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Sample records for containment shell stresses

  1. Design, fabrication and testing of a prototype stressed-shell fuel isolation container

    International Nuclear Information System (INIS)

    Crosthwaite, J.L.; Barrie, J.N.; Nuttall, K.

    1982-07-01

    Atomic Energy of Canada Limited is conducting and coordinating research into the development of engineered barriers for the disposal of unreprocessed irradiated fuel within a deep, stable geologic vault. In one approach, a containment shell of corrosion-resistant metal is proposed as the principal barrier to radionuclide release, giving a high probability of containment for at least 300 years, thus ensuring isolation of nearly all fission products for their hazardous lives. The simplest concept is the 'stressed-shell' container, designed with sufficient shell thickness to withstand the hydrostatic pressure within a 1000-m deep disposal vault postulated to have flooded with groundwater. This report describes the design, fabrication, analysis and hydrostatic testing of a full-scale stressed-shell prototype. The report concludes that the deformation and collapse performance of stressed-shell designs, based on short-term mechanical properties be modelled adequately by BOSOR 5, a commercially available stress-strain computer program. If the stressed-shell concept is retained as a viable fuel isolation concept, future analyses should include an assessment of the role of material creep on long-term container performance

  2. PARCS - A pre-stressed and reinforced concrete shell element for analysis of containment structures

    International Nuclear Information System (INIS)

    Buragohain, D.N.; Mukherjee, A.

    1993-01-01

    Containment structures are designed as pressure vessels against a huge internal pressure build up in the event of a postulated LOCA. In such situations the containment structures experience predominantly in-plane stress in tension. Therefore, pre-stressed concrete has been very frequently used for the construction of containment. For larger plants a dual containment with a pre-stressed concrete inner containment and a reinforced concrete outer containment has been adopted. These structures are required to perform within very stringent safety requirements under extremely severe loading. Naturally, their design has attracted a lot of investigators and a huge volume of literature has been published in previous SMiRT conferences. However, it seems that the structural modeling of the containment has not developed accordingly. It is a common practice to consider the concrete section only in the model and the effects of pre-stress and reinforcements are usually neglected. This is due to the difficulty in including these effects without generating an unduly large model. To include these effects using the existing software, the concrete can be modeled with 3D elements. The reinforcements can be included in the model as bar or cable elements. However, that would require a nodal line along every reinforcement. Therefore, this method would generate a huge model unmanageable even with modern computing facilities. Alternatively, the reinforcements can be assumed to be smeared uniformly within the structure and an average property can be included. This model is acceptable when the reinforcements are very closely spaced. However, for sparsely spaced reinforcements it would result in loss of accuracy, especially in important areas like the vicinity of large openings. In this paper a shell element for the analysis of pre-stressed and reinforced concrete structures has been proposed which alleviates this difficulty. This element can accommodate the reinforcing bars or cables anywhere

  3. Effect of reinforcement element folds on stresses in NPP containment shell in the zone of technological tunnels

    International Nuclear Information System (INIS)

    Ul'yanov, A.N.; Medvedev, V.N.; Kiselev, A.S.

    1993-01-01

    Basing on the results of experimental and calculational studies of stressed state in the zone of a technological tunnel with one-side thicker part the approximated problem solution taking into account the effect of reinforcement element folds on opening zone stressed state is obtained. The great effect of reinforcement ropes on shell stressed state in the zone of technological tunnels, which causes the necessity of its accounting during this zone design, is revealed. Special attention shoul be paid to the sections, where the stretching stresses arising as a result of bundle bending are not compensated (sections of bundle fold origin from normal trajectory)

  4. Double containment shell for nuclear power plants

    International Nuclear Information System (INIS)

    Sykora, D.

    1977-01-01

    A double containment shell is proposed for nuclear power plants, especially those equipped with pressurized water reactors. The shell offers increased environmental protection from primary circuit accidents. The inner shell is built of steel or concrete while the outer shell is always built of concrete. The space between the two shells is filled with water and is provided with several manholes and with stiffeners designed for compensation for load due to the water hydrostatic pressure. Water serves the airtight separation of the containment shell inside from the environment and the absorption of heat released in a primary circuit accident. In case the inner shell is made of concrete, it is provided with heat-removal tubes in-built in its walls ensuring rapid heat transfer from the inside of the containment to the water in the interwall space. (Z.M.)

  5. Analysis of anisotropic shells containing flowing fluid

    International Nuclear Information System (INIS)

    Lakis, A.A.

    1983-01-01

    A general theory for the dynamic analysis of anisotropic thin cylindrical shells containing flowing fluid is presented. The shell may be uniform or non-uniform, provided it is geometrically axially symmetric. This is a finite- element theory, using cylindrical finite elements, but the displacement functions are determined by using classical shell theory. A new solution of the wave equation of the liquid finite element leads to an expression of the fluid pressure, p, as a function of the nodal displacements of the element and three operative forces (inertia, centrifugal and Coriolis) of the moving fluid. (Author) [pt

  6. Bending stresses in Facetted Glass Shells

    DEFF Research Database (Denmark)

    Bagger, Anne; Jönsson, Jeppe; Almegaard, Henrik

    2008-01-01

    A shell structure of glass combines a highly effective structural principle with a material of optimal permeability to light. A facetted shell structure has a piecewise plane geometry, and together the facets form an approximation to a curved surface. A distributed load on a plane-based facetted...... structure will locally cause bending moments in the loaded facets. The bending stresses are dependent on the stiffness of the joints. Approximate solutions are developed to estimate the magnitude of the bending stresses. A FE-model of a facetted glass shell structure is used to validate the expressions...

  7. Residual Stresses In 3013 Containers

    International Nuclear Information System (INIS)

    Mickalonis, J.; Dunn, K.

    2009-01-01

    The DOE Complex is packaging plutonium-bearing materials for storage and eventual disposition or disposal. The materials are handled according to the DOE-STD-3013 which outlines general requirements for stabilization, packaging and long-term storage. The storage vessels for the plutonium-bearing materials are termed 3013 containers. Stress corrosion cracking has been identified as a potential container degradation mode and this work determined that the residual stresses in the containers are sufficient to support such cracking. Sections of the 3013 outer, inner, and convenience containers, in both the as-fabricated condition and the closure welded condition, were evaluated per ASTM standard G-36. The standard requires exposure to a boiling magnesium chloride solution, which is an aggressive testing solution. Tests in a less aggressive 40% calcium chloride solution were also conducted. These tests were used to reveal the relative stress corrosion cracking susceptibility of the as fabricated 3013 containers. Significant cracking was observed in all containers in areas near welds and transitions in the container diameter. Stress corrosion cracks developed in both the lid and the body of gas tungsten arc welded and laser closure welded containers. The development of stress corrosion cracks in the as-fabricated and in the closure welded container samples demonstrates that the residual stresses in the 3013 containers are sufficient to support stress corrosion cracking if the environmental conditions inside the containers do not preclude the cracking process.

  8. Ventilation of gloveboxes and containment shells

    International Nuclear Information System (INIS)

    Guetron, R.

    1984-01-01

    In this paper are defined fundamental principles for the ventilation of containment enclosures and gloveboxes, and examined criteria required to maintain containment in normal or accidental conditions. Dimensioning of ventilation network and associated equipment (adjustement and filtering devices). Some examples are given [fr

  9. Darlington GS vacuum building - containment shell

    International Nuclear Information System (INIS)

    Huterer, J.; Ha, E.C.; Brown, D.G.; Cheng, P.C.

    1985-01-01

    The paper describes the consequences of new design requirements for the Darlington vacuum building on its structural configuration, analytical and reinforcing steel layout. Attention focuses on the ring girder where the juncture of dome and perimeter wall produces a complex post-tensioning layout, and attendant difficulties in design and construction. At the wall base, full fixity imposes large local stresses. Long-term, shrinkage and creep, and temperature effects become significant. A research program and in-house analytical procedure established time-dependent concrete behaviour and corresponding wall-sectional stresses. The outcome is examined in terms of reinforcement, temperature controls, and wall liner requirements. (orig.)

  10. Shell finite element of reinforced concrete for internal pressure analysis of nuclear containment building

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hong Pyo, E-mail: hplee@kepri.re.k [Nuclear Power Laboratory, Korea Electric Power Research Institute, 103-16 Munji-Dong, Yuseong-Gu, Daejeon 305-380 (Korea, Republic of)

    2011-02-15

    Research highlights: Finite element program with 9-node degenerated shell element was developed. The developed program was mainly forced to analyze nuclear containment building. Concrete material model is adapted Niwa and Yamada failure criteria. The performance of program developed is verified through various numerical examples. The numerical analysis results similar to the experimental data. - Abstract: This paper describes a 9-node degenerated shell finite element (FE), an analysis program developed for ultimate pressure capacity evaluation and nonlinear analysis of a nuclear containment building. The shell FE developed adopts the Reissner-Mindlin (RM) assumptions to consider the degenerated shell solidification technique and the degree of transverse shear strain occurring in the structure. The material model of the concrete determines the level of the concrete stress and strain by using the equivalent stress-equivalent strain relationship. When a crack occurs in the concrete, the material behavior is expressed through the tension stiffening model that takes adhesive stress into account and through the shear transfer mechanism and compressive strength reduction model of the crack plane. In addition, the failure envelope proposed by Niwa is adopted as the crack occurrence criteria for the compression-tension region, and the failure envelope proposed by Yamada is used for the tension-tension region. The performance of the program developed is verified through various numerical examples. The analysis based on the application of the shell FE developed from the results of verified examples produced results similar to the experiment or other analysis results.

  11. Shell finite element of reinforced concrete for internal pressure analysis of nuclear containment building

    International Nuclear Information System (INIS)

    Lee, Hong Pyo

    2011-01-01

    Research highlights: → Finite element program with 9-node degenerated shell element was developed. → The developed program was mainly forced to analyze nuclear containment building. → Concrete material model is adapted Niwa and Yamada failure criteria. → The performance of program developed is verified through various numerical examples. → The numerical analysis results similar to the experimental data. - Abstract: This paper describes a 9-node degenerated shell finite element (FE), an analysis program developed for ultimate pressure capacity evaluation and nonlinear analysis of a nuclear containment building. The shell FE developed adopts the Reissner-Mindlin (RM) assumptions to consider the degenerated shell solidification technique and the degree of transverse shear strain occurring in the structure. The material model of the concrete determines the level of the concrete stress and strain by using the equivalent stress-equivalent strain relationship. When a crack occurs in the concrete, the material behavior is expressed through the tension stiffening model that takes adhesive stress into account and through the shear transfer mechanism and compressive strength reduction model of the crack plane. In addition, the failure envelope proposed by Niwa is adopted as the crack occurrence criteria for the compression-tension region, and the failure envelope proposed by Yamada is used for the tension-tension region. The performance of the program developed is verified through various numerical examples. The analysis based on the application of the shell FE developed from the results of verified examples produced results similar to the experiment or other analysis results.

  12. Design and analysis of reactor containment of steel-concrete composite laminated shell

    International Nuclear Information System (INIS)

    Ichikawa, K.; Isobata, O.; Kawamata, S.

    1977-01-01

    A new scheme of containment consisting of steel-concrete laminated shell is being developed. In the main part of a cylindrical vessel, the shell consists of two layers of thin steel plates located at the inner and outer surfaces, and a layer of concrete core into which both the steel plates are anchored. Because of the compressive and shearing resistance of the concrete core, the layers behave as a composite solid shell. Membrane forces are shared by steel plates and partly by concrete core. Bending moment is effectively resisted by the section with extreme layers of steel. Therefore, both surfaces can be designed as extremely thin plates: the inner plate, which is a load carrying members as well as a liner, can be welded without the laborious process of stress-relieving, and various jointing methods can be applied to the outer plate which is free from the need for leak tightness. The capability of the composite layers of behaving as a unified solid shell section depends largely on the shearing rigidity of the concrete core. However, as its resisting capacity to transverse shearing force is comparatively low, a device for reducing the shearing stress at the junction to the base mat is needed. In the new scheme, this part of the cylindrical shell is divided into multiple layers of the same kind of composite shell. This device makes the stiffness of the bottom of the cylindrical shell to lateral movement minimum while maintaining the proper resistance to membrane forces. The analysis shows that the transverse shearing stress can be reduced to less than 1√n of the ordinary case by dividing the thickness of the shell into n layers which are able to slip against each other at the contact surface. In order to validate the feasibility and safety of this new design, the results of analysis on the basis of up-to-date design loads are presented

  13. Stress analysis of HLW containers. Compas project

    International Nuclear Information System (INIS)

    1989-01-01

    This document reports the work carried out for the Compas project which looked at the performance of various computer codes in a selected benchmark exercise. This exercise consisted of several analyses on simplified models which have features typical of HLW containers. These analyses comprise two groups; one related to thick walled, stressed shell overpacks, the other related to thin walled, supported shell overpacks with a lead filler. The first set of analyses looked at an elastic-plastic behaviour and large deformation of a cylinder representative of the main body of thick walled containers). The second set looked at creep behaviour of the lead filler, and the shape the base of thin walled containers will take up, after hundreds of years in the repository. On the thick walled analyses with the cylinder subject to an external pressure all the codes gave consistent results in the elastic region and there is good agreement in the yield pressures. Once in the plastic region there is more divergence in the results although a consistent trend is predicted. One of the analyses predicted a non-axisymmetric mode of deformation as would be expected in reality. Fewer results were received for the creep analysis, however the transient creep results showed consistency, and were bounded by the final-state results

  14. Advanced stress analysis of PWR containments in the region of nozzles

    International Nuclear Information System (INIS)

    Schauer, G.

    1977-01-01

    As an example of the stress analysis of a nozzle in a PWR steel containment, an advanced stress analysis of a personnel lock is presented. Contrary to the calculations by means of numerical shell programs usual till now, this advanced stress analysis was executed with the finite-element-method. Because of their theory, the shell programs compute mathematically exact results, but at the intersection of two shells the notch stresses cannot be analyzed well. A further disadvantage must be seen in the fact that there is a great distance between the real critical region near the intersection line and the calculation point, which lies on the neutral axis of the shell

  15. Containment shells of reactor compartments at foreign NPPs

    International Nuclear Information System (INIS)

    Demidov, A.P.; Savchenko, V.A.

    1989-01-01

    The modern designes of containment shells (CS) of NPP reactor compartments is described. Much attention is paid to the PCS-3 project envisaging CS inclusion in the complex of NPP passive safety system. The PCS-3 system is developed in the USA for NPP with the improved PWR type reactor. The above system permits to cool the core quickly, to reduce steam pressure in CS down to a safe level and to prevent the discharge of radioactive products in the atmosphere in the case of accidents, even very serious, caused by loss of coolant and core dryout

  16. Advanced stress analysis of PWR containments in the region of nozzles

    International Nuclear Information System (INIS)

    Schauer, G.

    1977-01-01

    As an example of the stress analysis of a nozzle in a PWR steel containment, an advanced stress analysis of a personnel lock is presented. Contrary to the calculations by means of numerical shell programs usual till now, this advanced stress analysis was executed with the finite-element-method. Because of their theory, the shell programs compute mathematically exact results, but at the intersection of two shells the notch stresses cannot be analyzed well. A further disadvantage must be seen in the fact that there is a great distance between the real critical region near the intersection line and the calculation point, which lies on the neutral axis of the shell. The study shows that the results obtained to date which are based on the shell theory and calculate stresses at a fictitious intersection line can be improved and that there is a possibility to get stress values adjacent to the real intersection line. (Auth.)

  17. Design and analysis of reactor containment of steel-concrete composite laminated shell

    International Nuclear Information System (INIS)

    Ichikawa, K.

    1977-01-01

    Reinforced and prestressed concrete containments for reactors have been developed in order to avoid the difficulties of welding of steel containments encountered as their capacities have become large: growing thickness of steel shells gave rise to the requirement of stress relief at the construction sites. However, these concrete vessels also seem to face another difficulty: the lack of shearing resistance capacity. In order to improve the shearing resistance capacity of the containment vessel, while avoiding the difficulty of welding, a new scheme of containment consisting of steel-concrete laminated shell is being developed. In the main part of a cylindrical vessel, the shell consists of two layers of thin steel plates located at the inner and outer surfaces, and a layer of concrete core into which both the steel plates are anchored. In order to validate the feasibility and safety of this new design, the results of analysis on the basis of up-to-date design loads are presented. The results of model tests in 1:30 scale are also reported. (Auth.)

  18. Investigation of stresses in facetted glass shell structures

    DEFF Research Database (Denmark)

    Bagger, Anne; Jönsson, Jeppe; Wester, Ture

    2007-01-01

    by in-plane forces in the facets and the transfer of distributed in-plane forces across the joints. It is described how these facets work structurally, specifically how bending moments develop and cause possible stress concentrations in the corners, which are subjected to uplift. Apart from local...... bending moments from distributed load, other types of bending moments are likely to occur, especially if the shell has areas of low stiffness, for example along a free edge. A facetted shell structure has been modelled in a finite element program, and the resulting stresses are presented and discussed....

  19. Attractive electromagnetic Casimir stress on a spherical dielectric shell

    International Nuclear Information System (INIS)

    Graham, N.; Quandt, M.; Weigel, H.

    2013-01-01

    Based on calculations involving an idealized boundary condition, it has long been assumed that the stress on a spherical conducting shell is repulsive. We use the more realistic case of a Drude dielectric to show that the stress is attractive, matching the generic behavior of Casimir forces in electromagnetism. We trace the discrepancy between these two cases to interactions between the electromagnetic quantum fluctuations and the dielectric material

  20. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    Energy Technology Data Exchange (ETDEWEB)

    SHEN, E.J.

    2000-10-05

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system.

  1. Restoration of Secondary Containment in Double Shell Tank (DST) Pits

    International Nuclear Information System (INIS)

    SHEN, E.J.

    2000-01-01

    Cracks found in many of the double-shell tank (DST) pump and valve pits bring into question the ability of the pits to provide secondary containment and remain in compliance with State and Federal regulations. This study was commissioned to identify viable options for maintain/restoring secondary containment capability in these pits. The basis for this study is the decision analysis process which identifies the requirements to be met and the desired goals (decision criteria) that each option will be weighed against. A facilitated workshop was convened with individuals knowledgeable of Tank Farms Operations, engineering practices, and safety/environmental requirements. The outcome of this workshop was the validation or identification of the critical requirements, definition of the current problem, identification and weighting of the desired goals, baselining of the current repair methods, and identification of potential alternate solutions. The workshop was followed up with further investigations into the potential solutions that were identified in the workshop and through other efforts. These solutions are identified in the body of this report. Each of the potential solutions were screened against the list of requirements and only those meeting the requirements were considered viable options. To expand the field of viable options, hybrid concepts that combine the strongest features of different individual approaches were also examined. Several were identified. The decision analysis process then ranked each of the viable options against the weighted decision criteria, which resulted in a recommended solution. The recommended approach is based upon installing a sprayed on coating system

  2. Residual Stress Testing of Outer 3013 Containers

    International Nuclear Information System (INIS)

    Dunn, K.

    2004-01-01

    A Gas Tungsten Arc Welded (GTAW) outer 3013 container and a laser welded outer 3013 container have been tested for residual stresses according to the American Society for Testing Materials (ASTM) Standard G-36-94 [1]. This ASTM standard describes a procedure for conducting stress-corrosion cracking tests in boiling magnesium chloride (MgCl2) solution. Container sections in both the as-fabricated condition as well as the closure welded condition were evaluated. Significantly large residual stresses were observed in the bottom half of the as-fabricated container, a result of the base to can fabrication weld because through wall cracks were observed perpendicular to the weld. This observation indicates that regardless of the closure weld technique, sufficient residual stresses exist in the as-fabricated container to provide the stress necessary for stress corrosion cracking of the container, at the base fabrication weld. Additionally, sufficiently high residual stresses were observed in both the lid and the body of the GTAW as well as the laser closure welded containers. The stresses are oriented perpendicular to the closure weld in both the container lid and the container body. Although the boiling MgCl2 test is not a quantitative test, a comparison of the test results from the closure welds shows that there are noticeably more through wall cracks in the laser closure welded container than in the GTAW closure welded container

  3. Stresses at the intersection of two cylindrical shells

    International Nuclear Information System (INIS)

    Xue, M.D.; Chen, W.; Hwang, K.C.

    1995-01-01

    The stress analysis based on the theory of a thin shell is carried out for two normally intersecting cylindrical shells with a large diameter ratio. Instead of the Donnell shallow shell equation, the modified Morley equation, which is applicable to ρ 0 (R/T) 1/2 XXXX1, is used for the analysis of the shell with cut-out. The solution in terms of displacement function for the nozzle with a non-planar end is based on the Love equation. The boundary forces and displacements at the intersection are all transformed from Gaussian coordinates (α,β) on the shell, or Gaussian coordinates (ζ,θ) on the nozzle into three-dimensional cylindrical coordinates (ρ,θ,z). Their expressions on the intersecting curve are periodic functions of θ and expanded in Fourier series. Every harmonics of Fourier coefficients of boundary forces and displacements are obtained by numerical quadrature.The results obtained are in agreement with those from the finite element method and experiments for d/D≤0.8. ((orig.))

  4. Dynamics of two coaxial cylindrical shells containing viscous fluid

    International Nuclear Information System (INIS)

    Yeh, T.T.; Chen, S.S.

    1976-09-01

    This study was motivated by the need to design the thermal shield in reactor internals and other system components to avoid detrimental flow-induced vibrations. The system component is modeled as two coaxial shells separated by a viscous fluid. In the analysis, Flugge's shell equations of motion and linearized Navier-Stokes equation for viscous fluid are employed. First, a traveling-wave type solution is taken for shells and fluid. Then, from the interface conditions between the shells and fluid, the solution for the fluid medium is expressed in terms of shell displacements. Finally, using the shell equations of motion gives the frequency equation, from which the natural frequency, mode shape, and modal damping ratio of coupled modes can be calculated. The analytical results show a fairly good qualitative agreement with the published experimental data. Some important conclusions are as follows: (1) In computing the natural frequencies and mode shapes of uncoupled modes and coupled modes, the fluid may be considered inviscid and incompressible. (2) There exists out-of-phase and in-phase modes. The lowest natural frequency is always associated with the out-of-phase mode. (3) The lowest natural frequency of coupled modes is lower than the uncoupled modes. (4) The fluid viscosity contributes significantly to damping, in particular, the modal damping of the out-of-phase modes isrelatively large for small gaps. (5) If the fluid gap is small, or the fluid viscosity is relatively high, the simulation of the vibration Reynolds number should be included to ensure that modal damping of the model is properly accounted for. With the presented analysis and results, the frequency and damping characteristics can be analyzed and design parameters can be related to frequency and damping

  5. Study of laminated anisotropic cylindrical shells sensitive to transverse stresses

    International Nuclear Information System (INIS)

    Massard, Thierry

    1979-01-01

    A variational method for the determination of stresses and displacements in a multilayered cylindrical shell is presented. All included materials are linearly anisotropic (monoclinic) - i.e. directional fibres reinforced materials. This study uses a functional which is derived from the potential energy of the structure. The incoming stresses are σ RR , σ Rθ , σ RZ , and the displacements are u θ and u Z . This mixed group is the main variables of the formulation. It is shown that the stationarity conditions of the functional are the equilibrium equations and the associated boundary conditions. An approximate solution can be found using a finite element method which realizes a tridimensional discretization of the structure. The program issued is a specific mean for studying the transverse shear stresses in laminated cylindrical structures. From the results obtained it can be concluded that it meets all requirements for the purposes of this range of problems. (author) [fr

  6. Residual stress concerns in containment analysis

    International Nuclear Information System (INIS)

    Costantini, F.; Kulak, R. F.; Pfeiffer, P. A.

    1997-01-01

    The manufacturing of steel containment vessels starts with the forming of flat plates into curved plates. A steel containment structure is made by welding individual plates together to form the sections that make up the complex shaped vessels. The metal forming and welding process leaves residual stresses in the vessel walls. Generally, the effect of metal forming residual stresses can be reduced or virtually eliminated by thermally stress relieving the vesseL In large containment vessels this may not be practical and thus the residual stresses due to manufacturing may become important. The residual stresses could possibly tiect the response of the vessel to internal pressurization. When the level of residual stresses is significant it will affect the vessel's response, for instance the yielding pressure and possibly the failure pressure. The paper will address the effect of metal forming residual stresses on the response of a generic pressure vessel to internal pressurization. A scoping analysis investigated the effect of residual forming stresses on the response of an internally pressurized vessel. A simple model was developed to gain understanding of the mechanics of the problem. Residual stresses due to the welding process were not considered in this investigation

  7. The stress distribution in shell bodies and wings as an equilibrium problem

    Science.gov (United States)

    Wagner, H

    1937-01-01

    This report treats the stress distribution in shell-shaped airplane components (fuselage, wings) as an equilibrium problem; it includes both cylindrical and non-cylindrical shells. In particular, it treats the stress distribution at the point of stress application and at cut-out points.

  8. Mechanical characteristics of fully mechanized top-coal caving face and surrounding rock stress shell

    Energy Technology Data Exchange (ETDEWEB)

    Xie Guang-xiang [Anhui University of Science and Technology, Huainan (China)

    2005-06-15

    The distribution of surrounding rock stress in fully mechanized top-coal caving (FMTC) face was fully researched by large-scale and non-linear three-dimensional numerical simulation and equivalent laboratory. The results show that, there is the structure that is made of macroscopical stress shell composed of high stress binds in overlying strata of FMTC face. Stress shell, which bears and pass load of overlying strata, is primary supporting body. The stress in skewback of stress shell forms abutment pressure of surrounding rock in vicinity of working face. Bond-beam structure lies in reducing zone under stress shell. It only bear partial burden of strata under stress shell. The uppermost mechanical characteristic of FMTC face is lying in the low stress area under stress shell. It is the essential cause of strata behaviors of FMTC face relaxation. On the basis of analyzing stress shell, the mechanical essence that top coal performs a function of bedding is demonstrated. 4 refs., 7 figs.

  9. Random thermal stress in concrete containments

    International Nuclear Information System (INIS)

    Singh, M.P.; Heller, R.A.

    1980-01-01

    Currently, the overly conservative thermal design forces are obtained on the basis of simplified assumptions made about the temperature gradient across the containment wall. Using the method presented in this paper, a more rational and better estimate of the design forces can be obtained. Herein, the outside temperature is considered to consist of a constant mean on which yearly and daily harmonic changes plus a randomly varying part are superimposed. The random part is modeled as a stationary random process. To obtain the stresses due to random and harmonic temperatures, the complex frequency response function approach has been used. Numerical results obtained for a typical containment show that the higher frequency temperature variations, though of large magnitude, induce relatively small forces in a containment. Therefore, in a containment design, a rational separation of more effective, slowly varying temperatures, such as seasonal cycle from less effective but more frequently occuring daily and hourly changes, is desirable to obtain rational design forces. 7 refs

  10. Material properties for reactor pressure vessels and containment shells under dynamic loading

    International Nuclear Information System (INIS)

    Albertini, C.

    1997-01-01

    The effects of high strain rate, dynamic biaxial loading and deformation mode (tension, shear) on the mechanical properties of AISI 316 austenitic stainless steel in as-received and pre-damaged (creep, LCF) conditions are reported. This research was conducted to assess the performances of the containment shell of fast breeder reactors. The results of this research have been utilized to prepare similar investigations for SA 537 Class 1 ferritic steel used for the containment shell of LWR. The first results of these investigations are reported. A programme to study the mechanical properties of plain concrete with real size aggregate at high strain rate is described. (orig.)

  11. Evaluation charts of thermal stresses in cylindrical vessels induced by thermal stratification of contained fluid

    International Nuclear Information System (INIS)

    Furuhashi, Ichiro; Kawasaki, Nobuchika; Kasahara, Naoto

    2008-01-01

    Temperature and thermal stress in cylindrical vessels were analysed for the thermal stratification of contained fluid. Two kinds of temperature analysis results were obtained such as the exact temperature solution of eigenfunction series and the simple approximate one by the temperature profile method. Furthermore, thermal stress shell solutions were obtained for the simple approximate temperatures. Through comparison with FEM analyses, these solutions were proved to be adequate. The simple temperature solution is described by one parameter that is the temperature decay coefficient. The thermal stress shell solutions are described by two parameters. One is the ratio between the temperature decay coefficient and the load decay coefficient. Another is the nondimensional width of stratification. These solutions are so described by few parameters that those are suitable for the simplified thermal stress evaluation charts. These charts enable quick and accurate thermal stress evaluations of cylindrical vessel of this problem compared with conventional methods. (author)

  12. Evaluation charts of thermal stresses in cylindrical vessels induced by thermal stratification of contained fluid

    International Nuclear Information System (INIS)

    Furuhashi, Ichiro; Kawasaki, Nobuchika; Kasahara, Naoto

    2007-01-01

    Temperature and thermal stress in cylindrical vessels were analysed for the thermal stratification of contained fluid. Two kinds of temperature analysis results were obtained such as the exact temperature solution of eigen-function series and the simple approximate one by the temperature profile method. Furthermore, shell solutions of thermal stress were obtained for the simple approximate temperatures. Through comparison with FEM analyses, these solutions were proved to be adequate. The simple temperature solution is described by one parameter that is the temperature decay factor. The shell solutions of thermal stress are described by two parameters. One is the ratio between the temperature decay factor and the local decay factor. Another is the non-dimensional width of stratification. These solution are so described by few parameters that those are suitable for the simplified thermal stress evaluation charts. These charts enable quick and accurate thermal stress evaluations of cylindrical vessel of this problem compared with conventional methods. (author)

  13. Temperature/Humidity Conditions in Stacked Flexible Intermediate Bulk Containers for Shelled Peanuts

    Science.gov (United States)

    Shelled peanuts are loaded into flexible intermediate bulk containers, or totes. After loading, the 1000-kg totes are placed directly into cold storage at 3ºC and 65% relative humidity until shipment to the customer domestically in the United States or internationally requiring transport overseas. ...

  14. Shell-model calculations with a basis that contains correlated pairs

    International Nuclear Information System (INIS)

    Boisson, J.P.; Silvestre-Brac, B.A.; Liotta, R.J.

    1979-01-01

    A method to solve the shell-model equations within a basis that contains correlated pairs of particles is presented. The method is illustrated for the three-identical-particle system. Applications in nuclei around 208 Pb are given and comparisons with both experimental data and other calculations are carried out. (Auth.)

  15. Cylindrical shell under impact load including transverse shear and normal stress

    International Nuclear Information System (INIS)

    Shakeri, M.; Eslami, M.R.; Ghassaa, M.; Ohadi, A.R.

    1993-01-01

    The general governing equations of shell of revolution under shock loads are reduced to equations describing the elastic behavior of cylindrical shell under axisymmetric impact load. The effect of lateral normal stress, transverse shear, and rotary inertia are included, and the equations are solved by Galerkin finite element method. The results are compared with the previous works of authors. (author)

  16. Investigations into stress shell characteristics of surrounding rock in fully mechanized top-coal caving face

    Energy Technology Data Exchange (ETDEWEB)

    Xie, G.X.; Chang, J.C.; Yang, K. [Anhui University of Science and Technology, Huainan (China)

    2009-01-15

    A key issue in underground mining is to understand and master the evolving patterns of stress induced by mining, and to control and utilize the action of rock pressure. Numerical and physical modeling tests have been carried out to investigate the distribution patterns of stress in the rock surrounding a fully mechanized top-coal caving (FMTC) face. The results showed that a macro-stress shell composed of high stress exists in the rock surrounding an FMTC face. The stress of the shell is higher than its internal and external stress and the stresses at its skewback producing abutment pressure for the surrounding rock. The stress shell lies in the virgin coal and rock mass in the vicinity of the face and its sagging zone. The stress shell, which bears and transfers the loads of overlying strata, acts as the primary supporting system of forces, and is the corpus of characterizing three-dimensional and macro-rock pressure distribution of mining face. Its external and internal shape changes with the variations in the working face structure as the face advances. Within the low-stress zone inside the stress shell, another structure, i.e. voussoir beam, which only bears parts of the load from the lower-lying strata, will produce periodic pressures on the face instead of great dynamic pressure even if the beam ruptures and loses stability. The results show that the FMTC face is situated within the lower-stress zone, which is protected by the stress shell of the overlying surrounding rock. We give an explanation of lower occurrence of rock pressure on FMTC faces, and reveal the mechanical nature of the top coal of an FMTC face acting as a 'cushion'. The strata behaviors of the face and its neighboring gates are under control of the stress shell. Drastic rock pressure in mine may occur when the balance of the stress shell is destruction or the forces system of the stress shell transfers. Crown Copyright

  17. LUGS, Stress Analysis, Flexibility Factors for Rectangular Attachment on Thin Shell

    International Nuclear Information System (INIS)

    Dodge, W.G.

    1977-01-01

    1 - Description of problem or function: LUGS calculates stresses, stress indices, and flexibility factors for a rectangular attachment on a cylindrical shell. 2 - Method of solution: The program implements Bijlaard's series solution to the thin-shell equations. 3 - Restrictions on the complexity of the problem: Caution is recommended in using the code for attachments on very thin shells that have large circumferential dimension and small longitudinal dimension (GAMMA.GE.80, BETA2.LE.0.05, and BETA1.GE.0.3) as series convergence and/or numeric problems seem to exist

  18. Elastic stresses at reinforced nozzles in spherical shells with pressure and moment loading

    International Nuclear Information System (INIS)

    Rodabaugh, E.C.; Gwaltney, R.D.

    1976-01-01

    Calculated elastic stresses at reinforced nozzles in spherical shells with pressure and moment loading are presented. The models used in the calculations represent a wide variety of reinforced shapes; all meeting Code requirements. The results show Code stress indices for pressure loading for nozzles with local reinforcement are acceptable with some modification in coverage. Simple equations for stress indices for moment loading are developed. Potential application of the moment-loading stress indices is discussed. Several recommendations for Code changes are included

  19. Structural-performance testing of titanium-shell lead-matrix container MM2

    Energy Technology Data Exchange (ETDEWEB)

    Hosaluk, L. J.; Barrie, J. N.

    1992-05-15

    This report describes the hydrostatic structural-performance testing of a half-scale, titanium-shell, lead-matrix container (MM2) with a large, simulated volumetric casting defect. Mechancial behaviour of the container is assessed from extensive surface-strain measurements and post-test non-destructive and destructive examinations. Measured strain data are compared briefly with analytical results from a finite-element model of a previous test prototype, MM1, and with data generated by a finite-difference computer code. Finally, procedures are recommended for more detailed analytical modelling. (auth)

  20. Properties of concrete containing coconut shell powder (CSP) as a filler

    Science.gov (United States)

    Leman, A. S.; Shahidan, S.; Nasir, A. J.; Senin, M. S.; Zuki, S. S. Mohd; Ibrahim, M. H. Wan; Deraman, R.; Khalid, F. S.; Azhar, A. T. S.

    2017-11-01

    Coconut shellsare a type of agricultural waste which can be converted into useful material. Therefore,this study was conducted to investigate the properties of concrete which uses coconut shell powder (CSP) filler material and to define the optimum percentage of CSP which can be used asfiller material in concrete. Comparisons have been made between normal concrete mixes andconcrete containing CSP. In this study, CSP was added into concrete mixes invaryingpercentages (0%, 2%, 4%, 6%, 8% and 10%). The coconut shell was grounded into afine powder before use. Experimental tests which have been conducted in this study include theslump test, compressive test and splitting tensile strength test. CSP have the potential to be used as a concrete filler and thus the findings of this study may be applied to the construction industry. The use of CSP as a filler in concrete can help make the earth a more sustainable and greener place to live in.

  1. Extensions to a nonlinear finite-element axisymmetric shell model based on Reissner's shell theory

    International Nuclear Information System (INIS)

    Cook, W.A.

    1981-01-01

    Extensions to shell analysis not usually associated with shell theory are described in this paper. These extensions involve thick shells, nonlinear materials, a linear normal stress approximation, and a changing shell thickness. A finite element shell-of-revolution model has been developed to analyze nuclear material shipping containers under severe impact conditions. To establish the limits for this shell model, the basic assumptions used in its development were studied; these are listed in this paper. Several extensions were evident from the study of these limits: a thick shell, a plastic hinge, and a linear normal stress

  2. Coaxial nanofibers containing TiO2 in the shell for water treatment applications

    Science.gov (United States)

    Kizildag, N.; Geltmeyer, J.; Ucar, N.; De Buysser, K.; De Clerck, K.

    2017-10-01

    In recent years, the basic electrospinning setup has undergone many modifications carried out to enhance the quality and improve the functionality of the resulting nanofibers. Being one of these modifications, coaxial electrospinning has attracted great attention. It enables to use different materials in nanofiber production and produce multi-layered and functional nanofibers in one step. In this study, TiO2 has been added to the shell layer of coaxial nanofibers to develop functional nanofibers which may be used in water treatment applications. The coaxial nanofibers containing TiO2 in the shell layer are compared to uniaxial nanofibers containing TiO2 in bulk fiber structure, regarding their morphology and photocatalytic activity. Uniform uniaxial and coaxial nanofibers with TiO2 were obtained. The average nanofiber diameter of coaxial nanofibers were higher. Coaxial nanofibers, which contained lower amount of TiO2, displayed similar performance to uniaxial nanofibers with TiO2 in terms of photocatalytic degradation ability against isoproturon.

  3. 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.

  4. Burial container subsidence load stress calculations

    International Nuclear Information System (INIS)

    Veith, E.M.

    1995-11-01

    This document captures the supporting analyses conducted to determine if the LLCE (Long-Length Contaminated Equipment) burial containers are structurally adequate under different trench closure scenarios. The LLCE is equipment that was inside tank farm tanks

  5. Feasibility of local stress relieving close to main shell of a large vessel

    International Nuclear Information System (INIS)

    Hancinsky, O.A.

    1978-01-01

    This work determines the feasibility of local stress relieving for a circumferential pipe-to-nozzle field weld positioned close to the main shell of a large pressure vessel. This is applicable to nuclear as well as conventional vessels. ANSYS computer program is utilized to perform thermal and thermal stress analysis and ASME Pressure Vessels Code is adhered to. Conclusions and recommendations are made with a view on their applicability in practice

  6. Properties of palm oil fuel ash cement sand brick containing pulverized cockle shell as partial sand replacement

    Science.gov (United States)

    Mat Aris, S.; Muthusamy, K.; Uzer, A.; Ahmad, S. Wan

    2018-04-01

    Environmental pollution caused by the disposal of solid wastes generated from both palm oil industry and cockle shell trade has motivated researches to explore the potential of these wastes. Integrating these wastes in production of construction material is one of the ways to reduce amount of waste thrown at dumping area. Thus, the present investigation investigates the performance of palm oil fuel ash (POFA) cement sand brick containing pulverized cockle shell as partial fine aggregate replacement. All mixes used contain 20% of POFA as partial cement replacement. Total of six mixes were prepared by adding a range of pulverized cockle shell that is 0%, 10%, 20%, 30%, 40% and 50% as partial sand replacement. The mixes were prepared in form of brick. All the water cured samples were tested for compressive strength and flexural strength until 28 days. Findings show that brick produced using 20% pulverized cockle shell exhibit the highest compressive strength and flexural strength also the lowest water absorption value.

  7. Residual Stresses in SAVY 4000 and Hagan Container Bodies

    Energy Technology Data Exchange (ETDEWEB)

    Stroud, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hill, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tokash, Justin Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Forsyth, Robert Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hyer, Holden Christopher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-02

    Chloride-induced stress corrosion cracking (SCC) has been investigated as a potential failure mechanism for the SAVY 4000 and the Hagan containers used to store plutonium-bearing materials at Los Alamos National Laboratory. This report discusses the regions of the container bodies most susceptible to SCC and the magnitude of the residual stresses in those regions. Boiling MgCl2 testing indicated that for both containers the region near the top weld was most susceptible to SCC. The Hagan showed through wall cracking after 22-24 hours of exposure both parallel (axial stresses) and perpendicular (hoop stresses) to the weld. The SAVY 4000 container showed significant cracking above and below the weld after 47 hours of exposure but there was no visual evidence of a through wall crack and the cracks did not leak water. Two through wall holes formed in the bottom of the SAVY 4000 container after 44-46 hours of exposure. For both containers, average “through wall” residual stresses were determined from hole drilling data 4 mm below the weld. In the Hagan body, average tensile hoop stresses were 194 MPa and average compressive axial stresses were -120 MPa. In the SAVY 4000 body, average compressive hoop stresses were 11 MPa and average tensile axial stresses were 25 MPa. Results suggest that because the Hagan container exhibited through wall cracking in a shorter time in boiling MgCl2 and had the higher average tensile stress, 194 MPa hoop stress, it is more susceptible to SCC than the SAVY 4000 container.

  8. Shells and containers under complex impact shock conditions - a practical solution concept

    International Nuclear Information System (INIS)

    Krieg, R.

    2000-01-01

    Many practically relevant impact processes are not as hard as a projectile impact but calculation or experimental assessment are difficult. Recent experiments at Karlsruhe Research Center show that many of these processes are similar, independent of geometry and scale, even for complex geometries and conditions. The preconditions and scaling factors for transfer of the model results to real dimensions are presented, and experimental facilities for investigating liquid impact on container walls are described. The latter were originally developed for analyses of serious accidents in nuclear facilities but can be used for other purposes as well. Using a concrete example, it was shown that the load of liquid impact on a shell with relatively filigrane protruding structures is lower by a factor of 14 than the impact of a comparable solid [de

  9. Critical stresses in pintle, weldment and top head of nuclear waste container

    International Nuclear Information System (INIS)

    Ladkany, S.G.; Kniss, B.R.

    1992-01-01

    Critical stresses in the pintle, the weldment, and the top heads (flat and curved), of a high level nuclear waste container are evaluated under an annular loading. This loading is three times larger than the expected normal operating load. Results show that the shape and the thickness of the pintle and the top head, along with the thickness of the weldment, substantially affect the magnitude of the critical stresses and distortions in the various components (i.e. pintle, shell, and heads) when they are supporting a load. Stiffer top heads and pintles and larger weldment sizes reduce the critical stresses in all welded joints. Various shapes of curved top heads were investigated. In this paper an ASME flanged and dished top head, which has the same thickness as the canister, is analyzed

  10. Amphiphilic core shell nanoparticles containing dense polyethyleneimine shells for efficient delivery of microRNA to Kupffer cells

    Directory of Open Access Journals (Sweden)

    Liu Z

    2016-06-01

    Full Text Available Zuojin Liu,1,* Dechao Niu,2,3,* Junyong Zhang,1 Wenfeng Zhang,1 Yuan Yao,2 Pei Li,2 Jianping Gong1 1Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 2Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 3Lab of Low-Dimensional Materials Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Efficient and targeted delivery approach to transfer exogenous genes into macrophages is still a great challenge. Current gene delivery methods often result in low cellular uptake efficiency in vivo in some types of cells, especially for the Kupffer cells (KCs. In this article, we demonstrate that amphiphilic core–shell nanoparticles (NPs consisting of well-defined hydrophobic poly(methyl methacrylate (PMMA cores and branched polyethyleneimine (PEI shells (denoted as PEI@PMMA NPs are efficient nanocarriers to deliver microRNA (miRNA-loaded plasmid to the KCs. Average hydrodynamic diameter of PEI@PMMA NPs was 279 nm with a narrow size distribution. The NPs also possessed positive surface charges up to +30 mV in water, thus enabling effective condensation of negatively charged plasmid DNA. Gel electrophoresis assay showed that the resultant PEI@PMMA NPs were able to completely condense miRNA plasmid at a weight ratio of 25:1 (N/P ratio equal to 45:1. The Cell Counting Kit-8 assay and flow cytometry results showed that the PEI@PMMA/miRNA NPs displayed low cytotoxicity and cell apoptosis activity against the KCs. The maximum cell transfection efficiency reached 34.7% after 48 hours, which is much higher than that obtained by using the commercial Lipofectamine™ 2000 (1.7%. Bio-transmission electron microscope observation revealed that the PEI@PMMA NPs were mainly distributed in

  11. "Shell Shock": An Entity that Predated Combat-related Posttraumatic Stress Disorder

    Directory of Open Access Journals (Sweden)

    Ragul Ganesh

    2015-01-01

    Full Text Available In the last century, numerous soldiers had been diagnosed with various post combat disorders. The terminology that has been utilized to describe such patients include combat fatigue, combat stress reaction, soldier′s heart, effort syndrome, non-ulcer dyspepsia, effects of agent orange and gulf war syndrome. The initial description of such post combat disorder was probably ′shell shock′ which came into vogue during the World War I. The soldiers, undergoing unyielding artillery bombardment, in the trenches suffered persistent symptoms of headache, behavioural changes and memory impairment, and was designated at the time as ′shell shock′. Myers and Mott, independently studied numerous soldiers to elucidate the features and aetiology of the entity. An attempt was made to restrict the usage of the term, but the psychological distress of the soldiers persisted to be addressed in some manner or the other, culminating in the genesis of Post Traumatic Stress Disorder.

  12. Preparation of n-tetradecane-containing microcapsules with different shell materials by phase separation method

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui [Department of Chemical Engineering, Tsinghua University, Beijing (China); Zhang, Yan; Zhang, Qingwu [Department of Chemical Engineering, China University of Mining and Technology, Beijing (China); Wang, Xin; Zhang, Yinping [Department of Building Science, Tsinghua University, Beijing (China)

    2009-10-15

    Microcapsules for thermal energy storage and heat-transfer enhancement have attracted great attention. Microencapsulation of n-tetradecane with different shell materials was carried out by phase separation method in this paper. Acrylonitrile-styrene copolymer (AS), acrylonitrile-styrene-butadiene copolymer (ABS) and polycarbonate (PC) were used as the shell materials. The structures, morphologies and the thermal capacities of the microcapsules were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The ternary phase diagrams showed the potential encapsulation capabilities of the three shell materials. The effects of the shell/core ratio and the molecular weight of the shell material on the encapsulation efficiency and the thermal capacity of the microcapsules were also discussed. Microcapsules with melting enthalpy > 100 J/g, encapsulation efficiency 66-75%, particle size<1 {mu}m were obtained for all three shell materials. (author)

  13. Theoretical and experimental stress analyses of ORNL thin-shell cylinder-to-cylinder model 3

    International Nuclear Information System (INIS)

    Gwaltney, R.C.; Bolt, S.E.; Corum, J.M.; Bryson, J.W.

    1975-06-01

    The third in a series of four thin-shell cylinder-to-cylinder models was tested, and the experimentally determined elastic stress distributions were compared with theoretical predictions obtained from a thin-shell finite-element analysis. The models are idealized thin-shell structures consisting of two circular cylindrical shells that intersect at right angles. There are no transitions, reinforcements, or fillets in the junction region. This series of model tests serves two basic purposes: the experimental data provide design information directly applicable to nozzles in cylindrical vessels; and the idealized models provide test results for use in developing and evaluating theoretical analyses applicable to nozzles in cylindrical vessels and to thin piping tees. The cylinder of model 3 had a 10 in. OD and the nozzle had a 1.29 in. OD, giving a d 0 /D 0 ratio of 0.129. The OD/thickness ratios for the cylinder and the nozzle were 50 and 7.68 respectively. Thirteen separate loading cases were analyzed. In each, one end of the cylinder was rigidly held. In addition to an internal pressure loading, three mutually perpendicular force components and three mutually perpendicular moment components were individually applied at the free end of the cylinder and at the end of the nozzle. The experimental stress distributions for all the loadings were obtained using 158 three-gage strain rosettes located on the inner and outer surfaces. The loading cases were also analyzed theoretically using a finite-element shell analysis developed at the University of California, Berkeley. The analysis used flat-plate elements and considered five degrees of freedom per node in the final assembled equations. The comparisons between theory and experiment show reasonably good agreement for this model. (U.S.)

  14. Theoretical and experimental stress analyses of ORNL thin-shell cylinder-to-cylinder model 4

    International Nuclear Information System (INIS)

    Gwaltney, R.C.; Bolt, S.E.; Bryson, J.W.

    1975-06-01

    The last in a series of four thin-shell cylinder-to-cylinder models was tested, and the experimentally determined elastic stress distributions were compared with theoretical predictions obtained from a thin-shell finite-element analysis. The models in the series are idealized thin-shell structures consisting of two circular cylindrical shells that intersect at right angles. There are no transitions, reinforcements, or fillets in the junction region. This series of model tests serves two basic purposes: (1) the experimental data provide design information directly applicable to nozzles in cylindrical vessels, and (2) the idealized models provide test results for use in developing and evaluating theoretical analyses applicable to nozzles in cylindrical vessels and to thin piping tees. The cylinder of model 4 had an outside diameter of 10 in., and the nozzle had an outside diameter of 1.29 in., giving a d 0 /D 0 ratio of 0.129. The OD/thickness ratios were 50 and 20.2 for the cylinder and nozzle respectively. Thirteen separate loading cases were analyzed. For each loading condition one end of the cylinder was rigidly held. In addition to an internal pressure loading, three mutually perpendicular force components and three mutually perpendicular moment components were individually applied at the free end of the cylinder and at the end of the nozzle. The experimental stress distributions for each of the 13 loadings were obtained using 157 three-gage strain rosettes located on the inner and outer surfaces. Each of the 13 loading cases was also analyzed theoretically using a finite-element shell analysis developed at the University of California, Berkeley. The analysis used flat-plate elements and considered five degrees of freedom per node in the final assembled equations. The comparisons between theory and experiment show reasonably good agreement for this model. (U.S.)

  15. Stress intensity factors for complete internal and external cracks in spherical shells

    International Nuclear Information System (INIS)

    Chao, Y.J.; Chen, H.

    1989-01-01

    Cracks or flows found in the nuclear structure must be fully evaluated to assure the safety of the plant. The weight function method has been widely used in the determination of stress intensity factors for cracks under stress gradient e.g. for thermal shock loading. The unique features of the weight function method is that once the weight function for a particular cracked geometry is determined the stress intensity factors at the crack tip for any loading applied to the flawed structure can be calculated by a simple integration. In this paper the stress intensity factors of the complete, part-through internal and external cracks in a spherical shell are determined. The finite element method was used to develop the weight functions for the flawed geometry. The approximate crack surface profile was used to derive the weight functions. The stress intensity factors associated with the cracks in spherical shells under internal pressure are determined by both the weight functions and the direct finite element method

  16. Core/shell particles containing liquid cores : morphology prediction, synthesis and characterization

    NARCIS (Netherlands)

    Zyl, van A.J.P.; Sanderson, R.D.; Wet-Roos, de D.; Klumperman, B.

    2003-01-01

    The ability to synthesize core/shell particles with distinct geometries is becoming increasingly important due to their potential applications. In this study structured particles with liquid cores and polymeric shells were synthesized by an in situ miniemulsion polymerization reaction. The resulting

  17. THE STRESS STATE OF THE RADIALLY INHOMOGENEOUS HEMISPHERICAL SHELL UNDER LOCALLY DISTRIBUTED VERTICAL LOAD

    Directory of Open Access Journals (Sweden)

    Andreev Vladimir Igorevich

    2018-01-01

    Full Text Available Subject: one of the promising trends in the development of structural mechanics is the development of methods for solving problems in the theory of elasticity for bodies with continuous inhomogeneity of any deformation characteristics: these methods make it possible to use the strength of the material most fully. In this paper, we consider the two-dimensional problem for the case when a vertical, locally distributed load acts on the hemisphere and the inhomogeneity is caused by the influence of the temperature field. Research objectives: derive governing system of equations in spherical coordinates for determination of the stress state of the radially inhomogeneous hemispherical shell under locally distributed vertical load. Materials and methods: as a mechanical model, we chose a thick-walled reinforced concrete shell (hemisphere with inner and outer radii a and b, respectively, b > a. The shell’s parameters are a = 3.3 m, b = 4.5 m, Poisson’s ratio ν = 0.16; the load parameters are f = 10MPa - vertical localized load distributed over the outer face, θ0 = 30°, temperature on the internal surface of the shell Ta = 500 °C, temperature on the external surface of the shell Tb = 0 °C. The resulting boundary-value problem (a system of differential equations with variable coefficients is solved using the Maple software package. Results: maximal compressive stresses σr with allowance for material inhomogeneity are reduced by 10 % compared with the case when the inhomogeneity is ignored. But it is not so important compared with a 3-fold decrease in the tensile stress σθ on the inner surface and a 2-fold reduction in the tensile stress σθ on the outer surface of the hemisphere as concretes generally have a tensile strength substantially smaller than the compressive strength. Conclusions: the method presented in this article makes it possible to reduce the deformation characteristics of the material, i.e. it leads to a reduction in stresses

  18. Preliminary Investigation of Acoustical Properties of Concrete Containing Oil Palm Shell as an Aggregate Replacement

    Science.gov (United States)

    Zanariah, J.; Zaiton, H.; Musli Nizam, Y.; Khairulzan, Y.; Dianah, M.; Nadirah, D.; Hanifi, O. Mohd

    2018-03-01

    Research has been so far focused extensively on mechanical properties of oil palm shell (OPS) concrete but less on sound properties. Thus, the objective of this study is to investigate whether concrete containing OPS can be applied in the field of road noise barrier. The acoustic properties of the samples were determined by using an impedance tube connected to a sound source. The noise reduction coefficient (NRC) and weighted sound absorption coefficient (αw) which is more commonly use in the road traffic noise barrier field were calculated according to BS EN ISO 11654:1997. Compressive strengths of samples were also determined by using compressive test. The results presented that the compressive strength of the OPS composites decreased as increased in w/c wit minimum of 20.44 N/mm2 at 28 days for w/c = 0.6 but still satisfactory for structural use. The sound absorption coefficient demonstrated that they were decreased as the w/c are higher with typical curve of two peaks at 315Hz and 1000Hz. All samples were then can be classified as class E as 0.5< αw < 0.25 and should be classified as L due to favourable deviation higher than 0.25 for 250 Hz.

  19. Transcriptome response to copper heavy metal stress in hard-shelled mussel (Mytilus coruscus

    Directory of Open Access Journals (Sweden)

    Meiying Xu

    2016-03-01

    Full Text Available The hard-shelled mussel (Mytilus coruscus has considerably one of the most economically important marine shellfish worldwide and considered as a good invertebrate model for ecotoxicity study for a long time. In the present study, we used Illumina sequencing technology (HiSeq2000 to sequence, assemble and annotate the transcriptome of the hard-shelled mussel which challenged with copper pollution. A total of 21,723,913 paired-end clean reads (NCBI SRA database SRX1411195 were generated from HiSeq2000 sequencer and 96,403 contigs (with N50 = 1118 bp were obtained after de novo assembling with Trinity software. Digital gene expression analysis reveals 1156 unigenes are upregulated and 1681 unigenes are downregulated when challenged with copper. By KEGG pathway enrichment analysis, we found that unigenes in four KEGG pathways (aminoacyl-tRNA biosynthesis, apoptosis, DNA replication and mismatch repair show significant differential expressed between control and copper treated groups. We hope that the gill transcriptome in copper treated hard-shelled mussel can give useful information to understand how mussel handles with heavy metal stress at molecular level. Keywords: Hard-shelled mussel, Heavy metal, Transcriptome, Ecotoxicity

  20. Control of stress corrosion cracking in storage tanks containing radioactive waste

    International Nuclear Information System (INIS)

    Ondrejcin, R.S.; Rideout, S.P.; Donovan, J.A.

    1978-01-01

    Stress corrosion of carbon steel storage tanks containing alkaline nitrate radioactive waste, at the Savannah River Plant is controlled by specification of limits on waste composition and temperature. Cases of cracking have been observed in the primary steel shell of tanks designed and built before 1960 that were attributed to a combination of high residual stresses from fabrication welding and aggressiveness of fresh wastes from the reactor fuel reprocessing plants. The fresh wastes have the highest concentration of nitrate, which has been shown to be the cracking agent. Also as the waste solutions age and are reduced in volume by evaporation of water, nitrite and hydroxide ions become more concentrated and inhibit stress corrosion. Thus, by providing a heel of aged evaporated waste in tanks that receive fresh waste, concentrations of the inhibitor ions are maintained within specified ranges to protect against nitrate cracking. Tanks designed and built since 1960 have been made of steels with greater resistance to stress corrosion; these tanks have also been heat treated after fabrication to relieve residual stresses from construction operations. Temperature limits are also specified to protect against stress corrosion at elevated temperatures

  1. Theoretical and experimental stress analyses of ORNL thin-shell cylinder-to-cylinder model 2

    International Nuclear Information System (INIS)

    Gwaltney, R.C.; Bolt, S.E.; Bryson, J.W.

    1975-10-01

    Model 2 in a series of four thin-shell cylinder-to-cylinder models was tested, and the experimentally determined elastic stress distributions were compared with theoretical predictions obtained from a thin-shell finite-element analysis. Both the cylinder and the nozzle of model 2 had outside diameters of 10 in., giving a d 0 /D 0 ratio of 1.0, and both had outside diameter/thickness ratios of 100. Sixteen separate loading cases in which one end of the cylinder was rigidly held were analyzed. An internal pressure loading, three mutually perpendicular force components, and three mutually perpendicular moment components were individually applied at the free end of the cylinder and at the end of the nozzle. In addition to these 13 loadings, 3 additional loads were applied to the nozzle (in-plane bending moment, out-of-plane bending moment, and axial force) with the free end of the cylinder restrained. The experimental stress distributions for each of the 16 loadings were obtained using 152 three-gage strain rosettes located on the inner and outer surfaces. All the 16 loading cases were also analyzed theoretically using a finite-element shell analysis. The analysis used flat-plate elements and considered five degrees of freedom per node in the final assembled equations. The comparisons between theory and experiment show reasonably good general agreement, and it is felt that the analysis would be satisfactory for most engineering purposes. (auth)

  2. 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

  3. Application of the UV laser printing technique to soft gelatin capsules containing titanium dioxide in the shells.

    Science.gov (United States)

    Hosokawa, Akihiro; Kato, Yoshiteru

    2012-03-01

    The purpose of this study was to examine application of ultraviolet (UV) laser irradiation to printing soft gelatin capsules containing titanium dioxide (TiO(2)) in the shells and to study effect of UV laser power on the color strength of printing on the soft gelatin capsules. Size 6 Oval type soft gelatin capsules of which shells contained 0.685% TiO(2) and 0.005% ferric dioxide were used in this study. The capsules were irradiated pulsed UV laser at a wavelength 355 nm. The color strength of the printed capsules was determined by a spectrophotometer as total color difference (dE). The soft gelatin capsules which contained TiO(2) in the shells could be printed gray by the laser. Many black particles, which were associated with the printing, were formed at the colored parts of the shells. It was found that there were two inflection points in relationship between output laser energy of a pulse and dE. Below the lower point, the capsules were not printed. From the lower point to the upper point, the capsules were printed gray and total color difference of the printing increased linearly in proportion with the output laser energy. Beyond the upper point, total color difference showed saturation because of micro-bubbles formation at the laser irradiated spot. Soft gelatin capsules containing TiO(2) in the shells could be performed stable printing using the UV laser printing technique. Color strength of the printing could be controlled by regulating the laser energy between the two inflection points.

  4. Structural Color Palettes of Core-Shell Photonic Ink Capsules Containing Cholesteric Liquid Crystals.

    Science.gov (United States)

    Lee, Sang Seok; Seo, Hyeon Jin; Kim, Yun Ho; Kim, Shin-Hyun

    2017-06-01

    Photonic microcapsules with onion-like topology are microfluidically designed to have cholesteric liquid crystals with opposite handedness in their core and shell. The microcapsules exhibit structural colors caused by dual photonic bandgaps, resulting in a rich variety of color on the optical palette. Moreover, the microcapsules can switch the colors from either core or shell depending on the selection of light-handedness. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Geometrically Nonlinear Shell Analysis of Wrinkled Thin-Film Membranes with Stress Concentrations

    Science.gov (United States)

    Tessler, Alexander; Sleight, David W.

    2006-01-01

    Geometrically nonlinear shell finite element analysis has recently been applied to solar-sail membrane problems in order to model the out-of-plane deformations due to structural wrinkling. Whereas certain problems lend themselves to achieving converged nonlinear solutions that compare favorably with experimental observations, solutions to tensioned membranes exhibiting high stress concentrations have been difficult to obtain even with the best nonlinear finite element codes and advanced shell element technology. In this paper, two numerical studies are presented that pave the way to improving the modeling of this class of nonlinear problems. The studies address the issues of mesh refinement and stress-concentration alleviation, and the effects of these modeling strategies on the ability to attain converged nonlinear deformations due to wrinkling. The numerical studies demonstrate that excessive mesh refinement in the regions of stress concentration may be disadvantageous to achieving wrinkled equilibrium states, causing the nonlinear solution to lock in the membrane response mode, while totally discarding the very low-energy bending response that is necessary to cause wrinkling deformation patterns.

  6. Numerical simulation of stress-strain state of electrophoretic shell molds

    Science.gov (United States)

    Sviridov, A. V.; Odinokov, V. I.; Dmitriev, E. A.; Evstigneev, A. I.; Bashkov, O. V.

    2017-10-01

    In the foundry engineering, castings obtained in one-piece non-gas-generating high-refractory electrophoretic shell molds (ShM) by investment patterns (IP) have an increased rejects percentage associated with low deformation resistance and crack resistance of the SM at different stages of their formation and manufacturing. Crack resistance of the ShM based on IP depends mainly on their stress-strain state (SSS) at various stages of mold forming. SSS decrease significantly improves their crack resistance and decreases their rejects percentage of castings occurring due to clogging and surface defects. In addition, the known methods of decreasing the SSS are still poorly understood. Thus, current research trends are to determine SSS at each stage of ShM forming and develop the ways to decrease it. Theoretical predicting of crack formation in multiple-layer axisymmetric shell molds is given in the work [1], and SSS of multiple-layer axisymmetric shell molds is given in the work [2]. Monolayer electrophoretic ShM had a lack of concern in this field, thus it became an argument for the present workMathematical Model of ShM SSS

  7. Stress analysis of partial sphere used for bottom shell of off-shore structure

    International Nuclear Information System (INIS)

    Nishimaki, Ko; Matsumoto, Kohei; Hori, Tohru; Takeshita, Haruyuki; Iwata, Setsuo

    1976-01-01

    In the near future, various huge off-shore structures will be constructed. Concrete shall become a leading material in the structures, owing to its versatile properties. One of the limitations of concrete is its low tensile strength. The problem of low tensile strength of concrete is dealt with in main by two different methods: by applying prestressing and by designing the structural configuration so that no tensile stresses appear. In the paper, the authors discuss the application of partially spherical shell to huge off-shore structures. Structural analysis by using the finite element method were done in order to investigate the feasibility of the structure. The results were arranged as to certain parameters to derive design charts by which the stresses of check points can be presumed. Optimum shape is also discussed. (auth.)

  8. Stresses and strains in the steel containment resulting from transient pressure and temperature loading during loss-of-coolant accident

    International Nuclear Information System (INIS)

    Gruner, P.; Kuntze, W.M.; Jansky, J.

    1985-01-01

    Posttest calculations of stresses and strains in the steel containment of the German research reactor HDR were performed for a simulated LOCA. The results of the theoretical investigations are presented and compared to experimental findings. The pressure and temperature loading of the shell was determined with the thermodynamic code COFLOW on the basis of a multi-compartment model. Using a three-dimensional finite element model the temporal behaviour of the containment was calculated employing the structural mechanics code ASKA. Global bending deformations and local negative straining of the steel shell is discussed. Theoretical and experimental results agree in most cases rather well. Reasons for deviations will be discussed. The specific behaviour of strains found in the vicinity of locally heated areas will be explained by means of analytical considerations. (orig.)

  9. Imprinting on empty hard gelatin capsule shells containing titanium dioxide by application of the UV laser printing technique.

    Science.gov (United States)

    Hosokawa, Akihiro; Kato, Yoshiteru; Terada, Katsuhide

    2014-08-01

    The purpose of this study was to examine the application of ultraviolet (UV) laser irradiation to printing hard gelatin capsule shells containing titanium dioxide (TiO2) and to clarify how the color strength of the printing by the laser could be controlled by the power of the irradiated laser. Hard gelatin capsule shells containing 3.5% TiO2 were used in this study. The capsules were irradiated with pulsed UV laser at a wavelength of 355 nm. The color strength of the printed capsule was determined by a spectrophotometer as total color difference (dE). The capsules could be printed gray by the UV laser. The formation of many black particles which were agglomerates of oxygen-defected TiO2 was associated with the printing. In the relationship between laser peak power of a pulse and dE, there were two inflection points. The lower point was the minimal laser peak power to form the black particles and was constant regardless of the dosage forms, for example film-coated tablets, soft gelatin capsules and hard gelatin capsules. The upper point was the minimal laser peak power to form micro-bubbles in the shells and was variable with the formulation. From the lower point to the upper point, the capsules were printed gray and the dE of the printing increased linearly with the laser peak power. Hard gelatin capsule shells containing TiO2 could be printed gray using the UV laser printing technique. The color strength of the printing could be controlled by regulating the laser energy between the two inflection points.

  10. Compas project stress analysis of HLW containers intermediate testwork

    International Nuclear Information System (INIS)

    Ove Arup and Partners London

    1990-01-01

    The Compas project is concerned with the structural performance of metal overpacks which may be used to encapsulate vitrified high-level waste forms before disposal in deep geological repositories. This document describes the series of experiments and associated calculations performed in the Intermediate testwork phase of this project. Seven mild steel, one-third scale simplified models of HLW containers were manufactured in a variety of configurations of geometry and weld type. The effects of reducing the wall thickness, corroding the external surface of the container, and using different welding methods were all investigated. The containers were tested under the action of a uniform external pressure up to their respective failure points. All containers failed by buckling at pressures of between 42 and 87 MPa dependent upon the particular geometric and weld configuration. The outer surface of each container was comprehensively strain-gauged in order to provide strain histories at positions of interest. The Compas project partners, from five different European countries, independently modelled the behaviour of three of the five different containers. Test results and computer predictions were compared and an assessment of the overall performance of the codes demonstrated good agreement in the initial loading of each container. However once stresses exceeded the material yield point there was a considerable spread in the predicted container behaviour

  11. Silver-gold core-shell nanoparticles containing methylene blue as SERS labels for probing and imaging of live cells

    International Nuclear Information System (INIS)

    Guo, X.; Guo, Z.; Jin, Y.; Liu, Z.; Zhang, W.; Huang, D.

    2012-01-01

    We report on silver-gold core-shell nanostructures that contain Methylene Blue (MB) at the gold/x96silver interface. They can be used as reporter molecules in surface-enhanced Raman scattering (SERS) labels. The labels are stable and have strong SERS activity. TEM imaging revealed that these nanoparticles display bright and dark stripe structures. In addition, these labels can act as probes that can be detected and imaged through the specific Raman signatures of the reporters. We show that such SERS probes can identify cellular structures due to enhanced Raman spectra of intrinsic cellular molecules measured in the local optical fields of the core-shell nanostructures. They also provide structural information on the cellular environment as demonstrated for these nanoparticles as new SERS-active and biocompatible substrates for imaging of live cells. (author)

  12. Temperature-time distribution and thermal stresses on the RTG fins and shell during water cooling

    Science.gov (United States)

    Turner, R. H.

    1983-01-01

    Radioisotope thermoelectric generator (RTG) packages designed for space missions generally do not require active cooling. However, the heat they generate cannot remain inside of the launch vehicle bay and requires active removal. Therefore, before the Shuttle bay door is closed, the RTG coolant tubes attached to the heat rejection fins must be filled with water, which will circulate and remove most of the heat from the cargo bay. There is concern that charging a system at initial temperature around 200 C with water at 24 C can cause unacceptable thermal stresses in the RTG shell and fins. A computer model is developed to estimate the transient temperature distribution resulting from such charging. The thermal stresses resulting from the temperature gradients do not exceed the elastic deformation limit for the material. Since the simplified mathematical model for thermal stresses tends to overestimate stresses, it is concluded that the RTG can be cooled by introducing water at 24 C to the initially hot fin coolant tubes while the RTG is in the Shuttle cargo bay.

  13. Monte Carlo simulations of core/shell nanoparticles containing interfacial defects: Role of disordered ferromagnetic spins

    International Nuclear Information System (INIS)

    Ho, Le Bin; Lan, Tran Nguyen; Hai, Tran Hoang

    2013-01-01

    In this work, we have used the Monte Carlo simulation to investigate the magnetic properties of an isolated composite magnetic nanoparticle with ferromagnetic (FM) core and antiferromagnetic (AFM) shell morphology. The defects were assumed to be randomly located at the AFM interface. The Néel anisotropy was used for the FM interface spins at where there are the lacks of crystal symmetry due to the vacancies at AFM interface. With a moderate defect concentration, the coercive field non-monotonously depends on the Néel anisotropy. We have examined the dependence of coercivity, exchange bias field, and vertical shift on defect concentration. We found that in addition to AFM shell, the disordered FM interface is another pining-source for exchange bias phenomenon. We discuss our simulated results in the relation to recent experimental findings

  14. Design of the RC containment shell of a nuclear reactor for aircraft impact

    International Nuclear Information System (INIS)

    Filho, F.V.; Coombs, R.F.; Barreto, L.C.

    1981-01-01

    This paper deals with the following points: i) Characterization of a particular region of the shell which is modeled as a one-degree-of freedom system for the non-linear dynamic analysis. This is achieved through a proper interpretation of the results of the global analysis. ii) Development of a method of non-linear dynamic analysis for the considered one-degree-of freedom model. iii) Comparative analysis of the design for flexural strength, and punching shear, according to American and German standards. Interaction diagrams for bending and normal force are developed according to the two standards. The concepts of the foregoing items are exemplified with the verification of the shell reinforcement of a PWR reactor. A simplified method of non-linear dynamic analysis for airplane crash is presented. This method takes into account all the important influences of the problem. The results of this analysis are used in the design of the shell reinforcement according to American and German Standards. (orig./HP)

  15. Compressive strength, flexural strength and water absorption of concrete containing palm oil kernel shell

    Science.gov (United States)

    Noor, Nurazuwa Md; Xiang-ONG, Jun; Noh, Hamidun Mohd; Hamid, Noor Azlina Abdul; Kuzaiman, Salsabila; Ali, Adiwijaya

    2017-11-01

    Effect of inclusion of palm oil kernel shell (PKS) and palm oil fibre (POF) in concrete was investigated on the compressive strength and flexural strength. In addition, investigation of palm oil kernel shell on concrete water absorption was also conducted. Total of 48 concrete cubes and 24 concrete prisms with the size of 100mm × 100mm × 100mm and 100mm × 100mm × 500mm were prepared, respectively. Four (4) series of concrete mix consists of coarse aggregate was replaced by 0%, 25%, 50% and 75% palm kernel shell and each series were divided into two (2) main group. The first group is without POF, while the second group was mixed with the 5cm length of 0.25% of the POF volume fraction. All specimen were tested after 7 and 28 days of water curing for a compression test, and flexural test at 28 days of curing period. Water absorption test was conducted on concrete cube age 28 days. The results showed that the replacement of PKS achieves lower compressive and flexural strength in comparison with conventional concrete. However, the 25% replacement of PKS concrete showed acceptable compressive strength which within the range of requirement for structural concrete. Meanwhile, the POF which should act as matrix reinforcement showed no enhancement in flexural strength due to the balling effect in concrete. As expected, water absorption was increasing with the increasing of PKS in the concrete cause by the porous characteristics of PKS

  16. Structural capacity assessment of a generic pre-stressed concrete containment structure under aircraft impact

    International Nuclear Information System (INIS)

    Iliev, Alexander

    2013-01-01

    The studied containment expressed adequate capacity to resist impact loads in the upper range of the studied diapason. The aircraft impact capacity of the containment for impact in the upper part of the cylindrical shell is about 25‐30% higher than the capacity for impact in the middle part of the cylindrical shell. The obtained fragility curves reefed to MoA can be then used for various additional calculations in the safety assessment of nuclear facilities under aircraft impact

  17. Proceedings of the joint WANO/OECD-NEA workshop on pre-stress loss in NPP containments

    International Nuclear Information System (INIS)

    1997-01-01

    This joint WANO/OECD-NEA workshop on pre-stress loss in NPP containments started with Opening Remarks (by OECD and EDF) and two presentations on 'Creep and Shrinkage of Concrete: Physical Origins, Practical Measurements', and 'Past, Present and Future Techniques for Predicting Creep and Shrinkage of Concrete'. It was then followed by papers and presentations from 12 countries, which titles are: Assessment of Creep Methodologies for Predicting Prestressing Forces Losses in Nuclear Power Plant Containments; Prestress Behaviour in Belgian NPP Containments; Presentation of Gentilly 2 NPP Containment (abstract only); Containment Structure Monitoring and Prestress Losses; Experience from Daya Bay Nuclear Power Plant (China); Prestress losses in NPP containments - the EDF experience; Prestress Force Monitoring on the THTR Prestressed Concrete Reactor Vessel During 19 Years; NPP Containment Design: Evolution and Indian Experience; In-Service Inspections and R and D of PCCVs in Japan; Comparison of Grouted and Un-grouted Tendons in NPP Containments; Prestress Losses in Containment of VVER 1000 Units; Prestressing in Nuclear Power Plants; Anchor Lift-off Measuring System for 37 T 15 Tendons; Monitoring of Stressed-Strained State and Forces in Reinforcing Cables of Prestressed Containment Shells of Nuclear Power Plants; Long-Term In-Service Monitoring of Pre-stressing in Magnox Pre-stressed Concrete Pressure Vessels; The Measurement of Un-bonded Tendon Loads in PCPV and Primary Containment Buildings; The Long Term In-service Performance of Corrosion Protection to Prestressing Tendons in AGR Prestressed Concrete Pressure Vessels; Prestress Force Losses in Containments of U.S. Nuclear Power Plants. Discussions and a synthesis are also presented

  18. Thermal stress state of laminated shells of revolution made of isotropic and linearly orthotropic materials

    International Nuclear Information System (INIS)

    Savchenko, V.G.

    1995-01-01

    In this investigation, we will use a cylindrical coordinate system to study the stress state of laminated shells of revolution made of inelastically deforming isotropic materials and elastic materials with linear orthotropy. One of the principal directions of anisotropy coincides with the axis of revolution of the body. The shells will be subjected to nonaxisymmetric loading by body bar K (K Z , K r , K var-phi ) and surface bar t n (t nz , t nr , t nvar-phi ) forces and heating. The level of loading is such that the rheological properties of the materials of the layers are not a factor, although their thermomechanical characteristics depend on temperature. In addition, the loading and heating of the body occur in such a way that simple (or close to simple) deformation processes take place in its isotropic elements. These processes are accompanied by inelastic strains and the formation of unloading regions in which plastic strains having the sign opposite the initial strains develop. It is assumed that the layers of the body are secured to one another without interference and that conditions corresponding to ideal contact prevail at their interfaces

  19. Synthesis and Characterization of Microencapsulated Phase Change Materials with Poly(urea-urethane) Shells Containing Cellulose Nanocrystals.

    Science.gov (United States)

    Yoo, Youngman; Martinez, Carlos; Youngblood, Jeffrey P

    2017-09-20

    The main objective of this study is to develop microencapsulation technology for thermal energy storage incorporating a phase change material (PCM) in a composite wall shell, which can be used to create a stable environment and allow the PCM to undergo phase change without any outside influence. Surface modification of cellulose nanocrystals (CNCs) was conducted by grafting poly(lactic acid) oligomers and oleic acid to improve the dispersion of nanoparticles in a polymeric shell. A microencapsulated phase change material (methyl laurate) with poly(urea-urethane) (PU) composite shells containing the hydrophobized cellulose nanocrystals (hCNCs) was fabricated using an in situ emulsion interfacial polymerization process. The encapsulation process of the PCMs with subsequent interfacial hCNC-PU to form composite microcapsules as well as their morphology, composition, thermal properties, and release rates was examined in this study. Oil soluble Sudan II dye solution in methyl laurate was used as a model hydrophobic fill, representing other latent fills with low partition coefficients, and their encapsulation efficiency as well as dye release rates were measured spectroscopically in a water medium. The influence of polyol content in the PU polymer matrix of microcapsules was investigated. An increase in polyol contents leads to an increase in the mean size of microcapsules but a decrease in the gel content (degree of cross-linking density) and permeability of their shell structure. The encapsulated PCMs for thermal energy storage demonstrated here exhibited promising performance for possible use in building or paving materials in terms of released heat, desired phase transformation temperature, chemical and physical stability, and concrete durability during placement.

  20. Modelling by the SPH method of the impact of a shell containing a fluid

    International Nuclear Information System (INIS)

    Maurel, B.

    2008-01-01

    The aim of this work was to develop a numerical simulation tool using a mesh-less approach, able to simulate the deformation and the rupture of thin structures under the impact of a fluid. A model of thick mesh-less shell (Mindlin-Reissner) based on the SPH method has then been carried out. A contact algorithm has moreover been perfected for the interactions between the structure and the fluid, it is modelled too by the SPH method. These studies have been carried out and been included in the CEA Europlexus fast dynamics software. (O.M.)

  1. Stress corrosion cracking of candidate materials for nuclear waste containers

    International Nuclear Information System (INIS)

    Maiya, P.S.; Shack, W.J.; Kassner, T.F.

    1989-09-01

    Types 304L and 316L stainless steel (SS), Incoloy 825, Cu, Cu-30%Ni, and Cu-7%Al have been selected as candidate materials for the containment of high-level nuclear waste at the proposed Yucca Mountain Site in Nevada. The susceptibility of these materials to stress corrosion cracking has been investigated by slow-strain-rate tests (SSRTs) in water which simulates that from well J-13 (J-13 water) and is representative of the groundwater present at the Yucca Mountain site. The SSRTs were performed on specimens exposed to simulated J-13 water at 93 degree C and at a strain rate 10 -7 s -1 under crevice conditions and at a strain rate of 10 -8 s -1 under both crevice and noncrevice conditions. All the tests were interrupted after nominal elongation strains of 1--4%. Examination by scanning electron microscopy showed some crack initiation in virtually all specimens. Optical microscopy of metallographically prepared transverse sections of Type 304L SS suggests that the crack depths are small (<10 μm). Preliminary results suggest that a lower strain rate increases the severity of cracking of Types 304L and 316L SS, Incoloy 825, and Cu but has virtually no effect on Cu-30%Ni and Cu-7%Al. Differences in susceptibility to cracking were evaluated in terms of a stress ratio, which is defined as the ratio of the increase in stress after local yielding in the environment to the corresponding stress increase in an identical test in air, both computed at the same strain. On the basis of this stress ratio, the ranking of materials in order of increasing resistance to cracking is: Types 304L SS < 316L SS < Incoloy 825 congruent Cu-30%Ni < Cu congruent Cu-7%Al. 9 refs., 12 figs., 7 tabs

  2. The stress corrosion cracking of copper nuclear waste containers

    International Nuclear Information System (INIS)

    King, F.; Litke, C.D.; Ikeda, B.M.

    1999-01-01

    The extent of stress corrosion cracking (SCC) of copper nuclear waste containers is being predicted on the basis of a 'limited propagation' argument. In this argument, it is accepted that crack initiation may occur, but it is argued that the environmental conditions and material properties required for a through-wall crack to propagate will not be present. In this paper, the effect of one environmental parameter, the supply of oxidant (J ox ), on the crack growth rate is examined. Experiments have been conducted on two grades of Cu in NANO 2 environments using two loading techniques. The supply of oxidant has been varied either electrochemically in bulk solution using different applied current densities or by embedding the loaded test specimens in compacted buffer material containing O 2 as the oxidant. Measured and theoretical crack growth rates as a function of J ox are compared with the predicted oxidant flux to the containers in a disposal vault and an estimate of the maximum crack depth on a container obtained. (author)

  3. The stress corrosion cracking of copper nuclear waste containers

    International Nuclear Information System (INIS)

    King, F.; Litke, C.D.; Ikeda, B.M.

    1999-01-01

    The extent of stress corrosion cracking (SCC) of copper nuclear waste containers is being predicted on the basis of a limited propagation argument. In this argument, it is accepted that crack initiation may occur, but it is argued that the environmental conditions and material properties required for a through-wall crack to propagate will not be present. In this paper, the effect of one environmental parameter, the supply of oxidant (J OX ), on the crack growth rate is examined. Experiments have been conducted on two grades of Cu in NaNO 2 environments using two loading techniques. The supply of oxidant has been varied either electrochemically in bulk solution using different applied current densities or by embedding the loaded test specimens in compacted buffer material containing O 2 as the oxidant. Measured and theoretical crack growth rates as a function of J OX are compared with the predicted oxidant flux to the containers in a disposal vault and an estimate of the maximum crack depth on a container obtained

  4. Structure simulation of a pre-stressed concrete containment model

    International Nuclear Information System (INIS)

    Grebner, H.; Sievers, J.

    2004-01-01

    An axisymmetric Finite-Element-Model of the 1:4 pre-stressed containment model tested at SANDIA was developed. The model is loaded by the pre-stressing of the tendons and by increasing internal pressure (up to 1.3 MPa). The analyses results in terms of displacements and strains in the liner, the rebars, the tendons and the concrete of the cylindrical part agree well with measured data up to about 0.6 MPa internal pressure (i.e. 1.5 times design pressure). First circumferential micro-cracks in the concrete are found at about 0.75 MPa. With increasing pressure micro-cracks are present through the whole wall. Above about 0.9 MPa the formation of micro-cracks in radial and meridional direction is calculated. At the maximum load (1.3 MPa) almost all concrete parts of the model have micro-cracks which may cause leaks. Nevertheless the failure of the containment model is not expected for loads up to 1.3 MPa without consideration of geometric inhomogeneities due to penetrations in the wall. Although the calculated strains in liner, rebars and tendons show some plastification, the maximum values are below the critical ones. The safety margin against failure is smallest in some hoop tendons. At present parametric studies are performed to investigate the differences between calculations and measured data. Furthermore three-dimensional models are developed for a better simulation of the meridional tendons in the dome region. (orig.)

  5. Extensions to a nonlinear finite element axisymmetric shell model based on Reissner's shell theory

    International Nuclear Information System (INIS)

    Cook, W.A.

    1981-01-01

    A finite element shell-of-revolution model has been developed to analyze shipping containers under severe impact conditions. To establish the limits for this shell model, I studied the basic assumptions used in its development; these are listed in this paper. Several extensions were evident from the study of these limits: a thick shell, a plastic hinge, and a linear normal stress. (orig./HP)

  6. Corrective action strategy for single-shell tanks containing organic chemicals

    International Nuclear Information System (INIS)

    Turner, D.A.

    1993-08-01

    A Waste Tank Organic Safety Program (Program) Plan is to be transmitted to the U.S. Department of Energy, Richland Operations Office (RL) for approval by December 31, 1993. In April 1993 an agreement was reached among cognizant U.S. Department of Energy - Headquarters (HQ), RL and Westinghouse Hanford Company (WHC) staff that the Program Plan would be preceded by a ''Corrective Action Strategy,'' which addressed selected planning elements supporting the Program Plan. The ''Corrective Action Strategy'' would be reviewed and consensus reached regarding the planning elements. A Program Plan reflecting this consensus would then be prepared. A preliminary ''corrective action strategy'' is presented for resolving the organic tanks safety issue based on the work efforts recommended in the ISB (Interim Safety Basis for Hanford Site tank farm facilities). A ''corrective action strategy'' logic was prepared for individual SSTs (single-shell tanks), or a group of SSTs having similar characteristics, as appropriate. Four aspects of the organic tanks safety issue are addressed in the ISB: SSTs with the potential for combustion in the tank's headspace; combustion of a floating organic layer as a pool fire; surface fires in tanks that formerly held floating organic layers; SSTs with the potential for organic-nitrate reactions. A preliminary ''corrective action strategy'' for each aspect of the organic tanks safety issue is presented

  7. Piercing of the containment shell of a reactor building in case of airplane crash

    International Nuclear Information System (INIS)

    Herzog, M.

    1978-01-01

    The author presents a simple calculation model for a realistic check of the piercing safety of containments of reactor buildings in case of airplane crash. Its application is illustrated by a numerical example (Starfighter crash on the Unterweser nuclear power plant). (orig.) [de

  8. Stress analysis for shells with double curvature by finite element method

    International Nuclear Information System (INIS)

    Mueller, A.

    1981-08-01

    A simple triangular finite element for plates and shells, is presented. Since the rotation fields are assumed independent of the displacement fields, simple shape functions of second and third degree were used. An implicit penalty method allows one to solve thin shell problems since the Kirchoff-Love hypothesis are automatically satisfied. (Author) [pt

  9. STRESS DISTRIBUTION IN THE STRATIFIED MASS CONTAINING VERTICAL ALVEOLE

    Directory of Open Access Journals (Sweden)

    Bobileva Tatiana Nikolaevna

    2017-08-01

    Full Text Available Almost all subsurface rocks used as foundations for various types of structures are stratified. Such heterogeneity may cause specific behaviour of the materials under strain. Differential equations describing the behaviour of such materials contain rapidly fluctuating coefficients, in view of this, solution of such equations is more time-consuming when using today’s computers. The method of asymptotic averaging leads to getting homogeneous medium under study to averaged equations with fixed factors. The present article is concerned with stratified soil mass consisting of pair-wise alternative isotropic elastic layers. In the results of elastic modules averaging, the present soil mass with horizontal rock stratification is simulated by homogeneous transversal-isotropic half-space with isotropy plane perpendicular to the standing axis. Half-space is loosened by a vertical alveole of circular cross-section, and virgin ground is under its own weight. For horizontal parting planes of layers, the following two types of surface conditions are set: ideal contact and backlash without cleavage. For homogeneous transversal-isotropic half-space received with a vertical alveole, the analytical solution of S.G. Lekhnitsky, well known in scientific papers, is used. The author gives expressions for stress components and displacements in soil mass for different marginal conditions on the alveole surface. Such research problems arise when constructing and maintaining buildings and when composite materials are used.

  10. Calculation of stresses and deformations in a cylindrical shell with imperfect initial shape and at the circumference nonuniform temperature

    International Nuclear Information System (INIS)

    Leonchuk, M.P.; Pyl'chenkov, Eh.Kh.; Dvortsova, L.I.

    1976-01-01

    A method is proposed for calculating the stress-strain state of a thin cylindrical shell with initial shape imperfections under conditions of peripheral nonuniformity of temperatures and a prolonged effect of external loads. The method is based on the plane deformation hypothesis, it takes into account geometrical nonlinearity and also the steady and nonsteady stages of creep. Different schemes are considered of the problem realization on the computer. The possibility of using the method for analyzing stresses, strains and lifetime of the fuel elements and other reactor elements is demonstrated

  11. Three dimensional stress analysis of nozzle-to-shell intersections by the finite element method and a auto-mesh generation program

    International Nuclear Information System (INIS)

    Fujihara, Hirohiko; Ueda, Masahiro

    1975-01-01

    In the design of chemical reactors or nuclear pressure vessels it is often important to evaluate the stress distribution in nozzle-to-shell intersections. The finite element method is a powerful tool for stress analysis, but it has a defects to require troublesome work in preparing input data. Specially, the mesh data of oblique nozzles and tangential nozzles, in which stress concentration is very high, are very difficult to be prepared. The authors made a mesh generation program which can be used to any nozzle-to-shell intersections, and combining this program with a three dimensional stress analysis program by the finite element method they made the stress analysis of nozzle-to-shell intersections under internal pressure. Consequently, stresses, strains and deformations of nozzles nonsymmetrical to spherical shells and nozzles tangential to cylindrical shells were made clear and it was shown that the curvature of the inner surface of the nozzle corner was a controlling factor in reducing stress concentration. (auth.)

  12. Containment vessel stability analysis

    International Nuclear Information System (INIS)

    Harstead, G.A.; Morris, N.F.; Unsal, A.I.

    1983-01-01

    The stability analysis for a steel containment shell is presented herein. The containment is a freestanding shell consisting of a vertical cylinder with a hemispherical dome. It is stiffened by large ring stiffeners and relatively small longitudinal stiffeners. The containment vessel is subjected to both static and dynamic loads which can cause buckling. These loads must be combined prior to their use in a stability analysis. The buckling loads were computed with the aid of the ASME Code case N-284 used in conjunction with general purpose computer codes and in-house programs. The equations contained in the Code case were used to compute the knockdown factors due to shell imperfections. After these knockdown factors were applied to the critical stress states determined by freezing the maximum dynamic stresses and combining them with other static stresses, a linear bifurcation analysis was carried out with the aid of the BOSOR4 program. Since the containment shell contained large penetrations, the Code case had to be supplemented by a local buckling analysis of the shell area surrounding the largest penetration. This analysis was carried out with the aid of the NASTRAN program. Although the factor of safety against buckling obtained in this analysis was satisfactory, it is claimed that the use of the Code case knockdown factors are unduly conservative when applied to the analysis of buckling around penetrations. (orig.)

  13. Simulation of thermal stress and buckling instability in Si/Ge and Ge/Si core/shell nanowires.

    Science.gov (United States)

    Das, Suvankar; Moitra, Amitava; Bhattacharya, Mishreyee; Dutta, Amlan

    2015-01-01

    The present study employs the method of atomistic simulation to estimate the thermal stress experienced by Si/Ge and Ge/Si, ultrathin, core/shell nanowires with fixed ends. The underlying technique involves the computation of Young's modulus and the linear coefficient of thermal expansion through separate simulations. These two material parameters are combined to obtain the thermal stress on the nanowires. In addition, the thermally induced stress is perceived in the context of buckling instability. The analysis provides a trade-off between the geometrical and operational parameters of the nanostructures. The proposed methodology can be extended to other materials and structures and helps with the prediction of the conditions under which a nanowire-based device might possibly fail due to elastic instability.

  14. Computation of shrinkage stresses in prestressed concrete containments

    International Nuclear Information System (INIS)

    Wu, R.F.; Ouyang, H.

    1989-01-01

    According to a survey, surface cracking on PCRVs and PCCs under the investigations is confined to drying shrinkage and thermal strain effects and no instances of structurally significant cracking was been found. In this paper, the authors use FEM to compute humidity distribution in drying concrete and shrinkage stresses by internal restraint. Since PCC is built segment by segment in several years, a computational model taking into account construction sequence is presented and shrinkage stresses by external restraints are calculated with the model

  15. EFFECTS OF CHEMISTRY AND OTHER VARIABLES ON CORROSION AND STRESS CORROSION CRACKING IN HANFORD DOUBLE SHELL TANKS

    Energy Technology Data Exchange (ETDEWEB)

    BROWN MH

    2008-11-13

    Laboratory testing was performed to develop a comprehensive understanding of the corrosivity of the tank wastes stored in Double-Shell Tanks using simulants primarily from Tanks 241-AP-105, 241-SY-103 and 241-AW-105. Additional tests were conducted using simulants of the waste stored in 241-AZ-102, 241-SY-101, 241-AN-107, and 241-AY-101. This test program placed particular emphasis on defining the range of tank waste chemistries that do not induce the onset of localized forms of corrosion, particularly pitting and stress corrosion cracking. This document summarizes the key findings of the research program.

  16. EFFECTS OF CHEMISTRY AND OTHER VARIABLES ON CORROSION AND STRESS CORROSION CRACKING IN HANFORD DOUBLE-SHELL TANKS

    International Nuclear Information System (INIS)

    Brown, M.H.

    2008-01-01

    Laboratory testing was performed to develop a comprehensive understanding of the corrosivity of the tank wastes stored in Double-Shell Tanks using simulants primarily from Tanks 241-AP-105, 241-SY-103 and 241-AW-105. Additional tests were conducted using simulants of the waste stored in 241-AZ-102, 241-SY-101, 241-AN-107, and 241-AY-101. This test program placed particular emphasis on defining the range of tank waste chemistries that do not induce the onset of localized forms of corrosion, particularly pitting and stress corrosion cracking. This document summarizes the key findings of the research program

  17. Stress analysis of HLW containers advanced test work Compas project

    International Nuclear Information System (INIS)

    Ove Arup and Partners

    1990-01-01

    The Compas project is concerned with the structural performance of metal overpacks which may be used to encapsulate vitrified high-level waste forms before disposal in deep geological repositories. This document describes the activities performed between June and August 1989 forming the advanced test work phase of this project. This is the culmination of two years' analysis and test work to demonstrate whether the analytical ability exists to model containers subjected to realistic loads. Three mild steel containers were designed and manufactured to be one-third scale models of a realistic HLW container, modified to represent the effect of anisotropic loading and to facilitate testing. The containers were tested under a uniform external pressure and all failed by buckling in the mid-body region. The outer surface of each container was comprehensively strain-gauged to provide strain history data at all positions of interest. In parallel with the test work, Compas project partners, from five different European countries, independently modelled the behaviour of each of the containers using their computer codes to predict the failure pressure and produce strain history data at a number of specified locations. The first axisymmetric container was well modelled but predictions for the remaining two non-axisymmetric containers were much more varied, with differences of up to 50% occurring between failure predictions and test data

  18. A layered shell containing patches of piezoelectric fibers and interdigitated electrodes: Finite element modeling and experimental validation

    DEFF Research Database (Denmark)

    Nielsen, Bo Bjerregaard; Nielsen, Martin S.; Santos, Ilmar

    2017-01-01

    The work gives a theoretical and experimental contribution to the problem of smart materials connected to double curved flexible shells. In the theoretical part the finite element modeling of a double curved flexible shell with a piezoelectric fiber patch with interdigitated electrodes (IDEs......) is presented. The developed element is based on a purely mechanical eight-node isoparametric layered element for a double curved shell, utilizing first-order shear deformation theory. The electromechanical coupling of piezoelectric material is added to all elements, but can also be excluded by setting...... the piezoelectric material properties to zero. The electrical field applied via the IDEs is aligned with the piezoelectric fibers, and hence the direct d33 piezoelectric constant is utilized for the electromechanical coupling. The dynamic performance of a shell with a microfiber composite (MFC) patch...

  19. Reactor container

    International Nuclear Information System (INIS)

    Naruse, Yoshihiro.

    1990-01-01

    The thickness of steel shell plates in a reactor container embedded in sand cussions is monitored to recognize the corrosion of the steel shell plates. That is, the reactor pressure vessel is contained in a reactor container shell and the sand cussions are disposed on the lower outside of the reactor container shell to elastically support the shell. A pit is disposed at a position opposing to the sand cussions for measuring the thickness of the reactor container shell plates. The pit is usually closed by a closing member. In the reactor container thus constituted, the closing member can be removed upon periodical inspection to measure the thickness of the shell plates. Accordingly, the corrosion of the steel shell plates can be recognized by the change of the plate thickness. (I.S.)

  20. NPP containment pre-stress loss - summary statement

    International Nuclear Information System (INIS)

    1999-01-01

    Principal Working Group 3 of the CSNI deals with the integrity of structures and components, and has three sub-groups, dealing with the integrity of metal structures and components, ageing of concrete structures, and the seismic behaviour of structures. A status report on the ageing of concrete structures was prepared during 1995 by a task group to initiate activities in this field under PWG3. Tendon prestress loss was the first topic addressed by the group, with a workshop organised jointly by IPSN and EDF, and sponsored jointly by WANO and OECD-NEA. RILEM, FIB and IASMiRT also co-sponsored the workshop. Present experience suggests that the current methods for the prediction of the loss of tendon prestress are generally satisfactory. The nuclear industry has adopted regulatory and codified methods for predicting the loss of prestress in nuclear power plant (NPP) prestressed concrete containments from international and national standards that are not necessarily specific to nuclear design. The application of the different methods to a specific case is likely to lead to significant differences in the predicted losses. Theoretical and experimental research have established the importance of understanding how chemical, hygro, mechanical and thermal factors influence the short term and long term behaviour of prestressed concrete. Improved and simplified simulations of creep and shrinkage phenomena that can account for the environment and loading history of prestressed concrete containments and pressure vessels will assist: the development of design regulations/standards; the choice of concrete mix; the development of relevant monitoring programmes, and ageing management including plant life extension. Prestressed concrete containments and pressure vessels use both grouted (bonded) tendons and un-grouted (un-bonded) tendons. The workshop considered the relative merits of both systems. Experience presented at the workshop indicates that comprehensive and regular

  1. Thermal stresses at nozzles of nuclear steel containments under LOCA-conditions

    International Nuclear Information System (INIS)

    Sanchez Sarmiento, G.; Bergmann, A.N.

    1986-01-01

    During a loss of coolant accident (LOCA) of a PWR-nuclear power plant, a considerable heating of the containment atmosphere is expected to occur. Transient thermal stresses will appear at the containment as a consequence of a non-uniform rise of its temperature. Applying computer codes based on the finite element method, dimensionless general thermal stresses at nozzles of spherical steel containment have been calculated, varying the principal geometrical parameters and the Biot number for the containment internal surface. Atmosphere temperature and Biot number are assumed constant after the accident. Several plots of the maximum principal stresses are provided, which constitute general results applicable to stress analysis of any particular containment of this kind. (orig.)

  2. In-vitro investigations of skin closure using diode laser and protein solder containing gold nano shells

    International Nuclear Information System (INIS)

    Nourbakhsh, M. S.; Etrati Khosroshahi, M.

    2011-01-01

    Laser tissue soldering is a new technique for repair of various tissues including the skin, liver, articular cartilage and nerves and is a promising alternative to suture. To overcome the problems of thermal damage to surrounding tissues and low laser penetration depth, some exogenous chromophores such as gold nano shells, a new class of nanoparticles consisting of a dielectric core surrounded by a thin metal shell, are used. The aims of this study were to use two different concentrations of gold nano shells as the exogenous material for skin tissue soldering and also to examine the effects of laser soldering parameters on the properties of the repaired skin. Material and Methods: Two mixtures of albumin solder and different concentrations of gold nano shells were prepared. A full thickness incision of 2*20 mm 2 was made on the surface and after placing 50 μ1 of the solder mixture on the incision, an 810 nm diode laser was used to irradiate it at different power densities. The changes of tensile strength, σt, due to temperature rise, number of scan (Ns), and scan velocity (Vs) were investigated. Results: The results showed that the tensile strength of the repaired skin increased with increasing irradiance for both gold nano shell concentrations. In addition, at constant laser irradiance (I), the tensile strength of the repaired incision increased with increasing Ns and decreasing Vs. In our case, this corresponded to σt = 1610 g/cm 2 at I ∼ 60 W cm-2, T ∼ 65 d egree C , Ns = 10 and Vs = 0.2 mms-1. Discussion and Conclusion: Gold nano shells can be used as an indocyanine green dye alterative for laser tissue soldering. Although by increasing the laser power density, the tensile strength of the repaired skin increases, an optimum power density must be considered due to the resulting increase in tissue temperature.

  3. Piping systems, containment pre-stressing and steel ventilation chimney

    International Nuclear Information System (INIS)

    Stuessi, U.

    1996-01-01

    Units 5 and 6 of NPP Kozloduy have been designed initially for seismic levels which are considered too low today. In the frame of an IAEA Coordinated Research Programme, a Swiss team has been commissioned by Natsionalna Elektricheska Kompania, Sofia, to analyse the relevant piping system, the containment prestressing and the steel ventilation chimney and to recommend upgrade measures for adequate seismic capacity where applicable. Seismic input had been specified by and agreed upon earlier by IAEA experts. The necessary investigations have been performed in 1995 and discussed with internationally recognized experts. The main results may be summarized as follows: Upgrades are necessary at different piping sy ports (additional snubbers or viscous dampers). These fixes can be done easily at low cost. The containment prestressing tendons are adequately designed for the specified load combinations. However, unfavourable construction features endanger the reliability. It is therefore strongly recommended to replace the tendons stepwise and to upgrade the existing monitoring system. Finally, the steel ventilation chimney may not withstand a seismic event, however the containment and diesel generator building will not be destroyed at possible impact by the chimney. On the other hand the roof of the main building has to be reinforced partially. It is recommended to continue the project for 1996 and 1997 to implement the upgrade measures mentioned above, to analyse the remaining piping systems and to consolidate all results obtained by different research groups of the IAEA programme with respect to piping systems including components and tanks

  4. Restraint stress in lactating mice alters the levels of sulfur-containing amino acids in milk.

    Science.gov (United States)

    Nishigawa, Takuma; Nagamachi, Satsuki; Ikeda, Hiromi; Chowdhury, Vishwajit S; Furuse, Mitsuhiro

    2018-03-30

    It is well known that maternal stress during the gestation and lactation periods induces abnormal behavior in the offspring and causes a lowering of the offspring's body weight. Various causes of maternal stress during the lactation period, relating to, for example, maternal nutritional status and reduced maternal care, have been considered. However, little is known about the effects on milk of maternal stress during the lactation period. The current study aimed to determine whether free amino acids, with special reference to sulfur-containing amino acids in milk, are altered by restraint stress in lactating mice. The dams in the stress group were restrained for 30 min at postnatal days 2, 4, 6, 8, 10 and 12. Restraint stress caused a reduction in the body weight of lactating mice. The concentration of taurine and cystathionine in milk was significantly higher in the stress group, though stress did not alter their concentration in maternal plasma. The ratio of taurine concentration in milk to its concentration in maternal plasma was significantly higher in the stress group, suggesting that stress promoted taurine transportation into milk. Furthermore, taurine concentration in milk was positively correlated with corticosterone levels in plasma. In conclusion, restraint stress in lactating mice caused the changes in the metabolism and in the transportation of sulfur-containing amino acids and resulted in higher taurine concentration in milk. Taurine concentration in milk could also be a good parameter for determining stress status in dams.

  5. Contain calculations of debris conditions adjacent to the BWR Mark I drywell shell during the later phases of a severe accident

    International Nuclear Information System (INIS)

    Hyman, C.R.

    1988-01-01

    Best estimate CONTAIN calculations have recently been performed by the BWR Severe Accident Technology (BWRSAT) Program at Oak Ridge National Laboratory to predict the primary containment response during the later phases of an unmitigated low-pressure Short Term Station Blackout at the Peach Bottom Atomic Power Station. Debris pour conditions leaving the failed reactor vessel are taken from the results of best estimate BWRSAR analyses that are based upon an assumed metallic debris melting temperature of 2750/degree/F (1783 K) and an oxide debris melting temperature of 4350/degree/F (2672 K). Results of the CONTAIN analysis for the case without sprays indicate failure of the drywell seals due to the extremely hot atmospheric conditions extant in the drywell. The maximum calculated temperature of the debris adjacent to the drywell shell is less than the melting temperature of the shell, yet the sustained temperatures may be sufficient to induce primary containment pressure boundary failure by the mechanism of creep-rupture. It is also predicted that a significant portion of the reactor pedestal wall is ablated during the period of the calculation. Nevertheless, the calculated results are recognized to be influenced by large modeling uncertainties. Several deficiencies in the application of the CORCON module within the CONTAIN code to BWR severe accident sequences are identified and discussed. 5 refs., 9 figs., 4 tabs.,

  6. Assessment of Residual Stresses in 3013 Inner and Outer Containers and Teardrop Samples

    Energy Technology Data Exchange (ETDEWEB)

    Stroud, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Prime, Michael Bruce [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clausen, Bjorn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); DeWald, Adrian T. [Hill Engineering, LLC, Rancho Cordova, CA (United States)

    2015-12-08

    This report is an assessment performed by LANL that examines packaging for plutonium-bearing materials and the resilience of its design. This report discusses residual stresses in the 3013 outer, the SRS/Hanford and RFETS/LLNL inner containers, and teardrop samples used in studies to assess the potential for SCC in 3013 containers. Residual tensile stresses in the heat affected zones of the closure welds are of particular concern.

  7. Assessment of Residual Stresses in 3013 Inner and Outer Containers and Teardrop Samples

    International Nuclear Information System (INIS)

    Stroud, Mary Ann; Prime, Michael Bruce; Veirs, Douglas Kirk; Berg, John M.; Clausen, Bjorn; Worl, Laura Ann; DeWald, Adrian T.

    2015-01-01

    This report is an assessment performed by LANL that examines packaging for plutonium-bearing materials and the resilience of its design. This report discusses residual stresses in the 3013 outer, the SRS/Hanford and RFETS/LLNL inner containers, and teardrop samples used in studies to assess the potential for SCC in 3013 containers. Residual tensile stresses in the heat affected zones of the closure welds are of particular concern.

  8. Low-Stress Iridium Coatings for Thin-Shell X-Ray Telescopes, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and commercialize a new type of low-stress iridium (Ir) X-ray mirror coating technology that can be used for the construction of...

  9. A full-field residual stress estimation scheme for fitness-for-service assessment of pipe girth welds: Part II – A shell theory based implementation

    International Nuclear Information System (INIS)

    Song, Shaopin; Dong, Pingsha; Pei, Xianjun

    2015-01-01

    With the two key controlling parameters identified and their effectiveness demonstrated in Part I of this study series for constructing a continuous residual stress profile at weld region, a classical shell theory based model is proposed in this paper (Part II) for describing through-thickness residual stress distributions of both axial and hoop components at any axial location beyond weld region. The shell theory based model is analytically constructed through an assembly of two parts: One represents weld region and the other represents the remaining component section away from weld. The final assembly of the two parts leads to a closed form solution to both axial and hoop residual stress components as a function of axial distance from weld toe position. The effectiveness of the full-field residual stress estimation scheme is demonstrated by comparing with a series of finite element modeling results over a broad range of pipe weld geometries and welding conditions. The present development should provide a consistent and effective means for estimating through-thickness residual stress profile as a continuous function of pipe geometry, welding heat input, as well as material characteristics. - Highlights: • A shell theory based two-part assembly model is developed for generalizing residual stress distributions. • A full-field estimation of through-thickness residual stress profiles can be achieved. • The proposed estimation scheme offers both consistency and mechanics basis in residual stress profile generation. • An estimation scheme for welding-induced plastic zone size is proposed and validated. • The shell theory based estimation scheme can also provide a reasonable estimate on distortion in radial direction

  10. The stresses and displacements in cylindrical shells subject to arbitrary temperature distribution

    International Nuclear Information System (INIS)

    Tabakman, H.D.; Lin, Y.J.

    1977-01-01

    The paper begins with a statement of a reciprocal theorem in thermoelasticity based on a generalization of Betti's Reciprocal Theorem. This is followed by application to the solution of a simply supported thin walled cylindrical shell subject to arbitrary three-dimensional temperature distribution T(x,y,z). The usefulness of the theorem resides in the fact that existing solutions in elasticity may be used to obtain solutions of thermoelastic problems. This characteristic is of great importance, particularly when the temperature distribution is arbitrary, as is often the case in practise, and cannot be expressed in functional form; thus rendering solution of the thermoelastic equations very difficult. With solutions of a wide range of problems in elasticity in existence, application of the thermoelastic theorem is the key to solution of a broad class of problems in thermoelasticity, problems that cannot be solved by the classic process. (Auth.)

  11. Shell Venster

    International Nuclear Information System (INIS)

    De Wit, P.; Looijesteijn, B.; Regeer, B.; Stip, B.

    1995-03-01

    In the bi-monthly issues of 'Shell Venster' (window on Shell) attention is paid to the activities of the multinational petroleum company Shell Nederland and the Koninklijke/Shell Groep by means of non-specialist articles

  12. The oyster genome reveals stress adaptation and complexity of shell formation

    DEFF Research Database (Denmark)

    Zhang, Guofan; Fang, Xiaodong; Guo, Ximing

    2012-01-01

    The Pacific oyster Crassostrea gigas belongs to one of the most species-rich but genomically poorly explored phyla, the Mollusca. Here we report the sequencing and assembly of the oyster genome using short reads and a fosmid-pooling strategy, along with transcriptomes of development and stress re...

  13. A generic approach for a linear elastic fracture mechanics analysis of components containing residual stress

    International Nuclear Information System (INIS)

    Lee, Hyeong Y.; Nikbin, Kamran M.; O'Dowd, Noel P.

    2005-01-01

    A review of through thickness transverse residual stress distribution measurements in a number of components, manufactured from a range of steels, has been carried out. Residual stresses introduced by welding and mechanical deformation have been considered. The geometries consisted of welded T-plate joints, pipe butt joints, tube-on-plate joints, tubular Y-joints and tubular T-joints as well as cold bent tubes and repair welds. In addition, the collected data cover a range of engineering steels including ferritic, austenitic, C-Mn and Cr-Mo steels. The methods used to measure the residual stresses also varied. These included neutron diffraction, X-ray diffraction and deep hole drilling techniques. Measured residual stress data, normalised by their respective yield stress have shown an inverse linear correlation versus the normalised depth of the region containing the residual stress (up to 0.5 of the component thickness). A simplified generic residual stress profile based on a linear fit to the data is proposed for the case of a transverse residual tensile stress field. Whereas the profiles in assessment procedures are case specific the proposed linear profile can be varied to produce a combination of membrane and bending stress distributions to give lower or higher levels of conservatism on stress intensity factors, depending on the amount of case specific data available or the degree of safety required

  14. Effects of Different Solvents on the Surface Acidic Oxygen-containing Functional Groups on Xanthoceras sorbifolia Shell

    Directory of Open Access Journals (Sweden)

    Linan Liu

    2014-03-01

    Full Text Available This study reports the preparation of a novel biomaterial from a forestry residue - Xanthoceras sorbifolia shell (XSS - by solvent modification. The effects of acid and base (hydrochloric acerbic, acetic acid, sodium hydroxide, ammonia water and some organic solvents (ethanol, acetone, ethyl acetate, chloroform, petroleum ether, and n-hexane on the surface acidic functional groups (SAFGs on XSS were investigated. The amount of SAFGs was quantified using acid and alkali chemical titration methods, and the characteristics of virgin XSS were compared with treated ones by FT-IR spectroscopy. It was found that acid solutions can increase the concentration of SAFGs, while alkaline solutions reduce it. The XSS treated in 0.5 M HCl has the largest number of total acidic functional groups and phenolic hydroxyl groups. The shell extracted with 2 M acetic acid has the highest concentration of carboxyl. The SAFG contents were remarkably increased by treatments with ethanol and acetone, due to the outstanding enhancement of phenolic hydroxyl. These changes in the SAFGs of XSS brought about by treatments with various solutions could be a theoretical foundation for modifying this residue to create a new type of highly efficient absorbent material.

  15. On Inclusion-Matrix Interfacial Stresses in Composites Containing Phase-Transforming Phases

    International Nuclear Information System (INIS)

    Wang, Y.-C.; Ko, C.-C.

    2010-01-01

    Recent development in composites containing phase-transforming particles, such as vanadium dioxide or barium titanate, reveals the overall stiffness and viscoelastic damping of the composites may be unbounded. Negative stiffness is induced from phase transformation predicted by the Landau phase transformation theory. Although this unbounded phenomenon is theoretically supported with the composite homogenization theory, detailed stress analyses of the composites are still lacking. In this work, we analyze the two-dimensional plane stress elasticity problem of a square plate containing a circular inclusion, under the assumption that the Young's modulus of the inclusion is negative. Assumption of negative stiffness is a priori in the present analysis. A static loading condition is adopted to estimate the effective modulus of the composites by the ratio of applied stress to averaged strain on the loading edges. It is found that the interfacial stresses between the circular inclusion and matrix increase dramatically when the negative stiffness is so tuned that overall stiffness is unbounded. Furthermore, it is found that stress distributions in the inclusion are not uniform, contrary to Eshelby's theorem, which states, for two-phase, infinite composites, the inclusion's stress distribution is uniform when the shape of the inclusion has higher symmetry than an ellipse. The rationale for this nonuniform stress distributions is due to nonlocal effects induced from negative stiffness.

  16. Creep analysis of orthotropic shells

    International Nuclear Information System (INIS)

    Mehra, V.K.; Ghosh, A.

    1975-01-01

    A method of creep analysis of orthotropic cylindrical shells subjected to axisymmetric loads has been developed. A general study of creep behaviour of cylindrical shells subjected to a uniform internal pressure has been conducted for a wide range of values of anisotropy coefficients and creep law exponent. Analysis includes determination of stress re-distribution, strain rates, stationary state stresses. Application of reference stress technique has been extended to analysis of shells. (author)

  17. Stainless steel waste containers: an assessment of the probability of stress corrosion cracking

    International Nuclear Information System (INIS)

    Wanklyn, J.N.; Naish, C.C.

    1991-06-01

    The paper summarises information obtained from the literature and discussions held with corrosion experts from universities and industry, relevant to the possibility that stainless steel radioactive waste containers containing low level and intermediate level radioactive waste (LLW and ILW) could, when buried in concrete, suffer one or more of the forms of stress corrosion cracking (SCC). Stress corrosion cracking is caused by the simultaneous and synergistic action of a corrosive environment and stress. The initiation and propagation of SCC depend on a number of factors being present, namely a certain level of stress, an environment which will cause cracking and a susceptible metal or alloy. Generally the susceptibility of a metal or alloy to SCC increases as its strength level increases. The susceptibility in a specific environment will depend on: solution concentration, pH, temperature, and electrochemical potential of the metal/alloy. It is concluded that alkaline stress corrosion cracking is unlikely to occur under even the worst case conditions, that chloride stress corrosion cracking is a distinct possibility at the higher end of the temperature range (25-80 o C) and that stress corrosion related to sensitization of the steel will not be a problem for the majority of container material which is less than 5 mm in cross section. Thicker section material could become sensitized leading to a local problem in these areas. Contact with metals that are electrochemically more negative in corrosion potential is likely to reduce the incidence of SCC, at least locally. Measurement of repassivation potentials and rest potentials in solutions of relevant composition would provide a firmer prediction of the extent to which a high pH could reduce the likelihood of SCC caused by chlorides. (author)

  18. Enhanced energy density and thermostability in polyimide nanocomposites containing core-shell structured BaTiO3@SiO2 nanofibers

    Science.gov (United States)

    Wang, Junchuan; Long, Yunchen; Sun, Ying; Zhang, Xueqin; Yang, Hong; Lin, Baoping

    2017-12-01

    High energy density polymer nanocomposites with high-temperature resistance are quite desirable for film capacitors and many other power electronics. In this study, polyimide-based (PI) nanocomposite films containing the core-shell structured barium titanate@silicon dioxide (BT@SiO2) nanofibers have been successfully synthesized by the solution casting method. In the BT@SiO2/PI nanocomposite films, the dielectric permittivity as well as the breakdown strength increase significantly. The SiO2 shell layers with moderate dielectric permittivity could effectively mitigate the local field concentration induced by the large mismatch between the dielectric permittivity of BT and PI, which contributes to the enhancement of the breakdown strength of the PI nanocomposite films. As a result, the PI nanocomposite film filled with 3 vol% BT@SiO2 nanofibers exhibits a maximal energy density of 2.31 J cm-3 under the field of 346 kV/mm, which is 62% over the pristine PI (1.42 J cm-3 at 308 kV/mm) and about 200% greater than the best commercial polymer, i.e. biaxially oriented polypropylenes (BOPP) (≈1.2 J cm-3). The thermogravimetric analysis results indicate that the BT@SiO2/PI nanocomposite films have good thermal stability below 500 °C.

  19. Biaxial failure criteria and stress-strain response for concrete of containment structure

    International Nuclear Information System (INIS)

    Lee, S. K.; Woo, S. K.; Song, Y. C.; Kweon, Y. K.; Cho, C. H.

    2001-01-01

    Biaxial failure criteria and stress-strain response for plain concrete of containment structure on nuclear power plants are studied under uniaxial and biaxial stress(compression-compression, compression-tension, and tension-tension combined stress). The concrete specimens of a square plate type are used for uniaxial and biaxial loading. The experimental data indicate that the strength of concrete under biaxial compression, f 2 /f 1 =-1/-1, is 17 percent larger than under uniaxial compression and the poisson's ratio of concrete is 0.1745. On the base of the results, a biaxial failure envelope for plain concrete that the uniaxial strength is 5660 psi are provided, and the biaxial failure behaviors for three biaxial loading areas are plotted respectively. And, various analytical equations having the reliability are proposed for representations of the biaxial failure criteria and stress-strain response curves of concrete

  20. Caving thickness effects of surrounding rocks macro stress shell evolving characteristics

    Institute of Scientific and Technical Information of China (English)

    XIE Guang-xiang; YANG Ke

    2009-01-01

    In order to explore the influence of different caving thicknesses on the MSS dis-tribution and evolving characteristics of surrounding rocks in unsymmetrical disposal and fully mechanized top-coal caving (FMTC), based on unsymmetrical disposal characteris-tics, the analyses of numerical simulation, material simulation and in-situ observation were synthetically applied according to the geological and technical conditions of the 1151(3) working face in Xieqiao Mine. The results show that the stress peak value of the MSS-base and the ratio of MSS-body height to caving thickness are nonlinear and inversely proportional to the caving thickness. The MSS-base width, the MSS-body height, the MSS-base distance to working face wall and the rise distance of MSS-base beside coal pillar are nonlinear and directly proportional to the caving thickness. The characteristics of MSS distribution and its evolving rules of surrounding rocks and the integrated caving thickness effects are obtained. The investigations will provide lots of theoretic references to the surrounding rocks' stability control of the working face and roadway, roadway layout, gas extraction and exploitation, and efficiency of caving, etc.

  1. Containment

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The primary mission of the Containment Group is to ensure that underground nuclear tests are satisfactorily contained. The main goal is the development of sound technical bases for containment-related methodology. Major areas of activity include siting, geologic description, emplacement hole stemming, and phenomenological predictions. Performance results of sanded gypsum concrete plugs on the Jefferson, Panamint, Cornucopia, Labquark, and Bodie events are given. Activities are also described in the following areas: computational capabilities site description, predictive modeling, and cavity-pressure measurement. Containment publications are listed. 8 references

  2. Technique for calculating radioactivity penetration into soil through a break in the lower part of the containment shell during a nuclear power plant accident

    International Nuclear Information System (INIS)

    Basanskii, E.G.; Bondarenko, A.G.; Gavrilov, A.L.; Kudryashov, N.A.; Kul'zhik, M.N.; Pokrovskii, S.M.

    1992-01-01

    Accurate prediction of the development of processes which accompany severe accidents at nuclear power plants requires models of specific physical-chemical processes and the entire set of physical-chemical transformations. Developed here are two-dimensional methods for calculating the penetration of radionuclides into the soil through a break which arises in a buried part of the containment shell or the concrete foundation plate due to interactions with the melted core as a result of its complete destruction. The method discussed here for reducing the transport of radionuclides by a steam-gas mixture to a system of ordinary differential equations allows well-developed algorithms to be used effectively for calculating kinetics and radioactive decay-chain transformations in the examined problems. 10 refs., 3 figs

  3. Stress in pressurized spheres with imperfections

    International Nuclear Information System (INIS)

    Godoy, L.A.; Flores, F.G.

    1986-01-01

    Stresses due to geometric imperfections in pressurized thin spherical shells, which are used in containments of nuclear reactors and steam generation systems are studied. The analysis is carried out discretizing the imperfect geometry by finite element method. (Author) [pt

  4. Stress corrosion cracking of the tubing materials for nuclear steam generators in an environment containing lead

    International Nuclear Information System (INIS)

    Kim, Kyung Mo; Kim, Uh Chul; Lee, Eun Hee; Hwang, Seong Sik

    2004-01-01

    Steam generator tube materials show a high susceptibility to stress corrosion cracking (SCC) in an environment containing lead species and some nuclear power plants currently have degradation problems associated with lead-induced stress corrosion cracking in a caustic solution. Effects of an applied potential on SCC is tested for middle-annealed Alloy 600 specimens since their corrosion potential can be changed when lead oxide coexists with other oxidizing species like copper oxide in the sludge. In addition, all the steam generator tubing materials used for nuclear power plants being operated and currently under construction in Korea are tested in a caustic solution with lead oxide. (author)

  5. A finite-element for the analysis of shell intersections

    International Nuclear Information System (INIS)

    Koves, W.J.; Nair, S.

    1994-01-01

    The analysis of discontinuity stresses at shell intersections is a problem of great importance in several major industries. Some of the major areas of interest are pressure-containing equipment, such as reactors and piping, in the nuclear and fossil power industry; pressure vessels and heat exchangers in the petrochemical industry; bracing in offshore oil platforms; and aerospace structures. A specialized shell-intersection finite element, which is compatible with adjoining shell elements, has been developed that has the capability of physically representing the complex three-dimensional geometry and stress state at shell intersections. The element geometry is a contoured shape that matches a wide variety of practical nozzle configurations used in ASME Code pressure vessel construction, and allows computational rigor. A closed-form theory of elasticity solution was used to compute the stress state and strain energy in the element. The concept of an energy-equivalent nodal displacement and force vector set was then developed to allow complete compatibility with adjoining shell elements and retain the analytical rigor within the element. This methodology provides a powerful and robust computation scheme that maintains the computational efficiency of shell element solutions. The shell-intersection element was then applied to the cylinder-sphere and cylinder-cylinder intersection problems

  6. Stress concentration factors for an internally pressurized circular vessel containing a radial U-notch

    International Nuclear Information System (INIS)

    Carvalho, E.A. de

    2005-01-01

    This paper evaluates the stress concentration factors for an internally pressurized cylinder containing a radial U-notch along its length. This work studies the cases where the external to internal radius ratio (Ψ) is equal to 1.26, 1.52, 2.00, and 3.00 and the notch radius to internal radius ratio (Φ) is fixed and equal to 0.026. The U-notch depth varies from 0.1 to 0.6 of the wall thickness. Results are also presented for a fixed size semi-circular notch. Hoop stresses at the external wall are presented, showing regions where the stress matches the nominal one and the favourable places to install strain sensors. The finite element method is used to determine the stress concentration factors (K t ) for the above described situations and for a special case where a varying semi-circular notch is present with Ψ=3.00. This notch depth varies from 0.013 to 0.3 of the wall thickness. It is pointed out that even relatively small notches introduce large stress concentrations and disrupt the hoop stress distribution all over the cross section. Results are also compared to an example found in the literature for semi-circular notches and K t curves for both cases present the same shape

  7. Failure of MPC overpack and inner container under corrosion and mechanical stresses in a backfilled drift

    International Nuclear Information System (INIS)

    Ladkany, S.G.; Rajagopalan, R.

    1995-01-01

    The thickness and time at failure of the 100mm thick overpack and the 9.5mm thick inner container of a Multi-purpose canister have been assessed due to loads resulting from temperature, overburden, backfill pressure and seismic loads. Critical stresses at various reduced thicknesses, resulting from pitting corrosion over the years of emplacement, have been evaluated using Finite element analysis. Both simple and continuous support conditions of the overpack have been considered in the analysis. The anticipated failure time due to corrosion of overpack and inner container is further reduced due to overburden, self and seismic loads

  8. Pre-test analysis results of a PWR steel lined pre-stressed concrete containment model

    International Nuclear Information System (INIS)

    Basha, S.M.; Ghosh, Barnali; Patnaik, R.; Ramanujam, S.; Singh, R.K.; Kushwaha, H.S.; Venkat Raj, V.

    2000-02-01

    Pre-stressed concrete nuclear containment serves as the ultimate barrier against the release of radioactivity to the environment. This ultimate barrier must be checked for its ultimate load carrying capacity. BARC participated in a Round Robin analysis activity which is co-sponsored by Sandia National Laboratory, USA and Nuclear Power Engineering Corporation Japan for the pre-test prediction of a 1:4 size Pre-stressed Concrete Containment Vessel. In house finite element code ULCA was used to make the test predictions of displacements and strains at the standard output locations. The present report focuses on the important landmarks of the pre-test results, in sequential terms of first crack appearance, loss of pre-stress, first through thickness crack, rebar and liner yielding and finally liner tearing at the ultimate load. Global and local failure modes of the containment have been obtained from the analysis. Finally sensitivity of the numerical results with respect to different types of liners and different constitutive models in terms of bond strength between concrete and steel and tension-stiffening parameters are examined. The report highlights the important features which could be observed during the test and guidelines are given for improving the prediction in the post test computation after the test data is available. (author)

  9. EDF reactor building containment: Monitoring of the pre-stressed concrete structure

    International Nuclear Information System (INIS)

    Badez, N.

    2009-01-01

    The concrete containments of the EDF PWR are pre-stressed, and are monitored to observe the ageing effects on the structure, in particular the evolutions of creep, shrinkage, pre-stress loss, and air leakage tightness. Monitoring devices are installed during construction period, and measurements are checked, stored on a data base, and analysed during all the plant operating life time. The topic of the presentation is to present each part of the EDF monitoring organisation. A continuous monitoring makes it possible to produce periodical comprehensive reports about the mechanical analysis of the structure, the strain stabilisation,... Periodical tests (each 10 years) are planned. They consist to submit the containment to an internal air pressure at the accidental pressure level. The monitoring system gives the strain values in order to check their linearity and reversibility with decreasing pressure. At the same time, the containment tightness is checked with a specific instrumentation to verify that leak rate is lower than the required level. A general view of instrumentation implemented on the containment (sensors, data acquisition), and a data analysis are presented

  10. Perturbation of baseline thermal stress in the Mound 9516 Shipping Package primary containment vessel

    International Nuclear Information System (INIS)

    Sansalone, K.H.F.

    1995-01-01

    Full-capacity loading of heat sources into the Mound 9516 Shipping Package primary containment vessel (PCV) results in temperature gradients which are symmetric, due to the axisymmetry of the package design. Concern over the change in thermal gradients (and therefore, stress) in the PCV due to sub-capacity loading led to the analytical examination of this phenomenon. The PCVs are cylindrical in shape and are loaded into the package such that they and all containment components are concentrically arranged along a common longitudinal axis. If the design full-capacity loading of the PCVs in this package assumes the axisymmetric (or more precisely, cyclicly symmetric) arrangement of its heat-producing contents, then sub-capacity loading implies that in many cases, the load arrangement could be asymmetric with respect to the longitudinal axis. It is then feasible that the departure from heat load axisymmetry could perturb the nominal thermal gradients so that thermally-induced stress within the PCV might increase to levels deemed unacceptable. This study applies Finite Element analysis (FEA) to the problem and demonstrates that no such unacceptable thermal stress increase occurs in the PCV material due to the asymmetric arrangement of contents. copyright 1995 American Institute of Physics

  11. Self-contained in-vacuum in situ thin film stress measurement tool

    Science.gov (United States)

    Reinink, J.; van de Kruijs, R. W. E.; Bijkerk, F.

    2018-05-01

    A fully self-contained in-vacuum device for measuring thin film stress in situ is presented. The stress was measured by measuring the curvature of a cantilever on which the thin film was deposited. For this, a dual beam laser deflectometer was used. All optics and electronics needed to perform the measurement are placed inside a vacuum-compatible vessel with the form factor of the substrate holders of the deposition system used. The stand-alone nature of the setup allows the vessel to be moved inside a deposition system independently of optical or electronic feedthroughs while measuring continuously. A Mo/Si multilayer structure was analyzed to evaluate the performance of the setup. A radius of curvature resolution of 270 km was achieved. This allows small details of the stress development to be resolved, such as the interlayer formation between the layers and the amorphous-to-crystalline transition of the molybdenum which occurs at around 2 nm. The setup communicates with an external computer via a Wi-Fi connection. This wireless connection allows remote control over the acquisition and the live feedback of the measured stress. In principle, the vessel can act as a general metrology platform and add measurement capabilities to deposition setups with no modification to the deposition system.

  12. Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments

    International Nuclear Information System (INIS)

    Abraham, T.; Jain, H.; Soo, P.

    1986-06-01

    Types 304L, 316L, and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high-level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented

  13. A solid dietary fat containing fish oil redistributes lipoprotein subclasses without increasing oxidative stress in men

    DEFF Research Database (Denmark)

    Tholstrup, T.; Hellgren, Lars; Petersen, M.

    2004-01-01

    , a solid dietary fat containing (n-3) PUFA decreased plasma TAG, VLDL, and IDL cholesterol, and redistributed lipoprotein subclasses in LDL and HDL, with a higher concentration of the larger and less atherogenic subfractions. These changes took place without an increase in oxidative stress as measured...... of F than O fat (P oxidation measured as the ratio of plasma isoprostanes F-2 to arachidonic acid and urinary isoprostanes, whereas the vitamin E activity/plasma total lipids ratio was higher after intake of F than O (P = 0.008). In conclusion...

  14. Stress Corrosion Cracking of an Austenitic Stainless Steel in Nitrite-Containing Chloride Solutions

    Directory of Open Access Journals (Sweden)

    R. K. Singh Raman

    2014-12-01

    Full Text Available This article describes the susceptibility of 316L stainless steel to stress corrosion cracking (SCC in a nitrite-containing chloride solution. Slow strain rate testing (SSRT in 30 wt. % MgCl2 solution established SCC susceptibility, as evidenced by post-SSRT fractography. Addition of nitrite to the chloride solution, which is reported to have inhibitive influence on corrosion of stainless steels, was found to increase SCC susceptibility. The susceptibility was also found to increase with nitrite concentration. This behaviour is explained on the basis of the passivation and pitting characteristics of 316L steel in chloride solution.

  15. Stress corrosion cracking of steam generator tubing materials in lead containing solution

    International Nuclear Information System (INIS)

    Kim, H.P.; Hwang, S.S.; Kim, J.S.; Hong, J.H.

    2007-01-01

    Stress corrosion cracking (SCC) in lead (Pb) containing environments has been one of key issues in the nuclear power industry since Pb had been identified as a cause of the SCC of steam generator (SG) tubing materials in some power plants. To mitigate or prevent degradation of SG tubing materials, a mechanistic understanding of SCC in Pb containing environment is needed, along with an understanding of the source and transport behaviors of Pb species in the secondary circuit. In this work, SCC behaviors of Alloy 600 in Pb containing environments were studied. Influences of microstructures of Alloy 600 and the inhibitive additives were investigated using the C-ring and the slow strain rate tests in caustic solution and demineralized water at 315 o C. Microstructures of Alloy 600 were varied by heat treatment at different temperatures. The additives examined were nickel boride (NiB) and cerium boride (CeB 6 ). The surface films were analyzed using Auger Electron Spectroscopy (AES) and Energy Dispersive X-ray Spectroscopy (EDS). The SCC mode varied with microstructure. Effectiveness of the additives in Pb containing environments is discussed. (author)

  16. Artifacts Generated During Azoalkane Peroxy Radical Oxidative Stress Testing of Pharmaceuticals Containing Primary and Secondary Amines.

    Science.gov (United States)

    Nefliu, Marcela; Zelesky, Todd; Jansen, Patrick; Sluggett, Gregory W; Foti, Christopher; Baertschi, Steven W; Harmon, Paul A

    2015-12-01

    We report artifactual degradation of pharmaceutical compounds containing primary and secondary amines during peroxy radical-mediated oxidative stress carried out using azoalkane initiators. Two degradation products were detected when model drug compounds dissolved in methanol/water were heated to 40°C with radical initiators such as 2,2'-azobis(2-methylpropionitrile) (AIBN). The primary artifact was identified as an α-aminonitrile generated from the reaction of the amine group of the model drug with formaldehyde and hydrogen cyanide, generated as byproducts of the stress reaction. A minor artifact was generated from the reaction between the amine group and isocyanic acid, also a byproduct of the stress reaction. We report the effects of pH, initiator/drug molar ratio, and type of azoalkane initiator on the formation of these artifacts. Mass spectrometry and nuclear magnetic resonance were used for structure elucidation, whereas mechanistic studies, including stable isotope labeling experiments, cyanide analysis, and experiments exploring the effects of butylated hydroxyanisole addition, were employed to support the degradation pathways. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  17. Buckling of steel containment shells. Task 4. Use of the PANDA program for simple buckling analyses of stiffened cylindrical shells. Final report, 25 August 1980-30 September 1982

    International Nuclear Information System (INIS)

    Bushnell, D.

    1982-12-01

    Under Task 4 the PANDA computer program was modified to permit calculation of critical load interaction curves for buckling of stiffened cylindrical shells with stiffeners running axially or circumferentially or both. Knockdown factors for geometric imperfections and plasticity reduction factors were introduced so that interaction curves can now be calculated for imperfect elastic-plastic shells. The knockdown factors and plasticity reduction factors are computed from a modified form of ASME Code Case N-284. The new version of PANDA was checked by making numerous comparisons with tests on fabricated stiffened cylinders

  18. Seismic analysis of axisymmetric shells

    International Nuclear Information System (INIS)

    Jospin, R.J.; Toledo, E.M.; Feijoo, R.A.

    1984-01-01

    Axisymmetric shells subjected to multiple support excitation are studied. The shells are spatialy discretized by the finite element method and in order to obtain estimates for the maximum values of displacements and stresses the response spectrum tecnique is used. Finally, some numerical results are presented and discussed in the case of a shell of revolution with vertical symmetry axis, subjected to seismic ground motions in the horizontal, vertical and rocking directions. (Author) [pt

  19. A finite element model for nonlinear shells of revolution

    International Nuclear Information System (INIS)

    Cook, W.A.

    1979-01-01

    A shell-of-revolution model was developed to analyze impact problems associated with the safety analysis of nuclear material shipping containers. The nonlinear shell theory presented by Eric Reissner in 1972 was used to develop our model. Reissner's approach includes transverse shear deformation and moments turning about the middle surface normal. With these features, this approach is valid for both thin and thick shells. His theory is formulated in terms of strain and stress resultants that refer to the undeformed geometry. This nonlinear shell model is developed using the virtual work principle associated with Reissner's equilibrium equations. First, the virtual work principle is modified for incremental loading; then it is linearized by assuming that the nonlinear portions of the strains are known. By iteration, equilibrium is then approximated for each increment. A benefit of this approach is that this iteration process makes it possible to use nonlinear material properties. (orig.)

  20. C. elegans flavin-containing monooxygenase-4 is essential for osmoregulation in hypotonic stress

    Directory of Open Access Journals (Sweden)

    Nisha Hirani

    2016-05-01

    Full Text Available Studies in Caenorhabditis elegans have revealed osmoregulatory systems engaged when worms experience hypertonic conditions, but less is known about measures employed when faced with hypotonic stress. Inactivation of fmo-4, which encodes flavin-containing monooxygenase-4, results in dramatic hypoosmotic hypersensitivity; worms are unable to prevent overwhelming water influx and swell rapidly, finally rupturing due to high internal hydrostatic pressure. fmo-4 is expressed prominently in hypodermis, duct and pore cells but is excluded from the excretory cell. Thus, FMO-4 plays a crucial osmoregulatory role by promoting clearance of excess water that enters during hypotonicity, perhaps by synthesizing an osmolyte that acts to establish an osmotic gradient from excretory cell to duct and pore cells. C. elegans FMO-4 contains a C-terminal extension conserved in all nematode FMO-4s. The coincidently numbered human FMO4 also contains an extended C-terminus with features similar to those of FMO-4. Although these shared sequence characteristics suggest potential orthology, human FMO4 was unable to rescue the fmo-4 osmoregulatory defect. Intriguingly, however, mammalian FMO4 is expressed predominantly in the kidney – an appropriate site if it too is, or once was, involved in osmoregulation.

  1. Nonlinear analysis of pre-stressed concrete containment vessel (PCCV) using the damage plasticity model

    Energy Technology Data Exchange (ETDEWEB)

    Shokoohfar, Ahmad; Rahai, Alireza, E-mail: rahai@aut.ac.ir

    2016-03-15

    Highlights: • This paper describes nonlinear analyses of a 1:4 scale model of a (PCCV). • Coupled temp-disp. analysis and concrete damage plasticity are considered. • Temperature has limited effects on correct failure mode estimation. • Higher pre-stressing forces have limited effects on ultimate radial displacements. • Anchorage details of liner plates leads to prediction of correct failure mode. - Abstract: This paper describes the nonlinear analyses of a 1:4 scale model of a pre-stressed concrete containment vessel (PCCV). The analyses are performed under pressure and high temperature effects with considering anchorage details of liner plate. The temperature-time history of the model test is considered as an input boundary condition in the coupled temp-displacement analysis. The constitutive model developed by Chang and Mander (1994) is adopted in the model as the basis for the concrete stress–strain relation. To trace the crack pattern of the PCCV concrete faces, the concrete damage plasticity model is applied. This study includes the results of the thermal and mechanical behaviors of the PCCV subject to temperature loading and internal pressure at the same time. The test results are compared with the analysis results. The analysis results show that the temperature has little impact on the ultimate pressure capacity of the PCCV. To simulate the exact failure mode of the PCCV, the anchorage details of the liner plates around openings should be maintained in the analytical models. Also the failure mode of the PCCV structure hasn’t influenced by hoop tendons pre-stressing force variations.

  2. A directory of computer codes suitable for stress analysis of HLW containers - Compas project

    International Nuclear Information System (INIS)

    1989-01-01

    This document reports the work carried out for the Compas project which looked at the capabilities of various computer codes for the stress analysis of high-level nuclear-waste containers and overpacks. The report concentrates on codes used by the project partners, but also includes a number of the major commercial finite element codes. The report falls into two parts. The first part of the report describes the capabilities of the codes. This includes details of the solution methods used in the codes, the types of analysis which they can carry out and the interfacing with pre - and post - processing packages. This is the more comprehensive section of the report. The second part of the report looks at the performance of a selection of the codes (those used by the project partners). This look at how the codes perform in a number of test problems which require calculations typical of those encountered in the design and analysis of high-level waste containers and overpacks

  3. Thermal stress analysis of reactor containment building considering severe weather condition

    International Nuclear Information System (INIS)

    Lee, Yun; Kim, Yun-Yong; Hyun, Jung-Hwan; Kim, Do-Gyeum

    2014-01-01

    Highlights: • We examine that through-wall crack risk in cold weather is high. • It is predicted that cracking in concrete wall will not happen in hot region. • Cracking due to hydration heat can be controlled by appropriate curing condition. • Temperature differences between inner and outer face is relatively small in hot weather. - Abstract: Prediction of concrete cracking due to hydration heat in mass concrete such as reactor containment building (RCB) in nuclear power plant is a crucial issue in construction site. In this study, the numerical analysis for heat transfer and stress development is performed for the containment wall in RCB by considering the severe weather conditions. Finally, concrete cracking risk in hot and cold weather is discussed based on analysis results. In analyses considering severe weather conditions, it is found that the through-wall cracking risk in cold weather is high due to the abrupt temperature difference between inside concrete and the ambient air in cold region. In hot weather, temperature differences between inner and outer face is relatively small, and accordingly the relevant cracking risk is relatively low in contrast with cold weather

  4. Over-pressure test on BARCOM pre-stressed concrete containment

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, R.M.; Singh, Tarvinder; Thangamani, I.; Trivedi, Neha; Singh, Ram Kumar, E-mail: rksingh@barc.gov.in

    2014-04-01

    Bhabha Atomic Research Centre (BARC), Trombay has organized an International Round Robin Analysis program to carry out the ultimate load capacity assessment of BARC Containment (BARCOM) test model. The test model located in BARC facilities Tarapur; is a 1:4 scale representation of 540 MWe Pressurized Heavy Water Reactor (PHWR) pre-stressed concrete inner containment structure of Tarapur Atomic Power Station (TAPS) unit 3 and 4. There are a large number of sensors installed in BARCOM that include vibratory wire strain gauges of embedded and spot-welded type, surface mounted electrical resistance strain gauges, dial gauges, earth pressure cells, tilt meters and high resolution digital camera systems for structural response, crack monitoring and fracture parameter measurement to evaluate the local and global behavior of the containment test model. The model has been tested pneumatically during the low pressure tests (LPTs) followed by proof test (PT) and integrated leakage rate test (ILRT) during commissioning. Further the over pressure test (OPT) has been carried out to establish the failure mode of BARCOM Test-Model. The over-pressure test will be completed shortly to reach the functional failure of the test model. Pre-test evaluation of BARCOM was carried out with the results obtained from the registered international round robin participants in January 2009 followed by the post-test assessment in February 2011. The test results along with the various failure modes related to the structural members – concrete, rebars and tendons identified in terms of prescribed milestones are presented in this paper along with the comparison of the pre-test predictions submitted by the registered participants of the Round Robin Analysis for BARCOM test model.

  5. A study on the nonlinear finite element analysis of reinforced concrete structures: shell finite element formulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Jin; Seo, Jeong Moon

    2000-08-01

    The main goal of this research is to establish a methodology of finite element analysis of containment building predicting not only global behaviour but also local failure mode. In this report, we summerize some existing numerical analysis techniques to be improved for containment building. In other words, a complete description of the standard degenerated shell finite element formulation is provided for nonlinear stress analysis of nuclear containment structure. A shell finite element is derived using the degenerated solid concept which does not rely on a specific shell theory. Reissner-Mindlin assumptions are adopted to consider the transverse shear deformation effect. In order to minimize the sensitivity of the constitutive equation to structural types, microscopic material model is adopted. The four solution algorithms based on the standard Newton-Raphson method are discussed. Finally, two numerical examples are carried out to test the performance of the adopted shell medel.

  6. A study on the nonlinear finite element analysis of reinforced concrete structures: shell finite element formulation

    International Nuclear Information System (INIS)

    Lee, Sang Jin; Seo, Jeong Moon

    2000-08-01

    The main goal of this research is to establish a methodology of finite element analysis of containment building predicting not only global behaviour but also local failure mode. In this report, we summerize some existing numerical analysis techniques to be improved for containment building. In other words, a complete description of the standard degenerated shell finite element formulation is provided for nonlinear stress analysis of nuclear containment structure. A shell finite element is derived using the degenerated solid concept which does not rely on a specific shell theory. Reissner-Mindlin assumptions are adopted to consider the transverse shear deformation effect. In order to minimize the sensitivity of the constitutive equation to structural types, microscopic material model is adopted. The four solution algorithms based on the standard Newton-Raphson method are discussed. Finally, two numerical examples are carried out to test the performance of the adopted shell medel

  7. Elastic stresses at reinforced nozzles in spherical shells with pressure and moment loading. Phase report 117-9

    International Nuclear Information System (INIS)

    Rodabaugh, E.C.; Gwaltney, R.C.

    1975-01-01

    The ASME Boiler and Pressure Vessel Code gives design guidance for nozzles in pressure vessels in the form of ''stress indices.'' These stress indices enable the designer of Class 1 nuclear pressure vessels to quickly determine the magnitude of stresses due to internal pressure loading; a task otherwise requiring an expensive and time-consuming stress analysis. The Code gives stress indices for nozzles in both heads and cylindrical vessels. Results of calculations of stresses in spherical heads or vessels are summarized. The validity of the Code indices for this geometry is examined and, as a result, a few relatively minor changes are recommended. The definitions involved in the use of the Code stress indices are not sufficiently clear and explicit. Accordingly, recommendations for changes in the Code to improve these defintions as well as to correct some obvious errors are presented. These recommendations apply to nozzles in cylindrical vessels and any type of formed head (e.g., spherical, elliptical, torispherical). However, the data presented herein apply only to isolated nozzles in spherical heads or in other heads where the radius of curvature in the vicinity of the nozzle is sphere-like, e.g., as in the center of a torispherical head. (U.S.)

  8. Toxicity assessment of simulated urban runoff containing polycyclic musks and cadmium in Carassius auratus using oxidative stress biomarkers

    International Nuclear Information System (INIS)

    Chen Fang; Gao Jie; Zhou Qixing

    2012-01-01

    The objective of this study was to assess potential toxic effects of simulated urban runoff on Carassius auratus using oxidative stress biomarkers. The activity of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the content of malondialdehyde (MDA) in the liver of C. auratus were analyzed after a 7-, 14- and 21-day exposure to simulated urban runoff containing galaxolide (HHCB) and cadmium (Cd). The results showed that the activity of antioxidant enzymes and the content of MDA increased significantly exposed to the simulated urban runoff containing HHCB alone or mixture of HHCB and Cd. The activity of the investigated enzymes and the content of MDA then returned to the blank level over a longer period of exposure. The oxidative stress could be obviously caused in the liver of C. auratus under the experimental conditions. This could provide useful information for toxic risk assessment of urban runoff. - Highlights: ► We assessed potential toxicity of urban runoff containing HHCB and Cd. ► Exposure of simulated urban runoff can caused oxidative stress in C. auratus liver. ► SOD and CAT are more sensitive than POD and more suitable for indicating the toxicity of urban runoff. ► The present study using oxidative stress biomarkers could provide useful information for toxic risk assessment of urban runoff. - Simulated urban runoff containing HHCB and Cd could cause oxidative stress on the liver of Carassius auratus, which could provide useful information for toxic risk assessment of urban runoff.

  9. Stress-induced thickening of Ω phase in Al–Cu–Mg alloys containing various Ag additions

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Song [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China); Liu, Zhiyi, E-mail: liuzhiyi@mail.csu.edu.cn [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China); Zhou, Xuanwei; Xia, Peng; Liu, Meng [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China)

    2014-01-01

    The thickening of Ω phase in Al–Cu–Mg alloys containing various bulk Ag contents during stress aging at 200 °C with a tensile stress of 240 MPa was investigated by a combination of transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and atom probe tomography (APT). TEM characterization confirmed preferred orientation of Ω phase in all stress-aged samples. Corresponding quantitative TEM calculations revealed the thickening kinetics of Ω phase was significantly accelerated during stress aging as compared to that during stress-free aging at 200 °C. HRTEM analysis on the α/Ω interfacial structure confirmed that the applied tensile stress facilitated the rapid nucleation of the growth ledge on the broad face of Ω phase, thereby resulting in the accelerated plate thickening during stress aging at 200 °C. Meanwhile, quantitative TEM analysis highlighted the stress-induced thickening of Ω phase at 200 °C was affected by the bulk Ag content. This was consistent with the HRTEM observation as the ledge nucleation was found to be suppressed with increasing Ag addition. Our APT analysis on different stress-aged samples further suggested the progressive enrichment of Ag atoms in the segregation layer helped to stabilize the interfacial structure and was responsible for the lowest nucleation rate of the ledge in 1.77Ag alloy as compared to that in 0.46Ag alloy.

  10. Stress-induced thickening of Ω phase in Al–Cu–Mg alloys containing various Ag additions

    International Nuclear Information System (INIS)

    Bai, Song; Liu, Zhiyi; Zhou, Xuanwei; Xia, Peng; Liu, Meng

    2014-01-01

    The thickening of Ω phase in Al–Cu–Mg alloys containing various bulk Ag contents during stress aging at 200 °C with a tensile stress of 240 MPa was investigated by a combination of transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and atom probe tomography (APT). TEM characterization confirmed preferred orientation of Ω phase in all stress-aged samples. Corresponding quantitative TEM calculations revealed the thickening kinetics of Ω phase was significantly accelerated during stress aging as compared to that during stress-free aging at 200 °C. HRTEM analysis on the α/Ω interfacial structure confirmed that the applied tensile stress facilitated the rapid nucleation of the growth ledge on the broad face of Ω phase, thereby resulting in the accelerated plate thickening during stress aging at 200 °C. Meanwhile, quantitative TEM analysis highlighted the stress-induced thickening of Ω phase at 200 °C was affected by the bulk Ag content. This was consistent with the HRTEM observation as the ledge nucleation was found to be suppressed with increasing Ag addition. Our APT analysis on different stress-aged samples further suggested the progressive enrichment of Ag atoms in the segregation layer helped to stabilize the interfacial structure and was responsible for the lowest nucleation rate of the ledge in 1.77Ag alloy as compared to that in 0.46Ag alloy

  11. Porous metal revision shells for management of contained acetabular bone defects at a mean follow-up of six years: a comparison between up to 50% bleeding host bone contact and more than 50% contact.

    Science.gov (United States)

    Sternheim, A; Backstein, D; Kuzyk, P R T; Goshua, G; Berkovich, Y; Safir, O; Gross, A E

    2012-02-01

    We report the use of porous metal acetabular revision shells in the treatment of contained bone loss. The outcomes of 53 patients with ≤ 50% acetabular bleeding host bone contact were compared with a control group of 49 patients with > 50% to 85% bleeding host bone contact. All patients were treated with the same type of trabecular metal acetabular revision shell. The mean age at revision was 62.4 years (42 to 80) and the mean follow-up of both groups was 72.4 months (60 to 102). Clinical, radiological and functional outcomes were assessed. There were four (7.5%) mechanical failures in the ≤ 50% host bone contact group and no failures in the > 50% host bone contact group (p = 0.068). Out of both groups combined there were four infections (3.9%) and five recurrent dislocations (4.9%) with a stable acetabular component construct that were revised to a constrained liner. Given the complexity of the reconstructive challenge, porous metal revision acetabular shells show acceptable failure rates at five to ten years' follow-up in the setting of significant contained bone defects. This favourable outcome might be due to the improved initial stability achieved by a high coefficient of friction between the acetabular implant and the host bone, and the high porosity, which affords good bone ingrowth.

  12. Stress-corrosion-cracking studies on candidate container alloys for the Tuff Repository

    International Nuclear Information System (INIS)

    Beavers, J.A.; Durr, C.L.

    1992-05-01

    Cortest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials used for high-level waste package as part of the information needed by the Nuclear Regulatory Commission (NRC) to assess the Department of Energy's application to construct to geologic repository for high-level radioactive waste. At the direction of the NRC, the program focused on the Tuff Repository. This report summarizes the results of Stress-Corrosion-Cracking (SCC) studies performed in Tasks 3, 5, and 7 of the program. Two test techniques were used; U-bend exposures and Slow-Strain-Rate (SSR) tests. The testing was performed on two copper-base alloys (Alloy CDA 102 and Alloy CDA 175) and two Fe-Cr-Ni alloys (Alloy 304L and Alloy 825) in simulated J-13 groundwater and other simulated solutions for the Tuff Repository. These solutions were designed to simulate the effects of concentration and irradiation on the groundwater composition. All SCC testing on the Fe-Cr-Ni Alloys was performed on solution-annealed specimens and thus issues such as the effect of sensitization on SCC were not addressed

  13. The modified indeterminate couple stress model: Why Yang et al.'s arguments motivating a symmetric couple stress tensor contain a gap and why the couple stress tensor may be chosen symmetric nevertheless

    OpenAIRE

    Münch, Ingo; Neff, Patrizio; Madeo, Angela; Ghiba, Ionel-Dumitrel

    2015-01-01

    We show that the reasoning in favor of a symmetric couple stress tensor in Yang et al.'s introduction of the modified couple stress theory contains a gap, but we present a reasonable physical hypothesis, implying that the couple stress tensor is traceless and may be symmetric anyway. To this aim, the origin of couple stress is discussed on the basis of certain properties of the total stress itself. In contrast to classical continuum mechanics, the balance of linear momentum and the balance of...

  14. Modeling the carbon isotope composition of bivalve shells (Invited)

    Science.gov (United States)

    Romanek, C.

    2010-12-01

    The stable carbon isotope composition of bivalve shells is a valuable archive of paleobiological and paleoenvironmental information. Previous work has shown that the carbon isotope composition of the shell is related to the carbon isotope composition of dissolved inorganic carbon (DIC) in the ambient water in which a bivalve lives, as well as metabolic carbon derived from bivalve respiration. The contribution of metabolic carbon varies among organisms, but it is generally thought to be relatively low (e.g., 90%) in the shells from terrestrial organisms. Because metabolic carbon contains significantly more C-12 than DIC, negative excursions from the expected environmental (DIC) signal are interpreted to reflect an increased contribution of metabolic carbon in the shell. This observation contrasts sharply with modeled carbon isotope compositions for shell layers deposited from the inner extrapallial fluid (EPF). Previous studies have shown that growth lines within the inner shell layer of bivalves are produced during periods of anaerobiosis when acidic metabolic byproducts (e.g., succinic acid) are neutralized (or buffered) by shell dissolution. This requires the pH of EPF to decrease below ambient levels (~7.5) until a state of undersaturation is achieved that promotes shell dissolution. This condition may occur when aquatic bivalves are subjected to external stressors originating from ecological (predation) or environmental (exposure to atm; low dissolved oxygen; contaminant release) pressures; normal physiological processes will restore the pH of EPF when the pressure is removed. As a consequence of this process, a temporal window should also exist in EPF at relatively low pH where shell carbonate is deposited at a reduced saturation state and precipitation rate. For example, EPF chemistry should remain slightly supersaturated with respect to aragonite given a drop of one pH unit (6.5), but under closed conditions, equilibrium carbon isotope fractionation

  15. The effectiveness of a standardized rose hip powder, containing seeds and Shells of Rosa canina, on cell longevity, skin wrinkles, moisture, and elasticity 

    DEFF Research Database (Denmark)

    Phetcharat, L; Wongsuphasawat, K; Winther, Kaj

    2015-01-01

    Objective: To evaluate the effects of a rose hip powder (Hyben Vital®) made from seeds and shells on cell senescence, skin wrinkling, and aging. Methods: A total of 34 healthy subjects, aged 35–65 years, with wrinkles on the face (crow’s-feet) were subjected to a randomized and double-blinded cli...... hip product on cell membranes of stored erythrocyte cells observed in this study may contribute to improve the cell longevity and obstructing skin aging. Keywords: rose hip seed and shell powder, cell longevity, wrinkles, aging skin, moisture, elasticity......Objective: To evaluate the effects of a rose hip powder (Hyben Vital®) made from seeds and shells on cell senescence, skin wrinkling, and aging. Methods: A total of 34 healthy subjects, aged 35–65 years, with wrinkles on the face (crow’s-feet) were subjected to a randomized and double...... longevity was measured in terms of leakage of hemoglobin through red cell membranes (hemolytic index) in blood samples kept in a blood bank for 5 weeks. Significance of all values was attained with P#0.05. Results: In the double-blinded study, the rose hip group showed statistically significant improvements...

  16. The GDQ Method of Thermal Vibration Laminated Shell with Actuating Magnetostrictive Layers

    Directory of Open Access Journals (Sweden)

    C.C. Hong

    2017-06-01

    Full Text Available The research of laminated magnetostrictive shell under thermal vibration was computed by using the generalized differential quadrature (GDQ method. In the thermoelastic stress-strain equations that contain the terms linear temperature rise and the magnetostrictive material with velocity feedback control. The dynamic equilibrium differential equations with displacements were normalized and discretized into the dynamic discretized equations by the GDQ method. Two edges of laminated shell with clamped boundary conditions were considered. The values of interlaminar thermal stresses and center displacement of shell with and without velocity feedback control were calculated, respectively. The purpose of this research is to compute the time responses of displacement and stresses in the laminated magnetostrictive shell subjected to thermal vibration with suitable controlled gain values. The numerical GDQ results of displacement and stresses are also obtained and investigated. With velocity feedback and suitable control gain values are found to reduce the amplitude of displacement and stresses into a smaller value. The higher values of temperature get the higher amplitude of displacement and stresses. The GDQ results of actuating magnetostrictive shells can be applied in the field of morphing aircraft (adaptive structures and smart materials to reduce and suppress the vibration when under aero-thermal flutter.

  17. Dissolution of copper in chloride/ammonia mixtures and the implications for the stress corrosion cracking of copper containers

    International Nuclear Information System (INIS)

    King, F.; Greidanus, G.; Jobe, D.J.

    1999-05-01

    Stress-corrosion cracking is a possible failure mechanism for copper nuclear fuel waste disposal containers. One species known to cause the stress corrosion of copper alloys is ammonia. It is conceivable that ammonia could be produced in a disposal vault under certain, very specific conditions. There are a number of conditions, however, that mitigate against container failure by stress corrosion, one of which is the presence of chloride ions in deep Canadian Shield groundwaters. There are a number of reports in the literature that suggest that Cl - has an inhibitive effect on the stress corrosion of Cu alloys in ammonia solutions. The electrochemical behaviour of Cu in Cl - /ammonia solutions has been studied as a function of ammonia concentration, pH, the rate of mass transport and electrochemical potential. In particular, the effects of these parameters on the formation Of Cu 2 O films and the steady-state dissolution behaviour have been determined. All experiments were carried out in 0.1 mol·dm -3 NaC1 as a base solution. A series of aqueous speciation and equilibrium potential/pH diagrams are also presented for the quaternary system Cu-C1 - NH 3 /NH 4 + H 2 O. These diagrams are used to interpret the results of the electrochemical experiments reported here. In addition, it is demonstrated how these diagrams could be used to predict the time-dependence of the susceptibility to stress corrosion cracking of Cu containers in a disposal vault. (author)

  18. Steel containment buckling

    International Nuclear Information System (INIS)

    Bennett, J.G.; Fly, G.W.; Baker, W.E.

    1984-01-01

    The Steel Containment Buckling program is in its fourth phase of work directed at the evaluation of the effects of the structural failure mode of steel containments when the membrane stresses are compressive. The structural failure mode for this state of stress is instability or buckling. The program to date has investigated: (1) the effect on overall buckling capacity of the ASME area replacement method for reinforcing around circular penetrations; (2) a set of benchmark experiments on ring-stiffened shells having reinforced and framed penetrations; (3) large and small scale experiments on knuckle region buckling from internal pressure and post-buckling behavior to failure for vessel heads having torispherical geometries; and (4) buckling under time-dependent loadings (dynamic buckling). The first two investigations are complete, the knuckle buckling experimental efforts are complete with data analysis and reporting in progress, and the dynamic buckling experimental and analytical work is in progress

  19. Potential mechanisms for corrosion and stress corrosion cracking failure of 3013 storage containers composed of 316 stainless steel

    International Nuclear Information System (INIS)

    Kolman, D.G.; Butt, D.P.

    1998-01-01

    The degradation of 316 stainless steel (SS) storage container materials is a potential problem for radioactive waste disposition. Container materials will be exposed to significant ionizing radiation, elevated temperatures, embrittling and/or alloying agents (e.g., gallium), chloride-containing compounds (as much as 20 wt% Cl or Cl - ), oxidizing compounds, and a limited quantity of moisture. Additionally, containers will contain welds that have heterogeneous composition due to solute segregation and that may retain significant residual stress. All of the above-listed environmental and material conditions have been shown to be deleterious to material integrity under certain conditions. Unfortunately, the precise conditions within each container and environment is unknown and may vary widely from container to container. Thus, no single test or set of tests will be able mimic the broad range of storage container conditions. Additionally, material behavior cannot be predicted because the synergistic effects of temperature, time, chloride, moisture, sensitization, weldments, salt formation, etc., have not been fully studied. The complexity and uncertainty of storage conditions precludes any detailed recommendations. This document attempts to detail selected previous studies and to suggest some general guidelines for storage of radioactive waste. Because of the voluminous research in this area, this review cannot be considered to be comprehensive. Readers are directed to references that contain detailed reviews of particular processes for more information. Note that the effect of gallium on the degradation of SS storage containers has been discussed elsewhere and will not be discussed here

  20. Shell supports

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2004-01-01

    A new statical and conceptual model for membrane shell structures - the stringer system - has been found. The principle was first published at the IASS conference in Copenhagen (OHL91), and later the theory has been further developed (ALMO3)(ALMO4). From the analysis of the stringer model it can...... be concluded that all membrane shells can be described by a limited number of basic configurations of which quite a few have free edges....

  1. Stress-intensity factors for a thick-walled cylinder containing an annular imbedded or external or internal surface crack

    Science.gov (United States)

    Erdol, R.; Erdogan, F.

    1976-01-01

    The elastostatic axisymmetric problem for a long thick-walled cylinder containing a ring-shaped internal or edge crack is considered. Using the standard transform technique the problem is formulated in terms of an integral equation which has a simple Cauchy kernel for the internal crack and a generalized Cauchy kernel for the edge crack as the dominant part. As examples the uniform axial load and the steady-state thermal stress problems have been solved and the related stress intensity factors have been calculated. Among other findings the results show that in the cylinder under uniform axial stress containing an internal crack the stress intensity factor at the inner tip is always greater than that at the outer tip for equal net ligament thicknesses and in the cylinder with an edge crack which is under a state of thermal stress the stress intensity factor is a decreasing function of the crack depth, tending to zero as the crack depth approaches the wall thickness.

  2. Characterization of 1-Aminocyclopropane-1-Carboxylate (ACC) Deaminase-Containing Pseudomonas spp. in the Rhizosphere of Salt-Stressed Canola

    NARCIS (Netherlands)

    Akhgar, A.; Arzanlou, M.; Bakker, Peter; Hamidpour, M.

    2014-01-01

    When exposed to biotic or abiotic stress conditions, plants produce ethylene from its immediate precursor 1-aminocyclopropane-1- carboxylate (ACC), leading to retarded root growth and senescence. Many plant growth-promoting rhizobacteria contain the enzyme ACC deaminase and this enzyme can cleave

  3. Stress analysis of LOFT containment vessel attachments for the mainsteam and feedwater piping support structures

    International Nuclear Information System (INIS)

    Finicle, D.P.

    1977-01-01

    The LOFT Containment Vessel attachments for the Mainsteam and Feedwater Piping Support Structures have been analyzed for operating and faulted loading conditions. This report contains the analysis of the connections to the containment vessel for the most current design and loading. Also contained in this report is the analysis of the piping supports

  4. The PACE-1450 experiment - Crack and leakage behavior of a pre-stressed concrete containment wall considering ageing

    International Nuclear Information System (INIS)

    Hermann, N.; Mueller, H.S.; Niklasch, C.; Michel-Ponnelle, S.; Bento, C.; Masson, B.

    2015-01-01

    As an intermediate sized experiment the PACE-1450 experiment aims to investigate the behavior of a curved specimen (length: 3.5 m, width: 1.8 m, height: 1.2 m) which is representative for a 1450 MWe nuclear power plant containment under accidental loading conditions. One focus of this experimental test campaign is the consideration of the ageing of the structure which among other effects leads to a pre-stressing loss. The crack behavior of the realistically reinforced specimen is of as much interest as it is the leakage behavior when an inner pressure occurs within the containment. The reinforcement layout of the specimen is very similar to the original geometry and consists mainly of reinforcement meshes of bars near the inner and outer surface and four pre-stressing cables in the circumferential direction. During the tests the specimen is loaded by pressure which simulates the internal accidental containment pressure of up to 6 bars (absolute pressure). The resulting ring tensile stress in the cylindrical part of the containment is externally applied by hydraulic jacks. An initial pre-stressing of the specimen of 12 MPa is realized in such a way that decreasing the pre-stressing force for the purpose of simulating the ageing of the structure is possible. The facility allows for the cracking of the pre-stressed specimen and for leakage measurements at different controlled crack widths. The specimen is equipped with embedded optical fiber strain and temperature sensors and a sound detection system to record the initiation of cracks. The paper explains the test set-up and presents results of the ongoing test series regarding the cracking and leakage behavior of the specimen

  5. Static yield stress of a magnetorheological fluid containing Pickering emulsion polymerized Fe2O3/polystyrene composite particles.

    Science.gov (United States)

    Seo, Youngwook P; Kwak, Soonjong; Choi, Hyoung Jin; Seo, Yongsok

    2016-02-01

    The flow behaviors of magnetorheological (MR) suspensions containing Pickering emulsion polymerized Fe2O3/polystyrene (PS) composite particles were reanalyzed using the Seo-Seo model. The experimental shear stress data obtained experimentally from the magnetorheological fluid fit well to the Seo-Seo model, indicating that this model can describe the structural reformation process of the aligned fibers at various shear rates. Unlike the dynamic yield stress obtained from the Cho-Choi-Jhon (CCJ) model, the static yield stresses obtained from the Seo-Seo model exhibit the same quadratic dependence on the magnetic field strength for both pure Fe2O3 particle suspension and Fe2O3/PS particle suspensions, which is in agreement with the predictions of the polarization model. The static yield stress plausibly explains the difference in underlying mechanism of MR fluids. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. MODELING SOLIDIFICATION-INDUCED STRESSES IN CERAMIC WASTE FORMS CONTAINING NUCLEAR WASTES

    International Nuclear Information System (INIS)

    Solbrig, Charles W.; Bateman, Kenneth J.

    2010-01-01

    The goal of this work is to produce a ceramic waste form (CWF) that permanently occludes radioactive waste. This is accomplished by absorbing radioactive salts into zeolite, mixing with glass frit, heating to a molten state 915 C to form a sodalite glass matrix, and solidifying for long-term storage. Less long term leaching is expected if the solidifying cooling rate doesn't cause cracking. In addition to thermal stress, this paper proposes that a stress is formed during solidification which is very large for fast cooling rates during solidification and can cause severe cracking. A solidifying glass or ceramic cylinder forms a dome on the cylinder top end. The temperature distribution at the time of solidification causes the stress and the dome. The dome height, ''the length deficit,'' produces an axial stress when the solid returns to room temperature with the inherent outer region in compression, the inner in tension. Large tensions will cause cracking of the specimen. The temperature deficit, derived by dividing the length deficit by the coefficient of thermal expansion, allows solidification stress theory to be extended to the circumferential stress. This paper derives the solidification stress theory, gives examples, explains how to induce beneficial stresses, and compares theory to experimental data.

  7. Oxidative Stress Type Influences the Properties of Antioxidants Containing Polyphenols in RINm5F Beta Cells

    Directory of Open Access Journals (Sweden)

    Nathalie Auberval

    2015-01-01

    Full Text Available The in vitro methods currently used to screen bioactive compounds focus on the use of a single model of oxidative stress. However, this simplistic view may lead to conflicting results. The aim of this study was to evaluate the antioxidant properties of two natural extracts (a mix of red wine polyphenols (RWPs and epigallocatechin gallate (EGCG with three models of oxidative stress induced with hydrogen peroxide (H2O2, a mixture of hypoxanthine and xanthine oxidase (HX/XO, or streptozotocin (STZ in RINm5F beta cells. We employed multiple approaches to validate their potential as therapeutic treatment options, including cell viability, reactive oxygen species production, and antioxidant enzymes expression. All three oxidative stresses induced a decrease in cell viability and an increase in apoptosis, whereas the level of ROS production was variable depending on the type of stress. The highest level of ROS was found for the HX/XO-induced stress, an increase that was reflected by higher expression antioxidant enzymes. Further, both antioxidant compounds presented beneficial effects during oxidative stress, but EGCG appeared to be a more efficient antioxidant. These data indicate that the efficiency of natural antioxidants is dependent on both the nature of the compound and the type of oxidative stress generated.

  8. Assessment of density functional theory for bonds formed between rare gases and open-shell atoms: a computational study of small molecules containing He, Ar, Kr and Xe

    International Nuclear Information System (INIS)

    Bertolus, Marjorie; Major, Mohamed; Brenner, Valerie

    2012-01-01

    The validity of the description of the DFT approximations currently implemented in plane wave DFT codes (LDA, GGA, meta-GGA, hybrid, GGA + empirical dispersion correction) for interactions between rare gases and open-shell atoms which form materials is poorly known. We have performed a first assessment of the accuracy of these functionals for the description of the bonds formed by helium, argon, krypton and xenon with various open-shell atoms. This evaluation has been done on model molecular systems for which precise experimental data are available and reference post-Hartree-Fock calculations (CCSD(T) using large basis sets) are feasible. The results show that when the rare gas atom shares density with the neighbouring atoms, the GGA functionals yield good geometries and qualitatively correct binding energies, even if these are quite significantly overestimated. The use of hybrid functionals enables us to obtain good geometries and satisfactory binding energies. For compounds in which the rare gas atom forms weak dispersive-like bonding, the accuracy yielded by the various functionals is not as good. No functional gives satisfactory binding energies for all the compounds investigated. Several GGA and hybrid functionals yield correct geometries, even if some isomers are not obtained. One GGA functional (PBE) yields qualitatively correct results for the compounds of the three rare gases and several hybrid functionals give satisfactory energies for He compounds. The addition of an empirical dispersive correction improves the results on association compounds, but several isomers are not found. (authors)

  9. Assessment of density functional theory for bonds formed between rare gases and open-shell atoms: a computational study of small molecules containing He, Ar, Kr and Xe.

    Science.gov (United States)

    Bertolus, Marjorie; Major, Mohamed; Brenner, Valérie

    2012-01-14

    The validity of the description of the DFT approximations currently implemented in plane wave DFT codes (LDA, GGA, meta-GGA, hybrid, GGA + empirical dispersion correction) for interactions between rare gases and open-shell atoms which form materials is poorly known. We have performed a first assessment of the accuracy of these functionals for the description of the bonds formed by helium, argon, krypton and xenon with various open-shell atoms. This evaluation has been done on model molecular systems for which precise experimental data are available and reference post-Hartree-Fock calculations (CCSD(T) using large basis sets) are feasible. The results show that when the rare gas atom shares density with the neighbouring atoms, the GGA functionals yield good geometries and qualitatively correct binding energies, even if these are quite significantly overestimated. The use of hybrid functionals enables us to obtain good geometries and satisfactory binding energies. For compounds in which the rare gas atom forms weak dispersive-like bonding, the accuracy yielded by the various functionals is not as good. No functional gives satisfactory binding energies for all the compounds investigated. Several GGA and hybrid functionals yield correct geometries, even if some isomers are not obtained. One GGA functional (PBE) yields qualitatively correct results for the compounds of the three rare gases and several hybrid functionals give satisfactory energies for He compounds. The addition of an empirical dispersive correction improves the results on association compounds, but several isomers are not found.

  10. The effect of crack branching on the residual lifetime of machine components containing stress corrosion cracks

    International Nuclear Information System (INIS)

    Magdowski, R.M.; Uggowitzer, P.J.; Speidel, M.O.

    1985-01-01

    A comparison is presented of theoretical, numerical and experimental investigations concerning the effect of crack branching on the reduction of stress intensity at the tip of single cracks. The results indicate that the division of a single crack into n branches reduces the stress intensity at the branch tips by a factor of about 1/√n. This permits branched cracks to grow to larger depths before becoming critical. The implication is that longer residual lifetimes and longer operating times between inspections can be calculated for machine components with growing branched stress corrosion cracks. (author)

  11. Protein profiles of hatchery egg shell membrane.

    Science.gov (United States)

    Rath, N C; Liyanage, R; Makkar, S K; Lay, J O

    2016-01-01

    Eggshells which consist largely of calcareous outer shell and shell membranes, constitute a significant part of poultry hatchery waste. The shell membranes (ESM) not only contain proteins that originate from egg whites but also from the developing embryos and different contaminants of microbial and environmental origins. As feed supplements, during post hatch growth, the hatchery egg shell membranes (HESM) have shown potential for imparting resistance of chickens to endotoxin stress and exert positive health effects. Considering that these effects are mediated by the bioactive proteins and peptides present in the membrane, the objective of the study was to identify the protein profiles of hatchery eggshell membranes (HESM). Hatchery egg shell membranes were extracted with acidified methanol and a guanidine hydrochloride buffer then subjected to reduction/alkylation, and trypsin digestion. The methanol extract was additionally analyzed by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS). The tryptic digests were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS-MS) to identify the proteins. Our results showed the presence of several proteins that are inherent and abundant in egg white such as, ovalbumin, ovotransferrin, ovocleidin-116, and lysozyme, and several proteins associated with cytoskeletal, cell signaling, antimicrobial, and catalytic functions involving carbohydrate, nucleic acid, and protein metabolisms. There were some blood derived proteins most likely originating from the embryos and several other proteins identified with different aerobic, anaerobic, gram positive, gram negative, soil, and marine bacterial species some commensals and others zoonotic. The variety of bioactive proteins, particularly the cell signaling and enzymatic proteins along with the diverse microbial proteins, make the HESM suitable for nutritional and biological application to improve post hatch immunity of poultry.

  12. Liquid organomineral fertilizer containing humic substances on soybean grown under water stress

    Directory of Open Access Journals (Sweden)

    Marcelo R. V. Prado

    2016-05-01

    Full Text Available ABSTRACT This study evaluated the effect of an organomineral fertilizer enriched with humic substances on soybean grown under water stress. The experiment was performed in a greenhouse using a Red Latosol (Oxisol with adequate fertility as substrate, in which soybean plants were cultivated with and without water stress. The experimental design was randomized blocks, in a 2 x 5 factorial scheme (two moisture levels and five fertilizer doses: 0, 1, 2, 4 and 8 mL dm-3, totaling 10 treatments, with four replicates. The organomineral fertilizer was applied in the soil 21 days after plant emergence and the water regimes were established one week thereafter. The fertilizer was not able to attenuate the effects of water stress, reducing soybean grain yield by more than 50% compared with plants cultivated under no stress. Fertilizer doses caused positive response on soybean nutrition and grain yield and, under water stress condition, the most efficient dose was 5.4 mL dm-3. There were lower leaf concentrations of nitrogen, phosphorus and potassium and higher concentrations of sulfur in plants under stress. Humic substances favor the absorption of micronutrients.

  13. Oxytocin in the nucleus accumbens shell reverses CRFR2-evoked passive stress-coping after partner loss in monogamous male prairie voles.

    Science.gov (United States)

    Bosch, Oliver J; Dabrowska, Joanna; Modi, Meera E; Johnson, Zachary V; Keebaugh, Alaine C; Barrett, Catherine E; Ahern, Todd H; Guo, JiDong; Grinevich, Valery; Rainnie, Donald G; Neumann, Inga D; Young, Larry J

    2016-02-01

    Loss of a partner can have severe effects on mental health. Here we explore the neural mechanisms underlying increased passive stress-coping, indicative of depressive-like behavior, following the loss of the female partner in the monogamous male prairie vole. We demonstrate that corticotropin-releasing factor receptor 2 (CRFR2) in the nucleus accumbens shell mediates social loss-induced passive coping. Further, we show that partner loss compromises the oxytocin system through multiple mechanisms. Finally, we provide evidence for an interaction of the CRFR2 and oxytocin systems in mediating the emotional consequences of partner loss. Our results suggest that chronic activation of CRFR2 and suppression of striatal oxytocin signaling following partner loss result in an aversive emotional state that may share underlying mechanisms with bereavement. We propose that the suppression of oxytocin signaling is likely adaptive during short separations to encourage reunion with the partner and may have evolved to maintain long-term partnerships. Additionally, therapeutic strategies targeting these systems should be considered for treatment of social loss-mediated depression. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Oxytocin in the nucleus accumbens shell reverses CRFR2-evoked passive stress-coping after partner loss in monogamous male prairie voles

    Science.gov (United States)

    Bosch, Oliver J.; Dabrowska, Joanna; Modi, Meera E.; Johnson, Zachary V.; Keebaugh, Alaine C.; Barrett, Catherine E.; Ahern, Todd H.; Guo, JiDong; Grinevich, Valery; Rainnie, Donald G.; Neumann, Inga D.; Young, Larry J.

    2015-01-01

    Loss of a partner can have severe effects on mental health. Here we explore the neural mechanisms underlying increased passive stress-coping, indicative of depressive-like behavior, following the loss of the female partner in the monogamous male prairie vole. We demonstrate that corticotropin-releasing factor receptor 2 (CRFR2) in the nucleus accumbens shell mediates social loss-induced passive coping. Further, we show that partner loss compromises the oxytocin system through multiple mechanisms. Finally, we provide evidence for an interaction of the CRFR2 and oxytocin systems in mediating the emotional consequences of partner loss. Our results suggest that chronic activation of CRFR2 and suppression of striatal oxytocin signaling following partner loss result in an aversive emotional state that may share underlying mechanisms with bereavement. We propose that the suppression of oxytocin signaling is likely adaptive during short separations to encourage reunion with the partner and may have evolved to maintain long-term partnerships. Additionally, therapeutic strategies targeting these systems should be considered for treatment of social loss-mediated depression. PMID:26615473

  15. Assessment of stress-strain data suitable for finite-element elastic--plastic analysis of shipping containers

    International Nuclear Information System (INIS)

    Rack, H.J.; Knorovsky, G.A.

    1978-09-01

    Stress-strain data which describes the influence of strain rate and temperature on the mechanical response of materials presently being used for light water reactor fuel shipping containers have been assembled. Selection of data has been limited to that which is suitable for use in finite-element elastic--plastic analysis of shipping containers (e.g., they must include complete material history profiles). Based on this information, recommendations have been made for further work which is required to complete the necessary data base

  16. The stress-corrosion behaviour in water media containing chlorine of the brazing joint of grids for PWR fuel element

    International Nuclear Information System (INIS)

    Zhang Weijie; Li Wenqing.

    1985-01-01

    This paper details the testing results of the stress-corrosion behaviour in the 150 deg C water media containing chlorine for the brazing joints made from three alloy systems, which are Ni-Cr-Si, Ni-Cr-P and Ni-P, including 16 compositions. The test results indicate that, in the Ni-Cr-Si system, Ni-Cr-Si-Ge brazing joint is the best, to resist stress-corrosion, while Ni-Cr-Si-P-Ge-Pd and BNi5 brazing joints are better. In the Ni-Cr-P system, only the Ni-Cr-P-Mo-Zr brazing joint has an excellent resistance to stress-corrosion

  17. Dissolution of copper in chloride/ammonia mixtures and the implications for the stress corrosion cracking of copper containers

    Energy Technology Data Exchange (ETDEWEB)

    King, F.; Greidanus, G.; Jobe, D.J

    1999-05-01

    Stress-corrosion cracking is a possible failure mechanism for copper nuclear fuel waste disposal containers. One species known to cause the stress corrosion of copper alloys is ammonia. It is conceivable that ammonia could be produced in a disposal vault under certain, very specific conditions. There are a number of conditions, however, that mitigate against container failure by stress corrosion, one of which is the presence of chloride ions in deep Canadian Shield groundwaters. There are a number of reports in the literature that suggest that Cl{sup -} has an inhibitive effect on the stress corrosion of Cu alloys in ammonia solutions. The electrochemical behaviour of Cu in Cl{sup -}/ammonia solutions has been studied as a function of ammonia concentration, pH, the rate of mass transport and electrochemical potential. In particular, the effects of these parameters on the formation Of Cu{sub 2}O films and the steady-state dissolution behaviour have been determined. All experiments were carried out in 0.1 mol{center_dot}dm{sup -3} NaC1 as a base solution. A series of aqueous speciation and equilibrium potential/pH diagrams are also presented for the quaternary system Cu-C1{sup -}NH{sub 3}/NH{sub 4{sup +}}H{sub 2}O. These diagrams are used to interpret the results of the electrochemical experiments reported here. In addition, it is demonstrated how these diagrams could be used to predict the time-dependence of the susceptibility to stress corrosion cracking of Cu containers in a disposal vault. (author)

  18. Cytokinin-producing, plant growth-promoting rhizobacteria that confer resistance to drought stress in Platycladus orientalis container seedlings.

    Science.gov (United States)

    Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

    2013-10-01

    One of the proposed mechanisms through which plant growth-promoting rhizobacteria (PGPR) enhance plant growth is the production of plant growth regulators, especially cytokinin. However, little information is available regarding cytokinin-producing PGPR inoculation on growth and water stress consistence of forest container seedlings under drought condition. This study determined the effects of Bacillus subtilis on hormone concentration, drought resistance, and plant growth under water-stressed conditions. Although no significant difference was observed under well-watered conditions, leaves of inoculated Platycladus orientalis (oriental thuja) seedlings under drought stress had higher relative water content and leaf water potential compared with those of noninoculated ones. Regardless of water supply levels, the root exudates, namely sugars, amino acids and organic acids, significantly increased because of B. subtilis inoculation. Water stress reduced shoot cytokinins by 39.14 %. However, inoculation decreased this deficit to only 10.22 %. The elevated levels of cytokinins in P. orientalis shoot were associated with higher concentration of abscisic acid (ABA). Stomatal conductance was significantly increased by B. subtilis inoculation in well-watered seedlings. However, the promoting effect of cytokinins on stomatal conductance was hampered, possibly by the combined action of elevated cytokinins and ABA. B. subtilis inoculation increased the shoot dry weight of well-watered and drought seedlings by 34.85 and 19.23 %, as well as the root by 15.445 and 13.99 %, respectively. Consequently, the root/shoot ratio significantly decreased, indicative of the greater benefits of PGPR on shoot growth than root. Thus, inoculation of cytokinin-producing PGPR in container seedlings can alleviate the drought stress and interfere with the suppression of shoot growth, showing a real potential to perform as a drought stress inhibitor in arid environments.

  19. Genome-wide identification of VQ motif-containing proteins and their expression profiles under abiotic stresses in maize

    Directory of Open Access Journals (Sweden)

    Weibin eSong

    2016-01-01

    Full Text Available VQ motif-containing proteins play crucial roles in abiotic stress responses in plants. Recent studies have shown that some VQ proteins physically interact with WRKY transcription factors to activate downstream genes. In the present study, we identified and characterized genes encoding VQ motif-containing proteins using the most recent version of the maize genome sequence. In total, 61VQ genes were identified. In a cluster analysis, these genes clustered into nine groups together with their homologous genes in rice and Arabidopsis. Most of the VQ genes (57 out of 61 numbers identified in maize were found to be single-copy genes. Analyses of RNA-seq data obtained using seedlings under long-term drought treatment showed that the expression levels of most ZmVQ genes (41 out of 61 members changed during the drought stress response. Quantitative real-time PCR analyses showed that most of the ZmVQ genes were responsive to NaCl treatment. Also, approximately half of the ZmVQ genes were co-expressed with ZmWRKY genes. The identification of these VQ genes in the maize genome and knowledge of their expression profiles under drought and osmotic stresses will provide a solid foundation for exploring their specific functions in the abiotic stress responses of maize.

  20. Self-Assembly of 3D DNA Crystals Containing a Torsionally Stressed Component.

    Science.gov (United States)

    Hernandez, Carina; Birktoft, Jens J; Ohayon, Yoel P; Chandrasekaran, Arun Richard; Abdallah, Hatem; Sha, Ruojie; Stojanoff, Vivian; Mao, Chengde; Seeman, Nadrian C

    2017-11-16

    There is an increasing appreciation for structural diversity of DNA that is of interest to both DNA nanotechnology and basic biology. Here, we have explored how DNA responds to torsional stress by building on a previously reported two-turn DNA tensegrity triangle and demonstrating that we could introduce an extra nucleotide pair (np) into the original sequence without affecting assembly and crystallization. The extra np imposes a significant torsional stress, which is accommodated by global changes throughout the B-DNA duplex and the DNA lattice. The work reveals a near-atomic structure of naked DNA under a torsional stress of approximately 14%, and thus provides an example of DNA distortions that occur without a requirement for either an external energy source or the free energy available from protein or drug binding. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Strength Calculation of Locally Loaded Orthotropic Shells

    Directory of Open Access Journals (Sweden)

    Yu. I. Vinogradov

    2015-01-01

    Full Text Available The article studies laminated orthotropic cylindrical, conic, spherical, and toroidal shells, which are often locally loaded in the aircraft designs over small areas of their surfaces.The aim of this work is to determine stress concentration in shells versus structure of orthotropic composite material, shell form and parameters, forms of loading areas, which borders do not coincide with lines of main curvatures of shells. For this purpose, an analytical computing algorithm to estimate strength of shells in terms of stress is developed. It enables us to have solution results of the boundary value problem with a controlled error. To solve differential equations an analytical method is used. An algorithm of the boundary value problem solution is multiplicative.The main results of researches are graphs of stress concentration in the orthotropic shells versus their parameters and areas of loading lineated by circles and ellipses.Among the other works aimed at determination of stress concentration in shells, the place of this one is defined by the analytical solution of applied problems for strength estimation in terms of shell stresses of classical forms.The developed effective analytical algorithm to solve the boundary value problem and received results are useful in research and development.

  2. The effectiveness of a standardized rose hip powder, containing seeds and shells of Rosa canina, on cell longevity, skin wrinkles, moisture, and elasticity

    Directory of Open Access Journals (Sweden)

    Phetcharat L

    2015-11-01

    Full Text Available L Phetcharat,1,2 K Wongsuphasawat,1,2 K Winther31School of Antiaging and Regenerative Medicine, Mae Fah University, Bangkok, Thailand; 2Department of Anti-aging and Regenerative Medicine, Mae Fah University, Bangkok, Thailand; 3Institute for Nutrition, Exercise and Sports, University of Copenhagen, Frederiksberg C, DenmarkObjective: To evaluate the effects of a rose hip powder (Hyben Vital® made from seeds and shells on cell senescence, skin wrinkling, and aging.Methods: A total of 34 healthy subjects, aged 35–65 years, with wrinkles on the face (crow’s-feet were subjected to a randomized and double-blinded clinical study of the effects of the rose hip powder, as compared to astaxanthin, a well-known remedy against wrinkles. During the 8-week study, half of the participants ingested the standardized rose hip product, while the other half ingested astaxanthin. Objective measurements of facial wrinkles, skin moisture, and elasticity were made by using Visioscan, Corneometer, and Cutometer at the beginning of the study, after 4 weeks, and after 8 weeks. Evaluation of participant satisfaction of both supplements was assessed using questionnaires. In addition, the effect of the rose hip preparation on cell longevity was measured in terms of leakage of hemoglobin through red cell membranes (hemolytic index in blood samples kept in a blood bank for 5 weeks. Significance of all values was attained with P≤0.05.Results: In the double-blinded study, the rose hip group showed statistically significant improvements in crow’s-feet wrinkles (P<0.05, skin moisture (P<0.05, and elasticity (P<0.05 after 8 weeks of treatment. A similar improvement was observed for astaxanthin, with P-values 0.05, 0.001, and 0.05. Likewise, both groups expressed equal satisfaction with the results obtained in their self-assessment. The rose hip powder further resulted in increased cell longevity of erythrocyte cells during storage for 5 weeks in a blood bank

  3. Sex-dependent anti-stress effect of an α5 subunit containing GABAA receptor positive allosteric modulator

    Directory of Open Access Journals (Sweden)

    Sean C. Piantadosi

    2016-11-01

    Full Text Available Rationale: Current first-line treatments for stress-related disorders such as Major Depressive Disorder (MDD act on monoaminergic systems and take weeks to achieve a therapeutic effect with poor response and low remission rates. Recent research has implicated the GABAergic system in the pathophysiology of depression, including deficits in interneurons targeting the dendritic compartment of cortical pyramidal cells. Objectives: The present study evaluates whether SH-053-2'F-R-CH3 (denoted α5-PAM, a positive allosteric modulator selective for α5-subunit containing GABAA receptors found predominantly on cortical pyramidal cell dendrites has anti-stress effects. Methods: Female and male C57BL6/J mice were exposed to unpredictable chronic mild stress (UCMS and treated with α5-PAM acutely (30 minutes prior to assessing behavior or chronically before being assessed behaviorally. Results: Acute and chronic α5-PAM treatments produce a pattern of decreased stress-induced behaviors (denoted as behavioral emotionality across various tests in female, but not in male mice. Behavioral Z-scores calculated across a panel of tests designed to best model the range and heterogeneity of human symptomatology confirmed that acute and chronic α5-PAM treatments consistently produce significant decreases in behavioral emotionality in several independent cohorts of females. The behavioral responses to α5-PAM could not be completely accounted for by differences in drug brain disposition between female and male mice. In mice exposed to UCMS, expression of the Gabra5 gene was increased in the frontal cortex after acute treatment and in hippocampus after chronic treatment with α5-PAM in females only, and these expression changes correlated with behavioral emotionality. Conclusions: We showed that acute and chronic positive modulation of α5 subunit-containing GABAA receptors elicit anti-stress effects in a sex-dependent manner, suggesting novel therapeutic modalities.

  4. Recent developments in anisotropic heterogeneous shell theory

    CERN Document Server

    Grigorenko, Alexander Ya; Grigorenko, Yaroslav M; Vlaikov, Georgii G

    2016-01-01

    This volume focuses on the relevant general theory and presents some first applications, namely those based on classical shell theory. After a brief introduction, during which the history and state-of-the-art are discussed, the first chapter presents the mechanics of anisotropic heterogeneous shells, covering all relevant assumptions and the basic relations of 3D elasticity, classical and refined shell models. The second chapter examines the numerical techniques that are used, namely discrete orthogonalization, spline-collocation and Fourier series, while the third highlights applications based on classical theory, in particular, the stress-strain state of shallow shells, non-circular shells, shells of revolution, and free vibrations of conical shells. The book concludes with a summary and an outlook bridging the gap to the second volume.

  5. Vibrations of composite circular shell structures due to transient loads

    International Nuclear Information System (INIS)

    Schrader, K.-H.; Krutzik, N.; Winkel, G.

    1975-01-01

    Referring to a container consisting of different shell structures - such as spherical, cylindrical and conical shells - the dynamic behavior of coupled spatial shell structures due to transient loads will be investigated. The spatial structure including the filling of water will be idealized as a three-dimensional model consisting of ring elements. The influence of the water filling on the vibrations will be considered by virtual masses added to the shell structures. In circular direction as well as in meridional direction a consistent mass model has been used. By variation of the virtual masses it will be clarified, how these additional masses influence the vibrational behavior of the composed system. Another aspect which will be investigated is the influence of different stiffnesses of substructures or parts of substructures on the natural frequencies, and on their affiliated eigensystems. Furthermore, the maximum and minimum stresses in the structures caused by transient loads acting on the inner surface of the shells will be explored. Here it seems to be possible to locate an area of maximum strain. Rotational loads as well as nonrotational loads will be considered

  6. Enhanced adsorption of hydroxyl contained/anionic dyes on non functionalized Ni@SiO{sub 2} core–shell nanoparticles: Kinetic and thermodynamic profile

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhifeng, E-mail: ntjiangzf@sina.com; Xie, Jimin, E-mail: xiejm391@sohu.com; Jiang, Deli, E-mail: jiangdeli100@yahoo.com; Yan, Zaoxue, E-mail: yanzaoxue@163.com; Jing, Junjie, E-mail: jingjj1975@163.com; Liu, Dong, E-mail: 919457966@qq.com

    2014-02-15

    A green and low-cost adsorbent with both magnetic property and high adsorption capacity was prepared on the basis of nickel magnetic core with silica shell. The surface of the prepared Ni@SiO{sub 2} composite was not modified. The influence of different functional groups and different charged of the dyes on the adsorption process on the non functionalized Ni@SiO{sub 2} have been studied. The results indicated that synthesized adsorbent exhibited higher adsorption capacity for dyes with negative charge/hydroxyl groups as compared to dyes with positive charge/without hydroxyl groups due to the hydrogen bonding interaction and electrostatic interaction between the adsorbent and dyes. Adsorption kinetics and isotherms experiments were carried out and the results indicated that the adsorption process was fitted by pseudo second order kinetics and Freundlich model. The binding of these dyes with magnetic adsorbent surface mainly involves physical adsorption according to D–R model. Furthermore, the adsorption process is spontaneous and endothermic as studied from adsorption thermodynamics. The value of ΔH° and mean free energy further confirmed that physical adsorption is the major adsorption process. After regeneration, the adsorbent still shows high adsorption capacity even for 4 cycles of desorption–adsorption.

  7. Integrable structure in discrete shell membrane theory.

    Science.gov (United States)

    Schief, W K

    2014-05-08

    We present natural discrete analogues of two integrable classes of shell membranes. By construction, these discrete shell membranes are in equilibrium with respect to suitably chosen internal stresses and external forces. The integrability of the underlying equilibrium equations is proved by relating the geometry of the discrete shell membranes to discrete O surface theory. We establish connections with generalized barycentric coordinates and nine-point centres and identify a discrete version of the classical Gauss equation of surface theory.

  8. Experimental stress analysis of the attachment region of hemispherical shells with attached nozzles. Part 5c. Nonradial nozzle at 22-1/2 degrees 2.625 in. O.D.--2.5000 in. I.D., zero penetration

    International Nuclear Information System (INIS)

    Maxwell, R.L.; Holland, R.W.

    1975-06-01

    A continuing series of investigations has been conducted to determine experimentally the stress patterns for the junction region of spherical shells with radially and non-radially attached nozzles when subjected to internal pressure and various types of loadings on the nozzles. Results of the investigations conducted on a nonradially attached nozzle of 2.625 in.-OD, 2.500 in. ID, and finished flush with the inner surface of the hemisphere are reported. The nozzle was inclined at 22 1 / 2 0 from a radial axis. Stress values for the following types of loadings are tabulated: internal pressure applied to the hemisphere and nozzle assembly; an axial load applied collinear with nozzle; a pure torque applied in the radial plane of the nozzle; and a pure bending moment or axial couple applied in various axial planes of the nozzle. Various stress vs. profile curves are presented. These curves present the tabulated stress data in graphical format. (U.S.)

  9. Accident resistant transport container

    Science.gov (United States)

    Anderson, J.A.; Cole, K.K.

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  10. Accident resistant transport container

    International Nuclear Information System (INIS)

    Andersen, J.A.; Cole, J.K.

    1980-01-01

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident

  11. Correlation between stresses and adhesion of oxide scales on Si and Ti containing NiCrAlY alloys

    International Nuclear Information System (INIS)

    Vosberg, V.; Quadakkers, W.J.; Schubert, F.; Nickel, H.

    1998-09-01

    The relation between mechanical stresses and the adhesion of alumina scales on Si- and Ti-containing NiCrAlY alloys has been investigated. Therefore the Si and Ti contents in model alloys with the base composition Ni-20Cr-10Al-Y, which were cast to achieve high purity, were varied from 0 to 2 m/0 . These solid samples were subjected to cyclic oxidation in the temperature range from 950 to 1100 C. Growth and spallation of the oxide scale were observed by gravimetry. The stresses, present at ambient temperature, were periodically determined by X-ray stress evaluation. Using these results a reasoning of the mechanisms for stress relief and damage of the scale was carried out. The addition of Silicon as well as of titanium has an evident influence on phase composition of Ni-20Cr-10Al-Y type alloys. Due to the variation of phase stability regions the thermal expansion is affected by these additions in the range from 950 to 1100 C. The expansion is enlarged by the addition of Si and lowered with increasing Ti content. (orig.)

  12. The effectiveness of a standardized rose hip powder, containing seeds and shells of Rosa canina, on cell longevity, skin wrinkles, moisture, and elasticity.

    Science.gov (United States)

    Phetcharat, L; Wongsuphasawat, K; Winther, K

    2015-01-01

    To evaluate the effects of a rose hip powder (Hyben Vital(®)) made from seeds and shells on cell senescence, skin wrinkling, and aging. A total of 34 healthy subjects, aged 35-65 years, with wrinkles on the face (crow's-feet) were subjected to a randomized and double-blinded clinical study of the effects of the rose hip powder, as compared to astaxanthin, a well-known remedy against wrinkles. During the 8-week study, half of the participants ingested the standardized rose hip product, while the other half ingested astaxanthin. Objective measurements of facial wrinkles, skin moisture, and elasticity were made by using Visioscan, Corneometer, and Cutometer at the beginning of the study, after 4 weeks, and after 8 weeks. Evaluation of participant satisfaction of both supplements was assessed using questionnaires. In addition, the effect of the rose hip preparation on cell longevity was measured in terms of leakage of hemoglobin through red cell membranes (hemolytic index) in blood samples kept in a blood bank for 5 weeks. Significance of all values was attained with P≤0.05. In the double-blinded study, the rose hip group showed statistically significant improvements in crow's-feet wrinkles (Prose hip powder further resulted in increased cell longevity of erythrocyte cells during storage for 5 weeks in a blood bank. Results suggest that intake of the standardized rose hip powder (Hyben Vital(®)) improves aging-induced skin conditions. The apparent stabilizing effects of the rose hip product on cell membranes of stored erythrocyte cells observed in this study may contribute to improve the cell longevity and obstructing skin aging.

  13. Thermo-elastic stress analysis of containment wall penetrations using improved finite element formulation

    International Nuclear Information System (INIS)

    Ramani, D.T.; Dimopoulos, A.; Heglin, B.M.

    1979-01-01

    An increased application of finite element techniques, particularly in evaluating structural integrity of nuclear containment walls around penetration points, has aroused considerable interest. Due to extreme thermal effects in the vicinity of penetrations, the concrete containment wall is subject to unwarranted cracking effects, which must be controlled in accordance with ASME-III Code. This paper essentially deals with a unique finite element method of analysis in which nonlinear heat transfer problem across the penetration assembly in the nuclear containment drywell wall, is formulated. Using this technique, thermal analysis, dealing with an evaluation of temperature distribution around axisymmetric penetration assembly accomodating main steam lines or other vital piping at 600 0 F, is carried out. The method of analysis considers steady-state heat transfer energy balance across the process-pipe, insulation layer, guard-pipe sleeve, two intermediate air layers and an axisymmetric opening in the concrete containment wall, the outer faces of which are maintained at ambient temperature of 120 0 F. (orig.)

  14. The potential for stress corrosion cracking of copper containers in a Canadian nuclear fuel waste disposal vault

    International Nuclear Information System (INIS)

    King, F.

    1996-09-01

    The potential for stress corrosion cracking (SCC) of copper nuclear fuel waste containers in a conceptual Canadian disposal vault has been assessed through a review of the literature and comparison of those environmental factors that cause SCC with the expected disposal environment. Stress-corrosion cracking appears to be an unlikely failure mode for Cu containers in a Canadian disposal vault because of a combination of environmental factors. Most importantly, there is only a relatively short period during which the containers will be undergoing strain when cracking should be possible at all, and then cracking is not expected because of the absence of known SCC agents, such as NH 3 , NO 2 - or organic acids. In addition, other environmental factors will mitigate SCC, namely, the presence of C1 - and its effect on film properties and the limited supply of oxidants. These arguments, to greater or lesser extent, apply to the three major mechanisms proposed for SCC of Cu alloys in aqueous solutions: film-rupture/anodic dissolution, tarnish rupture and film-induced cleavage. Detailed reviews of the SCC literature are presented as Appendices. The literature on the SCC of Cu (>99 wt.% Cu) is reviewed, including studies carried out in a number of countries under nuclear waste disposal conditions. Because of similarities with the behaviour of Cu, the more extensive literature on the SCC of α-brass in ammonia solutions is also reviewed. (author). 140 refs., 3 tabs., 25 figs

  15. Mode of action of nifurtimox and N-oxide-containing heterocycles against Trypanosoma cruzi: is oxidative stress involved?

    Science.gov (United States)

    Boiani, Mariana; Piacenza, Lucia; Hernández, Paola; Boiani, Lucia; Cerecetto, Hugo; González, Mercedes; Denicola, Ana

    2010-06-15

    Chagas disease is caused by the trypanosomatid parasite Trypanosoma cruzi and threatens millions of lives in South America. As other neglected diseases there is almost no research and development effort by the pharmaceutical industry and the treatment relies on two drugs, Nifurtimox and Benznidazole, discovered empirically more than three decades ago. Nifurtimox, a nitrofurane derivative, is believed to exert its biological activity through the bioreduction of the nitro-group to a nitro-anion radical which undergoes redox-cycling with molecular oxygen. This hypothesis is generally accepted, although arguments against it have been presented. In the present work we studied the ability of Nifurtimox and five N-oxide-containing heterocycles to induce oxidative stress in T. cruzi. N-Oxide-containing heterocycles represent a promising group of new trypanosomicidal agents and their mode of action is not completely elucidated. The results here obtained argue against the oxidative stress hypothesis almost for all the studied compounds, including Nifurtimox. A significant reduction in the level of parasitic low-molecular-weight thiols was observed after Nifurtimox treatment; however, it was not linked to the production of reactive oxidant species. Besides, redox-cycling is only observed at high Nifurtimox concentrations (>400microM), two orders of magnitude higher than the concentration required for anti-proliferative activity (5microM). Our results indicate that an increase in oxidative stress is not the main mechanism of action of Nifurtimox. Among the studied N-oxide-containing heterocycles, benzofuroxan derivatives strongly inhibited parasite dehydrogenase activity and affected mitochondrial membrane potential. The indazole derivative raised intracellular oxidants production, but it was the least effective as anti-T. cruzi. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Stress Corrosion Cracking of Ni-base Alloys in Sulfur Containing Solutions at 340 .deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Hee; Hwang, Seong Sik; Kim, Dong Jin; Kim, Sung Woo [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Sulfur has been identified as one of the major impurities introduced into the secondary water of pressurized water-reactors (PWRs). Sulfur can originate from various sources, such as resin sources, feed water, cooling water in-leakage, and condenser leaks. Many authors have investigated effects of reduced sulfur in a wide pH range with or without additives. The presence of reduced sulfur species on the surfaces of pulled tubes having stress corrosion cracking (SCC) was also identified. In present work, SCC tests were conducted to investigate effects of reduced sulfur species on the SCC behavior of Ni-base Alloys. The Alloy 690 TT showed the most SCC resistant, regardless of the sulfur species. The Cr content and heat treatments of alloys appeared the increase in the SCC resistance.

  17. Safety margin evaluation of pre-stressed concrete nuclear containment vessel model with BARC code ULCA

    International Nuclear Information System (INIS)

    Basha, S.M.; Patnaik, R.; Ramanujam, S.; Singh, R.K.; Kushwaha, H.S.; Venkat Raj, V.

    2002-01-01

    Full text: Ultimate load capacity assessment of nuclear containments has been a thrust research area for Indian pressurised heavy water reactor (PHWR) power programme. For containment safety assessment of Indian PHWRs a finite element code ULCA was developed at BARC, Trombay. This code has been extensively benchmarked with experimental results and for prediction of safety margins of Indian PHWRs. The present paper highlights the analysis results for prestressed concrete containment vessel (PCCV) tested at Sandia National Labs, USA in a round robin analysis activity co-sponsored by Nuclear Power Engineering Corporation (NUPEC), Japan and the U.S Nuclear Regulatory Commission (NRC). Three levels of failure pressure predictions namely the upper bound, the most probable and the lower bound (all with 90% confidence) were made as per the requirements of the round robin analysis activity. The most likely failure pressure is predicted to be in the range of 2.95 Pd to 3.15 Pd (Pd = design pressure of 0.39 MPa for the PCCV model) depending on the type of liners used in the construction of the PCCV model. The lower bound value of the ultimate pressure of 2.80 Pd and the upper bound of the ultimate pressure of 3.45 Pd are also predicted from the analysis. These limiting values depend on the assumptions of the analysis for simulating the concrete tendon interaction and the strain hardening characteristics of the steel members. The experimental test has been recently concluded at Sandia Laboratory and the peak pressure reached during the test is 3.3 Pd that is enveloped by our upper bound prediction of 3.45 Pd and is close to the predicted most likely pressure of 3.15 Pd

  18. Topical application of ointment containing 0.5% green tea catechins suppresses tongue oxidative stress in 5-fluorouracil administered rats.

    Science.gov (United States)

    Miyai, Hisataka; Maruyama, Takayuki; Tomofuji, Takaaki; Yoneda, Toshiki; Azuma, Tetsuji; Mizuno, Hirofumi; Sugiura, Yoshio; Kobayashi, Terumasa; Ekuni, Daisuke; Morita, Manabu

    2017-10-01

    The purpose of this study was to investigate the preventive effects of topical application of green tea catechins on tongue oxidative stress induced by 5-fluorouracil (5-FU) administration in rats. Male Wistar rats (n=28, 8 weeks old) were divided into four groups of seven rats each: a negative control group (saline administration and application of ointment without green tea catechins), a positive control group (5-FU administration and application of ointment without green tea catechins), and two experimental groups (5-FU administration and application of ointment containing 0.1% or 0.5% green tea catechins). Topical application of each ointment to the ventral surface of the tongue was performed once a day for 5days. The level of 8-hydroxydeoxyguanosine (8-OHdG) was determined to evaluate oxidative stress. Fluorescence staining was also performed to confirm nuclear factor erythroid 2-related factor 2 (Nrf2) translocation to the nucleus. After the experimental period, the ratios of 8-OHdG-positive cells in the ventral tongue tissue were higher in the positive control group than in the negative control group (Ptea catechin group, but not in the 0.1% green tea catechin group, were lower than the positive control group (Ptea catechin group than in the positive control group (Ptea catechins could prevent tongue oxidative stress in 5-FU administered rats, via up-regulation of the Nrf2 signaling pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Periodic Safety Review of Tendon Pre-stress of Concrete Containment Building for a CA U-Type clear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Kwang Ho; Lim, Woo Sang [Korea Hydro and clear Power Co., Daejeon (Korea, Republic of)

    2009-10-15

    Generally, as the tendon pre-stress of concrete containment buildings at nuclear power plants decreases as time passes due to the concrete creep, concrete shrinkage and the relaxation of tendon strands, the tendon pre-stress must secure the structural integrity of these buildings by maintaining its value higher than that of the designed pre-stress during the overall service life of the nuclear power plants. Moreover, if necessary, the degree of tendon pre-stress must also guarantee the structural integrity of concrete containment buildings over their lifetimes. This paper evaluated the changes in the tendon pre-stress of a concrete containment building subject to time-limited aging as an item in a periodic safety review (PSR) of Wolsong unit 1, a CANDU-type nuclear power plant to ensure that the structural integrity can be maintained until the next PSR period after the designed lifetime.

  20. Coal and tire burning mixtures containing ultrafine and nanoparticulate materials induce oxidative stress and inflammatory activation in macrophages.

    Science.gov (United States)

    Gasparotto, Juciano; Somensi, Nauana; Caregnato, Fernanda F; Rabelo, Thallita K; DaBoit, Kátia; Oliveira, Marcos L S; Moreira, José C F; Gelain, Daniel P

    2013-10-01

    Ultra-fine and nano-particulate materials resulting from mixtures of coal and non-coal fuels combustion for power generation release to the air components with toxic potential. We evaluated toxicological and inflammatory effects at cellular level that could be induced by ultrafine/nanoparticles-containing ashes from burning mixtures of coal and tires from an American power plant. Coal fly ashes (CFA) samples from the combustion of high-S coal and tire-derived fuel, the latter about 2-3% of the total fuel feed, in a 100-MW cyclone utility boiler, were suspended in the cell culture medium of RAW 264.7 macrophages. Cell viability, assessed by MTT reduction, SRB incorporation and contrast-phase microscopy analysis demonstrated that CFA did not induce acute toxicity. However, CFA at 1mg/mL induced an increase of approximately 338% in intracellular TNF-α, while release of this proinflammatory cytokine was increased by 1.6-fold. The expression of the inflammatory mediator CD40 receptor was enhanced by 2-fold, the receptor for advanced glycation endproducts (RAGE) had a 5.7-fold increase and the stress response protein HSP70 was increased nearly 12-fold by CFA at 1mg/mL. Although CFA did not induce cell death, parameters of oxidative stress and reactive species production were found to be altered at several degrees, such as nitrite accumulation (22% increase), DCFH oxidation (3.5-fold increase), catalase (5-fold increase) and superoxide dismutase (35% inhibition) activities, lipoperoxidation (4.2 fold-increase) and sulfhydryl oxidation (40% decrease in free SH groups). The present results suggest that CFA containing ultra-fine and nano-particulate materials from coal and tire combustion may induce sub-chronic cell damage, as they alter inflammatory and oxidative stress parameters at the molecular and cellular levels, but do not induce acute cell death. © 2013.

  1. Compas project stress analysis of HLW containers: behaviour under realistic disposal conditions

    International Nuclear Information System (INIS)

    Ove Arup and Partners, London

    1990-01-01

    The Compas project is concerned with the structural performance of metal overpacks which may be used to encapsulate vitrified high-level waste (HLW) forms before disposal in deep geological repositories. In this final stage of the project, analysis of an HLW overpack of realistic design is performed to predict its behaviour when subjected to likely repository loads. This analysis work is undertaken with the benefit of experience gained in previous phases of the project in which the ability to accurately predict overpack behaviour, when subjected to a uniform external pressure, was demonstrated. Burial in clay, granite and salt environments has been considered and two distinct loading arrangements identified, in an attempt to represent the worst conditions that could be imposed by such media. The analysis successfully demonstrates the ability of the containers to withstand extreme, yet credible, repository loads

  2. Compensation effect of bacterium containing biofertilizer on the growth of Cucumis sativus L. under Al-stress conditions.

    Science.gov (United States)

    Tóth, Brigitta; Lévai, L; Kovács, B; Varga, Mária Borbélyné; Veres, Szilvia

    2013-03-01

    Biofertilizers are used to improve soil fertility and plant production in sustainable agriculture. However, their applicability depends on several environmental parameters. The aim of our study was to evaluate the effect of free-living bacteria containing fertilizer on the growth of cucumber (Cucumis sativus L. cvs. Delicates) under aluminium (Al) stress. Different responses to Al stress of cucumber growth parameters were examined in terms of root elongation and physiological traits, such as Spad index (relative chlorophyll value), biomass accumulation of root and shoot, Al uptake and selected element contents (Fe, Mn, Zn, Mg) of leaves and root. The applied bacteria containing biofertilizer contains Azotobacter chroococcum and Bacillus megaterium. The dry weights of cucumber shoots and roots decreased in line with the increasing Al concentration. Due to different Al treatments (10-3 M, 10-4 M) higher Al concentration was observed in the leaves, while the amounts of other elements (Fe, Mn, Zn, Mg) decreased. This high Al content of the leaves decreased below the control value when biofertilizer was applied. In the case of the roots the additional biofertilizer treatments compensated the effect of Al. The relative chlorophyll content was reduced during Al-stress in older plants and the biofertilizer moderated this effect. The root/shoot ratio was decreased in all the Al-treatments in comparison to the control. The living bacteria containing fertilizer also had a modifying effect. The root/shoot ratio increased at the 10-4 M Al2(SO4)2 + biofertilizer and 10-4 M Al(NO3)3 + biofertilizer treatments compared to the control and Al-treatments. According to our results the biofertilizer is an alternative nutrient supply for replacing chemical fertilizers because it enhances dry matter production. Biofertilizer usage is also offered under Al polluted environmental conditions. Although, the nutrient solution is a clean system where we can examine the main processes without

  3. The mode of stress corrosion cracking in Ni-base alloys in high temperature water containing lead

    International Nuclear Information System (INIS)

    Hwang, S.S.; Kim, H.P.; Lee, D.H.; Kim, U.C.; Kim, J.S.

    1999-01-01

    The mode of stress corrosion cracking (SCC) in Ni-base alloys in high temperature aqueous solutions containing lead was studied using C-rings and slow strain rate testing (SSRT). The lead concentration, pH and the heat treatment condition of the materials were varied. TEM work was carried out to observe the dislocation behavior in thermally treated (TT) and mill annealed (MA) materials. As a result of the C-ring test in 1M NaOH+5000 ppm lead solution, intergranular stress corrosion cracking (IGSCC) was found in Alloy 600MA, whereas transgranular stress corrosion cracking (TGSCC) was found in Alloy 600TT and Alloy 690TT. In most solutions used, the SCC resistance increased in the sequence Alloy 600MA, Alloy 600TT and Alloy 690TT. The number of cracks that was observed in alloy 690TT was less than in Alloy 600TT. However, the maximum crack length in Alloy 690TT was much longer than in Alloy 600TT. As a result of the SSRT, at a nominal strain rate of 1 x 10 -7 /s, it was found that 100 ppm lead accelerated the SCC in Alloy 600MA (0.01%C) in pH 10 at 340 C. IGSCC was found in a 100 ppm lead condition, and some TGSCC was detected on the fracture surface of Alloy 600MA cracked in the 10000 ppm lead solution. The mode of cracking for Alloy 600 and Alloy 690 changed from IGSCC to TGSCC with increasing grain boundary carbide content in the material and lead concentration in the solution. IGSCC seemed to be retarded by stress relaxation around the grain boundaries, and TGSCC in the TT materials seemed to be a result of the crack blunting at grain boundary carbides and the enhanced Ni dissolution with an increase of the lead concentration. (orig.)

  4. Buckling of steel containment shells. Task 1b. Buckling of Washington Public Power Supply Systems' plant No. 2 containment vessel. Final report, 25 August 1980-30 September 1982

    International Nuclear Information System (INIS)

    Meller, E.; Bushnell, D.

    1982-12-01

    Static buckling analyses of the steel containment vessel of the Washington Public Power Supply Systems' (WPPSS) plant No. 2 were conducted with use of several computer programs developed at the Lockheed Missiles and Space Company (LMSC). These analyses were conducted as part of Task 1, Evaluation of Two Steel Containment Designs. The report is divided into two main sections. The first gives results from analyses of the containment as if it were axisymmetric (computerized models with use of BOSOR4, BOSOR5, and PANDA), and the second gives results from a STAGSC-1 model in which the largest penetration is included. Good agreement is obtained from analyses with BOSOR5 and STAGSC-1 for a case in which both of these computer programs were applied to the same configuration and loading. It is important to include nonlinear material behavior (plasticity) in the computerized models for collapse. Predictions of collapse from STAGSC-1 indicate that the largest penetration of the WPPSS-2 containment vessel is reinforced such that there is no decrease in load carrying capability below that indicated from models in which this penetration is neglected

  5. Stress analysis of HLW containers. Preliminary ring test exercise Compas project

    International Nuclear Information System (INIS)

    1989-01-01

    This document describes the series of experiments and associated calculations performed as the Compas preliminary ring test exercise. A number of mild steel rings, representative of sections through HLW containers, some notched and pre-cracked, were tested in compression right up to and beyond their ultimate load. The Compas project partners independently modelled the behaviour of these rings using their finite element codes. Four different ring types were tested, and each test was repeated three times. For three of the ring types, the three test repetitions gave identical results. The fourth ring, which was not modelled by the partners, had a 4 mm thick layer of weld metal deposited on its surface. The three tests on this ring did not give identical results and suggested that the effect of welding methods should be addressed at a later stage of the project. Fracture was not found to be a significant cause of ring failure. The results of the ring tests were compared with the partners predictions, and additionally some time was spent assessing where the use of the codes could be improved. This exercise showed that the partners codes have the ability to produce results within acceptable limits. Most codes were unable to model stable crack growth. There were indications that some codes would not be able to cope with a significantly more complex three-dimensional analysis

  6. Tube-in-shell heat exchangers

    International Nuclear Information System (INIS)

    Richardson, J.

    1976-01-01

    Tube-in-shell heat exchangers normally comprise a bundle of parallel tubes within a shell container, with a fluid arranged to flow through the tubes in heat exchange with a second fluid flowing through the shell. The tubes are usually end supported by the tube plates that separate the two fluids, and in use the tube attachments to the tube plates and the tube plates can be subject to severe stress by thermal shock and frequent inspection and servicing are required. Where the heat exchangers are immersed in a coolant such as liquid Na such inspection is difficult. In the arrangement described a longitudinally extending central tube is provided incorporating axially spaced cylindrical tube plates to which the opposite ends of the tubes are attached. Within this tube there is a tubular baffle that slidably seals against the wall of the tube between the cylindrical tube plates to define two co-axial flow ducts. These ducts are interconnected at the closed end of the tube by the heat exchange tubes and the baffle comprises inner and outer spaced walls with the interspace containing Ar. The baffle is easily removable and can be withdrawn to enable insertion of equipment for inspecting the wall of the tube and tube attachments and to facilitate plugging of defective tubes. Cylindrical tube plates are believed to be superior for carrying pressure loads and resisting the effects of thermal shock. Some protection against thermal shock can be effected by arranging that the secondary heat exchange fluid is on the tube side, and by providing a thermal baffle to prevent direct impingement of hot primary fluid on to the cylindrical tube plates. The inner wall of the tubular baffle may have flexible expansible region. Some nuclear reactor constructions incorporating such an arrangement are described, including liquid metal reactors. (U.K.)

  7. Summary compilation of shell element performance versus formulation.

    Energy Technology Data Exchange (ETDEWEB)

    Heinstein, Martin Wilhelm; Hales, Jason Dean (Idaho National Laboratory, Idaho Falls, ID); Breivik, Nicole L.; Key, Samuel W. (FMA Development, LLC, Great Falls, MT)

    2011-07-01

    This document compares the finite element shell formulations in the Sierra Solid Mechanics code. These are finite elements either currently in the Sierra simulation codes Presto and Adagio, or expected to be added to them in time. The list of elements are divided into traditional two-dimensional, plane stress shell finite elements, and three-dimensional solid finite elements that contain either modifications or additional terms designed to represent the bending stiffness expected to be found in shell formulations. These particular finite elements are formulated for finite deformation and inelastic material response, and, as such, are not based on some of the elegant formulations that can be found in an elastic, infinitesimal finite element setting. Each shell element is subjected to a series of 12 verification and validation test problems. The underlying purpose of the tests here is to identify the quality of both the spatially discrete finite element gradient operator and the spatially discrete finite element divergence operator. If the derivation of the finite element is proper, the discrete divergence operator is the transpose of the discrete gradient operator. An overall summary is provided from which one can rank, at least in an average sense, how well the individual formulations can be expected to perform in applications encountered year in and year out. A letter grade has been assigned albeit sometimes subjectively for each shell element and each test problem result. The number of A's, B's, C's, et cetera assigned have been totaled, and a grade point average (GPA) has been computed, based on a 4.0-system. These grades, combined with a comparison between the test problems and the application problem, can be used to guide an analyst to select the element with the best shell formulation.

  8. Stiffeners in variational-difference method for calculating shells with complex geometry

    Directory of Open Access Journals (Sweden)

    Ivanov Vyacheslav Nikolaevich

    2014-05-01

    Full Text Available We have already considered an introduction of reinforcements in the variational-difference method (VDM of shells analysis with complex shape. At the moment only ribbed shells of revolution and shallow shells can be calculated with the help of developed analytical and finite-difference methods. Ribbed shells of arbitrary shape can be calculated only using the finite element method (FEM. However there are problems, when using FEM, which are absent in finite- and variational-difference methods: rigid body motion; conforming trial functions; parameterization of a surface; independent stress strain state. In this regard stiffeners are entered in VDM. VDM is based on the Lagrange principle - the principle of minimum total potential energy. Stress-strain state of ribs is described by the Kirchhoff-Clebsch theory of curvilinear bars: tension, bending and torsion of ribs are taken into account. Stress-strain state of shells is described by the Kirchhoff-Love theory of thin elastic shells. A position of points of the middle surface is defined by curvilinear orthogonal coordinates α, β. Curved ribs are situated along coordinate lines. Strain energy of ribs is added into the strain energy to account for ribs. A matrix form of strain energy of ribs is formed similar to a matrix form of the strain energy of the shell. A matrix of geometrical characteristics of a rib is formed from components of matrices of geometric characteristics of a shell. A matrix of mechanical characteristics of a rib contains rib’s eccentricity and geometrical characteristics of a rib’s section. Derivatives of displacements in the strain vector are replaced with finite-difference relations after the middle surface of a shell gets covered with a grid (grid lines coincide with the coordinate lines of principal curvatures. By this case the total potential energy functional becomes a function of strain nodal displacements. Partial derivatives of unknown nodal displacements are

  9. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  10. Bright conjugated polymer nanoparticles containing a biodegradable shell produced at high yields and with tuneable optical properties by a scalable microfluidic device.

    Science.gov (United States)

    Abelha, T F; Phillips, T W; Bannock, J H; Nightingale, A M; Dreiss, C A; Kemal, E; Urbano, L; deMello, J C; Green, M; Dailey, L A

    2017-02-02

    This study compares the performance of a microfluidic technique and a conventional bulk method to manufacture conjugated polymer nanoparticles (CPNs) embedded within a biodegradable poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG 5K -PLGA 55K ) matrix. The influence of PEG 5K -PLGA 55K and conjugated polymers cyano-substituted poly(p-phenylene vinylene) (CN-PPV) and poly(9,9-dioctylfluorene-2,1,3-benzothiadiazole) (F8BT) on the physicochemical properties of the CPNs was also evaluated. Both techniques enabled CPN production with high end product yields (∼70-95%). However, while the bulk technique (solvent displacement) under optimal conditions generated small nanoparticles (∼70-100 nm) with similar optical properties (quantum yields ∼35%), the microfluidic approach produced larger CPNs (140-260 nm) with significantly superior quantum yields (49-55%) and tailored emission spectra. CPNs containing CN-PPV showed smaller size distributions and tuneable emission spectra compared to F8BT systems prepared under the same conditions. The presence of PEG 5K -PLGA 55K did not affect the size or optical properties of the CPNs and provided a neutral net electric charge as is often required for biomedical applications. The microfluidics flow-based device was successfully used for the continuous preparation of CPNs over a 24 hour period. On the basis of the results presented here, it can be concluded that the microfluidic device used in this study can be used to optimize the production of bright CPNs with tailored properties with good reproducibility.

  11. Analysis of stress-strain relationship in materials containing voids by means of plastic finite element method

    International Nuclear Information System (INIS)

    Shiraishi, Haruki; Tabuchi, Masaaki

    2000-01-01

    Applying the finite element method in two dimensions, an analysis is performed to derive the stress-strain relationship of material containing voids in matrix, and which is subjected to large deformation. The conditions assumed for the analysis are applicability of continuum body mechanics, Mises yield criterion, J2 flow theory, power work-hardening, plane stress in two-dimensional system and uniform cyclically recurring void distribution. Taking as example a case of material presenting 0.3 work-hardening, it is indicated from the analysis that: With voids arrayed in square lattice, total elongation would be little affected by change in void size; With a void spacing in lattice of 10 μ m, a uniform elongation 12-14% should be obtained in a wide range of void sizes from 0.01 to 8.0 μm; Tensile strength should start to lower at a void areal fraction of around 1%; A sharply lowered uniform elongation of a level far below 1% should be presented by material of low work-hardening exponent. The severe decline of ductility seen with 316 stainless steel upon neutron irradiation at temperatures around 600 K is interpreted as resulting from a combination of low work-hardening and the presence of voids in matrix. (author)

  12. Isogeometric shell formulation based on a classical shell model

    KAUST Repository

    Niemi, Antti

    2012-09-04

    This paper constitutes the first steps in our work concerning isogeometric shell analysis. An isogeometric shell model of the Reissner-Mindlin type is introduced and a study of its accuracy in the classical pinched cylinder benchmark problem presented. In contrast to earlier works [1,2,3,4], the formulation is based on a shell model where the displacement, strain and stress fields are defined in terms of a curvilinear coordinate system arising from the NURBS description of the shell middle surface. The isogeometric shell formulation is implemented using the PetIGA and igakit software packages developed by the authors. The igakit package is a Python package used to generate NURBS representations of geometries that can be utilised by the PetIGA finite element framework. The latter utilises data structures and routines of the portable, extensible toolkit for scientific computation (PETSc), [5,6]. The current shell implementation is valid for static, linear problems only, but the software package is well suited for future extensions to geometrically and materially nonlinear regime as well as to dynamic problems. The accuracy of the approach in the pinched cylinder benchmark problem and present comparisons against the h-version of the finite element method with bilinear elements. Quadratic, cubic and quartic NURBS discretizations are compared against the isoparametric bilinear discretization introduced in [7]. The results show that the quadratic and cubic NURBS approximations exhibit notably slower convergence under uniform mesh refinement as the thickness decreases but the quartic approximation converges relatively quickly within the standard variational framework. The authors future work is concerned with building an isogeometric finite element method for modelling nonlinear structural response of thin-walled shells undergoing large rigid-body motions. The aim is to use the model in a aeroelastic framework for the simulation of flapping wings.

  13. Nuclear reactor containment device

    International Nuclear Information System (INIS)

    Ichiki, Tadaharu.

    1980-01-01

    Purpose: To reduce the volume of a containment shell and decrease the size of a containment equipment for BWR type reactors by connecting the containment shell and a suppression pool with slanted vent tubes to thereby shorten the vent tubes. Constitution: A pressure vessel containing a reactor core is installed at the center of a building and a containment vessel for the nuclear reactor that contains the pressure vessel forms a cabin. To a building situated below the containment shell, is provided a suppression chamber in which cooling water is charged to form a suppression pool. The suppression pool is communicated with vent tubes that pass through the partition wall of the containment vessel. The vent tubes are slanted and their lower openings are immersed in coolants. Therefore, if accident is resulted and fluid at high temperature and high pressure is jetted from the pressure vessel, the jetting fluid is injected and condensated in the cooling water. (Moriyama, K.)

  14. Vibration of liquid-filled thin shells

    International Nuclear Information System (INIS)

    Kalnins, A.

    1979-01-01

    This paper describes the analysis of free and forced vibration of a thin, axisymmetric shell, which contains some liquid. The axis of symmetry is vertical. Only such vibration is considered which can be produced by a horizontal movement of the base of shell. The objective of this paper is to examine the response of the coupled shell-liquid system for a frequency range lying between zero and the lowest natural sloshing frequency of the liquid. The mass of the liquid is modeled by a stationary and one or more sloshing masses. It is shown how the stationary mass can be incorporated in the vibration analysis of the shell and how to natural frequency of the coupled shell-liquid system can be obtained from a simple formula, if the lowest natural frequency of the shell, plus the stationary mass of the liquid, can be determined. A numerical example is given. (orig.)

  15. Transients in a reactor containment after a HCDA

    International Nuclear Information System (INIS)

    Ghosh, A.K.

    1984-01-01

    The consequences of a hypothetical core meltdown accident in a fast reactor is analysed. Shock waves are generated in the surrounding medium after the energy release, which is assumed to be instantaneous and at a point. After discussing the difference in the predicted and experimentally observed peak pressure a semi-empirical approach is taken to arrive at a better estimate. This defines the loading on the containment, which is idealised as a combination of a shell and a plate. To simplify the analysis the shell is assumed to be in plane strain and axial symmetry is assumed for both components. The shell response is evaluated by using elasticity theory. Numerical results are presented for peak overpressure and pressure-time history and dynamic stresses in the containment. (Author) [pt

  16. Ultimate internal pressure capacity of concrete containment structures

    International Nuclear Information System (INIS)

    Krishnaswamy, C.N.; Namperumal, R.; Al-Dabbagh, A.

    1983-01-01

    Lesson learned from the accident at Three-Mile Island nuclear plant has necessitated the computation of the ultimate internal pressure capacity of containment structures as a licensing requirement in the U.S. In general, a containment structure is designed to be essentially elastic under design accident pressure. However, as the containment pressure builds up beyond the design value due to a more severe postulated accident, the containment response turns nonlinear as it sequentially passes through cracking of concrete, yielding of linear plate, yielding of rebar, and yielding of post-tensioning tendon (if the containment concrete is prestressed). This paper reports on the determination of the ultimate internal pressure capacity and nonlinear behavior of typical reinforced and prestressed concrete BWR containments. The probable modes of failure, the criteria for ultimate pressure capacity, and the most critical sections are described. Simple equations to hand-calculate the ultimate pressure capacity and the nonlinear behavior at membrane sections of the containment shell are presented. A nonlinear finite element analysis performed to determine the nonlinear behavior of the entire shell including nonmembrane sections is briefly discribed. The analysis model consisted of laminated axisymmetric shell finite elements with nonlinear stress-strain properties for each material. Results presented for typical BWR concrete containments include nonlinear response plots of internal pressure versus containment deflection and strains in the liner, rebar, and post-tensioning tendons at the most stressed section in the shell. Leak-tightness of the containment liner and the effect of thermal loads on the ultimate capacity are discussed. (orig.)

  17. A combined interfacial and in-situ polymerization strategy to construct well-defined core-shell epoxy-containing SiO2-based microcapsules with high encapsulation loading, super thermal stability and nonpolar solvent tolerance

    Directory of Open Access Journals (Sweden)

    Yin Jia

    2016-10-01

    Full Text Available SiO2-based microcapsules containing hydrophobic molecules exhibited potential applications such as extrinsic self-healing, drug delivery, due to outstanding thermal and chemical stability of SiO2. However, to construct SiO2-based microcapsules with both high encapsulation loading and long-term structural stability is still a troublesome issue, limiting their further utilization. We herein design a single-batch route, a combined interfacial and in-situ polymerization strategy, to fabricate epoxy-containing SiO2-based microcapsules with both high encapsulation loading and long-term structural stability. The final SiO2-based microcapsules preserve high encapsulation loading of 85.7 wt% by controlling exclusively hydrolysis and condensed polymerization at oil/water interface in the initial interfacial polymerization step. In the subsequent in-situ polymerization step, the initial SiO2-based microcapsules as seeds could efficiently harvest SiO2 precursors and primary SiO2 particles to finely tune the SiO2 wall thickness, thereby enhancing long-term structural stability of the final SiO2-based microcapsules including high thermal stability with almost no any weight loss until 250°C, and strong tolerance against nonpolar solvents such as CCl4 with almost unchanged core-shell structure and unchanged core weight after immersing into strong solvents for up to 5 days. These SiO2-based microcapsules are extremely suited for processing them into anticorrosive coating in the presence of nonpolar solvents for self-healing application.

  18. Characterizing haploinsufficiency of SHELL gene to improve fruit form prediction in introgressive hybrids of oil palm

    OpenAIRE

    Teh, Chee Keng; Muaz, Siti Dalila; Tangaya, Praveena; Fong, Po-Yee; Ong, Ai Ling; Mayes, Sean; Chew, Fook Tim; Kulaveerasingam, Harikrishna; Appleton, David Ross

    2017-01-01

    The fundamental trait in selective breeding of oil palm (Eleais guineensis Jacq.) is the shell thickness surrounding the kernel. The monogenic shell thickness is inversely correlated to mesocarp thickness, where the crude palm oil accumulates. Commercial thin-shelled tenera derived from thick-shelled dura???shell-less pisifera generally contain 30% higher oil per bunch. Two mutations, sh MPOB (M1) and sh AVROS (M2) in the SHELL gene ? a type II MADS-box transcription factor mainly present in ...

  19. Inclusion of orbital relaxation and correlation through the unitary group adapted open shell coupled cluster theory using non-relativistic and scalar relativistic Hamiltonians to study the core ionization potential of molecules containing light to medium-heavy elements

    Science.gov (United States)

    Sen, Sangita; Shee, Avijit; Mukherjee, Debashis

    2018-02-01

    The orbital relaxation attendant on ionization is particularly important for the core electron ionization potential (core IP) of molecules. The Unitary Group Adapted State Universal Coupled Cluster (UGA-SUMRCC) theory, recently formulated and implemented by Sen et al. [J. Chem. Phys. 137, 074104 (2012)], is very effective in capturing orbital relaxation accompanying ionization or excitation of both the core and the valence electrons [S. Sen et al., Mol. Phys. 111, 2625 (2013); A. Shee et al., J. Chem. Theory Comput. 9, 2573 (2013)] while preserving the spin-symmetry of the target states and using the neutral closed-shell spatial orbitals of the ground state. Our Ansatz invokes a normal-ordered exponential representation of spin-free cluster-operators. The orbital relaxation induced by a specific set of cluster operators in our Ansatz is good enough to eliminate the need for different sets of orbitals for the ground and the core-ionized states. We call the single configuration state function (CSF) limit of this theory the Unitary Group Adapted Open-Shell Coupled Cluster (UGA-OSCC) theory. The aim of this paper is to comprehensively explore the efficacy of our Ansatz to describe orbital relaxation, using both theoretical analysis and numerical performance. Whenever warranted, we also make appropriate comparisons with other coupled-cluster theories. A physically motivated truncation of the chains of spin-free T-operators is also made possible by the normal-ordering, and the operational resemblance to single reference coupled-cluster theory allows easy implementation. Our test case is the prediction of the 1s core IP of molecules containing a single light- to medium-heavy nucleus and thus, in addition to demonstrating the orbital relaxation, we have addressed the scalar relativistic effects on the accuracy of the IPs by using a hierarchy of spin-free Hamiltonians in conjunction with our theory. Additionally, the contribution of the spin-free component of the two

  20. Inclusion of orbital relaxation and correlation through the unitary group adapted open shell coupled cluster theory using non-relativistic and scalar relativistic Hamiltonians to study the core ionization potential of molecules containing light to medium-heavy elements.

    Science.gov (United States)

    Sen, Sangita; Shee, Avijit; Mukherjee, Debashis

    2018-02-07

    The orbital relaxation attendant on ionization is particularly important for the core electron ionization potential (core IP) of molecules. The Unitary Group Adapted State Universal Coupled Cluster (UGA-SUMRCC) theory, recently formulated and implemented by Sen et al. [J. Chem. Phys. 137, 074104 (2012)], is very effective in capturing orbital relaxation accompanying ionization or excitation of both the core and the valence electrons [S. Sen et al., Mol. Phys. 111, 2625 (2013); A. Shee et al., J. Chem. Theory Comput. 9, 2573 (2013)] while preserving the spin-symmetry of the target states and using the neutral closed-shell spatial orbitals of the ground state. Our Ansatz invokes a normal-ordered exponential representation of spin-free cluster-operators. The orbital relaxation induced by a specific set of cluster operators in our Ansatz is good enough to eliminate the need for different sets of orbitals for the ground and the core-ionized states. We call the single configuration state function (CSF) limit of this theory the Unitary Group Adapted Open-Shell Coupled Cluster (UGA-OSCC) theory. The aim of this paper is to comprehensively explore the efficacy of our Ansatz to describe orbital relaxation, using both theoretical analysis and numerical performance. Whenever warranted, we also make appropriate comparisons with other coupled-cluster theories. A physically motivated truncation of the chains of spin-free T-operators is also made possible by the normal-ordering, and the operational resemblance to single reference coupled-cluster theory allows easy implementation. Our test case is the prediction of the 1s core IP of molecules containing a single light- to medium-heavy nucleus and thus, in addition to demonstrating the orbital relaxation, we have addressed the scalar relativistic effects on the accuracy of the IPs by using a hierarchy of spin-free Hamiltonians in conjunction with our theory. Additionally, the contribution of the spin-free component of the two

  1. Ultimate load capacity assessment of reinforced concrete shell structures

    International Nuclear Information System (INIS)

    Gupta, Amita; Singh, R.K.; Kushwaha, H.S.; Mahajan, S.C.; Kakodkar, A.

    1993-01-01

    The objective of this study is to develop capability for prediction of ultimate load capacity of reinforced concrete shell structures. The present finite element code ULCA (Ultimate Load Capacity Assessment) adopts a degenerate concept of formulating general isoparametric shell element with a layered approach in the thickness direction. Different failure modes such as crushing, tensile cracking and reinforcement yielding are recognised for various problems. The structure fails by crushing of concrete when the concrete strain/stress reaches the ultimate stress or strain of concrete. Material nonlinearities as a result of tension cracking, tension stiffening between reinforcement and concrete in cracked region and yielding of reinforcement are considered along with geometric nonlinearity. Thus with this code it is possible to predict the pressure at which the first cracking, first through thickness cracking, first yielding of reinforcement occurs. After validating the code with few bench mark problems for different failure modes a reinforced concrete nuclear containment is analysed for its ultimate capacity and the results are matched with the published results. Further the ultimate load capacity of outer containment wall of Narora Atomic Power Station is predicted. It is observed that containment fails in membrane region and has a sufficient margin against design pressure. (author). 9 refs., 56 figs., 3 tabs., 1 appendix with 4 tabs

  2. The Mancozeb-containing carbamate fungicide tattoo induces mild oxidative stress in goldfish brain, liver, and kidney.

    Science.gov (United States)

    Atamaniuk, Tetiana M; Kubrak, Olga I; Husak, Viktor V; Storey, Kenneth B; Lushchak, Volodymyr I

    2014-11-01

    Tattoo belongs to the group of carbamate fungicides and contains Mancozeb (ethylene(bis)dithiocarbamate) as its main constituent. The toxicity of Mancozeb to living organisms, particularly fish, is not resolved. This work investigated the effects of 96 h of exposure to 3, 5, or 10 mg L(-1) of Tattoo (corresponding to 0.9, 1.5, or 3 mg L(-1) of Mancozeb) on the levels of oxidative stress markers and the antioxidant enzyme system of brain, liver, and kidney of goldfish, Carassius auratus). In liver, Tattoo exposure resulted in increased activities of superoxide dismutase (SOD) by 70%-79%, catalase by 23%-52% and glutathione peroxidase (GPx) by 49%. The content of protein carbonyls (CP) in liver was also enhanced by 92%-125% indicating extensive damage to proteins. Similar increases in CP levels (by 98%-111%) accompanied by reduced glucose-6-phosphate dehydrogenase activity (by 13%-15%) was observed in kidney of fish exposed to Tattoo; however, SOD activity increased by 37% in this tissue after treatment with 10 mg L(-1) Tattoo. In brain, a rise in lipid peroxide level (by 29%) took place after exposure to 10 mg L(-1) Tattoo and was accompanied by elevation of high-molecular mass thiols (by 14%). Tattoo exposure also resulted in a concentration-dependent decrease in glutathione reductase activity (by 26%-37%) in brain. The data collectively show that exposure of goldfish to 3-10 mg L(-1) of the carbamate fungicide Tattoo resulted in the development of mild oxidative stress and activation of antioxidant defense systems in goldfish tissues. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

  3. Physiological characteristics and metabolomics of transgenic wheat containing the maize C4 phosphoenolpyruvate carboxylase (PEPC) gene under high temperature stress.

    Science.gov (United States)

    Qi, Xueli; Xu, Weigang; Zhang, Jianzhou; Guo, Rui; Zhao, Mingzhong; Hu, Lin; Wang, Huiwei; Dong, Haibin; Li, Yan

    2017-03-01

    In this paper, two transgenic wheat lines, PC27 and PC51, containing the maize PEPC gene and its wild-type (WT) were used as experimental material to study the effects of high temperature on their photosynthetic physiological characteristics and metabolome. The results showed that transgenic wheat lines had higher photosynthetic rate (P n ) than WT under non-stress treatment (NT) and high temperature stress treatment (HT), and more significantly under HT. The change trends of F v /F m , Ф PSII , and q P were similar to P n , whereas that of non-photochemical quenching (NPQ) was the opposite. Compared with WT, no differences in chlorophyll content between the transgenic wheat and WT were observed under NT, but two transgenic lines had relatively higher contents than WT under HT. The change trends of Chlorophyll a/b radio, the decreased values of F m , W k , and V j , and the activity of the antioxidant enzyme were consistent with the chlorophyll content. Compared with WT, transgenic wheat lines exhibited lower rate of superoxide anion production, H 2 O 2 and malondialdehyde content under HT, and no significant differences were observed under NT. The expression pattern of the ZmPEPC gene and wheat endogenous photosynthesis-related genes were in agreement with that of P n . Compared with WT, about 13 different metabolites including one organic acid, six amino acids, four sugars, and two polyols were identified under NT; 25 different metabolites including six organic acids, 12 amino acids, four sugars, and three polyols were identified under HT. Collectively, our results indicate that ZmPEPC gene can enhance photochemical and antioxidant enzyme activity, upregulate the expression of photosynthesis-related genes, delay degradation of chlorophyll, change contents of proline and other metabolites in wheat, and ultimately improves its heat tolerance.

  4. Glove holder system for containment shell

    International Nuclear Information System (INIS)

    Picco, B.

    1993-01-01

    A glove holder for an isolated chamber used e.g. for handling toxic or radioactive materials and made with at least one access port in its wall, equipped with a ring to which the glove is attached, has a sleeve which connects the ring to the glove proper and protects the forarm. The sleeve is in at least two sections, a first corrugated section and a second, supple section which is able to fold inside the first section. ADVANTAGE - Reduced costs and quantity of waste produced by enabling glove proper only to be replaced. (author)

  5. Cask for concrete shells transportation

    International Nuclear Information System (INIS)

    Labergri, F.

    2001-01-01

    Nowadays, nuclear plant radioactive waste are conditioned in situ into concrete shells. Most of them enter in the industrial waste category defined by the regulations of radioactive material transportation. However, the content of a few ones exceeds the limits set for low specific activity substances. Thus, these shells must be transported into type B packagings. To this end, Robatel has undertaken, for EDF (Electricite de France), the development of a container, named ROBATEL TM R68, for further licensing. The particularity of this packaging is that the lid must have a wide opening to allow the usual handling operations of the concrete shells. This leads to a non-conventional conception, and makes the package more vulnerable to drop test solicitations. In order to define a minimal drop test program on a reduced scale model, we use a simple method to find the most damageable drop angle. (author)

  6. Human proteins that specifically bind to 8-oxoguanine-containing RNA and their responses to oxidative stress

    International Nuclear Information System (INIS)

    Hayakawa, Hiroshi; Fujikane, Aya; Ito, Riyoko; Matsumoto, Masaki; Nakayama, Keiichi I.; Sekiguchi, Mutsuo

    2010-01-01

    Research highlights: → We performed comprehensive survey for proteins that bind to oxidized RNA. → HNRNPD and HNRNPC proteins were identified as oxidized RNA binding proteins. → Knockdown of HNRNPD/C expression caused increased sensitivity to H 2 O 2 . → Amounts of HNRNPD protein rapidly decreased when cells were exposed to H 2 O 2 . -- Abstract: Exposure of cells to oxygen radicals damage various biologically important molecules. Among the oxidized bases produced in nucleic acids, 8-oxo-7,8-dihydroguanine (8-oxoguanine) is particularly important since it causes base mispairing. To ensure accurate gene expression, organisms must have a mechanism to discriminate 8-oxoguanine-containing RNA from normal transcripts. We searched for proteins that specifically bind to 8-oxoguanine-containing RNA from human HeLa cell extracts, and the candidate proteins were identified using mass spectrometry. Among the identified candidates, splicing isoform 1 of heterogeneous nuclear ribonucleoprotein D0 (HNRNPD) and splicing isoform C1 of heterogeneous nuclear ribonucleoprotein C1/C2 (HNRNPC) exhibited strong abilities to bind to oxidized RNA. The amount of HNRNPD protein rapidly decreased when cells were exposed to hydrogen peroxide, an agent that enhances oxidative stress. Moreover, the suppression of HNRNPD expression by siRNA caused cells to exhibit an increased sensitivity to hydrogen peroxide. The application of siRNA against HNRNPC also caused an increase in sensitivity to hydrogen peroxide. Since no additive effect was observed with a combined addition of siRNAs for HNRNPD and HNRNPC, we concluded that the two proteins may function in the same mechanism for the accurate gene expression.

  7. Carbon isotopes in mollusk shell carbonates

    Science.gov (United States)

    McConnaughey, Ted A.; Gillikin, David Paul

    2008-10-01

    Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δ13C reflects the local mix of C3 and C4 plants consumed. Shell δ13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell δ13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell δ13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

  8. Creep buckling of shell structures

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki; Hagihara, Seiya

    2015-01-01

    The present article contains a review of the literatures on the creep buckling of shell structures published from late 1950's to recent years. In this article, the creep buckling studies on circular cylindrical shells, spherical shells, partial cylindrical shells and other shells are reviewed in addition to creep buckling criteria. Creep buckling is categorized into two types. One is the creep buckling due to quasi-static instability, in which the critical time for creep buckling is determined by tracing a creep deformation versus time curve. The other is the creep buckling due to kinetic instability, in which the critical time can be determined by examining the shape of total potential energy in the vicinity of a quasi-static equilibrium state. Bifurcation buckling and snap-through buckling during creep deformation belong to this type of creep buckling. A few detailed descriptions are given to the bifurcation and snap-through type of creep buckling based on the present authors' works. (author)

  9. Analysis study on change of tendon behavior during pressurization process of Pre-stressed Concrete Containment Vessel

    International Nuclear Information System (INIS)

    Kashiwase, Takako; Nagasaka, Hideo

    1999-01-01

    NUPEC has been planning the ultimate strength test of Pre-stressed Concrete Containment Vessel (PCCV). The test model is 1/4 uniform scale model of Japan actual PCCV. It involves an equipment hatch, several penetrations and liner with T-anchors. The ancillary test for the PCCV test was conducted, in which friction coefficient of hoop tendon was evaluated by tensile force distribution using the same tendon as that of 1/4 PCCV model. Tendon will be in plastic region under internal pressure above 3.5 times design pressure (Pd) and surface characteristic of tendon and the resultant friction coefficient will be changed. In the present paper, tendon friction coefficient in the plastic region was obtained by evaluating plastic region data of tendon in the ancillary test. The validity of the obtained friction coefficient was confirmed by the tendon elongation data. In addition to the formally developed elastic region friction coefficient, the obtained plastic region correlation was incorporated into ABAQUS Ver. 5.6. The effect of tendon tensile force distribution change on structural behavior up to 3.8 Pd was evaluated. (author)

  10. Selection of efficient salt-tolerant bacteria containing ACC deaminase for promotion of tomato growth under salinity stress

    Directory of Open Access Journals (Sweden)

    Kannika Chookietwattana* and Kedsukon Maneewan

    2012-05-01

    Full Text Available For successful application of plant growth promoting bacteria (PGPB in salt-affected soil, bioinoculant with salt-tolerant property is required in order to provide better survival and perform well in the field. The present study aimed to select the most efficient salt-tolerant bacterium containing 1-aminocyclopropane-1-carboxylic acid (ACC deaminase from eighty four bacterial strains and to investigate the effects of the selected bacterium on the germination and growth of tomato (Licopersicon esculentum Mill. cv. Seeda under saline conditions. The Bacillus licheniformis B2r was selected for its ability to utilize ACC as a sole nitrogen source under salinity stress. It also showed a high ACC deaminase activity at 0.6 M NaCl salinity. Tomato plants inoculated with the selected bacterium under various saline conditions (0, 30, 60, 90 and 120 mM NaCl revealed a significant increase in the germination percentage, germination index, root length, and seedling dry weight especially at salinity levels ranging from 30-90 mM NaCl. The work described in this report is an important step in developing an efficient salt-tolerant bioinoculant to facilitate plant growth in saline soil.

  11. Immune response, stress resistance and bacterial challenge in juvenile rainbow trouts Oncorhynchus mykiss fed diets containing chitosan-oligosaccharides

    Directory of Open Access Journals (Sweden)

    Lin LUO, Xuefeng CAI, Chuan HE, Min XUE, Xiufeng WU , Haining CAO

    2009-12-01

    Full Text Available Effects of dietary supplementation of chitosan-oligosaccharides (COS on the growth performance, immune response, stress resistance, and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied. Four experimental diets containing 0, 20, 40, or 60 mg/kg COS (COS0, COS20, COS40, and COS60, respectively were fed to juvenile rainbow trout (initial weight = 5.2 ± 0.3 g for 8 weeks. By the end of the feeding trial, representative groups of fish from each dietary treatment were challenged with stressor (30 sec air exposure and pathogen exposure (intraperitoneal injection with Aeromonas hydrophila. Results showed that supplementation of COS in diets did not affect production performance and body composition of rainbow trout. However, fish fed the COS40 diet demonstrated improved phagocytic activities, respiratory burst activities and decreased serum cortisol level. Additionally, survival following A. hydrophila challenge was significant higher among fish fed the COS-supplemented feeds, although there was no difference based on the level of supplementation. The present study suggests that COS can be used as an immuno-stimulant in rainbow trout feeds [Current Zoology 55 (6: 416– 422, 2009].

  12. Mathematical Modeling of the Thermal Shell State of the Cylindrical Cryogenic Tank During Filling and Emptying

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2015-01-01

    Full Text Available Liquid hydrogen and oxygen are used as the oxidizer and fuel for liquid rocket engines. Liquefied natural gas, which is based on methane, is seen as a promising motor fuel for internal combustion engines. One of the technical problems arising from the use of said cryogenic liquid is to provide containers for storage, transport and use in the propulsion system. In the design and operation of such vessels it is necessary to have reliable information about their temperature condition, on which depend the loss of cryogenic fluids due to evaporation and the stress-strain state of the structural elements of the containers.Uneven temperature distribution along the generatrix of the cylindrical thin-walled shell of rocket cryogenic tanks, in a localized zone of cryogenic liquid level leads to a curvature of the shell and reduce the permissible axle load in a hazard shell buckling in the preparation for the start of the missile in flight with an increasing acceleration. Moving the level of the cryogenic liquid during filling or emptying the tank at a certain combination of parameters results in an increase of the local temperature distribution nonuniformity.Along with experimental study of the shell temperature state of the cryogenic container, methods of mathematical modeling allow to have information needed for designing and testing the construction of cryogenic tanks. In this study a mathematical model is built taking into account features of heat transfer in a cryogenic container, including the boiling cryogenic liquid in the inner surface of the container. This mathematical model describes the temperature state of the thin-walled shell of cylindrical cryogenic tank during filling and emptying. The work also presents a quantitative analysis of this model in case of fixed liquid level, its movement at a constant speed, and harmonic oscillations relative to a middle position. The quantitative analysis of this model has allowed to find the limit options

  13. TaUBA, a UBA domain-containing protein in wheat (Triticum aestivum L.), is a negative regulator of salt and drought stress response in transgenic Arabidopsis.

    Science.gov (United States)

    Li, Xiao; Zhang, Shuang-shuang; Ma, Jun-xia; Guo, Guang-yan; Zhang, Xue-yong; Liu, Xu; Bi, Cai-li

    2015-05-01

    TaUBA functions as a negative regulator of salt and drought stress response in transgenic Arabidopsis, either the UBA domain or the zinc finger domain is crucial for TaUBA's function. TaUBA (DQ211935), which is a UBA domain-containing protein in wheat, was cloned and functionally characterized. Southern blot suggested that TaUBA is a low copy gene in common wheat. qRT-PCR assay showed that the expression of TaUBA was strongly induced by salt and drought stress. When suffering from drought and salt stresses, lower proline content and much higher MDA content in the TaUBA overexpressors were observed than those of the wild-type control, suggesting TaUBA may function as a negative regulator of salt and drought stress response in plants. To study whether the UBA domain or the zinc finger domain affects the function of TaUBA, TaUBAΔUBA (deletion of UBA domain) and TaUBA-M (Cys464Gly and Cys467Gly) overexpression vectors were constructed and transformed into Arabidopsis. Upon drought and salt stresses, the TaUBAΔUBA-and TaUBA-M-overexpressed plants accumulated much more proline and lower MDA than the wild-type control, the TaUBA-overexpressors lost water more quickly than TaUBAΔUBA-and TaUBA-M-overexpressed plants as well as the wild-type control, suggesting that overexpression of TaUBAΔUBA or TaUBA-M improved the drought and salt tolerance of transgenic Arabidopsis plants and the possibility of ubiquitination role in the regulation of osmolyte synthesis and oxidative stress responses in mediating stress tolerance. qRT-PCR assay of stress-related genes in transgenic plants upon drought and salt stresses suggested that TaUBA may function through down-regulating some stress related-transcription factors and by regulating P5CSs to cope with osmotic stress.

  14. Stress

    Science.gov (United States)

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  15. Finite element model for nonlinear shells of revolution

    International Nuclear Information System (INIS)

    Cook, W.A.

    1979-01-01

    Nuclear material shipping containers have shells of revolution as basic structural components. Analytically modeling the response of these containers to severe accident impact conditions requires a nonlinear shell-of-revolution model that accounts for both geometric and material nonlinearities. Existing models are limited to large displacements, small rotations, and nonlinear materials. The paper presents a finite element model for a nonlinear shell of revolution that will account for large displacements, large strains, large rotations, and nonlinear materials

  16. Plastic buckling of cylindrical shells

    International Nuclear Information System (INIS)

    Bandyopadhyay, K.; Xu, J.; Shteyngart, S.; Eckert, H.

    1994-01-01

    Cylindrical shells exhibit buckling under axial loads at stresses much less than the respective theoretical critical stresses. This is due primarily to the presence of geometrical imperfections even though such imperfections could be very small (e.g., comparable to thickness). Under internal pressure, the shell regains some of its buckling strength. For a relatively large radius-to-thickness ratio and low internal pressure, the effect can be reasonably estimated by an elastic analysis. However, for low radius-to-thickness ratios and greater pressures, the elastic-plastic collapse controls the failure load. in order to quantify the elastic-plastic buckling capacity of cylindrical shells, an analysis program was carried out by use of the computer code BOSOR5 developed by Bushnell of Lockheed Missiles and Space Company. The analysis was performed for various radius-to-thickness ratios and imperfection amplitudes. The purpose of the analytical program was to compute the buckling strength of underground cylindrical tanks, that are used for storage of nuclear wastes, for realistic geometric imperfections and internal pressure loads. This paper presents the results of the elastic-plastic analyses and compares them with other available information for various pressure loads

  17. Distribution of steady state temperatures and thermoelastic stresses in a cylindrical shell with internal heat generation and cooled on both sides or only on one side

    International Nuclear Information System (INIS)

    Melese d'Hospital, G.B.

    1979-10-01

    General expressions for steady state temperatures and elastic thermal stress distributions are derived for a hollow fuel element cooled on both sides. The main simplifying assumptions consist of one dimensional heat transfer and a single medium. Dimensionless numerical results are plotted in the case of uniform internal heat generation and for constant thermal conductivity. Solid rods and flat plates are treated as special cases. As could be expected, cooling on both sides rather than on only one side, leads to significant reduction in maximum fuel temperature and thermal stresses for a given power density, or to a significant increase in power density for either given maximum temperature drop in the fuel or for maximum tensile thermal stress. Typically, for a rod diameter ratio of 2, the power density could be increased by a factor of 3 to 4 without increasing the maximum stress. Similarly, for the same power density, replacing internal cooling of a hollow fuel element by external cooling reduces the maximum fuel temperature drop by a factor of 1.5 and the average fuel temperature drop (or maximum tensile stress) by a factor of 2, with the same maximum compressive stress

  18. Oscillating shells: A model for a variable cosmic object

    OpenAIRE

    Nunez, Dario

    1997-01-01

    A model for a possible variable cosmic object is presented. The model consists of a massive shell surrounding a compact object. The gravitational and self-gravitational forces tend to collapse the shell, but the internal tangential stresses oppose the collapse. The combined action of the two types of forces is studied and several cases are presented. In particular, we investigate the spherically symmetric case in which the shell oscillates radially around a central compact object.

  19. Elasto-plastic impact of hemispherical shell impacting on hard rigid sphere

    Science.gov (United States)

    Raftopoulos, D. D.; Spicer, A. L.

    1976-01-01

    An analysis of plastic stress waves for cylindrical metallic projectile in impact is extended to an analysis of a hemispherical shell suffereing plastic deformation during the process of impact. It is assumed that the hemispherical shell with a prescribed launch velocity impinges a fixed rigid sphere of diameter equal to the internal diameter of the shell. The dynamic biaxial state of stress present in the shell during deformation is investigated. The analysis is valuable for studying the state of stress during large plastic deformation of a hemispherical shell.

  20. Effect of laser shock peening on residual stress and fatigue life of clad 2024 aluminium sheet containing scribe defects

    International Nuclear Information System (INIS)

    Dorman, M.; Toparli, M.B.; Smyth, N.; Cini, A.; Fitzpatrick, M.E.; Irving, P.E.

    2012-01-01

    Highlights: ► Effect of laser peen intensity on local residual stress fields in 2024 aluminium. ► Peening induces significant changes in surface topography and local hardness. ► Residual stress at peen spot centre in tension, spot overlap in compression. ► Notched fatigue lives increased; crack morphology correlated to residual stress field. ► Large peening power densities can cause fatigue life reduction in notched samples. - Abstract: Laser peening at a range of power densities has been applied to 2 mm-thick sheets of 2024 T351 aluminium. The induced residual stress field was measured using incremental hole drilling and synchrotron X-ray diffraction techniques. Fatigue samples were subjected to identical laser peening treatments followed by scribing at the peen location to introduce stress concentrations, after which they were fatigue tested. The residual stresses were found to be non-biaxial: orthogonal to the peen line they were tensile at the surface, moving into the desired compression with increased depth. Regions of peen spot overlap were associated with large compression strains; the centre of the peen spot remaining tensile. Fatigue lives showed moderate improvement over the life of unpeened samples for 50 μm deep scribes, and slight improvement for samples with 150 μm scribes. Use of the residual stress intensity K resid approach to calculate fatigue life improvement arising from peening was unsuccessful at predicting the relative effects of the different peening treatments. Possible reasons for this are explored.

  1. Using an equation based on flow stress to estimate structural integrity of annealed Type 304 stainless steel plate and pipes containing surface defects

    International Nuclear Information System (INIS)

    Reuter, W.G.; Place, T.A.

    1981-01-01

    An accurate assessment of the influence of defects on structural component integrity is needed. Generally accepted analytical techniques are not available for the very ductile materials used in many nuclear reactor components. Some results are presented from a test programme to obtain data by which to evaluate proposed models. Plate and pipe specimens containing surface flaws were fabricated from annealed Type 304 stainless steel and tested at room temperature. An evaluation of an empirical equation based on flow stress is presented. In essentially all instances the flow stress is not a constant but varies as a function of the size of the surface flaw. (author)

  2. Induced wave propagation from a vibrating containment envelope

    International Nuclear Information System (INIS)

    Stout, R.B.; Thigpen, L.; Rambo, J.T.

    1985-09-01

    Low frequency wave forms are observed in the particle velocity measurements around the cavity and containment envelope formed by an underground nuclear test. The vibration solution for a spherical shell is used to formulate a model for the low frequency wave that propagates outward from this region. In this model the containment envelope is the zone of material that is crushed by the compressive shock wave of the nuclear explosion. The containment envelope is approximated by a spherical shell of material. The material in the spherical shell is densified and is given a relatively high kinetic energy density because of the high compressive stress and particle velocity of the shock wave. After the shock wave has propagated through the spherical shell, the spherical shell vibrates in order to dissipate the kinetic energy acquired from the shock wave. Based on the model, the frequency of vibration depends on the dimensions and material properties of the spherical shell. The model can also be applied in an inverse mode to obtain global estimates of averaged materials properties. This requires using experimental data and semi-empirical relationships involving the material properties. A particular case of estimating a value for shear strength is described. Finally, the oscillation time period of the lowest frequency from five nuclear tests is correlated with the energy of the explosion. The correlation provides another diagnostic to estimate the energy of a nuclear explosion. Also, the longest oscillation time period measurement provides additional experimental data that can be used to assess and validate various computer models. 11 refs., 2 figs

  3. Comparative functional analysis of wheat (Triticum aestivum) zinc finger-containing glycine-rich RNA-binding proteins in response to abiotic stresses.

    Science.gov (United States)

    Xu, Tao; Gu, Lili; Choi, Min Ji; Kim, Ryeo Jin; Suh, Mi Chung; Kang, Hunseung

    2014-01-01

    Although the functional roles of zinc finger-containing glycine-rich RNA-binding proteins (RZs) have been characterized in several plant species, including Arabidopsis thaliana and rice (Oryza sativa), the physiological functions of RZs in wheat (Triticum aestivum) remain largely unknown. Here, the functional roles of the three wheat RZ family members, named TaRZ1, TaRZ2, and TaRZ3, were investigated using transgenic Arabidopsis plants under various abiotic stress conditions. Expression of TaRZs was markedly regulated by salt, dehydration, or cold stress. The TaRZ1 and TaRZ3 proteins were localized to the nucleus, whereas the TaRZ2 protein was localized to the nucleus, endoplasmic reticulum, and cytoplasm. Germination of all three TaRZ-expressing transgenic Arabidopsis seeds was retarded compared with that of wild-type seeds under salt stress conditions, whereas germination of TaRZ2- or TaRZ3-expressing transgenic Arabidopsis seeds was retarded under dehydration stress conditions. Seedling growth of TaRZ1-expressing transgenic plants was severely inhibited under cold or salt stress conditions, and seedling growth of TaRZ2-expressing plants was inhibited under salt stress conditions. By contrast, expression of TaRZ3 did not affect seedling growth of transgenic plants under any of the stress conditions. In addition, expression of TaRZ2 conferred freeze tolerance in Arabidopsis. Taken together, these results suggest that different TaRZ family members play various roles in seed germination, seedling growth, and freeze tolerance in plants under abiotic stress.

  4. Transport containers for radioactive material

    International Nuclear Information System (INIS)

    Doroszlai, P.; Ferroni, F.

    1984-01-01

    A cylindrical container for the transportation of radioactive reactor elements includes a top end, a bottom end and a pair of removable outwardly curved shock absorbers, each including a double-shelled construction having an internal shell with a convex intrados configuration and an external shell with a convex extrados configuration, the shock absorbers being filled with a low density energy-absorbing material and mounted at the top end and the bottom end of the container, respectively, and each of the shock absorbers having a toroidal configuration, and deformable tubes disposed within the shock absorbers and extending in the axial direction of the container

  5. Localized corrosion and stress corrosion cracking behavior of austenitic stainless steel weldments containing retained ferrite. Annual progress report, June 1, 1978--March 31, 1979

    International Nuclear Information System (INIS)

    Savage, W.F.; Duquette, D.J.

    1979-03-01

    Localized corrosion and stress corrosion cracking experiments have been performed on single phase 304 stainless steel alloys and autogeneous weldments containing retained delta ferrite as a second phase. The results of the pitting experiments show that the pressure of delta ferrite decreases localized corrosion resistance with pits initiating preferentially at delta ferrite--gamma austenite interphase boundaries. This increased susceptibility is reversible with elevated temperature heat treatments which revert the metastable ferrite phase to the equilibrium austenite phase

  6. An endoplasmic reticulum-localized Coffea arabica BURP domain-containing protein affects the response of transgenic Arabidopsis plants to diverse abiotic stresses.

    Science.gov (United States)

    Dinh, Sy Nguyen; Kang, Hunseung

    2017-11-01

    The Coffea arabica BURP domain-containing gene plays an important role in the response of transgenic Arabidopsis plants to abiotic stresses via regulating the level of diverse proteins. Although the functions of plant-specific BURP domain-containing proteins (BDP) have been determined for a few plants, their roles in the growth, development, and stress responses of most plant species, including coffee plant (Coffea arabica), are largely unknown. In this study, the function of a C. arabica BDP, designated CaBDP1, was investigated in transgenic Arabidopsis plants. The expression of CaBDP1 was highly modulated in coffee plants subjected to drought, cold, salt, or ABA. Confocal analysis of CaBDP1-GFP fusion proteins revealed that CaBDP1 is localized in the endoplasmic reticulum. The ectopic expression of CaBDP1 in Arabidopsis resulted in delayed germination of the transgenic plants under abiotic stress and in the presence of ABA. Cotyledon greening and seedling growth of the transgenic plants were inhibited in the presence of ABA due to the upregulation of ABA signaling-related genes like ABI3, ABI4, and ABI5. Proteome analysis revealed that the levels of several proteins are modulated in CaBDP1-expressing transgenic plants. The results of this study underscore the importance of BURP domain proteins in plant responses to diverse abiotic stresses.

  7. Acute effect of sorghum flour-containing pasta on plasma total polyphenols, antioxidant capacity and oxidative stress markers in healthy subjects: A randomised controlled trial.

    Science.gov (United States)

    Khan, Imran; Yousif, Adel M; Johnson, Stuart K; Gamlath, Shirani

    2015-06-01

    It has been previously reported that pasta containing wholegrain sorghum flour exhibits high content of polyphenols and antioxidant capacity and hence might enhance antioxidant status and reduce markers of oxidative stress in vivo; however no clinical studies have yet been reported. Therefore, the present study assessed the effect of pasta containing red or white wholegrain sorghum flour on plasma total polyphenols, antioxidant capacity and oxidative stress markers in humans. The study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN: 12612000324819). In a randomised crossover design, healthy subjects (n = 20) consumed three test meals of control pasta (CP), 30% red sorghum pasta (RSP) or 30% white sorghum pasta (WSP), 1-2 wk apart. The test meals were consumed as breakfast after an overnight fast. Blood samples were obtained at fasting and 2 h after consumption and analysed for total polyphenols, antioxidant capacity, superoxide dismutase (SOD) activity, protein carbonyl and 8-isoprostanes. Compared to baseline, the 2 h post-prandial levels following the RSP meal of plasma polyphenols, antioxidant capacity and SOD activity were significantly (P pasta containing red wholegrain sorghum flour enhanced antioxidant status and improved markers of oxidative stress in healthy subjects. Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  8. Coal option. [Shell Co

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This paper notes the necessity of developing an international coal trade on a very large scale. The role of Shell in the coal industry is examined; the regions in which Shell companies are most active are Australia, Southern Africa, Indonesia; Europe and North America. Research is being carried out on marketing and transportation, especially via slurry pipelines; coal-oil emulsions; briquets; fluidized-bed combustion; recovery of coal from potential waste material; upgrading of low-rank coals; unconventional forms of mining; coal conversion (the Shell/Koppers high-pressure coal gasification process). Techniques for cleaning flue gas (the Shell Flue Gas Desulfurization process) are being examined.

  9. Shell-like structures

    CERN Document Server

    Altenbach, Holm

    2011-01-01

    In this volume, scientists and researchers from industry discuss the new trends in simulation and computing shell-like structures. The focus is put on the following problems: new theories (based on two-dimensional field equations but describing non-classical effects), new constitutive equations (for materials like sandwiches, foams, etc. and which can be combined with the two-dimensional shell equations), complex structures (folded, branching and/or self intersecting shell structures, etc.) and shell-like structures on different scales (for example: nano-tubes) or very thin structures (similar

  10. 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.

  11. Mechanical stability of cylindrical thin-shell wormholes

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, M. [University of the Punjab, Department of Mathematics, Lahore (Pakistan); Azam, M. [University of Education, Division of Science and Technology, Lahore (Pakistan)

    2013-04-15

    In this paper, we apply the cut and paste procedure to the charged black string for the construction of a thin-shell wormhole. We consider the Darmois-Israel formalism to determine the surface stresses of the shell. We take the Chaplygin gas to deal with the matter distribution on shell. The radial perturbation approach (preserving the symmetry) is used to investigate the stability of static solutions. We conclude that stable static solutions exist both for uncharged and charged black string thin-shell wormholes for particular values of the parameters. (orig.)

  12. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  13. Stress !!!

    OpenAIRE

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  14. Behavioral changes and feathering score in heat stressed broiler chickens fed diets containing different levels of propolis

    Science.gov (United States)

    This experiment was conducted to evaluate the effects of dietary supplementation of green Brazilian propolis on behavioral patterns and feather condition of heat stressed broiler chickens. Five hundred and four (504) male Ross 708 broiler chicks at 15-day old were randomly allotted to six dietary tr...

  15. Understanding the Risk of Chloride Induced Stress Corrosion Cracking of Interim Storage Containers for the Dry Storage of Spent Nuclear Fuel: Evolution of Brine Chemistry on the Container Surface

    International Nuclear Information System (INIS)

    Enos, David; Bryan, Charles R.

    2015-01-01

    Although the susceptibility of austenitic stainless steels to chloride-induced stress corrosion cracking is well known, uncertainties exist in terms of the environmental conditions that exist on the surface of the storage containers. While a diversity of salts is present in atmospheric aerosols, many of these are not stable when placed onto a heated surface. Given that the surface temperature of any container storing spent nuclear fuel will be well above ambient, it is likely that salts deposited on its surface may decompose or degas. To characterize this effect, relevant single and multi-salt mixtures are being evaluated as a function of temperature and relative humidity to establish the rates of degassing, as well as the likely final salt and brine chemistries that will remain on the canister surface.

  16. Understanding the Risk of Chloride Induced Stress Corrosion Cracking of Interim Storage Containers for the Dry Storage of Spent Nuclear Fuel: Evolution of Brine Chemistry on the Container Surface.

    Energy Technology Data Exchange (ETDEWEB)

    Enos, David; Bryan, Charles R.

    2015-10-01

    Although the susceptibility of austenitic stainless steels to chloride-induced stress corrosion cracking is well known, uncertainties exist in terms of the environmental conditions that exist on the surface of the storage containers. While a diversity of salts is present in atmospheric aerosols, many of these are not stable when placed onto a heated surface. Given that the surface temperature of any container storing spent nuclear fuel will be well above ambient, it is likely that salts deposited on its surface may decompose or degas. To characterize this effect, relevant single and multi-salt mixtures are being evaluated as a function of temperature and relative humidity to establish the rates of degassing, as well as the likely final salt and brine chemistries that will remain on the canister surface.

  17. Post-assessment of pre-stressed containment structures by evaluation of monitored long term deformation results

    International Nuclear Information System (INIS)

    Wienand, B.

    2015-01-01

    The comparison of monitored long term deformations of containment structures with calculated values achieved by using design material parameters shows occasionally considerable deviations, partly caused by conservative assumptions in the containments design phase. Systematic post-assessment and adaption of the decisive parameters attains better coincidence. In the present investigation measured long-term deformations are first of all compared to pre-calculated values based on the material parameters defined in the design phase. Afterwards, the deformations deviations are minimized by repeating the calculation with assessed material parameters. This method appears to be a suitable method to predict the future containment structure long-term behavior and to achieve a possible life-time extension. The presented investigation was performed as part of NUGENIA ACCEPPT project which researches the ageing of concrete containment structures in nuclear power plants

  18. Hanford double shell tank corrosion monitoring instrument tree prototype

    International Nuclear Information System (INIS)

    Nelson, J.L.; Edgemon, G.L.; Ohl, P.C.

    1995-11-01

    High-level nuclear wastes at the Hanford site are stored underground in carbon steel double-shell and single-shell tanks (DSTs and SSTs). The installation of a prototype corrosion monitoring instrument tree into DST 241-A-101 was completed in December 1995. The instrument tree has the ability to detect and discriminate between uniform corrosion, pitting, and stress corrosion cracking (SCC) through the use of electrochemical noise measurements and a unique stressed element, three-electrode probe. The tree itself is constructed of AISI 304L stainless steel (UNS S30403), with probes in the vapor space, vapor/liquid interface and liquid. Successful development of these trees will allow their application to single shell tanks and the transfer of technology to other US Department of Energy (DOE) sites. Keywords: Hanford, radioactive waste, high-level waste tanks, electrochemical noise, probes, double-shell tanks, single-shell tanks, corrosion

  19. A Clinical Trial about a Food Supplement Containing α-Lipoic Acid on Oxidative Stress Markers in Type 2 Diabetic Patients.

    Science.gov (United States)

    Derosa, Giuseppe; D'Angelo, Angela; Romano, Davide; Maffioli, Pamela

    2016-10-28

    The aim of this study was to evaluate the effect of a food supplement containing α-lipoic acid and of a placebo on glyco-metabolic control and on oxidative stress markers in type 2 diabetics. We randomized 105 diabetics to either a supplementation containing 600 mg of α-lipoic acid, 165 mg of L -carnosin, 7.5 mg of zinc, and vitamins of group B, or a placebo, for three months. We evaluated body mass index, fasting plasma glucose (FPG), post-prandial-glucose (PPG), glycated hemoglobin (HbA 1c ), fasting plasma insulin (FPI), HOMA-index (HOMA-IR), lipid profile, high sensitivity C-reactive protein (Hs-CRP), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA). There was a reduction of FPG, PPG, and HbA 1c with the food supplement containing α-lipoic acid compared with a baseline, and with the placebo. Concerning lipid profile, we observed a reduction of LDL-C, and Tg with the food supplement, compared with both the baseline, and the placebo. There was a reduction of Hs-CRP with the food supplement containing α-lipoic acid, both compared with the baseline and the placebo. An increase of SOD, and GSH-Px, and a decrease of MDA were reached by the food supplement containing α-lipoic acid, both compared with the baseline and the placebo. We can conclude that the food supplement containing α-lipoic acid, L -carnosin, zinc, and vitamins of group B improved glycemic control, lipid profile, and anti-oxidative stress markers.

  20. A Clinical Trial about a Food Supplement Containing α-Lipoic Acid on Oxidative Stress Markers in Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Giuseppe Derosa

    2016-10-01

    Full Text Available The aim of this study was to evaluate the effect of a food supplement containing α-lipoic acid and of a placebo on glyco-metabolic control and on oxidative stress markers in type 2 diabetics. We randomized 105 diabetics to either a supplementation containing 600 mg of α-lipoic acid, 165 mg of L-carnosin, 7.5 mg of zinc, and vitamins of group B, or a placebo, for three months. We evaluated body mass index, fasting plasma glucose (FPG, post-prandial-glucose (PPG, glycated hemoglobin (HbA1c, fasting plasma insulin (FPI, HOMA-index (HOMA-IR, lipid profile, high sensitivity C-reactive protein (Hs-CRP, superoxide dismutase (SOD, glutathione peroxidase (GSH-Px, malondialdehyde (MDA. There was a reduction of FPG, PPG, and HbA1c with the food supplement containing α-lipoic acid compared with a baseline, and with the placebo. Concerning lipid profile, we observed a reduction of LDL-C, and Tg with the food supplement, compared with both the baseline, and the placebo. There was a reduction of Hs-CRP with the food supplement containing α-lipoic acid, both compared with the baseline and the placebo. An increase of SOD, and GSH-Px, and a decrease of MDA were reached by the food supplement containing α-lipoic acid, both compared with the baseline and the placebo. We can conclude that the food supplement containing α-lipoic acid, L-carnosin, zinc, and vitamins of group B improved glycemic control, lipid profile, and anti-oxidative stress markers.

  1. Shell coal gasification process

    Energy Technology Data Exchange (ETDEWEB)

    Hennekes, B. [Shell Global Solutions (US) Inc. (United States). Technology Marketing

    2002-07-01

    The presentation, on which 17 slides/overheads are included in the papers, explained the principles of the Shell coal gasification process and the methods incorporated for control of sulfur dioxide, nitrogen oxides, particulates and mercury. The economics of the process were discussed. The differences between gasification and burning, and the differences between the Shell process and other processes were discussed.

  2. Wrinkling of Pressurized Elastic Shells

    KAUST Repository

    Vella, Dominic; Ajdari, Amin; Vaziri, Ashkan; Boudaoud, Arezki

    2011-01-01

    We study the formation of localized structures formed by the point loading of an internally pressurized elastic shell. While unpressurized shells (such as a ping-pong ball) buckle into polygonal structures, we show that pressurized shells

  3. Localized corrosion and stress corrosion cracking of candidate materials for high-level radioactive waste disposal containers in U.S

    International Nuclear Information System (INIS)

    Farmer, J.C.; McCright, R.D.

    1989-01-01

    Three ion-based to nickel-based austenitic alloys and three copper-based alloys are being considered in the United States as candidate materials for the fabrication of high-level radioactive waste containers. The austenitic alloys are Types 304L and 316L stainless steels as well as the high-nickel material Alloy 825. The copper-based alloys are CDA 102 (oxygen-free copper) CDA 613 (Cu7Al), and CDA 715 (Cu-30Ni). Waste in the forms of spent fuel assemblies from reactors and borosilicate glass will be sent to a proposed repository at Yucca Mountain, Nevada. The decay of radionuclides will result in the generation of substantial heat and in gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including: undesirable phase transformations due to a lack of phase stability; atmospheric oxidation; general aqueous corrosion; pitting; crevice corrosion; intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This paper is an analysis of data from the literature relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of these alloys

  4. Forced vibrations of rotating circular cylindrical shells

    International Nuclear Information System (INIS)

    Igawa, Hirotaka; Maruyama, Yoshiyuki; Endo, Mitsuru

    1995-01-01

    Forced vibrations of rotating circular cylindrical shells are investigated. Basic equations, including the effect of initial stress due to rotation, are formulated by the finite-element method. The characteristic relations for finite elements are derived from the energy principle by considering the finite strain. The equations of motion can be separated into quasi-static and dynamic ones, i.e., the equations in the steady rotating state and those in the vibration state. Radial concentrated impulses are considered as the external dynamic force. The transient responses of circular cylindrical shells are numerically calculated under various boundary conditions and rotating speeds. (author)

  5. Stress !!!

    NARCIS (Netherlands)

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten.

  6. High dielectric constant and energy density induced by the tunable TiO2 interfacial buffer layer in PVDF nanocomposite contained with core-shell structured TiO2@BaTiO3 nanoparticles

    Science.gov (United States)

    Hu, Penghao; Jia, Zhuye; Shen, Zhonghui; Wang, Peng; Liu, Xiaoru

    2018-05-01

    To realize application in high-capacity capacitors and portable electric devices, large energy density is eagerly desired for polymer-based nanocomposite. The core-shell structured nanofillers with inorganic buffer layer are recently supposed to be promising in improving the dielectric property of polymer nanocomposite. In this work, core-shell structured TO@BT nanoparticles with crystalline TiO2 buffer layer coated on BaTiO3 nanoparticle were fabricated via solution method and heat treatment. The thickness of the TO buffer layer can be tailored by modulating the additive amount of the titanate coupling agent in preparation process, and the apparent dielectric properties of nanocomposite are much related to the thickness of the TO layer. The relatively thin TO layer prefer to generate high polarization to increase dielectric constant while the relatively thick TO layer would rather to homogenize field to maintain breakdown strength. Simulation of electric field distribution in the interfacial region reveals the improving effect of the TO buffer layer on the dielectric properties of nanocomposite which accords with the experimental results well. The optimized nanoparticle TO@BT-2 with a mean thickness of 3-5 nm buffer layer of TO is effective in increasing both the ε and Eb in the PVDF composite film. The maximal discharged energy density of 8.78 J/cm3 with high energy efficiency above 0.6 is obtained in TO@BT-2/PVDF nanocomposite with 2.5 vol% loading close to the breakdown strength of 380 kV/mm. The present study demonstrates the approach to optimize the structure of core-shell nanoparticles by modulating buffer layer and provides a new way to further enlarge energy density in polymer nanocomposite.

  7. Degradation tests for C 32/40 concrete used for perimetral wall, reactor base and components of Cernavoda NPP containment, under thermal stress conditions and liner degradation

    International Nuclear Information System (INIS)

    Carlan, P.; Paraschiv, I.; Dinu, A.; Stanciulescu, M.; Olteanu, A. M.; Voica, I.; Stelian, R.; Buc, G.

    2016-01-01

    In order to evaluate the effect of thermal degradation on C 32/40 concrete used in nuclear constructions at Cernavoda NPP, continuous thermal stress tests were performed at 65, 80 and 100°C and cyclic thermal stress tests at 65°C in dry conditions. This paper presents the macroscopic properties of concrete, obtained after these treatments and also the microstructural changes that occur in the cement paste from the concrete composition, which has been tested in the same conditions as the concrete samples. Determinations performed for macroscopic properties of concrete included: compressive strength, loss of density, permeability and modulus of elasticity. Cement paste samples were analysed by XRD (for mineralogical composition) and SEM (for morphology). The obtained results shown an appropriate behaviour of the concrete used in this study; changes are insignificant and follow the normal evolution process of concrete, proving that concrete will preserve its safety functions, as part of the containment structure. (authors)

  8. Study of dinosaur's egg shell by EPR method

    International Nuclear Information System (INIS)

    Tleuberdina, R.A.; Nasirov, R.N.

    1998-01-01

    Two varieties of calcium carbonate are defined on base of ESR spectra radiation-inducted signals containing in mollusc shell and dinosaur and ostrich egg shell; their spectral characters are studied by infrared-spectroscopy methods and X-ray analysis. Possibility of correlation between ESR signals intensity of CO 2 -radical of investigated object and geological age is determined. (author)

  9. Molluscan shell colour.

    Science.gov (United States)

    Williams, Suzanne T

    2017-05-01

    The phylum Mollusca is highly speciose, and is the largest phylum in the marine realm. The great majority of molluscs are shelled, including nearly all bivalves, most gastropods and some cephalopods. The fabulous and diverse colours and patterns of molluscan shells are widely recognised and have been appreciated for hundreds of years by collectors and scientists alike. They serve taxonomists as characters that can be used to recognise and distinguish species, however their function for the animal is sometimes less clear and has been the focus of many ecological and evolutionary studies. Despite these studies, almost nothing is known about the evolution of colour in molluscan shells. This review summarises for the first time major findings of disparate studies relevant to the evolution of shell colour in Mollusca and discusses the importance of colour, including the effects of visual and non-visual selection, diet and abiotic factors. I also summarise the evidence for the heritability of shell colour in some taxa and recent efforts to understand the molecular mechanisms underpinning synthesis of shell colours. I describe some of the main shell pigments found in Mollusca (carotenoids, melanin and tetrapyrroles, including porphyrins and bile pigments), and their durability in the fossil record. Finally I suggest that pigments appear to be distributed in a phylogenetically relevant manner and that the synthesis of colour is likely to be energetically costly. © 2016 Cambridge Philosophical Society.

  10. Stress corrosion cracking of 316 SS and Incoloy-800 in high temperature aqueous containing sulfate and chloride

    International Nuclear Information System (INIS)

    Zhang Weiguo; Lin Fangliang; Gao Fengqin; Zhou Hongyi; Cao Xiaoning

    1992-03-01

    The stress corrosion cracking (SCC) susceptibility of 316 stainless steel (SS) which was welded for primary pipe and Incoloy-800 (shot peening) for steam generator (SG) tube have been investigated by a slow strain rate test (SSRT) at a strain rate of 4.2 x 10 -6 /s. Tests were conducted at 315 C degree for 316 SS and 270 C degree for In-800 in the oxygenated simulated resin intrusion environment (acidic sulfate). Tests of the effect of combination of SO 4 2- and Cl - on SCC of Incoloy-800 were also carried out. The results indicate that Incoloy-800 is unsusceptible to SCC either in the environment with SO 4 2- (from a few ppm to 1000 ppm, pH 3 ∼ 4) or in the environment of combination of SO 4 2- (1000 ppm) and Cl - (from 2 to 1000 ppm). The 316 NG SS is susceptible to transgranular stress corrosion cracking (TGSCC) in the resin intrusion environment with SO 4 2- in high temperature water

  11. Nuclear shell theory

    CERN Document Server

    de-Shalit, Amos; Massey, H S W

    1963-01-01

    Nuclear Shell Theory is a comprehensive textbook dealing with modern methods of the nuclear shell model. This book deals with the mathematical theory of a system of Fermions in a central field. It is divided into three parts. Part I discusses the single particle shell model. The second part focuses on the tensor algebra, two-particle systems. The last part covers three or more particle systems. Chapters on wave functions in a central field, tensor fields, and the m-Scheme are also presented. Physicists, graduate students, and teachers of nuclear physics will find the book invaluable.

  12. Structural qualification of the multifunctional instrument tree for installation in double-shell and 100-series single-shell tanks

    International Nuclear Information System (INIS)

    Strohlow, J.P.

    1995-12-01

    This document provides the technical basis and methodology for qualifying the multifunctional instrument tree (MIT) structure for installation in double-shell and 100-series single-shell tanks. Structural qualification for MIT installations in specific tanks are also contained in this document

  13. Leading singularities and off-shell conformal integrals

    CERN Document Server

    Drummond, James; Eden, Burkhard; Heslop, Paul; Pennington, Jeffrey; Smirnov, Vladimir A.

    2013-01-01

    The three-loop four-point function of stress-tensor multiplets in N=4 super Yang-Mills theory contains two so far unknown, off-shell, conformal integrals, in addition to the known, ladder-type integrals. In this paper we evaluate the unknown integrals, thus obtaining the three-loop correlation function analytically. The integrals have the generic structure of rational functions multiplied by (multiple) polylogarithms. We use the idea of leading singularities to obtain the rational coefficients, the symbol - with an appropriate ansatz for its structure - as a means of characterising multiple polylogarithms, and the technique of asymptotic expansion of Feynman integrals to obtain the integrals in certain limits. The limiting behaviour uniquely fixes the symbols of the integrals, which we then lift to find the corresponding polylogarithmic functions. The final formulae are numerically confirmed. The techniques we develop can be applied more generally, and we illustrate this by analytically evaluating one of the ...

  14. Scanning the parameter space of collapsing rotating thin shells

    Science.gov (United States)

    Rocha, Jorge V.; Santarelli, Raphael

    2018-06-01

    We present results of a comprehensive study of collapsing and bouncing thin shells with rotation, framing it in the context of the weak cosmic censorship conjecture. The analysis is based on a formalism developed specifically for higher odd dimensions that is able to describe the dynamics of collapsing rotating shells exactly. We analyse and classify a plethora of shell trajectories in asymptotically flat spacetimes. The parameters varied include the shell’s mass and angular momentum, its radial velocity at infinity, the (linear) equation-of-state parameter and the spacetime dimensionality. We find that plunges of rotating shells into black holes never produce naked singularities, as long as the matter shell obeys the weak energy condition, and so respects cosmic censorship. This applies to collapses of dust shells starting from rest or with a finite velocity at infinity. Not even shells with a negative isotropic pressure component (i.e. tension) lead to the formation of naked singularities, as long as the weak energy condition is satisfied. Endowing the shells with a positive isotropic pressure component allows for the existence of bouncing trajectories satisfying the dominant energy condition and fully contained outside rotating black holes. Otherwise any turning point occurs always inside the horizon. These results are based on strong numerical evidence from scans of numerous sections in the large parameter space available to these collapsing shells. The generalisation of the radial equation of motion to a polytropic equation-of-state for the matter shell is also included in an appendix.

  15. Pair of null gravitating shells: III. Algebra of Dirac's observables

    International Nuclear Information System (INIS)

    Kouletsis, I; Hajicek, P

    2002-01-01

    The study of the two-shell system started in 'pair of null gravitating shells I and II' is continued. The pull back of the Liouville form to the constraint surface, which contains complete information about the Poisson brackets of Dirac observables, is computed in the singular double-null Eddington-Finkelstein (DNEF) gauge. The resulting formula shows that the variables conjugate to the Schwarzschild masses of the intershell spacetimes are simple combinations of the values of the DNEF coordinates on these spacetimes at the shells. The formula is valid for any number of in- and outgoing shells. After applying it to the two-shell system, the symplectic form is calculated for each component of the physical phase space; regular coordinates are found, defining it as a symplectic manifold. The symplectic transformation between the initial and final values of observables for the shell-crossing case is given

  16. Temperature Scanning Stress Relaxation of an Autonomous Self-Healing Elastomer Containing Non-Covalent Reversible Network Junctions

    Directory of Open Access Journals (Sweden)

    Amit Das

    2018-01-01

    Full Text Available In this work, we report about the mechanical relaxation characteristics of an intrinsically self-healable imidazole modified commercial rubber. This kind of self-healing rubber was prepared by melt mixing of 1-butyl imidazole with bromo-butyl rubber (bromine modified isoprene-isobutylene copolymer, BIIR. By this melt mixing process, the reactive allylic bromine of bromo-butyl rubber was converted into imidazole bromide salt. The resulting development of an ionic character to the polymer backbone leads to an ionic association of the groups which ultimately results to the formation of a network structure of the rubber chains. The modified BIIR thus behaves like a robust crosslinked rubber and shows unusual self-healing properties. The non-covalent reversible network has been studied in detail with respect to stress relaxation experiments, scanning electron microscopic and X-ray scattering.

  17. Toward the AdS/CFT gravity dual for high energy collisions. III. Gravitationally collapsing shell and quasiequilibrium

    International Nuclear Information System (INIS)

    Lin, Shu; Shuryak, Edward

    2008-01-01

    The equilibration of matter and onset of hydrodynamics can be understood in the AdS/CFT context as a gravitational collapse process, in which 'collision debris' create a horizon. In this paper we consider the simplest geometry possible, a flat shell (or membrane) falling in the holographic direction toward the horizon. The metric is a combination of two well-known solutions: thermal AdS above the shell and pure AdS below, while motion of the shell is given by the Israel junction condition. Furthermore, when the shell motion can be considered slow, we were able to solve for two-point functions of all boundary stress tensors and found that an observer on the boundary sees a very peculiar quasiequilibrium: while the average stress tensor μν> contains the equilibrium plasma energy and pressure at all times, the spectral densities of the correlators (related with occupation probabilities of the modes) reveal additional oscillating terms absent in equilibrium. This is explained by the echo phenomenon, a partial return of the field coherence at certain echo times.

  18. Assessment of Ultimate Load Capacity for Pre-Stressed Concrete Containment Vessel Model of PWR Design With BARC Code ULCA

    International Nuclear Information System (INIS)

    Basha, S.M.; Singh, R.K.; Patnaik, R.; Ramanujam, S.; Kushwaha, H.S.; Venkat Raj, V.

    2002-01-01

    Ultimate load capacity assessment of nuclear containments has been a thrust research area for Indian Pressurised Heavy Water Reactor (PHWR) power programme. For containment safety assessment of Indian PHWRs a finite element code ULCA was developed at BARC, Trombay. This code has been extensively benchmarked with experimental results. The present paper highlights the analysis results for Prestressed Concrete Containment Vessel (PCCV) tested at Sandia National Labs, USA in a Round Robin analysis activity co-sponsored by Nuclear Power Engineering Corporation (NUPEC), Japan and the U.S Nuclear Regulatory Commission (NRC). Three levels of failure pressure predictions namely the upper bound, the most probable and the lower bound (all with 90% confidence) were made as per the requirements of the round robin analysis activity. The most likely failure pressure is predicted to be in the range of 2.95 Pd to 3.15 Pd (Pd= design pressure of 0.39 MPa for the PCCV model) depending on the type of liners used in the construction of the PCCV model. The lower bound value of the ultimate pressure of 2.80 Pd and the upper bound of the ultimate pressure of 3.45 Pd are also predicted from the analysis. These limiting values depend on the assumptions of the analysis for simulating the concrete-tendon interaction and the strain hardening characteristics of the steel members. The experimental test has been recently concluded at Sandia Laboratory and the peak pressure reached during the test is 3.3 Pd that is enveloped by our upper bound prediction of 3.45 Pd and is close to the predicted most likely pressure of 3.15 Pd. (authors)

  19. Shell Buckling Knockdown Factors

    Data.gov (United States)

    National Aeronautics and Space Administration — The Shell Buckling Knockdown Factor (SBKF) Project, NASA Engineering and Safety Center (NESC) Assessment #: 07-010-E, was established in March of 2007 by the NESC in...

  20. Measurements in a container ship of wave-induced hull girder stresses in excess of design values

    DEFF Research Database (Denmark)

    Andersen, Ingrid Marie Vincent; Jensen, Jørgen Juncher

    2014-01-01

    This paper describes full-scale measurements of the wave-induced vertical bending moment amidships a 9400 TEU container carrier and focuses on the effect of the hydro-elastic high-frequency vibration on the extreme hogging wave bending moment. One extreme event, where the vertical wave-induced ho...... is quite significant. Finally, the hydro-elastic behaviour of the hull girder is assessed by simple approximations using the measured statistical properties and closed-form expressions and the agreement with the actual measurements is found to be good. © 2014 Elsevier Ltd....

  1. Shells and Patterns

    Science.gov (United States)

    Sutley, Jane

    2009-01-01

    "Shells and Patterns" was a project the author felt would easily put smiles on the faces of her fifth-graders, and teach them about unity and the use of watercolor pencils as well. It was thrilling to see the excitement in her students as they made their line drawings of shells come to life. For the most part, they quickly got the hang of…

  2. Plasma-column instabilities in a reversed-field pinch without a shell

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, P.G.

    1988-01-01

    Plasma column instabilities in a Reversed Field Pinch (RFP) without a shell were investigated in the Colorado Reversatron RFP. The Reversatron RFP (aspect ration R/a = 50 cm/8cm) is a toroidal plasma containment device consisting of a vacuum chamber, a thick conducting shell, modular shells, magnetic field producing coils and diagnostics to characterize the plasma. RFP discharges were set up in the Reversatron in three different experimental configurations: with a thick conducting shell, with a modular shell and with no shell. In two of the configurations, a shell enclosed the plasma column to provide some plasma stability. A vertical magnetic field provided equilibrium in experiments without a shell. Data from discharges without a shell indicated that the plasma duration was greatly reduced and the plasma resistance increased compared to the discharges with a thick shell. Plasma position probes indicated large plasma centriod displacements corresponding to a n = 1 and a n = 3 kink coincident with the peak of the plasma current and the start of a discharge termination phase. The modular shell lengthened the discharge duration and lowered the plasma resistance to values intermediate between the plasma with a thick shell and the plasma with no shell. The modular shell suppressed the large plasma column displacements observed in the RFP plasma without a shell.

  3. Plasma-column instabilities in a reversed-field pinch without a shell

    International Nuclear Information System (INIS)

    Schmid, P.G.

    1988-01-01

    Plasma column instabilities in a Reversed Field Pinch (RFP) without a shell were investigated in the Colorado Reversatron RFP. The Reversatron RFP (aspect ration R/a = 50 cm/8cm) is a toroidal plasma containment device consisting of a vacuum chamber, a thick conducting shell, modular shells, magnetic field producing coils and diagnostics to characterize the plasma. RFP discharges were set up in the Reversatron in three different experimental configurations: with a thick conducting shell, with a modular shell and with no shell. In two of the configurations, a shell enclosed the plasma column to provide some plasma stability. A vertical magnetic field provided equilibrium in experiments without a shell. Data from discharges without a shell indicated that the plasma duration was greatly reduced and the plasma resistance increased compared to the discharges with a thick shell. Plasma position probes indicated large plasma centriod displacements corresponding to a n = 1 and a n = 3 kink coincident with the peak of the plasma current and the start of a discharge termination phase. The modular shell lengthened the discharge duration and lowered the plasma resistance to values intermediate between the plasma with a thick shell and the plasma with no shell. The modular shell suppressed the large plasma column displacements observed in the RFP plasma without a shell

  4. Shell extracts of the edible mussel and oyster induce an enhancement of the catabolic pathway of human skin fibroblasts, in vitro.

    Science.gov (United States)

    Latire, Thomas; Legendre, Florence; Bouyoucef, Mouloud; Marin, Frédéric; Carreiras, Franck; Rigot-Jolivet, Muriel; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

    2017-10-01

    Mollusc shells are composed of more than 95% calcium carbonate and less than 5% organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. In this study, we investigated the effects of matrix macromolecular components extracted from the shells of two edible molluscs of economic interest, i.e., the blue mussel Mytilus edulis and the Pacific oyster Crassostrea gigas. The potential biological activities of these organic molecules were analysed on human dermal fibroblasts in primary culture. Our results demonstrate that shell extracts of the two studied molluscs modulate the metabolic activities of the cells. In addition, the extracts caused a decrease of type I collagen and a concomitant increase of active MMP-1, both at the mRNA and the protein levels. Therefore, our results suggest that shell extracts from M. edulis and C. gigas contain molecules that promote the catabolic pathway of human dermal fibroblasts. This work emphasises the potential use of these shell matrices in the context of anti-fibrotic strategies, particularly against scleroderma. More generally, it stresses the usefulness to valorise bivalve shells that are coproducts of shellfish farming activity.

  5. Matrix analysis of the asymmetrical bending of conical shell-beams and their singular assemblies

    International Nuclear Information System (INIS)

    Kiedrzynski, A.; Coppens, L.

    1979-01-01

    As an alternative to refined finite element methodology a new method has been derived to investigate in much detail the linear static behaviour of singular assemblies of moderately thick conical shells of revolution submitted to non-axisymmetrical loads at their ends (an assembly of conical sections is said to be singular when the geometrical discontinuities are deformable, i.e. not stiffened by diaphragms). A detailed preliminary study has shown that the currently adopted simplifying assumptions in shell theories for moderate thickness lead to unconsistencies at any departure from axisymmetric loading. Therefore, FLUEGGE's general shell theory has been applied to a conical section, yielding a set of mixed first order differential equations in terms of displacements and conjuguated stress resultants well suited for a matrix formalism. The numerical integration is based on a fourth-order Runge-Kutta method and provides an 8 x 8 mixed matrix. This matrix contains complete information on the distribution of the displacements (exhibiting the warping and ovalization of the cross-section) and of the stress resultants along the meridian; also the stiffness coefficients proceed from it. (orig.)

  6. Off-shell CHY amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Lam, C.S., E-mail: Lam@physics.mcgill.ca [Department of Physics, McGill University, Montreal, Q.C., H3A 2T8 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Yao, York-Peng, E-mail: yyao@umich.edu [Department of Physics, The University of Michigan Ann Arbor, MI 48109 (United States)

    2016-06-15

    The Cachazo–He–Yuan (CHY) formula for on-shell scattering amplitudes is extended off-shell. The off-shell amplitudes (amputated Green's functions) are Möbius invariant, and have the same momentum poles as the on-shell amplitudes. The working principles which drive the modifications to the scattering equations are mainly Möbius covariance and energy momentum conservation in off-shell kinematics. The same technique is also used to obtain off-shell massive scalars. A simple off-shell extension of the CHY gauge formula which is Möbius invariant is proposed, but its true nature awaits further study.

  7. Evaluation of buckling on containment metallic vessels

    International Nuclear Information System (INIS)

    Silveira, Renato Campos da; Mattar Neto, Miguel

    2000-01-01

    The buckling analysis represents one of the most important aspects of the structural projects of nuclear power plants containment metallic vessels and in this work the Case N-284-1 ASME Code is used for evaluation of those structures submitted to this failure mode. From the stress analysis, performed by using finite element method on discrete structures with shell elements, the procedure of the Code Case are applied to the evaluation of the containment metallic vessel of the Angra 2 nuclear power plant submitted to the own weight, seismic loads and uplift in case of accident. A study of pressure vessel reinforced by rings submit ed to the external pressure. Conclusions and commentaries are established based on the obtained results

  8. Molecular analysis of UAS(E), a cis element containing stress response elements responsible for ethanol induction of the KlADH4 gene of Kluyveromyces lactis.

    Science.gov (United States)

    Mazzoni, C; Santori, F; Saliola, M; Falcone, C

    2000-01-01

    KlADH4 is a gene of Kluyveromyces lactis encoding a mitochondrial alcohol dehydrogenase activity, which is specifically induced by ethanol and insensitive to glucose repression. In this work, we report the molecular analysis of UAS(E), an element of the KlADH4 promoter which is essential for the induction of KlADH4 in the presence of ethanol. UAS(E) contains five stress response elements (STREs), which have been found in many genes of Saccharomyces cerevisiae involved in the response of cells to conditions of stress. Whereas KlADH4 is not responsive to stress conditions, the STREs present in UAS(E) seem to play a key role in the induction of the gene by ethanol, a situation that has not been observed in the related yeast S. cerevisiae. Gel retardation experiments showed that STREs in the KlADH4 promoter can bind factor(s) under non-inducing conditions. Moreover, we observed that the RAP1 binding site present in UAS(E) binds KlRap1p.

  9. Optimised photocatalytic hydrogen production using core–shell AuPd promoters with controlled shell thickness

    DEFF Research Database (Denmark)

    Jones, Wilm; Su, Ren; Wells, Peter

    2014-01-01

    of these materials towards the reforming of alcohols for hydrogen production. The core–shell structured Au–Pd bimetallic nanoparticle supported on TiO2 has being of interest as it exhibited extremely high quantum efficiencies for hydrogen production. However, the effect of shell composition and thickness...... of the nanoparticles by a combination of X-ray absorption fine structure and X-ray photoelectron spectroscopy. Photocatalytic ethanol reforming showed that the core–shell structured Au–Pd promoters supported on TiO2 exhibit enhanced activity compared to that of monometallic Au and Pd as promoters, whilst the core......–shell Au–Pd promoters containing one ML equivalent Pd provide the optimum reactivity....

  10. Nitrogen, oxygen or sulfur containing heterocyclic compounds as analgesic drugs used as modulators of the nitroxidative stress.

    Science.gov (United States)

    Salat, Kinga; Moniczewski, Andrzej; Librowski, Tadeusz

    2013-03-01

    Numerous lines of evidence suggest that heterocyclic compounds used as analgesic, anti-inflammatory and anti-migraine agents can be potent regulators of the nitroxidative stress and targeting free nitrogen and oxygen radicals is a very promising strategy for future pain management. Both classical analgesics (nonsteroidal anti-inflammatory drugs, opioid drugs) and many analgesic adjuvants, including desipramine, duloxetine, fluoxetine, paroxetine, escitalopram, phenytoin or carbamazepine and α-lipoic acid can modulate the balance between pro-oxidant and antioxidant processes in the mammalian tissues and these properties of drugs such as indomethacin, meloxicam, tenoxicam, valdecoxib or some metabolites of analgesic drugs formed by the activity of tissue peroxidases may contribute to their clinical efficacy and drug-related toxic effects, including gastrointestinal ulcers, hepatic failure, agranulocytosis, aplastic anemia, neutropenia, opiate-induced hyperalgesia and tolerance. The antioxidant capacities of novel heterocyclic compounds, including the compounds acting either by prevention of formation or catalyzed decomposition of peroxynitrite anion (ONOO-), namely the peroxynitrite decomposition catalysts or as superoxide (O2 •-)-scavengers which are the functional mimetics of superoxide dismutase (SOD) enzymes (SODm), as well as the derivatives of 6-nitro-3,4-methylenedioxyphenyl-Nacylhydrazone (LASSBio-881) or γ-butyrolactone (LPP1, BM113, BM113A, BM138 and BM138A) are also discussed as potent and promising future heterocyclic analgesics.

  11. Pharmacological activities of an eye drop containing Matricaria chamomilla and Euphrasia officinalis extracts in UVB-induced oxidative stress and inflammation of human corneal cells.

    Science.gov (United States)

    Bigagli, Elisabetta; Cinci, Lorenzo; D'Ambrosio, Mario; Luceri, Cristina

    2017-08-01

    Ultraviolet B (UVB) exposure is a risk factor for corneal damage resulting in oxidative stress, inflammation and cell death. The aim of this study was to investigate the potential protective effects of a commercial eye drop (Dacriovis™) containing Matricaria chamomilla and Euphrasia officinalis extracts on human corneal epithelial cells (HCEC-12) against UVB radiation-induced oxidative stress and inflammation as well as the underlying mechanisms. The antioxidant potential of the eye drops was evaluated by measuring the ferric reducing antioxidant power and the total phenolic content by Folin-Ciocalteu reagent. HCEC-12 cells were exposed to UVB radiation and treated with the eye drops at various concentrations. Cell viability, wound healing assay, reactive oxygen species (ROS) levels, protein and lipid oxidative damage and COX-2, IL-1β, iNOS, SOD-2, HO-1 and GSS gene expression, were assessed. Eye drops were able to protect corneal epithelial cells from UVB-induced cell death and ameliorated the wound healing; the eye drops exhibited a strong antioxidant activity, decreasing ROS levels and protein and lipid oxidative damage. Eye drops also exerted anti-inflammatory activities by decreasing COX-2, IL-1β, iNOS expression, counteracted UVB-induced GSS and SOD-2 expression and restored HO-1 expression to control levels. These findings suggest that an eye drop containing Matricaria chamomilla and Euphrasia officinalis extracts exerts positive effects against UVB induced oxidative stress and inflammation and may be useful in protecting corneal epithelial cells from UVB exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Localized corrosion and stress corrosion cracking of candidate materials for high-level radioactive waste disposal containers in the US: A literature review

    International Nuclear Information System (INIS)

    Farmer, J.C.; McCright, R.D.

    1988-01-01

    Container materials may undergo any of several modes of degradation in this environment, including: undesirable phase transformations due to lack of phase stability; atmospheric oxidation; general aqueous corrosion; pitting; crevice corrosion; intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This paper is an analysis of data from the literature relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of these alloys. Though all three austenitic candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these forms of localized attack. Both types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented for Alloy 825 under comparable conditions. Gamma irradiation has been found to enhance SCC of Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while microbiologically induced corrosion effects have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. Of the copper-based alloys, CDA 715 has the best overall resistance to localized attack. Its resistance to pitting is comparable to that of CDA 613 and superior to that of CDA 102. Observed rates of dealloying in CDA 715 are less than those observed in CDA 613 by orders of magnitude. The resistance of CDA 715 to SCC in tarnishing ammonical environments is comparable to that of CDA 102 and superior to that of CDA 613. Its resistance to SCC in nontarnishing ammonical environments is comparable to that of CDA 613 and superior to that of CDA 102. 22 refs., 8 figs., 4 tabs

  13. Double-shell tank system dangerous waste permit application

    International Nuclear Information System (INIS)

    1991-06-01

    This appendix contains the engineering design drawings for the double-shell tank system. Included are drawings of the electrical systems, structural members, piping systems, instrumentation and the many auxiliary systems. (JL)

  14. Stress.

    Science.gov (United States)

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  15. Design study on containers for geological disposal of high-level radioactive waste

    International Nuclear Information System (INIS)

    Arup, O.

    1985-01-01

    A study has been made of the requirements and design features for containers to isolate vitrified high-level radioactive waste from the environment for a period of 500 to 1000 years. The requirements for handling, storing and transporting containers have been identified following a study of disposal operations, and the pressures and temperatures which may possibly be experienced in clay, granite and salt formations have been estimated. A range of possible container designs have been proposed to satisfy the requirements of each of the disposal environments. Alternative design concepts in corrosion resistant or corrosion allowance material have been suggested. Some resist pressure by using a structural shell leaving the contents unstressed whereas others transmit loads to their contents. Potentially suitable container shell materials have been selected following a review of corrosion studies and although metals have not been specified in detail, titanium alloys and low carbon steels are thought to be appropriate for corrosion resistant and corrosion allowance designs respectively. Performance requirements for container filler materials have been identified and candidate materials assessed. However, no entirely suitable materials have been found and further research is required in this area. A preliminary container stress analysis has shown the importance of thermal modelling and that if lead is used as a filler it dominates the stress response of the container. Possible methods of manufacturing disposal containers have been assessed and found to be generally feasible although filling operations and container closure could be difficult

  16. Creep deformations of shells of revolution under asymmetrical loading

    International Nuclear Information System (INIS)

    Takezono, S.

    1975-01-01

    The numerical analysis of creep deformations of shells of revolution under unsymmetrical loads is described with application to a cylindrical shell. The analytical formulation of the creep of axisymmetric undergoing unsymmetrical deformations is developed for two hardening laws: the time hardening law and the strain hardening law. The method is based on the creep power law, and on the assumption of plane stress condition and the Euler-Bernoulli hypothesis used in the ordinary thin shell theory. The basic differential equations derived for incremental values with respect to time are numerically solved by a finite difference method and the solutions at any time are obtained by integration of the incremental values. In conclusion the computer programs are developed which can be used to predict the creep deformations of arbitrary axisymmetrical shells. As a numerical example the creep deformation of cylindrical shell of importance in practical use is treated, and the variations of displacements and internal forces with the lapse of time are discussed

  17. Containers and systems for the measurement of radioactive gases and related methods

    Science.gov (United States)

    Mann, Nicholas R; Watrous, Matthew G; Oertel, Christopher P; McGrath, Christopher A

    2017-06-20

    Containers for a fluid sample containing a radionuclide for measurement of radiation from the radionuclide include an outer shell having one or more ports between an interior and an exterior of the outer shell, and an inner shell secured to the outer shell. The inner shell includes a detector receptacle sized for at least partial insertion into the outer shell. The inner shell and outer shell together at least partially define a fluid sample space. The outer shell and inner shell are configured for maintaining an operating pressure within the fluid sample space of at least about 1000 psi. Systems for measuring radioactivity in a fluid include such a container and a radiation detector received at least partially within the detector receptacle. Methods of measuring radioactivity in a fluid sample include maintaining a pressure of a fluid sample within a Marinelli-type container at least at about 1000 psi.

  18. Freeze-thaw stress of Alhydrogel ® alone is sufficient to reduce the immunogenicity of a recombinant hepatitis B vaccine containing native antigen.

    Science.gov (United States)

    Clapp, Tanya; Munks, Michael W; Trivedi, Ruchit; Kompella, Uday B; Braun, LaToya Jones

    2014-06-24

    Preventing losses in vaccine potency due to accidental freezing has recently become a topic of interest for improving vaccines. All vaccines with aluminum-containing adjuvants are susceptible to such potency losses. Recent studies have described excipients that protect the antigen from freeze-induced inactivation, prevent adjuvant agglomeration and retain potency. Although these strategies have demonstrated success, they do not provide a mechanistic understanding of freeze-thaw (FT) induced potency losses. In the current study, we investigated how adjuvant frozen in the absence of antigen affects vaccine immunogenicity and whether preventing damage to the freeze-sensitive recombinant hepatitis B surface antigen (rHBsAg) was sufficient for maintaining vaccine potency. The final vaccine formulation or Alhydrogel(®) alone was subjected to three FT-cycles. The vaccines were characterized for antigen adsorption, rHBsAg tertiary structure, particle size and charge, adjuvant elemental content and in-vivo potency. Particle agglomeration of either vaccine particles or adjuvant was observed following FT-stress. In vivo studies demonstrated no statistical differences in IgG responses between vaccines with FT-stressed adjuvant and no adjuvant. Adsorption of rHBsAg was achieved; regardless of adjuvant treatment, suggesting that the similar responses were not due to soluble antigen in the frozen adjuvant-containing formulations. All vaccines with adjuvant, including the non-frozen controls, yielded similar, blue-shifted fluorescence emission spectra. Immune response differences could not be traced to differences in the tertiary structure of the antigen in the formulations. Zeta potential measurements and elemental content analyses suggest that FT-stress resulted in a significant chemical alteration of the adjuvant surface. This data provides evidence that protecting a freeze-labile antigen from subzero exposure is insufficient to maintain vaccine potency. Future studies should

  19. Dyson shells: a retrospective

    Science.gov (United States)

    Bradbury, Robert J.

    2001-08-01

    More than 40 years have passed since Freeman Dyson suggested that advanced technological civilizations are likely to dismantle planets in their solar systems to harvest all of the energy their stars wastefully radiate into space. Clearly this was an idea that was ahead of its time. Since that time, dozens of SETI searches have been conducted and almost all of them have focused their attention on stars which by definition cannot be the advanced civilizations that Dyson envisioned. I will review the data that created the confusion between Dyson spheres and Dyson shells. The sources that disprove Dyson spheres while still allowing Dyson shells will be discussed. The use of outmoded ideas that have biased the few searches for Dyson Shells that have occurred will be pointed out. An update of the concept of Dyson shells to include our current knowledge of biotechnology, nanotechnology and computer science will be explored. Finally, an approach to setting limits on the abundance of Dyson shells in our galaxy using existing optical astronomical data and future optical satellites will be proposed.

  20. Containment integrity of SEP plants under combined loads

    International Nuclear Information System (INIS)

    Lo, T.; Nelson, T.A.; Chen, P.Y.; Persinko, D.; Grimes, C.

    1984-06-01

    Because the containment structure is the last barrier against the release of radioactivity, an assessment was undertaken to identify the design weaknesses and estimate the margins of safety for the SEP containments under the postulated, combined loading conditions of a safe shutdown earthquake (SSE) and a design basis accident (DBA). The design basis accident is either a loss-of-coolant accident (LOCA) or a main steam line break (MSLB). The containment designs analyzed consisted of three inverted light-bulb shaped drywells used in boiling water reactor (BWR) systems, and three steel-lined concrete containments and a spherical steel shell used in pressurized water reactor (PWR) systems. These designs cover a majority of the containment types used in domestic operating plants. The results indicate that five of the seven designs are adequate even under current design standards. For the remaining two designs, the possible design weaknesses identified were buckling of the spherical steel shell and over-stress in both the radial and tangential directions in one of the concrete containments near its base

  1. WHAT IS THE SHELL AROUND R CORONAE BOREALIS?

    Energy Technology Data Exchange (ETDEWEB)

    Montiel, Edward J.; Clayton, Geoffrey C.; Marcello, Dominic C. [Dept. of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Lockman, Felix J., E-mail: emonti2@lsu.edu, E-mail: gclayton@fenway.phys.lsu.edu, E-mail: dmarce1@tigers.lsu.edu, E-mail: jlockman@nrao.edu [National Radio Astronomy Observatory, Green Bank, WV 24944 (United States)

    2015-07-15

    The hydrogen-deficient, carbon-rich R Coronae Borealis (RCB) stars are known for being prolific producers of dust which causes their large iconic declines in brightness. Several RCB stars, including R Coronae Borealis (R CrB), itself, have large extended dust shells seen in the far-infrared. The origin of these shells is uncertain but they may give us clues to the evolution of the RCB stars. The shells could form in three possible ways. (1) They are fossil Planetary Nebula (PN) shells, which would exist if RCB stars are the result of a final, helium-shell flash, (2) they are material left over from a white-dwarf (WD) merger event which formed the RCB stars, or (3) they are material lost from the star during the RCB phase. Arecibo 21 cm observations establish an upper limit on the column density of H I in the R CrB shell implying a maximum shell mass of ≲0.3 M{sub ☉}. A low-mass fossil PN shell is still a possible source of the shell although it may not contain enough dust. The mass of gas lost during a WD merger event will not condense enough dust to produce the observed shell, assuming a reasonable gas-to-dust ratio. The third scenario where the shell around R CrB has been produced during the star’s RCB phase seems most likely to produce the observed mass of dust and the observed size of the shell. But this means that R CrB has been in its RCB phase for ∼10{sup 4} years.

  2. On the mechanics of elastic lines in thin shells

    Science.gov (United States)

    Benet, Eduard; Vernerey, Franck

    The deformation of soft shells in nature and engineering is often conditioned by the presence of lines whose mechanical properties are different from the shell. For instance, the deformation of tree leaves is conditioned by the presence of harder stems, and cell mitosis is driven by a stiffening line along its membrane. From an experimental standpoint, many groups have taken advantage of this feature to develop self-actuated shells with prescribed deformations. Examples include the polymerization of gels along certain lines, or the inclusion of stiffer lines via 3D printing. However, there is not yet a general continuum theory that accounts for this type of discontinuity within the membrane. Hence, we extend the general shell theory to account for the inclusion of a line that potentially induces jumps in stresses, couple stresses and moments, across its thickness. This is achieved via coupling the rod and the membrane deformations, and ensuring continuity of displacements. The model is then applied to three important problems: a constriction disc inside a shell of revolution, the induced twisting of a shell via the torsion of an embedded line, and the effect of an helicoidal line on the uni-axial deformation of a cylindrical shell. National Science Foundation CAREER award 1350090.

  3. Rectangular Shell Plating Under Uniformly Distributed Hydrostatic Pressure

    Science.gov (United States)

    Neubert, M; Sommer, A

    1940-01-01

    A check of the calculation methods used by Foppl and Henky for investigating the reliability of shell plating under hydrostatic pressure has proved that the formulas yield practical results within the elastic range of the material. Foppl's approximate calculation leaves one on the safe side. It further was found on the basis of the marked ductility of the shell plating under tensile stress that the strength is from 50 to 100 percent higher in the elastic range than expected by either method.

  4. Triggered Snap-Through of Bistable Shells

    Science.gov (United States)

    Cai, Yijie; Huang, Shicheng; Trase, Ian; Hu, Nan; Chen, Zi

    Elastic bistable shells are common structures in nature and engineering, such as the lobes of the Venus flytrap or the surface of a toy jumping poppers. Despite their ubiquity, the parameters that control the bistability of such structures are not well understood. In this study, we explore how the geometrical features of radially symmetric elastic shells affect the shape and potential energy of a shell's stable states, and how to tune certain parameters in order to generate a snap-through transition from a convex semi-stable state to concave stable state. We fabricated a series of elastic shells with varying geometric parameters out of silicone rubber and measured the resulting potential energy in the semi-stable state. Finite element simulations were also conducted in order to determine the deformation and stress in the shells during snap-through. It was found that the energy of the semi-stable state is controlled by only two geometric parameters and a dimensionless ratio. We also noted two distinct transitions during snap-through, one between monostability and semi-bistability (the state a popper toy is in before it snaps-through and jumps), and a second transition between semi-bistability and true bistability. This work shows that it is possible to use a set of simple parameters to tailor the energy landscape of an elastic shell in order to generate complex trigger motions for their potential use in smart applications. Z.C. acknowledge support from Society in Science-Branco Weiss Fellowship, administered by ETH Zurich.

  5. From Shell Shock to Combat Stress

    NARCIS (Netherlands)

    Binneveld, Hans

    1997-01-01

    War confronts a soldier with extreme situations. Armed conflicts produce not only deaths and injuries but mental breakdowns as well. The field of military psychiatry was founded at the beginning of this century. This book presents a history of this field. The first part provides a historical survey

  6. Ni3Si(Al)/a-SiOx core shell nanoparticles: characterization, shell formation, and stability

    Science.gov (United States)

    Pigozzi, G.; Mukherji, D.; Gilles, R.; Barbier, B.; Kostorz, G.

    2006-08-01

    We have used an electrochemical selective phase dissolution method to extract nanoprecipitates of the Ni3Si-type intermetallic phase from two-phase Ni-Si and Ni-Si-Al alloys by dissolving the matrix phase. The extracted nanoparticles are characterized by transmission electron microscopy, energy-dispersive x-ray spectrometry, x-ray powder diffraction, and electron powder diffraction. It is found that the Ni3Si-type nanoparticles have a core-shell structure. The core maintains the size, the shape, and the crystal structure of the precipitates that existed in the bulk alloys, while the shell is an amorphous phase, containing only Si and O (SiOx). The shell forms around the precipitates during the extraction process. After annealing the nanoparticles in nitrogen at 700 °C, the tridymite phase recrystallizes within the shell, which remains partially amorphous. In contrast, on annealing in air at 1000 °C, no changes in the composition or the structure of the nanoparticles occur. It is suggested that the shell forms after dealloying of the matrix phase, where Si atoms, the main constituents of the shell, migrate to the surface of the precipitates.

  7. BcCFEM1, a CFEM Domain-Containing Protein with Putative GPI-Anchored Site, Is Involved in Pathogenicity, Conidial Production, and Stress Tolerance in Botrytis cinerea

    Directory of Open Access Journals (Sweden)

    Wenjun Zhu

    2017-09-01

    Full Text Available We experimentally isolated and characterized a CFEM protein with putative GPI-anchored site BcCFEM1 in Botrytis cinerea. BcCFEM1 contains a CFEM (common in several fungal extracellular membrane proteins domain with the characteristic eight cysteine residues at N terminus, and a predicted GPI modification site at C terminus. BcCFEM1 was significantly up-regulated during early stage of infection on bean leaves and induced chlorosis in Nicotiana benthamiana leaves using Agrobacterium infiltration method. Targeted deletion of BcCFEM1 in B. cinerea affected virulence, conidial production and stress tolerance, but not growth rate, conidial germination, colony morphology, and sclerotial formation. However, over expression of BcCFEM1 did not make any observable phenotype change. Therefore, our data suggested that BcCFEM1 contributes to virulence, conidial production, and stress tolerance. These findings further enhance our understanding on the sophisticated pathogenicity of B. cinerea beyond necrotrophic stage, highlighting the importance of CFEM protein to B. cinerea and other broad-host-range necrotrophic pathogens.

  8. Reactor container

    International Nuclear Information System (INIS)

    Oyamada, Osamu; Furukawa, Hideyasu; Uozumi, Hiroto.

    1979-01-01

    Purpose: To lower the position of an intermediate slab within a reactor container and fitting a heat insulating material to the inner wall of said intermediate slab, whereby a space for a control rod exchanging device and thermal stresses of the inner peripheral wall are lowered. Constitution: In the pedestal at the lower part of a reactor pressure vessel there is formed an intermediate slab at a position lower than diaphragm floor slab of the outer periphery of the pedestal thereby to secure a space for providing automatic exchanging device of a control rod driving device. Futhermore, a heat insulating material is fitted to the inner peripheral wall at the upper side of the intermediate slab part, and the temperature gradient in the wall thickness direction at the time of a piping rupture trouble is made gentle, and thermal stresses at the inner peripheral wall are lowered. (Sekiya, K.)

  9. DOUBLE SHELL TANK INTEGRITY PROJECT HIGH LEVEL WASTE CHEMISTRY OPTIMIZATION

    International Nuclear Information System (INIS)

    WASHENFELDER DJ

    2008-01-01

    The U.S. Department of Energy's Office (DOE) of River Protection (ORP) has a continuing program for chemical optimization to better characterize corrosion behavior of High-Level Waste (HLW). The DOE controls the chemistry in its HLW to minimize the propensity of localized corrosion, such as pitting, and stress corrosion cracking (SCC) in nitrate-containing solutions. By improving the control of localized corrosion and SCC, the ORP can increase the life of the Double-Shell Tank (DST) carbon steel structural components and reduce overall mission costs. The carbon steel tanks at the Hanford Site are critical to the mission of safely managing stored HLW until it can be treated for disposal. The DOE has historically used additions of sodium hydroxide to retard corrosion processes in HLW tanks. This also increases the amount of waste to be treated. The reactions with carbon dioxide from the air and solid chemical species in the tank continually deplete the hydroxide ion concentration, which then requires continued additions. The DOE can reduce overall costs for caustic addition and treatment of waste, and more effectively utilize waste storage capacity by minimizing these chemical additions. Hydroxide addition is a means to control localized and stress corrosion cracking in carbon steel by providing a passive environment. The exact mechanism that causes nitrate to drive the corrosion process is not yet clear. The SCC is less of a concern in the newer stress relieved double shell tanks due to reduced residual stress. The optimization of waste chemistry will further reduce the propensity for SCC. The corrosion testing performed to optimize waste chemistry included cyclic potentiodynamic volarization studies. slow strain rate tests. and stress intensity factor/crack growth rate determinations. Laboratory experimental evidence suggests that nitrite is a highly effective:inhibitor for pitting and SCC in alkaline nitrate environments. Revision of the corrosion control

  10. NIF Double Shell outer/inner shell collision experiments

    Science.gov (United States)

    Merritt, E. C.; Loomis, E. N.; Wilson, D. C.; Cardenas, T.; Montgomery, D. S.; Daughton, W. S.; Dodd, E. S.; Desjardins, T.; Renner, D. B.; Palaniyappan, S.; Batha, S. H.; Khan, S. F.; Smalyuk, V.; Ping, Y.; Amendt, P.; Schoff, M.; Hoppe, M.

    2017-10-01

    Double shell capsules are a potential low convergence path to substantial alpha-heating and ignition on NIF, since they are predicted to ignite and burn at relatively low temperatures via volume ignition. Current LANL NIF double shell designs consist of a low-Z ablator, low-density foam cushion, and high-Z inner shell with liquid DT fill. Central to the Double Shell concept is kinetic energy transfer from the outer to inner shell via collision. The collision determines maximum energy available for compression and implosion shape of the fuel. We present results of a NIF shape-transfer study: two experiments comparing shape and trajectory of the outer and inner shells at post-collision times. An outer-shell-only target shot measured the no-impact shell conditions, while an `imaging' double shell shot measured shell conditions with impact. The `imaging' target uses a low-Z inner shell and is designed to perform in similar collision physics space to a high-Z double shell but can be radiographed at 16keV, near the viable 2DConA BL energy limit. Work conducted under the auspices of the U.S. DOE by LANL under contract DE-AC52-06NA25396.

  11. Inelastic analysis of prestressed concrete secondary containments

    International Nuclear Information System (INIS)

    Murray, D.W.; Chitnuyanondh, L.; Wong, C.; Rijub-Agha, K.Y.

    1978-07-01

    An elastic-plastic constitutive model for the simulation of stress-strain response of concrete under any biaxial combination of compressive and/or tensile stresses is developed. An effective tensile stress-strain curve is obtained indirectly from experimental results of a test on a large scale prestressed concrete wall segment. These concrete properties are then utilized in predicting the response of a second test and the results compared with the experiment. Modificications to the BOSOR5 program, in order to incorporate the new constitutive relation into it, are described. Techniques of modelling structures in order to perform inelastic analysis of thin shell axisymmetric prestressed concrete secondary containments are investigated. The results of inelastic BOSOR5 analyses of two different models of the University of Alberta Test Structure are presented. The predicted deterioration of the structure and the limit states associated with its behaviour are determined and discussed. It is concluded that the technique is a practical one which can be used for the inelastic analysis of Gentilly-type containment structures. (author)

  12. Sidewall coring shell

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, Ya A; Konstantinov, L P; Martyshin, A N

    1966-12-12

    A sidewall coring shell consists of a housing and a detachable core catcher. The core lifter is provided with projections, the ends of which are situated in another plane, along the longitudinal axis of the lifter. The chamber has corresponding projections.

  13. BOWOOSS: bionic optimized wood shells with sustainability

    Science.gov (United States)

    Pohl, Göran

    2011-04-01

    In architecture, shell construction is used for the most efficient, large spatial structures. Until now the use of wood rather played a marginal role, implementing those examples of architecture, although this material offers manifold advantages, especially against the background of accelerating shortage of resources and increasing requirements concerning the energy balance. Regarding the implementation of shells, nature offers a wide range of suggestions. The focus of the examinations is on the shells of marine plankton, especially of diatoms, whose richness in species promises the discovery of entirely new construction principles. The project is targeting at transferring advantageous features of these organisms on industrial produced, modular wood shell structures. Currently a transfer of these structures in CAD - models is taking place, helping to perform stress analysis by computational methods. Micro as well as macro structures are the subject of diverse consideration, allowing to draw the necessary conclusions for an architectural design. The insights of these tests are the basis for the development of physical models on different scales, which are used to verify the different approaches. Another important aim which is promoted in the project is to enhance the competitiveness of timber construction. Downsizing of the prefabricated structural elements leads to considerable lower transportation costs as abnormal loads can be avoided as far as possible and means of transportation can be loaded with higher efficiency so that an important contribution to the sustainability in the field of architecture can also be made.

  14. Influence of initial imperfections on ultimate strength of spherical shells

    Directory of Open Access Journals (Sweden)

    Chang-Li Yu

    2017-09-01

    Full Text Available Comprehensive consideration regarding influence mechanisms of initial imperfections on ultimate strength of spherical shells is taken to satisfy requirement of deep-sea structural design. The feasibility of innovative numerical procedure that combines welding simulation and non-linear buckling analysis is verified by a good agreement to experimental and theoretical results. Spherical shells with a series of wall thicknesses to radius ratios are studied. Residual stress and deformations from welding process are investigated separately. Variant influence mechanisms are discovered. Residual stress is demonstrated to be influential to stress field and buckling behavior but not to the ultimate strength. Deformations are proved to have a significant impact on ultimate strength. When central angles are less than critical value, concave magnitudes reduce ultimate strengths linearly. However, deformations with central angles above critical value are of much greater harm. Less imperfection susceptibility is found in spherical shells with larger wall thicknesses to radius ratios.

  15. Behavior of cracked concrete nuclear containment vessels during earthquakes

    International Nuclear Information System (INIS)

    Gergely, P.; Stanton, J.F.; White, R.N.

    1975-01-01

    When pressure builds up in a reinforced concrete nuclear containment shell, its cylindrical wall cracks vertically and horizontally at intervals of about five feet. If an earthquake occurs simultaneously with this pressurization, inertia forces are transmitted across the horizontal crack planes. The forces and deformations must be small enough to maintain the integrity of the steel liner. A typical containment shell has a radius of about 65 ft. and a wall thickness of about 4 ft. It is heavily reinforced with vertical, horizontal, and sometimes diagonal bars. A steel shell of about 3 / 8 in. thickness is attached to the concrete with anchors. The seismic shear forces are transmitted across the horizontal cracks by interface shear transfer (combination of shear friction and aggregate interlocking), by dowel action of the bars, and by diagonal bars if they are used. One important question in the design of such vessels is whether the diagonal bars are necessary. In the experimental portion of the current investigation several types of tests were conducted to study the load-slip characteristics of interface shear transfer under high intensity cyclic loading. In some cases external bars provided the clamping action of reinforcement, in more recent tests large diameter embedded bars were used. This presentation summarizes the analytical part of the investigation. A representative load-slip curve has been used in the analyses to assess the intensity of the stresses and deformations, and to study the importance of the variables as an aid in planning future tests

  16. Effect of the shell on the transport properties of poly(glycerol) and Poly(ethylene imine) nanoparticles

    International Nuclear Information System (INIS)

    Adeli, M.; Haag, R.; Zarnegar, Z.

    2007-01-01

    Dendritic core-shell architectures containing poly (glycerol) and poly (ethylene imine) cores and poly(lactide) shell (PG-PLA and PEI-PLA respectively) were synthesized. Analogous of these core-shell architectures containing the same cores but poly (L-lactide) shell (PG-PLLA and PEI-PLLA, respectively) were also synthesized. In this work PG and PEI were used as macroinitiator for ring opening polymerization of the lactid and L-lactide monomers. Different molar ratios of monomer to end functional groups of PG ([LA]/[OH]) and PEI ([LA]/[NHn] (n = 1 or 2)) were used to prepare the core-shell architectures with different shell thickness. These core-shell architectures were able to encapsulate and transport the small guest molecules. Their transport capacity (TC) depended on the type and thickness of the shells. TC of core-shell architectures containing PLLA shell was higher than that for their analogs containing PLA shell. The diameter of core-shell architectures was between 20-80 nm. The rate of release of guest molecules from chloroform solution of nanocarriers to water phase was investigated and it depended on the type of the core, shell and solvent

  17. Stability of charged thin shells

    International Nuclear Information System (INIS)

    Eiroa, Ernesto F.; Simeone, Claudio

    2011-01-01

    In this article we study the mechanical stability of spherically symmetric thin shells with charge, in Einstein-Maxwell and Einstein-Born-Infeld theories. We analyze linearized perturbations preserving the symmetry, for shells around vacuum and shells surrounding noncharged black holes.

  18. Temporal structures in shell models

    DEFF Research Database (Denmark)

    Okkels, F.

    2001-01-01

    The intermittent dynamics of the turbulent Gledzer, Ohkitani, and Yamada shell-model is completely characterized by a single type of burstlike structure, which moves through the shells like a front. This temporal structure is described by the dynamics of the instantaneous configuration of the shell...

  19. 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.

  20. The influence of seagrass on shell layers and Florida Bay mudbanks

    Science.gov (United States)

    Prager, E.J.; Halley, R.B.

    1999-01-01

    Aerial photography indicates that sometime since the early 1970's, an emergent ridge of shell debris developed on a mudbank north of Calusa Key in Florida Bay. Coarse shell deposits on and within the Bay's shallow mudbanks are believed to be the product of transport during major storm events and subsequent winnowing. However, shell material from the ridge contains nuclear bomb 14C, supporting formation within the past 30 years and the last major hurricanes to influence Florida Bay were Donna and Betsy (1960 and 1965). Results from this study suggest that the Calusa ridge and other coarse shell deposits in Florida Bay can result from, 1) periodic seagrass mortality and wave-induced transport during frequent winter cold fronts and/or 2) mollusc blooms and subsequent burial. A survey of bottom types indicates that dense to intermediate beds of seagrass, mainly Thalassia testudinum (turtle grass), occur within the shallow basins of western Florida Bay and along the margins of Bay mudbanks. Wave measurements and modeling indicate that Thalassia along mudbank margins can reduce incoming wave-energy by over 80%. Seagrass beds also host particularly dense populations of molluscs from periodic 'blooms' and are believed to be the major source of coarse sediments in the Bay. Thus, if bank-edge seagrass dies, sediments, including shell debris, become exposed and subject to greatly increased wave energy. Modeling indicates that winds typical of winter cold fronts in South Florida can produce near-bottom velocities and shear stress at a grass-free bank edge which are sufficient to transport coarse carbonate grains. Shell layers found at depth in mudbank cores can also be explained by previous episodes of sediment accretion over mollusc-rich seagrass beds or grass bed mortality at the edge of a mudbank and shell transport during cold front passage. The latter implies that mortality of marginal seagrass beds has occurred throughout the history of Florida Bay and that the

  1. Insights from the Shell Proteome: Biomineralization to Adaptation.

    Science.gov (United States)

    Arivalagan, Jaison; Yarra, Tejaswi; Marie, Benjamin; Sleight, Victoria A; Duvernois-Berthet, Evelyne; Clark, Melody S; Marie, Arul; Berland, Sophie

    2017-01-01

    Bivalves have evolved a range of complex shell forming mechanisms that are reflected by their incredible diversity in shell mineralogy and microstructures. A suite of proteins exported to the shell matrix space plays a significant role in controlling these features, in addition to underpinning some of the physical properties of the shell itself. Although, there is a general consensus that a minimum basic protein tool kit is required for shell construction, to date, this remains undefined. In this study, the shell matrix proteins (SMPs) of four highly divergent bivalves (The Pacific oyster, Crassostrea gigas; the blue mussel, Mytilus edulis; the clam, Mya truncata, and the king scallop, Pecten maximus) were analyzed in an identical fashion using proteomics pipeline. This enabled us to identify the critical elements of a "basic tool kit" for calcification processes, which were conserved across the taxa irrespective of the shell morphology and arrangement of the crystal surfaces. In addition, protein domains controlling the crystal layers specific to aragonite and calcite were also identified. Intriguingly, a significant number of the identified SMPs contained domains related to immune functions. These were often are unique to each species implying their involvement not only in immunity, but also environmental adaptation. This suggests that the SMPs are selectively exported in a complex mix to endow the shell with both mechanical protection and biochemical defense. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  2. Multipurpose container for low-level radioactive waste

    International Nuclear Information System (INIS)

    Anderson, R.T.; Pearson, S.D.

    1993-01-01

    A method is described for disposing of low-level radioactive waste, comprising the steps of (a) introducing the waste into a multipurpose container, the multipurpose container comprising a polymeric inner container disposed within a concrete outer shell, the shape of the inner container conforming substantially to the shape of the outer shell's inner surface, (b) transporting the waste in the same multipurpose container to a storage location, and (c) storing the container at the storage location

  3. Are antimicrobial defences in bird eggs related to climatic conditions associated with risk of trans-shell microbial infection?

    Science.gov (United States)

    Horrocks, Nicholas Pc; Hine, Kathryn; Hegemann, Arne; Ndithia, Henry K; Shobrak, Mohammed; Ostrowski, Stéphane; Williams, Joseph B; Matson, Kevin D; Tieleman, B Irene

    2014-01-01

    All bird eggs are exposed to microbes in the environment, which if transmitted to the developing embryo, could cause hatching failure. However, the risk of trans-shell infection varies with environmental conditions and is higher for eggs laid in wetter environments. This might relate to generally higher microbial abundances and diversity in more humid environments, including on the surface of eggshells, as well as the need for moisture to facilitate microbial penetration of the eggshell. To protect against microbial infection, the albumen of avian eggs contains antimicrobial proteins, including lysozyme and ovotransferrin. We tested whether lysozyme and ovotransferrin activities varied in eggs of larks (Alaudidae) living along an arid-mesic gradient of environmental aridity, which we used as a proxy for risk of trans-shell infection. Contrary to expectations, lysozyme activity was highest in eggs from hotter, more arid locations, where we predicted the risk of trans-shell infection would be lower. Ovotransferrin concentrations did not vary with climatic factors. Temperature was a much better predictor of antimicrobial protein activity than precipitation, a result inconsistent with studies stressing the importance of moisture for trans-shell infection. Our study raises interesting questions about the links between temperature and lysozyme activity in eggs, but we find no support for the hypothesis that antimicrobial protein deposition is higher in eggs laid in wetter environments.

  4. Structural capacity assessment of WWER-1000 MW reactor containment. Progress report

    International Nuclear Information System (INIS)

    Jordanov, M.

    1999-01-01

    The objective of the project is to provide assessment of the structural behaviour and safety capacity of the WWER-1000 MW Reactor Building Containment at Kozloduy NPP under critical combination of loads according to the current international requirements. The analysis is focused on a realistic assessment of the Containment taking into account the non-linear shell behaviour of the pre-stressed reinforced concrete structure. Previous assessments of the status of pre stressing cables pointed out that the efficiency of the Containment as a final defence barrier for internal and external events depends on their reliability. Due to this, the experimental data obtained from embedded sensors (gauges) at pre-stressed shell structure is to be compared with the results from analytical investigations. The reliability of the WWER-1000 MW accident prevention system is under evaluation in the project. The Soviet standard design WWER-1000 MW type units installed in Kozloduy NPP were originally designed for a Safe Shutdown Earthquake (SSE) with a peak ground acceleration (PGA) of 0.1g. The new site seismicity studies revealed that the seismic hazard for the site significantly exceeds the originally estimated and a Review Level Earthquake (RLE) anchored to PGA=0.20g was proposed for re-assessment of the structures and equipment at Kozloduy NPP. The scope of the study is a re-assessment of the Containment structure under critical combination of loads according to the current safety and reliability requirements, including comparison between the Russian design requirements and the international regulations. Additionally, an investigation of the pre-stressing technology and the annual control of the cables' pre-stressing of the Containment is to be made. The crane influence on the dynamic behaviour of the Containment will be done as well as a study of the integrity of the Containment as a final defence barrier

  5. The local response of elastic tubes and shells to spherical pressure pulse loading

    International Nuclear Information System (INIS)

    Thompson, J.J.; Holy, Z.J.

    1977-01-01

    This paper develops a formulation and numerical solution technique for calculating the peak transient stresses developed in tubes or shells with external and internal acoustic media, as a result of shock loadings which may be represented as originating from external or internal point symmetric or dipole sources. The field of application is intended to be the local peak response of the cylindrical fuel cans, core barrels, pressure vessels, pipes and containment shells of Nuclear Reactor Technology, subjected to transient pressure shock loadings for a variety of operational or accident conditions, which cannot adequately be described as one dimensional plane shocks, for which elastic shell responses have been presented by other workers. The work reported here concerns the basic problem of an infinite static fluid filled hollow cylinder of arbitrary thickness, in an infinite static fluid medium, with a source at an arbitrary internal or external radial location. An acoustic model is used, with acoustic damping due to radiation as the only possible damping mechanism. The formulation and solution technique is based on the availability of the multi-dimensional Fast Fourier Transform algorithm. The basic result is the representation, in cylindrical co-ordinates, of the two dimensional (time and axial co-ordinate) Fourier Transform of the infinite medium frequency response function for outgoing waves from a point symmetrical source, as a series of azimuthal Fourier harmonics, from which the result for a dipole source of arbitrary orientation follows. Where possible numerical results will be presented

  6. Analysis and characterization of double shell tank 241-AP-108

    International Nuclear Information System (INIS)

    Miller, G.L.

    1994-01-01

    This document is the first part of a three-part report describing the analysis and characterization of double shell tank 241-AP-108 which is located at the Hanford Reservation.This document is the analytical laboratory data package entitled 'Analysis and Characterization of Double Shell Tank 241-AP-108' which contains a case sampling history, the sampling protocols, the analytical procedures, sampling and analysis quality assurance and quality control measures, and chemical analysis results for samples obtained from the tank

  7. Shells on elastic foundations

    International Nuclear Information System (INIS)

    Das, Y.C.; Kedia, K.K.

    1977-01-01

    No realistic analytical work in the area of Shells on Elastic Foundations has been reported in the literature. Various foundation models have been proposed by several authors. These models involve one or more than one parameters to characterise the foundation medium. Some of these models cannot be used to derive the basic equations governing the behaviour of shells on elastic foundations. In the present work, starting from an elastic continuum hypothesis, a mathematical model for foundation has been derived in curvilinear orthogonal coordinates by the help of principle of virtual displacements, treating one of the virtual displacements as known to satisfy certain given conditions at its edge surfaces. In this model, several foundation parameters can be considered and it can also be used for layered medium of both finite and infinite thickness. (Auth.)

  8. Regulation of abiotic stress signalling by Arabidopsis C-terminal domain phosphatase-like 1 requires interaction with a k-homology domain-containing protein.

    Directory of Open Access Journals (Sweden)

    In Sil Jeong

    Full Text Available Arabidopsis thaliana CARBOXYL-TERMINAL DOMAIN (CTD PHOSPHATASE-LIKE 1 (CPL1 regulates plant transcriptional responses to diverse stress signals. Unlike typical CTD phosphatases, CPL1 contains two double-stranded (ds RNA binding motifs (dsRBMs at its C-terminus. Some dsRBMs can bind to dsRNA and/or other proteins, but the function of the CPL1 dsRBMs has remained obscure. Here, we report identification of REGULATOR OF CBF GENE EXPRESSION 3 (RCF3 as a CPL1-interacting protein. RCF3 co-purified with tandem-affinity-tagged CPL1 from cultured Arabidopsis cells and contains multiple K-homology (KH domains, which were predicted to be important for binding to single-stranded DNA/RNA. Yeast two-hybrid, luciferase complementation imaging, and bimolecular fluorescence complementation analyses established that CPL1 and RCF3 strongly associate in vivo, an interaction mediated by the dsRBM1 of CPL1 and the KH3/KH4 domains of RCF3. Mapping of functional regions of CPL1 indicated that CPL1 in vivo function requires the dsRBM1, catalytic activity, and nuclear targeting of CPL1. Gene expression profiles of rcf3 and cpl1 mutants were similar during iron deficiency, but were distinct during the cold response. These results suggest that tethering CPL1 to RCF3 via dsRBM1 is part of the mechanism that confers specificity to CPL1-mediated transcriptional regulation.

  9. Cementing a wellbore using cementing material encapsulated in a shell

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  10. Cementing a wellbore using cementing material encapsulated in a shell

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

    2017-03-14

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  11. Storage of spent fuels: implementation of a research program on the risk of waste container rupture due to stress corrosion induced by fission products

    International Nuclear Information System (INIS)

    Parise, M.; Walle, E.; Foct, J.

    2001-01-01

    The following topics were dealt with: research programm on stress corrosion of spent fuel casks materials due to fission products, such as iodine, chemical interactions with zirconium, chemical aspects of stress corrosion, rupture risk assessment

  12. Slow expansion of the shell of the recurrent nova T Pyxidis and detection of a faint extended envelope

    International Nuclear Information System (INIS)

    Shara, M.M.; Moffat, A.F.J.; Williams, R.E.; Cohen, J.G.

    1989-01-01

    New H-alpha narrow-based CCD imaging of the recurrent nova T Pyxidis and the detection of a very faint, extended H-alpha halo surrounding the already known shell are reported. A forbidden O III image containing an emitting shell with a morphology different from that of the H-alpha shell is presented, and measurements of the H-alpha shell expansion are reported which rule out the 1966 eruption date for the shell origin, assuming uniform expansion. It is proposed that the observed shell consists of slowly moving, solar abundance ejecta which are photoionized. 18 references

  13. Reduction in oxidative stress levels in the colonic mucosa without fecal stream after the application of enemas containing aqueous Ilex paraguariensis extract.

    Science.gov (United States)

    Cunha, Fernando Lorenzetti da; Silva, Camila Morais Gonçalves da; Almeida, Marcos Gonçalves de; Lameiro, Thais Miguel do Monte; Marques, Letícia Helena Souza; Margarido, Nelson Fontana; Martinez, Carlos Augusto Real

    2011-08-01

    To evaluate the antioxidant effects of enemas containing aqueous extract of Ilex paraguariensis, comparing segments with and without fecal stream and correlating the segments with the duration of intervention. Twenty-six Wistar rats were subjected to a diversion of the fecal stream in the left colon by a proximal colostomy and distal mucosal fistula. The rats were distributed randomly into two experimental groups of 13 animals each based on the time of sacrifice after surgical procedure (two or four weeks). Each group was then divided into two experimental subgroups that received either second daily enemas containing 0.9% saline solution or aqueous extract of Ilex paraguariensis at 0.2g/100g. Colitis was diagnosed by histopathological analysis and the detection of oxidative tissue damage by measuring the levels of malondialdehyde. The Mann-Whitney test was used to compare the tissue levels of malondialdehyde between colon segments with and without fecal stream in each experimental group, and the Kruskal-Wallis test was used to verify the variance between the levels of oxidative stress according the duration of the irrigation; both tests determined significance at 5% (pirrigation were 0.05±0.006 and 0.06±0.006, and 0.05± 0.03 and 0.08 ±0.02, respectively. The malondialdehyde levels in the animals irrigated with Ilex paraguariensis with and without fecal stream after two and four weeks of irrigation were 0.010±0.002 and 0.02±0.004, and 0.03±0.007 and 0.04±0.01, respectively. After two and four weeks of intervention, the levels of malondialdehyde were lower in the animals irrigated with Ilex paraguariensis regardless of the time of irrigation (p=0.0001 and p=0.002, respectively). The daily rectal application of enemas containing aqueous extract of Ilex paraguariensis decreases oxidative tissue damage in the colon without fecal stream regardless of the time of irrigation.

  14. Coulomb ionization of inner shells by heavy charged particles

    International Nuclear Information System (INIS)

    Lapicki, G.

    1975-01-01

    The theory of inner-shell Coulomb ionization by heavy charged particles, of atomic number small compared to the target atomic number, is developed through the extension of work by Brandt and his coworkers for K shells to L shells. In slow collisions relative to the characteristic times of the inner shell electrons, the quantum-mechanical predictions in the plane-wave Born approximation (PWBA) can exceed experimental cross sections by orders of magnitude. The effects of the perturbation of the atom by and the Coulomb deflection of the particle during collisions are included in the theory. The perturbed atomic states amount to a binding of the inner-shell electrons to the moving particle in slow collisions, and to a polarization of the inner shells by the particle passing at large impact parameters during nonadiabatic collisions. These effects, not contained in the PWBA, are treated in the framework of the perturbed stationary state (PSS) theory for slow collisions and in terms of the harmonic oscillator model of Ashley, Brandt, and Ritchie for stopping powers in fast collisions. The effect of the Coulomb deflection of the particle in the field of the target nucleus on the cross sections is incorporated in the semiclassical approximation of Bang and Hansteen. Except for the lightest target atoms, the contribution of electron capture by the particles to inner-shell ionizations is shown to be negligible. The theory as developed earlier for the K shell, and here for L shells, agrees well with the vast body of experimental data on inner-shell Coulomb ionization by heavy charged particles

  15. Reactor container

    International Nuclear Information System (INIS)

    Shibata, Satoru; Kawashima, Hiroaki

    1984-01-01

    Purpose: To optimize the temperature distribution of the reactor container so as to moderate the thermal stress distribution on the reactor wall of LMFBR type reactor. Constitution: A good heat conductor (made of Al or Cu) is appended on the outer side of the reactor container wall from below the liquid level to the lower face of a deck plate. Further, heat insulators are disposed to the outside of the good heat conductor. Furthermore, a gas-cooling duct is circumferentially disposed at the contact portion between the good heat conductor and the deck plate around the reactor container. This enables to flow the cold heat from the liquid metal rapidly through the good heat conductor to the cooling duct and allows to maintain the temperature distribution on the reactor wall substantially linear even with the abrupt temperature change in the liquid metal. Further, by appending the good heat conductor covered with inactive metals not only on the outer side but also on the inside of the reactor wall to introduce the heat near the liquid level to the upper portion and escape the same to the cooling layer below the roof slab, the effect can be improved further. (Ikeda, J.)

  16. Modelling of the Global Geopotential Energy & Stress Field

    DEFF Research Database (Denmark)

    Schiffer, Christian; Nielsen, S.B.

    Lateral density and topography variations yield in and important contribution to the lithospheric stress field. The leading quantity is the Geopotential Energy, the integrated lithostatic pressure in a rock column. The horizontal gradient of this quantity is related to horizontal stresses through...... the Equations of equilibrium of stresses. The Geopotential Energy furthermore can be linearly related to the Geoid under assumption of local isostasy. Satellite Geoid measurements contain, however, also non-isostatic deeper mantle responses of long wavelength. Unfortunately, high-pass filtering of the Geoid...... flow in the presence of local isostasy and a steady state geotherm. Subsequently we use a FEM code to solve the Equations of equilibrium of stresses for a three dimensional elastic shell. The modelled results are shown and compared with the global stress field and other publications....

  17. FEATURES APPLICATION CIRCUIT MOMENT FINITE ELEMENT (MSSE) NONLINEAR CALCULATIONS OF PLATES AND SHELLS

    OpenAIRE

    Bazhenov V.A.; Sacharov A.S.; Guliar A. I.; Pyskunov S.O.; Maksymiuk Y.V.

    2014-01-01

    Based MSSE created shell CE general type, which allows you to analyze the stress-strain state of axisymmetrical shells and plates in problems of physical and geometric nonlinearity. The principal nonlinear elasticity theory, algorithms for solving systems of nonlinear equations for determining the temperature and plastic deformation.

  18. FEATURES APPLICATION CIRCUIT MOMENT FINITE ELEMENT (MSSE NONLINEAR CALCULATIONS OF PLATES AND SHELLS

    Directory of Open Access Journals (Sweden)

    Bazhenov V.A.

    2014-06-01

    Full Text Available Based MSSE created shell CE general type, which allows you to analyze the stress-strain state of axisymmetrical shells and plates in problems of physical and geometric nonlinearity. The principal nonlinear elasticity theory, algorithms for solving systems of nonlinear equations for determining the temperature and plastic deformation.

  19. Reactor container structure

    International Nuclear Information System (INIS)

    Sato, Yoshimi; Fukuda, Yoshio.

    1993-01-01

    A main container of an FBR type reactor using liquid sodium as coolants is attached to a roof slug. The main container contains, as coolants, lower temperature sodium, and high temperature sodium above a reactor core and a partitioning plate. The main container has a structure comprising only longitudinal welded joints in parallel with axial direction in the vicinity of the liquid surface of high temperature sodium where a temperature gradient is steep and great thermal stresses are caused without disposing lateral welded joints in perpendicular to axial direction. Only the longitudinal welded joints having a great fatigue strength are thus disposed in the vicinity of the liquid surface of the high temperature sodium where axial thermal stresses are caused. This can improve reliability of strength at the welded portions of the main container against repeating thermal stresses caused in vicinity of the liquid surface of the main container from a view point of welding method. (I.N.)

  20. Folding and unfolding of large-size shell construction for application in Earth orbit

    Science.gov (United States)

    Kondyurin, Alexey; Pestrenina, Irena; Pestrenin, Valery; Rusakov, Sergey

    2016-07-01

    A future exploration of space requires a technology of large module for biological, technological, logistic and other applications in Earth orbits [1-3]. This report describes the possibility of using large-sized shell structures deployable in space. Structure is delivered to the orbit in the spaceship container. The shell is folded for the transportation. The shell material is either rigid plastic or multilayer prepreg comprising rigid reinforcements (such as reinforcing fibers). The unfolding process (bringing a construction to the unfolded state by loading the internal pressure) needs be considered at the presence of both stretching and bending deformations. An analysis of the deployment conditions (the minimum internal pressure bringing a construction from the folded state to the unfolded state) of large laminated CFRP shell structures is formulated in this report. Solution of this mechanics of deformable solids (MDS) problem of the shell structure is based on the following assumptions: the shell is made of components whose median surface has a reamer; in the separate structural element relaxed state (not stressed and not deformed) its median surface coincides with its reamer (this assumption allows choose the relaxed state of the structure correctly); structural elements are joined (sewn together) by a seam that does not resist rotation around the tangent to the seam line. The ways of large shell structures folding, whose median surface has a reamer, are suggested. Unfolding of cylindrical, conical (full and truncated cones), and large-size composite shells (cylinder-cones, cones-cones) is considered. These results show that the unfolding pressure of such large-size structures (0.01-0.2 atm.) is comparable to the deploying pressure of pneumatic parts (0.001-0.1 atm.) [3]. It would be possible to extend this approach to investigate the unfolding process of large-sized shells with ruled median surface or for non-developable surfaces. This research was

  1. Wrinkling of Pressurized Elastic Shells

    KAUST Repository

    Vella, Dominic

    2011-10-01

    We study the formation of localized structures formed by the point loading of an internally pressurized elastic shell. While unpressurized shells (such as a ping-pong ball) buckle into polygonal structures, we show that pressurized shells are subject to a wrinkling instability. We study wrinkling in depth, presenting scaling laws for the critical indentation at which wrinkling occurs and the number of wrinkles formed in terms of the internal pressurization and material properties of the shell. These results are validated by numerical simulations. We show that the evolution of the wrinkle length with increasing indentation can be understood for highly pressurized shells from membrane theory. These results suggest that the position and number of wrinkles may be used in combination to give simple methods for the estimation of the mechanical properties of highly pressurized shells. © 2011 American Physical Society.

  2. Potential of using coconut shell particle fillers in eco-composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Sarki, J., E-mail: sarksj@yahoo.com [Department of Fire and Safety, Kaduna International Airport, Kaduna-State (Nigeria); Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Samaru, Zaria (Nigeria); Hassan, S.B., E-mail: hassbolaji@yahoo.com [Department of Fire and Safety, Kaduna International Airport, Kaduna-State (Nigeria); Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Samaru, Zaria (Nigeria); Aigbodion, V.S., E-mail: aigbodionv@yahoo.com [Department of Fire and Safety, Kaduna International Airport, Kaduna-State (Nigeria); Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Samaru, Zaria (Nigeria); Oghenevweta, J.E. [Department of Fire and Safety, Kaduna International Airport, Kaduna-State (Nigeria); Department of Metallurgical and Materials Engineering, Ahmadu Bello University, Samaru, Zaria (Nigeria)

    2011-02-03

    Research highlights: > The production and characterization of the composites has been done. - Abstract: Morphology and mechanical properties of coconut shell particles reinforced epoxy composites were evaluated to assess the possibility of using it as a new material in engineering applications. Coconut shell filled composites were prepared from epoxy polymer matrix containing up to 30 wt% coconut shell fillers. The effects of coconut shell particle content on the mechanical properties of the composites were investigated. Scanning electron microscopy (SEM) of the composite surfaces indicates that there are fairly good interfacial interaction between coconut shell particles and epoxy matrix. It was shown that the value of tensile modulus and tensile strength values increases with the increase of coconut shell particles content, while the impact strength slightly decreased, compared to pure epoxy resin. This work has shown that coconut shell particles can be used to improve properties of epoxy polymer composite to be used in eco-buildings.

  3. Potential of using coconut shell particle fillers in eco-composite materials

    International Nuclear Information System (INIS)

    Sarki, J.; Hassan, S.B.; Aigbodion, V.S.; Oghenevweta, J.E.

    2011-01-01

    Research highlights: → The production and characterization of the composites has been done. - Abstract: Morphology and mechanical properties of coconut shell particles reinforced epoxy composites were evaluated to assess the possibility of using it as a new material in engineering applications. Coconut shell filled composites were prepared from epoxy polymer matrix containing up to 30 wt% coconut shell fillers. The effects of coconut shell particle content on the mechanical properties of the composites were investigated. Scanning electron microscopy (SEM) of the composite surfaces indicates that there are fairly good interfacial interaction between coconut shell particles and epoxy matrix. It was shown that the value of tensile modulus and tensile strength values increases with the increase of coconut shell particles content, while the impact strength slightly decreased, compared to pure epoxy resin. This work has shown that coconut shell particles can be used to improve properties of epoxy polymer composite to be used in eco-buildings.

  4. Structural responses to plasma disruptions in toroidal shells

    International Nuclear Information System (INIS)

    Tillack, M.S.; Kazimi, M.S.; Lidsky, L.M.

    1985-01-01

    The induced pressures, stresses and strains in unrestrained axisymmetric toroidal shells are studied to scope the behavior of tokamak first walls during plasma disruptions. The modeling includes a circuit analog representation of the shell to solve for induced currents and pressures, and a separate quasi-static 1-D finite element solution for the mechanical response. This work demonstrates that the stresses in tokamkak first walls due to plasma disruption may be large, but to first order will not cause failure in the bulk structure. However, stress concentrations at structural supports and discontinuities together with resonant effects can result in large enhancements of the stresses, which could contribute to plastic deformation or failure when added to the already large steady state thermal and pressure loading of the first wall

  5. Buckling of long liquid-filled cylindrical shells

    International Nuclear Information System (INIS)

    Saal, H.

    1982-01-01

    The experimental investigation confirms the stresses and displacements which result from a nonlinear analysis of the shell. The linear analysis gives a good approximation for the stresses and deformations which significantly deviate from those according to beam theory. This approximation is to the safe side - (remarkably only for the displacements and circumferential stresses). The application of an equivalent cylinder model to the determination of the buckling load gives rather good agreement with the experimental results. There is only little imperfection sensitivity in this load case as the experiments show. Again the theoretical buckling load which is based on the stresses and displacements from linear shell theory is on the safe side. (orig./RW)

  6. Horizon shells and BMS-like soldering transformations

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Matthias [Albert Einstein Center for Fundamental Physics,Institute for Theoretical Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland); O’Loughlin, Martin [University of Nova Gorica,Vipavska 13, 5000 Nova Gorica (Slovenia)

    2016-03-07

    We revisit the theory of null shells in general relativity, with a particular emphasis on null shells placed at horizons of black holes. We study in detail the considerable freedom that is available in the case that one solders two metrics together across null hypersurfaces (such as Killing horizons) for which the induced metric is invariant under translations along the null generators. In this case the group of soldering transformations turns out to be infinite dimensional, and these solderings create non-trivial horizon shells containing both massless matter and impulsive gravitational wave components. We also rephrase this result in the language of Carrollian symmetry groups. To illustrate this phenomenon we discuss in detail the example of shells on the horizon of the Schwarzschild black hole (with equal interior and exterior mass), uncovering a rich classical structure at the horizon and deriving an explicit expression for the general horizon shell energy-momentum tensor. In the special case of BMS-like soldering supertranslations we find a conserved shell-energy that is strikingly similar to the standard expression for asymptotic BMS supertranslation charges, suggesting a direct relation between the physical properties of these horizon shells and the recently proposed BMS supertranslation hair of a black hole.

  7. Stress analysis of PCV nozzle junction

    International Nuclear Information System (INIS)

    Uchiyama, Shoichi; Oikawa, Tsuneo; Hoshino, Seizo

    1976-01-01

    Most of various pressure vessels comprise each one cylindrical shell and one or more nozzles. In this study, in order to analyze the stress in the structures of this type as minutely and exactly as possible, the program for stress analysis by the finite element method was made, which is required for the strength analysis for three-dimensional structures. Especially, the problem of the stress distribution around nozzle junctions was solved theoretically with the program. The program for the analysis developed in this study is provided with various functions, such as the input generator for cylindrical, conical and spherical shells, and plotter, and is very covenient. The accuracy of analysis is very good. The method of analysis and the calculation of the rigidity matrices for the deformation in plane and bending are explained. The result of the stress analysis around the nozzle junctions of a containment vessel with this program was in good agreement with experimental data and the result with SAP-4 code, therefore the propriety of the calculated result with this program was proved. Also calculations were carried out on three cases, namely a flat plate fixed at one end with distributed load, a cylinder fixed at one end with internal pressure, and an I-beam fixed at one end with concentrated load. The calculated results agreed well with theoretical solutions in all cases. (Kako, I.)

  8. The direct manipulation shell

    International Nuclear Information System (INIS)

    Allen, M.E.; Christiansen, M.

    1992-01-01

    Accelerator controls systems provide parameter display pages which allow the operator to monitor and manipulate selected control points in the system. Display pages are generally implemented as either hand-crafted, purpose-built programs; or by using a specialized display page layout tool. These two methods of display page development exhibit the classic trade-off between functionality vs. ease of implementation. In the Direct Manipulation Shell we approach the process of developing a display page in a manifestly object-oriented manner. This is done by providing a general framework for interactively instantiating and manipulating display objects. (author)

  9. Pretension construction of safety shell in Chashma nuclear power plant

    International Nuclear Information System (INIS)

    Gong Zhenbin; Li Yinong; Ni Shaowen

    1999-01-01

    19T16 post-tension grouped anchor system is applied to the safety shell pretension in Chashma Nuclear Power Plant. The stretching force of each bundle is about 3800 kN and the prestressed reinforcement is stretched in five stages. The double-control measurement of stress controlling and extension checking is applied in strict accordance with the principle of symmetrical construction

  10. Plate shell structures of glass

    DEFF Research Database (Denmark)

    Bagger, Anne

    to their curved shape. A plate shell structure maintains a high stiffness-to-weight ratio, while facilitating the use of plane structural elements. The study focuses on using laminated glass panes for the load bearing facets. Various methods of generating a plate shell geometry are suggested. Together with Ghent......, such as facet size, imperfections, and connection characteristics. The critical load is compared to that of a similar, but smoothly curved, shell structure. Based on the investigations throughout the study, a set of guidelines for the structural design of plate shells of glass is proposed....

  11. Antioxidative effects of magnetized extender containing bovine serum albumin on sperm oxidative stress during long-term liquid preservation of boar semen

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Hee; Park, Choon-Keun, E-mail: parkck@kangwon.ac.kr

    2015-08-21

    Magnetized water is defined as water that has passed through a magnet and shows increased permeability into cells and electron-donating characteristics. These attributes can protect against membrane damage and remove reactive oxygen species (ROS) in mammalian cells. We explored the effects of improved magnetized semen extenders containing bovine serum albumin (BSA) as antioxidants on apoptosis in boar sperm. Ejaculated semen was diluted in magnetized extender (0G and 6000G) with or without BSA (0G + BSA and 6000G + BSA), and sperm were analyzed based on viability, acrosome reaction, and H{sub 2}O{sub 2} level of live sperm using flow cytometry. Sperm were then preserved for 11 days at 18 °C. We found that viability was significantly higher in 6000G + BSA than under the other treatments (P < 0.05). The acrosome reaction was significantly lower in the 6000G + BSA group compared with the other treatments (P < 0.05). Live sperm with high intracellular H{sub 2}O{sub 2} level were significantly lower in the 6000G + BSA group than under other treatments (P < 0.05). Based on our results, magnetized extenders have antioxidative effects on the liquid preservation of boar sperm. - Highlights: • Magnetized water is water that has been passed through a magnetic field. • Magnetized extender improve viability and decrease oxidative stress of boar sperm for preservation. • Ejaculated semen diluted with magnetized extender can improve liquid preservation period.

  12. Antioxidative effects of magnetized extender containing bovine serum albumin on sperm oxidative stress during long-term liquid preservation of boar semen

    International Nuclear Information System (INIS)

    Lee, Sang-Hee; Park, Choon-Keun

    2015-01-01

    Magnetized water is defined as water that has passed through a magnet and shows increased permeability into cells and electron-donating characteristics. These attributes can protect against membrane damage and remove reactive oxygen species (ROS) in mammalian cells. We explored the effects of improved magnetized semen extenders containing bovine serum albumin (BSA) as antioxidants on apoptosis in boar sperm. Ejaculated semen was diluted in magnetized extender (0G and 6000G) with or without BSA (0G + BSA and 6000G + BSA), and sperm were analyzed based on viability, acrosome reaction, and H 2 O 2 level of live sperm using flow cytometry. Sperm were then preserved for 11 days at 18 °C. We found that viability was significantly higher in 6000G + BSA than under the other treatments (P < 0.05). The acrosome reaction was significantly lower in the 6000G + BSA group compared with the other treatments (P < 0.05). Live sperm with high intracellular H 2 O 2 level were significantly lower in the 6000G + BSA group than under other treatments (P < 0.05). Based on our results, magnetized extenders have antioxidative effects on the liquid preservation of boar sperm. - Highlights: • Magnetized water is water that has been passed through a magnetic field. • Magnetized extender improve viability and decrease oxidative stress of boar sperm for preservation. • Ejaculated semen diluted with magnetized extender can improve liquid preservation period

  13. Axisymmetric thermoviscoelastoplastic state of branched laminar shells, taking account of transverse-shear and torsional deformation

    International Nuclear Information System (INIS)

    Galishin, A.Z.

    1995-01-01

    The nonaxisymmetric thermoelastic stress-strain state (SSS) of branched laminar orthotropic shells was considered; the axisymmetric thermoviscoelastic SSS of branched laminar orthotropic shells was considered; and the axisymmetric thermoviscoelastoplastic SSS of branched laminar isotropic shells was considered, taking into account of the transverse-shear deformation. In the present work, in contrast, the axisymmetric thermoviscoelastoplastic SSS of branched laminar isotropic shells is considered, taking account of transverse-shear and torsional deformation. Layers that are made from orthotropic materials and deform in the elastic region may be present

  14. Curvature-Induced Instabilities of Shells

    Science.gov (United States)

    Pezzulla, Matteo; Stoop, Norbert; Steranka, Mark P.; Bade, Abdikhalaq J.; Holmes, Douglas P.

    2018-01-01

    Induced by proteins within the cell membrane or by differential growth, heating, or swelling, spontaneous curvatures can drastically affect the morphology of thin bodies and induce mechanical instabilities. Yet, the interaction of spontaneous curvature and geometric frustration in curved shells remains poorly understood. Via a combination of precision experiments on elastomeric spherical shells, simulations, and theory, we show how a spontaneous curvature induces a rotational symmetry-breaking buckling as well as a snapping instability reminiscent of the Venus fly trap closure mechanism. The instabilities, and their dependence on geometry, are rationalized by reducing the spontaneous curvature to an effective mechanical load. This formulation reveals a combined pressurelike term in the bulk and a torquelike term in the boundary, allowing scaling predictions for the instabilities that are in excellent agreement with experiments and simulations. Moreover, the effective pressure analogy suggests a curvature-induced subcritical buckling in closed shells. We determine the critical buckling curvature via a linear stability analysis that accounts for the combination of residual membrane and bending stresses. The prominent role of geometry in our findings suggests the applicability of the results over a wide range of scales.

  15. Coaxial electrospun polyurethane core-shell nanofibers for shape memory and antibacterial nanomaterials

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available A novel kind of shape memory polyurethane (SMPU nanofibers with core-shell nanostructure is fabricated using coaxial electrospinning. Transmission electron microscopy (TEM and scanning electron microscopy (SEM results show that nanofibers with core-shell structure or bead-on-string structure can be electrospun successfully from the core solution of polycaprolactone based SMPU (CLSMPU and shell solution of pyridine containing polyurethane (PySMPU. In addition to the excellent shape memory effect with good shape fixity, excellent antibacterial activity against both gramnegative bacteria and gram-positive bacteria are achieved in the CLSMPU-PySMPU core-shell nanofiber. Finally, it is proposed that the antibacterial mechanism should be resulted from the PySMPU shell materials containing amido group in γ position and the high surface area per unit mass of nanofibers. Thus, the CLSMPU-PySMPU core shell nanofibers can be used as both shape memory nanomaterials and antibacterial nanomaterials.

  16. Linear and nonlinear symmetrically loaded shells of revolution approximated with the finite element method

    International Nuclear Information System (INIS)

    Cook, W.A.

    1978-10-01

    Nuclear Material shipping containers have shells of revolution as a basic structural component. Analytically modeling the response of these containers to severe accident impact conditions requires a nonlinear shell-of-revolution model that accounts for both geometric and material nonlinearities. Present models are limited to large displacements, small rotations, and nonlinear materials. This report discusses a first approach to developing a finite element nonlinear shell of revolution model that accounts for these nonlinear geometric effects. The approach uses incremental loads and a linear shell model with equilibrium iterations. Sixteen linear models are developed, eight using the potential energy variational principle and eight using a mixed variational principle. Four of these are suitable for extension to nonlinear shell theory. A nonlinear shell theory is derived, and a computational technique used in its solution is presented

  17. Core-shell architectures as nano-size transporters

    International Nuclear Information System (INIS)

    Adeli, M.; Zarnegar, Z.; Kabiri, R.; Salimi, F.; Dadkah, A.

    2006-01-01

    Core-shell architectures containing poly (ethylene imine) (PEI) as a core and poly (lactide) (PLA) as arms were prepared. PEI was used as macro initiator for ring opening polymerization of lactide. PEI-PLA core-shell architectures were able to encapsulate guest molecules. Size of the core-shell architectures was between 10- 100 nm, hence they can be considered as nano carriers to transport the guest molecules. Transport capacity of nano carriers depends on their nano-environments and type of self-assembly in solvent. In solid state nano carriers self-assemble as long structures with nano-size diameter or they form network structures. Aggregations type depends on the concentration of nano carriers in solution. Effect of the shell thickness and aggregation type on the release rate are also investigated

  18. Dossier Shell Eco-Marathon; Dossier Shell Eco-Marathon

    Energy Technology Data Exchange (ETDEWEB)

    Matla, P.

    2012-05-15

    Three articles address subjects concerning the annual race with highly energy efficient cars: the Shell Eco-Marathon. [Dutch] In 3 artikelen wordt aandacht besteed aan de ontwerpen voor de jaarlijkse race met superzuinige auto's, de Shell Eco-Marathon.

  19. Structural Integrity Assessment of Reactor Containment Subjected to Aircraft Crash

    International Nuclear Information System (INIS)

    Kim, Junyong; Chang, Yoonsuk

    2013-01-01

    When an accident occurs at the NPP, containment building which acts as the last barrier should be assessed and analyzed structural integrity by internal loading or external loading. On many occasions that can occur in the containment internal such as LOCA(Loss Of Coolant Accident) are already reflected to design. Likewise, there are several kinds of accidents that may occur from the outside of containment such as earthquakes, hurricanes and strong wind. However, aircraft crash that at outside of containment is not reflected yet in domestic because NPP sites have been selected based on the probabilistic method. After intentional aircraft crash such as World Trade Center and Pentagon accident in US, social awareness for safety of infrastructure like NPP was raised world widely and it is time for assessment of aircraft crash in domestic. The object of this paper is assessment of reactor containment subjected to aircraft crash by FEM(Finite Element Method). In this paper, assessment of structural integrity of containment building subjected to certain aircraft crash was carried out. Verification of structure integrity of containment by intentional severe accident. Maximum stress 61.21MPa of horizontal shell crash does not penetrate containment. Research for more realistic results needed by steel reinforced concrete model

  20. Containment structure tendon investigation

    International Nuclear Information System (INIS)

    Fulton, J.F.; Murray, K.H.

    1983-01-01

    The paper describes an investigation into the possible causes of lower-than-predicted tendon forces which were measured during past tendon surveillances for a concrete containment. The containment is post tensioned by vertical tendons which are anchored into a rock foundation. The tendons were originally stressed in 1969, and lift-off tests were performed on six occasions subsequent to this date over a period of 11 years. The tendon forces measured in these tests were generally lower than predicted, and by 1979 the prestress level in the containment was only marginally above the design requirement. The tendons were retensioned in 1980, and by this time an investigation into the possible causes was underway. Potential causes investigated include the rock anchors and surrounding rock, elastomeric pad creep, wire stresses, thermal effects, stressing equipment and lift-off procedures, and wire stress relaxation. The investigation activities included stress relaxation testing of wires pulled from actual tendons. The stress relaxation test program included wire specimens at several different temperature and initial stress levels and the effect of a varying temperature history on the stress relaxation property of the wires. For purpose of future force predictions of the retensioned tendons, the test program included tests to determine the effect on stress relaxation due to restressing the wires after they had relaxed for 1000 hours and 10,000 hours. (orig./GL)

  1. Corrosion assessment of dry fuel storage containers

    Energy Technology Data Exchange (ETDEWEB)

    Graves, C.E.

    1994-09-01

    The structural stability as a function of expected corrosion degradation of 75 dry fuel storage containers located in the 200 Area Low-Level Waste Burial Grounds was evaluated. These containers include 22 concrete burial containers, 13 55-gal (208-l) drums, and 40 Experimental Breeder Reactor II (EBR-II) transport/storage casks. All containers are buried beneath at least 48 in. of soil and a heavy plastic tarp with the exception of 35 of the EBR-II casks which are exposed to atmosphere. A literature review revealed that little general corrosion is expected and pitting corrosion of the carbon steel used as the exterior shell for all containers (with the exception of the concrete containers) will occur at a maximum rate of 3.5 mil/yr. Penetration from pitting of the exterior shell of the 208-l drums and EBR-II casks is calculated to occur after 18 and 71 years of burial, respectively. The internal construction beneath the shell would be expected to preclude containment breach, however, for the drums and casks. The estimates for structural failure of the external shells, large-scale shell deterioration due to corrosion, are considerably longer, 39 and 150 years respectively for the drums and casks. The concrete burial containers are expected to withstand a service life of 50 years.

  2. Hi shells, supershells, shell-like objects, and ''worms''

    International Nuclear Information System (INIS)

    Heiles, C.

    1984-01-01

    We present photographic representations of the combination of two Hi surveys, so as to eliminate the survey boundaries at Vertical BarbVertical Bar = 10 0 . We also present high-contrast photographs for particular velocities to exhibit weak Hi features. All of these photographs were used to prepare a new list of Hi shells, supershells, and shell-like objects. We discuss the structure of three shell-like objects that are associated with high-velocity gas, and with gas at all velocities that is associated with radio continuum loops I, II, and III. We use spatial filtering to find wiggly gas filaments: ''worms'': crawling away from the galactic plane in the inner Galaxy. The ''worms'' are probably parts of shells that are open at the top; such shells should be good sources of hot gas for the galactic halo

  3. Design of radial reinforcement for prestressed concrete containments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shen, E-mail: swang@bechtel.com [Bechtel Power Corporation, 5275 Westview Drive, BP2-2C3, Frederick, MD 21703 (United States); Munshi, Javeed A., E-mail: jamunshi@bechtel.com [Bechtel Power Corporation, 5275 Westview Drive, BP2-2C3, Frederick, MD 21703 (United States)

    2013-02-15

    Highlights: ► A rigorous formulae is proposed to calculate radial stress within prestressed concrete containments. ► The proposed method is validated by finite element analysis in an illustrative practical example. ► A partially prestressed condition is more critical than a fully prestressed condition for radial tension. ► Practical design consideration is provided for detailing of radial reinforcement. -- Abstract: Nuclear containments are critical components for safety of nuclear power plants. Failure can result in catastrophic safety consequences as a result of leakage of radiation. Prestressed concrete containments have been used in large nuclear power plants with significant design internal pressure. These containments are generally reinforced with prestressing tendons in the circumferential (hoop) and meridional (vertical) directions. The curvature effect of the tendons introduces radial tensile stresses in the concrete shell which are generally neglected in the design of such structures. It is assumed that such tensile radial stresses are small as such no radial reinforcement is provided for this purpose. But recent instances of significant delaminations in Crystal River Unit 3 in Florida have elevated the need for reevaluation of the radial tension issue in prestressed containment. Note that currently there are no well accepted industry standards for design and detailing of radial reinforcement. This paper discusses the issue of radial tension in prestressed cylindrical and dome shaped structures and proposes formulae to calculate radial stresses. A practical example is presented to illustrate the use of the proposed method which is then verified by using state of art finite element analysis. This paper also provides some practical design consideration for detailing of radial reinforcement in prestressed containments.

  4. Analysis of thin composite structures using an efficient hex-shell finite element

    Energy Technology Data Exchange (ETDEWEB)

    Shiri, Seddik [Universite Bordeaux, Pessac (France); Naceur, Hakim [Universite de valenciennes, Valenciennes (France)

    2013-12-15

    In this paper a general methodology for the modeling of material composite multilayered shell structures is proposed using a Hex-shell finite element modeling. The first part of the paper is devoted to the general FE formulation of the present composite 8-node Hex-shell element called SCH8, based only on displacement degrees of freedom. A particular attention is given to alleviate shear, trapezoidal and thickness locking, without resorting to the classical plane-stress assumption. The anisotropic material behavior of layered shells is modeled using a fully three dimensional elastic orthotropic material law in each layer, including the thickness stress component. Applications to laminate thick shell structures are studied to validate the methodology, and good results have been obtained in comparison with ABAQUS commercial code.

  5. Design study on containers for geological disposal of high-level radioactive waste. Phase 2

    International Nuclear Information System (INIS)

    1986-01-01

    This study has considered the feasibility of three designs for containers which would isolate the waste from the environment for a minimum period of 500 to 1000 years. The candidate container designs were taken from the results of a previous study by Ove Arup and Partners (1985) and were developed as the study progressed. Their major features can be summarized as follows: Type A: A thin-walled corrosion-resistant metal shell filled with lead or cement grout. Type B: An unfilled thick-walled carbon steel shell. Type C: an unfilled carbon steel shell plated externally with corrosion-resistant metal. Reference repository conditions in clay, granite and salt, reference disposal operations and metals corrosion data have been taken from various European Community radioactive waste management research and engineering projects. The study concludes that design types A and B are feasible in manufacturing terms but design Type C is not. Furthermore, a titanium-palladium alloy is considered the most suitable metal for Type A container shells and lead is the preferred filler. The analysis shows that design Types A and B both have adequate resistance to pressure and temperature loadings and both would resist accidental impact damage when upright. A reduction in waste heat output at disposal would lower the stress levels in Type A containers but would have virtually no effect on Type B. There is insufficient data to compare the relative costs and benefits of design Types A and B. In conclusion design Types A and B are both considered feasible but Type A would require more development than Type B. In both cases further research is needed to confirm the long-term corrosion performance of the candidate materials. It is recommended that model containers should be produced to demonstrate the proposed methods of manufacture and that they should be tested to validate the analytical techniques used

  6. Shell Trumpets from Western Mexico

    Directory of Open Access Journals (Sweden)

    Robert Novella

    1991-11-01

    Full Text Available Marine shells have been used as musical instruments in almost all parts of the world (Izikowitz 1935, including Mesoamerica, where large univalves, also called conch shells in the literature, had a utilitarian function as trumpets. Their use is well documented in most cultural areas of Mesoamerica, as in Western Mexico, through their various occurrences in archaeological contexts and museums collections.

  7. Cylindrical thin-shell wormholes

    International Nuclear Information System (INIS)

    Eiroa, Ernesto F.; Simeone, Claudio

    2004-01-01

    A general formalism for the dynamics of nonrotating cylindrical thin-shell wormholes is developed. The time evolution of the throat is explicitly obtained for thin-shell wormholes whose metric has the form associated with local cosmic strings. It is found that the throat collapses to zero radius, remains static, or expands forever, depending only on the sign of its initial velocity

  8. Shell model and spectroscopic factors

    International Nuclear Information System (INIS)

    Poves, P.

    2007-01-01

    In these lectures, I introduce the notion of spectroscopic factor in the shell model context. A brief review is given of the present status of the large scale applications of the Interacting Shell Model. The spectroscopic factors and the spectroscopic strength are discussed for nuclei in the vicinity of magic closures and for deformed nuclei. (author)

  9. Conventional shell model: some issues

    International Nuclear Information System (INIS)

    Vallieres, M.; Pan, X.W.; Feng, D.H.; Novoselsky, A.

    1997-01-01

    We discuss some important issues in shell-model calculations related to the effective interactions used in different regions of the periodic table; in particular the quality of different interactions is discussed, as well as the mass dependence of the interactions. Mention is made of the recently developed Drexel University shell-model (DUSM). (orig.)

  10. Expert system development (ESD) shell

    International Nuclear Information System (INIS)

    Padmini, S.; Diwakar, M.P.; Rathode, N.C.; Bairi, B.R.

    1991-01-01

    An Expert System Development (ESD) Shell design implementation is desribed in detail. The shell provides high-level generic facilities for Knowledge Representation (KR) and inferencing and tools for developing user interfaces. Powerful set of tools in the shell relieves much of the programming burden in the ES development. The shell is written in PROLOG under IBM PC/AT. KR facilities are based on two very powerful formalisms namely, frames and rules. Inference Engine (IE) draws most of its power from unification and backward reasoning strategy in PROLOG. This basic mechanism is enhanced further by incorporating both forward and backward chaining of rules and frame-based inferencing. Overall programming style integrates multiple paradigms including logic, object oriented, access-oriented and imperative programming. This permits ES designer a lot of flexibility in organizing inference control. Creation and maintainance of knowledge base is a major activity. The shell, therefore, provides number of facilities to simplify these tasks. Shell design also takes note of the fact that final success of any system depends on end-user satisfaction and hence provides features to build use-friendly interfaces. The shell also provides a set of interfacing predicates so that it can be embedded within any PROLOG program to incorporate functionalilty of the shell in the user program. (author). 10 refs., 8 figs

  11. Elastoplastic State of an Elliptical Cylindrical Shell with a Circular Hole

    Science.gov (United States)

    Storozhuk, E. A.; Chernyshenko, I. S.; Pigol', O. V.

    2017-11-01

    Static problems for an elastoplastic elliptical cylindrical shell with a circular hole are formulated and a numerical method for solving it is developed. The basic equations are derived using the Kirchhoff-Love theory of deep shells and the theory of small elastoplastic strains. The method employs the method of additional stresses and the finite-element method. The influence of plastic strains and geometrical parameters of the shell subject to internal pressure on the distributions of stresses, strains, and displacements in the zone of their concentration is studied.

  12. 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.

  13. Nonlinear Local Bending Response and Bulging Factors for Longitudinal and Circumferential Cracks in Pressurized Cylindrical Shells

    Science.gov (United States)

    Young, Richard D.; Rose, Cheryl A.; Starnes, James H., Jr.

    2000-01-01

    Results of a geometrically nonlinear finite element parametric study to determine curvature correction factors or bulging factors that account for increased stresses due to curvature for longitudinal and circumferential cracks in unstiffened pressurized cylindrical shells are presented. Geometric parameters varied in the study include the shell radius, the shell wall thickness, and the crack length. The major results are presented in the form of contour plots of the bulging factor as a function of two nondimensional parameters: the shell curvature parameter, lambda, which is a function of the shell geometry, Poisson's ratio, and the crack length; and a loading parameter, eta, which is a function of the shell geometry, material properties, and the applied internal pressure. These plots identify the ranges of the shell curvature and loading parameters for which the effects of geometric nonlinearity are significant. Simple empirical expressions for the bulging factor are then derived from the numerical results and shown to predict accurately the nonlinear response of shells with longitudinal and circumferential cracks. The numerical results are also compared with analytical solutions based on linear shallow shell theory for thin shells, and with some other semi-empirical solutions from the literature, and limitations on the use of these other expressions are suggested.

  14. Dynamic centering of liquid shells

    International Nuclear Information System (INIS)

    Tsamopoulos, J.A.; Brown, R.A.

    1987-01-01

    The moderate-amplitude axisymmetric oscillations of an inviscid liquid shell surrounding an incompressible gas bubble are calculated by a multiple-time-scale expansion for initial deformations composed of two-lobed perturbations of the shell and a displacement of the bubble from the center of mass of the liquid. Two types of small-amplitude motion are identified and lead to very different nonlinear dynamic interactions, as described by the results valid up to second order in the amplitude of the initial deformation. In the ''bubble mode,'' the oscillations of the captive bubble and the liquid shell are exactly in phase and the bubble vibrates about its initial eccentric location. The bubble moves toward the center of the drop when the shell is perturbed into a ''sloshing mode'' of oscillation where both interfaces move out of phase. These results explain the centering of liquid shells observed in several experiments

  15. New oil skimmer from shell

    Energy Technology Data Exchange (ETDEWEB)

    1978-06-01

    Under a program initiated by the US Coast Guard (USCG), Shell Development Co. has developed the Zero-Relative Velocity Skimmer (ZRVS) (Abstract No. 24-30285) which can recover spilled oil in currents up to eight knots. Tests of a full-scale mockup of the system gave excellent results up to the test limit of eight knots and in waves up to 2 ft high. Conventional oil skimmers slow down the floating oil relative to the water so that it can be contained and collected. But when the relative velocity of water and skimmer exceeds 1 to 2 knots, turbulence caused by the skimmer's surface piercing equipment leads to oil escaping. The ZRVS combats this by laying twin floating, adsorbent belts on the surface so they move at the same speed as the water and oil relative to the skimmer. With no relative velocity between them, turbulence is removed, allowing the skimmer to operate effectively in fast currents. The skimmer is a 41 ft catamaran, built in three sections so it can be transported in two aircraft and assembled at the port nearest the spill. The first prototype is due to be completed at the USCG shipyard in the summer of 1978.

  16. Mark III Containment vessel/annulus concrete design

    International Nuclear Information System (INIS)

    Chang, P.S.; Moussa, M.M.

    1981-01-01

    Recently, engineers have been considering the significant dynamic impact of safety/relief valve (S/RV) discharge loads on the containment structures, safety equipment, and piping systems in BWR type reactors. For a plant in the construction stage, extensive modifications will be made to qualify these new loads. The lower portion of the containment vessel serves as a suppression pool pressure boundary and is designed to sustain the effects of postulated loss of coolant accidents, seismic occurrences, S/RV discharge loads, and other effects. Extremely high spectral peak accelerations of the free-standing steel containment vessel can be obtained during the air dearing process of the S/RV discharge. Parametric studies indicated that a substantial reduction in response can be obtained by increasing the stiffness of the steel containment vessel in the lover area. A concrete backing configuration in the suppression pool area of Mark III Containment is proposed in this paper. A composite action is assumed between the steel containment vessel shell and the concrete section. The system is physically separated from the shield building. This approach warrants an early erection of the shield building and a late installation of piping systems in the containment vessel suppression pool area. Finite element analyses are performed by using ASHSD2 and EASE2 computer codes. The results of the analyses have shown the proposed stress criteria are satisfied. The approach pressented is justified to be a workable system for a new plant design. (orig./HP)

  17. First-Ply-Failure Performance of Composite Clamped Spherical Shells

    Science.gov (United States)

    Ghosh, A.; Chakravorty, D.

    2018-05-01

    The failure aspects of composites are available for plates, but studies of the literature on shells unveils that similar reports on them are very limited in number. The aim of this work was to investigate the first-ply-failure of industrially and aesthetically important spherical shells under uniform loadings. Apart from solving benchmark problems, numerical experiments were carried out with different variations of their parameters to obtain the first-ply-failure stresses by using the finite-element method. The load was increased in steps, and the lamina strains and stresses were put into well-established failure criteria to evaluate their first-ply-failure stress, the failed ply, the point of initiation of failure, and failure modes and tendencies. The results obtained are analyzed to extract the points of engineering significance.

  18. Ex-vivo evaluation of crab shell chitosan as absorption enhancer in ...

    African Journals Online (AJOL)

    This study was aimed at evaluating crab shell chitosan as absorption enhancer in ciprofloxacin tablet formulation using the ex-vivo model. Six batches of ciprofloxacin tablets containing varying concentrations of crab shell-derived chitosan ranging from 0 to 5% w/w at 1% w/w intervals were produced. Batch CTS-0 ...

  19. Study of dinosaur's egg shell by EPR method; Issledovaniya metodom EhPR skorlupy yaits dinozavrov

    Energy Technology Data Exchange (ETDEWEB)

    Tleuberdina, R A; Nasirov, R N

    1998-07-01

    Two varieties of calcium carbonate are defined on base of ESR spectra radiation-inducted signals containing in mollusc shell and dinosaur and ostrich egg shell; their spectral characters are studied by infrared-spectroscopy methods and X-ray analysis. Possibility of correlation between ESR signals intensity of CO{sub 2}-radical of investigated object and geological age is determined. (author)

  20. Dynamic nonlinear analysis of shells of revolution

    International Nuclear Information System (INIS)

    Von Riesemann, W.A.; Stricklin, J.A.; Haisler, W.E.

    1975-01-01

    DYNAPLAS is a program for the transient response of ring stiffened shells of revolution subjected to either asymmetric initial velocities or to asymmetric pressure loadings. Both material and geometric nonlinearities may be considered. The present version, DYNAPLAS II, began with the programs SAMMSOR and DYNASOR. As is the case for the earlier programs, a driver program, SAMMSOR III, generates the stiffness and mass matrices for the harmonics under consideration. A highly refined meridionally curved axisymmetric thin shell of revolution element is used in conjunction with beam type ring stiffeners in the circumferential direction. The shell element uses a cubic displacement function and through static condensation a basic eight degree of freedom element is generated. The shell material may be isotropic or orthotropic. DYNAPLAS II uses the 'displacement' method of analysis in which the nonlinearities are treated as pseudo loads on the right-hand side of the equations of motion. The equations are written for each Fourier harmonic used in representing the asymmetric loading components, and although the left-hand side of the equations is uncoupled, the right-hand side is coupled by the nonlinear pseudo loads. The strain displacement equations of Novozhilov are used and the incremental theory of plasticity is used with the von Mises yield condition and associated flow rule. Either isotropic work hardening or the mechanical sublayer model may be used. Strain rate effects may be included. Either the explicit central difference method or the implcit Houbolt method are available. The program has found use in the analysis of containment vessels for light water reactors

  1. Leading singularities and off-shell conformal integrals

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, James; Duhr, Claude; Eden, Burkhard; Heslop, Paul; Pennington, Jeffrey; Smirnov, Vladimir A.

    2013-08-29

    The three-loop four-point function of stress-tensor multiplets in N=4 super Yang-Mills theory contains two so far unknown, off-shell, conformal integrals, in addition to the known, ladder-type integrals. In our paper we evaluate the unknown integrals, thus obtaining the three-loop correlation function analytically. The integrals have the generic structure of rational functions multiplied by (multiple) polylogarithms. We use the idea of leading singularities to obtain the rational coefficients, the symbol — with an appropriate ansatz for its structure — as a means of characterising multiple polylogarithms, and the technique of asymptotic expansion of Feynman integrals to obtain the integrals in certain limits. The limiting behaviour uniquely fixes the symbols of the integrals, which we then lift to find the corresponding polylogarithmic functions. The final formulae are numerically confirmed. Furthermore, we develop techniques that can be applied more generally, and we illustrate this by analytically evaluating one of the integrals contributing to the same four-point function at four loops. This example shows a connection between the leading singularities and the entries of the symbol.

  2. Hydrogen and helium shell burning during white dwarf accretion

    Science.gov (United States)

    Cui, Xiao; Meng, Xiang-Cun; Han, Zhan-Wen

    2018-05-01

    Type Ia supernovae (SNe Ia) are believed to be thermonuclear explosions of carbon oxygen (CO) white dwarfs (WDs) with masses close to the Chandrasekhar mass limit. How a CO WD accretes matter and grows in mass to this limit is not well understood, hindering our understanding of SN Ia explosions and the reliability of using SNe Ia as a cosmological distance indicator. In this work, we employed the stellar evolution code MESA to simulate the accretion process of hydrogen-rich material onto a 1.0 M ⊙ CO WD at a high rate (over the Eddington limit) of 4.3 × 10‑7 M ⊙ yr‑1. The simulation demonstrates the characteristics of the double shell burning on top of the WD, with a hydrogen shell burning on top of a helium burning shell. The results show that helium shell burning is not steady (i.e. it flashes). Flashes from the helium shell are weaker than those in the case of accretion of helium-rich material onto a CO WD. The carbon to oxygen mass ratio resulting from the helium shell burning is higher than what was previously thought. Interestingly, the CO WD growing due to accretion has an outer part containing a small fraction of helium in addition to carbon and oxygen. The flashes become weaker and weaker as the accretion continues.

  3. Molluscan shell evolution with review of shell calcification hypothesis

    Czech Academy of Sciences Publication Activity Database

    Furuhashi, T.; Schwarzinger, C.; Mikšík, Ivan; Smrž, Miloslav; Beran, A.

    2009-01-01

    Roč. 154, č. 3 (2009), s. 351-371 ISSN 1096-4959 Institutional research plan: CEZ:AV0Z50110509 Keywords : mollusca * shell * biomineralization Subject RIV: CE - Biochemistry Impact factor: 1.607, year: 2009

  4. MicroShell Minimalist Shell for Xilinx Microprocessors

    Science.gov (United States)

    Werne, Thomas A.

    2011-01-01

    MicroShell is a lightweight shell environment for engineers and software developers working with embedded microprocessors in Xilinx FPGAs. (MicroShell has also been successfully ported to run on ARM Cortex-M1 microprocessors in Actel ProASIC3 FPGAs, but without project-integration support.) Micro Shell decreases the time spent performing initial tests of field-programmable gate array (FPGA) designs, simplifies running customizable one-time-only experiments, and provides a familiar-feeling command-line interface. The program comes with a collection of useful functions and enables the designer to add an unlimited number of custom commands, which are callable from the command-line. The commands are parameterizable (using the C-based command-line parameter idiom), so the designer can use one function to exercise hardware with different values. Also, since many hardware peripherals instantiated in FPGAs have reasonably simple register-mapped I/O interfaces, the engineer can edit and view hardware parameter settings at any time without stopping the processor. MicroShell comes with a set of support scripts that interface seamlessly with Xilinx's EDK tool. Adding an instance of MicroShell to a project is as simple as marking a check box in a library configuration dialog box and specifying a software project directory. The support scripts then examine the hardware design, build design-specific functions, conditionally include processor-specific functions, and complete the compilation process. For code-size constrained designs, most of the stock functionality can be excluded from the compiled library. When all of the configurable options are removed from the binary, MicroShell has an unoptimized memory footprint of about 4.8 kB and a size-optimized footprint of about 2.3 kB. Since MicroShell allows unfettered access to all processor-accessible memory locations, it is possible to perform live patching on a running system. This can be useful, for instance, if a bug is

  5. Ni(3)Si(Al)/a-SiO(x) core-shell nanoparticles: characterization, shell formation, and stability.

    Science.gov (United States)

    Pigozzi, G; Mukherji, D; Gilles, R; Barbier, B; Kostorz, G

    2006-08-28

    We have used an electrochemical selective phase dissolution method to extract nanoprecipitates of the Ni(3)Si-type intermetallic phase from two-phase Ni-Si and Ni-Si-Al alloys by dissolving the matrix phase. The extracted nanoparticles are characterized by transmission electron microscopy, energy-dispersive x-ray spectrometry, x-ray powder diffraction, and electron powder diffraction. It is found that the Ni(3)Si-type nanoparticles have a core-shell structure. The core maintains the size, the shape, and the crystal structure of the precipitates that existed in the bulk alloys, while the shell is an amorphous phase, containing only Si and O (SiO(x)). The shell forms around the precipitates during the extraction process. After annealing the nanoparticles in nitrogen at 700 °C, the tridymite phase recrystallizes within the shell, which remains partially amorphous. In contrast, on annealing in air at 1000 °C, no changes in the composition or the structure of the nanoparticles occur. It is suggested that the shell forms after dealloying of the matrix phase, where Si atoms, the main constituents of the shell, migrate to the surface of the precipitates.

  6. Hanford Double Shell Waste Tank Corrosion Studies - Final Report FY2015

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, R. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wyrwas, R. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-05-01

    During FY15, SRNL performed corrosion testing that supported Washington River Protection Solutions (WRPS) with their double shell tank (DST) integrity program. The testing investigated six concerns including, 1) the possibility of corrosion of the exterior of the secondary tank wall; 2) the effect of ammonia on vapor space corrosion (VSC) above waste simulants; 3) the determination of the minimum required nitrite and hydroxide concentrations that prevent pitting in concentrated nitrate solutions (i.e., waste buffering); 4) the susceptibility to liquid air interface (LAI) corrosion at proposed stress corrosion cracking (SCC) inhibitor concentrations; 5) the susceptibility of carbon steel to pitting in dilute solutions that contain significant quantities of chloride and sulfate; and 6) the effect of different heats of A537 carbon steel on the corrosion response. For task 1, 2, and 4, the effect of heat treating and/ or welding of the materials was also investigated.

  7. Double-shell tank system dangerous waste permit application

    International Nuclear Information System (INIS)

    1991-06-01

    This Double-Shell Tank System Dangerous Waste Permit Application should be read in conjunction with the 242-A Evaporator Dangerous Waste Permit Application and the Liquid Effluent Retention Facility Dangerous Waste Permit Application, also submitted on June 28, 1991. Information contained in the Double-Shell Tank System permit application is referenced in the other two permit applications. The Double-Shell Tank System stores and treats mixed waste received from a variety of sources on the Hanford Site. The 242-A Evaporator treats liquid mixed waste received from the double-shell tanks. The 242-A Evaporator returns a mixed-waste slurry to the double-shell tanks and generates the dilute mixed-waste stream stored in the Liquid Effluent Retention Facility. This report contains information on the following topics: Facility Description and General Provisions; Waste Characteristics; Process Information; Groundwater Monitoring; Procedures to Prevent Hazards; Contingency Plan; Personnel Training; Exposure Information Report; Waste Minimization Plan; Closure and Postclosure Requirements; Reporting and Recordkeeping; other Relevant Laws; and Certification. 150 refs., 141 figs., 118 tabs

  8. Oxidative stress and anxiety-like symptoms related to withdrawal of passive cigarette smoke in mice: beneficial effects of pecan nut shells extract, a by-product of the nut industry.

    Science.gov (United States)

    Reckziegel, P; Boufleur, N; Barcelos, R C S; Benvegnú, D M; Pase, C S; Muller, L G; Teixeira, A M; Zanella, R; Prado, A C P; Fett, R; Block, J M; Burger, M E

    2011-09-01

    The present study evaluated the role of pecan nut (Carya illinoensis) shells aqueous extract (AE) against oxidative damage induced by cigarette smoke exposure (CSE) and behavioral parameters of smoking withdrawal. Mice were passively exposed to cigarette smoke for 3 weeks (6, 10, and 14 cigarettes/day) and orally treated with AE (25 g/L). CSE induced lipid peroxidation in brain and red blood cells (RBC), increased catalase (CAT) activity in RBC, and decreased plasma ascorbic acid levels. AE prevented oxidative damage and increased antioxidant defenses of mice exposed to cigarette smoke. In addition, AE reduced the locomotor activity and anxiety symptoms induced by smoking withdrawal, and these behavioral parameters showed a positive correlation with RBC lipid peroxidation. Our results showed the beneficial effects of this by-product of the pecan industry, indicating its usefulness in smoking cessation. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Enceladus's crust as a non-uniform thin shell: I tidal deformations

    Science.gov (United States)

    Beuthe, Mikael

    2018-03-01

    The geologic activity at Enceladus's south pole remains unexplained, though tidal deformations are probably the ultimate cause. Recent gravity and libration data indicate that Enceladus's icy crust floats on a global ocean, is rather thin, and has a strongly non-uniform thickness. Tidal effects are enhanced by crustal thinning at the south pole, so that realistic models of tidal tectonics and dissipation should take into account the lateral variations of shell structure. I construct here the theory of non-uniform viscoelastic thin shells, allowing for depth-dependent rheology and large lateral variations of shell thickness and rheology. Coupling to tides yields two 2D linear partial differential equations of the fourth order on the sphere which take into account self-gravity, density stratification below the shell, and core viscoelasticity. If the shell is laterally uniform, the solution agrees with analytical formulas for tidal Love numbers; errors on displacements and stresses are less than 5% and 15%, respectively, if the thickness is less than 10% of the radius. If the shell is non-uniform, the tidal thin shell equations are solved as a system of coupled linear equations in a spherical harmonic basis. Compared to finite element models, thin shell predictions are similar for the deformations due to Enceladus's pressurized ocean, but differ for the tides of Ganymede. If Enceladus's shell is conductive with isostatic thickness variations, surface stresses are approximately inversely proportional to the local shell thickness. The radial tide is only moderately enhanced at the south pole. The combination of crustal thinning and convection below the poles can amplify south polar stresses by a factor of 10, but it cannot explain the apparent time lag between the maximum plume brightness and the opening of tiger stripes. In a second paper, I will study the impact of a non-uniform crust on tidal dissipation.

  10. Positive column of the discharge in a cylindrical shell

    International Nuclear Information System (INIS)

    Uehara, M.; Maciel, H.S.

    1991-01-01

    A Schottky type theoretical model is presented for the positive column of a discharge on a cylindric shell contained gas, with the discharge current flowing in the longitudinal direction. Some analytical results and the conclusion are presented. (L.C.J.A.). 5 refs

  11. Mixer pump test plan for double shell tank AZ-101

    International Nuclear Information System (INIS)

    STAEHR, T.W.

    1999-01-01

    Mixer pump systems have been chosen as the method for retrieval of tank wastes contained in double shell tanks at Hanford. This document describes the plan for testing and demonstrating the ability of two 300 hp mixer pumps to mobilize waste in tank AZ-101. The mixer pumps, equipment and instrumentation to monitor the test were installed by Project W-151

  12. Au@Ag core-shell nanocubes with finely tuned and well-controlled sizes, shell thicknesses, and optical properties.

    Science.gov (United States)

    Ma, Yanyun; Li, Weiyang; Cho, Eun Chul; Li, Zhiyuan; Yu, Taekyung; Zeng, Jie; Xie, Zhaoxiong; Xia, Younan

    2010-11-23

    This paper describes a facile method for generating Au@Ag core-shell nanocubes with edge lengths controllable in the range of 13.4-50 nm. The synthesis involved the use of single-crystal, spherical Au nanocrystals of 11 nm in size as the seeds in an aqueous system, with ascorbic acid serving as the reductant and cetyltrimethylammonium chloride (CTAC) as the capping agent. The thickness of the Ag shells could be finely tuned from 1.2 to 20 nm by varying the ratio of AgNO(3) precursor to Au seeds. We also investigated the growth mechanism by examining the effects of seeds (capped by CTAC or cetyltrimethylammonium bromide(CTAB)) and capping agent (CTAC vs CTAB) on both size and shape of the resultant core-shell nanocrystals. Our results clearly indicate that CTAC worked much better than CTAB as a capping agent in both the syntheses of Au seeds and Au@Ag core-shell nanocubes. We further studied the localized surface plasmon resonance properties of the Au@Ag nanocubes as a function of the Ag shell thickness. By comparing with the extinction spectra obtained from theoretical calculations, we derived a critical value of ca. 3 nm for the shell thickness at which the plasmon excitation of the Au cores would be completely screened by the Ag shells. Moreover, these Au@Ag core-shell nanocubes could be converted into Au-based hollow nanostructures containing the original Au seeds in the interiors through a galvanic replacement reaction.

  13. Instant Windows PowerShell

    CERN Document Server

    Menon, Vinith

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A practical, hands-on tutorial approach that explores the concepts of PowerShell in a friendly manner, taking an adhoc approach to each topic.If you are an administrator who is new to PowerShell or are looking to get a good grounding in these new features, this book is ideal for you. It's assumed that you will have some experience in PowerShell and Windows Server, as well being familiar with the PowerShell command-line.

  14. Patterning of the turtle shell.

    Science.gov (United States)

    Moustakas-Verho, Jacqueline E; Cebra-Thomas, Judith; Gilbert, Scott F

    2017-08-01

    Interest in the origin and evolution of the turtle shell has resulted in a most unlikely clade becoming an important research group for investigating morphological diversity in developmental biology. Many turtles generate a two-component shell that nearly surrounds the body in a bony exoskeleton. The ectoderm covering the shell produces epidermal scutes that form a phylogenetically stable pattern. In some lineages, the bones of the shell and their ectodermal covering become reduced or lost, and this is generally associated with different ecological habits. The similarity and diversity of turtles allows research into how changes in development create evolutionary novelty, interacting modules, and adaptive physiology and anatomy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Smart construction of polyaniline shell on cobalt oxides as integrated core-shell arrays for enhanced lithium ion batteries

    International Nuclear Information System (INIS)

    Qi, Meili; Xie, Dong; Zhong, Yu; Chen, Minghua; Xia, Xinhui

    2017-01-01

    Smart construction of advanced anode materials is extremely critical to develop high-performance lithium ion batteries. In this work, we have reported a facile strategy for fabricating Co 3 O 4 /polyaniline (PANI) core–shell arrays (CSAs) by chemical bath deposition (CBD) + electrodeposition methods Electrodeposited PANI shell is intimately decorated on the CBD-Co 3 O 4 nanorods forming composite CSAs. Highly conductive network and stress buffer layer are achieved with the aid of tailored PANI shell. Due to these advantages above, the designed Co 3 O 4 /PANI CSA S exhibit good electrochemical performance with higher reversible capacity (787 mAh g −1 ) and better cycle stability than the unmodified Co 3 O 4 counterpart. Our results show a new way for preparing advanced inorganic-organic composite electrodes for electrochemical energy storage.

  16. Shell-side single-phase flows and heat transfer in shell-and-tube heat exchangers, 4

    International Nuclear Information System (INIS)

    Matsushita, Hitoshi; Nakayama, Wataru; Yanagida, Takehiko; Kudo, Akio.

    1987-01-01

    Refering to the results of our previous works, a procedure for estimating the distribution of heat flux in shell-and-tube heat exchangers is proposed. The steam generator used in a high temperature reactor plant is taken up as the subject of analysis. Particular attention is paid to critical conditions for burnout and the strength of material in high temperature conditions. It is found that the distribution of heat transfer coefficient on the shell-side is crucial to the occurrence of burnout in the tubes. The use of a relatively large inlet nozzle (the ratio of its diameter to the shell is roughly half) is recommended. A low level of thermal stress on heat transfer tubes can be realized by the adoption of a relatively thin 2.25 Cr-1 Mo Steel tube wall of 1.24 mm thickness. (author)

  17. 40 Years of Shell Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Shell has been using scenario planning for four decades. During that time these scenarios have helped the company and governments across the world to make better strategic choices. Scenarios provide lenses that help see future prospects more clearly, make richer judgments and be more sensitive to uncertainties. Discover how the Shell Scenarios team has helped guide decision makers at major moments in history and get a peek at the team future focus, including the intricate relationship between energy, water and food.

  18. Model experiment and numerical simulation of drop impact response of multilayer-combinational container

    International Nuclear Information System (INIS)

    Xie Ruoze; Zhong Weizhou; Wan Qiang; Huang Xicheng; Zhang Fangju

    2015-01-01

    The drop impact process of multilayer-combinational container was simulated experimentally using a gas gun, and the normal impact and oblique impact of scaled models were tested. The experiments of scaled models were simulated numerically, and the stress distribution and plastic deformation in the tested structures during collision process were obtained. The results were compared with the experiment data. It was shown that the impact work mainly converted into plastic work due to the plastic deformation of the cushion wood and the plastic hinge in the buckled steel shell. The plastic deformation mainly happened at the collided end of the scaled models, and there was no plastic deformation found far from the collided end. The compressive stress-strain curve of the wood in texture direction can be used to simulate numerically the drop impact process of multilayer-combinational container. (authors)

  19. Collapsing shells and black holes: a quantum analysis

    Science.gov (United States)

    Leal, P.; Bernardini, A. E.; Bertolami, O.

    2018-06-01

    The quantization of a spherically symmetric null shells is performed and extended to the framework of phase-space noncommutative (NC) quantum mechanics. This shell is considered to be inside a black hole event horizon. The encountered properties are investigated making use of the Israel junction conditions on the shell, considering that it is the boundary between two spherically symmetric spacetimes. Using this method, and considering two different Kantowski–Sachs spacetimes as a representation for the Schwarzschild spacetime, the relevant quantities on the shell are computed, such as its stress-energy tensor and the action for the whole spacetime. From the obtained action, the Wheeler–deWitt equation is deduced in order to provide the quantum framework for the system. Solutions for the wave function of the system are found on both the commutative and NC scenarios. It is shown that, on the commutative version, the wave function has a purely oscillatory behavior in the interior of the shell. In the NC setting, it is shown that the wave function vanishes at the singularity, as well as, at the event horizon of the black hole.

  20. Molecular cloning and expression of a transformation-sensitive human protein containing the TPR motif and sharing identity to the stress-inducible yeast protein STI1

    DEFF Research Database (Denmark)

    Honoré, B; Leffers, H; Madsen, Peder

    1992-01-01

    in families of fungal proteins required for mitosis and RNA synthesis. In particular, the protein has 42% amino acid sequence identity to STI1, a stress-inducible mediator of the heat shock response in Saccharomyces cerevisiae. Northern blot analysis indicated that the 3521 mRNA is up-regulated in several...

  1. Comparative effectiveness of Pseudomonas and Serratia sp. containing ACC-deaminase for improving growth and yield of wheat (Triticum aestivum L.) under salt-stressed conditions.

    Science.gov (United States)

    Zahir, Zahir Ahmad; Ghani, Usman; Naveed, Muhammad; Nadeem, Sajid Mahmood; Asghar, Hafiz Naeem

    2009-05-01

    Ethylene synthesis is accelerated in response to various environmental stresses like salinity. Ten rhizobacterial strains isolated from wheat rhizosphere taken from different salt affected areas were screened for growth promotion of wheat under axenic conditions at 1, 5, 10 and 15 dS m(-1). Three strains, i.e., Pseudomonas putida (N21), Pseudomonas aeruginosa (N39) and Serratia proteamaculans (M35) showing promising performance under axenic conditions were selected for a pot trial at 1.63 (original), 5, 10 and 15 dS m(-1). Results showed that inoculation was effective even in the presence of higher salinity levels. P. putida was the most efficient strain compared to the other strains and significantly increased the plant height, root length, grain yield, 100-grain weight and straw yield up to 52, 60, 76, 19 and 67%, respectively, over uninoculated control at 15 dS m(-1). Similarly, chlorophyll content and K(+)/Na(+) of leaves also increased by P. putida over control. It is highly likely that under salinity stress, 1-aminocyclopropane-1-carboxylic acid-deaminase activity of these microbial strains might have caused reduction in the synthesis of stress (salt)-induced inhibitory levels of ethylene. The results suggested that these strains could be employed for salinity tolerance in wheat; however, P. putida may have better prospects in stress alleviation/reduction.

  2. Failure internal pressure of spherical steel containments

    International Nuclear Information System (INIS)

    Sanchez Sarmiento, G.

    1985-01-01

    An application of the British CEGB's R6 Failure Assessment Approach to the determination of failure internal pressure of nuclear power plant spherical steel containments is presented. The presence of hypothetical cracks both in the base metal and in the welding material of the containment, with geometrical idealizations according to the ASME Boiler and Pressure Vessel Code (Section XI), was taken into account in order to analyze the sensitivity of the failure assessment with the values of the material fracture properties. Calculations of the elastoplastic collapse load have been performed by means of the Finite Element System SAMCEF. The clean axisymmetric shell (neglecting the influence of nozzles and minor irregularities) and two major penetrations (personnel and emergency locks) have been taken separately into account. Large-strain elastoplastic behaviour of the material was considered in the Code, using lower bounds of true stress-true strain relations obtained by testing a collection of tensile specimens. Assuming the presence of cracks in non-perturbed regions, the reserve factor for test pressure and the failure internal pressure have been determined as a function of the flaw depth. (orig.)

  3. Stability of the Regular Hayward Thin-Shell Wormholes

    Directory of Open Access Journals (Sweden)

    M. Sharif

    2016-01-01

    Full Text Available The aim of this paper is to construct regular Hayward thin-shell wormholes and analyze their stability. We adopt Israel formalism to calculate surface stresses of the shell and check the null and weak energy conditions for the constructed wormholes. It is found that the stress-energy tensor components violate the null and weak energy conditions leading to the presence of exotic matter at the throat. We analyze the attractive and repulsive characteristics of wormholes corresponding to ar>0 and ar<0, respectively. We also explore stability conditions for the existence of traversable thin-shell wormholes with arbitrarily small amount of fluid describing cosmic expansion. We find that the space-time has nonphysical regions which give rise to event horizon for 0shell wormholes.

  4. Notes from the Nordic Spring Symposium on atomic inner shell phenomena

    International Nuclear Information System (INIS)

    Hansteen, J.M.; Gundersen, R.

    1978-01-01

    The purpose of the symposium was to bring together scientists from those various fields of physics that involve atomic inner shell processes. Vol. 2 contains the submitted complete lecture notes in chronological order. (JIW)

  5. Creep buckling of shells

    International Nuclear Information System (INIS)

    Stone, C.M.; Nickell, R.E.

    1977-01-01

    Because of the characteristics of LMFBR primary piping components (thin-walled, low pressure, high temperature), the designer must guard against creep buckling as a potential failure mode for certain critical regions, such as elbows, where structural flexibility and inelastic response may combine to concentrate deformation and cause instability. The ASME Boiler and Pressure Vessel Code, through its elevated temperature Code Case 1592 (Section III, Division 1) provides design rules for Class 1 components aimed at preventing creep buckling during the design life. A similar set of rules is being developed for Class 2 and 3 components at this time. One of the original concepts behind the creep buckling rules was that the variability in creep properties (especially due to the effects of prior heat treatment), the uncertainty about initial imperfections, and the lack of confirmed accuracy of design analysis meant that conservatism would be difficult to assure. As a result, a factor of ten on service life was required (i.e. analysis must show that, under service conditions that extrapolate the life of the component by ten times, creep buckling does not occur). Two obvious problems with this approach are that: first, the creep behavior must also be extrapolated (since most creep experiments are terminated at a small fraction of the design life, extrapolation of creep data is already an issue, irrespective of the creep buckling question); second the nonlinear creep analysis, which is very nearly prohibitively expensive for design life histograms, becomes even more costly. Analytical results for an aluminum cylindrical shell subjected to axial loads at elevated temperatures are used to examine the supposed equivalence of two types of time-dependent buckling safety factors - a factor of ten on service life and a factor of 1.5 on loading

  6. Reinforced concrete containment structures in high seismic zones

    International Nuclear Information System (INIS)

    Aziz, T.S.

    1977-01-01

    A new structural concept for reinforced concrete containment structures at sites where earthquake ground motions in terms of the Safe Shutdown Earthquake (SSE) exceeds 0.3 g is presented. The structural concept is based on: (1) an inner steel-lined concrete shell which houses the reactor and provides shielding and containment in the event of loss of coolant accident; (2) an outer annular concrete shell structure which houses auxiliary reactor equipment and safeguards systems. These shell structures are supported on a common foundation mat which is embedded in the subgrade. Under stipulated earthquake conditions the two shell structures interact to resist lateral inertia forces. Thus the annular structure which is not a pressure boundary acts as a lateral support for the inner containment shell. The concept is practical, economically feasible and new to practice. (Auth.)

  7. Not a mystery. Inner containment of the pressurized water reactor (EPR trademark type)

    Energy Technology Data Exchange (ETDEWEB)

    Ostermann, Dirk; Wienand, Burkhard; Krumb, Christian [AREVA NP GmbH (Germany)

    2012-11-01

    The containment of the advanced pressurized water reactor EPR trademark type is developed on the basis of the French nuclear power plant operational experience and consists of - The reinforced outer containment structure, designed to withstand external hazards (e.g. APC), - The pre-stressed inner containment structure, designed to bear the loads resulting from internal hazards (LOCA), - The steel liner, designed to provide leak tightness resulting from internal hazards. The main advantage of the pre-stressed inner containment design is that the structure remains in linear-elastic behavior during the whole life-time. Even in case of postulated design accidents (LOCA) concrete tensile strains are strongly limited. Due to pre-stressing the concrete structure remains practically free of cracks. Due to pre-stressing the leak tightness ensuring steel liner, embedded into the inner concrete shell, is exposed to more favorable compression loads. In addition to detailed calculations several test programs have been performed to verify and confirm the predicted behavior in normal operation and in accident condition. (orig.)

  8. Irradiation creep and growth behavior of Zircaloy-4 inner shell of HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jong-Ha; Cho, Yeong-Garp; Kim, Jong-In [Korea Atomic Energy Research Inst., Daejeon (Korea, Republic of)

    2012-03-15

    The inner shell of the reflector vessel of HANARO was made of Zircaloy-4 rolled plate. Zircaloy-4 rolled plate shows highly anisotropic behavior by fast neutron irradiation. This paper describes the analysis method for the irradiation induced creep and growth of the inner shell of HANARO. The anisotropic irradiation creep behavior was modeled as uniaxial strain-hardening power law modified by Hill's stress potential and the anisotropic irradiation growth was modeled by using volumetric swelling with anisotropic strain rate. In this study, the irradiation induced creep and growth behavior of the inner shell of the HANARO reflector vessel was re-evaluated. The rolling direction, the fast neutron flux, and the boundary conditions were applied with the same conditions as the actual inner shell. Analysis results show that deformation of the inner shell due to irradiation does not raise any problem for the lifetime of HANARO. (author)

  9. Arabidopsis thaliana Contains Both Ni2+ and Zn2+ Dependent Glyoxalase I Enzymes and Ectopic Expression of the Latter Contributes More towards Abiotic Stress Tolerance in E. coli.

    Directory of Open Access Journals (Sweden)

    Muskan Jain

    Full Text Available The glyoxalase pathway is ubiquitously found in all the organisms ranging from prokaryotes to eukaryotes. It acts as a major pathway for detoxification of methylglyoxal (MG, which deleteriously affects the biological system in stress conditions. The first important enzyme of this system is Glyoxalase I (GLYI. It is a metalloenzyme which requires divalent metal ions for its activity. This divalent metal ion can be either Zn2+ as found in most of eukaryotes or Ni2+ as seen in prokaryotes. In the present study, we have found three active GLYI enzymes (AtGLYI2, AtGLYI3 and AtGLYI6 belonging to different metal activation classes coexisting in Arabidopsis thaliana. These enzymes have been found to efficiently complement the GLYI yeast mutants. These three enzymes have been characterized in terms of their activity, metal dependency, kinetic parameters and their role in conferring tolerance to multiple abiotic stresses in E. coli and yeast. AtGLYI2 was found to be Zn2+ dependent whereas AtGLYI3 and AtGLYI6 were Ni2+ dependent. Enzyme activity of Zn2+ dependent enzyme, AtGLYI2, was observed to be exceptionally high (~250-670 fold as compared to Ni2+ dependent enzymes, AtGLYI3 and AtGLYI6. The activity of these GLYI enzymes correlated well to their role in stress tolerance. Heterologous expression of these enzymes in E. coli led to better tolerance against various stress conditions. This is the first report of a higher eukaryotic species having multiple active GLYI enzymes belonging to different metal activation classes.

  10. PDX vacuum vessel stress analysis

    International Nuclear Information System (INIS)

    Nikodem, Z.D.

    1975-01-01

    A stress analysis of PDX vacuum vessel is described and the summary of results is presented. The vacuum vessel is treated as a toroidal shell of revolution subjected to an internal vacuum. The critical buckling pressure is calculated. The effects of the geometrical discontinuity at the juncture of toroidal shell head and cylindrical outside wall, and the concavity of the cylindrical wall are examined. An effect of the poloidal field coil supports and the vessel outside supports on the stress distribution in the vacuum vessel is determined. A method evaluating the influence of circular ports in the vessel wall on the stress level in the vessel is outlined

  11. Nuclear reactor installation with outer shell enclosing a primary pressure vessel

    International Nuclear Information System (INIS)

    1975-01-01

    The high temperature nuclear reactor installation described includes a fluid cooled nuclear heat source, a primary pressure vessel and outer shell around the primary pressure vessel and acting as a protection for it against outside projectiles. A floor is provided internally dividing the outside shell into two upper and lower sections and an inside wall dividing the lower section into one part containing the primary pressure vessel and a second part, both made pressure tight with respect to each other and with the outside shell and forming with the latter a secondary means of containment [fr

  12. Valosin-containing protein VCP/p97 is essential for the intracellular development of Leishmania and its survival under heat stress.

    Science.gov (United States)

    Aguiar, Bruno G; Padmanabhan, Prasad K; Dumas, Carole; Papadopoulou, Barbara

    2018-06-12

    VCP/p97/Cdc48 is one of the best-characterized type II cytosolic AAA+ ATPases most known for their role in ubiquitin-dependent protein quality control. Here, we provide functional insights into the role of the Leishmania VCP/p97 homolog (LiVCP) in the parasite intracellular development. We demonstrate that although LiVCP is an essential gene, L. infantum promastigotes can grow with less VCP. In contrast, growth of axenic and intracellular amastigotes is dramatically affected upon decreased LiVCP levels in heterozygous and temperature sensitive LiVCP mutants or the expression of dominant negative mutants known to specifically target the second conserved VCP ATPase domain, a major contributor of the VCP overall ATPase activity. Interestingly, these VCP mutants are also unable to survive heat stress and a temperature sensitive VCP mutant is defective in amastigote growth. Consistent with LiVCP's essential function in amastigotes, LiVCP mRNA undergoes 3'UTR-mediated developmental regulation, resulting in higher VCP expression in amastigotes. Furthermore, we show that parasite mutant lines expressing lower VCP levels or dominant negative VCP forms exhibit high accumulation of polyubiquitinated proteins and increased sensitivity to proteotoxic stress, supporting the ubiquitin-selective chaperone function of LiVCP. Together, these results emphasize the crucial role LiVCP plays under heat stress and during the parasite intracellular development. This article is protected by copyright. All rights reserved.

  13. Antidepressant-like effect of a new selenium-containing compound is accompanied by a reduction of neuroinflammation and oxidative stress in lipopolysaccharide-challenged mice.

    Science.gov (United States)

    Casaril, Angela M; Domingues, Micaela; Fronza, Mariana; Vieira, Beatriz; Begnini, Karine; Lenardão, Eder J; Seixas, Fabiana K; Collares, Tiago; Nogueira, Cristina W; Savegnago, Lucielli

    2017-09-01

    Organoselenium compounds and indoles have gained attention due to their wide range of pharmacological properties. Depression is a recurrent and disabling psychiatric illness and current evidences support that oxidative stress and neuroinflammation are mechanisms underlying the pathophysiology of this psychiatric condition. Here, we evaluated the effect of 3-((4-chlorophenyl)selanyl)-1-methyl-1H-indole (CMI) in lipopolysaccharide (LPS)-induced depressive-like behaviour, neuroinflammation and oxidative stress in male mice. CMI pre-treatment (20 and 50 mg/kg, intragastrically) significantly attenuated LPS (0.83 mg/kg, intraperitoneally)-induced depressive-like behaviour in mice by reducing the immobility time in the tail suspension test (TST) and forced swimming test (FST). CMI pre-treatment ameliorated LPS-induced neuroinflammation by reducing the levels of interleukin (IL)-1β, IL-4 and IL-6 in the hippocampus and prefrontal cortex, as well as markers of oxidative damage. Additionally, we investigated the toxicological effects of CMI (200 mg/kg, i.g.) in the liver, kidney and brain through determination of the activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), δ-aminolevulinate dehydratase (δ-ALA-D) and creatinine levels. These biomarkers were not modified, indicating the possible absence of neuro-, hepato- and nephrotoxic effects. Our results suggest that CMI could be a therapeutic approach for the treatment of depression and other neuropsychiatric disorders associated with inflammation and oxidative stress.

  14. Many-body forces in nuclear shell-model

    International Nuclear Information System (INIS)

    Rath, P.K.

    1985-01-01

    In the microscopic derivation of the effective Hamiltonian for the nuclear shell model many-body forces between the valence nucleons occur. These many-body forces can be discriminated in ''real'' many-body forces, which can be related to mesonic and internal degrees of freedom of the nucleons, and ''effective'' many-body forces, which arise by the confinement of the nucleonic Hilbert space to the finite-dimension shell-model space. In the present thesis the influences of such three-body forces on the spectra of sd-shell nuclei are studied. For this the two common techniques for shell-model calculations (Oak Ridge-Rochester and Glasgow representation) are extended in such way that a general three-body term in the Hamiltonian can be regarded. The studies show that the repulsive contributions of the considered three-nucleon forces become more important with increasing number of valence nucleons. By this the particle-number dependence of empirical two-nucleon forces can be qualitatively explained. A special kind of effective many-body force occurs in the folded diagram expansion of the energy-dependent effective Hamiltonian for the shell model. Thereby it is shown that the contributions of the folded diagrams with three nucleons are just as important as those with two nucleons. Thus it is to be suspected that the folded diagram expansion contains many-particle terms with arbitrary particle number. The present studies however show that four nucleon effects are neglegible so that the folded diagram expansion can be confined to two- and three-particle terms. In shell-model calculations which extend over several main shells the influences of the spurious center-of-mass motion must be regarded. A procedure is discussed by which these spurious degrees of freedom can be exactly separated. (orig.) [de

  15. Passive cooling containment study

    International Nuclear Information System (INIS)

    Shin, J.J.; Iotti, R.C.; Wright, R.F.

    1993-01-01

    Pressure and temperature transients of nuclear reactor containment following postulated loss of coolant accident with a coincident station blackout due to total loss of all alternating current power are studied analytically and experimentally for the full scale NPR (New Production Reactor). All the reactor and containment cooling under this condition would rely on the passive cooling system which removes reactor decay heat and provides emergency core and containment cooling. Containment passive cooling for this study takes place in the annulus between containment steel shell and concrete shield building by natural convection air flow and thermal radiation. Various heat transfer coefficients inside annular air space were investigated by running the modified CONTEMPT code CONTEMPT-NPR. In order to verify proper heat transfer coefficient, temperature, heat flux, and velocity profiles were measured inside annular air space of the test facility which is a 24 foot (7.3m) high, steam heated inner cylinder of three foot (.91m) diameter and five and half foot (1.7m) diameter outer cylinder. Comparison of CONTEMPT-NPR and WGOTHIC was done for reduced scale NPR

  16. Natural draft cooling tower with shell disconnected from the substructure

    International Nuclear Information System (INIS)

    Diver, Marius

    1982-01-01

    The aim of this paper is the analysis of results of a research done by Electricite de France, concerning a new type of cooling tower. The traditional structure (i.e. a hyperbolic shell supported by X shaped or diagonal columns) is replaced by two independent structures: the shell, becoming a self-contained structure, the lower rim being stiffened by an annular beam; the substructure, resting on the soil. This new type of cooling tower has an improved thermal performance due to the increase of the area of air entrance. Bearing pads are provided between the lower ring beam of the shell and the substructure. Any differential settlement can be coped with by jacking. The water distribution structure can be laid out so as to benefit from advantages offered by the presence of the stiff ring and columns of the substructure [fr

  17. Acoustic resonances in two-dimensional radial sonic crystal shells

    Energy Technology Data Exchange (ETDEWEB)

    Torrent, Daniel; Sanchez-Dehesa, Jose, E-mail: jsdehesa@upvnet.upv.e [Wave Phenomena Group, Departamento de Ingenieria Electronica, Universidad Politecnica de Valencia, C/Camino de Vera s.n., E-46022 Valencia (Spain)

    2010-07-15

    Radial sonic crystals (RSC) are fluidlike structures infinitely periodic along the radial direction that verify the Bloch theorem and are possible only if certain specially designed acoustic metamaterials with mass density anisotropy can be engineered (see Torrent and Sanchez-Dehesa 2009 Phys. Rev. Lett. 103 064301). A comprehensive analysis of two-dimensional (2D) RSC shells is reported here. A given shell is in fact a circular slab with a central cavity. These finite crystal structures contain Fabry-Perot-like resonances and modes strongly localized at the central cavity. Semi-analytical expressions are developed to obtain the quality factors of the different resonances, their symmetry features and their excitation properties. The results reported here are completely general and can be extended to equivalent 3D spherical shells and to their photonic counterparts.

  18. The homogeneous boundary value problem of the thick spherical shell

    International Nuclear Information System (INIS)

    Linder, F.

    1975-01-01

    With the aim to solve boundary value problems in the same manner as it is attained at thin shell theory (Superposition of Membrane solution to solution of boundary values), one has to search solutions of the equations of equilibrium of the three dimensional thick shell which produce tensions at the cut edge and are zero on the whole shell surface inside and outside. This problem was solved with the premissions of the linear theory of Elasticity. The gained solution is exact and contains the symmetric and non-symmetric behaviour and is described in relatively short analytical expressions for the deformations and tensions, after the problem of the coupled system had been solved. The static condition of the two surfaces (zero tension) leads to a homogeneous system of complex equations with the index of the Legendre spherical function as Eigenvalue. One symmetrical case is calculated numerically and is compared with the method of finite elements. This comparison results in good accordance. (Auth.)

  19. Surface energy effect on free vibration of nano-sized piezoelectric double-shell structures

    Science.gov (United States)

    Fang, Xue-Qian; Zhu, Chang-Song; Liu, Jin-Xi; Liu, Xiang-Lin

    2018-01-01

    Combining Goldenveizer-Novozhilov shell theory, thin plate theory and electro-elastic surface theory, the size-dependent vibration of nano-sized piezoelectric double-shell structures under simply supported boundary condition is presented, and the surface energy effect on the natural frequencies is discussed. The displacement components of the cylindrical nano-shells and annular nano-plates are expanded as the superposition of standard Fourier series based on Hamilton's principle. The total stresses with consideration of surface energy effect are derived, and the total energy function is obtained by using Rayleigh-Ritz energy method. The free vibration equation is solved, and the natural frequency is analyzed. In numerical examples, it is found that the surface elastic constant, piezoelectric constant and surface residual stress show different effects on the natural frequencies. The effect of surface piezoelectric constant is the maximum. The effect of dimensions of the double-shell under different surface material properties is also examined.

  20. The effect of creep ratchetting on thin shells

    International Nuclear Information System (INIS)

    Hibbeler, R.C.; Wang, P.Y.

    1975-01-01

    The behavior of thin shells, in particular, cylindrical and spherical shells, which are subjected to a long-time cyclic thermal gradient is discussed. Like many reactor components (shells) which are subjected to start-up and shut-down conditions, provided the temperature is high enough, the shell will exhibit a progressive growth with each cycle of temperature. This phenomena is often referred to as ratchetting and is caused by inelastic strains developed by creep. Although the thermal stress distribution is biaxial it is possible to represent the material behavior using a simple uniaxial-stress model. Assuming thermal stress interaction occurs, the equations which determine the solution of the strain growth and stress per cycle are presented. The flexibility of the analysis provides a means for including the effects of an arbitrary temperature-cycle time and temperature dependence of material properties. A step temperature variation is considered. During each part of the temperature cycle it is necessary to satisfy the equilibrium and compatibility conditions for the model. At any instant, the total strain will depend upon elastic, thermal, and creep strain components in addition to prior inelastic creep strains accumulated during previous temperature cycles. Accounting for all these conditions, the relations describing the behavior of the material can be determined during an arbitrary jth cycle of temperature. In particular, the cases of material properties are considered which are used for reactor components. Where possible, a closed form solution is given for appropriate values of the creep law exponents n and m. For the general case, an algorithm for the computer-solution to the problem is given. Using the general solution, the analysis appears to offer a suitable compromise between accurate behavior description and analytical complexity

  1. Characterizing haploinsufficiency of SHELL gene to improve fruit form prediction in introgressive hybrids of oil palm.

    Science.gov (United States)

    Teh, Chee-Keng; Muaz, Siti Dalila; Tangaya, Praveena; Fong, Po-Yee; Ong, Ai-Ling; Mayes, Sean; Chew, Fook-Tim; Kulaveerasingam, Harikrishna; Appleton, David

    2017-06-08

    The fundamental trait in selective breeding of oil palm (Eleais guineensis Jacq.) is the shell thickness surrounding the kernel. The monogenic shell thickness is inversely correlated to mesocarp thickness, where the crude palm oil accumulates. Commercial thin-shelled tenera derived from thick-shelled dura × shell-less pisifera generally contain 30% higher oil per bunch. Two mutations, sh MPOB (M1) and sh AVROS (M2) in the SHELL gene - a type II MADS-box transcription factor mainly present in AVROS and Nigerian origins, were reported to be responsible for different fruit forms. In this study, we have tested 1,339 samples maintained in Sime Darby Plantation using both mutations. Five genotype-phenotype discrepancies and eight controls were then re-tested with all five reported mutations (sh AVROS , sh MPOB , sh MPOB2 , sh MPOB3 and sh MPOB4 ) within the same gene. The integration of genotypic data, pedigree records and shell formation model further explained the haploinsufficiency effect on the SHELL gene with different number of functional copies. Some rare mutations were also identified, suggesting a need to further confirm the existence of cis-compound mutations in the gene. With this, the prediction accuracy of fruit forms can be further improved, especially in introgressive hybrids of oil palm. Understanding causative variant segregation is extremely important, even for monogenic traits such as shell thickness in oil palm.

  2. Formulas for determination of fundamental periods of cylindrical shells in contact with liquid

    International Nuclear Information System (INIS)

    Mikami, Takashi; Yoshimura, Jin

    1990-01-01

    The fundamental period of a cylindrical shell in contact with liquid is probably the first item of interest in the dynamic analysis. This paper presents simple practical formulas for estimating the fundamental periods of the cantilever shells in beam-type (n=1) motion. The formulas are obtained by using Dunkerley's approximation in combination with the collocation method developed in the authors' past work and by considering both the shell mass and the liquid mass. The formulas are applicable to the following types of shells: (1) the liquid is contained within the shell; (2) the shell is submerged in the liquid; and (3) both sides of the shell are in contact with the liquid. A comparison with other solutions suggests that the proposed formulas provide satisfactory accuracy for a wide range of shells. In addition, the formulas presented are useful not only for a better understanding of the vibration characteristics of the shell but also available for a check on the numerical methods. (author)

  3. Foam shell project: Progress report

    International Nuclear Information System (INIS)

    Overturf, G.; Reibold, B.; Cook, B.; Schroen-Carey, D.

    1994-01-01

    The authors report on their work to produce a foam shell target for two possible applications: (1) as liquid-layered cryogenic target on Omega Upgrade, and (2) as a back-up design for the NIF. This target consists of a roughly 1 mm diameter and 100 μm thick spherical low-density foam shell surrounding a central void. The foam will be slightly overfilled with liquid D 2 or DT, the overfilled excess being symmetrically distributed on the inside of the shell and supported by thermal gradient techniques. The outside of the foam is overcoated with full density polymer which must be topologically smooth. The technology for manufacturing this style of foam shell involves microencapsulation techniques and has been developed by the Japanese at ILE. Their goal is to determine whether this technology can be successfully adapted to meet US ICF objectives. To this end a program of foam shell development has been initiated at LLNL in collaboration with both the General Atomics DOE Target Fabrication Contract Corporation and the Target Fabrication Group at LLE

  4. The evolution of mollusc shells.

    Science.gov (United States)

    McDougall, Carmel; Degnan, Bernard M

    2018-05-01

    Molluscan shells are externally fabricated by specialized epithelial cells on the dorsal mantle. Although a conserved set of regulatory genes appears to underlie specification of mantle progenitor cells, the genes that contribute to the formation of the mature shell are incredibly diverse. Recent comparative analyses of mantle transcriptomes and shell proteomes of gastropods and bivalves are consistent with shell diversity being underpinned by a rapidly evolving mantle secretome (suite of genes expressed in the mantle that encode secreted proteins) that is the product of (a) high rates of gene co-option into and loss from the mantle gene regulatory network, and (b) the rapid evolution of coding sequences, particular those encoding repetitive low complexity domains. Outside a few conserved genes, such as carbonic anhydrase, a so-called "biomineralization toolkit" has yet to be discovered. Despite this, a common suite of protein domains, which are often associated with the extracellular matrix and immunity, appear to have been independently and often uniquely co-opted into the mantle secretomes of different species. The evolvability of the mantle secretome provides a molecular explanation for the evolution and diversity of molluscan shells. These genomic processes are likely to underlie the evolution of other animal biominerals, including coral and echinoderm skeletons. This article is categorized under: Comparative Development and Evolution > Regulation of Organ Diversity Comparative Development and Evolution > Evolutionary Novelties. © 2018 Wiley Periodicals, Inc.

  5. Core-Shell-Corona Micelles with a Responsive Shell.

    Science.gov (United States)

    Gohy, Jean-François; Willet, Nicolas; Varshney, Sunil; Zhang, Jian-Xin; Jérôme, Robert

    2001-09-03

    A reactor for the synthesis of gold nanoparticles is one of the uses of a poly(styrene)-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) triblock copolymer (PS-b-P2VP-b-PEO) which forms core-shell-corona micelles in water. Very low polydispersity spherical micelles are observed that consist of a PS core surrounded by a pH-sensitive P2VP shell and a corona of PEO chains end-capped by a hydroxyl group. The corona can act as a site for attaching responsive or sensing molecules. © 2001 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.

  6. Study Added of Waste Chicken Egg Shell in Soils

    Directory of Open Access Journals (Sweden)

    Keng Wong Irwan Lie

    2016-01-01

    Full Text Available Soil is the foundation of structure or construction that will receive the load transfer through to foundation. If the soil has a carrying capacity of small and cannot withstand the load transfer can result in the failure of construction. If the soil has a carrying capacity of small ground it is necessary to stabilize or improve the soil so that an increase in the carrying capacity of the land so that it can be used for construction. One material is commonly used for soil stabilization with the addition of lime. Waste chicken egg shell is waste that is still rarely used, the results of research [1], states that composition egg shell broadly consists of water (1,6% and dry material (98,4%. The total dry ingredients are there, in shell eggs contained mineral elements (95,1% and protein (3,3%. Based on the existing mineral composition, then the egg shells are composed of crystalline CaCO3 (98,43%, MgCO3 (0,84% and Ca3(PO42 (0,75%. This research was done by adding powdered chicken egg shell waste in clay with a composition of 5%, 7,5%, 10% and 14% with physical properties test and soil compaction test.

  7. Study of shrimp shell derivatives for treating of low-level radioactive liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Hayeripour, S. [Tonkabon Islamic Azad Univ., Tonkabon (Iran, Islamic Republic of). College of the Environment; Malmasi, S. [North Tehran Islamic Azad Univ., Tehran (Iran, Islamic Republic of). College of the Environment

    2006-07-01

    Chitin derivatives can be used to treat liquid wastes that include heavy metals of radionuclides. In this study, 4 types of chitin derivatives from shrimp shell waste were investigated for their potential in decontaminating and treating low-level radioactive liquid waste (LLW). The adsorption of caesium (Cs); cobalt (Co); and manganese (Mn) isotopes on chitin derivatives were investigated using a batch and column system with variations in diameter, pH, and length of treatment. Chitin derivatives included shrimp shells; de-mineralized shrimp shells; chitin extracted from shrimp shells; and chitosan extracted from shrimp shell waste. Three types of simulated solutions were prepared to study and compare adsorption performance: (1) a mono cationic solution consisting of stable isotopes; (2) a solution containing 3 stable cations; and (3) a simulated radioactive waste containing Cs-137, Co-60, and Mn-54. Results of the experiments showed that all 4 chitin derivatives were capable of adsorbing the isotopes. Despite its low pH, chitosan showed the highest adsorption efficiency. It was concluded that shrimps shells provided unreliable results under different operating conditions. The demineralized shells were suitable for removing Co from solutions. Row shells were not recommended as a suitable adsorbent for radionuclides removal. 14 refs., 2 tabs., 6 figs.

  8. Dominant thermogravimetric signatures of lignin in cashew shell as compared to cashew shell cake.

    Science.gov (United States)

    Gangil, Sandip

    2014-03-01

    Dominant thermogravimetric signatures related to lignin were observed in cashew shell as compared to these signatures in cashew shell cake. The phenomenon of weakening of lignin from cashew shell to cashew shell cake was explained on the basis of changes in the activation energies. The pertinent temperature regimes responsible for the release of different constituents of both the bio-materials were identified and compared. The activation energies of cashew shell and cashew shell cake were compared using Kissinger-Akahira-Sunose method. Thermogravimetric profiling of cashew shell and cashew shell cake indicated that these were different kinds of bio-materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Proof testing of an explosion containment vessel

    Energy Technology Data Exchange (ETDEWEB)

    Esparza, E.D. [Esparza (Edward D.), San Antonio, TX (United States); Stacy, H.; Wackerle, J. [Los Alamos National Lab., NM (United States)

    1996-10-01

    A steel containment vessel was fabricated and proof tested for use by the Los Alamos National Laboratory at their M-9 facility. The HY-100 steel vessel was designed to provide total containment for high explosives tests up to 22 lb (10 kg) of TNT equivalent. The vessel was fabricated from an 11.5-ft diameter cylindrical shell, 1.5 in thick, and 2:1 elliptical ends, 2 in thick. Prior to delivery and acceptance, three types of tests were required for proof testing the vessel: a hydrostatic pressure test, air leak tests, and two full design charge explosion tests. The hydrostatic pressure test provided an initial static check on the capacity of the vessel and functioning of the strain instrumentation. The pneumatic air leak tests were performed before, in between, and after the explosion tests. After three smaller preliminary charge tests, the full design charge weight explosion tests demonstrated that no yielding occurred in the vessel at its rated capacity. The blast pressures generated by the explosions and the dynamic response of the vessel were measured and recorded with 33 strain channels, 4 blast pressure channels, 2 gas pressure channels, and 3 displacement channels. This paper presents an overview of the test program, a short summary of the methodology used to predict the design blast loads, a brief description of the transducer locations and measurement systems, some of the hydrostatic test strain and stress results, examples of the explosion pressure and dynamic strain data, and some comparisons of the measured data with the design loads and stresses on the vessel.

  10. Transient response of rotating laminated functionally graded cylindrical shells in thermal environment

    International Nuclear Information System (INIS)

    Malekzadeh, P.; Heydarpour, Y.; Haghighi, M.R. Golbahar; Vaghefi, M.

    2012-01-01

    Based on the elasticity theory, the transient analysis of dynamically pressurized rotating multi-layered functionally graded (FG) cylindrical shells in thermal environment is presented. The variations of the field variables across the shell thickness are accurately modeled by dividing the shell into a set of co-axial mathematical layers in the radial direction. The initial thermo-mechanical stresses are obtained by solving the thermoelastic equilibrium equations. The differential quadrature method and Newmark's time integration scheme are employed to discretize the obtained governing equations of each mathematical layer. After performing the convergence and comparison studies, parametric studies for two common types of FG sandwich shells, namely, the shell with homogeneous inner/outer layers and FG core and the shell with FG inner/outer layers and homogeneous core are carried out. The influences of the temperature dependence of material properties, material graded index, the convective heat transfer coefficient, the angular velocity, the boundary condition and the geometrical parameters (length and thickness to outer radius ratios) on the dynamic response of the FG shells are investigated. Highlights: ► As a first endeavor, transient analysis of rotating laminated functionally graded cylinders. ► Employing an elasticity based discrete layer-differential quadrature method. ► Evaluating and including the initial thermo-mechanical stresses accurately. ► Considering the temperature-dependence of the material properties. ► Presenting some new results, which can be used as benchmark solution for future works.

  11. Analytical Investigation of Elastic Thin-Walled Cylinder and Truncated Cone Shell Intersection Under Internal Pressure

    OpenAIRE

    Zamani, J.; Soltani, B.; Aghaei, M.

    2014-01-01

    An elastic solution of cylinder-truncated cone shell intersection under internal pressure is presented. The edge solution theory that has been used in this study takes bending moments and shearing forces into account in the thin-walled shell of revolution element. The general solution of the cone equations is based on power series method. The effect of cone apex angle on the stress distribution in conical and cylindrical parts of structure is investigated. In addition, the effect of the inter...

  12. Shielding container

    International Nuclear Information System (INIS)

    Darling, K.A.M.

    1981-01-01

    A shielding container incorporates a dense shield, for example of depleted uranium, cast around a tubular member of curvilinear configuration for accommodating a radiation source capsule. A lining for the tubular member, in the form of a close-coiled flexible guide, provides easy replaceability to counter wear while the container is in service. Container life is extended, and maintenance costs are reduced. (author)

  13. Shell model Monte Carlo methods

    International Nuclear Information System (INIS)

    Koonin, S.E.; Dean, D.J.; Langanke, K.

    1997-01-01

    We review quantum Monte Carlo methods for dealing with large shell model problems. These methods reduce the imaginary-time many-body evolution operator to a coherent superposition of one-body evolutions in fluctuating one-body fields; the resultant path integral is evaluated stochastically. We first discuss the motivation, formalism, and implementation of such Shell Model Monte Carlo (SMMC) methods. There then follows a sampler of results and insights obtained from a number of applications. These include the ground state and thermal properties of pf-shell nuclei, the thermal and rotational behavior of rare-earth and γ-soft nuclei, and the calculation of double beta-decay matrix elements. Finally, prospects for further progress in such calculations are discussed. (orig.)

  14. Shell model Monte Carlo methods

    International Nuclear Information System (INIS)

    Koonin, S.E.

    1996-01-01

    We review quantum Monte Carlo methods for dealing with large shell model problems. These methods reduce the imaginary-time many-body evolution operator to a coherent superposition of one-body evolutions in fluctuating one-body fields; resultant path integral is evaluated stochastically. We first discuss the motivation, formalism, and implementation of such Shell Model Monte Carlo methods. There then follows a sampler of results and insights obtained from a number of applications. These include the ground state and thermal properties of pf-shell nuclei, thermal behavior of γ-soft nuclei, and calculation of double beta-decay matrix elements. Finally, prospects for further progress in such calculations are discussed. 87 refs

  15. Windows PowerShell 20 Bible

    CERN Document Server

    Lee, Thomas; Schill, Mark E; Tanasovski, Tome

    2011-01-01

    Here's the complete guide to Windows PowerShell 2.0 for administrators and developers Windows PowerShell is Microsoft's next-generation scripting and automation language. This comprehensive volume provides the background that IT administrators and developers need in order to start using PowerShell automation in exciting new ways. It explains what PowerShell is, how to use the language, and specific ways to apply PowerShell in various technologies. Windows PowerShell is Microsoft's standard automation tool and something that every Windows administrator will eventually have to understand; this b

  16. Shell Analysis Manual

    Science.gov (United States)

    1968-04-01

    1.34-8) ax 2 X=0 2 A A 9 1 •z t/2 V2 = ii 1/ 1~ e1 +2 2 + 12 121 91 0 -t/2•1 2 e r" + e- 0 + T e aa 1 td +2 121a d•, 2 d (1.34-9) The strain and stress...Rk sin2 01 -24Rksin2 0 1 Et 2Et tD 0 1 - i To obtain N,, Ne0 Q10 Mo, M enter C 1 and C2 in the preceding general formulas. Table 2. 64-1 presents a...Formulas for the Elastic Constants of Plates with Integral Waffle-Like Stiffening. NACA RM L53 El3a (1953). 3-27 Gerard, G. "Compressive Stability of

  17. Fast synthesis, formation mechanism, and control of shell thickness of CuS–polystyrene core–shell microspheres

    International Nuclear Information System (INIS)

    Zhao, Li-min; Shao, Xin; Yin, Yi-bin; Li, Wen-zhi

    2012-01-01

    Graphical abstract: Core–shell structure PSt/CuS were prepared using polystyrene which were modified by 3-methacryloxypropyltrimethoxysilane as template. The coating thickness of CuS can be controlled by the amount of 3-methacryloxypropyltrimethoxysilane and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. Highlights: ► Core–shell structure PSt/CuS were prepared using silanol-modified polystyrene microspheres as template. ► The coating thickness of core–shell structure PSt/CuS can be controlled by a simple method. ► The UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. -- Abstract: The silanol-modified polystyrene microspheres were prepared through dispersion polymerization. Then copper sulfide particles were grown on silanol-modified polystyrene through sonochemical deposition in an aqueous bath containing copper acetate and sulfide, released through the hydrolysis of thioacetamide. The resulting particles were continuous and uniform as characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fourier transform infrared, thermogravimetric analysis and UV–vis absorption spectroscopy were used to characterize the structure and properties of core–shell particles. The results showed the coating thickness of CuS shell can be controlled by the amount of silanol and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS.

  18. r-Adaptive mesh generation for shell finite element analysis

    International Nuclear Information System (INIS)

    Cho, Maenghyo; Jun, Seongki

    2004-01-01

    An r-adaptive method or moving grid technique relocates a grid so that it becomes concentrated in the desired region. This concentration improves the accuracy and efficiency of finite element solutions. We apply the r-adaptive method to computational mesh of shell surfaces, which is initially regular and uniform. The r-adaptive method, given by Liao and Anderson [Appl. Anal. 44 (1992) 285], aggregate the grid in the region with a relatively high weight function without any grid-tangling. The stress error estimator is calculated in the initial uniform mesh for a weight function. However, since the r-adaptive method is a method that moves the grid, shell surface geometry error such as curvature error and mesh distortion error will increase. Therefore, to represent the exact geometry of a shell surface and to prevent surface geometric errors, we use the Naghdi's shell theory and express the shell surface by a B-spline patch. In addition, using a nine-node element, which is relatively less sensitive to mesh distortion, we try to diminish mesh distortion error in the application of an r-adaptive method. In the numerical examples, it is shown that the values of the error estimator for a cylinder, hemisphere, and torus in the overall domain can be reduced effectively by using the mesh generated by the r-adaptive method. Also, the reductions of the estimated relative errors are demonstrated in the numerical examples. In particular, a new functional is proposed to construct an adjusted mesh configuration by considering a mesh distortion measure as well as the stress error function. The proposed weight function provides a reliable mesh adaptation method after a parameter value in the weight function is properly chosen

  19. 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.

  20. Shell shock, trauma, and the First World War: the making of a diagnosis and its histories.

    Science.gov (United States)

    Loughran, Tracey

    2012-01-01

    During the First World War, thousands of soldiers were treated for "shell shock," a condition which encompassed a range of physical and psychological symptoms. Shell shock has most often been located within a "genealogy of trauma," and identified as an important marker in the gradual recognition of the psychological afflictions caused by combat. In recent years, shell shock has increasingly been viewed as a powerful emblem of the suffering of war. This article, which focuses on Britain, extends scholarly analyses which question characterizations of shell shock as an early form of post-traumatic stress disorder. It also considers some of the methodological problems raised by recasting shell shock as a wartime medical construction rather than an essentially timeless manifestation of trauma. It argues that shell shock must be analyzed as a diagnosis shaped by a specific set of contemporary concerns, knowledges, and practices. Such an analysis challenges accepted understandings of what shell shock "meant" in the First World War, and also offers new perspectives on the role of shell shock in shaping the emergence of psychology and psychiatry in the early part of the twentieth century. The article also considers what relation, if any, might exist between intellectual and other histories, literary approaches, and perceptions of trauma as timeless and unchanging.

  1. Deformation Behavior of Press Formed Shell by Indentation and Its Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Minoru Yamashita

    2015-01-01

    Full Text Available Deformation behavior and energy absorbing performance of the press formed aluminum alloy A5052 shells were investigated to obtain the basic information regarding the mutual effect of the shell shape and the indentor. Flat top and hemispherical shells were indented by the flat- or hemispherical-headed indentor. Indentation force in the rising stage was sharper for both shell shapes when the flat indentor was used. Remarkable force increase due to high in-plane compressive stress arisen by the appropriate tool constraint was observed in the early indentation stage, where the hemispherical shell was deformed with the flat-headed indentor. This aspect is preferable for energy absorption performance per unit mass. Less fluctuation in indentation force was achieved in the combination of the hemispherical shell and similar shaped indentor. The consumed energy in the travel length of the indentor equal to the shell height was evaluated. The increase ratio of the energy is prominent when the hemispherical indentor is replaced by a flat-headed one in both shell shapes. Finite element simulation was also conducted. Deformation behaviors were successfully predicted when the kinematic hardening plasticity was introduced in the material model.

  2. The expanding shell test: Numerical simulation of the experiment

    International Nuclear Information System (INIS)

    Buy, Francois; Llorca, Fabrice

    2002-01-01

    The behavior of materials at very high strain rates is a broad field of investigation. One of the major problem is to impose a well known velocity and stress loading. The expanding shell, because of its ability to impose a sudden loading with no ulterior stress, has been retained to analyze the mechanical behavior of several metals through the free flight of a deforming structure. We perform several simulations on various metals in order to evaluate the strain rates and velocity in the sample. A second step consists in interpreting experimental data obtained on these metals

  3. Learning Shell scripting with Zsh

    CERN Document Server

    Festari, Gaston

    2014-01-01

    A step-by-step tutorial that will teach you, through real-world examples, how to configure and use Zsh and its various features. If you are a system administrator, developer, or computer professional involved with UNIX who are looking to improve on their daily tasks involving the UNIX shell, ""Learning Shell Scripting with Zsh"" will be great for you. It's assumed that you have some familiarity with an UNIX command-line interface and feel comfortable with editors such as Emacs or vi.

  4. Elastic-plastic transition on rotating spherical shells in dependence of compressibility

    Directory of Open Access Journals (Sweden)

    Thakur Pankaj

    2017-01-01

    Full Text Available The purpose of this paper is to establish the mathematical model on the elastic-plastic transitions occurring in the rotating spherical shells based on compressibility of materials. The paper investigates the elastic-plastic stresses and angular speed required to start yielding in rotating shells for compressible and incompressible materials. The paper is based on the non-linear transition theory of elastic-plastic shells given by B.R. Seth. The elastic-plastic transition obtained is treated as an asymptotic phenomenon at critical points & the solution obtained at these points generates stresses. The solution obtained does not require the use of semi-empirical yield condition like Tresca or Von Mises or other certain laws. Results are obtained numerically and depicted graphically. It has been observed that Rotating shells made of the incompressible material are on the safer side of the design as compared to rotating shells made of compressible material. The effect of density variation has been discussed numerically on the stresses. With the effect of density variation parameter, rotating spherical shells start yielding at the internal surface with the lower values of the angular speed for incompressible/compressible materials.

  5. Elemental compositions of crab and snail shells from the Kueishantao hydrothermal field in the southwestern Okinawa Trough

    Science.gov (United States)

    Zeng, Zhigang; Ma, Yao; Wang, Xiaoyuan; Chen, Chen-Tung Arthur; Yin, Xuebo; Zhang, Suping; Zhang, Junlong; Jiang, Wei

    2018-04-01

    To reveal differences in the behavior of benthic vent animals, and the sources and sinks of biogeochemical and fluid circulations, it is necessary to constrain the chemical characteristics of benthic animals from seafloor hydrothermal fields. We measured the abundances of 27 elements in shells of the crab Xenograpsus testudinatus and the snail Anachis sp., collected from the Kueishantao hydrothermal field (KHF) in the southwestern Okinawa Trough, with the aim of improving our understanding of the compositional variations between individual vent organisms, and the sources of the rare earth elements (REEs) in their shells. The Mn, Hg, and K concentrations in the male X. testudinatus shells are found to be higher than those in female crab shells, whereas the reverse is true for the accumulation of B, implying that the accumulation of K, Mn, Hg, and B in the crab shells is influenced by sex. This is inferred to be a result of the asynchronous molting of the male and female crab shells. Snail shells are found to have higher Ca, Al, Fe, Ni, and Co concentrations than crab shells. This may be attributed to different metal accumulation times. The majority of the light rare earth element (LREE) distribution patterns in the crab and snail shells are similar to those of Kueishantao vent fluids, with the crab and snail shells also exhibiting LREE enrichment, implying that the LREEs contained in crab and snail shells in the KHF are derived from vent fluids.

  6. Reactor container

    International Nuclear Information System (INIS)

    Ichiki, Tadaharu; Saba, Kazuhisa.

    1979-01-01

    Purpose: To improve the earthquake resistance as well as reduce the size of a container for a nuclear reactor with no adverse effects on the decrease of impact shock to the container and shortening of construction step. Constitution: Reinforcing profile steel materials are welded longitudinally and transversely to the inner surface of a container, and inner steel plates are secured to the above profile steel materials while keeping a gap between the materials and the container. Reactor shielding wall planted to the base concrete of the container is mounted to the pressure vessel, and main steam pipeways secured by the transverse beams and led to the outside of container is connected. This can improve the rigidity earthquake strength and the safetiness against the increase in the inside pressure upon failures of the container. (Yoshino, Y.)

  7. Isogeometric shell formulation based on a classical shell model

    KAUST Repository

    Niemi, Antti; Collier, Nathan; Dalcí n, Lisandro D.; Ghommem, Mehdi; Calo, Victor M.

    2012-01-01

    The authors future work is concerned with building an isogeometric finite element method for modelling nonlinear structural response of thin-walled shells undergoing large rigid-body motions. The aim is to use the model in a aeroelastic framework for the simulation of flapping wings.

  8. Linux shell scripting cookbook

    CERN Document Server

    Tushar, Shantanu

    2013-01-01

    This book is written in a Cookbook style and it offers learning through recipes with examples and illustrations. Each recipe contains step-by-step instructions about everything necessary to execute a particular task. The book is designed so that you can read it from start to end for beginners, or just open up any chapter and start following the recipes as a reference for advanced users.If you are a beginner or an intermediate user who wants to master the skill of quickly writing scripts to perform various tasks without reading the entire manual, this book is for you. You can start writing scri

  9. Durability of coconut shell powder (CSP) concrete

    Science.gov (United States)

    Leman, A. S.; Shahidan, S.; Senin, M. S.; Shamsuddin, S. M.; Anak Guntor, N. A.; Zuki, S. S. Mohd; Khalid, F. S.; Azhar, A. T. S.; Razak, N. H. S.

    2017-11-01

    The rising cost of construction in developing countries like Malaysia has led concrete experts to explore alternative materials such as coconut shells which are renewable and possess high potential to be used as construction material. Coconut shell powder in varying percentages of1%, 3% and 5% was used as filler material in concrete grade 30 and evaluated after a curing period of 7 days and 28days respectively. Compressive strength, water absorption and carbonation tests were conducted to evaluate the strength and durability of CSP concrete in comparison with normal concrete. The test results revealed that 1%, 3% and 5% of CSP concrete achieved a compressive strength of 47.65 MPa, 45.6 MPa and 40.55% respectively. The rate of water absorption of CSP concrete was recorded as 3.21%, 2.47%, and 2.73% for 1%, 3% and 5% of CSP concrete respectively. Although CSP contained a carbon composition of 47%, the carbonation test showed that CSP no signs of carbon were detected inside the concrete. To conclude, CSP offers great prospects as it demonstrated relatively high durability as a construction material.

  10. Activated carbons prepared from hazelnut shells, walnut shells and peanut shells for high CO2 adsorption

    Directory of Open Access Journals (Sweden)

    Lewicka Katarzyna

    2017-06-01

    Full Text Available Research treats about producing activated carbons for CO2 capture from hazelnut shells (HN, walnut shells (WN and peanut shells (PN. Saturated solution of KOH was used as an activating agent in ratio 1:1. Samples were carbonized in the furnace in the range of temperatures 600°C–900°C. Properties of carbons were tested by N2 adsorption method, using BET equation, DFT method and volumetric CO2 adsorption method. With the increase of carbonization temperature specific surface area of studied samples increased. The largest surface area was calculated for samples carbonized at 900°C and the highest values of CO2 adsorption had samples: PN900 at 0°C (5.5 mmol/g and WN900 at 25°C (4.34 mmol/g. All of the samples had a well-developed microporous structure.

  11. Characterization of Physic nut (Jatropha curcas L.) shells

    International Nuclear Information System (INIS)

    Wever, Diego-Armando Z.; Heeres, H.J.; Broekhuis, Antonius A.

    2012-01-01

    The characterization of Physic nut shells was done using the wet chemical analysis of wood components. The obtained fractions were analyzed using IR, NMR, GPC, ICP and MALDI-TOF mass spectroscopy. TGA was used to determine the fixed carbon (+ash) and water content of the shells. The results of wet chemical analysis of wood components offered a clear procedure to isolate the main components in Physic nut shells (a). The fractions obtained were: polar extract (b), non-polar extract (c), Acid Insoluble Lignin (d), Holocellulose (e), α-Cellulose (f). The total Lignin content present in the shells equaled 48.84%. IR and NMR spectroscopy demonstrated that the non-polar extract is Lignin, which corresponds to the extractable Lignin (1.24%) in the Physic nut shells and the Acid Insoluble Lignin was 47.60%. Elemental analysis showed no Sulfur present in the investigated materials. Furthermore both 1 H and 13 C NMR of the non-polar extract showed the presence of aliphatic hydrocarbon chains. The α-Cellulose content (22.29%) and the Hemicelluloses content (23.84%) were in line with that of agricultural residues. The water content and the fixed carbon content (+ash [2.8%]) equal 5–6% and 35.6%, respectively. GPC showed that the polydispersity of the non-polar extract (3.6) lies between Alcell Lignin and Kraft Lignin. The polar extract contains a variety of metals, with especially a high amount of the alkali metals K and Na. The extraction with water is proposed to generate a fertilizer fraction and may be applied to reduce potential sintering issues during eventual combustion or gasification of the shells. -- Highlights: ► Physic nut shell is a potential source of value added chemicals due to its high lignin content (48.8 wt%). ► Lignin extracted from Jatropha curcas L. shells is rich in aliphatic linkages. ► Water extraction of the shells yields a potential fertilizer fraction rich in alkali metals and phosphorous. ► Pre-extraction is recommended to eliminate

  12. Experimental stress analysis of the attachment region of hemispherical shells with attached nozzles. Part 2b. Radial nozzle 7.875 in. O.D.--7.500 in. I.D. 10.00 in. penetration

    International Nuclear Information System (INIS)

    Maxwell, R.L.; Holland, R.W.; Stengl, G.R.

    1970-06-01

    The report presents the results of investigations conducted on a hemisphere with a radial nozzle of 7.875'' O.D. and 7.500'' I.D. and 10'' penetration into the hemisphere. Stress values were determined for the following five types of loadings: (1) internal pressure applied to the hemisphere and nozzle assembly, (2) an axial load applied collinear with nozzle, (3) a pure bending moment, or axial couple, applied to the nozzle, (4) a transverse or shear load applied normal to the nozzle, and (5) a pure torque applied in the radial plane of the nozzle

  13. Indentation of Ellipsoidal and Cylindrical Elastic Shells

    KAUST Repository

    Vella, Dominic; Ajdari, Amin; Vaziri, Ashkan; Boudaoud, Arezki

    2012-01-01

    Thin shells are found in nature at scales ranging from viruses to hens' eggs; the stiffness of such shells is essential for their function. We present the results of numerical simulations and theoretical analyses for the indentation of ellipsoidal

  14. Adaptative mixed methods to axisymmetric shells

    International Nuclear Information System (INIS)

    Malta, S.M.C.; Loula, A.F.D.; Garcia, E.L.M.

    1989-09-01

    The mixed Petrov-Galerkin method is applied to axisymmetric shells with uniform and non uniform meshes. Numerical experiments with a cylindrical shell showed a significant improvement in convergence and accuracy with adaptive meshes. (A.C.A.S.) [pt

  15. Estimation of shell thickness in a continuously cast steel billet using radiotracers

    International Nuclear Information System (INIS)

    Prasad, A.S.; Pandey, J.C.; Kaur, G.

    1994-01-01

    In the continuous casting of steel, one of the factors which limits the rate of faster withdrawal of the casting from the mould is the thickness of the solid shell below the mould. If the shell can not contain the liquid pool, breakouts occur and process of casting disrupts. Estimates of shell thickness have been made on the basis of heat- transfer considerations. The shell thickness could also be delineated, to some extent, by adding radiotracers during casting and subsequently determining the dispersion of radioactivity by autoradiography. The paper presents the results of the estimation of shell thickness based on the heat-transfer model and validation of the model by plant trials using radiotracers. (author). 11 refs., 5 figs., 1 tab

  16. Ancient DNA analysis identifies marine mollusc shells as new metagenomic archives of the past

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Pichereau, Vianney; Dupont, Catherine

    2017-01-01

    Marine mollusc shells enclose a wealth of information on coastal organisms and their environment. Their life history traits as well as (palaeo-) environmental conditions, including temperature, food availability, salinity and pollution, can be traced through the analysis of their shell (micro...... extraction, high-throughput shotgun DNA sequencing and metagenomic analyses to marine mollusc shells spanning the last ~7,000 years. We report successful DNA extraction from shells, including a variety of ancient specimens, and find that DNA recovery is highly dependent on their biomineral structure......, carbonate layer preservation and disease state. We demonstrate positive taxonomic identification of mollusc species using a combination of mitochondrial DNA genomes, barcodes, genome-scale data and metagenomic approaches. We also find shell biominerals to contain a diversity of microbial DNA from the marine...

  17. Absence of molecular deuterium dissociation during room-temperature permeation into polystyrene ICF target shells

    International Nuclear Information System (INIS)

    Honig, A.; Alexander, N.; Fan, Q.; Gram, R.; Kim, H.

    1991-01-01

    Polystyrene microshells filled with deuterium and tritium gas are important target shells for inertially confined fusion (ICF) and are particularly promising for target containing spin-polarized hydrogens fuels. A currently active approach to the latter uses polarized D in HD, in a method which requires preservation of the high purity of the initially prepared HD (very low specified H 2 and D 2 concentrations). This would not be possible if dissociation should occur during permeation into the target shells. We have thus tested polystyrene shells using a novel method which employs very pure polystyrene shells using a novel method which employs very pure ortho-D 2 as the test gas. An upper limit of 6 x 10 -4 was deduced for the dissociation of D 2 upon room temperature permeation through an approximately 8 um wall of polystyrene, clearing the way for use of polystyrene target shells for ICF fusion experiments with spin-polarized hydrogens fuels. 19 refs., 1 fig

  18. Facile fabrication of siloxane @ poly (methylacrylic acid) core-shell microparticles with different functional groups

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zheng-Bai; Tai, Li; Zhang, Da-Ming; Jiang, Yong, E-mail: yj@seu.edu.cn [Southeast University, School of Chemistry and Chemical Engineering (China)

    2017-02-15

    Siloxane @ poly (methylacrylic acid) core-shell microparticles with functional groups were prepared by a facile hydrolysis-condensation method in this work. Three different silane coupling agents 3-methacryloxypropyltrimethoxysilane (MPS), 3-triethoxysilylpropylamine (APTES), and 3-glycidoxypropyltrimethoxysilane (GPTMS) were added along with tetraethoxysilane (TEOS) into the polymethylacrylic acid (PMAA) microparticle ethanol dispersion to form the Si@PMAA core-shell microparticles with different functional groups. The core-shell structure and the surface special functional groups of the resulting microparticles were measured by transmission electron microscopy and FTIR. The sizes of these core-shell microparticles were about 350–400 nm. The corresponding preparation conditions and mechanism were discussed in detail. This hydrolysis-condensation method also could be used to functionalize other microparticles which contain active groups on the surface. Meanwhile, the Si@PMAA core-shell microparticles with carbon-carbon double bonds and amino groups have further been applied to prepare hydrophobic coatings.

  19. Facile fabrication of siloxane @ poly (methylacrylic acid) core-shell microparticles with different functional groups

    International Nuclear Information System (INIS)

    Zhao, Zheng-Bai; Tai, Li; Zhang, Da-Ming; Jiang, Yong

    2017-01-01

    Siloxane @ poly (methylacrylic acid) core-shell microparticles with functional groups were prepared by a facile hydrolysis-condensation method in this work. Three different silane coupling agents 3-methacryloxypropyltrimethoxysilane (MPS), 3-triethoxysilylpropylamine (APTES), and 3-glycidoxypropyltrimethoxysilane (GPTMS) were added along with tetraethoxysilane (TEOS) into the polymethylacrylic acid (PMAA) microparticle ethanol dispersion to form the Si@PMAA core-shell microparticles with different functional groups. The core-shell structure and the surface special functional groups of the resulting microparticles were measured by transmission electron microscopy and FTIR. The sizes of these core-shell microparticles were about 350–400 nm. The corresponding preparation conditions and mechanism were discussed in detail. This hydrolysis-condensation method also could be used to functionalize other microparticles which contain active groups on the surface. Meanwhile, the Si@PMAA core-shell microparticles with carbon-carbon double bonds and amino groups have further been applied to prepare hydrophobic coatings.

  20. A container

    DEFF Research Database (Denmark)

    2012-01-01

    A container assembly for the containment of fluids or solids under a pressure different from the ambient pressure comprising a container (2) comprising an opening and an annular sealing, a lid (3) comprising a central portion (5) and engagement means (7) for engaging the annular flange, and sealing...... means (10) wherein the engagement means (7) is adapted, via the sealing means, to seal the opening when the pressure of the container assembly differs from the ambient pressure in such a way that the central portion (5) flexes in the axial direction which leads to a radial tightening of the engagement...... means (7) to the container, wherein the container further comprises locking means (12) that can be positioned so that the central portion is hindered from flexing in at least one direction....

  1. Response of immunocompetent cells of bone marrow and spleen of mouse males of several strains to stress and to pyrazine containing chemosignals

    Directory of Open Access Journals (Sweden)

    Eugene V Daev

    2012-06-01

    Full Text Available The quantity of antibody producing cells and mitotic disturbances in dividing bone marrow cells of mice were studied after exposure of animals to a physical stressor or various pyrazinecontaining chemosignals. Several different strains of mice were used. We demonstrate that immune suppression and destabilization of the chromosome apparatus in dividing cells depend on: а mouse genotype and b side chains position  in the pyrazine ring. Importance of this effects in the light of wide usage of pyrazine containing substances in perfume industry, food production and pharmacology is discussed.

  2. Shielded container

    International Nuclear Information System (INIS)

    Fries, B.A.

    1978-01-01

    A shielded container for transportation of radioactive materials is disclosed in which leakage from the container is minimized due to constructional features including, inter alia, forming the container of a series of telescoping members having sliding fits between adjacent side walls and having at least two of the members including machine sealed lids and at least two of the elements including hand-tightenable caps

  3. Tube in shell heat exchangers

    International Nuclear Information System (INIS)

    Hayden, O.; Willby, C.R.; Sheward, G.E.; Ormrod, D.T.; Firth, G.F.

    1980-01-01

    An improved tube-in-shell heat exchanger to be used between liquid metal and water is described for use in the liquid metal coolant system of fast breeder reactors. It is stated that this design is less prone to failures which could result in sodium water reactions than previous exchangers. (UK)

  4. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  5. Nonlinear theory of elastic shells

    International Nuclear Information System (INIS)

    Costa Junior, J.A.

    1979-08-01

    Nonlinear theory of elastic shells is developed which incorporates both geometric and physical nonlinearities and which does not make use of the well known Love-Kirchhoff hypothesis. The resulting equations are formulated in tensorial notation and are reduced to the ones of common use when simplifying assumptions encountered in the especific litterature are taken. (Author) [pt

  6. Shell energy scenarios to 2050

    International Nuclear Information System (INIS)

    2008-01-01

    Shell developed two scenarios that describe alternative ways the energy future may develop. In the first scenario (Scramble) policymakers pay little attention to more efficient energy use until supplies are tight. Likewise, greenhouse gas emissions are not seriously addressed until there are major climate shocks. In the second scenario (Blueprints) growing local actions begin to address the challenges of economic development, energy security and environmental pollution. A price is applied to a critical mass of emissions giving a huge stimulus to the development of clean energy technologies, such as carbon dioxide capture and storage, and energy efficiency measures. The result is far lower carbon dioxide emissions. Both these scenarios can help Shell to test their strategy against a range of possible developments over the long-term. However, according to Shell, the Blueprints' outcomes offer the best hope for a sustainable future, whether or not they arise exactly in the way described. However, with the right combination of policy, technology and commitment from governments, industry and society globally, Shell believes it can be realized. But achieving the targets will not be easy, and time is short. Clear thinking, huge investment, and effective leadership are required

  7. Collapse analysis of toroidal shell

    International Nuclear Information System (INIS)

    Pomares, R.J.

    1990-01-01

    This paper describes a study performed to determine the collapse characteristics of a toroidal shell using finite element method (FEM) analysis. The study also included free drop testing of a quarter scale prototype to verify the analytical results. The full sized toroidal shell has a 24-inch toroidal diameter with a 24-inch tubal diameter. The shell material is type 304 strainless steel. The toroidal shell is part of the GE Model 2000 transportation packaging, and acts as an energy absorbing device. The analyses performed were on a full sized and quarter scaled models. The finite element program used in all analyses was the LIBRA code. The analytical procedure used both the elasto-plastic and large displacement options within the code. The loading applied in the analyses corresponded to an impact of an infinite rigid plane oriented normal to the drop direction vector. The application of the loading continued incrementally until the work performed by the deforming structure equalled the kinetic energy developed in the free fall. The comparison of analysis and test results showed a good correlation

  8. Studies of dust shells around stars

    International Nuclear Information System (INIS)

    Bedijn, P.J.

    1977-01-01

    This thesis deals with some aspects of circumstellar dust shells. This dust shell, emitting infrared radiation, is described by way of its absorptive and emissive properties as well as by the transfer of radiation through the dust shell itself. Model calculations are compared to experimental results and agree reasonably well. The author also discusses the dynamics of the extended shells of gas and dust around newly formed stars

  9. Unique morphology and gradient arrangement of nacre's platelets in green mussel shells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jun; Zhang, Gangsheng, E-mail: zhanggs@gxu.edu.cn

    2015-07-01

    Nacre has long served as a classic model in biomineralization and the synthesis of biomimetic materials. However, the morphology and arrangement of its basic building blocks, the aragonite platelets, are still under hot debate. In this study, using a field emission scanning electron microscope (SEM), a high-resolution transmission electron microscope (HRTEM), and an X-ray diffractometer (XRD), we investigate the platelets at the edges and centers of green mussel shells. We find that 1) flat and curved platelets coexist in green mussel shells; 2) the immature platelets at the shell edge are aggregates of aragonite nanoparticles, whereas the immature ones at the shell center are single crystals; and 3) the morphology and thickness of the platelets exhibit a gradient arrangement. Based on these findings, we hypothesize that the gradient in the thickness and curvature of the platelets may probably result from the difference in growth rate between the edge and the center of the shell and from the gradient in compressive stress imposed by the closing of the shells by the adductor muscles or the withdrawal of the periostracum by the mantle. We expect that the presented results will shed new light on the formation mechanisms of natural composite materials. - Highlights: • Flat and curved platelets coexist in green mussel shells. • The immature platelets at the shell edge consist of aragonite nanoparticles. • The immature platelets at the shell center are single crystals. • The morphology and thickness of platelets exhibit a gradient arrangement. • The gradient arrangement of platelets may result from the stress gradient.

  10. 7 CFR 983.29 - Shelled pistachios.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Shelled pistachios. 983.29 Section 983.29 Agriculture... and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND NEW MEXICO Definitions § 983.29 Shelled pistachios. Shelled pistachios means pistachio...

  11. Thin-shell wormholes in dilaton gravity

    International Nuclear Information System (INIS)

    Eiroa, Ernesto F.; Simeone, Claudio

    2005-01-01

    In this work we construct charged thin-shell Lorentzian wormholes in dilaton gravity. The exotic matter required for the construction is localized in the shell and the energy conditions are satisfied outside the shell. The total amount of exotic matter is calculated and its dependence with the parameters of the model is analyzed

  12. Shell film- and video catalogue 1996

    International Nuclear Information System (INIS)

    1996-01-01

    An overview is given of films and videos that are available through 'Shell Nederland Filmcentrale' (Shell Netherlands Film Center), subdivided into the subjects (1) About Shell; (2) Health, Safety and Environment; (3) Science and Technology; (4) The History of Car(racing); and (5) Historical Overview. 5 ills

  13. A finite element for plates and shells

    International Nuclear Information System (INIS)

    Muller, A.; Feijoo, R.A.; Bevilacqua, L.

    1981-08-01

    A simple triangular finite element for plates and shells, is presented. Since the rotation fields are assumed independent of the displacement fields, the element allows one to solve thick shells problems. In the limit for thin shell, the Kirchoff-Love hypothesis is automatically satisfied, thus enlarging its range of application. (Author) [pt

  14. Vibrations of Thin Piezoelectric Shallow Shells

    Indian Academy of Sciences (India)

    Abstract. In this paper we consider the eigenvalue problem for piezoelectric shallow shells and we show that, as the thickness of the shell goes to zero, the eigensolutions of the three-dimensional piezoelectric shells converge to the eigensolutions of a two-dimensional eigenvalue problem.

  15. 7 CFR 981.6 - Shelled almonds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Shelled almonds. 981.6 Section 981.6 Agriculture... and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 981.6 Shelled almonds. Shelled almonds mean raw or roasted almonds after...

  16. Coulomb excitations for a short linear chain of metallic shells

    Energy Technology Data Exchange (ETDEWEB)

    Zhemchuzhna, Liubov, E-mail: lzhemchuzhna@unm.edu [Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065 (United States); Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Gumbs, Godfrey [Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065 (United States); Donostia International Physics Center (DIPC), P de Manuel Lardizabal, 4, 20018 San Sebastian, Basque Country (Spain); Iurov, Andrii [Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Huang, Danhong [Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117 (United States); Gao, Bo [Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065 (United States)

    2015-03-15

    A self-consistent-field theory is given for the electronic collective modes of a chain containing a finite number, N, of Coulomb-coupled spherical two-dimensional electron gases arranged with their centers along a straight line, for simulating electromagnetic response of a narrow-ribbon of metallic shells. The separation between nearest-neighbor shells is arbitrary and because of the quantization of the electron energy levels due to their confinement to the spherical surface, all angular momenta L of the Coulomb excitations, as well as their projections M on the quantization axis, are coupled. However, for incoming light with a given polarization, only one angular momentum quantum number is usually required. Therefore, the electromagnetic response of the narrow-ribbon of metallic shells is expected to be controlled externally by selecting different polarizations for incident light. We show that, when N = 3, the next-nearest-neighbor Coulomb coupling is larger than its value if they are located at opposite ends of a right-angle triangle forming the triad. Additionally, the frequencies of the plasma excitations are found to depend on the orientation of the line joining them with respect to the axis of quantization since the magnetic field generated from the induced oscillating electric dipole moment on one sphere can couple to the induced magnetic dipole moment on another. Although the transverse inter-shell electromagnetic coupling can be modeled by an effective dynamic medium, the longitudinal inter-shell Coulomb coupling, on the other hand, can still significantly modify the electromagnetic property of this effective medium between shells.

  17. HeLa Cells Containing a Truncated Form of DNA Polymerase Beta are More Sensitized to Alkylating Agents than to Agents Inducing Oxidative Stress.

    Science.gov (United States)

    Khanra, Kalyani; Chakraborty, Anindita; Bhattacharyya, Nandan

    2015-01-01

    The present study was aimed at determining the effects of alkylating and oxidative stress inducing agents on a newly identified variant of DNA polymerase beta (polβ Δ208-304) specific for ovarian cancer. Pol β Δ208-304 has a deletion of exons 11-13 which lie in the catalytic part of enzyme. We compared the effect of these chemicals on HeLa cells and HeLa cells stably transfected with this variant cloned into in pcDNAI/neo vector by MTT, colony forming and apoptosis assays. Polβ Δ208-304 cells exhibited greater sensitivity to an alkylating agent and less sensitivity towards H2O2 and UV when compared with HeLa cells alone. It has been shown that cell death in Pol β Δ208-304 transfected HeLa cells is mediated by the caspase 9 cascade. Exon 11 has nucleotidyl selection activity, while exons 12 and 13 have dNTP selection activity. Hence deletion of this part may affect polymerizing activity although single strand binding and double strand binding activity may remain same. The lack of this part may adversely affect catalytic activity of DNA polymerase beta so that the variant may act as a dominant negative mutant. This would represent clinical significance if translated into a clinical setting because resistance to radiation or chemotherapy during the relapse of the disease could be potentially overcome by this approach.

  18. Silica-Based and Borate-Based, Titania-Containing Bioactive Coatings Characterization: Critical Strain Energy Release Rate, Residual Stresses, Hardness, and Thermal Expansion

    Directory of Open Access Journals (Sweden)

    Omar Rodriguez

    2016-12-01

    Full Text Available Silica-based and borate-based glass series, with increasing amounts of TiO2 incorporated, are characterized in terms of their mechanical properties relevant to their use as metallic coating materials. It is observed that borate-based glasses exhibit CTE (Coefficient of Thermal Expansion closer to the substrate’s (Ti6Al4V CTE, translating into higher mode I critical strain energy release rates of glasses and compressive residual stresses and strains at the coating/substrate interface, outperforming the silica-based glasses counterparts. An increase in the content of TiO2 in the glasses results in an increase in the mode I critical strain energy release rate for both the bulk glass and for the coating/substrate system, proving that the addition of TiO2 to the glass structure enhances its toughness, while decreasing its bulk hardness. Borate-based glass BRT3, with 15 mol % TiO2 incorporated, exhibits superior properties overall compared to the other proposed glasses in this work, as well as 45S5 Bioglass® and Pyrex.

  19. Axisymmetric analysis of a 1:6-scale reinforced concrete containment building using a distributed cracking model for the concrete

    International Nuclear Information System (INIS)

    Weatherby, J.R.

    1987-09-01

    Results of axisymmetric structural analyses of a 1:6 scale model of a reinforced concrete nuclear containment building are presented. Both a finite element shell analysis and a simplified membrane analysis were made to predict the structural response and ultimate pressure capacity of the model. Analytical results indicate that the model will fail at an internal pressure of 187 psig when the stress level in the hoop reinforcement at the midsection of the cylinder exceeds the ultimate strength of the bar splices. 5 refs., 34 figs., 6 tabs

  20. Antioxidative effects of magnetized extender containing bovine serum albumin on sperm oxidative stress during long-term liquid preservation of boar semen.

    Science.gov (United States)

    Lee, Sang-Hee; Park, Choon-Keun

    2015-08-21

    Magnetized water is defined as water that has passed through a magnet and shows increased permeability into cells and electron-donating characteristics. These attributes can protect against membrane damage and remove reactive oxygen species (ROS) in mammalian cells. We explored the effects of improved magnetized semen extenders containing bovine serum albumin (BSA) as antioxidants on apoptosis in boar sperm. Ejaculated semen was diluted in magnetized extender (0G and 6000G) with or without BSA (0G + BSA and 6000G + BSA), and sperm were analyzed based on viability, acrosome reaction, and H2O2 level of live sperm using flow cytometry. Sperm were then preserved for 11 days at 18 °C. We found that viability was significantly higher in 6000G + BSA than under the other treatments (P extenders have antioxidative effects on the liquid preservation of boar sperm. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Reactor container

    International Nuclear Information System (INIS)

    Fukazawa, Masanori.

    1991-01-01

    A system for controlling combustible gases, it has been constituted at present such that the combustible gases are controlled by exhausting them to the wet well of a reactor container. In this system, however, there has been a problem, in a reactor container having plenums in addition to the wet well and the dry well, that the combustible gases in such plenums can not be controlled. In view of the above, in the present invention, suction ports or exhaust ports of the combustible gas control system are disposed to the wet well, the dry well and the plenums to control the combustible gases in the reactor container. Since this can control the combustible gases in the entire reactor container, the integrity of the reactor container can be ensured. (T.M.)

  2. Biosorption of rare earth elements, thorium and uranium using Buccinum tenuissimum shell biomass

    International Nuclear Information System (INIS)

    Wang, Yudan; Koto, Yusuke; Sakamoto, Nobuo; Kano, Naoki; Imaizumi, Hiroshi

    2010-01-01

    In order to evaluate the efficiency of shell biomass as sorbent for rare earth elements (REEs), thorium (Th) and uranium (U), sorption experiment from multi-element solutions containing known amount of REEs, Th and U using Buccinum tenuissimum shell was explored. Furthermore, to confirm the characteristics of the shell biomass, the surface morphology, the crystal structure, and the specific surface area of the shell (both original sample and the heat-treatment (480degC, 6h) sample) was determined. Consequently, the following matters have been mainly clarified. (1) By heat-treatment (480degC, 6h), the crystal structure of the shell biomass was transformed from aragonite (CaCO 3 ) into calcite (CaCO 3 ) phase, and the specific surface area of the biomass have decreased remarkably (i.e., by a factor of less than one eighth). (2) The shell biomass (both original sample and the heat-treated sample) showed excellent sorption capacity for REEs, although the sorption capacity decreases slightly after heat-treatment. (3) Adsorption isotherms using the shell biomass can be described by Langmuir and Freundlich isotherms satisfactorily for REEs, but not for Th and U in this work. (4) Shell biomass (usually treated as waste material) could be an efficient sorbent for REEs in future. (author)

  3. Antioxidant and Anti-Adipogenic Activities of Trapa japonica Shell Extract Cultivated in Korea

    Science.gov (United States)

    Lee, DooJin; Lee, Ok-Hwan; Choi, Geunpyo; Kim, Jong Dai

    2017-01-01

    Trapa japonica shell contains phenolic compounds such as tannins. Studies regarding the antioxidant and anti-adipogenic effects of Trapa japonica shell cultivated in Korea are still unclear. Antioxidant and anti-adipogenic activities were measured by in vitro assays such as 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging activity, 2,2′-azinobis( 3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, ferric reducing ability of plasma assay, reducing power, superoxide dismutase-like activity, and iron chelating ability in 3T3-L1 cells. We also measured the total phenol and flavonoids contents (TPC and TFC, respectively) in Trapa japonica shell extract. Our results show that TPC and TFC of Trapa japonica shell extract were 157.7±0.70 mg gallic acid equivalents/g and 25.0±1.95 mg quercetin equivalents/g, respectively. Trapa japonica shell extract showed strong antioxidant activities in a dose-dependent manner in DPPH and ABTS radical scavenging activities and other methods. Especially, the whole antioxidant activity test of Trapa japonica shell extract exhibited higher levels than that of butylated hydroxytoluene as a positive control. Furthermore, Trapa japonica shell extract inhibited lipid accumulation and reactive oxygen species production during the differentiation of 3T3-L1 preadipocytes. Trapa japonica shell extract possessed a significant antioxidant and anti-adipogenic property, which suggests its potential as a natural functional food ingredient. PMID:29333386

  4. Ancient DNA analysis identifies marine mollusc shells as new metagenomic archives of the past.

    Science.gov (United States)

    Der Sarkissian, Clio; Pichereau, Vianney; Dupont, Catherine; Ilsøe, Peter C; Perrigault, Mickael; Butler, Paul; Chauvaud, Laurent; Eiríksson, Jón; Scourse, James; Paillard, Christine; Orlando, Ludovic

    2017-09-01

    Marine mollusc shells enclose a wealth of information on coastal organisms and their environment. Their life history traits as well as (palaeo-) environmental conditions, including temperature, food availability, salinity and pollution, can be traced through the analysis of their shell (micro-) structure and biogeochemical composition. Adding to this list, the DNA entrapped in shell carbonate biominerals potentially offers a novel and complementary proxy both for reconstructing palaeoenvironments and tracking mollusc evolutionary trajectories. Here, we assess this potential by applying DNA extraction, high-throughput shotgun DNA sequencing and metagenomic analyses to marine mollusc shells spanning the last ~7,000 years. We report successful DNA extraction from shells, including a variety of ancient specimens, and find that DNA recovery is highly dependent on their biomineral structure, carbonate layer preservation and disease state. We demonstrate positive taxonomic identification of mollusc species using a combination of mitochondrial DNA genomes, barcodes, genome-scale data and metagenomic approaches. We also find shell biominerals to contain a diversity of microbial DNA from the marine environment. Finally, we reconstruct genomic sequences of organisms closely related to the Vibrio tapetis bacteria from Manila clam shells previously diagnosed with Brown Ring Disease. Our results reveal marine mollusc shells as novel genetic archives of the past, which opens new perspectives in ancient DNA research, with the potential to reconstruct the evolutionary history of molluscs, microbial communities and pathogens in the face of environmental changes. Other future applications include conservation of endangered mollusc species and aquaculture management. © 2017 John Wiley & Sons Ltd.

  5. Mg/Ca of Continental Ostracode Shells

    Science.gov (United States)

    Ito, E.; Forester, R. M.; Marco-Barba, J.; Mezquita, F.

    2007-12-01

    Marine ionic chemistry is thought to remain constant. This, together with the belief that marine calcifiers partition Mg/Ca in a systematic manner as functions of temperature (and Mg/Ca) of water forms the basis of the Mg/Ca thermometer. In continental settings both of these assumptions are usually not true. Continental waters contain a wide variety of solutes in absolute and relative ion concentrations. Hence, waters with identical Mg/Ca may have very different concentrations of Mg and Ca and very different anions. Here we use two examples to focus on the effects of ion chemistry on Mg/Ca partitioning in continental ostracode shells and we ignore the complexities of solute evolution, which can change Mg/Ca over timescales of minutes to millennia. Palacios-Fest and Dettman (2001) conducted a monthly study of ,Cypridopsis vidua at El Yeso Lake in Sonora, Mexico. They established a relation between temperature and average shell Mg/Ca using regression analyses on averaged data. When their Mg/Ca-temperature relation is applied to monthly ,C. vidua data from Page Pond near Cleveland, Ohio, water temperatures of -8 to -1°C are obtained. The observed Mg/Ca ranges for El Yeso Lake (0.31 to 0.46) and Page Pond (0.33 to 0.46) are similar, as are their specific conductivities (700 to 850μS for El Yeso Lake; 400 to 600μS for Page Pond). However, [Ca] is 140-260 mg/L for El Yeso, but only 70-90 mg/L for Page Pond. Page Pond data, in fact, shows a good temperature shell Mg/Ca relation for .C. vidua, but the relation is different from that at El Yeso. Hence, shell Mg/Ca is a multi-valued, family of curves function of temperature and Mg/Ca of water that depends on the [Mg] and [Ca] values in water and perhaps other factors. Our second example comes from sites near Valencia, Spain and involves shell data for ,Cyprideis torosa, an estuarine ostracode that is tolerant of a wide range of salinity and can live in continental waters as long as the carbonate alkalinity to Ca ratio is

  6. Sensitivity study of buckling strength for cylindrical shells

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Hideo; Sasaki, Toru [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2001-09-01

    Aiming at making clear buckling behavior of cylindrical shells under earthquake loadings, we investigated procedure of recent elastic-plastic buckling analysis by finite element method (FEM). Thereby it is confirmed that the buckling strength becomes as well as that of a shell with a cross section of a perfect cylinder, if we apply the first buckling eigenvector to imperfection mode and assume the maximum imperfection amplitude to be 1% of the wall thickness. And then, by carrying out sensitivity study of buckling with geometrical parameters, such as length (L), radius (R), wall thickness (t), and load parameter, such as pressure, we obtained several characteristics about buckling strength and buckling mode for cylindrical shells. From the geometrical parameter analysis, it is seen that bending buckling occurs for small R/t (thick wall) and elastic buckling occurs for 2{<=}L/R{<=}4 and R/t{>=}400. And from the load parameter analysis, it is shown that hoop stress caused by the inner pressure increases shear buckling strength but decreases bending buckling strength, and hoop stress by hydrostatic pressure changes buckling mode and generates local deformation. (author)

  7. AarF Domain Containing Kinase 3 (ADCK3 Mutant Cells Display Signs of Oxidative Stress, Defects in Mitochondrial Homeostasis and Lysosomal Accumulation.

    Directory of Open Access Journals (Sweden)

    Jason K Cullen

    Full Text Available Autosomal recessive ataxias are a clinically diverse group of syndromes that in some cases are caused by mutations in genes with roles in the DNA damage response, transcriptional regulation or mitochondrial function. One of these ataxias, known as Autosomal Recessive Cerebellar Ataxia Type-2 (ARCA-2, also known as SCAR9/COQ10D4; OMIM: #612016, arises due to mutations in the ADCK3 gene. The product of this gene (ADCK3 is an atypical kinase that is thought to play a regulatory role in coenzyme Q10 (CoQ10 biosynthesis. Although much work has been performed on the S. cerevisiae orthologue of ADCK3, the cellular and biochemical role of its mammalian counterpart, and why mutations in this gene lead to human disease is poorly understood. Here, we demonstrate that ADCK3 localises to mitochondrial cristae and is targeted to this organelle via the presence of an N-terminal localisation signal. Consistent with a role in CoQ10 biosynthesis, ADCK3 deficiency decreased cellular CoQ10 content. In addition, endogenous ADCK3 was found to associate in vitro with recombinant Coq3, Coq5, Coq7 and Coq9, components of the CoQ10 biosynthetic machinery. Furthermore, cell lines derived from ARCA-2 patients display signs of oxidative stress, defects in mitochondrial homeostasis and increases in lysosomal content. Together, these data shed light on the possible molecular role of ADCK3 and provide insight into the cellular pathways affected in ARCA-2 patients.

  8. Analytical Investigation of Elastic Thin-Walled Cylinder and Truncated Cone Shell Intersection Under Internal Pressure.

    Science.gov (United States)

    Zamani, J; Soltani, B; Aghaei, M

    2014-10-01

    An elastic solution of cylinder-truncated cone shell intersection under internal pressure is presented. The edge solution theory that has been used in this study takes bending moments and shearing forces into account in the thin-walled shell of revolution element. The general solution of the cone equations is based on power series method. The effect of cone apex angle on the stress distribution in conical and cylindrical parts of structure is investigated. In addition, the effect of the intersection and boundary locations on the circumferential and longitudinal stresses is evaluated and it is shown that how quantitatively they are essential.

  9. Reactor containment

    International Nuclear Information System (INIS)

    Kawabe, Ryuhei; Yamaki, Rika.

    1990-01-01

    A water vessel is disposed and the gas phase portion of the water vessel is connected to a reactor container by a pipeline having a valve disposed at the midway thereof. A pipe in communication with external air is extended upwardly from the liquid phase portion to a considerable height so as to resist against the back pressure by a waterhead in the pipeline. Accordingly, when the pressure in the container is reduced to a negative level, air passes through the pipeline and uprises through the liquid phase portion in the water vessel in the form of bubbles and then flows into the reactor container. When the pressure inside of the reactor goes higher, since the liquid surface in the water vessel is forced down, water is pushed up into the pipeline. Since the waterhead pressure of a column of water in the pipeline and the pressure of the reactor container are well-balanced, gases in the reactor container are not leaked to the outside. Further, in a case if a great positive pressure is formed in the reactor container, the inner pressure overcomes the waterhead of the column of water, so that the gases containing radioactive aerosol uprise in the pipeline. Since water and the gases flow being in contact with each other, this can provide the effect of removing aerosol. (T.M.)

  10. Experimental buckling investigation of ring-stiffened cylindrical shells under unsymmetrical axial loads

    International Nuclear Information System (INIS)

    Baker, W.E.; Babock, C.D.; Bennett, J.G.

    1983-01-01

    Six steel shells having nuclear containment-like features were fabricated and loaded to failure with an offset axial load. The shells of R/t = 500 buckled plastically. Four of the shells had reinforced circular cutouts. These penetrations were sized to cut no ring-stiffener, a single, two- or three-ring stiffeners. Reinforcing and framing around the penetrations were based upon the area-replacement rule of the applicable portion of the American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code and were of a design to stimulate actual practice for nuclear steel containments. Prior to testing, imperfections were measured and strain gages were applied to determine information on load distribution at the ends of the cylinder and strain fields at areas likely to buckle. Buckling loads were determined for an axial load applied with an eccentricity of R/2 where R is the cylinder radius. The results showed that the buckling load and mode for the shell having a penetration that did not cut a ring stiffener were essentially the same as those for the unpenetrated shell. The buckling loads for the penetrated shells in which stiffeners were interrupted were less than that for the unpenetrated shells. Results of all tests are compared to numerical solutions carried out using a nonlinear collapse analysis and to the predictions of ASME Code Case N-284

  11. Sharps container

    Science.gov (United States)

    Lee, Angelene M. (Inventor)

    1992-01-01

    This invention relates to a system for use in disposing of potentially hazardous items and more particularly a Sharps receptacle for used hypodermic needles and the like. A Sharps container is constructed from lightweight alodined nonmagnetic metal material with a cup member having an elongated tapered shape and length greater than its transverse dimensions. A magnet in the cup member provides for metal retention in the container. A nonmagnetic lid member has an opening and spring biased closure flap member. The flap member is constructed from stainless steel. A Velcro patch on the container permits selective attachment at desired locations.

  12. The effect of increasing levels of fish oil-containing structured triglycerides on protein metabolism in parenterally fed rats stressed by burn plus endotoxin.

    Science.gov (United States)

    Gollaher, C J; Fechner, K; Karlstad, M; Babayan, V K; Bistrian, B R

    1993-01-01

    This report investigates the effect of various levels of medium-chain/fish oil structured triglycerides on protein and energy metabolism in hypermetabolic rats. Male Sprague-Dawley rats (192 to 226 g) were continuously infused with isovolemic diets that provided 200 kcal/kg per day and 2 g of amino acid nitrogen per kilogram per day. The percentage of nonnitrogen calories as structured triglyceride was varied: no fat, 5%, 15%, or 30%. A 30% long-chain triglyceride diet was also provided as a control to compare the protein-sparing abilities of these two types of fat. Nitrogen excretion, plasma albumin, plasma triglycerides, and whole-body and liver and muscle protein kinetics were determined after 3 days of feeding. Whole-body protein breakdown, flux, and oxidation were similar in all groups. The 15% structured triglyceride diet maximized whole-body protein synthesis (p structured triglyceride (p triglycerides were markedly elevated in the 30% structured triglyceride-fed rats. The 30% structured triglyceride diet maintained plasma albumin levels better than those diets containing no fat, 5% medium-chain triglyceride/fish oil structured triglyceride, or 30% long-chain triglycerides. Nitrogen excretion was lower in animals receiving 30% of nonnitrogen calories as a structured triglyceride than in those receiving 30% as long-chain triglycerides, but this difference did not reach statistical significance (p = .1). These data suggest that protein metabolism is optimized when structured triglyceride is provided at relatively low dietary fat intakes.

  13. Establishment of the evaluation method of the tendon effective stress in the containment building and the concrete material nonlinear model(II)

    International Nuclear Information System (INIS)

    Chung, Chul Hun; Park, Jae Gyun; Kim, Jong Suk; Yun, Yeon Suk; Kim, Se Hun; Chung, Dong Jin

    2006-12-01

    To elevate the structural integrity of the NPP containment building more rigorously, the effective prestress, which is one of the most affecting elements, needs to be estimated exactly. In the second year study, we evaluated the proposed effective prestress measuring method which uses pressure decreasing technique through experiments. It is possible to improve the effective prestress measuring method by test beam, which is being applied for the investigation of the Nuclear Power Plant in operation. We performed a finite element analysis to evaluate the effect of the prestress loss of the tendon to the behavior of the structure. According to the results, the effect of the prestress loss of the vertical and circumventive tendon to some level in the confinement building was analyzed. Another requirement for te rigorous evaluation of the structural soundness is the fast and exact analysis of structural responses under such extreme loads as earthquakes. To achieve this goal, we need analysis models that can describe nonlinear behavior of each material well. In this second year, based on the analysis results during first year, we propose a guideline for the concrete modeling via ABAQUS, a multi-purpose finite element analysis program, and perform static and dynamic analyses

  14. Design aids for stiffened composite shells with cutouts

    CERN Document Server

    Sahoo, Sarmila

    2017-01-01

    This book focuses on the free vibrations of graphite-epoxy laminated composite stiffened shells with cutout both in terms of the natural frequencies and mode shapes. The dynamic analysis of shell structures, which may have complex geometry and arbitrary loading and boundary conditions, is solved efficiently by the finite element method, even including cutouts in shells. The results may be readily used by practicing engineers dealing with stiffened composite shells with cutouts. Several shell forms viz. cylindrical shell, hypar shell, conoidal shell, spherical shell, saddle shell, hyperbolic paraboloidal shell and elliptic paraboloidal shell are considered in the book. The dynamic characteristics of stiffened composite shells with cutout are described in terms of the natural frequency and mode shapes. The size of the cutouts and their positions with respect to the shell centre are varied for different edge constraints of cross-ply and angle-ply laminated composite shells. The effects of these parametric variat...

  15. A role for progesterone and α4-containing GABAA receptors of hippocampal pyramidal cells in the exacerbated running response of adolescent female mice to repeated food restriction stress

    Science.gov (United States)

    Wable, Gauri; Chen, Yi-Wen; Rashid, Shannon; Aoki, Chiye

    2015-01-01

    Adolescent females are particularly vulnerable to mental illnesses with comorbidity of anxiety, such as anorexia nervosa (AN). We used an animal model of AN, called activity-based anorexia (ABA), to investigate the neurobiological basis of vulnerability to repeated, food restriction (FR) stress-evoked anxiety. Twenty-one of 23 adolescent female mice responded to the 1st FR with increased wheel running activity (WRA), even during the limited period of food access, thereby capturing AN's symptoms of voluntary FR and over-exercise. Baseline WRA was an excellent predictor of FR-elicited WRA (severity of ABA, SOA), with high baseline-runners responding to FR with minimal SOA (i.e., negative correlation). Nine gained resistance to ABA following the 1st FR. Even though allopregnanolone (3α-OH-5α-pregnan-20-one, THP), the metabolite of progesterone (P4), is a well-recognized anxiolytic agent, subcutaneous P4 to these ABA-resistant animals during the 2nd FR was exacerbative, evoking greater WRA than the counterpart resistant group that received oil vehicle, only. Moreover, P4 had no WRA-reducing effect on animals that remained ABA-vulnerable. To explain the sensitizing effect of P4 upon the resistant mice, we examined the relationship between P4 treatment and levels of the α4 subunit of GABAARs at spines of pyramidal cells of the hippocampal CA1, a parameter previously shown to correlate with resistance to ABA. α4 levels at spine membrane correlated strongly and negatively with SOA during the 1st ABA (prior to P4 injection), confirming previous findings. α4 expression levels were greater among P4-treated animals that had gained resistance than of vehicle-treated resistant animals or of the vulnerable animals with or without P4. We propose that α4-GABAARs play a protective role by counterbalancing the ABA-induced increase in excitability of CA1 pyramidal neurons, and although exogenous P4's metabolite, THP, enhances α4 expression, especially among those that can gain

  16. Effect of feeding Rumen-protected capsule containing niacin, K2SO4, vitamin C, and gamma-aminobutyric acid on heat stress and performance of dairy cows.

    Science.gov (United States)

    Guo, W J; Zhen, L; Zhang, J X; Lian, S; Si, H F; Guo, J R; Yang, H M

    2017-10-01

    This study was conducted to evaluate the effects of supplemental rumen-protected capsule (RPC) on animal performance, serological indicators, and serum heat shock protein 70 (HSP70) of lactating Holstein cows under heat stress (HS). During summer months, 30 healthy multiparous lactating Holstein cows with a parity number of 3.1 ± 0.44, 70 ± 15 d in milk, an average body weight of 622 ± 62kg, and an average milk yield of 32.28 ± 0.96kg/d, were used. The cows were randomly allocated to two groups: a control group and an RPC-supplemented group (0.13373kg K 2 SO 4 , 0.02488kg vitamin C, 0.021148kg niacin, and 0.044784kggamma-aminobutyric acid per cow). During the 42-d experiment, ambient air temperature and relative humidity inside and outside the barn were recorded hourly every day for the determination of temperature-humidity index (THI). Milk and blood samples were collected every week, and body weight and body condition scoring were measured on day 0. Based on the THI values, the animals had moderate HS. On day 42, the RPC group had lower HSP70, adrenocorticotropic hormone (P = 0.0001), lactate dehydrogenase (P = 0.0338), and IL-6 (P = 0.0724) levels than the control group, with no significant differences in creatine kinase, glucocorticoid, or IL-2 levels. Milk yield, energy-corrected milk, and dry matter intake were higher in RPC than in the control group (P = 0.0196). There were no significant differences in milk fat or daily protein levels between the two groups; however, daily protein and milk fat levels were higher in the RPC group than in the control group (P = 0.0114 and P = 0.0665, respectively). Somatic cell counts were no different between the two groups. In conclusion, RPC may alleviate HS and improve dairy cow performance. Copyright © 2017. Published by Elsevier Ltd.

  17. Pressure Shell Approach to Integrated Environmental Protection

    Science.gov (United States)

    Kennedy, Kriss J.

    2011-01-01

    The next generation of exploration mission human systems will require environmental protection such as radiation protection that is effective and efficient. In order to continue human exploration, habitat systems will require special shells to protect astronauts from hostile environments. The Pressure Shell Approach to integrated environmental (radiation) protection is a multi-layer shell that can be used for multifunctional environmental protection. Self-healing, self-repairing nano technologies and sensors are incorporated into the shell. This shell consists of multiple layers that can be tailored for specific environmental protection needs. Mainly, this innovation focuses on protecting crew from exposure to micrometeorites, thermal, solar flares, and galactic cosmic ray (GCR) radiation. The Pressure Shell Approach consists of a micrometeoroid and secondary ejecta protection layer; a thin, composite shell placed in between two layers that is non-structural; an open cavity layer that can be filled with water, regolith, or polyethylene foam; a thicker composite shell that is a structural load bearing that is placed between two layers; and a bladder coating on the interior composite shell. This multi-layer shell creates an effective radiation protection system. Most of its layers can be designed with the materials necessary for specific environments. In situ materials such as water or regolith can be added to the shell design for supplemental radiation protection.

  18. Charged shells in Lovelock gravity: Hamiltonian treatment and physical implications

    International Nuclear Information System (INIS)

    Dias, Goncalo A. S.; Gao, Sijie; Lemos, Jose P. S.

    2007-01-01

    Using a Hamiltonian treatment, charged thin shells, static and dynamic, in spherically symmetric spacetimes, containing black holes or other specific types of solutions, in d dimensional Lovelock-Maxwell theory are studied. The free coefficients that appear in the Lovelock theory are chosen to obtain a sensible theory, with a negative cosmological constant appearing naturally. Using an Arnowitt-Deser-Misner (ADM) description, one then finds the Hamiltonian for the charged shell system. Variation of the Hamiltonian with respect to the canonical coordinates and conjugate momenta, and the relevant Lagrange multipliers, yields the dynamic and constraint equations. The vacuum solutions of these equations yield a division of the theory into two branches, namely d-2k-1>0 (which includes general relativity, Born-Infeld type theories, and other generic gravities) and d-2k-1=0 (which includes Chern-Simons type theories), where k is the parameter giving the highest power of the curvature in the Lagrangian. There appears an additional parameter χ=(-1) k+1 , which gives the character of the vacuum solutions. For χ=1 the solutions, being of the type found in general relativity, have a black hole character. For χ=-1 the solutions, being of a new type not found in general relativity, have a totally naked singularity character. Since there is a negative cosmological constant, the spacetimes are asymptotically anti-de Sitter (AdS), and AdS when empty (for zero cosmological constant the spacetimes are asymptotically flat). The integration from the interior to the exterior vacuum regions through the thin shell takes care of a smooth junction, showing the power of the method. The subsequent analysis is divided into two cases: static charged thin shell configurations, and gravitationally collapsing charged dust shells (expanding shells are the time reversal of the collapsing shells). In the collapsing case, into an initially nonsingular spacetime with generic character or an empty

  19. Reactor container

    International Nuclear Information System (INIS)

    Kojima, Yoshihiro; Hosomi, Kenji; Otonari, Jun-ichiro.

    1997-01-01

    In the present invention, a catalyst for oxidizing hydrogen to be disposed in a reactor container upon rupture of pipelines of a reactor primary coolant system is prevented from deposition of water droplets formed from a reactor container spray to suppress elevation of hydrogen concentration in the reactor container. Namely, a catalytic combustion gas concentration control system comprises a catalyst for oxidizing hydrogen and a support thereof. In addition, there is also disposed a water droplet deposition-preventing means for preventing deposition of water droplets in a reactor pressure vessel on the catalyst. Then, the effect of the catalyst upon catalytic oxidation reaction of hydrogen can be kept high. The local elevation of hydrogen concentration can be prevented even upon occurrence of such a phenomenon that various kinds of mobile forces in the container such as dry well cooling system are lost. (I.S.)

  20. Indentation of Ellipsoidal and Cylindrical Elastic Shells

    KAUST Repository

    Vella, Dominic

    2012-10-01

    Thin shells are found in nature at scales ranging from viruses to hens\\' eggs; the stiffness of such shells is essential for their function. We present the results of numerical simulations and theoretical analyses for the indentation of ellipsoidal and cylindrical elastic shells, considering both pressurized and unpressurized shells. We provide a theoretical foundation for the experimental findings of Lazarus etal. [following paper, Phys. Rev. Lett. 109, 144301 (2012)PRLTAO0031-9007] and for previous work inferring the turgor pressure of bacteria from measurements of their indentation stiffness; we also identify a new regime at large indentation. We show that the indentation stiffness of convex shells is dominated by either the mean or Gaussian curvature of the shell depending on the pressurization and indentation depth. Our results reveal how geometry rules the rigidity of shells. © 2012 American Physical Society.