French R&D on Materials for the Core Components of SFRs

International Nuclear Information System (INIS)

Le Flem, M.; Séran, J.L.; Blat-Yrieix, M.; Garat, V.

2013-01-01

ASTRID demonstrator 480-700°C, 110 dpa. • Use of reference materials benefiniting from a large feed-back from the previous French SFRs (Rapsodie, Phénix, SuperPhénix) • Austenitic steels (cladding), Martensitic steels (wrapper tube), B4C (absorbers). • Improving the description of their behavior (swelling, high temperature) • Qualifying the materials regarding the specificities of ASTRID core. Future SFRs 530-750, 180 dpa. • Use of advanced materials with improved properties • ODS ferritic/martensitic steels (cladding), Other metallic solutions as V alloys (cladding), SiC/SiC composites (wrapper tube), Innovative absorbers and reflectors. • R&D to develop/fabricate suitable grades • Qualifying these materials in ASTRID

In-situ synthetize multi-walled carbon nanotubes@MnO2 nanoflake core-shell structured materials for supercapacitors

Science.gov (United States)

Zheng, Huajun; Wang, Jiaoxia; Jia, Yi; Ma, Chun'an

2012-10-01

A new type of core-shell structured material consisting of multi-walled carbon nanotubes (MWCNTs) and manganese dioxide (MnO2) nanoflake is synthesized using an in-situ co-precipitation method. By scanning electron microscopy and transition electron microscope, it is confirmed that the core-shell nanostructure is formed by the uniform incorporation of birnessite-type MnO2 nanoflake growth round the surface of the activated-MWCNTs. That core-shell structured material electrode presents excellent electrochemical capacitance properties with the specific capacitance reaching 380 F g-1 at the current density of 5 A g-1 in 0.5 M Na2SO4 electrolyte. In addition, the electrode also exhibits good performance (the power density: 11.28 kW kg-1 at 5 A g-1) and long-term cycling stability (retaining 82.7% of its initial capacitance after 3500 cycles at 5 A g-1). It mainly attributes to MWCNTs not only providing considerable specific surface area for high mass loading of MnO2 nanoflakes to ensure effective utilization of MnO2 nanoflake, but also offering an electron pathway to improve electrical conductivity of the electrode materials. It is clearly indicated that such core-shell structured materials including MWCNTs and MnO2 nanoflake may find important applications for supercapacitors.

Fatigue Characterization of Fire Resistant Syntactic Foam Core Material

Science.gov (United States)

Hossain, Mohammad Mynul

Eco-Core is a fire resistant material for sandwich structural application; it was developed at NC A&T State University. The Eco-Core is made of very small amount of phenolic resin and large volume of flyash by a syntactic process. The process development, static mechanical and fracture, fire and toxicity safety and water absorption properties and the design of sandwich structural panels with Eco-Core material was established and published in the literature. One of the important properties that is needed for application in transportation vehicles is the fatigue performance under different stress states. Fatigue data are not available even for general syntactic foams. The objective of this research is to investigate the fatigue performance of Eco-Core under three types of stress states, namely, cyclic compression, shear and flexure, then document failure modes, and develop empherical equations for predicting fatigue life of Eco-Core under three stress states. Compression-Compression fatigue was performed directly on Eco-Core cylindrical specimen, whereas shear and flexure fatigue tests were performed using sandwich beam made of E glass-Vinyl Ester face sheet and Eco-Core material. Compression-compression fatigue test study was conducted at two values of stress ratios (R=10 and 5), for the maximum compression stress (sigmamin) range of 60% to 90% of compression strength (sigmac = 19.6 +/- 0.25 MPa) for R=10 and 95% to 80% of compression strength for R=5. The failure modes were characterized by the material compliance change: On-set (2% compliance change), propagation (5%) and ultimate failure (7%). The number of load cycles correspond to each of these three damages were characterized as on-set, propagation and total lives. A similar approach was used in shear and flexure fatigue tests with stress ratio of R=0.1. The fatigue stress-number of load cycles data followed the standard power law equation for all three stress states. The constant of the equation were

[Comparative investigation of compressive resistance of glass-cermet cements used as a core material in post-core systems].

Science.gov (United States)

Ersoy, E; Cetiner, S; Koçak, F

1989-09-01

In post-core applications, addition to the cast designs restorations that are performed on fabrication posts with restorative materials are being used. To improve the physical properties of glass-ionomer cements that are popular today, glass-cermet cements have been introduced and those materials have been proposed to be an alternative restorative material in post-core applications. In this study, the compressive resistance of Ketac-Silver as a core material was investigated comparatively with amalgam and composite resins.

Materials problems related to the core catcher of sodium cooled reactors

International Nuclear Information System (INIS)

Goetzmann, O.

1975-05-01

There are in principal two possible solutions for the external core catcher as far as materials are concerned. 1) A barrier consisting of a material with a high melting point, 2) a tray of comparatively low melting material with a high solubility for the fuel. In case of the first concept one has to look for materials whose melting temperatures are above the temperature of the molten core. Based on metallurgical reasons it seems very likely that the molten core does not exceed a temperature in the range between 2,500 and 2,800 0 C. Due to the compatibility situation with the molten core only a few high melting oxides will be suitable as liner materials for a core catcher. In the second case basalt or concrete, if free of water and lime, are suitable materials. Graphite is a high melting material, however, due to its behaviour with the molten core it should be listed under the second group. By the reaction of graphite with the core materials the melt can be kept liquid down to temperatures of around 1,100 0 C. The evolution of CO by this reaction should be supportable. It is an endothermal reaction. Experiments on the behaviour of core catcher materials have shown that sodium is capable of penetrating into sintered bodies of UO 2 with densities of 90% TD at temperatures higher than 200 0 C. This may lead to the desintegration of these bodies. The exposure to moist air has not done much harm to UO 2 pellets of densities from 80 to 90% TD. Even after one year of exposure, swelling or desintegration could not be observed. Sodium is also capable of penetrating into bodies of synthetic carbon and graphite. Only well graphitized material will not be destroyed. (orig.) [de

Scaling of Core Material in Rubble Mound Breakwater Model Tests

DEFF Research Database (Denmark)

Burcharth, H. F.; Liu, Z.; Troch, P.

1999-01-01

The permeability of the core material influences armour stability, wave run-up and wave overtopping. The main problem related to the scaling of core materials in models is that the hydraulic gradient and the pore velocity are varying in space and time. This makes it impossible to arrive at a fully...... correct scaling. The paper presents an empirical formula for the estimation of the wave induced pressure gradient in the core, based on measurements in models and a prototype. The formula, together with the Forchheimer equation can be used for the estimation of pore velocities in cores. The paper proposes...... that the diameter of the core material in models is chosen in such a way that the Froude scale law holds for a characteristic pore velocity. The characteristic pore velocity is chosen as the average velocity of a most critical area in the core with respect to porous flow. Finally the method is demonstrated...

76 FR 58122 - Defense Federal Acquisition Regulation Supplement; Material Inspection and Receiving Report...

Science.gov (United States)

2011-09-20

... acceptance point and replacing it with more specific data entries for inspection, acceptance, and ship to Do..., acceptance, and ship-to fields but kept the source, destination, and other inspection and acceptance points... Acquisition Regulation Supplement; Material Inspection and Receiving Report (DFARS Case 2009-D023) AGENCY...

Comparison of the fractional power motor with cores made of various magnetic materials

Science.gov (United States)

Gmyrek, Zbigniew; Lefik, Marcin; Cavagnino, Andrea; Ferraris, Luca

2017-12-01

The optimization of the motor cores, coupled with new core shapes as well as powering the motor at high frequency are the primary reasons for the use of new materials. The utilization of new materials, like SMC (soft magnetic composite), reduce the core loss and/or provide quasi-isotropic core's properties in any magnetization direction. Moreover, the use of SMC materials allows for avoiding degradation of the material portions, resulting from punching process, thereby preventing the deterioration of operating parameters of the motor. The authors examine the impact of technological parameters on the properties of a new type of SMC material and analyze the possibility of its use as the core of the fractional power motor. The result of the work is an indication of the shape of the rotor core made of a new SMC material to achieve operational parameters similar to those that have a motor with a core made of laminations.

Comparison of the fractional power motor with cores made of various magnetic materials

Directory of Open Access Journals (Sweden)

Gmyrek Zbigniew

2017-12-01

Full Text Available The optimization of the motor cores, coupled with new core shapes as well as powering the motor at high frequency are the primary reasons for the use of new materials. The utilization of new materials, like SMC (soft magnetic composite, reduce the core loss and/or provide quasi-isotropic core’s properties in any magnetization direction. Moreover, the use of SMC materials allows for avoiding degradation of the material portions, resulting from punching process, thereby preventing the deterioration of operating parameters of the motor. The authors examine the impact of technological parameters on the properties of a new type of SMC material and analyze the possibility of its use as the core of the fractional power motor. The result of the work is an indication of the shape of the rotor core made of a new SMC material to achieve operational parameters similar to those that have a motor with a core made of laminations.

List of Nuclear Materials Licensing Actions Received

Data.gov (United States)

Nuclear Regulatory Commission — A catalog of all Materials Licensing Actions received for review. The catalog lists the name of the entity submitting the license application, their city and state,...

The influence of core materials and mix on the performance of a 100 kVA three phase transformer core

Energy Technology Data Exchange (ETDEWEB)

Snell, David E-mail: dave.snell@cogent-power.com; Coombs, Alan

2003-01-01

Various grades of grain-oriented electrical steel, and the effect of mixing domain refined and non-domain refined materials in the same three phase transformer core have been assessed using a developed computer-based test system. Ball unit domain refined material and non-domain refined material can be successfully mixed in the same core, without degrading performance.

Comparative study of mechanical properties of direct core build-up materials

Directory of Open Access Journals (Sweden)

Girish Kumar

2015-01-01

Full Text Available Background and Objectives: The strength greatly influences the selection of core material because core must withstand forces due to mastication and para-function for many years. This study was conducted to evaluate certain mechanical properties of commonly used materials for direct core build-up, including visible light cured composite, polyacid modified composite, resin modified glass ionomer, high copper amalgam, and silver cermet cement. Materials and Methods: All the materials were manipulated according to the manufacturer′s recommendations and standard test specimens were prepared. A universal testing machine at different cross-head speed was used to determine all the four mechanical properties. Mean compressive strength, diametral tensile strength, flexural strength, and elastic modulus with standard deviations were calculated. Multiple comparisons of the materials were also done. Results: Considerable differences in compressive strength, diametral tensile strength, and flexural strength were observed. Visible light cured composite showed relatively high compressive strength, diametral tensile strength, and flexural strength compared with the other tested materials. Amalgam showed the highest value for elastic modulus. Silver cermet showed less value for all the properties except for elastic modulus. Conclusions: Strength is one of the most important criteria for selection of a core material. Stronger materials better resist deformation and fracture provide more equitable stress distribution, greater stability, and greater probability of clinical success.

Ge/Si core/shell quantum dots in alumina: tuning the optical absorption by the core and shell size

Directory of Open Access Journals (Sweden)

Nekić Nikolina

2017-03-01

Full Text Available Ge/Si core/shell quantum dots (QDs recently received extensive attention due to their specific properties induced by the confinement effects of the core and shell structure. They have a type II confinement resulting in spatially separated charge carriers, the electronic structure strongly dependent on the core and shell size. Herein, the experimental realization of Ge/Si core/shell QDs with strongly tunable optical properties is demonstrated. QDs embedded in an amorphous alumina glass matrix are produced by simple magnetron sputtering deposition. In addition, they are regularly arranged within the matrix due to their self-assembled growth regime. QDs with different Ge core and Si shell sizes are made. These core/shell structures have a significantly stronger absorption compared to pure Ge QDs and a highly tunable absorption peak dependent on the size of the core and shell. The optical properties are in agreement with recent theoretical predictions showing the dramatic influence of the shell size on optical gap, resulting in 0.7 eV blue shift for only 0.4 nm decrease at the shell thickness. Therefore, these materials are very promising for light-harvesting applications.

Nanostructured core-shell electrode materials for electrochemical capacitors

Science.gov (United States)

Jiang, Long-bo; Yuan, Xing-zhong; Liang, Jie; Zhang, Jin; Wang, Hou; Zeng, Guang-ming

2016-11-01

Core-shell nanostructure represents a unique system for applications in electrochemical energy storage devices. Owing to the unique characteristics featuring high power delivery and long-term cycling stability, electrochemical capacitors (ECs) have emerged as one of the most attractive electrochemical storage systems since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review aims to summarize recent progress on core-shell nanostructures for advanced supercapacitor applications in view of their hierarchical architecture which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The core-shell nanostructures include carbon/carbon, carbon/metal oxide, carbon/conducting polymer, metal oxide/metal oxide, metal oxide/conducting polymer, conducting polymer/conducting polymer, and even more complex ternary core-shell nanoparticles. The preparation strategies, electrochemical performances, and structural stabilities of core-shell materials for ECs are summarized. The relationship between core-shell nanostructure and electrochemical performance is discussed in detail. In addition, the challenges and new trends in core-shell nanomaterials development have also been proposed.

Opalescence of all-ceramic core and veneer materials.

Science.gov (United States)

Cho, Moon-Sang; Yu, Bin; Lee, Yong-Keun

2009-06-01

The enamel of natural teeth is opalescent, where there is light scattering of the shorter wavelengths of the visible spectrum, giving a tooth a bluish appearance in the reflected color and an orange/brown appearance in the transmitted color. The objective of this study was to determine the opalescence of all-ceramic core, veneer and layered specimens with a color measuring spectrophotometer. Colors of core (A2-corresponding shade), veneer (A2- and A3-corresponding shades) and layered (A2- and A3-layered) ceramics for all-ceramic restorations in clinically relevant thicknesses were measured in the reflectance and transmittance modes. The opalescence parameter (OP), which was calculated as the difference in blue-yellow coordinate (Deltab(*)) and red-green coordinate (Deltaa(*)), and the differences in blue-yellow coordinate (Deltab(*)) and in color (DeltaE(ab)(*)) between the reflected and transmitted colors were calculated. One-way ANOVA was performed for the OP values of the core, veneer and layered specimens by the kind of materials. Regression analysis was performed between the OP and Deltab(*), and the OP and DeltaE(ab)(*) values. The range of the OP value was 1.6-6.1, 2.0-7.1, 1.3-5.0 and 1.6-4.2 for the core, veneer, A2- and A3-layered specimens, respectively, all of which were significantly influenced by the kind of materials (pOpalescence varied by kind of ceramics. The OP values of ceramics were lower than those of tooth enamel. All-ceramic materials that can simulate the opalescence of natural teeth should be developed.

New sacrificial material for ex-vessel core catcher

Energy Technology Data Exchange (ETDEWEB)

Komlev, Andrei A., E-mail: komlev@kth.se [Kungliga Tekniska Högskolan (KTH), AlbaNova University Centre, Nuclear Power Safety Division, Roslagstullsbacken 21, SE-106 91, Stockholm (Sweden); Almjashev, Vyacheslav I., E-mail: vac@mail.ru [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Bechta, Sevostian V., E-mail: bechta@safety.sci.kth.se [Kungliga Tekniska Högskolan (KTH), AlbaNova University Centre, Roslagstullsbacken 21, SE-106 91, Stockholm (Sweden); Khabensky, Vladimir B., E-mail: vladimirkhabensky@gmail.com [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Granovsky, Vladimir S., E-mail: gran@niti.ru [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Gusarov, Victor V., E-mail: victor.v.gusarov@gmail.com [Ioffe Institute, 26 Polytekhnicheskaya Str., St. Petersburg, 194021 (Russian Federation)

2015-12-15

A new functional (sacrificial) material has been developed in the Fe{sub 2}O{sub 3}–SrO–Al{sub 2}O{sub 3}–CaO system based on strontium hexaferrite ceramic in concrete matrix. The method of producing SM has been advanced technologically; this technological effectiveness allows the SM to be used in ex-vessel core catchers with corium spreading as well as in crucible-type core catchers. Critical properties regarding the efficiency of SM in ex-vessel core catchers, such as porosity, pycnometric density, apparent density, solidus and liquidus temperatures, and water content have been measured. Suitable fractions of SrFe{sub 12}O{sub 19} and high alumina cement (HAC) were found in the SM based on thermodynamic analysis of the SM/corium interaction. The use of sacrificial steel as an additional heat adsorption component in the core catcher allowed us to increase the mass fraction range of SrFe{sub 12}O{sub 19} in the SM from 0.3−0.5 to 0.3–0.85. The activation temperature of the SM/corium interaction has been shown to correspond to the liquidus temperature of the local composition at the SM/corium interface. The calculated value of this temperature was 1716 °C. Analysis of phase transformations in the SrO–Fe{sub 2}O{sub 3} system revealed advantages of the SrFe{sub 12}O{sub 19}–based sacrificial material compared with the Fe{sub 2}O{sub 3}-contained material owing to the time proximity of SrFe{sub 12}O{sub 19} decomposition and corium interaction activation. - Highlights: • A sacrificial material (SM) was developed for ex-vessel core catcher. • Suitable proportions in the SrFe{sub 12}O{sub 19}–Al{sub 2}O{sub 3}·CaO–Fe system were determined. • Hydrogen release limitation was shown for ex-vessel corium retention with the SM. • Calculated temperature of the active initiation of corium/SM interaction is 1716 °C. • Functional properties of the SM were measured.

Applications of simulation experiments in LMFBR core materials technology

International Nuclear Information System (INIS)

Appleby, W.K.

1976-01-01

The development of charged particle bombardment experiments to simulate neutron irradiation induced swelling in austenitic alloys is briefly described. The applications of these techniques in LMFBR core materials technology are discussed. It is shown that use of the techniques to study the behavior of cold-worked Type-316 was instrumental in demonstrating at an early date the need for advanced materials. The simulation techniques then were used to identify alloying elements which can markedly decrease swelling and thus a focused reactor irradiation program is now in place to allow the future use of a lower swelling alloy for LMFBR core components

Technical Meeting on Liquid Metal Reactor Concepts: Core Design and Structural Materials. Working Material

International Nuclear Information System (INIS)

2013-01-01

The objective of the TM on “Liquid metal reactor concept: core design and structural materials” was to present and discuss innovative liquid metal fast reactor (LMFR) core designs with special focus on the choice, development, testing and qualification of advanced reactor core structural materials. Main results arising from national and international R&D programmes and projects in the field were reviewed, and new activities to be carried out under the IAEA aegis were identified on the basis of the analysis of current research and technology gaps

Research activities at JAERI on core material behaviour under severe accident conditions

International Nuclear Information System (INIS)

Uetsuka, H.; Katanashi, S.; Ishijima, K.

1996-01-01

At the Japan Atomic Energy Research Institute (JAERI), experimental studies on physical phenomena under the condition of a severe accident have been conducted. This paper presents the progress of the experimental studies on fuel and core materials behaviour such as the thermal shock fracture of fuel cladding due to quenching, the chemical interaction of core materials at high temperatures and the examination of TMI-2 debris. The mechanical behaviour of fuel rod with heavily embrittled cladding tube due to the thermal shock during delayed reflooding have been investigated at the Nuclear Safety Research Reactor (NSSR) of JAERI. A test fuel rod was heated in steam atmosphere by both electric and nuclear heating using the NSSR, then the rod was quenched by reflooding at the test section. Melting of core component materials having relatively low melting points and their eutectic reaction with other materials significantly influence on the degradation and melt down of fuel bundles during severe accidents. Therefore basic information on the reaction of core materials is necessary to understand and analyze the progress of core melting and relocation. Chemical interactions have been widely investigated at high temperatures for various binary systems of core component materials including absorber materials such as Zircaloy/Inconel, Zircaloy/stainless steel, Zircaloy/(Ag-In-Cd), stainless steel B 4 C and Zircaloy/B 4 C. It was found that the reaction generally obeyed a parabolic rate law and the reaction rate was determined for each reaction system. Many debris samples obtained from the degraded core of TMI-2 were transported to JAERI for numerous examinations and analyses. The microstructural examination revealed that the most part of debris was ceramic and it was not homogeneous in a microscopic sense. The thermal diffusivity data was also obtained for the temperature range up to about 1800K. The data from the large scale integral experiments were also obtained through the

Seasonal and pod-specific differences in core use areas by resident killer whales in the Northern Gulf of Alaska

Science.gov (United States)

Olsen, Daniel W.; Matkin, Craig O.; Andrews, Russel D.; Atkinson, Shannon

2018-01-01

The resident killer whale is a genetically and behaviorally distinct ecotype of killer whale (Orcinus orca) found in the North Pacific that feeds primarily on Pacific salmon (Oncorhynchus spp .). Details regarding core use areas have been inferred by boat surveys, but are subject to effort bias and weather limitations. To investigate core use areas, 37 satellite tags were deployed from 2006 to 2014 on resident killer whales representing 12 pods in the Northern Gulf of Alaska, and transmissions were received during the months of June to January. Core use areas were identified through utilization distributions using a biased Brownian Bridge movement model. Distinct differences in these core use areas were revealed, and were highly specific to season and pod. In June, July, and August, the waters of Hinchinbrook Entrance and west of Kayak Island were primary areas used, mainly by 3 separate pods. These same pods shifted their focus to Montague Strait in August, September, and October. Port Gravina was a focal area for 2 other pods in June, July, and August, but this was not the case in later months. These pods were responsible for seven of eight documented trips into the deeper fjords of Prince William Sound, yet these fjords were not a focus for most groups of killer whales. The seasonal differences in core use may be a response to the seasonal returns of salmon, though details on specific migration routes and timing for the salmon are limited. We found strong seasonal and pod-specific shifts in patterns between core use areas. Future research should investigate pod differences in diet composition and relationships between core area use and bathymetry.

Mechanical properties of chemically bonded sand core materials dipped in sol-gel coating impregnated with filter

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

2012-01-01

A novel sol-gel coating impregnated with filter dust was applied on chemically bonded sand core materials by dipping. After curing, the strengths of the core materials were measured under uniaxial loading using a new strength testing machine (STM). The STM presents the loading history as a force-...... of the chemically bonded sand core materials, a combination of flexural and compression tests is suggested for improving the casting quality. © 2012 W. S. Maney & Son Ltd.......A novel sol-gel coating impregnated with filter dust was applied on chemically bonded sand core materials by dipping. After curing, the strengths of the core materials were measured under uniaxial loading using a new strength testing machine (STM). The STM presents the loading history as a force...... the strengths were increased under compression. The mode of fracture of the chemically bonded sand core materials was observed to be intergranular through the binder. The stiffness of the chemically bonded sand core materials was determined. For better understanding of the mechanical properties...

Relative translucency of six all-ceramic systems. Part I: core materials.

Science.gov (United States)

Heffernan, Michael J; Aquilino, Steven A; Diaz-Arnold, Ana M; Haselton, Debra R; Stanford, Clark M; Vargas, Marcos A

2002-07-01

All-ceramic restorations have been advocated for superior esthetics. Various materials have been used to improve ceramic core strength, but it is unclear whether they affect the opacity of all-ceramic systems. This study compared the translucency of 6 all-ceramic system core materials at clinically appropriate thicknesses. Disc specimens 13 mm in diameter and 0.49 +/- 0.01 mm in thickness were fabricated from the following materials (n = 5 per group): IPS Empress dentin, IPS Empress 2 dentin, In-Ceram Alumina core, In-Ceram Spinell core, In-Ceram Zirconia core, and Procera AllCeram core. Empress and Empress 2 dentin specimens also were fabricated and tested at a thickness of 0.77 +/- 0.02 mm (the manufacturer's recommended core thickness is 0.8 mm). A high-noble metal-ceramic alloy (Porc. 52 SF) served as the control, and Vitadur Alpha opaque dentin was used as a standard. Sample reflectance (ratio of the intensity of reflected light to that of the incident light) was measured with an integrating sphere attached to a spectrophotometer across the visible spectrum (380 to 700 nm); 0-degree illumination and diffuse viewing geometry were used. Contrast ratios were calculated from the luminous reflectance (Y) of the specimens with a black (Yb) and a white (Yw) backing to give Yb/Yw with CIE illuminant D65 and a 2-degree observer function (0.0 = transparent, 1.0 = opaque). One-way analysis of variance and Tukey's multiple-comparison test were used to analyze the data (P In-Ceram Spinell > Empress, Procera, Empress 2 > In-Ceram Alumina > In-Ceram Zirconia, 52 SF alloy.

Static analysis of material testing reactor cores:critical core calculations

International Nuclear Information System (INIS)

Nawaz, A. A.; Khan, R. F. H.; Ahmad, N.

1999-01-01

A methodology has been described to study the effect of number of fuel plates per fuel element on critical cores of Material Testing Reactors (MTR). When the number of fuel plates are varied in a fuel element by keeping the fuel loading per fuel element constant, the fuel density in the fuel plates varies. Due to this variation, the water channel width needs to be recalculated. For a given number of fuel plates, water channel width was determined by optimizing k i nfinity using a transport theory lattice code WIMS-D/4. The dimensions of fuel element and control fuel element were determined using this optimized water channel width. For the calculated dimensions, the critical cores were determined for the given number of fuel plates per fuel element by using three dimensional diffusion theory code CITATION. The optimization of water channel width gives rise to a channel width of 2.1 mm when the number of fuel plates is 23 with 290 g ''2''3''5U fuel loading which is the same as in the case of Pakistan Reactor-1 (PARR-1). Although the decrease in number of fuel element results in an increase in optimal water channel width but the thickness of standard fuel element (SFE) and control fuel element (CFE) decreases and it gives rise to compact critical and equilibrium cores. The criticality studies of PARR-1 are in good agreement with the predictions

Analytical methods to characterize heterogeneous raw material for thermal spray process: cored wire Inconel 625

Science.gov (United States)

Lindner, T.; Bonebeau, S.; Drehmann, R.; Grund, T.; Pawlowski, L.; Lampke, T.

2016-03-01

In wire arc spraying, the raw material needs to exhibit sufficient formability and ductility in order to be processed. By using an electrically conductive, metallic sheath, it is also possible to handle non-conductive and/or brittle materials such as ceramics. In comparison to massive wire, a cored wire has a heterogeneous material distribution. Due to this fact and the complex thermodynamic processes during wire arc spraying, it is very difficult to predict the resulting chemical composition in the coating with sufficient accuracy. An Inconel 625 cored wire was used to investigate this issue. In a comparative study, the analytical results of the raw material were compared to arc sprayed coatings and droplets, which were remelted in an arc furnace under argon atmosphere. Energy-dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF) analysis were used to determine the chemical composition. The phase determination was performed by X-ray diffraction (XRD). The results were related to the manufacturer specifications and evaluated in respect to differences in the chemical composition. The comparison between the feedstock powder, the remelted droplets and the thermally sprayed coatings allows to evaluate the influence of the processing methods on the resulting chemical and phase composition.

Which Preschool Children with Specific Language Impairment Receive Language Intervention?

Science.gov (United States)

Wittke, Kacie; Spaulding, Tammie J.

2018-01-01

Purpose: Potential biases in service provision for preschool children with specific language impairment (SLI) were explored. Method: In Study 1, children with SLI receiving treatment (SLI-T) and those with SLI not receiving treatment (SLI-NT) were compared on demographic characteristics and developmental abilities. Study 2 recruited children with…

Survey of melt interactions with core retention material

International Nuclear Information System (INIS)

Powers, D.A.

1979-01-01

A survey of the interactions of up to 220 kg stainless steel melts at 1973 0 K with the candidate core retention materials borax, firebrick, high alumina cement, and magnesia is described. Data collected for the interactions include rates of material erosion, aerosol generation, gas evolution, and upward heat flux. Borax acts as an ablative solid that rapidly quenches the melt. Firebrick is ablated by the steel melt at a rate of 8.2 x 10 -6 m/s. High alumina cement is found to be an attractive melt retention material especially if it can be used in the unhydrated form. Magnesia is also found to be an attractive material though it can be eroded by the molten oxides of steel

How cores grow by pebble accretion. I. Direct core growth

Science.gov (United States)

Brouwers, M. G.; Vazan, A.; Ormel, C. W.

2018-03-01

Context. Planet formation by pebble accretion is an alternative to planetesimal-driven core accretion. In this scenario, planets grow by the accretion of cm- to m-sized pebbles instead of km-sized planetesimals. One of the main differences with planetesimal-driven core accretion is the increased thermal ablation experienced by pebbles. This can provide early enrichment to the planet's envelope, which influences its subsequent evolution and changes the process of core growth. Aims: We aim to predict core masses and envelope compositions of planets that form by pebble accretion and compare mass deposition of pebbles to planetesimals. Specifically, we calculate the core mass where pebbles completely evaporate and are absorbed before reaching the core, which signifies the end of direct core growth. Methods: We model the early growth of a protoplanet by calculating the structure of its envelope, taking into account the fate of impacting pebbles or planetesimals. The region where high-Z material can exist in vapor form is determined by the temperature-dependent vapor pressure. We include enrichment effects by locally modifying the mean molecular weight of the envelope. Results: In the pebble case, three phases of core growth can be identified. In the first phase (Mcore mixes outwards, slowing core growth. In the third phase (Mcore > 0.5M⊕), the high-Z inner region expands outwards, absorbing an increasing fraction of the ablated material as vapor. Rainout ends before the core mass reaches 0.6 M⊕, terminating direct core growth. In the case of icy H2O pebbles, this happens before 0.1 M⊕. Conclusions: Our results indicate that pebble accretion can directly form rocky cores up to only 0.6 M⊕, and is unable to form similarly sized icy cores. Subsequent core growth can proceed indirectly when the planet cools, provided it is able to retain its high-Z material.

Core-Shell Structured Electro- and Magneto-Responsive Materials: Fabrication and Characteristics

Directory of Open Access Journals (Sweden)

Hyoung Jin Choi

2014-11-01

Full Text Available Core-shell structured electrorheological (ER and magnetorheological (MR particles have attracted increasing interest owing to their outstanding field-responsive properties, including morphology, chemical and dispersion stability, and rheological characteristics of shear stress and yield stress. This study covers recent progress in the preparation of core-shell structured materials as well as their critical characteristics and advantages. Broad emphasises from the synthetic strategy of various core-shell particles to their feature behaviours in the magnetic and electric fields have been elaborated.

Electronic warfare receivers and receiving systems

CERN Document Server

Poisel, Richard A

2014-01-01

Receivers systems are considered the core of electronic warfare (EW) intercept systems. Without them, the fundamental purpose of such systems is null and void. This book considers the major elements that make up receiver systems and the receivers that go in them.This resource provides system design engineers with techniques for design and development of EW receivers for modern modulations (spread spectrum) in addition to receivers for older, common modulation formats. Each major module in these receivers is considered in detail. Design information is included as well as performance tradeoffs o

Radiation quality factor of spherical antennas with material cores

DEFF Research Database (Denmark)

Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

2011-01-01

This paper gives a description of the radiation quality factor and resonances of spherical antennas with material cores. Conditions for cavity and radiating resonances are given, and a theoretical description of the radiation quality factor, as well as simple expressions describing the relative...

Core OCD Symptoms: Exploration of Specificity and Relations with Psychopathology

Science.gov (United States)

Stasik, Sara M.; Naragon-Gainey, Kristin; Chmielewski, Michael; Watson, David

2012-01-01

Obsessive-compulsive disorder (OCD) is a heterogeneous condition, comprised of multiple symptom domains. This study used aggregate composite scales representing three core OCD dimensions (Checking, Cleaning, Rituals), as well as Hoarding, to examine the discriminant validity, diagnostic specificity, and predictive ability of OCD symptom scales. The core OCD scales demonstrated strong patterns of convergent and discriminant validity – suggesting that these dimensions are distinct from other self-reported symptoms – whereas hoarding symptoms correlated just as strongly with OCD and non-OCD symptoms in most analyses. Across analyses, our results indicated that Checking is a particularly strong, specific marker of OCD diagnosis, whereas the specificity of Cleaning and Hoarding to OCD was less strong. Finally, the OCD Checking scale was the only significant predictor of OCD diagnosis in logistic regression analyses. Results are discussed with regard to the importance of assessing OCD symptom dimensions separately and implications for classification. PMID:23026094

A volatile-rich Earth's core inferred from melting temperature of core materials

Science.gov (United States)

Morard, G.; Andrault, D.; Antonangeli, D.; Nakajima, Y.; Auzende, A. L.; Boulard, E.; Clark, A. N.; Lord, O. T.; Cervera, S.; Siebert, J.; Garbarino, G.; Svitlyk, V.; Mezouar, M.

2016-12-01

Planetary cores are mainly constituted of iron and nickel, alloyed with lighter elements (Si, O, C, S or H). Understanding how these elements affect the physical and chemical properties of solid and liquid iron provides stringent constraints on the composition of the Earth's core. In particular, melting curves of iron alloys are key parameter to establish the temperature profile in the Earth's core, and to asses the potential occurrence of partial melting at the Core-Mantle Boundary. Core formation models based on metal-silicate equilibration suggest that Si and O are the major light element components1-4, while the abundance of other elements such as S, C and H is constrained by arguments based on their volatility during planetary accretion5,6. Each compositional model implies a specific thermal state for the core, due to the different effect that light elements have on the melting behaviour of Fe. We recently measured melting temperatures in Fe-C and Fe-O systems at high pressures, which complete the data sets available both for pure Fe7 and other binary alloys8. Compositional models with an O- and Si-rich outer core are suggested to be compatible with seismological constraints on density and sound velocity9. However, their crystallization temperatures of 3650-4050 K at the CMB pressure of 136 GPa are very close to, if not higher than the melting temperature of the silicate mantle and yet mantle melting above the CMB is not a ubiquitous feature. This observation requires significant amounts of volatile elements (S, C or H) in the outer core to further reduce the crystallisation temperature of the core alloy below that of the lower mantle. References 1. Wood, B. J., et al Nature 441, 825-833 (2006). 2. Siebert, J., et al Science 339, 1194-7 (2013). 3. Corgne, A., et al Earth Planet. Sc. Lett. 288, 108-114 (2009). 4. Fischer, R. a. et al. Geochim. Cosmochim. Acta 167, 177-194 (2015). 5. Dreibus, G. & Palme, H. Geochim. Cosmochim. Acta 60, 1125-1130 (1995). 6. Mc

LANMAS core: Update and current directions

International Nuclear Information System (INIS)

Claborn, J.

1995-01-01

Local Area Network Material Accountability system (LANMAS) core software provides the framework of a material accountability system. It tracks the movement of material throughout a site and generates the required material accountability reports. LANMAS is a net-work- based nuclear material accountability system that runs in a client/server mode. The database of material type and location resides on the server, while the user interface runs on the client. The user interface accesses the data stored on the server via a network. The LANMAS core can be used as the foundation for building required materials control and accountability (MCA) functionality at any site requiring a new MCA system. An individual site will build on the LANMAS core by supplying site-specific software. This paper will provide an update on the current LANMAS development activities and discuss the current direction of the LANMAS project

Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Tensile properties of sodium exposed and nickel diffused materials

International Nuclear Information System (INIS)

Kato, Shoichi; Yoshida, Eiichi

2002-12-01

An oxide dispersion strengthened (ODS) ferritic steel is candidate for a long-life core materials of future FBR, because of good swelling resistance and high creep strength. In this study, tensile tests were carried out the long-term extrapolation of sodium environmental effects on the mechanical properties of ODS steels. The tested heats of materials are M93, M11 and F95. The specimens were pre-exposed to sodium for 1,000 and 3,000 hours under non-stress conditions. The pre-exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperature was 650 and 700degC, the oxygen concentration in sodium was about 1 ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/seconds (nearly static). Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The tensile strength and the fracture elongation after sodium exposure (maximum 3,000 hours) were same as that of as-received materials. If was considered that the sodium environmental effect is negligible under the condition of this study. (2) Tensile properties of nickel diffused specimens were slightly lower than that of the as-received specimens, but it remains equal to that of thermal aging specimens. (3) The change in microstructure such as a degraded layer was observed on the surface of nickel diffused specimen. In the region of the degraded layer, phase transformations from the α-phase to the γ-phase were recognized. But, the microscopic oxide particles were observed same as that of α-phase base metal. (author)

Technical Meeting on Liquid Metal Reactor Concepts: Core Design and Structural Materials. Presentations

International Nuclear Information System (INIS)

2013-01-01

The objective of the Technical Meeting is to present and discuss innovative liquid metal fast reactor (LMFR) core designs with special focus on the choice, development, testing and qualification of advanced reactor core structural materials

Side core lifter

Energy Technology Data Exchange (ETDEWEB)

Edelman, Ya A

1982-01-01

A side core lifter is proposed which contains a housing with guide slits and a removable core lifter with side projections on the support section connected to the core receiver. In order to preserve the structure of the rock in the core sample by means of guaranteeing rectilinear movement of the core lifter in the rock, the support and core receiver sections are hinged. The device is equipped with a spring for angular shift in the core-reception part.

LANMAS core: Update and current directions

International Nuclear Information System (INIS)

Claborn, J.

1994-01-01

Local Area Network Material Accountability System (LANMAS) core software will provide the framework of a material accountability system. LANMAS is a network-based nuclear material accountability system. It tracks the movement of material throughout a site and generates the required reports on material accountability. LANMAS will run in a client/server mode. The database of material type and location will reside on the server, while the user interface runs on the client. The user interface accesses the server via a network. The LANMAS core can be used as the foundation for building required Materials Control and Accountability (MC ampersand A) functionality at any site requiring a new MC ampersand A system. An individual site will build on the LANMAS core by supplying site-specific software. This paper will provide an update on the current LANMAS development activities and discuss the current direction of the LANMAS project

Designing Class Activities to Meet Specific Core Training Competencies: A Developmental Approach

Science.gov (United States)

Guth, Lorraine J.; McDonnell, Kelly A.

2004-01-01

This article presents a developmental model for designing and utilizing class activities to meet specific Association for Specialists in Group Work (ASGW) core training competencies for group workers. A review of the relevant literature about teaching group work and meeting core training standards is provided. The authors suggest a process by…

Electrical properties of spherical dipole antennas with lossy material cores

DEFF Research Database (Denmark)

Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

2012-01-01

A spherical magnetic dipole antenna with a linear, isotropic, homogenous, passive, and lossy material core is modeled analytically, and closed form expressions are given for the internally stored magnetic and electric energies, the radiation efficiency, and radiation quality factor. This model...... and all the provided expressions are exact and valid for arbitrary core sizes, permeability, permittivity, electric and magnetic loss tangents. Arbitrary dispersion models for both permeability and permittivity can be applied. In addition, we present an investigation for an antenna of fixed electrical...

Assessment of the technical specifications for a flip-standard TRIGA core

International Nuclear Information System (INIS)

Feltz, D.E.; Randall, J.D.

1974-01-01

The Technical Specifications for the Texas A and M University mixed, FLIP-Standard TRIGA core were the first submitted and approved under the draft version of Standard ANS-15.1. According to one AEC official these were the best Technical Specifications ever issued to a Research Reactor. The Technical Specifications are evaluated after operating under them for over seven months. (author)

Assessment of the technical specifications for a flip-standard TRIGA core

Energy Technology Data Exchange (ETDEWEB)

Feltz, D E; Randall, J D [Texas A and M University (United States)

1974-07-01

The Technical Specifications for the Texas A and M University mixed, FLIP-Standard TRIGA core were the first submitted and approved under the draft version of Standard ANS-15.1. According to one AEC official these were the best Technical Specifications ever issued to a Research Reactor. The Technical Specifications are evaluated after operating under them for over seven months. (author)

Nanocrystalline material in toroidal cores for current transformer: analytical study and computational simulations

Directory of Open Access Journals (Sweden)

Benedito Antonio Luciano

2005-12-01

Full Text Available Based on electrical and magnetic properties, such as saturation magnetization, initial permeability, and coercivity, in this work are presented some considerations about the possibilities of applications of nanocrystalline alloys in toroidal cores for current transformers. It is discussed how the magnetic characteristics of the core material affect the performance of the current transformer. From the magnetic characterization and the computational simulations, using the finite element method (FEM, it has been verified that, at the typical CT operation value of flux density, the nanocrystalline alloys properties reinforce the hypothesis that the use of these materials in measurement CT cores can reduce the ratio and phase errors and can also improve its accuracy class.

Sport-specific endurance plank test for evaluation of global core muscle function.

Science.gov (United States)

Tong, Tom K; Wu, Shing; Nie, Jinlei

2014-02-01

To examine the validity and reliability of a sports-specific endurance plank test for the evaluation of global core muscle function. Repeated-measures study. Laboratory environment. Twenty-eight male and eight female young athletes. Surface electromyography (sEMG) of selected trunk flexors and extensors, and an intervention of pre-fatigue core workout were applied for test validation. Intraclass correlation coefficient (ICC), coefficient of variation (CV), and the measurement bias ratio */÷ ratio limits of agreement (LOA) were calculated to assess reliability and measurement error. Test validity was shown by the sEMG of selected core muscles, which indicated >50% increase in muscle activation during the test; and the definite discrimination of the ∼30% reduction in global core muscle endurance subsequent to a pre-fatigue core workout. For test-retest reliability, when the first attempt of three repeated trials was considered as familiarisation, the ICC was 0.99 (95% CI: 0.98-0.99), CV was 2.0 ± 1.56% and the measurement bias ratio */÷ ratio LOA was 0.99 */÷ 1.07. The findings suggest that the sport-specific endurance plank test is a valid, reliable and practical method for assessing global core muscle endurance in athletes given that at least one familiarisation trial takes place prior to measurement. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phenomena in the interaction among a core melt and protective and sacrificial materials

International Nuclear Information System (INIS)

Steinwarz, W.; Koller, W.; Dyllong, N.; Fischer, M.; Hellmann, S.; Lansmann, V.; Nie, M.; Haefner, W.; Alkan, Z.; Andrae, P.; Rensing, B.

2000-01-01

In a postulated core meltdown accident in a light water reactor there are bound to be interactions, in the ex-vessel phase, among the core melt and the structural materials within and below the reactor cavity. In existing plants, these structural materials normally are structural concrete, while future, evolutionary reactor lines are to have sacrificial and protective materials specially designed for this hypothetical case. To add to the state of knowledge about the phenomena occurring, experiments need to be conducted under conditions as realistic as possible. Within the research programs funded by the European Union, the German Federal Ministry for Economics, and the German nuclear power plant operators, experiments on a laboratory as well as an industrial scale on these problems are being carried out in the two projects called CORESA (COrium on REfractory and SAcrificial materials) and ECOSTAR (Ex-vessel COre melt STAbilization Research). The experiments are accompanied by an extensive analytical theoretical program also serving to advance and validate computer codes on the problems under investigation. The projects, which are carried out with international European participation, are expected to allow a concept to be developed for managing postulated accident scenarios involving core meltdown for innovative nuclear power plants, and to provide findings on risk evaluation of plants now in operation so as to further develop accident management measures. (orig.) [de

Nano-sized LiFePO4/C composite with core-shell structure as cathode material for lithium ion battery

International Nuclear Information System (INIS)

Liu, Yang; Zhang, Min; Li, Ying; Hu, Yemin; Zhu, Mingyuan; Jin, Hongming; Li, Wenxian

2015-01-01

Graphical abstract: Nano-sized LiFePO4/C composite with core-shell structure was fabricated via a well-designed approach as cathode material forlithium ion battery. The nano-sized LiFePO4/C composite with whole carbon shell coating layer showed an excellent electrical performance. - Abstract: Nano-sized composite with LiFePO 4 -core and carbon-shell was synthesized via a facile route followed by heat treatment at 650 °C. X-ray diffraction (XRD) shows that the core is well crystallized LiFePO 4 . The electron microscopy (SEM and TEM) observations show that the core-shell structured LiFePO 4 /C composite coating with whole carbon shell layer of ∼2.8 nm, possesses a specific surface area of 51 m 2 g −1 . As cathode material for lithium ion battery, the core-shell LiFePO 4 /C composite exhibits high initial capacity of 161 mAh g −1 at 0.1 C, excellent high-rate discharge capacity of 135 mAh g −1 at 5 C and perfect cycling retention of 99.6% at 100 th cycle. All these promising results should be contributed to the core-shell nanostructure which prevents collapse of the particle structure in the long-term charge and discharge cycles, as well as the large surface area of the nano-sized LiFePO 4 /C composite which enhances the electronic conductivity and shortens the distance of lithium ion diffusion

Effect of silica fiber on the mechanical and chemical behavior of alumina-based ceramic core material

OpenAIRE

Weiguo Jiang; Kaiwen Li; Jiuhan Xiao; Langhong Lou

2017-01-01

In order to improve the chemical leachability, the alumina-based ceramic core material with the silica fiber was injected and sintered at 1100 °C/4 h, 1200 °C/4 h, 1300 °C/4 h and 1400 °C/4 h, respectively. The micrographs of ceramic core materials at sintered and leached state were characterized by scanning electron microscopy (SEM). The phase composition of ceramic core material after sintering and the leaching product after leaching were detected by X-ray diffraction (XRD). The porosity, r...

Core and Valence Structures in K beta X-ray Emission Spectra of Chromium Materials

NARCIS (Netherlands)

Torres Deluigi, Maria; de Groot, Frank M. F.; Lopez-Diaz, Gaston; Tirao, German; Stutz, Guillermo; Riveros de la Vega, Jose

2014-01-01

We analyze the core and valence transitions in chromium in a series of materials with a number of different ligands and including the oxidation states: Cr-II, Cr-III, Cr-IV, and Cr-VI. To study the core-to-core transitions we employ the CTM4XAS program and investigate the shapes, widths,

Irradiation-Accelerated Corrosion of Reactor Core Materials. Final Report

Energy Technology Data Exchange (ETDEWEB)

Jiao, Zhujie [Univ. of Michigan, Ann Arbor, MI (United States); Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States); Bartels, David [Univ. of Notre Dame, IN (United States)

2015-04-02

This project aims to understand how radiation accelerates corrosion of reactor core materials. The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, as well as the success of most all GenIV concepts. Of these four drivers, the combination of radiation and corrosion places the most severe demands on materials, for which an understanding of the fundamental science is simply absent. Only a few experiments have been conducted to understand how corrosion occurs under irradiation, yet the limited data indicates that the effect is large; irradiation causes order of magnitude increases in corrosion rates. Without a firm understanding of the mechanisms by which radiation and corrosion interact in film formation, growth, breakdown and repair, the extension of the current LWR fleet beyond 60 years and the success of advanced nuclear energy systems are questionable. The proposed work will address the process of irradiation-accelerated corrosion that is important to all current and advanced reactor designs, but remains very poorly understood. An improved understanding of the role of irradiation in the corrosion process will provide the community with the tools to develop predictive models for in-reactor corrosion, and to address specific, important forms of corrosion such as irradiation assisted stress corrosion cracking.

Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts

OpenAIRE

PANITIWAT, Prapaporn; SALIMEE, Prarom

2017-01-01

Abstract Objective This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC), MultiCore Flow (MCF), and LuxaCore Z-Dual (LCZ)), and a nanohybrid composite, (Tetric N-Ceram (TNC)). Material and Methods Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post) cemented with resin cement (Panavia F2...

Communications received from Members regarding the Export of Nuclear Material and of Certain Categories of Equipment and other Material

International Nuclear Information System (INIS)

1993-05-01

On 13 December 1990 the Director General received a letter dated 10 December 1990 from the Resident Representative of Austria to the Agency in the same terms as the letter and its Annex reproduced in document INFCIRC/209/Rev.1. That document deals with communications received from Members regarding the export of nuclear material and of certain categories of equipment and other material [ru

Communications received from Members regarding the Export of Nuclear Material and of Certain Categories of Equipment and other Material

International Nuclear Information System (INIS)

1993-06-01

On 13 December 1990 the Director General received a letter dated 10 December 1990 from the Resident Representative of Austria to the Agency in the same terms as the letter and its Annex reproduced in document INFCIRC/209/Rev.1. That document deals with communications received from Members regarding the export of nuclear material and of certain categories of equipment and other material [es

Size-exclusion chromatography using core-shell particles.

Science.gov (United States)

Pirok, Bob W J; Breuer, Pascal; Hoppe, Serafine J M; Chitty, Mike; Welch, Emmet; Farkas, Tivadar; van der Wal, Sjoerd; Peters, Ron; Schoenmakers, Peter J

2017-02-24

Size-exclusion chromatography (SEC) is an indispensable technique for the separation of high-molecular-weight analytes and for determining molar-mass distributions. The potential application of SEC as second-dimension separation in comprehensive two-dimensional liquid chromatography demands very short analysis times. Liquid chromatography benefits from the advent of highly efficient core-shell packing materials, but because of the reduced total pore volume these materials have so far not been explored in SEC. The feasibility of using core-shell particles in SEC has been investigated and contemporary core-shell materials were compared with conventional packing materials for SEC. Columns packed with very small core-shell particles showed excellent resolution in specific molar-mass ranges, depending on the pore size. The analysis times were about an order of magnitude shorter than what could be achieved using conventional SEC columns. Copyright © 2016 Elsevier B.V. All rights reserved.

The recent advances on carrier materials for microencapsulating lipophilic cores

Directory of Open Access Journals (Sweden)

JIN Minfeng

2014-12-01

Full Text Available Lipophilic ingredients,such as polyunsaturated fatty acids,play an important role in industrialized foods to fortify the nutrients.However,these materials are normally sensitive to oxygen,light or heat to be oxidized,and hard to flow and mix within the bulk food due to the hydrophobic nature.Microencapsulation of lipophilic materials could effectively extend their shelf lives,mask unsatisfied flavors,change their physicochemical properties,and enhance the mixing capacities.This work reviewed the different carrier materials applied in microencapsulating the lipophilic ingredients,and discussed their characteristics and effects on encapsulation efficiencies and release profiles of lipophilic cores.

The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 1 Core.

Science.gov (United States)

Hucka, Michael; Bergmann, Frank T; Hoops, Stefan; Keating, Sarah M; Sahle, Sven; Schaff, James C; Smith, Lucian P; Wilkinson, Darren J

2015-09-04

Computational models can help researchers to interpret data, understand biological function, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that can be exchanged between different software systems. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 1 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project web site, http://sbml.org/.

Effect of adhesive resin cements on bond strength of ceramic core materials to dentin.

Science.gov (United States)

Gundogdu, M; Aladag, L I

2018-03-01

The aim of the present study was to evaluate the effects of self-etch and self-adhesive resin cements on the shear bond strength of ceramic core materials bonded to dentin. Extracted, caries-free, human central maxillary incisor teeth were selected, and the vestibule surfaces were cut flat to obtain dentin surfaces. Ceramic core materials (IPS e.max Press and Prettau Zirconia) were luted to the dentin surfaces using three self-etch adhesive systems (Duo-Link, Panavia F 2.0, and RelyX Ultimate Clicker) and two self-adhesive resin systems (RelyX U200 Automix and Maxcem Elite). A shear bond strength test was performed using a universal testing machine. Failure modes were observed under a stereomicroscope, and bonding interfaces between the adhesive resin cements and the teeth were evaluated with a scanning electron microscope. Data were analyzed with Student's t-test and one-way analysis of variance followed by Tukey's test (α = 0.05). The type of adhesive resin cement significantly affected the shear bond strengths of ceramic core materials bonded to dentin (P materials when the specimens were luted with self-adhesive resin cements (P materials.

Dependences of optical properties of spherical two-layered nanoparticles on parameters of gold core and material shell

International Nuclear Information System (INIS)

Pustovalov, V.K.; Astafyeva, L.G.; Zharov, V.P.

2013-01-01

Modeling of nonlinear dependences of optical properties of spherical two-layered gold core and some material shell nanoparticles (NPs) placed in water on parameters of core and shell was carried out on the basis of the extended Mie theory. Efficiency cross-sections of absorption, scattering and extinction of radiation with wavelength 532 nm by core–shell NPs in the ranges of core radii r 00 =5–40 nm and of relative NP radii r 1 /r 00 =1–8 were calculated (r 1 —radius of two-layered nanoparticle). Shell materials were used with optical indexes in the ranges of refraction n 1 =0.2–1.5 and absorption k 1 =0–3.5 for the presentation of optical properties of wide classes of shell materials (including dielectrics, metals, polymers, vapor shell around gold core). Results show nonlinear dependences of optical properties of two-layered NPs on optical indexes of shell material, core r 00 and relative NP r 1 /r 00 radii. Regions with sharp decrease and increase of absorption, scattering and extinction efficiency cross-sections with changing of core and shell parameters were investigated. These dependences should be taken into account for applications of two-layered NPs in laser nanomedicine and optical diagnostics of tissues. The results can be used for experimental investigation of shell formation on NP core and optical determination of geometrical parameters of core and shell of two-layered NPs. -- Highlights: • Absorption, scattering and extinction of two-layered nanoparticles are studied. • Shell materials change in wide regions of materials (metals, dielectrics, vapor). • Effect of sharp decrease and increase of optical characteristics is established. • Explanation of sharp decreasing and increasing optical characteristics is presented

MTR (Materials Testing Reactors) cores fuel management. Application of a low enrichment reactor for the equilibrium and transitory core calculation

International Nuclear Information System (INIS)

Relloso, J.M.

1990-01-01

This work describes a methodology to define the equilibrium core and a MTR (Materials Testing Reactors) type reactor's fuel management upon multiple boundary conditions, such as: end cycle and permitted maximum reactivities, burn-up extraction and maximun number of movements by rechange. The methodology proposed allows to determine the best options through conceptual relations, prior to a detailed calculation with the core code, reducing the test number with these codes and minimizing in this way CPU cost. The way to better systematized search of transient cores from the first one to the equilibrium one is presented. (Author) [es

Effect of curing mode on the hardness of dual-cured composite resin core build-up materials

Directory of Open Access Journals (Sweden)

César Augusto Galvão Arrais

2010-06-01

Full Text Available This study evaluated the Knoop Hardness (KHN values of two dual-cured composite resin core build-up materials and one resin cement exposed to different curing conditions. Two dual-cured core build-up composite resins (LuxaCore®-Dual, DMG; and FluoroCore®2, Dentsply Caulk, and one dual-cured resin cement (Rely X ARC, 3M ESPE were used in the present study. The composite materials were placed into a cylindrical matrix (2 mm in height and 3 mm in diameter, and the specimens thus produced were either light-activated for 40 s (Optilux 501, Demetron Kerr or were allowed to self-cure for 10 min in the dark (n = 5. All specimens were then stored in humidity at 37°C for 24 h in the dark and were subjected to KHN analysis. The results were submitted to 2-way ANOVA and Tukey's post-hoc test at a pre-set alpha of 5%. All the light-activated groups exhibited higher KHN values than the self-cured ones (p = 0.00001, regardless of product. Among the self-cured groups, both composite resin core build-up materials showed higher KHN values than the dual-cured resin cement (p = 0.00001. LuxaCore®-Dual exhibited higher KHN values than FluoroCore®2 (p = 0.00001 when they were allowed to self-cure, while no significant differences in KHN values were observed among the light-activated products. The results suggest that dual-cured composite resin core build-up materials may be more reliable than dual-cured resin cements when curing light is not available.

Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts

Directory of Open Access Journals (Sweden)

Prapaporn PANITIWAT

Full Text Available Abstract Objective This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC, MultiCore Flow (MCF, and LuxaCore Z-Dual (LCZ, and a nanohybrid composite, (Tetric N-Ceram (TNC. Material and Methods Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post cemented with resin cement (Panavia F2.0. Samples were randomly divided into four groups (n=10. Each group was built-up with one of the four core materials following its manufacturers’ instructions. The teeth were embedded in acrylic resin blocks. Nickel-Chromium crowns were fixed on the specimens with resin cement. The fracture resistance was determined using a universal testing machine with a crosshead speed of 1 mm/min at 1350 to the tooth axis until failure occurred. All core materials used in the study were subjected to test for the flexural modulus according to ISO 4049:2009. Results One-way ANOVA and Bonferroni multiple comparisons test indicated that the fracture resistance was higher in the groups with CPC and MCF, which presented no statistically significant difference (p>0.05, but was significantly higher than in those with LCZ and TNC (p<0.05. In terms of the flexural modulus, the ranking from the highest values of the materials was aligned with the same tendency of fracture loads. Conclusion Among the cores used in this study, the composite core with high filler content tended to enhance fracture thresholds of teeth restored with fiber posts more than others.

Effect of the phase change material in a solar receiver on thermal performance of parabolic dish collector

Directory of Open Access Journals (Sweden)

Senthil Ramalingam

2017-01-01

Full Text Available In this work, the use of phase change material in the circular tank solar receiver is proposed for a 16 m2 Scheffler parabolic dish solar concentrator to improve the heat transfer in the receiver. Magnesium chloride hexahydrate with melting temperature of 117°C is selected as the phase change material in the annular space of the receiver with rectangular fins inside the phase change material. Experimental work is carried out to analyze heat transfer from the receiver to heat transfer fluid with and without phase change material in the inner periphery. Energy and exergy efficiency are determined from the measurements of solar radiation intensity, receiver temperature, surroundings temperature, heat transfer fluid inlet and outlet temperatures, storage tank temperature, and wind speed. The experiments were conducted in SRM University, Chennai, India (latitude: 13° 5′ N, longitude: 80°16′ E in April 2014. Use of phase change material in receiver periphery increased energy efficiency by 5.62%, exergy efficiency by 12.8% and decreased time to reach the boiling point of water by 20% when compared with the receiver without phase change material.

Interrelationship between core interventions and core competencies of forensic psychiatric nursing in Finland.

Science.gov (United States)

Tenkanen, Helena; Tiihonen, Jari; Repo-Tiihonen, Eila; Kinnunen, Juha

2011-03-01

The importance of core competencies (CC) and their relationship to core interventions in clinical practice guidelines on schizophrenia (CPGS), and the abilities to master these competencies were studied among registered nurses (RN) and practical mental nurses (PMN) in a forensic psychiatric setting. Data were collected from RNs, PMNs, and managers of all five forensic psychiatric facilities in Finland. The research material was obtained by using a 360-degree feedback method. The response rate was 68% (N = 428). The differences between the nurse groups were statistically significant (p ≤ 0.05) regarding the importance of and ability to master the following CCs: (1) pharmacotherapy, (2) knowledge in forensic psychiatry and violent behavior, (3) the treatment of violent patients, (4) processing patient's and own emotion, and (5) need-adapted treatment of the patient. Overall, RNs exceeded PMNs in mastering the CCs, however the principles of the CPGS were not achieved within the current resources in Finland. In summary, RNs, rather than PMNs, should be recruited for work in forensic psychiatric nursing, although a considerable amount of specific training would still be required to achieve competence. Implications of our research indicate that all nurses working in this area need to receive further education in forensic psychiatry and in forensic psychiatric nursing. © 2011 International Association of Forensic Nurses.

The Relative Impact of Aligning Tier 2 Intervention Materials with Classroom Core Reading Materials in Grades K-2

Science.gov (United States)

Foorman, Barbara R.; Herrera, Sarah; Dombek, Jennifer

2018-01-01

This randomized controlled trial in 55 low-performing schools across Florida compared 2 early literacy interventions--1 using stand-alone materials and 1 using materials embedded in the existing core reading/language arts program. A total of 3,447 students who were below the 30th percentile in vocabulary and reading-related skills participated in…

In-core materials testing under LWR conditions in the Halden reactor

International Nuclear Information System (INIS)

Bennett, P.J.; Hauso, E.; Hoegberg, N.W.; Karlsen, T.M.; McGrath, M.A.

2002-01-01

The Halden boiling water reactor (HBWR) has been in operation since 1958. It is a test reactor with a maximum power of 18 MW and is cooled and moderated by boiling heavy water, with a normal operating temperature of 230 C and a pressure of 34 bar. In the past 15 years increasing emphasis has been placed on materials testing, both of in-core structural materials and fuel claddings. These tests require representative light water reactor (LWR) conditions, which are achieved by housing the test rigs in pressure flasks that are positioned in fuel channels in the reactor and connected to dedicated water loops, in which boiling water reactor (BWR) or pressurised water reactor (PWR) conditions are simulated. Understanding of the in-core behaviour of fuel or reactor materials can be greatly improved by on-line measurements during power operation. The Halden Project has performed in-pile measurements for a period of over 35 years, beginning with fuel temperature measurements using thermocouples and use of differential transformers for measurement of fuel pellet or cladding dimensional changes and internal rod pressure. Experience gained over this period has been applied to on-line instrumentation for use in materials tests. This paper gives details of the systems used at Halden for materials testing under LWR conditions. The techniques used to provide on-line data are described and illustrative results are presented. (authors)

In-core materials testing under LWR conditions in the Halden reactor

Energy Technology Data Exchange (ETDEWEB)

Bennett, P.J.; Hauso, E.; Hoegberg, N.W.; Karlsen, T.M.; McGrath, M.A. [OECD Halden Reactor Project (Norway)

2002-07-01

The Halden boiling water reactor (HBWR) has been in operation since 1958. It is a test reactor with a maximum power of 18 MW and is cooled and moderated by boiling heavy water, with a normal operating temperature of 230 C and a pressure of 34 bar. In the past 15 years increasing emphasis has been placed on materials testing, both of in-core structural materials and fuel claddings. These tests require representative light water reactor (LWR) conditions, which are achieved by housing the test rigs in pressure flasks that are positioned in fuel channels in the reactor and connected to dedicated water loops, in which boiling water reactor (BWR) or pressurised water reactor (PWR) conditions are simulated. Understanding of the in-core behaviour of fuel or reactor materials can be greatly improved by on-line measurements during power operation. The Halden Project has performed in-pile measurements for a period of over 35 years, beginning with fuel temperature measurements using thermocouples and use of differential transformers for measurement of fuel pellet or cladding dimensional changes and internal rod pressure. Experience gained over this period has been applied to on-line instrumentation for use in materials tests. This paper gives details of the systems used at Halden for materials testing under LWR conditions. The techniques used to provide on-line data are described and illustrative results are presented. (authors)

Engineered inorganic core/shell nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Mélinon, Patrice, E-mail: patrice.melinon@univ-lyon1.fr [Institut Lumière matière Université Claude Bernard Lyon 1 et CNRS et OMNT, Domaine Scientifique de la Doua, Bâtiment Léon Brillouin, 43 Boulevard du 11 Novembre 1918, F 69622 Villeurbanne (France); Begin-Colin, Sylvie [IPCMS et OMNT, 23 rue du Loess BP 43, 67034 STRASBOURG Cedex 2 (France); Duvail, Jean Luc [IMN UMR 6502 et OMNT Campus Sciences : 2 rue de la Houssinire, BP32229, 44322 Nantes Cedex3 (France); Gauffre, Fabienne [SPM et OMNT : Institut des sciences chimiques de Rennes - UMR 6226, 263 Avenue du General Leclerc, CS 74205, 35042 RENNES Cedex (France); Boime, Nathalie Herlin [IRAMIS-NIMBE, Laboratoire Francis Perrin (CEA CNRS URA 2453) et OMNT, Bat 522, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Ledoux, Gilles [Institut Lumière Matière Université Claude Bernard Lyon 1 et CNRS et OMNT, Domaine Scientifique de la Doua, Bâtiment Alfred Kastler 43 Boulevard du 11 Novembre 1918 F 69622 Villeurbanne (France); Plain, Jérôme [Universit de technologie de Troyes LNIO-ICD, CNRS et OMNT 12 rue Marie Curie - CS 42060 - 10004 Troyes cedex (France); Reiss, Peter [CEA Grenoble, INAC-SPrAM, UMR 5819 CEA-CNRS-UJF et OMNT, Grenoble cedex 9 (France); Silly, Fabien [CEA, IRAMIS, SPEC, TITANS, CNRS 2464 et OMNT, F-91191 Gif sur Yvette (France); Warot-Fonrose, Bénédicte [CEMES-CNRS, Université de Toulouse et OMNT, 29 rue Jeanne Marvig F 31055 Toulouse (France)

2014-10-20

It has been for a long time recognized that nanoparticles are of great scientific interest as they are effectively a bridge between bulk materials and atomic structures. At first, size effects occurring in single elements have been studied. More recently, progress in chemical and physical synthesis routes permitted the preparation of more complex structures. Such structures take advantages of new adjustable parameters including stoichiometry, chemical ordering, shape and segregation opening new fields with tailored materials for biology, mechanics, optics magnetism, chemistry catalysis, solar cells and microelectronics. Among them, core/shell structures are a particular class of nanoparticles made with an inorganic core and one or several inorganic shell layer(s). In earlier work, the shell was merely used as a protective coating for the core. More recently, it has been shown that it is possible to tune the physical properties in a larger range than that of each material taken separately. The goal of the present review is to discuss the basic properties of the different types of core/shell nanoparticles including a large variety of heterostructures. We restrict ourselves on all inorganic (on inorganic/inorganic) core/shell structures. In the light of recent developments, the applications of inorganic core/shell particles are found in many fields including biology, chemistry, physics and engineering. In addition to a representative overview of the properties, general concepts based on solid state physics are considered for material selection and for identifying criteria linking the core/shell structure and its resulting properties. Chemical and physical routes for the synthesis and specific methods for the study of core/shell nanoparticle are briefly discussed.

Feasibility study of passive gamma spectrometry of molten core material from Fukushima Daiichi Nuclear Power Station unit 1, 2, and 3 cores for special nuclear material accountancy - low-volatile FP and special nuclear material inventory analysis and fundamental characteristics of gamma-rays from fuel debris

International Nuclear Information System (INIS)

Sagara, Hiroshi; Tomikawa, Hirofumi; Watahiki, Masaru; Kuno, Yusuke

2014-01-01

The technologies applied to the analysis of the Three Mile Island accident were examined in a feasibility study of gamma spectrometry of molten core material from the Fukushima Daiichi Nuclear Power Station unit 1, 2, and 3 cores for special nuclear material accountancy. The focus is on low-volatile fission products and heavy metal inventory analysis, and the fundamental characteristics of gamma-rays from fuel debris with respect to passive measurements. The inventory ratios of the low-volatile lanthanides, "1"5"4Eu and "1"4"4Ce, to special nuclear materials were evaluated by the entire core inventories in units 1, 2, and 3 with an estimated uncertainty of 9%-13% at the 1σ level for homogenized molten fuel material. The uncertainty is expected to be larger locally owing to the use of the irradiation cycle averaging approach. The ratios were also evaluated as a function of burnup for specific fuel debris with an estimated uncertainty of 13%-25% at the 1σ level for units 1 and 2, and most of the fuels in unit 3, although the uncertainty regarding the separated mixed oxide fuel in unit 3 would be significantly higher owing to the burnup dependence approach. Source photon spectra were also examined and cooling-time-dependent data sets were prepared. The fundamental characteristics of high-energy gamma-rays from fuel debris were investigated by a bare-sphere model transport calculation. Mass attenuation coefficients of fuel debris were evaluated to be insensitive to its possible composition in a high-energy region. The leakage photon ratio was evaluated using a variety of parameters, and a significant impact was confirmed for a certain size of fuel debris. Its correlation was summarized with respect to the leakage photopeak ratio of source "1"5"4Eu. Finally, a preliminary study using a hypothetical canister model of fuel debris based on the experience at Three Mile Island was presented, and future plans were introduced. (author)

Numerical simulation of the insulation material transport to a PWR core under loss of coolant accident conditions

International Nuclear Information System (INIS)

Höhne, Thomas; Grahn, Alexander; Kliem, Sören; Rohde, Ulrich; Weiss, Frank-Peter

2013-01-01

Highlights: ► Detailed results of a numerical simulation of the insulation material transport to a PWR core are shown. ► The spacer grid is modeled as a strainer which completely retains the insulation material carried by coolant. ► The CFD calculations showed that the fibers at the upper spacer grid plane are not uniformly distributed. ► Furthermore the pressure loss does not exceed a critical limit. ► The PWR core coolablity can be guaranteed all the time during the transient. -- Abstract: In 1992, strainers on the suction side of the ECCS pumps in Barsebäck NPP Unit 2 became partially clogged with mineral wool because after a safety valve opened the steam impinged on thermally insulated equipment and released mineral wool. This event pointed out that strainer clogging is an issue in the course of a loss-of-coolant accident. Modifications of the insulation material, the strainer area and mesh size were carried out in most of the German NPPs. Moreover, back flushing procedures to remove the mineral wool from the strainers and differential pressure measurements were implemented to assure the performance of emergency core cooling during the containment sump recirculation mode. Nevertheless, it cannot be completely ruled out, that a limited amount of small fractions of the insulation material is transported into the RPV. During a postulated cold leg LOCA with hot leg ECC injection, the fibers enter the upper plenum and can accumulate at the fuel element spacer grids, preferably at the uppermost grid level. This effect might affect the ECC flow into the core and could result in degradation of core cooling. It was the aim of the numerical simulations presented to study where and how many mineral wool fibers are deposited at the upper spacer grid. The 3D, time dependent, multi-phase flow problem was modeled applying the CFD code ANSYS CFX. The CFD calculation does not yet include steam production in the core and also does not include re-suspension of the

IP cores design from specifications to production modeling, verification, optimization, and protection

CERN Document Server

Mohamed, Khaled Salah

2016-01-01

This book describes the life cycle process of IP cores, from specification to production, including IP modeling, verification, optimization, and protection. Various trade-offs in the design process are discussed, including  those associated with many of the most common memory cores, controller IPs  and system-on-chip (SoC) buses. Readers will also benefit from the author’s practical coverage of new verification methodologies. such as bug localization, UVM, and scan-chain.  A SoC case study is presented to compare traditional verification with the new verification methodologies. ·         Discusses the entire life cycle process of IP cores, from specification to production, including IP modeling, verification, optimization, and protection; ·         Introduce a deep introduction for Verilog for both implementation and verification point of view.  ·         Demonstrates how to use IP in applications such as memory controllers and SoC buses. ·         Describes a new ver...

Technicians work with Apollo 14 lunar sample material in Lunar Receiving Lab.

Science.gov (United States)

1971-01-01

Glove handlers work with freshly opened Apollo 14 lunar sample material in modularized cabinets in the Lunar Receiving Laboratory at the Manned Spacecraft Center. The glove operator on the right starts to pour fine lunar material which he has just taken from a tote bag. This powdery sample was among the last to be revealed of the 90-odd pounds of material brought back to Earth by the Apollo 14 crewmen.

Construction and material specification

Science.gov (United States)

2002-01-01

These Construction and Material Specifications are written to the Bidder before award of the : Contract and to the Contractor after award of the Contract. The sentences that direct the Contractor to perform Work are written as commands. For example, ...

Communication Received from Argentina regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

1993-10-01

The Director General has received letters dated 27 May 1993 from the Resident Representatives of Portugal and Spain to the Agency concerning the export of nuclear material and of certain categories of equipment and other material [ru

Communications received from Members regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

1993-10-01

The Director General has received letters dated 27 May 1993 from the Resident Representatives of Portugal and Spain to the Agency concerning the export of nuclear material and of certain categories of equipment and other material [es

Use of stainless steel as structural materials in reactor cores

International Nuclear Information System (INIS)

Teodoro, C.A.

1990-01-01

Austenitic stainless steels are used as structural materials in reactor cores, due to their good mechanical properties at working temperatures and high generalized corrosion resistance in aqueous medium. The objective of this paper is to compare several 300 series austenitic stainless steels related to mechanical properties, localized corrosion resistance (SCC and intergranular) and content of delta ferrite. (author)

Fundamentals of GPS Receivers A Hardware Approach

CERN Document Server

Doberstein, Dan

2012-01-01

While much of the current literature on GPS receivers is aimed at those intimately familiar with their workings, this volume summarizes the basic principles using as little mathematics as possible, and details the necessary specifications and circuits for constructing a GPS receiver that is accurate to within 300 meters. Dedicated sections deal with the features of the GPS signal and its data stream, the details of the receiver (using a hybrid design as exemplar), and more advanced receivers and topics including time and frequency measurements. Later segments discuss the Zarlink GPS receiver chip set, as well as providing a thorough examination of the TurboRogue receiver, one of the most accurate yet made. Guiding the reader through the concepts and circuitry, from the antenna to the solution of user position, the book’s deployment of a hybrid receiver as a basis for discussion allows for extrapolation of the core ideas to more complex, and more accurate designs. Digital methods are used, but any analogue c...

High-resolution gamma ray attenuation density measurements on mining exploration drill cores, including cut cores

Science.gov (United States)

Ross, P.-S.; Bourke, A.

2017-01-01

Physical property measurements are increasingly important in mining exploration. For density determinations on rocks, one method applicable on exploration drill cores relies on gamma ray attenuation. This non-destructive method is ideal because each measurement takes only 10 s, making it suitable for high-resolution logging. However calibration has been problematic. In this paper we present new empirical, site-specific correction equations for whole NQ and BQ cores. The corrections force back the gamma densities to the "true" values established by the immersion method. For the NQ core caliber, the density range extends to high values (massive pyrite, 5 g/cm3) and the correction is thought to be very robust. We also present additional empirical correction factors for cut cores which take into account the missing material. These "cut core correction factors", which are not site-specific, were established by making gamma density measurements on truncated aluminum cylinders of various residual thicknesses. Finally we show two examples of application for the Abitibi Greenstone Belt in Canada. The gamma ray attenuation measurement system is part of a multi-sensor core logger which also determines magnetic susceptibility, geochemistry and mineralogy on rock cores, and performs line-scan imaging.

Size-Dependent Specific Surface Area of Nanoporous Film Assembled by Core-Shell Iron Nanoclusters

Directory of Open Access Journals (Sweden)

Jiji Antony

2006-01-01

Full Text Available Nanoporous films of core-shell iron nanoclusters have improved possibilities for remediation, chemical reactivity rate, and environmentally favorable reaction pathways. Conventional methods often have difficulties to yield stable monodispersed core-shell nanoparticles. We produced core-shell nanoclusters by a cluster source that utilizes combination of Fe target sputtering along with gas aggregations in an inert atmosphere at 7∘C. Sizes of core-shell iron-iron oxide nanoclusters are observed with transmission electron microscopy (TEM. The specific surface areas of the porous films obtained from Brunauer-Emmett-Teller (BET process are size-dependent and compared with the calculated data.

Effects of core-to-dentin thickness ratio on the biaxial flexural strength, reliability, and fracture mode of bilayered materials of zirconia core (Y-TZP) and veneer indirect composite resins.

Science.gov (United States)

Su, Naichuan; Liao, Yunmao; Zhang, Hai; Yue, Li; Lu, Xiaowen; Shen, Jiefei; Wang, Hang

2017-01-01

Indirect composite resins (ICR) are promising alternatives as veneering materials for zirconia frameworks. The effects of core-to-dentin thickness ratio (C/Dtr) on the mechanical property of bilayered veneer ICR/yttria-tetragonal zirconia polycrystalline (Y-TZP) core disks have not been previously studied. The purpose of this in vitro study was to assess the effects of C/Dtr on the biaxial flexural strength, reliability, and fracture mode of bilayered veneer ICR/ Y-TZP core disks. A total of 180 bilayered 0.6-mm-thick composite resin disks in core material and C/Dtr of 2:1, 1:1, and 1:2 were tested with either core material placed up or placed down for piston-on-3-ball biaxial flexural strength. The mean biaxial flexural strength, Weibull modulus, and fracture mode were measured to evaluate the variation trend of the biaxial flexural strength, reliability, and fracture mode of the bilayered disks with various C/Dtr. One-way analysis of variance (ANOVA) and chi-square tests were used to evaluate the variation tendency of fracture mode with the C/Dtr or material placed down during testing (α=.05). Light microscopy was used to identify the fracture mode. The mean biaxial flexural strength and reliability improved with the increase in C/Dtr when specimens were tested with the core material either up and down, and depended on the materials that were placed down during testing. The rates of delamination, Hertzian cone cracks, subcritical radial cracks, and number of fracture fragments partially depended on the C/Dtr and the materials that were placed down during testing. The biaxial flexural strength, reliability, and fracture mode in bilayered structures of Y-TZP core and veneer ICR depend on both the C/Dtr and the material that was placed down during testing. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Safeguarding of emergency core cooling in case of loss-of-coolant accidents with insulation material release

International Nuclear Information System (INIS)

Pointner, W.; Broecker, A.

2012-01-01

The report on safeguarding of emergency core cooling in case of loss-of-coolant accidents with insulation material release covers the following issues: assessment of the relevant status for PWR, evaluation of the national and international (USA, Canada, France) status, actualization of recommendations, transferability from PWR to BWR. Generic studies on the core cooling capability in case of insulation material release in BWR-type reactors were evaluated.

Core@shell Nanoparticles: Greener Synthesis Using Natural Plant Products

Directory of Open Access Journals (Sweden)

Mehrdad Khatami

2018-03-01

Full Text Available Among an array of hybrid nanoparticles, core-shell nanoparticles comprise of two or more materials, such as metals and biomolecules, wherein one of them forms the core at the center, while the other material/materials that were located around the central core develops a shell. Core-shell nanostructures are useful entities with high thermal and chemical stability, lower toxicity, greater solubility, and higher permeability to specific target cells. Plant or natural products-mediated synthesis of nanostructures refers to the use of plants or its extracts for the synthesis of nanostructures, an emerging field of sustainable nanotechnology. Various physiochemical and greener methods have been advanced for the synthesis of nanostructures, in contrast to conventional approaches that require the use of synthetic compounds for the assembly of nanostructures. Although several biological resources have been exploited for the synthesis of core-shell nanoparticles, but plant-based materials appear to be the ideal candidates for large-scale green synthesis of core-shell nanoparticles. This review summarizes the known strategies for the greener production of core-shell nanoparticles using plants extract or their derivatives and highlights their salient attributes, such as low costs, the lack of dependence on the use of any toxic materials, and the environmental friendliness for the sustainable assembly of stabile nanostructures.

Monodisperse MnO2@NiCo2O4 core/shell nanospheres with highly opened structures as electrode materials for good-performance supercapacitors

Science.gov (United States)

Zhou, You; Ma, Li; Gan, Mengyu; Ye, Menghan; Li, Xiurong; Zhai, Yanfang; Yan, Fabing; Cao, Feifei

2018-06-01

The monodisperse MnO2@NiCo2O4 core/shell nanospheres for good-performance supercapacitors are designed and synthesized by a two-step solution-based method and a simple post annealing process. In the composite, both MnO2 (the "core") and NiCo2O4 (the "shell") are formed by the accumulation of nanoflakes. Thus, nearly all the core/shell nanoflakes are highly opened and accessible to electrolyte, making them give full play to the Faradaic reaction. Our results demonstrate that the composite electrode exhibits desirable pseudocapacitive behaviors with higher specific capacitance (1127.27 F g-1 at a current density of 1 A g-1), better rate capability (81.0% from 1 to 16 A g-1) and superior cycling stability (actually 126.8% capacitance retention after 1000 cycles and only 3.7% loss after 10,000 cycles at 10 A g-1) in 3 M KOH aqueous solution. Moreover, it offers the excellent specific energy density of 26.6 Wh kg-1 at specific power density of 800 W kg-1. The present MnO2@NiCo2O4 core/shell nanospheres with remarkable electrochemical properties are considered as potential electrode materials for the next generation supercapacitors.

Standard Test Method for Water Absorption of Core Materials for Structural Sandwich Constructions

CERN Document Server

American Society for Testing and Materials. Philadelphia

2001-01-01

1.1 This test method covers the determination of the relative amount of water absorption by various types of structural core materials when immersed or in a high relative humidity environment. This test method is intended to apply to only structural core materials; honeycomb, foam, and balsa wood. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts.

Science.gov (United States)

Panitiwat, Prapaporn; Salimee, Prarom

2017-01-01

This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC), MultiCore Flow (MCF), and LuxaCore Z-Dual (LCZ)), and a nanohybrid composite, (Tetric N-Ceram (TNC)). Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post) cemented with resin cement (Panavia F2.0). Samples were randomly divided into four groups (n=10). Each group was built-up with one of the four core materials following its manufacturers' instructions. The teeth were embedded in acrylic resin blocks. Nickel-Chromium crowns were fixed on the specimens with resin cement. The fracture resistance was determined using a universal testing machine with a crosshead speed of 1 mm/min at 1350 to the tooth axis until failure occurred. All core materials used in the study were subjected to test for the flexural modulus according to ISO 4049:2009. One-way ANOVA and Bonferroni multiple comparisons test indicated that the fracture resistance was higher in the groups with CPC and MCF, which presented no statistically significant difference (p>0.05), but was significantly higher than in those with LCZ and TNC (paligned with the same tendency of fracture loads. Among the cores used in this study, the composite core with high filler content tended to enhance fracture thresholds of teeth restored with fiber posts more than others.

TMI-2 core-examination program: INEL facilities-readiness study

International Nuclear Information System (INIS)

McLaughlin, T.B.

1982-09-01

This document is a review of the Idaho National Engineering Laboratory's (INEL) remote handling facilities. Their availability and readiness to conduct examination and analyses of TMI-2 core samples was determined. Examination of these samples require that the facilities be capable of receiving commercial casks, unloading canisters from the casks, opening the canisters, handling the fuel debris and assemblies, and performing various examinations. The documentation that was necessary for the INEL to have before the receipt of the core material was identified. The core information was also required for input to these documents. The costs, schedules, and a preliminary-project plan are presented for the tasks which are identified as prerequisites to the receipt of the first core sample

Porous Core-Shell Nanostructures for Catalytic Applications

Science.gov (United States)

Ewers, Trevor David

Porous core-shell nanostructures have recently received much attention for their enhanced thermal stability. They show great potential in the field of catalysis, as reactant gases can diffuse in and out of the porous shell while the core particle is protected from sintering, a process in which particles coalesce to form larger particles. Sintering is a large problem in industry and is the primary cause of irreversible deactivation. Despite the obvious advantages of high thermal stability, porous core-shell nanoparticles can be developed to have additional interactive properties from the combination of the core and shell together, rather than just the core particle alone. This dissertation focuses on developing new porous core-shell systems in which both the core and shell take part in catalysis. Two types of systems are explored; (1) yolk-shell nanostructures with reducible oxide shells formed using the Kirkendall effect and (2) ceramic-based porous oxide shells formed using sol-gel chemistry. Of the Kirkendall-based systems, Au FexOy and Cu CoO were synthesized and studied for catalytic applications. Additionally, ZnO was explored as a potential shelling material. Sol-gel work focused on optimizing synthetic methods to allow for coating of small gold particles, which remains a challenge today. Mixed metal oxides were explored as a shelling material to make dual catalysts in which the product of a reaction on the core particle becomes a reactant within the shell.

Relating the structural strength of concrete sewer pipes and material properties retrieved from core samples

NARCIS (Netherlands)

Stanic, N.; Langeveld, J.G.; Salet, Theo; Clemens, F.H.L.R.

2016-01-01

Drill core samples are taken in practice for an analysis of the material characteristics of concrete pipes in order to improve the quality of the decision-making on rehabilitation actions. Earlier research has demonstrated that core sampling is associated with a significant uncertainty. In this

Interfacial characterization of ceramic core materials with veneering porcelain for all-ceramic bi-layered restorative systems.

Science.gov (United States)

Tagmatarchis, Alexander; Tripodakis, Aris-Petros; Filippatos, Gerasimos; Zinelis, Spiros; Eliades, George

2014-01-01

The aim of the study was to characterize the elemental distribution at the interface between all-ceramic core and veneering porcelain materials. Three groups of all-ceramic cores were selected: A) Glass-ceramics (Cergo, IPS Empress, IPS Empress 2, e-max Press, Finesse); B) Glass-infiltrated ceramics (Celay Alumina, Celay Zirconia) and C) Densely sintered ceramics (Cercon, Procera Alumina, ZirCAD, Noritake Zirconia). The cores were combined with compatible veneering porcelains and three flat square test specimens were produced for each system. The core-veneer interfaces were examined by scanning electron microscopy and energy dispersive x-ray microanalysis. The glass-ceramic systems showed interfacial zones reach in Si and O, with the presence of K, Ca, Al in core and Ca, Ce, Na, Mg or Al in veneer material, depending on the system tested. IPS Empress and IPS Empress 2 demonstrated distinct transitional phases at the core-veneer interface. In the glassinfiltrated systems, intermixing of core (Ce, La) with veneer (Na, Si) elements occurred, whereas an abrupt drop of the core-veneer elemental concentration was documented at the interfaces of all densely sintered ceramics. The results of the study provided no evidence of elemental interdiffusion at the core-veneer interfaces in densely sintered ceramics, which implies lack of primary chemical bonding. For the glass-containing systems (glassceramics and glass-infiltrated ceramics) interdiffusion of the glass-phase seems to play a critical role in establishing a primary bonding condition between ceramic core and veneering porcelain.

Materials considerations for UF6 gas-core reactor. Interim report for preliminary design study

International Nuclear Information System (INIS)

Wagner, P.

1977-04-01

The limiting materials problem in a high-temperature UF 6 core reactor is the corrosion of the core containment vessel. The UF 6 , the lower fluorides of uranium, and the fluorine that exist at the anticipated reactor operating conditions (1000 K and about one atmosphere UF 6 ) are all corrosive. Because of this, the materials evaluation effort for this reactor design study has concentrated on the identification of a viable system for the containment vessel that meets both the materials and neutronic requirements. A study of the literature has revealed that the most promising corrosion-resistant candidates are Ni or Ni-Al alloys. One of the conclusions of this work is that the containment vessel use a nickel liner or clad since the use of Ni as a structural member is precluded by its relative blackness to thermal neutrons. Estimates of corrosion rates of Ni and Ni-Al alloys, the effects of the pressure and temperature of F 2 on the corrosion rates, calculated equilibrium gas compositions at reactor core operating conditions, suggested methods of fabrication, and recommendations for future research and development are included

The Percent of Positive Biopsy Cores Improves Prediction of Prostate Cancer-Specific Death in Patients Treated With Dose-Escalated Radiotherapy

International Nuclear Information System (INIS)

Qian Yushen; Feng, Felix Y.; Halverson, Schuyler; Blas, Kevin; Sandler, Howard M.; Hamstra, Daniel A.

2011-01-01

Purpose: To examine the prognostic utility of the percentage of positive cores (PPC) at the time of prostate biopsy for patients treated with dose-escalated external beam radiation therapy. Methods and Materials: We performed a retrospective analysis of patients treated at University of Michigan Medical Center to at least 75 Gy. Patients were stratified according to PPC by quartile, and freedom from biochemical failure (nadir + 2 ng/mL), freedom from metastasis (FFM), cause-specific survival (CSS), and overall survival (OS) were assessed by log-rank test. Receiver operator characteristic (ROC) curve analysis was used to determine the optimal cut point for PPC stratification. Finally, Cox proportional hazards multivariate regression was used to assess the impact of PPC on clinical outcome when adjusting for National Comprehensive Cancer Network (NCCN) risk group and androgen deprivation therapy. Results: PPC information was available for 651 patients. Increasing-risk features including T stage, prostate-specific antigen, Gleason score, and NCCN risk group were all directly correlated with increasing PPC. On log-rank evaluation, all clinical endpoints, except for OS, were associated with PPC by quartile, with worse clinical outcomes as PPC increased, with the greatest impact seen in the highest quartile (>66.7% of cores positive). ROC curve analysis confirmed that a cut point using two-thirds positive cores was most closely associated with CSS (p = 0.002; area under ROC curve, 0.71). On univariate analysis, stratifying patients according to PPC less than or equal to 66.7% vs. PPC greater than 66.7% was prognostic for freedom from biochemical failure (p = 0.0001), FFM (p = 0.0002), and CSS (p = 0.0003) and marginally prognostic for OS (p = 0.055). On multivariate analysis, after adjustment for NCCN risk group and androgen deprivation therapy use, PPC greater than 66.7% increased the risk for biochemical failure (p = 0.0001; hazard ratio [HR], 2.1 [95% confidence

The Common Core State Standards and the Role of Instructional Materials: A Case Study on EdReports.org

Science.gov (United States)

Watt, Michael G.

2016-01-01

The purpose of this study was to review research studies investigating the role of instructional materials in relation to the Common Core State Standards and to evaluate whether a new organisation, EdReports.org, founded to evaluate the alignment of instructional materials to the Common Core State Standards, has achieved its objectives. Content…

Influence of different post core materials on the color of Empress 2 full ceramic crowns.

Science.gov (United States)

Ge, Jing; Wang, Xin-zhi; Feng, Hai-lan

2006-10-20

For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a metal post core. Therefore, this experiment was conducted to test the esthetical possibility of applying cast metal post core in a full ceramic crown restoration. The color of full ceramic crowns on gold and Nickel-Chrome post cores was compared with the color of the same crowns on tooth colored post cores. Different try-in pastes were used to imitate the influence of a composite cementation on the color of different restorative combinations. The majority of patients could not detect any color difference less than DeltaE 1.8 between the two ceramic samples. So, DeltaE 1.8 was taken as the objective evaluative criterion for the evaluation of color matching and patients' satisfaction. When the Empress 2 crown was combined with the gold alloy post core, the color of the resulting material was similar to that of a glass fiber reinforced resin post core (DeltaE = 0.3). The gold alloy post core and the try-in paste did not show a perceptible color change in the full ceramic crowns, which indicated that the color of the crowns might not be susceptible to change between lab and clinic as well as during the process of composite cementation. Without an opaque covering the Ni-Cr post core would cause an unacceptable color effect on the crown (DeltaE = 2.0), but with opaque covering, the color effect became more clinically satisfactory (DeltaE = 1.8). It may be possible to apply a gold alloy post core in the Empress 2 full ceramic crown restoration when necessary. If a non-extractible Ni-Cr post core exists in the root canal, it might be possible to restore the tooth with an Empress 2 crown after covering the labial surface of the core with one layer of opaque resin cement.

Irradiation experiments on materials for core internals, pressure vessel and fuel cladding

Energy Technology Data Exchange (ETDEWEB)

Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Materials degradation due to the aging phenomena is one of the key issues for the life assessment and extension of the light water reactors (LWRs). This presentation introduces JAERI`s activities in the field of LWR material researches which utilize the research and testing reactors for irradiation experiments. The activities are including the material studies for the core internals, pressure vessel and fuel cladding. These materials are exposed to the neutron/gamma radiation and high temperature water environments so that it is worth reviewing their degradation phenomena as the continuum. Three topics are presented; For the core internal materials, the irradiation assisted stress corrosion cracking (IASCC) of austenitic stainless steels is the present major concern. At JAERI the effects of alloying elements on IASCC have been investigated through the post-irradiation stress corrosion cracking tests in high-temperature water. The radiation embrittlement of pressure vessel steels is still a significant issue for LWR safety, and at JAERI some factors affecting the embrittlement behavior such as a dose rate have been investigated. Waterside corrosion of Zircaloy fuel cladding is one of the limiting factors in fuel rod performance and an in-situ measurement of the corrosion rate in high-temperature water was performed in JMTR. To improve the reliability of experiments and to extent the applicability of experimental techniques, a mutual utilization of the technical achievements in those irradiation experiments is desired. (author)

Behaviour of contact layer material between cermet fuel element core and can

International Nuclear Information System (INIS)

Gavrilin, S.S.; Permyakov, L.N.; Simakov, G.A.; Chernikov, A.S.

1996-01-01

The structural state of the contact layer between the shell of the Zr1Nb alloy and cermet fuel element core containing up to 70% of uranium dioxides is experimental studied. The silumin alloy was used as contact material. The results of studies on interaction zones, formed on the Zr1Nb - silumin boundary after fuel elements manufacture and also under temperature conditions, modeling the maximum design and hypothetical accidents accompanied by the contact material melting, are presented [ru

Studies on the core-support carbon material for VHTR, (1)

International Nuclear Information System (INIS)

Matsuo, Hideto; Saito, Tamotsu; Fukuda, Yasumasa; Sasaki, Yasuichi; Hasegawa, Takashi.

1979-11-01

To obtain information of core-support carbon material for VHTR, thermal conductivity and electrical resistivity of three domestic carbon blocks were measured. Results indicated the need for development of carbon material with lower thermal conductivity for VHTR. These two were also measured of the samples heat-treated between 1000 0 C and 3040 0 C for one hour. Thermal conductivity increased with heat-treatment above 1200 0 C and resistivity stayed constant between 1500 0 C and 2000 0 C. The results should be useful in choosing the final heat-treatment temperature in carbon material production. The changes of Lorentz number with heat treatment were classified into three heat-treatment temperature regions of below 1500 0 C, 1500 0 C - 2500 0 C, and above 2500 0 C; the results are interpreted with a graphitization model. (author)

Core-shelled mesoporous CoFe2O4-SiO2 material with good adsorption and high-temperature magnetic recycling capabilities

Science.gov (United States)

Li, Zhi'ang; Wang, Jianlin; Liu, Min; Chen, Tong; Chen, Jifang; Ge, Wen; Fu, Zhengping; Peng, Ranran; Zhai, Xiaofang; Lu, Yalin

2018-04-01

Residues of organic dye in industrial effluents cause severe water system pollution. Although several methods, such as biodegradation and activated carbon adsorption, are available for treating these effluents before their discharge into waterbodies, secondary pollution by adsorbents and degrading products remains an issue. Therefore, new materials should be identified to solve this problem. In this work, CoFe2O4-SiO2 core-shell structures were synthesized using an improved Stöber method by coating mesoporous silica onto CoFe2O4 nanoparticles. The specific surface areas of the synthesized particles range from 30 m2/g to 150 m2/g and vary according to the dosage amount of tetraethoxysilane. Such core-shelled nanoparticles have the following advantages for treating industrial effluents mixed with dye: good adsorption capability, above-room-temperature magnetic recycling capability, and heat-enduring stability. Through adsorption of methylene blue, a typical dyeing material, the core-shell-structured particles show a good adsorption capability of approximately 33 mg/L. The particles are easily and completely collected by magnets, which is possible due to the magnetic property of core CoFe2O4. Heat treatment can burn out the adsorbed dyes and good adsorption performance is sustained even after several heat-treating loops. This property overcomes the common problem of particles with Fe3O4 as a core, by which Fe3O4 is oxidized to nonmagnetic α-Fe2O3 at the burning temperature. We also designed a miniature of effluent-treating pipeline, which demonstrates the potential of the application.

Behaviour of LWR core materials under accident conditions. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

1996-12-01

At the invitation of the Government of the Russian Federation, following a proposal of the International Working Group on Water Reactor Fuel Performance and Technology, the IAEA convened a Technical Committee Meeting on Behaviour of LWR Core Materials Under Accident Conditions from 9 to 13 October 1995 in Dimitrovgrad to analyze and evaluate the behaviour of LWR core materials under accident conditions with special emphasis on severe accidents. In-vessel severe accidents phenomena were considered in detail, but specialized thermal hydraulic aspects as well as ex-vessel phenomena were outside the scope of the meeting. Forty participants representing eight countries attended the meeting. Twenty-three papers were presented and discussed during five sessions. Refs, figs, tabs

Magnetite Core-Shell Nanoparticles in Nondestructive Flaw Detection of Polymeric Materials.

Science.gov (United States)

Hetti, Mimi; Wei, Qiang; Pohl, Rainer; Casperson, Ralf; Bartusch, Matthias; Neu, Volker; Pospiech, Doris; Voit, Brigitte

2016-10-04

Nondestructive flaw detection in polymeric materials is important but difficult to achieve. In this research, the application of magnetite nanoparticles (MNPs) in nondestructive flaw detection is studied and realized, to the best of our knowledge, for the first time. Superparamagnetic and highly magnetic (up to 63 emu/g) magnetite core-shell nanoparticles are prepared by grafting bromo-end-group-functionalized poly(glycidyl methacrylate) (Br-PGMA) onto surface-modified Fe 3 O 4 NPs. These Fe 3 O 4 -PGMA NPs are blended into bisphenol A diglycidylether (BADGE)-based epoxy to form homogeneously distributed magnetic epoxy nanocomposites (MENCs) after curing. The core Fe 3 O 4 of the Fe 3 O 4 -PGMA NPs endows the MENCs with magnetic property, which is crucial for nondestructive flaw detection of the materials, while the shell PGMA promotes colloidal stability and prevents NP aggregation during curing. The eddy current testing (ET) technique is first applied to detect flaws in the MENCs. Through the brightness contrast of the ET image, surficial and subsurficial flaws in MENCs can be detected, even for MENCs with low content of Fe 3 O 4 -PGMA NPs (1 wt %). The incorporation of Fe 3 O 4 -PGMA NPs can be easily extended to other polymer and polymer-based composite systems and opens a new and very promising pathway toward MNP-based nondestructive flaw detection in polymeric materials.

Further work on sodium borates as sacrificial materials for a core-catcher

International Nuclear Information System (INIS)

Dalle Donne, M.; Dorner, S.; Roth, A.; Werle, H.

1982-01-01

Sodium borates are suitable low melting point sacrificial materials for a core-catcher of a fast reactor. Concept, design and initial development work have been described previously. Here we report on the measurements of density, volumetric thermal expansion coefficients and viscosity of borax and sodium metaborate, pure and with various percentages of dissolved UO 2 . The density of these molten salts was measured with the buoyancy method in the temperature range 850 - 1300 0 C, while the viscosity was measured in the temperature range 700 - 1250 0 C with a Haake viscosity balance. Simulation experiments with low melting point materials were performed to investigate the ratio of the downward to sideward melt velocity. The results of these experiments show that this ratio is equal to 0.34 for a solid to liquid density ratio rho = 1.66. For the real borax core-catcher rho = 4 and this would correspond to a velocity ratio of about one

The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 2 Core.

Science.gov (United States)

Hucka, Michael; Bergmann, Frank T; Dräger, Andreas; Hoops, Stefan; Keating, Sarah M; Le Novère, Nicolas; Myers, Chris J; Olivier, Brett G; Sahle, Sven; Schaff, James C; Smith, Lucian P; Waltemath, Dagmar; Wilkinson, Darren J

2018-03-09

Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 2 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML, their encoding in XML (the eXtensible Markup Language), validation rules that determine the validity of an SBML document, and examples of models in SBML form. The design of Version 2 differs from Version 1 principally in allowing new MathML constructs, making more child elements optional, and adding identifiers to all SBML elements instead of only selected elements. Other materials and software are available from the SBML project website at http://sbml.org/.

Dielectric properties of 3D-printed materials for anatomy specific 3D-printed MRI coils

Science.gov (United States)

Behzadnezhad, Bahareh; Collick, Bruce D.; Behdad, Nader; McMillan, Alan B.

2018-04-01

Additive manufacturing provides a low-cost and rapid means to translate 3D designs into the construction of a prototype. For MRI, this type of manufacturing can be used to construct various components including the structure of RF coils. In this paper, we characterize the material properties (dielectric constant and loss tangent) of several common 3D-printed polymers in the MRI frequency range of 63-300 MHz (for MRI magnetic field strengths of 1.5-7 T), and utilize these material properties in full-wave electromagnetic simulations to design and construct a very low-cost subject/anatomy-specific 3D-printed receive-only RF coil that fits close to the body. We show that the anatomy-specific coil exhibits higher signal-to-noise ratio compared to a conventional flat surface coil.

Communication received from Argentina regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

1995-10-01

The Director General has received a letter of 27 June 1995 from the Resident Representative of Argentina to the Agency concerning the export of nuclear material and of certain categories of equipment and other material. In the light of the wish expressed at the end of the letter, the text of the letter is attached hereto

Contrasting two models of academic self-efficacy--domain-specific versus cross-domain--in children receiving and not receiving special instruction in mathematics.

Science.gov (United States)

Jungert, Tomas; Hesser, Hugo; Träff, Ulf

2014-10-01

In social cognitive theory, self-efficacy is domain-specific. An alternative model, the cross-domain influence model, would predict that self-efficacy beliefs in one domain might influence performance in other domains. Research has also found that children who receive special instruction are not good at estimating their performance. The aim was to test two models of how self-efficacy beliefs influence achievement, and to contrast children receiving special instruction in mathematics with normally-achieving children. The participants were 73 fifth-grade children who receive special instruction and 70 children who do not receive any special instruction. In year four and five, the children's skills in mathematics and reading were assessed by national curriculum tests, and in their fifth year, self-efficacy in mathematics and reading were measured. Structural equation modeling showed that in domains where children do not receive special instruction in mathematics, self-efficacy is a mediating variable between earlier and later achievement in the same domain. Achievement in mathematics was not mediated by self-efficacy in mathematics for children who receive special instruction. For normal achieving children, earlier achievement in the language domain had an influence on later self-efficacy in the mathematics domain, and self-efficacy beliefs in different domains were correlated. Self-efficacy is mostly domain specific, but may play a different role in academic performance depending on whether children receive special instruction. The results of the present study provided some support of the Cross-Domain Influence Model for normal achieving children. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Fracture Resistance of Endodontically Treated Teeth Restored with Biodentine, Resin Modified GIC and Hybrid Composite Resin as a Core Material.

Science.gov (United States)

Subash, Dayalan; Shoba, Krishnamma; Aman, Shibu; Bharkavi, Srinivasan Kumar Indu; Nimmi, Vijayan; Abhilash, Radhakrishnan

2017-09-01

The restoration of a severely damaged tooth usually needs a post and core as a part of treatment procedure to provide a corono - radicular stabilization. Biodentine is a class of dental material which possess high mechanical properties with excellent biocompatibility and bioactive behaviour. The sealing ability coupled with optimum physical properties could make Biodentine an excellent option as a core material. The aim of the study was to determine the fracture resistance of Biodentine as a core material in comparison with resin modified glass ionomer and composite resin. Freshly extracted 30 human permanent maxillary central incisors were selected. After endodontic treatment followed by post space preparation and luting of Glass fibre post (Reforpost, Angelus), the samples were divided in to three groups based on the type of core material. The core build-up used in Group I was Biodentine (Septodont, France), Group II was Resin-Modified Glass Ionomer Cement (GC, Japan) and Group III was Hybrid Composite Resin (TeEconom plus, Ivoclar vivadent). The specimens were subjected to fracture toughness using Universal testing machine (1474, Zwick/Roell, Germany) and results were compared using One-way analysis of variance with Tukey's Post hoc test. The results showed that there was significant difference between groups in terms of fracture load. Also, composite resin exhibited highest mean fracture load (1039.9 N), whereas teeth restored with Biodentine demonstrated the lowest mean fracture load (176.66 N). Resin modified glass ionomer exhibited intermediate fracture load (612.07 N). The primary mode of failure in Group I and Group II was favourable (100%) while unfavourable fracture was seen in Group III (30%). Biodentine, does not satisfy the requirements to be used as an ideal core material. The uses of RMGIC's as a core build-up material should be limited to non-stress bearing areas. Composite resin is still the best core build-up material owing to its high fracture

Parameters for Building Materials Specifications in Lagos, Nigeria

Directory of Open Access Journals (Sweden)

Clement Oluwole Folorunso

2013-07-01

Full Text Available The responsibility of specifying materials for building construction purposes within Nigeria rests on the architects. Understanding the appropriate parameters for specifying building materials that could lead to immense financial proportion is required from the architects. The level of understanding and knowledge of architects is germane to the optimum performance of buildings throughout their life cycle. The methodology applied for this research involved the administration of a structured questionnaire on professional architects within the study area to determine the basis of their decision on the materials they specify or chose for building finishes. The parameters used to measure the specification of materials for finishes are client’s choice, cost, climatic compliance, and maintenance demand of materials. Findings show that the maintenance demand of materials is the most important factor that determines the specification of materials irrespective of the choice of client and climate. However, cost occupies a prominent role in the decision process. It also shows that most architects are not fully aware about the role of climate in determining the life cycle of materials in tropical environments. The compliance of materials to ever-changing climate does not constitute a major factor in the specification of materials in the area.

The influence of anisotropy on the core structure of Shockley partial dislocations within FCC materials

Science.gov (United States)

Szajewski, B. A.; Hunter, A.; Luscher, D. J.; Beyerlein, I. J.

2018-01-01

Both theoretical and numerical models of dislocations often necessitate the assumption of elastic isotropy to retain analytical tractability in addition to reducing computational load. As dislocation based models evolve towards physically realistic material descriptions, the assumption of elastic isotropy becomes increasingly worthy of examination. We present an analytical dislocation model for calculating the full dissociated core structure of dislocations within anisotropic face centered cubic (FCC) crystals as a function of the degree of material elastic anisotropy, two misfit energy densities on the γ-surface ({γ }{{isf}}, {γ }{{usf}}) and the remaining elastic constants. Our solution is independent of any additional features of the γ-surface. Towards this pursuit, we first demonstrate that the dependence of the anisotropic elasticity tensor on the orientation of the dislocation line within the FCC crystalline lattice is small and may be reasonably neglected for typical materials. With this approximation, explicit analytic solutions for the anisotropic elasticity tensor {B} for both nominally edge and screw dislocations within an FCC crystalline lattice are devised, and employed towards defining a set of effective isotropic elastic constants which reproduce fully anisotropic results, however do not retain the bulk modulus. Conversely, Hill averaged elastic constants which both retain the bulk modulus and reasonably approximate the dislocation core structure are employed within subsequent numerical calculations. We examine a wide range of materials within this study, and the features of each partial dislocation core are sufficiently localized that application of discrete linear elasticity accurately describes the separation of each partial dislocation core. In addition, the local features (the partial dislocation core distribution) are well described by a Peierls-Nabarro dislocation model. We develop a model for the displacement profile which depends upon

Results and Prospects of Development of Works on Structural Core Materials for Russian Fast Reactors

International Nuclear Information System (INIS)

Nikitina, A.A.; Ageev, V.S.; Leontyeva-Smirnova, M.V.; Mitrofanova, N.M.; Tselishchev, A.V.

2015-01-01

The strategy of development of atomic energy in Russia in the first half of XXI century contemplates construction and putting in operation of fast reactors of new generation with different types of coolant: sodium (BN-800, BN-1200, MBIR), lead (BREST-OD-300) and lead-bismuth eutectic (SVBR-100). For assurance of the working capacity of reactors that are under construction and achievement of economically reasonable burn-up of nuclear fuel the structural core materials with necessary level of radiation resistance, heat resistance, corrosion resistance to products of fuel fission, corrosion resistance in coolant and in water must be developed and justified. For sodium cooled reactors the key challenge is creation of radiation resistant and heat resistant cladding materials, which must ensure the achievement of damage doses at least 140 dpa. The solution of this problem is provided by phased use as cladding materials of austenitic steels ChS68 and EK164 (maximum damage doses ~ 92 and ~110-115 dpa, respectively), precipitation-hardening heat resistant ferritic-martensitic steels EK181 and ChS139 (maximum damage dose ~140 dpa) and oxide dispersion strengthened (ODS) steels (maximum damage dose more than 140 dpa). For development of core materials for reactors with lead and lead-bismuth eutectic coolants the most serious challenge is corrosion resistance of materials in coolant. Therefore at present time a very wide range of works on study of corrosion resistance of candidate materials is carrying out. As the basic material for the cladding tubes is considered a ferritic-martensitic steel EP823 with high silicon content. In this report the main results of works on justification of the working capacity of materials of different classes in respect to use it in cores of operating and prospective fast reactors with different types of coolant and prospects of further development of works are presented. (author)

Core design studies on various forms of coolants and fuel materials. 2. Studies on liquid heavy metal and gas cooled cores, small cores and evaluation of 4-type cores

International Nuclear Information System (INIS)

Hayashi, Hideyuki; Sakashita, Yoshiyuki; Naganuma, Masayuki; Takaki, Naoyuki; Mizuno, Tomoyasu; Ikegami, Tetsuo

2001-01-01

Alternative concepts to sodium cooled fast reactors, such as heavy metal liquid cooled reactors and gas cooled fast reactors were studied in Phase-1 of the feasibility studies, aiming at simplification of the system, high thermal efficiency and enhancing safety. Fuel and core specifications and nuclear characteristics were surveyed to meet the targets for commercialization of fast reactor cycle. Nuclear characteristics of small fast reactor cores were also surveyed from the perspective of the possibility of multi-purpose use and dispersed power stations. The key points of the design study for each concept in Phase-2 were summarized from the aspect of the screening of the candidates for FR commercialization. (author)

Flowing and freezing of molten core materials during unprotected loss of flow accidents in sodium cooled fast reactors

International Nuclear Information System (INIS)

Maschek, W.; Royl, P.

1988-09-01

Flowing and freezing of mobile core materials change the fissile material distribution and core-inventory under hypothetical accident conditions and determine the path to permanent shutdown of the neutronic events and the energetic potentials. The report classifies the bondary conditions for such flowing and freezing processes by going through the different situations under which these processes can occur in the scenario of the unprotected loss of flow (ULOF) accident. The classification is based on ULOF-accident simulations for a homogeneous reactor core concept of a 300 MWe LMFBR (e. g. SNR-300), but many boundary conditions are also characteristic for other core designs. A review of the relevant experiments is then made to correlate the available experimental information with these classified boundary conditions and to look at the resulting flowing and freezing processes. Boundary conditions that have been experimentally shown to be important are assigned high priorities. The data are specifically valued in relation to these boundary conditions of high priorities. The review includes the major experimental programs with published results. The discussion shows that the results from most clean condition tests for melt relocations are valuable for a better understanding of basic phenomena and analytical model development, but are not directly applicable to real accident conditions. The database for relevant boundary conditions from the ULOF scenario is limited and largely included in integral sequence tests from which quantitative information for modelling is difficult to obtain. Needs for additional investigations are identified. The suggestions are mainly restricted to investigations of the early phase of fuel removal. They are given with reference to candidate facilities and include relocations in the subassemblies and in the inter-subassembly gaps. Particular emphasis is put on the leading edge properties and possible driving forces to which more attention

Experimental study of the mechanical behaviour of pin reinforced foam core sandwich materials under shear load

International Nuclear Information System (INIS)

Dimassi, M A; Brauner, C; Herrmann, A S

2016-01-01

Sandwich structures with a lightweight closed cell hard foam core have the potential to be used in primary structures of commercial aircrafts. Compared to honeycomb core sandwich, the closed cell foam core sandwich overcomes the issue of moisture take up and makes the manufacturing of low priced and highly integrated structures possible. However, lightweight foam core sandwich materials are prone to failure by localised external loads like low velocity impacts. Invisible cracks could grow in the foam core and threaten the integrity of the structure. In order to enhance the out-of-plane properties of foam core sandwich structures and to improve the damage tolerance (DT) dry fibre bundles are inserted in the foam core. The pins are infused with resin and co-cured with the dry fabric face sheets in an out-of-autoclave process. This study presents the results obtained from shear tests following DIN 53294-standard, on flat sandwich panels. All panels were manufactured with pin-reinforcement manufactured with the Tied Foam Core Technology (TFC) developed by Airbus. The effects of pin material (CFRP and GFRP) and pin volume fraction on the shear properties of the sandwich structure and the crack propagation were investigated and compared to a not pinned reference. It has been concluded that the pin volume fraction has a remarkable effect on the shear properties and damage tolerance of the observed structure. Increasing the pin volume fraction makes the effect of crack redirection more obvious and conserves the integrity of the structure after crack occurrence. (paper)

A Comparison of General and Work-Specific Measures of Core Self-Evaluations

Science.gov (United States)

Bowling, Nathan A.; Wang, Qiang; Tang, Han Ying; Kennedy, Kellie D.

2010-01-01

During the past decade, considerable research attention has been given to core self-evaluations (CSEs). Although this research has found that CSE is related to several important work-related outcomes (e.g., job satisfaction, job performance), we believe that researchers' reliance on general rather than work-specific CSE has resulted in…

Metallic nanoshells with semiconductor cores: optical characteristics modified by core medium properties.

Science.gov (United States)

Bardhan, Rizia; Grady, Nathaniel K; Ali, Tamer; Halas, Naomi J

2010-10-26

It is well-known that the geometry of a nanoshell controls the resonance frequencies of its plasmon modes; however, the properties of the core material also strongly influence its optical properties. Here we report the synthesis of Au nanoshells with semiconductor cores of cuprous oxide and examine their optical characteristics. This material system allows us to systematically examine the role of core material on nanoshell optical properties, comparing Cu(2)O core nanoshells (ε(c) ∼ 7) to lower core dielectric constant SiO(2) core nanoshells (ε(c) = 2) and higher dielectric constant mixed valency iron oxide nanoshells (ε(c) = 12). Increasing the core dielectric constant increases nanoparticle absorption efficiency, reduces plasmon line width, and modifies plasmon energies. Modifying the core medium provides an additional means of tailoring both the near- and far-field optical properties in this unique nanoparticle system.

The bond of different post materials to a resin composite cement and a resin composite core material.

Science.gov (United States)

Stewardson, D; Shortall, A; Marquis, P

2012-01-01

To investigate the bond of endodontic post materials, with and without grit blasting, to a resin composite cement and a core material using push-out bond strength tests. Fiber-reinforced composite (FRC) posts containing carbon (C) or glass (A) fiber and a steel (S) post were cemented into cylinders of polymerized restorative composite without surface treatment (as controls) and after grit blasting for 8, 16, and 32 seconds. Additional steel post samples were sputter-coated with gold before cementation to prevent chemical interaction with the cement. Cylindrical composite cores were bonded to other samples. After sectioning into discs, bond strengths were determined using push-out testing. Profilometry and electron microscopy were used to assess the effect of grit blasting on surface topography. Mean (standard deviation) bond strength values (MPa) for untreated posts to resin cement were 8.41 (2.80) for C, 9.61(1.88) for A, and 19.90 (3.61) for S. Prolonged grit blasting increased bond strength for FRC posts but produced only a minimal increase for S. After 32 seconds, mean values were 20.65 (4.91) for C, 20.41 (2.93) for A, and 22.97 (2.87) for S. Gold-coated steel samples produced the lowest bond strength value, 7.84 (1.40). Mean bond strengths for untreated posts bonded to composite cores were 6.19 (0.95) for C, 13.22 (1.61) for A, and 8.82 (1.18) for S, and after 32 seconds of grit blasting the values were 17.30 (2.02) for C, 26.47 (3.09) for A, and 20.61 (2.67) for S. FRC materials recorded higher roughness values before and after grit blasting than S. With prolonged grit blasting, roughness increased for A and C, but not for S. There was no evidence of significant bonding to untreated FRC posts, but significant bonding occurred between untreated steel posts and the resin cement. Increases in the roughness of FRC samples were material dependent and roughening significantly increased bond strength values (p<0.05). Surface roughening of the tested FRC posts is

Penetration of molten core materials into basaltic and limestone concrete

International Nuclear Information System (INIS)

Sutherland, H.J.

1978-01-01

In conjunction with the small-scale, melt-concrete interaction tests being conducted at Sandia Laboratories, an acoustic technique has been used to monitor the penetration of molten core materials into basaltic and limestone concrete. Real time plots of the position of the melt/concrete interface have been obtained, and they illustrate that the initial penetration rate of the melt may be of the order of 80 mm/min. Phenomena deduced by the technique include a non-wetted melt/concrete interface

Relative translucency of six all-ceramic systems. Part II: core and veneer materials.

Science.gov (United States)

Heffernan, Michael J; Aquilino, Steven A; Diaz-Arnold, Ana M; Haselton, Debra R; Stanford, Clark M; Vargas, Marcos A

2002-07-01

STATEMENT OF PROBLEM All-ceramic core materials with various strengthening compositions have a range of translucencies. It is unknown whether translucency differs when all-ceramic materials are fabricated similarly to the clinical restoration with a veneered core material. This study compared the translucency of 6 all-ceramic materials veneered and glazed at clinically appropriate thicknesses. Core specimens (n = 5 per group) of Empress dentin, Empress 2 dentin, In-Ceram Alumina, In-Ceram Spinell, In-Ceram Zirconia, and Procera AllCeram were fabricated as described in Part I of this study and veneered with their corresponding dentin porcelain to a final thickness of 1.47 +/- 0.01 mm. These specimens were compared with veneered Vitadur Alpha opaque dentin (as a standard), a clear glass disc (positive control), and a high-noble metal-ceramic alloy (Porc. 52 SF) veneered with Vitadur Omega dentin (negative control). Specimen reflectance was measured with an integrating sphere attached to a spectrophotometer across the visible spectrum (380 to 700 nm); 0-degree illumination and diffuse viewing geometry were used. Measurements were repeated after a glazing cycle. Contrast ratios were calculated from the luminous reflectance (Y) of the specimens with a black (Yb) and a white backing (Yw) to give Yb/Yw with CIE illuminant D65 and a 2-degree observer function (0.0 = transparent, 1.0 = opaque). One-way analysis of variance and Tukey's multiple-comparison test were used to analyze the data (P<.05). Significant differences in contrast ratios were found among the ceramic systems tested when they were veneered (P<.0001) and after the glazing cycle (P<.0001). Significant changes in contrast ratios (P<.0001) also were identified when the veneered specimens were glazed. Within the limitations of this study, a range of translucency was identified in the veneered all-ceramic systems tested. Such variability may affect their ability to match natural teeth. The glazing cycle resulted

Evaluation of materials for retention of sodium and core debris in reactor systems. Annual progress report, September 1977-December 1978

International Nuclear Information System (INIS)

Swanson, D.G.; Zehms, E.H.; McClelland, J.D.; Meyer, R.A.; van Paassen, H.L.L.

1978-12-01

This report considers some of the consequences of a hypothetical core disruptive accident in a nuclear reactor. The interactions expected between molten core debris, liquid sodium, and materials that might be employed in an ex-vessel sacrificial-bed or in the reactor building are discussed. Experimental work performed for NRC by Sandia Laboratories and Hanford Engineering Development Laboratory on the interactions between liquid sodium and basalt concrete is reviewed. Studies of molten steel interactions with concrete at Sandia Laboratories and molten UO 2 interactions with concrete at The Aerospace Corporation are also discussed. The potential of MgO for use in core containment is discussed and refractory materials other than MgO are reviewed. Finally, results from earlier experiments with molten core debris and various materials performed at The Aerospace Corporation are presented

Core outcome measurement instruments for clinical trials in non-specific low back pain

NARCIS (Netherlands)

Chiarotto, Alessandro; Boers, Maarten; Deyo, Richard A; Buchbinder, Rachelle; Corbin, Terry P; Costa, Leonardo O P; Foster, Nadine E; Grotle, Margreth; Koes, Bart W; Kovacs, Francisco M; Christine Lin, Chung-Wei; Maher, Chris G; Pearson, Adam M; Peul, Wilco C; Schoene, Mark L; Turk, Dennis C; van Tulder, Maurits W; Terwee, Caroline B; Ostelo, Raymond W

2017-01-01

To standardize outcome reporting in clinical trials of patients with non-specific low back pain (LBP), an international multidisciplinary panel recommended physical functioning, pain intensity, and health-related quality of life (HRQoL) as core outcome domains. Given the lack of consensus on

Permeability analysis of Asbuton material used as core layers of water resistance in the body of dam

Science.gov (United States)

Rahim, H.; Tjaronge, M. W.; Thaha, A.; Djamaluddin, R.

2017-11-01

In order to increase consumption of the local materials and national products, large reserves of Asbuton material about 662.960 million tons in the Buton Islands became an alternative as a waterproof core layer in the body of dam. The Asbuton material was used in this research is Lawele Granular Asphalt (LGA). This study was an experimental study conducted in the laboratory by conducting density testing (content weight) and permeability on Asbuton material. Testing of the Asbuton material used Falling Head method to find out the permeability value of Asbuton material. The data of test result to be analyzed are the relation between compaction energy and density value also relation between density value and permeability value of Asbuton material. The result shows that increases the number of blow apply to the Asbuton material at each layer will increase the density of the Asbuton material. The density value of Asbuton material that satisfies the requirements for use as an impermeable core layer in the dam body is 1.53 grams/cm3. The increase the density value (the weight of the contents) of the Asbuton material will reduce its permeability value of the Asbuton material.

A novel core 1 O-linked glycan-specific binding lectin from the fruiting body of Hericium erinaceus.

Science.gov (United States)

Kim, Seonghun

2018-02-01

Mucin-type O-glycans are involved in biological functions on the cell surface as well as the glycoproteins and can also be used as specific carbohydrate biomarkers of many diseases. In this study, I purified a novel core 1 O-linked glycan specific lectin, Hericium erinaceus lecin (HeL), from the fruiting body of the mushroom Hericium erinaceus, which is known as the natural source for a sialic acid-binding lectin. Upon optimization of the purification conditions, a sequence of ion exchange, affinity, ion exchange, and size-exclusion chromatography resulted in the highest yield and best quality of lectin without protease activity. The resulting purified HeL is an apparent hexameric protein with a subunit molecular weight of 15kDa, and a pI of 4.3. In hemagglutination inhibition assay, the purified lectin was only inhibited by glycoproteins containing mucin-type O-glycans and reacted weakly with Galβ(1,3)GalNAc. Glycan array analyses showed that HeL specifically interacts with core 1 O-linked glycans as well as extended O-glycan structures containing sialylation or fucosylation. The glycan binding specificity of HeL is comparable to that of peanut agglutinin for detection of a broader range of extended core 1 O-glycan structures. Taken together, these results provide an efficient and optimized procedure for the purification of HeL from the fruiting body of the mushroom Hericium erinaceus. Moreover, HeL represents a powerful tool for analyzing core 1 and extended core 1 O- glycan structures in diagnosis assays. Copyright © 2017 Elsevier B.V. All rights reserved.

Method and device for catching reactor core melt-down masses in hypothetical accidents of nuclear power plants

International Nuclear Information System (INIS)

Morlock, G.; Wiesemes, J.; Bachner, D.

1977-01-01

The device is to receive the afterheat of the molten core and in this way to prevent afterflow of coolant and a new criticality. A tank below the reactor pressure vessel, with the proper diameter, contains a store of salt or a salt mixture suitable to receive the afterheat of a core melt-down as heat of fusion or conversion. Above the salt, there is a layer of thermoplastics or of a material forming a hardening foam. Coolant eventually continuing to flow out is separated from the core melt by this barrier layer, and thus the build-up of high steam pressures is prevented. Neutron-absorbing materials, like boron salts mixed to the salts, as well as a subdivision of the salt surface, e.g. by means of canalizing firebricks, prevent the formation of new criticality. Further installations within the tank, like pipings or channels, permit the introduction of water after cooling down of the core or salt melt-down mass and to wash out the brine with all radioactive and other constituents for transport to reprocessing or ultimate storage. (HP) [de

Material specification for ductile cast iron in the United States

International Nuclear Information System (INIS)

Sorenson, K.B.

1987-01-01

The United States currently does not have formal design criteria for qualifying ductile cast iron (DCI) transportation casks. There is also no dedicated material standard for DCI for this particular application. Recognizing the importance of a material standard for this application, Lawrence Livermore Laboratories, in a report to the NRC, recommended that steps be taken to develop an ASTM material specification suitable for spent fuel shipping containers. A draft ASTM material specification has been written and is currently in the ASTM approval process. This paper reviews the brief history of the development of the specification, the technical basis for the material properties, the ASTM approval process and the current status of the draft specification. The expected implications of having an adopted ASTM specification on the licensing process are also discussed. The relationship of fracture toughness to composition, microstructure and tensile properties has been evaluated at Sandia National Laboratories. The first main conclusion reached is that static fracture toughness is essentially decoupled from tensile properties such as yield strength, tensile strength and ductility. The significance of this finding is that tensile properties provided for in existing DCI specifications should not be used as an indicator of a material's ability to resist crack initiation. A material specification which includes fracture toughness requirements is needed to address the brittle fracture concerns. Second, static fracture toughness was found to correlate well with material microstructure; specifically, graphite nodule count or nodule spacing

The development of learning materials based on core model to improve students’ learning outcomes in topic of Chemical Bonding

Science.gov (United States)

Avianti, R.; Suyatno; Sugiarto, B.

2018-04-01

This study aims to create an appropriate learning material based on CORE (Connecting, Organizing, Reflecting, Extending) model to improve students’ learning achievement in Chemical Bonding Topic. This study used 4-D models as research design and one group pretest-posttest as design of the material treatment. The subject of the study was teaching materials based on CORE model, conducted on 30 students of Science class grade 10. The collecting data process involved some techniques such as validation, observation, test, and questionnaire. The findings were that: (1) all the contents were valid, (2) the practicality and the effectiveness of all the contents were good. The conclusion of this research was that the CORE model is appropriate to improve students’ learning outcomes for studying Chemical Bonding.

Design and development of an ultrasonic pulser-receiver unit for non-destructive testing of materials

International Nuclear Information System (INIS)

Patankar, V.H.; Joshi, V.M.

2002-11-01

The pulser/receiver constitutes the most vital part of an ultrasonic flaw detector or an ultrasonic imaging system used for inspection of materials. The ultrasonic properties of the material and resolution requirements govern the choice of the frequency of ultrasound that can be optimally used. The pulser/receiver in turn decides the efficiency of excitation of the transducer and the overall signal to noise ratio of the system for best sensitivity and resolution. A variety of pulsers are used in the ultrasonic instruments employed for materials inspection. This report describes a square wave type of an ultrasonic pulser-receiver unit developed at Ultrasonic Instrumentation Section, Electronics Division, BARC. It has been primarily designed for excitation of the transducer that is used with a multi-channel ultrasonic imaging system ULTIMA 100M targeted for inspection of SS403 billets, which are in turn used as the base material for fabrication of end fittings for coolant channels of pressurized heavy water nuclear reactors (PHWRs). The design of the pulser is based upon very fast MOSFETs, configured as electronic switches. The pulser is operated with a linear bipolar H.V. supply (+/- 500V max.). The receiver provides a 60 dB gain with a -3 dB BW of 40 MHz. This pulser/receiver unit has been successfully interfaced with a 4 channel ULTIMA 100 M4 multichannel ultrasonic C-scan imaging system, also designed and developed by the authors at Ultrasonic Instrumentation Section (Electronics Division, BARC) and supplied to Centre for Design and Manufacturer - CDM, BARC. This system is being regularly used in C-scan imaging mode for volumetric inspection of SS403 billets for end fittings of 500 MWe PHWRs. (author)

The Systems Biology Markup Language (SBML: Language Specification for Level 3 Version 2 Core

Directory of Open Access Journals (Sweden)

Hucka Michael

2018-03-01

Full Text Available Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML is a file format for representing computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 2 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML, their encoding in XML (the eXtensible Markup Language, validation rules that determine the validity of an SBML document, and examples of models in SBML form. The design of Version 2 differs from Version 1 principally in allowing new MathML constructs, making more child elements optional, and adding identifiers to all SBML elements instead of only selected elements. Other materials and software are available from the SBML project website at http://sbml.org/.

The Systems Biology Markup Language (SBML: Language Specification for Level 3 Version 1 Core

Directory of Open Access Journals (Sweden)

Hucka Michael

2018-04-01

Full Text Available Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML is a file format for representing computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Release 2 of Version 1 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML, their encoding in XML (the eXtensible Markup Language, validation rules that determine the validity of an SBML document, and examples of models in SBML form. No design changes have been made to the description of models between Release 1 and Release 2; changes are restricted to the format of annotations, the correction of errata and the addition of clarifications. Other materials and software are available from the SBML project website at http://sbml.org/.

Material Tracking Using LANMAS

International Nuclear Information System (INIS)

Armstrong, F.

2010-01-01

LANMAS is a transaction-based nuclear material accountability software product developed to replace outdated and legacy accountability systems throughout the DOE. The core underlying purpose of LANMAS is to track nuclear materials inventory and report transactions (movement, mixing, splitting, decay, etc.) to the Nuclear Materials Management and Safeguards System (NMMSS). While LANMAS performs those functions well, there are many additional functions provided by the software product. As a material is received onto a site or created at a site, its entire lifecycle can be tracked in LANMAS complete to its termination of safeguards. There are separate functions to track material movements between and within material balance areas (MBAs). The level of detail for movements within a MBA is configurable by each site and can be as high as a site designation or as detailed as building/room/rack/row/position. Functionality exists to track the processing of materials, either as individual items or by modeling a bulk process as an individual item to track inputs and outputs from the process. In cases where sites have specialized needs, the system is designed to be flexible so that site specific functionality can be integrated into the product. This paper will demonstrate how the software can be used to input material into an account and track it to its termination of safeguards.

Integration of Biosafety into Core Facility Management

Science.gov (United States)

Fontes, Benjamin

2013-01-01

This presentation will discuss the implementation of biosafety policies for small, medium and large core laboratories with primary shared objectives of ensuring the control of biohazards to protect core facility operators and assure conformity with applicable state and federal policies, standards and guidelines. Of paramount importance is the educational process to inform core laboratories of biosafety principles and policies and to illustrate the technology and process pathways of the core laboratory for biosafety professionals. Elevating awareness of biohazards and the biosafety regulatory landscape among core facility operators is essential for the establishment of a framework for both project and material risk assessment. The goal of the biohazard risk assessment process is to identify the biohazard risk management parameters to conduct the procedure safely and in compliance with applicable regulations. An evaluation of the containment, protective equipment and work practices for the procedure for the level of risk identified is facilitated by the establishment of a core facility registration form for work with biohazards and other biological materials with potential risk. The final step in the biocontainment process is the assumption of Principal Investigator role with full responsibility for the structure of the site-specific biosafety program plan by core facility leadership. The presentation will provide example biohazard protocol reviews and accompanying containment measures for core laboratories at Yale University.

Reception receiving new materials on a basis monotechtical alloys by methods of thermal processing

International Nuclear Information System (INIS)

Aubakirova, R.K.; Zhumakanova, V.R.; Kudasova, D.K.

2005-01-01

Full text: Achievements of science and technique, the development of new technologies requires development and receiving of new materials with a complex of given properties satisfying to concrete conditions of operation. In this connection one of perspective materials are mono technical alloys of systems representing natural composites. At the moment there are materials about an opportunity, new materials from receiving of with the given complex of properties, such as anti-corrosive etc. As a result we chose mono technical alloys of systems such as Zn-Pb, Cu-Pb, Zn-Bi, each of which is characterized by rather extensive area of unmixed components in a liquid status, exposed thermodiffusion and thermal processing. The analysis of the received results has allowed us to open a number of features inherent in alloys of concrete system. So, in alloys of system Zn-Pb it was revealed, that after heat treatment at 690, 720, 750 deg. C brighter interaction between components expressing in proceeding on border of contact, of a proceeding of on borders, carrying liquid phase character proceeds, that, in turn, is shown in detection of an intermediate component and 'finger' of formations. In alloys of system Cu-Pb it was revealed, that most informed the data come to light after heat treatment within 5-15 minutes at 870 and 970 deg. C, that is expressed in more advanced dendritic structure of a leaden phase and fixing intermediate making on border of contact of two basic phases. At the same time, the realization of thermal processing on alloys of system Zn-Bi has allowed to find out a number of the interesting facts. The speed of display fixed before channels fast diffusion, essentially does not depend on a degree chemical relations in of components making diffusion a pair. And the choice of temperature-temporary parameters necessary for fixing of a beginning of interaction of components on channels fast diffusion should depend not only on a type of interaction of components, but

Device for removal of oriented core

Energy Technology Data Exchange (ETDEWEB)

Shakhmalov, A.M.

1981-05-04

A device for removal of an oriented core, which contains an external core barrel, connected with a gear, a rock-crushing bit, nonrotary core-receiving pipe, and a core marker, placed in the core-receiving pipe and connected kinematically with the external core barrel and gear, is distinguished by the fact that in order to increase the accuracy of determination of the spatial orientation of the core the gear of the core barrel and the marker come in the form of an electric drill, and a magnetic compass witha remote-fix indicator is attached to its housing. The device is also distinguished by the fact that it is equipped with an auxillary marker positioned symmetrically with respect to the first one.

The effect of core material, veneering porcelain, and fabrication technique on the biaxial flexural strength and weibull analysis of selected dental ceramics.

Science.gov (United States)

Lin, Wei-Shao; Ercoli, Carlo; Feng, Changyong; Morton, Dean

2012-07-01

The objective of this study was to compare the effect of veneering porcelain (monolithic or bilayer specimens) and core fabrication technique (heat-pressed or CAD/CAM) on the biaxial flexural strength and Weibull modulus of leucite-reinforced and lithium-disilicate glass ceramics. In addition, the effect of veneering technique (heat-pressed or powder/liquid layering) for zirconia ceramics on the biaxial flexural strength and Weibull modulus was studied. Five ceramic core materials (IPS Empress Esthetic, IPS Empress CAD, IPS e.max Press, IPS e.max CAD, IPS e.max ZirCAD) and three corresponding veneering porcelains (IPS Empress Esthetic Veneer, IPS e.max Ceram, IPS e.max ZirPress) were selected for this study. Each core material group contained three subgroups based on the core material thickness and the presence of corresponding veneering porcelain as follows: 1.5 mm core material only (subgroup 1.5C), 0.8 mm core material only (subgroup 0.8C), and 1.5 mm core/veneer group: 0.8 mm core with 0.7 mm corresponding veneering porcelain with a powder/liquid layering technique (subgroup 0.8C-0.7VL). The ZirCAD group had one additional 1.5 mm core/veneer subgroup with 0.7 mm heat-pressed veneering porcelain (subgroup 0.8C-0.7VP). The biaxial flexural strengths were compared for each subgroup (n = 10) according to ISO standard 6872:2008 with ANOVA and Tukey's post hoc multiple comparison test (p≤ 0.05). The reliability of strength was analyzed with the Weibull distribution. For all core materials, the 1.5 mm core/veneer subgroups (0.8C-0.7VL, 0.8C-0.7VP) had significantly lower mean biaxial flexural strengths (p Empress and e.max groups, regardless of core thickness and fabrication techniques. Comparing fabrication techniques, Empress Esthetic/CAD, e.max Press/CAD had similar biaxial flexural strength (p= 0.28 for Empress pair; p= 0.87 for e.max pair); however, e.max CAD/Press groups had significantly higher flexural strength (p Empress Esthetic/CAD groups. Monolithic core

Fluid flow distribution optimization for minimizing the peak temperature of a tubular solar receiver

International Nuclear Information System (INIS)

Wei, Min; Fan, Yilin; Luo, Lingai; Flamant, Gilles

2015-01-01

High temperature solar receiver is a core component of solar thermal power plants. However, non-uniform solar irradiation on the receiver walls and flow maldistribution of heat transfer fluid inside the tubes may cause the excessive peak temperature, consequently leading to the reduced lifetime. This paper presents an original CFD (computational fluid dynamics)-based evolutionary algorithm to determine the optimal fluid distribution in a tubular solar receiver for the minimization of its peak temperature. A pressurized-air solar receiver comprising of 45 parallel tubes subjected to a Gaussian-shape net heat flux absorbed by the receiver is used for study. Two optimality criteria are used for the algorithm: identical outlet fluid temperatures and identical temperatures on the centerline of the heated surface. The influences of different filling materials and thermal contact resistances on the optimal fluid distribution and on the peak temperature reduction are also evaluated and discussed. Results show that the fluid distribution optimization using the algorithm could minimize the peak temperature of the receiver under the optimality criterion of identical temperatures on the centerline. Different shapes of optimal fluid distribution are determined for various filling materials. Cheap material with low thermal conductivity can also meet the peak temperature threshold through optimizing the fluid distribution. - Highlights: • A 3D pressurized-air solar receiver based on the tube-in-matrix concept is studied. • An original evolutionary algorithm is developed for fluid distribution optimization. • A new optimality criterion is proposed for minimizing the receiver peak temperature. • Different optimal fluid distributions are determined for various filling materials. • Filling material with high thermal conductivity is more favorable in practical use.

Preparation of plant-specific NDA reference material

International Nuclear Information System (INIS)

Abedin-Zadeh, R.; Beetle, T.; Kuhn, E.; Terrey, D.; Turel, S.; Busca, G.; Guardini, S.

1983-01-01

The importance of having suitable and well characterized non-destructive assay (NDA) reference materials for the verification activities of the safeguards control authorities is stressed. The Euratom Inspectorate and the IAEA have initiated an extensive programme for the procurement and preparation of Joint Euratom/IAEA safeguards NDA reference materials with the active participation of the Ispra Establishment of the Euratom Joint Research Centre. The different type and nature of materials, condition of measurements, and plant characteristics and provisions had to be taken into account for plant-specific NDA reference materials. The preparation of each reference material was planned case by case and specific criteria such as limitations in different facilities, measurement capabilities, conditions, product availability and population variability are being ascertained. A procurement scheme was prepared describing step-by-step procedures detailing responsibilities, measurement conditions, destructive analysis schemes, desired characteristics and methods of data evaluation. This paper describes the principles and procedures carried out for the preparation of a reference MOX pin, low enriched uranium reference rods, low enriched uranium reference drums, reference MTR assemblies, and THTR reference pebbles. The scheme for each characterization technique is presented. (author)

Patient-specific core decompression surgery for early-stage ischemic necrosis of the femoral head.

Directory of Open Access Journals (Sweden)

Wei Wang

Full Text Available Core decompression is an efficient treatment for early stage ischemic necrosis of the femoral head. In conventional procedures, the pre-operative X-ray only shows one plane of the ischemic area, which often results in inaccurate drilling. This paper introduces a new method that uses computer-assisted technology and rapid prototyping to enhance drilling accuracy during core decompression surgeries and presents a validation study of cadaveric tests.Twelve cadaveric human femurs were used to simulate early-stage ischemic necrosis. The core decompression target at the anterolateral femoral head was simulated using an embedded glass ball (target. Three positioning Kirschner wires were drilled into the top and bottom of the large rotor. The specimen was then subjected to computed tomography (CT. A CT image of the specimen was imported into the Mimics software to construct a three-dimensional model including the target. The best core decompression channel was then designed using the 3D model. A navigational template for the specimen was designed using the Pro/E software and manufactured by rapid prototyping technology to guide the drilling channel. The specimen-specific navigation template was installed on the specimen using positioning Kirschner wires. Drilling was performed using a guide needle through the guiding hole on the templates. The distance between the end point of the guide needle and the target was measured to validate the patient-specific surgical accuracy.The average distance between the tip of the guide needle drilled through the guiding template and the target was 1.92±0.071 mm.Core decompression using a computer-rapid prototyping template is a reliable and accurate technique that could provide a new method of precision decompression for early-stage ischemic necrosis.

Characterization of a Porous Carbon Material Functionalized with Cobalt-Oxide/Cobalt Core-Shell Nanoparticles for Lithium Ion Battery Electrodes

KAUST Repository

Anjum, Dalaver H.

2016-04-18

A nanoporous carbon (C) material, functionalized with Cobalt-Oxide/Cobalt (CoO/Co) core-shell nanoparticles (NPs), was structurally and chemically characterized with transmission electron microcopy (TEM) while its electrochemical response for Lithium ion battery (LIB) applications was evaluated as well. The results herein show that the nanoporous C material was uniformly functionalized with the CoO/Co core-shell NPs. Further the NPs were crystalline with fcc-Type lattice on the Co2+ oxide shell and hcp-Type core of metallic Co0. The electrochemical study was carried out by using galvanostatic charge/discharge cycling at a current density of 1000 mA g-1. The potential of this hybrid material for LIB applications was confirmed and it is attributed to the successful dispersion of the Co2+/ Co0 NPs in the C support.

JOYO MK-II core characteristics database

International Nuclear Information System (INIS)

Tabuchi, Shiro; Aoyama, Takafumi; Nagasaki, Hideaki; Kato, Yuichi

1998-12-01

The experimental fast reactor JOYO served as the MK-II irradiation bed core for testing fuel and material for FBR development for 15 years from 1982 to 1997. During the MK-II operation, extensive data were accumulated from the core characteristics tests conducted in thirty-one duty operations and thirteen special test operations. These core management data and core characteristics data were compiled into a database. The code system MAGI has been developed and used for core management of JOYO MK-II, and the core characteristics and the irradiation test conditions were calculated using MAGI on the basis of three dimensional diffusion theory with seven neutron energy groups. The core management data include extensive data, which were recorded on CD-ROM for user convenience. The data are specifications and configurations of the core, and for about 300 driver fuel subassemblies and about 60 uninstrumented irradiation subassemblies are core composition before and after irradiation, neutron flux, neutron fluences, fuel and control rod burn-up, and temperature and power distributions. MK-II core characteristics and test conditions were stored in the database for post analysis. Core characteristics data include excess reactivities, control rod worths, and reactivity coefficients, e.g., temperature, power and burn-up. Test conditions include both measured and calculated data for irradiation conditions. (author)

Exploratory study of molten core material/concrete interactions, July 1975--March 1977

International Nuclear Information System (INIS)

Powers, D.A.; Dahlgren, D.A.; Muir, J.F.; Murfin, W.D.

1978-02-01

An experimental study of the interaction between high-temperature molten materials and structural concrete is described. The experimental efforts focused on the interaction of melts of reactor core materials weighing 12 to 200 kg at temperatures 1700 to 2800 0 C with calcareous and basaltic concrete representative of that found in existing light-water nuclear reactors. Observations concerning the rate and mode of melt penetration into concrete, the nature and generation rate of gases liberated during the interaction, and heat transfer from the melt to the concrete are described. Concrete erosion is shown to be primarily a melting process with little contribution from mechanical spallation. Water and carbon dioxide thermally released from the concrete are extensively reduced to hydrogen and carbon monoxide. Heat transfer from the melt to the concrete is shown to be dependent on gas generation rate and crucible geometry. Interpretation of results from the interaction experiments is supported by separate studies of the thermal decomposition of concretes, response of bulk concrete to intense heat fluxes (28 to 280 W/cm 2 ), and heat transfer from molten materials to decomposing solids. The experimental results are compared to assumptions made in previous analytic studies of core meltdown accidents in light-water nuclear reactors. A preliminary computer code, INTER, which models and extrapolates results of the experimental program is described. The code allows estimation of the effect of physical parameters on the nature of the melt/concrete interaction

Heat Storage Performance of the Prefabricated Hollow Core Concrete Deck Element with Integrated Microencapsulated Phase Change Material

DEFF Research Database (Denmark)

Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

2012-01-01

The paper presents the numerically calculated dynamic heat storage capacity of the prefabricated hollow core concrete deck element with and without microencapsulated phase change material (PCM). The reference deck is the ordinary deck made of standard concrete material and that is broadly used...

Reactor core and initially loaded reactor core of nuclear reactor

International Nuclear Information System (INIS)

Koyama, Jun-ichi; Aoyama, Motoo.

1989-01-01

In BWR type reactors, improvement for the reactor shutdown margin is an important characteristic condition togehter with power distribution flattening . However, in the reactor core at high burnup degree, the reactor shutdown margin is different depending on the radial position of the reactor core. That is , the reactor shutdown margin is smaller in the outer peripheral region than in the central region of the reactor core. In view of the above, the reactor core is divided radially into a central region and as outer region. The amount of fissionable material of first fuel assemblies newly loaded in the outer region is made less than the amount of the fissionable material of second fuel assemblies newly loaded in the central region, to thereby improve the reactor shutdown margin in the outer region. Further, the ratio between the amount of the fissionable material in the upper region and that of the fissionable material in the lower portion of the first fuel assemblies is made smaller than the ratio between the amount of the fissionable material in the upper region and that of the fissionable material in the lower region of the second fuel assemblies, to thereby obtain a sufficient thermal margin in the central region. (K.M.)

Molten LWR core material interactions with water and with concrete

International Nuclear Information System (INIS)

Dahlgren, D.A.; Buxton, L.D.; Muir, J.F.; Murfin, W.B.; Nelson, L.S.; Powers, D.A.

1977-01-01

Nuclear power reactors are designed and operated to minimize the possibility of fuel melting. Nevertheless, in order to assess the risks associated with reactor operation, a realistic assessment is required for postulated accident sequences in which melting occurs. To investigate the experimental basis of the fuel melt accident analyses, a comprehensive review was performed at Sandia Laboratories. The results of that study indicated several phenomenological areas where additional experimental data should be gathered to verify common assumptions made in risk studies. In particular, vapor explosions and molten core material/concrete interactions were identified for further study. Results of these studies are presented

Isotope specific arbitrary material flow meter

Science.gov (United States)

Barty, Christopher P. J.; Post, John C.; Jones, Edwin

2016-10-25

A laser-based mono-energetic gamma-ray source is used to provide non-destructive and non-intrusive, quantitative determination of the absolute amount of a specific isotope contained within pipe as part of a moving fluid or quasi-fluid material stream.

46 CFR 164.009-3 - Noncombustible materials not requiring specific approval.

Science.gov (United States)

2010-10-01

...) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Noncombustible Materials for... noncombustible materials may be used in merchant vessel construction though not specifically approved under this subpart: (a) Sheet glass, block glass, clay, ceramics, and uncoated fibers. (b) All metals, except...

Material specification for ductile cast iron in the United States

International Nuclear Information System (INIS)

Sorenson, K.B.

1987-01-01

The United States currently does not have formal design criteria for qualifying ductile cast iron (DCI) transportation casks. There is also no dedicated material standard for DCI for this particular application. A draft ASTM material specification has been written and is currently in the ASTM approval process. This paper reviews the brief history of the development of the specification, the technical basis for the material properties, the ASTM approval process and the current status of the draft specification. The expected implications of having an adopted ASTM specification on the licensing process are also discussed. (orig./DG)

Digital Materialisms: Frameworks for Digital Media Studies

OpenAIRE

Casemajor, Nathalie

2015-01-01

Since the 1980s, digital materialism has received increasing interest in the field of media studies. Materialism as a theoretical paradigm assumes that all things in the world are tied to physical processes and matter. Yet within digital media studies, the understanding of what should be the core object of a materialist analysis is debated. This paper proposes to untangle some of the principal theoretical propositions that compose the field of digital materialism. It outlines six frameworks t...

Exchange of core chromosomes and horizontal transfer of lineage-specific chromosomes in Fusarium oxysporum

NARCIS (Netherlands)

Vlaardingerbroek, I.; Beerens, B.; Rose, L.; Fokkens, L.; Cornelissen, B.J.C.; Rep, M.

2016-01-01

Horizontal transfer of supernumerary or lineage-specific (LS) chromosomes has been described in a number of plant pathogenic filamentous fungi. So far it was not known whether transfer is restricted to chromosomes of certain size or properties, or whether 'core' chromosomes can also undergo

Polyaniline/multi-walled carbon nanotubes composite with core-shell structures as a cathode material for rechargeable lithium-polymer cells

Energy Technology Data Exchange (ETDEWEB)

Liu, Pan [School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209 (China); Han, Jia-Jun, E-mail: hanjiajunhitweihai@163.com [School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209 (China); Jiang, Li-Feng [Dalian Chemical Institute of Chinese Academy of Sciences, Dalian 116011 (China); Li, Zhao-Yu; Cheng, Jin-Ning [School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209 (China)

2017-04-01

Highlights: • The polyaniline multi-walled carbon nanotubes composite with core-shell structures was synthetized via in situ chemical oxidative polymerization, and the materials were characterized by physical and chemical methods. • The PANI/WMCNTs was synthetized via in situ chemical oxidative polymerization with core-shell structures. • The WMCNTs highly enhanced the conductivity of composites. • The comopsites were more conducive to the intercalation and deintercalation of anions and cations. • The much better performance as the cathode for lithium-ion cells was acquired for the composites. • The composites are low cost and eco-friendly which have a good prospect in future. - Abstract: The aniline was polymerized onto functionalized multi-walled carbon nanotubes in order to obtain a cathode material with core-shell structures for lithium batteries. The structure and morphology of the samples were investigated by Fourier transform infrared spectroscopy analysis, scanning electron microscope, transmission electron microscope and X-ray diffraction. The electrochemical properties of the composite were characterized by the cyclic voltammetry, the charge/discharge property, coulombic efficiency, and ac impedance spectroscopy in detail. At a constant current density of 0.2 C, the first specific discharge capacity of the reduced and oxidized PANI/WMCNTs were 181.8 mAh/g and 135.1 mAh/g separately, and the capacity retention rates were corresponding to 76.75% and 86.04% for 100 cycles with 99% coulombic efficiency. It was confirmed that the CNTs obviously enhanced the conductivity and electrochemical performance of polyaniline, and compared with the pure PANI, the reduced composite possessed a quite good performance for the cathode of lithium batteries.

Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La.

Science.gov (United States)

Wei, Liqiu; Che, Ruxin; Jiang, Yijun; Yu, Bing

2013-12-01

Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

International Nuclear Information System (INIS)

Toivonen, A.; Moilanen, P.; Pyykkoenen, M.; Taehtinen, S.; Rintamaa, R.; Saario, T.

1998-01-01

Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (orig.)

The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

Energy Technology Data Exchange (ETDEWEB)

Toivonen, A.; Moilanen, P.; Pyykkoenen, M.; Taehtinen, S.; Rintamaa, R.; Saario, T. [Valtion Teknillinen Tutkimuskeskus, Espoo (Finland)

1998-11-01

Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (orig.)

Modelling mechanical properties of the multilayer composite materials with the polyamide core

Directory of Open Access Journals (Sweden)

Talaśka Krzysztof

2018-01-01

Full Text Available Due to the wide range of application for belt conveyors, engineers look for many different combinations of mechanical properties of conveyor and transmission belts. It can be made by creating multilayer or fibre reinforced composite materials from base thermoplastic or thermosetting polymers. In order to gain high strength with proper elasticity and friction coefficient, the core of the composite conveyor belt is made of polyamide film core, which can be combined with various types of polymer fabrics, films or even rubbers. In this paper authors show the complex model of multilayer composite belt with the polyamide core, which can be used in simulation analyses. The following model was derived based on the experimental research, which consisted of tensile, compression and shearing tests. In order to achieve the most accurate model, proper simulations in ABAQUS were made and then the results were compared with empirical mechanical characteristics of a conveyor belt. The main goal of this research is to fully describe the perforation process of conveyor and transmission belts for vacuum belt conveyors. The following model will help to develop design briefs for machines used for mechanical perforation.

Manufacturing of microcapsules with liquid core and their healing performance in epoxy for resin transfer molding

OpenAIRE

Yılmaz, Çağatay; Yilmaz, Cagatay

2013-01-01

Microcapsules with different active core materials have been receiving a great deal of attention for developing polymer based materials with selfhealing abilities. The self-healing ability is crucial in particular for matrix materials having brittle nature such as epoxy resin. In order for abstaining from an abrupt failure of structural brittle manner polymeric materials, microcapsules can be used excellently as a viable repair agent. In this work, we present a study on the catalyst-free micr...

AUTHENTIC MATERIALS VS TEXTBOOKS IN ESP (ENGLISH FOR SPECIFIC PURPOSES

Directory of Open Access Journals (Sweden)

Elena Spirovska Tevdovska

2018-03-01

Full Text Available The purpose of this study is to analyze and compare the value of authentic materials and textbooks in ESP English for Specific Purposes learning and teaching context. The study compares the characteristics of the authentic materials and the characteristics of textbooks designed and selected for the purpose of teaching and learning English as a foreign language in ESP setting. The study defines the role of materials in ESP setting and compares the benefits and possible drawbacks of both types of materials and resources: the authentic materials in English for Specific Purposes context compared to traditional textbooks designed for the purpose of teaching and learning English for Specific Purposes. The study identifies the benefits of authentic materials, which include the richness as an input source and the authenticity of the tasks offered to learners, as well as the negative sides of authentic materials, which include the level of difficulty that these materials might present to the learner . Furthermore, the study identifies the benefits of textbooks, which include available sources for the learners and less time consuming class preparation for the teachers, as well as the drawbacks which include the impossibility of finding a textbook which corresponds entirely to learners’ needs. In addition, the article focuses on teachers’ attitudes and opinions regarding the appropriateness and exploitability of each source and their preferences and reasons for material selection. The target population consists of eleven lecturers who teach English for Specific Purposes in tertiary education. The lecturers teach various branches of ESP, including ESP for Computer Sciences, Business, Communication and Legal Studies. Data collection is conducted through a specifically designed questionnaire, addressing the questions of materials selection, teachers’ preferences regarding textbooks or authentic materials and the selection criteria applied by the

Simulant-material experimental investigation of flow dynamics in the CRBR Upper-Core Structure

International Nuclear Information System (INIS)

Wilhelm, D.; Starkovich, V.S.; Chapyak, E.J.

1982-09-01

The results of a simulant-material experimental investigation of flow dynamics in the Clinch River Breeder Reactor (CRBR) Upper Core Structure are described. The methodology used to design the experimental apparatus and select test conditions is detailed. Numerous comparisons between experimental data and SIMMER-II Code calculations are presented with both advantages and limitations of the SIMMER modeling features identified

Vaccination with lipid core peptides fails to induce epitope-specific T cell responses but confers non-specific protective immunity in a malaria model.

Directory of Open Access Journals (Sweden)

Simon H Apte

Full Text Available Vaccines against many pathogens for which conventional approaches have failed remain an unmet public health priority. Synthetic peptide-based vaccines offer an attractive alternative to whole protein and whole organism vaccines, particularly for complex pathogens that cause chronic infection. Previously, we have reported a promising lipid core peptide (LCP vaccine delivery system that incorporates the antigen, carrier, and adjuvant in a single molecular entity. LCP vaccines have been used to deliver several peptide subunit-based vaccine candidates and induced high titre functional antibodies and protected against Group A streptococcus in mice. Herein, we have evaluated whether LCP constructs incorporating defined CD4(+ and/or CD8(+ T cell epitopes could induce epitope-specific T cell responses and protect against pathogen challenge in a rodent malaria model. We show that LCP vaccines failed to induce an expansion of antigen-specific CD8(+ T cells following primary immunization or by boosting. We further demonstrated that the LCP vaccines induced a non-specific type 2 polarized cytokine response, rather than an epitope-specific canonical CD8(+ T cell type 1 response. Cytotoxic responses of unknown specificity were also induced. These non-specific responses were able to protect against parasite challenge. These data demonstrate that vaccination with lipid core peptides fails to induce canonical epitope-specific T cell responses, at least in our rodent model, but can nonetheless confer non-specific protective immunity against Plasmodium parasite challenge.

About the use of approximations, which ensure materials mass balance conservation by spatial meshes, in Sn full core calculations

International Nuclear Information System (INIS)

Voloshchenko, A.M.; Russkov, A.A.; Gurevich, M.I.; Olejnik, D.S.

2008-01-01

One analyzes a possibility to make use of the geometry approximations conserving the materials mass local balance in every mesh via adding of mixtures in the meshes containing several feed materials to perform the kinetic calculation of the reactor core neutron fields. To set the 3D-geometry of the reactor core one makes use of the combinatorial geometry methods implemented in the MCI Program to solve the diffusivity equations by the Monte Carlo method, to convert the combinatorial prescribing of the geometry into the mesh representation - the ray tracing method. According to the calculations of the WWER-1000 reactor core and the simulations of the spent fuel storage facility, the described procedure compares favorably with the conventional geometry approximations [ru

Exfoliated BN shell-based high-frequency magnetic core-shell materials.

Science.gov (United States)

Zhang, Wei; Patel, Ketan; Ren, Shenqiang

2017-09-14

The miniaturization of electric machines demands high frequency magnetic materials with large magnetic-flux density and low energy loss to achieve a decreased dimension of high rotational speed motors. Herein, we report a solution-processed high frequency magnetic composite (containing a nanometal FeCo core and a boron nitride (BN) shell) that simultaneously exhibits high electrical resistivity and magnetic permeability. The frequency dependent complex initial permeability and the mechanical robustness of nanocomposites are intensely dependent on the content of BN insulating phase. The results shown here suggest that insulating magnetic nanocomposites have potential for application in next-generation high-frequency electric machines with large electrical resistivity and permeability.

Repairing rabbit radial defects by combining bone marrow stroma stem cells with bone scaffold material comprising a core-cladding structure.

Science.gov (United States)

Wu, H; Liu, G H; Wu, Q; Yu, B

2015-10-05

We prepared a bone scaffold material comprising a PLGA/β-TCP core and a Type I collagen cladding, and recombined it with bone marrow stroma stem cells (BMSCs) to evaluate its potential for use in bone tissue engineering by in vivo and in vitro experiments. PLGA/β-TCP without a cladding was used for comparison. The adherence rate of the BMSCs to the scaffold was determined by cell counting. Cell proliferation rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The osteogenic capability was evaluated by alkaline phosphatase activity. The scaffold materials were recombined with the BMSCs and implanted into a large segmental rabbit radial defect model to evaluate defect repair. Osteogenesis was assessed in the scaffold materials by histological and double immunofluorescence labeling, etc. The adherence number, proliferation number, and alkaline phosphatase expression of the cells on the bone scaffold material with core-cladding structure were significantly higher than the corresponding values in the PLGA/β-TCP composite scaffold material (P structure completely degraded at the bone defect site and bone formation was completed. The rabbit large sentimental radial defect was successfully repaired. The degradation and osteogenesis rates matched well. The bone scaffold with core-cladding structure exhibited better osteogenic activity and capacity to repair a large segmental bone defect compared to the PLGA/β-TCP composite scaffold. The bone scaffold with core-cladding structure has excellent physical properties and biocompatibility. It is an ideal scaffold material for bone tissue engineering.

Parts, Materials, and Processes Control Program for Expendable Launch Vehicles

Science.gov (United States)

2015-07-31

Resistors 1. All hollow glass or hollow ceramic core devices 2. Unpassivated Nicrome film resistors F-6 3. All hermetic hollow ceramic core film...be the core material, the insulation of the magnet, etc. 2/ Current rating for each winding shall be less than or equal to the rating for a bundle...Instrument Type, General Specification for MIL-PRF-23648 Resistors, Thermal (Thermistor) Insulated , General Specification for MIL-DTL-24308

Case for non-material specific thermal aging

International Nuclear Information System (INIS)

Bessey, R.L.

1982-01-01

The state-of-the-art model for accelerated thermal aging of components prior to seismic testing is the Arrhenius Model. The most pertinent independent variable in the equation is the minimum activation energy constant characterizing the component aging. With minor exceptions, existing measured values of the activation energy constant are inadequate as input to the model where a material specific aging acceleration factor is to be determined, for reasons described. The model itself is not very accurate. A case is made for a statistically justified minimum activation energy constant which is not material specific. The advantages of this are assessed. The major advantage is that this would provide the industry with a practical and uniform aging method that is consistent with the accuracy of the model

Thermal interactions of a molten core debris pool with surrounding structural materials

International Nuclear Information System (INIS)

Baker, L. Jr.; Cheung, F.B.; Farhadieh, R.; Stein, R.P.; Gabor, J.D.; Bingle, J.D.

1979-01-01

Analytical and experimental results on individual aspects of the overall problem of the interaction of a large mass of LMFBR core debris with concrete or other materials are reviewed. Results of recent heat transfer experiments with molten UO 2 have indicated the importance of internal thermal radiation and methods to take account of this are developed. Effects of gas release and density difference are considered. The GROWS-2 Code is used to illustrate the effects of various assumptions

Single Shell Tank Waste Characterization Project for Tank B-110, Core 9 - data package and PNL validation summary report

International Nuclear Information System (INIS)

Pool, K.N.; Jones, T.E.; McKinley, S.G.; Tingey, J.M.; Longaker, T.M.; Gibson, J.A.

1990-01-01

This Data Package contains results obtained by Pacific Northwest Laboratory (PNL) staff in the characterization and analyses of Core 9 segments taken from the Single-Shell Tank (SST) 110B. The characterization and analysis of Core 9 segments are outlined in the Waste Characterization Plan for Hanford Site Single-Shell Tanks and in the Pacific Northwest Laboratory (PNL) Single-Shell Tank Waste Characterization Support FY 89/90 Statement of Work (SOW), Rev. 1 dated March, 1990. Specific analyses for each sub-sample taken from a segment are delineated in Test Instructions prepared by the PNL Single-Shell Tank Waste Characterization Project Management Office (SST Project) in accordance with procedures contained in the SST Waste Characterization Procedure Compendium (PNL-MA-599). Analytical procedures used in the characterization activities are also included in PNL-MA-599. Core 9 included five segments although segment 1 did not have sufficient material for characterization. The five samplers were received from Westinghouse Hanford Company (WHC) on 11/21-22/89. Each segment was contained in a sampler and was enclosed in a shipping cask. The shipping cask was butted up to the 325-A hot cell and the sampler moved into the hot cell. The material in the sampler (i.e., the segment) was extruded from the sampler, limited physical characteristics assessed, and photographed. At this point samples were taken for particle size and volatile organic analyses. Each segment was then homogenized. Sub-samples were taken for required analyses as delineated in the appropriate Test Instruction. Table 1 includes sample numbers assigned to Core 9 segment materials being transferred from 325-A Hot Cell. Sample numbers 90-0298, 90-0299, 90-0302, and 90-0303 were included in Table 1 although no analyses were requested for these samples. Table 2 lists Core 9 sub-sample numbers per sample preparation method

Measuring technique of super high temperature thermal properties of reactor core materials

International Nuclear Information System (INIS)

Ono, Akira; Baba, Tetsuya; Watanabe, Hideo; Matsumoto, Tsuyoshi

1998-01-01

In this study, thermal properties of reactor core materials used for water cooled reactors and FBR were tried to develop a technique to measure their melt states at less than 3,000degC in order to contribute more correct evaluation of the reactor core behavior at severe accident. Then, a thermal property measuring method of high temperature melt by using floating method was investigated and its fundamental design was begun to investigate under a base of optimum judgement on the air flow floating throw-down method. And, in order to measure emissivity of melt specimen surface essential for correct temperature measurement using the throw down method, a spectroscopic emissivity measuring unit using an ellipsometer was prepared and induced. On the thermal properties measurement using the holding method, a specimen container to measure thermal diffusiveness of the high temperature melts by using laser flashing method was tried to prepare. (G.K.)

Communications received from Members regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

1992-05-01

The document reproduces the text of the letters dated 2 March 1992, received by the Director General of the IAEA from the Resident Representatives to the Agency of Australia, Austria, Canada, Czechoslovakia, Denmark, Finland, the Federal Republic of Germany, Greece, Hungary, Ireland, Japan, Luxemburg, the Netherlands, Norway, Poland, Romania, Sweden, the United Kingdom of Great Britain and Northern Ireland and the United States of America regarding the export of nuclear material and of certain categories of equipment and other material, namely plants for the production of heavy water, deuterium and deuterium compound and equipment especially designed or prepared thereof

Effect of Three Different Core Materials on Masking Ability of a Zirconia Ceramic

Directory of Open Access Journals (Sweden)

Farhad Tabatabaian

2016-12-01

Full Text Available Objectives: Masking ability of a restorative material plays a role in hiding colored substructures; however, the masking ability of zirconia ceramic (ZRC has not yet been clearly understood in zirconia-based restorations. This study evaluated the effect of three different core materials on masking ability of a ZRC.Materials and Methods: Ten zirconia disc samples, 0.5mm in thickness and 10mm in diameter, were fabricated. A white (W substrate (control and three substrates of nickel-chromium alloy (NCA, non-precious gold alloy (NPGA, and ZRC were prepared. The zirconia discs were placed on the four types of substrates for spectrophotometry. The L*, a*, and b* values of the specimens were measured by a spectrophotometer and color change (ΔE values were calculated to determine color differences between the test and control groups and were then compared with the perceptual threshold. Randomized block ANOVA and Bonferroni test analyzed the data. A significance level of 0.05 was considered.Results: The mean and standard deviation values of ΔE for NCA, NPGA, and ZRC groups were 10.26±2.43, 9.45±1.74, and 6.70±1.91 units, respectively. Significant differences were found in the ΔE values between ZRC and the other two experimental groups (NCA and NPGA; P<0.0001 and P=0.001, respectively. The ΔE values for the groups were more than the predetermined perceptual threshold.Conclusions: Within the limitations of this study, it was concluded that the tested ZRC could not well mask the examined core materials.Keywords: Color; Spectrophotometry; Visual Perception; Yttria Stabilized Tetragonal Zirconia

Single-mode waveguides with SU-8 polymer core and cladding for MOEMS applications

DEFF Research Database (Denmark)

Nordström, Maria; Zauner, Dan; Boisen, Anja

2007-01-01

Fabrication and optical characterization of singlemode polymeric embedded waveguides are performed. A specific material combination (SU-8 2005 as core and the modified SU-8 mr-L 6050XP as cladding) is chosen in order to obtain a small refractive index difference for single-mode propagation combined...... can fabricate waveguides with an index difference in the order of 10−3, where both the core material and the cladding material are based on SU-8. The refractive index measurements are performed on thin polymeric films, while further optical characterizations are performed on waveguides with a height...

Structural materials issues for the next generation fission reactors

Science.gov (United States)

Chant, I.; Murty, K. L.

2010-09-01

Generation-IV reactor design concepts envisioned thus far cater to a common goal of providing safer, longer lasting, proliferation-resistant, and economically viable nuclear power plants. The foremost consideration in the successful development and deployment of Gen-W reactor systems is the performance and reliability issues involving structural materials for both in-core and out-of-core applications. The structural materials need to endure much higher temperatures, higher neutron doses, and extremely corrosive environments, which are beyond the experience of the current nuclear power plants. Materials under active consideration for use in different reactor components include various ferritic/martensitic steels, austenitic stainless steels, nickel-base superalloys, ceramics, composites, etc. This article addresses the material requirements for these advanced fission reactor types, specifically addressing structural materials issues depending on the specific application areas.

Development of the evaluation methodology for the material relocation behavior in the core disruptive accident of sodium cooled fast reactors

International Nuclear Information System (INIS)

Tobita, Yoshiharu; Kamiyama, Kenji; Tagami, Hirotaka; Matsuba, Ken-ichi; Suzuki, Tohru; Isozaki, Mikio; Yamano, Hidemasa; Morita, Koji; Guo, Liancheng; Zhang, Bin

2014-01-01

The in-vessel retention (IVR) of core disruptive accident (CDA) is of prime importance in enhancing safety characteristics of sodium-cooled fast reactors (SFRs). In the CDA of SFRs, molten core material relocates to the lower plenum of reactor vessel and may impose significant thermal load on the structures, resulting in the melt through of the reactor vessel. In order to enable the assessment of this relocation process and prove that IVR of core material is the most probable consequence of the CDA in SFRs, a research program to develop the evaluation methodology for the material relocation behavior in the CDA of SFRs has been conducted. This program consists of three developmental studies, namely the development of the analysis method of molten material discharge from the core region, the development of evaluation methodology of molten material penetration into sodium pool, and the development of the simulation tool of debris bed behavior. The analysis method of molten material discharge was developed based on the computer code SIMMER-III since this code is designed to simulate the multi-phase, multi-component fluid dynamics with phase changes involved in the discharge process. Several experiments simulating the molten material discharge through duct using simulant materials were utilized as the basis of validation study of the physical models in this code. It was shown that SIMMER-III with improved physical models could simulate the molten material discharge behavior including the momentum exchange with duct wall and thermal interaction with coolant. In order to develop evaluation methodology of molten material penetration into sodium pool, a series of experiments simulating jet penetration behavior into sodium pool in SFR thermal condition were performed. These experiments revealed that the molten jet was fragmented in significantly shorter penetration length than the prediction by existing correlation for light water reactor conditions, due to the direct

Development of the evaluation methodology for the material relocation behavior in the core disruptive accident of sodium-cooled fast reactors

International Nuclear Information System (INIS)

Tobita, Yoshiharu; Kamiyama, Kenji; Tagami, Hirotaka; Matsuba, Ken-ichi; Suzuki, Tohru; Isozaki, Mikio; Yamano, Hidemasa; Morita, Koji; Guo, LianCheng; Zhang, Bin

2016-01-01

The in-vessel retention (IVR) of core disruptive accident (CDA) is of prime importance in enhancing safety characteristics of sodium-cooled fast reactors (SFRs). In the CDA of SFRs, molten core material relocates to the lower plenum of reactor vessel and may impose significant thermal load on the structures, resulting in the melt-through of the reactor vessel. In order to enable the assessment of this relocation process and prove that IVR of core material is the most probable consequence of the CDA in SFRs, a research program to develop the evaluation methodology for the material relocation behavior in the CDA of SFRs has been conducted. This program consists of three developmental studies, namely the development of the analysis method of molten material discharge from the core region, the development of evaluation methodology of molten material penetration into sodium pool, and the development of the simulation tool of debris bed behavior. The analysis method of molten material discharge was developed based on the computer code SIMMER-III since this code is designed to simulate the multi-phase, multi-component fluid dynamics with phase changes involved in the discharge process. Several experiments simulating the molten material discharge through duct using simulant materials were utilized as the basis of validation study of the physical models in this code. It was shown that SIMMER-III with improved physical models could simulate the molten material discharge behavior, including the momentum exchange with duct wall and thermal interaction with coolant. In order to develop an evaluation methodology of molten material penetration into sodium pool, a series of experiments simulating jet penetration behavior into sodium pool in SFR thermal condition were performed. These experiments revealed that the molten jet was fragmented in significantly shorter penetration length than the prediction by existing correlation for light water reactor conditions, due to the direct

Implication of irradiation effects on materials data for the design of near core components

International Nuclear Information System (INIS)

Dietz, W.; Breitling, H.

1995-01-01

For LWR's strict regulations exist for the consideration of irradiation in the design and surveillance of the reactor pressure vessel in the various codes (ASME, RCC-M, KTA) but less for near core components. For FBR's no firm rules exist either for the vessel nor the reactor internals. In this paper the German design practices for the loop type SNR-300 will be presented, and also some information from the surveillance programme of the KNK-reactor. Austenitic stainless steels have been mainly selected for the near core components. For some special applications Ni-alloys and a stabilized 2 1/4 Cr 1 Mo-alloy were specified. Considerations of the irradiation effects on material properties will be made for the various temperature and fluence levels around the core. The surveillance programmes will be described. Both, the consideration of irradiation effects in the elastic and inelastic analysis and the surveillance programmes had been a part of the licensing process for SNR-300. (author). 8 figs, 4 tabs

Role of core support material in veneer failure of brittle layer structures.

Science.gov (United States)

Hermann, Ilja; Bhowmick, Sanjit; Lawn, Brian R

2007-07-01

A study is made of veneer failure by cracking in all-ceramic crown-like layer structures. Model trilayers consisting of a 1 mm thick external glass layer (veneer) joined to a 0.5 mm thick inner stiff and hard ceramic support layer (core) by epoxy bonding or by fusion are fabricated for testing. The resulting bilayers are then glued to a thick compliant polycarbonate slab to simulate a dentin base. The specimens are subjected to cyclic contact (occlusal) loading with spherical indenters in an aqueous environment. Video cameras are used to record the fracture evolution in the transparent glass layer in situ during testing. The dominant failure mode is cone cracking in the glass veneer by traditional outer (Hertzian) cone cracks at higher contact loads and by inner (hydraulically pumped) cone cracks at lower loads. Failure is deemed to occur when one of these cracks reaches the veneer/core interface. The advantages and disadvantages of the alumina and zirconia core materials are discussed in terms of mechanical properties-strength and toughness, as well as stiffness. Consideration is also given to the roles of interface strength and residual thermal expansion mismatch stresses in relation to the different joining methods. Copyright 2006 Wiley Periodicals, Inc.

Appendix BB: long coring facility (LCF)

International Nuclear Information System (INIS)

Driscoll, A.H.; Silva, A.J.

1981-01-01

During the 1979 performance period the Engineering Design of the Long Coring Facility has addressed a variety of tasks relating to the establishment of a series of operating parameters for a conceptual 50 meter long coring system. The results of these efforts have indicated that an operational system capable of the recovery of 50 meter long cores, from oceanic depths in sediments of 400 gm cm 2 is wholly possible given existing technology. Specific tasks included in the 1979 Engineering Design are as follows: (1) Hydrodynamic Stability; (2) Corer Structural Stability; (3) Corer Penetration Mechanics; (4) Anticipated Corer Pullout forces; (5) LCF Cable Dynamics; and (6) Core Head Instrumentation. Within the realm of Subseabed Disposal Programs Master Plan the LCF, as a part of the Instrumentation Development activity, is currently on schedule. Delays in receiving funding during 1979 have reduced, some what, the latitude enjoyed by the LCF project and have limited our progress to a point where any future delay can result in the LCF's falling behind the program schedule. However, at this time the LCF is considered to be on schedule, but lacking in flexibility to respond to any major contingency that may arise in the future

Proceedings of the AECB sponsored workshop on control of the ordering and receiving of radioactive material

International Nuclear Information System (INIS)

1997-07-01

The workshop was held in Mississauga, Ontario, on February 4, 1997 for the purpose of bringing together radiation safety professionals to exchange information and propose options for action for the improved control of the ordering and receiving of radioactive materials. The focus was on unsealed radioisotopes and Type 'A' shipments. The workshop participants represented five major processors or distributors and five users who manage large radiation safety programs. These participants were invited because of their knowledge, experience and proximity. Workshop objectives were developed from a review of AECB files, from an AECB report which analysed, in a systematic manner, controls on the ordering and receiving of radioactive material, and from the participants' responses to a pre-workshop request for additional information. The objectives were to propose options for action: to prevent unauthorized persons from placing an order with a supplier; to prevent unauthorized persons from receiving radioactive material by establishing tighter control on the transfer of radioactive material and improving the control of radioactive material during and after delivery. This report provides a record of the presentations and discussions as well as the options for action developed during the workshop. The proposed options for action suggest additional regulatory requirements and guidance documents. Also identified was a need for better assessment, stricter enforcement and future discussions. Included in this report are new licence conditions which were developed as a result of this workshop, several 'parking lot' issues which were raised but considered outside the scope of the discussion and a list of participants. This workshop met the needs and expectation of the Materials Regulation Division (MRD) staff and addressed the needs of the participants. It also provided an opportunity to share information and ideas. It is MRDs intention to keep this collaborative workshop approach for

General surgery training in Spain: core curriculum and specific areas of training.

Science.gov (United States)

Miguelena Bobadilla, José Ma; Morales-García, Dieter; Iturburu Belmonte, Ignacio; Alcázar Montero, José Antonio; Serra Aracil, Xabier; Docobo Durantez, Fernando; López de Cenarruzabeitia, Ignacio; Sanz Sánchez, Mercedes; Hernández Hernández, Juan Ramón

2015-03-01

The royal decree RD 639/2014 has been published, regulating among others, the core curriculum, and specific areas of training (SAT). It is of great interest for the specialty of General and Digestive Surgery (GS and DS). The aim is to expose and clarify the main provisions and reflect on their implications for the practical application of the core curriculum and SAT in the specialty of General and Digestive Surgery, to promote initiatives and regulations. This RD will be a milestone in our specialty that will test the strength of the specialty, if it does not finally culminate in its degradation against the emergence of new surgical specialties. A new stage begins in which the Spanish Association of Surgeons should be involved to define the conceptual basis of GS and DS in the XXI century, and the creation of new SAT to continue to maintain the "essence of our specialty". Copyright © 2014 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Computed tomography-guided core-needle biopsy of lung lesions: an oncology center experience

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, Marcos Duarte; Fonte, Alexandre Calabria da; Chojniak, Rubens, E-mail: marcosduarte@yahoo.com.b [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. of Radiology and Imaging Diagnosis; Andrade, Marcony Queiroz de [Hospital Alianca, Salvador, BA (Brazil); Gross, Jefferson Luiz [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. of Chest Surgery

2011-03-15

Objective: The present study is aimed at describing the experience of an oncology center with computed tomography guided core-needle biopsy of pulmonary lesions. Materials and Methods: Retrospective analysis of 97 computed tomography-guided core-needle biopsy of pulmonary lesions performed in the period between 1996 and 2004 in a Brazilian reference oncology center (Hospital do Cancer - A.C. Camargo). Information regarding material appropriateness and the specific diagnoses were collected and analyzed. Results: Among 97 lung biopsies, 94 (96.9%) supplied appropriate specimens for histological analyses, with 71 (73.2%) cases being diagnosed as malignant lesions and 23 (23.7%) diagnosed as benign lesions. Specimens were inappropriate for analysis in three cases. The frequency of specific diagnosis was 83 (85.6%) cases, with high rates for both malignant lesions with 63 (88.7%) cases and benign lesions with 20 (86.7%). As regards complications, a total of 12 cases were observed as follows: 7 (7.2%) cases of hematoma, 3 (3.1%) cases of pneumothorax and 2 (2.1%) cases of hemoptysis. Conclusion: Computed tomography-guided core needle biopsy of lung lesions demonstrated high rates of material appropriateness and diagnostic specificity, and low rates of complications in the present study. (author)

Core mechanics and configuration behavior of advanced LMFBR core restraint concepts

International Nuclear Information System (INIS)

Fox, J.N.; Wei, B.C.

1978-02-01

Core restraint systems in LMFBRs maintain control of core mechanics and configuration behavior. Core restraint design is complex due to the close spacing between adjacent components, flux and temperature gradients, and irradiation-induced material property effects. Since the core assemblies interact with each other and transmit loads directly to the core restraint structural members, the core assemblies themselves are an integral part of the core restraint system. This paper presents an assessment of several advanced core restraint system and core assembly concepts relative to the expected performance of currently accepted designs. A recommended order for the development of the advanced concepts is also presented

The accretion of solar material onto white dwarfs: No mixing with core material implies that the mass of the white dwarf is increasing

Directory of Open Access Journals (Sweden)

Sumner Starrfield

2014-02-01

Full Text Available Cataclysmic Variables (CVs are close binary star systems with one component a white dwarf (WD and the other a larger cooler star that fills its Roche Lobe. The cooler star is losing mass through the inner Lagrangian point of the binary and some unknown fraction of this material is accreted by the WD. One consequence of the WDs accreting material, is the possibility that they are growing in mass and will eventually reach the Chandrasekhar Limit. This evolution could result in a Supernova Ia (SN Ia explosion and is designated the Single Degenerate Progenitor (SD scenario. This paper is concerned with the SD scenario for SN Ia progenitors. One problem with the single degenerate scenario is that it is generally assumed that the accreting material mixes with WD core material at some time during the accretion phase of evolution and, since the typical WD has a carbon-oxygen CO core, the mixing results in large amounts of carbon and oxygen being brought up into the accreted layers. The presence of enriched carbon causes enhanced nuclear fusion and a Classical Nova explosion. Both observations and theoretical studies of these explosions imply that more mass is ejected than is accreted. Thus, the WD in a Classical Nova system is losing mass and cannot be a SN Ia progenitor. However, the composition in the nuclear burning region is important and, in new calculations reported here, the consequences to the WD of no mixing of accreted material with core material have been investigated so that the material involved in the explosion has only a Solar composition. WDs with a large range in initial masses and mass accretion rates have been evolved. I find that once sufficient material has been accreted, nuclear burning occurs in all evolutionary sequences and continues until a thermonuclear runaway (TNR occurs and the WD either ejects a small amount of material or its radius grows to about 1012 cm and the evolution is ended. In all cases where mass ejection occurs

Survival of extensively damaged endodontically treated incisors restored with different types of posts-and-core foundation restoration material.

Science.gov (United States)

Lazari, Priscilla Cardoso; de Carvalho, Marco Aurélio; Del Bel Cury, Altair A; Magne, Pascal

2018-05-01

Which post-and-core combination will best improve the performance of extensively damaged endodontically treated incisors without a ferrule is still unclear. The purpose of this in vitro study was to investigate the restoration of extensively damaged endodontically treated incisors without a ferrule using glass-ceramic crowns bonded to various composite resin foundation restorations and 2 types of posts. Sixty decoronated endodontically treated bovine incisors without a ferrule were divided into 4 groups and restored with various post-and-core foundation restorations. NfPfB=no-ferrule (Nf) with glass-fiber post (Pf) and bulk-fill resin foundation restoration (B); NfPfP=no-ferrule (Nf) with glass-fiber post (Pf) and dual-polymerized composite resin core foundation restoration (P); NfPt=no-ferrule (Nf) with titanium post (Pt) and resin core foundation restoration; and NfPtB=no-ferrule (Nf) with titanium post (Pt) and bulk-fill resin core foundation restoration (B). Two additional groups from previously published data from the same authors (FPf=2mm of ferrule (F) and glass-fiber post (Pf) and composite resin core foundation restoration; and NfPf=no-ferrule (Nf) with glass-fiber post (Pf) and composite resin core foundation restoration), which were tested concomitantly and using the same experimental arrangement, were included for comparison. All teeth were prepared to receive bonded glass-ceramic crowns luted with dual-polymerized resin cement and were subjected to accelerated fatigue testing under submerged conditions at room temperature. Cyclic isometric loading was applied to the incisal edge at an angle of 30 degrees with a frequency of 5 Hz, beginning with a load of 100 N (5000 cycles). A 100-N load increase was applied every 15000 cycles. The specimens were loaded until failure or to a maximum of 1000 N (140000 cycles). The 6 groups (4 groups from the present study and 2 groups from the previously published study) were compared using the Kaplan-Meier survival

Recombinant in vitro assembled hepatitis C virus core particles induce strong specific immunity enhanced by formulation with an oil-based adjuvant

Directory of Open Access Journals (Sweden)

NELSON ACOSTA-RIVERO

2009-01-01

Full Text Available In the present work, immunogenicity of recombinant in vitro assembled hepatitis C virus core particles, HCcAg.120-VLPs, either alone or in combination with different adjuvants was evaluated in BALB/c mice. HCcAg.120-VLPs induced high titers of anti-HCcAg.120 antibodies and virus-specific cellular immune responses. Particularly, HCcAg.120-VLPs induced specific delayed type hypersensitivity, and generated a predominant T helper 1 cytokine pro file in immunized mice. In addition, HCcAg.120-VLPs prime splenocytes proliferate in vitro against different HCcAg.120-specific peptides, depending on either the immunization route or the adjuvant used. Remarkably, immunization with HCcAg.120-VLPs/Montanide ISA888 formulation resulted in a significant control of vaccinia virus titer in mice after challenge with a recombinant vaccinia virus expressing HCV core protein, vvCore. Animals immunized with this formulation had a marked increase in the number of IFN-γ producing spleen cells, after stimulation with P815 cells infected with vvCore. These results suggest the use of recombinant HCV core particles as components of therapeutic or preventive vaccine candidates against HCV.

Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes

International Nuclear Information System (INIS)

Font Vivanco, David; Puig Ventosa, Ignasi; Gabarrell Durany, Xavier

2012-01-01

Highlights: ► Sustainability and proximity principles have a key role in waste management. ► Core indicators are needed in order to quantify and evaluate them. ► A systematic, step-by-step approach is developed in this study for their development. ► Transport may play a significant role in terms of environmental and economic costs. ► Policy action is required in order to advance in the consecution of these principles. - Abstract: In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of

A study on 80 fuel assemblies core for HFETR

International Nuclear Information System (INIS)

Sun Shouhua; Wu Yinghua; Bu Yongxi; Liu Shuiqing; Duan Tianyuan; Zhang Liangwan; Lin Jisen

1996-12-01

The performance of 80 and 60 fuel assemblies cores for High Flux Engineering Test Reactor (HFETR) has been compared with theoretical analysis and operating results. These results show that the core performance of 80 fuel assemblies is the same as that of 60 fuel assemblies in the following aspects: the permission power of core, the irradiation test of materials, the transmutation doping of single crystalline silicon, the production of Mo-Tc isotopes, etc. The core of 80 fuel assemblies is more convenient in operation after 500 kw test loop installed, and in greatly raising the production of 60 Co source with high specific radioactivity and the usage of fuel. As compared to the production of 60 Co source of 60 fuel assemblies core, the benefit of 80 fuel assemblies core can increase more than 3.8 millions RMB yuan per year. (2 refs., 2 tabs.)

Standard practice for radiologic examination of flat panel composites and sandwich core materials used in aerospace applications

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 This practice is intended to be used as a supplement to Practices E 1742, E 1255, and E 2033. 1.2 This practice describes procedures for radiologic examination of flat panel composites and sandwich core materials made entirely or in part from fiber-reinforced polymer matrix composites. Radiologic examination is: a) radiographic (RT) with film, b) Computed Radiography (CR) with Imaging Plate, c) Digital Radiology (DR) with Digital Detector Array’s (DDA), and d) Radioscopic (RTR) Real Time Radiology with a detection system such as an Image Intensifier. The composite materials under consideration typically contain continuous high modulus fibers (> 20 GPa), such as those listed in 1.4. 1.3 This practice describes established radiological examination methods that are currently used by industry that have demonstrated utility in quality assurance of flat panel composites and sandwich core materials during product process design and optimization, process control, after manufacture inspection, in service exami...

Listener: a probe into information based material specification

DEFF Research Database (Denmark)

Ramsgaard Thomsen, Mette; Karmon, Ayelet

2011-01-01

This paper presents the thinking and making of the architectural research probe Listener. Developed as an interdisciplinary collaboration between textile design and architecture, Listener explores how information based fabrication technologies are challenging the material practices of architecture....... The paper investigates how textile design can be understood as a model for architectural production providing new strategies for material specification and allowing the thinking of material as inherently variegated and performative. The paper traces the two fold information based strategies present...

k-core covers and the core

NARCIS (Netherlands)

Sanchez-Rodriguez, E.; Borm, Peter; Estevez-Fernandez, A.; Fiestras-Janeiro, G.; Mosquera, M.A.

This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

Specific power of liquid-metal-cooled reactors

International Nuclear Information System (INIS)

Dobranich, D.

1987-10-01

Calculations of the core specific power for conceptual space-based liquid-metal-cooled reactors, based on heat transfer considerations, are presented for three different fuel types: (1) pin-type fuel; (2) cermet fuel; and (3) thermionic fuel. The calculations are based on simple models and are intended to provide preliminary comparative results. The specific power is of interest because it is a measure of the core mass required to produce a given amount of power. Potential problems concerning zero-g critical heat flux and loss-of-coolant accidents are also discussed because these concerns may limit the core specific power. Insufficient experimental data exists to accurately determine the critical heat flux of liquid-metal-cooled reactors in space; however, preliminary calculations indicate that it may be a concern. Results also indicate that the specific power of the pin-type fuels can be increased significantly if the gap between the fuel and the clad is eliminated. Cermet reactors offer the highest specific power because of the excellent thermal conductivity of the core matrix material. However, it may not be possible to take fuel advantage of this characteristic when loss-of-coolant accidents are considered in the final core design. The specific power of the thermionic fuels is dependent mainly on the emitter temperature. The small diameter thermionic fuels have specific powers comparable to those of pin-type fuels. 11 refs., 12 figs, 2 tabs

Process to make core-shell structured nanoparticles

Science.gov (United States)

Luhrs, Claudia; Phillips, Jonathan; Richard, Monique N

2014-01-07

Disclosed is a process for making a composite material that contains core-shell structured nanoparticles. The process includes providing a precursor in the form of a powder a liquid and/or a vapor of a liquid that contains a core material and a shell material, and suspending the precursor in an aerosol gas to produce an aerosol containing the precursor. In addition, the process includes providing a plasma that has a hot zone and passing the aerosol through the hot zone of the plasma. As the aerosol passes through the hot zone of the plasma, at least part of the core material and at least part of the shell material in the aerosol is vaporized. Vapor that contains the core material and the shell material that has been vaporized is removed from the hot zone of the plasma and allowed to condense into core-shell structured nanoparticles.

Communications received from Members regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

1994-04-01

The Director General has received a letter dated 7 October 1993 from the Permanent Mission of Bulgaria, letters dated 8 October 1993 from the Permanent Missions of Australia, Austria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Japan, Luxembourg, the Netherlands, Norway, Portugal, the Russian Federation, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, the United States of America, and a letter dated 11 October 1993 from the Permanent Mission of Poland to the International Atomic Energy Agency concerning the export of nuclear material and of certain categories of equipment and other material. Text of the letter is presented

Fabrication of the novel core-shell MCM-41@mTiO{sub 2} composite microspheres with large specific surface area for enhanced photocatalytic degradation of dinitro butyl phenol (DNBP)

Energy Technology Data Exchange (ETDEWEB)

Wei, Xiao-Na; Wang, Hui-Long, E-mail: hlwang@dlut.edu.cn; Li, Zhen-Duo; Huang, Zhi-Qiang; Qi, Hui-Ping; Jiang, Wen-Feng

2016-05-30

Graphical abstract: The mesoporous MCM-41@mTiO{sub 2} composite microspheres with core/shell structure, well-crystallized mesoporous TiO{sub 2} layer, high specific surface, large pore volume and excellent photocatalytic activity were synthesized by combining sol-gel and simple hydrothermal treatment. - Highlights: • The mesoporous MCM-41@mTiO{sub 2} composite was synthesized successfully. • The composite was facilely prepared by combining sol-gel and hydrothermal method. • The composite exhibited high photocatalytic degradation activity for DNBP. • The composite photocatalyst has excellent reproducibility. - Abstract: The mesoporous MCM-41@mTiO{sub 2} core-shell composite microspheres were synthesized successfully by combining sol-gel and simple hydrothermal treatment. The morphology and microstructure characteristics of the synthesized materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N{sub 2} adsorption-desorption measurements, X-ray powder diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis/DRS) and Fourier transform infrared spectroscopy (FT-IR). The results indicate that the composite material possesses obvious core/shell structure, a pure mesoporous and well-crystallized TiO{sub 2} layer (mTiO{sub 2}), high specific surface area (316.8 m{sup 2}/g), large pore volume (0.42 cm{sup 3}/g) and two different pore sizes (2.6 nm and 11.0 nm). The photocatalytic activity of the novel MCM-41@mTiO{sub 2} composite was evaluated by degrading 2-sec-butyl-4,6-dinitrophenol (DNBP) in aqueous suspension under UV and visible light irradiation. The results were compared with commercial anatase TiO{sub 2} and Degussa P25 and the enhanced degradation were obtained with the synthesized MCM-41@mTiO{sub 2} composite under the same conditions, which meant that this material can serve as an efficient photocatalyst for the degradation of hazardous organic pollutants in wastewaters.

Low Specific Activity materials concepts are being reevaluated

International Nuclear Information System (INIS)

Rawl, R.R.

1993-01-01

Many types of radioactive low-level waste are classified, packaged, and transported as Low-Specific Activity (LSA) material. The transportation regulations allow LSA materials to be shipped in economical packagings and, under certain conditions, waives compliance with other detailed requirements such as labeling. The fundamental concepts which support the LSA category are being thoroughly reevaluated to determine the defensibility of the provisions. A series of national and international events are leading to the development of new dose models which are likely to fundamentally change the ways these materials are defined. Similar basis changes are likely for the packaging requirements applicable to these materials

Offloading of a Wireless Node Authentication with Core Network

DEFF Research Database (Denmark)

2017-01-01

An example technique may include controlling receiving, by a second node from a first node in a wireless network, a request to offload authentication of the first node with the core network to the second node, controlling receiving, by the second node from the first node, data to be forwarded...... to the core network, performing, by the second node based on the request, an authentication with the core network on behalf of the first node while the first node is not connected with the second node, and controlling forwarding the received data from the second node to the core network while the first node...

TMI-2 core-examination program: INEL facilities readiness study

International Nuclear Information System (INIS)

McLaughlin, T.B.

1983-02-01

This report reviews the capability and readiness of remote handling facilities at the Idaho National Engineering Laboratory (INEL) to receive, and store the TMI-2 core, and to examine and analyze TMI-2 core samples. To accomplish these objectives, the facilities must be able to receive commercial casks, unload canisters from the casks, store the canisters, open the canisters, handle the fuel debris and assemblies, and perform various examinations. The report identifies documentation, including core information, necessary to INEL before receiving the entire TMI-2 core. Also identified are prerequisites to INEL's receipt of the first canister: costs, schedules, and a preliminary project plan for the tasks

Engaging design materials, formats and Framings in specific, situated co-designing

DEFF Research Database (Denmark)

Agger Eriksen, Mette

Engaging co-designers in specific situations of co- designing often also means engaging tangible working materials. However, it can be challenging, so rather than seeing it as applying design methods, the paper propose applying what I call a micro-material perspective. The practical concept captu......-design situations" clustered in three quite well- known types of co-design situations framed for; Exploring Current Use(r) Practices, Mapping Networks and Co-Designing (Possible) Futures.......Engaging co-designers in specific situations of co- designing often also means engaging tangible working materials. However, it can be challenging, so rather than seeing it as applying design methods, the paper propose applying what I call a micro-material perspective. The practical concept...... captures both paying attention to the physical design materials, the formats of their exploration and the framings of focus when understanding and planning such specific co-design situations. To exemplify applying the perspective, the paper describes and discusses six specific examples of "co...

Lifetime embrittlement of reactor core materials

International Nuclear Information System (INIS)

Kreyns, P.H..; Bourgeois, W.F.; Charpentier, P.L.; Kammenzind, B.F.; Franklin, D.G.; White, C.J.

1994-08-01

Over a core lifetime, the reactor materials Zircaloy-2, Zircaloy-4, and hafnium may become embrittled due to the absorption of corrosion- generated hydrogen and to neutron irradiation damage. Results are presented on the effects of fast fluence on the fracture toughness of wrought Zircaloy-2, Zircaloy-4, and hafnium; Zircaloy-4 to hafnium butt welds; and hydrogen precharged beta treated and weld metal Zircaloy-4 for fluences up to a maximum of approximately 150 x 10 24 n/M 2 (> 1 Mev). While Zircaloy-4 did not exhibit a decrement in K IC due to irradiation, hafnium and butt welds between hafnium and Zircaloy-4 are susceptible to embrittlement with irradiation. The embrittlement can be attributed to irradiation strengthening, which promotes cleavage fracture in hafnium and hafnium-Zircaloy welds, and, in part, to the lower chemical potential of hydrogen in Zircaloy-4 compared to hafnium, which causes hydrogen, over time, to drift from the hafnium end toward the Zircaloy-4 end and to precipitate at the interface between the weld and base-metal interface. Neutron radiation apparently affects the fracture toughness of Zircaloy-2, Zircaloy-4, and hafnium in different ways. Possible explanations for these differences are suggested. It was found that Zircaloy-4 is preferred over Zircaloy-2 in hafnium-to- Zircaloy butt-weld applications due to its absence of a radiation- induced reduction in K IC plus its lower hydrogen absorption characteristics compared with Zircaloy-2

Solar energy receiver

Science.gov (United States)

Schwartz, Jacob

1978-01-01

An improved long-life design for solar energy receivers provides for greatly reduced thermally induced stress and permits the utilization of less expensive heat exchanger materials while maintaining receiver efficiencies in excess of 85% without undue expenditure of energy to circulate the working fluid. In one embodiment, the flow index for the receiver is first set as close as practical to a value such that the Graetz number yields the optimal heat transfer coefficient per unit of pumping energy, in this case, 6. The convective index for the receiver is then set as closely as practical to two times the flow index so as to obtain optimal efficiency per unit mass of material.

ORIGEN2.1 Cycle Specific Calculation of Krsko Nuclear Power Plant Decay Heat and Core Inventory

International Nuclear Information System (INIS)

Vukovic, J.; Grgic, D.; Konjarek, D.

2010-01-01

This paper presents ORIGEN2.1 computer code calculation of Krsko Nuclear Power Plant core for Cycle 24. The isotopic inventory, core activity and decay heat are calculated in one run for the entire core using explicit depletion and decay of each fuel assembly. Separate pre-ori application which was developed is utilized to prepare corresponding ORIGEN2.1 inputs. This application uses information on core loading pattern to determine fuel assembly specific depletion history using 3D burnup which is obtained from related PARCS computer code calculation. That way both detailed single assembly calculations as well as whole core inventory calculations are possible. Because of the immense output of the ORIGEN2.1, another application called post-ori is used to retrieve and plot any calculated property on the basis of nuclide, element, summary isotope or group of elements for activation products, actinides and fission products segments. As one additional possibility, with the post-ori application it is able to calculate radiotoxicity from calculated ORIGEN2.1 inventory. The results which are obtained using the calculation model of ORIGEN2.1 computer code are successfully compared against corresponding ORIGEN-S computer code results.(author).

The effect of uncertainties in nuclear reactor plant-specific failure data on core damage frequency

International Nuclear Information System (INIS)

Martz, H.F.

1995-05-01

It is sometimes the case in PRA applications that reported plant-specific failure data are, in fact, only estimates which are uncertain. Even for detailed plant-specific data, the reported exposure time or number of demands is often only an estimate of the actual exposure time or number of demands. Likewise the reported number of failure events or incidents is sometimes also uncertain because incident or malfunction reports may be ambiguous. In this report we determine the corresponding uncertainty in core damage frequency which can b attributed to such uncertainties in plant-specific data using a simple but typical nuclear power reactor example

Hysteresis effects in the cores of particle accelerator magnets

CERN Document Server

AUTHOR|(CDS)2086181; Schoerling, Daniel

A study of the hysteresis effects in the cores of particle accelerator magnets has been performed in the framework of the work presented in this thesis. This study has been focused on normal conducting particle accelerator magnets whose cores are manufactured using ferromagnetic materials. The magnetic circuits have been modelled using the developed models: one model for the magnetic circuit and one for the magnetization of the material in the core. The parameters of the magnetic circuit model have been identified with the help of simulations which rely on the finite element method (Opera 3D), while the parameters of the magnetic hysteresis model have been identified through experimental measurements performed using a method developed in the framework of this work. The modelling results have been validated by means of experimental measurements performed on two magnets: one small size magnet which has been specifically designed and manufactured, and one magnet which is currently used in a particle accelerator ...

A Core-Shell Fe/Fe2 O3 Nanowire as a High-Performance Anode Material for Lithium-Ion Batteries.

Science.gov (United States)

Na, Zhaolin; Huang, Gang; Liang, Fei; Yin, Dongming; Wang, Limin

2016-08-16

The preparation of novel one-dimensional core-shell Fe/Fe2 O3 nanowires as anodes for high-performance lithium-ion batteries (LIBs) is reported. The nanowires are prepared in a facile synthetic process in aqueous solution under ambient conditions with subsequent annealing treatment that could tune the capacity for lithium storage. When this hybrid is used as an anode material for LIBs, the outer Fe2 O3 shell can act as an electrochemically active material to store and release lithium ions, whereas the highly conductive and inactive Fe core functions as nothing more than an efficient electrical conducting pathway and a remarkable buffer to tolerate volume changes of the electrode materials during the insertion and extraction of lithium ions. The core-shell Fe/Fe2 O3 nanowire maintains an excellent reversible capacity of over 767 mA h g(-1) at 500 mA g(-1) after 200 cycles with a high average Coulombic efficiency of 98.6 %. Even at 2000 mA g(-1) , a stable capacity as high as 538 mA h g(-1) could be obtained. The unique composition and nanostructure of this electrode material contribute to this enhanced electrochemical performance. Due to the ease of large-scale fabrication and superior electrochemical performance, these hybrid nanowires are promising anode materials for the next generation of high-performance LIBs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reactor core of FBR type reactor

International Nuclear Information System (INIS)

Hayashi, Hideyuki; Ichimiya, Masakazu.

1994-01-01

A reactor core is a homogeneous reactor core divided into two regions of an inner reactor core region at the center and an outer reactor core region surrounding the outside of the inner reactor core region. In this case, the inner reactor core region has a lower plutonium enrichment degree and less amount of neutron leakage in the radial direction, and the outer reactor core region has higher plutonium enrichment degree and greater amount of neutron leakage in the radial direction. Moderator materials containing hydrogen are added only to the inner reactor core fuels in the inner reactor core region. Pins loaded with the fuels with addition of the moderator materials are inserted at a ratio of from 3 to 10% of the total number of the fuel pins. The moderator materials containing hydrogen comprise zirconium hydride, titanium hydride, or calcium hydride. With such a constitution, fluctuation of the power distribution in the radial direction along with burning is suppressed. In addition, an absolute value of the Doppler coefficient can be increased, and a temperature coefficient of coolants can be reduced. (I.N.)

Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

Science.gov (United States)

Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

2011-10-01

Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

Electromechanical modeling of a honeycomb core integrated vibration energy converter with increased specific power for energy harvesting applications

Science.gov (United States)

Chandrasekharan, Nataraj

especially if the application imposes a space/size constraint. Moreover, the bimorph with increased thickness will now require a larger mechanical force to deform the structure which can fall outside the input ambient excitation amplitude range. In contrast, the honeycomb core bimorph offers an advantage in terms of preserving the global geometric dimensions. The natural frequency of the honeycomb core bimorph can be altered by manipulating honeycomb cell design parameters, such as cell angle, cell wall thickness, vertical cell height and inclined cell length. This results in a change in the mass and stiffness properties of the substrate and hence the bimorph, thereby altering the natural frequency of the harvester. Design flexibility of honeycomb core bimorphs is demonstrated by varying honeycomb cell parameters to alter mass and stiffness properties for power harvesting. The influence of honeycomb cell parameters on power generation is examined to evaluate optimum design to attain highest specific power. In addition, the more compliant nature of a honeycomb core bimorph decreases susceptibility towards fatigue and can increase the operating lifetime of the harvester. The second component of this dissertation analyses an uncoupled equivalent circuit model for piezoelectric energy harvesting. Open circuit voltage developed on the piezoelectric materials can be easily computed either through analytical or finite element models. The efficacy of a method to determine power developed across a resistive load, by representing the coupled piezoelectric electromechanical problem with an external load as an open circuit voltage driven equivalent circuit, is evaluated. The lack of backward feedback at finite resistive loads resulting from such an equivalent representation is examined by comparing the equivalent circuit model to the governing equations of a fully coupled circuit model for the electromechanical problem. It is found that the backward feedback is insignificant for weakly

HPLC-CUPRAC post-column derivatization method for the determination of antioxidants: a performance comparison between porous silica and core-shell column packing.

Science.gov (United States)

Haque, Syed A; Cañete, Socrates Jose P

2018-01-01

An HPLC method employing a post-column derivatization strategy using the cupric reducing antioxidant capacity reagent (CUPRAC reagent) for the determining antioxidants in plant-based materials leverages the separation capability of regular HPLC approaches while allowing for detection specificity for antioxidants. Three different column types, namely core-shell and porous silica including two chemically different core-shell materials (namely phenyl-hexyl and C18), were evaluated to assess potential improvements that could be attained by changing from a porous silica matrix to a core-shell matrix. Tea extracts were used as sample matrices for the evaluation specifically looking at catechin and epigallocatechin gallate (EGCG). Both the C18 and phenyl-hexyl core-shell columns showed better performance compared to the C18 porous silica one in terms of separation, peak shape, and retention time. Among the two core-shell materials, the phenyl-hexyl column showed better resolving power compared to the C18 column. The CUPRAC post-column derivatization method can be improved using core-shell columns and suitable for quantifying antioxidants, exemplified by catechin and EGCG, in tea samples.

Core-to-core dimers forming switchable mesophase

Czech Academy of Sciences Publication Activity Database

Horčic, M.; Svoboda, J.; Novotná, Vladimíra; Pociecha, D.; Gorecka, E.

2017-01-01

Roč. 53, č. 18 (2017), s. 2721-2724 ISSN 1359-7345 R&D Projects: GA ČR GA15-02843S Institutional support: RVO:68378271 Keywords : liquid crystals * bent- core mesogens * dimers Subject RIV: JJ - Other Materials OBOR OECD: Nano-materials (production and properties) Impact factor: 6.319, year: 2016

Determination of the neutron fluence in the welding of the 'Core shroud' of the BWR reactor core

International Nuclear Information System (INIS)

Lucatero, M.A.; Xolocostli M, J.V.; Gomez T, A.M.; Palacios H, J.C.

2006-01-01

With the purpose of defining the inspection frequency, in function of the embrittlement of the materials that compose the welding of the 'Core Shroud' or encircling of the core of a BWR type reactor, is necessary to know the neutron fluence received for this welding. In the work the calculated values of neutron fluence accumulated maxim (E > 1 MeV) during the first 8 operation cycles of the reactor are presented. The calculations were carried out according to the NRC Regulatory Guide 1.190, making use of the DORT code, which solves the transport equation in discreet ordinate in two dimensions (xy, rΘ, and rz). The results in 3D were obtained applying the Synthesis method according to the guide before mentioned. Results are presented for the horizontal welding H3, H4, and H5, showing the corresponding curves to the fluence accumulated to the cycle 8 and a projection for the cycle 14 is presented. (Author)

DOE Radiological Control Manual Core Training Program

International Nuclear Information System (INIS)

Scott, H.L.; Maisler, J.

1993-01-01

Over the past year, the Department of Energy (DOE) Office of Health (EH-40) has taken a leading role in the development of new standardized radiological control training programs for use throughout the DOE complex. The Department promulgated its Radiological Control (RadCon) Manual in June 1992. To ensure consistent application of the criteria presented in the RadCon Manual, standardized radiological control core training courses and training materials have been developed for implementation at all DOE facilities. In producing local training programs, standardized core courses are to be supplemented with site-specific lesson plans, viewgraphs, student handbooks, qualification standards, question banks, and wallet-sized training certificates. Training programs for General Employee Radiological Training, Radiological Worker I and II Training, and Radiological Control Technician Training have been disseminated. Also, training committees under the direction of the Office of Health (EH-40) have been established for the development of additional core training courses, development of examination banks, and the update of the existing core training courses. This paper discusses the current activities and future direction of the DOE radiological control core training program

Replaceable LMFBR core components

International Nuclear Information System (INIS)

Evans, E.A.; Cunningham, G.W.

1976-01-01

Much progress has been made in understanding material and component performance in the high temperature, fast neutron environment of the LMFBR. Current data have provided strong assurance that the initial core component lifetime objectives of FFTF and CRBR can be met. At the same time, this knowledge translates directly into the need for improved core designs that utilize improved materials and advanced fuels required to meet objectives of low doubling times and extended core component lifetimes. An industrial base for the manufacture of quality core components has been developed in the US, and all procurements for the first two core equivalents for FFTF will be completed this year. However, the problem of fabricating recycled plutonium while dramatically reducing fabrication costs, minimizing personnel exposure, and protecting public health and safety must be addressed

[Clinical benefit of HCV core antigen assay in patients receiving interferon and ribavirin combination therapy].

Science.gov (United States)

Higashimoto, Makiko; Takahashi, Masahiko; Jokyu, Ritsuko; Saito, Hidetsugu

2006-02-01

A highly sensitive second generation HCV core antigen assay has recently been developed. We compared viral disappearance and kinetics data between commercially available core antigen assays, Lumipulse Ortho HCV Ag, and a quantitative HCV RNA PCR assay, Cobas Amplicor HCV Monitor Test, Version 2 to estimate the predictive benefit of sustained viral response (SVR) and non-SVR in 59 patients treated with interferon and ribavirin combination therapy. We found a good correlation between HCV core Ag and HCV RNA level regardless of genotype. Although the sensitivity of the core antigen assay was lower than PCR, the dynamic range was broader than that of the PCR assay, so that we did not need to dilute the samples in 59 patients. We detected serial decline of core Ag levels in 24 hrs, 7 days and 14 days after interferon combination therapy. The decline of core antigen levels was significant in SVR patients compared to non-SVR as well as in genotype 2a, 2b patients compared to 1b. Core antigen-negative on day 1 could predict all 10 SVR patients (PPV = 100%), whereas RNA-negative could predict 22 SVR out of 25 on day 14 (PPV = 88.0%). None of the patients who had detectable serum core antigen on day 14 became SVR(NPV = 100%), although NPV was 91.2% on RNA negativity. An easy, simple, low cost new HCV core antigen detecting system seems to be useful for assessing and monitoring IFN treatment for HCV.

Transformer core

NARCIS (Netherlands)

Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

2008-01-01

A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

Transformer core

NARCIS (Netherlands)

Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

2010-01-01

A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

Material correlations and models for the irradiation behavior of fissile and fertile material in SNR-300, Mark-II and KNK II, third core

International Nuclear Information System (INIS)

Fenneker; Steinmetz; Toebbe

1986-07-01

The report contains the material correlations and models used in the fuel pin design code IAMBUS for the irradiation behavior of PuO 2 -UO 2 fissile materials and UO 2 fertile materials of the SNR-300 Mark-II reload and the KNK II third core. They are applicable for pellet densities of more than 90 % of the theoretical density. The presented models of the fuel behavior and the applied material correlations have been derived either from single experiments or from the comparison of theoretically predicted integral fuel behavior with the results of fuel pin irradiation experiments. The material correlations have been examined and extended in the frame of the collaborations INTERATOM/KWU and INTERATOM/KfK. French and British results were included, when available from the European fast reactor knowledge exchange [de

Effect of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal solar cells.

Science.gov (United States)

Sahin, Mehmet

2018-05-23

In this study, the effects of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal (QDNC) solar cells have been investigated in detail. For this purpose, the conventional, i.e. original, detailed balance model, developed by Shockley and Queisser to calculate an upper limit for the conversion efficiency of silicon p-n junction solar cells, is modified in a simple and effective way to calculate the conversion efficiency of core/shell QDNC solar cells. Since the existing model relies on the gap energy ([Formula: see text]) of the solar cell, it does not make an estimation about the effect of QDNC materials on the efficiency of the solar cells, and gives the same efficiency values for several QDNC solar cells with the same [Formula: see text]. The proposed modification, however, estimates a conversion efficiency in relation to the material properties and also the confinement type of the QDNCs. The results of the modified model show that, in contrast to the original one, the conversion efficiencies of different QDNC solar cells, even if they have the same [Formula: see text], become different depending upon the confinement type and shell material of the core/shell QDNCs, and this is crucial in the design and fabrication of the new generation solar cells to predict the confinement type and also appropriate QDNC materials for better efficiency.

Effect of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal solar cells

Science.gov (United States)

Sahin, Mehmet

2018-05-01

In this study, the effects of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal (QDNC) solar cells have been investigated in detail. For this purpose, the conventional, i.e. original, detailed balance model, developed by Shockley and Queisser to calculate an upper limit for the conversion efficiency of silicon p–n junction solar cells, is modified in a simple and effective way to calculate the conversion efficiency of core/shell QDNC solar cells. Since the existing model relies on the gap energy () of the solar cell, it does not make an estimation about the effect of QDNC materials on the efficiency of the solar cells, and gives the same efficiency values for several QDNC solar cells with the same . The proposed modification, however, estimates a conversion efficiency in relation to the material properties and also the confinement type of the QDNCs. The results of the modified model show that, in contrast to the original one, the conversion efficiencies of different QDNC solar cells, even if they have the same , become different depending upon the confinement type and shell material of the core/shell QDNCs, and this is crucial in the design and fabrication of the new generation solar cells to predict the confinement type and also appropriate QDNC materials for better efficiency.

A new mechanism of hydrogen absorption in water-water reactor core materials

International Nuclear Information System (INIS)

Gann, V.V.; Gann, A.V.

2012-01-01

The spectrum of fast protons, generated in water by fast neutrons of WWER-1000 reactor core, has been calculated using the code MCNPX. The main mechanism of fast proton generation in the moderator is found to be elastic scattering of fast neutrons on hydrogen nuclei. Fast protons with mean energy 1 MeV flow towards the surface of cladding material at flux density ∼ 0.1 μA/cm 2 . Proton range distribution profile in cladding material is calculated. The range of fast protons in zirconium averages 20 μm, the maximal proton range is larger than 200 μm. The rate of hydrogen deposition in 40 μm layer amounts to 5 x 10 -5 H/n/μ. A role of the suggested mechanism in process of zirconium clad hydrogenation during reactor irradiation is discussed.

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1993-01-01

The document reproduces the Note Verbale dated 2 December 1992 received by the Director General from the Resident Representative of Argentina to the Agency relating to the export of nuclear material, equipment or technology, in order to provide information on that Government's Guidelines for Transfers of Nuclear-related Dual-use Equipment, Material and related Technology

Casting core for a cooling arrangement for a gas turbine component

Science.gov (United States)

Lee, Ching-Pang; Heneveld, Benjamin E

2015-01-20

A ceramic casting core, including: a plurality of rows (162, 166, 168) of gaps (164), each gap (164) defining an airfoil shape; interstitial core material (172) that defines and separates adjacent gaps (164) in each row (162, 166, 168); and connecting core material (178) that connects adjacent rows (170, 174, 176) of interstitial core material (172). Ends of interstitial core material (172) in one row (170, 174, 176) align with ends of interstitial core material (172) in an adjacent row (170, 174, 176) to form a plurality of continuous and serpentine shaped structures each including interstitial core material (172) from at least two adjacent rows (170, 174, 176) and connecting core material (178).

Core outcome domains for clinical trials in non-specific low back pain.

Science.gov (United States)

Chiarotto, Alessandro; Deyo, Richard A; Terwee, Caroline B; Boers, Maarten; Buchbinder, Rachelle; Corbin, Terry P; Costa, Leonardo O P; Foster, Nadine E; Grotle, Margreth; Koes, Bart W; Kovacs, Francisco M; Lin, Chung-Wei Christine; Maher, Chris G; Pearson, Adam M; Peul, Wilco C; Schoene, Mark L; Turk, Dennis C; van Tulder, Maurits W; Ostelo, Raymond W

2015-06-01

Inconsistent reporting of outcomes in clinical trials of patients with non-specific low back pain (NSLBP) hinders comparison of findings and the reliability of systematic reviews. A core outcome set (COS) can address this issue as it defines a minimum set of outcomes that should be reported in all clinical trials. In 1998, Deyo et al. recommended a standardized set of outcomes for LBP clinical research. The aim of this study was to update these recommendations by determining which outcome domains should be included in a COS for clinical trials in NSLBP. An International Steering Committee established the methodology to develop this COS. The OMERACT Filter 2.0 framework was used to draw a list of potential core domains that were presented in a Delphi study. Researchers, care providers and patients were invited to participate in three Delphi rounds and were asked to judge which domains were core. A priori criteria for consensus were established before each round and were analysed together with arguments provided by panellists on importance, overlap, aggregation and/or addition of potential core domains. The Steering Committee discussed the final results and made final decisions. A set of 280 experts was invited to participate in the Delphi; response rates in the three rounds were 52, 50 and 45%. Of 41 potential core domains presented in the first round, 13 had sufficient support to be presented for rating in the third round. Overall consensus was reached for the inclusion of three domains in this COS: 'physical functioning', 'pain intensity' and 'health-related quality of life'. Consensus on 'physical functioning' and 'pain intensity' was consistent across all stakeholders, 'health-related quality of life' was not supported by the patients, and all the other domains were not supported by two or more groups of stakeholders. Weighting all possible argumentations, the Steering Committee decided to include in the COS the three domains that reached overall consensus and

Characterizing the Core via K-Core Covers

NARCIS (Netherlands)

Sanchez, S.M.; Borm, P.E.M.; Estevez, A.

2013-01-01

This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

Element-specific and site-specific ion desorption from adsorbed molecules by deep core-level photoexcitation at the K-edges

CERN Document Server

Baba, Y H

2003-01-01

This article reviews our recent works on the ion desorption from adsorbed and condensed molecules at low temperature following the core-level photoexcitations using synchrotron soft x-rays. The systems investigated here are adsorbed molecules with relatively heavy molecular weight containing third-row elements such as Si, P, S, and Cl. Compared with molecules composed of second-row elements, the highly element-specific and site-specific fragment-ion desorption were observed when we tune the photon energy at the dipole-allowed 1s -> sigma sup * (3p sup *) resonance. On the basis of the resonance Auger decay spectra around the 1s ionization thresholds, the observed highly specific ion desorption is interpreted by the localization of the excited electrons (here we call as 'spectator electrons') in the antibonding sigma sup * orbital. In order to separate the direct photo-induced process from the indirect processes triggered by the secondary electrons, the photon-stimulated ion desorption was also investigated in...

In vitro shear bond strength of Y-TZP ceramics to different core materials with the use of three primer/resin cement systems.

Science.gov (United States)

Al-Harbi, Fahad A; Ayad, Neveen M; Khan, Zahid A; Mahrous, Amr A; Morgano, Steven M

2016-01-01

Durability of the bond between different core materials and zirconia retainers is an important predictor of the success of a dental prosthesis. Nevertheless, because of its polycrystalline structure, zirconia cannot be etched and bonded to a conventional resin cement. The purpose of this in vitro study was to compare the effects of 3 metal primer/resin cement systems on the shear bond strength (SBS) of 3 core materials bonded to yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic retainers. Zirconia ceramic (Cercon) disks (5×3 mm) were airborne-particle abraded, rinsed, and air-dried. Disk-shaped core specimens (7×7 mm) that were prepared of composite resin, Ni-Cr, and zirconia were bonded to the zirconia ceramic disks by using one of 3 metal primer/cement systems: (Z-Prime Plus/BisCem, Zirconia Primer/Multilink Automix, or Clearfil Ceramic Primer/Clearfil SA). SBS was tested in a universal testing machine. Stereomicroscopy was used to evaluate the failure mode of debonded specimens. Data were analyzed using 2-way ANOVA and post hoc analysis using the Scheffe procedure (α=.05). Clearfil SA/Clearfil Ceramic Primer system with an Ni-Cr core yielded the highest SBS value (19.03 MPa), whereas the lowest SBS value was obtained when Multilink Automix/Zirconia Primer system was used with the zirconia core group (4.09 MPa). Differences in mean SBS values among the cement/primer groups were statistically significant, except for Clearfil SA and BisCem with both composite resin and zirconia cores. Differences in mean SBS values among the core subgroups were not statistically significant, except for zirconia core with BisCem, Multilink, and Clearfil SA. The predominant failure mode was adhesive, except for Clearfil SA and BisCem luting agents with composite resin cores, which displayed cohesive failure, and Multilink Automix with a composite resin, core as well as Clearfil SA with Ni-Cr cores, where the debonded specimens of each group displayed a mixed

Laser ultrasonic receivers based on photorefractive materials in non-destructive testing

International Nuclear Information System (INIS)

Zamiri Hosseinzadeh, S.

2014-01-01

SiO 20 ), LiNbO:Fe+2 and polymer composites like AODCST/PVK/BBP/PCBM and Dc/PVK/ECZ/C 60 are presented and their sensitivities and response times are compared. In these types of interferometers, a reference beam and a phase modulated signal beam (due to generated ultrasonic waves) interfere inside the photorefractive material and the reference beam is diffracted in the signal beam direction. The planar wave front of the reference beam adapts to the distorted wave front of the object beam and because of this reason, such interferometers are called adaptive interferometers. By interference of both beams on a fast photodiode surface, one can detect the generated bulk and surface ultrasonic pulses. This laser receiver is not as sensitive as contact receivers such as piezoelectric transducers. Different methods were used in this work to enhance the sensitivity of TWMIs and to detect the ultrasonic waves with a higher Signal to Noise Ratio (SNR). For instance, focusing the ultrasound waves with a spatial light modulator (SLM) to shape the beam profile of a picosecond laser with a 1064nm wavelength in a ring shape, using PR materials with higher coupling gain and using a special balanced detection based on two PR crystals are some methods which are performed to enhance the efficiency of TWMIs. Based on presented details in this work, a better understanding of the photorefractive effect principle as well as of the TWMI operation based on different PR materials, such as crystals and polymer composites, is possible. Furthermore fabrication of PR polymers and application of TWMI in industrial applications, such as defect detection, phase transformation and thickness measurement in metal sheets, are presented. (author) [de

Communication of 15 November 2001 Received from the People's Republic of China regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

2002-01-01

The Director General has received a letter of 15 November 2001 from the Resident Representative of the People's Republic of China concerning the export of nuclear material and of certain categories of equipment and other material

General problems specific to hot nuclear materials research facilities

International Nuclear Information System (INIS)

Bart, G.

1996-01-01

During the sixties, governments have installed hot nuclear materials research facilities to characterize highly radioactive materials, to describe their in-pile behaviour, to develop and test new reactor core components, and to provide the industry with radioisotopes. Since then, the attitude towards the nuclear option has drastically changed and resources have become very tight. Within the changed political environment, the national research centres have defined new objectives. Given budgetary constraints, nuclear facilities have to co-operate internationally and to look for third party research assignments. The paper discusses the problems and needs within experimental nuclear research facilities as well as industrial requirements. Special emphasis is on cultural topics (definition of the scope of nuclear research facilities, the search for competitive advantages, and operational requirements), social aspects (overageing of personnel, recruitment, and training of new staff), safety related administrative and technical issues, and research needs for expertise and state of the art analytical infrastructure

Fabrication of Fe3O4@CuO core-shell from MOF based materials and its antibacterial activity

Science.gov (United States)

Rajabi, S. K.; Sohrabnezhad, Sh.; Ghafourian, S.

2016-12-01

Magnetic Fe3O4@CuO nanocomposite with a core/shell structure was successfully synthesized via direct calcinations of magnetic Fe3O4@HKUST-1 in air atmosphere. The morphology, structure, magnetic and porous properties of the as-synthesized nano composites were characterized by using scanning electron microscope (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and vibration sample magnetometer (VSM). The results showed that the nanocomposite material included a Fe3O4 core and a CuO shell. The Fe3O4@CuO core-shell can be separated easily from the medium by a small magnet. The antibacterial activity of Fe3O4-CuO core-shell was investigated against gram-positive and gram-negative bacteria. A new mechanism was proposed for inactivation of bacteria over the prepared sample. It was demonstrated that the core-shell exhibit recyclable antibacterial activity, acting as an ideal long-acting antibacterial agent.

Study of diluting and absorber materials to control the reactivity during a postulated core meltdown accident in generation IV reactors

International Nuclear Information System (INIS)

Plevacova, Kamila

2010-01-01

In order to limit the consequences of a hypothetical core meltdown accident in Generation IV Sodium Fast Reactors, absorber materials in or near the core, such as boron carbide B 4 C, and diluting materials in the core catcher will be used to prevent recriticality within the mixture of molten oxide fuel and molten structures called corium. The aim of the PhD thesis was to select materials of both types and to understand their behaviour during their interaction with corium, from chemical and thermodynamic points of view. Concerning B 4 C, thermodynamic calculations and experiments agree with the formation of two immiscible phases at high temperature in the B 4 C - UO 2 system: one oxide and one boride. This separation of phases can reduce the efficiency of the neutrons absorption inside the molten fuel contained in the oxide phase. Moreover, volatilization of a part of the boron element can occur. According to these results, the necessary quantity of B 4 C to be introduced should be reconsidered for postulated severe accident sequence. Other solution could be the use of Eu 2 O 3 or HfO 2 as absorber material. These oxides form a solid solution with the oxide fuel. Concerning the diluting materials, mixed oxides Al 2 O 3 - HfO 2 and Al 2 O 3 - Eu 2 O 3 were preselected. These systems being completely unknown to date at high temperature in association with UO 2 , first points on the corresponding ternary phase diagrams were researched. Contrary to Al 2 O 3 - Eu 2 O 3 - UO 2 system, the Al 2 O 3 - HfO 2 - UO 2 mixture presents only one eutectic and thus only one solidification path which makes easier forecasting the behaviour of corium in the core catcher. (author)

Study of diluting and absorber materials to control reactivity during a postulated core melt down accident in Generation IV reactors

International Nuclear Information System (INIS)

Plevacova, K.

2010-01-01

In order to limit the consequences of a hypothetical core meltdown accident in Generation IV Sodium Fast Reactors, absorber materials in or near the core, such as boron carbide B 4 C, and diluting materials in the core catcher will be used to prevent recriticality within the mixture of molten oxide fuel and molten structures called corium. The aim of the PhD thesis was to select materials of both types and to understand their behaviour during their interaction with corium, from chemical and thermodynamic point of view. Concerning B 4 C, thermodynamic calculations and experiments agree with the formation of two immiscible phases at high temperature in the B 4 C - UO 2 system: one oxide and one boride. This separation of phases can reduce the efficiency of the neutrons absorption inside the molten fuel contained in the oxide phase. Moreover, a volatilization of a part of the boron element can occur. According to these results, the necessary quantity of B 4 C to be introduced should be reconsidered for postulated severe accident sequence. Other solution could be the use of Eu 2 O 3 or HfO 2 as absorber material. These oxides form a solid solution with the oxide fuel. Concerning the diluting materials, mixed oxides Al 2 O 3 - HfO 2 and Al 2 O 3 - Eu 2 O 3 were preselected. These systems being completely unknown to date at high temperature in association with UO 2 , first points on the corresponding ternary phase diagrams were researched. Contrary to Al 2 O 3 - Eu 2 O 3 - UO 2 system, the Al 2 O 3 - HfO 2 - UO 2 mixture presents only one eutectic and thus only one solidification path which makes easier forecasting the behaviour of corium in the core catcher. (author) [fr

Communications received from Member States regarding the Export of Nuclear Material and of Certain Categories of Equipment and other Material

International Nuclear Information System (INIS)

1994-08-01

The Director General has received letters concerning the export of nuclear material and of certain categories of equipment and other material from the following Resident Representatives to the International Atomic Energy Agency: a letter dated 28 February 1994 from the Resident Representative of France; letters dated 1 March 1994 from the Resident Representatives of Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, Germany, Greece, Hungary, Ireland, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, and the United States of America; and a letter dated 22 March 1994 from the Resident Representative of Romania [es

Communications received from Member States regarding the Export of Nuclear Material and of Certain Categories of Equipment and other Material

International Nuclear Information System (INIS)

1994-01-01

The Director General has received letters concerning the export of nuclear material and of certain categories of equipment and other material from the following Resident Representatives to the International Atomic Energy Agency: a letter dated 28 February 1994 from the Resident Representative of France; letters dated 1 March 1994 from the Resident Representatives of Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, Germany, Greece, Hungary, Ireland, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, and the United States of America; and a letter dated 22 March 1994 from the Resident Representative of Romania [fr

Insertion material for controlling reactivity

International Nuclear Information System (INIS)

Baba, Iwao.

1994-01-01

Moderators and a group of suspended materials having substantially the same density as the moderator are sealed in a hollow rod vertically inserted to a fuel assembly. Specifically, the group of suspended materials is adapted to have a density changing stepwise from density of the moderator at the exit temperature of the reactor core to that at the inlet temperature of the reactor core. Reactivity is selectively controlled for a portion of high power and a portion of high reactivity by utilizing the density of the moderator and the distribution of the density. That is, if the power distribution is flat, the density of the moderators changes at a constant rate over the vertical direction of the reactor core and the suspended materials stay at a portion of the same density, to form a uniform distribution. Further, upon reactor shutdown, since the liquid temperature of the moderators is lowered and the density is increased, all of beads are collected at the upper portion to remove water at the upper portion of the reactor core of low burnup degree thereby selectively controlling the reactivity at a portion of high power and a portion of high reactivity. (N.H.)

Structural analysis of a reflux pool-boiler solar receiver

Energy Technology Data Exchange (ETDEWEB)

Hoffman, E.L.; Stone, C.M.

1991-06-01

Coupled thermal-structural finite element calculations of a reflux pool-boiler solar receiver were performed to characterize the operating stresses and to address issues affecting the service life of the receiver. Analyses performed using shell elements provided information for receiver material selection and design optimization. Calculations based on linear elastic fracture mechanics principles were performed using continuum elements to assess the vulnerability of a seam-weld to fatigue crack growth. All calculations were performed using ABAQUS, a general purpose finite element code, and elements specifically formulated for coupled thermal-structural analysis. Two materials were evaluated: 316L SS and Haynes 230 alloys. The receiver response was simulated for a combination of structural and thermal loads that represent the startup and operating conditions of the receiver. For both materials, maximum stresses in the receiver developed shortly after startup due to uneven temperature distribution across the receiver surface. The largest effective stress was near yield in the 316L SS receiver and below 39 percent of yield in the Haynes 230 receiver. The calculations demonstrated that stress reductions of over 25 percent could be obtained by reducing the aft dome thickness to one closer to the absorber. The fatigue calculations demonstrated that the stress distribution near the seam-weld notch depends primarily on the structural load created by internal pressurization of the receiver rather than the thermal, indicating that the thermal loads can be neglected when assessing the stress intensity near the seam-weld notch. The stress intensity factor, computed using the J-integral method and crack opening-displacement field equations, was significantly below the fatigue threshold for most steels. The calculations indicated that the weld notch was always loaded in compression, a condition which is not conducive to fatigue crack growth. 15 refs., 30 figs., 3 tabs.

Development of Structural Core Components for Breeder Reactors

International Nuclear Information System (INIS)

Saibaba, N.

2013-01-01

Core structural materials: • The desire is to have only fuel in the core, structural material form 25% of the total core: – To support and to retain the fuel in position; – Provide necessary ducts to make coolant flow through & transfer/remove heat. • For 500 MWe FBR with Oxide fuel (Peak Linear Power 450 W/cm), total fuel pins required in the core are of the order 39277 pins (both inner & outer core Fuel SA); • Considering 217 pins/Fuel SA there are 181 Fuel SA wrapper tubes • These structural materials see hostile core with max temperature and neutron flux

Influence of high dose irradiation on core structural and fuel materials in advanced reactors

International Nuclear Information System (INIS)

1998-08-01

The IAEA International Working Group on Fast Reactors (IWGFR) periodically organizes meeting to discuss and review important aspects of fast reactor technology. The fifth meeting held in Obninsk, Russian Federation, 16-19 June 1997, was devoted to the influence of high dose irradiation on the mechanical properties of reactor core structural and fuel materials. The proceedings includes the papers submitted at this meeting each with a separate abstract

An endoglycosidase-assisted LC-MS/MS-based strategy for the analysis of site-specific core-fucosylation of low-concentrated glycoproteins in human serum using prostate-specific antigen (PSA) as example.

Science.gov (United States)

Lang, Robert; Leinenbach, Andreas; Karl, Johann; Swiatek-de Lange, Magdalena; Kobold, Uwe; Vogeser, Michael

2018-05-01

Recently, site-specific fucosylation of glycoproteins has attracted attention as it can be associated with several types of cancers including prostate cancer. However, individual glycoproteins, which might serve as potential cancer markers, often are very low-concentrated in complex serum matrices and distinct glycan structures are hard to detect by immunoassays. Here, we present a mass spectrometry-based strategy for the simultaneous analysis of core-fucosylated and total prostate-specific antigen (PSA) in human serum in the low ng/ml concentration range. Sample preparation comprised an immunoaffinity capture step to enrich total PSA from human serum using anti-PSA antibody coated magnetic beads followed by consecutive two-step on-bead partial deglycosylation with endoglycosidase F3 and tryptic digestion prior to LC-MS/MS analysis. The method was shown to be linear from 0.5 to 60 ng/ml total PSA concentrations and allows the simultaneous quantification of core-fucosylated PSA down to 1 ng/ml and total PSA lower than 0.5 ng/ml. The imprecision of the method over two days ranged from 9.7-23.2% for core-fucosylated PSA and 10.3-18.3% for total PSA depending on the PSA level. The feasibility of the method in native sera was shown using three human specimens. To our knowledge, this is the first MS-based method for quantification of core-fucosylated PSA in the low ng/ml concentration range in human serum. This method could be used in large patient cohorts as core-fucosylated PSA may be a diagnostic biomarker for the differentiation of prostate cancer and other prostatic diseases, such as benign prostatic hyperplasia (BPH). Furthermore, the described strategy could be used to monitor potential changes in site-specific core-fucosylation of other low-concentrated glycoproteins, which could serve as more specific markers ("marker refinement") in cancer research. Copyright © 2018 Elsevier B.V. All rights reserved.

Statistical analysis on hollow and core-shell structured vanadium oxide microspheres as cathode materials for Lithium ion batteries

Directory of Open Access Journals (Sweden)

Xing Liang

2018-06-01

Full Text Available In this data, the statistical analyses of vanadium oxide microspheres cathode materials are presented for the research article entitled “Statistical analyses on hollow and core-shell structured vanadium oxides microspheres as cathode materials for Lithium ion batteries” (Liang et al., 2017 [1]. This article shows the statistical analyses on N2 adsorption-desorption isotherm and morphology vanadium oxide microspheres as cathode materials for LIBs. Keywords: Adsorption-desorption isotherm, Pore size distribution, SEM images, TEM images

Nonlinear Thermo-mechanical Finite Element Analysis of Polymer Foam Cored Sandwich Structures including Geometrical and Material Nonlinearity

DEFF Research Database (Denmark)

Palleti, Hara Naga Krishna Teja; Thomsen, Ole Thybo; Taher, Siavash Talebi

In this paper, polymer foam cored sandwich structures with fibre reinforced composite face sheets subjected to combined mechanical and thermal loads will be analysed using the commercial FE code ABAQUS® incorporating both material and geometrical nonlinearity. Large displacements and rotations...

Fabrication of Fe3O4@CuO core-shell from MOF based materials and its antibacterial activity

International Nuclear Information System (INIS)

Rajabi, S.K.; Sohrabnezhad, Sh.; Ghafourian, S.

2016-01-01

Magnetic Fe 3 O 4 @CuO nanocomposite with a core/shell structure was successfully synthesized via direct calcinations of magnetic Fe 3 O 4 @HKUST-1 in air atmosphere. The morphology, structure, magnetic and porous properties of the as-synthesized nano composites were characterized by using scanning electron microscope (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and vibration sample magnetometer (VSM). The results showed that the nanocomposite material included a Fe 3 O 4 core and a CuO shell. The Fe 3 O 4 @CuO core-shell can be separated easily from the medium by a small magnet. The antibacterial activity of Fe 3 O 4 -CuO core-shell was investigated against gram-positive and gram-negative bacteria. A new mechanism was proposed for inactivation of bacteria over the prepared sample. It was demonstrated that the core-shell exhibit recyclable antibacterial activity, acting as an ideal long-acting antibacterial agent. - Graphical abstract: Fe 3 O 4 @CuO core-shell release of copper ions. These Cu 2+ ions were responsible for the exhibited antibacterial activity. - Highlights: • The Fe 3 O 4 @CuO core-shell was prepared by MOF method. • This is the first study of antibacterial activity of core-shell consist of CuO and Fe 3 O 4 . • The core-shell can be reused effectively. • Core-shell was separated from the reaction solution by external magnetic field.

Propagation law of impact elastic wave based on specific materials

Directory of Open Access Journals (Sweden)

Chunmin CHEN

2017-02-01

Full Text Available In order to explore the propagation law of the impact elastic wave on the platform, the experimental platform is built by using the specific isotropic materials and anisotropic materials. The glass cloth epoxy laminated plate is used for anisotropic material, and an organic glass plate is used for isotropic material. The PVDF sensors adhered on the specific materials are utilized to collect data, and the elastic wave propagation law of different thick plates and laminated plates under impact conditions is analyzed. The Experimental results show that in anisotropic material, transverse wave propagation speed along the fiber arrangement direction is the fastest, while longitudinal wave propagation speed is the slowest. The longitudinal wave propagation speed in anisotropic laminates is much slower than that in the laminated thick plates. In the test channel arranged along a particular angle away from the central region of the material, transverse wave propagation speed is larger. Based on the experimental results, this paper proposes a material combination mode which is advantageous to elastic wave propagation and diffusion in shock-isolating materials. It is proposed to design a composite material with high acoustic velocity by adding regularly arranged fibrous materials. The overall design of the barrier material is a layered structure and a certain number of 90°zigzag structure.

ATE accomplishes receiver specification testing with increased speed and throughput

Science.gov (United States)

Moser, S. A.

1982-12-01

The use of automatic test equipment (ATE) for receiver specifications testing can result in a 90-95% reduction of test time, with a corresponding reduction of labor costs due both to the reduction of personnel numbers and a simplification of tasks that permits less skilled personnel to be employed. These benefits free high-level technicians for more challenging system management assignments. Accuracy and repeatability also improve with the adoption of ATE, since no possibility of human error can be introduced into the readings that are taken by the system. A massive and expensive software design and development effort is identified as the most difficult aspect of ATE implementation, since programming is both time-consuming and labor intensive. An attempt is therefore made by system manufacturers to conduct an integrated development program for both ATE system hardware and software.

Core Community Specifications for Electron Microprobe Operating Systems: Software, Quality Control, and Data Management Issues

Science.gov (United States)

Fournelle, John; Carpenter, Paul

2006-01-01

Modem electron microprobe systems have become increasingly sophisticated. These systems utilize either UNIX or PC computer systems for measurement, automation, and data reduction. These systems have undergone major improvements in processing, storage, display, and communications, due to increased capabilities of hardware and software. Instrument specifications are typically utilized at the time of purchase and concentrate on hardware performance. The microanalysis community includes analysts, researchers, software developers, and manufacturers, who could benefit from exchange of ideas and the ultimate development of core community specifications (CCS) for hardware and software components of microprobe instrumentation and operating systems.

Heterogeneous gas core reactor

International Nuclear Information System (INIS)

Diaz, N.J.; Dugan, E.T.

1983-01-01

A heterogeneous gas core nuclear reactor is disclosed comprising a core barrel provided interiorly with an array of moderator-containing tubes and being otherwise filled with a fissile and/or fertile gaseous fuel medium. The fuel medium may be flowed through the chamber and through an external circuit in which heat is extracted. The moderator may be a fluid which is flowed through the tubes and through an external circuit in which heat is extracted. The moderator may be a solid which may be cooled by a fluid flowing within the tubes and through an external heat extraction circuit. The core barrel is surrounded by moderator/coolant material. Fissionable blanket material may be disposed inwardly or outwardly of the core barrel

SCDAP/RELAP5 lower core plate model

International Nuclear Information System (INIS)

Coryell, E.W.; Griffin, F.P.

1999-01-01

The SCDAP/RELAP5 computer code is a best-estimate analysis tool for performing nuclear reactor severe accident simulations. This report describes the justification, theory, implementation, and testing of a new modeling capability which will refine the analysis of the movement of molten material from the core region to the vessel lower head. As molten material moves from the core region through the core support structures it may encounter conditions which will cause it to freeze in the region of the lower core plate, delaying its arrival to the vessel head. The timing of this arrival is significant to reactor safety, because during the time span for material relocation to the lower head, the core may be experiencing steam-limited oxidation. The time at which hot material arrives in a coolant-filled lower vessel head, thereby significantly increasing the steam flow rate through the core region, becomes significant to the progression and timing of a severe accident. This report is a revision of a report INEEL/EXT-00707, entitled ''Preliminary Design Report for SCDAP/RELAP5 Lower Core Plate Model''

Feasibility study of thermal insulation materials for core support of experimental VHTR

International Nuclear Information System (INIS)

Kawakami, H.; Nakanishi, T.

1982-01-01

Thermal insulation materials for core support of the experimental VHTR, planned by JAERI, should maintain moderate compressive strength and dimensional stability as well as low thermal conductivity at the maximum service temperature of 1100 0 C for 20 years. For selecting materials, we investigate properties of some candidates, and evaluate their feasibility. Preliminary tests, heat treatment test and compressive creep tests for 1000 hours at 900 0 C and 1000 0 C were conducted. In the preliminary tests, EG-38B (carbon baked at 1350 0 C) and Fine Finnex 600 (silicon nitride) showed acceptable physical stability. In the heat treatment tests, silicon nitride showed weight loss probably caused by thermal decomposition. Compressive creep deformation of Fine Finnex 600 was negligible under stress of 100 kg/cm 2 for 1000 hours. Heat treatment at 1200 to 1300 0 C for 50 hours improved dimensional stability of carbon at 1000 0 C

Corrosion Characteristics of the SMART Materials

Energy Technology Data Exchange (ETDEWEB)

Baek, Jong Hyuk; Jeong, Y. H.; Choi, B. K.; Soh, J. R.; Lee, D. J.; Choi, B. S

2000-05-01

This report summarized the corrosion characteristics of the candidate steam generator tubes (PT-7M, ASTM Gr.2, Inconel-600), which are considering as the core materials in SMART. Also, this evaluated the waterchemstry conditions of commercial power plant including the PWR, BWR, WWER, PHWR, RBMK plants in comparison with that of SMART. And this report described that the microstructures of as-received PT-7M, ASTM Gr.2, and Inconel-600 as the candidate materials of fuel cladding and steam generator tubes and characterized the corrosion properties of the materials, which were tested systematically in the conditions of standard, ammonia solution and ammonia nodular to evaluate the corrosion resistance.

Corrosion Characteristics of the SMART Materials

International Nuclear Information System (INIS)

Baek, Jong Hyuk; Jeong, Y. H.; Choi, B. K.; Soh, J. R.; Lee, D. J.; Choi, B. S.

2000-05-01

This report summarized the corrosion characteristics of the candidate steam generator tubes (PT-7M, ASTM Gr.2, Inconel-600), which are considering as the core materials in SMART. Also, this evaluated the waterchemstry conditions of commercial power plant including the PWR, BWR, WWER, PHWR, RBMK plants in comparison with that of SMART. And this report described that the microstructures of as-received PT-7M, ASTM Gr.2, and Inconel-600 as the candidate materials of fuel cladding and steam generator tubes and characterized the corrosion properties of the materials, which were tested systematically in the conditions of standard, ammonia solution and ammonia nodular to evaluate the corrosion resistance

Engineered magnetic core shell nanoprobes: Synthesis and applications to cancer imaging and therapeutics.

Science.gov (United States)

Mandal, Samir; Chaudhuri, Keya

2016-02-26

Magnetic core shell nanoparticles are composed of a highly magnetic core material surrounded by a thin shell of desired drug, polymer or metal oxide. These magnetic core shell nanoparticles have a wide range of applications in biomedical research, more specifically in tissue imaging, drug delivery and therapeutics. The present review discusses the up-to-date knowledge on the various procedures for synthesis of magnetic core shell nanoparticles along with their applications in cancer imaging, drug delivery and hyperthermia or cancer therapeutics. Literature in this area shows that magnetic core shell nanoparticle-based imaging, drug targeting and therapy through hyperthermia can potentially be a powerful tool for the advanced diagnosis and treatment of various cancers.

CT-guided core-needle biopsy in omental pathology

International Nuclear Information System (INIS)

Pombo, F.; Rodriguez, E.; Martin, R.; Lago, M.

1997-01-01

Purpose: To assess the accuracy and clinical usefulness of CT-guided core-needle biopsy in the diagnosis of omental pathology. Material and Methods: We retrospectively reviewed the results of CT-guided percutaneous core biopsies in 25 patients with focal (n=2) or diffuse (n=23) omental pathology. These results were compared to the final diagnoses as determined by laparotomy (n=15), laparoscopic biopsy (n=3), endoscopic biopsy (n=1), or by the results of percutaneous biopsy and clinical-radiological and bacteriological modalities (n=6). The final diagnoses showed 4 patients with isolated omental pathology and 21 with widespread peritoneal involvement. The CT-guided biopsies were performed with 1.0=1.8-mm Surecut core-needles. Results: In 16 patients, the final diagnosis was metastatic adenocarcinoma - with the primary tumor sites in the ovary (n=3), stomach (n=1), appendix (n=2), and unknown (n=10). In the remaining 9 patients, the final diagnosis was hepatocellular carcinoma, lymphoma, and mesothelioma in 1 patient each; tuberculosis in 5; and actinomycosis in 1. Sufficient histological (n=16) or cytological (n=8) material was obtained by CT biopsy in 24/25 (96%) cases; the specimen was insufficient for diagnosis in 1 case. In differentiating benign from malignant disease, CT-guided biopsy showed a sensitivity, specificity and accuracy of respectively 89.5%, 100% and 92%. It gave a specific diagnosis in 78.9% (15/19) of patients with malignant conditions and in 50% (3/6) of patients with benign disorders. There were no biopsy-related complications. Conclusion: CT-guided percutaneous core-needle biopsy of the omentum is a safe, useful and highly accurate procedure for diagnosing malignant omental pathology. (orig.)

Core Stability Exercise Versus General Exercise for Chronic Low Back Pain.

Science.gov (United States)

Coulombe, Brian J; Games, Kenneth E; Neil, Elizabeth R; Eberman, Lindsey E

2017-01-01

Reference: Wang XQ, Zheng JJ, Yu ZW, et al. A meta-analysis of core stability exercise versus general exercise for chronic low back pain. PLoS One. 2012;7(12):e52082. Clinical Questions: Is core stability exercise more effective than general exercise in the treatment of patients with nonspecific low back pain (LBP)?  The authors searched the following databases: China Biological Medicine disc, Cochrane Library, Embase, and PubMed from 1970 through 2011. The key medical subject headings searched were chronic pain, exercise, LBP, lumbosacral region, and sciatica.  Randomized controlled trials comparing core stability exercise with general exercise in the treatment of chronic LBP were investigated. Participants were male and female adults with LBP for at least 3 months that was not caused by a specific known condition. A control group receiving general exercise and an experimental group receiving core stability exercise were required for inclusion in the meta-analysis. Core stability was defined as the ability to ensure a stable neutral spine position, but the type of exercise was not specified. Outcome measures of pain intensity, back-specific functional status, quality of life, and work absenteeism were recorded at 3-, 6-, and 12-month intervals.  The study design, participant information, description of interventions in the control and experimental groups, outcome measures, and follow-up period were extracted. The mean difference (MD) and 95% confidence interval (CI) were calculated to evaluate statistical significance. Risk of bias was assessed using the Cochrane Collaboration Recommendations, and all articles were rated as high risk for other bias with no further explanation given.  Five studies involving 414 patients were included. Four studies assessed pain intensity using the visual analog scale or numeric rating scale. In the core stability exercise group, the reduction in pain was significant at 3 months (MD = -1.29, 95% CI = -2.47, -0.11; P

A Strategy for Material-specific e-Textile Interaction Design

DEFF Research Database (Denmark)

Gowrishankar, Ramyah; Bredies, Katharina; Ylirisku, Salu

2017-01-01

The interaction design of e-Textile products are often characterized by conventions adopted from electronic devices rather than developing interactions that can be specific to e-Textiles. We argue that textile materials feature a vast potential for the design of novel digital interactions....... Especially the shape-reformation capabilities of textiles may inform the design of expressive and aesthetically rewarding applications. In this chapter, we propose ways in which the textileness of e-Textiles can be better harnessed. We outline an e-Textile Interaction Design strategy that is based...... on defining the material-specificity of e-Textiles as its ability to deform in ways that match the expectations we have of textile materials. It embraces an open-ended exploration of textile-related interactions (for e.g. stretching, folding, turning-inside-out etc.) and their potential for electronic...

Route-specific analysis for radioactive materials transportation

International Nuclear Information System (INIS)

1986-01-01

This report addresses a methodology for route-specific analysis, of which route-selection is one aspect. Identification and mitigation of specific hazards along a chosen route is another important facet of route-specific analysis. Route-selection and route-specific mitigation are two tools to be used in minimizing the risk of radioactive materials transportation and promoting public confidence. Other tools exist to improve the safety of transportation under the Nuclear Waste Policy Act. Selection of a transportation mode and other, non-route-specific measures, such as improved driver training and improved cask designs, are additional tools to minimize transportation risk and promote public confidence. This report addresses the route-specific analysis tool and does not attempt to evaluate its relative usefulness as compared to other available tools. This report represents a preliminary attempt to develop a route-specific analysis methodlogy. The Western Interstate Energy Board High-Level Waste Committee has formed a Route-Specific Analysis Task Force which will build upon the methodology proposed in this Staff Report. As western states continue to investigate route-specific analysis issues, it is expected that the methodology will evolve into a more refined product representing the views of a larger group of interested parties in the West

Photoelastic stress analysis of different prefabricated post-and-core materials.

Science.gov (United States)

Asvanund, Pattapon; Morgano, Steven M

2011-01-01

The purpose of this study was to investigate stress developed by a combination of a stainless steel post or a fiber-reinforced resin post with a silver amalgam core or a composite resin core. Two-dimensional photoelastic models were used to simulate root dentin. Posts (ParaPost XT and ParaPost-FiberWhite) were cemented with a luting agent (RelyX Unicem). Silver amalgam cores and composite resin cores were fabricated on the posts. Complete crowns were fabricated and cemented on the cores. Each model was analyzed with 2 force magnitudes and in 2 directions. Fringe orders were recorded and compared using ANOVA (p=0.05) and the Scheffe's test. With vertical force, no stress differences occurred among the 4 groups (p=0.159). With a 30-degree force, there was stress differences among the 4 groups (p<0.001). The combination of a fiber-reinforced post and composite resin core could potentially reduce stresses within the radicular dentin when angled loads are applied.

Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes

Energy Technology Data Exchange (ETDEWEB)

Font Vivanco, David, E-mail: font@cml.leidenuniv.nl [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d' Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain); Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA Leiden (Netherlands); Puig Ventosa, Ignasi [ENT Environment and Management, Carrer Sant Joan 39, First Floor, 08800 Vilanova i la Geltru, Barcelona (Spain); Gabarrell Durany, Xavier [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d' Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain)

2012-12-15

Highlights: Black-Right-Pointing-Pointer Sustainability and proximity principles have a key role in waste management. Black-Right-Pointing-Pointer Core indicators are needed in order to quantify and evaluate them. Black-Right-Pointing-Pointer A systematic, step-by-step approach is developed in this study for their development. Black-Right-Pointing-Pointer Transport may play a significant role in terms of environmental and economic costs. Black-Right-Pointing-Pointer Policy action is required in order to advance in the consecution of these principles. - Abstract: In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy

Communications of 30 June 1995 received from Member States regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

1995-10-01

The Director General has received letters of 30 June 1995 from the Resident Representative of Argentina, Australia, Austria, Canada, the Czech Republic, Denmark, Finland, Germany, Greece, Hungary Ireland, Italy, Japan, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, the Slovak Republic, South Africa, Spain, Sweden, the United Kingdom, and the United States of America, concerning the export of nuclear material and of certain categories of equipment and other material

Assessment of the Possibility of Using Reclaimed Materials for Making Cores by the Blowing Method

Directory of Open Access Journals (Sweden)

Dańko R.

2017-03-01

Full Text Available The cumulative results of investigations of the possibility of using the reclaimed materials after the mechanical, thermal or mechanical-thermal reclamation for making cores by means of the blowing method in the alkaline CO2 technology, are presented in the paper. Three kinds of spent sands: with furfuryl resin, bentonite and alkaline phenolic resin, obtained from the foundry, were subjected to three kinds of reclamation: mechanical, thermal and combined mechanical-thermal, applying for this aim adequate experimental devices. The obtained reclaims were assessed with regard to the degree of the matrix liberation from the determined binding material. Reclaims of moulding sands with binders of the form of resin were assessed with regard to ignition loss values and pH reaction, while reclaims of moulding sands with bentonite with regard to the residual clay content and pH value. In all cases the results of the performed sieve analyses were estimated and the average characteristic diameter dl was determined. The reclaimed matrix was applied as a full substitute of the fresh high-silica sand in typical procedures of preparing core sands used for making shaped samples for bending strength investigations, Rgu.

Fracture resistance of endodontically treated teeth restored with Zirconia filler containing composite core material and fiber posts.

Science.gov (United States)

Jeaidi, Zaid Al

2016-01-01

To assess the fracture resistance of endodontically treated teeth with a novel Zirconia (Zr) nano-particle filler containing bulk fill resin composite. Forty-five freshly extracted maxillary central incisors were endodontically treated using conventional step back preparation and warm lateral condensation filling. Post space preparation was performed using drills compatible for fiber posts (Rely X Fiber Post) on all teeth (n=45), and posts were cemented using self etch resin cement (Rely X Unicem). Samples were equally divided into three groups (n=15) based on the type of core materials, ZirconCore (ZC) MulticCore Flow (MC) and Luxacore Dual (LC). All specimens were mounted in acrylic resin and loads were applied (Universal testing machine) at 130° to the long axis of teeth, at a crosshead speed of 0.5 mm/min until failure. The loads and the site at which the failures occurred were recorded. Data obtained was tabulated and analyzed using a statistical program. The means and standard deviations were compared using ANOVA and Multiple comparisons test. The lowest and highest failure loads were shown by groups LC (18.741±3.02) and MC (25.16±3.30) respectively. Group LC (18.741±3.02) showed significantly lower failure loads compared to groups ZC (23.02±4.21) and MC (25.16±3.30) (pcomposite cores was comparable to teeth restored with conventional Zr free bulk fill composites. Zr filled bulk fill composites are recommended for restoration of endodontically treated teeth as they show comparable fracture resistance to conventional composite materials with less catastrophic failures.

Solid oxide fuel cell having a monolithic core

International Nuclear Information System (INIS)

Ackerman, J.P.; Young, J.E.

1984-01-01

A solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween, and each interconnect wall consists of thin layers of the cathode and anode materials sandwiching a thin layer of interconnect material therebetween. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces thereof have only the anode material or only the cathode material exposed. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageway; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte and interconnect materials is of the order of 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick

Adaptation of adhesive post and cores to dentin after in vitro occlusal loading: evaluation of post material influence.

Science.gov (United States)

Dietschi, Dider; Ardu, Stefano; Rossier-Gerber, Anne; Krejci, Ivo

2006-12-01

Fatigue resistance of post and cores is critical to the long term behavior of restored nonvital teeth. The purpose of this in vitro trial was to evaluate the influence of the post material's physical properties on the adaptation of adhesive post and core restorations after cyclic mechanical loading. Composite post and cores were made on endodontically treated deciduous bovine teeth using 3 anisotropic posts (made of carbon, quartz, or quartz-and-carbon fibers) and 3 isotropic posts (zirconium, stainless steel, titanium). Specimens were submitted to 3 successive loading phases--250,000 cycles at 50 N, 250,000 at 75 N, and 500,000 at 100 N--at a rate of 1.5 Hz. Restoration adaptation was evaluated under SEM, before and during loading (margins) and after test completion (margins and internal interfaces). Six additional samples were fabricated for the characterization of interface micromorphology using confocal microscopy. Mechanical loading increased the proportion of marginal gaps in all groups; carbon fiber posts presented the lowest final gap proportion (7.11%) compared to other stiffer metal-ceramic or softer fiber posts (11.0% to 19.1%). For internal adaptation, proportions of debonding between dentin and core or cement varied from 21.69% (carbon post) to 47.37% (stainless steel post). Debonding at the post-cement interface occurred only with isotropic materials. Confocal microscopy observation revealed that gaps were generally associated with an incomplete hybrid layer and reduced resin tags. Regardless of their rigidity, metal and ceramic isotropic posts proved less effective than fiber posts at stabilizing the post and core structure in the absence of the ferrule effect, due to the development of more interfacial defects with either composite or dentin.

Characterization of a Porous Carbon Material Functionalized with Cobalt-Oxide/Cobalt Core-Shell Nanoparticles for Lithium Ion Battery Electrodes

KAUST Repository

Anjum, Dalaver H.; Rasul, Shahid; Roldan-Gutierrez, Manuel A.; Da Costa, Pedro M. F. J.

2016-01-01

A nanoporous carbon (C) material, functionalized with Cobalt-Oxide/Cobalt (CoO/Co) core-shell nanoparticles (NPs), was structurally and chemically characterized with transmission electron microcopy (TEM) while its electrochemical response

Radiation resistivity of pure-silica core image guide

International Nuclear Information System (INIS)

Hayami, H.; Ishitani, T.; Kishihara, O.; Suzuki, K.

1988-01-01

Radiation resistivity of pure-silica core image guides were investigated in terms of incremental spectral loss and quality of pictures transmitted through the image guides. Radiation-induced spectral losses were measured so as to clarify the dependences of radiation resistivity on such parameters as core materials (OH and Cl contents), picture element dimensions, (core packing density and cladding thickness), number of picture elements and drawing conditions. As the results, an image guide with OH-and Cl-free pure-silica core, 30-45% in core packing density, and 1.8 ∼ 2.2 μm in cladding thickness showed the lowest loss. The parameters to design this image guide were almost the same as those to obtain a image guide with good picture quality. Radiation resistivity of the image guide was not dependent on drawing conditions and number of picture elements, indicating that the image guide has large allowable in production conditions and that reliable quality is constantly obtained in production. Radiation resistivity under high total doses was evaluated using the image guide with the lowest radiation-induced loss. Maximum usable lengths of the image guide for practical use under specific high total doses and maximum allowable total doses for the image guide in specific lengths were extrapolated. Picture quality in terms of radiation-induced degradation in color fidelity in the pictures transmitted through image guides was quantitatively evaluated in the chromaticity diagram based on the CIE standard colorimetric system and in the color specification charts according to three attributes of colors. The image guide with the least spectral incremental loss gives the least radiation-induced degradation in color fidelity in the pictures as well. (author)

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment or technology

International Nuclear Information System (INIS)

1988-11-01

The document reproduces the text of a Note Verbale dated 20 October 1988 received by the IAEA Director General from the Permanent Mission of Spain relating to the export of nuclear material, equipment or technology

ZnO@MnO2 Core-Shell Nanofiber Cathodes for High Performance Asymmetric Supercapacitors.

Science.gov (United States)

Radhamani, A V; Shareef, K M; Rao, M S Ramachandra

2016-11-09

Asymmetric supercapacitors (ASCs) with aqueous electrolyte medium have recently become the focus of increasing research. For high performance ASCs, selection of cathode materials play a crucial role, and core-shell nanostructures are found to be a good choice. We successfully synthesized, ZnO@MnO 2 core-shell nanofibers (NFs) by modification of high-aspect-ratio-electrospun ZnO NFs hydrothermally with MnO 2 nanoflakes. High conductivity of the ZnO NFs and the exceptionally high pseudocapacitive nature of MnO 2 nanoflakes coating delivered a specific capacitance of 907 Fg -1 at 0.6 Ag -1 for the core-shell NFs. A simple and cost-effective ASC construction was demonstrated with ZnO@MnO 2 NFs as a battery-type cathode material and a commercial-quality activated carbon as a capacitor-type anode material. The fabricated device functioned very well in a voltage window of 0-2.0 V, and a red-LED was illuminated using a single-celled fabricated ASC device. It was found to deliver a maximum energy density of 17 Whkg -1 and a power density of 6.5 kWkg -1 with capacitance retention of 94% and Coulombic efficiency of 100%. The novel architecture of the ZnO@MnO 2 core-shell nanofibrous material implies the importance of using simple design of fiber-based electrode material by mere changes of core and shell counterparts.

Multi-core MgO NPs(at)C core-shell nanospheres for selective CO2 capture under mild conditions

International Nuclear Information System (INIS)

Tae Kyung Kim; Kyung Joo Lee; Hoi Ri Moon; Junhan Yuh; Sang Kyu Kwak

2014-01-01

The core-shell structures have attracted attention in catalysis, because the outer shells isolate the catalytically active NP cores and prevent the possibility of sintering of core particles during catalytic reaction under physically and chemically harsh conditions. We aimed to adopt this core-shell system for CO 2 sorption materials. In this study, a composite material of multi-core 3 nm-sized magnesium oxide nanoparticles embedded in porous carbon nanospheres (MgO NPs(at)C) was synthesized by a gas phase reaction via a solvent-free process. It showed selective CO 2 adsorption capacity over N 2 under mild regeneration conditions. (authors)

Calculation of doses received while crossing a plume of radioactive material

International Nuclear Information System (INIS)

Scherpelz, R.I.; Desrosiers, A.E.

1981-04-01

A method has been developed for determining the dose received by a person while crossing a plume of radioactive material. The method uses a Gaussian plume model to arrive at a dose rate on the plume centerline at the position of the plume crossing. This dose rate may be due to any external or internal dose pathway. An algebraic formula can then be used to convert the plume centerline dose rate to a total dose integrated over the total time of plume crossing. Correction factors are presented for dose pathways in which the dose rate is not normally distributed about the plume centerline. The method is illustrated by a study done at the Pacific Northwest Laboratory, and results of this study are presented

Status of core material development for fast reactor in Japan

International Nuclear Information System (INIS)

Ukai, S.; Shibahara, I.; Nagai, S.

1994-01-01

In the last two decades, extensive efforts have been devoted to the development of mixed-oxide fuel for LMFBR in Japan. For the fuel of the prototype reactor MONJU, drastic improvement in creep rupture strength and swelling resistance were attained by modification within the compositional specification of the standard Type 316 stainless steel (PNC316). For the fuel of future large-scale reactors, extensive research and development program are under way to realize the long life fuel. The candidate material for demonstration reactor is advanced austenitic stainless steel (PNC1520) which intended to modify the composition beyond the Type 316 stainless steel specification. In order to further improve the swelling resistance, the austenitic stainless steel with higher nickel content (High Ni alloy) and ferritic/martensitic steel (PNC-FMS) are developed. In a prospective cladding material for the long life fuel, the development of oxide dispersion strengthened (ODS) ferritic steel is focused to establish the alloying design and fabrication process toward as high as 250dpa. (author)

Design of a PWR emergency core cooling simulator loop

International Nuclear Information System (INIS)

Melo, C.A. de.

1982-12-01

The preliminary design of a PWR Emergency Core Cooling Simulator Loop for investigations of the phenomena involved in a postulated Loss-of-Coolant Accident, during the Reflooding Phase, is presented. The functions of each component of the loop, the design methods and calculations, the specification of the instrumentation, the system operation sequence, the materials list and a cost assessment are included. (Author) [pt

Communications received from Member States regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

1994-04-01

The Director General has received letters concerning the export of nuclear material and of certain categories of equipment and other material from the following Resident Representatives to the International Atomic Energy Agency: a letter dated 28 February 1994 from the Resident Representative of France; letters dated 1 March 1994 from the Resident Representatives of Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, Germany, Greece, Hungary, Ireland, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, and the United States of America; and a letter dated 22 March 1994 from the Resident Representative of Romania. In the light of the wish expressed at the end of each letter, the text of the letters is attached hereto

Receiver subsystem analysis report (RADL Item 4-1). The 10-MWe solar thermal central-receiver pilot plant: Solar-facilities design integration

Science.gov (United States)

1982-04-01

The results of thermal hydraulic, design for the stress analyses which are required to demonstrate that the receiver design for the Barstow Solar Pilot Plant satisfies the general design and performance requirements during the plant's design life are presented. Recommendations are made for receiver operation. The analyses are limited to receiver subsystem major structural parts (primary tower, receiver unit core support structure), pressure parts (absorber panels, feedwater, condensate and steam piping/components, flash tank, and steam mainfold) and shielding.

Analysis of the thermal response of a BWR Mark-I containment shell to direct contact by molten core materials

International Nuclear Information System (INIS)

Kress, T.S.; Cleveland, J.C.

1988-01-01

This study was undertaken to evaluate the thermal response of a BWR Mark-I containment shell in the event of an accident severe enough for molten core materials to fall into the cavity beneath the rector vessel and eventually come into direct contact with the shell. An existing ORNL three-dimensional transient heat transport computer code, HEATING-6, was used for a specific 2-D case (and variations) for which representative melt/shell boundary conditions required as input were available from other studies. In addition to the use of HEATING-6, a simplified analytical steady-state correlation was developed and given the name BWR Liner Analysis Program (BWRLAP). BWRLAP was ''benchmarked'' by comparison with HEATING-6 and was then used to make a number of parametric calculations to investigate the sensitivities of the results to the inputs. 5 refs., 11 figs., 2 tabs

Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

International Nuclear Information System (INIS)

Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T; Padipatvuthikul, P

2011-01-01

Silicon nitride (Si 3 N 4 ) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si 3 N 4 ceramic as a dental core material. The white Si 3 N 4 was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si 3 N 4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si 3 N 4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder ( 2 O 3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si 3 N 4 specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10 -6 deg. C -1 , rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

Super-paramagnetic core-shell material with tunable magnetic behavior by regulating electron transfer efficiency and structure stability of the shell

Directory of Open Access Journals (Sweden)

Wenyan Zhang

Full Text Available In this work, a spherical nano core-shell material was constructed by encapsulating Fe3O4 microsphere into conductive polymer-metal composite shell. The Fe3O4 microspheres were fabricated by assembling large amounts of Fe3O4 nano-crystals, which endowed the microspheres with super-paramagnetic property and high saturation magnetization. The polymer-metal composite shell was constructed by inserting Pt nano-particles (NPs into the conductive polymer polypyrrole (PPy. As size and dispersion of the Pt NPs has an important influence on their surface area and surface energy, it was effective to enlarge the interface area between PPy and Pt NPs, enhance the electron transfer efficiency of PPy/Pt composite shell, and reinforced the shell’s structural stability just by tuning the size and dispersion of Pt NPs. Moreover, core-shell structure of the materials made it convenient to investigate the PPy/Pt shell’s shielding effect on the Fe3O4 core’s magnetic response to external magnetic fields. It was found that the saturation magnetization of Fe3O4/PPy/Pt core-shell material could be reduced by 20.5% by regulating the conductivity of the PPy/Pt shell. Keywords: Super-paramagnetic, Conductivity, Magnetic shielding, Structural stability

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment or technology

International Nuclear Information System (INIS)

1990-08-01

The document reproduces the text of the Note Verbale dated 1 August 1990 received by the Director General of the IAEA from the Permanent Mission of Romania and relating to the export of nuclear material, equipment and technology

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1992-01-01

The document reproduces the text of the Note Verbale dated 18 December 1991 received by the Director General of the IAEA from the Permanent Mission of Austria and relating to the export of nuclear material, equipment and technology

Stress analysis of shielded receiver lifting frame for core sampler truck number-sign 2

International Nuclear Information System (INIS)

Ziada, H.H.

1994-01-01

This analysis evaluates the structural design adequacy of the shielded receiver lifting frame (SRLF) for the rotary mode core sampler truck number 2 (RMCST number-sign 2). The analysis considers the loads expected during operation of the SRLF. Most of the existing welds were not in conformance with those specified on the drawings, H-2-91715 and -91716 (RHO 1988a and RHO 1988b). Stress analysts and engineers examined the configuration of the welds connecting the frame members of the SRLF and those connecting the SRLF to the drill rig. In comparison to those shown on the drawing, some of the actual welds appear stronger and others undersized. For example, the actual fillet welds completely encircle the junctures of members, although the drawings show some welds to be on two sides only. Attempts to find the original design calculations were unsuccessful. To resolve the nonconformance, the critical welds were identified by analysis and subsequently inspected to ensure they are as large or larger than the minimum is defined by weld leg size. A required weld size, as determined by stress analysis, of 0.1 inch or larger is considered to be critical. This size was selected because no existing welds were found to be less than 0.125 inch. Analysis results led to weld modifications to strengthen the SRLF. The weld modifications performed are described in WHC 1994

Global Positioning System receiver evaluation results

Energy Technology Data Exchange (ETDEWEB)

Byrne, R.H.

1993-09-01

A Sandia project currently uses an outdated Magnavox 6400 Global Positioning System (GPS) receiver as the core of its navigation system. The goal of this study was to analyze the performance of the current GPS receiver compared to newer, less expensive models and to make recommendations on how to improve the performance of the overall navigation system. This paper discusses the test methodology used to experimentally analyze the performance of different GPS receivers, the test results, and recommendations on how an upgrade should proceed. Appendices contain detailed information regarding the raw data, test hardware, and test software.

On the specific surface area of nanoporous materials

NARCIS (Netherlands)

Detsi, E.; De Jong, E.; Zinchenko, A.; Vukovic, Z.; Vukovic, I.; Punzhin, S.; Loos, K.; ten Brinke, G.; De Raedt, H. A.; Onck, P. R.; De Hosson, J. T. M.

2011-01-01

A proper quantification of the specific surface area of nanoporous materials is necessary for a better understanding of the properties that are affected by the high surface-area-to-volume ratio of nanoporous metals, nanoporous polymers and nanoporous ceramics. In this paper we derive an analytical

Influence of Nonfused Cores on the Photovoltaic Performance of Linear Triphenylamine-Based Hole-Transporting Materials for Perovskite Solar Cells.

Science.gov (United States)

Wu, Yungen; Wang, Zhihui; Liang, Mao; Cheng, Hua; Li, Mengyuan; Liu, Liyuan; Wang, Baiyue; Wu, Jinhua; Prasad Ghimire, Raju; Wang, Xuda; Sun, Zhe; Xue, Song; Qiao, Qiquan

2018-05-18

The core plays a crucial role in achieving high performance of linear hole transport materials (HTMs) toward the perovskite solar cells (PSCs). Most studies focused on the development of fused heterocycles as cores for HTMs. Nevertheless, nonfused heterocycles deserve to be studied since they can be easily synthesized. In this work, we reported a series of low-cost triphenylamine HTMs (M101-M106) with different nonfused cores. Results concluded that the introduced core has a significant influence on conductivity, hole mobility, energy level, and solubility of linear HTMs. M103 and M104 with nonfused oligothiophene cores are superior to other HTMs in terms of conductivity, hole mobility, and surface morphology. PSCs based on M104 exhibited the highest power conversion efficiency of 16.50% under AM 1.5 sun, which is comparable to that of spiro-OMeTAD (16.67%) under the same conditions. Importantly, the employment of M104 is highly economical in terms of the cost of synthesis as compared to that of spiro-OMeTAD. This work demonstrated that nonfused heterocycles, such as oligothiophene, are promising cores for high performance of linear HTMs toward PSCs.

Visible-light photochemical activity of heterostructured core-shell materials composed of selected ternary titanates and ferrites coated by tiO2.

Science.gov (United States)

Li, Li; Liu, Xuan; Zhang, Yiling; Nuhfer, Noel T; Barmak, Katayun; Salvador, Paul A; Rohrer, Gregory S

2013-06-12

Heterostructured photocatalysts comprised of microcrystalline (mc-) cores and nanostructured (ns-) shells were prepared by the sol-gel method. The ability of titania-coated ATiO3 (A = Fe, Pb) and AFeO3 (A = Bi, La, Y) catalysts to degrade methylene blue in visible light (λ > 420 nm) was compared. The catalysts with the titanate cores had enhanced photocatalytic activities for methylene blue degradation compared to their components alone, whereas the catalysts with ferrite cores did not. The temperature at which the ns-titania shell is crystallized influences the photocatalytic dye degradation. mc-FeTiO3/ns-TiO2 annealed at 500 °C shows the highest reaction rate. Fe-doped TiO2, which absorbs visible light, did not show enhanced photocatalytic activity for methylene blue degradation. This result indicates that iron contamination is not a decisive factor in the reduced reactivity of the titania coated ferrite catalysts. The higher reactivity of materials with the titanate cores suggests that photogenerated charge carriers are more easily transported across the titanate-titanate interface than the ferrite-titanate interface and this provides guidance for materials selection in composite catalyst design.

The effect of different soft segments on the formation and properties of binary core microencapsulated phase change materials with polyurea/polyurethane double shell.

Science.gov (United States)

Ma, Yanhong; Chu, Xiaodong; Tang, Guoyi; Yao, Youwei

2013-02-15

A series of polyurea/polyurethane microcapsules with butyl stearate and paraffin as binary core materials are successfully synthesized via interfacial polymerization method. The phase change temperature of these microencapsulated phase change materials (micro-PCMs) can be adjusted by regulating the composition of the binary core. SEM photographs show that these micro-PCMs have relatively spherical profiles and compact surfaces with diameter ranging from 5 to 15 μm. DSC results indicate that the binary core content in micro-PCMs is in a range of 45-60 wt%. Moreover, after being treated under 50°C for 7 days or subjected to thermal-cycling test for 500 times, the micro-PCMs keep good thermal performances and stabilities. Besides, these micro-PCMs show good thermal stability, and the degradation temperature differs from the different compositions of the binary core and molecular weight of the water-soluble monomers. Copyright © 2012 Elsevier Inc. All rights reserved.

Core-Shell Composite Fibers for High-Performance Flexible Supercapacitor Electrodes.

Science.gov (United States)

Lu, Xiaoyan; Shen, Chen; Zhang, Zeyang; Barrios, Elizabeth; Zhai, Lei

2018-01-31

Core-shell nanofibers containing poly(acrylic acid) (PAA) and manganese oxide nanoparticles as the core and polypyrrole (PPy) as the shell were fabricated through electrospinning the solution of PAA and manganese ions (PAA/Mn 2+ ). The obtained nanofibers were stabilized by Fe 3+ through the interaction between Fe 3+ ions and carboxylate groups. Subsequent oxidation of Mn 2+ by KMnO 4 produced uniform manganese dioxide (MnO 2 ) nanoparticles in the fibers. A PPy shell was created on the fibers by immersing the fibers in a pyrrole solution where the Fe 3+ ions in the fiber polymerized the pyrrole on the fiber surfaces. In the MnO 2 @PAA/PPy core-shell composite fibers, MnO 2 nanoparticles function as high-capacity materials, while the PPy shell prevents the loss of MnO 2 during the charge/discharge process. Such a unique structure makes the composite fibers efficient electrode materials for supercapacitors. The gravimetric specific capacity of the MnO 2 @PAA/PPy core-shell composite fibers was 564 F/g based on cyclic voltammetry curves at 10 mV/s and 580 F/g based on galvanostatic charge/discharge studies at 5 A/g. The MnO 2 @PAA/PPy core-shell composite fibers also present stable cycling performance with 100% capacitance retention after 5000 cycles.

Chemical insights into the roles of nanowire cores on the growth and supercapacitor performances of Ni-Co-O/Ni(OH)₂ core/shell electrodes.

Science.gov (United States)

Yin, Xuesong; Tang, Chunhua; Zhang, Liuyang; Yu, Zhi Gen; Gong, Hao

2016-02-09

Nanostructured core/shell electrodes have been experimentally demonstrated promising for high-performance electrochemical energy storage devices. However, chemical insights into the significant roles of nanowire cores on the growth of shells and their supercapacitor behaviors still remain as a research shortfall. In this work, by substituting 1/3 cobalt in the Co3O4 nanowire core with nickel, a 61% enhancement of the specific mass-loading of the Ni(OH)2 shell, a tremendous 93% increase of the volumetric capacitance and a superior cyclability were achieved in a novel NiCo2O4/Ni(OH)2 core/shell electrode in contrast to a Co3O4/Ni(OH)2 one. A comparative study suggested that not only the growth of Ni(OH)2 shells but also the contribution of cores were attributed to the overall performances. Importantly, their chemical origins were revealed through a theoretical simulation of the core/shell interfacial energy changes. Besides, asymmetric supercapacitor devices and applications were also explored. The scientific clues and practical potentials obtained in this work are helpful for the design and analysis of alternative core/shell electrode materials.

Communications of 15 November 1999 Received from Member States Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

2000-03-01

The Director General of the International Atomic Energy Agency has received letters of 17 October 1996 from the Resident Representatives of Argentina, Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, the Netherlands, Norway, Poland, Portugal, Romania, the Russian Federation, the Slovak Republic, South Africa, Spain, Sweden, the United Kingdom, and the United States of America, concerning the export of nuclear material and of certain categories of equipment and other material [fr

Communications of 15 November 1999 Received from Member States Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

2009-01-01

The Director General of the International Atomic Energy Agency has received letters of 17 October 1996 from the Resident Representatives of Argentina, Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, the Netherlands, Norway, Poland, Portugal, Romania, the Russian Federation, the Slovak Republic, South Africa, Spain, Sweden, the United Kingdom, and the United States of America, concerning the export of nuclear material and of certain categories of equipment and other material [es

Communications of 15 November 1999 Received from Member States Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

2009-01-01

The Director General of the International Atomic Energy Agency has received letters of 17 October 1996 from the Resident Representatives of Argentina, Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, the Netherlands, Norway, Poland, Portugal, Romania, the Russian Federation, the Slovak Republic, South Africa, Spain, Sweden, the United Kingdom, and the United States of America, concerning the export of nuclear material and of certain categories of equipment and other material

Communications of 15 November 1999 Received from Member States Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

2000-01-01

The Director General of the International Atomic Energy Agency has received letters of 17 October 1996 from the Resident Representatives of Argentina, Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, the Netherlands, Norway, Poland, Portugal, Romania, the Russian Federation, the Slovak Republic, South Africa, Spain, Sweden, the United Kingdom, and the United States of America, concerning the export of nuclear material and of certain categories of equipment and other material

Determination of the neutron fluence in the welding of the 'Core shroud' of the BWR reactor core; Determinacion de la fluencia neutronica en las soldaduras del 'core shroud' del nucleo de un reactor BWR

Energy Technology Data Exchange (ETDEWEB)

Lucatero, M A; Xolocostli M, J V; Gomez T, A M; Palacios H, J C [ININ, 52750 Ocoyoacac, Estado de mexico (Mexico)

2006-07-01

With the purpose of defining the inspection frequency, in function of the embrittlement of the materials that compose the welding of the 'Core Shroud' or encircling of the core of a BWR type reactor, is necessary to know the neutron fluence received for this welding. In the work the calculated values of neutron fluence accumulated maxim (E > 1 MeV) during the first 8 operation cycles of the reactor are presented. The calculations were carried out according to the NRC Regulatory Guide 1.190, making use of the DORT code, which solves the transport equation in discreet ordinate in two dimensions (xy, r{theta}, and rz). The results in 3D were obtained applying the Synthesis method according to the guide before mentioned. Results are presented for the horizontal welding H3, H4, and H5, showing the corresponding curves to the fluence accumulated to the cycle 8 and a projection for the cycle 14 is presented. (Author)

On the use of moderating material to enhance the feedback coefficients in SFR cores with high minor actinide content

International Nuclear Information System (INIS)

Merk, B.; Weiss, F. P.

2012-01-01

The use of fine distributed moderating material to enhance the feedback effects and to reduce the sodium void effecting sodium cooled fast reactor cores is described. The influence of the moderating material on the neutron spectrum, the power distribution, and the burnup distribution is shown. The consequences of the use of fine distributed moderating material into fuel assemblies with fuel configurations foreseen for minor actinide transmutation is analyzed and the transmutation efficiency is compared. The degradation of the feedback effects due to the insertion of minor actinides and the compensation by the use of moderating materials is discussed. (authors)

On the use of moderating material to enhance the feedback coefficients in SFR cores with high minor actinide content

Energy Technology Data Exchange (ETDEWEB)

Merk, B. [Helmholtz-Zentrum Dresden-Rossendorf, Institut fuer Sicherheitsforschung, Postfach 51 01 19, 01314 Dresden (Germany); Weiss, F. P. [Gesellschaft fuer Anlagen- und Reaktorsicherheit GRS MbH Forschungszentrum, Boltzmannstr. 14, 85748 Garching (Germany)

2012-07-01

The use of fine distributed moderating material to enhance the feedback effects and to reduce the sodium void effecting sodium cooled fast reactor cores is described. The influence of the moderating material on the neutron spectrum, the power distribution, and the burnup distribution is shown. The consequences of the use of fine distributed moderating material into fuel assemblies with fuel configurations foreseen for minor actinide transmutation is analyzed and the transmutation efficiency is compared. The degradation of the feedback effects due to the insertion of minor actinides and the compensation by the use of moderating materials is discussed. (authors)

Hybridization of MOFs and COFs: A New Strategy for Construction of MOF@COF Core-Shell Hybrid Materials.

Science.gov (United States)

Peng, Yongwu; Zhao, Meiting; Chen, Bo; Zhang, Zhicheng; Huang, Ying; Dai, Fangna; Lai, Zhuangchai; Cui, Xiaoya; Tan, Chaoliang; Zhang, Hua

2018-01-01

The exploration of new porous hybrid materials is of great importance because of their unique properties and promising applications in separation of materials, catalysis, etc. Herein, for the first time, by integration of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), a new type of MOF@COF core-shell hybrid material, i.e., NH 2 -MIL-68@TPA-COF, with high crystallinity and hierarchical pore structure, is synthesized. As a proof-of-concept application, the obtained NH 2 -MIL-68@TPA-COF hybrid material is used as an effective visible-light-driven photocatalyst for the degradation of rhodamine B. The synthetic strategy in this study opens up a new avenue for the construction of other MOF-COF hybrid materials, which could have various promising applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Humidity Effects on Soluble Core Mechanical and Thermal Properties (Polyvinyl Alcohol/Microballoon Composite)

Science.gov (United States)

1993-01-01

This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties. This report describes test results, procedures employed, and any unusual occurrences or specific observations associated with this test program.

Simulations of the Light Scattering Properties of Metal/Oxide Core/Shell Nanospheres

International Nuclear Information System (INIS)

Ruffino, F.; Piccitto, G.; Grimaldi, M.G.; Ruffino, F.; Grimaldi, M.G.

2014-01-01

Given the importance of the optical properties of metal/dielectric core/shell nanoparticles, in this work we focus our attention on the light scattering properties, within the Mie framework, of some specific categories of these noteworthy nano structures. In particular, we report theoretical results of angle-dependent light scattering intensity and scattering efficiency for Ag/Ag 2 O, Al/Al 2 O 2 , Cu/Cu 2 O, Pd/PdO, and Ti/TiO 2 core/shell nanoparticles as a function of the core radius/shell thickness ratio and on a relative comparison. The results highlight the light scattering characteristics of these systems as a function of the radius/shell thickness ratio, helping in the choice of the more suitable materials and sizes for specific applications (i.e., dynamic light scattering for biological and molecular recognition, increasing light trapping in thin-film silicon, organic solar cells for achieving a higher photocurrent).

Physical property control in core/shell inorganic nanostructures for fluorescence and magnetic targeting applications

Science.gov (United States)

Roberts, Stephen K.

Nanomaterials show immense promise for the future in numerous areas of application. Properties that are unique from the bulk material and are tunable allow for innovation in material design. This thesis will focus on controlling the physical properties of core/shell nanostructures to enhance the utility of the materials. The first focus is on the impact of different solvent mixtures during the shell growth phase of SILAR based core/shell quantum dot synthesis is studied. Gaining insight into the mechanism for SILAR growth of core/shell nanoparticles allows improved synthetic yields and precursor binding, providing enhanced control to synthesis of core/shell nanoparticles. The second focus of this thesis is exploring the use of magnetic nanoparticles for magnetic drug targeting for cardiovascular conditions. Magnetic targeting for drug delivery enables increased local drug concentration, while minimizing non-specific interactions. In order to be effective for magnetic targeting, it must be shown that low magnetic strength is sufficient to capture flowing nanoparticles. By demonstrating the binding of a therapeutic agent to the surface at medicinal levels, the viability for use as a nanoparticle drug delivery system is improved.

Building waste management core indicators through Spatial Material Flow Analysis: net recovery and transport intensity indexes.

Science.gov (United States)

Font Vivanco, David; Puig Ventosa, Ignasi; Gabarrell Durany, Xavier

2012-12-01

In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of hypothetical scenarios, thus proving its adequacy for strategic planning. Copyright © 2012 Elsevier Ltd. All rights reserved.

ANTIMICROBIAL ACTIVITY OF THE SUBSTANCES RECEIVED FROM RAW MATERIALS OF BIRCH FAMILY PLANTS

Directory of Open Access Journals (Sweden)

Fedchenkova Yu.A

2016-12-01

Full Text Available Introduction. In accordance with the last events in Ukraine (considering military operations in anti-terrorist operation in the Luhansk and Donetsk regions the domestic medicine is in great need in preparations with antimicrobial activity. Our attention as the sources of receiving biologically active substances with antimicrobial activity was drawn with birch Betulaceae family plants – hazel ordinary Corylus avellana L. and black alder Alnus glutinosa (L. Gaertn. It is known that in medicine the leaves of hazel ordinary are used as antiseptic, anti-inflammatory, vesselrestorative drug, and the leaves of black alder reveal the antiinflammatory, astringent, wound healing, spasmolytic and choleretic action. However, the drugs with antimicrobial action received from the leaves of these plants are absent on the market of Ukraine. Therefore the studying of antimicrobial activity of this type of raw materials received from hazel ordinary and black alder, for creation of new medicines, is now one of the main directions in pharmacy. For this purpose we have revealed tinctures, spirit, lipophilic and polysacharid fractions received from the leaves of hazel ordinary and black alder. The purpose of our research is studying of antimicrobial activity of revealed substance received from the leaves of black alder and hazel ordinary. Materials and methods. There were being examined tinctures, lipophilic, spirit and polysacharid fractions received from the leaves of hazel ordinary and black alder. The test of antimicrobial effect of substances was carried out by means of serial dilution concerning the following six reference cultures: Staphylococcus aureus ATCC 6538-P, Candida albicans ATCC 885-653, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6833, Bacillus cereus ATCC 10702, Pseudomonas aeruginosa ATCC 9027, according to the State Pharmacopoeia of Ukraine, in the Department of Microbiology and Immunology of KMAPE. For the experiment there was prepared

Effect of varying core thicknesses and artificial aging on the color difference of different all-ceramic materials.

Science.gov (United States)

Dikicier, Sibel; Ayyildiz, Simel; Ozen, Julide; Sipahi, Cumhur

2014-11-01

Clinicians should reserve all-ceramics with high translucency for clinical applications in which high-level esthetics are required. Furthermore, it is unclear whether a correlation exists between core thickness and color change. The aim of this study was to examine the effects of different core thicknesses and artificial aging on the color stability of three all-ceramic systems. Ninety disc-shaped cores with different thicknesses (0.5 mm, 0.8 mm and 1.0 mm) were prepared from three all-ceramic systems, In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K). The colors of the samples were measured with a spectrophotometer and the color parameters (L*, a*, b*, ΔE) were calculated according to the CIE L*a*b* (Commission Internationale de L'Eclairage) color system before and after aging. The effects of aging on color parameters were statistically significant (p artificial aging affected color stability of the all-ceramic materials tested.

From harmful Microcystis blooms to multi-functional core-double-shell microsphere bio-hydrochar materials.

Science.gov (United States)

Bi, Lei; Pan, Gang

2017-11-13

Harmful algal blooms (HABs) induced by eutrophication is becoming a serious global environmental problem affecting public health and aquatic ecological sustainability. A novel strategy for the utilization of biomass from HABs was developed by converting the algae cells into hollow mesoporous bio-hydrochar microspheres via hydrothermal carbonization method. The hollow microspheres were used as microreactors and carriers for constructing CaO 2 core-mesoporous shell-CaO 2 shell microspheres (OCRMs). The CaO 2 shells could quickly increase dissolved oxygen to extremely anaerobic water in the initial 40 min until the CaO 2 shells were consumed. The mesoporous shells continued to act as regulators restricting the release of oxygen from CaO 2 cores. The oxygen-release time using OCRMs was 7 times longer than when directly using CaO 2 . More interestingly, OCRMs presented a high phosphate removal efficiency (95.6%) and prevented the pH of the solution from rising to high levels in comparison with directly adding CaO 2 due to the OH - controlled-release effect of OCRMs. The distinct core-double-shell micro/nanostructure endowed the OCRMs with triple functions for oxygen controlled-release, phosphorus removal and less impact on water pH. The study is to explore the possibility to prepare smarter bio-hydrochar materials by utilizing algal blooms.

Communications of 17 October 1996 received from Member States regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

1999-01-01

The document reproduces the text of the letter received by the Director General of the IAEA on 17 October 1996 from the Resident Representatives of Argentina, Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, the Netherlands, Norway, Poland, Portugal, Romania, the Russian Federation, the Slovak Republic, South Africa, Spain, Sweden, the United Kingdom, and the United States of America, concerning the export of nuclear materials and of certain categories of equipment and other material

Communications of 15 November 1999 received from Member States regarding the export of nuclear material and of certain categories of equipment and other material

International Nuclear Information System (INIS)

2000-01-01

The document reproduces the text of the letters dated 15 November 1999 received by the Director General of the IAEA from the Resident Representatives of Argentina, Australia, Austria, Belgium, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, the Slovak Republic, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom, and the United States of America, concerning the export of nuclear material and of certain categories of equipment and other material

Development and evaluation of an X-ray radioscopy device for drill cores study

International Nuclear Information System (INIS)

Bertrand, L.; Gentier, S.; Massal, P.

1993-01-01

This work is a cost-sharing contract with the European Atomic Energy Community within the framework of research and development program on management, storage and radioactive waste disposal. The aim of this project is to conceive an X-ray radioscopy mobile unit, adapted to the study of cored geological materials. A prestudy based on the X-ray absorption theory by the material has enabled to design the apparatus and specially the X-ray tube power. Then the schematic diagram of the device is presented and the principle on which it works is described. The main components of the XCORE device may be put together into three big sets: - The X-ray part includes the high-voltage generator, the X-ray transmitter tube, the receiver or brightness-amplifying tube and all the acquisition, visualization and recording system for the video images, and at last the X-ray controls rack, -The mechanical part is composed of the handling cores system, the location system of the radioscopied core sections, the control mechanism of the core's motions, - A PC/AT microcomputer and its peripherals fitted out with a digitizing and processing image card makes up the computing part. The equipment is mounted into a container transportable by lorry, 2.5 x 2.5 x 6 m. in size and 9 T. weight. 6 refs., 79 figs., 3 tabs

TMI-2 core damage: a summary of present knowledge

International Nuclear Information System (INIS)

Owen, D.E.; Mason, R.E.; Meininger, R.D.; Franz, W.A.

1983-01-01

Extensive fuel damage (oxidation and fragmentation) has occurred and the top approx. 1.5 m of the center portion of the TMI-2 core has relocated. The fuel fragmentation extends outward to slightly beyond one-half the core radius in the direction examined by the CCTV camera. While the radial extent of core fragmentation in other directions was not directly observed, control and spider drop data and in-core instrument data suggest that the core void is roughly symmetrical, although there are a few indications of severe fuel damage extending to the core periphery. The core material fragmented into a broad range of particle sizes, extending down to a few microns. APSR movement data, the observation of damaged fuel assemblies hanging unsupported from the bottom of the reactor upper plenum structure, and the observation of once-molten stainless steel immediately above the active core indicate high temperatures (up to at least 1720 K) extended to the very top of the core. The relative lack of damage to the underside of the plenum structure implies a sharp temperature demarcation at the core/plenum interface. Filter debris and leadscrew deposit analyses indicate extensive high temperature core materials interaction, melting of the Ag-In-Cd control material, and transport of particulate control material to the plenum and out of the vessel

Communication of 30 June 1995 Received from France Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

1995-01-01

The Director General has received letters concerning the export of nuclear material and of certain categories of equipment and other material from the following Resident Representatives to the International Atomic Energy Agency: a letter dated 28 February 1994 from the Resident Representative of France; letters dated 1 March 1994 from the Resident Representatives of Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, Germany, Greece, Hungary, Ireland, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, and the United States of America; and a letter dated 22 March 1994 from the Resident Representative of Romania

Propagation of Electromagnetic Waves in Slab Waveguide Structure Consisting of Chiral Nihility Claddings and Negative-Index Material Core Layer

Science.gov (United States)

Helal, Alaa N. Abu; Taya, Sofyan A.; Elwasife, Khitam Y.

2018-06-01

The dispersion equation of an asymmetric three-layer slab waveguide, in which all layers are chiral materials is presented. Then, the dispersion equation of a symmetric slab waveguide, in which the claddings are chiral materials and the core layer is negative index material, is derived. Normalized cut-off frequencies, field profile, and energies flow of right-handed and left-handed circularly polarized modes are derived and plotted. We consider both odd and even guided modes. Numerical results of guided low-order modes are provided. Some novel features, such as abnormal dispersion curves, are found.

The treatment of mixing in core helium-burning models - III. Suppressing core breathing pulses with a new constraint on overshoot

Science.gov (United States)

Constantino, Thomas; Campbell, Simon W.; Lattanzio, John C.

2017-12-01

Theoretical predictions for the core helium burning phase of stellar evolution are highly sensitive to the uncertain treatment of mixing at convective boundaries. In the last few years, interest in constraining the uncertain structure of their deep interiors has been renewed by insights from asteroseismology. Recently, Spruit proposed a limit for the rate of growth of helium-burning convective cores based on the higher buoyancy of material ingested from outside the convective core. In this paper we test the implications of such a limit for stellar models with a range of initial mass and metallicity. We find that the constraint on mixing beyond the Schwarzschild boundary has a significant effect on the evolution late in core helium burning, when core breathing pulses occur and the ingestion rate of helium is fastest. Ordinarily, core breathing pulses prolong the core helium burning lifetime to such an extent that models are at odds with observations of globular cluster populations. Across a wide range of initial stellar masses (0.83 ≤ M/M⊙ ≤ 5), applying the Spruit constraint reduces the core helium burning lifetime because core breathing pulses are either avoided or their number and severity reduced. The constraint suggested by Spruit therefore helps to resolve significant discrepancies between observations and theoretical predictions. Specifically, we find improved agreement for R2 (the observed ratio of asymptotic giant branch to horizontal branch stars in globular clusters), the luminosity difference between these two groups, and in asteroseismology, the mixed-mode period spacing detected in red clump stars in the Kepler field.

Materials Selection for Aerospace Systems

Science.gov (United States)

Arnold, Steven M.; Cebon, David; Ashby, Mike

2012-01-01

A systematic design-oriented, five-step approach to material selection is described: 1) establishing design requirements, 2) material screening, 3) ranking, 4) researching specific candidates and 5) applying specific cultural constraints to the selection process. At the core of this approach is the definition performance indices (i.e., particular combinations of material properties that embody the performance of a given component) in conjunction with material property charts. These material selection charts, which plot one property against another, are introduced and shown to provide a powerful graphical environment wherein one can apply and analyze quantitative selection criteria, such as those captured in performance indices, and make trade-offs between conflicting objectives. Finding a material with a high value of these indices maximizes the performance of the component. Two specific examples pertaining to aerospace (engine blades and pressure vessels) are examined, both at room temperature and elevated temperature (where time-dependent effects are important) to demonstrate the methodology. The discussion then turns to engineered/hybrid materials and how these can be effectively tailored to fill in holes in the material property space, so as to enable innovation and increases in performance as compared to monolithic materials. Finally, a brief discussion is presented on managing the data needed for materials selection, including collection, analysis, deployment, and maintenance issues.

Core antigen and circulating anti-core antibody in hepatitis B infection

Energy Technology Data Exchange (ETDEWEB)

Howard, C R; Zuckerman, A J [London School of Hygiene and Tropical Medicine (UK)

1977-02-01

Core antigen was obtained from the sera of persistent chronic carriers of hepatitis B virus by centrifugation and treatment with Nonidet P40 and 2-mercaptoethanol. The separated core antigen was radiolabelled and identified as a nucleoprotein structure of buoyant density 1.36 g/cm/sup 3/ and possessing an isoelectric point of 4.4. This material was employed in a radioimmnoassay procedure of high sensitivity for the detection of core antibody. In a series of sera from patients with acute type B hepatitis, core antibody was demonstrated 2 to 3 weeks after the onset of jaundice during the period of surface antigenaemia. The presence of core antibody may therefore provide an accurate serological marker for the detection of active or recent virus replication in future epidemiological studies of hepatitis B infection.

Discovery of core-structurally novel PTP1B inhibitors with specific selectivity containing oxindole-fused spirotetrahydrofurochroman by one-pot reaction.

Science.gov (United States)

Dong, Suzhen; Lei, Yubing; Jia, Shikun; Gao, Lixin; Li, Jia; Zhu, Tong; Liu, Shunying; Hu, Wenhao

2017-02-15

Protein tyrosine phosphatase 1B (PTP1B) has been proposed to be an ideal target for treatment of type II diabetes and obesity. However, no druggable PTP1B inhibitor has been established and there is still an urgent demand for the development of structurally novel PTPIB inhibitor. Herein, we reported core-structurally novel PTP1B inhibitors with low micromole-ranged inhibitory activity by one-pot reaction from simple starting materials. Further studies demonstrated some of these active compounds had a specific selectivity over other PTPs. The structure and activity relationship was also described. The best active and selective compound 5e inhibited PTP1B activity with an IC 50 of 4.53μM. Molecular docking analysis further demonstrated that compound 5e bound to the active pocket of PTP1B. The results might provide some insights for further development of new drugs for type II diabetes and obesity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seaurchin-like hierarchical NiCo2O4@NiMoO4 core-shell nanomaterials for high performance supercapacitors.

Science.gov (United States)

Zhang, Qiang; Deng, Yanghua; Hu, Zhonghua; Liu, Yafei; Yao, Mingming; Liu, Peipei

2014-11-14

A novel electrode material of the three-dimensional (3D) multicomponent oxide NiCo2O4@NiMoO4 core-shell was synthesized via a facile two-step hydrothermal method using a post-annealing procedure. The uniform NiMoO4 nanosheets were grown on the seaurchin-like NiCo2O4 backbone to form a NiCo2O4@NiMoO4 core-shell material constructed by interconnected ultrathin nanosheets, so as to produce hierarchical mesopores with a large specific surface area of 100.3 m(2) g(-1). The porous feature and core-shell structure can facilitate the penetration of electrolytic ions and increases the number of electroactive sites. Hence, the NiCo2O4@NiMoO4 material exhibited a high specific capacitance of 2474 F g(-1) and 2080 F g(-1) at current densities of 1 A g(-1) and 20 A g(-1) respectively, suggesting that it has not only a very large specific capacitance, but also a good rate performance. In addition, the capacitance loss was only 5.0% after 1000 cycles of charge and discharge tests at the current density of 10 A g(-1), indicating high stability. The excellent electrochemical performance is mainly attributed to its 3D core-shell and hierarchical mesoporous structures which can provide unobstructed pathways for the fast diffusion and transportation of ions and electrons, a large number of active sites and good strain accommodation.

Synthetic bone substitute material comparable with xenogeneic material for bone tissue regeneration in oral cancer patients: First and preliminary histological, histomorphometrical and clinical results.

Science.gov (United States)

Ghanaati, Shahram; Barbeck, Mike; Lorenz, Jonas; Stuebinger, Stefan; Seitz, Oliver; Landes, Constantin; Kovács, Adorján F; Kirkpatrick, Charles J; Sader, Robert A

2013-07-01

The present study was first to evaluate the material-specific cellular tissue response of patients with head and neck cancer to a nanocrystalline hydroxyapatite bone substitute NanoBone (NB) in comparison with a deproteinized bovine bone matrix Bio-Oss (BO) after implantation into the sinus cavity. Eight patients with tumor resection for oral cancer and severely resorbed maxillary bone received materials according to a split mouth design for 6 months. Bone cores were harvested prior to implantation and analyzed histologically and histomorphometrically. Implant survival was followed-up to 2 years after placement. Histologically, NB underwent a higher vascularization and induced significantly more tartrate-resistant acid phosphatase-positive (TRAP-positive) multinucleated giant cells when compared with BO, which induced mainly mononuclear cells. No significant difference was observed in the extent of new bone formation between both groups. The clinical follow-up showed undisturbed healing of all implants in the BO-group, whereas the loss of one implant was observed in the NB-group. Within its limits, the present study showed for the first time that both material classes evaluated, despite their induction of different cellular tissue reactions, may be useful as augmentation materials for dental and maxillofacial surgical applications, particularly in patients who previously had oral cancer.

Mixing core material into the envelopes of red grants

International Nuclear Information System (INIS)

Deupree, R.G.

1986-01-01

A discussion is presented of calculations of four core helium flashes in red giant stars. The starting point for these calculations is a point source explosion on the polar axis of a two-dimensional finite difference grid. The amount of residue of the core helium flash mixed into and above the hydrogen shell is calculated at four temperatures for the elements carbon, oxygen, neon, magnesium, silicon, and sulfur. 7 refs., 1 tab

Derivation of Accident-Specific Material-at-Risk Equivalency Factors

Energy Technology Data Exchange (ETDEWEB)

Jason P. Andrus; Dr. Chad L. Pope

2012-05-01

A novel method for calculating material at risk (MAR) dose equivalency developed at the Idaho National Laboratory (INL) now allows for increased utilization of dose equivalency for facility MAR control. This method involves near-real time accounting for the use of accident and material specific release and transport. It utilizes all information from the committed effective dose equation and the five factor source term equation to derive dose equivalency factors which can be used to establish an overall facility or process MAR limit. The equivalency factors allow different nuclide spectrums to be compared for their respective dose consequences by relating them to a specific quantity of an identified reference nuclide. The ability to compare spectrums to a reference limit ensures that MAR limits are in fact bounding instead of attempting to establish a representative or bounding spectrum which may lead to unintended or unanalyzed configurations. This methodology is then coupled with a near real time material tracking system which allows for accurate and timely material composition information and corresponding MAR equivalency values. The development of this approach was driven by the complex nature of processing operations in some INL facilities. This type of approach is ideally suited for facilities and processes where the composition of the MAR and possible release mechanisms change frequently but in well defined fashions and in a batch-type nature.

INVESTIGATION OF HEAT CONDUCTION AND SPECIFIC ELECTRIC IMPEDANCE OF POROUS MATERIALS

Directory of Open Access Journals (Sweden)

E. S. Golubtsova

2004-01-01

Full Text Available In this article there was investigated the influence of porosity and temperature change on heat condition and electrical resistance of porous iron (PZh4M nickel and steel 14X17H2. There are received the adequate equations of regression, establishing connection between heat conduction and electrical resistance of the investigated materials with their porosity and temperature.

Specification of steam generator, condenser and regenerative heat exchanger materials for nuclear applications

International Nuclear Information System (INIS)

Jovasevic, J.V.; Stefanovic, V.M.; Spasic, Z.LJ.

1977-01-01

The basic standards specifications of materials for nuclear applications are selected. Seamless Ni-Cr-Fe alloy Tubes (Inconel-600) for steam generators, condensers and other heat exchangers can be employed instead of austenitic stainless steal or copper alloys tubes; supplementary requirements for these materials are given. Specifications of Ni-Cr-Fe alloy plate, sheet and strip for steam generator lower sub-assembly, U-bend seamless copper-alloy tubes for heat exchanger and condensers are also presented. At the end, steam generator channel head material is proposed in the specification for carbon-steel castings suitable for welding

Modified Organosilica Core-Shell Nanoparticles for Stable pH Sensing in Biological Solutions.

Science.gov (United States)

Robinson, Kye J; Huynh, Gabriel T; Kouskousis, Betty P; Fletcher, Nicholas L; Houston, Zachary H; Thurecht, Kristofer J; Corrie, Simon R

2018-04-19

Continuous monitoring using nanoparticle-based sensors has been successfully employed in complex biological systems, yet the sensors still suffer from poor long-term stability partially because of the scaffold materials chosen to date. Organosilica core-shell nanoparticles containing a mixture of covalently incorporated pH-sensitive (shell) and pH-insensitive (core) fluorophores is presented as a continuous pH sensor for application in biological media. In contrast to previous studies focusing on similar materials, we sought to investigate the sensor characteristics (dynamic range, sensitivity, response time, stability) as a function of material properties. The ratio of the fluorescence intensities at specific wavelengths was found to be highly sensitive to pH over a physiologically relevant range (4.5-8) with a response time of pH-specific signals when stored at room temperature for more than 80 days. Finally, we demonstrated that the nanosensors successfully monitored the pH of a bacterial culture over 15 h and that pH changes in the skin of mouse cadavers could also be observed via in vivo fluorescence imaging following subcutaneous injection. The understanding gained from linking sensor characteristics and material properties will inform the next generation of optical nanosensors for continuous-monitoring applications.

Technical specification improvements to containment heat removal and emergency core cooling systems: Final report

International Nuclear Information System (INIS)

Sullivan, W.P.; Ha, C.; Pentzien, D.C.; Visweswaran, S.

1988-07-01

This report presents the results of an analysis for technical specification improvements to the emergency core cooling systems (ECCS) and containment heat removal systems (EPRI Research Project 2142-3). The objective of this project is to further develop a reliability- and risk-based methodology to provide improvements by considering groups of surveillance test intervals and allowed out-of-service times jointly. This was done for the technical specifications for the ECCS, containment heat removal equipment, and supporting systems of a boiling water reactor plant. The project (1) developed a methodology for optimizing groups of surveillance test intervals and allowed out-of-service times jointly, (2) applied the methodology in a case study of a specific operating plant, Hatch-2, and (3) evaluated benefits of the application. The results of the case study demonstrate that beneficial technical specification improvements can be realized with application of the methodology. By tightening a small group of sensitive surveillance test intervals (STIs) and allowed out-of-service times (AOTs), a larger group of less sensitive STIs and AOTs can be extended resulting in an overall plant operating cost improvement without reducing the plant safety. The reliability- and risk-based methodology and results from this project can be effectively applied for technical specification improvements at other operating plants

Systematic investigation of the synthesis of core-shell poly(styrene-co-acrylic acid) colloids with varying shell thickness and core diameter

DEFF Research Database (Denmark)

Hinge, Mogens; Keiding, Kristian

2006-01-01

the morphology of the material for an specific application is going on. It is known from SFEP of styrene that the final colloidal size can be controlled by adjusting the ionic strength of the synthesis feed [1] and it is suggested that adding acrylic acid to the synthesis will result in a change...... in polymerization locus from the core to the surface [2]. There is at present not performed a systematically investigation in controlling the core size and shell thickness of poly(styrene-co-acrylic acid) core-shell colloids  (poly(ST-co-AA)).   Poly(ST-co-AA) colloids were synthesized by free-radical surfactant......-free emulsion co-polymerization (SFECP) at 70°C, using styrene as monomer and acrylic acid as co-monomer. Different batches of poly(ST-co-AA) colloids were synthesized with varying ionic strength and acrylic acid concentrations in the synthesis feed. The produced poly(ST-co-AA) colloids were analysed...

Sol-gel processing to form doped sol-gel monoliths inside hollow core optical fiber and sol-gel core fiber devices made thereby

Science.gov (United States)

Shaw, Harry C. (Inventor); Ott, Melanie N. (Inventor); Manuel, Michele V. (Inventor)

2002-01-01

A process of fabricating a fiber device includes providing a hollow core fiber, and forming a sol-gel material inside the hollow core fiber. The hollow core fiber is preferably an optical fiber, and the sol-gel material is doped with a dopant. Devices made in this manner includes a wide variety of sensors.

Materials and methods for higher performance screen-printed flexible MRI receive coils.

Science.gov (United States)

Corea, Joseph R; Lechene, P Balthazar; Lustig, Michael; Arias, Ana C

2017-08-01

To develop methods for characterizing materials used in screen-printed MRI coils and improve signal-to-noise ratio (SNR) with new lower-loss materials. An experimental apparatus was created to characterize dielectric properties of plastic substrates used in receive coils. Coils were fabricated by screen printing conductive ink onto several plastic substrates. Unloaded and sample loaded quality factor (Q Unloaded /Q Loaded ) measurements and scans on a 3T scanner were used to characterize coil performance. An experimental method was developed to describe the relationship between a coil's Q Unloaded and the SNR it provides in images of a phantom. In addition, 3T scans of a phantom and the head of a volunteer were obtained with a proof-of-concept printed eight-channel array, and the results were compared with a commercial 12-channel array. Printed coils with optimized substrates exhibited up to 97% of the image SNR when compared with a traditional coil on a loading phantom. Q Unloaded and the SNR of coils were successfully correlated. The printed array resulted in images comparable to the quality given by the commercial array. Using the proposed methods and materials, the SNR of printed coils approached that of commercial coils while using a new fabrication technique that provided more flexibility and close contact with the patient's body. Magn Reson Med 78:775-783, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

High-temperature thermal storage systems for advanced solar receivers materials selections

Science.gov (United States)

Wilson, D. F.; Devan, J. H.; Howell, M.

1990-01-01

Advanced space power systems that use solar energy and Brayton or Stirling heat engines require thermal energy storage (TES) systems to operate continuously through periods of shade. The receiver storage units, key elements in both Brayton and Stirling systems, are designed to use the latent heat of fusion of phase-change materials (PCMs). The power systems under current consideration for near-future National Aeronautics and Space Administration space missions require working fluid temperatures in the 1100 to 1400 K range. The PCMs under current investigation that gave liquid temperatures within this range are the fluoride family of salts. However, these salts have low thermal conductivity, which causes large temperature gradients in the storage systems. Improvements can be obtained, however, with the use of thermal conductivity enhancements or metallic PCMs. In fact, if suitable containment materials can be found, the use of metallic PCMs would virtually eliminate the orbit associated temperature variations in TES systems. The high thermal conductivity and generally low volume change on melting of germanium and alloys based on silicon make them attractive for storage of thermal energy in space power systems. An approach to solving the containment problem, involving both chemical and physical compatibility, preparation of NiSi/NiSi2, and initial results for containment of germanium and NiSi/NiSi2, are presented.

Communications Received from Members regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material. Two Further Communications dated 26 September 1975

International Nuclear Information System (INIS)

1975-01-01

On 3 October 1975 the Director General received a letter from the Resident Representative of the Netherlands to the Agency transmitting two communications dated 10 September from the Minister for Foreign Affairs of Luxembourg dealing respectively with the export of nuclear material and the export of certain categories of equipment and other material. The Resident Representative requested that all Members be informed of the contents of the two communications, and they are accordingly reproduced below

Fabrication of Fe{sub 3}O{sub 4}@CuO core-shell from MOF based materials and its antibacterial activity

Energy Technology Data Exchange (ETDEWEB)

Rajabi, S.K. [Department of Chemistry, University of Guilan, University Campus 2, Rasht (Iran, Islamic Republic of); Sohrabnezhad, Sh., E-mail: sohrabnezhad@guilan.ac.ir [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht (Iran, Islamic Republic of); Ghafourian, S. [Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam (Iran, Islamic Republic of)

2016-12-15

Magnetic Fe{sub 3}O{sub 4}@CuO nanocomposite with a core/shell structure was successfully synthesized via direct calcinations of magnetic Fe{sub 3}O{sub 4}@HKUST-1 in air atmosphere. The morphology, structure, magnetic and porous properties of the as-synthesized nano composites were characterized by using scanning electron microscope (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and vibration sample magnetometer (VSM). The results showed that the nanocomposite material included a Fe{sub 3}O{sub 4} core and a CuO shell. The Fe{sub 3}O{sub 4}@CuO core-shell can be separated easily from the medium by a small magnet. The antibacterial activity of Fe{sub 3}O{sub 4}-CuO core-shell was investigated against gram-positive and gram-negative bacteria. A new mechanism was proposed for inactivation of bacteria over the prepared sample. It was demonstrated that the core-shell exhibit recyclable antibacterial activity, acting as an ideal long-acting antibacterial agent. - Graphical abstract: Fe{sub 3}O{sub 4}@CuO core-shell release of copper ions. These Cu{sup 2+} ions were responsible for the exhibited antibacterial activity. - Highlights: • The Fe{sub 3}O{sub 4}@CuO core-shell was prepared by MOF method. • This is the first study of antibacterial activity of core-shell consist of CuO and Fe{sub 3}O{sub 4}. • The core-shell can be reused effectively. • Core-shell was separated from the reaction solution by external magnetic field.

The Development of a Mindfulness-Based Music Therapy (MBMT) Program for Women Receiving Adjuvant Chemotherapy for Breast Cancer

OpenAIRE

Lesiuk, Teresa

2016-01-01

Problems with attention and symptom distress are common clinical features reported by women who receive adjuvant chemotherapy for breast cancer. Mindfulness practice significantly improves attention and mindfulness programs significantly reduce symptom distress in patients with cancer, and, more specifically, in women with breast cancer. Recently, a pilot investigation of a music therapy program, built on core attitudes of mindfulness practice, reported significant benefits of enhanced attent...

Influence of core thickness and artificial aging on the biaxial flexural strength of different all-ceramic materials: An in-vitro study.

Science.gov (United States)

Dikicier, Sibel; Ayyildiz, Simel; Ozen, Julide; Sipahi, Cumhur

2017-05-31

The purpose of this study was to investigate the flexural strength of all-ceramics with varying core thicknesses submitted to aging. In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K) (n=40), were selected. Each group contained two core groups based on the core thickness as follows: IC/0.5, IC/0.8, EM/0.5, EM/0.8, K/0.5 and K/0.8 mm in thickness (n=20 each). Ten specimens from each group were subjected to aging and all specimens were tested for strength in a testing machine either with or without being subjected aging. The mean strength of the K were higher (873.05 MPa) than that of the IC (548.28 MPa) and EM (374.32 MPa) regardless of core thickness. Strength values increased with increasing core thickness for all IC, EM and K regardless of aging. Results of this study concluded that strength was not significantly affected by aging. Different core thicknesses affected strength of the all-ceramic materials tested (p<0.05).

Experimental investigation of material chemical effects on emergency core cooling pump suction filter performance after loss of coolant accident

International Nuclear Information System (INIS)

Park, Jong Woon; Park, Byung Gi; Kim, Chang Hyun

2009-01-01

Integral tests of head loss through an emergency core cooling filter screen are conducted, simulating reactor building environmental conditions for 30 days after a loss of coolant accident. A test rig with five individual loops each of whose chamber is established to test chemical product formation and measure the head loss through a sample filter. The screen area at each chamber and the amounts of reactor building materials are scaled down according to specific plant condition. A series of tests have been performed to investigate the effects of calcium-silicate, reactor building spray, existence of calcium-silicate with tri-sodium phosphate (TSP), and composition of materials. The results showed that head loss across the chemical bed with even a small amount of calcium-silicate insulation instantaneously increased as soon as TSP was added to the test solution. Also, the head loss across the filter screen is strongly affected by spray duration and the head loss increase is rapid at the early stage, because of high dissolution and precipitation of aluminum and zinc. After passivation of aluminum and zinc by corrosion, the head loss increase is much slowed down and is mainly induced by materials such as calcium, silicon, and magnesium leached from NUKON TM and concrete. Furthermore, it is newly found that the spay buffer agent, tri-sodium phosphate, to form protective coating on the aluminum surface and reduce aluminum leaching is not effective for a large amount of aluminum and a long spray.

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1992-07-01

The document reproduces the text of the notes verbales dated 15 May 1992, received by the Director General from the Resident Representatives to the Agency of Australia, Austria, Belgium, Bulgaria, Canada, Czech and Slovak Federal Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Russia Federation, Spain, Sweden, Switzerland, the United Kingdom of Great Britain and Northern Ireland, and the United States of America relating to the export of nuclear material, equipment and technology and the Guidelines for Transfer of Nuclear-Related Dual-Use Equipment, Material and Related Technology. An Annex to these Guidelines contains the list of Nuclear-Related Dual-Use Equipment and Materials and Related Technology

Communications received from certain member states regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1993-04-01

The document reproduces the Note Verbale dated 8 February 1993 received by the Director General from the Permanent Mission of the Russian Federation to the International Organizations in Vienna, relating to the export of nuclear material, equipment or technology, in order to provide information on that Government's Guidelines for Nuclear Transfer

77 FR 36017 - Regulatory Guide 7.3, Procedures for Picking Up and Receiving Packages of Radioactive Material

Science.gov (United States)

2012-06-15

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0139] Regulatory Guide 7.3, Procedures for Picking Up and... Guide (RG) 7.3, ``Procedures for Picking Up and Receiving Packages of Radioactive Material.'' The guide..., please contact the NRC's Public Document Room (PDR) reference staff at 1-800-397-4209, or 301-415-4737...

Communication of 30 June 1995 Received from France Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

1995-10-01

The Director General has received letters concerning the export of nuclear material and of certain categories of equipment and other material from the following Resident Representatives to the International Atomic Energy Agency: a letter dated 28 February 1994 from the Resident Representative of France; letters dated 1 March 1994 from the Resident Representatives of Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, Germany, Greece, Hungary, Ireland, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, and the United States of America; and a letter dated 22 March 1994 from the Resident Representative of Romania [ru

Communication of 30 June 1995 Received from France Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material

International Nuclear Information System (INIS)

1995-01-01

The Director General has received letters concerning the export of nuclear material and of certain categories of equipment and other material from the following Resident Representatives to the International Atomic Energy Agency: a letter dated 28 February 1994 from the Resident Representative of France; letters dated 1 March 1994 from the Resident Representatives of Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, Germany, Greece, Hungary, Ireland, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, and the United States of America; and a letter dated 22 March 1994 from the Resident Representative of Romania [es

Analysis of ringing effects due to magnetic core materials in pulsed nuclear magnetic resonance circuits

International Nuclear Information System (INIS)

Prabhu Gaunkar, N.; Bouda, N. R. Y.; Nlebedim, I. C.; Hadimani, R. L.; Mina, M.; Jiles, D. C.; Bulu, I.; Ganesan, K.; Song, Y. Q.

2015-01-01

This work presents investigations and detailed analysis of ringing in a non-resonant pulsed nuclear magnetic resonance (NMR) circuit. Ringing is a commonly observed phenomenon in high power switching circuits. The oscillations described as ringing impede measurements in pulsed NMR systems. It is therefore desirable that those oscillations decay fast. It is often assumed that one of the causes behind ringing is the role of the magnetic core used in the antenna (acting as an inductive load). We will demonstrate that an LRC subcircuit is also set-up due to the inductive load and needs to be considered due to its parasitic effects. It is observed that the parasitics associated with the inductive load become important at certain frequencies. The output response can be related to the response of an under-damped circuit and to the magnetic core material. This research work demonstrates and discusses ways of controlling ringing by considering interrelationships between different contributing factors

Analysis of ringing effects due to magnetic core materials in pulsed nuclear magnetic resonance circuits

Energy Technology Data Exchange (ETDEWEB)

Prabhu Gaunkar, N., E-mail: neelampg@iastate.edu; Bouda, N. R. Y.; Nlebedim, I. C.; Hadimani, R. L.; Mina, M.; Jiles, D. C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Bulu, I.; Ganesan, K.; Song, Y. Q. [Schlumberger-Doll Research, Cambridge, Massachusetts 02139 (United States)

2015-05-07

This work presents investigations and detailed analysis of ringing in a non-resonant pulsed nuclear magnetic resonance (NMR) circuit. Ringing is a commonly observed phenomenon in high power switching circuits. The oscillations described as ringing impede measurements in pulsed NMR systems. It is therefore desirable that those oscillations decay fast. It is often assumed that one of the causes behind ringing is the role of the magnetic core used in the antenna (acting as an inductive load). We will demonstrate that an LRC subcircuit is also set-up due to the inductive load and needs to be considered due to its parasitic effects. It is observed that the parasitics associated with the inductive load become important at certain frequencies. The output response can be related to the response of an under-damped circuit and to the magnetic core material. This research work demonstrates and discusses ways of controlling ringing by considering interrelationships between different contributing factors.

Core degradation and fission product release

International Nuclear Information System (INIS)

Wright, R.W.; Hagen, S.J.L.

1992-01-01

Experiments on core degradation and melt progression in severe LWR accidents have provided reasonable understanding of the principal processes involved in the early phase of melt progression that extends through core degradation and metallic material melting and relocation. A general but not a quantitative understanding of late phase melt progression that involves ceramic material melting and relocation has also been obtained, primarily from the TMI-2 core examination. A summary is given of the current state of knowledge on core degradation and melt progression obtained from these integral experiments and of the principal remaining significant uncertainties. A summary is also given of the principal results on in-vessel fission product release obtained from these experiments. (author). 8 refs, 5 figs, 3 tabs

Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

Energy Technology Data Exchange (ETDEWEB)

Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Padipatvuthikul, P, E-mail: raayaa_chula@hotmail.com [Faculty of Dentistry, Srinakharinwirot University, Bangkok (Thailand)

2011-10-29

Silicon nitride (Si{sub 3}N{sub 4}) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si{sub 3}N{sub 4} ceramic as a dental core material. The white Si{sub 3}N{sub 4} was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si{sub 3}N{sub 4} ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si{sub 3}N{sub 4} specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y{sub 2}O{sub 3} - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si{sub 3}N{sub 4} specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10{sup -6} deg. C{sup -1}, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

Report on material and fabrication tests of the KUHFR core vessel

International Nuclear Information System (INIS)

Yoshida, H.; Kozuka, T.; Achiwa, N.; Mitani, S.; Kawano, S.; Araki, Y.; Shibata, T.

1983-01-01

For the material of the cylindrical reactor core vessel of the Kyoto University High Flux Reactor (KUHFR), A6061 alloy is selected because the aged state of the alloy is known to show the highest resistance against void swelling due to high-dose irradiation. The fabrication possibility of the large-scale tubes is also tested because the sizes (40 cmdiameter and 43 cmdiameter x 960 cm with a thickness of 10 mm for the inner- and outer-tubes, respectively) are just over the largest limit of the conventional factory fabrication. The results are summarized as follows. (1) From an ingot of A6061 alloy a raw inner-tube is hot-extruded by the 3,000 ton press machine. The shape of the extruded tubes is effectively corrected by stretch forming and other special methods. (2) The real scale tubes are heat-treated under the various conditions (T1, T4 and T6) and their size changes are measured just after the every heat-treatment. (3) The hydropressure for a pipe prepared by welding from an aged-tube shows a fairly uniform strain distribution and the breaking initiation at the reasonable pressure in the welded part. (4) Each of the welded specimens prepared using three kinds of welding rods shows sufficient strength in both of bending and tensile test for the JIS standard. Their microstructures correspond to the result of the mechanical tests for each welded specimen. The confidence for the fabrication possibility of the real core vessel has been given through the present tests. (author)

IAEA Coordinated Research Project on the Establishment of a Material Properties Database for Irradiated Core Structural Components for Continued Safe Operation and Lifetime Extension of Ageing Research Reactors

Energy Technology Data Exchange (ETDEWEB)

Borio Di Tigliole, A.; Schaaf, Van Der; Barnea, Y.; Bradley, E.; Morris, C.; Rao, D. V. H. [Research Reactor Section, Vianna (Australia); Shokr, A. [Research Reactor Safety Section, Vienna (Australia); Zeman, A. [International Atomic Energy Agency, Vienna (Australia)

2013-07-01

Today more than 50% of operating Research Reactors (RRs) are over 45 years old. Thus, ageing management is one of the most important issues to face in order to ensure availability (including life extension), reliability and safe operation of these facilities for the future. Management of the ageing process requires, amongst others, the predictions for the behavior of structural materials of primary components subjected to irradiation such as reactor vessel and core support structures, many of which are extremely difficult or impossible to replace. In fact, age-related material degradation mechanisms resulted in high profile, unplanned and lengthy shutdowns and unique regulatory processes of relicensing the facilities in recent years. These could likely have been prevented by utilizing available data for the implementation of appropriate maintenance and surveillance programmes. This IAEA Coordinated Research Project (CRP) will provide an international forum to establish a material properties Database for irradiated core structural materials and components. It is expected that this Database will be used by research reactor operators and regulators to help predict ageing related degradation. This would be useful to minimize unpredicted outages due to ageing processes of primary components and to mitigate lengthy and costly shutdowns. The Database will be a compilation of data from RRs operators' inputs, comprehensive literature reviews and experimental data from RRs. Moreover, the CRP will specify further activities needed to be addressed in order to bridge the gaps in the new created Database, for potential follow-on activities. As per today, 13 Member States (MS) confirmed their agreement to contribute to the development of the Database, covering a wide number of materials and properties. The present publication incorporates two parts: the first part includes details on the pre-CRP Questionnaire, including the conclusions drawn from the answers received from

IAEA Coordinated Research Project on the Establishment of a Material Properties Database for Irradiated Core Structural Components for Continued Safe Operation and Lifetime Extension of Ageing Research Reactors

International Nuclear Information System (INIS)

Borio Di Tigliole, A.; Schaaf, Van Der; Barnea, Y.; Bradley, E.; Morris, C.; Rao, D. V. H.; Shokr, A.; Zeman, A.

2013-01-01

Today more than 50% of operating Research Reactors (RRs) are over 45 years old. Thus, ageing management is one of the most important issues to face in order to ensure availability (including life extension), reliability and safe operation of these facilities for the future. Management of the ageing process requires, amongst others, the predictions for the behavior of structural materials of primary components subjected to irradiation such as reactor vessel and core support structures, many of which are extremely difficult or impossible to replace. In fact, age-related material degradation mechanisms resulted in high profile, unplanned and lengthy shutdowns and unique regulatory processes of relicensing the facilities in recent years. These could likely have been prevented by utilizing available data for the implementation of appropriate maintenance and surveillance programmes. This IAEA Coordinated Research Project (CRP) will provide an international forum to establish a material properties Database for irradiated core structural materials and components. It is expected that this Database will be used by research reactor operators and regulators to help predict ageing related degradation. This would be useful to minimize unpredicted outages due to ageing processes of primary components and to mitigate lengthy and costly shutdowns. The Database will be a compilation of data from RRs operators' inputs, comprehensive literature reviews and experimental data from RRs. Moreover, the CRP will specify further activities needed to be addressed in order to bridge the gaps in the new created Database, for potential follow-on activities. As per today, 13 Member States (MS) confirmed their agreement to contribute to the development of the Database, covering a wide number of materials and properties. The present publication incorporates two parts: the first part includes details on the pre-CRP Questionnaire, including the conclusions drawn from the answers received from the MS

Synthesis and properties of Pr-substituted MgZn ferrites for core materials and high frequency applications

International Nuclear Information System (INIS)

Mukhtar, Muhammad Waqas; Irfan, Muhammad; Ahmad, Ishtiaq; Ali, Ihsan; Akhtar, Majid Niaz; Khan, Muhammad Azhar; Abbas, Ghazanfar; Rana, M.U.; Ali, Akbar; Ahmad, Mukhtar

2015-01-01

A series of single phase spinel ferrites having chemical formula Mg 0.5 Zn 0.5 Pr x Fe 2−x O 4 (x=0.00, 0.05, 0.10, 0.15, 0.20, 0.25) were prepared using the sol–gel technique after sintering at 700 °C. The thermal decomposition behavior of an as prepared powder was investigated by means of DTA/TGA analyses. The sintered powders were then characterized by Fourier transform infrared spectroscope, X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscope and vibrating sample magnetometer. X-ray diffraction patterns confirm the single phase spinel structure of prepared ferrites without the presence of any impurity phase. The value of lattice parameter (a) increases with the increase of Pr contents (x) into the spinel lattice. The grain size estimated from electron microscope images is in the range of 2.75–5.4 µm which confirms the spinel crystalline nature of the investigated samples. The saturation magnetization (M s ) decreases whereas coercivity (H c ) increases with the increase of Pr contents (x). The measured parameters suggest that these materials are favorable for high frequency applications and as core materials. - Highlights: • Pr-substituted spinel ferrites synthesized by autocombustion route have been investigated. • The average grain size was in the range of 2.75–5.4 µm estimated by SEM technique. • The (M s ) decreases whereas (H c ) increases with the increase of Pr contents (x). • These parameters are favorable for high frequency applications and as core materials

Fabrication, characterization and comparison of composite magnetic materials for high efficiency integrated voltage regulators with embedded magnetic core micro-inductors

International Nuclear Information System (INIS)

Bellaredj, Mohamed L F; Mueller, Sebastian; Davis, Anto K; Swaminathan, Madhavan; Mano, Yasuhiko; Kohl, Paul A

2017-01-01

High-efficiency integrated voltage regulators (IVRs) require the integration of power inductors, which have low loss and reduced size at very high frequency. The use of a magnetic material core can reduce significantly the inductor area and simultaneously increase the inductance. This paper focuses on the fabrication, characterization and modeling of nickel zinc (NiZn) ferrite and carbonyl iron powder (CIP)-epoxy magnetic composite materials, which are used as the magnetic core materials of embedded inductors in a printed wiring board (PWB) for a system in package (SIP) based buck type IVR. The fabricated composite materials and process are fully compatible with FR4 epoxy resin prepreg and laminate. For 85% weight loading of the magnetic powder (around 100 MHz at room temperature), the composite materials show a relative permeability of 7.5–8.1 for the NiZn ferrite composite and 5.2–5.6 for the CIP composite and a loss tangent value of 0.24–0.28 for the NiZn ferrite composite and 0.09–0.1 for the CIP-composite. The room temperature saturation flux density values are 0.1351 T and 0.5280 T for the NiZn ferrite and the CIP composites, respectively. The frequency dispersion parameters of the magnetic composites are modeled using a simplified Lorentz and Landau–Lifshitz–Gilbert equation for a Debye type relaxation. Embedded magnetic core solenoid inductors were designed based on the composite materials for the output filter of a high-efficiency SIP based buck type IVR. Evaluation of a SIP based buck type IVR with the designed inductors shows that it can reach peak efficiencies of 91.7% at 11 MHz for the NiZn ferrite-composite, 91.6% at 14 MHz for CIP-composite and 87.5% (NiZn ferrite-composite) and 87.3% (CIP-composite) efficiency at 100 MHz for a 1.7 V:1.05 V conversion. For a direct 5 V:1 V conversion using a stacked topology, a peak efficiency of 82% at 10 MHz and 72% efficiency at 100 MHz can be achieved for both materials. (paper)

Fabrication, characterization and comparison of composite magnetic materials for high efficiency integrated voltage regulators with embedded magnetic core micro-inductors

Science.gov (United States)

Bellaredj, Mohamed L. F.; Mueller, Sebastian; Davis, Anto K.; Mano, Yasuhiko; Kohl, Paul A.; Swaminathan, Madhavan

2017-11-01

High-efficiency integrated voltage regulators (IVRs) require the integration of power inductors, which have low loss and reduced size at very high frequency. The use of a magnetic material core can reduce significantly the inductor area and simultaneously increase the inductance. This paper focuses on the fabrication, characterization and modeling of nickel zinc (NiZn) ferrite and carbonyl iron powder (CIP)-epoxy magnetic composite materials, which are used as the magnetic core materials of embedded inductors in a printed wiring board (PWB) for a system in package (SIP) based buck type IVR. The fabricated composite materials and process are fully compatible with FR4 epoxy resin prepreg and laminate. For 85% weight loading of the magnetic powder (around 100 MHz at room temperature), the composite materials show a relative permeability of 7.5-8.1 for the NiZn ferrite composite and 5.2-5.6 for the CIP composite and a loss tangent value of 0.24-0.28 for the NiZn ferrite composite and 0.09-0.1 for the CIP-composite. The room temperature saturation flux density values are 0.1351 T and 0.5280 T for the NiZn ferrite and the CIP composites, respectively. The frequency dispersion parameters of the magnetic composites are modeled using a simplified Lorentz and Landau-Lifshitz-Gilbert equation for a Debye type relaxation. Embedded magnetic core solenoid inductors were designed based on the composite materials for the output filter of a high-efficiency SIP based buck type IVR. Evaluation of a SIP based buck type IVR with the designed inductors shows that it can reach peak efficiencies of 91.7% at 11 MHz for the NiZn ferrite-composite, 91.6% at 14 MHz for CIP-composite and 87.5% (NiZn ferrite-composite) and 87.3% (CIP-composite) efficiency at 100 MHz for a 1.7 V:1.05 V conversion. For a direct 5 V:1 V conversion using a stacked topology, a peak efficiency of 82% at 10 MHz and 72% efficiency at 100 MHz can be achieved for both materials.

Communications received from certain member states regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1993-04-01

The document reproduces the text of a Note Verbale dated 5 March 1993 received by the Director General from the Ministry of Foreign Affairs of the Slovak Republic, in order to provide information on that Government's Guidelines for Nuclear Transfer and for Transfers of Nuclear - Related Dual-Use Equipment, Material and Related Technology

Fabrication of Core-Shell Structural SiO2@H3[PM12O40] Material and Its Catalytic Activity

Directory of Open Access Journals (Sweden)

Xin Yang

2014-01-01

Full Text Available Through a natural tree grain template and sol-gel technology, the heterogeneous catalytic materials based on polyoxometalate compounds H3[PM12O40] encapsulating SiO2: SiO2@H3[PM12O40] (SiO2@PM12, M = W, Mo with core-shell structure had been prepared. The structure and morphology of the core-shell microspheres were characterized by the XRD, IR spectroscopy, UV-Vis absorbance, and SEM. These microsphere materials can be used as heterogeneous catalysts with high activity and stability for catalytic wet air oxidation of pollutant dyes safranine T (ST at room condition. The results show that the catalysts have excellent catalytic activity in treatment of wastewater containing 10 mg/L ST, and 94% of color can be removed within 60 min. Under different cycling runs, it is shown that the catalysts are stable under such operating conditions and the leaching tests show negligible leaching effect owing to the lesser dissolution.

Evaluating Community Health Advisor (CHA) Core Competencies: The CHA Core Competency Retrospective Pretest/Posttest (CCCRP).

Science.gov (United States)

Story, Lachel; To, Yen M

2016-05-01

Health care and academic systems are increasingly collaborating with community health advisors (CHAs) to provide culturally relevant health interventions that promote sustained community transformation. Little attention has been placed on CHA training evaluation, including core competency attainment. This study identified common CHA core competencies, generated a theoretically based measure of those competencies, and explored psychometric properties of that measure. A concept synthesis revealed five CHA core competencies (leadership, translation, guidance, advocacy, and caring). The CHA Core Competency Retrospective Pretest/Posttest (CCCRP) resulted from that synthesis, which was administered using multiple approaches to individuals who previously received CHA training (N= 142). Exploratory factor analyses revealed a two-factor structure underlying the posttraining data, and Cronbach's alpha indicated high internal consistency. This study suggested some CHA core competencies might be more interrelated than previously thought, and two major competencies exist rather than five and supported the CCCRP's use to evaluate core competency attainment resulting from training. © The Author(s) 2014.

Technical specification for IR rig manufacture

Energy Technology Data Exchange (ETDEWEB)

Han Hyon Soo; Cho, W. K.; Kim, S. D.; Park, U. J.; Hong, S. B.; Yoo, K. M

2000-10-01

IR Rig is one of the equipments are required in HANARO core for a radioisotope target. The various conditions like high radiation, high heat, rapid flow and vibration may cause swelling, Brittleness and acceleration of corrosion in HANARO core. These specific problems can be prevented and the safety of such equipment are prerequisite as well as durableness and surveillance. Therefore, the selection of material has to be made on the basis of small cross-section area, low energy emission by the gamma ray due to the absorption of neutron and short half life. The body is consist of aluminum and Inconel-750 was used for the internal spring(coil) which is known to be durable. The whole production process including the purchase of accessory, mechanical processing, welding and assembly was carried out according to the standard procedure to meet the requirement. A design, manufacture, utilization of reactor core and the other relevant uses were fit to class ''T'' to certify the whole process as general. And design, fabrication, analytical test, materials and accessory were carried out based on the ASME, ASTM, ANSI, AWS, JIS and KS standard.

Graded territories: Towards the design, specification and simulation of materially graded bending active structures

DEFF Research Database (Denmark)

Nicholas, Paul; Tamke, Martin; Ramsgaard Thomsen, Mette

2012-01-01

these structures, the property of bending is activated and varied through bespoke material means so as to match a desired form. Within the architectural design process, formal control depends upon design approaches for material specification and simulation that consider behavior at the level of the material...... element as well as the structure. We describe an evolving approach to material specification and simulation, and highlight the digital and material considerations that frame the process.......The ability to make materials with bespoke behavior affords new perspectives on incorporating material properties within the design process not available through natural materials. This paper reports the design and assembly of two bending-active, fibre-reinforced composite structures. Within...

Low void effect (CFV) core concept flexibility: from self-breeder to burner core - 15091

International Nuclear Information System (INIS)

Buiron, L.; Dujcikova, L.

2015-01-01

In the frame of the French strategy on sustainable nuclear energy, several scenarios consider fuel cycle transition toward a plutonium multi-recycling strategy in sodium cooled fast reactor (SFR). Basically, most of these scenarios consider the deployment of a 60 GWe SFR fleet in 2 steps to renew the French PWR fleet. As scenarios do investigate long term deployment configurations, some of them require tools for nuclear phase-out studies. Instead of designing new reactors, the adopted strategy does focus on adaptation of existing ones into burner configurations. This is what was done in the frame of the EFR project at the end of the 90's using the CAPRA approach (French acronym for Enhance Plutonium Consumption in Fast Reactor). The EFR burner configuration was obtained by inserting neutronic penalties inside the core (absorber material and/or diluent subassembly). Starting from the preliminary industrial image of a SFR 3600 MWth core based on Low Sodium Void concept (CFV in French), a 'CAPRA-like' approach has been studied. As the CFV self-breeding is ensured by fertile blankets, a first modification consisted in the substitution of the corresponding depleted uranium by 'inert' or absorber material leading to a 'natural burner' core with only small impacts on flux distribution. The next step forward CAPRA configuration was the substitution of 1/3 of the fuel pins by 'dummy' pins (MgO pellets). The small spectrum shift due to MgO material insertion leads to an increase Doppler constant which exceeds the value of the reference case. As the core sodium void worth value is conserved, the CFV CAPRA core 'safety' potential is quite similar to the one of the reference core. Fuel thermo-mechanical requirements are met by both nominal core power and fuel time residence reduction. However, these reduction factors are lower than those obtained for EFR core. The management of the enhanced reactivity swing is discussed

Determination of the neutron fluence in the welding of the 'Core shroud' of the BWR reactor core; Determinacion de la fluencia neutronica en las soldaduras del 'core shroud' del nucleo de un reactor BWR

Energy Technology Data Exchange (ETDEWEB)

Lucatero, M.A.; Xolocostli M, J.V.; Gomez T, A.M.; Palacios H, J.C. [ININ, 52750 Ocoyoacac, Estado de mexico (Mexico)]. e-mail: mal@nuclear.inin.mx

2006-07-01

With the purpose of defining the inspection frequency, in function of the embrittlement of the materials that compose the welding of the 'Core Shroud' or encircling of the core of a BWR type reactor, is necessary to know the neutron fluence received for this welding. In the work the calculated values of neutron fluence accumulated maxim (E > 1 MeV) during the first 8 operation cycles of the reactor are presented. The calculations were carried out according to the NRC Regulatory Guide 1.190, making use of the DORT code, which solves the transport equation in discreet ordinate in two dimensions (xy, r{theta}, and rz). The results in 3D were obtained applying the Synthesis method according to the guide before mentioned. Results are presented for the horizontal welding H3, H4, and H5, showing the corresponding curves to the fluence accumulated to the cycle 8 and a projection for the cycle 14 is presented. (Author)

First in-core measurement results obtained with the innovative mobile calorimeter CALMOS inside the OSIRIS material testing reactor

International Nuclear Information System (INIS)

Carcreff, Hubert; Salmon, Laurent; Courtaux, Cedric

2014-01-01

Nuclear heating rate inside an MTR has to be known in order to design and to run irradiation experiments which have to fulfill target temperature constraints. This measurement is usually carried out by calorimetry. An innovative calorimetric system, CALMOS, has been studied and built in 2011 for the 70 MWth OSIRIS reactor operated by CEA. Thanks to a new calorimetric probe, associated to a specific displacement system, it provides measurements along the fissile height and above the core. Development of the calorimetric probe required manufacturing and irradiation of mock-ups in the ex-core area, where nuclear heating rate does not exceed 2 W.g -1 . The calorimeter working mode, the different measurement procedures, main modeling and ex-core experimental results have been already presented in previous papers. In this paper, we present in-core results obtained from 2011 to 2013 with the final device. For the first time, this new experimental measurement system was operated in several experimental locations, with nominal in-core thermal hydraulic conditions, nominal neutron flux and nuclear heating rate up to 6 W.g -1 (in graphite). After a brief presentation of the displacement system specificities, first nuclear heating distributions are presented and discussed. The Finite Element model of the calorimeter was upgraded in order to match calculated temperatures with measured ones. This 'validated' model allowed to estimate a Kc factor which tends to correct small nonlinearities when heating rate is calculated from the 'calibration method'. A comparison is made between nuclear heating rates determined from 'calibration' and 'zero methods'. In addition, an evaluation of the global uncertainty associated to the measurements is detailed. Finally, a comparison is made with available measurements obtained from previous calorimeters. (authors)

Core Hunter 3: flexible core subset selection.

Science.gov (United States)

De Beukelaer, Herman; Davenport, Guy F; Fack, Veerle

2018-05-31

Core collections provide genebank curators and plant breeders a way to reduce size of their collections and populations, while minimizing impact on genetic diversity and allele frequency. Many methods have been proposed to generate core collections, often using distance metrics to quantify the similarity of two accessions, based on genetic marker data or phenotypic traits. Core Hunter is a multi-purpose core subset selection tool that uses local search algorithms to generate subsets relying on one or more metrics, including several distance metrics and allelic richness. In version 3 of Core Hunter (CH3) we have incorporated two new, improved methods for summarizing distances to quantify diversity or representativeness of the core collection. A comparison of CH3 and Core Hunter 2 (CH2) showed that these new metrics can be effectively optimized with less complex algorithms, as compared to those used in CH2. CH3 is more effective at maximizing the improved diversity metric than CH2, still ensures a high average and minimum distance, and is faster for large datasets. Using CH3, a simple stochastic hill-climber is able to find highly diverse core collections, and the more advanced parallel tempering algorithm further increases the quality of the core and further reduces variability across independent samples. We also evaluate the ability of CH3 to simultaneously maximize diversity, and either representativeness or allelic richness, and compare the results with those of the GDOpt and SimEli methods. CH3 can sample equally representative cores as GDOpt, which was specifically designed for this purpose, and is able to construct cores that are simultaneously more diverse, and either are more representative or have higher allelic richness, than those obtained by SimEli. In version 3, Core Hunter has been updated to include two new core subset selection metrics that construct cores for representativeness or diversity, with improved performance. It combines and outperforms the

Thermohydraulic behaviour and heat transfer in the molten core

International Nuclear Information System (INIS)

Reineke, H.H.

1977-01-01

Increasing the application of nuclear reactors to produce electrical power extremely unprobable accidents should be investigated too. In the Federal Republic of Germany, a research program is performed for some years engaged in accidents at light water reactors in which the melting of the reactor core is presumed. A part of this program is to investigate the thermohydraulic and the heat transfer behavior in an accumulation of molten core material. The knowledge of these events is necessary to analyse the accident exactly. Further on the results of this work are of great importance to build a catcher for the molten core material. As a result of the decay heat the molten material is heated up and the density differences induce a free convection motion. In this work the thermohydraulic behavior and the distribution of the escaping heat fluxes for several accumulations of molten core material were determined. The numerical methods for solving the system of partial differential equation were used to develop computer codes, able to compute the average and local heat fluxes at the walls enclosing the molten core material and the inside increase of the temperature. The numerical computations were confirmed and verified by experimental investigations. In these investigations the molten core material was always assumed as a homogeneous fluid. In this case, the results could be reproduced by simple power laws

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1993-01-01

The document reproduces the Note Verbale dated 2 December 1992 received by the Director General from the Resident Representative of Argentina to the Agency relating to the export of nuclear material, equipment and technology in order to clarify parts of the Trigger List which is incorporated in Annex A to the Guidelines for Nuclear Transfers

Optomagnetic Detection of MicroRNA Based on Duplex-Specific Nuclease-Assisted Target Recycling and Multilayer Core-Satellite Magnetic Superstructures

DEFF Research Database (Denmark)

Tian, Bo; Ma, Jing; Qiu, Zhen

2017-01-01

-efficiency, and potential for bioresponsive multiplexing. Herein, we demonstrate a sensitive and rapid miRNA detection method based on optomagnetic read-out, duplex-specific nuclease (DSN)-assisted target recycling, and the use of multilayer core-satellite magnetic superstructures. Triggered by the presence of target mi...

INFLUENCE OF THE SHELL MATERIAL IN THE MICROCAPSULES FORMATION BY SPRAY DRYING

Directory of Open Access Journals (Sweden)

FERRÁNDIZ Marcela

2015-05-01

Full Text Available Microencapsulation is a process of entrapment, packaging or immobilizing an active (core material, which can be in the state of solid, liquid or gas, within a more stable, protective secondary (wall material that can be released at controlled rates under specific conditions. There are several microencapsulation techniques such as: spray drying, spray cooling/chilling, freeze drying, extrusion, fluidized bed coating, coacervation, liposome entrapment, coextrusion, interfacial polymerization, radical polymerization, molecular inclusion in cyclodextrins, etc. Spray drying has been commonly applied due to their simplicity process, wide availability of equipment facilities, significant merits in terms of reductions in product volume, easy of handling, etc. In the spray drying process the wall materials (shells and their properties are parameters to be considered to achieve proper encapsulation of the active ingredients (core materials. Some commonly used wall materials and their properties related to spray drying encapsulation, including proteins, carbohydrates, and other materials, or mixtures of some of them. Proper encapsulation of the active ingredient (core is essential to achieve this active material protecting the outer. The aim of this work is encapsulated an essential oil, sage oil, using two differet wall materials in order to determine which is the best wall material. Scanning electron microscopy (SEM has been used in order to know the microcapsules morphology. Core, Shell, Gum Arabic, Alginate, Sage oil, Scanning Electron Microscopy (SEM

Implementing a DVB-T/H Receiver on a Software-Defined Radio Platform

Directory of Open Access Journals (Sweden)

Yong Jiang

2009-01-01

Full Text Available Digital multimedia broadcasting is available in more and more countries with various forms. One of the most successful forms is Digital Video Broadcasting for Terrestrial (DVB-T, which has been deployed in most countries of the world for years. In order to bring the digital multimedia broadcasting services to battery-powered handheld receivers in a mobile environment, Digital Video Broadcasting for Handheld (DVB-H has been formally adopted by ETSI. More advanced and complex digital multimedia broadcasting systems are under development, for example, the next generation of DVB-T, a.k.a. DVB-T2. Current commercial DVB-T/H receivers are usually built upon dedicated application-specific integrated circuits (ASICs. However, ASICs are not flexible for incoming evolved standards and less overall-area efficient since they cannot be efficiently reused and shared among different radio standards, when we integrate a DVB-T/H receiver into a mobile phone. This paper presents an example implementation of a DVB-T/H receiver on the prototype of Infineon Technologies' Software-Defined Radio (SDR platform called MuSIC (Multiple SIMD Cores, which is a DSP-centered and accelerator-assisted architecture and aims at battery-powered mass-market handheld terminals.

Communications received from certain Member States regarding guidelines for the export of nuclear material, equipment and technology

International Nuclear Information System (INIS)

1994-04-01

The Director General has received notes verbales dated 27 August 1993 and 28 October 1993 from the Permanent Missions of Finland and Spain to the International Atomic Energy relating to the export of nuclear material, equipment and technology. The purpose of these notes verbales is to provide further information on those Governments' nuclear export policies and practices

Communications Received from the United States of America Regarding the Supply of Nuclear Material Through the Agency

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-08-29

On 17 April 1975 the Director General received a letter dated 15 April from the Resident Representative of the United States of America to the Agency providing information in connection with contracts and other agreements signed by or on behalf of the United States Atomic Energy Commission for the supply of nuclear material through the Agency.

How to Determine the Core-Shell Nature in Bimetallic Catalyst Particles?

Directory of Open Access Journals (Sweden)

Emma Westsson

2014-11-01

Full Text Available Nanometer-sized materials have significantly different chemical and physical properties compared to bulk material. However, these properties do not only depend on the elemental composition but also on the structure, shape, size and arrangement. Hence, it is not only of great importance to develop synthesis routes that enable control over the final structure but also characterization strategies that verify the exact nature of the nanoparticles obtained. Here, we consider the verification of contemporary synthesis strategies for the preparation of bimetallic core-shell particles in particular in relation to potential particle structures, such as partial absence of core, alloying and raspberry-like surface. It is discussed what properties must be investigated in order to fully confirm a covering, pin-hole free shell and which characterization techniques can provide such information. Not uncommonly, characterization strategies of core-shell particles rely heavily on visual imaging like transmission electron microscopy. The strengths and weaknesses of various techniques based on scattering, diffraction, transmission and absorption for investigating core-shell particles are discussed and, in particular, cases where structural ambiguities still remain will be highlighted. Our main conclusion is that for particles with extremely thin or mono-layered shells—i.e., structures outside the limitation of most imaging techniques—other strategies, not involving spectroscopy or imaging, are to be employed. We will provide a specific example of Fe-Pt core-shell particles prepared in bicontinuous microemulsion and point out the difficulties that arise in the characterization process of such particles.

Surveillance test of the JMTR core components

International Nuclear Information System (INIS)

Takeda, Takashi; Amezawa, Hiroo; Tobita, Kenji

1986-02-01

Surveillance test for the core components of Japan Materials Testing Reactor (JMTR) was started in 1966, and completed in 1985 without one capsule. Most of capsules in the program, except one beryllium specimens, were removed from the core, and carred out the post-irradiation tests at the JMTR Hot Laboratory. The data is applied to review of JMTR core components management plan. JMTR surveillance test was carried out with several kind of materials of JMTR core components, Berylium as the reflector, Hafnium as the neutron absorber of control rod, 17-4PH stainless steel as a roller spring of the control rod, and 304 stainless steel as the grid plate. Results are described in this report. (author)

Core losses of a permanent magnet synchronous motor with an amorphous stator core under inverter and sinusoidal excitations

Science.gov (United States)

Yao, Atsushi; Sugimoto, Takaya; Odawara, Shunya; Fujisaki, Keisuke

2018-05-01

We report core loss properties of permanent magnet synchronous motors (PMSM) with amorphous magnetic materials (AMM) core under inverter and sinusoidal excitations. To discuss the core loss properties of AMM core, a comparison with non-oriented (NO) core is also performed. In addition, based on both experiments and numerical simulations, we estimate higher (time and space) harmonic components of the core losses under inverter and sinusoidal excitations. The core losses of PMSM are reduced by about 59% using AMM stator core instead of NO core under sinusoidal excitation. We show that the average decrease obtained by using AMM instead of NO in the stator core is about 94% in time harmonic components.

Core losses of a permanent magnet synchronous motor with an amorphous stator core under inverter and sinusoidal excitations

Directory of Open Access Journals (Sweden)

Atsushi Yao

2018-05-01

Full Text Available We report core loss properties of permanent magnet synchronous motors (PMSM with amorphous magnetic materials (AMM core under inverter and sinusoidal excitations. To discuss the core loss properties of AMM core, a comparison with non-oriented (NO core is also performed. In addition, based on both experiments and numerical simulations, we estimate higher (time and space harmonic components of the core losses under inverter and sinusoidal excitations. The core losses of PMSM are reduced by about 59% using AMM stator core instead of NO core under sinusoidal excitation. We show that the average decrease obtained by using AMM instead of NO in the stator core is about 94% in time harmonic components.

Updated procedures for using drill cores and cuttings at the Lithologic Core Storage Library, Idaho National Laboratory, Idaho

Science.gov (United States)

Hodges, Mary K.V.; Davis, Linda C.; Bartholomay, Roy C.

2018-01-30

In 1990, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy Idaho Operations Office, established the Lithologic Core Storage Library at the Idaho National Laboratory (INL). The facility was established to consolidate, catalog, and permanently store nonradioactive drill cores and cuttings from subsurface investigations conducted at the INL, and to provide a location for researchers to examine, sample, and test these materials.The facility is open by appointment to researchers for examination, sampling, and testing of cores and cuttings. This report describes the facility and cores and cuttings stored at the facility. Descriptions of cores and cuttings include the corehole names, corehole locations, and depth intervals available.Most cores and cuttings stored at the facility were drilled at or near the INL, on the eastern Snake River Plain; however, two cores drilled on the western Snake River Plain are stored for comparative studies. Basalt, rhyolite, sedimentary interbeds, and surficial sediments compose most cores and cuttings, most of which are continuous from land surface to their total depth. The deepest continuously drilled core stored at the facility was drilled to 5,000 feet below land surface. This report describes procedures and researchers' responsibilities for access to the facility and for examination, sampling, and return of materials.

Synthesis of Au@Ag core-shell nanocubes containing varying shaped cores and their localized surface plasmon resonances.

Science.gov (United States)

Gong, Jianxiao; Zhou, Fei; Li, Zhiyuan; Tang, Zhiyong

2012-06-19

We have synthesized Au@Ag core-shell nanocubes containing Au cores with varying shapes and sizes through modified seed-mediated methods. Bromide ions are found to be crucial in the epitaxial growth of Ag atoms onto Au cores and in the formation of the shell's cubic shape. The Au@Ag core-shell nanocubes exhibit very abundant and distinct localized surface plasmon resonance (LSPR) properties, which are core-shape and size-dependent. With the help of theoretical calculation, the physical origin and the resonance mode profile of each LSPR peak are identified and studied. The core-shell nanocrystals with varying shaped cores offer a new rich category for LSPR control through the plasmonic coupling effect between core and shell materials.

Synthesis and properties of Pr-substituted MgZn ferrites for core materials and high frequency applications

Energy Technology Data Exchange (ETDEWEB)

Mukhtar, Muhammad Waqas; Irfan, Muhammad [Department of Physics, Federal Urdu University of Arts, Science and Technology, Islamabad 44000 (Pakistan); Ahmad, Ishtiaq; Ali, Ihsan [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Akhtar, Majid Niaz [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan); Khan, Muhammad Azhar [Department of Physics, Islamia University, Bahawalpur (Pakistan); Abbas, Ghazanfar [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan); Rana, M.U. [Center of Excellence in Solid State Physics, University of the Punjab, Lahore (Pakistan); Ali, Akbar [Department of Basic Sciences, Riphah International University, Islamabad-44000 (Pakistan); Ahmad, Mukhtar, E-mail: ahmadmr25@yahoo.com [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

2015-05-01

A series of single phase spinel ferrites having chemical formula Mg{sub 0.5}Zn{sub 0.5}Pr{sub x}Fe{sub 2−x}O{sub 4} (x=0.00, 0.05, 0.10, 0.15, 0.20, 0.25) were prepared using the sol–gel technique after sintering at 700 °C. The thermal decomposition behavior of an as prepared powder was investigated by means of DTA/TGA analyses. The sintered powders were then characterized by Fourier transform infrared spectroscope, X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscope and vibrating sample magnetometer. X-ray diffraction patterns confirm the single phase spinel structure of prepared ferrites without the presence of any impurity phase. The value of lattice parameter (a) increases with the increase of Pr contents (x) into the spinel lattice. The grain size estimated from electron microscope images is in the range of 2.75–5.4 µm which confirms the spinel crystalline nature of the investigated samples. The saturation magnetization (M{sub s}) decreases whereas coercivity (H{sub c}) increases with the increase of Pr contents (x). The measured parameters suggest that these materials are favorable for high frequency applications and as core materials. - Highlights: • Pr-substituted spinel ferrites synthesized by autocombustion route have been investigated. • The average grain size was in the range of 2.75–5.4 µm estimated by SEM technique. • The (M{sub s}) decreases whereas (H{sub c}) increases with the increase of Pr contents (x). • These parameters are favorable for high frequency applications and as core materials.

Prioritizing stream types according to their potential risk to receive crop plant material--A GIS-based procedure to assist in the risk assessment of genetically modified crops and systemic insecticide residues.

Science.gov (United States)

Bundschuh, Rebecca; Kuhn, Ulrike; Bundschuh, Mirco; Naegele, Caroline; Elsaesser, David; Schlechtriemen, Ulrich; Oehen, Bernadette; Hilbeck, Angelika; Otto, Mathias; Schulz, Ralf; Hofmann, Frieder

2016-03-15

Crop plant residues may enter aquatic ecosystems via wind deposition or surface runoff. In the case of genetically modified crops or crops treated with systemic pesticides, these materials may contain insecticidal Bt toxins or pesticides that potentially affect aquatic life. However, the particular exposure pattern of aquatic ecosystems (i.e., via plant material) is not properly reflected in current risk assessment schemes, which primarily focus on waterborne toxicity and not on plant material as the route of uptake. To assist in risk assessment, the present study proposes a prioritization procedure of stream types based on the freshwater network and crop-specific cultivation data using maize in Germany as a model system. To identify stream types with a high probability of receiving crop materials, we developed a formalized, criteria-based and thus transparent procedure that considers the exposure-related parameters, ecological status--an estimate of the diversity and potential vulnerability of local communities towards anthropogenic stress--and availability of uncontaminated reference sections. By applying the procedure to maize, ten stream types out of 38 are expected to be the most relevant if the ecological effects from plant-incorporated pesticides need to be evaluated. This information is an important first step to identifying habitats within these stream types with a high probability of receiving crop plant material at a more local scale, including accumulation areas. Moreover, the prioritization procedure developed in the present study may support the selection of aquatic species for ecotoxicological testing based on their probability of occurrence in stream types having a higher chance of exposure. Finally, this procedure can be adapted to any geographical region or crop of interest and is, therefore, a valuable tool for a site-specific risk assessment of crop plants carrying systemic pesticides or novel proteins, such as insecticidal Bt toxins, expressed

The seismic assessment of radially keyed graphite moderator cores

International Nuclear Information System (INIS)

Steer, A.G.; Payne, J.F.B.

1996-01-01

The modelling of AGR and Magnox cores has to deal with the very large number of components that make up the core, and the non-linear response due to the clearances in the keying system. This paper examines the conditions under which it is permissible to linearise the response. By comparing the results of discrete and continuum models of the core, the paper also shows that the number of components in the core is sufficiently large that the core can be approximated satisfactorily by an anisotropic solid material. The material has unusual properties, but these can be handled within the standard framework for the description of the elastic properties of an anisotropic solid. This description of the core by an equivalent solid material can readily be incorporated into finite element models of the reactor internal structure. Such models have been set up for both AGR and Magnox reactors. The models are being used to assess the seismic response of these reactors. (author). 5 refs, 6 figs

Effect of Core-Shell Ag@TiO2 Volume Ratio on Characteristics of TiO2-Based DSSCs

Directory of Open Access Journals (Sweden)

Ho Chang

2014-01-01

Full Text Available This paper aims to develop photoanode material required by dye-sensitized solar cells. The material prepared is in the form of Ag@TiO2 core-shell-type nanocomposites. This material is used to replace the titanium oxide powder commonly used in general DSSCs. The prepared Ag@TiO2 core-shell-type nanocomposites are mixed with Degussa P25 TiO2 in different proportions. Triton X-100 is added and polyethylene glycol (PEG at 20 wt% is used as a polymer additive. This study tests the particle size and material properties of Ag@TiO2 core-shell-type nanocomposites and measures the photoelectric conversion efficiency and IPCE of DSSCs. Experimental results show that the DSSC prepared by Ag@TiO2 core-shell-type nanocomposites can achieve a photoelectric conversion efficiency of 3.67%. When Ag@TiO2 core-shell-type nanocomposites are mixed with P25 nanoparticles in specific proportions, and when the thickness of the photoelectrode thin film is 28 μm, the photoelectric conversion efficiency can reach 6.06%, with a fill factor of 0.52, open-circuit voltage of 0.64V, and short-circuit density of 18.22 mAcm−2. Compared to the DSSC prepared by P25 TiO2 only, the photoelectric conversion efficiency can be raised by 38% under the proposed approach.

The effects of radiations on materials for core internals of PWRs: EDF-CEA-Framatome joint research programme

International Nuclear Information System (INIS)

Mathan, N. de; Buisine, D.; Goltrant, O.; Dubuisson, P.; Scott, P.; Deydier, D.; Trenty, A.

1998-01-01

The effects of neutron irradiation on materials for the core internals of PWRs (austenitic stainless steels) are potentially a significant economic and regulatory concern for EDF. The maintenance strategy for EDF relies primarily on in-service inspection, safety analysis and characterization of materials irradiated in-service. In addition, to anticipate likely future behaviour of highly irradiated materials, EDF has initiated, in collaboration with CEA and Framatome, a large R and D programme designed to (i) evaluate the effects of neutron irradiation on mechanical properties and stress corrosion cracking sensitivity (IASCC), and (ii) identify possible replacement materials. The programme, currently in progress, involves mechanical tests (tensile, fracture toughness, irradiation creep), stress corrosion cracking tests (in flux and out of flux) and metallurgical examinations. The test materials are being irradiated in several experimental reactors in France and Russia up to PWR-related end of life doses (∼ 80 dpa) at several PWR-relevant irradiation temperatures (300-400 deg. C). The presentation will describe the objectives and early results of this ongoing R and D programme. (author)

IGCSE core mathematics

CERN Document Server

Wall, Terry

2013-01-01

Give your core level students the support and framework they require to get their best grades with this book dedicated to the core level content of the revised syllabus and written specifically to ensure a more appropriate pace. This title has been written for Core content of the revised Cambridge IGCSE Mathematics (0580) syllabus for first teaching from 2013. ? Gives students the practice they require to deepen their understanding through plenty of practice questions. ? Consolidates learning with unique digital resources on the CD, included free with every book. We are working with Cambridge

Coated ceramic breeder materials

Science.gov (United States)

Tam, Shiu-Wing; Johnson, Carl E.

1987-01-01

A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

Analysis of an out-of-pile experiment for materials redistribution under core disruptive accident condition of fast breeder reactors

International Nuclear Information System (INIS)

Sawada, Tetsuo; Ninokata, Hisashi; Shimizu, Akinao

1995-01-01

Calculation of one of the SIMBATH experiments was performed using the SIMMER-II code. The experiments were intended to simulate the fuel pin disintegration, the molten materials relocation and following materials redistribution that could occur during core disruptive accidents assumed in fast breeder reactors. The calculation by SIMMER-II showed that the incorporated step-wise fuel pin disintegration model and the modified particle jamming model were capable of reproducing the course of materials relocation within the identified ranges of the parameters which governed the blockages formation, i.e. the characteristic radius of solid particles jamming and/or sieving out in the flow and the effective particle viscosity. In particular the final materials redistribution calculated by SIMMER-II very well reproduced the experiment. This fact made it possible to interpret theoretically the mechanisms of flow blockages formation and related materials redistribution. (author)

Development of a certified reference material for specific surface area of quartz sand

Directory of Open Access Journals (Sweden)

Egor P Sobina

2017-01-01

Full Text Available The paper presents results of conducting research on the development of a certified reference material (CRM for specific surface area of quartz sand, which is practically non-porous and therefore has low specific surface area value ~ 0.8 m2/g. The standard uncertainty due to RM inhomogeneity, the standard uncertainty due to RM instability, as well as the standard uncertainty due to characterization were estimated using the State Primary Standard GET 210‑2014 for Units of Specific Absorption of Gases, Specific Surface Area, Specific Volume, and Pore Size of Solid Substances and Materials. The metrological characteristics of the CRM were determined using a low-temperature gas adsorption method. Krypton was used as an adsorbate to increase measurement accuracy.

A method to determine site-specific, anisotropic fracture toughness in biological materials

International Nuclear Information System (INIS)

Bechtle, Sabine; Özcoban, Hüseyin; Yilmaz, Ezgi D.; Fett, Theo; Rizzi, Gabriele; Lilleodden, Erica T.; Huber, Norbert; Schreyer, Andreas; Swain, Michael V.; Schneider, Gerold A.

2012-01-01

Many biological materials are hierarchically structured, with highly anisotropic structures and properties on several length scales. To characterize the mechanical properties of such materials, detailed testing methods are required that allow precise and site-specific measurements on several length scales. We propose a fracture toughness measurement technique based on notched focused ion beam prepared cantilevers of lower and medium micron size scales. Using this approach, site-specific fracture toughness values in dental enamel were determined. The usefulness and challenges of the method are discussed.

221-U Facility concrete and reinforcing steel evaluations specification for the canyon disposition initiative (CDI)

International Nuclear Information System (INIS)

Baxter, J.T.

1998-01-01

This describes a test program to establish the in-situ material properties of the reinforced concrete in Building 221-U for comparison to the original design specifications. Field sampling and laboratory testing of concrete and reinforcing steel structural materials in Building 221-U for design verification will be undertaken. Forty seven samples are to be taken from radiologically clean exterior walls of the canyon. Laboratory testing program includes unconfined compressive strength of concrete cores, tensile strength of reinforcing steel, and petrographic examinations of concrete cores taken from walls below existing grade

The CERN antiproton target: hydrocode analysis of its core material dynamic response under proton beam impact

CERN Document Server

Martin, Claudio Torregrosa; Calviani, Marco; Muñoz-Cobo, José-Luis

2016-01-01

Antiprotons are produced at CERN by colliding a 26 GeV/c proton beam with a fixed target made of a 3 mm diameter, 55 mm length iridium core. The inherent characteristics of antiproton production involve extremely high energy depositions inside the target when impacted by each primary proton beam, making it one of the most dynamically demanding among high energy solid targets in the world, with a rise temperature above 2000 {\\deg}C after each pulse impact and successive dynamic pressure waves of the order of GPa's. An optimized redesign of the current target is foreseen for the next 20 years of operation. As a first step in the design procedure, this numerical study delves into the fundamental phenomena present in the target material core under proton pulse impact and subsequent pressure wave propagation by the use of hydrocodes. Three major phenomena have been identified, (i) the dominance of a high frequency radial wave which produces destructive compressive-to-tensile pressure response (ii) The existence of...

Material Removal and Specific Energy in the Dynamic Scratching of Gamma Titanium Aluminides

Energy Technology Data Exchange (ETDEWEB)

Wang, Hong [ORNL; Lin, Hua-Tay [ORNL; Wereszczak, Andrew A [ORNL

2006-11-01

Mechanical responses of three gamma titanium aluminides (TiAls) (denoted as Alloy A, Alloy B and Alloy C) subjected to dynamic scratching were studied by using a single-grit pendulum (rotating) scratch tester. The maximum depth of groove was ~ 0.07 mm, and the scratch velocity used was ~ 1.0 m/s. Normal and tangential forces were monitored. The material removal mechanisms were examined using a scanning electron microscope (SEM) and the scratches were measured by using a laser profilometer. The mechanical properties of the tested TiAls were characterized by the instantaneous specific energy, scratch resistance and scratch hardness as related to the depth of groove. Extensive thermal softening was observed in the dynamic scratch of the tested TiAls, which facilitated both the detachments of developing chips and the pile-ups of materials on side ridges. Sizable fractures were observed in the transverse direction on the tested TiAls; these fractures tended to participate in the chip formation, depending on the microstructure of the TiAl and the size of the scratch groove. Specific energy and scratch hardness are depth-dependent to various degrees for the tested TiAls. The materiel removal might be subjected to different mechanisms, but the overall response of materials can be effectively characterized by the HEM (Hwang, Evans and Malkin) model and the PSR (proportional specimen resistance) model. The obtained depth-independent specific energy and scratch hardness can be used to screen the candidate materials for the specific purpose depending on whether the application is scratch-dominant or impact-dominant. Among the three tested TiAls, the TiAl with larger colony or grain size exhibits a stronger capability of energy dissipation in the material loss or material removal (higher depth-independent specific energy), while the TiAl with smaller colony size show a higher resistance against the indentation (higher depth-independent scratch hardness). The observations and

Stress relaxation and creep of high-temperature gas-cooled reactor core support ceramic materials: a literature search

International Nuclear Information System (INIS)

Selle, J.E.; Tennery, V.J.

1980-05-01

Creep and stress relaxation in structural ceramics are important properties to the high-temperature design and safety analysis of the core support structure of the HTGR. The ability of the support structure to function for the lifetime of the reactor is directly related to the allowable creep strain and the ability of the structure to withstand thermal transients. The thermal-mechanical response of the core support pads to steady-state stresses and potential thermal transients depends on variables, including the ability of the ceramics to undergo some stress relaxation in relatively short times. Creep and stress relaxation phenomena in structural ceramics of interest were examined. Of the materials considered (fused silica, alumina, silicon nitride, and silicon carbide), alumina has been more extensively investigated in creep. Activation energies reported varied between 482 and 837 kJ/mole, and consequently, variations in the assigned mechanisms were noted. Nabarro-Herring creep is considered as the primary creep mechanism and no definite grain size dependence has been identified. Results for silicon nitride are in better agreement with reported activation energies. No creep data were found for fused silica or silicon carbide and no stress relaxation data were found for any of the candidate materials. While creep and stress relaxation are similar and it is theoretically possible to derive the value of one property when the other is known, no explicit demonstrated relationship exists between the two. For a given structural ceramic material, both properties must be experimentally determined to obtain the information necessary for use in high-temperature design and safety analyses

Waste management issues and their potential impact on technical specifications of CANDU fuel materials

International Nuclear Information System (INIS)

Tait, J.C.; Johnson, L.H.

1997-01-01

The technical specifications for the composition of nuclear fuels and materials used in Canada's CANDU reactors have been developed by AECL and materials manufacturers, taking into account considerations specific to their manufacture and the effect of minor impurities on fuel behaviour in reactor. Nitrogen and chlorine are examples of UO 2 impurities, however, where there is no technical specification limit. These impurities are present in the source materials or introduced in the fabrication process and are neutron activated to 14 C and 36 C1, which after 129 I , are the two most significant contributors to dose in safety assessments for the disposal of used fuel. For certain impurities, environmental factors, particularly the safety of the disposal of used fuels, should be taken into consideration when deriving 'allowable' impurity limits for nuclear fuel materials. (author)

Diagnostic accuracy of 22/25-gauge core needle in endoscopic ultrasound-guided sampling: systematic review and meta-analysis.

Science.gov (United States)

Oh, Hyoung-Chul; Kang, Hyun; Lee, Jae Young; Choi, Geun Joo; Choi, Jung Sik

2016-11-01

To compare the diagnostic accuracy of endoscopic ultrasound-guided core needle aspiration with that of standard fine-needle aspiration by systematic review and meta-analysis. Studies using 22/25-gauge core needles, irrespective of comparison with standard fine needles, were comprehensively reviewed. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic curves for the diagnosis of malignancy were used to estimate the overall diagnostic efficiency. The pooled sensitivity, specificity, and DOR of the core needle for the diagnosis of malignancy were 0.88 (95% confidence interval [CI], 0.84 to 0.90), 0.99 (95% CI, 0.96 to 1), and 167.37 (95% CI, 65.77 to 425.91), respectively. The pooled sensitivity, specificity, and DOR of the standard needle were 0.84 (95% CI, 0.79 to 0.88), 1 (95% CI, 0.97 to 1), and 130.14 (95% CI, 34.00 to 495.35), respectively. The area under the curve of core and standard needle in the diagnosis of malignancy was 0.974 and 0.955, respectively. The core and standard needle were comparable in terms of pancreatic malignancy diagnosis. There was no significant difference in procurement of optimal histologic cores between core and standard needles (risk ratio [RR], 0.545; 95% CI, 0.187 to 1.589). The number of needle passes for diagnosis was significantly lower with the core needle (standardized mean difference, -0.72; 95% CI, -1.02 to -0.41). There were no significant differences in overall complications (RR, 1.26; 95% CI, 0.34 to 4.62) and technical failure (RR, 5.07; 95% CI, 0.68 to 37.64). Core and standard needles were comparable in terms of diagnostic accuracy, technical performance, and safety profile.

Method of fabricating a monolithic core for a solid oxide fuel cell

International Nuclear Information System (INIS)

Zwick, S.A.; Ackerman, J.P.

1985-01-01

A method is disclosed for forming a core for use in a solid oxide fuel cell that electrochemically combines fuel and oxidant for generating galvanic output. The core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support consisting instead only of the active anode, cathode, electrolyte and interconnect materials. Each electrolyte wall consists of cathode and anode materials sandwiching electrolyte material therebetween, and each interconnect wall consists of the cathode and anode materials sandwiching interconnect material therebetween. The electrolyte and interconnect walls define a plurality of substantially parallel core passageways alternately having respectively the inside faces thereof with only the anode material or with only the cathode material exposed. In the wall structure, the electrolyte and interconnect materials are only 0.002-0.01 cm thick; and the cathode and anode materials are only 0.002-0.05 cm thick. The method consists of building up the electrolyte and interconnect walls by depositing each material on individually and endwise of the wall itself, where each material deposit is sequentially applied for one cycle; and where the depositing cycle is repeated many times until the material buildup is sufficient to formulate the core. The core is heat cured to become dimensionally and structurally stable

Attosecond Electron Processes in Materials: Excitons, Plasmons, and Charge Dynamics

Science.gov (United States)

2015-05-19

focused using a f=1.5 m lens into a 250 micron hollow core fiber (HCF) filled with neon gas at atmospheric pressure to stretch the pulse spectrum from... insulator to metal transition. Introduction: The goal of this work was to understand the generation, transport, and manipulation of electronic charge...chemically sensitive probe pulse utilizing specific core level transitions in atoms that are part of a material under study. The measurements follow

Collapsing stellar cores and supernovae

Energy Technology Data Exchange (ETDEWEB)

Epstein, R J [Nordisk Inst. for Teoretisk Atomfysik, Copenhagen (Denmark); Noorgaard, H [Nordisk Inst. for Teoretisk Atomfysik, Copenhagen (Denmark); Chicago Univ., IL (USA). Enrico Fermi Inst.); Bond, J R [Niels Bohr Institutet, Copenhagen (Denmark); California Inst. of Tech., Pasadena (USA). W.K. Kellogg Radiation Lab.)

1979-05-01

The evolution of a stellar core is studied during its final quasi-hydrostatic contraction. The core structure and the (poorly known) properties of neutron rich matter are parametrized to include most plausible cases. It is found that the density-temperature trajectory of the material in the central part of the core (the core-center) is insensitive to nearly all reasonable parameter variations. The central density at the onset of the dynamic phase of the collapse (when the core-center begins to fall away from the rest of the star) and the fraction of the emitted neutrinos which are trapped in the collapsing core-center depend quite sensitively on the properties of neutron rich matter. We estimate that the amount of energy Ecm which is imparted to the core-mantle by the neutrinos which escape from the imploded core-center can span a large range of values. For plausible choices of nuclear and model parameters Ecm can be large enough to yield a supernova event.

Materials Science and X-ray Techniques

International Nuclear Information System (INIS)

Brock, J.; Sutton, M.

2008-01-01

Many novel synchrotron-based X-ray techniques directly address the core questions of modern materials science but are not yet at the stage of being easy to use because of the lack of dedicated beamlines optimized for specific measurements. In this article, we highlight a few of these X-ray techniques and discuss why, with ongoing upgrades of existing synchrotrons and with new linear-accelerator-based sources under development, now is the time to ensure that these techniques are readily available to the larger materials research community.

Design and fabrication of self-powered in-core neutron flux monitor assembly

International Nuclear Information System (INIS)

Chung, M.K.; Cho, S.W.; Kang, H.D.; Cho, K.K.; Cho, B.S.; Kang, S.S.

1980-01-01

This is the final report on the prototypical fabrication of an in-core neutron flux monitor detector assembly for a specific power reactor conducted by KAERI from July 1, 1978 to December 31, 1979. It is well known that power reactors require a large number of in-core neutron flux detector for reactor regulation and the structures of detector assemblies are different from reactor to reactor. Therefore, from the nature of this project, it should be noted here that the target model of the prototypical farbrication of an in-core neutron flux monitor detector assembly is a VFD-2 System for Wolsung CANDU. It is concluded that fabrication of in-core neutron flux monitor detector assembly for CANDU reactor is technically feasible and will bring economical benefit as much as 50 % of the unit price if they are fabricated in Korea by using partially materials which are available from local market. (author)

TMI-2 reactor-vessel head removal and damaged-core-removal planning

International Nuclear Information System (INIS)

Logan, J.A.; Hultman, C.W.; Lewis, T.J.

1982-01-01

A major milestone in the cleanup and recovery effort at TMI-2 will be the removal of the reactor vessel closure head, planum, and damaged core fuel material. The data collected during these operations will provide the nuclear power industry with valuable information on the effects of high-temperature-dissociated coolant on fuel cladding, fuel materials, fuel support structural materials, neutron absorber material, and other materials used in reactor structural support components and drive mechanisms. In addition, examination of these materials will also be used to determine accident time-temperature histories in various regions of the core. Procedures for removing the reactor vessel head and reactor core are presented

A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration.

Science.gov (United States)

Almaroof, A; Rojo, L; Mannocci, F; Deb, S

2016-02-01

To formulate and evaluate new dual cured resin composite based on the inclusion of eugenyl methacrylate monomer (EgMA) with Bis-GMA/TEGDMA resin systems for intracanal post cementation and core build-up restoration of endodontically treated teeth. EgMA was synthesized and incorporated at 5% (BTEg5) or 10% (BTEg10) into dual-cure formulations. Curing properties, viscosity, Tg, radiopacity, static and dynamic mechanical properties of the composites were determined and compared with Clearfil™DC Core-Plus, a commercial dual-cure, two-component composite. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The experimental composites were successfully prepared, which exhibited excellent curing depths of 4.9, 4.7 and 4.2 mm for BTEg0, BTEg5 and BTEg10 respectively, which were significantly higher than Clearfil™DC. However, the inclusion of EgMA initially led to a lower degree of cure, which increased when measured at 24 h with values comparable to formulations without EgMA, indicating post-curing. The inclusion of EgMA also lowered the polymerization exotherm thereby reducing the potential of thermal damage to host tissue. Both thermal and viscoelastic analyses confirmed the ability of the monomer to reduce the stiffness of the composites by forming a branched network. The compressive strength of BTEg5 was significantly higher than the control whilst flexural strength increased significantly from 95.9 to 114.8 MPa (BTEg5) and 121.9 MPa (BTEg10). Radiopacity of the composites was equivalent to ∼3 mm Al allowing efficient diagnosis. The incorporation of EgMA within polymerizable formulations provides a novel approach to prepare reinforced resin composite material for intracanal post cementation and core build-up and the potential to impart antibacterial properties of eugenol to endodontic restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Heat and fission product transport in molten core material pool with crust

International Nuclear Information System (INIS)

Yun, J.I.; Suh, K.Y.; Kang, C.S.

2005-01-01

Heat transfer and fluid flow in a molten pool are influenced by internal volumetric heat generated from the radioactive decay of fission product species retained in the reactor vessel during a severe accident. The pool superheat is determined based on the overall energy balance that equates the heat production rate to the heat loss rate. Decay heat of fission products in the pool is estimated by product of the mass concentration and energy conversion factor of each fission product. Twenty-nine elements are chosen and classified by their chemical properties to calculate heat generation rate in the pool. The mass concentration of a fission product is obtained from released fraction and the tabular output of the ORIGEN 2 code. The initial core and pool inventories at each time can also be estimated using ORIGEN 2. The released fraction of each fission product is calculated based on the bubble dynamics and mass transport. Numerical analysis is performed for heat and fission product transport in a molten core material pool during the Three Mile Island Unit 2 (TMI-2) accident. The pool is assumed to be a partially filled hemisphere, whose change in geometry is neglected during the numerical calculation. Calculated results indicate that the peak temperature in the molten pool is significantly lowered, since a substantial amount of the volatile fission products is released from the molten pool during progression of the accident. The results may directly be applied to the existing severe accident analysis codes to more mechanistically determine the thermal load to the reactor vessel lower head during the in-vessel retention

Waste management issues and their potential impact on technical specifications of CANDU fuel materials

Energy Technology Data Exchange (ETDEWEB)

Tait, J.C.; Johnson, L.H. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

1997-07-01

The technical specifications for the composition of nuclear fuels and materials used in Canada's CANDU reactors have been developed by AECL and materials manufacturers, taking into account considerations specific to their manufacture and the effect of minor impurities on fuel behaviour in reactor. Nitrogen and chlorine are examples of UO{sub 2} impurities, however, where there is no technical specification limit. These impurities are present in the source materials or introduced in the fabrication process and are neutron activated to {sup 14}C and {sup 36}C1, which after {sup 129}I , are the two most significant contributors to dose in safety assessments for the disposal of used fuel. For certain impurities, environmental factors, particularly the safety of the disposal of used fuels, should be taken into consideration when deriving 'allowable' impurity limits for nuclear fuel materials. (author)

HEP specific benchmarks of virtual machines on multi-core CPU architectures

International Nuclear Information System (INIS)

Alef, M; Gable, I

2010-01-01

Virtualization technologies such as Xen can be used in order to satisfy the disparate and often incompatible system requirements of different user groups in shared-use computing facilities. This capability is particularly important for HEP applications, which often have restrictive requirements. The use of virtualization adds flexibility, however, it is essential that the virtualization technology place little overhead on the HEP application. We present an evaluation of the practicality of running HEP applications in multiple Virtual Machines (VMs) on a single multi-core Linux system. We use the benchmark suite used by the HEPiX CPU Benchmarking Working Group to give a quantitative evaluation relevant to the HEP community. Benchmarks are packaged inside VMs and then the VMs are booted onto a single multi-core system. Benchmarks are then simultaneously executed on each VM to simulate highly loaded VMs running HEP applications. These techniques are applied to a variety of multi-core CPU architectures and VM configurations.

Modelling the carbonation of cementitious matrixes by means of the unreacted-core model, UR-CORE

International Nuclear Information System (INIS)

Castellote, M.; Andrade, C.

2008-01-01

This paper presents a model for the carbonation of cementitious matrixes (UR-CORE). The model is based on the principles of the 'unreacted-core' systems, typical of chemical engineering processes, in which the reacted product remains in the solid as a layer of inert ash, adapted for the specific case of carbonation. Development of the model has been undertaken in three steps: 1) Establishment of the controlling step in the global carbonation rate, by using data of fractional conversion of different phases of the cementitious matrixes, obtained by the authors through neutron diffraction data experiments, and reported in [M. Castellote, C. Andrade, X. Turrillas, J. Campo, G. Cuello, Accelerated carbonation of cement pastes in situ monitored by neutron diffraction, Cem. Concr. Res. (2008), doi:10.1016/j.cemconres.2008.07.002]. 2) Then, the model has been adapted and applied to the cementitious materials using different concentrations of CO 2 , with the introduction of the needed assumptions and factors. 3) Finally, the model has been validated with laboratory data at different concentrations (taken from literature) and for long term natural exposure of concretes. As a result, the model seems to be reliable enough to be applied to cementitious materials, being able to extrapolate the results from accelerated tests in any conditions to predict the rate of carbonation in natural exposure, being restricted, at present stage, to conditions with a constant relative humidity

Humidity effects on soluble core mechanical and thermal properties (polyvinyl alcohol/microballoon composite) type CG extendospheres, volume 2

Science.gov (United States)

1993-01-01

This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties under Contract No. 100345. This report describes test results procedures employed, and any unusual occurrences or specific observations associated with this test program. The primary objective of this work was to determine if cured soluble core filler material regains its tensile and compressive strength after exposure to high humidity conditions and following a drying cycle. Secondary objectives include measurements of tensile and compressive modulus, and Poisson's ratio, and coefficient of thermal expansion (CTE) for various moisture exposure states. A third objective was to compare the mechanical and thermal properties of the composite using 'SG' and 'CG' type extendospheres. The proposed facility for the manufacture of soluble cores at the Yellow Creek site incorporates no capability for the control of humidity. Recent physical property tests performed with the soluble core filler material showed that prolonged exposure to high humidity significantly degradates in strength. The purpose of these tests is to determine if the product, process or facility designs require modification to avoid imparting a high risk condition to the ASRM.

Constructive and thermal design of a core fast discharge

International Nuclear Information System (INIS)

Schroer, H.

1979-08-01

The present study is concerned with the development and thermal design of a fast discharge system for balls for the PR 3000 MWsub(th) process heat reactor. The term 'fast discharge system for balls' denotes a very short-time discharge procedure of the entire core contents, i.e. the flowing out of the fuel elements due to gravity into a receiver tank underneath the prestressed-concrete vessel. From a safety-engineering point of view, the fast discharge system for balls constitutes an additional possibility of active decay heat removal, besides the multiply redundant and diversitary reactor protection system, serving to further reduce the remaining residual risk. A fast discharge system for balls, however, is to be used only in the event of all the other possibilities of active decay heat removal having failed and when the maximum permissible temperatures for particularly exposed primary circuit components have been reached. However, the application range of such a system is restricted exclusively to high-temperature reactors with spherical fuel elements; the procedure cannot be applied to other reactor systems because of the rigidly fixed position of the fuel elements inside the core and for reasons of fuel element geometry. Besides the purpose of application, the influence of in-core temperature development on the possible actuation of the fast discharge system is being described in particular detail. This is followed by a description of the structural and thermal design of three specific major components, i.e. the piping system, shut-off devices and fuel element receiver tank, which will have to be installed additionally for the implementation of a fast discharge system for balls as compared to previous plant concepts. (orig.) [de

Laser Heating of the Core-Shell Nanowires

Science.gov (United States)

Astefanoaei, Iordana; Dumitru, Ioan; Stancu, Alexandru

2016-12-01

The induced thermal stress in a heating process is an important parameter to be known and controlled in the magnetization process of core-shell nanowires. This paper analyses the stress produced by a laser heating source placed at one end of a core-shell type structure. The thermal field was computed with the non-Fourier heat transport equation using a finite element method (FEM) implemented in Comsol Multiphysics. The internal stresses are essentially due to thermal gradients and different expansion characteristics of core and shell materials. The stress values were computed using the thermo elastic formalism and are depending on the laser beam parameters (spot size, power etc.) and system characteristics (dimensions, thermal characteristics). Stresses in the GPa range were estimated and consequently we find that the magnetic state of the system can be influenced significantly. A shell material as the glass which is a good thermal insulator induces in the magnetic core, the smaller stresses and consequently the smaller magnetoelastic energy. These results lead to a better understanding of the switching process in the magnetic materials.

Core calculations of JMTR

Energy Technology Data Exchange (ETDEWEB)

Nagao, Yoshiharu [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

1998-03-01

In material testing reactors like the JMTR (Japan Material Testing Reactor) of 50 MW in Japan Atomic Energy Research Institute, the neutron flux and neutron energy spectra of irradiated samples show complex distributions. It is necessary to assess the neutron flux and neutron energy spectra of an irradiation field by carrying out the nuclear calculation of the core for every operation cycle. In order to advance core calculation, in the JMTR, the application of MCNP to the assessment of core reactivity and neutron flux and spectra has been investigated. In this study, in order to reduce the time for calculation and variance, the comparison of the results of the calculations by the use of K code and fixed source and the use of Weight Window were investigated. As to the calculation method, the modeling of the total JMTR core, the conditions for calculation and the adopted variance reduction technique are explained. The results of calculation are shown. Significant difference was not observed in the results of neutron flux calculations according to the difference of the modeling of fuel region in the calculations by K code and fixed source. The method of assessing the results of neutron flux calculation is described. (K.I.)

One-Pot Synthesis of Tunable Crystalline Ni3 S4 @Amorphous MoS2 Core/Shell Nanospheres for High-Performance Supercapacitors.

Science.gov (United States)

Zhang, Yu; Sun, Wenping; Rui, Xianhong; Li, Bing; Tan, Hui Teng; Guo, Guilue; Madhavi, Srinivasan; Zong, Yun; Yan, Qingyu

2015-08-12

Transition metal sulfides gain much attention as electrode materials for supercapacitors due to their rich redox chemistry and high electrical conductivity. Designing hierarchical nanostructures is an efficient approach to fully utilize merits of each component. In this work, amorphous MoS(2) is firstly demonstrated to show specific capacitance 1.6 times as that of the crystalline counterpart. Then, crystalline core@amorphous shell (Ni(3)S(4)@MoS(2)) is prepared by a facile one-pot process. The diameter of the core and the thickness of the shell can be independently tuned. Taking advantages of flexible protection of amorphous shell and high capacitance of the conductive core, Ni(3)S(4) @amorphous MoS(2) nanospheres are tested as supercapacitor electrodes, which exhibit high specific capacitance of 1440.9 F g(-1) at 2 A g(-1) and a good capacitance retention of 90.7% after 3000 cycles at 10 A g(-1). This design of crystalline core@amorphous shell architecture may open up new strategies for synthesizing promising electrode materials for supercapacitors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

AGR core safety assessment methodologies

International Nuclear Information System (INIS)

McLachlan, N.; Reed, J.; Metcalfe, M.P.