a License To Export Reactor Components Pursuant to 10 CFR 110.70 (b) ``Public Notice... reactor 12 Perform seismic China. LLC, August 18, 2011, October control rod system testing necessary 6, 2011, XR174, 11005963. and associated for qualification equipment. of AP1000 (design) nuclear reactors...

  1. 77 FR 23513 - Updated Aging Management Criteria for Reactor Vessel Internal Components of Pressurized Water... (United States)


    ... COMMISSION Updated Aging Management Criteria for Reactor Vessel Internal Components of Pressurized Water... Management Criteria for PWR Reactor Vessel Internal Components.'' The original notice provided the ADAMS... published a notice requesting public comments on draft LR-ISG-2011-04, ``Updated Aging Management Criteria...

  2. Thermodynamic characterization of salt components for Molten Salt Reactor fuel

    NARCIS (Netherlands)

    Capelli, E.


    The Molten Salt Reactor (MSR) is a promising future nuclear fission reactor technology with excellent performance in terms of safety and reliability, sustainability, proliferation resistance and economics. For the design and safety assessment of this concept, it is extremely important to have a

  3. Failure prediction of full-size reactor components from tensile specimen data on NBG-18 nuclear graphite

    Energy Technology Data Exchange (ETDEWEB)

    Hindley, Michael P., E-mail: [Pebble Bed Modular Reactor (Pty) Ltd., P.O. Box 9396, Centurion 0046 (South Africa); Blaine, Deborah C.; Groenwold, Albert A.; Becker, Thorsten H. [Department of Mechanical and Mechatronic Engineering, Stellenbosch University, Private Bag X1, Matieland 7602 (South Africa)


    Highlights: • Predicts failure on a full scale reactor component and compare it to experiments. • Shows the effect of volume on NBG-18 nuclear graphite failure prediction. • Provide independent verification of a previously published methodology. • Describe the influence of multiple locations of high stress on failure prediction. - Abstract: This paper concerns itself with predicting the failure of a full-size NBG-18 nuclear graphite reactor component based only on test data obtained from standard tensile test specimens. A full-size specimen structural test was developed to simulate the same failure conditions expected during a normal operation of the reactor in order to validate the failure prediction. The full-size specimen designed for this test is almost a hundred times larger than the tensile test specimen, has a completely different geometry and experiences a different loading condition to the standard tensile test specimen. Failure of the full-size component is predicted realistically, but conservatively.

  4. Mechanical strength characterization of three-component composite structural components (United States)

    Chumaevskii, A. V.; Tarasov, S. Yu.; Kolubaev, E. A.; Rubtsov, V. E.; Eliseev, A. A.


    Mechanical strength characterization of structural components made of three-component composite material using additive manufacturing has been carried out. The deformation and fracture behaviour of two types was revealed. Mechanical strength characteristics of structural components have been determined in connection with the material properties.

  5. Code qualification of structural materials for AFCI advanced recycling reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Li, M.; Majumdar, S.; Nanstad, R.K.; Sham, T.-L. (Nuclear Engineering Division); (ORNL)


    This report summarizes the further findings from the assessments of current status and future needs in code qualification and licensing of reference structural materials and new advanced alloys for advanced recycling reactors (ARRs) in support of Advanced Fuel Cycle Initiative (AFCI). The work is a combined effort between Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL) with ANL as the technical lead, as part of Advanced Structural Materials Program for AFCI Reactor Campaign. The report is the second deliverable in FY08 (M505011401) under the work package 'Advanced Materials Code Qualification'. The overall objective of the Advanced Materials Code Qualification project is to evaluate key requirements for the ASME Code qualification and the Nuclear Regulatory Commission (NRC) approval of structural materials in support of the design and licensing of the ARR. Advanced materials are a critical element in the development of sodium reactor technologies. Enhanced materials performance not only improves safety margins and provides design flexibility, but also is essential for the economics of future advanced sodium reactors. Code qualification and licensing of advanced materials are prominent needs for developing and implementing advanced sodium reactor technologies. Nuclear structural component design in the U.S. must comply with the ASME Boiler and Pressure Vessel Code Section III (Rules for Construction of Nuclear Facility Components) and the NRC grants the operational license. As the ARR will operate at higher temperatures than the current light water reactors (LWRs), the design of elevated-temperature components must comply with ASME Subsection NH (Class 1 Components in Elevated Temperature Service). However, the NRC has not approved the use of Subsection NH for reactor components, and this puts additional burdens on materials qualification of the ARR. In the past licensing review for the Clinch River Breeder Reactor Project (CRBRP

  6. In-Service Inspection for HANARO Reactor Structure

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Sang Ik; Lee, Young Sub; Lee, Jung Hee; Jung, Hoan Sung; Cho, Yeong Garp [KAERI, Daejeon (Korea, Republic of)


    As results of the visual inspection (VT-3) on HANARO, there was no defect such as a crack, corrosion, abrasion, erosion, and physical or chemical deformation on the welded parts and other surfaces of the reactor structures and its parts. Also, the bolts and steel wire, which was tied as an indicator whether got released or not, are well being kept its integrity. Throughout this visual inspection results, it turned out that HANARO is well maintaining its integrity and initial condition after installation and assembly in 1995. This inspection was done as a second change in Sep. 2006 according to the long term inspection plan for the safety class component by ASME Sec. XI article IWB and HANARO procedure. The next five year inspection shall be done no later than the end of 2011. This inspection results such as photos taken inside the reactor pool will be helpful to find out a solution for some problem, which may cause a view point of the reactor structure and its parts during operating

  7. A study on the establishment of component/equipment performance criteria considering Heavy Water Reactor characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Keun Sun; Kwon, Young Chul; Lee, Min Kyu; Lee, Yun Soo [Sunmoon Univ., Asan (Korea, Republic of); Chang, Seong Hoong; Ryo, Chang Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Kim, Soong Pyung; Hwnag, Jung Rye; Chung, Chul Kee [Chosun Univ., Gwangju (Korea, Republic of)


    Foreign and domestic technology trends, regulatory requirements, design and researches for heavy water reactors are analyzed. Safety design guides of Canada industry and regulatory documents and consultative documents of Canada regulatory agency are reviewed. Applicability of MOST guidance 16 Revision 'guidance for technical criteria of nuclear reactor facility' is reviewed. Specific performance criteria are established for components and facilities for heavy water reactor.

  8. Structural integrity of nuclear reactor pressure vessels (United States)

    Knott, John F.


    The paper starts from concerns expressed by Sir Alan Cottrell, in the early 1970s, related to the safety of the pressurized water reactor (PWR) proposed at that time for the next phase of electrical power generation. It proceeds to describe the design and operation of nuclear generation plant and gives details of the manufacture of PWR reactor pressure vessels (RPVs). Attention is paid to stress-relief cracking and under-clad cracking, experienced with early RPVs, explaining the mechanisms for these forms of cracking and the means taken to avoid them. Particular note is made of the contribution of non-destructive inspection to structural integrity. Factors affecting brittle fracture in RPV steels are described: in particular, effects of neutron irradiation. The use of fracture mechanics to assess defect tolerance is explained, together with the failure assessment diagram embodied in the R6 procedure. There is discussion of the Master Curve and how it incorporates effects of irradiation on fracture toughness. Dangers associated with extrapolation of data to low probabilities are illustrated. The treatment of fatigue-crack growth is described, in the context of transients that may be experienced in the operation of PWR plant. Detailed attention is paid to the thermal shock associated with a large loss-of-coolant accident. The final section reviews the arguments advanced to justify 'Incredibility of Failure' and how these are incorporated in assessments of the integrity of existing plant and proposed 'new build' PWR pressure vessels.

  9. Facility Configuration Study of the High Temperature Gas-Cooled Reactor Component Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    S. L. Austad; L. E. Guillen; D. S. Ferguson; B. L. Blakely; D. M. Pace; D. Lopez; J. D. Zolynski; B. L. Cowley; V. J. Balls; E.A. Harvego, P.E.; C.W. McKnight, P.E.; R.S. Stewart; B.D. Christensen


    A test facility, referred to as the High Temperature Gas-Cooled Reactor Component Test Facility or CTF, will be sited at Idaho National Laboratory for the purposes of supporting development of high temperature gas thermal-hydraulic technologies (helium, helium-Nitrogen, CO2, etc.) as applied in heat transport and heat transfer applications in High Temperature Gas-Cooled Reactors. Such applications include, but are not limited to: primary coolant; secondary coolant; intermediate, secondary, and tertiary heat transfer; and demonstration of processes requiring high temperatures such as hydrogen production. The facility will initially support completion of the Next Generation Nuclear Plant. It will secondarily be open for use by the full range of suppliers, end-users, facilitators, government laboratories, and others in the domestic and international community supporting the development and application of High Temperature Gas-Cooled Reactor technology. This pre-conceptual facility configuration study, which forms the basis for a cost estimate to support CTF scoping and planning, accomplishes the following objectives: • Identifies pre-conceptual design requirements • Develops test loop equipment schematics and layout • Identifies space allocations for each of the facility functions, as required • Develops a pre-conceptual site layout including transportation, parking and support structures, and railway systems • Identifies pre-conceptual utility and support system needs • Establishes pre-conceptual electrical one-line drawings and schedule for development of power needs.

  10. Evaluation of aging degradation of structural components

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Shack, W.J.


    Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at < 232{degrees}C. The shift in CTT is not as severe as that observed in surveillance samples from the High Flux Isotope Reactor (HFIR): however, it shows very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor. The results indicate that fluence rate has not effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center_dot}s at the low operating temperature of the Shippingport NST, i.e., 55{degrees}C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y.

  11. Evaluation of aging degradation of structural components

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Shack, W.J.


    Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at < 232{degrees}C. The shift in CTT is not as severe as that observed in surveillance samples from the High Flux Isotope Reactor (HFIR): however, it shows very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor. The results indicate that fluence rate has not effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center dot}s at the low operating temperature of the Shippingport NST, i.e., 55{degrees}C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y.

  12. Three-component U-Pu-Th fuel for plutonium irradiation in heavy water reactors

    Directory of Open Access Journals (Sweden)

    Peel Ross


    Full Text Available This paper discusses concepts for three-component fuel bundles containing plutonium, uranium and thorium for use in pressurised heavy water reactors, and cases for and against implementation of such a nuclear energy system in the United Kingdom. Heavy water reactors are used extensively in Canada, and are deploying within India and China, whilst the UK is considering the use of heavy water reactors to manage its plutonium inventory of 140 tonnes. The UK heavy water reactor proposal uses a mixed oxide (MOX fuel of plutonium in depleted uranium, within the enhanced CANDU-6 (EC-6 reactor. This work proposes an alternative heterogeneous fuel concept based on the same reactor and CANFLEX fuel bundle, with eight large-diameter fuel elements loaded with natural thorium oxide and 35 small-diameter fuel elements loaded with a MOX of plutonium and reprocessed uranium stocks from UK MAGNOX and AGR reactors. Indicative neutronic calculations suggest that such a fuel would be neutronically feasible. A similar MOX may alternatively be fabricated from reprocessed <5% enriched light water reactor fuel, such as the fuel of the AREVA EPR reactor, to consume newly produced plutonium from reprocessing, similar to the DUPIC (direct use of PWR fuel in CANDU process.

  13. Catalyst support structure, catalyst including the structure, reactor including a catalyst, and methods of forming same (United States)

    Van Norman, Staci A.; Aston, Victoria J.; Weimer, Alan W.


    Structures, catalysts, and reactors suitable for use for a variety of applications, including gas-to-liquid and coal-to-liquid processes and methods of forming the structures, catalysts, and reactors are disclosed. The catalyst material can be deposited onto an inner wall of a microtubular reactor and/or onto porous tungsten support structures using atomic layer deposition techniques.

  14. Component-Level Prognostics Health Management Framework for Passive Components - Advanced Reactor Technology Milestone: M2AT-15PN2301043

    Energy Technology Data Exchange (ETDEWEB)

    Ramuhalli, Pradeep; Roy, Surajit; Hirt, Evelyn H.; Prowant, Matthew S.; Pitman, Stan G.; Tucker, Joseph C.; Dib, Gerges; Pardini, Allan F.


    This report describes research results to date in support of the integration and demonstration of diagnostics technologies for prototypical advanced reactor passive components (to establish condition indices for monitoring) with model-based prognostics methods. Achieving this objective will necessitate addressing several of the research gaps and technical needs described in previous technical reports in this series.

  15. An Analysis of Testing Requirements for Fluoride Salt Cooled High Temperature Reactor Components

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David Eugene [ORNL; Cetiner, Sacit M [ORNL; Flanagan, George F [ORNL; Peretz, Fred J [ORNL; Yoder Jr, Graydon L [ORNL


    This report provides guidance on the component testing necessary during the next phase of fluoride salt-cooled high temperature reactor (FHR) development. In particular, the report identifies and describes the reactor component performance and reliability requirements, provides an overview of what information is necessary to provide assurance that components will adequately achieve the requirements, and then provides guidance on how the required performance information can efficiently be obtained. The report includes a system description of a representative test scale FHR reactor. The reactor parameters presented in this report should only be considered as placeholder values until an FHR test scale reactor design is completed. The report focus is bounded at the interface between and the reactor primary coolant salt and the fuel and the gas supply and return to the Brayton cycle power conversion system. The analysis is limited to component level testing and does not address system level testing issues. Further, the report is oriented as a bottom-up testing requirements analysis as opposed to a having a top-down facility description focus.

  16. Research in nondestructive evaluation techniques for nuclear reactor concrete structures (United States)

    Clayton, Dwight; Smith, Cyrus


    The purpose of the Materials Aging and Degradation (MAaD) Pathway of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program is to develop the scientific basis for understanding and predicting longterm environmental degradation behavior of material in nuclear power plants and to provide data and methods to assess the performance of systems, structures, and components (SSCs) essential to safe and sustained nuclear power plant operations. The understanding of aging-related phenomena and their impacts on SSCs is expected to be a significant issue for any nuclear power plant planning for long-term operations (i.e. service beyond the initial license renewal period). Management of those phenomena and their impacts during long-term operations can be better enable by improved methods and techniques for detection, monitoring, and prediction of SSC degradation. The MAaD Pathway R&D Roadmap for Concrete, "Light Water Reactor Sustainability Nondestructive Evaluation for Concrete Research and Development Roadmap", focused initial research efforts on understanding the recent concrete issues at nuclear power plants and identifying the availability of concrete samples for NDE techniques evaluation and testing. [1] An overview of the research performed by ORNL in these two areas is presented here.

  17. Corrosion of structural materials by lead-based reactor coolants.

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, D. P.; Leibowitz, L.; Maroni, V. A.; McDeavitt, S. M.; Raraz, A. G.


    Advanced nuclear reactor design has, in recent years, focused increasingly on the use of heavy-liquid-metal coolants, such as lead and lead-bismuth eutectic. Similarly, programs on accelerator-based transmutation systems have also considered the use of such coolants. Russian experience with heavy-metal coolants for nuclear reactors has lent credence to the validity of this approach. Of significant concern is the compatibility of structural materials with these coolants. We have used a thermal convection-based test method to allow exposure of candidate materials to molten lead and lead-bismuth flowing under a temperature gradient. The gradient was deemed essential in evaluating the behavior of the test materials in that should preferential dissolution of components of the test material occur we would expect dissolution in the hotter regions and deposition in the colder regions, thus promoting material transport. Results from the interactions of a Si-rich mild steel alloy, AISI S5, and a ferritic-martensitic stainless steel, HT-9, with the molten lead-bismuth are presented.

  18. Component and Technology Development for Advanced Liquid Metal Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark [Univ. of Wisconsin, Madison, WI (United States)


    The following report details the significant developments to Sodium Fast Reactor (SFR) technologies made throughout the course of this funding. This report will begin with an overview of the sodium loop and the improvements made over the course of this research to make it a more advanced and capable facility. These improvements have much to do with oxygen control and diagnostics. Thus a detailed report of advancements with respect to the cold trap, plugging meter, vanadium equilibration loop, and electrochemical oxygen sensor is included. Further analysis of the university’s moving magnet pump was performed and included in a section of this report. A continuous electrical resistance based level sensor was built and tested in the sodium with favorable results. Materials testing was done on diffusion bonded samples of metal and the results are presented here as well. A significant portion of this work went into the development of optical fiber temperature sensors which could be deployed in an SFR environment. Thus, a section of this report presents the work done to develop an encapsulation method for these fibers inside of a stainless steel capillary tube. High temperature testing was then done on the optical fiber ex situ in a furnace. Thermal response time was also explored with the optical fiber temperature sensors. Finally these optical fibers were deployed successfully in a sodium environment for data acquisition. As a test of the sodium deployable optical fiber temperature sensors they were installed in a sub-loop of the sodium facility which was constructed to promote the thermal striping effect in sodium. The optical fibers performed exceptionally well, yielding unprecedented 2 dimensional temperature profiles with good temporal resolution. Finally, this thermal striping loop was used to perform cross correlation velocimetry successfully over a wide range of flow rates.

  19. The efficiency of two anaerobic reactor components; Eficiencias de dos componentes de un reactor anaerobio

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Borges, E.; Mendez Novelo, R.; Magana Pietra, A. [Facultad de Ingenieria. Universidad de Yucatan (Mexico); Martinez Pereda, P.; Fernandez Villagomez, G. [Universidad Nacional Autonoma de Mexico. Division de Estudios de posgrado de la Facultad de Ingenieria. Mexico (Mexico)


    This study examined the behaviour of an anaerobic digester in treating pig farm sewage. The experimental model consisted of a UASB reactor at the bottom and a high-rate sedimentator at the top with a total capacity of 534 litres. The digester was installed on a pig farm and its performance under different operating conditions was determined, with hydraulic retention time (HRT) as the critical parameter for evaluating the anaerobic system`s efficiency. The results obtained during the experiment to establish the critical operating parameters are reported. The organic loads applied for a HRT of 1 day were 7.3 kg/m``3/day of total DQO and 3 kg/m``3/day of soluble DQO, following organic matter removal rates (as total DQO) of 36% and 49% respectively and removal rates (as soluble DQO) of 74% in the UASB and 8% in the sedimentator. The efficiency of the reactor as a whole at this HRT time was a removal rate of 74% of total DQO and 75% of soluble DQO. (Author) 25 refs.

  20. Optimization of structures and components

    CERN Document Server

    Muñoz-Rojas, Pablo Andrés


    Written by an international group of active researchers in the field, this volume presents innovative formulations and applied procedures for sensitivity analysis and structural design optimization. Eight chapters discuss subjects ranging from recent developments in the determination and application of topological gradients, to the use of evolutionary algorithms and meta-models to solve practical engineering problems. With such a comprehensive set of contributions, the book is a valuable source of information for graduate students and researchers entering or working in the matter.

  1. Analysis of Removal Alternatives for the Heavy Water Components Test Reactor at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Owen, M.B. [Westinghouse Savannah River Co., Aiken, SC (United States)


    This engineering study was developed to evaluate different options for decommissioning of the Heavy Water Components Test Reactor (HWCTR) at the Savannah River Site. This document will be placed in the DOE-SRS Area reading rooms for a period of 30 days in order to obtain public input to plans for the demolition of HWCTR.

  2. Thermal aging of some decommissioned reactor components and methodology for life prediction

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.


    Since a realistic aging of cast stainless steel components for end-of-life or life-extension conditions cannot be produced, it is customary to simulate the thermal aging embrittlement by accelerated aging at /approximately/400/degree/C. In this investigation, field components obtained from decommissioned reactors have been examined after service up to 22 yr to provide a benchmark of the laboratory simulation. The primary and secondary aging processes were found to be identical to those of the laboratory-aged specimens, and the kinetic characteristics were also similar. The extent of the aging embrittlement processes and other key factors that are known to influence the embrittlement kinetics have been compared for the decommissioned reactor components and materials aged under accelerated conditions. On the basis of the study, a mechanistic understanding of the causes of the complex behavior in kinetics and activation energy of aging (i.e., the temperature dependence of aging embrittlement between the accelerated and reactor-operating conditions) is presented. A mechanistic correlation developed thereon is compared with a number of available empirical correlations to provide an insight for development of a better methodology of life prediction of the reactor components. 18 refs., 18 figs., 5 tabs.


    Directory of Open Access Journals (Sweden)

    Phani Kumar Domalapally


    Full Text Available Some components of the fusion reactor receives high heat fluxes either during the startup and shutdown or during the operation of the machine. This paper analyzes different ways of enhancing heat transfer using helium and water for cooling of these high heat flux components and then conclusions are drawn to decide the best choice of coolant, for usage in near and long term applications.

  4. Measurement and Analysis of Structural Integrity of Reactor Core Support Structure in Pressurized Water Reactor (PWR) Plant (United States)

    Ansari, Saleem A.; Haroon, Muhammad; Rashid, Atif; Kazmi, Zafar


    Extensive calculation and measurements of flow-induced vibrations (FIV) of reactor internals were made in a PWR plant to assess the structural integrity of reactor core support structure against coolant flow. The work was done to meet the requirements of the Fukushima Response Action Plan (FRAP) for enhancement of reactor safety, and the regulatory guide RG-1.20. For the core surveillance measurements the Reactor Internals Vibration Monitoring System (IVMS) has been developed based on detailed neutron noise analysis of the flux signals from the four ex-core neutron detectors. The natural frequencies, displacement and mode shapes of the reactor core barrel (CB) motion were determined with the help of IVMS. The random pressure fluctuations in reactor coolant flow due to turbulence force have been identified as the predominant cause of beam-mode deflection of CB. The dynamic FIV calculations were also made to supplement the core surveillance measurements. The calculational package employed the computational fluid dynamics, mode shape analysis, calculation of power spectral densities of flow & pressure fields and the structural response to random flow excitation forces. The dynamic loads and stiffness of the Hold-Down Spring that keeps the core structure in position against upward coolant thrust were also determined by noise measurements. Also, the boron concentration in primary coolant at any time of the core cycle has been determined with the IVMS.

  5. Irradiation of Electronic Components and Circuits at the Portuguese Research Reactor: Lessons Learned (United States)

    Marques, J. G.; Ramos, A. R.; Fernandes, A. C.; Santos, J. P.


    A program was started in 1999 in the Portuguese Research Reactor to test electronics components and circuits for the LHC facility at CERN, initially with a dedicated in-pool irradiation container used at a reactor power of 2 kW and later an irradiation chamber outside the pool, with tailored neutron and gamma filters that could be used at 1 MW. Practice has shown the need to introduce several improvements to the irradiation procedures and infrastructures over the years. In this paper, we review the lessons learned and the major improvements introduced.

  6. The performance of structured packings in trickle-bed reactors.

    NARCIS (Netherlands)

    Frank, M.J.W.; Frank, M.J.W.; Kuipers, J.A.M.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria


    An experimental study was carried out to investigate whether the use of structured packings might improve the mass transfer characteristics and the catalyst effectiveness of a trickle-bed reactor. Therefore, the performances of a structured packing, consisting of KATAPAK elements, and a dumped

  7. The Performance of Structured Packings in Trickle-Bed Reactors

    NARCIS (Netherlands)

    Frank, M.J.W.; Kuipers, J.A.M.; Versteeg, G.F.; Swaaij, W.P.M. van


    An experimental study was carried out to investigate whether the use of structured packings might improve the mass transfer characteristics and the catalyst effectiveness of a trickle-bed reactor. Therefore, the performances of a structured packing, consisting of KATAPAK elements, and a dumped

  8. Embrittlement and Flow Localization in Reactor Structural Materials

    Energy Technology Data Exchange (ETDEWEB)

    Xianglin Wu; Xiao Pan; James Stubbins


    Many reactor components and structural members are made from metal alloys due, in large part, to their strength and ability to resist brittle fracture by plastic deformation. However, brittle fracture can occur when structural material cannot undergo extensive, or even limited, plastic deformation due to irradiation exposure. Certain irradiation conditions lead to the development of a damage microstructure where plastic flow is limited to very small volumes or regions of material, as opposed to the general plastic flow in unexposed materials. This process is referred to as flow localization or plastic instability. The true stress at the onset of necking is a constant regardless of the irradiation level. It is called 'critical stress' and this critical stress has strong temperature dependence. Interrupted tensile testes of 316L SS have been performed to investigate the microstructure evolution and competing mechanism between mechanic twinning and planar slip which are believed to be the controlling mechanism for flow localization. Deformation twinning is the major contribution of strain hardening and good ductility for low temperatures, and the activation of twinning system is determined by the critical twinning stress. Phases transform and texture analyses are also discussed in this study. Finite element analysis is carried out to complement the microstructural analysis and for the prediction of materaials performance with and without stress concentration and irradiation.

  9. Simulating the behaviour of zirconium-alloy components in nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, C.E


    To prevent failure in nuclear components one needs to understand the interactions between adjacent materials and the changes in their physical properties during all phases of reactor operation. Three examples from CANDU reactors are described to illustrate the use of simulations that imitate complicated reactor situations. These are: swelling tests that led to a method for increasing the tolerance or Zircaloy fuel cladding to power ramps; observations of the behaviour of leaking cracks in Zr-2.5Nb pressure tubes that provide confidence in the use of leak-before-break as part of the defence against flaw development; and contact boiling tests on modifications to the surfaces of Zircaloy calandria tubes that enhance the ability of the heavy water moderator to act as a heat sink after a postulated loss-of-coolant accident. (author)

  10. Reactor Safety Gap Evaluation of Accident Tolerant Components and Severe Accident Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Mitchell T. [Argonne National Lab. (ANL), Argonne, IL (United States); Bunt, R. [Southern Nuclear, Atlanta, GA (United States); Corradini, M. [Univ. of Wisconsin, Madison, WI (United States); Ellison, Paul B. [GE Power and Water, Duluth, GA (United States); Francis, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Gabor, John D. [Erin Engineering, Walnut Creek, CA (United States); Gauntt, R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Henry, C. [Fauske and Associates, Burr Ridge, IL (United States); Linthicum, R. [Exelon Corp., Chicago, IL (United States); Luangdilok, W. [Fauske and Associates, Burr Ridge, IL (United States); Lutz, R. [PWR Owners Group (PWROG); Paik, C. [Fauske and Associates, Burr Ridge, IL (United States); Plys, M. [Fauske and Associates, Burr Ridge, IL (United States); Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rempe, J. [Rempe and Associates LLC, Idaho Falls, ID (United States); Robb, K. [Argonne National Lab. (ANL), Argonne, IL (United States); Wachowiak, R. [Electric Power Research Inst. (EPRI), Knovville, TN (United States)


    The overall objective of this study was to conduct a technology gap evaluation on accident tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist, given the current state of light water reactor (LWR) severe accident research, and additionally augmented by insights obtained from the Fukushima accident. The ultimate benefit of this activity is that the results can be used to refine the Department of Energy’s (DOE) Reactor Safety Technology (RST) research and development (R&D) program plan to address key knowledge gaps in severe accident phenomena and analyses that affect reactor safety and that are not currently being addressed by the industry or the Nuclear Regulatory Commission (NRC).

  11. Analysis of space reactor system components: Investigation through simulation and non-nuclear testing (United States)

    Bragg-Sitton, Shannon M.

    The use of fission energy in space power and propulsion systems offers considerable advantages over chemical propulsion. Fission provides over six orders of magnitude higher energy density, which translates to higher vehicle specific impulse and lower specific mass. These characteristics enable ambitious space exploration missions. The natural space radiation environment provides an external source of protons and high energy, high Z particles that can result in the production of secondary neutrons through interactions in reactor structures. Applying the approximate proton source in geosynchronous orbit during a solar particle event, investigation using MCNPX 2.5.b for proton transport through the SAFE-400 heat pipe cooled reactor indicates an incoming secondary neutron current of (1.16 +/- 0.03) x 107 n/s at the core-reflector interface. This neutron current may affect reactor operation during low power maneuvers (e.g., start-up) and may provide a sufficient reactor start-up source. It is important that a reactor control system be designed to automatically adjust to changes in reactor power levels, maintaining nominal operation without user intervention. A robust, autonomous control system is developed and analyzed for application during reactor start-up, accounting for fluctuations in the radiation environment that result from changes in vehicle location or to temporal variations in the radiation field. Development of a nuclear reactor for space applications requires a significant amount of testing prior to deployment of a flight unit. High confidence in fission system performance can be obtained through relatively inexpensive non-nuclear tests performed in relevant environments, with the heat from nuclear fission simulated using electric resistance heaters. A series of non-nuclear experiments was performed to characterize various aspects of reactor operation. This work includes measurement of reactor core deformation due to material thermal expansion and

  12. Requirements for Prognostic Health Management of Passive Components in Advanced Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Ryan M.; Coble, Jamie B.; Ramuhalli, Pradeep


    Advanced small modular reactors (aSMRs), which are based on modularization of advanced reactor concepts, may provide a longer-term alternative to traditional light-water reactors and near term small modular reactors (SMRs), which are based on integral pressurized water reactor (iPWR) concepts. aSMRs are conceived for applications in remote locations and for diverse missions that include providing process or district heating, water desalination, and hydrogen production. Several challenges exist with respect to cost-effective operations and maintenance (O&M) of aSMRs, including the impacts of aggressive operating environments and modularity, and limiting these costs and staffing needs will be essential to ensuring the economic feasibility of aSMR deployment. In this regard, prognostic health management (PHM) systems have the potential to play a vital role in supporting the deployment of aSMR systems. This paper identifies requirements and technical gaps associated with implementation of PHM systems for passive aSMR components.

  13. Analysis of removal alternatives for the Heavy Water Components Test Reactor at the Savannah River Site. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Owen, M.B.


    This engineering study evaluates different alternatives for decontamination and decommissioning of the Heavy Water Components Test Reactor (HWCTR). Cooled and moderated with pressurized heavy water, this uranium-fueled nuclear reactor was designed to test fuel assemblies for heavy water power reactors. It was operated for this purpose from march of 1962 until December of 1964. Four alternatives studied in detail include: (1) dismantlement, in which all radioactive and hazardous contaminants would be removed, the containment dome dismantled and the property restored to a condition similar to its original preconstruction state; (2) partial dismantlement and interim safe storage, where radioactive equipment except for the reactor vessel and steam generators would be removed, along with hazardous materials, and the building sealed with remote monitoring equipment in place to permit limited inspections at five-year intervals; (3) conversion for beneficial reuse, in which most radioactive equipment and hazardous materials would be removed and the containment building converted to another use such as a storage facility for radioactive materials, and (4) entombment, which involves removing hazardous materials, filling the below-ground structure with concrete, removing the containment dome and pouring a concrete cap on the tomb. Also considered was safe storage, but this approach, which has, in effect, been followed for the past 30 years, did not warrant detailed evaluation. The four other alternatives were evaluate, taking into account factors such as potential effects on the environment, risks, effectiveness, ease of implementation and cost. The preferred alternative was determined to be dismantlement. This approach is recommended because it ranks highest in the comparative analysis, would serve as the best prototype for the site reactor decommissioning program and would be most compatible with site property reuse plans for the future.

  14. Management of research reactor; dynamic characteristics analysis for reactor structures related with vibration of HANARO fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Chang Kee; Shim, Joo Sup [Shinwa Technology Information, Seoul (Korea)


    The objective of this study is to deduce the dynamic correlation between the fuel assembly and the reactor structure. Dynamic characteristics analyses for reactor structure related with vibration of HANARO fuel assembly have been performed For the dynamic characteristic analysis, the in-air models of the round and hexagonal flow tubes, 18-element and 36-element fuel assemblies, and reactor structure were developed. By calculating the hydrodynamic mass and distributing it on the in-air models, the in-water models of the flow tubes, the fuel assemblies, and the reactor structure were developed. Then, modal analyses for developed in-air and in-water models have been performed. Especially, two 18-element fuel assemblies and three 36-element fuel assemblies were included in the in-water reactor models. For the verification of the modal analysis results, the natural frequencies and the mode shapes of the fuel assembly were compared with those obtained from the experiment. Finally the analysis results of the reactor structure were compared with them performed by AECL Based on the reactor model without PCS piping, the in-water reactor model including the fuel assemblies was developed, and its modal analysis was performed. The analysis results demonstrate that there are no resonance between the fuel assembly and the reactor structures. 26 refs., 419 figs., 85 tabs. (Author)

  15. Development of Underwater Laser Cladding and Underwater Laser Seal Welding Techniques for Reactor Components (United States)

    Hino, Takehisa; Tamura, Masataka; Tanaka, Yoshimi; Kouno, Wataru; Makino, Yoshinobu; Kawano, Shohei; Matsunaga, Keiji

    Stress corrosion cracking (SCC) has been reported at the aged components in many nuclear power plants. Toshiba has been developing the underwater laser welding. This welding technique can be conducted without draining the water in the reactor vessel. It is beneficial for workers not to exposure the radiation. The welding speed can be attaining twice as fast as that of Gas Tungsten Arc Welding (GTAW). The susceptibility of SCC can also be lower than the Alloy 600 base metal.

  16. Swelling in light water reactor internal components: Insights from computational modeling

    Energy Technology Data Exchange (ETDEWEB)

    Stoller, Roger E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barashev, Alexander V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Golubov, Stanislav I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    A modern cluster dynamics model has been used to investigate the materials and irradiation parameters that control microstructural evolution under the relatively low-temperature exposure conditions that are representative of the operating environment for in-core light water reactor components. The focus is on components fabricated from austenitic stainless steel. The model accounts for the synergistic interaction between radiation-produced vacancies and the helium that is produced by nuclear transmutation reactions. Cavity nucleation rates are shown to be relatively high in this temperature regime (275 to 325°C), but are sensitive to assumptions about the fine scale microstructure produced under low-temperature irradiation. The cavity nucleation rates observed run counter to the expectation that void swelling would not occur under these conditions. This expectation was based on previous research on void swelling in austenitic steels in fast reactors. This misleading impression arose primarily from an absence of relevant data. The results of the computational modeling are generally consistent with recent data obtained by examining ex-service components. However, it has been shown that the sensitivity of the model s predictions of low-temperature swelling behavior to assumptions about the primary damage source term and specification of the mean-field sink strengths is somewhat greater that that observed at higher temperatures. Further assessment of the mathematical model is underway to meet the long-term objective of this research, which is to provide a predictive model of void swelling at relevant lifetime exposures to support extended reactor operations.

  17. Component Representation for Shock Qualified Foundation Structure


    Timothy Coats; Michael Cooper; Kevin Arden; Fred Russell


    Navy ship foundations are typically designed for shock using the Navy's Dynamic Design Analysis Method. The NAVSEA 0908-LP-000-3010, Rev. 1 manual states that a component modeled as a lumped mass with rigid links should not provide constraint to the support structure. This ensures foundations are designed to withstand all shock loads without accounting for additional stiffness provided by the component. Investigations are provided herein to illustrate the trade-offs and consequences of severa...

  18. Determination of floor response spectra for the Brookhaven HFBR reactor building structure

    Energy Technology Data Exchange (ETDEWEB)

    Subudhi, M.; Goradia, H.


    In order to perform the dynamic analysis of various structural components of the HFBR reactor building at Brookhaven National Laboratory (BNL) subjected to seismic disturbances, it is necessary to obtain the floor response spectra of the primary structure. The mathematical model includes the four floor levels of the internal structure, the dome, and soil spring effects. The standard time history analysis is adopted to obtain the response spectrum for each floor of the internal structure. This report summarizes the results both in tabular and graphical form for various damping values.

  19. Structural integrity aspects of reactor safety

    Indian Academy of Sciences (India)

    The principles followed such as safety classification, design rules based on failure modes, detailed stress analysis, stress categorization, consideration of design basis events, failure probability, ... The R6 procedure, which is used for evaluation of structures containing flaws, has been incorporated in the software BARC-R6.

  20. Residual strength evaluation of concrete structural components ...

    Indian Academy of Sciences (India)

    This paper presents methodologies for residual strength evaluation of concrete structural components using linear elastic and nonlinear fracture mechanics principles. The effect of cohesive forces due to aggregate bridging has been represented mathematically by employing tension softening models. Various tension ...

  1. Residual strength evaluation of concrete structural components ...

    Indian Academy of Sciences (India)

    Abstract. This paper presents methodologies for residual strength evaluation of concrete structural components using linear elastic and nonlinear fracture mechan- ics principles. The effect of cohesive forces due to aggregate bridging has been represented mathematically by employing tension softening models. Various ...

  2. Development of fiber-delivered laser peening system to prevent stress corrosion cracking of reactor components

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Y.; Kimura, M.; Yoda, M.; Mukai, N.; Sato, K.; Uehara, T.; Ito, T.; Shimamura, M.; Sudo, A.; Suezono, N. [Toshiba Corp., Yokohama (Japan)


    The authors have developed a system to deliver water-penetrable intense laser pulses of frequency-doubled Nd:YAG laser through optical fiber. The system is capable of improving a residual stress on water immersed metal material remotely, which is effective to prevent the initiation of stress corrosion cracking (SCC) of reactor components. Experimental results showed that a compressive residual stress with enough amplitude and depth was built in the surface layer of type 304 stainless steel (SUS304) by irradiating laser pulses through optical fiber with diameter of 1 mm. A prototype peening head with miniaturized dimensions of 88 mm x 46 mm x 25 mm was assembled to con-firm the accessibility to the heat affected zone (HAZ) along weld lines of a reactor core shroud. The accessibility was significantly improved owing to the flexible optical fiber and the miniaturized peening head. The fiber delivered system opens up the possibility of new applications of laser peening. (author)

  3. Mechanical properties of thermally aged cast stainless steels from Shippingport reactor components

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Shack, W.J. [Argonne National Lab., IL (United States)


    Thermal embrittlement of static-cast CF-8 stainless steel components from the decommissioned Shippingport reactor has been characterized. Cast stainless steel materials were obtained from four cold-leg check valves, three hot-leg main shutoff valves, and two pump volutes. The actual time-at-temperature for the materials was {approximately}13 y at {approximately}281 C (538 F) for the hot-leg components and {approximately}264 C (507 F) for the cold-leg components. Baseline mechanical properties for as-cast material were determined from tests on either recovery-annealed material, i.e., annealed for 1 h at 550 C and then water quenched, or material from the cooler region of the component. The Shippingport materials show modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength because of relatively low service temperatures and ferrite content of the steel. The procedure and correlations developed at Argonne National Laboratory for estimating mechanical properties of cast stainless steels predict accurate or slightly lower values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predicted the mechanical properties of the Ringhals 2 reactor hot and crossover-leg elbows (CF-8M steel) after service of {approximately} 15 y and the KRB reactor pump cover plate (CF-8) after {approximately} 8 y of service.

  4. Mechanical properties of thermally aged cast stainless steels from shippingport reactor components.

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O. K.; Shack, W. J.; Energy Technology


    Thermal embrittlement of static-cast CF-8 stainless steel components from the decommissioned Shippingport reactor has been characterized. Cast stainless steel materials were obtained from four cold-leg check valves, three hot-leg main shutoff valves, and two pump volutes. The actual time-at-temperature for the materials was {approx}13 y at {approx}281 C (538 F) for the hot-leg components and {approx}264 C (507 F) for the cold-leg components. Baseline mechanical properties for as-cast material were determined from tests on either recovery-annealed material, i.e., annealed for 1 h at 550 C and then water quenched, or material from the cooler region of the component. The Shippingport materials show modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength because of relatively low service temperatures and ferrite content of the steel. The procedure and correlations developed at Argonne National Laboratory for estimating mechanical properties of cast stainless steels predict accurate or slightly lower values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predicted the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y and the KRB reactor pump cover plate (CF-8) after {approx}8 y of service.

  5. Finite element based stress analysis of graphite component in high temperature gas cooled reactor core using linear and nonlinear irradiation creep models

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish, E-mail:; Majumdar, Saurindranath


    Highlights: • High temperature gas cooled reactor. • Finite element based stress analysis. • H-451 graphite. • Irradiation creep model. • Graphite reflector stress analysis. - Abstract: Irradiation creep plays a major role in the structural integrity of the graphite components in high temperature gas cooled reactors. Finite element procedures combined with a suitable irradiation creep model can be used to simulate the time-integrated structural integrity of complex shapes, such as the reactor core graphite reflector and fuel bricks. In the present work a comparative study was undertaken to understand the effect of linear and nonlinear irradiation creep on results of finite element based stress analysis. Numerical results were generated through finite element simulations of a typical graphite reflector.

  6. Component Representation for Shock Qualified Foundation Structure

    Directory of Open Access Journals (Sweden)

    Timothy Coats


    Full Text Available Navy ship foundations are typically designed for shock using the Navy's Dynamic Design Analysis Method. The NAVSEA 0908-LP-000-3010, Rev. 1 manual states that a component modeled as a lumped mass with rigid links should not provide constraint to the support structure. This ensures foundations are designed to withstand all shock loads without accounting for additional stiffness provided by the component. Investigations are provided herein to illustrate the trade-offs and consequences of several approaches for component representations. The observations reinforce the notion that one must give careful consideration for the system being modeled, the expected modal characteristics, and compliance with NAVSEA 0908-LP-000-3010, Rev. 1.

  7. A review of the US joining technologies for plasma facing components in the ITER fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Odegard, B.C. Jr.; Cadden, C.H. [Sandia National Labs., Livermore, CA (United States); Watson, R.D. [Sandia National Labs., Albuquerque, NM (United States); Slattery, K.T. [Boeing Co., St. Louis, MO (United States)


    This paper is a review of the current joining technologies for plasma facing components in the US for the International Thermonuclear Experimental Reactor (ITER) project. Many facilities are involved in this project. Many unique and innovative joining techniques are being considered in the quest to join two candidate armor plate materials (beryllium and tungsten) to a copper base alloy heat sink (CuNiBe, OD copper, CuCrZr). These techniques include brazing and diffusion bonding, compliant layers at the bond interface, and the use of diffusion barrier coatings and diffusion enhancing coatings at the bond interfaces. The development and status of these joining techniques will be detailed in this report.

  8. Simulation in equivalent beams of reactor vessel internal components 900 MW; Modelisation en poutres equivalentes des internes de cuve 900 MW

    Energy Technology Data Exchange (ETDEWEB)

    Metivier, V


    The nuclear safety imperatives of PWR type reactors require a good knowledge of the dynamic behaviour of the reactor vessel internal components in case of seism. Indeed, in case of seism, safety and reliability of reactor vessel internal components have to be proved because their size could induce their partial or total damage. It is then indispensable to dispose of a good dynamic simulation of the vessel internal components. In the first part of this work, a model of equivalent beams of the reactor vessel internal components has been carried out in air. In fact, each core structure is simulated by an equivalent beam. These equivalent beams are also subdivided into several beams, identified by their extremities. It is then possible to characterize the section changes and materials for one element, assigning at each of these beams proper characteristics, as its length, its density, its inertial moment...After a validation of this model by a modal calculus, a second step has consisted of taking into account the fluid-structure coupling. Indeed, the vessel internal components lies under a coolant fluid flow, called ``primary fluid``. The effect of this fluid is to add mass, absorption or stiffness to structures with which it is bound. The dynamic behaviour of the structures can then be highly influenced by this coupling. A fluid coupling has then been considered in this work. It is of inertial type because it is proportional to the structures acceleration. The results of the modal calculus has been compared to the experimental ones. Three softwares have been used in this study: GIBI, IDEAS and the Aster code. (O.M.) 11 refs.

  9. Modeling accelerator structures and RF components

    Energy Technology Data Exchange (ETDEWEB)

    Ko, K., Ng, C.K.; Herrmannsfeldt, W.B.


    Computer modeling has become an integral part of the design and analysis of accelerator structures RF components. Sophisticated 3D codes, powerful workstations and timely theory support all contributed to this development. We will describe our modeling experience with these resources and discuss their impact on ongoing work at SLAC. Specific examples from R&D on a future linear collide and a proposed e{sup +}e{sup {minus}} storage ring will be included.

  10. 76 FR 16842 - Request for a License To Export Reactor Components (United States)


    ... six AP- Construction, China. Mechanical Corporation. coolant pump 1000 (design) maintenance, and systems, related reactors. operation of AP- equipment, and 1000 (design) spare parts. nuclear reactors...

  11. Structured automated code checking through structural components and systems engineering

    NARCIS (Netherlands)

    Coenders, J.L.; Rolvink, A.


    This paper presents a proposal to employ the design computing methodology proposed as StructuralComponents (Rolvink et al [6] and van de Weerd et al [7]) as a method to perform a digital verification process to fulfil the requirements related to structural design and engineering as part of a

  12. Structured catalysts and reactors for three phase catalytic reactions: manipulating activity and selectivity in nitrite hydrogenation

    NARCIS (Netherlands)

    Brunet Espinosa, Roger


    This work aimed at fabricating structured catalytic reactors for fast multiphase reactions, namely, nitrite hydrogenation and H2O2 decomposition. These reactors allowed a better understanding of these reactions and an improvement in terms of catalytic activity and selectivity.

  13. Argonne Liquid-Metal Advanced Burner Reactor : components and in-vessel system thermal-hydraulic research and testing experience - pathway forward.

    Energy Technology Data Exchange (ETDEWEB)

    Kasza, K.; Grandy, C.; Chang, Y.; Khalil, H.; Nuclear Engineering Division


    from normal high-flow operation to natural circulation. Low-flow coolant events are the most difficult to design for because they involve the most complex thermal-hydraulic behavior induced by the dominance of thermal-buoyancy forces acting on the coolants. Such behavior can cause multiple-component flow interaction phenomena, which are not adequately understood or appreciated by reactor designers as to their impact on reactor performance and safety. Since the early 1990s, when DOE canceled the U.S. Liquid Metal Fast Breeder Reactor (LMFBR) program, little has been done experimentally to further understand the importance of the complex thermal-buoyancy phenomena and their impact on reactor design or to improve the ability of three-dimensional (3-D) transient computational fluid dynamics (CFD) and structures codes to model the phenomena. An improved experimental data base and the associated improved validated codes would provide needed design tools to the reactor community. The improved codes would also facilitate scale-up from small-scale testing to prototype size and would facilitate comparing performance of one reactor/component design with another. The codes would also have relevance to the design and safety of water-cooled reactors. To accomplish the preceding, it is proposed to establish a national GNEP-LMR research and development center at Argonne having as its foundation state-of-art science-based infrastructure consisting of: (a) thermal-hydraulic experimental capabilities for conducting both water and sodium testing of individual reactor components and complete reactor in-vessel models and (b) a computational modeling development and validation capability that is strongly interfaced with the experimental facilities. The proposed center would greatly advance capabilities for reactor development by establishing the validity of high-fidelity (i.e., close to first principles) models and tools. Such tools could be used directly for reactor design or for qualifying

  14. FDC, rapid fabrication of structural components

    Energy Technology Data Exchange (ETDEWEB)

    Agarwala, M.K.; Bandyopadhyay, A.; Weeren, R. van; Safari, A.; Danforth, S.C.; Langrana, N.A. [Rutgers-the State Univ., Piscataway, NJ (United States); Jamalabad, V.R.; Whalen, P.J. [AlliedSignal Research and Technology, Morristown, NJ (United States)


    Solid freeform fabrication (SFF) is used to make 3-D components directly from computer-aided design (CAD) files. Many SFF techniques have been developed to fabricate parts and prototypes from CAD without hard tooling, dies or molds. Most of these techniques have been commercialized for fabrication of polymer and plastic parts for design verification and form and fit. Other SFF techniques are being developed for production of ceramic components with functional properties. One such technique, called fused deposition of ceramics (FDC), has been developed and demonstrated for structural ceramics. FDC is based on existing fused deposition modeling (FDM{trademark}) technology, commercialized by Stratasys Inc. (Eden Prairie, Minn.), for processing of polymers and waxes. High-green-density, simple- and complex-shaped silicon nitride parts have been formed by fused deposition of ceramics.

  15. Relationships between chemical oxygen demand (COD) components and toxicity in a sequential anaerobic baffled reactor/aerobic completely stirred reactor system treating Kemicetine

    Energy Technology Data Exchange (ETDEWEB)

    Sponza, Delia Teresa, E-mail: [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eyluel University, Buca Kaynaklar Campus, Tinaztepe, 35160 Izmir (Turkey); Demirden, Pinar, E-mail: [Environmental Engineer, Koza Gold Company, Environmental Department, Ovacik, Bergama Izmir (Turkey)


    In this study the interactions between toxicity removals and Kemicetine, COD removals, intermediate products of Kemicetine and COD components (CODs originating from slowly degradable organics, readily degradable organics, inert microbial products and from the inert compounds) were investigated in a sequential anaerobic baffled reactor (ABR)/aerobic completely stirred tank reactor (CSTR) system with a real pharmaceutical wastewater. The total COD and Kemicetine removal efficiencies were 98% and 100%, respectively, in the sequential ABR/CSTR systems. 2-Amino-1 (p-nitrophenil)-1,3 propanediol, l-p-amino phenyl, p-amino phenol and phenol were detected in the ABR as the main readily degradable inter-metabolites. In the anaerobic ABR reactor, the Kemicetin was converted to corresponding inter-metabolites and a substantial part of the COD was removed. In the aerobic CSTR reactor the inter-metabolites produced in the anaerobic reactor were completely removed and the COD remaining from the anerobic reactor was biodegraded. It was found that the COD originating from the readily degradable organics did not limit the anaerobic degradation process, while the CODs originating from the slowly degradable organics and from the inert microbial products significantly decreased the anaerobic ABR reactor performance. The acute toxicity test results indicated that the toxicity decreased from the influent to the effluent of the aerobic CSTR reactor. The ANOVA test statistics showed that there was a strong linear correlation between acute toxicity, CODs originating from the slowly degradable organics and inert microbial products. A weak correlation between acute toxicity and CODs originating from the inert compounds was detected.

  16. Mechanical-property degradation of cast stainless steel components from the Shippingport reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.


    The mechanical properties of cast stainless steels from the Shippingport reactor have been characterized. Baseline properties for unaged materials were obtained from tests on either recovery-annealed material or material from a cooler region of the component. The materials exhibited modest decrease in impact energy and fracture toughness and a small increase in tensile strength. The fracture toughness J-R curve, J{sub IC} value, tensile flow stress, and Charpy-impact energy of the materials showed very good agreement with estimations based on accelerated laboratory aging studies. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy that would be achieved after long-term aging, were established from materials that were aged further in the laboratory at temperatures between 320 and 400{degrees}C. The results showed very good agreement with estimates; the activation energies ranged from 125 to 250 kJ/mole and the minimum room temperature impact energy was <75 J/cm{sup 2}. The estimated impact energy and fracture toughness J-R curve for materials from the Ringhals reactor hot and crossover-leg elbows are also presented.

  17. Structure analysis of a reactor pressure vessel by two and three-dimensional models

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, H.; Mayr, M. (Technischer Ueberwachungs-Verein Bayern e.V., Muenchen (Germany, F.R.))


    This paper investigates the reactor pressure vessel of a 1300 MW pressurised water reactor. In order to determine the stresses and deformations of the vessel, two- and three-dimensional finite element models are used which represent the real structure with different degrees of accuracy. The results achieved by these different models are compared for the case of the transient called 'Start up of the nuclear power plant'. It was found that axisymmetric models, which consider non-axisymmetric components by correction factors, together with special attention to holes and other stress concentrations, allow a sufficient computation of stresses and deformations in the vessel, with the exception of the coolant nozzle region. In this latter case a fully three-dimensional analysis may be necessary.

  18. StructuralComponents : A software system for conceptual structural design

    NARCIS (Netherlands)

    Van de Weerd, B.; Rolvink, A.; Coenders, J.L.


    Conceptual design is the starting point of the design process. The conceptual design stage comprises the formation of several ideas or design concepts to meet the imposed constraints. StructuralComponents is a software application that attempts to provide the designing engineer with a suitable set

  19. Research of lithium capillary-pore systems for fusion reactor plasma facing components

    Energy Technology Data Exchange (ETDEWEB)

    Evtikhin, V.A. E-mail:; Vertkov, A.V.; Lyublinski, I.E.; Khripunov, B.I.; Petrov, V.B.; Mirnov, S.V


    To date there is no adequate solution for high heat load plasma facing components of the next step fusion reactor among solid material options. A lithium-filled capillary porous systems (CPS) was proposed as a plasma facing material and experimental work on this subject is now in progress. Steady-state experiments with CPS-based target and lithium supply systems have shown successful operation at heat fluxes of 1-10 MW/m{sup 2} during several hours. Experimental data is obtained on lithium CPS stability at heat flux up to 25-50 MW/m{sup 2}. The lithium CPS behaviour in contact with real tokamak plasma is considered for normal discharge condition at 10 MW/m{sup 2} and for plasma disruption at 15 MJ/m{sup 2}. Erosion mechanism of lithium under tokamak plasma impact was analysed. Stability of lithium CPS in tokamak conditions was shown.

  20. Approaches to experimental validation of high-temperature gas-cooled reactor components

    Energy Technology Data Exchange (ETDEWEB)

    Belov, S.E. [Joint Stock Company ' Afrikantov OKB Mechanical Engineering' , Burnakovsky Proezd, 15, Nizhny Novgorod 603074 (Russian Federation); Borovkov, M.N., E-mail: [Joint Stock Company ' Afrikantov OKB Mechanical Engineering' , Burnakovsky Proezd, 15, Nizhny Novgorod 603074 (Russian Federation); Golovko, V.F.; Dmitrieva, I.V.; Drumov, I.V.; Znamensky, D.S.; Kodochigov, N.G. [Joint Stock Company ' Afrikantov OKB Mechanical Engineering' , Burnakovsky Proezd, 15, Nizhny Novgorod 603074 (Russian Federation); Baxi, C.B.; Shenoy, A.; Telengator, A. [General Atomics, 3550 General Atomics Court, CA (United States); Razvi, J., E-mail: [General Atomics, 3550 General Atomics Court, CA (United States)


    Highlights: Black-Right-Pointing-Pointer Computational and experimental investigations of thermal and hydrodynamic characteristics for the equipment. Black-Right-Pointing-Pointer Vibroacoustic investigations. Black-Right-Pointing-Pointer Studies of the electromagnetic suspension system on GT-MHR turbo machine rotor models. Black-Right-Pointing-Pointer Experimental investigations of the catcher bearings design. - Abstract: The special feature of high-temperature gas-cooled reactors (HTGRs) is stressed operating conditions for equipment due to high temperature of the primary circuit helium, up to 950 Degree-Sign C, as well as acoustic and hydrodynamic loads upon the gas path elements. Therefore, great significance is given to reproduction of real operation conditions in tests. Experimental investigation of full-size nuclear power plant (NPP) primary circuit components is not practically feasible because costly test facilities will have to be developed for the power of up to hundreds of megawatts. Under such conditions, the only possible process to validate designs under development is representative tests of smaller scale models and fragmentary models. At the same time, in order to take in to validated account the effect of various physical factors, it is necessary to ensure reproduction of both individual processes and integrated tests incorporating needed integrated investigations. Presented are approaches to experimental validation of thermohydraulic and vibroacoustic characteristics for main equipment components and primary circuit path elements under standard loading conditions, which take account of their operation in the HTGR. Within the framework of the of modular helium reactor project, including a turbo machine in the primary circuit, a new and difficult problem is creation of multiple-bearing flexible vertical rotor. Presented are approaches to analytical and experimental validation of the rotor electromagnetic bearings, catcher bearings, flexible rotor


    Directory of Open Access Journals (Sweden)



    Full Text Available The CUPID code has been developed at KAERI for a transient, three-dimensional analysis of a two-phase flow in light water nuclear reactor components. It can provide both a component-scale and a CFD-scale simulation by using a porous media or an open media model for a two-phase flow. In this paper, recent advances in the CUPID code are presented in three sections. First, the domain decomposition parallel method implemented in the CUPID code is described with the parallel efficiency test for multiple processors. Then, the coupling of CUPID-MARS via heat structure is introduced, where CUPID has been coupled with a system-scale thermal-hydraulics code, MARS, through the heat structure. The coupled code has been applied to a multi-scale thermal-hydraulic analysis of a pool mixing test. Finally, CUPID-SG is developed for analyzing two-phase flows in PWR steam generators. Physical models and validation results of CUPID-SG are discussed.

  2. 10 CFR 110.26 - General license for the export of nuclear reactor components. (United States)


    ... 10 Energy 2 2010-01-01 2010-01-01 false General license for the export of nuclear reactor... NUCLEAR EQUIPMENT AND MATERIAL Licenses § 110.26 General license for the export of nuclear reactor... nuclear power or research reactor in the United States: Austria Belgium Bulgaria Canada Czech Republic...

  3. Online stress corrosion crack and fatigue usages factor monitoring and prognostics in light water reactor components: Probabilistic modeling, system identification and data fusion based big data analytics approach

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish M. [Argonne National Lab. (ANL), Argonne, IL (United States); Jagielo, Bryan J. [Argonne National Lab. (ANL), Argonne, IL (United States); Oakland Univ., Rochester, MI (United States); Iverson, William I. [Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Illinois at Urbana-Champaign, Champaign, IL (United States); Bhan, Chi Bum [Argonne National Lab. (ANL), Argonne, IL (United States); Pusan National Univ., Busan (Korea, Republic of); Soppet, William S. [Argonne National Lab. (ANL), Argonne, IL (United States); Majumdar, Saurin M. [Argonne National Lab. (ANL), Argonne, IL (United States); Natesan, Ken N. [Argonne National Lab. (ANL), Argonne, IL (United States)


    Nuclear reactors in the United States account for roughly 20% of the nation's total electric energy generation, and maintaining their safety in regards to key component structural integrity is critical not only for long term use of such plants but also for the safety of personnel and the public living around the plant. Early detection of damage signature such as of stress corrosion cracking, thermal-mechanical loading related material degradation in safety-critical components is a necessary requirement for long-term and safe operation of nuclear power plant systems.

  4. Technical Needs for Prototypic Prognostic Technique Demonstration for Advanced Small Modular Reactor Passive Components

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Ryan M.; Coble, Jamie B.; Hirt, Evelyn H.; Ramuhalli, Pradeep; Mitchell, Mark R.; Wootan, David W.; Berglin, Eric J.; Bond, Leonard J.; Henager, Charles H.


    This report identifies a number of requirements for prognostics health management of passive systems in AdvSMRs, documents technical gaps in establishing a prototypical prognostic methodology for this purpose, and describes a preliminary research plan for addressing these technical gaps. AdvSMRs span multiple concepts; therefore a technology- and design-neutral approach is taken, with the focus being on characteristics that are likely to be common to all or several AdvSMR concepts. An evaluation of available literature is used to identify proposed concepts for AdvSMRs along with likely operational characteristics. Available operating experience of advanced reactors is used in identifying passive components that may be subject to degradation, materials likely to be used for these components, and potential modes of degradation of these components. This information helps in assessing measurement needs for PHM systems, as well as defining functional requirements of PHM systems. An assessment of current state-of-the-art approaches to measurements, sensors and instrumentation, diagnostics and prognostics is also documented. This state-of-the-art evaluation, combined with the requirements, may be used to identify technical gaps and research needs in the development, evaluation, and deployment of PHM systems for AdvSMRs. A preliminary research plan to address high-priority research needs for the deployment of PHM systems to AdvSMRs is described, with the objective being the demonstration of prototypic prognostics technology for passive components in AdvSMRs. Greater efficiency in achieving this objective can be gained through judicious selection of materials and degradation modes that are relevant to proposed AdvSMR concepts, and for which significant knowledge already exists. These selections were made based on multiple constraints including the analysis performed in this document, ready access to laboratory-scale facilities for materials testing and measurement, and

  5. Design and Fabrication Technique of the Key Components for Very High Temperature Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Jin; Song, Ki Nam; Kim, Yong Wan


    The gas outlet temperature of Very High Temperature Reactor (VHTR) may be beyond the capability of conventional metallic materials. The requirement of the gas outlet temperature of 950 .deg. C will result in operating temperatures for metallic core components that will approach very high temperature on some cases. The materials that are capable of withstanding this temperature should be prepared, or nonmetallic materials will be required for limited components. The Ni-base alloys such as Alloy 617, Hastelloy X, XR, Incoloy 800H, and Haynes 230 are being investigated to apply them on components operated in high temperature. Currently available national and international codes and procedures are needed reviewed to design the components for HTGR/VHTR. Seven codes and procedures, including five ASME Codes and Code cases, one French code (RCC-MR), and on British Procedure (R5) were reviewed. The scope of the code and code cases needs to be expanded to include the materials with allowable temperatures of 950 .deg. C and higher. The selection of compact heat exchangers technology depends on the operating conditions such as pressure, flow rates, temperature, but also on other parameters such as fouling, corrosion, compactness, weight, maintenance and reliability. Welding, brazing, and diffusion bonding are considered proper joining processes for the heat exchanger operating in the high temperature and high pressure conditions without leakage. Because VHTRs require high temperature operations, various controlled materials, thick vessels, dissimilar metal joints, and precise controls of microstructure in weldment, the more advanced joining processes are needed than PWRs. The improved solid joining techniques are considered for the IHX fabrication. The weldability for Alloy 617 and Haynes 230 using GTAW and SMAW processes was investigated by CEA.

  6. Biofiltration of paint solvent mixtures in two reactor types: overloading by polar components. (United States)

    Paca, Jan; Halecky, Martin; Misiaczek, Ondrej; Kozliak, Evguenii I; Jones, Kim


    Steady-state performances of a trickle bed reactor (TBR) and a biofilter (BF) in loading experiments with increasing inlet concentrations of polar solvents, acetone, methyl ethyl ketone, methyl isobutyl ketone and n-butyl acetate, were investigated, along with the system's dynamic responses. Throughout the entire experimentation time, a constant loading rate of aromatic components of 4 g(c)·m(-3)·h(-1) was maintained to observe the interactions between the polar substrates and aromatic hydrocarbons. Under low combined substrate loadings, the BF outperformed TBR not only in the removal of aromatic hydrocarbons but also in the removal of polar substrates. However, increasing the loading rate of polar components above the threshold value of 31-36 g(c)·m(-3)·h(-1) resulted in a steep and significant drop in the removal efficiencies of both polar (except for butyl acetate) and hydrophobic components, which was more pronounced in the BF; so the relative TBR/BF efficiency became reversed under such overloading conditions. A step-drop of the overall OL(POLAR) (combined loading by polar air pollutants) from overloading values to 7 g(c)·m(-3)·h(-1) resulted in an increase of all pollutant removal efficiencies, although in TBR the recovery was preceded by lag periods lasting between 5 min (methyl ethyl ketone) to 3.7 h (acetone). The occurrence of lag periods in the TBR recovery was, in part, due to the saturation of mineral medium with water-soluble polar solvents, particularly, acetone. The observed bioreactor behavior was consistent with the biological steps being rate-limiting.

  7. Bulk-bronzied graphites for plasma-facing components in ITER (International Thermonuclear Experimental Reactor)

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, Y.; Conn, R.W.; Doerner, R.; Khandagle, M. (California Univ., Los Angeles, CA (USA). Inst. of Plasma and Fusion Research); Causey, R.; Wilson, K. (Sandia National Labs., Livermore, CA (USA)); Croessmann, D.; Whitley, J. (Sandia National Labs., Albuquerque, NM (USA)); Holland, D.; Smolik, G. (Idaho National Engineering Lab., Idaho Falls, ID (USA)); Matsuda, T.; Sogabe, T. (Toyo Tanso Co. Ltd., O


    Newly developed bulk-boronized graphites and boronized C-C composites with a total boron concentration ranging from 1 wt % to 30 wt % have been evaluated as plasma-facing component materials for the International Thermonuclear Experimental Reactor (ITER). Bulk-boronized graphites have been bombarded with high-flux deuterium plasmas at temperatures between 200 and 1600{degree}C. Plasma interaction induced erosion of bulk-boronized graphites is observed to be a factor of 2--3 smaller than that of pyrolytic graphite, in regimes of physical sputtering, chemical sputtering and radiation enhanced sublimation. Postbombardment thermal desorption spectroscopy indicates that bulk-boronized graphites enhance recombinative desorption of deuterium, which leads to a suppression of the formation of deuterocarbon due to chemical sputtering. The tritium inventory in graphite has been found to decrease by an order of magnitude due to 10 wt % bulk-boronization at temperatures above 1000{degree}C. The critical heat flux to induce cracking for bulk-boronized graphites has been found to be essentially the same as that for non-boronized graphites. Also, 10 wt % bulk-boronization of graphite hinders air oxidation nearly completely at 800{degree}C and reduces the steam oxidation rate by a factor of 2--3 at around 1100 and 1350{degree}C. 38 refs., 5 figs.

  8. Structure and creep of Russian reactor steels with a BCC structure (United States)

    Sagaradze, V. V.; Kochetkova, T. N.; Kataeva, N. V.; Kozlov, K. A.; Zavalishin, V. A.; Vil'danova, N. F.; Ageev, V. S.; Leont'eva-Smirnova, M. V.; Nikitina, A. A.


    The structural phase transformations have been revealed and the characteristics of the creep and long-term strength at 650, 670, and 700°C and 60-140 MPa have been determined in six Russian reactor steels with a bcc structure after quenching and high-temperature tempering. Creep tests were carried out using specially designed longitudinal and transverse microsamples, which were fabricated from the shells of the fuel elements used in the BN-600 fast neutron reactor. It has been found that the creep rate of the reactor bcc steels is determined by the stability of the lath martensitic and ferritic structures in relation to the diffusion processes of recovery and recrystallization. The highest-temperature oxide-free steel contains the maximum amount of the refractory elements and carbides. The steel strengthened by the thermally stable Y-Ti nanooxides has a record high-temperature strength. The creep rate at 700°C and 100 MPa in the samples of this steel is lower by an order of magnitude and the time to fracture is 100 times greater than that in the oxide-free reactor steels.

  9. Eulerian formulation of fluid-structure interaction in reactor containment system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C Y


    This paper is concerned with an Eulerian formulation for a fluid-structure interface developed for the nonlinear fluid-structure interaction analysis encountered in the primary containment and piping components of nuclear reactors. The Eulerian finite difference methodology is chosen because of its decisive abilities in: (1) investigating material motion with large distortions, (2) treating fluid flow around internal structures having a geometrical discontinuity, (3) handling wave transients in the vicinity of perforated structures. The ultimate objective is to perform the analysis of the reactor integrity when subject to the transient load. Two types of irregular cells are considered and their formulation corresponding to the ICE technique are described. The first one is for interfaces between a coolant and a deformable structure, where the fluid slides tangentially along the moving boundary. A relaxation equation is derived here, allowing the adjustment of the pressure on the moving boundary of the fluid by an amount proportional to the actual mass flux across the boundary. The second irregular cell is for fluid adjacent to the perforated structure where fluid flow through coolant passage takes place. A modified Poisson equation is obtained to appropriately account for the volume perforation and the flow-area availability of the perforated structure. These two equations, in conjunction with the governing Poisson equation of the ICE technique, are solved iteratively. Convergence is attained when boundary conditions at all interfaces are satisified. The development scheme enables the implicit Eulerian hydrodynamic techniques to be coupled with any structural dynamic program. Presently, a corotational coordinate finite element program, WHAMS, is employed for calculating the structural response. Three sample problems are presented to illustrate the analysis. The results are discussed.

  10. An Evaluation Report on the High Temperature Design of the KALIMER-600 Reactor Structures

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Gyu; Lee, Jae Han


    This report is on the validity evaluation of high temperature structural design for the reactor structures and piping of the pool-type Liquid Metal Reactor, KALIMER-600 subjected to the high temperature thermal load condition. The structural concept of the Upper Internal Structure located above the core is analyzed and the adequate UIS conceptual design for KALIMER-600 is proposed. Also, the high temperature structural integrity of the thermal liner which is to protect the UIS bottom plate from the high frequency thermal fatigue damage was evaluated by the thermal stripping analysis. The high temperature structural design of the reactor internal structure by considering the reactor startup-shutdown cycle was carried out and the structural integrity of it for a normal operating condition as well as the transient condition of the primary pump trip accident was confirmed. Additionally the structure design of the reactor internal structural was changed to prevent the non-uniform deformation of the primary pump which is induced by the thermal expansion difference between the reactor head and the baffle plate. The arrangement of the IHTS piping system which is a part of the reactor system is carried out and the structural integrity and the accumulated deformation by considering the reactor startup-shutdown cycle of a normal operating condition were evaluated. The structural integrity and the accumulated deformation of the PDRC hot leg piping by considering the PDRC operating condition were evaluated. The validity of KALIMER-600 high temperature structural design is confirmed through this study, and it is clearly found that the methodology research to evaluate the structural integrity considering the reactor life time of 60 years ensured is necessary.

  11. Modular fabrication and characterization of complex silicon carbide composite structures Advanced Reactor Technologies (ART) Research Final Report (Feb 2015 – May 2017)

    Energy Technology Data Exchange (ETDEWEB)

    Khalifa, Hesham [General Atomics, San Diego, CA (United States)


    Advanced ceramic materials exhibit properties that enable safety and fuel cycle efficiency improvements in advanced nuclear reactors. In order to fully exploit these desirable properties, new processing techniques are required to produce the complex geometries inherent to nuclear fuel assemblies and support structures. Through this project, the state of complex SiC-SiC composite fabrication for nuclear components has advanced significantly. New methods to produce complex SiC-SiC composite structures have been demonstrated in the form factors needed for in-core structural components in advanced high temperature nuclear reactors. Advanced characterization techniques have been employed to demonstrate that these complex SiC-SiC composite structures provide the strength, toughness and hermeticity required for service in harsh reactor conditions. The complex structures produced in this project represent a significant step forward in leveraging the excellent high temperature strength, resistance to neutron induced damage, and low neutron cross section of silicon carbide in nuclear applications.

  12. Final Report: Safety of Plasma Components and Aerosol Transport During Hard Disruptions and Accidental Energy Release in Fusion Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bourham, Mohamed A.; Gilligan, John G.


    Safety considerations in large future fusion reactors like ITER are important before licensing the reactor. Several scenarios are considered hazardous, which include safety of plasma-facing components during hard disruptions, high heat fluxes and thermal stresses during normal operation, accidental energy release, and aerosol formation and transport. Disruption events, in large tokamaks like ITER, are expected to produce local heat fluxes on plasma-facing components, which may exceed 100 GW/m{sup 2} over a period of about 0.1 ms. As a result, the surface temperature dramatically increases, which results in surface melting and vaporization, and produces thermal stresses and surface erosion. Plasma-facing components safety issues extends to cover a wide range of possible scenarios, including disruption severity and the impact of plasma-facing components on disruption parameters, accidental energy release and short/long term LOCA's, and formation of airborne particles by convective current transport during a LOVA (water/air ingress disruption) accident scenario. Study, and evaluation of, disruption-induced aerosol generation and mobilization is essential to characterize database on particulate formation and distribution for large future fusion tokamak reactor like ITER. In order to provide database relevant to ITER, the SIRENS electrothermal plasma facility at NCSU has been modified to closely simulate heat fluxes expected in ITER.

  13. 78 FR 57904 - Request for a License To Export; Reactor Components (United States)


    ..., and 1000 (design) spare parts. nuclear reactors. Dated this 16th day of September 2013 in Rockville... eight Construction, China. Mechanical Corporation, August coolant pump AP-1000 (design) maintenance, and...

  14. Dedicated Solutions for Structural Health Monitoring of Aircraft Components


    Pitropakis, Ioannis


    Aircraft structures, like any other mechanical structure, are subjected to various external factors that influence their lifetime. Mechanicalnbsp;and the environment are only some of the factors that can degrade the structure of aircraft components. Monitoring of these degradations by regular inspections or automated data recording is vital for the structural health of the critical components of an aircraft. This research proposes a number of dedicated solutions for structural health monitori...

  15. Development of a Versatile Ultrasonic Internal Pipe/Vessel Component Monitor for In-Service Inspection of Nuclear Reactor Components

    Energy Technology Data Exchange (ETDEWEB)

    Searfass, Clifford T. [Structural Integrity Associates, Inc., State College, PA (United States); Malinowski, Owen M. [Structural Integrity Associates, Inc., State College, PA (United States); Van Velsor, Jason K. [Structural Integrity Associates, Inc., State College, PA (United States)


    The stated goal of this work was to develop a versatile system which could accurately measure vessel and valve internal vibrations and cavitation formation under in-service conditions in nuclear power plants, ultrasonically. The developed technology will benefit the nuclear power generation industry by allowing plant operators to monitor valve and vessel internals during operation. This will help reduce planned outages and plant component failures. During the course of this work, Structural Integrity Associates, Inc. gathered information from industry experts that target vibration amplitudes to be detected should be in the range of 0.001-in to 0.005-in (0.025-mm to 0.127-mm) and target vibration frequency ranges which should be detected were found to be between 0-Hz and 300-Hz. During the performed work, an ultrasonic measuring system was developed which utilized ultrasonic pulse-echo time-of-flight measurements to measure vibration frequency and amplitude. The developed system has been shown to be able to measure vibration amplitudes as low as 0.0008-in (0.020-mm) with vibration frequencies in the range of 17-Hz to 1000-Hz. Therefore, the developed system was able to meet the industry needs for vibration measurement. The developed ultrasonic system was also to be able to measure cavitation formation by monitoring the received ultrasonic time- and frequency-domain signals. This work also demonstrated the survivability of commercially available probes at temperatures up to 300-F for several weeks.

  16. Structural analysis of fuel rod applied to pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Danilo P.; Pinheiro, Andre Ricardo M.; Lotto, André A., E-mail: [Centro Tecnológico da Marinha em São Paulo (CTMSP), São Paulo, SP (Brazil)


    The design of fuel assemblies applied to Pressurized Water Reactors (PWR) has several requirements and acceptance criteria that must be attended for licensing. In the case of PWR fuel rods, an important mechanical structural requirement is to keep the radial stability when submitted to the coolant external pressure. In the framework of the Accident Tolerant Fuel (ATF) program new materials have been studied to replace zirconium based alloys as cladding, including iron-based alloys. In this sense, efforts have been made to evaluate the behavior of these materials under PWR conditions. The present work aims to evaluate the collapse cold pressure of a stainless steel thin-walled tube similar to that used as cladding material of fuel rods by means of the comparison of numeric data, and experimental results. As a result of the simulations, it was observed that the collapse pressure has a value intermediate value between those found by regulatory requirements and analytical calculations. The experiment was carried out for the validation of the computational model using test specimens of thin-walled tubes considering empty tube. The test specimens were sealed at both ends by means of welding. They were subjected to a high pressure device until the collapse of the tubes. Preliminary results obtained from experiments with the empty test specimens indicate that the computational model can be validated for stainless steel cladding, considering the difference between collapse pressure indicated in the regulatory document and the actual limit pressure concerning to radial instability of tubes with the studied characteristics. (author)

  17. Factor structure underlying components of allostatic load.

    Directory of Open Access Journals (Sweden)

    Jeanne M McCaffery

    Full Text Available Allostatic load is a commonly used metric of health risk based on the hypothesis that recurrent exposure to environmental demands (e.g., stress engenders a progressive dysregulation of multiple physiological systems. Prominent indicators of response to environmental challenges, such as stress-related hormones, sympatho-vagal balance, or inflammatory cytokines, comprise primary allostatic mediators. Secondary mediators reflect ensuing biological alterations that accumulate over time and confer risk for clinical disease but overlap substantially with a second metric of health risk, the metabolic syndrome. Whether allostatic load mediators covary and thus warrant treatment as a unitary construct remains to be established and, in particular, the relation of allostatic load parameters to the metabolic syndrome requires elucidation. Here, we employ confirmatory factor analysis to test: 1 whether a single common factor underlies variation in physiological systems associated with allostatic load; and 2 whether allostatic load parameters continue to load on a single common factor if a second factor representing the metabolic syndrome is also modeled. Participants were 645 adults from Allegheny County, PA (30-54 years old, 82% non-Hispanic white, 52% female who were free of confounding medications. Model fitting supported a single, second-order factor underlying variance in the allostatic load components available in this study (metabolic, inflammatory and vagal measures. Further, this common factor reflecting covariation among allostatic load components persisted when a latent factor representing metabolic syndrome facets was conjointly modeled. Overall, this study provides novel evidence that the modeled allostatic load components do share common variance as hypothesized. Moreover, the common variance suggests the existence of statistical coherence above and beyond that attributable to the metabolic syndrome.

  18. Study of EAS neutron component temporal structure (United States)

    Gromushkin, D. M.; Petrukhin, A. A.; Stenkin, Yu. V.; Yashin, I. I.


    The neutron component of Extensive Air Showers (EAS) carries information about the primary cosmic ray flux as well as about parameters of hadronic interactions at ultra-high energies. We present here the data obtained with the "Neutron" array which is a prototype of a novel type EAS array PRISMA (Stenkin, 2009). The prototype consists of 5 large area scintillator detectors (0.75 m2 each) placed in the corners and in the center of 5 m side square. The scintillator consisting of an alloy of ZnS(Ag) and 6LiF is shaped as a thin layer of grains covered with thin transparent plastic film.

  19. Polymer matrix nanocomposites for automotive structural components. (United States)

    Naskar, Amit K; Keum, Jong K; Boeman, Raymond G


    Over the past several decades, the automotive industry has expended significant effort to develop lightweight parts from new easy-to-process polymeric nanocomposites. These materials have been particularly attractive because they can increase fuel efficiency and reduce greenhouse gas emissions. However, attempts to reinforce soft matrices by nanoscale reinforcing agents at commercially deployable scales have been only sporadically successful to date. This situation is due primarily to the lack of fundamental understanding of how multiscale interfacial interactions and the resultant structures affect the properties of polymer nanocomposites. In this Perspective, we critically evaluate the state of the art in the field and propose a possible path that may help to overcome these barriers. Only once we achieve a deeper understanding of the structure-properties relationship of polymer matrix nanocomposites will we be able to develop novel structural nanocomposites with enhanced mechanical properties for automotive applications.

  20. Conversion of Tobacco Biomass to Flavor Components by Means of Microwave and Parr Reactors

    Directory of Open Access Journals (Sweden)

    Ara Katayoun Mahdavi


    Full Text Available In the present work, microwave and Parr reactors were utilized for synthesis of pyrazines from plant-based biomass in the presence of ammonia and different amino acids. Using these techniques led to synthesis of a relatively wide range of pyrazines with sweet odor and chocolate-like smell. The optimum synthetic conditions to have maximum pyrazine yield for both the microwave and Parr reactions were 41 g of fructose/glucose syrup derived from cellulosic biomass, 28 mL NH4OH (30%, and 0.96 g L-threonine, 0.56 g L-valine, 0.5 g L-leucine, and 0.5 g L-isoleucine at 120 °C for 30 min. Quantitative results obtained via gas chromatography-mass spectrometry (GC-MS using the traditional open-heated oil bath method have been compared with data obtained via microwave and Parr reactors. In these two latter methods, sealed vessels under high pressure and higher temperature were used. The yield of synthesized pyrazines increased dramatically with both microwave and Parr reactors. Surprisingly, the yield of synthesized pyrazines was both reproducible and nearly two times higher via the Parr reactor than that observed with the microwave reactor under comparable conditions.

  1. Production of specific-structured lipids by enzymatic interesterification in a pilot continuous enzyme bed reactor

    DEFF Research Database (Denmark)

    Xu, Xuebing; Balchen, Steen; Høy, Carl-Erik


    Production of specific-structured lipids (interesterified lipids with a specific structure) by enzymatic interesterification was carried out in a continuous enzyme bed pilot scale reactor. Commercial immobilized lipase (Lipozyme IM) was used and investigations of acyl migration, pressure drop......, water dependence, production efficiency and other basic features of the process were performed. The extent of acyl migration (defined as a side reaction) occurring in the present enzyme bed reactor was compared to that in a pilot batch reactor. The continuous enzyme bed reactor was better than the batch...... reactor in minimizing acyl migration. Generally the former produced about one fourth the acyl migration produced by the latter at a similar extent of incorporation. Pressure drop and production efficiency were evaluated in order to obtain a suitable yield in one reaction step. High incorporation...

  2. Light Water Reactor Sustainability Program Advanced Seismic Soil Structure Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bolisetti, Chandrakanth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin Leigh [Idaho National Lab. (INL), Idaho Falls, ID (United States)


    Risk calculations should focus on providing best estimate results, and associated insights, for evaluation and decision-making. Specifically, seismic probabilistic risk assessments (SPRAs) are intended to provide best estimates of the various combinations of structural and equipment failures that can lead to a seismic induced core damage event. However, in some instances the current SPRA approach has large uncertainties, and potentially masks other important events (for instance, it was not the seismic motions that caused the Fukushima core melt events, but the tsunami ingress into the facility). SPRA’s are performed by convolving the seismic hazard (this is the estimate of all likely damaging earthquakes at the site of interest) with the seismic fragility (the conditional probability of failure of a structure, system, or component given the occurrence of earthquake ground motion). In this calculation, there are three main pieces to seismic risk quantification, 1) seismic hazard and nuclear power plants (NPPs) response to the hazard, 2) fragility or capacity of structures, systems and components (SSC), and 3) systems analysis. Two areas where NLSSI effects may be important in SPRA calculations are, 1) when calculating in-structure response at the area of interest, and 2) calculation of seismic fragilities (current fragility calculations assume a lognormal distribution for probability of failure of components). Some important effects when using NLSSI in the SPRA calculation process include, 1) gapping and sliding, 2) inclined seismic waves coupled with gapping and sliding of foundations atop soil, 3) inclined seismic waves coupled with gapping and sliding of deeply embedded structures, 4) soil dilatancy, 5) soil liquefaction, 6) surface waves, 7) buoyancy, 8) concrete cracking and 9) seismic isolation The focus of the research task presented here-in is on implementation of NLSSI into the SPRA calculation process when calculating in-structure response at the area

  3. Electronics speckle interferometry applications for NDE of spacecraft structural components (United States)

    Rao, M. V.; Samuel, R.; Ananthan, A.; Dasgupta, S.; Nair, P. S.


    The spacecraft components viz., central cylinder, deck plates, solar panel substrates, antenna reflectors are made of aluminium/composite honeycomb sandwich construction. Detection of these defects spacecraft structural components is important to assess the integrity of the spacecraft structure. Electronic Speckle Interferometry (ESI) techniques identify the defects as anomalous regions in the interferometric fringe patterns of the specklegram while the component is suitably stressed to give rise to differential displacement/strain around the defective region. Calibration studies, different phase shifting methods associated with ESI and the development of a prototype Twin Head ESSI System (THESSIS) and its use for the NDE of a typical satellite structural component are presented.

  4. The nuclear data, A key component for reactor studies, Overview of AREVA NP needs and applications


    Ravaux Simon; Demy Pierre-Marie; Rechatin Clément


    The quality of the nuclear data is essential for AREVA NP. Indeed, many AREVA NP activities such as reactor design, safety studies or reactor instrumentation use them as input data. So, the nuclear data can be considered as a key element for AREVA NP. REVA NP’s contribution in the improvement of the nuclear data consists in a joint effort with the CEA. It means a financing and a sharing of information which can give an orientation to the future research axis. The aim of this article is to pre...

  5. High pressure water abrasive suspension JET cutting - An innovative cutting technology for the dismantling of reactor core components

    Energy Technology Data Exchange (ETDEWEB)

    Kalwa, H. [VAK, Kahl (Germany); Schwarz, T. [RWE NUKEM Limited, B7 Windscale, Seascale, Cumbria CA20 1PF (United Kingdom)


    In the frame of decommissioning of nuclear facilities the dismantling of reactor pressure vessels and their internals represent one special challenge. Due to their high activation, associated high dose rate levels, and to some extent the complex geometry and high material thickness of the components, there are particular demands for dismantling techniques. The task is to safely and economically work in every respect and therefore employ techniques with a wide area of application. As a proven technique, RWE NUKEM offers High Pressure Water Abrasive Suspension Jet Cutting. High pressure Water Abrasive Suspension Jet cutting (WASJ), well established in non-nuclear applications, has now been upgraded to meet the demands of decommissioning in the nuclear industry. The application at the Nuclear Power Plant in Kahl (VAK) was one of the first industrial scale applications. Based on several tests and parametric studies, High Water Abrasive Suspension Jet Cutting was tested against other cutting technologies. Because the overall performance in terms of fast and easy cutting operations, ability for remote handling, production of secondary waste WASJ was chosen at VAK Kahl for the dismantling of the lower core shroud and the reactor pressure vessel itself. The dismantling of the core shroud and the reactor vessel took place in-situ (component in its built-in position) using the WASJ technology. As example of application the core shroud of VAK is given. The total mass of the VAK lower shroud was about 3 tons and the wall thickness varied from 30 to 135 mm. The shroud was cut into segments in its in-vessel position, each segment being 500 x 900 mm and having a mass of about 0.25 tons. Cutting was performed in such a way that the separated pieces could be loaded directly into standard waste containers. All secondary waste (abrasives and dross) was collected in two 200 liter drums and, after drying, the drums were sent directly to waste storage. Reactor Pressure Vessel of VAK

  6. Database structure and file layout of Nuclear Power Plant Database. Database for design information on Light Water Reactors in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Nobuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Izumi, Fumio


    The Nuclear Power Plant Database (PPD) has been developed at the Japan Atomic Energy Research Institute (JAERI) to provide plant design information on domestic Light Water Reactors (LWRs) to be used for nuclear safety research and so forth. This database can run on the main frame computer in the JAERI Tokai Establishment. The PPD contains the information on the plant design concepts, the numbers, capacities, materials, structures and types of equipment and components, etc, based on the safety analysis reports of the domestic LWRs. This report describes the details of the PPD focusing on the database structure and layout of data files so that the users can utilize it efficiently. (author).

  7. Development of fuels and structural materials for fast breeder reactors

    Indian Academy of Sciences (India)

    Fast breeder reactors (FBRs) are destined to play a crucial role inthe Indian nuclear power programme in the foreseeable future. FBR technology involves a multi-disciplinary approach to solve the various challenges in the areas of fuel and materials development. Fuels for FBRs have significantly higher concentration of ...

  8. The nuclear data, A key component for reactor studies, Overview of AREVA NP needs and applications

    Directory of Open Access Journals (Sweden)

    Ravaux Simon


    Full Text Available The quality of the nuclear data is essential for AREVA NP. Indeed, many AREVA NP activities such as reactor design, safety studies or reactor instrumentation use them as input data. So, the nuclear data can be considered as a key element for AREVA NP. REVA NP’s contribution in the improvement of the nuclear data consists in a joint effort with the CEA. It means a financing and a sharing of information which can give an orientation to the future research axis. The aim of this article is to present the industrial point of view from AREVA NP on the research on nuclear data. Several examples of collaborations with the CEA which have resulted in an improvement of the nuclear data are presented.

  9. The nuclear data, A key component for reactor studies, Overview of AREVA NP needs and applications (United States)

    Ravaux, Simon; Demy, Pierre-Marie; Rechatin, Clément


    The quality of the nuclear data is essential for AREVA NP. Indeed, many AREVA NP activities such as reactor design, safety studies or reactor instrumentation use them as input data. So, the nuclear data can be considered as a key element for AREVA NP. REVA NP's contribution in the improvement of the nuclear data consists in a joint effort with the CEA. It means a financing and a sharing of information which can give an orientation to the future research axis. The aim of this article is to present the industrial point of view from AREVA NP on the research on nuclear data. Several examples of collaborations with the CEA which have resulted in an improvement of the nuclear data are presented.


    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A.; Reigel, M.


    The Department of Energy (DOE) intends to close 100-150 facilities in the DOE complex using an in situ decommissioning (ISD) strategy that calls for grouting the below-grade interior volume of the structure and leaving the above-grade interior open or demolishing it and disposing of it in the slit trenches in E Area. These closures are expected to persist and remain stable for centuries, but there are neither facility-specific monitoring approaches nor studies on the rate of deterioration of the materials used in the original construction or on the ISD components added during closure (caps, sloped roofs, etc). This report will focus on the evaluation of the actual aging/degradation of the materials of construction used in the ISD structures at Savannah River Site (SRS) above grade, specifically P & R reactor buildings. Concrete blocks (six 2 to 5 ton blocks) removed from the outer wall of the P Reactor Building were turned over to SRNL as the first source for concrete cores. Larger cores were received as a result of grouting activities in P and R reactor facilities. The cores were sectioned and evaluated using microscopy, x-ray diffraction (XRD), ion chromatography (IC) and thermal analysis. Scanning electron microscopy shows that the aggregate and cement phases present in the concrete are consistent with the mix design and no degradation mechanisms are evident at the aggregate-cement interfaces. Samples of the cores were digested and analyzed for chloride ingress as well as sulfate attack. The concentrations of chloride and sulfate ions did not exceed the limits of the mix design and there is no indication of any degradation due to these mechanisms. Thermal analysis on samples taken along the longitudinal axis of the cores show that there is a 1 inch carbonation layer (i.e., no portlandite) present in the interior wall of the reactor building and a negligible carbonation layer in the exterior wall. A mixed layer of carbonate and portlandite extends deeper into the

  11. Optimization of composite wood structural components : processing and design choices (United States)

    Theodore L. Laufenberg


    Decreasing size and quality of the world's forest resources are responsible for interest in producing composite wood structural components. Process and design optimization methods are offered in this paper. Processing concepts for wood composite structural products are reviewed to illustrate manufacturing boundaries and areas of high potential. Structural...

  12. Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor (United States)

    Polzin, Kurt A.; Godfroy, Thomas J.


    A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 5 psi, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.5 GPM.

  13. Evaluation of induced radioactivity in structural material of Toshiba Training Reactor 'TTR1'. (United States)

    Uematsu, Mikio; Kurosawa, Masahiko; Haruguchi, Yoshiko


    A decommissioning programme for the Toshiba Training Reactor (TTR1), a swimming pool type reactor used for reactor physics experiments and material irradiation, was started in August 2001. As a part of the programme, induced radioactivity in structural material was evaluated using neutron flux data obtained with the three-dimensional Sn code TORT. Induced activity was calculated with the isotope generation code ORIGEN-79 using activation cross section data created from multi-group library based on JENDL-3. The obtained results for radioactivities such as 60Co, 65Zn, 54Mn and 152Eu were compared with measured ones, and the present calculational method was confirmed to have enough accuracy.

  14. Vibration test on KMRR reactor structure and primary cooling system piping

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Seung Hoh; Kim, Tae Ryong; Park, Jin Hoh; Park, Jin Suk; Ryoo, Jung Soo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)


    Most equipments, piping systems and reactor structures in nuclear power plants are subjected to flow induced vibration due to high temperature and high pressure coolant flowing inside or outside of the equipments, systems and structures. Because the flow induced vibration sometimes causes significant damage to reactor structures and piping systems, it is important and necessary to evaluate the vibration effect on them and to prove their structural integrity. Korea Multipurpose Research Reactor (KMRR) being constructed by KAERI is 30 MWt pool type research reactor. Since its main structures and piping systems were designed and manufactured in accordance with the standards and guidelines for commercial nuclear power plant, it was decided to evaluate their vibratory response in accordance with the standards and guidelines for commercial NPP. The objective of this vibration test is the assessment of vibration levels of KMRR reactor structure and primary cooling piping system for their structural integrity under the steady-state or transient operating condition. 38 figs, 14 tabs, 2 refs. (Author).

  15. Probabilistic Structural Integrity Analysis of Boiling Water Reactor Pressure Vessel under Low Temperature Overpressure Event

    Directory of Open Access Journals (Sweden)

    Hsoung-Wei Chou


    Full Text Available The probabilistic structural integrity of a Taiwan domestic boiling water reactor pressure vessel has been evaluated by the probabilistic fracture mechanics analysis. First, the analysis model was built for the beltline region of the reactor pressure vessel considering the plant specific data. Meanwhile, the flaw models which comprehensively simulate all kinds of preexisting flaws along the vessel wall were employed here. The low temperature overpressure transient which has been concluded to be the severest accident for a boiling water reactor pressure vessel was considered as the loading condition. It is indicated that the fracture mostly happens near the fusion-line area of axial welds but with negligible failure risk. The calculated results indicate that the domestic reactor pressure vessel has sufficient structural integrity until doubling of the present end-of-license operation.

  16. Mixing-Structure Relationship in Jet-Stirred Reactors

    KAUST Repository

    Ayass, Wassim W.


    In this study, measurements were performed to assess the overall mixing in jet-stirred reactors (JSRs) passively agitated by feed nozzles. The reactor diameter, nozzle shape, and nozzle diameter were varied to determine the effects of these geometrical parameters on mixing. The mixing was studied at ambient conditions using laser absorption spectroscopy to follow the exit concentration of a tracer gas, carbon dioxide, after a step change in its input flow. The results indicate that the use of a JSR of diameter D = 40 mm, having inclined or crossed nozzles of diameter d = 1 mm is recommended for low residence times up to 0.4 sec, while at moderate/high residence times 0.5-5 sec the use of a JSR of D = 56 mm and d = 0.3 mm having crossed nozzles is suggested.

  17. 3D printed components with ultrasonically arranged microscale structure


    Llewellyn-Jones, Thomas M; Drinkwater, Bruce W.; Trask, Richard S.


    This paper shows the first application of in situ manipulation of discontinuous fibrous structure mid-print, within a 3D printed polymeric composite architecture. Currently, rapid prototyping methods (fused filament fabrication, stereolithography) are gaining increasing popularity within the engineering commnity to build structural components. Unfortunately, the full potential of these components is limited by the mechanical properties of the materials used. The aim of this study is to create...

  18. Applications of holographic interferometry for spacecraft structural components (United States)

    Rao, M. V.; Samuel, R.; Nair, P. S.


    An overview of the applications of holographic interferometry for spacecraft structural components at ISRO Satellite Center, Bangalore, India, is presented. The details of the development of a dual vacuum stressing technique and its application for holographic nondestructive testing (HNDT) of honeycomb panels are presented. Results of some calibration studies conducted for HNDT of propellant tanks are also presented. It is found that holographic interferometry is quite useful, particularly for HNDT of honeycomb panels and propellant tanks used for spacecraft structural components.

  19. Structure analysis of a reactor pressure vessel by two- and three-dimensional models. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, H.; Mayr, M.


    This paper investigates the reactor pressure vessel of a 1300 MW pressurised water reactor. In order to determine the stresses and deformations of the vessel, two- and three-dimensional finite element models are used which represent the real structure with different degrees of accuracy. The results achieved by these different models are compared for the case of the transient called ''Start up of the nuclear power plant''. 5 refs.

  20. Nuclear reactor melt-retention structure to mitigate direct containment heating (United States)

    Tutu, Narinder K.; Ginsberg, Theodore; Klages, John R.


    A light water nuclear reactor melt-retention structure to mitigate the extent of direct containment heating of the reactor containment building. The structure includes a retention chamber for retaining molten core material away from the upper regions of the reactor containment building when a severe accident causes the bottom of the pressure vessel of the reactor to fail and discharge such molten material under high pressure through the reactor cavity into the retention chamber. In combination with the melt-retention chamber there is provided a passageway that includes molten core droplet deflector vanes and has gas vent means in its upper surface, which means are operable to deflect molten core droplets into the retention chamber while allowing high pressure steam and gases to be vented into the upper regions of the containment building. A plurality of platforms are mounted within the passageway and the melt-retention structure to direct the flow of molten core material and help retain it within the melt-retention chamber. In addition, ribs are mounted at spaced positions on the floor of the melt-retention chamber, and grid means are positioned at the entrance side of the retention chamber. The grid means develop gas back pressure that helps separate the molten core droplets from discharged high pressure steam and gases, thereby forcing the steam and gases to vent into the upper regions of the reactor containment building.

  1. 10 CFR 50.69 - Risk-informed categorization and treatment of structures, systems and components for nuclear... (United States)


    ..., systems and components for nuclear power reactors. 50.69 Section 50.69 Energy NUCLEAR REGULATORY..., systems and components for nuclear power reactors. (a) Definitions. Risk-Informed Safety Class (RISC)-1... holder of a license to operate a light water reactor (LWR) nuclear power plant under this part; a holder...

  2. Joining and fabrication techniques for high temperature structures including the first wall in fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Jin; Lee, B. S.; Kim, K. B


    The materials for PFC's (Plasma Facing Components) in a fusion reactor are severely irradiated with fusion products in facing the high temperature plasma during the operation. The refractory materials can be maintained their excellent properties in severe operating condition by lowering surface temperature by bonding them to the high thermal conducting materials of heat sink. Hence, the joining and bonding techniques between dissimilar materials is considered to be important in case of the fusion reactor or nuclear reactor which is operated at high temperature. The first wall in the fusion reactor is heated to approximately 1000 .deg. C and irradiated severely by the plasma. In ITER, beryllium is expected as the primary armour candidate for the PFC's; other candidates including W, Mo, SiC, B4C, C/C and Si{sub 3}N{sub 4}. Since the heat affected zones in the PFC's processed by conventional welding are reported to have embrittlement and degradation in the sever operation condition, both brazing and diffusion bonding are being considered as prime candidates for the joining technique. In this report, both the materials including ceramics and the fabrication techniques including joining technique between dissimilar materials for PFC's are described. The described joining technique between the refractory materials and the dissimilar materials may be applicable for the fusion reactor and Generation-4 future nuclear reactor which are operated at high temperature and high irradiation.

  3. Structure learning by pruning in independent component analysis

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch; Hansen, Lars Kai


    We discuss pruning as a means of structure learning in independent component analysis (ICA). Learning the structure is attractive in both signal processing and in analysis of abstract data, where it can assist model interpretation, generalizability and reduce computation. We derive the relevant...

  4. Protein structure similarity from principle component correlation analysis

    Directory of Open Access Journals (Sweden)

    Chou James


    Full Text Available Abstract Background Owing to rapid expansion of protein structure databases in recent years, methods of structure comparison are becoming increasingly effective and important in revealing novel information on functional properties of proteins and their roles in the grand scheme of evolutionary biology. Currently, the structural similarity between two proteins is measured by the root-mean-square-deviation (RMSD in their best-superimposed atomic coordinates. RMSD is the golden rule of measuring structural similarity when the structures are nearly identical; it, however, fails to detect the higher order topological similarities in proteins evolved into different shapes. We propose new algorithms for extracting geometrical invariants of proteins that can be effectively used to identify homologous protein structures or topologies in order to quantify both close and remote structural similarities. Results We measure structural similarity between proteins by correlating the principle components of their secondary structure interaction matrix. In our approach, the Principle Component Correlation (PCC analysis, a symmetric interaction matrix for a protein structure is constructed with relationship parameters between secondary elements that can take the form of distance, orientation, or other relevant structural invariants. When using a distance-based construction in the presence or absence of encoded N to C terminal sense, there are strong correlations between the principle components of interaction matrices of structurally or topologically similar proteins. Conclusion The PCC method is extensively tested for protein structures that belong to the same topological class but are significantly different by RMSD measure. The PCC analysis can also differentiate proteins having similar shapes but different topological arrangements. Additionally, we demonstrate that when using two independently defined interaction matrices, comparison of their maximum

  5. A Self-Switchable Polymer Reactor for Controlled Catalytic Chemistry Processes with a Hyperbranched Structure

    Directory of Open Access Journals (Sweden)

    Rong Luo


    Full Text Available A self-switchable polymer reactor with a hyperbranched structure for controlled catalytic chemistry processes is reported. This polymer reactor was made of silver nanoparticles and a polymer carrier consisting of hyperbranched polyethylenimine and hydroxyethyl acrylate that behaved as thermally switchable domains. Below the transfer temperature, relatively strong catalytic reactivity was demonstrated due to the leading role of hydrophilic groups in the switchable domains, which opened access to the substrate for the packaged silver nanoparticles. In contrast, it showed weak catalysis at relatively high temperatures, reducing from the significantly increased hydrophobicity in the switchable domains. In this way, the polymer reactor displays controllable, tunable, catalytic activity based on this approach. This novel design opens up the opportunity to develop intelligent polymer reactors for controlled catalytic processes.

  6. Specificities of micro-structured reactors for hydrogen production and purification

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, N.; Germani, G.; Van Veen, A.C.; Schuurman, Y.; Mirodatos, C. [Institut de Recherches sur la Catalyse - CNRS, 2, Avenue Albert Einstein, 69626 Villeurbanne Cedex (France); Schaefer, G. [Atotech Deutschland GmbH, PO Box 210780, 10507 Berlin (Germany)


    This paper presents the specificities of micro-structured reactors as compared to conventional fixed-bed reactors through two case studies devoted to (i) hydrogen production by methanol steam reforming, (ii) hydrogen purification by water-gas shift (WGS). Key features like catalyst coating stability, temperature and pressure management, effects of operating conditions (residence time, pressure drops, etc.) are well identified as controlling the micro-reactor performances for methanol reforming. These devices are also shown to be excellent tools for fast access to reaction kinetics as exemplified for the WGS reaction, subject to operating conditions carefully chosen to ensure proper hydrodynamics, in order to use conventional plug flow reactor models for extracting rate constants. (author)

  7. OECD - HRP Summer School on Light Water Reactor Structural Materials. August 26th - 30th, 2002

    Energy Technology Data Exchange (ETDEWEB)



    In cooperation with the OECD Nuclear Energy Agency (NEA), the Halden Reactor Project organised a Summer School on Light Water Reactor Structural Materials in the period August 26 - 30, 2002. The summer school was primarily intended for people who wanted to become acquainted with materials-related subjects and issues without being experts. It is especially hoped that the summer school served to transfer knowledge to the ''young generation'' in the field of nuclear. Experts from Halden Project member organisations were solicited for the following programme: (1) Overview of The Nuclear Community and Current Issues, (2) Regulatory Framework for Ensuring Structural Integrity, (3) Non-Destructive Testing for Detection of Cracks, (4) Part I - Basics of Radiation and Radiation Damage, (5) Part II - Radiation Effects on Reactor Internal Materials, (6) Water Chemistry and Radiolysis Effects in LWRs, (7) PWR and Fast Breeder Reactor Internals, (8) PWR and Fast Breeder Reactor Internals, (9) Secondary Side Corrosion Cracking of PWR Steam Generator Tubes, (10) BWR Materials and Their Interaction with the Environment, (11) Radiation Damage in Reactor Pressure Vessels.

  8. Engineering review of the core support structure of the Gas Cooled Fast Breeder Reactor

    Energy Technology Data Exchange (ETDEWEB)



    The review of the core support structure of the gas cooled fast breeder reactor (GCFR) covered such areas as the design criteria, the design and analysis of the concepts, the development plan, and the projected manufacturing costs. Recommendations are provided to establish a basis for future work on the GCFR core support structure.

  9. Evaluation of thermal protection structure mechanism of LMR reactor vessels and design improvement for thermal stress reduction

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Koo, Gyeong Hoi; Kim, Jong Bum; Kim, Seok Hun; Lee, Jae Han


    LMR reactor vessels operated in high temperature have a severe thermal damage due to the significant temperature gradient in the hot pool free surface regions of reactor vessel. The thermal protection mechanism of LMR reactor vessel should be designed for the structural integrity in high temperature condition. In this study, the thermal protection mechanism of foreign LMR reactor vessels is investigated for the power upgrade of KALIMER and the modified reactor baffle design with a Y-piece type structure is proposed for the reduction of thermal damage for KALIMER reactor vessel. The modified reactor baffle design leads to reduce the thermal damage such as creep-fatigue and ratcheting in the transient operation condition.

  10. Fluid flow structure around the mixer in a reactor with mechanical mixing

    Energy Technology Data Exchange (ETDEWEB)

    Lecheva, A., E-mail: [Department of Mathematics, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria); Zheleva, I., E-mail: [Department of Heat Technology, Hydraulics and Ecology, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria)


    Fluid flow structure around the mixer in a cylindrical reactor with mechanical mixing is studied and numerical results are presented in this article. The model area is complex because of the presence of convex corners of the mixer in the fluid flow. Proper boundary conditions for the vorticity calculated on the base of the stream function values near solid boundaries of the examined area are presented. The boundary value problem of motion of swirling incompressible viscous fluid in a vertical tank reactor with a mixer is solved numerically. The calculations are made by a computer code, written in MATLAB. The complex structure of the flow around the mixing disk is described and commented.

  11. Micronutrient component changes in the biogas slurry treated by a pilot solar-heated anaerobic reactor (United States)

    Yang, Z. Y.; Xu, Y. B.; Li, P. F.; Wang, Y. J.; Sun, J.; Zhang, Y. P.


    A solar-heated anaerobic reactor system was applied to decompose livestock wastewater, in which cattle manure and chopped straw were mixed (CODCr 15,000∼25,000 mg·l-1), the commercial microorganisms were added to ambient acidification (about 32°C) and the acclimated sludge was inoculated. Then, the experiments were carried out on wastewater anaerobic degradation and biogas production at 40∼42°C, as fed every 10 days till stable running. The results showed that NH3-N and PO4 3- of the biogas slurry were 441 mg·l-1 and 65.0 mg·l-1 on the 35th day, respectively. The concentration of K was up to 350 mg·l-1 in the biogas slurry, rather higher than that of Mg and Fe, which indicated that the available K could contribute more in the agricultural irrigation. Total amino acids were up to 23.7 mg·l-1 after anaerobic digestion, in which Lys, Thr, Ala and Arg were prominent in the biogas slurry. These amino acids could be beneficial to seed soaking, feed adding and apply as foliar fertilizer. The major volatile organic compounds were detected in the biogas slurry, including toluene, m-cresol (up to 0.036% in the process of ambient acidification) and triethylsilane, which could be reduced to scarcely influence on agricultural application after anaerobic digestion.

  12. Continuous electrochemical treatment of simulated industrial textile wastewater from industrial components in a tubular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Koerbahti, Bahadir K., E-mail: [Faculty of Engineering, Department of Chemical Engineering, University of Mersin, Ciftlikkoey, 33343 Mersin (Turkey); Tanyolac, Abdurrahman, E-mail: [Faculty of Engineering, Department of Chemical Engineering, Hacettepe University, Beytepe, 06800 Ankara (Turkey)


    The continuous electrochemical treatment of industrial textile wastewater in a tubular reactor was investigated. The synthetic wastewater was based on the real process information of pretreatment and dyeing stages of the industrial mercerized and non-mercerized cotton and viscon production. The effects of residence time on chemical oxygen demand (COD), color and turbidity removals and pH change were studied under response surface optimized conditions of 30 deg. C, 25 g/L electrolyte concentration and 3505 mg/L COD feed concentration with 123.97 mA/cm{sup 2} current density. Increasing residence time resulted in steady profiles of COD and color removals with higher treatment performances. The best column performance was realized at 3 h of residence time as 53.5% and 99.3% for COD and color removals, respectively, at the expense of 193.1 kWh/kg COD with a mass transfer coefficient of 9.47 x 10{sup -6} m/s.

  13. Insights for aging management of light water reactor components: Metal containments. Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    Shah, V.N.; Sinha, U.P. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Smith, S.K. [Ogden Environmental and Energy Services, Southfield, MI (United States)


    This report evaluates the available technical information and field experience related to management of aging damage to light water reactor metal containments. A generic aging management approach is suggested for the effective and comprehensive aging management of metal containments to ensure their safe operation. The major concern is corrosion of the embedded portion of the containment vessel and detection of this damage. The electromagnetic acoustic transducer and half-cell potential measurement are potential techniques to detect corrosion damage in the embedded portion of the containment vessel. Other corrosion-related concerns include inspection of corrosion damage on the inaccessible side of BWR Mark I and Mark II containment vessels and corrosion of the BWR Mark I torus and emergency core cooling system piping that penetrates the torus, and transgranular stress corrosion cracking of the penetration bellows. Fatigue-related concerns include reduction in the fatigue life (a) of a vessel caused by roughness of the corroded vessel surface and (b) of bellows because of any physical damage. Maintenance of surface coatings and sealant at the metal-concrete interface is the best protection against corrosion of the vessel.

  14. Cladding Effects on Structural Integrity of Nuclear Components

    Energy Technology Data Exchange (ETDEWEB)

    Sattari-Far, Iradi; Andersson, Magnus [lnspecta Technology AB, Stockholm (Sweden)


    Based on this study, the following conclusions and recommendations can be made: Due to significant differences in the thermal and mechanical properties between the austenitic cladding and the ferritic base metal, residual stresses are induced in the cladding and the underlying base metal. These stresses are left in clad components even after Post-Weld Heat Treatment (PWHT). The different restraint conditions of the clad component have a minor influence on the magnitude of the cladding residual stresses in the cladding layer. The thickness of the clad object is the main impacting geometrical dimension in developing cladding residual stresses. A clad object having a base material thickness exceeding 10 times the cladding thickness would be practically sufficient to introduce cladding residual stresses of a thick reactor pressure vessel. For a clad component that received PWHT, the peak tensile stress is in the cladding layer, and the residual stresses in the underlying base material are negligible. However, for clad components not receiving PWHT, for instance the repair welding of the cladding, the cladding residual stresses of tensile type exist even in the base material. This implies a higher risk for underclad cracking for clad repairs that received no PWHT. For certain clad geometries, like nozzles, the profile of the cladding residual stresses depends on the clad thickness and position, and significant tensile stresses can also exist in the base material. Based on different measurements reported in the literature, a value of 150 GPa can be used as Young's Modulus of the austenitic cladding material at room temperature. The control measurements of small samples from the irradiated reactor pressure vessel head did not reveal a significant difference of Young's Modulus between the irradiated and the unirradiated cladding material condition. No significant differences between the axial and tangential cladding residual stresses are reported in the

  15. Balance of Plant System Analysis and Component Design of Turbo-Machinery for High Temperature Gas Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ballinger, Ronald G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Wang, Chun Yun [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Kadak, Andrew [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Todreas, Neil [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Mirick, Bradley [Concepts, Northern Engineering and Research, Woburn, MA (United States); Demetri, Eli [Concepts, Northern Engineering and Research, Woburn, MA (United States); Koronowski, Martin [Concepts, Northern Engineering and Research, Woburn, MA (United States)


    The Modular Pebble Bed Reactor system (MPBR) requires a gas turbine cycle (Brayton cycle) as the power conversion system for it to achieve economic competitiveness as a Generation IV nuclear system. The availability of controllable helium turbomachinery and compact heat exchangers are thus the critical enabling technology for the gas turbine cycle. The development of an initial reference design for an indirect helium cycle has been accomplished with the overriding constraint that this design could be built with existing technology and complies with all current codes and standards. Using the initial reference design, limiting features were identified. Finally, an optimized reference design was developed by identifying key advances in the technology that could reasonably be expected to be achieved with limited R&D. This final reference design is an indirect, intercooled and recuperated cycle consisting of a three-shaft arrangement for the turbomachinery system. A critical part of the design process involved the interaction between individual component design and overall plant performance. The helium cycle overall efficiency is significantly influenced by performance of individual components. Changes in the design of one component, a turbine for example, often required changes in other components. To allow for the optimization of the overall design with these interdependencies, a detailed steady state and transient control model was developed. The use of the steady state and transient models as a part of an iterative design process represents a key contribution of this work. A dynamic model, MPBRSim, has been developed. The model integrates the reactor core and the power conversion system simultaneously. Physical parameters such as the heat exchangers; weights and practical performance maps such as the turbine characteristics and compressor characteristics are incorporated into the model. The individual component models as well as the fully integrated model of the

  16. Structure Learning by Pruning in Independent Component Analysis

    DEFF Research Database (Denmark)

    Kjems, Andreas; Hansen, Lars Kai


    We discuss pruning as a means of structure learning in independent component analysis. Sparse models are attractive in both signal processing and in analysis of abstract data, they can assist model interpretation, generalizability and reduce computation. We derive the relevant saliency expressions...

  17. Emotional component in the structure of English emotive adjectives


    Melnychuk, Natalia


    The research is devoted to the problem of emotive component in the structure of English emotive adjective. An attempt was made to explore the features of the functioning of emotive adjectives in English language and to consider their lexical and semantic characteristics.

  18. Jacking mechanism for upper internals structure of a liquid metal nuclear reactor (United States)

    Gillett, James E.; Wineman, Arthur L.


    A jacking mechanism for raising the upper internals structure of a liquid metal nuclear reactor which jacking mechanism uses a system of gears and drive shafts to transmit force from a single motor to four mechanically synchronized ball jacks to raise and lower support columns which support the upper internals structure. The support columns have a pin structure which rides up and down in a slot in a housing fixed to the reactor head. The pin has two locking plates which can be rotated around the pin to bring bolt holes through the locking plates into alignment with a set of bolt holes in the housing, there being a set of such housing bolt holes corresponding to both a raised and a lowered position of the support column. When the locking plate is so aligned, a surface of the locking plate mates with a surface in the housing such that the support column is then supported by the locking plate and not by the ball jacks. Since the locking plates are to be installed and bolted to the housing during periods of reactor operation, the ball jacks need not be sized to react the large forces which occur or potentially could occur on the upper internals structure of the reactor during operation. The locking plates react these loads. The ball jacks, used only during refueling, can be smaller, which enable conventionally available equipment to fulfill the precision requirements for the task within available space.

  19. Continuous Production of Structured Phospholipids in a Packed Red Reactor with Lipase from Thermomyces lanuginosa

    DEFF Research Database (Denmark)

    Vikbjerg, Anders Falk; Peng, Lifeng; Mu, Huiling


    The possibilities of producing structured phospholipids by lipase-catalyzed acidolysis between soybean phospholipids and caprylic acid were examined in continuous packed bed enzyme reactors. Acidolysis reactions were performed in both a solvent system and a solvent-free system with the commercial...

  20. Structural analysis of the SNAP-8 developmental reactor fuel element cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dalcher, A.W.


    Primary, secondary, and thermal stresses were calculated and evaluated for the SNAP-8 developmental reactor fuel element cladding. The effects of fabrication and assembly stresses, as well as test and operational stresses were included in the analysis. With the assumption that fuel-swelling-induced stresses are nil, the analytical results indicate that the cladding assembly is structurally adequate for the proposed operation.

  1. Improved Joining of Metal Components to Composite Structures (United States)

    Semmes, Edmund


    Systems requirements for complex spacecraft drive design requirements that lead to structures, components, and/or enclosures of a multi-material and multifunctional design. The varying physical properties of aluminum, tungsten, Invar, or other high-grade aerospace metals when utilized in conjunction with lightweight composites multiply system level solutions. These multi-material designs are largely dependent upon effective joining techAn improved method of joining metal components to matrix/fiber composite material structures has been invented. The method is particularly applicable to equipping such thin-wall polymer-matrix composite (PMC) structures as tanks with flanges, ceramic matrix composite (CMC) liners for high heat engine nozzles, and other metallic-to-composite attachments. The method is oriented toward new architectures and distributing mechanical loads as widely as possible in the vicinities of attachment locations to prevent excessive concentrations of stresses that could give rise to delaminations, debonds, leaks, and other failures. The method in its most basic form can be summarized as follows: A metal component is to be joined to a designated attachment area on a composite-material structure. In preparation for joining, the metal component is fabricated to include multiple studs projecting from the aforementioned face. Also in preparation for joining, holes just wide enough to accept the studs are molded into, drilled, or otherwise formed in the corresponding locations in the designated attachment area of the uncured ("wet') composite structure. The metal component is brought together with the uncured composite structure so that the studs become firmly seated in the holes, thereby causing the composite material to become intertwined with the metal component in the joining area. Alternately, it is proposed to utilize other mechanical attachment schemes whereby the uncured composite and metallic parts are joined with "z-direction" fasteners. The

  2. Crystal structure of the RNA component of bacterial ribonuclease P

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Larios, Alfredo; Swinger, Kerren K.; Krasilnikov, Andrey S.; Pan, Tao; Mondragon, Alfonso (NWU); (UC)


    Transfer RNA (tRNA) is produced as a precursor molecule that needs to be processed at its 3' and 5' ends. Ribonuclease P is the sole endonuclease responsible for processing the 5' end of tRNA by cleaving the precursor and leading to tRNA maturation. It was one of the first catalytic RNA molecules identified and consists of a single RNA component in all organisms and only one protein component in bacteria. It is a true multi-turnover ribozyme and one of only two ribozymes (the other being the ribosome) that are conserved in all kingdoms of life. Here we show the crystal structure at 3.85 {angstrom} resolution of the RNA component of Thermotoga maritima ribonuclease P. The entire RNA catalytic component is revealed, as well as the arrangement of the two structural domains. The structure shows the general architecture of the RNA molecule, the inter- and intra-domain interactions, the location of the universally conserved regions, the regions involved in pre-tRNA recognition and the location of the active site. A model with bound tRNA is in agreement with all existing data and suggests the general basis for RNA-RNA recognition by this ribozyme.

  3. Structural assessments of plate type support system for APR1400 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Anh Tung; Namgung, Ihn, E-mail:


    Highlights: • This paper investigates plate-type support structure for the reactor vessel of the APR 1400. • The tall column supports of APR1400 reactor challenges in seismic and severe accident events. • A plate-type support of reactor vessel was proposed and evaluated based on ASME code. • The plate-type support was assessed to show its higher rigidity than column-type. - Abstract: This paper investigates an alternative form of support structure for the reactor vessel of the APR 1400. The current reactor vessel adopts a four-column support arrangement locating on the cold legs of the vessel. Although having been successfully designed, the tall column structure challenges in seismic events. In addition, for the mitigation of severe accident consequences, the columns inhibit ex-vessel coolant flow, hence the elimination of the support columns proposes extra safety advantages. A plate-type support was proposed and evaluated for the adequacy of meeting the structural stiffness by Finite Element Analysis (FEA) approach. ASME Boiler and Pressure Vessel Code was used to verify the design. The results, which cover thermal and static structural analysis, show stresses are within allowable limits in accordance with the design code. Even the heat conduction area is increased for the plate-type of support system, the results showed that the thermal stresses are within allowable limits. A comparison of natural frequencies and mode shapes for column support and plate-type support were presented as well which showed higher fundamental frequencies for the plate-type support system resulting in greater rigidity of the support system. From the outcome of this research, the plate-type support is proven to be an alternative to current APR column type support design.

  4. Safety apparatus for nuclear reactor to prevent structural damage from overheating by core debris (United States)

    Gabor, J.D.; Cassulo, J.C.; Pedersen, D.R.; Baker, L. Jr.

    The invention teaches safety apparatus that can be included in a nuclear reactor, either when newly fabricated or as a retrofit add-on, that will minimize proliferation of structural damage to the reactor in the event the reactor is experiencing an overheating malfunction whereby radioactive nuclear debris might break away from and can be discharged from the reactor core. The invention provides a porous bed of sublayer on the lower surface of the reactor containment vessel so that the debris falls on and piles up on the bed. Vapor release elements upstand from the bed in some laterally spaced array. Thus should the high heat flux of the debris interior vaporize the coolant at that location, the vaporized coolant can be vented downwardly to and laterally through the bed to the vapor release elements and in turn via the release elements upwardly through the debris. This minimizes the pressure buildup in the debris and allows for continuing infiltration of the liquid coolant into the debris interior.

  5. Evaluation of copper alloys for fusion reactor divertor and first wall components

    DEFF Research Database (Denmark)

    Fabritsiev, S.A.; Zinkle, S.J.; Singh, B.N.


    This paper presents a critical analysis of the main factors of radiation damage limiting the possibility to use copper alloys in the ITER divertor and first wall structure. In copper alloys the most significant types of radiation damage in the proposed temperature-dose operation range are swellin...

  6. Crack growth behaviour of low alloy steels for pressure boundary components under transient light water reactor operating conditions (CASTOC)

    Energy Technology Data Exchange (ETDEWEB)

    Foehl, J.; Weissenberg, T. [Materialpruefungsanstalt, Univ. Stuttgart (Germany); Gomez-Briceno, D.; Lapena, J. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT) (Spain); Ernestova, M.; Zamboch, M. [Nuclear Research Inst. (NRI) (Czech Republic); Seifert, H.P.; Ritter, S. [Paul Scherrer Inst. (PSI) (Switzerland); Roth, A.; Devrient, B. [Framatome ANP GmbH (F ANP) (Germany); Ehrnsten, U. [Technical Research Centre of Finland (VTT) (Finland)


    The CASTOC project addresses environmentally assisted cracking (EAC) phenomena in low alloy steels used for pressure boundary components in both Western type boiling water reactors (BWR) and Russian type pressurised water reactors (VVER). It comprises the four work packages (WP): inter-laboratory comparison test (WP1); EAC behaviour under static load (WP2), EAC behaviour under cyclic load and load transients (WP3); evaluation of the results with regard to their relevance for components in practice (WP4). The use of sophisticated test facilities and measurement techniques for the on-line detection of crack advances have provided a more detailed understanding of the mechanisms of environmentally assisted cracking and provided quantitative data of crack growth rates as a function of loading events and time, respectively. The effect of several major parameters controlling EAC was investigated with particular emphasis on the transferability of the results to components in service. The obtained crack growth rate data were reflected on literature data and on commonly applied prediction curves as presented in the appropriate Code. At relevant stress intensity factors it could be shown that immediate cessation of growing cracks occurs after changing from cyclic to static load in high purity oxygenated BWR water and oxygen-free VVER water corresponding to steady state operation conditions. Susceptibility to environmentally assisted cracking under static load was observed for a heat affected zone material in oxygenated high purity water and also in base materials during a chloride transient representing BWR water condition below Action Level 1 of the EPRI Water Chemistry Guidelines according to the lectrical conductivity of the water but in the range of Action Level 2 according to the content of chlorides. Time based crack growth was also observed in one Russian type base material in oxygenated VVER water and in one Western type base material in oxygenated high purity BWR

  7. Evaluation of Halpern's "structural component" for improving critical thinking. (United States)

    Nieto, Ana Ma; Saiz, Carlos


    Halpern (1998) proposed a four-component model for promoting the transfer of critical thinking. One of them, the "structural component," focuses on how to organize teaching so that critical thinking skills can be generalized. Here, we assess the efficiency of that type of organization. Thus, one group of university students received instruction following the suggestions specified in that component and their performance was compared with that of other university students who received instruction in the same skills but using a different procedure, and with that of a control group. In comparison with the control group, the performance of both instructed groups was better after training. However, no significant differences were observed between either instruction group; both forms of instruction afforded very similar results.

  8. Homogenization of the internal structures of a reactor with the cooling fluid

    Energy Technology Data Exchange (ETDEWEB)

    Robbe, M.F. [CEA Saclay, SEMT, 91 - Gif sur Yvette (France); Bliard, F. [Socotec Industrie, Service AME, 78 - Montigny le Bretonneux (France)


    To take into account the influence of a structure net among a fluid flow, without modelling exactly the structure shape, a concept of ''equivalent porosity method'' was developed. The structures are considered as solid pores inside the fluid. The structure presence is represented by three parameters: a porosity, a shape coefficient and a pressure loss coefficient. The method was studied for an Hypothetical Core Disruptive Accident in a Liquid Metal Fast Breeder Reactor, but it can be applied to any problem involving fluid flow getting through a solid net. The model was implemented in the computer code CASTEM-PLEXUS and validated on an analytical shock tube test, simulating an horizontal slice of a schematic LMFBR in case of a HCDA (bubble at high pressure, liquid sodium and internal structures of the reactor). A short parametric study shows the influence of the porosity and the structure shape on the pressure wave impacting the shock tube bottom. These results were used to simulate numerically the HCDA mechanical effects in a small scale reactor mock-up. (author)

  9. Functional and component structure of the population trading service system


    Кобилін, П. О.


    Formulation the problem. Over the past decade the system of population trading service has seen substantial qualitative changes, particularly the ownership form of retail, restaurant business institutions changed, the range of products expanded, new types of stores, forms of trade (supermarkets, hypermarkets, shopping malls, internet commerce, vending machines etc.) appeared. These changes affect the functional and component structure of population trading service system that has become more ...

  10. Structural ECM components in the premetastatic and metastatic niche

    DEFF Research Database (Denmark)

    Høye, Anette M; Erler, Janine T


    The aim of this review is to give an overview of the extracellular matrix (ECM) components that are important for creating structural changes in the premetastatic and metastatic niche. The successful arrival and survival of cancer cells that have left the primary tumor and colonized distant sites...... depends on the new microenvironment they encounter. The primary tumor itself releases factors into the circulation that travel to distant organs and then initiate structural changes, both non-enzymatic and enzymatic, to create a favorable niche for the disseminating tumor cells. Therapeutic strategies...

  11. Mechanical and materials engineering of modern structure and component design

    CERN Document Server

    Altenbach, Holm


    This book presents the latest findings on mechanical and materials engineering as applied to the design of modern engineering materials and components. The contributions cover the classical fields of mechanical, civil and materials engineering, as well as bioengineering and advanced materials processing and optimization. The materials and structures discussed can be categorized into modern steels, aluminium and titanium alloys, polymers/composite materials, biological and natural materials, material hybrids and modern nano-based materials. Analytical modelling, numerical simulation, state-of-the-art design tools and advanced experimental techniques are applied to characterize the materials’ performance and to design and optimize structures in different fields of engineering applications.

  12. An automatic chip structure optical inspection system for electronic components (United States)

    Song, Zhichao; Xue, Bindang; Liang, Jiyuan; Wang, Ke; Chen, Junzhang; Liu, Yunhe


    An automatic chip structure inspection system based on machine vision is presented to ensure the reliability of electronic components. It consists of four major modules, including a metallographic microscope, a Gigabit Ethernet high-resolution camera, a control system and a high performance computer. An auto-focusing technique is presented to solve the problem that the chip surface is not on the same focusing surface under the high magnification of the microscope. A panoramic high-resolution image stitching algorithm is adopted to deal with the contradiction between resolution and field of view, caused by different sizes of electronic components. In addition, we establish a database to storage and callback appropriate parameters to ensure the consistency of chip images of electronic components with the same model. We use image change detection technology to realize the detection of chip images of electronic components. The system can achieve high-resolution imaging for chips of electronic components with various sizes, and clearly imaging for the surface of chip with different horizontal and standardized imaging for ones with the same model, and can recognize chip defects.

  13. Structural Component Fabrication and Characterization of Advanced Radiation Resistant ODS Steel for Next Generation Nuclear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sang Hoon; Kim, Young Chun; Jin, Hyun Ju; Choi, Byoung Kwon; Kang, Suk Hoon; Kim, Tae Kyu [KAERI, Daejeon (Korea, Republic of)


    In a sodium-cooled fast reactor (SFR), the coolant outlet temperature and peak temperature of the fuel cladding tube will be about 545 .deg. C and 700 .deg. C with 250 dpa of a very high neutron dose rate. To realize this system, it is necessary to develop an advanced structural material having high creep and irradiation resistance at high temperatures. Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling severely occurred to 120dpa at high temperatures and this eventually leads to a decrease of the mechanical properties and dimensional stability. Advanced radiation resistant ODS steel (ARROS) has been newly developed for the in-core structural components in SFR, which has very attractive microstructures to achieve both superior creep and radiation resistances at high temperatures [4]. Nevertheless, the use of ARROS as a structural material essentially requires the fabrication technology development for component parts such as sheet, plate and tube. In this study, plates and tubes were tentatively fabricated with a newly developed alloy, ARROS. Microstructures as well as mechanical properties were also investigated to determine the optimized condition of the fabrication processes.

  14. Development of and verification test integral reactor major components - Development of manufacturing process and fabrication of prototype for SG and CEDM

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hee; Park, Hwa Kyu; Kim, Yong Kyu; Choi, Yong Soon; Kang, Ki Su; Hyun, Young Min [Korea Heavy Industries and Construction Co., LTD., Changwon (Korea)


    Integral SMART(System integrated Modular Advanced Reactor) type reactor is under conceptual design. Because major components is integrated within in a single pressure vessel, compact design using advanced technology is essential. It means that manufacturing process for these components is more complex and difficult. The objective of this study is to confirm the possibility of manufacture of Steam Generator, Control Element Drive Mechanism(CEDM) and Reactor Assembly which includes Reactor Pressure Vessel, it is important to understand the design requirement and function of the major components. After understanding the design requirement and function, it is concluded that the helical bending and weld qualification of titanium tube for Steam Generator and the applicability of electron beam weld for CEDM step motor parts is the critical to fabricate the components. Therefore, bending mock-up and weld qualification of titanium tube was performed and the results are quite satisfactory. Also, it is concluded that electron beam welding technique can be applicable to the CEDM step motor part. (author). 22 refs., 14 figs., 46 tabs.

  15. Novel electrode structure in a DBD reactor applied to the degradation of phenol in aqueous solution (United States)

    Mercado-Cabrera, Antonio; Peña-Eguiluz, Rosendo; López-Callejas, Régulo; Jaramillo-Sierra, Bethsabet; Valencia-Alvarado, Raúl; Rodríguez-Méndez, Benjamín; Muñoz-Castro, Arturo E.


    Phenol degradation experimental results are presented in a similar wastewater aqueous solution using a non-thermal plasma reactor in a coaxial dielectric barrier discharge. The novelty of the work is that one of the electrodes of the reactor has the shape of a hollow screw which shows an enhanced efficiency compared with a traditional smooth structure. The experimentation was carried out with gas mixtures of 90% Ar-10% O2, 80% Ar-20% O2 and 0% Ar-100% O2. After one hour of treatment the removal efficiency was 76%, 92%, and 97%, respectively, assessed with a gas chromatographic mass spectrometry technique. For both reactors used, the ozone concentration was measured. The screw electrode required less energy, for all gas mixtures, than the smooth electrode, to maintain the same ozone concentration. On the other hand, it was also observed that in both electrodes the electrical conductivity of the solution changed slightly from ˜0.0115 S m-1 up to ˜0.0430 S m-1 after one hour of treatment. The advantages of using the hollow screw electrode structure compared with the smooth electrode were: (1) lower typical power consumption, (2) the generation of a uniform plasma throughout the reactor benefiting the phenol degradation, (3) a relatively lower temperature of the aqueous solution during the process, and (4) the plasma generation length is larger.

  16. An experimental study of hypervapotron structure in external reactor vessel cooling

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yufeng; Zhang, Ming [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Hou, Fangxin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); Gao, Tianfang [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Chen, Peipei, E-mail: [State Power Investment Group Corporation, Beijing (China)


    Highlights: • Experiments are performed to study the application of hypervapotron in ERVC design. • CHF experiments on two surfaces are conducted under different flow conditions. • Hypervapotron improves CHF performance by 40–60% compared with smooth surface. • Visualization shows fin structure removes vapor mushroom for better liquid supply. - Abstract: In vessel retention (IVR) is one of the key strategies for many advanced LWR designs to mitigate postulated severe accidents. The success of IVR substantially relies on external reactor vessel cooling (ERVC) by which the decay heat is removed from the melt core in the reactor vessel lower head. The main challenge of IVR is to provide an adequate safety margin of ERVC against critical heat flux (CHF) of subcooled flow boiling in the reactor lower head flow channel. Due to uncertainties in corium melt pool configuration, large CHF margin of ERVC is usually required by regulatory authorities to demonstrate reliability of severe accident mitigation methods. Various CHF enhancement designs have been proposed and studied in literature. In this paper, an experimental study of hypervapotron structure as a novel design to improve CHF performance of ERVC is conducted. Hypervapotron is chosen as one of the potential engineering options for International Thermonuclear Experimental Reactor (ITER) program as a divertor structure to remove highly intense heat from fusion chamber. This study is to conduct CHF experiments at typical PWR ERVC working conditions. The CHF experiments are performed in a 30 mm by 61 mm rectangular flow channel with a 200 mm long heated surface along the flow direction. Both smooth and hypervapotron surface are tested at various inclination angles of the test section to simulate various positions of the reactor lower head. The hypervapotron is found to have a 40–60% CHF improvement compared with the smooth surface. The high speed visualization indicates that hypervapotron is able to

  17. Structural design optimization of vehicle components using Cuckoo Search Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Yildiz, Ali Riza [Bursa Technical Univ., Bursa (Turkey). Dept. of Mechanical Engineering; Durgun, Ismail


    In order to meet today's vehicle design requirements and to improve the cost and fuel efficiency, there is an increasing interest to design light-weight and cost-effective vehicle components. In this research, a new optimization algorithm, called the Cuckoo Search Algorithm (CS) algorithm, is introduced for solving structural design optimization problems. This research is the first application of the CS to the shape design optimization problems in the literature. The CS algorithm is applied to the structural design optimization of a vehicle component to illustrate how the present approach can be applied for solving structural design problems. Results show the ability of the CS to find better optimal structural design. [German] Um heutige Anforderungen an das Fahrzeugdesign zu beruecksichtigen und um die Kosten- und Kraftstoffeffektivitaet zu erhoehen, nimmt das Interesse am Design leichter und kosteneffektiver Fahrzeugkomponenten weiterhin zu. In der diesem Beitrag zugrunde liegenden Studie wurde ein neuer Optimierungsalgorithmus angewendet, der so genannte Cuckoo Suchalgorithmus (CS). Es handelt sich um die erste CS-Applikation fuer das Formdesign in der Literatur. Der CS-Algorithmus wird hierbei zur Strukturdesignoptimierung einer Fahrzeugkomponente angewendet, um zu zeigen, wie er bei der Loesung von Strukturdesignaufgaben angewendet werden kann. Die Ergebnisse zeigen, wie damit ein verbessertes Design erreicht werden kann.

  18. Nuclear reactor shield including magnesium oxide (United States)

    Rouse, Carl A.; Simnad, Massoud T.


    An improvement in nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux, the reactor shielding including means providing structural support, neutron moderator material, neutron absorber material and other components as described below, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron.

  19. The component content of active particles in a plasma-chemical reactor based on volume barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Soloshenko, I A [Institute of Physics of National Academy of Sciences of Ukraine, 46 Nauki Avenue, 03028, Kiev (Ukraine); Tsiolko, V V [Institute of Physics of National Academy of Sciences of Ukraine, 46 Nauki Avenue, 03028, Kiev (Ukraine); Pogulay, S S [Institute of Physics of National Academy of Sciences of Ukraine, 46 Nauki Avenue, 03028, Kiev (Ukraine); Terent' yeva, A G [Institute of Physics of National Academy of Sciences of Ukraine, 46 Nauki Avenue, 03028, Kiev (Ukraine); Bazhenov, V Yu [Institute of Physics of National Academy of Sciences of Ukraine, 46 Nauki Avenue, 03028, Kiev (Ukraine); Shchedrin, A I [Institute of Physics of National Academy of Sciences of Ukraine, 46 Nauki Avenue, 03028, Kiev (Ukraine); Ryabtsev, A V [Institute of Physics of National Academy of Sciences of Ukraine, 46 Nauki Avenue, 03028, Kiev (Ukraine); Kuzmichev, A I [National Technical University ' KPI' , 37 Peremogy Avenue, KPI-2230, 03056, Kiev, (Ukraine)


    In this paper the results of theoretical and experimental studies of the component content of active particles formed in a plasma-chemical reactor composed of a multiple-cell generator of active particles, based on volume barrier discharge, and a working chamber are presented. For calculation of the content of uncharged plasma components an approach is proposed which is based on averaging of the power introduced over the entire volume. Advantages of such an approach lie in an absence of fitting parameters, such as the dimensions of microdischarges, their surface density and rate of breakdown. The calculation and the experiment were accomplished with the use of dry air (20% relative humidity) as the plasma generating medium. Concentrations of O{sub 3}, HNO{sub 3}, HNO{sub 2}, N{sub 2} O{sub 5} and NO{sub 3} were measured experimentally in the discharge volume and working chamber for the residence time of particles on a discharge of 0.3 s and more and discharge specific power of 1.5 W cm{sup -3}. It has been determined that the best agreement between the calculation and the experiment occurs at calculated gas medium temperatures in the discharge plasma of about 400-425 K, which correspond to the experimentally measured rotational temperature of nitrogen. In most cases the calculated concentrations of O{sub 3}, HNO{sub 3}, HNO{sub 2}, N{sub 2}O{sub 5} and NO{sub 3} for the barrier discharge and the working chamber are in fairly good agreement with the respective measured values.


    Directory of Open Access Journals (Sweden)

    E. K. Agakhanov


    Full Text Available The necessity of studying the effect impact of elementary particles impact on the strength and deformation materials properties used in protective constructions nuclear reactors and reactor technology has been stipulated. A nuclear reactor pressure vessel from prestressed concrete, combining the functions of biological protection is to be considered. The neutron flux problem distribution in the pressure vessel of a nuclear reactor has been solved. The solution is made in axisymmetric with the finite element method using a flat triangular finite element. Computing has been conducted in Matlab package. The comparison with the results has been obtained using the finite difference method, as well as the graphs of changes under the influence of radiation exposure and the elastic modulus of concrete radiation deformations have been constructed. The proposed method allows to simulate changes in the deformation properties of concrete under the influence of neutron irradiation. Results of the study can be used in the calculation of stress-strain state of structures, taking into account indirect heterogeneity caused by the physical fields influence.

  1. Fuel processing in integrated micro-structured heat-exchanger reactors (United States)

    Kolb, G.; Schürer, J.; Tiemann, D.; Wichert, M.; Zapf, R.; Hessel, V.; Löwe, H.

    Micro-structured fuel processors are under development at IMM for different fuels such as methanol, ethanol, propane/butane (LPG), gasoline and diesel. The target application are mobile, portable and small scale stationary auxiliary power units (APU) based upon fuel cell technology. The key feature of the systems is an integrated plate heat-exchanger technology which allows for the thermal integration of several functions in a single device. Steam reforming may be coupled with catalytic combustion in separate flow paths of a heat-exchanger. Reactors and complete fuel processors are tested up to the size range of 5 kW power output of a corresponding fuel cell. On top of reactor and system prototyping and testing, catalyst coatings are under development at IMM for numerous reactions such as steam reforming of LPG, ethanol and methanol, catalytic combustion of LPG and methanol, and for CO clean-up reactions, namely water-gas shift, methanation and the preferential oxidation of carbon monoxide. These catalysts are investigated in specially developed testing reactors. In selected cases 1000 h stability testing is performed on catalyst coatings at weight hourly space velocities, which are sufficiently high to meet the demands of future fuel processing reactors.

  2. Kinetics of ammonia oxidation over Pt foil studied in a micro-structured quartz-reactor


    Kraehnert, Ralf; Baerns, Manfred


    The kinetics of Pt-catalyzed ammonia oxidation on polycrystalline Pt were investigated at partial pressures of ammonia and oxygen up to 6 kPa and temperatures between 286 and 385 °C, applying a micro-structured reactor that ascertained temperature control of the exothermic reaction. Using literature-based mechanistic models, a micro-kinetic model was derived based on parameter optimization and a model discrimination procedure. The model described the rates of formation of all nitrogen-contain...

  3. Improved computation method in residual life estimation of structural components

    Directory of Open Access Journals (Sweden)

    Maksimović Stevan M.


    Full Text Available This work considers the numerical computation methods and procedures for the fatigue crack growth predicting of cracked notched structural components. Computation method is based on fatigue life prediction using the strain energy density approach. Based on the strain energy density (SED theory, a fatigue crack growth model is developed to predict the lifetime of fatigue crack growth for single or mixed mode cracks. The model is based on an equation expressed in terms of low cycle fatigue parameters. Attention is focused on crack growth analysis of structural components under variable amplitude loads. Crack growth is largely influenced by the effect of the plastic zone at the front of the crack. To obtain efficient computation model plasticity-induced crack closure phenomenon is considered during fatigue crack growth. The use of the strain energy density method is efficient for fatigue crack growth prediction under cyclic loading in damaged structural components. Strain energy density method is easy for engineering applications since it does not require any additional determination of fatigue parameters (those would need to be separately determined for fatigue crack propagation phase, and low cyclic fatigue parameters are used instead. Accurate determination of fatigue crack closure has been a complex task for years. The influence of this phenomenon can be considered by means of experimental and numerical methods. Both of these models are considered. Finite element analysis (FEA has been shown to be a powerful and useful tool1,6 to analyze crack growth and crack closure effects. Computation results are compared with available experimental results. [Projekat Ministarstva nauke Republike Srbije, br. OI 174001

  4. Magnons in one-dimensional k-component Fibonacci structures

    Energy Technology Data Exchange (ETDEWEB)

    Costa, C. H., E-mail: [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Vasconcelos, M. S. [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil)


    We have studied the magnon transmission through of one-dimensional magnonic k-component Fibonacci structures, where k different materials are arranged in accordance with the following substitution rule: S{sub n}{sup (k)}=S{sub n−1}{sup (k)}S{sub n−k}{sup (k)} (n≥k=0,1,2,…), where S{sub n}{sup (k)} is the nth stage of the sequence. The calculations were carried out in exchange dominated regime within the framework of the Heisenberg model and taking into account the RPA approximation. We have considered multilayers composed of simple cubic spin-S Heisenberg ferromagnets, and, by using the powerful transfer-matrix method, the spin wave transmission is obtained. It is demonstrated that the transmission coefficient has a rich and interesting magnonic pass- and stop-bands structures, which depends on the frequency of magnons and the k values.

  5. Detection of Component Failures for Smart Structure Control Systems (United States)

    Okubo, Hiroshi

    Uncertainties in the dynamics model of a smart structure are often of significance due to model errors caused by parameter identification errors and reduced-order modeling of the system. Design of a model-based Failure Detection and Isolation (FDI) system for smart structures, therefore, needs careful consideration regarding robustness with respect to such model uncertainties. In this paper, we proposes a new method of robust fault detection that is insensitive to the disturbances caused by unknown modeling errors while it is highly sensitive to the component failures. The capability of the robust detection algorithm is examined for the sensor failure of a flexible smart beam control system. It is shown by numerical simulations that the proposed method suppresses the disturbances due to model errors and markedly improves the detection performance.

  6. Damage by radiation in structural materials of BWR reactor vessels; Dano por radiacion en materiales estructurales de vasijas de reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Robles, E.; Balcazar, M.; Alpizar, A.M.; Calderon, B.E. [Departamento de Sintesis y Caracterizacion de Materiales, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)


    The structural materials which are manufactured the pressure vessels of the BWR reactors undergo degradation in their mechanical properties mainly due to the damage produced by the fast neutrons (E> 1 MeV) coming from the reactor core. The mechanisms of neutron damage in this type of materials are experimentally studied, through the irradiation of vessel steel in experimental reactors for a quickly ageing. Alternately the neutron damage through steel irradiation with heavy ions is simulated. In this work the first results of the damage induced by irradiation of a similar steel to the vessel of a BWR reactor are shown. The irradiation was performed with fast neutrons (E> 1 MeV, fluence of 1.45 x 10{sup 18} n/cm{sup 2}) in the TRIGA Mark III Salazar reactor and separately with Ni{sup +3} ions in a Tandetrom accelerator (E= 4.8 MeV and an ion flux rank of 0.1 to 53 ions/A{sup 2}). (Author)

  7. Structural Components of Synaptic Plasticity and Memory Consolidation (United States)

    Bailey, Craig H.; Kandel, Eric R.; Harris, Kristen M.


    Consolidation of implicit memory in the invertebrate Aplysia and explicit memory in the mammalian hippocampus are associated with remodeling and growth of preexisting synapses and the formation of new synapses. Here, we compare and contrast structural components of the synaptic plasticity that underlies these two distinct forms of memory. In both cases, the structural changes involve time-dependent processes. Thus, some modifications are transient and may contribute to early formative stages of long-term memory, whereas others are more stable, longer lasting, and likely to confer persistence to memory storage. In addition, we explore the possibility that trans-synaptic signaling mechanisms governing de novo synapse formation during development can be reused in the adult for the purposes of structural synaptic plasticity and memory storage. Finally, we discuss how these mechanisms set in motion structural rearrangements that prepare a synapse to strengthen the same memory and, perhaps, to allow it to take part in other memories as a basis for understanding how their anatomical representation results in the enhanced expression and storage of memories in the brain. PMID:26134321

  8. Composite load spectra for select space propulsion structural components (United States)

    Newell, J. F.; Ho, H. W.; Kurth, R. E.


    The work performed to develop composite load spectra (CLS) for the Space Shuttle Main Engine (SSME) using probabilistic methods. The three methods were implemented to be the engine system influence model. RASCAL was chosen to be the principal method as most component load models were implemented with the method. Validation of RASCAL was performed. High accuracy comparable to the Monte Carlo method can be obtained if a large enough bin size is used. Generic probabilistic models were developed and implemented for load calculations using the probabilistic methods discussed above. Each engine mission, either a real fighter or a test, has three mission phases: the engine start transient phase, the steady state phase, and the engine cut off transient phase. Power level and engine operating inlet conditions change during a mission. The load calculation module provides the steady-state and quasi-steady state calculation procedures with duty-cycle-data option. The quasi-steady state procedure is for engine transient phase calculations. In addition, a few generic probabilistic load models were also developed for specific conditions. These include the fixed transient spike model, the poison arrival transient spike model, and the rare event model. These generic probabilistic load models provide sufficient latitude for simulating loads with specific conditions. For SSME components, turbine blades, transfer ducts, LOX post, and the high pressure oxidizer turbopump (HPOTP) discharge duct were selected for application of the CLS program. They include static pressure loads and dynamic pressure loads for all four components, centrifugal force for the turbine blade, temperatures of thermal loads for all four components, and structural vibration loads for the ducts and LOX posts.

  9. Report on Understanding and Predicting Effects of Thermal Aging on Microstructure and Tensile Properties of Grade 91 Steel for Structural Components

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meimei [Argonne National Lab. (ANL), Argonne, IL (United States); Natesan, K. [Argonne National Lab. (ANL), Argonne, IL (United States); Chen, Weiying [Argonne National Lab. (ANL), Argonne, IL (United States)


    This report provides an update on understanding and predicting the effects of long-term thermal aging on microstructure and tensile properties of G91 to corroborate the ASME Code rules in strength reduction due to elevated temperature service. The research is to support the design and long-term operation of G91 structural components in sodium-cooled fast reactors (SFRs). The report is a Level 2 deliverable in FY17 (M2AT-17AN1602017), under the Work Package AT-17AN160201, “SFR Materials Testing” performed by the Argonne National Laboratory (ANL), as part of the Advanced Reactor Technologies Program.

  10. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E


    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel.

  11. X-Aerogels for Structural Components and High Temperature Applications (United States)


    Future NASA missions and space explorations rely on the use of materials that are strong ultra lightweight and able to withstand extreme temperatures. Aerogels are low density (0.01-0.5 g/cu cm) high porosity materials that contain a glass like structure formed through standard sol-gel chemistry. As a result of these structural properties, aerogels are excellent thermal insulators and are able to withstand temperatures in excess of l,000 C. The open structure of aerogels, however, renders these materials extremely fragile (fracturing at stress forces less than 0.5 N/sq cm). The goal of NASA Glenn Research Center is to increase the strength of these materials by templating polymers and metals onto the surface of an aerogel network facilitating the use of this material for practical applications such as structural components of space vehicles used in exploration. The work this past year focused on two areas; (1) the research and development of new templated aerogels materials and (2) process development for future manufacturing of structural components. Research and development occurred on the production and characterization of new templating materials onto the standard silica aerogel. Materials examined included polymers such as polyimides, fluorinated isocyanates and epoxies, and, metals such as silver, gold and platinum. The final properties indicated that the density of the material formed using an isocyanate is around 0.50 g/cc with a strength greater than that of steel and has low thermal conductivity. The process used to construct these materials is extremely time consuming and labor intensive. One aspect of the project involved investigating the feasibility of shortening the process time by preparing the aerogels in the templating solvent. Traditionally the polymerization used THF as the solvent and after several washes to remove any residual monomers and water, the solvent around the aerogels was changed to acetonitrile for the templating step. This process

  12. Technical Letter Report, An Evaluation of Ultrasonic Phased Array Testing for Reactor Piping System Components Containing Dissimilar Metal Welds, JCN N6398, Task 2A

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Aaron A.; Cinson, Anthony D.; Crawford, Susan L.; Anderson, Michael T.


    Research is being conducted for the U.S. Nuclear Regulatory Commission at the Pacific Northwest National Laboratory to assess the effectiveness and reliability of advanced nondestructive examination (NDE) methods for the inspection of light-water reactor components. The scope of this research encom¬passes primary system pressure boundary materials including dissimilar metal welds (DMWs), cast austenitic stainless steels (CASS), piping with corrosion-resistant cladding, weld overlays, inlays and onlays, and far-side examinations of austenitic piping welds. A primary objective of this work is to evaluate various NDE methods to assess their ability to detect, localize, and size cracks in steel components that challenge standard and/or conventional inspection methodologies. This interim technical letter report provides a summary of a technical evaluation aimed at assessing the capabilities of phased-array (PA) ultrasonic testing (UT) methods as applied to the inspection of small-bore DMW components that exist in the reactor coolant systems (RCS) of pressurized water reactors (PWRs). Operating experience and events such as the circumferential cracking in the reactor vessel nozzle-to-RCS hot leg pipe at V.C. Summer nuclear power station, identified in 2000, show that in PWRs where primary coolant water (or steam) are present under normal operation, Alloy 82/182 materials are susceptible to pressurized water stress corrosion cracking. The extent and number of occurrences of DMW cracking in nuclear power plants (domestically and internationally) indicate the necessity for reliable and effective inspection techniques. The work described herein was performed to provide insights for evaluating the utility of advanced NDE approaches for the inspection of DMW components such as a pressurizer surge nozzle DMW, a shutdown cooling pipe DMW, and a ferritic (low-alloy carbon steel)-to-CASS pipe DMW configuration.

  13. On the Deflexion of Anisotropic Structural Composite Aerodynamic Components

    Directory of Open Access Journals (Sweden)

    J. Whitty


    Full Text Available This paper presents closed form solutions to the classical beam elasticity differential equation in order to effectively model the displacement of standard aerodynamic geometries used throughout a number of industries. The models assume that the components are constructed from in-plane generally anisotropic (though shown to be quasi-isotropic composite materials. Exact solutions for the displacement and strains for elliptical and FX66-S-196 and NACA 63-621 aerofoil approximations thin wall composite material shell structures, with and without a stiffening rib (shear-web, are presented for the first time. Each of the models developed is rigorously validated via numerical (Runge-Kutta solutions of an identical differential equation used to derive the analytical models presented. The resulting calculated displacement and material strain fields are shown to be in excellent agreement with simulations using the ANSYS and CATIA commercial finite element (FE codes as well as experimental data evident in the literature. One major implication of the theoretical treatment is that these solutions can now be used in design codes to limit the required displacement and strains in similar components used in the aerospace and most notably renewable energy sectors.

  14. 3D printed components with ultrasonically arranged microscale structure (United States)

    Llewellyn-Jones, Thomas M.; Drinkwater, Bruce W.; Trask, Richard S.


    This paper shows the first application of in situ manipulation of discontinuous fibrous structure mid-print, within a 3D printed polymeric composite architecture. Currently, rapid prototyping methods (fused filament fabrication, stereolithography) are gaining increasing popularity within the engineering commnity to build structural components. Unfortunately, the full potential of these components is limited by the mechanical properties of the materials used. The aim of this study is to create and demonstrate a novel method to instantaneously orient micro-scale glass fibres within a selectively cured photocurable resin system, using ultrasonic forces to align the fibres in the desired 3D architecture. To achieve this we have mounted a switchable, focused laser module on the carriage of a three-axis 3D printing stage, above an in-house ultrasonic alignment rig containing a mixture of photocurable resin and discontinuous 14 μm diameter glass fibre reinforcement(50 μm length). In our study, a suitable print speed of 20 mm s-1 was used, which is comparable to conventional additive layer techniques. We show the ability to construct in-plane orthogonally aligned sections printed side by side, where the precise orientation of the configurations is controlled by switching the ultrasonic standing wave profile mid-print. This approach permits the realisation of complex fibrous architectures within a 3D printed landscape. The versatile nature of the ultrasonic manipulation technique also permits a wide range of particle types (diameters, aspect ratios and functions) and architectures (in-plane, and out-plane) to be patterned, leading to the creation of a new generation of fibrous reinforced composites for 3D printing.

  15. Mechanical systems development of integral reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Keun Bae; Chang, M. H.; Kim, J. I.; Choi, S.; Kim, K. S.; Kim, T. W.; Jeong, K. H.; Kim, J. H.; Kim, Y. W.; Lee, G. M.


    While Korean nuclear reactor strategy seems to remain focused on the large capacity power generation, it is expected that demand of small and medium size reactor will arise for multi-purpose applications such as small capacity power generation, co-generation and sea water desalination. This in mind, survey has been made on the worldwide small and medium integral reactors under development. Reviewed are their technical characteristics, development status, design features, application plans, etc. For the mechanical design scope of work, the structural concept compatible with the characteristics and requirements of integral reactor has been established. Types of major components were evaluated and selected. Functional and structural concept, equipment layout and supporting concept within the reactor pressure vessel have also been established. Preliminary mechanical design requirements were developed considering the reactor lifetime, operation conditions, and the expected loading combinations. To embody the concurrent design approach, recent CAD technology and team engineering concept were evaluated. (author). 31 refs.,16 tabs., 35 figs.

  16. Recognizing genes and other components of genomic structure

    Energy Technology Data Exchange (ETDEWEB)

    Burks, C. (Los Alamos National Lab., NM (USA)); Myers, E. (Arizona Univ., Tucson, AZ (USA). Dept. of Computer Science); Stormo, G.D. (Colorado Univ., Boulder, CO (USA). Dept. of Molecular, Cellular and Developmental Biology)


    The Aspen Center for Physics (ACP) sponsored a three-week workshop, with 26 scientists participating, from 28 May to 15 June, 1990. The workshop, entitled Recognizing Genes and Other Components of Genomic Structure, focussed on discussion of current needs and future strategies for developing the ability to identify and predict the presence of complex functional units on sequenced, but otherwise uncharacterized, genomic DNA. We addressed the need for computationally-based, automatic tools for synthesizing available data about individual consensus sequences and local compositional patterns into the composite objects (e.g., genes) that are -- as composite entities -- the true object of interest when scanning DNA sequences. The workshop was structured to promote sustained informal contact and exchange of expertise between molecular biologists, computer scientists, and mathematicians. No participant stayed for less than one week, and most attended for two or three weeks. Computers, software, and databases were available for use as electronic blackboards'' and as the basis for collaborative exploration of ideas being discussed and developed at the workshop. 23 refs., 2 tabs.

  17. Expression profiling reveals metabolic and structural components of extraocular muscles. (United States)

    Fischer, M Dominik; Gorospe, J Rafael; Felder, Edward; Bogdanovich, Sasha; Pedrosa-Domellöf, F; Ahima, Rexford S; Rubinstein, Neal A; Hoffman, Eric P; Khurana, Tejvir S


    The extraocular muscles (EOM) are anatomically and physiologically distinct from other skeletal muscles. EOM are preferentially affected in mitochondrial myopathies, but spared in Duchenne's muscular dystrophy. The anatomical and pathophysiological properties of EOM have been attributed to their unique molecular makeup: an allotype. We used expression profiling to define molecular features of the EOM allotype. We found 346 differentially expressed genes in rat EOM compared with tibialis anterior, based on a twofold difference cutoff. Genes required for efficient, fatigue-resistant, oxidative metabolism were increased in EOM, whereas genes for glycogen metabolism were decreased. EOM also showed increased expression of genes related to structural components of EOM such as vessels, nerves, mitochondria, and neuromuscular junctions. Additionally, genes related to specialized functional roles of EOM such as the embryonic and EOM-specific myosin heavy chains and genes for muscle growth, development, and/or regeneration were increased. The EOM expression profile was validated using biochemical, structural, and molecular methods. Characterization of the EOM expression profile begins to define gene transcription patterns associated with the unique anatomical, metabolic, and pathophysiological properties of EOM.

  18. Bonding and structure in dense multi-component molecular mixtures. (United States)

    Meyer, Edmund R; Ticknor, Christopher; Bethkenhagen, Mandy; Hamel, Sebastien; Redmer, Ronald; Kress, Joel D; Collins, Lee A


    We have performed finite-temperature density functional theory molecular dynamics simulations on dense methane, ammonia, and water mixtures (CH4:NH3:H2O) for various compositions and temperatures (2000 K ≤ T ≤ 10,000 K) that span a set of possible conditions in the interiors of ice-giant exoplanets. The equation-of-state, pair distribution functions, and bond autocorrelation functions (BACF) were used to probe the structure and dynamics of these complex fluids. In particular, an improvement to the choice of the cutoff in the BACF was developed that allowed analysis refinements for density and temperature effects. We note the relative changes in the nature of these systems engendered by variations in the concentration ratios. A basic tenet emerges from all these comparisons that varying the relative amounts of the three heavy components (C,N,O) can effect considerable changes in the nature of the fluid and may in turn have ramifications for the structure and composition of various planetary layers.

  19. Thermochemical storage for CSP via redox structured reactors/heat exchangers: The RESTRUCTURE project (United States)

    Karagiannakis, George; Pagkoura, Chrysoula; Konstandopoulos, Athanasios G.; Tescari, Stefania; Singh, Abhishek; Roeb, Martin; Lange, Matthias; Marcher, Johnny; Jové, Aleix; Prieto, Cristina; Rattenbury, Michael; Chasiotis, Andreas


    The present work provides an overview of activities performed in the framework of the EU-funded collaborative project RESTRUCTURE, the main goal of which was to develop and validate a compact structured reactor/heat exchanger for thermochemical storage driven by 2-step high temperature redox metal oxide cycles. The starting point of development path included redox materials qualification via both theoretical and lab-scale experimental studies. Most favorable compositions were cobalt oxide/alumina composites. Preparation of small-scale structured bodies included various approaches, ranging from perforated pellets to more sophisticated honeycomb geometries, fabricated by extrusion and coating. Proof-of-concept of the proposed novel reactor/heat exchanger was successfully validated in small-scale structures and the next step included scaling up of redox honeycombs production. Significant challenges were identified for the case of extruded full-size bodies and the final qualified approach related to preparation of cordierite substrates coated with cobalt oxide. The successful experimental evaluation of the pilot reactor/heat exchanger system constructed motivated the preliminary techno-economic evaluation of the proposed novel thermochemical energy storage concept. Taking into account experimental results, available technologies and standard design aspects a model for a 70.5 MWe CSP plant was defined. Estimated LCOE costs were calculated to be in the range of reference values for Combined Cycle Power Plants operated by natural gas. One of main cost contributors was the storage system itself, partially due to relatively high cost of cobalt oxide. This highlighted the need to identify less costly and equally efficient to cobalt oxide redox materials.

  20. Component

    Directory of Open Access Journals (Sweden)

    Tibor Tot


    Full Text Available A unique case of metaplastic breast carcinoma with an epithelial component showing tumoral necrosis and neuroectodermal stromal component is described. The tumor grew rapidly and measured 9 cm at the time of diagnosis. No lymph node metastases were present. The disease progressed rapidly and the patient died two years after the diagnosis from a hemorrhage caused by brain metastases. The morphology and phenotype of the tumor are described in detail and the differential diagnostic options are discussed.

  1. Structural biology facilities at Brookhaven National Laboratory`s high flux beam reactor

    Energy Technology Data Exchange (ETDEWEB)

    Korszun, Z.R.; Saxena, A.M.; Schneider, D.K. [Brookhaven National Laboratory, Upton, NY (United States)


    The techniques for determining the structure of biological molecules and larger biological assemblies depend on the extent of order in the particular system. At the High Flux Beam Reactor at the Brookhaven National Laboratory, the Biology Department operates three beam lines dedicated to biological structure studies. These beam lines span the resolution range from approximately 700{Angstrom} to approximately 1.5{Angstrom} and are designed to perform structural studies on a wide range of biological systems. Beam line H3A is dedicated to single crystal diffraction studies of macromolecules, while beam line H3B is designed to study diffraction from partially ordered systems such as biological membranes. Beam line H9B is located on the cold source and is designed for small angle scattering experiments on oligomeric biological systems.

  2. 3D printing in chemical engineering and catalytic technology: structured catalysts, mixers and reactors. (United States)

    Parra-Cabrera, Cesar; Achille, Clement; Kuhn, Simon; Ameloot, Rob


    Computer-aided fabrication technologies combined with simulation and data processing approaches are changing our way of manufacturing and designing functional objects. Also in the field of catalytic technology and chemical engineering the impact of additive manufacturing, also referred to as 3D printing, is steadily increasing thanks to a rapidly decreasing equipment threshold. Although still in an early stage, the rapid and seamless transition between digital data and physical objects enabled by these fabrication tools will benefit both research and manufacture of reactors and structured catalysts. Additive manufacturing closes the gap between theory and experiment, by enabling accurate fabrication of geometries optimized through computational fluid dynamics and the experimental evaluation of their properties. This review highlights the research using 3D printing and computational modeling as digital tools for the design and fabrication of reactors and structured catalysts. The goal of this contribution is to stimulate interactions at the crossroads of chemistry and materials science on the one hand and digital fabrication and computational modeling on the other.

  3. Sodium effects on mechanical performance and consideration in high temperature structural design for advanced reactors

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K., E-mail: natesan@anl.go [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Li Meimei; Chopra, O.K.; Majumdar, S. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)


    Sodium environmental effects are key limiting factors in the high temperature structural design of advanced sodium-cooled reactors. A guideline is needed to incorporate environmental effects in the ASME design rules to improve the performance reliability over long operating times. This paper summarizes the influence of sodium exposure on mechanical performance of selected austenitic stainless and ferritic/martensitic steels. Focus is on Type 316SS and mod.9Cr-1Mo. The sodium effects were evaluated by comparing the mechanical properties data in air and sodium. Carburization and decarburization were found to be the key factors that determine the tensile and creep properties of the steels. A beneficial effect of sodium exposure on fatigue life was observed under fully reversed cyclic loading in both austenitic stainless steels and ferritic/martensitic steels. However, when hold time was applied during cyclic loading, the fatigue life was significantly reduced. Based on the mechanical performance of the steels in sodium, consideration of sodium effects in high temperature structural design of advanced fast reactors is discussed.

  4. 76 FR 74831 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water (United States)


    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY...- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water... management of stainless steel structures and components exposed to treated borated water. In response to a...

  5. 77 FR 27815 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water (United States)


    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY..., ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG... stainless steel structures and components exposed to treated borated water. The NRC published Revision 2 of...

  6. Strength of Composite Joints in Structural Components and Articles

    Directory of Open Access Journals (Sweden)

    A. A. Bakulin


    Full Text Available Currently, the composite materials (CM are widely used in the aerospace technology and mechanical engineering where the key parameters characterizing structural components and articles are related to their weight characteristics as well as their performance under high temperatures.For the experimental investigation of composite-based threaded items, the rod-based 3Dreinforced carbon-carbon composite material (CCCM was chosen.The subject of the research was the metric thread. The test samples were cut of the aforesaid material along one of the reinforcement direction. The following thread sizes were analyzed: М24×1.5; М24×2; М24×3.Dependence of the thread strength on the number of thread turns was determined within the range of 1 to 10 thread turns for М24×2 thread size. The remaining test samples were used to obtain the relationship between the thread load bearing capacity and the thread pitch.The obtained dependence of the thread load bearing capacity on the number of thread turns showed the following:a An increment in the thread load bearing capacity decreases with increasing number of thread turns. However, this effect is less pronounced than that observed for the metal ‘screw/nut’ pair.b With the CCCM material under study, it proved to be impossible to test configurations having only 1 or 2 thread turns.c The wide confidence range (CR of the failure load can be explained by the fact that the material under study features an apparent structural heterogeneity, with a different probability of hitting a unit cell of the matrix and filler of the material. Nevertheless, the confidence range is stable, thus indicating indirectly the possibility of using this test method for further study of composite-based threaded items.There is an explicit correlation between the thread load bearing capacity and the thread pitch. Increase in the thread strength with increasing thread pitch depends on the relationship between the pitch size and the

  7. Vacuum Plasma Spraying W-coated Reduced Activation Structural Steels for Fusion Plasma Facing Components

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    Tungsten (W) and its alloys are considered as candidate materials for plasma facing materials of the first wall and diverter components in fusion reactor systems because of high sputtering resistance and low tritium retention in a fusion environment. Therefore, it is considered that the joining between W and reduced activation structural steels, and its evaluation, are critical issues for the development of fusion reactors. However, the joining between these materials is a very challenging process because of significant differences in their physical properties, particularly the mismatch of coefficients of thermal expansion (CTE). For instance, the CTE of pure W is known to be about 4.3Χ10{sup -6}K{sup -1}; however, that of martensitic steels reaches over three times, about 12-14Χ10{sup -6}K{sup -1} at room temperature even up to 373K. Nevertheless, several joining techniques have been developed for joining between W and structural steels, such as a vapor deposition method, brazing and diffusion bonding. Meanwhile, vacuum plasma spraying (VPS) is supposed to be one of the prospective methods to fabricate a sufficient W layer on the steel substrates because of the coating of a large area with a relatively high fabricating rate. In this study, the VPS method of W powders on reduced activation steels was employed, and its microstructure and hardness distribution were investigated. ODS ferritic steels and F82H steel were coated by VPS-W, and the microstructure and hardness distribution were investigated. A microstructure analysis revealed that pure W was successfully coated on steel substrates by the VPS process without an intermediate layer, in spite of a mismatch of the CTE between dissimilar materials. After neutron irradiation, irradiation hardening significantly occurred in the VPSW. However, the hardening of VPS-W was lesser than that of bulk W irradiated HFIR at 773K. Substrate materials, ODS ferritic steels, and F82H steel, did not show irradiation hardening

  8. Investigation of structure of noise component in molecular spectra (United States)

    Sibgatullin, M. E.; Galimullin, D. Z.; Kamalova, D. I.; Salakhov, M. Kh


    In the work the noise component of molecular spectra is investigated by use the Hurst index which is the quantitative parameter of memory effects. It was shown that the low- frequency noise component predominates. The Hurst index is from 0.6 to 0.7 for the studied FTIR spectra registered at different temperatures.

  9. UV-A photocatalytic treatment of Legionella pneumophila bacteria contaminated airflows through three-dimensional solid foam structured photocatalytic reactors. (United States)

    Josset, Sébastien; Hajiesmaili, Shabnam; Begin, Dominique; Edouard, David; Pham-Huu, Cuong; Lett, Marie-Claire; Keller, Nicolas; Keller, Valérie


    A 3D-structured photocatalytic media was designed for allowing a tubular reactor to work in a traversing-flow mode at low pressure drops with a strong increase in the surface area-to-volume ratio inside the reactor. A protective polysiloxane coating was performed for protecting a structured polyurethane foam and anchoring the active TiO(2) particles. Filled with the 3D-structured solid foam supporting TiO(2) photocatalyst, the reactor could thus take advantages from the static mixer effect and from the low pressure drop resulting from the reticulated foam support. Very efficient decontamination levels towards airborne Legionella pneumophila bacteria were reached in a single-pass test mode. (c) 2009 Elsevier B.V. All rights reserved.

  10. UV-A photocatalytic treatment of Legionella pneumophila bacteria contaminated airflows through three-dimensional solid foam structured photocatalytic reactors

    Energy Technology Data Exchange (ETDEWEB)

    Josset, Sebastien; Hajiesmaili, Shabnam; Begin, Dominique; Edouard, David; Pham-Huu, Cuong [Laboratoire des Materiaux, Surfaces et Procedes pour la Catalyse (LMSPC), European Laboratory for Catalysis and Surface Sciences (ELCASS), CNRS, Strasbourg University, 25 rue Becquerel 67087 Strasbourg (France); Lett, Marie-Claire [Laboratoire de Genetique Moleculaire, Genomique, Microbiologie, CNRS, Strasbourg University, 28, rue Goethe 67083 Strasbourg Cedex (France); Keller, Nicolas, E-mail: [Laboratoire des Materiaux, Surfaces et Procedes pour la Catalyse (LMSPC), European Laboratory for Catalysis and Surface Sciences (ELCASS), CNRS, Strasbourg University, 25 rue Becquerel 67087 Strasbourg (France); Keller, Valerie [Laboratoire des Materiaux, Surfaces et Procedes pour la Catalyse (LMSPC), European Laboratory for Catalysis and Surface Sciences (ELCASS), CNRS, Strasbourg University, 25 rue Becquerel 67087 Strasbourg (France)


    A 3D-structured photocatalytic media was designed for allowing a tubular reactor to work in a traversing-flow mode at low pressure drops with a strong increase in the surface area-to-volume ratio inside the reactor. A protective polysiloxane coating was performed for protecting a structured polyurethane foam and anchoring the active TiO{sub 2} particles. Filled with the 3D-structured solid foam supporting TiO{sub 2} photocatalyst, the reactor could thus take advantages from the static mixer effect and from the low pressure drop resulting from the reticulated foam support. Very efficient decontamination levels towards airborne Legionella pneumophila bacteria were reached in a single-pass test mode.

  11. Synthesis and characterization of alumina-coated aluminum sponges manufactured by sintering and dissolution process as possible structured reactors

    Energy Technology Data Exchange (ETDEWEB)

    Méndez, Franklin J., E-mail: [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado Postal 21827, Caracas 1020-A (Venezuela, Bolivarian Republic of); Rivero-Prince, Sayidh [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado Postal 21827, Caracas 1020-A (Venezuela, Bolivarian Republic of); Facultad de Ingeniería, Universidad Central de Venezuela, Caracas (Venezuela, Bolivarian Republic of); Escalante, Yelisbeth; Villasana, Yanet [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado Postal 21827, Caracas 1020-A (Venezuela, Bolivarian Republic of); Brito, Joaquín L., E-mail: [Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado Postal 21827, Caracas 1020-A (Venezuela, Bolivarian Republic of)


    Al{sub 2}O{sub 3}–Al sponges were manufactured by sintering and dissolution process with the aim of using these materials as structured catalytic reactors. For this purpose, several synthesis conditions were examined for the design of the cellular material, such as: particle size of NaCl, weight fraction of Al, compaction pressure, and sintering temperature or time. An alumina layers was grown on top of the aluminum surfaces during both: sintering and thermal treatment. The obtained results showed that the synthesized materials could be promising as structured reactors for endothermic or exothermic reactions. - Highlights: • An efficient method for manufactured of aluminum sponges is reported. • Methods for productions of superficial Al{sub 2}O{sub 3} are studied. • Al{sub 2}O{sub 3}–Al sponges could be used as structured reactors.

  12. The effect of carbon crystal structure on treat reactor physics calculations

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, R.W.; Harrison, L.J.


    The Transient Reactor Test Facility (TREAT) at Argonne National Laboratory-West (ANL-W) is fueled with urania in a graphite and carbon mixture. This fuel was fabricated from a mixture of graphite flour, thermax (a thermatomic carbon produced by ''cracking'' natural gas), coal-tar resin and U/sub 3/O/sub 8/. During the fabrication process, the fuel was baked to dissociate the resin, but the high temperature necessary to graphitize the carbon in the thermax and in the resin was avoided. Therefore, the carbon crystal structure is a complex mixture of graphite particles in a nongraphitized elemental carbon matrix. Results of calculations using macroscopic carbon cross sections obtained by mixing bound-kernel graphite cross sections for the graphitized carbon and free-gas carbon cross sections for the remainder of the carbon and calculations using only bound-kernel graphite cross sections are compared to experimental data. It is shown that the use of the hybridized cross sections which reflect the allotropic mixture of the carbon in the TREAT fuel results in a significant improvement in the accuracy of calculated neutronics parameters for the TREAT reactor. 6 refs., 2 figs., 3 tabs.

  13. All-Fiber Components for Micro-Structured Fibers Project (United States)

    National Aeronautics and Space Administration — We propose new concepts for developing components for high performance space based Lidar systems. While it is generally recognized that photonic crystal fiber...

  14. No Longer the Outlier: Updating the Air Component Structure (United States)


    sanction of the Department of Defense, Air Force, Air Education and Training Command, Air University, or other agencies or departments of the US government...area of responsibility. The air component has succeeded at its primary mission of delivering airpower to the joint and coalition environment over the...Optional) Figure 3. Current air component framework. (Adapted from Air Force Instruction 13-1AOC, vol. 3, Opera - tional Procedures—Air Operations Center

  15. Parametric dynamic structural components for prefabricated reinforced concrete elements


    Česnik, Jure


    Advanced 3D modelling computer programs for authoring of building projects are gaining on popularity among civil engineers and architects and are thus developing with lightning speed. One of the main areas of development are parametric dynamic components and their use in BIM environments. The first part of the presented work deals with the development and use of parametric dynamic components in BIM software, focusing on prefabricated construction elements. It also explains how ...

  16. the use and integration of Tekla Structures components for steel connections' calculations


    Starešinič, Marko


    The main objective of this graduation thesis is the development of Tekla Structures integrated Excel Macro files, which allow for design of steel connections: moment connection with end plate, pinned connection with fin plate and bracing connection. After building a model of a steel structures and appliying components for steel connections in Tekla Structures, a user can export component data from Tekla Structures to Excel Macro using a ComponentVariableImporter tool. Excel Macro ...

  17. Sentan: A Novel Specific Component of the Apical Structure of Vertebrate Motile Cilia


    Kubo, Akiharu; Yuba-Kubo, Akiko; Tsukita, Sachiko; Tsukita, Shoichiro; Amagai, Masayuki


    Human respiratory and oviductal cilia have specific apical structures characterized by a narrowed distal portion and a ciliary crown. These structures are conserved among vertebrates that have air respiration systems; however, the molecular components of these structures have not been defined, and their functions are unknown. To identify the molecular component(s) of the cilia apical structure, we screened EST libraries to identify gene(s) that are exclusively expressed in ciliated tissues, a...

  18. Standardization of accelerator irradiation procedures for simulation of neutron induced damage in reactor structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Lin; Gigax, Jonathan; Chen, Di; Kim, Hyosim; Garner, Frank A.; Wang, Jing; Toloczko, Mychailo B.


    Self-ion irradiation is widely used as a method to simulate neutron damage in reactor structural materials. Accelerator-based simulation of void swelling, however, introduces a number of neutron-atypical features which require careful data extraction and in some cases introduction of innovative irradiation techniques to alleviate these issues. We briefly summarize three such atypical features: defect imbalance effects, pulsed beam effects, and carbon contamination. The latter issue has just been recently recognized as being relevant to simulation of void swelling and is discussed here in greater detail. It is shown that carbon ions are entrained in the ion beam by Coulomb force drag and accelerated toward the target surface. Beam-contaminant interactions are modeled using molecular dynamics simulation. By applying a multiple beam deflection technique, carbon and other contaminants can be effectively filtered out, as demonstrated in an irradiation of HT-9 alloy by 3.5 MeV Fe ions.

  19. An integrated approach to assessing the fracture safe margins of fusion reactor structures

    Energy Technology Data Exchange (ETDEWEB)

    Odette, G.R. [Univ. of California, Santa Barbara, CA (United States)


    Design and operation of fusion reactor structures will require an appropriate data base closely coupled to a reliable failure analysis method to safely manage irradiation embrittlement. However, ongoing irradiation programs will not provide the information on embrittlement necessary to accomplish these objectives. A new engineering approach is proposed based on the concept of a master toughness-temperature curve indexed on an absolute temperature scale using shifts to account for variables such as size scales, crack geometry and loading rates as well as embrittlement. While providing a simple practical engineering expedient, the proposed method can also be greatly enhanced by fundamental mechanism based models of fracture and embrittlement. Indeed, such understanding is required for the effective use of small specimen test methods, which is a integral element in developing the necessary data base.

  20. Evaluation of Nb-base alloys for the divertor structure in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Purdy, I.M. [Argonne National Laboratory, Upton, IL (United States)


    Niobium-base alloys are candidate materials for the divertor structure in fusion reactors. For this application, an alloy should resist aqueous corrosion, hydrogen embrittlement, and radiation damage and should have high thermal conductivity and low thermal expansion. Results of corrosion and embrittlement screening tests of several binary and ternary Nb alloys in high-temperature water indicated the Mb-1Zr, Nb-5MO-1Zr, and Nb-5V-1Z4 (wt %) showed sufficient promise for further investigation. These alloys, together with pure Nb and Zircaloy-4 have been exposed to high purity water containing a low concentration of dissolved oxygen (<12 ppb) at 170, 230, and 300{degrees}C for up to {approx}3200 h. Weight-change data, microstructural observations, and qualitative mechanical-property evaluation reveal that Nb-5V-1Zr is the most promising alloy at higher temperatures. Below {approx}200{degrees}C, the alloys exhibit similiar corrosion behavior.

  1. Structural response of 1/20-scale models of the Clinch River Breeder Reactor to a simulated hypothetical core-disruptive accident

    Energy Technology Data Exchange (ETDEWEB)

    Romander, C M; Cagliostro, D J


    Five experiments were performed to help evaluate the structural integrity of the reactor vessel and head design and to verify code predictions. In the first experiment (SM 1), a detailed model of the head was loaded statically to determine its stiffness. In the remaining four experiments (SM 2 to SM 5), models of the vessel and head were loaded dynamically under a simulated 661 MW-s hypothetical core disruptive accident (HCDA). Models SM 2 to SM 4, each of increasing complexity, systematically showed the effects of upper internals structures, a thermal liner, core support platform, and torospherical bottom on vessel response. Model SM 5, identical to SM 4 but more heavily instrumented, demonstrated experimental reproducibility and provided more comprehensive data. The models consisted of a Ni 200 vessel and core barrel, a head with shielding and simulated component masses, and an upper internals structure (UIS).

  2. Helium heater design for the helium direct cycle component test facility. [for gas-cooled nuclear reactor power plant (United States)

    Larson, V. R.; Gunn, S. V.; Lee, J. C.


    The paper describes a helium heater to be used to conduct non-nuclear demonstration tests of the complete power conversion loop for a direct-cycle gas-cooled nuclear reactor power plant. Requirements for the heater include: heating the helium to a 1500 F temperature, operating at a 1000 psia helium pressure, providing a thermal response capability and helium volume similar to that of the nuclear reactor, and a total heater system helium pressure drop of not more than 15 psi. The unique compact heater system design proposed consists of 18 heater modules; air preheaters, compressors, and compressor drive systems; an integral control system; piping; and auxiliary equipment. The heater modules incorporate the dual-concentric-tube 'Variflux' heat exchanger design which provides a controlled heat flux along the entire length of the tube element. The heater design as proposed will meet all system requirements. The heater uses pressurized combustion (50 psia) to provide intensive heat transfer, and to minimize furnace volume and heat storage mass.

  3. Guide for Visual Inspection of Structural Concrete Building Components. (United States)


    reveals only generalized dangers . For a complete analysis of major structural deficiencies, the services of an experienced structural engineer are required...cured concrete; dark, partly refined mo- lasses may attack concrete that is not thoroughly cured Niter None Sal ammoniac Same as ammonium chloride...potentially dangerous , structural problem. Spalling :s characterized by circular or elliptical depressions in the concrete surfaces. A small spall is not

  4. Airway structural components drive airway smooth muscle remodeling in asthma

    NARCIS (Netherlands)

    Dekkers, Bart G J; Maarsingh, Harm; Meurs, Herman; Gosens, Reinoud


    Chronic asthma is an inflammatory airways disease characterized by pathological changes in the airway smooth muscle (ASM) bundle that contribute to airway obstruction and hyperresponsiveness. Remodeling of the ASM is associated with an increased smooth muscle mass, involving components of cellular

  5. 76 FR 69292 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water (United States)


    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY... structures and components exposed to treated borated water and adding reduction of heat transfer due to... Staff Guidance (LR-ISG), LR- ISG-2011-01, ``Aging Management of Stainless Steel Structures and...

  6. The influence of selected containment structures on debris dispersal and transport following high pressure melt ejection from the reactor vessel

    Energy Technology Data Exchange (ETDEWEB)

    Pilch, M.; Tarbell, W.W.; Brockmann, J.E.


    High pressure expulsion of molten core debris from the reactor pressure vessel may result in dispersal of the debris from the reactor cavity. In most plants, the cavity exits into the containment such that the debris impinges on structures. Retention of the debris on the structures may affect the further transport of the debris throughout the containment. Two tests were done with scaled structural shapes placed at the exit of 1:10 linear scale models of the Zion cavity. The results show that the debris does not adhere significantly to structures. The lack of retention is attributed to splashing from the surface and reentrainment in the gas flowing over the surface. These processes are shown to be applicable to reactor scale. A third experiment was done to simulate the annular gap between the reactor vessel and cavity wall. Debris collection showed that the fraction of debris exiting through the gap was greater than the gap-to-total flow area ratio. Film records indicate that dispersal was primarily by entrainment of the molten debris in the cavity. 29 refs., 36 figs., 11 tabs.

  7. Thermoplastic behaviour and structural evolution of coke and char particles in a single particle reactor

    Energy Technology Data Exchange (ETDEWEB)

    Vladimir Strezov; Jianglong Yu; Guisu Liu; John A. Lucas [University of Newcastle, Mayfield, NSW (Australia). Newbolds Applied Research


    Although coking and thermal coals have quite disparate properties and applications, both coal types undergo devolatilisation in their respective utilisation processes. The resultant carbonised materials, coke and char, show significant variations in the resulting physical structure. In both cases, particles ranging from highly porous cenospheres to very dense particles are produced. Previous studies have concluded that the physical structure affects highly significant process variables such as burnout efficiency of char, ash formation during combustion and the strength of lump coke in the blast furnace. It is therefore necessary to understand the evolution of physical structure during carbonisation of coals. In the present work a direct observation of particle swelling behaviour and bubbling phenomena during pyrolysis of coking and thermal coal particles was conducted using a single particle reactor. Coking and thermal coals were thermally treated under conditions pertinent to their thermoplastic development, e.g. coking coals were subjected to low heating rates while the thermal coals under high heating rates. Bubble growth and ruptures during the plastic stage were captured using a CCD video camera equipped with a long distance microscopic lens. There were similarities in bubble formation between both thermal and coking coals such as multi-bubble and single bubble development and rupture and consequent particle shrinkage. Comparative and quantitative analysis of the thermoplastic behaviour of the coking and thermal coals are here outlined in detail. 13 refs., 8 figs., 2 tabs.

  8. Nominal and Structural Subtyping in Component-Based Programming

    DEFF Research Database (Denmark)

    Ostermann, Klaus


    In nominal type systems, the subtype relation is between names of types, and subtype links are explicitly declared. In structural type systems, names are irrelevant; in determining type compatibility, only the structure of types is considered, and a type name is just an abbreviation for the full ...... and delineates the frontiers of the subtyping design space. In addition, we propose a new subtyping definition in one particularly interesting corner of the design space which combines the safety of nominal subtyping with the flexibility of structural subtyping....

  9. Analytical complex at the PIK reactor for studying the supra-atomic structure and dynamics of materials by neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, V. M., E-mail:; Lebedev, V. T.; Ivanova, I. N.; Orlova, D. N. [Russian Academy of Sciences, St. Petersburg Nuclear Physics Institute (Russian Federation)


    A project of the center for studying reactor materials and solving problems of materials science is presented which will be equipped with the following neutron instruments: a small-angle Membrana diffractometer, a spin-echo spectrometer, and a time-of-flight spectrometer. It is proposed to irradiate materials in the PIK reactor core and use neutron-scattering tools to analyze the structure and dynamics of these materials and investigate radiative defects in the complete experimental cycle (initial material-irradiation-strength tests, thermal loads, and other effects) using materials science techniques.

  10. Reactor Materials Program - Baseline Material Property Handbook - Mechanical Properties of 1950's Vintage Stainless Steel Weldment Components, Task Number 89-23-A-1

    Energy Technology Data Exchange (ETDEWEB)

    Stoner, K.J.


    The Process Water System (primary coolant) piping of the nuclear production reactors constructed in the 1950''s at Savannah River Site is comprised primarily of Type 304 stainless steel with Type 308 stainless steel weld filler. A program to measure the mechanical properties of archival PWS piping and weld materials (having approximately six years of service at temperatures between 25 and 100 degrees C) has been completed. The results from the mechanical testing has been synthesized to provide a mechanical properties database for structural analyses of the SRS piping.

  11. Reactor safeguards against insider sabotage

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, H.A.


    A conceptual safeguards system is structured to show how both reactor operations and physical protection resources could be integrated to prevent release of radioactive material caused by insider sabotage. Operational recovery capabilities are addressed from the viewpoint of both detection of and response to disabled components. Physical protection capabilities for preventing insider sabotage through the application of work rules are analyzed. Recommendations for further development of safeguards system structures, operational recovery, and sabotage prevention are suggested.

  12. Modeling of quantitative effects of water components on the photocatalytic degradation of 17α-ethynylestradiol in a modified flat plate serpentine reactor. (United States)

    Wang, Dawei; Li, Yi; Li, Guoping; Wang, Chao; Zhang, Wenlong; Wang, Qing


    The effect of water components on the photocatalytic degradation of organic pollutants was incompletely understood, especially in the case of hydroxyl radical (•OH) generation and scavenging. Previous studies have used various methods to determine the rate constants for the reactions between •OH and water components, but the interactions between water components were not taken into concern. In this study, a sequential relative rate technique was used to investigate the effects of water components on the rates of •OH generation and EE2 degradation in a modified flat plate serpentine reactor, including NO₃(-), H₂PO₄(-), SO₄(2-), CO₃(2-), Cl(-), Na(+), Fe(3+), dissolved organic matter (DOM) etc. The results reflected that NO₃(-) and DOM accelerated the photodegradation of 17α-ethynylestradiol (EE2) (3.2% and 21.2%, respectively). Cl(-) and Fe(3+) inhibited that process (5.2% and 3.1%, respectively). Finally, a model for the photocatalytic degradation of EE2 was developed for the first time, taking the obtained rate constants, catalyst concentrations, flow velocities and light intensities into concern. A good agreement was observed between the model and experimental profiles. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. International Atomic Energy Agency (IAEA) Coordinated Research Projects on Structural Integrity of Reactor Pressure Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Server, W. L. [ATI Consulting, Pinehurst, NC; Nanstad, Randy K [ORNL


    The International Atomic Energy Agency (IAEA) has conducted a series of Coordinated Research Projects (CRPs) that have focused on irradiated reactor pressure vessel (RPV) steel fracture toughness properties and approaches for assuring structural integrity of RPVs throughout operating life. A series of nine CRPs have been sponsored by the IAEA, starting in the early 1970s, focused on neutron radiation effects on RPV steels. The purpose of the CRPs was to develop comparisons and correlations to test the uniformity of irradiated results through coordinated international research studies and data sharing. Consideration of dose rate effects, effects of alloying (nickel, manganese, silicon, etc.) and residual elements (eg., copper and phosphorus), and drop in upper shelf toughness are also important for assessing neutron embrittlement effects. The ultimate use of embrittlement understanding is assuring structural integrity of the RPV under current and future operation and accident conditions. Material fracture toughness is the key ingredient needed for this assessment, and many of the CRPs have focused on measurement and application of irradiated fracture toughness. This paper presents an overview of the progress made since the inception of the CRPs in the early 1970s. The chronology and importance of each CRP have been reviewed and put into context for continued and long-term safe operation of RPVs.

  14. Nuclear reactor fuel structure containing uranium alloy wires embedded in a metallic matrix plate (United States)

    Travelli, A.


    A flat or curved plate structure, to be used as fuel in a nuclear reactor, comprises elongated fissionable wires or strips embedded in a metallic continuous non-fissionable matrix plate. The wires or strips are made predominantly of a malleable uranium alloy, such as uranium silicide, uranium gallide or uranium germanide. The matrix plate is made predominantly of aluminum or an aluminum alloy. The wires or strips are located in a single row at the midsurface of the plate, parallel with one another and with the length dimension of the plate. The wires or strips are separated from each other, and from the surface of the plate, by sufficient thicknesses of matrix material, to provide structural integrity and effective fission product retention, under neutron irradiation. This construction makes it safely feasible to provide a high uranium density, so that the uranium enrichment with uranium 235 may be reduced below about 20%, to deter the reprocessing of the uranium for use in nuclear weapons.

  15. Mechanical analysis of an assembly box with honeycomb structure designed for a performance light water reactor; Strukturmechanische Auslegung eines HPLWR Brennelementkastens in Leichtbauweise

    Energy Technology Data Exchange (ETDEWEB)

    Herbell, H.; Himmel, S.


    The High Performance Light Water Reactor (HPLWR) is a water cooled reactor concept of the 4{sup th} generation, operated at a pressure beyond the critical point of water. In this report an innovative design for moderator- and assembly boxes is investigated, consisting of an alumina filled stainless steel honeycomb structure, built as a sandwich design between two stainless steel liners. Such temperatures and pressures (25 MPa, 500 C) require the use of stainless steel assembly boxes; however, such walls cause significant neutron absorption. Moreover, the moderator water is heated up, which makes it less effective. Therefore, the thermal conductivity of the box walls should be decreased by a good thermal isolation, ensuring that the moderator water remains at high density. As an innovative approach, thin walled assembly boxes with sufficient stiffness and low thermal conductivity could be made from honeycomb structures, in which the cavities are filled with alumina for thermal insulation. Finite element analyses are used to verify the required stiffness, to identify stress concentrations and to optimize the design. The sandwich panel has been designed with regard to sandwich specific failure modes. A stress analysis of the assembly box according to KTA 3201.2 guideline as used for components of the primary circle of light water reactors is performed. The corner pieces turned out as the weak points of the initial design. Even a significant increase of the number of stiffening ribs in corner pieces did not reduce the stress peaks sufficiently, thus massive corner pieces were finally taken. Panel deflection is within the design limits whereas the estimated bending line along the total height of the assembly box exceeds geometrical boundaries. Therefore some spacers between the fuel elements are necessary. The results presented in this study indicate that honeycomb sandwich structures could be applicable in the core of the HPLWR reactor. This feature will minimize the

  16. The Effect of Initial Inoculum Source on the Microbial Community Structure and Dynamics in Laboratory-Scale Sequencing Batch Reactors

    KAUST Repository

    Hernandez, Susana


    Understanding the factors that shapes the microbial community assembly in activated sludge wastewater treatment processes provide a conceptual foundation for improving process performance. The aim of this study was to compare two major theories (deterministic theory and neutral theory) regarding the assembly of microorganisms in activated sludge: Six lab-scale activated sludge sequencing batch reactors were inoculated with activated sludge collected from three different sources (domestic, industrial, and sugar industry WWTP). Additionally, two reactors were seeded with equal proportion of sludge from the three WWTPs. Duplicate reactors were used for each sludge source (i.e. domestic, industrial, sugar and mix). Reactors were operated in parallel for 11 weeks under identical conditions. Bacterial diversity and community structure in the eight SBRs were assessed by 16S rRNA gene pyrosequencing. The 16S rRNA gene sequences were analyzed using taxonomic and clustering analysis and by measuring diversity indices (Shannon-weaver and Chao1 indices). Cluster analysis revealed that the microbial community structure was dynamic and that replicate reactors evolved differently. Also the microbial community structure in the SBRs seeded with a different sludge did not converge after 11 weeks of operation under identical conditions. These results suggest that history and distribution of taxa in the source inoculum were stronger regulating factors in shaping bacterial community structure than environmental factors. This supports the neutral theory which states that the assembly of the local microbial community from the metacommunity is random and is regulated by the size and diversity of the metacommunity. Furthermore, sludge performance, measured by COD and ammonia removal, confirmed that broad-scale functions (e.g. COD removal) are not influenced by dynamics in the microbial composition, while specific functions (e.g. nitrification) are more susceptible to these changes.

  17. The Structural Geographic Components of a Territorial Survey

    Directory of Open Access Journals (Sweden)



    Full Text Available When using regional geographic approaches, i.e. when applying its concepts to the problems of anthropic communities from a certain territory, is compulsory. In this study we have taken into account the complex and the etymologically adequate meaning of the notion and not the meaning most commonly used at present (i.e. the functional zoning and regionalisation of the territory. Relying on the estimations of territorial surveys, one may give the solutions for the extant malfunctions and for optimising future developments. The geographic components of this parameter (the territorial survey are: the natural support basis, the population and its settlements, the social and economic development level, the technical equipment of the territory, and the extant risks and malfunctions. Indices from 1 to 10 will be summed in order to give us the big picture, namely the present-day situation and the favourability level of that territory for various anthropic interventions.

  18. Radiation facilities for fusion-reactor first-wall and blanket structural-materials development

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L.; Bloom, E.E.


    Present and future irradiation facilities for the study of fusion reactor irradiation damage are reviewed. Present studies are centered on irradiation in accelerator-based neutron sources, fast- and mixed-spectrum fission reactors, and ion accelerators. The accelerator-based neutron sources are used to demonstrate damage equivalence between high-energy neutrons and fission reactor neutrons. Once equivalence is demonstrated, the large volume of test space available in fission reactors can be used to study displacement damage, and in some instances, the effects of high-helium concentrations and the interaction of displacement damage and helium on properties. Ion bombardment can be used to study the mechanisms of damage evolution and the interaction of displacement damage and helium. These techniques are reviewed, and typical results obtained from such studies are examined. Finally, future techniques and facilities for developing damage levels that more closely approach those expected in an operating fusion reactor are discussed.

  19. Microchannel Reactors for ISRU Applications (United States)

    Carranza, Susana; Makel, Darby B.; Blizman, Brandon; Ward, Benjamin J.


    Affordable planning and execution of prolonged manned space missions depend upon the utilization of local resources and the waste products which are formed in manned spacecraft and surface bases. Successful in-situ resources utilization (ISRU) will require component technologies which provide optimal size, weight, volume, and power efficiency. Microchannel reactors enable the efficient chemical processing of in situ resources. The reactors can be designed for the processes that generate the most benefit for each mission. For instance, propellants (methane) can be produced from carbon dioxide from the Mars atmosphere using the Sabatier reaction and ethylene can be produced from the partial oxidation of methane. A system that synthesizes ethylene could be the precursor for systems to synthesize ethanol and polyethylene. Ethanol can be used as a nutrient for Astrobiology experiments, as well as the production of nutrients for human crew (e.g. sugars). Polyethylene can be used in the construction of habitats, tools, and replacement parts. This paper will present recent developments in miniature chemical reactors using advanced Micro Electro Mechanical Systems (MEMS) and microchannel technology to support ISRU of Mars and lunar missions. Among other applications, the technology has been demonstrated for the Sabatier process and for the partial oxidation of methane. Microchannel reactors were developed based on ceramic substrates as well as metal substrates. In both types of reactors, multiple layers coated with catalytic material are bonded, forming a monolithic structure. Such reactors are readily scalable with the incorporation of extra layers. In addition, this reactor structure minimizes pressure drop and catalyst settling, which are common problems in conventional packed bed reactors.

  20. Design-Load Basis for LANL Structures, Systems, and Components

    Energy Technology Data Exchange (ETDEWEB)

    I. Cuesta


    This document supports the recommendations in the Los Alamos National Laboratory (LANL) Engineering Standard Manual (ESM), Chapter 5--Structural providing the basis for the loads, analysis procedures, and codes to be used in the ESM. It also provides the justification for eliminating the loads to be considered in design, and evidence that the design basis loads are appropriate and consistent with the graded approach required by the Department of Energy (DOE) Code of Federal Regulation Nuclear Safety Management, 10, Part 830. This document focuses on (1) the primary and secondary natural phenomena hazards listed in DOE-G-420.1-2, Appendix C, (2) additional loads not related to natural phenomena hazards, and (3) the design loads on structures during construction.

  1. Optimal glass-ceramic structures: Components of giant mirror telescopes (United States)

    Eschenauer, Hans A.


    Detailed investigations are carried out on optimal glass-ceramic mirror structures of terrestrial space technology (optical telescopes). In order to find an optimum design, a nonlinear multi-criteria optimization problem is formulated. 'Minimum deformation' at 'minimum weight' are selected as contradictory objectives, and a set of further constraints (quilting effect, optical faults etc.) is defined and included. A special result of the investigations is described.

  2. Status of LWR primary pressure boundary structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Se Hwan; Hong, Jun Hwa; Byun, Taek Sang; Kang, Sung Sik; Ryu, Woo Seog; Lee, Bong Sang; Kook, Il Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)


    The integrity of major systems, structures and components is a prerequisite to the economy and safety of an existing light water reactor and also for the next generation reactors. As few reactor structural materials are being manufactured by domestic companies, based on economic and safety reasons, a new demand to improve the quality of domestic reactor structural materials and to develop reactor structural steels has arisen. Investigations on the state-of-the-art of the materials specifications, performance and current state of structural materials development were performed as a first step to domestic reactor structural steel development and summarized the result in the present report. (Author) 10 refs., 10 figs., 21 tabs.

  3. Nonlinear time-domain soil–structure interaction analysis of embedded reactor structures subjected to earthquake loads

    Energy Technology Data Exchange (ETDEWEB)

    Solberg, Jerome M., E-mail: [Methods Development Group, Lawrence Livermore Nat’l Lab, P.O. Box 808, Mailstop L-125, Livermore, CA 94550 (United States); Hossain, Quazi, E-mail: [Structural and Applied Mechanics Group, Lawrence Livermore Nat’l Lab, P.O. Box 808, Mailstop L-129, Livermore, CA 94550 (United States); Mseis, George, E-mail: [Structural and Applied Mechanics Group, Lawrence Livermore Nat’l Lab, P.O. Box 808, Mailstop L-129, Livermore, CA 94550 (United States)


    Highlights: • Derived modified version of Bielak’s SSI method for nonlinear time-domain analysis. • Utilized a Ramberg–Osgood material with parameters that can be fit to EPRI data. • Matched vertically propagating shear wave results from CARES. • Applied this technique to a representative SMR, compared well with SASSI. • The technique is extensible to other material models and nonlinear effects. - Abstract: A generalized time-domain method for soil–structure interaction analysis is developed, based upon an extension of the work of the domain reduction method of Bielak et al. The methodology is combined with the use of a simple hysteretic soil model based upon the Ramberg–Osgood formulation and applied to a notional Small Modular Reactor. These benchmark results compare well (with some caveats) with those obtained by using the industry-standard frequency-domain code SASSI. The methodology provides a path forward for investigation of other sources of nonlinearity, including those associated with the use of more physically-realistic material models incorporating pore-pressure effects, gap opening/closing, the effect of nonlinear structural elements, and 3D seismic inputs.

  4. Mechanical Analysis of an Innovative Assembly Box with Honeycomb Structures Designed for a High Performance Light Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Herbell, Heiko [EnBW Kernkraft GmbH, 76661 Philippsburg (Germany); Himmel, Steffen; Schulenberg, Thomas [Forschungszentrum Karlsruhe, Institute for Nuclear and Energy Technologies, 76021 Karlsruhe (Germany)


    The High Performance Light Water Reactor (HPLWR) is a water cooled reactor concept of the 4. generation, operated at a pressure beyond the critical point of water. Assemblies of this innovative reactor concept need to be built with assembly and moderator boxes, like boiling water reactors, to provide enough moderator water between them to compensate the low coolant density in the core. Hot, superheated steam conditions, on the other hand, require thermally insulated box walls rather than solid box walls to reduce the heat up of the moderator water. As a new an innovative approach, this paper describes moderator- and assembly boxes built from stainless steel honeycomb sandwich structures, in which the honeycomb cells are filled with alumina for thermal insulation. In comparison to solid box walls, the use of the presented design can provide the same stiffness but allows a drastic reduction of structural material and thus less neutron absorption. Finite element analyses are used to verify the required stiffness, to identify stress concentrations and to optimize the design. (authors)

  5. Effects of non-structural components and soil-structure interaction on the seismic response of framed structures (United States)

    Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Nigro, Antonella; Carlo Ponzo, Felice


    In this paper, several nonlinear numerical models of reinforced concrete framed structures have been defined in order to evaluate the effects of non-structural elements and soil-structure interaction on the elastic dynamic behaviour of buildings. In the last few years, many and various studies have highlighted the significant effects derived from the interaction between structural and non-structural components on the main dynamic characteristics of a building. Usually, structural and non-structural elements act together, adding both masses and stiffness. The presence of infill panels is generally neglected in the design process of structural elements, although these elements can significantly increase the lateral stiffness of a structure leading to a modification in the dynamic properties. Particularly, at the Damage Limit State (where an elastic behaviour is expected), soil-structure interaction effects and non-structural elements may further affect the elastic natural period of buildings, changing the spectral accelerations compared with those provided by seismic codes in case of static analyses. In this work, a parametric study has been performed in order to evaluate the elastic fundamental period of vibration of buildings as a function of structural morphology (height, plan area, ratio between plan dimensions), infills presence and distribution and soil characteristics. Acknowledgements This study was partially funded by the Italian Department of Civil Protection within the project DPC-RELUIS 2016 - RS4 ''Seismic observatory of structures and health monitoring'' and by the "Centre of Integrated Geomorphology for the Mediterranean Area - CGIAM" within the Framework Agreement with the University of Basilicata "Study, Research and Experimentation in the Field of Analysis and Monitoring of Seismic Vulnerability of Strategic and Relevant Buildings for the purposes of Civil Protection and Development of Innovative Strategies of Seismic Reinforcement".

  6. Studies of low temperature, low flux radiation embrittlement of nuclear reactor structural materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Odette, G.R.; Lucas, G.E.


    A large matrix of simple alloys and complex commercial type steels was irradiated over a range of fluxes at 60 C up to a fast fluence of about 3 {times} 10{sup 22} n/m{sup 2}. Combined with data in the literature, these results show a negligible effect of flux on irradiation hardening in the range of 2 {times} 10{sup 13} to 5 {times} 10{sup 18} n/m{sup 2}-s. This observation lends indirect support to the proposal that the accelerated embrittlement in the High Flux Isotope Reactor surveillance steels was due to an anomalously high level of damage from gamma rays. A weak dependence of hardening on a number of elements, including copper, nickel, phosphorus, molybdenum and manganese, can be described by a simple empirical chemistry factor. Particular combinations of elements resulted in hardening differences of up to about 60% in the complex commercial type steels and up to about 100% in simple model alloys. Direct effects of microstructure appear to be minimal. Hardening varies with the square root of fluence above a threshold around 4 {times} 10{sup 20} n/m{sup 2}. The results suggest that low temperature hardening is dominated by local intracascade processes leading to the formation of small defect-solute clusters/complexes. The observed hardening corresponds to nominal maximum end-of-life transition temperature shifts in support structure steels of about 120 C.

  7. Different substrates and starter inocula govern microbial community structures in biogas reactors. (United States)

    Satpathy, Preseela; Steinigeweg, Sven; Cypionka, Heribert; Engelen, Bert


    The influence of different starter inocula on the microbial communities in biogas batch reactors fed with fresh maize and maize silage as substrates was investigated. Molecular biological analysis by Denaturing Gradient Gel Electrophoresis (DGGE) of 16S rRNA gene fragments showed that each inoculum bore specific microbial communities with varying predominant phylotypes. Both, bacterial and archaeal DGGE profiles displayed three distinct communities that developed depending on the type of inoculum. Although maize and silage are similar substrates, different communities dominated the lactate-rich silage compared to lactate-free fresh maize. Cluster analysis of DGGE gels showed the communities of the same substrates to be stable with their respective inoculum. Bacteria-specific DGGE analysis revealed a rich diversity with Firmicutes being predominant. The other abundant phylotypes were Bacteroidetes and Synergistetes. Archaea-specific DGGE analysis displayed less diverse community structures, identifying members of the Methanosarcinales as the dominant methanogens present in all the three biogas digesters. In general, the source of inoculum played a significant role in shaping microbial communities. Adaptability of the inoculum to the substrates fed also influenced community compositions which further impacted the rates of biogas production.

  8. Irradiation of structural materials in contact with lead bismuth eutectic in the high flux reactor

    Energy Technology Data Exchange (ETDEWEB)

    Magielsen, A.J., E-mail: [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands); Jong, M.; Bakker, T.; Luzginova, N.V.; Mutnuru, R.K.; Ketema, D.J.; Fedorov, A.V. [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands)


    In the framework of the materials domain DEMETRA in the European Transmutation research and development project EUROTRANS, irradiation experiment IBIS has been performed in the High Flux Reactor in Petten. The objective was to investigate the synergystic effects of irradiation and lead bismuth eutectic exposure on the mechanical properties of structural materials and welds. In this experiment ferritic martensitic 9 Cr steel, austenitic 316L stainless steel and their welds have been irradiated for 250 Full Power Days up to a dose level of 2 dpa. Irradiation temperatures have been kept constant at 300 deg. C and 500 deg. C. During the post-irradiation test phase, tensile tests performed on the specimens irradiated at 300 deg. C have shown that the irradiation hardening of ferritic martensitic 9 Cr steel at 1.3 dpa is 254 MPa, which is in line with the irradiation hardening obtained for ferritic martensitic Eurofer97 steel investigated in the fusion program. This result indicates that no LBE interaction at this irradiation temperature is present. A visual inspection is performed on the specimens irradiated in contact with LBE at 500 deg. C and have shown blackening on the surface of the specimens and remains of LBE that makes a special cleaning procedure necessary before post-irradiation mechanical testing.


    Directory of Open Access Journals (Sweden)

    Liudmyla Zubkova


    Full Text Available Nowadays, life competence of a person plays a very important role as it helps to solve effectively problems that every person can face in his/her life. Nevertheless, contemporary students show an unsatisfactory level of life competence, so it is very important for teachers in high education to pay attention to its formation. It was found that structural components of life competence have been researched by such scientists as M. Stepanenko, N. Nischeta, L. Scherbakova and others. However, in our opinion structural components of life competence should be generalized, so it is the purpose of our article. It is in studies revealing that there is no unified point of view of life competence structural components. In particular, scientists have distinguished such life competence structural components as 1 meta anthropologic, individual and personal, contextual, and social components (M. Stepanenko; 2 self-conception, axiological values, emotional and characterful components (V. Nischeta, 3 social, educative, communicative, and auto psychological components (L. Scherbakova. It should be noticed that the meta anthropologic component concentrates on the ability of a person to reflect individually main attributes of a human life; the individual and personal component focuses on self-identification and self-realization; the contextual component considers the ability of an individual to take real-life situations in good sense; the social component focuses on personal ability to solve real-life tasks regarding to social circumstances. The educative component of life competence includes knowledge of educational process essence and specific features of higher educational establishments. The communicative component represents knowledge about the role of communication in life success strategy. Taking into account scientists’ opinion and the author’s consideration it is concluded that the elucidation and generalization of life competence structural components

  10. Effects of photochemical smog from a flow reactor on bacteria. II. Determination of bactericidal components in photochemical smog

    Energy Technology Data Exchange (ETDEWEB)

    Nover, H.; Botzenhart, K.


    The mixture of substances in the photochemical smog could be detected by different reduction rates of exposed bacteria. Beside ozone other products of the ozone/olefine-reaction could reduce the survival of exposed bacteria. For Staph. epidermidis a toxic influence from the reaction products could be found only after UV-irradiation. The main components were aldehydes, hydrocarbons, radicals, peroxiradicals and radicaloxides. For peroxiacetylnitrate (PAN) no bactericidal effect could be found for bacteria adsorbed on membrane filters in concentrations of 300 ppb in the smog (UV-irradiation was put off for two hours) and even in concentrations of 1000 ppb prepared by gaschromatography. The influence on lipopolysaccharide (lps) defective mutants of Salmonella minnesota showed the protection of the lps-layer against e.g. relative humidity and ozone (500 ppb), but no specific protection against smog components.

  11. Vertical Distribution of Structural Components in Corn Stover

    Directory of Open Access Journals (Sweden)

    Jane M. F. Johnson


    Full Text Available In the United States, corn (Zea mays L. stover has been targeted for second generation fuel production and other bio-products. Our objective was to characterize sugar and structural composition as a function of vertical distribution of corn stover (leaves and stalk that was sampled at physiological maturity and about three weeks later from multiple USA locations. A small subset of samples was assessed for thermochemical composition. Concentrations of lignin, glucan, and xylan were about 10% greater at grain harvest than at physiological maturity, but harvestable biomass was about 25% less due to stalk breakage. Gross heating density above the ear averaged 16.3 ± 0.40 MJ kg−1, but with an alkalinity measure of 0.83 g MJ−1, slagging is likely to occur during gasification. Assuming a stover harvest height of 10 cm, the estimated ethanol yield would be >2500 L ha−1, but it would be only 1000 L ha−1 if stover harvest was restricted to the material from above the primary ear. Vertical composition of corn stover is relatively uniform; thus, decision on cutting height may be driven by agronomic, economic and environmental considerations.

  12. Vertical distribution of structural components in corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Jane M. F. Johnson; Douglas L. Karlen; Garold L. Gresham; Keri B. Cantrell; David W. Archer; Brian J. Wienhold; Gary E. Varvel; David A. Laird; John Baker; Tyson E. Ochsner; Jeff M. Novak; Ardell D. Halvorson; Francisco Arriaga; David T. Lightle; Amber Hoover; Rachel Emerson; Nancy W. Barbour


    In the United States, corn (Zea mays L.) stover has been targeted for second generation fuel production and other bio-products. Our objective was to characterize sugar and structural composition as a function of vertical distribution of corn stover (leaves and stalk) that was sampled at physiological maturity and about three weeks later from multiple USA locations. A small subset of samples was assessed for thermochemical composition. Concentrations of lignin, glucan, and xylan were about 10% greater at grain harvest than at physiological maturity, but harvestable biomass was about 25% less due to stalk breakage. Gross heating density above the ear averaged 16.3 ± 0.40 MJ kg?¹, but with an alkalinity measure of 0.83 g MJ?¹, slagging is likely to occur during gasification. Assuming a stover harvest height of 10 cm, the estimated ethanol yield would be >2500 L ha?¹, but it would be only 1000 L ha?¹ if stover harvest was restricted to the material from above the primary ear. Vertical composition of corn stover is relatively uniform; thus, decision on cutting height may be driven by agronomic, economic and environmental considerations.

  13. Identifying the component structure of job satisfaction by principal components analysis among extension officers in North West Province, South Africa

    Directory of Open Access Journals (Sweden)

    Lenah Karabo Mabe


    Full Text Available The component structure of a 34-item scale measuring different aspects of job satisfaction was investigated among extension officers in North West Province, South Africa. A simple random sampling technique was used to select 40 extension officers from which data were collected. A structured questionnaire consisting of 34 job satisfaction and 10 personal characteristic items was administered to the extension officers. Items on job satisfaction were measured at interval level and analyzedwith Principal ComponentAnalysis. Most of the respondents (82.5% weremales, between 40 to 45 years, 85% were married and 87.5% had a diploma as their educational qualification. Furthermore, 54% of the households size between 4 to 6 persons, whereas 75% were Christians. The majority of the extension officers lived in their job area (82.5, while 80% covered at least 3 communities and 3 farmer groups. In terms of number of farmers covered, only 40% of the extension officers covered more than 500 farmers and 45% travelled more than 40 km to reach their farmers. From the job satisfaction items 9 components were extracted to show areas for job satisfaction among extension officers. These were in-service training, research policies, communicating recommended practices, financial support for self and family, quality of technical help, opportunity to advance education, management and control of operations, rewarding system and sanctions. The results have several implications for motivating extension officers for high job performance especially with large number of clients and small number of extension agents.

  14. Investigation of two-phase flow structure in model of draught pipe of water boiling reactor VK-300

    Energy Technology Data Exchange (ETDEWEB)

    Efanov, A.D.; Kuznetzov, Y.N.; Kaliakin, S.G.; Lisitza, F.D.; Remizov, O.V.; Serdun, N.P. [Institute of Physics and Power Engineering State Scientific Center, Obninsk (Russian Federation)


    VK-300 reactor represents a vessel-type boiling reactor with integral arrangement of assemblies and in-vessel steam separation at one-circuit scheme. The circuit consists of core, draught pipes, and separation facilities. The vessel of VK-300 reactor is chosen on the base of the dimensions of that of VVER-1000 reactor. The following thermal-hydraulic parameters of nuclear power plant (NPP) were investigated experimentally: dependence of void fraction upon the steam quality in mixing chamber (on the draught section input); pressure losses at different, specific zones of up-flow and down-flow sections of the circuit with free circulation; degree of steam separation in the separating chamber (at the first step of phase separation) and its dependence upon steam quality; structure of steam-water flow in draught pipes (distribution of phases over the draught pipe cross- section); presence of steam hovering and height of this hovering in inter-pipe space of draught section. (author)

  15. Media arrangement impacts cell growth in anaerobic fixed-bed reactors treating sugarcane vinasse: Structured vs. randomic biomass immobilization. (United States)

    de Aquino, Samuel; Fuess, Lucas Tadeu; Pires, Eduardo Cleto


    This study reports on the application of an innovative structured-bed reactor (FVR) as an alternative to conventional packed-bed reactors (PBRs) to treat high-strength solid-rich wastewaters. Using the FVR prevents solids from accumulating within the fixed-bed, while maintaining the advantages of the biomass immobilization. The long-term operation (330days) of a FVR and a PBR applied to sugarcane vinasse under increasing organic loads (2.4-18.0kgCODm -3 day -1 ) was assessed, focusing on the impacts of the different media arrangements over the production and retention of biomass. Much higher organic matter degradation rates, as well as long-term operational stability and high conversion efficiencies (>80%) confirmed that the FVR performed better than the PBR. Despite the equivalent operating conditions, the biomass growth yield was different in both reactors, i.e., 0.095gVSSg -1 COD (FVR) and 0.066gVSSg -1 COD (PBR), indicating a clear control of the media arrangement over the biomass production in fixed-bed reactors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Related activities on management of ageing of Dalat Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Pham Van Lam [Reactor Dept., Nuclear Research Institute, Dalat (Viet Nam)


    The Dalat Nuclear Research Reactor (DNRR) is a pool type research reactor which was reconstructed in 1982 from the previous 250 kW TRIGA-MARK II reactor. The reactor core, the control and instrumentation system, the primary and secondary cooling systems as well as other associated systems were newly designed and installed. The renovated reactor reached its initial criticality in November 1983 and attained its nominal power of 500 kW in February 1984. Since then DNRR has been operated safely. Retained structures of the former reactor such as the reactor aluminum tank, the graphite reflector, the thermal column, the horizontal beam tubes and the radiation concrete shielding are 35 years old. During the recent years, in-service inspection has been carried out, the reactor control and instrumentation system were renovated due to ageing and obsolescence of its components, reactor general inspection and refurbishment were performed. Efforts are being made to cope with ageing of old reactor components to maintain safe operation of the DNRR. (author)

  17. A study on nuclear properties of Zr, Nb, and Ta nuclei used as structural material in fusion reactor

    Directory of Open Access Journals (Sweden)

    Sahan Halide


    Full Text Available Fusion has a practically limitless fuel supply and is attractive as an energy source. The main goal of fusion research is to construct and operate an energy generating system. Fusion researches also contains fusion structural materials used fusion reactors. Material issues are very important for development of fusion reactors. Therefore, a wide range of fusion structural materials have been considered for fusion energy applications. Zirconium (Zr, Niobium (Nb and Tantalum (Ta containing alloys are important structural materials for fusion reactors and many other fields. Naturally Zr includes the 90Zr (%51.5, 91Zr (%11.2, 92Zr (%17.1, 94Zr (%17.4, 96Zr (%2.80 isotopes and 93Nb and 181Ta include the 93Nb (%100 and 181Ta (%99.98, respectively. In this study, the charge, mass, proton and neutron densities and the root-mean-square (rms charge radii, rms nuclear mass radii, rms nuclear proton, and neutron radii have been calculated for 87-102Zr, 93Nb, 181Ta target nuclei isotopes by using the Hartree–Fock method with an effective Skyrme force with SKM*. The calculated results have been compared with those of the compiled experimental taken from Atomic Data and Nuclear Data Tables and theoretical values of other studies.

  18. Development of W-composites/EUROFER brazed joints for the first wall component of future fusion reactors (United States)

    de Prado, J.; Sánchez, M.; Antusch, S.; Ureña, A.


    The present work describes a joining procedure between two different tungsten composite materials (W–2Y2O3 and W–1TiC) with reduced activation ferritic–martensitic steel (Eurofer). The results indicated the achievement, in both cases, of high quality W-composites/Eurofer joints using 80Cu–20Ti as filler material. The braze is constituted by several ternary Cu–Ti–Fe phases distributed along a Cu-matrix, which acts as ductile phase capable of relieving the residual stresses, which could be produced during the service life of the component. Some cracks growing from W–braze interface into the base material have been detected. They are originated by the stresses produced during the cooling stage of the brazing cycle. Regarding the strength of the joints, similar shear strengths of both joints were obtained (∼105 MPa). These values were slightly lower than the ones obtained when pure tungsten was used as the base metal.

  19. Development of mechanical design technology for integral reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Keun Bae; Choi, Suhn; Kim, Kang Soo; Kim, Tae Wan; Jeong, Kyeong Hoon; Lee, Gyu Mahn


    While Korean nuclear reactor strategy seems to remain focused on the large capacity power generation, it is expected that demand of small and medium size reactor will arise for multi-purpose application such as small capacity power generation, co-generation and sea water desalination. With this in mind, an integral reactor SMART is under development. Design concepts, system layout and types of equipment of integral reactor are significantly different from those of loop type reactor. Conceptual design development of mechanical structures of integral reactor SMART is completed through the first stage of the project. Efforts were endeavored for the establishment of design basis and evaluation of applicable codes and standards. Design and functional requirements of major structural components were setup, and three dimensional structural modelling of SMART reactor vessel assembly was prepared. Also, maintenance and repair scheme as well as preliminary fabricability evaluation were carried out. Since small integral reactor technology includes sensitive technologies and know-how's, it is hard to achieve systematic and comprehensive technology transfer from nuclear-advanced countries. Thus, it is necessary to develop the related design technology and to verify the adopted methodologies through test and experiments in order to assure the structural integrity of reactor system. (author)

  20. Design guide for category II reactors light and heavy water cooled reactors. [US DOE

    Energy Technology Data Exchange (ETDEWEB)

    Brynda, W J; Lobner, P R; Powell, R W; Straker, E A


    The Department of Energy (DOE), in the ERDA Manual, requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification operation, maintainance, and decommissioning of DOW-owned reactors be in accordance with generally uniform standards, guide and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirements of Category II reactor structure, components, and systems.

  1. Design guide for Category III reactors: pool type reactors. [US DOE

    Energy Technology Data Exchange (ETDEWEB)

    Brynda, W J; Lobner, P R; Powell, R W; Straker, E A


    The Department of Energy (DOE) in the ERDA Manual requires that all DOE-owned reactors be sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that gives adequate consideration to health and safety factors. Specific guidance pertinent to the safety of DOE-owned reactors is found in Chapter 0540 of the ERDA Manual. The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC). This Design Guide deals principally with the design and functional requirement of Category III reactor structures, components, and systems.

  2. Thermal-Fatigue Analysis of W-coated Ferritic-Martensitic Steel Mockup for Fusion Reactor Components

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Kim, Suk Kwon; Park, Seong Dae; Kim, Dong Jun [KAERI, Daejeon (Korea, Republic of); Moon, Se Yeon; Hong, Bong Guen [Chonbuk University, Jeonju (Korea, Republic of)


    In this study, commercial ANSYS-CFX for thermalhydraulic analysis and ANSYS-mechanical for the thermo-mechanical analysis are used to evaluate the thermal-lifetime of the mockup to determine the test conditions. Also, the Korea Heat Load Test facility with an Electron Beam (KoHLT-EB) will be used and its water cooling system is considered to perform the thermal-hydraulic analysis especially for considering the two-phase analysis with a higher heat flux conditions. Through the ITER blanket first wall (BFW) development project in Korea, the joining methods were developed with a beryllium (Be) layer as a plasma-facing material, a copper alloy (CuCrZr) layer as a heat sink, and type 316L austenitic stainless steel (SS316L) as a structural material. And joining methods were developed such as Be as an armor and FMS as a structural material, or W as an armor and FMS as a structural material were developed through the test blanket module (TBM) program. As a candidate of PFC for DEMO, a new W/FMS joining methods, W coating with plasma torch, have been developed. The HHF test conditions are found by performing a thermal-hydraulic and thermo-mechanical analysis with the conventional codes such as ANSYSCFX and .mechanical especially for considering the two-phase condition in cooling tube.

  3. Principal component analysis for surface reflection components and structure in facial images and synthesis of facial images for various ages (United States)

    Hirose, Misa; Toyota, Saori; Ojima, Nobutoshi; Ogawa-Ochiai, Keiko; Tsumura, Norimichi


    In this paper, principal component analysis is applied to the distribution of pigmentation, surface reflectance, and landmarks in whole facial images to obtain feature values. The relationship between the obtained feature vectors and the age of the face is then estimated by multiple regression analysis so that facial images can be modulated for woman aged 10-70. In a previous study, we analyzed only the distribution of pigmentation, and the reproduced images appeared to be younger than the apparent age of the initial images. We believe that this happened because we did not modulate the facial structures and detailed surfaces, such as wrinkles. By considering landmarks and surface reflectance over the entire face, we were able to analyze the variation in the distributions of facial structures and fine asperity, and pigmentation. As a result, our method is able to appropriately modulate the appearance of a face so that it appears to be the correct age.

  4. Analysis of the micro-structural damages by neutronic irradiation of the steel of reactor vessels of the nuclear power plant of Laguna Verde. Characterization of the design steel; Analisis de los danos micro-estructurales por irradiacion neutronica del acero de la vasija de los reactores de la Central Nuclear de Laguna Verde. Caracterizacion del acero de diseno

    Energy Technology Data Exchange (ETDEWEB)

    Moranchel y Rodriguez, M.; Garcia B, A. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Fisica, Av. Luis Enrique Erro s/n, Unidad Profesional Adolfo Lopez Mateos, Col. Lindavista, 07738 Mexico D. F. (Mexico); Longoria G, L. C., E-mail: mmoranchel@ipn.m [ININ, Direccion de Investigacion Cientifica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)


    The vessel of a nuclear reactor is one of the safety barriers more important in the design, construction and operation of the reactor. If the vessel results affected to the grade of to have fracture and/or cracks it is very probable the conclusion of their useful life in order to guarantee the nuclear safety and the radiological protection of the exposure occupational personnel, of the public and the environment avoiding the exposition to radioactive sources. The materials of the vessel of a nuclear reactor are exposed continually to the neutronic irradiation that generates the same nuclear reactor. The neutrons that impact to the vessel have the sufficient energy to penetrate certain depth in function of the energy of the incident neutron until reaching the repose or to be absorbed by some nucleus. In the course of their penetration, the neutrons interact with the nuclei, atoms, molecules and with the same crystalline nets of the vessel material producing vacuums, interstitial, precipitate and segregations among other defects that can modify the mechanical properties of the steel. The steel A533-B is the material with which is manufactured the vessel of the nuclear reactors of nuclear power plant of Laguna Verde, is an alloy that, among other components, it contains atoms of Ni that if they are segregated by the neutrons impact this would favor to the cracking of the same vessel. This work is part of an investigation to analyze the micro-structural damages of the reactor vessels of the nuclear power plant of Laguna Verde due to the neutronic irradiation which is exposed in a continuous way. We will show the characterization of the design steel of the vessel, what offers a comprehension about their chemical composition, the superficial topography and the crystalline nets of the steel A533-B. It will also allow analyze the existence of precipitates, segregates, the type of crystalline net and the distances inter-plains of the design steel of the vessel. (Author)

  5. Microbial community structure and diversity in an integrated system of anaerobic-aerobic reactors and a constructed wetland for the treatment of tannery wastewater in Modjo, Ethiopia

    National Research Council Canada - National Science Library

    Desta, Adey Feleke; Assefa, Fassil; Leta, Seyoum; Stomeo, Francesca; Wamalwa, Mark; Njahira, Moses; Djikeng, Appolinaire; Appolinaire, Djikeng


    A culture-independent approach was used to elucidate the microbial diversity and structure in the anaerobic-aerobic reactors integrated with a constructed wetland for the treatment of tannery waste...

  6. Studies of low temperature, low flux radiation embrittlement of nuclear reactor structural materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Odette, G.R.; Lucas, G.E.


    There are several existing research programs which have components pertinent to the issue of low flux/low temperature embrittlement; in particular, examination of the Shippingport shield tank which has been exposed to low flux and relatively low temperature is being performed by ANL, and evaluation of low temperature embrittlement in A508 and A533B steels in support of the HTGR is currently being performed by ORNL. However, these programs are not specifically directed at the broader issue of low flux/low temperature embrittlement in a range of structural steels. Hence, the authors coordinated their effort with these programs so that their investigations were complementary to existing programs, and they focused on a set of materials which expand the data base developed in these programs. In particular, the authors have investigated embrittlement phenomena in steels that are similar to those used in support structure.

  7. Emergency heat removal system for a nuclear reactor (United States)

    Dunckel, Thomas L.


    A heat removal system for nuclear reactors serving as a supplement to an Emergency Core Cooling System (ECCS) during a Loss of Coolant Accident (LOCA) comprises a plurality of heat pipes having one end in heat transfer relationship with either the reactor pressure vessel, the core support grid structure or other in-core components and the opposite end located in heat transfer relationship with a heat exchanger having heat transfer fluid therein. The heat exchanger is located external to the pressure vessel whereby excessive core heat is transferred from the above reactor components and dissipated within the heat exchanger fluid.

  8. CMS experiment : animation showing the construction of the main structural components of CMS together

    CERN Multimedia


    This 17-minute long animation shows the construction of the main structural components of CMS in the surface hall in Cessy and offers a detailed overview of the installation in the experimental cavern.

  9. CMS experiment : animation showing the construction of the main structural components of CMS together

    CERN Document Server

    CERN Multimedia Production Unit


    This 17-minute long animation shows the construction of the main structural components of CMS in the surface hall in Cessy and offers a detailed overview of the installation in the experimental cavern.

  10. Free vibrations of an arbitrary structure in terms of component modes. (United States)

    Dowell, E. H.


    A method for the analysis of the free vibrations of an arbitrary structure in terms of component modes is presented based upon the use of the normal, free-free modes of the components in a Rayleigh-Ritz analysis with the constraint or continuity conditions

  11. Microbial community structure of a starch-feeding fermentative hydrogen production reactor operated under different incubation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chin-Hung; Hung, Chun-Hsiung; Liau, Pei-Yu.; Liang, Chih-Ming [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402 (China); Lee, Kuo-Shing [Department of Health and Safety and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung 40601 (China); Yang, Lee-Hao; Lin, Ping-Jei [Department Chemical Engineering, Feng Chia University, Taichung 40724 (China); Lin, Chiu-Yue [Department Environmental Engineering and Science, Feng Chia University, Taichung 40724 (China)


    The aim of this study was to establish the particular biohydrogen-production related microbial community structure in a starch-feeding dark fermentation agitated granular sludge bed (AGSB) reactor which was operated under pH 6.0 and 5.5 as well as under different hydraulic retention times (HRTs). The bacterial community diversity and percent of their cell count of the bioreactor were ascertained using denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH) individually. Based on the comparison of bacterial structure and hydrogen production efficiency under different HRT, no conclusion could be made on whether the diversity of Clostridium community could directly affect the reactor performance in these two pH systems. However, bacterial cell counts showed that the viable number of dominated Clostridium sp. changed along with the hydrogen production rate (HPR). It was believed that it could directly affect the hydrogen production efficiency. The highest HPR and hydrogen yield (HY) occurred when the reactor was operated at HRT 0.5 h, while the ratio of Clostridium sp. cell count and Bifidobacterium sp. cell count over the total Eubacteria cell count were around 40% and 40-60%, respectively. Therefore, we suggested that bacterial species which could degrade starch, such as Bifidobacterium sp. in this study, broke down starch into small molecules first and then these less complex compounds were utilized by the Clostridium species for hydrogen production. (author)

  12. Prolongation of the BOR-60 reactor operation

    Directory of Open Access Journals (Sweden)

    Alexey l. Izhutov


    Full Text Available The fast neutron reactor BOR-60 is one of the key experimental facilities worldwide to perform large-scale tests of fuel, absorbing, and structural materials for advanced reactors. The BOR-60 reactor was put into operation in December 1969, and by the end of 2014 it had been operating on power for ∼265,000 hours. BOR-60 still demonstrates potential capabilities to extend the lifetime of sodium-cooled fast reactors. The BOR-60 lifetime should have expired at the end of 2014. Over the past few years, a great scope of work has been performed to justify the possibility of extending its lifetime. The work included inspection of the equipment conditions, calculations and experimental research on operating parameters and the conditions of nonremovable components, investigation of the structural material samples after their long-term operation under irradiation, etc. Based on the results of the work performed, the residual lifetime was evaluated and the reactor operator made a decision to extend the lifetime period of the BOR-60 reactor. After considering both a set of documents about the reactor conditions and the positive decision of independent experts, the Regulatory Authority of the Russian Federation extended the BOR-60 operating license up to 2020.

  13. Nanocomposite YSZ-NiO Particles with Tailored Structure Synthesized in a Two-Stage Continuous Hydrothermal Flow Reactor

    DEFF Research Database (Denmark)

    Zielke, Philipp; Xu, Yu; Kiebach, Wolff-Ragnar


    -composites. Here we report on the design of the two-stage continuous hydrothermal flow synthesis reactor and first results on obtaining structured nano-composite consisting of yttria-stabilized zirconia (YSZ) and NiO materials. These materials are commonly applied in the fuel electrodes of today’s state......-of-the-art solid oxide fuel and electrolysis cells. The prepared particles were characterized by X-ray powder diffraction, (high resolution) transmission electron microscopy, scanning tunnel transmission microscopy and Raman spectroscopy in order to determine crystal structure, particle size, surface morphology...

  14. Seismic Behaviour of Post-Installed Anchors: Non-Structural Components and Art Objects Fastening


    Abate, Marco


    The damage observation in recent seismic events (L’Aquila 2009, Chile 2010, Christchurch 2011, Tohoku 2011, Emilia 2012) helps in the identification of the critical aspects related to the response to earthquake of non-structural components (Miranda et al. 2012). Generally these elements are included in buildings and may belong to the architectural system, to the utility system or to the building content. The failure of the non-structural components can represent a significant danger for life ...

  15. The deterministic structural integrity assessment of reactor pressure vessels under pressurized thermal shock loading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mingya, E-mail:; Lu, Feng; Wang, Rongshan; Huang, Ping; Liu, Xiangbin; Zhang, Guodong; Xu, Chaoliang


    Highlights: • The conservative and non-conservative assumptions in the codes were shown. • The influence of different loads on the SM was given. • The unloading effect of the cladding was studied. • A concentrated reflection of the safety was shown based on 3-D FE analyses. - Abstract: The deterministic structural integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs) has been extensively studied. While the nil-ductility-transition temperature (RT{sub NDT}) parameter is widely used, the influence of fluence and temperature distributions along the thickness of the base metal wall cannot be reflected in the comparative analysis. This paper introduces the method using a structure safety margin (SM) parameter which is based on a comparison between the material toughness (the fracture initiation toughness K{sub IC} or fracture arrest toughness K{sub Ia}) and the stress intensity factor (SIF) along the crack front for the integrity analysis of a RPV subjected to PTS transients. A 3-D finite element model is used to perform fracture mechanics analyses considering both crack initiation assessment and arrest assessment. The results show that the critical part along the crack front is always the clad-base metal interface point (IP) rather than the deepest point (DP) for either crack initiation assessment or crack arrest assessment under the thermal load. It is shown that the requirement in Regulatory Guide 1.154 that ‘axial flaws with depths less than 20% of the wall thickness and all circumferential flaws should be modeled in infinite length’ may be non-conservative. As the assessment result is often poor universal for a given material, crack and transient, caution is recommended in the safety assessment, especially for the IP. The SIF reduces under the thermal or pressure load if the map cracking (MC) effect is considered. Therefore, the assumption in the ASME and RCCM codes that the cladding should be taken into account in

  16. Production of structured lipids in a packed-bed reactor with Thermomyces lanuginosa lipase

    DEFF Research Database (Denmark)

    Xu, Xuebing; Porsgaard, Trine; Zhang, Hong


    Lipase-catalyzed interesterification between fish oil and medium-chain TAG has been investigated in a packed-bed reactor with a commercially immobilized enzyme. The enzyme, a Thermomyces lanuginosa lipase immobilized on silica by granulation (Lipozyme TL IM; Novozymes A/S, Bagsvaerd, Denmark), has...... recently been developed for fat modification. This study focuses on the new characteristics of the lipase in a packed-bed reactor when applied to interesterification of TAG. The degree of reaction was strongly related to the flow rate (residence time) and temperature, whereas formation of hydrolysis by...

  17. Proceedings of the Office of Fusion Energy/DOE workshop on ceramic matrix composites for structural applications in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.H. (Pacific Northwest Lab., Richland, WA (USA)); Lucas, G.E. (California Univ., Santa Barbara, CA (USA))


    A workshop to assess the potential application of ceramic matrix composites (CMCs) for structural applications in fusion reactors was held on May 21--22, 1990, at University of California, Santa Barbara. Participants included individuals familiar with materials and design requirements in fusion reactors, ceramic composite processing and properties and radiation effects. The primary focus was to list the feasibility issues that might limit the application of these materials in fusion reactors. Clear advantages for the use of CMCs are high-temperature operation, which would allow a high-efficiency Rankine cycle, and low activation. Limitations to their use are material costs, fabrication complexity and costs, lack of familiarity with these materials in design, and the lack of data on radiation stability at relevant temperatures and fluences. Fusion-relevant feasibility issues identified at this workshop include: hermetic and vacuum properties related to effects of matrix porosity and matrix microcracking; chemical compatibility with coolant, tritium, and breeder and multiplier materials, radiation effects on compatibility; radiation stability and integrity; and ability to join CMCs in the shop and at the reactor site, radiation stability and integrity of joints. A summary of ongoing CMC radiation programs is also given. It was suggested that a true feasibility assessment of CMCs for fusion structural applications could not be completed without evaluation of a material tailored'' to fusion conditions or at least to radiation stability. It was suggested that a follow-up workshop be held to design a tailored composite after the results of CMC radiation studies are available and the critical feasibility issues are addressed.

  18. Cluster structure of anaerobic aggregates of an expanded granular sludge bed reactor

    NARCIS (Netherlands)

    Gonzalez-Gil, G.; Lens, P.N.L.; Aelst, van A.; As, van H.; Versprille, A.I.; Lettinga, G.


    The metabolic properties and ultrastructure of mesophilic aggregates from a full-scale expanded granular sludge bed reactor treating brewery wastewater are described. The aggregates had a very high methanogenic activity on acetate (17.19 mmol of CH4/g of volatile suspended solids [VSS]?day or 1.1 g

  19. The probabilistic structural integrity assessment of reactor pressure vessels under pressurized thermal shock loading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mingya, E-mail: [Suzhou Nuclear Power Research Institute, 215004 Suzhou, Jiangsu Province (China); Lu, Feng; Wang, Rongshan; Yu, Weiwei [Suzhou Nuclear Power Research Institute, 215004 Suzhou, Jiangsu Province (China); Wang, Donghui [State Nuclear Power Plant Service Company, 200237 Shanghai (China); Zhang, Guodong; Xue, Fei [Suzhou Nuclear Power Research Institute, 215004 Suzhou, Jiangsu Province (China)


    Highlights: • The methodology and the case study of the FAVOR software were shown. • The over-conservative parameters in the DFM were shown. • The differences between the PFM and the DFM were discussed. • The limits in the current FAVOR were studied. - Abstract: The pressurized thermal shock (PTS) event poses a potentially significant challenge to the structural integrity of the reactor pressure vessel (RPV) during the long time operation (LTO). In the USA, the “screening criteria” for maximum allowable embrittlement of RPV material, which forms part of the USA regulations, is based on the probabilistic fracture mechanics (PFM). The FAVOR software developed by Oak Ridge National Laboratory (ORNL) is used to establish the regulation. As the technical basis of FAVOR is not the most widely-used and codified methodologies, such as the ASME and RCC-M codes, in most countries (with exception of the USA), proving RPV integrity under the PTS load is still based on the deterministic fracture mechanics (DFM). As the maximum nil-ductility-transition temperature (RT{sub NDT}) of the beltline material for the 54 French RPVs after 40 years operation is higher than the critical values in the IAEA-TECDOC-1627 and European NEA/CSNI/R(99)3 reports (while still obviously lower than the “screening criteria” of the USA), it may conclude that the RPV will not be able to run in the LTO based on the DFM. In the FAVOR, the newest developments of fracture mechanics are applied, such as the warm pre-stress (WPS) effect, more accurate estimation of the flaw information and less conservation of the toughness (such as the three-parameter Weibull distribution of the fracture toughness). In this paper, the FAVOR software is first applied to show both the methodology and the results of the PFM, and then the limits in the current FAVOR software (Version 6.1, which represents the baseline for re-assessing the regulation of 10 CFR 50.61), lack of the impact of the constraint effect

  20. Structural response of 1/20-scale models of the Clinch River Breeder Reactor to a simulated hypothetical core disruptive accident. Technical report 4

    Energy Technology Data Exchange (ETDEWEB)

    Romander, C. M.; Cagliostro, D. J.


    Five experiments were performed to help evaluate the structural integrity of the reactor vessel and head design and to verify code predictions. In the first experiment (SM 1), a detailed model of the head was loaded statically to determine its stiffness. In the remaining four experiments (SM 2 to SM 5), models of the vessel and head were loaded dynamically under a simulated 661 MW-sec hypothetical core disruptive accident (HCDA). Models SM 2 to SM 4, each of increasing complexity, systematically showed the effects of upper internals structures, a thermal liner, core support platform, and torospherical bottom on vessel response. Model SM 5, identical to SM 4 but more heavily instrumented, demonstrated experimental reproducibility and provided more comprehensive data. The models consisted of a Ni 200 vessel and core barrel, a head with shielding and simulated component masses, an upper internals structure (UIS), and, in the more complex models SM 4 and SM 5, a Ni 200 thermal liner and core support structure. Water simulated the liquid sodium coolant and a low-density explosive simulated the HCDA loads.

  1. Development of reactor graphite (United States)

    Haag, G.; Mindermann, D.; Wilhelmi, G.; Persicke, H.; Ulsamer, W.


    The German graphite development programme for High Temperature Reactors has been based on the assumption that reactor graphite for core components with lifetime fluences of up to 4 × 10 22 neutrons per cm 2 (EDN) at 400°C can be manufactured from regular pitch coke. The use of secondary coke and vibrational moulding techniques have allowed production of materials with very small anisotropy, high strength, and high purity which are the most important properties of reactor graphite. A variety of graphite grades has been tested in fast neutron irradiation experiments. The results show that suitable graphites for modern High Temperature Reactors with spherical fuel elements are available.

  2. Structural Analysis of Surface-Modified Oxidation-Resistant Zirconium Alloy Cladding for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho; No, Hee Cheon; Lee, Jeong Ik [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)


    While the current zirconium-based alloy cladding (Zircaloy, here after) has served well for fission-product barrier and heat transfer medium for the nuclear fuel of light water reactors (LWRs) in steady-states, concerns surrounding its mechanical behavior during accidents have drawn serious attentions. In accidents, strength degradation of the current-zirconium based alloy cladding manifests at temperature around ∼800 .deg. C, which results in fuel ballooning. Above 1000 .deg. C, zircaloy undergoes rapid oxidation with steam. Formation of brittle oxide (ZrO{sub 2}) and underlying oxygen-saturated α-zircaloy as a consequence of steam oxidation leads to loss of cladding ductility. Indeed, the loss of zircaloy ductility upon the steam oxidation has been taken as a measure of fuel failure criteria as stated in 10 CFR 50.46. In addition, zircaloy steam oxidation is an exothermic reaction, which is an energy source that sharply accelerates temperature increase under loss of coolant accidents, decreasing allowable coping time for loss of coolant accidents, decreasing allowable coping time for loss of coolant accidents (LOCA) before significant fuel/core melting starts. Hydrogen generated as a result of zircaloy oxidation could cause an explosion if certain conditions are met. In steady-state operation, zircaloy embrittlement limits the burnup of the fuel rod to assure remaining cladding ductility to cope with accidents. As a way to suppress hydrogen generation and cladding embrittlement by oxidation, ideas of cladding coating with an oxidation-preventive layer have emerged. Indeed, among a numbers of 'accident-tolerant-fuel (ATF)' concepts, the concept of coating the current fuel rod. Some signs of success on the lab-scale oxidation-prevention have been confirmed with a few coating candidates. Yet, relatively less attention has been given to structural integrity of coated zirconium-based alloy cladding. It is important to note that oxidation

  3. On feasibility of optimizing the neutronic parameters of a laser system pumped by a pulsed reactor


    A.V. Gulevich; O.F. Kukharchuk; A.I. Brezhnev; A.A. Suvorov


    The paper examines the calculated feasibility of improving the energy characteristics of power pulses in a system consisting of a reactor and a subcritical block. A BARS-type fast neutron reactor is used as a self-quenching pulsed reactor. The subcritical block is a cylindrical structure comprising laser-active elements, moderator components and two reflectors (internal and external). The internal reflector material is zirconium hydride, and the external reflector material is beryllium. Th...

  4. 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


    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

  5. 77 FR 74883 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1 (United States)


    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1... Structures and Components in Treated Borated Water,'' which was announced in the Federal Register on May 11... Staff Guidance LR-ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in...

  6. An Overview of Reactor Concepts, a Survey of Reactor Designs. (United States)


    implies, this reactor uses gas as the primary coolant . The coolant has a higher exit temperature when leaving the core than the PWR water 6 AFWL-TN-84...nuclear reactors, coolants must be used to ensure material components are not subject to failure due to the temperature exceeding melting points...Reactors that use deu- terium (heavy water) as a coolant can use natural uranium as a fuel. The * Canadian reactor, CANDU , utilizes this concept

  7. High-temperature gas-cooled reactor technology development program. Annual progress report for period ending December 31, 1982

    Energy Technology Data Exchange (ETDEWEB)

    Kasten, P.R.; Rittenhouse, P.L.; Bartine, D.E.; Sanders, J.P.


    During 1982 the High-Temperature Gas-Cooled Reactor (HTGR) Technology Program at Oak Ridge National Laboratory (ORNL) continued to develop experimental data required for the design and licensing of cogeneration HTGRs. The program involves fuels and materials development (including metals, graphite, ceramic, and concrete materials), HTGR chemistry studies, structural component development and testing, reactor physics and shielding studies, performance testing of the reactor core support structure, and HTGR application and evaluation studies.

  8. Estimation of canopy structure parameters from multiangular measurements of scattering components

    DEFF Research Database (Denmark)

    Kirk, Kristian; Andersen, Hans Jørgen


    Structure parameters for characterization of vegetation canopies are often estimated from remote optical measurements. Existing methods include those based on measurements of gap fraction, spectral vegetation indices, or the inversion of spectral canopy reflectance models. This paper proposes...... a novel method based on inversion of multiangular measurements of the abundances of light scattering components, which may be estimated using spectral unmixing. An algorithm is described for predicting the abundances of various scattering components using Monte Carlo simulation with a Poisson canopy model...

  9. H Reactor (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...


    Directory of Open Access Journals (Sweden)

    Kostiantyn S. Khoruzhyi


    Full Text Available In this article, problems and features of forming the educational quality management information system for the future economists are examined, its component structure is presented and the significance and functions of every component are explained. The functions, which bind the components mentioned to each other, are also examined. To ensure functioning of the developed components of the EQMIS an indicator system is proposed. The article also covers the program components of this system, formed according to the requirements analysis, their technical description, as well as the importance and role in operation of the EQMIS of the future economists based on the individually-oriented, professionally-competent, informational-communicational and systematic approach methods.

  11. Nonlinear low frequency electrostatic structures in a magnetized two-component auroral plasma

    Energy Technology Data Exchange (ETDEWEB)

    Rufai, O. R., E-mail: [University of the Western Cape, Bellville 7535, Cape-Town (South Africa); Scientific Computing, Memorial University of Newfoundland, St John' s, Newfoundland and Labrador A1C 5S7 (Canada); Bharuthram, R., E-mail: [University of the Western Cape, Bellville 7535, Cape-Town (South Africa); Singh, S. V., E-mail:; Lakhina, G. S., E-mail: [University of the Western Cape, Bellville 7535, Cape-Town (South Africa); Indian Institute of Geomagnetism, New Panvel (W), Navi Mumbai 410218 (India)


    Finite amplitude nonlinear ion-acoustic solitons, double layers, and supersolitons in a magnetized two-component plasma composed of adiabatic warm ions fluid and energetic nonthermal electrons are studied by employing the Sagdeev pseudopotential technique and assuming the charge neutrality condition at equilibrium. The model generates supersoliton structures at supersonic Mach numbers regime in addition to solitons and double layers, whereas in the unmagnetized two-component plasma case only, soliton and double layer solutions can be obtained. Further investigation revealed that wave obliqueness plays a critical role for the evolution of supersoliton structures in magnetized two-component plasmas. In addition, the effect of ion temperature and nonthermal energetic electron tends to decrease the speed of oscillation of the nonlinear electrostatic structures. The present theoretical results are compared with Viking satellite observations.

  12. Seismic assessment and performance of nonstructural components affected by structural modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Jieun; Althoff, Eric; Sezen, Halil; Denning, Richard; Aldemir, Tunc [Ohio State University, Columbus (United States)


    Seismic probabilistic risk assessment (SPRA) requires a large number of simulations to evaluate the seismic vulnerability of structural and nonstructural components in nuclear power plants. The effect of structural modeling and analysis assumptions on dynamic analysis of 3D and simplified 2D stick models of auxiliary buildings and the attached nonstructural components is investigated. Dynamic characteristics and seismic performance of building models are also evaluated, as well as the computational accuracy of the models. The presented results provide a better understanding of the dynamic behavior and seismic performance of auxiliary buildings. The results also help to quantify the impact of uncertainties associated with modeling and analysis of simplified numerical models of structural and nonstructural components subjected to seismic shaking on the predicted seismic failure probabilities of these systems.

  13. Seismic Assessment and Performance of Nonstructural Components Affected by Structural Modeling

    Directory of Open Access Journals (Sweden)

    Jieun Hur


    Full Text Available Seismic probabilistic risk assessment (SPRA requires a large number of simulations to evaluate the seismic vulnerability of structural and nonstructural components in nuclear power plants. The effect of structural modeling and analysis assumptions on dynamic analysis of 3D and simplified 2D stick models of auxiliary buildings and the attached nonstructural components is investigated. Dynamic characteristics and seismic performance of building models are also evaluated, as well as the computational accuracy of the models. The presented results provide a better understanding of the dynamic behavior and seismic performance of auxiliary buildings. The results also help to quantify the impact of uncertainties associated with modeling and analysis of simplified numerical models of structural and nonstructural components subjected to seismic shaking on the predicted seismic failure probabilities of these systems.

  14. Formation, physical characteristics and microbial community structure of aerobic granules in a pilot-scale sequencing batch reactor for real wastewater treatment. (United States)

    Liu, Yong-Qiang; Moy, Benjamin; Kong, Yun-Hua; Tay, Joo-Hwa


    In this study, aerobic granular sludge was successfully developed in a pilot-scale sequencing batch reactor (SBR) installed on site to treat real wastewater using traditional activated sludge as inoculum. Compared with 1 or 2 months required by lab-scale reactor for aerobic granulation, it took about 400 days for activated sludge to transform into granule-dominant sludge in the pilot-scale SBR on site. Although the sludge in the reactor after 400-day operation was a mixture of flocs and granules with floc ratio ranged from 5 to 30%, sludge volume index with 5min settling (SVI5) always maintained at around 30mL/g. The similar microbial community structures represented by denaturing gradient gel electrophoresis (DGGE) between coexisted flocs and granules in the reactor indicated no strong microbial selection after the granules were dominant in the reactor. Chemical oxygen demand (COD) and NH4(+)-N removal efficiencies were above 80 and 98%, respectively, after 50-day operation, and the total inorganic N removal efficiency was about 50%. The results in this study demonstrate that it is feasible to form aerobic granules in pilot-scale SBR reactor and maintain the long-term stability of granular sludge with a high influent quality fluctuation. Meanwhile, stable COD and NH4(+)-N removal efficiencies can be obtained in the reactor. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Specific Features of Structural-Phase State and Properties of Reactor Pressure Vessel Steel at Elevated Irradiation Temperature

    Directory of Open Access Journals (Sweden)

    E. A. Kuleshova


    Full Text Available This paper considers influence of elevated irradiation temperature on structure and properties of 15Kh2NMFAA reactor pressure vessel (RPV steel. The steel is investigated after accelerated irradiation at 300°C (operating temperature of VVER-1000-type RPV and 400°C supposed to be the operating temperature of advanced RPVs. Irradiation at 300°C leads to formation of radiation-induced precipitates and radiation defects-dislocation loops, while no carbide phase transformation is observed. Irradiation at a higher temperature (400°C neither causes formation of radiation-induced precipitates nor provides formation of dislocation loops, but it does increase the number density of the main initial hardening phase—of the carbonitrides. Increase of phosphorus concentration in grain boundaries is more pronounced for irradiation at 400°C as compared to irradiation at 300°C due to influence of thermally enhanced diffusion at a higher temperature. The structural-phase changes determine the changes of mechanical properties: at both irradiation temperatures irradiation embrittlement is mainly due to the hardening mechanism with some contribution of the nonhardening one for irradiation at 400°C. Lack of formation of radiation-induced precipitates at T = 400°C provides a small ΔTK shift (17°C. The obtained results demonstrate that the investigated 15Kh2NMFAA steel may be a promising material for advanced reactors with an elevated operating temperature.

  16. Structural lifetime, reliability and risk analysis approaches for power plant components and systems

    Energy Technology Data Exchange (ETDEWEB)

    Cronvall, O.


    Lifetime, reliability and risk analysis methods and applications for structural systems and components of power plants are discussed in this thesis. These analyses involve many fields of science, such as structural mechanics, fracture mechanics, probability mathematics, material science and fluid mechanics. An overview of power plant environments and a description of the various degradation mechanisms damaging the power plant systems and components are presented first. This is followed with a description of deterministic structural analysis methods, covering e.g. structural mechanics and fracture mechanics based analysis methods as well as the disadvantages of the deterministic analysis approach. Often, physical probabilistic methods are based on deterministic analysis methods with the modification that one or more of the model parameters are considered as probabilistically distributed. Several probabilistic analysis procedures are presented, e.g. Monte Carlo Simulation (MCS) and importance sampling. Description of probabilistic analysis methods covers both physical and statistical approaches. When the system/component failure probabilities are combined with knowledge of failure consequences, it is possible to assess system/component risks. Several risk analysis methods are presented as well as some limitations and shortcomings concerning to them. Modelling methods for various degradation (or ageing) mechanisms are presented. These methods are needed in the lifetime analyses of structural systems and components of power plants. In general, the lifetime analyses in question necessitate a thorough knowledge of structural properties, loads, the relevant degradation mechanisms and prevailing environmental conditions. The nature of degradation models of structural systems/components can be deterministic, probabilistic or a combination of these two types. Degradation models of all these kinds are presented here. Some important risk analysis applications are described

  17. Structural assessment of aerospace components using image processing algorithms and Finite Element models

    DEFF Research Database (Denmark)

    Stamatelos, Dimtrios; Kappatos, Vassilios


    Purpose – This paper presents the development of an advanced structural assessment approach for aerospace components (metallic and composites). This work focuses on developing an automatic image processing methodology based on Non Destructive Testing (NDT) data and numerical models, for predicting...... of the damaged plates showed that strength reduction occurs compare to reference plates. This methodology is a promising method for structural assessment of aerospace components, since conclusions regarding their functionality can be drawn. Research limitations/implications – The investigated structural...... in a tough economic area. Originality/value – As far as it is known, this is the first time that an aerospace structural assessment combines image processing algorithms and FE models....

  18. Retrofitting the Structure of the Catalytic Cracking Reactor, from Petrobrazi Refinery, Ploieşti by Transforming the Steel Structure into a Moment Resisting Frame and Enhancing the Damping of the Structure by Means of Viscous Dampers

    Directory of Open Access Journals (Sweden)

    Vasilescu Ionuţ


    Full Text Available The present paper presents the structural and seismic retrofit solution for the structure of the Catalytic Cracking Reactor, from Petrobrazi Refinery, Ploiești, Romania. The spatial truss type steel structure was designed and built during 1965-1968, following United States codes of that time. The capacity of the reactor is intended to be increased, thus its weight increases by approx. 43%. The retrofit solution had to take into consideration many criteria, not only technical, but also technological. After analyzing several possibilities, it was decided that the only feasible solution in order to fulfill all these requirements was to significantly increase the viscous damping of the structure – by introducing viscous dampers in its diagonals, accompanied by the strengthening of steel structure and changing the structural system into a moment resisting frame.


    Directory of Open Access Journals (Sweden)

    V. V. Kachinskaya


    Full Text Available Тhe structural organization and a biological variety of ground mesofauna on consortium level of the organization of ecosystems are considered. The analysis of indicators of the structural organization and a biodiversity of ground mesofauna in consortium Ulmus and Populus in the conditions of territories of industrial mining – metallurgical complex of Krivyi Rig Basin is carried out. It is established that taxonomical structure of ground mesofauna is characterized by insignificant number and quantity of taxonomical groups. Prevalence in morfo-ecological structure of hortobiontes and herpetobiontes testifies about faunae considerable attachment to consortium determinants and influences of a steppe climate on its structure. Prevalence of phytophages and polyphages in trophic structure is caused by combination of determinants specificity of consortium and zone source of fauna formations. The structural organization of ground mesofauna in consortium Ulmus and Populus in the conditions of industrial sites is characterized simplified taxonomical structure with a low biodiversity at all levels. It was suggested that structural and functional organization of destructive components of the block consortium of Ulmus and Populus in the conditions of industrial sites are simplified and determined by biogeochemical patterns of pedogenic and leaf litter layer of consortium and type of anthropogenic impact. Management and sustainable use of consortium under technogenic pressure should be based on the effects of extreme and critical components in the evolution of consortium. These critical points are the type of leading man-made factors and pedogenic and leaf litter biogeochemical conditions of consortium determinants, which results in inhibition of development and simplification of the structural and functional organization of destructive components of the block. The elaboration of measures to restore and maintain that structural and functional organization

  20. Peroxynitrous acid induces structural and functional modifications to basement membranes and its key component, laminin

    DEFF Research Database (Denmark)

    Degendorfer, Georg; Chuang, Christine Y.; Hammer, Astrid


    Basement membranes (BM) are specialized extracellular matrices underlying endothelial cells in the artery wall. Laminin, the most abundant BM glycoprotein, is a structural and biologically active component. Peroxynitrous acid (ONOOH), a potent oxidizing and nitrating agent, is formed in vivo...... and functional changes. These modifications, and resulting compromised cell-matrix interactions, may contribute to endothelial cell dysfunction, a weakening of the structure of atherosclerotic lesions, and an increased propensity to rupture....

  1. 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


    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)


    Directory of Open Access Journals (Sweden)

    Paul Robert Martin Werfette


    Full Text Available Analysis of quantitative structure - activity relationship (QSAR for a series of antimalarial compound artemisinin derivatives has been done using principal component regression. The descriptors for QSAR study were representation of electronic structure i.e. atomic net charges of the artemisinin skeleton calculated by AM1 semi-empirical method. The antimalarial activity of the compound was expressed in log 1/IC50 which is an experimental data. The main purpose of the principal component analysis approach is to transform a large data set of atomic net charges to simplify into a data set which known as latent variables. The best QSAR equation to analyze of log 1/IC50 can be obtained from the regression method as a linear function of several latent variables i.e. x1, x2, x3, x4 and x5. The best QSAR model is expressed in the following equation,  (;;   Keywords: QSAR, antimalarial, artemisinin, principal component regression


    Directory of Open Access Journals (Sweden)

    Kachinskaya V.V.


    Full Text Available Тhe structural organization and a biological variety of ground mesofauna on consortium level of the organization of ecosystems are considered. The analysis of indicators of the structural organization and a biodiversity of ground mesofauna in consortium Ulmus and Populus in the conditions of territories of industrial mining – metallurgical complex of Krivyi Rig Basin is carried out. It is established that taxonomical structure of ground mesofauna is characterized by insignificant number and quantity of taxonomical groups. Prevalence in morfo-ecological structure of hortobiontes and herpetobiontes testifies about faunae considerable attachment to consortium determinants and influences of a steppe climate on its structure. Prevalence of phytophages and polyphages in trophic structure is caused by combination of determinants specificity of consortium and zone source of fauna formations. The structural organization of ground mesofauna in consortium Ulmus and Populus in the conditions of industrial sites is characterized simplified taxonomical structure with a low biodiversity at all levels. It was suggested that structural and functional organization of destructive components of the block consortium of Ulmus and Populus in the conditions of industrial sites are simplified and determined by biogeochemical patterns of pedogenic and leaf litter layer of consortium and type of anthropogenic impact. Management and sustainable use of consortium under technogenic pressure should be based on the effects of extreme and critical components in the evolution of consortium. These critical points are the type of leading man-made factors and pedogenic and leaf litter biogeochemical conditions of consortium determinants, which results in inhibition of development and simplification of the structural and functional organization of destructive components of the block. The elaboration of measures to restore and maintain that structural and functional organization

  4. Structural studies on dihydrolipoyl transacetylase : the core component of the pyruvate dehydrogenase complex of Azotobacter vinelandii

    NARCIS (Netherlands)

    Hanemaaijer, J.R.O.


    The studies described in this thesis deal with the structure of the Azotobactervinelandii dihydrolipoyl transacetylase, the core component (E 2 ) of the pyruvate dehydrogenase complex. in all organisms

  5. Fiber Optic Sensors to Monitor Structural Components Made of Composite Materials

    Directory of Open Access Journals (Sweden)



    Full Text Available New fiber reinforced composite materials and integrated sensors are converging to form smart structural components. They excel by their higher reliability, lead to more economical maintenance procedures and contribute significantly to reducing the cost of operating air fleets.

  6. Next Generation Nuclear Plant Structures, Systems, and Components Safety Classification White Paper

    Energy Technology Data Exchange (ETDEWEB)

    Pete Jordan


    This white paper outlines the relevant regulatory policy and guidance for a risk-informed approach for establishing the safety classification of Structures, Systems, and Components (SSCs) for the Next Generation Nuclear Plant and sets forth certain facts for review and discussion in order facilitate an effective submittal leading to an NGNP Combined Operating License application under 10 CFR 52.


    Directory of Open Access Journals (Sweden)

    Efim L. Kon


    Full Text Available The purpose of this paper is a development of approaches and recommendations on the selection of quantitative and qualitative component structure of disciplinary competencies, as well as ways of its formal description. One of the main problems, which it is necessary to decide while developing a studying and methodical discipline complex (for example, a discipline program, a fund of estimation tools, etc. of competence-oriented educational program, is designing of a component structure of each part of competence (a disciplinary competence, that is involved in the formation of the discipline. In this case, a significant impact on this process has not only the content of thematic plan and selected kinds of class and self works of students, but proposed control tools and diagnosing methods of learning outcomes specified in the competency format. Methods. It is proposed to use joint (testable design component structure of disciplinary competencies and control tools (tests, test materials, check the level of development of their constituent elements described in the triad of «to know», «to be able to», «to master». Requirements to the basic quantitative and qualitative properties of disciplinary competence component structure are formulated and substantiated. A structure of diagnostic table that makes it possible to set a correspondence between disciplinary competence elements and components and their control tests, and also to fix outcomes of current control of development level (test reactions in the binary and not binary alphabets is proposed and analyzed. A classification of diagnostic tests is given; their impact on format and properties of diagnostic table is shown. Scientific novelty. The approach to designing of a testable component structure of disciplinary competence is proposed; it allows setting some properties of control object, which can increase procedure effective and decoding precision of diagnosis of learning outcomes

  8. Kinetics of deactivation of catalysts for vinyl acetate synthesis in the fluidized-bed reactor: The optimal loading and distribution of zinc acetate in the porous structure of a support

    Energy Technology Data Exchange (ETDEWEB)

    Romanchuk, S.V.; Makhlin, V.A. [Karpov Institute of Physical Chemistry, Moscow (Russian Federation)


    The deactivation of a catalyst (zinc acetate on activated carbon) including a change of the phase state of the active component is considered. The mechanism and relevant kinetic model of the deactivation are presented. A degree of thermal decomposition of zinc acetate controls the deactivation rate, which depends on the loading and distribution of zinc acetate in the porous structure of a support. A modeling of the process in an industrial reactor is performed with regard to the deactivation, attrition, and loss of a catalyst. Each carbon support has an optimal loading of zinc acetate (equal to the critical value), which provides both a high activity and stability of catalyst operation. The reasons behind the fast deactivation of the commercial catalyst are revealed. The possibility is demonstrated of extending the life time of a catalyst on available carbon supports by a factor of {approximately}2.5, due to the optimal loading and distribution of the active component in the porous support structure.

  9. Characterisation of well-adhered ZrO2 layers produced on structured reactors using the sonochemical sol-gel method (United States)

    Jodłowski, Przemysław J.; Chlebda, Damian K.; Jędrzejczyk, Roman J.; Dziedzicka, Anna; Kuterasiński, Łukasz; Sitarz, Maciej


    The aim of this study was to obtain thin zirconium dioxide coatings on structured reactors using the sonochemical sol-gel method. The preparation method of metal oxide layers on metallic structures was based on the synergistic combination of three approaches: the application of ultrasonic irradiation during the synthesis of Zr sol-gel based on a precursor solution containing zirconium(IV) n-propoxide, the addition of stabilszing agents, and the deposition of ZrO2 on the metallic structures using the dip-coating method. As a result, dense, uniform zirconium dioxide films were obtained on the FeCrAlloy supports. The structured reactors were characterised by various physicochemical methods, such as BET, AFM, EDX, XRF, XRD, XPS and in situ Raman spectroscopy. The results of the structural analysis by Raman and XPS spectroscopy confirmed that the metallic surface was covered by a ZrO2 layer without any impurities. SEM/EDX mapping revealed that the deposited ZrO2 covered the metallic support uniformly. The mechanical and high temperature tests showed that the developed ultrasound assisted sol-gel method is an efficient way to obtain thin, well-adhered zirconium dioxide layers on the structured reactors. The prepared metallic supports covered with thin ZrO2 layers may be a good alternative to layered structured reactors in several dynamics flow processes, for example for gas exhaust abatement.

  10. Component mode synthesis and large deflection vibrations of complex structures. [beams and trusses (United States)

    Mei, C.


    The accuracy of the NASTRAN modal synthesis analysis was assessed by comparing it with full structure NASTRAN and nine other modal synthesis results using a nine-bay truss. A NASTRAN component mode transient response analysis was also performed on the free-free truss structure. A finite element method was developed for nonlinear vibration of beam structures subjected to harmonic excitation. Longitudinal deformation and inertia are both included in the formula. Tables show the finite element free vibration results with and without considering the effects of longitudinal deformation and inertia as well as the frequency ratios for a simply supported and a clamped beam subjected to a uniform harmonic force.

  11. Crystallization and structural studies of components of the protein-synthesizing system from Thermus thermophilus (United States)

    Garber, M.; Davydova, N.; Eliseikina, I.; Fomenkova, N.; Gryaznova, O.; Gryshkovskaya, I.; Nevskaya, N.; Nikonov, S.; Rak, A.; Sedelnikova, S.; Serganov, A.; Shcherbakov, D.; Tishchenko, S.; Vysotskaya, V.; Zheltonosova, J.; Liljas, A.; Aevarsson, A.; Al-Karadaghi, S.


    A long-term program on crystallization and structural studies of the protein synthesis machinery components from an extreme thermophile Thermus thermophilus was set up at the Institute of Protein Research (Russia) about 15 years ago. These studies have recently revealed the structures of elongation factor G, aspartyl-tRNA synthetase and ribosomal proteins S6 and L1. Different components of the protein synthesis machinery from T.thermophilus are also being investigated in other groups and many important results have been obtained recently. Here we describe only some special problems on crystal handling and non-isomorphism that have been overcome during structural studies of EF-G and ribosomal proteins in our group. This paper presents also new data on the crystallization of ribosomal proteins S7, S8, S15, L22 and leucyl-tRNA synthetase from T.thermophilus.

  12. Introduction to reactor internal materials for pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Suk; Hong, Joon Hwa; Jee, Se Hwan; Lee, Bong Sang; Kuk, Il Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)


    This report reviewed the R and D states of reactor internal materials in order to be a reference for researches and engineers who are concerning on localization of the materials in the field or laboratory. General structure of PWR internals and material specification for YGN 3 and 4 were reviewed. States-of-arts on R and D of stainless steel and Alloy X-750 were reviewed, and degradation mechanisms of the components were analyzed. In order to develop the good domestic materials for reactor internal, following studies would be carried out: microstructure, sensitization behavior, fatigue property, irradiation-induced stress corrosion cracking/radiation-induced segregation, radiation embrittlement. (Author) 7 refs., 14 figs., 5 tabs.,.

  13. Advanced Helicopter Structural Design Investigation. Volume I. Investigation of Advanced Structural Component Design Concepts (United States)


    pressure for the flight control system. The system consists of an accumulator, an ac electric-driven hydraulic pump, a two-stage handpump, plus filters ...compression strength. No one fibrous composite either woven or nonwoven stands out as the panacea, but each has its place in aerospace structures

  14. Solving Component Structural Dynamic Failures Due to Extremely High Frequency Structural Response on the Space Shuttle Program (United States)

    Frady, Greg; Nesman, Thomas; Zoladz, Thomas; Szabo, Roland


    For many years, the capabilities to determine the root-cause failure of component failures have been limited to the analytical tools and the state of the art data acquisition systems. With this limited capability, many anomalies have been resolved by adding material to the design to increase robustness without the ability to determine if the design solution was satisfactory until after a series of expensive test programs were complete. The risk of failure and multiple design, test, and redesign cycles were high. During the Space Shuttle Program, many crack investigations in high energy density turbomachines, like the SSME turbopumps and high energy flows in the main propulsion system, have led to the discovery of numerous root-cause failures and anomalies due to the coexistences of acoustic forcing functions, structural natural modes, and a high energy excitation, such as an edge tone or shedding flow, leading the technical community to understand many of the primary contributors to extremely high frequency high cycle fatique fluid-structure interaction anomalies. These contributors have been identified using advanced analysis tools and verified using component and system tests during component ground tests, systems tests, and flight. The structural dynamics and fluid dynamics communities have developed a special sensitivity to the fluid-structure interaction problems and have been able to adjust and solve these problems in a time effective manner to meet budget and schedule deadlines of operational vehicle programs, such as the Space Shuttle Program over the years.

  15. Galates with perovskite-related structure as membrane reactors for hydrogen production from water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Al Daroukh, M.; Georgi, G.; Hoffmann, M. [Leibniz Institute for Catalysis, Rostock (Germany)


    Hydrogen production from water splitting will be the most promising energy source in the future [1-2]. Dense membranes of the type La{sub a}Sr{sub b}Ga{sub c}Mg{sub d}O{sub x} were prepared from powders by solid state reaction syntheses. The Galates show a very high ionic conductivity [3]. The water splitting is achieved thermically, while the Diffusion of oxygen through the dense galate membrane is realized thermically and electrically. The electrically achieved oxygen permeability is three times higher than the thermically achieved. Due to this fact, the hydrogen production increases by the same factor. In a special reactor (Fig. 1) the dense tablet of the polyoxid is fastened between two gold rings. The tablet is coated with a platinum layer on both sides which work as electrodes. Helium with water is flowing towards the negative pole while on the other side after tablet (positive pole) an Ar or Ar/H{sub 2} flow is realized. The reactor in the furnace is heated to 1050 C and slowly cooled to the chosen reaction temperature (e.g. 800 C). In both sides of the dense tablet an electric current of 2 A is used. Two ampere corresponds to 8 volts at these high temperatures. The whole investigation was measured by a solid electrolyte device (Fig. 2) (ZIROX SGM5EL) [4]. The oxygen concentration was measured before and after the permeation. At 800 C the oxygen permeation has a value of 0.6 ml/(cm-2.min.) (Fig. 3-4). (orig.)

  16. Model Updating of Complex Structures Using the Combination of Component Mode Synthesis and Kriging Predictor

    Directory of Open Access Journals (Sweden)

    Yang Liu


    Full Text Available Updating the structural model of complex structures is time-consuming due to the large size of the finite element model (FEM. Using conventional methods for these cases is computationally expensive or even impossible. A two-level method, which combined the Kriging predictor and the component mode synthesis (CMS technique, was proposed to ensure the successful implementing of FEM updating of large-scale structures. In the first level, the CMS was applied to build a reasonable condensed FEM of complex structures. In the second level, the Kriging predictor that was deemed as a surrogate FEM in structural dynamics was generated based on the condensed FEM. Some key issues of the application of the metamodel (surrogate FEM to FEM updating were also discussed. Finally, the effectiveness of the proposed method was demonstrated by updating the FEM of a real arch bridge with the measured modal parameters.

  17. Effect of mechanical disruption on the effectiveness of three reactors used for dilute acid pretreatment of corn stover Part 2: morphological and structural substrate analysis. (United States)

    Ciesielski, Peter N; Wang, Wei; Chen, Xiaowen; Vinzant, Todd B; Tucker, Melvin P; Decker, Stephen R; Himmel, Michael E; Johnson, David K; Donohoe, Bryon S


    Lignocellulosic biomass is a renewable, naturally mass-produced form of stored solar energy. Thermochemical pretreatment processes have been developed to address the challenge of biomass recalcitrance, however the optimization, cost reduction, and scalability of these processes remain as obstacles to the adoption of biofuel production processes at the industrial scale. In this study, we demonstrate that the type of reactor in which pretreatment is carried out can profoundly alter the micro- and nanostructure of the pretreated materials and dramatically affect the subsequent efficiency, and thus cost, of enzymatic conversion of cellulose. Multi-scale microscopy and quantitative image analysis was used to investigate the impact of different biomass pretreatment reactor configurations on plant cell wall structure. We identify correlations between enzymatic digestibility and geometric descriptors derived from the image data. Corn stover feedstock was pretreated under the same nominal conditions for dilute acid pretreatment (2.0 wt% H2SO4, 160°C, 5 min) using three representative types of reactors: ZipperClave® (ZC), steam gun (SG), and horizontal screw (HS) reactors. After 96 h of enzymatic digestion, biomass treated in the SG and HS reactors achieved much higher cellulose conversions, 88% and 95%, respectively, compared to the conversion obtained using the ZC reactor (68%). Imaging at the micro- and nanoscales revealed that the superior performance of the SG and HS reactors could be explained by reduced particle size, cellular dislocation, increased surface roughness, delamination, and nanofibrillation generated within the biomass particles during pretreatment. Increased cellular dislocation, surface roughness, delamination, and nanofibrillation revealed by direct observation of the micro- and nanoscale change in accessibility explains the superior performance of reactors that augment pretreatment with physical energy.

  18. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A


    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.

  19. Structured Sparse Principal Components Analysis with the TV-Elastic Net Penalty. (United States)

    de Pierrefeu, Amicie; Lofstedt, Tommy; Hadj-Selem, Fouad; Dubois, Mathieu; Jardri, Renaud; Fovet, Thomas; Ciuciu, Philippe; Frouin, Vincent; Duchesnay, Edouard


    Principal component analysis (PCA) is an exploratory tool widely used in data analysis to uncover dominant patterns of variability within a population. Despite its ability to represent a data set in a low-dimensional space, PCA's interpretability remains limited. Indeed, the components produced by PCA are often noisy or exhibit no visually meaningful patterns. Furthermore, the fact that the components are usually non-sparse may also impede interpretation, unless arbitrary thresholding is applied. However, in neuroimaging, it is essential to uncover clinically interpretable phenotypic markers that would account for the main variability in the brain images of a population. Recently, some alternatives to the standard PCA approach, such as Sparse PCA, have been proposed, their aim being to limit the density of the components. Nonetheless, sparsity alone does not entirely solve the interpretability problem in neuroimaging, since it may yield scattered and unstable components. We hypothesized that the incorporation of prior information regarding the structure of the data may lead to improved relevance and interpretability of brain patterns. We therefore present a simple extension of the popular PCA framework that adds structured sparsity penalties on the loading vectors in order to identify the few stable regions in the brain images that capture most of the variability. Such structured sparsity can be obtained by combining e.g., ℓ1 and total variation (TV) penalties, where the TV regularization encodes information on the underlying structure of the data. This paper presents the structured sparse PCA (denoted SPCATV) optimization framework and its resolution. We demonstrate SPCA-TV's effectiveness and versatility on three different data sets. It can be applied to any kind of structured data, such as e.g., N-dimensional array images or meshes of cortical surfaces. The gains of SPCA-TV over unstructured approaches (such as Sparse PCA and ElasticNet PCA) or structured

  20. Reactor operation safety information document

    Energy Technology Data Exchange (ETDEWEB)


    The report contains a reactor facility description which includes K, P, and L reactor sites, structures, operating systems, engineered safety systems, support systems, and process and effluent monitoring systems; an accident analysis section which includes cooling system anomalies, radioactive materials releases, and anticipated transients without scram; a summary of onsite doses from design basis accidents; severe accident analysis (reactor core disruption); a description of operating contractor organization and emergency planning; and a summary of reactor safety evolution. (MB)

  1. On the structure of dynamic principal component analysis used in statistical process monitoring

    DEFF Research Database (Denmark)

    Vanhatalo, Erik; Kulahci, Murat; Bergquist, Bjarne


    -dependent data. In DPCA the input matrix is augmented by adding time-lagged values of the variables. In building a DPCA model the analyst needs to decide on (1) the number of lags to add, and (2) given a specific lag structure, how many principal components to retain. In this article we propose a new analyst...... driven method to determine the maximum number of lags in DPCA with a foundation in multivariate time series analysis. The method is based on the behavior of the eigenvalues of the lagged autocorrelation and partial autocorrelation matrices. Given a specific lag structure we also propose a method......When principal component analysis (PCA) is used for statistical process monitoring it relies on the assumption that data are time independent. However, industrial data will often exhibit serial correlation. Dynamic PCA (DPCA) has been suggested as a remedy for high-dimensional and time...

  2. Load assumption for fatigue design of structures and components counting methods, safety aspects, practical application

    CERN Document Server

    Köhler, Michael; Pötter, Kurt; Zenner, Harald


    Understanding the fatigue behaviour of structural components under variable load amplitude is an essential prerequisite for safe and reliable light-weight design. For designing and dimensioning, the expected stress (load) is compared with the capacity to withstand loads (fatigue strength). In this process, the safety necessary for each particular application must be ensured. A prerequisite for ensuring the required fatigue strength is a reliable load assumption. The authors describe the transformation of the stress- and load-time functions which have been measured under operational conditions to spectra or matrices with the application of counting methods. The aspects which must be considered for ensuring a reliable load assumption for designing and dimensioning are discussed in detail. Furthermore, the theoretical background for estimating the fatigue life of structural components is explained, and the procedures are discussed for numerous applications in practice. One of the prime intentions of the authors ...

  3. Structural Reliability Methods for Wind Power Converter System Component Reliability Assessment

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard


    Wind power converter systems are essential subsystems in both off-shore and on-shore wind turbines. It is the main interface between generator and grid connection. This system is affected by numerous stresses where the main contributors might be defined as vibration and temperature loadings....... The temperature variations induce time-varying stresses and thereby fatigue loads. A probabilistic model is used to model fatigue failure for an electrical component in the power converter system. This model is based on a linear damage accumulation and physics of failure approaches, where a failure criterion...... is defined by the threshold model. The attention is focused on crack propagation in solder joints of electrical components due to the temperature loadings. Structural Reliability approaches are used to incorporate model, physical and statistical uncertainties. Reliability estimation by means of structural...

  4. Vibration-based structural health monitoring of the aircraft large component (United States)

    Pavelko, V.; Kuznetsov, S.; Nevsky, A.; Marinbah, M.


    In the presented paper there are investigated the basic problems of the local system of SHM of large scale aircraft component. Vibration-based damage detection is accepted as a basic condition, and main attention focused to a low-cost solution that would be attractive for practice. The conditions of small damage detection in the full scale structural component at low-frequency excitation were defined in analytical study and modal FEA. In experimental study the dynamic test of the helicopter Mi-8 tail beam was performed at harmonic excitation with frequency close to first natural frequency of the beam. The index of correlation coefficient deviation (CCD) was used for extraction of the features due to embedded pseudo-damage. It is shown that the problem of vibration-based detection of a small damage in the large scale structure at low-frequency excitation can be solved successfully.

  5. Building Block Approach' for Structural Analysis of Thermoplastic Composite Components for Automotive Applications (United States)

    Carello, M.; Amirth, N.; Airale, A. G.; Monti, M.; Romeo, A.


    Advanced thermoplastic prepreg composite materials stand out with regard to their ability to allow complex designs with high specific strength and stiffness. This makes them an excellent choice for lightweight automotive components to reduce mass and increase fuel efficiency, while maintaining the functionality of traditional thermosetting prepreg (and mechanical characteristics) and with a production cycle time and recyclability suited to mass production manufacturing. Currently, the aerospace and automotive sectors struggle to carry out accurate Finite Elements (FE) component analyses and in some cases are unable to validate the obtained results. In this study, structural Finite Elements Analysis (FEA) has been done on a thermoplastic fiber reinforced component designed and manufactured through an integrated injection molding process, which consists in thermoforming the prepreg laminate and overmolding the other parts. This process is usually referred to as hybrid molding, and has the provision to reinforce the zones subjected to additional stresses with thermoformed themoplastic prepreg as required and overmolded with a shortfiber thermoplastic resin in single process. This paper aims to establish an accurate predictive model on a rational basis and an innovative methodology for the structural analysis of thermoplastic composite components by comparison with the experimental tests results.

  6. Irradiation effects on austenitic stainless steels for structural materials of IFMIF components

    Energy Technology Data Exchange (ETDEWEB)

    Jitsukawa, S.; Suzuki, K. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan); Zinkle, S. [Oak Ridge National Laboratory, Materials Science and Technology Div., AK TN (United States); Hirose, T. [Blanket Engineering Group, Japan Atomic Energy Agency, Naka, Ibaraki (Japan)


    Full text of publication follows: Austenitic stainless steel, such as 316 stainless steel is one of the candidate structural materials for the target component and test modules of the International Fusion Materials Irradiation Facility IFMIF, as well as that for ITER shield blanket. Anticipated displacement damage levels for the ITER shield blanket are as large as 3 displacements per atom (dpa), while those for the IFMIF target components and test modules will attain a high damage level of 50 dpa or even higher, depending on the service period. The anticipated operating temperature of the components is lower than 400 deg. C; therefore irradiation will cause hardening and reduction of elongation, as well as degradation of fracture toughness. This paper reviews the degradation of mechanical properties of austenitic stainless steels introduced by irradiation to some tens of dpa level; degradation of fatigue properties, fracture toughness and ductility, as well as irradiation induced creep. Additional data, especially those at temperatures lower than 300 deg. C, are also introduced. The results have been obtained during the collaborative irradiation experiment between JAEA and US-DOE using HFIR. Irradiation causes degradation in mechanical properties of the austenitic stainless steels. However, residual ductility and fracture toughness still seem to be large enough for the application as structural materials. This, however, does not assure that the current design criterion is applicable for the component engineering. A dedicated effort to develop engineering design criteria also needs to be accomplished. (authors)

  7. Reactor safeguards

    CERN Document Server

    Russell, Charles R


    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

  8. Reactor operation

    CERN Document Server

    Shaw, J


    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

  9. Mechanical properties of multifunctional structure with viscoelastic components based on FVE model (United States)

    Hao, Dong; Zhang, Lin; Yu, Jing; Mao, Daiyong


    Based on the models of Lion and Kardelky (2004) and Hofer and Lion (2009), a finite viscoelastic (FVE) constitutive model, considering the predeformation-, frequency- and amplitude-dependent properties, has been proposed in our earlier paper [1]. FVE model is applied to investigating the dynamic characteristics of the multifunctional structure with the viscoelastic components. Combing FVE model with the finite element theory, the dynamic model of the multifunctional structure could be obtained. Additionally, the parametric identification and the experimental verification are also given via the frequency-sweep tests. The results show that the computational data agree well with the experimental data. FVE model has made a success of expressing the dynamic characteristics of the viscoelastic materials utilized in the multifunctional structure. The multifunctional structure technology has been verified by in-orbit experiments.

  10. Agile Modeling of Component Connections for Simulation and Design of Complex Vehicle Structures (Slides) (United States)


    1996) • Optimal design of spot-weld and adhesive bond patterns for static compliance Chickermane and Gea (1997) • Multi-component structural...Shifted Lagrangian in OC MMA (Method of Moving Asymptotes) – K. Svanberg (’87) Convex Linearization with Asymptotes of Objective and Constraints Joining...Applicability both dynamic and static problems Design domain modeling SIMP (Solid Isotropic Material with Penalization) MMA (Method of Moving Asymptote

  11. The influence of differential evaporation on the structure of a three-component biofuel spray


    Keller, Peter; Knorsch, Tobias; Wensing, Michael; Hasse, Christian


    A high-pressure spray injected under gasoline engine conditions in a constant volume chamber is studied in detail using a three-dimensional computational fluid dynamics approach. Both single-component and ternary mixture (n-alkane and alcohols) spray results are compared with the experimental data from shadowgraphy, Schlieren imaging and phase-Doppler anemometry. Activity coefficient models are used to cover non-ideal thermodynamic effects occurring when mixtures of structurally dissimilar co...

  12. Structural characterization of the lipid A component of pathogenic Neisseria meningitidis.


    Kulshin, V A; Zähringer, U; Lindner, B; Frasch, C E; Tsai, C M; Dmitriev, B A; Rietschel, E T


    The lipid A component of meningococcal lipopolysaccharide was structurally characterized by using chemical modification methods, methylation analysis, 31P nuclear magnetic resonance, and laser desorption mass spectroscopy. It was shown that Neisseria meningitidis lipid A consists of a 1,4'-bisphosphorylated beta(1'----6)-linked D-glucosamine disaccharide (lipid A backbone), both phosphate groups being largely replaced by O-phosphorylethanolamine. This disaccharide harbors two nonsubstituted h...

  13. The influence of cellular structures on flow stress of high strength components manufactured using SLM

    DEFF Research Database (Denmark)

    Mahshid, Rasoul; Hansen, Hans Nørgaard; Loft Højbjerre, Klaus


    Additive manufacturing has shown significant improvement in material and machines for high-quality solid freeform fabrication processes such as selective laser melting (SLM). In particular, manufacturing lattice structures using the SLM procedure is of interest. This research examines the effect...... of cellular materials on compression strength. The specimens are manufactured additively using industrial 3D printing systems from high-strength alloy. The material has the right mechanical properties for manufacturing tool components. This includes samples with solid and lattice structures. The Compression...


    Directory of Open Access Journals (Sweden)

    Alina Mykytyshyn


    Full Text Available The concepts of the professional foreign language communicative training and professional foreign language communicative competence of the future software engineers have been analyzed in the article. Different approaches to the interpretation of these concepts in the contemporary scientific literature have been described. The essence and the structural components of the professional foreign language communicative competence of software engineers in accordance with the objectives and tasks of the program of study. The expediency of the chosen approach to the structuring of the professional foreign language communicative competence has been provided. The recommendations, regarding their practical implementation in the educational process of students of the technical universities.

  15. Improving Thermal Insulation Properties for Prefabricated Wall Components Made Of Lightweight Aggregate Concrete with Open Structure (United States)

    Abramski, Marcin


    Porous concrete is commonly used in civil engineering due to its good thermal insulation properties in comparison with normal concrete and high compression strength in comparison with other building materials. Reducing of the concrete density can be obviously obtained by using lightweight aggregate (e.g. pumice). The concrete density can be further minimized by using specially graded coarse aggregate and little-to-no fine aggregates. In this way a large number of air voids arise. The aggregate particles are coated by a cement paste and bonded together with it just in contact points. Such an extremely porous concrete, called ‘lightweight aggregate concrete with open structure’ (LAC), is used in some German plants to produce prefabricated wall components. They are used mainly in hall buildings, e.g. supermarkets. The need of improving thermal insulation properties was an inspiration for the prefabrication plant managers, engineers and a scientific staff of the Technical University of Kaiserslautern / Germany to realise an interesting project. Its aim was to reduce the heat transfer coefficient for the wall components. Three different wall structure types were designed and compared in full-scale laboratory tests with originally produced wall components in terms of load-carrying capacity and stiffness. The load was applied perpendicularly to the wall plane. As the components are not originally used for load-bearing walls, but for curtain walls only, the wind load is the main load for them. The wall components were tested in horizontal position and the load was applied vertically. Totally twelve wall components 8.00 × 2.00 × 0.25m (three for every series) were produced in the prefabrication plant and tested in the University of Kaiserslautern laboratory. The designed and tested components differed from each other in the amount of expanded polystyrene (EPS), which was placed in the plant inside the wall structure. The minimal amount of it was designed in the

  16. Brain structure correlates of component reading processes: implications for reading disability. (United States)

    Phinney, Erin; Pennington, Bruce F; Olson, Richard; Filley, Christopher M; Filipek, Pauline A


    Brain structures implicated in developmental dyslexia (reading disability - RD) vary greatly across structural magnetic resonance imaging (MRI) studies due to methodological differences regarding the definition of RD and the exact measurements of a specific brain structure. The current study attempts to resolve some of those methodological concerns by examining brain volume as it relates to components of proposed RD subtypes. We performed individual regression analyses on total cerebral volume, neocortical volume, subcortical volume, 9 neo-cortical structures and 2 sub-cortical structures. These analyses used three dimensions of reading, phonemic ability (PA), orthographic ability, and rapid naming (RN) ability, while accounting for total cerebral volume, age, and performance IQ (PIQ). Primary analyses included membership to a group (poor reader vs. good reader) in the analysis. The result was a significant interaction between PA and reading ability as it predicts total cerebral volume. Analyses revealed that poor readers lacked a relationship between PA and brain size, but that good readers had a significant positive relationship. This pattern of interaction was not present for the other two reading component factors. These findings bring into question the general belief that individuals with RD are at the low end of a reading ability distribution and do not have a unique disorder. Additional analyses revealed only a few significant relationships between brain size and task performance, most notably a positive correlation between orthographic ability and the angular gyrus (AG), as well as a negative correlation between RN ability and the parietal operculum (PO).

  17. Independent component analysis reveals new and biologically significant structures in micro array data

    Directory of Open Access Journals (Sweden)

    Veerla Srinivas


    Full Text Available Abstract Background An alternative to standard approaches to uncover biologically meaningful structures in micro array data is to treat the data as a blind source separation (BSS problem. BSS attempts to separate a mixture of signals into their different sources and refers to the problem of recovering signals from several observed linear mixtures. In the context of micro array data, "sources" may correspond to specific cellular responses or to co-regulated genes. Results We applied independent component analysis (ICA to three different microarray data sets; two tumor data sets and one time series experiment. To obtain reliable components we used iterated ICA to estimate component centrotypes. We found that many of the low ranking components indeed may show a strong biological coherence and hence be of biological significance. Generally ICA achieved a higher resolution when compared with results based on correlated expression and a larger number of gene clusters with significantly enriched for gene ontology (GO categories. In addition, components characteristic for molecular subtypes and for tumors with specific chromosomal translocations were identified. ICA also identified more than one gene clusters significant for the same GO categories and hence disclosed a higher level of biological heterogeneity, even within coherent groups of genes. Conclusion Although the ICA approach primarily detects hidden variables, these surfaced as highly correlated genes in time series data and in one instance in the tumor data. This further strengthens the biological relevance of latent variables detected by ICA.

  18. Estimation of the Lithospheric Component Share in the Earth Natural Pulsed Electromagnetic Field Structure (United States)

    Malyshkov, S. Y.; Gordeev, V. F.; Polyvach, V. I.; Shtalin, S. G.; Pustovalov, K. N.


    Article describes the results of the atmosphere and Earth’s crust climatic and ecological parameters integrated monitoring. The estimation is made for lithospheric component share in the Earth natural pulsed electromagnetic field structure. To estimate lithospheric component we performed a round-the-clock monitoring of the Earth natural pulsed electromagnetic field background variations at the experiment location and measured the Earth natural pulsed electromagnetic field under electric shields. Natural materials in a natural environment were used for shielding, specifically lakes with varying parameters of water conductivity. Skin effect was used in the experiment - it is the tendency of electromagnetic waves amplitude to decrease with greater depths in the conductor. Atmospheric and lithospheric component the Earth natural pulsed electromagnetic field data recorded on terrain was compared against the recorded data with atmosphere component decayed by an electric shield. In summary we have demonstrated in the experiment that thunderstorm discharge originating electromagnetic field decay corresponds to the decay calculated using Maxwell equations. In the absence of close lightning strikes the ratio of field intensity recorded on terrain to shielded field intensity is inconsistent with the ratio calculated for atmospheric sources, that confirms there is a lithospheric component present to the Earth natural pulsed electromagnetic field.

  19. Design for beam splitting components employing silicon-on-insulator rib waveguide structures. (United States)

    Hsiao, C S; Wang, Likarn


    We present a new design for beam splitting components employing a silicon-on-insulator rib waveguide structures. In the new design, a high-index thin-film layer is deposited in the rib section to reduce the wave field dispersive tails in the slab section and accordingly render the mode field a confined spot. This in turn improves the beam splitting performance of some conventional waveguide components such as y branches and multimode interference couplers (MMICs), in terms of the excess loss, fiber coupling loss, and compactness of these components. For a 1 x 2 y-branch beam splitter, the excess loss can be as small as 0.43 dB in the new design, which is much lower than that for a conventional rib waveguide structure (which is 1.28 dB). For a 1 x 2 MMIC in our example, the new rib waveguide structure presents an excess loss of 0.064 dB for the TE mode and 0.046 dB for the TM mode, with negligible nonuniformity in dimensions of 30 microm x 1040 microm, whereas its counterpart (i.e., the one with the same dimensions but without a thin-film layer) presents an excess loss of approximately 0.86 dB for both modes. A conventional MMIC must have dimensions larger than 70 microm x 5650 microm to maintain almost the same low excess loss.

  20. Effects of the gene carrier polyethyleneimines on structure and function of blood components. (United States)

    Zhong, Dagen; Jiao, Yanpeng; Zhang, Yi; Zhang, Wei; Li, Nan; Zuo, Qinhua; Wang, Qian; Xue, Wei; Liu, Zonghua


    As a synthetic polycation, polyethylenimine (PEI) is currently one of the most effective non-viral gene carriers. For in vivo applications, PEI will enter systemic circulation and interact with various blood components and then affect their individual bio-functions. Up to now, overall and systematic investigation on the interaction of PEI with multiple blood components at cellular, membrane, and molecular levels is lacking, even though it is critically important for the in vivo safety of PEI. To learn a structure-activity relationship, we investigated the effects of PEI with different molecular weight (MW) and shape (branched or linear) on key blood components and function, specifically, on RBC aggregation and morphological change, platelet activation, conformation change of albumin (as a representative of plasma proteins), and blood coagulation process. Additionally, more proteins from plasma were screened and identified to have associations with PEI by a proteomic analysis. It was found that, the PEIs have severe impact on RBC membrane structure, albumin conformation, and blood coagulation process, but do not significantly activate platelets at low concentrations. Furthermore, 41 plasma proteins were identified to have some interaction with PEI. This indicates that, besides albumin, PEI does interact with a variety of blood plasma proteins, and could have unexplored effects on their structures and bio-functions. The results provide good insight into the molecular design and blood safety of PEI and other polycations for in vivo applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Effect of fine-grained components on concrete properties and structure formation

    Directory of Open Access Journals (Sweden)

    Zimakova Galina


    Full Text Available The paper investigates the influence of fine-grained components on the synthesis of new formations and structure of cellular concrete. Grain size composition was defined with the aid of a laser diffraction analyzer of particles ANALYSETTE 22 NanoTecplus. The composition of the obtained hydrated phases was studied using electron microscopy and X-ray phase analysis. The introduction of silica and aluminosilicate components with the specific surface area >350 m2/kg enabled to directly influence the mechanism of the hydrated phases formation. Complex hydrated calcium aluminosilicates of the frame structure of zeolite type and non-permanent composition were identified in the hydration products. The formation of the total set of properties is attributed to the morphological features of the hydrated phases, the nature of connections between the crystalline hydrates, and their location in the material structure. X-ray phase analysis showed that ultra-micro-dispersed components have the stimulating impact on the processes of silicate formation. With the increase in the amount of hydrated new formations and decrease in the liquid phase volume the conditions for building of strong crystal intergrowth contacts were created.

  2. Methane oxidation in a landfill cover soil reactor: Changing of kinetic parameters and microorganism community structure. (United States)

    Xing, Zhi L; Zhao, Tian T; Gao, Yan H; Yang, Xu; Liu, Shuai; Peng, Xu Y


    Changing of CH4 oxidation potential and biological characteristics with CH4 concentration was studied in a landfill cover soil reactor (LCSR). The maximum rate of CH4 oxidation reached 32.40 mol d-1 m-2 by providing sufficient O2 in the LCSR. The kinetic parameters of methane oxidation in landfill cover soil were obtained by fitting substrate diffusion and consumption model based on the concentration profile of CH4 and O2. The values of [Formula: see text] (0.93-2.29%) and [Formula: see text] (140-524 nmol kgsoil-DW-1·s-1) increased with CH4 concentration (9.25-20.30%), while the values of [Formula: see text] (312.9-2.6%) and [Formula: see text] (1.3 × 10-5 to 9.0 × 10-3 nmol mL-1 h-1) were just the opposite. MiSeq pyrosequencing data revealed that Methylobacter (the relative abundance was decreased with height of LCSR) and Methylococcales_unclassified (the relative abundance was increased expect in H 80) became the key players after incubation with increasing CH4 concentration. These findings provide information for assessing CH4 oxidation potential and changing of biological characteristics in landfill cover soil.


    Directory of Open Access Journals (Sweden)

    Vladimir I. Freyman


    Full Text Available The aim of the study is to present new methods of quality results assessment of the education corresponding to requirements of Federal State Educational Standards (FSES of the Third Generation developed for the higher school. The urgency of search of adequate tools for quality competency measurement and its elements formed in the course of experts’ preparation are specified. Methods. It is necessary to consider interference of competency components such as knowledge, abilities, possession in order to make procedures of assessment of students’ achievements within the limits of separate discipline or curriculum section more convenient, effective and exact. While modeling of component structure of the disciplinary competence the testable design of components is used; the approach borrowed from technical diagnostics. Results. The research outcomes include the definition and analysis of general iterative methodology for testable designing component structure of the disciplinary competence. Application of the proposed methodology is illustrated as the example of an abstract academic discipline with specified data and index of labour requirement. Methodology restrictions are noted; practical recommendations are given. Scientific novelty. Basic data and a detailed step-by-step implementation phase of the proposed common iterative approach to the development of disciplinary competence testable component structure are considered. Tests and diagnostic tables for different options of designing are proposed. Practical significance. The research findings can help promoting learning efficiency increase, a choice of adequate control devices, accuracy of assessment, and also efficient use of personnel, temporal and material resources of higher education institutions. Proposed algorithms, methods and approaches to procedure of control results organization and realization of developed competences and its components can be used as methodical base while

  4. Structural characterisation of pretreated solids from flow-through liquid hot water treatment of sugarcane bagasse in a fixed-bed reactor

    CSIR Research Space (South Africa)

    Reddy, P


    Full Text Available Untreated sugarcane bagasse and sugarcane bagasse pretreated with flow-through liquid hot water (LHW) treatment (170-207°C and 204-250 ml/min) in a fixed-bed reactor have been structurally characterised. Field emission gun scanning electron...

  5. Preliminary Development of a Work Breakdown Structure (WBS) for Small Modular Reactors (SMRs)

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Thomas J [ORNL; Moses, Rebecca J [ORNL; Flanagan, George F [ORNL


    In summary, this preliminary WBS serves as an initial basis for the capital cost component of the economic analysis of SMRs. This preliminary WBS comes from the known WBS for existing, large nuclear power plants and develops the methodology for accounting for the anticipated differences between the current large plants and the projected SMR designs.

  6. Seismic design technology for breeder reactor structures. Volume 4. Special topics in piping and equipment

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, D.P.


    This volume is divided into five chapters: experimental verification of piping systems, analytical verification of piping restraint systems, seismic analysis techniques for piping systems with multisupport input, development of floor spectra from input response spectra, and seismic analysis procedures for in-core components. (DLC)

  7. Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Martens, Frederick H. [Argonne National Laboratory; Jacobson, Norman H.


    This booklet discusses research reactors - reactors designed to provide a source of neutrons and/or gamma radiation for research, or to aid in the investigation of the effects of radiation on any type of material.

  8. Advanced Gas Cooled Nuclear Reactor Materials Evaluation and Development Program: Topical report I, selection of candidate alloys. Volume 3. Selection of surface coating/substrate systems for screening creep and structural stability studies

    Energy Technology Data Exchange (ETDEWEB)


    Considering the high temperature, low O/sub 2/, high C environment of operation in the Very High Temperature Reactor (VHTR) Systems, the utilization of coatings is envisaged to hold potential for extending component lifetimes through the formation of stable and continuous oxide films with enhanced resistance to C diffusion. A survey of the current state of technology for high temperature coatings has been performed. The usefulness of these coatings on the Mo, Ni, and Fe base alloys is discussed. Specifically, no coating substitute was identified for TZM other than the well known W-3 (pack silicide) and Al/sub 2/O/sub 3/ forming coatings were recommended for the Fe and Ni base structural materials. Recommendations as to coating types and processng have been made based on the predicted VHTR component size, shape, base metal and operational environment. Four tests designed to evaluate the effects of selected combinations of coatings and substrate matrices are recommended for consideration.

  9. Secondary structure, a missing component of sequence-based minimotif definitions.

    Directory of Open Access Journals (Sweden)

    David P Sargeant

    Full Text Available Minimotifs are short contiguous segments of proteins that have a known biological function. The hundreds of thousands of minimotifs discovered thus far are an important part of the theoretical understanding of the specificity of protein-protein interactions, posttranslational modifications, and signal transduction that occur in cells. However, a longstanding problem is that the different abstractions of the sequence definitions do not accurately capture the specificity, despite decades of effort by many labs. We present evidence that structure is an essential component of minimotif specificity, yet is not used in minimotif definitions. Our analysis of several known minimotifs as case studies, analysis of occurrences of minimotifs in structured and disordered regions of proteins, and review of the literature support a new model for minimotif definitions that includes sequence, structure, and function.

  10. Capturing multidimensionality in stroke aphasia: mapping principal behavioural components to neural structures. (United States)

    Butler, Rebecca A; Lambon Ralph, Matthew A; Woollams, Anna M


    Stroke aphasia is a multidimensional disorder in which patient profiles reflect variation along multiple behavioural continua. We present a novel approach to separating the principal aspects of chronic aphasic performance and isolating their neural bases. Principal components analysis was used to extract core factors underlying performance of 31 participants with chronic stroke aphasia on a large, detailed battery of behavioural assessments. The rotated principle components analysis revealed three key factors, which we labelled as phonology, semantic and executive/cognition on the basis of the common elements in the tests that loaded most strongly on each component. The phonology factor explained the most variance, followed by the semantic factor and then the executive-cognition factor. The use of principle components analysis rendered participants' scores on these three factors orthogonal and therefore ideal for use as simultaneous continuous predictors in a voxel-based correlational methodology analysis of high resolution structural scans. Phonological processing ability was uniquely related to left posterior perisylvian regions including Heschl's gyrus, posterior middle and superior temporal gyri and superior temporal sulcus, as well as the white matter underlying the posterior superior temporal gyrus. The semantic factor was uniquely related to left anterior middle temporal gyrus and the underlying temporal stem. The executive-cognition factor was not correlated selectively with the structural integrity of any particular region, as might be expected in light of the widely-distributed and multi-functional nature of the regions that support executive functions. The identified phonological and semantic areas align well with those highlighted by other methodologies such as functional neuroimaging and neurostimulation. The use of principle components analysis allowed us to characterize the neural bases of participants' behavioural performance more robustly and

  11. Capturing multidimensionality in stroke aphasia: mapping principal behavioural components to neural structures (United States)

    Butler, Rebecca A.


    Stroke aphasia is a multidimensional disorder in which patient profiles reflect variation along multiple behavioural continua. We present a novel approach to separating the principal aspects of chronic aphasic performance and isolating their neural bases. Principal components analysis was used to extract core factors underlying performance of 31 participants with chronic stroke aphasia on a large, detailed battery of behavioural assessments. The rotated principle components analysis revealed three key factors, which we labelled as phonology, semantic and executive/cognition on the basis of the common elements in the tests that loaded most strongly on each component. The phonology factor explained the most variance, followed by the semantic factor and then the executive-cognition factor. The use of principle components analysis rendered participants’ scores on these three factors orthogonal and therefore ideal for use as simultaneous continuous predictors in a voxel-based correlational methodology analysis of high resolution structural scans. Phonological processing ability was uniquely related to left posterior perisylvian regions including Heschl’s gyrus, posterior middle and superior temporal gyri and superior temporal sulcus, as well as the white matter underlying the posterior superior temporal gyrus. The semantic factor was uniquely related to left anterior middle temporal gyrus and the underlying temporal stem. The executive-cognition factor was not correlated selectively with the structural integrity of any particular region, as might be expected in light of the widely-distributed and multi-functional nature of the regions that support executive functions. The identified phonological and semantic areas align well with those highlighted by other methodologies such as functional neuroimaging and neurostimulation. The use of principle components analysis allowed us to characterize the neural bases of participants’ behavioural performance more robustly and

  12. Components of Appearance in the Structure of Perception of Visual Representations of Age

    Directory of Open Access Journals (Sweden)

    Shkurko T.A.


    Full Text Available The article discusses the problem of perception of age (one’s own and that of other people, which is regarded as a special case of social perception. The aim of this study was to analyze the components of another person’s appearance in the structure of perception of visual representations of age. For these purposes the authors created a special technique, “Identifying Age through Photo Visualization” (Shkurko T.A., Nikolaeva E. G.. The study enrolled 20 individuals (10 men, 10 women aged 18 to 58 years as “models” (i.e. objects of perception and 60 individuals (47 women and 13 men aged 18 to 77 years as subjects of perception. The paper shows that in the structure of perception of visual representations of age the most important are stable, moderately stable and dynamic components of appearance, among which the stable parameters prevail. The face as the focus of the stable, moderately stable and dynamic components of appearance is the key element of appearance in one’s perception of other people’s age.

  13. Circadian Time Structure of Circulating Plasma Lipid Components in Healthy Indians of Different Age Groups. (United States)

    Singh, Ranjana; Sharma, Sumita; Singh, Raj K; Cornelissen, Germaine


    The circadian rhythm of human circulating lipid components was studied under nearnormal tropical conditions in 162 healthy volunteers (103 males and 59 females; 7 to 75 years of age). They followed a diurnal activity from about 06:00 to about 22:00 and nocturnal rest. These volunteers were divided into four groups: Group A (7-20 years), Group B (21-40 years), Group C (41-60 years) and Group D (61-75 years), comprising 42, 60, 35 and 25 participants, respectively. A marked circadian rhythm was demonstrated for each studied variable in each group by population-mean cosinor analysis (almost invariably p groups by parameter tests and regressed as a function of age, separately for males and females. A second-order polynomial characterized the MESOR of HDL cholesterol, phospholipids and total lipids, as well as the 24-h amplitude of total cholesterol and phospholipids. The 24-h amplitude of total lipids decreased linearly with age. The 24-h acrophase of the oldest age group (Group D) was advanced in the case of total cholesterol, HDL cholesterol, and total lipids, whereas that of phospholipids was delayed. Mapping the circadian rhythm (an important component of the broader time structure or chronome, which includes a. o., trends with age and extra-circadian components) of lipid components is needed to explore their role in the aging process in health.

  14. The Influence of Internal Structures in Fused Deposition Modeling Method on Dimensional Accuracy of Components

    Directory of Open Access Journals (Sweden)

    Milde Ján


    Full Text Available The paper investigates the influence of infill (internal structures of components in the Fused Deposition Modeling (FDM method on dimensional and geometrical accuracy of components. The components in this case were real models of human mandible, which were obtained by Computed Tomography (CT mostly used in medical applications. In the production phase, the device used for manufacturing, was a 3D printer Zortrax M200 based on the FDM technology. In the second phase, the mandibles made by the printer, were digitized using optical scanning device of GOM ATOS Triple Scan II. They were subsequently evaluated in the final phase. The practical part of this article describes the procedure of jaw model modification, the production of components using a 3D printer, the procedure of digitization of printed parts by optical scanning device and the procedure of comparison. The outcome of this article is a comparative analysis of individual printed parts, containing tables with mean deviations for individual printed parts, as well as tables for groups of printed parts with the same infill parameter.

  15. The reactor core TRIGA Mark-III with fuels type 30/20; El nucleo del reactor TRIGA Mark-III con combustible tipo 30/20

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F., E-mail: [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)


    This work describes the calculation series carried out with the program MCNP5 in order to define the configuration of the reactor core with fuels 30/20 (fuels with 30% of uranium content in the Or-Zr-H mixture and a nominal enrichment of 20%). To select the configuration of the reactor core more appropriate to the necessities and future uses of the reactor, the following criterions were taken into account: a) the excess in the reactor reactivity, b) the switch out margin and c) to have new irradiation facilities inside the reactor core. Taking into account these criterions is proceeded to know the characteristics of the components that form the reactor core (dimensions, geometry, materials, densities and positions), was elaborated a base model of the reactor core, for the MCNP5 code, with a configuration composed by 85 fuel elements, 4 control bars and the corresponding structural elements. The high reactivity excess obtained with this model, gave the rule to realize other models of the reactor core in which the reactivity excess and the switch out margin were approximate to the values established in the technical specifications of the reactor operation. Several models were realized until finding the satisfactory model; this is composite for 74 fuels, 4 control bars and 6 additional experimental positions inside the reactor core. (Author)

  16. "Structuration" by intellectual organization: the configuration of knowledge in relations among structural components in networks of science. (United States)

    Leydesdorff, Loet


    Using aggregated journal-journal citation networks, the measurement of the knowledge base in empirical systems is factor-analyzed in two cases of interdisciplinary developments during the period 1995-2005: (i) the development of nanotechnology in the natural sciences and (ii) the development of communication studies as an interdiscipline between social psychology and political science. The results are compared with a case of stable development: the citation networks of core journals in chemistry. These citation networks are intellectually organized by networks of expectations in the knowledge base at the specialty (that is, above-journal) level. The "structuration" of structural components (over time) can be measured as configurational information. The latter is compared with the Shannon-type information generated in the interactions among structural components: the difference between these two measures provides us with a measure for the redundancy generated by the specification of a model in the knowledge base of the system. This knowledge base incurs (against the entropy law) to variable extents on the knowledge infrastructures provided by the observable networks of relations.

  17. An agent-based method for simulating porous fluid-saturated structures with indistinguishable components (United States)

    Kashani, Jamal; Pettet, Graeme John; Gu, YuanTong; Zhang, Lihai; Oloyede, Adekunle


    Single-phase porous materials contain multiple components that intermingle up to the ultramicroscopic level. Although the structures of the porous materials have been simulated with agent-based methods, the results of the available methods continue to provide patterns of distinguishable solid and fluid agents which do not represent materials with indistinguishable phases. This paper introduces a new agent (hybrid agent) and category of rules (intra-agent rule) that can be used to create emergent structures that would more accurately represent single-phase structures and materials. The novel hybrid agent carries the characteristics of system's elements and it is capable of changing within itself, while also responding to its neighbours as they also change. As an example, the hybrid agent under one-dimensional cellular automata formalism in a two-dimensional domain is used to generate patterns that demonstrate the striking morphological and characteristic similarities with the porous saturated single-phase structures where each agent of the ;structure; carries semi-permeability property and consists of both fluid and solid in space and at all times. We conclude that the ability of the hybrid agent to change locally provides an enhanced protocol to simulate complex porous structures such as biological tissues which could facilitate models for agent-based techniques and numerical methods.

  18. Computational 3D imaging to quantify structural components and assembly of protein networks. (United States)

    Asgharzadeh, Pouyan; Özdemir, Bugra; Reski, Ralf; Röhrle, Oliver; Birkhold, Annette I


    Traditionally, protein structures have been described by the secondary structure architecture and fold arrangement. However, the relatively novel method of 3D confocal microscopy of fluorescent-protein-tagged networks in living cells allows resolving the detailed spatial organization of these networks. This provides new possibilities to predict network functionality, as structure and function seem to be linked at various scales. Here, we propose a quantitative approach using 3D confocal microscopy image data to describe protein networks based on their nano-structural characteristics. This analysis is constructed in four steps: (i) Segmentation of the microscopic raw data into a volume model and extraction of a spatial graph representing the protein network. (ii) Quantifying protein network gross morphology using the volume model. (iii) Quantifying protein network components using the spatial graph. (iv) Linking these two scales to obtain insights into network assembly. Here, we quantitatively describe the filamentous temperature sensitive Z protein network of the moss Physcomitrella patens and elucidate relations between network size and assembly details. Future applications will link network structure and functionality by tracking dynamic structural changes over time and comparing different states or types of networks, possibly allowing more precise identification of (mal) functions or the design of protein-engineered biomaterials for applications in regenerative medicine. Protein networks are highly complex and dynamic structures that play various roles in biological environments. Analyzing the detailed spatial structure of these networks may lead to new insight into biological functions and malfunctions. Here, we propose a tool set that extracts structural information at two scales of the protein network and allows therefore to address questions such as "how is the network built?" or "how networks grow?". Copyright © 2018 Acta Materialia Inc. Published by

  19. Numerical analysis of a SO{sub 3} packed column decomposition reactor with alloy RA 330 structural material for nuclear hydrogen production using the sulfur- iodine process

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Hyuk [Korea Maritime University, Busan (Korea, Republic of); Tak, Nam Il; Shin, Young Joon; Kim, Chan Soo; Lee, Ki Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    A directly heated SO{sub 3} decomposer for the sulfur-iodine and hybrid-sulfur processes has been introduced and analyzed using the computational fluid dynamics (CFD) code CFX 11. The use of a directly heated decomposition reactor in conjunction with a very high temperature reactor (VHTR) allows for higher decomposition reactor operating temperatures. However, the high temperatures and strongly corrosive operating conditions associated with SO{sub 3} decomposition present challenges for the structural materials of decomposition reactors. In order to resolve these problems, we have designed a directly heated SO{sub 3} decomposer using RA 330 alloy as a structural material and have performed a CFD analysis of the design based on the finite rate chemistry model. The CFD results show the maximum temperature of the structural material could be maintained sufficiently below 1073 K, which is considered the target temperature for RA 330. The CFD simulations also indicated good performance in terms of SO{sub 3} decomposition for the design parameters of the present study

  20. Interrelation between in-service inspection and structural integrity in reactors residual lifetime assessment

    Energy Technology Data Exchange (ETDEWEB)

    Karzov, Georgy; Timofeev, Boris; Rozina, Marina [Central Research Inst. of Structural Materials ' Prometey' , St. Petersburg (Russian Federation)


    The object of this paper is to show that in-service inspection (ISI) is of a great importance in structural integrity provision of NPP equipment as it permits: to assess material properties degradation during operation, to describe production flaws propagation under operating factors influence, to detect flaws appearance from structural concentrators and corrosion damages and to observe their development, to verify material loading conditions in structure depending on operating damages. It is presented the detailed scheme of possible production and operating flaws development during structure lifetime. The following flaws distribution function are considered in the schema: distribution probability of detected flaws (detectability), distribution density of actual flaws, distribution density of detected flaws. On the basis of stated above functions it is performed the selection of reference flow size and its outline (surface and internal flaws, cracks in cladding). (author)

  1. Nuclear reactor construction with bottom supported reactor vessel (United States)

    Sharbaugh, John E.


    An improved liquid metal nuclear reactor construction has a reactor core and a generally cylindrical reactor vessel for holding a large pool of low pressure liquid metal coolant and housing the core within the pool. The reactor vessel has an open top end, a closed flat bottom end wall and a continuous cylindrical closed side wall interconnecting the top end and bottom end wall. The reactor also has a generally cylindrical concrete containment structure surrounding the reactor vessel and being formed by a cylindrical side wall spaced outwardly from the reactor vessel side wall and a flat base mat spaced below the reactor vessel bottom end wall. A central support pedestal is anchored to the containment structure base mat and extends upwardly therefrom to the reactor vessel and upwardly therefrom to the reactor core so as to support the bottom end wall of the reactor vessel and the lower end of the reactor core in spaced apart relationship above the containment structure base mat. Also, an annular reinforced support structure is disposed in the reactor vessel on the bottom end wall thereof and extends about the lower end of the core so as to support the periphery thereof. In addition, an annular support ring having a plurality of inward radially extending linear members is disposed between the containment structure base mat and the bottom end of the reactor vessel wall and is connected to and supports the reactor vessel at its bottom end on the containment structure base mat so as to allow the reactor vessel to expand radially but substantially prevent any lateral motions that might be imposed by the occurrence of a seismic event. The reactor construction also includes a bed of insulating material in sand-like granular form, preferably being high density magnesium oxide particles, disposed between the containment structure base mat and the bottom end wall of the reactor vessel and uniformly supporting the reactor vessel at its bottom end wall on the containment

  2. A Multi-Scale, Multi-Physics Optimization Framework for Additively Manufactured Structural Components (United States)

    El-Wardany, Tahany; Lynch, Mathew; Gu, Wenjiong; Hsu, Arthur; Klecka, Michael; Nardi, Aaron; Viens, Daniel

    This paper proposes an optimization framework enabling the integration of multi-scale / multi-physics simulation codes to perform structural optimization design for additively manufactured components. Cold spray was selected as the additive manufacturing (AM) process and its constraints were identified and included in the optimization scheme. The developed framework first utilizes topology optimization to maximize stiffness for conceptual design. The subsequent step applies shape optimization to refine the design for stress-life fatigue. The component weight was reduced by 20% while stresses were reduced by 75% and the rigidity was improved by 37%. The framework and analysis codes were implemented using Altair software as well as an in-house loading code. The optimized design was subsequently produced by the cold spray process.

  3. CONVECTION REACTOR (United States)

    Hammond, R.P.; King, L.D.P.


    An homogeneous nuclear power reactor utilizing convection circulation of the liquid fuel is proposed. The reactor has an internal heat exchanger looated in the same pressure vessel as the critical assembly, thereby eliminating necessity for handling the hot liquid fuel outside the reactor pressure vessel during normal operation. The liquid fuel used in this reactor eliminates the necessity for extensive radiolytic gas rocombination apparatus, and the reactor is resiliently pressurized and, without any movable mechanical apparatus, automatically regulates itself to the condition of criticality during moderate variations in temperature snd pressure and shuts itself down as the pressure exceeds a predetermined safe operating value.

  4. Structure Analysis of Aerobic Granule from a Sequencing Batch Reactor for Organic Matter and Ammonia Nitrogen Removal

    Directory of Open Access Journals (Sweden)

    Jun Li


    Full Text Available Aerobic granules were cultivated in a sequencing batch reactor (SBR. COD and ammonia nitrogen removal rate were 94% and 99%, respectively. The diameter, settling velocity and SVI10 of granules ranged from 2 to 5 mm, 80 to 110 m/h and about 40 mL/g, respectively. Freezing microtome images, DO concentration profiles by microelectrode, distribution of bacteria and EPS by confocal laser scanning microscopy (CLSM show that the aerobic granules have a three-layer structure. Each layer has different thickness, character, bacteria, and DO transfer rate. A hypothesis for granule structure is proposed: the first layer, the surface of the granule, is composed mostly of heterotrophic organisms for organic matter removal, with a thickness range from 150 to 350 μm; the second layer, mostly composed of autotrophic organisms for ammonia nitrogen removal, with a thickness range from 250 to 450 μm; the third layer, located in the core of the granule, has mostly an inorganic composition and contains pores and channels.

  5. Numerical simulation study on monoblock casting process of ultra-slender structural components and experimental validation

    Directory of Open Access Journals (Sweden)

    Xu-liang Zhang


    Full Text Available Substrate, a typical ultra-slender aluminum alloy structural components with a large aspect ratio and complex internal structure, was traditionally manufactured by re-assembly and sub-welding. In order to realize the monoblock casting of the substrate, the Pro/E software was utilized to carry out three-dimensional (3D modeling of the substrate casting, and the filling and solidification processes were calculated, as well as the location and types of casting defects were predicted by the casting simulation software Anycasting. Results of the filling process simulation show that the metal liquid is distributed into each gap runner evenly and smoothly. There is no serious vortex phenomenon in the mold cavity, and the trajectory of the virtual particles is clear. Results of the solidification process simulation show that shrinkage cavities mainly appear at the junction of gap runners and the rail surface of the substrate. The average deformation is 0.6 mm in X direction, 3.8 mm in Y direction, and 8.2 mm in Z direction. Based on the simulation results, the casting process of the substrate was optimized, and qualified castings were successfully produced, which will provide a reference for the casting process design of other ultra-slender aluminum alloy structural components.

  6. Aero Engine Component Fault Diagnosis Using Multi-Hidden-Layer Extreme Learning Machine with Optimized Structure

    Directory of Open Access Journals (Sweden)

    Shan Pang


    Full Text Available A new aero gas turbine engine gas path component fault diagnosis method based on multi-hidden-layer extreme learning machine with optimized structure (OM-ELM was proposed. OM-ELM employs quantum-behaved particle swarm optimization to automatically obtain the optimal network structure according to both the root mean square error on training data set and the norm of output weights. The proposed method is applied to handwritten recognition data set and a gas turbine engine diagnostic application and is compared with basic ELM, multi-hidden-layer ELM, and two state-of-the-art deep learning algorithms: deep belief network and the stacked denoising autoencoder. Results show that, with optimized network structure, OM-ELM obtains better test accuracy in both applications and is more robust to sensor noise. Meanwhile it controls the model complexity and needs far less hidden nodes than multi-hidden-layer ELM, thus saving computer memory and making it more efficient to implement. All these advantages make our method an effective and reliable tool for engine component fault diagnosis tool.

  7. Stress Analysis of B-52B and B-52H Air-Launching Systems Failure-Critical Structural Components (United States)

    Ko, William L.


    The operational life analysis of any airborne failure-critical structural component requires the stress-load equation, which relates the applied load to the maximum tangential tensile stress at the critical stress point. The failure-critical structural components identified are the B-52B Pegasus pylon adapter shackles, B-52B Pegasus pylon hooks, B-52H airplane pylon hooks, B-52H airplane front fittings, B-52H airplane rear pylon fitting, and the B-52H airplane pylon lower sway brace. Finite-element stress analysis was performed on the said structural components, and the critical stress point was located and the stress-load equation was established for each failure-critical structural component. The ultimate load, yield load, and proof load needed for operational life analysis were established for each failure-critical structural component.

  8. Structural health monitoring of power plant components based on a local temperature measurement concept

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, Juergen; Bergholz, S.; Hilpert, R.; Jouan, B.; Goetz, A. [AREVA NP GmbH, Erlangen (Germany)


    The fatigue assessment of power plant components based on fatigue monitoring approaches is an essential part of the integrity concept and modern lifetime management. It is comparable to structural health monitoring approaches in other engineering fields. The methods of fatigue evaluation of nuclear power plant components based on realistic thermal load data measured on the plant are addressed. In this context the Fast Fatigue Evaluation (FFE) and Detailed Fatigue Calculation (DFC) of nuclear power plant components are parts of the three staged approach to lifetime assessment and lifetime management of the AREVA Fatigue Concept (AFC). The three stages Simplified Fatigue Estimation (SFE), Fast Fatigue Evaluation (FFE) and Detailed Fatigue Calculation (DFC) are characterized by increasing calculation effort and decreasing degree of conservatism. Their application is case dependent. The quality of the fatigue lifetime assessment essentially depends on one hand on the fatigue model assumptions and on the other hand on the load data as the basic input. In the case of nuclear power plant components thermal transient loading is most fatigue relevant. Usual global fatigue monitoring approaches rely on measured data from plant instrumentation. As an extension, the application of a local fatigue monitoring strategy (to be described in detail within the scope of this paper) paves the way of delivering continuously (nowadays at a frequency of 1 Hz) realistic load data at the fatigue relevant locations. Methods of qualified processing of these data are discussed in detail. Particularly, the processing of arbitrary operational load sequences and the derivation of representative model transients is discussed. This approach related to realistic load-time histories is principally applicable for all fatigue relevant components and ensures a realistic fatigue evaluation. (orig.)

  9. Natural phenomena hazards performance categorization guidelines for structures, systems, and components

    Energy Technology Data Exchange (ETDEWEB)



    The purpose of this standard is as follows: (a) To provide, for the purpose of Natural Phenomena Hazard (NPH) design and evaluation, criteria for selecting performance categories (PCs) of structures, systems, and components (SSCs) in accordance with the requirements specified in DOE Order 420.1 and the NPH Implementation Guide to DOE Order 420.1. (b) To recommend general procedures for consistent application of the above performance categorization criteria so that the Department of Energy (DOE) review and approval process is simplified.

  10. Detailed analysis of surface asperity deformation mechanism in diffusion bonding of steel hollow structural components

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C. [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Laboratoire de Mecanique des Contacts et des Structures (LaMCoS), INSA Lyon, 20 Avenue des Sciences, F-69621 Villeurbanne Cedex (France); Li, H. [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Li, M.Q., E-mail: [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China)


    Graphical abstract: This study focused on the detailed analysis of surface asperity deformation mechanism in diffusion bonding of steel hollow structural component. A special surface with regular patterns was processed to be joined so as to observe the extent of surface asperity deformation under different applied bonding pressures. Fracture surface characteristic combined with surface roughness profiles distinctly revealed the enhanced surface asperity deformation as the applied pressure increases. The influence of surface asperity deformation mechanism on joint formation was analyzed: (a) surface asperity deformation not only directly expanded the interfacial contact areas, but also released deformation heat and caused defects, indirectly accelerating atomic diffusion, then benefits to void shrinkage; (b) surface asperity deformation readily introduced stored energy difference between two opposite sides of interface grain boundary, resulting in strain induced interface grain boundary migration. In addition, the influence of void on interface grain boundary migration was analyzed in detail. - Highlights: • A high quality hollow structural component has been fabricated by diffusion bonding. • Surface asperity deformation not only expands the interfacial contact areas, but also causes deformation heat and defects to improve the atomic diffusion. • Surface asperity deformation introduces the stored energy difference between the two opposite sides of interface grain boundary, leading to strain induced interface grain boundary migration. • The void exerts a dragging force on the interface grain boundary to retard or stop interface grain boundary migration. - Abstract: This study focused on the detailed analysis of surface asperity deformation mechanism in similar diffusion bonding as well as on the fabrication of high quality martensitic stainless steel hollow structural components. A special surface with regular patterns was processed to be joined so as to

  11. Compton imaging tomography for nondestructive evaluation of large multilayer aircraft components and structures (United States)

    Romanov, Volodymyr; Grubsky, Victor; Zahiri, Feraidoon


    We present a novel NDT/NDE tool for non-contact, single-sided 3D inspection of aerospace components, based on Compton Imaging Tomography (CIT) technique, which is applicable to large, non-uniform, and/or multilayer structures made of composites or lightweight metals. CIT is based on the registration of Compton-scattered X-rays, and permits the reconstruction of the full 3D (tomographic) image of the inspected objects. Unlike conventional computerized tomography (CT), CIT requires only single-sided access to objects, and therefore can be applied to large structures without their disassembly. The developed tool provides accurate detection, identification, and precise 3D localizations and measurements of any possible internal and surface defects (corrosions, cracks, voids, delaminations, porosity, and inclusions), and also disbonds, core and skin defects, and intrusion of foreign fluids (e.g., fresh and salt water, oil) inside of honeycomb sandwich structures. The NDE capabilities of the system were successfully demonstrated on various aerospace structure samples provided by several major aerospace companies. Such a CIT-based tool can detect and localize individual internal defects with dimensions about 1-2 mm3, and honeycomb disbond defects less than 6 mm by 6 mm area with the variations in the thickness of the adhesive by 100 m. Current maximum scanning speed of aircraft/spacecraft structures is about 5-8 min/ft2 (50-80 min/m2).

  12. Effects of inulin on the structure and emulsifying properties of protein components in dough. (United States)

    Liu, Juan; Luo, Denglin; Li, Xuan; Xu, Baocheng; Zhang, Xiaoyu; Liu, Jianxue


    High-purity gliadin, glutenin and gluten fractions were extracted from wheat gluten flour. To investigate the effects of three types of inulin with different degrees of polymerization (DP) on the emulsifying properties, disulfide contents, secondary structures and microstructures of these fractions, Turbidimetry, spectrophotometer, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used in this study. The results showed that the emulsifying activity of gliadin was higher than that of glutenin and gluten, but its emulsion stability was lower than that of glutenin. Adding inulin increased the emulsifying activity of the three protein fractions and emulsion stability of gliadin and gluten, but decreased the emulsion stability of glutenin and disulfide bond contents of glutenin and gluten. In the presence of inulin, the α-helical structure of the three proteins had no significant change, whereas the β-turn structure decreased and β-sheet structure increased. The SEM images showed that inulin had the most significant effect on the glutenin microstructure. In general, inulin with a higher DP had greater effects on the structure and emulsifying properties of protein components in dough. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Preparation and application of multiple-component-doped keggin polyoxometalate microtubes--towards a component-tunable hollow structure. (United States)

    Shen, Yan; Peng, Jun; Pang, Haijun; Zhang, Pengpeng; Chen, Dan; Chen, Changyun; Zhang, Huanqiu; Meng, Cuili; Su, Zhongmin


    In this paper, the preparation of ascorbic acid (AA)-doped polyoxometalate (SiW(12)-AA) microtubes is described. The SiW(12)-AA microtubes convert to heteropoly blue microtubes upon exposure to ammonia gas, which is an ammonia-triggered solid-solid redox reaction between AA molecules and polyoxometalates, and can possibly be applied to a chemical sensor for detecting ammonia and volatile organic amines. Furthermore, the SiW(12)-AA microtubes have been applied to the in situ synthesis of Ag nanoparticles (NPs) through the redox reaction between the AA component and Ag(+) ions occurring on the surfaces of the SiW(12)-AA microtubes to give silver NPs immobilized on polyoxometalate microtubes (Ag@SiW(12)). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Polysaccharide components from the scape of Musa paradisiaca: main structural features of water-soluble polysaccharide component. (United States)

    Anjaneyalu, Y V; Jagadish, R L; Raju, T S


    Polysaccharide components present in the pseudo-stem (scape) of M. paradisiaca were purified from acetone powder of the scape by delignification followed by extraction with aqueous solvents into water soluble polysaccharide (WSP), EDTA-soluble polysaccharide (EDTA-SP), alkali-soluble polysaccharide (ASP) and alkali-insoluble polysaccharide (AISP) fractions. Sugar compositional analysis showed that WSP and EDTA-SP contained only D-Glc whereas ASP contained D-Glc, L-Ara and D-Xyl in approximately 1:1:10 ratio, respectively, and AISP contained D-Glc, L-Ara and D-Xyl in approximately 10:1:2 ratio, respectively. WSP was further purified by complexation with iso-amylalcohol and characterized by specific rotation, IR spectroscopy, Iodine affinity, ferricyanide number, blue value, hydrolysis with alpha-amylase and glucoamylase, and methylation linkage analysis, and shown to be a amylopectin type alpha-D-glucan.

  15. Damage Assessment of Aerospace Structural Components by Impedance Based Health Monitoring (United States)

    Gyekenyesi, Andrew L.; Martin, Richard E.; Sawicki, Jerzy T.; Baaklini, George Y.


    This paper addresses recent efforts at the NASA Glenn Research Center at Lewis Field relating to the set-up and assessment of electro-mechanical (E/M) impedance based structural health monitoring. The overall aim is the application of the impedance based technique to aeronautic and space based structural components. As initial steps, a laboratory was created, software written, and experiments conducted on aluminum plates in undamaged and damaged states. A simulated crack, in the form of a narrow notch at various locations, was analyzed using piezoelectric-ceramic (PZT: lead, zirconate, titarate) patches as impedance measuring transducers. Descriptions of the impedance quantifying hardware and software are provided as well as experimental results. In summary, an impedance based health monitoring system was assembled and tested. The preliminary data showed that the impedance based technique was successful in recognizing the damage state of notched aluminum plates.

  16. The structure of bovine complement component 3 reveals the basis for thioester function

    DEFF Research Database (Denmark)

    Fredslund, Folmer; Jenner, Lasse Bohl; Husted, Lise Bjerre


    The third component of complement (C3) is a 190 kDa glycoprotein essential for eliciting the complement response. The protein consists of two polypeptide chains (α and β) held together with a single disulfide bridge. The β-chain is made up of six MG domains of which one of which is shared...... but not in C5) is cleaved during complement activation. This mediates covalent attachment of the activated C3b to immune complexes and invading microorganisms hereby opsonising the target. We present the structure of bovine C3 determined at 3 Å resolution. The structure shows that the ester is deeply buried......-chain of C3, which appears essential for conformational changes in C3....

  17. Discriminant analysis of principal components: a new method for the analysis of genetically structured populations (United States)


    Background The dramatic progress in sequencing technologies offers unprecedented prospects for deciphering the organization of natural populations in space and time. However, the size of the datasets generated also poses some daunting challenges. In particular, Bayesian clustering algorithms based on pre-defined population genetics models such as the STRUCTURE or BAPS software may not be able to cope with this unprecedented amount of data. Thus, there is a need for less computer-intensive approaches. Multivariate analyses seem particularly appealing as they are specifically devoted to extracting information from large datasets. Unfortunately, currently available multivariate methods still lack some essential features needed to study the genetic structure of natural populations. Results We introduce the Discriminant Analysis of Principal Components (DAPC), a multivariate method designed to identify and describe clusters of genetically related individuals. When group priors are lacking, DAPC uses sequential K-means and model selection to infer genetic clusters. Our approach allows extracting rich information from genetic data, providing assignment of individuals to groups, a visual assessment of between-population differentiation, and contribution of individual alleles to population structuring. We evaluate the performance of our method using simulated data, which were also analyzed using STRUCTURE as a benchmark. Additionally, we illustrate the method by analyzing microsatellite polymorphism in worldwide human populations and hemagglutinin gene sequence variation in seasonal influenza. Conclusions Analysis of simulated data revealed that our approach performs generally better than STRUCTURE at characterizing population subdivision. The tools implemented in DAPC for the identification of clusters and graphical representation of between-group structures allow to unravel complex population structures. Our approach is also faster than Bayesian clustering algorithms by

  18. Microbial community structure in aerobic and fluffy granules formed in a sequencing batch reactor supplied with 4-chlorophenol at different settling times. (United States)

    Gómez-Acata, Selene; Vital-Jácome, Miguel; Pérez-Sandoval, Mariana Vivian; Navarro-Noya, Yendi E; Thalasso, Frederic; Luna-Guido, Marco; Conde-Barajas, Eloy; Dendooven, Luc


    Toxic compounds, such as 4-chlorophenol (4-CP), which is a common pollutant in wastewater, are removed efficiently from sequencing batch reactors (SBRs) by microorganisms. The bacterial community in aerobic granules formed during the removal of 4-CP in a SBR was monitored for 63days. The SBR reactor was operated with a constant filling and withdrawal time of 7 and 8min and decreasing settling time (30, 5, 3 and 2min) to induce the formation of aerobic granules. During the acclimation period lasting 15days (30min settling time) had a strong effect on the bacterial community. From day 18 onwards, Sphingobium and Comamonadaceae were detected. Rhizobiaceae were dominant from day 24 to day 28 when stable aerobic granules were formed. At day 35, fluffy granules were formed, but the bacterial community structure did not change, despite the changes in the reactor operation to inhibit filamentous bacteria growth. This is the first report on changes in the bacterial community structure of aerobic and fluffy granules during granulation process in a reactor fed with 4-CP and the prediction of its metabolic pathways. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Implementation of Speed Variation in the Structural Dynamic Assessment of Turbomachinery Flow-Path Components (United States)

    Brown, Andrew M.; Davis, R. Benjamin; DeHaye, Michael


    During the design of turbomachinery flow path components, the assessment of possible structural resonant conditions is critical. Higher frequency modes of these structures are frequently found to be subject to resonance, and in these cases, design criteria require a forced response analysis of the structure with the assumption that the excitation speed exactly equals the resonant frequency. The design becomes problematic if the response analysis shows a violation of the HCF criteria. One possible solution is to perform "finite-life" analysis, where Miner's rule is used to calculate the actual life in seconds in comparison to the required life. In this situation, it is beneficial to incorporate the fact that, for a variety of turbomachinery control reasons, the speed of the rotor does not actually dwell at a single value but instead dithers about a nominal mean speed and during the time that the excitation frequency is not equal to the resonant frequency, the damage accumulated by the structure is diminished significantly. Building on previous investigations into this process, we show that a steady-state assumption of the response is extremely accurate for this typical case, resulting in the ability to quickly account for speed variation in the finite-life analysis of a component which has previously had its peak dynamic stress at resonance calculated. A technique using Monte Carlo simulation is also presented which can be used when specific speed time histories are not available. The implementation of these techniques can prove critical for successful turbopump design, as the improvement in life when speed variation is considered is shown to be greater than a factor of two

  20. Molecular manipulation of solid state structure: influences of organic components on vanadium oxide architectures (United States)

    Hagrman, Pamela J.; Finn, Robert C.; Zubieta, Jon


    Among the inorganic materials enjoying widespread contemporary interest, the metal oxide based solid phases occupy a prominent position by virtue of their applications to catalysis, sorption, molecular electronics, energy storage, optical materials and ceramics. The diversity of properties associated with these materials reflects the chemical composition, which allows variations in covalency, geometry and oxidation states, and the crystalline architecture, which may provide different pore structures, coordination sites, or juxtapositions of functional groups. Despite such fundamental and practical significance, the design of the structure of such materials remains a challenge in solid state chemistry. While organic materials have been synthesized which self-assemble into ordered arrays at low temperature and which exhibit molecular recognition and biomimetic activity, the ability to synthesize inorganic materials by rational design remains elusive. Small, soluble molecular building blocks with well-defined reaction chemistries which allow their low-temperature assembly into crystalline solid state inorganic materials are not well known. However, the existence of naturally occurring, structurally complex minerals establishes that hydrothermal synthesis can provide a low temperature pathway to produce open-framework and layered metastable structures utilizing inorganic starting materials. Thus, hydrothermal conditions have been used to prepare microporous tetrahedral framework solids that are capable of shape-selective absorption, like zeolites and aluminophosphates, and more recently in the preparation of complex solid arrays of the M/O/PO 3-4 and M/O/RPO 2-3 systems (M=V and Mo). The hydrothermal technique may be combined with the introduction of organic components which may act as charge compensating groups, space-filling units, structure directing agents, templates, tethers between functional groups, or conventional ligands in the preparation of inorganic


    Directory of Open Access Journals (Sweden)

    Yuliana Yuliana


    Full Text Available Quantitative Electronic Structure Activity Relationship (QSAR analysis of a series of benzalacetones has been investigated based on semi empirical PM3 calculation data using Principal Components Regression (PCR. Investigation has been done based on antimutagen activity from benzalacetone compounds (presented by log 1/IC50 and was studied as linear correlation with latent variables (Tx resulted from transformation of atomic net charges using Principal Component Analysis (PCA. QSAR equation was determinated based on distribution of selected components and then was analysed with PCR. The result was described by the following QSAR equation : log 1/IC50 = 6.555 + (2.177.T1 + (2.284.T2 + (1.933.T3 The equation was significant on the 95% level with statistical parameters : n = 28 r = 0.766  SE  = 0.245  Fcalculation/Ftable = 3.780 and gave the PRESS result 0.002. It means that there were only a relatively few deviations between the experimental and theoretical data of antimutagenic activity.          New types of benzalacetone derivative compounds were designed  and their theoretical activity were predicted based on the best QSAR equation. It was found that compounds number 29, 30, 31, 32, 33, 35, 36, 37, 38, 40, 41, 42, 44, 47, 48, 49 and 50  have  a relatively high antimutagenic activity.   Keywords: QSAR; antimutagenic activity; benzalaceton; atomic net charge

  2. Structural Molecular Components of Septate Junctions in Cnidarians Point to the Origin of Epithelial Junctions in Eukaryotes

    KAUST Repository

    Ganot, P.


    Septate junctions (SJs) insure barrier properties and control paracellular diffusion of solutes across epithelia in invertebrates. However, the origin and evolution of their molecular constituents in Metazoa have not been firmly established. Here, we investigated the genomes of early branching metazoan representatives to reconstruct the phylogeny of the molecular components of SJs. Although Claudins and SJ cytoplasmic adaptor components appeared successively throughout metazoan evolution, the structural components of SJs arose at the time of Placozoa/Cnidaria/Bilateria radiation. We also show that in the scleractinian coral Stylophora pistillata, the structural SJ component Neurexin IV colocalizes with the cortical actin network at the apical border of the cells, at the place of SJs. We propose a model for SJ components in Cnidaria. Moreover, our study reveals an unanticipated diversity of SJ structural component variants in cnidarians. This diversity correlates with gene-specific expression in calcifying and noncalcifying tissues, suggesting specific paracellular pathways across the cell layers of these diploblastic animals.

  3. Resolving the Stellar Outskirts of M81: Evidence for a Faint, Extended Structural Component (United States)

    Barker, M. K.; Ferguson, A. M. N.; Irwin, M.; Arimoto, N.; Jablonka, P.


    We present a wide field census of resolved stellar populations in the northern half of M81, conducted with Suprime-Cam on the 8 m Subaru telescope and covering an area ~0.3 deg2. The resulting color-magnitude diagram reaches over one magnitude below the red giant branch (RGB) tip, allowing a detailed comparison between the young and old stellar spatial distributions. The surface density of stars with ages lsim100 Myr is correlated with that of neutral hydrogen in a manner similar to the disk-averaged Kennicutt-Schmidt relation. We trace this correlation down to gas densities of ~2 × 1020 cm-2, lower than typically probed with Hα flux. Both diffuse light and resolved RGB star counts show compelling evidence for a faint, extended structural component beyond the bright optical disk, with a much flatter surface brightness profile. The star counts allow us to probe this component to significantly fainter levels than is possible with the diffuse light alone. From the colors of its RGB stars, we estimate that this component has a peak global metallicity [M/H] ~ -1.1 ± 0.3 at deprojected radii 32-44 kpc assuming an age of 10 Gyr and distance of 3.6 Mpc. The spatial distribution of its RGB stars follows a power-law surface density profile, I(r) vprop r -γ, with γ ~ 2. If this component were separate from the bulge and from the bright optical disk, then it would contain ~10%-15% of M81's total V-band luminosity. We discuss the possibility that this is M81's halo or thick disk, and in particular highlight its similarities and differences with these components in the Milky Way. Other possibilities for its nature, such as a perturbed disk or the faint extension of the bulge, cannot be completely ruled out, though our data disfavor the latter. These observations add to the growing body of evidence for faint, complex extended structures beyond the bright disks of spiral galaxies. Based on data collected at the Subaru telescope, which is operated by the National Astronomical

  4. Major components of a sea urchin block to polyspermy are structurally and functionally conserved. (United States)

    Wong, Julian L; Wessel, Gary M


    One sperm fusing with one egg is requisite for successful fertilization; additional sperm fusions are lethal to the embryo. Because sperm usually outnumber eggs, evolution has selected for mechanisms that prevent this polyspermy by immediately modifying the egg extracellular matrix. We focus here on the contribution of cortical granule contents in the sea urchin block to polyspermy to begin to understand how well this process is conserved. We identified each of the major constituents of the fertilization envelope in two species of seaurchins, Strongylocentrotus purpuratus and Lytechinus variegatus, that diverged 30 to 50 million years ago. Our results show that the five major structural components of the fertilization envelope, derived from the egg cortical granules, are semiconserved. Most of these orthologs share sequence identity and encode multiple low-density lipoprotein receptor type A repeats or CUB domains but at least two contain radically different carboxy-terminal repeats. Using a new association assay, we also show that these major structural components are functionally conserved during fertilization envelope construction. Thus, it seems that this population of female reproductive proteins has retained functional motifs while gaining significant sequence diversity-two opposing paths that may reflect cooperativity among the proteins that compose the fertilization envelope.

  5. Asymmetric segregation of damaged cellular components in spatially structured multicellular organisms.

    Directory of Open Access Journals (Sweden)

    Charlotte Strandkvist

    Full Text Available The asymmetric distribution of damaged cellular components has been observed in species ranging from fission yeast to humans. To study the potential advantages of damage segregation, we have developed a mathematical model describing ageing mammalian tissue, that is, a multicellular system of somatic cells that do not rejuvenate at cell division. To illustrate the applicability of the model, we specifically consider damage incurred by mutations to mitochondrial DNA, which are thought to be implicated in the mammalian ageing process. We show analytically that the asymmetric distribution of damaged cellular components reduces the overall damage level and increases the longevity of the cell population. Motivated by the experimental reports of damage segregation in human embryonic stem cells, dividing symmetrically with respect to cell-fate, we extend the model to consider spatially structured systems of cells. Imposing spatial structure reduces, but does not eliminate, the advantage of asymmetric division over symmetric division. The results suggest that damage partitioning could be a common strategy for reducing the accumulation of damage in a wider range of cell types than previously thought.

  6. Damage prognosis of adhesively-bonded joints in laminated composite structural components of unmanned aerial vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles R [Los Alamos National Laboratory; Gobbato, Maurizio [UCSD; Conte, Joel [UCSD; Kosmatke, John [UCSD; Oliver, Joseph A [UCSD


    The extensive use of lightweight advanced composite materials in unmanned aerial vehicles (UAVs) drastically increases the sensitivity to both fatigue- and impact-induced damage of their critical structural components (e.g., wings and tail stabilizers) during service life. The spar-to-skin adhesive joints are considered one of the most fatigue sensitive subcomponents of a lightweight UAV composite wing with damage progressively evolving from the wing root. This paper presents a comprehensive probabilistic methodology for predicting the remaining service life of adhesively-bonded joints in laminated composite structural components of UAVs. Non-destructive evaluation techniques and Bayesian inference are used to (i) assess the current state of damage of the system and, (ii) update the probability distribution of the damage extent at various locations. A probabilistic model for future loads and a mechanics-based damage model are then used to stochastically propagate damage through the joint. Combined local (e.g., exceedance of a critical damage size) and global (e.g.. flutter instability) failure criteria are finally used to compute the probability of component failure at future times. The applicability and the partial validation of the proposed methodology are then briefly discussed by analyzing the debonding propagation, along a pre-defined adhesive interface, in a simply supported laminated composite beam with solid rectangular cross section, subjected to a concentrated load applied at mid-span. A specially developed Eliler-Bernoulli beam finite element with interlaminar slip along the damageable interface is used in combination with a cohesive zone model to study the fatigue-induced degradation in the adhesive material. The preliminary numerical results presented are promising for the future validation of the methodology.

  7. Complete primary structure of the major component myoglobin of California gray whale (Eschrichtius gibbosus). (United States)

    Bogardt, R A; Dwulet, F E; Lehman, L D; Jones, B N; Gurd, F R


    The complete primary structure of the major component myoglobin from the California gray whale, Eschrichtius gibbosus, was determined by specific cleavage of the protein to obtain large peptides for degradation by the automatic sequenator. Cleavage at the two methionine residues of the apomyoglobin with cyanogen bromide and at the three arginine residues of the methyl acetimidated protein with trypsin resulted in three and four easily separable peptides, respectively, which when sequenced accounted for 85% of the primary structure. The remainder of the covalent structure was obtained by further digestion of the central cyanogen bromide peptide with trypsin and S. aureus strain V8 protease. This protein differs from that of the sperm whale, Physeter catodon, at 12 positions, from that of the common porpoise, Phocoena phocoena, and the Black Sea dolphin, Delphinus delphis, at 14 positions, and from that of the Amazon River dolphin, Inia geoffrensis, at 7 positions. All substitutions observed in this sequence fit easily into the tertiary structure of sperm whale myoglobin.

  8. Insights into Bacteriophage T5 Structure from Analysis of Its Morphogenesis Genes and Protein Components (United States)

    Zivanovic, Yvan; Confalonieri, Fabrice; Ponchon, Luc; Lurz, Rudi; Chami, Mohamed; Flayhan, Ali; Renouard, Madalena; Huet, Alexis; Decottignies, Paulette; Davidson, Alan R.; Breyton, Cécile


    Bacteriophage T5 represents a large family of lytic Siphoviridae infecting Gram-negative bacteria. The low-resolution structure of T5 showed the T=13 geometry of the capsid and the unusual trimeric organization of the tail tube, and the assembly pathway of the capsid was established. Although major structural proteins of T5 have been identified in these studies, most of the genes encoding the morphogenesis proteins remained to be identified. Here, we combine a proteomic analysis of T5 particles with a bioinformatic study and electron microscopic immunolocalization to assign function to the genes encoding the structural proteins, the packaging proteins, and other nonstructural components required for T5 assembly. A head maturation protease that likely accounts for the cleavage of the different capsid proteins is identified. Two other proteins involved in capsid maturation add originality to the T5 capsid assembly mechanism: the single head-to-tail joining protein, which closes the T5 capsid after DNA packaging, and the nicking endonuclease responsible for the single-strand interruptions in the T5 genome. We localize most of the tail proteins that were hitherto uncharacterized and provide a detailed description of the tail tip composition. Our findings highlight novel variations of viral assembly strategies and of virion particle architecture. They further recommend T5 for exploring phage structure and assembly and for deciphering conformational rearrangements that accompany DNA transfer from the capsid to the host cytoplasm. PMID:24198424

  9. Degradation of fastener in reactor internal of PWR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. W.; Ryu, W. S.; Jang, J. S.; Kim, S. H.; Kim, W. G.; Chung, M. K.; Han, C. H


    Main component degraded in reactor internal structure of PWR is fastener such as bolts, stud, cap screw, and pins. The failure of these components may damage nuclear fuel and limits the operation of nuclear reactor. In foreign reactors operated more than 10 years, an increasing number of incidents of degraded thread fasteners have been reported. The degradation of these components impair the integrity of reactor internal structure and limit the life extension of nuclear power plant. To solve the problem of fastener failure, the incidents of failure and main mechanisms should be investigated. the purpose of this state-of-the -art report is to investigate the failure incidents and mechanisms of fastener in foreign and domestic PWR and make a guide to select a proper materials. There is no intent to describe each event in detail in this report. This report covers the failures of fastener and damage mechanisms reported by the licensees of operating nuclear power plants and the applications of plants constructed after 1964. This information is derived from pertinent licensee event report, reportable occurrence reports, operating reactor event memoranda, failure analysis reports, and other relevant documents. (author)

  10. Analytical Approach for Estimating Preliminary Mass of ARES I Crew Launch Vehicle Upper Stage Structural Components (United States)

    Aggarwal, Pravin


    electrical power functions to other Elements of the CLV, is included as secondary structure. The MSFC has an overall responsibility for the integrated US element as well as structural design an thermal control of the fuel tanks, intertank, interstage, avionics, main propulsion system, Reaction Control System (RCS) for both the Upper Stage and the First Stage. MSFC's Spacecraft and Vehicle Department, Structural and Analysis Design Division is developing a set of predicted mass of these elements. This paper details the methodology, criterion and tools used for the preliminary mass predictions of the upper stage structural assembly components. In general, weight of the cylindrical barrel sections are estimated using the commercial code Hypersizer, whereas, weight of the domes are developed using classical solutions. HyperSizer is software that performs automated structural analysis and sizing optimization based on aerospace methods for strength, stability, and stiffness. Analysis methods range from closed form, traditional hand calculations repeated every day in industry to more advanced panel buckling algorithms. Margin-of-safety reporting for every potential failure provides the engineer with a powerful insight into the structural problem. Optimization capabilities include finding minimum weight panel or beam concepts, material selections, cross sectional dimensions, thicknesses, and lay-ups from a library of 40 different stiffened and sandwich designs and a database of composite, metallic, honeycomb, and foam materials. Multiple different concepts (orthogrid, isogrid, and skin stiffener) were run for multiple loading combinations of ascent design load with and with out tank pressure as well as proof pressure condition. Subsequently, selected optimized concept obtained from Hypersizer runs was translated into a computer aid design (CAD) model to account for the wall thickness tolerance, weld land etc for developing the most probable weight of the components. The flow diram

  11. Seismic design technology for breeder reactor structures. Volume 2. Special topics in soil/structure interaction analyses

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, D.P.


    This volume is divided into six chapters: definition of seismic input ground motion, review of state-of-the-art procedures, analysis guidelines, rock/structure interaction analysis example, comparison of two- and three-dimensional analyses, and comparison of analyses using FLUSH and TRI/SAC Codes. (DLC)

  12. The effects of wet heat treatment on the structural and chemical components of Bacillus sporothermodurans spores. (United States)

    Tabit, Frederick T; Buys, Elna


    The objective of this research was to study the rate of structural damage and survival of Bacillus sporothermodurans spores following treatment at high temperatures by determining the amount of Dipicolinic acid (DPA) and soluble protein leakage over time. A reference strain of B. sporothermodurans (DSM 10599) and a South African strain (UP20A) isolated from UHT milk were used. To determine the survival of spores at 130 degrees C, spores were heated for 4, 8 and 12min. To check the viability of spores plate counts were determined, while structural damage was determined using the Transmission Electron Microscopy. The filtrate of the heated spore suspension was analysed for the amount of DPA and soluble protein release due to heating. The amount of DPA released was quantified by HPLC analysis while the amount of soluble protein released from heated spores was quantified using the Bradford method. The log values of spore counts, released DPA and soluble proteins from triplicate experiments were analysed. The results of this study indicate that the inactivation of B. sporothermodurans spores during wet heat treatment is due to the penetration of hot moisture into the spore which then moistens the spore components, and inactivates enzymes, and because of the high water pressure, vital spore components such as proteins and DPA in solution leak out of the spore. Interestingly a vast majority of heated spores were inactivated before a significant amount of DPA was released. This research is the first to determine the effect of high temperature wet heat treatment on the structure of B. sporothermodurans spores and has given an insight regarding the mechanisms of destruction of B. sporothermodurans spores by wet heat. Copyright 2010 Elsevier B.V. All rights reserved.

  13. A passively-safe fusion reactor blanket with helium coolant and steel structure

    Energy Technology Data Exchange (ETDEWEB)

    Crosswait, Kenneth Mitchell [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)


    Helium is attractive for use as a fusion blanket coolant for a number of reasons. It is neutronically and chemically inert, nonmagnetic, and will not change phase during any off-normal or accident condition. A significant disadvantage of helium, however, is its low density and volumetric heat capacity. This disadvantage manifests itself most clearly during undercooling accident conditions such as a loss of coolant accident (LOCA) or a loss of flow accident (LOFA). This thesis describes a new helium-cooled tritium breeding blanket concept which performs significantly better during such accidents than current designs. The proposed blanket uses reduced-activation ferritic steel as a structural material and is designed for neutron wall loads exceeding 4 MW/m{sup 2}. The proposed geometry is based on the nested-shell concept developed by Wong, but some novel features are used to reduce the severity of the first wall temperature excursion. These features include the following: (1) A ``beryllium-joint`` concept is introduced, which allows solid beryllium slabs to be used as a thermal conduction path from the first wall to the cooler portions of the blanket. The joint concept allows for significant swelling of the beryllium (10 percent or more) without developing large stresses in the blanket structure. (2) Natural circulation of the coolant in the water-cooled shield is used to maintain shield temperatures below 100 degrees C, thus maintaining a heat sink close to the blanket during the accident. This ensures the long-term passive safety of the blanket.

  14. REACTOR COOLING (United States)

    Quackenbush, C.F.


    A nuclear reactor with provisions for selectively cooling the fuel elements is described. The reactor has a plurality of tubes extending throughout. Cylindrical fuel elements are disposed within the tubes and the coolant flows through the tubes and around the fuel elements. The fuel elements within the central portion of the reactor are provided with roughened surfaces of material. The fuel elements in the end portions of the tubes within the reactor are provlded with low conduction jackets and the fuel elements in the region between the central portion and the end portions are provided with smooth surfaces of high heat conduction material.

  15. Reactor Safety Research Programs

    Energy Technology Data Exchange (ETDEWEB)

    Edler, S. K.


    This document summarizes the work performed by Pacific Northwest Laboratory (PNL) from January 1 through March 31, 1981, for the Division of Reactor Safety Research within the U.S. Nuclear Regulatory Commission (NRC). Evaluations of nondestructive examination (NDE) techniques and instrumentation are reported; areas of investigation include demonstrating the feasibility of determining the strength of structural graphite, evaluating the feasibility of detecting and analyzing flaw growth in reactor pressure boundary systems, examining NDE reliability and probabilistic fracture mechanics, and assessing the integrity of pressurized water reactor (PWR) steam generator tubes where service-induced degradation has been indicated. Experimental data and analytical models are being provided to aid in decision-making regarding pipeto- pipe impacts following postulated breaks in high-energy fluid system piping. Core thermal models are being developed to provide better digital codes to compute the behavior of full-scale reactor systems under postulated accident conditions. Fuel assemblies and analytical support are being provided for experimental programs at other facilities. These programs include loss-ofcoolant accident (LOCA) simulation tests at the NRU reactor, Chalk River, Canada; fuel rod deformation, severe fuel damage, and postaccident coolability tests for the ESSOR reactor Super Sara Test Program, Ispra, Italy; the instrumented fuel assembly irradiation program at Halden, Norway; and experimental programs at the Power Burst Facility, Idaho National Engineering Laboratory (INEL). These programs will provide data for computer modeling of reactor system and fuel performance during various abnormal operating conditions.

  16. Neutral Buoyancy Simulator: MSFC-Langley joint test of large space structures component assembly: (United States)


    Once the United States' space program had progressed from Earth's orbit into outerspace, the prospect of building and maintaining a permanent presence in space was realized. To accomplish this feat, NASA launched a temporary workstation, Skylab, to discover the effects of low gravity and weightlessness on the human body, and also to develop tools and equipment that would be needed in the future to build and maintain a more permanent space station. The structures, techniques, and work schedules had to be carefully designed to fit this unique construction site. The components had to be lightweight for transport into orbit, yet durable. The station also had to be made with removable parts for easy servicing and repairs by astronauts. All of the tools necessary for service and repairs had to be designed for easy manipulation by a suited astronaut. And construction methods had to be efficient due to limited time the astronauts could remain outside their controlled environment. In lieu of all the specific needs for this project, an environment on Earth had to be developed that could simulate a low gravity atmosphere. A Neutral Buoyancy Simulator (NBS) was constructed by NASA Marshall Space Flight Center (MSFC) in 1968. Since then, NASA scientists have used this facility to understand how humans work best in low gravity and also provide information about the different kinds of structures that can be built. With the help of the NBS, building a space station became more of a reality. In a joint venture between NASA/Langley Research Center in Hampton, VA and MSFC, the Assembly Concept for Construction of Erectable Space Structures (ACCESS) was developed and demonstrated at MSFC's NBS. The primary objective of this experiment was to test the ACCESS structural assembly concept for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction. Pictured is a demonstration of ACCESS.

  17. Sulfamethoxazole and COD increase abundance of sulfonamide resistance genes and change bacterial community structures within sequencing batch reactors. (United States)

    Guo, Xueping; Pang, Weihai; Dou, Chunling; Yin, Daqiang


    The abundant microbial community in biological treatment processes in wastewater treatment plants (WWTPs) may potentially enhance the horizontal gene transfer of antibiotic resistance genes with the presence of antibiotics. A lab-scale sequencing batch reactor was designed to investigate response of sulfonamide resistance genes (sulI, sulII) and bacterial communities to various concentrations of sulfamethoxazole (SMX) and chemical oxygen demand (COD) of wastewater. The SMX concentrations (0.001 mg/L, 0.1 mg/L and 10 mg/L) decreased with treatment time and higher SMX level was more difficult to remove. The presence of SMX also significantly reduced the removal efficiency of ammonia nitrogen, affecting the normal function of WWTPs. All three concentrations of SMX raised both sulI and sulII genes with higher concentrations exhibiting greater increases. The abundance of sul genes was positive correlated with treatment time and followed the second-order reaction kinetic model. Interestingly, these two genes have rather similar activity. SulI and sulII gene abundance also performed similar response to COD. Simpson index and Shannon-Weiner index did not show changes in the microbial community diversity. However, the 16S rRNA gene cloning and sequencing results showed the bacterial community structures varied during different stages. The results demonstrated that influent antibiotics into WWTPs may facilitate selection of ARGs and affect the wastewater conventional treatment as well as the bacteria community structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Reactor core stability monitoring method for BWR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanemoto, Shigeru; Ebata, Shigeo.


    In an operation for a BWR type reactor, reactor power is usually increased or decreased by controlling both of control rods and reactor core flow rate. Under a certain condition, the reactor core is made unstable by the coupling of nuclear and thermohydrodynamic characteristics in the reactor. Therefore, the reactor power and the reactor core flow rate are changed within a range predetermined by a design calculation. However, if reactor core stability can be always measured and monitored, it is useful for safe operation, as well as an existent operation range can be extended to enable more effective operation. That is, autoregressive a coefficient is determined successively on real time based on fluctuation components of neutron flux signals. Based on the result, an amplification ratio, as a typical measure of the reactor core stability, is determined on a real time. A time constant of the successive calculation for the autoregressive coefficient can be made variable by the amplification ratio. Then, the amplification ratio is estimated at a constant accuracy. With such procedures, the reactor core stability can be monitored successively in an ON-line manner at a high accuracy, thereby enabling to improve the operation performance. (I.S.).

  19. Enzymatic Degradation Identifies Components Responsible for the Structural Properties of the Vitreous Body (United States)

    Filas, Benjamen A.; Zhang, Qianru; Okamoto, Ruth J.; Shui, Ying-Bo; Beebe, David C.


    Purpose. Vitreous degeneration contributes to several age-related eye diseases, including retinal detachment, macular hole, macular traction syndrome, and nuclear cataracts. Remarkably little is understood about the molecular interactions responsible for maintaining vitreous structure. The purpose of this study was to measure the structural properties of the vitreous body after enzymatic degradation of selected macromolecules. Methods. Mechanical properties of plugs of bovine and porcine vitreous were analyzed using a rheometer. Oscillatory and extensional tests measured vitreous stiffness and adhesivity, respectively. Major structural components of the vitreous were degraded by incubation overnight in collagenase, trypsin, or hyaluronidase, singly or in combination. Vitreous bodies were also incubated in hyper- or hypotonic saline. Effects of these treatments on the mechanical properties of the vitreous were measured by rheometry. Results. Enzymatic digestion of each class of macromolecules decreased the stiffness of bovine vitreous by approximately half (P vitreous (P vitreous and increased adhesivity. Collagen degradation resulted in the opposite effect, whereas digestion of proteins and proteoglycans with trypsin did not alter behavior relative to controls. Osmotic perturbations and double-enzyme treatments further implicated hyaluronan and hyaluronan-associated water as a primary regulator of adhesivity and material behavior in extension. Conclusions. Collagen, hyaluronan, and proteoglycans act synergistically to maintain vitreous stiffness. Hyaluronan is a key mediator of vitreous adhesivity, and mechanical damping is an important factor influencing dynamic vitreous behavior. PMID:24222300

  20. Underdetermined blind modal identification of structures by earthquake and ambient vibration measurements via sparse component analysis (United States)

    Amini, Fereidoun; Hedayati, Yousef


    Sparse component analysis (SCA) approach was adopted to handle underdetermined blind modal identification of structures, where the number of sensors is less than the number of active modes. To exploit the sparsity of structural responses in time-frequency domain, Short Time Fourier Transform (STFT) was used in this study. The proposed SCA-based approach has two main stages: modal matrix estimation and modal displacement estimation. In the first stage, hierarchical clustering algorithm was used to estimate the modal matrix. The clustering algorithm was preceded by a preprocessing step to select the points in time-frequency domain that only one mode makes contribution in the responses. These points were fed to the clustering algorithm as an input. Performing this analysis enhanced the modal matrix estimation accuracy and reduced the computational cost while conducting clustering analysis. Having estimated mixing matrix, the complex-valued modal responses in the transformed domain were recovered via Smoothed zero-norm (SL-0) algorithm. In a broad sense, using the SL-0 algorithm permits researchers to use any kind of transform in seeking sparsity, regardless of obtaining real-valued or complex-valued signals in transformed domain. Natural frequencies and damping ratios were extracted from the recovered modal responses. Performance of the proposed method was investigated using a synthetic example and a benchmark structure with earthquake and ambient excitation, respectively.

  1. Heat-pipe thermionic reactor concept

    DEFF Research Database (Denmark)

    Storm Pedersen, E.


    Main components are reactor core, heat pipe, thermionic converter, secondary cooling system, and waste heat radiator; thermal power generated in reactor core is transported by heat pipes to thermionic converters located outside reactor core behind radiation shield; thermionic emitters are in direct...


    Directory of Open Access Journals (Sweden)



    Full Text Available A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1 the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2 the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3 the responses of isolated reactor building fall below the range of the prescribed criteria.

  3. Radiation Shielding for Fusion Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.T.


    Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel. Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor

  4. Nano-casted Metal Oxide Aerogels as Dual Purpose Structural Components for Space Exploration (United States)

    Vassilaras, Plousia E.


    NASA missions and space exploration rely on strong, ultra lightweight materials. Such materials are needed for building up past and present space vehicles such as the Sojourner Rover (1997) or the two MERs (2003), but also for a number of components and/or systems including thermal insulators, Solar Sails, Rigid Aeroshells, and Ballutes. The purpose of my internship here at Glenn Research Center is to make dual purpose materials; materials that in addition to being lightweight have electronic, photophysical and magnetic properties and, therefore, act as electronic components and sensors as well as structural components. One type of ultra lightweight material of great interest is aerogels, which have densities ranging from 0.003 g/cc to 0.8 g/cc . However, aerogels are extremely fragile and, as a result, have limited practical applications. Recently, Glenn Research Center has developed a process of nano-casting polymers onto the inorganic network of silica-based aerogels increasing the strength 300 fold while only increasing the density 3 fold. By combining the process of nano-casting polymers with inorganic oxide networks other than silica, we are actively pursuing lightweight dual purpose materials. To date, thirty different inorganic oxide aerogels have been prepared using either standard sol-gel chemistry or a non-alkoxide method involving metal chloride precursors and an epoxide; epichlorohydrin, propylene oxide or trimethylene oxide, as proton scavengers. More importantly, preliminary investigations show that the residual surface hydroxyl groups on each of these inorganic oxide aerogels can be successfully crosslinked with urethane. In addition to characterizing physical and mechanical properties such as density, strength and flexibility, each of these metal oxide aerogels are being characterized for thermal and electronic conductivity and magnetic and optical properties.

  5. Structural studies on the major component of Gladiolus style mucilage, an arabinogalactan-protein. (United States)

    Gleeson, P A; Clarke, A E


    The major component of the Gladiolus style mucilage was shown to be an arabinogalactan-protein. The arabinogalactan-protein was isolated from the style extract by affinity chromatography with tridacnin (the galactose-binding lectin from the clam Tridacna maxima) coupled to Sepharose 4B. The isolated arabinogalactan-protein represents 40% of the soluble style extract; it contains 90% (w/w) carbohydrate and 3% protein. The major monosaccharides of the carbohydrate component are galactose and arabinose, in the proportions 6:1. A component with a similar composition was also isolated from the crude extract by precipitation with the beta-glucosyl artifical carbohydrate antigen. The protein moiety of the arabinogalactan-protein remained associated with the carbohydrate after chromatography in urea, and has high contents of serine, glutamic acid, aspartic acid, glycine and alanine. The arabinogalactan-protein is apparently chemically homogeneous; it eluted as a single symmetrical peak from Sepharose 4B, and three fractions collected across the peak were structurally similar. Ultracentrifugal studies showed it to be polydisperse in the mol.wt. range 150 000--400 000. The information obtained from methylation analyses, oxalic acid and enzymic hydrolyses is consistent with a model having a beta 1 leads to 3 galactan backbone, branched through C(O)6 to beta 1 leads to 6 galactan side chains. The arabinose is exclusively present as terminal alpha-L-arabinofuranosyl residues. Enzymic removal of the arabinose residues resulted in a marked decrease in solubility of the molecule. The localization of the arabinogalactan-protein in the mucilage of the style canal was demonstrated cytochemically. The possible roles of the arabinogalactan-protein in relation to recognition of compatible pollen and pollen-tube growth are discussed.

  6. Computer Program of SIE ASME-NH Code for Structural Integrity Evaluation of Next Generation Reactors Subjecting to Elevated Temperature Operations

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Gyeong Hoi; Lee, J. H


    In this report, the SIE ASME (Structural Integrity Evaluations by ASME-NH), which has a computerized implementation of ASME Pressure Vessels and Piping Code Section III Subsection NH rules, is developed to apply to the next generation reactor design subjecting to the elevated temperature operations over 500 .deg. C and over 30 years design lifetime, and the user's manual for this program is described in detail.

  7. Nuclear component horizontal seismic restraint (United States)

    Snyder, Glenn J.


    A nuclear component horizontal seismic restraint. Small gaps limit horizontal displacement of components during a seismic occurrence and therefore reduce dynamic loadings on the free lower end. The reactor vessel and reactor guard vessel use thicker section roll-forged rings welded between the vessel straight shell sections and the bottom hemispherical head sections. The inside of the reactor guard vessel ring forging contains local vertical dovetail slots and upper ledge pockets to mount and retain field fitted and installed blocks. As an option, the horizontal displacement of the reactor vessel core support cone can be limited by including shop fitted/installed local blocks in opposing alignment with the reactor vessel forged ring. Beams embedded in the wall of the reactor building protrude into apertures in the thermal insulation shell adjacent the reactor guard vessel ring and have motion limit blocks attached thereto to provide to a predetermined clearance between the blocks and reactor guard vessel ring.

  8. Structural and functional alterations of cellular components as revealed by electron microscopy. (United States)

    Condello, Maria; Caraglia, Michele; Castellano, Maria; Arancia, Giuseppe; Meschini, Stefania


    Scanning (SEM) and transmission electron microscopy (TEM) are two fundamental microscopic techniques widely applied in biological research for the study of ultrastructural cell components. With these methods, especially TEM, it is possible to detect and quantify the morphological and ultrastructural parameters of intracellular organelles (mitochondria, Golgi apparatus, lysosomes, peroxisomes, endosomes, endoplasmic reticulum, cytoskeleton, nucleus, etc.) in normal and pathological conditions. The study of intracellular vesicle compartmentalization is raising even more interest in the light of the importance of intracellular localization of mediators of the signaling in eliciting different biological responses. The study of the morphology of some intracellular organelles can supply information on the bio-energetic status of the cells. TEM has also a pivotal role in the determination of different types of programmed cell death. In fact, the visualization of autophagosomes and autophagolysosomes is essential to determine the occurrence of autophagy (and also to discriminate micro-autophagy from macro-autophagy), while the presence of fragmented nuclei and surface blebbing is characteristic of apoptosis. SEM is particularly useful for the study of the morphological features of the cells and, therefore, can shed light, for instance, on cell-cell interactions. After a brief introduction on the basic principles of the main electron microscopy methods, the article describes some cell components with the aim to demonstrate the huge role of the ultrastructural analysis played in the knowledge of the relationship between function and structure of the biological objects. Copyright © 2013 Wiley Periodicals, Inc.

  9. Effect of environmental variables and stand structure on ecosystem respiration components in a Mediterranean beech forest. (United States)

    Guidolotti, Gabriele; Rey, Ana; D'Andrea, Ettore; Matteucci, Giorgio; De Angelis, Paolo


    The temporal variability of ecosystem respiration (RECO) has been reported to have important effects on the temporal variability of net ecosystem exchange, the net amount of carbon exchanged between an ecosystem and the atmosphere. However, our understanding of ecosystem respiration is rather limited compared with photosynthesis or gross primary productivity, particularly in Mediterranean montane ecosystems. In order to investigate how environmental variables and forest structure (tree classes) affect different respiration components and RECO in a Mediterranean beech forest, we measured soil, stem and leaf CO2 efflux rates with dynamic chambers and RECO by the eddy-covariance technique over 1 year (2007-2008). Ecosystem respiration showed marked seasonal variation, with the highest rates in spring and autumn and the lowest in summer. We found that the soil respiration (SR) was mainly controlled by soil water content below a threshold value of 0.2 m(3) m(-3), above which the soil temperature explained temporal variation in SR. Stem CO2 effluxes were influenced by air temperature and difference between tree classes with higher rates measured in dominant trees than in co-dominant ones. Leaf respiration (LR) varied significantly between the two canopy layers considered. Non-structural carbohydrates were a very good predictor of LR variability. We used these measurements to scale up respiration components to ecosystem respiration for the whole canopy and obtained cumulative amounts of carbon losses over the year. Based on the up-scaled chamber measurements, the relative contributions of soil, stem and leaves to the total annual CO2 efflux were: 56, 8 and 36%, respectively. These results confirm that SR is the main contributor of ecosystem respiration and provided an insight on the driving factors of respiration in Mediterranean montane beech forests.

  10. Crystal structure of prunin-1, a major component of the almond (Prunus dulcis) allergen amandin. (United States)

    Jin, Tengchuan; Albillos, Silvia M; Guo, Feng; Howard, Andrew; Fu, Tong-Jen; Kothary, Mahendra H; Zhang, Yu-Zhu


    Seed storage proteins are accumulated during seed development and act as a reserve of nutrition for seed germination and young sprout growth. Plant seeds play an important role in human nutrition by providing a relatively inexpensive source of protein. However, many plant foods contain allergenic proteins, and the number of people suffering from food allergies has increased rapidly in recent years. The 11S globulins are the most widespread seed storage proteins, present in monocotyledonous and dicotyledonous seeds as well as in gymnosperms (conifers) and other spermatophytes. This family of proteins accounts for a number of known major food allergens. They are of interest to both the public and industry due to food safety concerns. Because of the interests in the structural basis of the allergenicity of food allergens, we sought to determine the crystal structure of Pru1, the major component of the 11 S storage protein from almonds. The structure was refined to 2.4 A, and the R/Rfree for the final refined structure is 17.2/22.9. Pru1 is a hexamer made of two trimers. Most of the back-to-back trimer-trimer association was contributed by monomer-monomer interactions. An alpha helix (helix 6) at the C-terminal end of the acidic domain of one of the interacting monomers lies at the cleft of the two protomers. The residues in this helix correspond to a flexible region in the peanut allergen Ara h 3 that encompasses a previously defined linear IgE epitope.

  11. Structural studies of the activation of the two component receiver domain NTRC by multidimensional heteronuclear NMR

    Energy Technology Data Exchange (ETDEWEB)

    Nohaile, Michael James [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry


    Multidimensional heteronuclear NMR spectroscopy was used to investigate the N-terminal domain of the transcriptional enhancer NTRC (NiTrogen Regulatory protein C). This domain belongs to the family of receiver domains of two-component regulatory systems involved in signal transduction. Phosphorylation of NTRC at D54 leads to an activated form of the molecule which stimulates transcription of genes involved in nitrogen regulation. Three and four dimensional NMR techniques were used to determine an intermediate resolution structure of the unphosphorylated, inactive form of the N-terminal domain of NTRC. The structure is comprised of five α-helices and a five-stranded β-sheet in a (β/α)5 topology. Analysis of the backbone dynamics of NTRC indicate that helix 4 and strand 5 are significantly more flexible than the rest of the secondary structure of the protein and that the loops making up the active site are flexible. The short lifetime of phospho-NTRC hampers the study of this form. However, conditions for determining the resonance assignments and, possibly, the three dimensional structure of phosphorylated NTRC have been obtained. Tentative assignments of the phosphorylated form indicate that the majority of the changes that NTRC experiences upon phosphorylation occur in helix 3, strand 4, helix 4, strand 5, and the loop between strand 5 and helix 5 (the 3445 face of NTRC) as well as near the site of phosphorylation. In order to examine a stable, activated form of the protein, constitutively active mutants of NTRC were investigated.

  12. Multifunctional reactors

    NARCIS (Netherlands)

    Westerterp, K.R.


    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

  13. Response of Basic Structural Elements and B-52 Structural Components to Simulated Nuclear Overpressure. Volume I-Program Description and Results (Basic Structural Elements) (United States)


    determining the response of high-frequency structural components, such as aircraft skin panels, stringers, frames and radomes. As a result of the moratorium ...5) 00 C\\1 co a u- Cj 0 V) w CD -) (D - ~LLJO( 4-3 COD ) Ci Il 02 0 S-i 61 LL. 41) 05C LLI- <w C3 Co 0C 0l I-0 M- u cX< I- Z CD - Li -::I C.D 0 X: LLI

  14. High gamma-rays irradiation tests of critical components for ITER (International Thermonuclear Experimental Reactor) in-vessel remote handling system

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi [Department of Fusion Engineering Research, Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Naka, Ibaraki (Japan)] [and others


    In ITER, the in-vessel remote handling is inevitably required to assemble and maintain the activated in-vessel components due to deuterium and tritium operation. Since the in-vessel remote handling system has to be operated under the intense of gamma ray irradiation, the components of the remote handling system are required to have radiation hardness so as to allow maintenance operation for a sufficient length of time under the ITER in-vessel environments. For this, the Japan, European and Russian Home Teams have extensively conducted gamma ray irradiation tests and quality improvements including optimization of material composition through ITER R and D program in order to develop radiation hard components which satisfy the doses from 10 MGy to 100 MGy at a dose rate of 1 x 10{sup 6} R/h (ITER R and D Task: T252). This report describes the latest status of radiation hard component development which has been conducted by the Japan Home Team in the ITER R and D program. The number of remote handling components tested is about seventy and these are categorized into robotics (Subtask 1), viewing system (Subtask 2) and common components (Subtask 3). The irradiation tests, including commercial base products for screening, modified products and newly developed products to improve the radiation hardness, were carried out using the gamma ray irradiation cells in Takasaki Establishment, JAERI. As a result, the development of the radiation hard components which can be tolerable for high temperature and gamma radiation has been well progressed, and many components, such as AC servo motor with ceramics insulated wire, optical periscope and CCD camera, have been newly developed. (author)

  15. Temperature increases from 55 to 75 C in a two-phase biogas reactor result in fundamental alterations within the bacterial and archaeal community structure

    Energy Technology Data Exchange (ETDEWEB)

    Rademacher, Antje [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abt. Bioverfahrenstechnik; Technische Univ. Berlin (Germany). Inst. fuer Technischen Umweltschutz; Nolte, Christine; Schoenberg, Mandy; Klocke, Michael [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abt. Bioverfahrenstechnik


    Agricultural biogas plants were operated in most cases below their optimal performance. An increase in the fermentation temperature and a spatial separation of hydrolysis/acetogenesis and methanogenesis are known strategies in improving and stabilizing biogas production. In this study, the dynamic variability of the bacterial and archaeal community was monitored within a two-phase leach bed biogas reactor supplied with rye silage and straw during a stepwise temperature increase from 55 to 75 C within the leach bed reactor (LBR), using TRFLP analyses. To identify the terminal restriction fragments that were obtained, bacterial and archaeal 16S rRNA gene libraries were constructed. Above 65 C, the bacterial community structure changed from being Clostridiales-dominated toward being dominated by members of the Bacteroidales, Clostridiales, and Thermotogales orders. Simultaneously, several changes occurred, including a decrease in the total cell count, degradation rate, and biogas yield along with alterations in the intermediate production. A bioaugmentation with compost at 70 C led to slight improvements in the reactor performance; these did not persist at 75 C. However, the archaeal community within the downstream anaerobic filter reactor (AF), operated constantly at 55 C, altered by the temperature increase in the LBR. At an LBR temperature of 55 C, members of the Methanobacteriales order were prevalent in the AF, whereas at higher LBR temperatures Methanosarcinales prevailed. Altogether, the best performance of this two-phase reactor was achieved at an LBR temperature of below 65 C, which indicates that this temperature range has a favorable effect on the microbial community responsible for the production of biogas. (orig.)

  16. Chemical composition and structural features of the macromolecular components of plantation Acacia mangium wood. (United States)

    Pinto, Paula C; Evtuguin, Dmitry V; Pascoal Neto, Carlos


    The wood of Acacia mangium, a prominent fast-growing plantation species used in the pulp-and-paper industry and, so far, poorly investigated for its chemical structure, was submitted to a detailed characterization of its main macromolecular components. Lignin (28% wood weight) isolated by mild acidolysis and characterized by permanganate oxidation, 1H and 13C NMR, and GPC, showed a very low content of syringylpropane-derived units (S:G:H of 48:49:3), a high degree of condensation, a low content of beta-O-4 ( approximately 0.40-0.43 per C6) structures, and a Mw of 2230. Glucuronoxylan (14% wood weight) isolated by alkaline (KOH) or by dimethyl sulfoxide extraction was characterized by methylation analysis, 1H NMR, and GPC. About 10% of the xylopyranose (Xylp) units constituting the linear backbone were substituted at O-2 with 4-O-methylglucuronic acid residues. Almost half of the Xylp units (45%) were O-2 (18%), O-3 (24%) or O-2,3 (3%) acetylated. X-ray diffraction analysis of cellulose (46% wood weight), isolated according to the Kürschner-Hoffer method, showed a degree of crystallinity of 67.6%.

  17. Effect of Cholesterol on the Structure of a Five-Component Mitochondria-Like Phospholipid Membrane (United States)

    Cathcart, Kelly; Patel, Amit; Dies, Hannah; Rheinstädter, Maikel C.; Fradin, Cécile


    Cellular membranes have a complex phospholipid composition that varies greatly depending on the organism, cell type and function. In spite of this complexity, most structural data available for phospholipid bilayers concern model systems containing only one or two different phospholipids. Here, we examine the effect of cholesterol on the structure of a complex membrane reflecting the lipid composition of mitochondrial membranes, with five different types of headgroups (phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS) and cardiolipin (CL)) and a variety of hydrocarbon tails. This particular system was chosen because elevated cholesterol contents in mitochondrial membranes have been linked to a breaking down of Bax-mediated membrane permeabilization and resistance to cancer treatments. High resolution electron density profiles were determined by X-ray reflectivity, while the area per phospholipid chain, Apc, and the chain order parameter, SX-ray, were determined by wide-angle X-ray scattering (WAXS). We show that chain order increases upon the addition of cholesterol, resulting in both a thickening of the lipid bilayer and a reduction in the average surface area per phospholipid chain. This effect, well known as cholesterol’s condensation effect, is similar, but not as pronounced as for single-component phospholipid membranes. We conclude by discussing the relevance of these findings for the insertion of the pro-apoptotic protein Bax in mitochondrial membranes with elevated cholesterol content. PMID:26529029

  18. Characterization of ABS specimens produced via the 3D printing technology for drone structural components (United States)

    Ferro, Carlo Giovanni; Brischetto, Salvatore; Torre, Roberto; Maggiore, Paolo


    The Fused Deposition Modelling (FDM) technology is widely used in rapid prototyping. 3D printers for home desktop applications are usually employed to make non-structural objects. When the mechanical stresses are not excessive, this technology can also be successfully employed to produce structural objects, not only in prototyping stage but also in the realization of series pieces. The innovative idea of the present work is the application of this technology, implemented in a desktop 3D printer, to the realization of components for aeronautical use, especially for unmanned aerial systems. For this purpose, the paper is devoted to the statistical study of the performance of a desktop 3D printer to understand how the process performs and which are the boundary limits of acceptance. Mechanical and geometrical properties of ABS (Acrylonitrile Butadiene Styrene) specimens, such as tensile strength and stiffness, have been evaluated. ASTM638 type specimens have been used. A capability analysis has been applied for both mechanical and dimensional performances. Statistically stable limits have been determined using experimentally collected data.

  19. Mixing efficiency inside micro-droplets coalesced by two components in cross-structure (United States)

    Ren, Yanlin; Liu, Zhaomiao; Pang, Yan


    The mixing of micro-droplets is used in analytical chemistry, medicine production and material synthesis owing to its advantages including the encapsulation and narrow time residence distribution. In this work, droplets are coalesced by two dispersed phase with different flow rates, generated in cross-structure and mixed in planar serpentine structure. The mixing efficiency of micro-droplets under control characters including the width of entrance and the flow rate of dispersed phases have been investigated by experiments and numerical simulations. The UDS (user-defined scalar) as dimensionless concentration of the solution is adopted in simulation, and is used to calculate the concentration and the mixing effect. By changing the flow rates and the entrances` width, the changing rules of the mixing characters have been obtained. The asymmetry distributions of components make rapid mixing process in half part of each droplet when travel through a straight channel. Increasing of the ratio of entrance width result into larger droplet and weaken the chaotic mixing effect. Meanwhile, the coalesced mechanism can be performed by ranging the ratio of flow rates, the ranges are also determined by the widths of entrances. The authors gratefully acknowledge the support of National Natural Science Foundation of China (Grant No. 11572013).

  20. Effect of Cholesterol on the Structure of a Five-Component Mitochondria-Like Phospholipid Membrane

    Directory of Open Access Journals (Sweden)

    Kelly Cathcart


    Full Text Available Cellular membranes have a complex phospholipid composition that varies greatly depending on the organism, cell type and function. In spite of this complexity, most structural data available for phospholipid bilayers concern model systems containing only one or two different phospholipids. Here, we examine the effect of cholesterol on the structure of a complex membrane reflecting the lipid composition of mitochondrial membranes, with five different types of headgroups (phosphatidylcholine (PC, phosphatidylethanolamine (PE, phosphatidylinositol (PI, phosphatidylserine (PS and cardiolipin (CL and a variety of hydrocarbon tails. This particular system was chosen because elevated cholesterol contents in mitochondrial membranes have been linked to a breaking down of Bax-mediated membrane permeabilization and resistance to cancer treatments. High resolution electron density profiles were determined by X-ray reflectivity, while the area per phospholipid chain, Apc, and the chain order parameter, SX-ray, were determined by wide-angle X-ray scattering (WAXS. We show that chain order increases upon the addition of cholesterol, resulting in both a thickening of the lipid bilayer and a reduction in the average surface area per phospholipid chain. This effect, well known as cholesterol’s condensation effect, is similar, but not as pronounced as for single-component phospholipid membranes. We conclude by discussing the relevance of these findings for the insertion of the pro-apoptotic protein Bax in mitochondrial membranes with elevated cholesterol content.

  1. Effect of sea component dissolution on fibrous structure of islands-in-the-sea spunbond nonwovens (United States)

    Suvari, F.; Ulcay, Y.; Pourdeyhimi, B.


    This work presents the preliminary results of our efforts that focused on the development of lightweight and more fibrous nonwoven. For this objective, nonwoven webs that contain bicomponent filaments with island-in-the-sea cross section was produced by spunbonding, which involves extruding of sea and island polymer melts through dies, cooling, and attenuating the bicomponent filaments by high velocity air streams. Nylon-6 and Polyethylene were chosen as the island and sea polymers, respectively. Bonding process was applied to web first to keep structural integrity after removing the sea polymer. The web was hydroentangled with high speed water jets prior to the dissolving process to obtain fiber entanglement. Xylene, which is one of the few chemical that can dissolve Polyethylene, was used for the dissolution of the sea component from the fibrous structure of the spunbond nonwoven. Removal of the sea polymer from spunbond nonwovens that contain bicomponent filaments with islands-in-the-sea cross section was achieved by the developed dissolution process. Weight, thickness, and area of the nonwoven samples changed after the dissolution. After removing the sea polymer, spunbond nonwoven contains only thin island fibers and also gets lighter. Lightweight and more fibrous nonwovens can be obtained with the method given in this study.

  2. Ultrasonic damage imaging of structural components with bulk and guided waves using match coefficients (United States)

    Sternini, S.; Quattrocchi, A.; Montanini, R.; Lanza di Scalea, F.


    Damage imaging of structural components in the field of Non Destructive Evaluations (NDE) and Structural Health Monitoring (SHM) using ultrasonic waves is usually performed by conventional imaging techniques, such as DelayAnd-Sum (DAS), by back-propagating the recorded waveforms to identify locations and size of defects and damages. This technique results in sidelobes and artifacts that worsen the accuracy of the damage identification. Here we propose a novel imaging approach that derives from the well-known technique of Matched Field Processing (MFP), often used in underwater acoustics and seismology. In MFP, the source or damage is located by a matching procedure between measurements ("data vector") and expected responses ("replica vectors") computed for each point of the imaging volume. In this work, we apply this matching approach only to selected features extracted from the recorded waveforms. These features, for example time-of-flights or amplitudes, will be selected for multiple modes of propagation of the ultrasonic waves (longitudinal and shear in bulk waves, multiple guided modes in waveguides). By considering multiple features and multiple wave modes, it is possible to increase the performance of this matching procedure, which can be possibly further improved by also combining different signal frequencies and excitation sources in analogy with biomedical ultrasonic imaging. A correlation metric showing high computational efficiency in the image reconstruction process will be tested as matching coefficient. Applications of this imaging approach to a metallic plate with holes and simulated defects will be shown.


    Directory of Open Access Journals (Sweden)



    Full Text Available The aim of this research is to determine the relationship between environmental, behavioral, health services, education, and economic variables to health status in the Province of Bali. These variables are constructs (latents that can not be measured directly by observation. If there was a relationship between latent and its indicators, it is recomended to use Structural Equation Modeling (SEM. In this research we used variance-based SEM i.e. Generalized Structured Component Analysis (GSCA. This method not based on many assumptions such as the data does not have a multivariate normal distribution, the sample size does is not necessary large. Moreover, GSCA provides by overall goodness-fit of the model. The result of this research indicates that the environmental, behavioral, economic and educational variable influenced health status, but health service does not significantly affect the health status; economic does not significantly affect the environment; and education does not significantly affect the behavior. The result of the FIT value ?0.450 and the AFIT value 0.429 showed that overall model in this research is not good enough because of both of these values are under 0.50.

  4. A simple iterative independent component analysis algorithm for vibration source signal identification of complex structures

    Directory of Open Access Journals (Sweden)

    Dong-Sup Lee


    Full Text Available Independent Component Analysis (ICA, one of the blind source separation methods, can be applied for extracting unknown source signals only from received signals. This is accomplished by finding statistical independence of signal mixtures and has been successfully applied to myriad fields such as medical science, image processing, and numerous others. Nevertheless, there are inherent problems that have been reported when using this technique: insta- bility and invalid ordering of separated signals, particularly when using a conventional ICA technique in vibratory source signal identification of complex structures. In this study, a simple iterative algorithm of the conventional ICA has been proposed to mitigate these problems. The proposed method to extract more stable source signals having valid order includes an iterative and reordering process of extracted mixing matrix to reconstruct finally converged source signals, referring to the magnitudes of correlation coefficients between the intermediately separated signals and the signals measured on or nearby sources. In order to review the problems of the conventional ICA technique and to vali- date the proposed method, numerical analyses have been carried out for a virtual response model and a 30 m class submarine model. Moreover, in order to investigate applicability of the proposed method to real problem of complex structure, an experiment has been carried out for a scaled submarine mockup. The results show that the proposed method could resolve the inherent problems of a conventional ICA technique.

  5. Structural Basis for DNA Recognition by the Two-Component Response Regulator RcsB. (United States)

    Filippova, Ekaterina V; Zemaitaitis, Bozena; Aung, Theint; Wolfe, Alan J; Anderson, Wayne F


    RcsB is a highly conserved transcription regulator of the Rcs phosphorelay system, a complex two-component signal transduction system (N. Majdalani and S. Gottesman, Annu Rev Microbiol 59:379-405, 2005; A. J. Wolfe, Curr Opin Microbiol 13:204-209, 2010,; D. J. Clarke, Future Microbiol 5:1173-1184, 2010, RcsB plays an important role in virulence and pathogenicity in human hosts by regulating biofilm formation. RcsB can regulate transcription alone or together with its auxiliary transcription regulators by forming heterodimers. This complexity allows RcsB to regulate transcription of more than 600 bacterial genes in response to different stresses (D. Wang et al., Mol Plant Microbe Interact 25:6-17, 2012, Despite increasing knowledge of RcsB importance, molecular mechanisms that drive the ability of RcsB to control transcription of a large number of genes remain unclear. Here, we present crystal structures of unphosphorylated RcsB in complex with the consensus DNA-binding sequence of 22-mer (DNA22) and 18-mer (DNA18) of the flhDC operon from Escherichia coli determined at 3.15- and 3.37-Å resolution, respectively. The results of our structural analysis combined with the results of in vitro binding assays provide valuable insights to the protein regulatory mechanism, demonstrate how RcsB recognizes target DNA sequences, and reveal a unique oligomeric state that allows RcsB to form homo- and heterodimers. This information will help us understand the complex mechanisms of transcriptional regulation by RcsB in bacteria. IMPORTANCE RcsB is a well-studied two-component response regulator of the Rcs phosphorelay system, conserved within the family Enterobacteriaceae , which includes many pathogens. It is a global regulator, controlling more than 5% of bacterial genes associated with capsule biosynthesis, flagellar biogenesis, cell wall biosynthesis

  6. Embedded fiber optic sensors for monitoring processing, quality and structural health of resin transfer molded components (United States)

    Keulen, C.; Rocha, B.; Yildiz, M.; Suleman, A.


    Due to their small size and flexibility fiber optics can be embedded into composite materials with little negative effect on strength and reliability of the host material. Fiber optic sensors such as Fiber Bragg Gratings (FBG) or Etched Fiber Sensors (EFS) can be used to detect a number of relevant parameters such as flow, degree of cure, quality and structural health throughout the life of a composite component. With a detection algorithm these embedded sensors can be used to detect damage in real time while the component remains in service. This paper presents the research being conducted on the use of fiber optic sensors for process and Structural Health Monitoring (SHM) of Resin Transfer Molded (RTM) composite structures. Fiber optic sensors are used at all life stages of an RTM composite panel. A laboratory scale RTM apparatus was developed with the capability of visually monitoring the resin filling process. A technique for embedding fiber optic sensors with this apparatus has also been developed. Both FBGs and EFSs have been embedded in composite panels using the apparatus. EFSs to monitor the fabrication process, specifically resin flow have been embedded and shown to be capable of detecting the presence of resin at various locations as it is injected into the mold. Simultaneously these sensors were multiplexed on the same fiber with FBGs, which have the ability to measure strain. Since multiple sensors can be multiplexed on a single fiber the number of ingress/egress locations required per sensor can be significantly reduced. To characterize the FBGs for strain detection tensile test specimens with embedded FBG sensors have been produced. These specimens have been instrumented with a resistive strain gauge for benchmarking. Both specimens and embedded sensors were characterized through tensile testing. Furthermore FBGs have been embedded into composite panels in a manner that is conducive to detection of Lamb waves generated with a centrally located PZT

  7. Embedded fiber optic sensors for monitoring processing, quality and structural health of resin transfer molded components

    Energy Technology Data Exchange (ETDEWEB)

    Keulen, C; Rocha, B; Suleman, A [University of Victoria, Department of Mechanical Engineering, PO Box 3055, Stn. CSC, Victoria, B.C., V8W 3P6 (Canada); Yildiz, M, E-mail: [Sabanci University, Faculty of Engineering and Natural Sciences, Orhanli - Tuzla, 34956, Istanbul (Turkey)


    Due to their small size and flexibility fiber optics can be embedded into composite materials with little negative effect on strength and reliability of the host material. Fiber optic sensors such as Fiber Bragg Gratings (FBG) or Etched Fiber Sensors (EFS) can be used to detect a number of relevant parameters such as flow, degree of cure, quality and structural health throughout the life of a composite component. With a detection algorithm these embedded sensors can be used to detect damage in real time while the component remains in service. This paper presents the research being conducted on the use of fiber optic sensors for process and Structural Health Monitoring (SHM) of Resin Transfer Molded (RTM) composite structures. Fiber optic sensors are used at all life stages of an RTM composite panel. A laboratory scale RTM apparatus was developed with the capability of visually monitoring the resin filling process. A technique for embedding fiber optic sensors with this apparatus has also been developed. Both FBGs and EFSs have been embedded in composite panels using the apparatus. EFSs to monitor the fabrication process, specifically resin flow have been embedded and shown to be capable of detecting the presence of resin at various locations as it is injected into the mold. Simultaneously these sensors were multiplexed on the same fiber with FBGs, which have the ability to measure strain. Since multiple sensors can be multiplexed on a single fiber the number of ingress/egress locations required per sensor can be significantly reduced. To characterize the FBGs for strain detection tensile test specimens with embedded FBG sensors have been produced. These specimens have been instrumented with a resistive strain gauge for benchmarking. Both specimens and embedded sensors were characterized through tensile testing. Furthermore FBGs have been embedded into composite panels in a manner that is conducive to detection of Lamb waves generated with a centrally located PZT

  8. The ecological structures as components of flood and erosion vulnerability analysis in costal landscapes (United States)

    Valentini, E.; Taramelli, A.; Martina, M.; Persichillo, M. G.; Casarotti, C.; Meisina, C.


    The direct and the indirect changes of natural habitats for coastal development can affect the level of exposure to erosion and flooding (inundation). Although engineered structures are still preferred for coastal safety there is an increasing number of applications of ecosystem-based solutions worldwide as the building with nature approaches and the arising natural capital evaluation. A question to which we should respond, is the possibility of using the wide range of satellite data and the already available Earth Observation based products to make a synoptic structural and environmental vulnerability assessment. By answering to this, we could also understand, if and how many markers/signals can be identified in the landscape components, to define transitions to and from nonlinear processes - to and from scale invariant spatial distributions- characterizing the evolution of the environmental patch size mosaic, the landscape. The Wadden Sea, in example, is a productive estuarine area in the south-eastern coastal zone of the North Sea. It is characterized by extensive tidal mud flats, saltmarshes and by the tidal channel network between the mainland and the chain of islands along the North Sea side. The area has a UNESCO World Heritage Status and a Natura 2000 status. Here, we identified thresholds to distinguish spatial and temporal patterns controlled by changes in environmental variables. These patterns are represented by the cover percent and by the structural level of vegetation and sediment/soil in each identified patch. The environmental variables are those able to act on the patch size distribution as the forcing factors from the sea (wind and waves fields) or from the climate and the hydrology drivers. The Bayesian approach defines the dependencies of the spatial patch size distribution from the major flooding and erosion environmental variables. When the analysis is scaled up from the ecosystem units to the landscape level thanks to the satellite

  9. CANDU in-reactor quantitative visual-based inspection techniques (United States)

    Rochefort, P. A.


    This paper describes two separate visual-based inspection procedures used at CANDU nuclear power generating stations. The techniques are quantitative in nature and are delivered and operated in highly radioactive environments with access that is restrictive, and in one case is submerged. Visual-based inspections at stations are typically qualitative in nature. For example a video system will be used to search for a missing component, inspect for a broken fixture, or locate areas of excessive corrosion in a pipe. In contrast, the methods described here are used to measure characteristic component dimensions that in one case ensure ongoing safe operation of the reactor and in the other support reactor refurbishment. CANDU reactors are Pressurized Heavy Water Reactors (PHWR). The reactor vessel is a horizontal cylindrical low-pressure calandria tank approximately 6 m in diameter and length, containing heavy water as a neutron moderator. Inside the calandria, 380 horizontal fuel channels (FC) are supported at each end by integral end-shields. Each FC holds 12 fuel bundles. The heavy water primary heat transport water flows through the FC pressure tube, removing the heat from the fuel bundles and delivering it to the steam generator. The general design of the reactor governs both the type of measurements that are required and the methods to perform the measurements. The first inspection procedure is a method to remotely measure the gap between FC and other in-core horizontal components. The technique involves delivering vertically a module with a high-radiation-resistant camera and lighting into the core of a shutdown but fuelled reactor. The measurement is done using a line-of-sight technique between the components. Compensation for image perspective and viewing elevation to the measurement is required. The second inspection procedure measures flaws within the reactor's end shield FC calandria tube rolled joint area. The FC calandria tube (the outer shell of the FC) is

  10. Multiple amino acid sequence alignment nitrogenase component 1: insights into phylogenetics and structure-function relationships.

    Directory of Open Access Journals (Sweden)

    James B Howard

    Full Text Available Amino acid residues critical for a protein's structure-function are retained by natural selection and these residues are identified by the level of variance in co-aligned homologous protein sequences. The relevant residues in the nitrogen fixation Component 1 α- and β-subunits were identified by the alignment of 95 protein sequences. Proteins were included from species encompassing multiple microbial phyla and diverse ecological niches as well as the nitrogen fixation genotypes, anf, nif, and vnf, which encode proteins associated with cofactors differing at one metal site. After adjusting for differences in sequence length, insertions, and deletions, the remaining >85% of the sequence co-aligned the subunits from the three genotypes. Six Groups, designated Anf, Vnf , and Nif I-IV, were assigned based upon genetic origin, sequence adjustments, and conserved residues. Both subunits subdivided into the same groups. Invariant and single variant residues were identified and were defined as "core" for nitrogenase function. Three species in Group Nif-III, Candidatus Desulforudis audaxviator, Desulfotomaculum kuznetsovii, and Thermodesulfatator indicus, were found to have a seleno-cysteine that replaces one cysteinyl ligand of the 8Fe:7S, P-cluster. Subsets of invariant residues, limited to individual groups, were identified; these unique residues help identify the gene of origin (anf, nif, or vnf yet should not be considered diagnostic of the metal content of associated cofactors. Fourteen of the 19 residues that compose the cofactor pocket are invariant or single variant; the other five residues are highly variable but do not correlate with the putative metal content of the cofactor. The variable residues are clustered on one side of the cofactor, away from other functional centers in the three dimensional structure. Many of the invariant and single variant residues were not previously recognized as potentially critical and their identification

  11. Peroxynitrous acid induces structural and functional modifications to basement membranes and its key component, laminin. (United States)

    Degendorfer, Georg; Chuang, Christine Y; Hammer, Astrid; Malle, Ernst; Davies, Michael J


    Basement membranes (BM) are specialized extracellular matrices underlying endothelial cells in the artery wall. Laminin, the most abundant BM glycoprotein, is a structural and biologically active component. Peroxynitrous acid (ONOOH), a potent oxidizing and nitrating agent, is formed in vivo at sites of inflammation from superoxide and nitric oxide radicals. Considerable data supports ONOOH formation in human atherosclerotic lesions, and an involvement of this oxidant in atherosclerosis development and lesion rupture. These effects may be mediated, at least in part, via extracellular matrix damage. In this study we demonstrate co-localization of 3-nitrotyrosine (a product of tyrosine damage by ONOOH) and laminin in human atherosclerotic lesions. ONOOH-induced damage to BM was characterized for isolated murine BM, and purified murine laminin-111. Exposure of laminin-111 to ONOOH resulted in dose-dependent loss of protein tyrosine and tryptophan residues, and formation of 3-nitrotyrosine, 6-nitrotryptophan and the cross-linked material di-tyrosine, as detected by amino acid analysis and Western blotting. These changes were accompanied by protein aggregation and fragmentation as detected by SDS-PAGE. Endothelial cell adhesion to isolated laminin-111 exposed to 10 μM or higher levels of ONOOH was significantly decreased (~25%) compared to untreated controls. These data indicate that laminin is oxidized by equimolar or greater concentrations of ONOOH, with this resulting in structural and functional changes. These modifications, and resulting compromised cell-matrix interactions, may contribute to endothelial cell dysfunction, a weakening of the structure of atherosclerotic lesions, and an increased propensity to rupture. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Effect of halloysite nanotubes on the structure and function of important multiple blood components. (United States)

    Wu, Keke; Feng, Ru; Jiao, Yanpeng; Zhou, Changren


    Many researchers have investigated the application of halloysite nanotubes (HNTs) in biomedicine, because of their special nanoscale hollow tubular structure. Although the cytocompatibility of HNTs has been studied, their blood compatibility has not been systematically investigated. In this work, the effect of HNTs on the structure and function of different blood components has been studied, including the morphology and hemolysis of red blood cells (RBCs). Based on scanning electron microscopy (SEM) observations, optical density test and flow cytometry analysis, we found that HNTs can affect the morphology and membrane integrity of RBCs in phosphate buffered saline (PBS) in a content-dependent way. In particular, based on UV-vis absorption spectra, fluorescence spectra and circular dichroism (CD) spectra, HNTs can alter the secondary structure and conformation of human fibrinogen and γ-globulins. In addition, the detection of biomarker molecules C3a and C5a in plasma suggests that HNTs can trigger complement activation. In the blood clotting assay, HNTs were found to significantly prolong the activated partial thromboplastin time (APTT), shorten the prothrombin time (PT) of platelet-poor plasma (PPP), and change the thromboelastography (TEG) parameters of whole blood coagulation. Furthermore, confocal laser scanning microscopy and flow cytometry analysis were used to test intracellular uptake by macrophages, and the cellular uptake of HNTs in the RAW 264.7 was found to be content-dependent, but not time-dependent. These findings provide insight for the potential use of HNTs as biofriendly nanocontainers for biomaterials in vivo. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Thermal analysis on the EAST tungsten plasma facing components with shaping structure counteracting the misalignment issues (United States)

    Wang, Baoguo; Zhu, Dahuan; Ding, Rui; Chen, Junling


    Tungsten monoblock type tiles with ITER dimensions along with supporting cassette components were installed at EAST’s upper diverter during 2014 and EAST’s lower diverter will also be upgraded in the future. These cassette structures pose critical issues on the high cumulative incident heat flux due to the leading edges and misalignments (0 ˜ 1.5 mm), which may result in the destruction or even melting of the tungsten tile. The present work summarizes the thermal analysis using ANSYS multiphysics software 15.0 performed on the actively cooled W tiles to evaluate the shaping effect on surface temperature. In the current heat flux conditions (Q|| ˜ 100 MW m-2), the adopted chamfer shaping (1 × 1 mm) can only reduce the maximum temperature by about 14%, but it also has a melting risk at the maximum misalignment of 1.5 mm. The candidate shaping solutions elliptical (round) edge, dome and fish-scale are analyzed for comparison and are identified not as good as the dual chamfer structure. A relatively good dual chamfer (2 × 13 mm) shaping forming a symmetrical sloping roof structure can effectively counteract the 1.5 mm misalignment, reducing the maximum temperature by up to 50%. However, in the future heat flux conditions (Q|| ˜ 287 MW m-2), it may only endure about 0.5 mm misalignment. Moreover, no proper shaping solution has been found that can avoid melting at the maximum misalignment of 1.5 mm. Thus, the engineering misalignment has to be limited to an acceptable level. Supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB107004 and 2013GB105003) and National Natural Science Foundation of China (No. 11405209).

  14. Seismic evaluation of the structures of the reactor building. Project IAEA-EBP KARISMA; Evaluacion sismica de las estructuras del edificio del Reactor. Proyecto KARISMA IAEA-EBP

    Energy Technology Data Exchange (ETDEWEB)

    Ezeberry, J.; Fernandez, A.; Garcia, M.; Moreno, A.; Jimenez, A. M.; Sanchez, J. G.


    This research project includes a number tasks where an evaluation of the seismic response of the plant. The first phase of the project involves the assessment of the response of the structure to static, modal analysis, analysis of the soil column and analysis of soil structure interaction. In a second task evaluates RHR system behavior to seismic loads. This paper describes the work done within these two activities.

  15. Neutron radiation embrittlement studies in support of continued operation, and validation by sampling of Magnox reactor steel pressure vessels and components

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.B.; Bolton, C.J. [Magnox Electric plc, Berkeley Centre, Glos (United Kingdom)


    Magnox steel reactor pressure vessels differ significantly from US LWR vessels in terms of the type of steel used, as well as their operating environment (dose level, exposure temperature range, and neutron spectra). The large diameter ferritic steel vessels are constructed from C-Mn steel plates and forgings joined together with manual metal and submerged-arc welds which are stress-relieved. All Magnox vessels are now at least thirty years old and their continued operation is being vigorously pursued. Vessel surveillance and other programmes are summarized which support this objective. The current understanding of the roles of matrix irradiation damage, irradiation-enhanced copper impurity precipitation and intergranular embrittlement effects is described in so far as these influence the form of the embrittlement and hardening trend curves for each material. An update is given on the influence of high temperature exposure, and on the role of differing neutron spectra. Finally, the validation offered by the results of an initial vessel sampling exercise is summarized together with the objectives of a more extensive future sampling programme.

  16. Design concept of conducting shell and in-vessel components suitable for plasma vertical stability and remote maintenance scheme in DEMO reactor

    Energy Technology Data Exchange (ETDEWEB)

    Utoh, Hiroyasu, E-mail: [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); International Fusion Energy Research Centre, 2-166, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Takase, Haruhiko [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); International Fusion Energy Research Centre, 2-166, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Sakamoto, Yoshiteru; Tobita, Kenji [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); Mori, Kazuo; Kudo, Tatsuya [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); International Fusion Energy Research Centre, 2-166, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Someya, Youji; Asakura, Nobuyuki; Hoshino, Kazuo; Nakamura, Makoto; Tokunaga, Shinsuke [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan)


    Highlights: • Conceptual design of in-vessel component including conducting shell has been investigated. • The conducting shell design for plasma vertical stability was clarified from the plasma vertical stability analysis. • The calculation results showed that the double-loop shell has the most effect on plasma vertical stability. - Abstract: In order to realize a feasible DEMO, we designed an in-vessel component including the conducting shell. The project is affiliated with the broader approach DEMO design activities and is conceptualized from a plasma vertical stability and engineering viewpoint. The dependence of the plasma vertical stability on the conducing shell parameters and the electromagnetic force at plasma disruption were investigated in numerical simulations (programmed in the 3D eddy current analysis code and a plasma position control code). The simulations assumed the actual shape and position of the vacuum vessel and in-vessel components. The plasma vertical stability was most effectively maintained by the double-loop shell.

  17. Calculation of Added Mass for Submerged Reactor with Complex Shape

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jong-Oh; Kim, Gyeongho; Choo, Yeon-Seok; Yoo, Yeon-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    Kijang Research Reactor (KJRR) is currently under construction. Its reactor is located on the bottom of a reactor pool which is filled with water to a depth of 12m. Some components are installed on or inside the reactor and their structural integrity and safety performance need to be verified under seismic situations. For the verification, time history data or Floor Response Spectrum (FRS) on their support location, which is the reactor, should be obtained. A Finite Element (FE) model with fluid elements can give very accurate results for the matter; however, it costs too many resources and takes too much time for the transient analyses. In order to make the model more efficient and simple, added masses are often used to simulate the effect of water instead of the fluid elements. Many literatures introduce methods to calculate the added mass according to the exterior shape of structures. In this paper, how to calculate added masses for complex shaped structure was suggested. The proposed method was applied to RSA for KJRR and its accuracy was verified through comparison of the natural frequencies of RSA with fluid elements and the added masses. They showed the differences less than 1.5% between two models. Finally, it is concluded that the proposed method is quite useful to obtain added masses for complex shaped structure.

  18. ACDOS1: a computer code to calculate dose rates from neutron activation of neutral beamlines and other fusion-reactor components

    Energy Technology Data Exchange (ETDEWEB)

    Keney, G.S.


    A computer code has been written to calculate neutron induced activation of neutral-beam injector components and the corresponding dose rates as a function of geometry, component composition, and time after shutdown. The code, ACDOS1, was written in FORTRAN IV to calculate both activity and dose rates for up to 30 target nuclides and 50 neutron groups. Sufficient versatility has also been incorporated into the code to make it applicable to a variety of general activation problems due to neutrons of energy less than 20 MeV.

  19. Nuclear reactor apparatus (United States)

    Wade, Elman E.


    A lifting, rotating and sealing apparatus for nuclear reactors utilizing rotating plugs above the nuclear reactor core. This apparatus permits rotation of the plugs to provide under the plug refueling of a nuclear core. It also provides a means by which positive top core holddown can be utilized. Both of these operations are accomplished by means of the apparatus lifting the top core holddown structure off the nuclear core while stationary, and maintaining this structure in its elevated position during plug rotation. During both of these operations, the interface between the rotating member and its supporting member is sealingly maintained.

  20. Selection of support structure materials for irradiation experiments in the HFIR (High Flux Isotope Reactor) at temperatures up to 500 degrees C

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, K.; Longest, A.W.


    The key factor in the design of capsules for irradiation of test specimens in the High Flux Isotope Reactor at preselected temperatures up to 500{degree}C utilizing nuclear heating is a narrow gas-filled gap which surrounds the specimens and controls the transfer of heat from the specimens through the wall of a containment tube to the reactor cooling water. Maintenance of this gap to close tolerances is dependent on the characteristics of the materials used to support the specimens and isolate them from the water. These support structure materials must have low nuclear heating rates, high thermal conductivities, and good dimensional stabilities under irradiation. These conditions are satisfied by certain aluminum alloys. One of these alloys, a powder metallurgy product containing a fine dispersion of aluminum oxide, is no longer manufactured. A new alloys of this type, with the trade name DISPAL, is determined to be a suitable substitute. 23 refs., 13 figs., 3 tabs.


    Directory of Open Access Journals (Sweden)

    Constantin POPESCU


    Full Text Available The authors contribution to this paper is to present a concept solution of a remote control robot (RCR used for the horizontal fuel channels pressure tube decommissioning in the CANDU nuclear reactor. The authors highlight in this paper, few details of geometry, operations, constraints by kinematics and dynamics of the robot movement outside of the reactor fuel channel. Outside operations performed has as the main steps of dismantling process the followings: positioning front of Calandria structure at the fuel channel to be decommissioned, coupling and locking to the End Fitting (EF, sorting and storage extracted items in the safe container. All steps are performed in automatic mode. The remote control robot (RCR represents a safety system controlled by sensors and has the capability to analyze any error registered and decide next activities or abort the outside decommissioning procedure in case of any risk rise in order to ensure the environmental and workers protection.

  2. Structural and thermodynamic study of dicesium molybdate Cs2Mo2O7: Implications for fast neutron reactors (United States)

    Smith, A. L.; Kauric, G.; van Eijck, L.; Goubitz, K.; Wallez, G.; Griveau, J.-C.; Colineau, E.; Clavier, N.; Konings, R. J. M.


    The structure of α-Cs2Mo2O7 (monoclinic in space group P21 / c), which can form during irradiation in fast breeder reactors in the space between nuclear fuel and cladding, has been refined in this work at room temperature from neutron diffraction data. Furthermore, the compounds' thermal expansion and polymorphism have been investigated using high temperature X-ray diffraction combined with high temperature Raman spectroscopy. A phase transition has been observed at Ttr(α → β)=(621.9±0.8) K using Differential Scanning Calorimetry, and the structure of the β-Cs2Mo2O7 phase, orthorhombic in space group Pbcm, has been solved ab initio from the high temperature X-ray diffraction data. Furthermore, the low temperature heat capacity of α-Cs2Mo2O7 has been measured in the temperature range T=(1.9-313.2) K using a Quantum Design PPMS (Physical Property Measurement System) calorimeter. The heat capacity and entropy values at T=298.15 K have been derived as Cp,mo (Cs2Mo2O7 , cr , 298.15 K) = (211.9 ± 2.1) J K-1mol-1 and Smo (Cs2Mo2O7 , cr , 298.15 K) = (317.4 ± 4.3) J K-1mol-1 . When combined with the enthalpy of formation reported in the literature, these data yield standard entropy and Gibbs energy of formation as ΔfSmo (Cs2Mo2O7 , cr , 298.15 K) = - (628.2 ± 4.4) J K-1mol-1 and ΔfGmo (Cs2Mo2O7 , cr , 298.15 K) = - (2115.1 ± 2.5) kJmol-1 . Finally, the cesium partial pressure expected in the gap between fuel and cladding following the disproportionation reaction 2Cs2MoO4=Cs2Mo2O7+2Cs(g)+ 1/2 O2(g) has been calculated from the newly determined thermodynamic functions.

  3. Dynamic GSCA (Generalized Structured Component Analysis) with Applications to the Analysis of Effective Connectivity in Functional Neuroimaging Data (United States)

    Jung, Kwanghee; Takane, Yoshio; Hwang, Heungsun; Woodward, Todd S.


    We propose a new method of structural equation modeling (SEM) for longitudinal and time series data, named Dynamic GSCA (Generalized Structured Component Analysis). The proposed method extends the original GSCA by incorporating a multivariate autoregressive model to account for the dynamic nature of data taken over time. Dynamic GSCA also…

  4. LINE retrotransposon RNA is an essential structural and functional epigenetic component of a core neocentromeric chromatin.

    Directory of Open Access Journals (Sweden)

    Anderly C Chueh


    Full Text Available We have previously identified and characterized the phenomenon of ectopic human centromeres, known as neocentromeres. Human neocentromeres form epigenetically at euchromatic chromosomal sites and are structurally and functionally similar to normal human centromeres. Recent studies have indicated that neocentromere formation provides a major mechanism for centromere repositioning, karyotype evolution, and speciation. Using a marker chromosome mardel(10 containing a neocentromere formed at the normal chromosomal 10q25 region, we have previously mapped a 330-kb CENP-A-binding domain and described an increased prevalence of L1 retrotransposons in the underlying DNA sequences of the CENP-A-binding clusters. Here, we investigated the potential role of the L1 retrotransposons in the regulation of neocentromere activity. Determination of the transcriptional activity of a panel of full-length L1s (FL-L1s across a 6-Mb region spanning the 10q25 neocentromere chromatin identified one of the FL-L1 retrotransposons, designated FL-L1b and residing centrally within the CENP-A-binding clusters, to be transcriptionally active. We demonstrated the direct incorporation of the FL-L1b RNA transcripts into the CENP-A-associated chromatin. RNAi-mediated knockdown of the FL-L1b RNA transcripts led to a reduction in CENP-A binding and an impaired mitotic function of the 10q25 neocentromere. These results indicate that LINE retrotransposon RNA is a previously undescribed essential structural and functional component of the neocentromeric chromatin and that retrotransposable elements may serve as a critical epigenetic determinant in the chromatin remodelling events leading to neocentromere formation.

  5. Application of Hastelloy X in Gas-Cooled Reactor Systems

    DEFF Research Database (Denmark)

    Brinkman, C. R.; Rittenhouse, P. L.; Corwin, W.R.


    Hastelloy X, an Ni--Cr--Fe--Mo alloy, may be an important structural alloy for components of gas-cooled reactor systems. Expected applications of this alloy in the High-Temperature Gas-Cooled Reactor (HTGR) are discussed, and the development of interim mechanical properties and supporting data...... extensive amount of information has been generated on this material at Oak Ridge National Laboratory and elsewhere concerning behavior in air, which is reviewed. However, only limited data are available from tests conducted in helium. Comparisons of the fatigue and subcritical growth behavior in air between...

  6. Criteria for design of the Yucca Mountain structures, systems and components for fault displacement

    Energy Technology Data Exchange (ETDEWEB)

    Stepp, C. [Woodward-Clyde Federal Services, Austin, TX (United States); Hossain, Q. [Lawrence Livermore National Lab., CA (United States); Nesbit, S. [M and O/Duke Engineering, Las Vegas, NV (United States); Pezzopane, S. [Geological Survey, Denver, CO (United States); Hardy, M. [A.F.T. Agapito and Associates, Inc., Grand Junction, CO (United States)


    The DOE intends to design the Yucca Mountain high-level waste facility structures, systems and components (SSCs) for fault displacements to provide reasonable assurance that they will meet the preclosure safety performance objectives established by 10 CFR Part 60. To the extent achievable, fault displacement design of the facility will follow guidance provided in the NRC Staff Technical Position. Fault avoidance will be the primary design criterion, especially for spatially compact or clustered SSCs. When fault avoidance is not reasonably achievable, expected to be the case for most spatially extended SSCs, engineering design procedures and criteria or repair and rehabilitation actions, depending on the SSC`s importance to safety, are provided. SSCs that have radiological safety importance will be designed for fault displacements that correspond to the hazard exceedance frequency equal to their established seismic safety performance goals. Fault displacement loads are generally localized and may cause local inelastic response of SSCs. For this reason, the DOE intends to use strain-based design acceptance criteria similar to the strain-based criteria used to design nuclear plant SSCs for impact and impulsive loads.

  7. Analysis of Influence of Foaming Mixture Components on Structure and Properties of Foam Glass (United States)

    Karandashova, N. S.; Goltsman, B. M.; Yatsenko, E. A.


    It is recommended to use high-quality thermal insulation materials to increase the energy efficiency of buildings. One of the best thermal insulation materials is foam glass - durable, porous material that is resistant to almost any effect of substance. Glass foaming is a complex process depending on the foaming mode and the initial mixture composition. This paper discusses the influence of all components of the mixture – glass powder, foaming agent, enveloping material and water - on the foam glass structure. It was determined that glass powder is the basis of the future material. A foaming agent forms a gas phase in the process of thermal decomposition. This aforementioned gas foams the viscous glass mass. The unreacted residue thus changes a colour of the material. The enveloping agent slows the foaming agent decomposition preventing its premature burning out and, in addition, helps to accelerate the sintering of glass particles. The introduction of water reduces the viscosity of the foaming mixture making it evenly distributed and also promotes the formation of water gas that additionally foams the glass mass. The optimal composition for producing the foam glass with the density of 150 kg/m3 is defined according to the results of the research.

  8. Chromate removal as influenced by the structural changes of soil components upon carbonization at different temperatures. (United States)

    Chen, K Y; Liu, J C; Chiang, P N; Wang, S L; Kuan, W H; Tzou, Y M; Deng, Y; Tseng, K J; Chen, C C; Wang, M K


    Surface fire could induce heat transferring into the soil, creating a carbonized environment, which may alter the chemical compositions of soil organic matters (SOM). In the study, a surface soil was carbonized at up to 600 °C with limited air to simulate soils experiencing a surface fire, and Cr(VI) removal on the carbonized soils was investigated. NMR and FTIR analyses demonstrated a remarkable change of SOM structures at 300-400 °C. TGA-MS spectra indicated that (e.g. C(2)H(4), CH(3)OH and C(3)H(8)) were the major components in the evolved gases from the pyrolyzed soil. A maximum amount of Cr(VI) removal (ca. 4 mg g(-1) soil) occurred for the 200 °C-carbonized soils, attributed mainly to a significant increase of Cr(VI) reduction by 0.1 M KCl extractable organic carbon (EOC) with abundant carboxylic groups. Nonetheless, the formation of aromatic C upon carbonization of the soil at >400 °C may be responsible for Cr(VI) reduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Changing body structure components and motor skills in military high school students within one year

    Directory of Open Access Journals (Sweden)

    Glavač Boris


    Full Text Available Background/Aim. Proper growth and development of adolescents in the morphological, functional and psychosocial aspects is the imperative of the educational process. The aim of this study was to determine the status and changes in the indicators of morphological characteristics, motor skills and lifestyle habits among the students of the Military High School in Belgrade. Methods. The study included 217 students aged 15 to 18 years (from the first to the fourth grade. The two measurements performed at the intervals of one year were used to determine: the body structure by means of 10 variables and motor skills by 4 variables, while life habits were determined by 25 variables. Results. The differences in the indicators of morphological characteristics were recorded in all the groups, being the highest in the first year of schooling. During the period of growing up, a reduction of fatty component in percentage values was found, as well as an increase of muscle mass. The progressive growth of motor skills in the first, second and the third grade was recorded in the manifestation of power, and endurance improved only in the first year. In terms of dietary habits, there was no difference among the groups. Conclusion. The obtained results indicate proper morphological and motor development and the formation of lifestyle habits. The data obtained will serve as a basis for health and functional prevention and upgrading in terms of improvement of the process of military education. [Projekat Ministarstva nauke Republike Srbije, br. III47015

  10. Structural characterization of biomedical Co–Cr–Mo components produced by direct metal laser sintering

    Energy Technology Data Exchange (ETDEWEB)

    Barucca, G., E-mail: [SIMAU, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy); Santecchia, E.; Majni, G. [SIMAU, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy); Girardin, E. [DISCO, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy); Bassoli, E.; Denti, L.; Gatto, A. [DIMeC, University of Modena and Reggio Emilia, via Vignolese 905/B, Modena 41125 (Italy); Iuliano, L. [DISPEA, Politecnico di Torino, Duca degli Abruzzi 24, 10129 Torino (Italy); Moskalewicz, T. [Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków (Poland); Mengucci, P. [SIMAU, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy)


    Direct metal laser sintering (DMLS) is a technique to manufacture complex functional mechanical parts from a computer-aided design (CAD) model. Usually, the mechanical components produced by this procedure show higher residual porosity and poorer mechanical properties than those obtained by conventional manufacturing techniques. In this work, a Co–Cr–Mo alloy produced by DMLS with a composition suitable for biomedical applications was submitted to hardness measurements and structural characterization. The alloy showed a hardness value remarkably higher than those commonly obtained for the same cast or wrought alloys. In order to clarify the origin of this unexpected result, the sample microstructure was investigated by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and energy dispersive microanalysis (EDX). For the first time, a homogeneous microstructure comprised of an intricate network of thin ε (hcp)-lamellae distributed inside a γ (fcc) phase was observed. The ε-lamellae grown on the {111}{sub γ} planes limit the dislocation slip inside the γ (fcc) phase, causing the measured hardness increase. The results suggest possible innovative applications of the DMLS technique to the production of mechanical parts in the medical and dental fields. - Highlights: • Samples of a Co–Cr–Mo biomedical alloy were produced by direct metal laser sintering. • Hardness values unexpectedly high were attributed to a peculiar microstructure. • Fine lamellae of the ε-phase alternated to the γ-phase were observed for the first time. • A nucleation and growth model for the observed microstructure is proposed.

  11. Improvement in the surface quality of structural components produced by the RTM-process

    Energy Technology Data Exchange (ETDEWEB)

    Michaeli, W.; Dyckhoff, J. [Institute of Plastics Processing, Aachen (Germany)


    During the production of long or continuous fiber reinforced structural components in Resin Transfer Moulding (RTM), surface defects like voids, pinholes or unevenness frequently occur. These have to be repaired by manual labor before final painting. The conditions for the formation of voids in the laminate as well as surface defects are investigated by model experiments, making use of a window mould. Generally the resin is assumed to flow through the fiber reinforcement in a plug flow. The investigations indicate that advance either in the nonwovens of the surface or in the center of the laminate depends on the flow front velocity. This can be attributed to a superposition of capillary and flow effects. In order to obtain a high surface quality, the flow front velocity has to be kept within a material-related band width. Otherwise, areas of air enclosure in the laminate or surface defects like pinholes will result. With the aid of a steel mould with a large area, procedural variants are investigated to reduce surface faults and to decrease the air content in the laminate. The analysis indicates that the air content can be significantly reduced by injecting the resin into a cavity filled with gaseous acetone and increasing the cavity pressure during the time of curing. Furthermore the long and short-term waviness of the surface is improved by these process modifications.

  12. NUCLEAR REACTOR (United States)

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


    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.

  13. Bacterial structure of aerobic granules is determined by aeration mode and nitrogen load in the reactor cycle. (United States)

    Cydzik-Kwiatkowska, Agnieszka


    This study investigated how the microbial composition of biomass and kinetics of nitrogen conversions in aerobic granular reactors treating high-ammonium supernatant depended on nitrogen load and the number of anoxic phases in the cycle. Excellent ammonium removal and predomination of full nitrification was observed in the reactors operated at 1.1 kg TKN m(-3) d(-1) and with anoxic phases in the cycle. In all reactors, Proteobacteria and Actinobacteria predominated, comprising between 90.14% and 98.59% of OTUs. Extracellular polymeric substances-producing bacteria, such as Rhodocyclales, Xanthomonadaceae, Sphingomonadales and Rhizobiales, were identified in biomass from all reactors, though in different proportions. Under constant aeration, bacteria capable of autotrophic nitrification were found in granules, whereas under variable aeration heterotrophic nitrifiers such as Pseudomonas sp. and Paracoccus sp. were identified. Constant aeration promoted more even bacteria distribution among taxa; with 1 anoxic phase, Paracoccus aminophilus predominated (62.73% of OTUs); with 2 phases, Corynebacterium sp. predominated (65.10% of OTUs). Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Anaerobic co-digestion of biodiesel waste glycerin with municipal wastewater sludge: microbial community structure dynamics and reactor performance. (United States)

    Razaviarani, Vahid; Buchanan, Ian D


    Two 10 L completely mixed reactors operating at 37°C and 20 days SRT were used to evaluate the relationships between reactor performance and microbial community dynamics during anaerobic co-digestion of biodiesel waste glycerin (BWG) with municipal wastewater sludge (MWS). The addition of up to 1.35% (v/v) BWG to reactor feeds yielded increased VS and COD removal together with enhanced the biogas production and methane yield. This represented 50% of the MWS feed COD. Pyrosequencing analysis showed Methanosaeta (acetoclastic) and Methanomicrobium (hydrogenotrophic) to be the methanogenic genera present in greatest diversity during stable reactor operation. Methanosaeta sequences predominated at the lowest BWG loading while those of Methanomicrobium were present in greatest abundance at the higher BWG loadings. Genus Candidatus cloacamonas was present in the greatest number of bacterial sequences at all loadings. Alkalinity, pH, biogas production and methane yield declined and VFA concentrations (especially propionate) increased during the highest BWG loading. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Environmentally-assisted cracking in austenitic light water reactor structural materials. Final report of the KORA-I project

    Energy Technology Data Exchange (ETDEWEB)

    Seifert, H.-P.; Ritter, S


    The following document is the final report of the KORA-I project, which was performed at the Paul Scherrer Institute (PSI) between 2006 and 2008 and was funded by the Swiss Nuclear Safety Inspectorate (ENSI). The three sub-projects of KORA-I covered the experimental characterisation of the effect of the reactor coolant environment on fatigue initiation and crack growth in austenitic stainless steels under boiling and pressurised water reactor conditions, the experimental evaluation of the potential and limits of the electrochemical noise measurement technique for the early detection of stress corrosion cracking initiation in austenitic stainless steels under boiling water reactor/normal water chemistry conditions, as well as the characterisation of the stress corrosion crack growth behaviour in the fusion line region of an Alloy 182-low-alloy reactor pressure vessel steel dissimilar metal weld. The main scientific results and major conclusions of the three sub-projects are discussed in three independent parts of this report. (author)

  16. NUCLEAR REACTOR (United States)

    Grebe, J.J.


    High temperature reactors which are uniquely adapted to serve as the heat source for nuclear pcwered rockets are described. The reactor is comprised essentially of an outer tubular heat resistant casing which provides the main coolant passageway to and away from the reactor core within the casing and in which the working fluid is preferably hydrogen or helium gas which is permitted to vaporize from a liquid storage tank. The reactor core has a generally spherical shape formed entirely of an active material comprised of fissile material and a moderator material which serves as a diluent. The active material is fabricated as a gas permeable porous material and is interlaced in a random manner with very small inter-connecting bores or capillary tubes through which the coolant gas may flow. The entire reactor is divided into successive sections along the direction of the temperature gradient or coolant flow, each section utilizing materials of construction which are most advantageous from a nuclear standpoint and which at the same time can withstand the operating temperature of that particular zone. This design results in a nuclear reactor characterized simultaneously by a minimum critiral size and mass and by the ability to heat a working fluid to an extremely high temperature.

  17. Crystal Structure of a Group I Energy Coupling Factor Vitamin Transporter S Component in Complex with Its Cognate Substrate. (United States)

    Josts, Inokentijs; Almeida Hernandez, Yasser; Andreeva, Antonina; Tidow, Henning


    Energy coupling factor (ECF) transporters are responsible for the uptake of essential scarce nutrients in prokaryotes. This ATP-binding cassette transporter family comprises two subgroups that share a common architecture forming a tripartite membrane protein complex consisting of a translocation component and ATP hydrolyzing module and a substrate-capture (S) component. Here, we present the crystal structure of YkoE from Bacillus subtilis, the S component of the previously uncharacterized group I ECF transporter YkoEDC. Structural and biochemical analyses revealed the constituent residues of the thiamine-binding pocket as well as an unexpected mode of vitamin recognition. In addition, our experimental and bioinformatics data demonstrate major differences between YkoE and group II ECF transporters and indicate how group I vitamin transporter S components have diverged from other group I and group II ECF transporters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Crystal structure of Escherichia coli CusC, the outer membrane component of a heavy metal efflux pump. (United States)

    Kulathila, Rithika; Kulathila, Ragini; Indic, Mridhu; van den Berg, Bert


    While copper has essential functions as an enzymatic co-factor, excess copper ions are toxic for cells, necessitating mechanisms for regulating its levels. The cusCBFA operon of E. coli encodes a four-component efflux pump dedicated to the extrusion of Cu(I) and Ag(I) ions. We have solved the X-ray crystal structure of CusC, the outer membrane component of the Cus heavy metal efflux pump, to 2.3 Å resolution. The structure has the largest extracellular opening of any outer membrane factor (OMF) protein and suggests, for the first time, the presence of a tri-acylated N-terminal lipid anchor. The CusC protein does not have any obvious features that would make it specific for metal ions, suggesting that the narrow substrate specificity of the pump is provided by other components of the pump, most likely by the inner membrane component CusA.

  19. Nuclear reactor sealing system (United States)

    McEdwards, James A.


    A liquid metal-cooled nuclear reactor sealing system. The nuclear reactor includes a vessel sealed at its upper end by a closure head. The closure head comprises at least two components, one of which is rotatable; and the two components define an annulus therebetween. The sealing system includes at least a first and second inflatable seal disposed in series in an upper portion of the annulus. The system further includes a dip seal extending into a body of insulation located adjacent a bottom portion of the closure head. The dip seal comprises a trough formed by a lower portion of one of the components, and a seal blade pendently supported from the other component and extending downwardly into the trough. A body of liquid metal is contained in the trough which submerges a portion of the seal blade. The seal blade is provided with at least one aperture located above the body of liquid metal for providing fluid communication between the annulus intermediate the dip seal and the inflatable seals, and a body of cover gas located inside the vessel. There also is provided means for introducing a purge gas into the annulus intermediate the inflatable seals and the seal blade. The purge gas is introduced in an amount sufficient to substantially reduce diffusion of radioactive cover gas or sodium vapor up to the inflatable seals. The purge gas mixes with the cover gas in the reactor vessel where it can be withdrawn from the vessel for treatment and recycle to the vessel.

  20. Infographics as a Mnemonic structure: Analysis of the informative and identity components of infographic online compositions in Iberic newspapers


    Túñez-López, M. (Miguel); Nogueira, A.G. (Ana Gabriela)


    Infographics as a transdisciplinary component that permits to objectify depth that amplifies and potentiates time and space, is the proper structure for the reading characteristics of Net Generation and outputs the dynamic skills of visual intelligence, creating mnemonic frameworks. This article analyses the use of its Informative content, and its appliance to the qualities of Online Information (accurate, timely, complete and concise), its components of Identity (periodicity, animation, stat...

  1. Probabilistic Structural Analysis Methods for select space propulsion system components (PSAM). Volume 3: Literature surveys and technical reports (United States)


    The technical effort and computer code developed during the first year are summarized. Several formulations for Probabilistic Finite Element Analysis (PFEA) are described with emphasis on the selected formulation. The strategies being implemented in the first-version computer code to perform linear, elastic PFEA is described. The results of a series of select Space Shuttle Main Engine (SSME) component surveys are presented. These results identify the critical components and provide the information necessary for probabilistic structural analysis.

  2. Hydrodynamics of a Monolithic Stirrer Reactor

    NARCIS (Netherlands)

    Kritzinger, H.P.


    The Monolithic Stirrer Reactor (MSR) is a novel concept for heterogeneously catalyzed reactors and is presented as an alternative device to slurry reactors. It uses a modified stirrer on which structured catalyst supports (monoliths) are fixed to form permeable blades. The monoliths consist of small

  3. Chemical structure of the lipid A component of lipopolysaccharides of the genus Pectinatus. (United States)

    Helander, I M; Kilpeläinen, I; Vaara, M; Moran, A P; Lindner, B; Seydel, U


    The chemical structure of the lipid A components of smooth-type lipopolysaccharides isolated from the type strains of strictly anaerobic beer-spoilage bacteria Pectinatus cerevisiiphilus and Pectinatus frisingensis were analyzed. The hydrophilic backbone of lipid A was shown, by controlled degradation of lipopolysaccharide combined with chemical assays and 31P-NMR spectroscopy, to consist of the common beta 1-6-linked disaccharide of pyranosidic 2-deoxy-glucosamine (GlcN), phosphorylated at the glycosidic position and at position 4'. In de-O-acylated lipopolysaccharide, the latter phosphate was shown to be quantitatively substituted with 4-amino-4-deoxyarabinose, whereas the glycosidically linked phosphate was present as a monoester. Laser-desorption mass spectrometry of free dephosphorylated lipid A revealed that the distal (non-reducing) GlcN was substituted at positions 2' and 3' with (R)-3-(undecanoyloxy)tridecanoic acid, whereas the reducing GlcN carried two unsubstituted (R)-3-hydroxytetradecanoic acids at positions 2 and 3. The lipid A of both Pectinatus species were thus of the asymmetric hexaacyl type. The linkage of lipid A to polysaccharide in the lipopolysaccharide was relatively resistant to acid-catalyzed hydrolysis, enabling the preparation of a dephosphorylated and deacylated saccharide backbone. Methylation analysis of the backbone revealed that position 6' of the distal GlcN of lipid A was the attachment site of the polysaccharide. Despite the quantitative substitution of the lipid A 4'-phosphate by 4-amino-4-deoxyarabinose, which theoretically should render the bacteria resistant to polymyxin, P. cerevisiiphilus was shown to be susceptible to this antibiotic. P. cerevisiiphilus was, however, also susceptibile to vancomycin and bacitracin, indicating that the outer membrane of this bacterium does not act as an effective permeability barrier.

  4. Investigation of effective factors of transient thermal stress of the MONJU-System components

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Masaaki; Hirayama, Hiroshi; Kimura, Kimitaka; Jinbo, M. [Toshiba Corp., Kawasaki, Kanagawa (Japan)


    Transient thermal stress of each system Component in the fast breeder reactor is an uncertain factor on it's structural design. The temperature distribution in a system component changes over a wide range in time and in space. An unified evaluation technique of thermal, hydraulic, and structural analysis, in which includes thermal striping, temperature stratification, transient thermal stress and the integrity of the system components, is required for the optimum design of tho fast reactor plant. Thermal boundary conditions should be set up by both the transient thermal stress analysis and the structural integrity evaluation of each system component. The reasonable thermal boundary conditions for the design of the MONJU and a demonstration fast reactor, are investigated. The temperature distribution analysis models and the thermal boundary conditions on the Y-piece structural parts of each system component, such as reactor vessel, intermediate heat exchanger, primary main circulation pump, steam generator, superheater and upper structure of reactor core, are illustrated in the report. (M. Suetake)

  5. Principal component structure and sport-specific differences in the running one-leg vertical jump. (United States)

    Laffaye, G; Bardy, B G; Durey, A


    The aim of this study is to identify the kinetic principal components involved in one-leg running vertical jumps, as well as the potential differences between specialists from different sports. The sample was composed of 25 regional skilled athletes who play different jumping sports (volleyball players, handball players, basketball players, high jumpers and novices), who performed a running one-leg jump. A principal component analysis was performed on the data obtained from the 200 tested jumps in order to identify the principal components summarizing the six variables extracted from the force-time curve. Two principal components including six variables accounted for 78 % of the variance in jump height. Running one-leg vertical jump performance was predicted by a temporal component (that brings together impulse time, eccentric time and vertical displacement of the center of mass) and a force component (who brings together relative peak of force and power, and rate of force development). A comparison made among athletes revealed a temporal-prevailing profile for volleyball players, and a force-dominant profile for Fosbury high jumpers. Novices showed an ineffective utilization of the force component, while handball and basketball players showed heterogeneous and neutral component profiles. Participants will use a jumping strategy in which variables related to either the magnitude or timing of force production will be closely coupled; athletes from different sporting backgrounds will use a jumping strategy that reflects the inherent demands of their chosen sport.

  6. Two-Component Systems of Mycobacterium tuberculosisStructure-Based Approaches

    DEFF Research Database (Denmark)

    Tucker, Paul; Nowak, Elzbieta; Morth, Jens Preben


    Mycobacterium tuberculosis contains few two‐component systems compared to many other bacteria, possibly because it has more serine/threonine signaling pathways. Even so, these two‐component systems appear to play an important role in early intracellular survival of the pathogen as well as in aspe...

  7. Final Report on Isotope Ratio Techniques for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, David C.; Gesh, Christopher J.; Hurley, David E.; Mitchell, Mark R.; Meriwether, George H.; Reid, Bruce D.


    The Isotope Ratio Method (IRM) is a technique for estimating the energy or plutonium production in a fission reactor by measuring isotope ratios in non-fuel reactor components. The isotope ratios in these components can then be directly related to the cumulative energy production with standard reactor modeling methods.

  8. Liquid metal cooled nuclear reactor plant system (United States)

    Hunsbedt, Anstein; Boardman, Charles E.


    A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting for fuel decay during reactor shutdown, or heat produced during a mishap. The reactor system is enhanced with sealing means for excluding external air from contact with the liquid metal coolant leaking from the reactor vessel during an accident. The invention also includes a silo structure which resists attack by leaking liquid metal coolant, and an added unique cooling means.

  9. Long{sub t}erm performance of structural component of intermediate- and low-level radioactive waste disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Whang, J. H.; Kim, S. S.; Chun, T. H.; Lee, J. M.; Yum, M. O.; Kim, J. H.; Kim, M. S. [Kyunghee Univ., Seoul (Korea, Republic of)


    Underground repository for intermediate- and low-level radioactive waste is to be sealed and closed after operation. Structural components, which are generally made of cement concrete, are designed and accommodated in the repository for the purpose of operational convenience and stability after closure. To forecast the change of long-term integrity of the structural components, experimental verification, using in-situ or near in-situ conditions, is necessary. Domestic and foreign requirements with regard to the selection criteria and the performance criteria for structural components in disposal facility were surveyed. Characteristics of various types of cement were studied. Materials and construction methods of structural components similar to those of disposal facility was investigated and test items and methods for integrity of cement concrete were included. Literature survey for domestic groundwater characteristics was performed together with Ca-type bentonite ore which is a potential backfill material. Causes or factors affecting the durability of the cement structures were summarized. Experiments to figure out the ions leaching out from and migrating into cement soaked in distilled water and synthetic groundwater, respectively, were carried out. And finally, diffusion of chloride ion through cement was experimentally measured.

  10. Relation between growth rate and structure of graphene grown in a 4″ showerhead chemical vapor deposition reactor (United States)

    Bekdüz, B.; Beckmann, Y.; Meier, J.; Rest, J.; Mertin, W.; Bacher, G.


    The chemical vapor deposition (CVD) growth of graphene on copper is controlled by a complex interplay of substrate preparation, substrate temperature, pressure and flow of reactive gases. A large variety of recipes have been suggested in literature, often quite specific to the reactor, which is being used. Here, we report on a relation between growth rate and quality of graphene grown in a scalable 4″ CVD reactor. The growth rate is varied by substrate pre-treatment, chamber pressure, and methane to hydrogen (CH4:H2) ratio, respectively. We found that at lower growth rates graphene grains become hexagonal rather than randomly shaped, which leads to a reduced defect density and a sheet resistance down to 268 Ω/sq.

  11. Gas-cooled reactor programs: high-temperature gas-cooled reactor technology development program. Annual progress report for period ending December 31, 1981

    Energy Technology Data Exchange (ETDEWEB)


    Information is presented concerning HTGR chemistry; fueled graphite development; irradiation services for General Atomic Company; prestressed concrete pressure vessel development; HTGR structural materials; graphite development; high-temperature reactor physics studies; shielding studies; component flow test loop studies; core support performance test; and application and project assessments.

  12. Phenomenological and mechanistic modeling of melt-structure-water interactions in a light water reactor severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Bui, V.A


    The objective of this work is to address the modeling of the thermal hydrodynamic phenomena and interactions occurring during the progression of reactor severe accidents. Integrated phenomenological models are developed to describe the accident scenarios, which consist of many processes, while mechanistic modeling, including direct numerical simulation, is carried out to describe separate effects and selected physical phenomena of particular importance 88 refs, 54 figs, 7 tabs

  13. Small specimen test technology of fracture toughness in structural material F82H steel for fusion nuclear reactors


    若井 栄一; 大塚 英男; 松川 真吾; 安堂 正己; 實川 資朗


    Small specimen test technology (SSTT) has been developed to investigate mechanical properties of nuclear materials. SSTT has been driven by limited availability of effective irradiation volumes in test reactors and accelerator-based neutron and charged particle sources, and it is very useful for the reduction of waste materials produced in nuclear engineering. In this study new bend test machines have been developed to obtain fracture behaviors of F82H steel for very small bend specimens of p...

  14. Gray Correlation Analysis on the Relationship Between Colloidal Structure and Chemical Component of Asphalt Colloid and Performance

    Directory of Open Access Journals (Sweden)

    X. J. Cao


    Full Text Available Asphalt is considered a colloidal material and it is important to study the relationship between its colloidal structure, chemical components and performance. The aromatic nucleus content of asphalt at different depth analysed by attenuated total reflection (ATR was taken as the index of colloid structure. The gray correlation was used to analyse the relationship between colloidal structure and chemical components of asphalt gel and performance. The results show that the correlation degree between the index of colloidal structure and saturates and resins is high, which proves that saturates and resins play an important role in asphalt colloid structure. With regard to the asphalt performance indexes, the complex modulus G* and the tangent of the phase angle (tan δ have good correlation with the index of colloidal structure at the temperature of 30 – 70 °C but poor correlation at the temperature of 70 – 90 °C. Low temperature performance has a good correlation with colloid structure index, and tg can better reflect the characteristics of colloidal structure. The analysis shows that the colloidal structure of asphalt is a complex system and it is necessary to use more than one index to characterize the performance.

  15. Research on plasma core reactors (United States)

    Jarvis, G. A.; Barton, D. M.; Helmick, H. H.; Bernard, W.; White, R. H.


    Experiments and theoretical studies are being conducted for NASA on critical assemblies with one-meter diameter by one-meter long low-density cores surrounded by a thick beryllium reflector. These assemblies make extensive use of existing nuclear propulsion reactor components, facilities, and instrumentation. Due to excessive porosity in the reflector, the initial critical mass was 19 kg U(93.2). Addition of a 17 cm thick by 89 cm diameter beryllium flux trap in the cavity reduced the critical mass to 7 kg when all the uranium was in the zone just outside the flux trap. A mockup aluminum UF6 container was placed inside the flux trap and fueled with uranium-graphite elements. Fission distributions and reactivity worths of fuel and structural materials were measured. Finally, an 85,000 cu cm aluminum canister in the central region was fueled with UF6 gas and fission density distributions determined. These results are to be used to guide the design of a prototype plasma core reactor which will test energy removal by optical radiation.

  16. Reactor containment research and development

    Energy Technology Data Exchange (ETDEWEB)

    Weil, N. A.


    An outline is given of containment concepts, sources and release rates of energy, responses of containment structures, effects of projectiles, and leakage rates of radioisotopes, with particular regard to major reactor accidents. (T.F.H.)

  17. Reactor Neutrinos

    CERN Document Server

    Lasserre, T; Lasserre, Thierry; Sobel, Henry W.


    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 neutrino oscillation physics in the last years. It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the last undetermined neutrino mixing angle theta13. We conclude by opening on possible use of neutrinos for Society: NonProliferation of Nuclear materials and Geophysics.

  18. NEUTRONIC REACTORS (United States)

    Wigner, E.P.; Young, G.J.


    A method is presented for loading and unloading rod type fuel elements of a neutronic reactor of the heterogeneous, solld moderator, liquid cooled type. In the embodiment illustrated, the fuel rods are disposed in vertical coolant channels in the reactor core. The fuel rods are loaded and unloaded through the upper openings of the channels which are immersed in the coolant liquid, such as water. Unloading is accomplished by means of a coffer dam assembly having an outer sleeve which is placed in sealing relation around the upper opening. A radiation shield sleeve is disposed in and reciprocable through the coffer dam sleeve. A fuel rod engaging member operates through the axial bore in the radiation shield sleeve to withdraw the fuel rod from its position in the reactor coolant channel into the shield, the shield snd rod then being removed. Loading is accomplished in the reverse procedure.

  19. Interlocking multi-material components made of structured steel sheets and high-pressure die cast aluminium (United States)

    Senge, S.; Brachmann, J.; Hirt, G.; Bührig-Polaczek, A.


    Lightweight design is a major driving force of innovation, especially in the automotive industry. Using hybrid components made of two or more different materials is one approach to reduce the vehicles weight and decrease fuel consumption. As a possible way to increase the stiffness of multi-material components, this paper presents a process chain to produce such components made of steel sheets and high-pressure die cast aluminium. Prior to the casting sequence the steel sheets are structured in a modified rolling process which enables continuous interlocking with the aluminium. Two structures manufactured by this rolling process are tested. The first one is a channel like structure and the second one is a channel like structure with undercuts. These undercuts enable the formation of small anchors when the molten aluminium fills them. The correlation between thickness reduction during rolling and the shape of the resulting structure was evaluated for both structures. It can be stated that channels with a depth of up to 0.5 mm and a width of 1 mm could be created. Undercuts with different size depending on the thickness reduction could be realised. Subsequent aluminium high-pressure die casting experiments were performed to determine if the surface structure can be filled gap-free with molten aluminium during the casting sequence and if a gap-free connection can be achieved after contraction of the aluminium. The casting experiments showed that both structures could be filled during the high-pressure die casting. The channel like structure results in a gap between steel and aluminium after contraction of the cast metal whereas the structure with undercuts leads to a good interlocking resulting in a gap-free connection.

  20. Non-linear modal analysis of structural components subjected to unilateral constraints (United States)

    Attar, M.; Karrech, A.; Regenauer-Lieb, K.


    In this paper, we present a detailed numerical study of the non-linear dynamics in structural components under unilateral contact constraints. Here, the unilateral term characterises the constitutive law of the restoring force in the constraints as they only sustain elastic reactions in one direction, either compressive or tensile. Thus, the non-differentiability of the contact law at the discontinuity point is the only source of non-linearity. In our approach, the discrete lattice method (DLM) is used to treat the continuous system as a piecewise linear model. Thus, the trajectory of each node in the discrete model would be a sequence of smooth solutions with the switching times between them. The application of the one-step integration scheme allows us to detect the occurrence of contact (i.e. the instants that the lattice nodes cross the discontinuity boundary) and consequently update the active constraints. We also consider embedding the bisection algorithm into the time integration procedure to localise the instants at which the nodes cross the boundary and minimise the accumulative error. Subsequently, the resulting unconditionally stable integration scheme is utilised as the modelling tool in combination with the shooting technique to perform a novel non-smooth modal analysis. In analogy with the smooth non-linear systems, the evolution of non-smooth periodic motions is presented in the frequency-stiffness plots. We apply our method to obtain non-linear normal modes (NNMs) for a number of representative problems, including a bar-obstacle system, a beam-substrate system and a granular chain with tensionless interactions. These numerical examples demonstrate the efficiency of the solution procedure to trace the family of energy-independent non-linear modes across the range of contact stiffnesses. Moreover, the stability analysis of the modes on the plot backbone reveal that they may become unstable due to the interaction with the higher modes or bifurcation of

  1. Three-component assembly of structurally diverse 2-aminopyrimidine-5-carbonitriles. (United States)

    Val, Cristina; Crespo, Abel; Yaziji, Vicente; Coelho, Alberto; Azuaje, Jhonny; El Maatougui, Abdelaziz; Carbajales, Carlos; Sotelo, Eddy


    An expedient route for the synthesis of libraries of diversely decorated 2-aminopyrimidine-5-carbonitriles is reported. This approach is based on a three-component reaction followed by spontaneous aromatization.

  2. Updating of ASME Nuclear Code Case N-201 to Accommodate the Needs of Metallic Core Support Structures for High Temperature Gas Cooled Reactors Currently in Development

    Energy Technology Data Exchange (ETDEWEB)

    Mit Basol; John F. Kielb; John F. MuHooly; Kobus Smit


    On September 29, 2005, ASME Standards Technology, LLC (ASME ST-LLC) executed a multi-year, cooperative agreement with the United States DOE for the Generation IV Reactor Materials project. The project's objective is to update and expand appropriate materials, construction, and design codes for application in future Generation IV nuclear reactor systems that operate at elevated temperatures. Task 4 was embarked upon in recognition of the large quantity of ongoing reactor designs utilizing high temperature technology. Since Code Case N-201 had not seen a significant revision (except for a minor revision in September, 2006 to change the SA-336 forging reference for 304SS and 316SS to SA-965 in Tables 1.2(a) and 1.2(b), and some minor editorial changes) since December 1994, identifying recommended updates to support the current high temperature Core Support Structure (CSS) designs and potential new designs was important. As anticipated, the Task 4 effort identified a number of Code Case N-201 issues. Items requiring further consideration range from addressing apparent inconsistencies in definitions and certain material properties between CC-N-201 and Subsection NH, to inclusion of additional materials to provide the designer more flexibility of design. Task 4 developed a design parameter survey that requested input from the CSS designers of ongoing high temperature gas cooled reactor metallic core support designs. The responses to the survey provided Task 4 valuable input to identify the design operating parameters and future needs of the CSS designers. Types of materials, metal temperature, time of exposure, design pressure, design life, and fluence levels were included in the Task 4 survey responses. The results of the survey are included in this report. This research proves that additional work must be done to update Code Case N-201. Task 4 activities provide the framework for the Code Case N-201 update and future work to provide input on materials. Candidate

  3. Temperature-controlled structure and kinetics of ripple phases in one- and two-component supported lipid bilayers

    DEFF Research Database (Denmark)

    Kaasgaard, Thomas; Leidy, Chad; Crowe, J.H.


    ripples was seen. From height profiles of the AFM images, estimates of the amplitudes of the different ripple phases are reported. To elucidate the processes of ripple formation and disappearance, a ripple-phase DPPC lipid bilayer was taken through the pretransition in the cooling and the heating......Temperature-controlled atomic force microscopy (AFM) has been used to visualize and study the structure and kinetics of ripple phases in one-component dipalmitoylphosphaticlylcholine (DPPC) and two-component dimyristoylphosphatidylcholine-distearoylphosphatidylcholine (DMPC-DSPC) lipid bilayers....... The lipid bilayers are mica-supported double bilayers in which ripple-phase formation occurs in the top bilayer. In one-component DPPC lipid bilayers, the stable and metastable ripple phases were observed. In addition, a third ripple structure with approximately twice the wavelength of the metastable...

  4. Development of Structural Components of Future Technicians' Professional Competencies during Their Studies of General Disciplines in College (United States)

    Kopilov, Sergey N.; Dorozhkin, Evgenij M.; Tarasyuk, Olga V.; Osipova, Irina V.; Lazareva, Natalia V.


    The relevance of the problem stems from the necessity to develop and implement the formation model for structural components of future technicians' professional competencies during their studies of general professional disciplines. The purpose of the article is to carry out a theoretical study, to develop and approbate a model that forms the…

  5. Non-linear analysis in Light Water Reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Y.R.; Sharabi, M.N.; Nickell, R.E.; Esztergar, E.P.; Jones, J.W.


    The results obtained from a scoping study sponsored by the US Department of Energy (DOE) under the Light Water Reactor (LWR) Safety Technology Program at Sandia National Laboratories are presented. Basically, this project calls for the examination of the hypothesis that the use of nonlinear analysis methods in the design of LWR systems and components of interest include such items as: the reactor vessel, vessel internals, nozzles and penetrations, component support structures, and containment structures. Piping systems are excluded because they are being addressed by a separate study. Essentially, the findings were that nonlinear analysis methods are beneficial to LWR design from a technical point of view. However, the costs needed to implement these methods are the roadblock to readily adopting them. In this sense, a cost-benefit type of analysis must be made on the various topics identified by these studies and priorities must be established. This document is the complete report by ANATECH International Corporation.

  6. Design and R&D Progress of China Lead-Based Reactor for ADS Research Facility

    Directory of Open Access Journals (Sweden)

    Yican Wu


    Full Text Available In 2011, the Chinese Academy of Sciences launched an engineering project to develop an accelerator-driven subcritical system (ADS for nuclear waste transmutation. The China Lead-based Reactor (CLEAR, proposed by the Institute of Nuclear Energy Safety Technology, was selected as the reference reactor for ADS development, as well as for the technology development of the Generation IV lead-cooled fast reactor. The conceptual design of CLEAR-I with 10 MW thermal power has been completed. KYLIN series lead-bismuth eutectic experimental loops have been constructed to investigate the technologies of the coolant, key components, structural materials, fuel assembly, operation, and control. In order to validate and test the key components and integrated operating technology of the lead-based reactor, the lead alloy-cooled non-nuclear reactor CLEAR-S, the lead-based zero-power nuclear reactor CLEAR-0, and the lead-based virtual reactor CLEAR-V are under realization.

  7. Nonlinear dynamic response analysis of localized damaged laminated composite structures in the context of component mode synthesis (United States)

    Mahmoudi, S.; Trivaudey, F.; Bouhaddi, N.


    The aim of this study is the prediction of the dynamic response of damaged laminated composite structures in the context of component mode synthesis. Hence, a method of damage localization of complex structures is proposed. The dynamic behavior of transversely isotropic layers is expressed through elasticity coupled with damage based on an existing macro model for cracked structures. The damage is located only in some regions of the whole structure, which is decomposed on substructures. The incremental linear dynamic governing equations are obtained by using the classical linear Kirchhoff-Love theory of plates. Then, considering the damage-induced nonlinearity, the obtained nonlinear dynamic equations are solved in time domain. However, a detailed finite element modelling of such structure on the scale of localized damage would generate very high computational costs. To reduce this cost, Component Mode Synthesis method (CMS) is used for modelling a nonlinear fine-scale substructure damaged, connected to linear dynamic models of the remaining substructures, which can be condensed and not updated at each iteration. Numerical results show that the mechanical properties of the structure highly change when damage is taken into account. Under an impact load, damage increases and reaches its highest value with the maximum of the applied load and then remains unchanged. Besides, the eigenfrequencies of the damaged structure decrease comparing with those of an undamaged one. This methodology can be used for monitoring strategies and lifetime estimations of hybrid complex structures due to the damage state is known in space and time.

  8. Advanced burner test reactor preconceptual design report.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y. I.; Finck, P. J.; Grandy, C.; Cahalan, J.; Deitrich, L.; Dunn, F.; Fallin, D.; Farmer, M.; Fanning, T.; Kim, T.; Krajtl, L.; Lomperski, S.; Moisseytsev, A.; Momozaki, Y.; Sienicki, J.; Park, Y.; Tang, Y.; Reed, C.; Tzanos, C; Wiedmeyer, S.; Yang, W.; Chikazawa, Y.; JAEA


    advanced fuel cycle; (2) To qualify the transuranics-containing fuels and advanced structural materials needed for a full-scale ABR; and (3) To support the research, development and demonstration required for certification of an ABR standard design by the U.S. Nuclear Regulatory Commission. The ABTR should also address the following additional objectives: (1) To incorporate and demonstrate innovative design concepts and features that may lead to significant improvements in cost, safety, efficiency, reliability, or other favorable characteristics that could promote public acceptance and future private sector investment in ABRs; (2) To demonstrate improved technologies for safeguards and security; and (3) To support development of the U.S. infrastructure for design, fabrication and construction, testing and deployment of systems, structures and components for the ABRs. Based on these objectives, a pre-conceptual design of a 250 MWt ABTR has been developed; it is documented in this report. In addition to meeting the primary and additional objectives listed above, the lessons learned from fast reactor programs in the U.S. and worldwide and the operating experience of more than a dozen fast reactors around the world, in particular the Experimental Breeder Reactor-II have been incorporated into the design of the ABTR to the extent possible.

  9. Design of single-winding energy-storage reactors for dc-to-dc converters using air-gapped magnetic-core structures (United States)

    Ohri, A. K.; Wilson, T. G.; Owen, H. A., Jr.


    A procedure is presented for designing air-gapped energy-storage reactors for nine different dc-to-dc converters resulting from combinations of three single-winding power stages for voltage stepup, current stepup and voltage stepup/current stepup and three controllers with control laws that impose constant-frequency, constant transistor on-time and constant transistor off-time operation. The analysis, based on the energy-transfer requirement of the reactor, leads to a simple relationship for the required minimum volume of the air gap. Determination of this minimum air gap volume then permits the selection of either an air gap or a cross-sectional core area. Having picked one parameter, the minimum value of the other immediately leads to selection of the physical magnetic structure. Other analytically derived equations are used to obtain values for the required turns, the inductance, and the maximum rms winding current. The design procedure is applicable to a wide range of magnetic material characteristics and physical configurations for the air-gapped magnetic structure.

  10. Nuclear Reactors and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. [eds.


    This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

  11. Neutronic reactor (United States)

    Wende, Charles W. J.; Babcock, Dale F.; Menegus, Robert L.


    A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

  12. Neutronic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Babcock, D.F.; Menegus, R.L.; Wende, C.W.


    A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

  13. Simultaneous bio-autotrophic reduction of perchlorate and nitrate in a sulfur packed bed reactor: Kinetics and bacterial community structure. (United States)

    Wan, Dongjin; Liu, Yongde; Wang, Yiyi; Wang, Hongjie; Xiao, Shuhu


    This study investigated the simultaneous removal of perchlorate and nitrate from aqueous solution in an up-flow sulfur autotrophic reduction reactor. A nitrate and perchlorate containing pollution solution was treated with a remarkable removal efficiency greater than 97%. The concentration of nitrate was 22.03 ± 1.07 mg-N/L coexisting with perchlorate either 21.87 ± 1.03 mg/L or 471.7 ± 50.3 μg/L, in this case the reactor could be operated at a hydraulic retention time (HRT) ranging from 12.00 h to 0.75 h. Half-order kinetics model fit the experimental data well; this indicates that diffusion in the biofilm was the limiting step. Perchlorate reduction required a longer reaction time than the coexisting nitrate, regardless of the perchlorate concentration. Sulfur (S) disproportionation was inhibited when nitrate was not completely removed; whereas it was accelerated when perchlorate decreased to low concentrations. This process therefore generated excessive sulfate and consumed much more alkalinity. High-throughput sequencing method was used to analyze bacterial community spatial distribution in the reactor under different operational conditions. The reduction of the two contaminants was accompanied by a decrease in biodiversity. The results indicated that Sulfuricella, Sulfuritalea Thiobacillus, and Sulfurimonas are effective DB (denitrification bacteria)/PRB (perchlorate reduction bacteria). The Chlorobaculum genus was the dominant bacteria associated with S disproportionation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A single frequency component-based re-estimated MUSIC algorithm for impact localization on complex composite structures (United States)

    Yuan, Shenfang; Bao, Qiao; Qiu, Lei; Zhong, Yongteng


    The growing use of composite materials on aircraft structures has attracted much attention for impact monitoring as a kind of structural health monitoring (SHM) method. Multiple signal classification (MUSIC)-based monitoring technology is a promising method because of its directional scanning ability and easy arrangement of the sensor array. However, for applications on real complex structures, some challenges still exist. The impact-induced elastic waves usually exhibit a wide-band performance, giving rise to the difficulty in obtaining the phase velocity directly. In addition, composite structures usually have obvious anisotropy, and the complex structural style of real aircrafts further enhances this performance, which greatly reduces the localization precision of the MUSIC-based method. To improve the MUSIC-based impact monitoring method, this paper first analyzes and demonstrates the influence of measurement precision of the phase velocity on the localization results of the MUSIC impact localization method. In order to improve the accuracy of the phase velocity measurement, a single frequency component extraction method is presented. Additionally, a single frequency component-based re-estimated MUSIC (SFCBR-MUSIC) algorithm is proposed to reduce the localization error caused by the anisotropy of the complex composite structure. The proposed method is verified on a real composite aircraft wing box, which has T-stiffeners and screw holes. Three typical categories of 41 impacts are monitored. Experimental results show that the SFCBR-MUSIC algorithm can localize impact on complex composite structures with an obviously improved accuracy.

  15. Interaction-component analysis of the effects of urea and its alkylated derivatives on the structure of T4-lysozyme (United States)

    Yamamori, Yu; Matubayasi, Nobuyuki


    The effects of urea and its alkylated derivatives on the structure of T4-lysozyme were analyzed from the standpoint of energetics. Molecular dynamics simulations were conducted with explicit solvent, and the energy-representation method was employed to compute the free energy of transfer of the protein from pure-water solvent to the mixed solvents of water with urea, methylurea, 1,1-dimethylurea, and isopropylurea. Through the decomposition of the transfer free energy into the cosolvent and water contributions, it was observed that the former is partially cancelled by the latter and governs the total free energy of transfer. To determine the interaction component responsible for the transfer energetics, the correlations of the transfer free energy were also examined against the change in the solute-solvent interaction energy upon transfer and the corresponding changes in the electrostatic, van der Waals, and excluded-volume components. It was then found over the set of protein structures ranging from native to (partially) unfolded ones that the transfer free energy changes in parallel with the van der Waals component even when the cosolvent is alkylated. The electrostatic and excluded-volume components play minor roles in the structure modification of the protein, and the denaturing ability of alkylurea is brought by the van der Waals interaction.

  16. Methods of assessing the effects of interface oxide growth in Magnox and advanced gas-cooled reactor plant

    Energy Technology Data Exchange (ETDEWEB)

    McLauchlin, I.R.; Wooton, M.R.; Morgan, J.D.; Watson, L.H.


    Growth of oxide at interfaces between structural steel components in CO/sub 2/-cooled reactors can deform fastenings such as bolts and welds. The mechanical response of joint members to oxide growth is discussed, and methods of assessment are outlined which contribute to procedures for ensuring continued structural integrity.

  17. Structure and distribution of inorganic components in the cake layer of a membrane bioreactor treating municipal wastewater. (United States)

    Zhou, Lijie; Xia, Siqing; Alvarez-Cohen, Lisa


    A laboratory-scale submerged anoxic-oxic membrane bioreactor treating municipal wastewater was operated to investigate the structure and distribution of the inorganic cake layer buildup on the membrane. BCR (European Community Bureau of Reference) sequential extraction, X-ray photoelectron spectroscopy (XPS), and both map and line scan of energy-dispersive X-ray analysis (EDX) were performed for cake layer characterization. BCR results showed that Si, Al, Ca, Mg, Fe, and Ba were the predominant inorganic elements in the cake layer, and they occurred mostly as crystal particles. Crystal SiO2 was the dominant inorganic compound while Ca in the form of CaSO4 (dominant) and CaCO3 were also present, but exerted little effect on the cake layer structure because most of these compounds were deposited as precipitates on the reactor bottom. EDX results indicated that Si and Al accumulated together along the cross-sectional cake layer in the form of Si-Al (SiO2-Al2O3) crystal particles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The polysaccharide and low molecular weight components of Opuntia ficus indica cladodes: Structure and skin repairing properties. (United States)

    Di Lorenzo, Flaviana; Silipo, Alba; Molinaro, Antonio; Parrilli, Michelangelo; Schiraldi, Chiara; D'Agostino, Antonella; Izzo, Elisabetta; Rizza, Luisa; Bonina, Andrea; Bonina, Francesco; Lanzetta, Rosa


    The Opuntia ficus-indica multiple properties are reflected in the increasing interest of chemists in the identification of its natural components having pharmaceutical and/or cosmetical applications. Here we report the structural elucidation of Opuntia ficus-indica mucilage that highlighted the presence of components differing for their chemical nature and the molecular weight distribution. The high molecular weight components were identified as a linear galactan polymer and a highly branched xyloarabinan. The low molecular weight components were identified as lactic acid, D-mannitol, piscidic, eucomic and 2-hydroxy-4-(4'-hydroxyphenyl)-butanoic acids. A wound healing assay was performed in order to test the cicatrizing properties of the various components, highlighting the ability of these latter to fasten dermal regeneration using a simplified in vitro cellular model based on a scratched keratinocytes monolayer. The results showed that the whole Opuntia mucilage and the low molecular weight components are active in the wound repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Aging of reactor vessels in LWR type reactors; Envejecimiento de la vasija y de los internos del nuclear de los reactores tipo LWR

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Briceno, D.; Lapena, J.; Serrano, M.


    Most of the degradation mechanisms of nuclear components were not included on the design so they have to be treated a posteriori, and that imply a loss of capacity. In this paper the state of the art on the reactor pressure vessel neutron embrittlement and on the irradiation assisted stress corrosion cracking that affects internal components, are explained. Special attention is devoted on the influence of the neutron fluence on IASCC process, on the material alterations promoted by irradiation and their consequences on the susceptibility to this phenomenon. Regarding the reactor pressure vessel degradation, this paper discuss the application of the Master Curve on the structural integrity evaluation of the vessel. Other aspects related to further developments are also mentioned and the importance of a good materials ageing management on the operation of the plant is pointed out. (Author) 12 refs.

  20. Structural damage continuous monitoring by using a data driven approach based on principal component analysis and cross-correlation analysis (United States)

    Camacho-Navarro, Jhonatan; Ruiz, Magda; Villamizar, Rodolfo; Mujica, Luis; Moreno-Beltrán, Gustavo; Quiroga, Jabid


    Continuous monitoring for damage detection in structural assessment comprises implementation of low cost equipment and efficient algorithms. This work describes the stages involved in the design of a methodology with high feasibility to be used in continuous damage assessment. Specifically, an algorithm based on a data-driven approach by using principal component analysis and pre-processing acquired signals by means of cross-correlation functions, is discussed. A carbon steel pipe section and a laboratory tower were used as test structures in order to demonstrate the feasibility of the methodology to detect abrupt changes in the structural response when damages occur. Two types of damage cases are studied: crack and leak for each structure, respectively. Experimental results show that the methodology is promising in the continuous monitoring of real structures.

  1. Two-component injection moulding simulation of ABS-POM micro structured surfaces

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Islam, Aminul


    a pair of thermoplastic materials (ABS and POM) were conducted. Three dimensional process simulations based on the finite element method have been performed to explore the capability of predicting filling pattern shape at component-level and surface micro feature-level in a polymer/polymer overmoulding...

  2. Microbial community structure of a simultaneous nitrogen and phosphorus removal reactor following treatment in a UASB-DHS system. (United States)

    Hatamoto, Masashi; Saito, Yayoi; Dehama, Kazuya; Nakahara, Nozomi; Kuroda, Kyohei; Takahashi, Masanobu; Yamaguchi, Takashi


    The anaerobic-anoxic sequence batch reactor (A2SBR) was applied to achieve nitrogen and phosphorus removal in an energy-saving sewage treatment system involving an up-flow anaerobic sludge blanket combined with a down-flow hanging sponge reactor to treat municipal sewage. After sludge acclimation, the A2SBR showed satisfactory denitrification and phosphorus removal performance with total phosphate and nitrate concentrations of the effluent of 8.4 ± 3.4 mg-N L⁻¹ and 0.9 ± 0.6 mg-P L⁻¹, respectively. 16S rRNA gene sequence and fluorescence in situ hybridization analyses revealed that 'Candidatus Accumulibacter phosphatis' was the dominant phosphate-accumulating micro-organism. Although a competitive bacterium for polyphosphate-accumulating organisms, 'Ca. Competibacter phosphatis', was not detected, Dechloromonas spp. were abundant. The ppk1 gene sequence analysis showed that the type II lineage of 'Ca. Accumulibacter' was dominant. The results suggest that denitrification and phosphorus removal in the A2SBR could be achieved by cooperative activity of 'Ca. Accumulibacter' and nitrate-reducing bacteria.

  3. Analysis of Nonlinear Soil-Structure Interaction Effects on the response of Three-Dimensional Frame Structures using a One-Direction Three-ComponentWave Propagation Model

    CERN Document Server

    d'Avila, Maria Paola Santisi


    In this paper, a model of one-directional propagation of three-component seismic waves in a nonlinear multilayered soil profile is coupled with a multi-story multi-span frame model to consider, in a simple way, the soil-structure interaction modelled in a finite element scheme. Modeling the three-component wave propagation enables the effects of a soil multiaxial stress state to be taken into account. These reduce soil strength and increase nonlinear effects, compared with the axial stress state. The simultaneous propagation of three components allows the prediction of the incident direction of seismic loading at the ground surface and the analysis of the behavior of a frame structure shaken by a three-component earthquake. A parametric study is carried out to characterize the changes in the ground motion due to dynamic features of the structure, for different incident wavefield properties and soil nonlinear effects. A seismic response depending on parameters such as the frequency content of soil and structur...

  4. Distribution, structure and diversity of “bacterial” genes encoding two-component proteins in the Euryarchaeota

    Directory of Open Access Journals (Sweden)

    Mark K. Ashby


    Full Text Available The publicly available annotated archaeal genome sequences (23 complete and three partial annotations, October 2005 were searched for the presence of potential two-component open reading frames (ORFs using gene category lists and BLASTP. A total of 489 potential two-component genes were identified from the gene category lists and BLASTP. Two-component genes were found in 14 of the 21 Euryarchaeal sequences (October 2005 and in neither the Crenarchaeota nor the Nanoarchaeota. A total of 20 predicted protein domains were identified in the putative two-component ORFs that, in addition to the histidine kinase and receiver domains, also includes sensor and signalling domains. The detailed structure of these putative proteins is shown, as is the distribution of each class of two-component genes in each species. Potential members of orthologous groups have been identified, as have any potential operons containing two or more two-component genes. The number of two-component genes in those Euryarchaeal species which have them seems to be linked more to lifestyle and habitat than to genome complexity, with most examples being found in Methanospirillum hungatei, Haloarcula marismortui, Methanococcoides burtonii and the mesophilic Methanosarcinales group. The large numbers of two-component genes in these species may reflect a greater requirement for internal regulation. Phylogenetic analysis of orthologous groups of five different protein classes, three probably involved in regulating taxis, suggests that most of these ORFs have been inherited vertically from an ancestral Euryarchaeal species and point to a limited number of key horizontal gene transfer events.

  5. Heat transfer and structure stress analysis of micro packaging component of high power light emitting diode

    Directory of Open Access Journals (Sweden)

    Hsu Chih-Neng


    Full Text Available This paper focuses on the heat transfer and structural stress analysis of the micro- scale packaging structure of a high-power light emitting diode. The thermal-effect and thermal-stress of light emitting diode are determined numerically. Light emitting diode is attached to the silicon substrate through the wire bonding process by using epoxy as die bond material. The silicon substrate is etched with holes at the bottom and filled with high conductivity copper material. The chip temperature and structure stress increase with input power consumption. The micro light emitting diode is mounted on the heat sink to increase the heat dissipation performance, to decrease chip temperature, to enhance the material structure reliability and safety, and to avoid structure failure as well. This paper has successfully used the finite element method to the micro-scale light emitting diode heat transfer and stress concentration at the edges through etched holes.

  6. Further development of the structure mechanics analysis method for the calculation of the structure reliability of passive components, phase II. Final report; Weiterentwicklung der strukturmechanischen Analysemethodik zur Bestimmung der Strukturzuverlaessigkeit passiver Komponenten, Phase II. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Grebner, H.; Wang, Y.; Schmipfke, T.; Sievers, J.


    Within the framework of research project RS 1163 the computer code PROST for the quantitative assessment of the structural reliability of pipe components has been further developed. Thereby models were provided and tested for the consideration of the damage mechanism 'corrosion' to determine leak and break probabilities in cylindrical structures of ferritic and austenitic reactor steels. These models are now additionally available to the model for the consideration of the damage mechanism 'fatigue'. Furthermore, the application range of the code was extended to complex geometries in regards to loading and boundary conditions. Additional code modules were developed to be able to include the results of finite element (FE) calculations. The extended analysis method was tested, amongst others, in the context of calculations for a cracked feedwater nozzle of a steam generator under thermal-mechanical cyclic loading. The stress on cracks was calculated with the FE-method. For the determination of leak probabilities the crack growth due to fatigue was estimated taking into account the ''mixed-mode'' - loading within the J-integral vector approach. Altogether, the analyses show that with the provided flexible probabilistic analysis method quantitative determination of leak probabilities of a detected or postulated crack in a complex structure geometry under thermal-mechanical loading as function of the operating time in the range of very small probability values (<1.0 E-8) to large values (>1.0 E-2) are possible. The next development steps should comprise especially the improvement of the accuracy of the method to determine break probabilities and also the consideration of approaches on crack formation due to the damage mechanisms 'fatigue' and 'corrosion', based on evaluations of national and international operating experiences.

  7. On estimating the fracture probability of nuclear graphite components (United States)

    Srinivasan, Makuteswara


    The properties of nuclear grade graphites exhibit anisotropy and could vary considerably within a manufactured block. Graphite strength is affected by the direction of alignment of the constituent coke particles, which is dictated by the forming method, coke particle size, and the size, shape, and orientation distribution of pores in the structure. In this paper, a Weibull failure probability analysis for components is presented using the American Society of Testing Materials strength specification for nuclear grade graphites for core components in advanced high-temperature gas-cooled reactors. The risk of rupture (probability of fracture) and survival probability (reliability) of large graphite blocks are calculated for varying and discrete values of service tensile stresses. The limitations in these calculations are discussed from considerations of actual reactor environmental conditions that could potentially degrade the specification properties because of damage due to complex interactions between irradiation, temperature, stress, and variability in reactor operation.



    Vladimir I. Freyman


    The aim of the study is to present new methods of quality results assessment of the education corresponding to requirements of Federal State Educational Standards (FSES) of the Third Generation developed for the higher school. The urgency of search of adequate tools for quality competency measurement and its elements formed in the course of experts’ preparation are specified. Methods. It is necessary to consider interference of competency components such as knowledge, abilities, possession in...

  9. [Changes in chemistry component structure and microstructure characterization of acetylated wood before and after UV radiation]. (United States)

    Fu, Zhan; Liu, Yi; Xing, Fang-Ru; Guo, Hong-Wu


    The poplar powder was acetylated with different duration as sample, processed ray radiation by using ultraviolet test box, contrasting the influences to lightfastness of wood with different acetylation degree, analyzing changing rules of characteristic peaks' intensity which belonged to the chemistry components of samples based on FTIR spectra, and the relationship between duration of acetylation and changes of chemistry components was established, The results showed that: Before UV radiation, the characteristic peaks' intensity of acetylated poplar powder at 1 739 cm(-1) which belonged to C = O in saturated esters compounds and 1 385 cm(-1) which belonged to C-H in acetate were higher than untreated ones', the poplar powder with 40 min's acetylation has the highest characteristic peaks' intensity, highest weight gain rate, remarkable acetylation effect; After UV radiation, characteristic peaks' intensity of Benzene at 1 504 cm(-1) which belonged to lignin of poplar powder was obviously higher than untreated ones', and characteristic peaks' intensity of poplar powder with 40 min's acetylation was the highest, this showed that acetylation could effectively reduce the light degradation of wood chemistry components, in order to improve the lightfastness, especially the poplar powder with 40 min's acetylation; SEM photos showed that, the fibrous surface of acetylated poplar powder was more smooth and had more narrow particle size than untreated ones', so acetylation can effectively improve the stability of wood.

  10. Cellular convection in vertical annuli of fast breeder reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hemanath, M.G. [Fast Reactor Technology Group, Indira Gandhi Center for Atomic Research, Kalpakkam (India)], E-mail:; Meikandamurthy, C.; Ramakrishnan, V.; Rajan, K.K.; Rajan, M.; Vaidyanathan, G. [Fast Reactor Technology Group, Indira Gandhi Center for Atomic Research, Kalpakkam (India)


    In the pool type fast reactors the roof structure is penetrated by a number of pumps and heat exchangers that are cylindrical in shape. Sandwiched between the free surface of sodium and the roof structure, is stagnant argon gas, which can flow in the annular space between the components and roof structure, as a thermosyphon. These thermosyphons not only transport heat from sodium to roof structure, but also result in cellular convection in vertical annuli resulting in circumferential temperature asymmetry of the penetrating components. There is need to know the temperature asymmetry as it can cause tilting of the components. Experiments were carried out in an annulus model to predict the circumferential temperature difference with and without sodium in the test vessel. Three-dimensional analysis was also carried out using PHOENICS CFD code and compared with the experiment. This paper describes the experimental details, the theoretical analysis and their comparison.

  11. Structural changes of wood during hydro-thermal and thermal treatments evaluated through NIR spectroscopy and principal component analysis (United States)

    Popescu, Carmen-Mihaela; Navi, Parviz; Placencia Peña, María Inés; Popescu, Maria-Cristina


    Spruce wood samples were subjected to different conditions of thermal and hydro-thermal treatment by varying the temperature, relative humidity and period of exposure. The obtained treated samples were evaluated using near infrared spectroscopy (NIR), principal component analysis (PCA) and hierarchical cluster analysis (HCA) in order to evidence the structural changes which may occur during the applied treatment conditions. Following this, modification in all wood components were observed, modifications which were dependent on the temperature, amount of relative humidity and also the treatment time. Therefore, higher variations were evidenced for samples treated at higher temperatures and for longer periods. At the same time, the increase in the amount of water vapours in the medium induced a reduced rate of side chains and condensation reactions occurring in the wood structure. Further, by PCA and HCA was possible to discriminate the modifications in the wood samples according to treatment time and amount of relative humidity.

  12. A Procedure for Determination of Degradation Acceptance Criteria for Structures and Passive Components in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Nie, J.; Braverman, J.; Hofmayer, C.; Choun, Y-S.; Hahm, D.; Choi, I-K.


    The Korea Atomic Energy Research Institute (KAERI) has been collaborating with Brookhaven National Laboratory since 2007 to develop a realistic seismic risk evaluation system which includes the consideration of aging of structures and components in nuclear power plants (NPPs). This collaboration program aims at providing technical support to a five-year KAERI research project, which includes three specific areas that are essential to seismic probabilistic risk assessment: (1) probabilistic seismic hazard analysis, (2) seismic fragility analysis including the effects of aging, and (3) a plant seismic risk analysis. The understanding and assessment of age-related degradations of structures, systems, and components and their impact on plant safety is the major goal of this KAERI-BNL collaboration. Four annual reports have been published before this report as a result of the collaboration research.

  13. Coupling Neumann development and component mode synthesis methods for stochastic analysis of random structures

    Directory of Open Access Journals (Sweden)

    Driss Sarsri


    Full Text Available In this paper, we propose a method to calculate the first two moments (mean and variance of the structural dynamics response of a structure with uncertain variables and subjected to random excitation. For this, Newmark method is used to transform the equation of motion of the structure into a quasistatic equilibrium equation in the time domain. The Neumann development method was coupled with Monte Carlo simulations to calculate the statistical values of the random response. The use of modal synthesis methods can reduce the dimensions of the model before integration of the equation of motion. Numerical applications have been developed to highlight effectiveness of the method developed to analyze the stochastic response of large structures.

  14. Automated Design and Analysis Tool for CLV/CEV Composite and Metallic Structural Components Project (United States)

    National Aeronautics and Space Administration — The innovation of the proposed effort is a unique automated process for the analysis, design, and sizing of CLV/CEV composite and metallic structures. This developed...

  15. Automated Design and Analysis Tool for CEV Structural and TPS Components Project (United States)

    National Aeronautics and Space Administration — The innovation of the proposed effort is a unique automated process for the analysis, design, and sizing of CEV structures and TPS. This developed process will...

  16. Structural Characterization of Outer Membrane Components of the Type IV Pili System in Pathogenic Neisseria

    NARCIS (Netherlands)

    Jain, Samta; Moscicka, Katarzyna B.; Bos, Martine P.; Pachulec, Emilia; Stuart, Marc C. A.; Keegstra, Wilko; Boekema, Egbert J.; van der Does, Chris; B. Mościcka, K.; Ahmed, Niyaz


    Structures of the type IV pili secretin complexes from Neisseria gonorrhoeae and Neisseria meningitidis, embedded in outer membranes were investigated by transmission electron microscopy. Single particle averaging revealed additional domains not observed previously. Secretin complexes of N.

  17. Reactor Dosimetry State of the Art 2008 (United States)

    Voorbraak, Wim; Debarberis, Luigi; D'Hondt, Pierre; Wagemans, Jan


    Oral session 1: Retrospective dosimetry. Retrospective dosimetry of VVER 440 reactor pressure vessel at the 3rd unit of Dukovany NPP / M. Marek ... [et al.]. Retrospective dosimetry study at the RPV of NPP Greifswald unit 1 / J. Konheiser ... [et al.]. Test of prototype detector for retrospective neutron dosimetry of reactor internals and vessel / K. Hayashi ... [et al.]. Neutron doses to the concrete vessel and tendons of a magnox reactor using retrospective dosimetry / D. A. Allen ... [et al.]. A retrospective dosimetry feasibility study for Atucha I / J. Wagemans ... [et al.]. Retrospective reactor dosimetry with zirconium alloy samples in a PWR / L. R. Greenwood and J. P. Foster -- Oral session 2: Experimental techniques. Characterizing the Time-dependent components of reactor n/y environments / P. J. Griffin, S. M. Luker and A. J. Suo-Anttila. Measurements of the recoil-ion response of silicon carbide detectors to fast neutrons / F. H. Ruddy, J. G. Seidel and F. Franceschini. Measurement of the neutron spectrum of the HB-4 cold source at the high flux isotope reactor at Oak Ridge National Laboratory / J. L. Robertson and E. B. Iverson. Feasibility of cavity ring-down laser spectroscopy for dose rate monitoring on nuclear reactor / H. Tomita ... [et al.]. Measuring transistor damage factors in a non-stable defect environment / D. B. King ... [et al.]. Neutron-detection based monitoring of void effects in boiling water reactors / J. Loberg ... [et al.] -- Poster session 1: Power reactor surveillance, retrospective dosimetry, benchmarks and inter-comparisons, adjustment methods, experimental techniques, transport calculations. Improved diagnostics for analysis of a reactor pulse radiation environment / S. M. Luker ... [et al.]. Simulation of the response of silicon carbide fast neutron detectors / F. Franceschini, F. H. Ruddy and B. Petrović. NSV A-3: a computer code for least-squares adjustment of neutron spectra and measured dosimeter responses / J. G

  18. Lead-Cooled Fast Reactor (LFR) Design: Safety, Neutronics, Thermal Hydraulics, Structural Mechanics, Fuel, Core, and Plant Design

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C


    The idea of developing fast spectrum reactors with molten lead (or lead alloy) as a coolant is not a new one. Although initially considered in the West in the 1950s, such technology was not pursued to completion because of anticipated difficulties associated with the corrosive nature of these coolant materials. However, in the Soviet Union, such technology was actively pursued during the same time frame (1950s through the 1980s) for the specialized role of submarine propulsion. More recently, there has been a renewal of interest in the West for such technology, both for critical systems as well as for Accelerator Driven Subcritical (ADS) systems. Meanwhile, interest in the former Soviet Union, primarily Russia, has remained strong and has expanded well beyond the original limited mission of submarine propulsion. This section reviews the past and current status of LFR development.

  19. Synthesis of Core@Shell Nanostructures in a Continuous Flow Droplet Reactor: Controlling Structure through Relative Flow Rates. (United States)

    Santana, Joshua S; Koczkur, Kallum M; Skrabalak, Sara E


    Bimetallic nanostructures are primarily synthesized in small volume batches. However, droplet-based reactors are receiving attention due to their ability to maintain thermal and compositional equilibrium within and between droplets, enabling flow operations for inline analyses and the scale-up of nanomaterial syntheses. Here, the syntheses of shape-controlled core@shell Au@Pd nanostructures with variable shell thicknesses are reported through control of the relative flow rates of reagents within the microreactor. Specifically, Pd shells were grown on cubic or octahedral Au seeds, selected as a model system. In batch reactions, shell thickness is determined by precursor concentration; however, as shown here, precursor feedstock concentration can be held constant, with the precursor concentration within the droplets being controlled through relative flow rates. This approach allows process conditions to be modified inline rather than from batch to batch to achieve particles with different shell thicknesses, and this procedure should be applicable to other multicomponent systems.

  20. Super-Hamiltonian Structures and Conservation Laws of a New Six-Component Super-Ablowitz-Kaup-Newell-Segur Hierarchy

    Directory of Open Access Journals (Sweden)

    Fucai You


    Full Text Available A six-component super-Ablowitz-Kaup-Newell-Segur (-AKNS hierarchy is proposed by the zero curvature equation associated with Lie superalgebras. Supertrace identity is used to furnish the super-Hamiltonian structures for the resulting nonlinear superintegrable hierarchy. Furthermore, we derive the infinite conservation laws of the first two nonlinear super-AKNS equations in the hierarchy by utilizing spectral parameter expansions. PACS: 02.30.Ik; 02.30.Jr; 02.20.Sv.