WorldWideScience

Sample records for drip shield corrosion

  1. General Corrosion and Localized Corrosion of the Drip Shield

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua

    2004-09-16

    The repository design includes a drip shield (BSC 2004 [DIRS 168489]) that provides protection for the waste package both as a barrier to seepage water contact and a physical barrier to potential rockfall. The purpose of the process-level models developed in this report is to model dry oxidation, general corrosion, and localized corrosion of the drip shield plate material, which is made of Ti Grade 7. This document is prepared according to ''Technical Work Plan For: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The models developed in this report are used by the waste package degradation analyses for TSPA-LA and serve as a basis to determine the performance of the drip shield. The drip shield may suffer from other forms of failure such as the hydrogen induced cracking (HIC) or stress corrosion cracking (SCC), or both. Stress corrosion cracking of the drip shield material is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]). Hydrogen induced cracking of the drip shield material is discussed in ''Hydrogen Induced Cracking of Drip Shield'' (BSC 2004 [DIRS 169847]).

  2. General Corrosion and Localized Corrosion of the Drip Shield

    International Nuclear Information System (INIS)

    F. Hua

    2004-01-01

    The repository design includes a drip shield (BSC 2004 [DIRS 168489]) that provides protection for the waste package both as a barrier to seepage water contact and a physical barrier to potential rockfall. The purpose of the process-level models developed in this report is to model dry oxidation, general corrosion, and localized corrosion of the drip shield plate material, which is made of Ti Grade 7. This document is prepared according to ''Technical Work Plan For: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The models developed in this report are used by the waste package degradation analyses for TSPA-LA and serve as a basis to determine the performance of the drip shield. The drip shield may suffer from other forms of failure such as the hydrogen induced cracking (HIC) or stress corrosion cracking (SCC), or both. Stress corrosion cracking of the drip shield material is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]). Hydrogen induced cracking of the drip shield material is discussed in ''Hydrogen Induced Cracking of Drip Shield'' (BSC 2004 [DIRS 169847])

  3. General Corrosion and Localized Corrosion of the Drip Shield

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua; K. Mon

    2003-06-24

    The recommended waste package (WP) design is described in BSC (2001a). The design includes a double-wall WP underneath a protective drip shield (DS) (BSC 2003a). The purpose of the process-level models developed in this report is to model dry oxidation (DOX), general corrosion (GC) and localized corrosion (LC) of the DS plate material, which is made of Ti Grade 7. The DS design also includes structural supports fabricated from Ti Grade 24. Degradation of Ti Grade 24 is not considered in this report. The DS provides protection for the waste package outer barrier (WPOB) both as a barrier to seepage water contact and a physical barrier to potential rockfall. This Model Report (MR) serves as a feed to the Integrated Waste Package Degradation Model (IWPD) analyses, and was developed in accordance with the Technical Work Plan (TWP) (BSC 2002a). The models contained in this report serve as a basis to determine whether or not the performance requirements for the DS can be met.

  4. General Corrosion and Localized Corrosion of the Drip Shield

    International Nuclear Information System (INIS)

    Hua, F.; Mon, K.

    2003-01-01

    The recommended waste package (WP) design is described in BSC (2001a). The design includes a double-wall WP underneath a protective drip shield (DS) (BSC 2003a). The purpose of the process-level models developed in this report is to model dry oxidation (DOX), general corrosion (GC) and localized corrosion (LC) of the DS plate material, which is made of Ti Grade 7. The DS design also includes structural supports fabricated from Ti Grade 24. Degradation of Ti Grade 24 is not considered in this report. The DS provides protection for the waste package outer barrier (WPOB) both as a barrier to seepage water contact and a physical barrier to potential rockfall. This Model Report (MR) serves as a feed to the Integrated Waste Package Degradation Model (IWPD) analyses, and was developed in accordance with the Technical Work Plan (TWP) (BSC 2002a). The models contained in this report serve as a basis to determine whether or not the performance requirements for the DS can be met

  5. Abstraction of Models for Pitting and Crevice Corrosion of Drip Shield and Waste Package Outer Barrier

    International Nuclear Information System (INIS)

    Mon, K.

    2001-01-01

    This analyses and models report (AMR) was conducted in response to written work direction (CRWMS M and O 1999a). ICN 01 of this AMR was developed following guidelines provided in TWP-MGR-MD-000004 REV 01, ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001, Addendum B). The purpose and scope of this AMR is to review and analyze upstream process-level models (CRWMS M and O 2000a and CRWMS M and O 2000b) and information relevant to pitting and crevice corrosion degradation of waste package outer barrier (Alloy 22) and drip shield (Titanium Grade 7) materials, and to develop abstractions of the important processes in a form that is suitable for input to the WAPDEG analysis for long-term degradation of waste package outer barrier and drip shield in the repository. The abstraction is developed in a manner that ensures consistency with the process-level models and information and captures the essential behavior of the processes represented. Also considered in the model abstraction are the probably range of exposure conditions in emplacement drifts and local exposure conditions on drip shield and waste package surfaces. The approach, method, and assumptions that are employed in the model abstraction are documented and justified

  6. Abstraction of Models for Pitting and Crevice Corrosion of Drip Shield and Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    K. Mon

    2001-08-29

    This analyses and models report (AMR) was conducted in response to written work direction (CRWMS M and O 1999a). ICN 01 of this AMR was developed following guidelines provided in TWP-MGR-MD-000004 REV 01, ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001, Addendum B). The purpose and scope of this AMR is to review and analyze upstream process-level models (CRWMS M and O 2000a and CRWMS M and O 2000b) and information relevant to pitting and crevice corrosion degradation of waste package outer barrier (Alloy 22) and drip shield (Titanium Grade 7) materials, and to develop abstractions of the important processes in a form that is suitable for input to the WAPDEG analysis for long-term degradation of waste package outer barrier and drip shield in the repository. The abstraction is developed in a manner that ensures consistency with the process-level models and information and captures the essential behavior of the processes represented. Also considered in the model abstraction are the probably range of exposure conditions in emplacement drifts and local exposure conditions on drip shield and waste package surfaces. The approach, method, and assumptions that are employed in the model abstraction are documented and justified.

  7. Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material

    International Nuclear Information System (INIS)

    Gordon, G.

    2004-01-01

    Stress corrosion cracking is one of the most common corrosion-related causes for premature breach of metal structural components. Stress corrosion cracking is the initiation and propagation of cracks in structural components due to three factors that must be present simultaneously: metallurgical susceptibility, critical environment, and static (or sustained) tensile stresses. This report was prepared according to ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of this report is to provide an evaluation of the potential for stress corrosion cracking of the engineered barrier system components (i.e., the drip shield, waste package outer barrier, and waste package stainless steel inner structural cylinder) under exposure conditions consistent with the repository during the regulatory period of 10,000 years after permanent closure. For the drip shield and waste package outer barrier, the critical environment is conservatively taken as any aqueous environment contacting the metal surfaces. Appendix B of this report describes the development of the SCC-relevant seismic crack density model (SCDM). The consequence of a stress corrosion cracking breach of the drip shield, the waste package outer barrier, or the stainless steel inner structural cylinder material is the initiation and propagation of tight, sometimes branching, cracks that might be induced by the combination of an aggressive environment and various tensile stresses that can develop in the drip shields or the waste packages. The Stainless Steel Type 316 inner structural cylinder of the waste package is excluded from the stress corrosion cracking evaluation because the Total System Performance Assessment for License Application (TSPA-LA) does not take credit for the inner cylinder. This document provides a detailed description of the process-level models that can be applied to assess the performance of Alloy 22

  8. Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material

    Energy Technology Data Exchange (ETDEWEB)

    G. Gordon

    2004-10-13

    Stress corrosion cracking is one of the most common corrosion-related causes for premature breach of metal structural components. Stress corrosion cracking is the initiation and propagation of cracks in structural components due to three factors that must be present simultaneously: metallurgical susceptibility, critical environment, and static (or sustained) tensile stresses. This report was prepared according to ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of this report is to provide an evaluation of the potential for stress corrosion cracking of the engineered barrier system components (i.e., the drip shield, waste package outer barrier, and waste package stainless steel inner structural cylinder) under exposure conditions consistent with the repository during the regulatory period of 10,000 years after permanent closure. For the drip shield and waste package outer barrier, the critical environment is conservatively taken as any aqueous environment contacting the metal surfaces. Appendix B of this report describes the development of the SCC-relevant seismic crack density model (SCDM). The consequence of a stress corrosion cracking breach of the drip shield, the waste package outer barrier, or the stainless steel inner structural cylinder material is the initiation and propagation of tight, sometimes branching, cracks that might be induced by the combination of an aggressive environment and various tensile stresses that can develop in the drip shields or the waste packages. The Stainless Steel Type 316 inner structural cylinder of the waste package is excluded from the stress corrosion cracking evaluation because the Total System Performance Assessment for License Application (TSPA-LA) does not take credit for the inner cylinder. This document provides a detailed description of the process-level models that can be applied to assess the

  9. Hydrogen-Induced Cracking of the Drip Shield

    International Nuclear Information System (INIS)

    F. Hua

    2004-01-01

    Hydrogen-induced cracking is characterized by the decreased ductility and fracture toughness of a material due to the absorption of atomic hydrogen in the metal crystal lattice. Corrosion is the source of hydrogen generation. For the current design of the engineered barrier without backfill, hydrogen-induced cracking may be a concern because the titanium drip shield can be galvanically coupled to rock bolts (or wire mesh), which may fall onto the drip shield, thereby creating conditions for hydrogen production by electrochemical reaction. The purpose of this report is to analyze whether the drip shield will fail by hydrogen-induced cracking under repository conditions within 10,000 years after emplacement. Hydrogen-induced cracking is a scenario of premature failure of the drip shield. This report develops a realistic model to assess the form of hydrogen-induced cracking degradation of the drip shield under the hydrogen-induced cracking. The scope of this work covers the evaluation of hydrogen absorbed due to general corrosion and galvanic coupling to less noble metals (e.g., Stainless Steel Type 316 and carbon steels) under the repository conditions during the 10,000-year regulatory period after emplacement and whether the absorbed hydrogen content will exceed the critical hydrogen concentration value, above which the hydrogen-induced cracking is assumed to occur. This report also provides the basis for excluding the features, events, and processes (FEPs) related to hydrogen-induced cracking of the drip shield with particular emphasis on FEP 2.1.03.04.OB, hydride cracking of drip shields (DTN: M00407SEPFEPLA.000 [DIRS 170760]). This report is prepared according to ''Technical Work Plan (TWP) for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 169944])

  10. Hydrogen Induced Cracking of Drip Shield

    Energy Technology Data Exchange (ETDEWEB)

    G. De

    2003-02-24

    One potential failure mechanism for titanium and its alloys under repository conditions is via the absorption of atomic hydrogen in the metal crystal lattice. The resulting decreased ductility and fracture toughness may lead to brittle mechanical fracture called hydrogen-induced cracking (HIC) or hydrogen embrittlement. For the current design of the engineered barrier without backfill, HIC may be a problem since the titanium drip shield can be galvanically coupled to rock bolts (or wire mesh), which may fall onto the drip shield, thereby creating conditions for hydrogen production by electrochemical reaction. The purpose of this scientific analysis and modeling activity is to evaluate whether the drip shield will fail by HIC or not under repository conditions within 10,000 years of emplacement. This Analysis and Model Report (AMR) addresses features, events, and processes related to hydrogen induced cracking of the drip shield. REV 00 of this AMR served as a feed to ''Waste Package Degradation Process Model Report'' and was developed in accordance with the activity section ''Hydrogen Induced Cracking of Drip Shield'' of the development plan entitled ''Analysis and Model Reports to Support Waste Package PMR'' (CRWMS M&O 1999a). This AMR, prepared according to ''Technical Work Plan for: Waste Package Materials Data Analyses and Modeling'' (BSC 2002), is to feed the License Application.

  11. WAPDEG Analysis of Waste Package and Drip shield Degradation

    International Nuclear Information System (INIS)

    K. Mon

    2004-01-01

    As directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), an analysis of the degradation of the engineered barrier system (EBS) drip shields and waste packages at the Yucca Mountain repository is developed. The purpose of this activity is to provide the TSPA with inputs and methodologies used to evaluate waste package and drip shield degradation as a function of exposure time under exposure conditions anticipated in the repository. This analysis provides information useful to satisfy ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]) requirements. Several features, events, and processes (FEPs) are also discussed (Section 6.2, Table 15). The previous revision of this report was prepared as a model report in accordance with AP-SIII.10Q, Models. Due to changes in the role of this report since the site recommendation, it no longer contains model development. This revision is prepared as a scientific analysis in accordance with AP-SIII.9Q, ''Scientific Analyses'' and uses models previously validated in (1) ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]); (2) ''General Corrosion and Localized Corrosion of Waste Package Outer Barrier'' (BSC 2004 [DIRS 169984]); and (3) ''General Corrosion and Localized Corrosion of Drip Shield'' (BSC 2004 [DIRS 169845]). The integrated waste package degradation (IWPD) analysis presented in this report treats several implementation-related issues, such as defining the number and size of patches per waste package that undergo stress corrosion cracking; recasting the weld flaw analysis in a form as implemented in the Closure Weld Defects (CWD) software; and, general corrosion rate manipulations (e.g., change of scale in Section 6.3.4). The weld flaw portion of this report takes input from an engineering calculation (BSC 2004

  12. 2003 International High-Level Radioactive Waste Management Conference Breached Drip Shield Test and Validation of a TSPA Sub-Model

    International Nuclear Information System (INIS)

    Walton, Z.P.; Kam, J.T.

    2002-01-01

    The Engineered Barrier System (EBS) represents the system of human engineered barriers in the isolation of high-level radioactive waste in the proposed repository at Yucca Mountain. It is designed to complement and enhance the natural barriers to isolate and prevent the transport of radionuclides into the surrounding environment. The transport mechanism most frequently postulated for radionuclides is liquid water flux that has penetrated the EBS through corrosion breaches in the drip shield and waste packages (WP). A water flux-splitting model is used to predict flow through WP and drip shield breaches and is documented in the ''EBS Radionuclide Transport Abstraction''. A future revision of the ''EBS Radionuclide Transport Abstraction'' will be one component of the total system performance assessment--license application (TSPA-LA) for the Yucca Mountain repository. The flux-splitting model is conservative based on the following assumptions: (1) Drip impact occurs without a loss of water mass. (2) Dripping flux falls exactly at the crown of the drip shield as opposed to different locations on the curved surface, which will effect splashing and flow patterns. (3) The flux passing through a drip shield patch is proportional to the ratio of the length of the penetration in the axial direction to the total axial length of the drip shield. In this assumption all fluid that drips and flows from the drip shield crown toward a penetration will be collected if the axial locations of the source and patch coincide. (4) The potential for evaporation is ignored. Because of these conservatisms, the current version of the flux-splitting model is incapable of accounting for water that has been splashed from the impact location, the deviation of water paths (rivulets) from the axis of impact, and water loss due to evaporation. This paper will present the results of a series of breached drip shield tests used to collect empirical data for the initial validation and further

  13. FEPs Screening of Processes and Issues in Drip Shield and Waste Package Degradation

    Energy Technology Data Exchange (ETDEWEB)

    K. Mon

    2004-10-11

    The purpose of this report is to evaluate and document the inclusion or exclusion of features, events and processes (FEPs) with respect to drip shield and waste package modeling used to support the Total System Performance Assessment for License Application (TSPA-LA). Thirty-three FEPs associated with the waste package and drip shield performance have been identified (DTN: MO0407SEPFEPLA.000 [DIRS 170760]). A screening decision, either ''included'' or ''excluded,'' has been assigned to each FEP, with the technical bases for screening decisions, as required by the Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs analyses in this report address issues related to the degradation and potential failure of the drip shield and waste package over the post closure regulatory period of 10,000 years after permanent closure. For included FEPs, this report summarizes the disposition of the FEP in TSPA-LA. For excluded FEPs, this report provides the technical bases for the screening arguments for exclusion from TSPA-LA. The analyses are for the TSPA-LA base-case design (BSC 2004 [DIRS 168489]), where a drip shield is placed over the waste package without backfill over the drip shield (BSC 2004 [DIRS 168489]). Each FEP includes one or more specific issues, collectively described by a FEP name and description. The FEP description encompasses a single feature, event, or process, or a few closely related or coupled processes, provided the entire FEP can be addressed by a single specific screening argument or TSPA-LA disposition. The FEPs were assigned to associated Project reports, so the screening decisions reside with the relevant subject-matter experts.

  14. FEPs Screening of Processes and Issues in Drip Shield and Waste Package Degradation

    International Nuclear Information System (INIS)

    K. Mon

    2004-01-01

    The purpose of this report is to evaluate and document the inclusion or exclusion of features, events and processes (FEPs) with respect to drip shield and waste package modeling used to support the Total System Performance Assessment for License Application (TSPA-LA). Thirty-three FEPs associated with the waste package and drip shield performance have been identified (DTN: MO0407SEPFEPLA.000 [DIRS 170760]). A screening decision, either ''included'' or ''excluded,'' has been assigned to each FEP, with the technical bases for screening decisions, as required by the Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs analyses in this report address issues related to the degradation and potential failure of the drip shield and waste package over the post closure regulatory period of 10,000 years after permanent closure. For included FEPs, this report summarizes the disposition of the FEP in TSPA-LA. For excluded FEPs, this report provides the technical bases for the screening arguments for exclusion from TSPA-LA. The analyses are for the TSPA-LA base-case design (BSC 2004 [DIRS 168489]), where a drip shield is placed over the waste package without backfill over the drip shield (BSC 2004 [DIRS 168489]). Each FEP includes one or more specific issues, collectively described by a FEP name and description. The FEP description encompasses a single feature, event, or process, or a few closely related or coupled processes, provided the entire FEP can be addressed by a single specific screening argument or TSPA-LA disposition. The FEPs were assigned to associated Project reports, so the screening decisions reside with the relevant subject-matter experts

  15. FEPs Screening of Processes and Issues in Drip Shield and Waste Package Degradation

    International Nuclear Information System (INIS)

    K.G. Mon; L.A. Rottinghaus

    2004-01-01

    As directed by a written development plan (BSC 2002 [DIRS 161132]), the primary purpose of this scientific analysis is to identify and document the analyses and resolution of the features, events, and processes (FEPs) affecting the waste package and drip shield performance in the repository. Thirty-three FEPs were identified that are associated with the waste package and drip shield performance. This scientific analysis has been prepared to document the screening methodology used in the process of FEP inclusion and exclusion. The scope of this scientific analysis is to identify the treatment of the FEPs affecting postclosure waste package and drip shield performance. It should be noted that seismic effects are not treated within this report. A full discussion of seismic effects is contained in the ''Engineered Barrier System Features, Events, and Processes'' report (BSC 2004 [DIRS 167253]). The FEPs that are deemed potentially important to repository postclosure performance are evaluated, either as components of the total system performance assessment (TSPA) or as a separate discussion in a scientific analysis report. The scope for this activity involves two tasks, namely: Task 1: Identify which FEPs are to be considered explicitly in the TSPA (called included FEPs) and in which scientific analyses these FEPs are addressed. Task 2: Identify FEPs not to be included in the TSPA (called excluded FEPs) and provide justification for why these FEPs do not need to be a part of the TSPA model. The analyses documented in this scientific analysis are for the license application (LA) base case design (BSC 2004 [DIRS 167040]). In this design, a drip shield is placed over the waste package and no backfill is placed over the drip shield (BSC 2004 [DIRS 167040]). Each FEP may include one or more specific issues that are collectively described by a FEP name, a FEP description, and descriptor phrases. The FEP Description may encompass a single feature, process or event, or a few

  16. FEPs Screening of Processes and Issues in Drip Shield and Waste Package Degradation

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon; L.A. Rottinghaus

    2004-03-26

    As directed by a written development plan (BSC 2002 [DIRS 161132]), the primary purpose of this scientific analysis is to identify and document the analyses and resolution of the features, events, and processes (FEPs) affecting the waste package and drip shield performance in the repository. Thirty-three FEPs were identified that are associated with the waste package and drip shield performance. This scientific analysis has been prepared to document the screening methodology used in the process of FEP inclusion and exclusion. The scope of this scientific analysis is to identify the treatment of the FEPs affecting postclosure waste package and drip shield performance. It should be noted that seismic effects are not treated within this report. A full discussion of seismic effects is contained in the ''Engineered Barrier System Features, Events, and Processes'' report (BSC 2004 [DIRS 167253]). The FEPs that are deemed potentially important to repository postclosure performance are evaluated, either as components of the total system performance assessment (TSPA) or as a separate discussion in a scientific analysis report. The scope for this activity involves two tasks, namely: Task 1: Identify which FEPs are to be considered explicitly in the TSPA (called included FEPs) and in which scientific analyses these FEPs are addressed. Task 2: Identify FEPs not to be included in the TSPA (called excluded FEPs) and provide justification for why these FEPs do not need to be a part of the TSPA model. The analyses documented in this scientific analysis are for the license application (LA) base case design (BSC 2004 [DIRS 167040]). In this design, a drip shield is placed over the waste package and no backfill is placed over the drip shield (BSC 2004 [DIRS 167040]). Each FEP may include one or more specific issues that are collectively described by a FEP name, a FEP description, and descriptor phrases. The FEP Description may encompass a single feature, process

  17. Oxidative corrosion of spent UO2 fuel in vapor and dripping groundwater at 900C

    International Nuclear Information System (INIS)

    Finch, R. J.

    1999-01-01

    Corrosion of spent UO 2 fuel has been studied in experiments conducted for nearly six years. Oxidative dissolution in vapor and dripping groundwater at 90 C occurs via general corrosion at fuel-fragment surfaces. Dissolution along fuel-grain boundaries is also evident in samples contacted by the largest volumes of groundwater, and corroded grain boundaries extend at least 20 or 30 grains deep (> 200 microm), possibly throughout millimeter-sized fragments. Apparent dissolution of fuel along defects that intersect grain boundaries has created dissolution pits that are 50 to 200 nm in diameter. Dissolution pits penetrate 1-2 microm into each grain, producing a ''worm-like'' texture along fuel-grain-boundaries. Sub-micrometer-sized fuel shards are common between fuel grains and may contribute to the reactive surface area of fuel exposed to groundwater. Outer surfaces of reacted fuel fragments develop a fine-grained layer of corrosion products adjacent to the fuel (5-15 microm thick). A more coarsely crystalline layer of corrosion products commonly covers the fine-grained layer, the thickness of which varies considerably among samples (from less than 5 microm to greater than 40 microm). The thickest and most porous corrosion layers develop on fuel fragments exposed to the largest volumes of groundwater. Corrosion-layer compositions depend strongly on water flux, with uranyl oxy-hydroxides predominating in vapor experiments, and alkali and alkaline earth uranyl silicates predominating in high drip-rate experiments. Low drip-rate experiments exhibit a complex assemblage of corrosion products, including phases identified in vapor and high drip-rate experiments

  18. Environment on the Surfaces of the Drip Shield and Waste Package Outer Barrier

    International Nuclear Information System (INIS)

    T. Wolery

    2005-01-01

    This report provides supporting analysis of the conditions at which an aqueous solution can exist on the drip shield or waste package surfaces, including theoretical underpinning for the evolution of concentrated brines that could form by deliquescence or evaporation, and evaluation of the effects of acid-gas generation on brine composition. This analysis does not directly feed the total system performance assessment for the license application (TSPA-LA), but supports modeling and abstraction of the in-drift chemical environment (BSC 2004 [DIRS 169863]; BSC 2004 [DIRS 169860]). It also provides analyses that may support screening of features, events, and processes, and input for response to regulatory inquiries. This report emphasizes conditions of low relative humidity (RH) that, depending on temperature and chemical conditions, may be dry or may be associated with an aqueous phase containing concentrated electrolytes. Concentrated solutions at low RH may evolve by evaporative concentration of water that seeps into emplacement drifts, or by deliquescence of dust on the waste package or drip shield surfaces. The minimum RH for occurrence of aqueous conditions is calculated for various chemical systems based on current understanding of site geochemistry and equilibrium thermodynamics. The analysis makes use of known characteristics of Yucca Mountain waters and dust from existing tunnels, laboratory data, and relevant information from the technical literature and handbooks

  19. Environment on the Surfaces of the Drip Shield and Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    T. Wolery

    2005-02-22

    This report provides supporting analysis of the conditions at which an aqueous solution can exist on the drip shield or waste package surfaces, including theoretical underpinning for the evolution of concentrated brines that could form by deliquescence or evaporation, and evaluation of the effects of acid-gas generation on brine composition. This analysis does not directly feed the total system performance assessment for the license application (TSPA-LA), but supports modeling and abstraction of the in-drift chemical environment (BSC 2004 [DIRS 169863]; BSC 2004 [DIRS 169860]). It also provides analyses that may support screening of features, events, and processes, and input for response to regulatory inquiries. This report emphasizes conditions of low relative humidity (RH) that, depending on temperature and chemical conditions, may be dry or may be associated with an aqueous phase containing concentrated electrolytes. Concentrated solutions at low RH may evolve by evaporative concentration of water that seeps into emplacement drifts, or by deliquescence of dust on the waste package or drip shield surfaces. The minimum RH for occurrence of aqueous conditions is calculated for various chemical systems based on current understanding of site geochemistry and equilibrium thermodynamics. The analysis makes use of known characteristics of Yucca Mountain waters and dust from existing tunnels, laboratory data, and relevant information from the technical literature and handbooks.

  20. W1045 environment surf drip shield and waste package outer barrier

    International Nuclear Information System (INIS)

    Gdowski, G.

    1999-01-01

    The environments on the drip shield and waste package outer barrier are controlled by the compositions of the waters that contact these components. the temperature (T) of these components, and the effective relative humidity (RH) at these components. Because the composition of the waters that are expected to enter the emplacement drifts (either by seepage flow or by episodic flow) have not been specified: well J13 water was chosen as the reference water (Harrar 1990). Section 6.2 discusses the accessible RH for the temperatures of interest at the repository horizon. Section 6.3 discusses the adsorption of water on metal alloys in the absence of hygroscopic salts. Because the temperatures of the DSs and the WPOBs are higher than those of the surrounding near-field environment, the relative humidity at the DSs and the WPOBs will be lower than that of the surrounding near-field environment. This difference is a result of the water partial pressure in the drift being constant and no higher than the equilibrium water vapor pressure at the temperature of the drift wall

  1. Mechanical Assessment of the Drip Shield Subject to Vibratory Motion and Dynamic and Static Rock Loading

    International Nuclear Information System (INIS)

    R.C. Quittmeyer

    2005-01-01

    The purpose of the drip shield (DS) is to divert water that may seep into emplacement drifts from contacting the waste packages, and to protect the waste packages from impact or static loading from rockfall. The objective of this document is to summarize, into one location, the results of a series of supporting engineering calculations that were developed to study the effect of static and dynamic loads on the mechanical performance of the DS. The potential DS loads are a result of: (1) Potential earthquake vibratory ground motion, and resulting interaction of the DS, waste package and pallet, and drift invert; (2) Dynamic impacts of rockfall resulting from emplacement drift damage as a result of earthquake vibratory motion; and (3) Static load of the caved rock rubble that may come to rest on the DS as a result of vibratory motion or from time-dependent yielding of the rock mass surrounding the emplacement drift. The potential mechanical failure mechanisms that may result from these loads include: (1) Overturning and/or separation of the interlocking DS segments; (2) Loss of structural integrity and stability of the DS, including excessive deformation or buckling; and (3) Localized damage to the top and side-wall plates of the DS. The scope of this document is limited to summarizing results presented in the supporting calculations in the areas of analysis of the potential for DS collapse, and determination of the damaged surface area of the DS plates. New calculations are presented to determine whether or not separation of DSs occur under vibratory motion

  2. Technical Work Plan For: Calculation of Waste Package and Drip Shield Response to Vibratory Ground Motion and Revision of the Seismic Consequence Abstraction

    International Nuclear Information System (INIS)

    M. Gross

    2006-01-01

    The overall objective of the work scope covered by this technical work plan (TWP) is to develop new damage abstractions for the seismic scenario class in total system performance assessment (TSPA). The new abstractions will be based on a new set of waste package and drip shield damage calculations in response to vibratory ground motion and fault displacement. The new damage calculations, which are collectively referred to as damage models in this TWP, are required to represent recent changes in waste form packaging and in the regulatory time frame. The new damage models also respond to comments from the Independent Validation Review Team (IVRT) postvalidation review of the draft TSPA model regarding performance of the drip shield and to an Additional Information Need (AIN) from the U.S. Nuclear Regulatory Commission (NRC)

  3. Technical Work Plan For: Calculation of Waste Packave and Drip Shield Response to Vibratory Ground Motion and Revision of the Seismic Consequence Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross

    2006-12-08

    The overall objective of the work scope covered by this technical work plan (TWP) is to develop new damage abstractions for the seismic scenario class in total system performance assessment (TSPA). The new abstractions will be based on a new set of waste package and drip shield damage calculations in response to vibratory ground motion and fault displacement. The new damage calculations, which are collectively referred to as damage models in this TWP, are required to represent recent changes in waste form packaging and in the regulatory time frame. The new damage models also respond to comments from the Independent Validation Review Team (IVRT) postvalidation review of the draft TSPA model regarding performance of the drip shield and to an Additional Information Need (AIN) from the U.S. Nuclear Regulatory Commission (NRC).

  4. Monitoring Cathodic Shielding and Corrosion under Disbonded Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Varela, F.; Tan, M. Y. J.; Hinton, B.; Forsyth, M. [Deakin University, Victoria (Australia)

    2017-06-15

    Monitoring of corrosion is in most cases based on simulation of environmental conditions on a large and complex structure such as a buried pipeline using a small probe, and the measurement of thermodynamics and kinetics of corrosion processes occurring on the probe surface. This paper presents a hybrid corrosion monitoring probe designed for simulating deteriorating conditions wrought by disbonded coatings and for measuring current densities and distribution of such densities on a simulated pipeline surface. The concept of the probe was experimentally evaluated using immersion tests under cathodic protection (CP) in high resistivity aqueous solution. Underneath the disbonded area, anodic currents and cathodic currents were carefully measured. Anodic current densities were used to calculate metal loss according to Faraday’s law. Calculated corrosion patterns were compared with corrosion damage observed at the surface of the probe after a series of stringent tests. The capability of the probe to measure anodic current densities under CP, without requiring interruption, was demonstrated in high resistivity aqueous solution. The pattern of calculated metal loss correlated well with corrosion products distribution observed at the array surface. Working principles of the probe are explained in terms of electrochemistry.

  5. Yucca Mountain engineered barrier system corrosion model (EBSCOM)

    International Nuclear Information System (INIS)

    King, F.; Kolar, M.; Kessler, J.H.; Apted, M.

    2008-01-01

    A revised engineered barrier system model has been developed by the Electric Power Research Institute to predict the time dependence of the failure of the drip shields and waste packages in the proposed Yucca Mountain repository. The revised model is based on new information on various corrosion processes developed by the US Department of Energy and others and for a 20-mm-thick waste package design with a double closure lid system. As with earlier versions of the corrosion model, the new EBSCOM code produces a best-estimate of the failure times of the various barriers. The model predicts that only 15% of waste packages will fail within a period of 1 million years. The times for the first corrosion failures are 40,000 years, 336,000 years, and 375,000 years for the drip shield, waste package, and combination of drip shield and the associated waste package, respectively

  6. Influence of nitrogen in the shielding gas on corrosion resistance of duplex stainless steel welds

    Science.gov (United States)

    Bhatt, R. B.; Kamat, H. S.; Ghosal, S. K.; de, P. K.

    1999-10-01

    The influence of nitrogen in shielding gas on the corrosion resistance of welds of a duplex stainless steel (grade U-50), obtained by gas tungsten arc (GTA) with filler wire, autogenous GTA (bead-on-plate), electron beam welding (EBW), and microplasma techniques, has been evaluated in chloride solutions at 30 °C. Pitting attack has been observed in GTA, electron beam welding, and microplasma welds when welding has been carried out using pure argon as the shielding gas. Gas tungsten arc welding with 5 to 10% nitrogen and 90 to 95% argon, as the shielding gas, has been found to result in an improved pitting corrosion resistance of the weldments of this steel. However, the resistance to pitting of autogenous welds (bead-on-plate) obtained in pure argon as the shielding gas has been observed to remain unaffected. Microscopic examination, electron probe microanalysis (EPMA), and x-ray diffraction studies have revealed that the presence of nitrogen in the shielding gas in the GTA welds not only modifies the microstructure and the austenite to ferrite ratio but also results in a nearly uniform distribution of the various alloying elements, for example, chromium, nickel, and molybdenum among the constitutent phases, which are responsible for improved resistance to pitting corrosion.

  7. Corrosion of lead shielding in a radiology department

    International Nuclear Information System (INIS)

    Schick, D.K.; CAsey, R.N.; Sim, L.H.; Siddle, K.J.

    1999-01-01

    Corrosion of lead sheet used for structural radiation protection in the Princess Alexandra Hospital Radiology Department has been identified. The corrosion is thought to have been caused by organic acid vapours released from oregon timber wall panelling. Non-destructive testing (NDT) and X-ray transmission measurements were used to define the extent and severity of damage, and subsequently to provide the data necessary for estimation of staff and public radiation doses. Although radiation dose limits have not been exceeded, corrective actions including structural modifications and staff information sessions have been undertaken. Copyright (1999) Blackwell Science Pty Ltd

  8. General and crevice corrosion study of the in-wall shielding materials for ITER vacuum vessel

    Science.gov (United States)

    Joshi, K. S.; Pathak, H. A.; Dayal, R. K.; Bafna, V. K.; Kimihiro, Ioki; Barabash, V.

    2012-11-01

    Vacuum vessel In-Wall Shield (IWS) will be inserted between the inner and outer shells of the ITER vacuum vessel. The behaviour of IWS in the vacuum vessel especially concerning the susceptibility to crevice of shielding block assemblies could cause rapid and extensive corrosion attacks. Even galvanic corrosion may be due to different metals in same electrolyte. IWS blocks are not accessible until life of the machine after closing of vacuum vessel. Hence, it is necessary to study the susceptibility of IWS materials to general corrosion and crevice corrosion under operations of ITER vacuum vessel. Corrosion properties of IWS materials were studied by using (i) Immersion technique and (ii) Electro-chemical Polarization techniques. All the sample materials were subjected to a series of examinations before and after immersion test, like Loss/Gain weight measurement, SEM analysis, and Optical stereo microscopy, measurement of surface profile and hardness of materials. After immersion test, SS 304B4 and SS 304B7 showed slight weight gain which indicate oxide layer formation on the surface of coupons. The SS 430 material showed negligible weight loss which indicates mild general corrosion effect. On visual observation with SEM and Metallography, all material showed pitting corrosion attack. All sample materials were subjected to series of measurements like Open Circuit potential, Cyclic polarization, Pitting potential, protection potential, Critical anodic current and SEM examination. All materials show pitting loop in OC2 operating condition. However, its absence in OC1 operating condition clearly indicates the activity of chloride ion to penetrate oxide layer on the sample surface, at higher temperature. The critical pitting temperature of all samples remains between 100° and 200°C.

  9. Effects of nitrogen in shielding gas on microstructure evolution and localized corrosion behavior of duplex stainless steel welding joint

    Science.gov (United States)

    Zhang, Zhiqiang; Jing, Hongyang; Xu, Lianyong; Han, Yongdian; Zhao, Lei; Zhou, Chao

    2017-05-01

    The effects of nitrogen addition in shielding gas on microstructure evolution and localized corrosion behavior of duplex stainless steel (DSS) welds were studied. N2-supplemented shielding gas facilitated the primary austenite formation, suppressed the Cr2N precipitation in weld root, and increased the microhardnesses of weld metal. Furthermore, N2-supplemented shielding gas increased pitting resistance equivalent number (PREN) of austenite, but which decreased slightly PREN of ferrite. The modified double loop electrochemical potentiokinetic reactivation in 2 M H2SO4 + 1 M HCl was an effective method to study the localized corrosion of the different zones in the DSS welds. The adding 2% N2 to pure Ar shielding gas improved the localized corrosion resistance in the DSS welds, which was due to compensation for nitrogen loss and promoting nitrogen further solution in the austenite phases, suppression of the Cr2N precipitation in the weld root, and increase of primary austenite content with higher PREN than the ferrite and secondary austenite. Secondary austenite are prone to selective corrosion because of lower PREN compared with ferrite and primary austenite. Cr2N precipitation in the pure Ar shielding weld root and heat affected zone caused the pitting corrosion within the ferrite and the intergranular corrosion at the ferrite boundary. In addition, sigma and M23C6 precipitation resulted in the intergranular corrosion at the ferrite boundary.

  10. Microstructure and pitting corrosion of shielded metal arc welded high nitrogen stainless steel

    Directory of Open Access Journals (Sweden)

    Raffi Mohammed

    2015-09-01

    Full Text Available The present work is aimed at studying the microstructure and pitting corrosion behaviour of shielded metal arc welded high nitrogen steel made of Cromang-N electrode. Basis for selecting this electrode is to increase the solubility of nitrogen in weld metal due to high chromium and manganese content. Microscopic studies were carried out using optical microscopy (OM and field emission scanning electron microscopy (FESEM. Energy back scattered diffraction (EBSD method was used to determine the phase analysis, grain size and orientation image mapping. Potentio-dynamic polarization testing was carried out to study the pitting corrosion resistance in aerated 3.5% NaCl environment using a GillAC electrochemical system. The investigation results showed that the selected Cr–Mn–N type electrode resulted in a maximum reduction in delta-ferrite and improvement in pitting corrosion resistance of the weld zone was attributed to the coarse austenite grains owing to the reduction in active sites of the austenite/delta ferrite interface and the decrease in galvanic interaction between austenite and delta-ferrite.

  11. Studies on microstructure, mechanical and corrosion properties of high nitrogen stainless steel shielded metal arc welds

    Science.gov (United States)

    Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

    2018-03-01

    The present work is aimed at studying the microstructure, mechanical and corrosion properties of high nitrogen stainless steel shielded metal arc (SMA) welds made with Cromang-N electrode. Basis for selecting this electrode is to increase the solubility of nitrogen in weld metal due to high chromium and manganese content. Microstructures of the welds were characterized using optical microscopy (OM), field emission scanning electron microscopy (FESEM) and electron back scattered diffraction (EBSD) mainly to determine the morphology, phase analysis, grain size and orientation image mapping. Hardness, tensile and ductility bend tests were carried out to determine mechanical properties. Potentio-dynamic polarization testing was carried out to study the pitting corrosion resistance using a GillAC basic electrochemical system. Constant load type testing was carried out to study stress corrosion cracking (SCC) behaviour of welds. The investigation results shown that the selected Cr–Mn–N type electrode resulted in favourable microstructure and completely solidified as single phase coarse austenite. Mechanical properties of SMA welds are found to be inferior when compared to that of base metal and is due to coarse and dendritic structure.

  12. General Corrosion and Localized Corrosion of Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon

    2004-10-01

    The waste package design for the License Application is a double-wall waste package underneath a protective drip shield (BSC 2004 [DIRS 168489]; BSC 2004 [DIRS 169480]). The purpose and scope of this model report is to document models for general and localized corrosion of the waste package outer barrier (WPOB) to be used in evaluating waste package performance. The WPOB is constructed of Alloy 22 (UNS N06022), a highly corrosion-resistant nickel-based alloy. The inner vessel of the waste package is constructed of Stainless Steel Type 316 (UNS S31600). Before it fails, the Alloy 22 WPOB protects the Stainless Steel Type 316 inner vessel from exposure to the external environment and any significant degradation. The Stainless Steel Type 316 inner vessel provides structural stability to the thinner Alloy 22 WPOB. Although the waste package inner vessel would also provide some performance for waste containment and potentially decrease the rate of radionuclide transport after WPOB breach before it fails, the potential performance of the inner vessel is far less than that of the more corrosion-resistant Alloy 22 WPOB. For this reason, the corrosion performance of the waste package inner vessel is conservatively ignored in this report and the total system performance assessment for the license application (TSPA-LA). Treatment of seismic and igneous events and their consequences on waste package outer barrier performance are not specifically discussed in this report, although the general and localized corrosion models developed in this report are suitable for use in these scenarios. The localized corrosion processes considered in this report are pitting corrosion and crevice corrosion. Stress corrosion cracking is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]).

  13. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua; K. Mon; P. Pasupathi; G. Gordon

    2004-05-11

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review.

  14. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    International Nuclear Information System (INIS)

    Hua, F.; Mon, K.; Pasupathi, P.; Gordon, G.

    2004-01-01

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review

  15. Microstructure and corrosion behavior of shielded metal arc-welded dissimilar joints comprising duplex stainless steel and low alloy steel

    Science.gov (United States)

    Srinivasan, P. Bala; Muthupandi, V.; Sivan, V.; Srinivasan, P. Bala; Dietzel, W.

    2006-12-01

    This work describes the results of an investigation on a dissimilar weld joint comprising a boiler-grade low alloy steel and duplex stainless steel (DSS). Welds produced by shielded metal arc-welding with two different electrodes (an austenitic and a duplex grade) were examined for their microstructural features and properties. The welds were found to have overmatching mechanical properties. Although the general corrosion resistance of the weld metals was good, their pitting resistance was found to be inferior when compared with the DSS base material.

  16. THE ROLE OF SHIELDING GAS ON MECHANICAL, METALLURGICAL AND CORROSION PROPERTIES OF CORTEN STEEL WELDED JOINTS OF RAILWAY COACHES USING GMAW

    Directory of Open Access Journals (Sweden)

    Byju John

    2016-12-01

    Full Text Available This analysis lays emphasis on finding a suitable combination of shielding gas for welding underframe members such as sole bar of Railway Coaches made of corten steel; for improved mechanical, metallurgical and corrosion properties of welds using copper coated solid MIG/MAG welding filler wire size 1.2 mm conforming to AWS/SFA 5.18 ER 70 S in Semi-automatic GMAW process. Solid filler wire is preferred by welders due to less fumes, practically no slag and easy manipulation of welding torch with smooth wire flow during corrosion repair attention, when compared to Flux cored wire. Three joints using Gas metal arc welding (GMAW with shielding gases viz., Pure CO2, (80% Ar – 20% CO2 and (90% Ar – 10% CO2 were made from test pieces cut from Sole bar material of Railway Coach. Study of Mechanical properties such as tensile strength, hardness and toughness revealed that welded joint made using shielding gas (80% Ar – 20% CO2 has better Mechanical properties compared to the other two shielding gases and comparable to that of Parent metal. Type of Shielding gas used has influence on the chemical composition and macro & micro structures. The Tafel extrapolation study of freshly ground samples in 3.5% NaCl solution revealed that the welded joint made using shielding gas (80% Ar – 20% CO2 has also better corrosion resistance which is comparable to the Parent metal as well as similar commercial steels.

  17. Influence of the nitrogen gas addition in the Ar shielding gas on the erosion-corrosion of tube-to-tube sheet welds of hyper duplex stainless steel

    International Nuclear Information System (INIS)

    Kim, Hye-Jin; Jeon, Soon-Hyeok; Kim, Soon-Tae; Lee, In-Sung; Park, Yong-Soo

    2014-01-01

    Duplex stainless steels with nearly equal fraction of the ferrite(α) phase and austenite(γ) phase have been increasingly used for various applications such as power plants, desalination facilities due to their high resistance to corrosion, good weldability, and excellent mechanical properties. Hyper duplex stainless steel (HDSS) is defined as the future duplex stainless steel with a pitting resistance equivalent (PRE= wt.%Cr+3.3(wt.%Mo+0.5wt.%W)+30wt.%N) of above 50. However, when HDSS is welded with gas tungsten arc (GTA), incorporation of nitrogen in the Ar shielding gas are very important because the volume fraction of α-phase and γ-phase is changed and harmful secondary phases can be formed in the welded zone. In other words, the balance of corrosion resistance between two phases and reduction of Cr 2 N are the key points of this study. The primary results of this study are as follows. The addition of N 2 to the Ar shielding gas provides phase balance under weld-cooling conditions and increases the transformation temperature of the α-phase to γ-phase, increasing the fraction of γ-phase as well as decreasing the precipitation of Cr2N. In the anodic polarization test, the addition of nitrogen gas in the Ar shielding gas improved values of the electrochemical parameters, compared to the Pure Ar. Also, in the erosion-corrosion test, the HDSS welded with shielding gas containing N 2 decreased the weight loss, compared to HDSS welded with the Ar pure gas. This result showed the resistance of erosion-corrosion was increased due to increasing the fraction of γ-phase and the stability of passive film according to the addition N 2 gas to the Ar shielding gas. As a result, the addition of nitrogen gas to the shielding gas improved the resistance of erosion-corrosion

  18. Influence of the nitrogen gas addition in the Ar shielding gas on the erosion-corrosion of tube-to-tube sheet welds of hyper duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hye-Jin; Jeon, Soon-Hyeok; Kim, Soon-Tae; Lee, In-Sung; Park, Yong-Soo [Yonsei University, Seoul (Korea, Republic of)

    2014-03-15

    Duplex stainless steels with nearly equal fraction of the ferrite(α) phase and austenite(γ) phase have been increasingly used for various applications such as power plants, desalination facilities due to their high resistance to corrosion, good weldability, and excellent mechanical properties. Hyper duplex stainless steel (HDSS) is defined as the future duplex stainless steel with a pitting resistance equivalent (PRE= wt.%Cr+3.3(wt.%Mo+0.5wt.%W)+30wt.%N) of above 50. However, when HDSS is welded with gas tungsten arc (GTA), incorporation of nitrogen in the Ar shielding gas are very important because the volume fraction of α-phase and γ-phase is changed and harmful secondary phases can be formed in the welded zone. In other words, the balance of corrosion resistance between two phases and reduction of Cr{sub 2}N are the key points of this study. The primary results of this study are as follows. The addition of N{sub 2} to the Ar shielding gas provides phase balance under weld-cooling conditions and increases the transformation temperature of the α-phase to γ-phase, increasing the fraction of γ-phase as well as decreasing the precipitation of Cr2N. In the anodic polarization test, the addition of nitrogen gas in the Ar shielding gas improved values of the electrochemical parameters, compared to the Pure Ar. Also, in the erosion-corrosion test, the HDSS welded with shielding gas containing N{sub 2} decreased the weight loss, compared to HDSS welded with the Ar pure gas. This result showed the resistance of erosion-corrosion was increased due to increasing the fraction of γ-phase and the stability of passive film according to the addition N{sub 2} gas to the Ar shielding gas. As a result, the addition of nitrogen gas to the shielding gas improved the resistance of erosion-corrosion.

  19. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  20. Cell Microencapsulation: Dripping Methods.

    Science.gov (United States)

    Bidoret, A; Martins, E; De Smet, B Poncelet; Poncelet, D

    2017-01-01

    Microencapsulation processes may be divided into three steps, namely: incorporation of the bioactive substance in the matrix, dispersion of the matrix in droplets, and conversion in microcapsules. This contribution is focused on the second step and more specifically using the dripping approach to form droplets by extrusion of liquid through a nozzle. Different technologies of dripping are described, using as an example the production of alginate beads.

  1. The Effect of Shielding N{sub 2} gas on The Pitting Corrosion of Seal-welded Super Austenitic Stainless Steel by Autogenous Welding

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Tae; Kim, Young Sik [Andong National University, Andong (Korea, Republic of); Chang, Hyun Young [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of)

    2017-04-15

    Many research efforts on the effect of nitrogen on the corrosion resistance of stainless steels have been reported, but little research has been conducted on the effect of nitrogen for the weldment of stainless steels by the seal-weld method. Therefore, this work focused on the determining the corrosion resistance of tube/tube sheet mock-up specimen for sea water condensers, and elucidating the effect of shielding nitrogen gas on its resistance. The pitting corrosion of autogenously welded specimen propagated preferentially along the dendritic structure. Regardless of the percent of shielding nitrogen gas, the analyzed nitrogen contents were very much lower than that of the bulk specimen. This can be arisen because the nitrogen in shielding gas may partly dissolve into the weldment, but simultaneously during the welding process, nitrogen in the alloy may escape into the atmosphere. However, the pitting resistance equivalent number (PREN) of the interdendrite area was higher than that of the dendrite arm, regardless of the shielding gas percent; and the PREN of the interdendrite area was higher than that of the base metal; the PREN of the dendrite arm was lower than that of the base metal because of the formation of (Cr, Mo) rich phases by welding.

  2. Corrosion of dissimilar metal crevices in simulated concentrated ground water solutions at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, B.M.; Quinn, M.J

    2003-01-01

    The disposal of high-level nuclear waste in the Yucca Mountain, Nevada is under consideration by the US Department of Energy. The proposed facility will be located in the unsaturated zone approximately 300 m below the surface and 300 m above the water table. The proposed waste container consists of an outer corrosion-resistant Alloy 22 shell surrounding a 316 NG stainless steel structural inner container that encapsulates the used nuclear fuel waste. A titanium drip shield is proposed to protect the waste container from ground water seepage arid rock-fail. A cycle of dripping/evaporation could result in the generation of concentrated aggressive solutions, which could contact the waste container. The waste container material could be susceptible to crevice corrosion from such solutions. The experiments described in this report support the modeling of waste package degradation processes. The intent was to provide parameter values that are required to model crevice corrosion chemistry, as it relates to hydrogen pick-up, and stress corrosion cracking for selected candidate waste package materials. The purpose of the experiments was to study the crevice corrosion behavior of various candidate materials under near freely corroding conditions and to determine the pH developed in crevice solutions. Experimental results of crevice corrosion of dissimilar metal pairs (Alloy 22, Grade-7 and -16 titanium and 316 stainless steel) immersed in a simulated concentrated ground water at {approx}90{sup o}C are reported. The corrosion potential was measured during exposure periods of between 330 and 630 h. Following the experiments, the pH of the crevice solution was measured. The results indicate that a limited degree of crevice acidification occurred during the experiment. The values for corrosion potential suggest that crevice corrosion may have initiated. The total corrosion was limited, with little visible evidence for crevice corrosion being observed on the sample coupon faces

  3. Corrosion of dissimilar metal crevices in simulated concentrated ground water solutions at elevated temperature

    International Nuclear Information System (INIS)

    Ikeda, B.M.; Quinn, M.J.

    2003-01-01

    The disposal of high-level nuclear waste in the Yucca Mountain, Nevada is under consideration by the US Department of Energy. The proposed facility will be located in the unsaturated zone approximately 300 m below the surface and 300 m above the water table. The proposed waste container consists of an outer corrosion-resistant Alloy 22 shell surrounding a 316 NG stainless steel structural inner container that encapsulates the used nuclear fuel waste. A titanium drip shield is proposed to protect the waste container from ground water seepage arid rock-fail. A cycle of dripping/evaporation could result in the generation of concentrated aggressive solutions, which could contact the waste container. The waste container material could be susceptible to crevice corrosion from such solutions. The experiments described in this report support the modeling of waste package degradation processes. The intent was to provide parameter values that are required to model crevice corrosion chemistry, as it relates to hydrogen pick-up, and stress corrosion cracking for selected candidate waste package materials. The purpose of the experiments was to study the crevice corrosion behavior of various candidate materials under near freely corroding conditions and to determine the pH developed in crevice solutions. Experimental results of crevice corrosion of dissimilar metal pairs (Alloy 22, Grade-7 and -16 titanium and 316 stainless steel) immersed in a simulated concentrated ground water at ∼90 o C are reported. The corrosion potential was measured during exposure periods of between 330 and 630 h. Following the experiments, the pH of the crevice solution was measured. The results indicate that a limited degree of crevice acidification occurred during the experiment. The values for corrosion potential suggest that crevice corrosion may have initiated. The total corrosion was limited, with little visible evidence for crevice corrosion being observed on the sample coupon faces. The

  4. Radiation shielding lead shield

    International Nuclear Information System (INIS)

    Dei, Shoichi.

    1991-01-01

    The present invention concerns lead shields for radiation shielding. Shield boxes are disposed so as to surround a pipeline through which radioactive liquids, mists or like other objects are passed. Flanges are formed to each of the end edges of the shield boxes and the shield boxes are connected to each other by the flanges. Upon installation, empty shield boxes not charged with lead particles and iron plate shields are secured at first at the periphery of the pipeline. Then, lead particles are charged into the shield boxes. This attains a state as if lead plate corresponding to the depth of the box is disposed. Accordingly, operations for installation, dismantling and restoration can be conducted in an empty state with reduced weight to facilitate the operations. (I.S.)

  5. Preface for DRIP X proceedings

    Science.gov (United States)

    Landesman (Chairman), Jean-Pierre; Montgomery (Co-Chairman), Paul C.

    2004-07-01

    This issue of the “European Physical Journal Applied Physics” contains the papers presented at the Tenth International Conference on Defects: Recognition, Imaging and Physics in Semiconductors (DRIP X), held in Batz-sur-Mer, France, from 29th September to 2nd October, 2003. The conference gathered 150 scientists from academic institutions and industry of 20 countries from around the world, showing the pertinence of the biennial series of DRIP conferences. A much appreciated aspect of DRIP X was the variety of the different backgrounds of the participants, leading to much fruitful exchange and stimulating discussion. Following the spirit of previous DRIP conferences, the main concern of DRIP X was the methodology and the physics of measurement procedures, together with specific developments in instrumentation, and their relationship with the structural, optical and electrical properties of semiconductor defects. The topics covered related to the different methods and techniques used for the recognition and imaging of defects in semiconductor materials (Si, III-V's including nitrides, SiC, IV-IV's, II-VI's, organic compounds, ...) and in semiconductor devices ranging from defects in the raw materials at the wafer level, through process-induced defects and defects that appear during operation (burn-in, aging tests, ...). One of the highlights of the social events of DRIP X was the awards ceremony as part of the celebrations for the Tenth meeting of DRIP. The founders of the DRIP series, Professor Jean-Pierre Fillard and Professor Tomoya Ogawa were both invited to be permanent members of the International Steering Committee and awarded with appropriately engraved trophies to mark the occasion. With help form Tomoya Ogawa, Jean-Pierre Fillard organized the first DRIP conference in 1985 in La Grande Motte, France. The amusing and thought provoking slide presentation by Jean-Pierre Fillard went a great way to remind us of the history of this conference series and to

  6. Technical and economical evaluation of tape drip and drip line irrigation systems in a strawberry greenhouse

    Directory of Open Access Journals (Sweden)

    Soghra HOSSEINIAN

    2016-04-01

    Full Text Available This study was done in a strawberry greenhouse to examine the technical and the economical evaluation of two drip irrigation systems including the tape and the drip line in the northern part of Iran. The result showed that all of the technical indices with tape were higher than drip line, and due to statistical analysis reveal a significant difference (P < 0.05. Yield and water productivity (WP with tape were higher than drip line (P < 0.05. Benefit per drop (BPD and net benefit per drop (NBPD with tape were higher than drip line. Net present value, internal rate of capital return and benefit to cost ratio in drip line were higher than tape. In general, regarding technical evaluation tape was better than drip line, besides according to the economical evaluation the drip ­lines were better than tape.

  7. Crevice Corrosion Behavior of Candidate Nuclear Waste Container Materials in Repository Environment Paper Number 02529

    International Nuclear Information System (INIS)

    Hua, F.; Sarver, J.; Mohn, W.

    2001-01-01

    Alloy 22 (UNS N06022) and Ti Grade 7 (UNS R52400) have been proposed as the corrosion resistant materials for fabricating the waste package outer barrier and the drip shield, respectively for the proposed nuclear waste repository Yucca Mountain Project. In this work, the susceptibility of welded and annealed Alloy 22 (N06022) and Ti Grade 7 (UNS R52400) to crevice corrosion was studied by the Multiple Crevice Assembly (ASTM G78) method combined with surface morphological observation after four and eight weeks of exposure to the Basic Saturated Water (BSW-12) in a temperature range from 60 to 105 C. The susceptibility of the materials to crevice corrosion was evaluated based on the appearance of crevice attack underneath the crevice formers and the weight loss data. The results showed that, after exposed to BSW-12 for four and eight weeks, no obvious crevice attack was observed on these materials. The descaled weight loss increased with the increase in temperature for all materials. The weight loss, however, is believed to be caused by general corrosion, rather than crevice corrosion. There was no significant difference between the annealed and welded materials either. On the other hand, to conclude that these materials are immune to crevice corrosion in BSW-12 will require longer term testing

  8. Implementation of Localized Corrosion in the Performance Assessment Model for Yucca Mountain

    International Nuclear Information System (INIS)

    Vivek Jain, S.; David Sevougian; Patrick D. Mattie; Kevin G. Mon; Robert J. Mackinnon

    2006-01-01

    A total system performance assessment (TSPA) model has been developed to analyze the ability of the natural and engineered barriers of the Yucca Mountain repository to isolate nuclear waste over the 10,000-year period following repository closure. The principal features of the engineered barrier system (EBS) are emplacement tunnels (or ''drifts'') containing a two-layer waste package (WP) for waste containment and a titanium drip shield to protect the waste package from seeping water and falling rock, The 20-mm-thick outer shell of the WP is composed of Alloy 22, a highly corrosion-resistant nickel-based alloy. The barrier function of the EBS is to isolate the waste from migrating water. The water and its associated chemical conditions eventually lead to degradation of the waste packages and mobilization of the radionuclides within the packages. There are five possible waste package degradation modes of the Alloy 22: general corrosion, microbially influenced corrosion, stress corrosion cracking, early failure due to manufacturing defects, and localized corrosion. This paper specifically examines the incorporation of the Alloy-22 localized corrosion model into the Yucca Mountain TSPA model, particularly the abstraction and modeling methodology, as well as issues dealing with scaling, spatial variability, uncertainty, and coupling to other sub-models that are part of the total system model

  9. Walking at the drip line

    International Nuclear Information System (INIS)

    Bonaccorso, Angela

    2015-01-01

    Among exotic nuclei those at the drip line which are unstable against neutron emission are particularly interesting because they convey information on the nuclear force in the most extreme situations. Strictly speaking they are not ''nuclei'' but they exist thanks to long living resonances between a neutron and a bound ''core'' nucleus. Adding one more neutron they become bound and are called ''borromean''. Being particularly exotic they have attracted much attention in past years. One very challenging example is 13 Be whose level ordering has been discussed in a large number of papers in which it has been studied by transfer and fragmentation experiments, or it has been discussed theoretically. Although projectile fragmentation spectra show evident similarities, the interpretations of data all differ from each other. In this paper we argue that a way trough the problem could be to try to establish first, or at the same time, the quite elusive ''nature'' of the second s-state in the Beryllium isotopes with A=9-14. On the other hand there are other recent neutron removal experiments leading to nuclei unstable by one or more proton emissions, and thus somewhat mirror to borromean nuclei, performed with nuclei close to the proton drip line. It has been shown that by taking in coincidence all (charged) particles but the removed neutron, reconstructing the invariant mass and gating on the ground state peak, it is possible to obtain the longitudinal momentum distribution of the unbound ''core''. One can link it to the original wave function of the bound orbital and thus determine the initial neutron angular momentum from the shape of the distribution and the initial occupation probability from the absolute removal cross section. Then it is clear that modern experiments and theories are able to study unstable nuclei with the same degree of accuracy as stable nuclei. Such a

  10. Phosphorus absorption in drip irrigation

    International Nuclear Information System (INIS)

    Guennelon, R.; Habib, R.

    1979-01-01

    Introducing the use of solute phosphate with drip irrigation may be an unsatisfying practice on account of the very weak mobility of PO 4 anion. Nevertheless P can move down to 30-40 cm depth by following the saturated flux along earth-worms holes or crakes, or by displacement in very narrow structural porosity, even in heavy soils. In this case roots cannot easily absorb PO 4 from soil solution, as soon as the soil is quite saturated. On the other hand, it seems that P absorption occurs very quickly and easily when the implantation of 32 P tagged solution is carried out at the border of zone which is concerned by the irrigation effects [fr

  11. Assessment of risk associated with long-term corrosion of alloy 22 and Ti-7 in the potential yucca mountain high-level nuclear waste repository

    International Nuclear Information System (INIS)

    Ahn, T.M.; Pensado, O.; Dunn, D.

    2004-01-01

    Full text of publication follows: The potential high-level nuclear waste (HLW) repository at Yucca Mountain (YM) may rely on the robustness of the outer container of the waste package (WP) as one of many barriers for waste isolation. The container is proposed to be constructed of Alloy 22, a Ni-Cr-Mo alloy known to be resistant to localized corrosion and stress corrosion cracking. Additionally, drip shields (DS) will be emplaced above the WP to minimize the groundwater contact, in the form of seepage, with the WP. The candidate alloy to construct the drip shields is a titanium based alloy (Ti-7) with some small amounts of Pd and is also known for resistance to localized corrosion. To enhance confidence of long-term WP and DS lifetimes, it is necessary to assess the conditions under which loss of passivity or localized degradation processes could occur. The accelerated degradation processes may include uniform passivity breakdown, localized corrosion, and stress corrosion cracking. This paper evaluates how such processes may occur under the long-term YM repository conditions. In the uniform passivity breakdown, three potential concerns are evaluated. The first is anodic sulphur segregation at the interface between the passive film and the bare metal. This paper models the cyclic behavior of free transient fast dissolution (induced by sulfur segregation) and re-passivation. The second is the potential accumulation of corrosion products on the WP surface, which may act as cathode of large surface area leading to fast corrosion. The effective ratio of the corrosion product area to the bare metal area is evaluated. The third is the ion selectivity in the corrosion products to alter the aqueous chemistry, which may accelerate or inhibit the corrosion. Thermodynamics of ionic sorption in the corrosion products is reviewed. In the localized corrosion, the groundwater chemistry on the WP surface is evaluated at the temperatures of the WP above 100 deg. C during the early

  12. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings

    International Nuclear Information System (INIS)

    Farmer, J C; Haslam, J J; Wong, F; Ji, X; Day, S D; Branagan, D J; Marshall, M C; Meacham, B E; Buffa, E J; Blue, C A; Rivard, J K; Beardsley, M B; Weaver, D T; Aprigliano, L F; Kohler, L; Bayles, R; Lemieux, E J; Wolejsza, T M; Martin, F J; Yang, N; Lucadamo, G; Perepezko, J H; Hildal, K; Kaufman, L; Heuer, A H; Ernst, F; Michal, G M; Kahn, H; Lavernia, E J

    2004-01-01

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an ''integral drip shield'' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

  13. Shielding practice

    International Nuclear Information System (INIS)

    Sauermann, P.F.

    1985-08-01

    The basis of shielding practice against external irradiation is shown in a simple way. For most sources of radiation (point sources) occurring in shielding practice, the basic data are given, mainly in the form of tables, which are required to solve the shielding problems. The application of these data is explained and discussed using practical examples. Thickness of shielding panes of glove boxes for α and β radiation; shielding of sealed γ-radiography sources; shielding of a Co-60 radiation source, and of the manipulator panels for hot cells; damping factors for γ radiation and neutrons; shielding of fast and thermal neutrons, and of bremsstrahlung (X-ray tubes, Kr-85 pressure gas cylinders, 42 MeV betatrons, 20 MeV linacs); two-fold shielding (lead glass windows for hot cells, 14 MeV neutron generators); shielding against scattered radiation. (orig./HP) [de

  14. Electromagnetic shielding

    International Nuclear Information System (INIS)

    Tzeng, Wen-Shian V.

    1991-01-01

    Electromagnetic interference (EMI) shielding materials are well known in the art in forms such as gaskets, caulking compounds, adhesives, coatings and the like for a variety of EMI shielding purposes. In the past, where high shielding performance is necessary, EMI shielding has tended to use silver particles or silver coated copper particles dispersed in a resin binder. More recently, aluminum core silver coated particles have been used to reduce costs while maintaining good electrical and physical properties. (author). 8 figs

  15. Low Cost Constant – Head Drip Irrigation Emitter for Climate ...

    African Journals Online (AJOL)

    Low Cost Constant – Head Drip Irrigation Emitter for Climate Change Adaptation in Nigeria: Engineering Design and Calibration. ... The drip system comprises of abarrel, sub-main line, lateral lines, tubes and emitters, it can irrigate140 crop ...

  16. Drip Irrigation for Commercial Vegetable and Fruit Production

    OpenAIRE

    Maughn, Tiffany; Allen, Niel; Drost, Dan

    2017-01-01

    Drip irrigation is a highly efficient irrigation method well suited to many fruit and vegetable row crops. Drip tubing or tape discharges water to the soil through emitters positioned close to the plant. The drip tubing can be placed uncovered on the soil surface, under plastic mulch, buried in the soil, or suspended above the ground (e.g., on a trellis system). Water application rate is relatively low and irrigations are usually frequent. Properly designed and maintained drip-irrigation syst...

  17. Water and nitrogen requirements of subsurface drip irrigated pomegranate

    Science.gov (United States)

    Surface drip irrigation is a well-developed practice for both annual and perennial crops. The use of subsurface drip is a well-established practice in many annual row crops, e.g. tomatoes, strawberries, lettuce. However, the use of subsurface drip on perennial crops has been slow to develop. With th...

  18. Temperature effects on neutron drip line

    International Nuclear Information System (INIS)

    Rajasekaran, M.; Aggarwal, Mamta

    1996-01-01

    Extremely neutron rich hot nuclei formed in high energy collisions having high thermal excitation energies are investigated in the framework of statistical theory and the effect of level density parameter a = U/T 2 , on the drip line is analysed

  19. The efficiency of drip irrigation unpacked

    NARCIS (Netherlands)

    Kooij, van der S.; Zwarteveen, M.Z.; Boesveld, H.; Kuper, M.

    2013-01-01

    Drip irrigation figures prominently in water policy debates as a possible solution to water scarcity problems, based on the assertion that it will improve water use efficiencies. We use this article to carefully trace the scientific basis of this assertion. Through a systematic review of the

  20. Shielding plugs

    International Nuclear Information System (INIS)

    Makishima, Kenji.

    1986-01-01

    Purpose: In shielding plugs of an LMFBR type reactor, to restrain natural convection of heat in an annular space between a thermal shield layer and a shield shell, to prevent the lowering of heat-insulation performance, and to alleviate a thermal stress in a reactor container and the shield shell. Constitution: A ring-like leaf spring split in the direction of height is disposed in an annular space between a thermal shield layer and a shield shell. In consequence, the space is partitioned in the direction of height and, therefore, if axial temperature conditions and space width are the same and the space is low, the natural convection is hard to occur. Thus the rise of upper surface temperature of the shielding plugs can prevent the lowering of the heat insulation performance which will result in the increment of shielding plug cooling capacity, thereby improving reliability. In the meantime, since there is mounted an earthquake-resisting support, the thermal shield layer will move for a slight gap in case of an earthquake, being supported by the earthquake-resisting support, and the movement of the thermal shield layer is restricted, thereby maintaining integrity without increasing the stroke of the ring-like spring. (Kawakami, Y.)

  1. 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)

  2. Collective properties of drip-line nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hamamoto, I. [Univ. of Lund (Sweden); Sagawa, H. [Univ. of Aizu, Fukushima (Japan)

    1996-12-31

    Performing the spherical Hartree-Fock (HF) calculations with Skyrme interactions and, then, using RPA solved in the coordinate space with the Green`s function method, the authors have studied the effect of the unique shell structure as well as the very low particle threshold on collective modes in drip line nuclei. In this method a proper strength function in the continuum is obtained, though the spreading width of collective modes is not included. They have examined also one-particle resonant states in the obtained HF potential. Unperturbed particle-hole (p-h) response functions are carefully studied, which contain all basic information on the exotic behaviour of the RPA strength function in drip line nuclei.

  3. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO and DOE OCRWM Co-Sponsored Advanced Materials Program

    International Nuclear Information System (INIS)

    Farmer, J; Haslam, J; Wong, F; Ji, S; Day, S; Branagan, D; Marshall, M; Meacham, B; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Weaver, D; Aprigliano, L; Kohler, L; Bayles, R; Lemieux, E; Wolejsza, T; Martin, F; Yang, N; Lucadamo, G; Perepezko, J; Hildal, K; Kaufman, L; Heuer, A; Ernst, F; Michal, G; Kahn, H; Lavernia, E

    2007-01-01

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

  4. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO & DOE OCRWM Co-Sponsored Advanced Materials Program

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Haslam, J; Wong, F; Ji, S; Day, S; Branagan, D; Marshall, M; Meacham, B; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Weaver, D; Aprigliano, L; Kohler, L; Bayles, R; Lemieux, E; Wolejsza, T; Martin, F; Yang, N; Lucadamo, G; Perepezko, J; Hildal, K; Kaufman, L; Heuer, A; Ernst, F; Michal, G; Kahn, H; Lavernia, E

    2007-09-19

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent.

  5. Electromagnetic shield

    International Nuclear Information System (INIS)

    Miller, J.S.

    1987-01-01

    An electromagnetic shield is described comprising: closed, electrically-conductive rings, each having an open center; and binder means for arranging the rings in a predetermined, fixed relationship relative to each other, the so-arranged rings and binder means defining an outer surface; wherein electromagnetic energy received by the shield from a source adjacent its outer surface induces an electrical current to flow in a predetermined direction adjacent and parallel to the outer surface, through the rings; and wherein each ring is configured to cause source-induced alternating current flowing through the portion of the ring closest to the outer surface to electromagnetically induce an oppositely-directed current in the portion of the ring furthest from the surface, such oppositely-directed current bucking any source-induced current in the latter ring portion and thus reducing the magnitude of current flowing through it, whereby the electromagnetic shielding effected by the shield is enhanced

  6. Neutron shieldings

    International Nuclear Information System (INIS)

    Tarutani, Kohei

    1979-01-01

    Purpose: To decrease the stresses resulted by the core bendings to the base of an entrance nozzle. Constitution: Three types of round shielding rods of different diameter are arranged in a hexagonal tube. The hexagonal tube is provided with several spacer pads receiving the loads from the core constrain mechanism at its outer circumference, a handling head for a fuel exchanger at its top and an entrance nozzle for self-holding the neutron shieldings and flowing heat-removing coolants at its bottom. The diameters for R 1 , R 2 and R 3 for the round shielding rods are designed as: 0.1 R 1 2 1 and 0.2 R 1 2 1 . Since a plurality of shielding rods of small diameter are provided, soft structure are obtained and a plurality of coolant paths are formed. (Furukawa, Y.)

  7. Nuclear shields

    International Nuclear Information System (INIS)

    Linares, R.C.; Nienart, L.F.; Toelcke, G.A.

    1976-01-01

    A process is described for preparing melt-processable nuclear shielding compositions from chloro-fluoro substituted ethylene polymers, particularly PCTFE and E-CTFE, containing 1 to 75 percent by weight of a gadolinium compound. 13 claims, no drawings

  8. REACTOR SHIELD

    Science.gov (United States)

    Wigner, E.P.; Ohlinger, L.E.; Young, G.J.; Weinberg, A.M.

    1959-02-17

    Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

  9. Drip Planner Chart: a simple irrigation scheduling tool for smallholder drip farmers

    NARCIS (Netherlands)

    Boesveld, H.; Zisengwe, L.S.; Yakami, S.

    2012-01-01

    Drip irrigation is widely recognized as potentially one of the most efficient irrigation methods. However, this efficiency is often not achieved because systems are not always well designed or maintained and many farmers lack the tools to assess the crop water requirements and to monitor the soil

  10. Spent fuel's behavior under dynamic drip tests

    International Nuclear Information System (INIS)

    Finn, P.A.; Buck, E.C.; Hoh, J.C.; Bates, J.K.

    1995-01-01

    In the potential repository at Yucca Mountain, failure of the waste package container and the cladding of the spent nuclear fuel would expose the fuel to water under oxidizing conditions. To simulate the release behavior of radionuclides from spent fuel, dynamic drip and vapor tests with spent nuclear fuel have been ongoing for 2.5 years. Rapid alteration of the spent fuel has been noted with concurrent release of radionuclides. Colloidal species containing americium and plutonium have been found in the leachate. This observation suggests that colloidal transport of radionuclides should be included in the performance assessment of a potential repository

  11. Corrosion and corrosion control

    International Nuclear Information System (INIS)

    Khanna, A.S.; Totlani, M.K.

    1995-01-01

    Corrosion has always been associated with structures, plants, installations and equipment exposed to aggressive environments. It effects economy, safety and product reliability. Monitoring of component corrosion has thus become an essential requirement for the plant health and safety. Protection methods such as appropriate coatings, cathodic protection and use of inhibitors have become essential design parameters. High temperature corrosion, especially hot corrosion, is still a difficult concept to accommodate in corrosion allowance; there is a lack of harmonized system of performance testing of materials at high temperatures. In order to discuss and deliberate on these aspects, National Association for Corrosion Engineers International organised a National Conference on Corrosion and its Control in Bombay during November 28-30, 1995. This volume contains papers presented at the symposium. Paper relevant to INIS is indexed separately. refs., figs., tabs

  12. Dictionary corrosion and corrosion control

    International Nuclear Information System (INIS)

    1985-01-01

    This dictionary has 13000 entries in both languages. Keywords and extensive accompanying information simplify the choice of word for the user. The following topics are covered: Theoretical principles of corrosion; Corrosion of the metals and alloys most frequently used in engineering. Types of corrosion - (chemical-, electro-chemical, biological corrosion); forms of corrosion (superficial, pitting, selective, intercrystalline and stress corrosion; vibrational corrosion cracking); erosion and cavitation. Methods of corrosion control (material selection, temporary corrosion protection media, paint and plastics coatings, electro-chemical coatings, corrosion prevention by treatment of the corrosive media); Corrosion testing methods. (orig./HP) [de

  13. Introduction: Panda or Hydra? The untold stories of drip irrigation

    NARCIS (Netherlands)

    Kuper, M.; Venot, J.P.; Zwarteveen, M.; Venot, J.P.; Kuper, M.; Zwarteveen, M.

    2017-01-01

    Irrigated areas in the world are witnessing a transformation from open canal systems to more ‘modern’ irrigation methods such as drip irrigation that convey water through closed pipe systems. Initially associated with hi-tech irrigated agriculture, drip irrigation is now being used by a wide range

  14. Radiation shielding

    International Nuclear Information System (INIS)

    Aitken, D.

    1979-01-01

    Shields for equipment in which ionising radiation is associated with high electrical gradients, for example X-ray tubes and particle accelerators, incorporate a radiation-absorbing metal, as such or as a compound, and are electrically non-conducting and can be placed in the high electrical gradient region of the equipment. Substances disclosed include dispersions of lead, tungsten, uranium or oxides of these in acrylics polyesters, PVC, ABS, polyamides, PTFE, epoxy resins, glass or ceramics. The material used may constitute an evacuable enclosure of the equipment or may be an external shield thereof. (U.K.)

  15. E-Cigarettes and "Dripping" Among High-School Youth.

    Science.gov (United States)

    Krishnan-Sarin, Suchitra; Morean, Meghan; Kong, Grace; Bold, Krysten W; Camenga, Deepa R; Cavallo, Dana A; Simon, Patricia; Wu, Ran

    2017-03-01

    Electronic cigarettes (e-cigarettes) electrically heat and vaporize e-liquids to produce inhalable vapors. These devices are being used to inhale vapors produced by dripping e-liquids directly onto heated atomizers. The current study conducts the first evaluation of the prevalence rates and reasons for using e-cigarettes for dripping among high school students. In the spring of 2015, students from 8 Connecticut high schools ( n = 7045) completed anonymous surveys that examined tobacco use behaviors and perceptions. We assessed prevalence rates of ever using e-cigarettes for dripping, reasons for dripping, and predictors of dripping behaviors among those who reported ever use of e-cigarettes. Among 1080 ever e-cigarette users, 26.1% of students reported ever using e-cigarettes for dripping. Reasons for dripping included produced thicker clouds of vapor (63.5%), made flavors taste better (38.7%), produced a stronger throat hit (27.7%), curiosity (21.6%), and other (7.5%). Logistic regression analyses indicated that male adolescents (odds ratio [OR] = 1.64), whites (OR = 1.46), and those who had tried multiple tobacco products (OR = 1.34) and had greater past-month e-cigarette use frequency (OR = 1.07) were more likely to use dripping ( P s e-cigarettes also report using the device for dripping. Future efforts must examine the progression and toxicity of the use of e-cigarettes for dripping among youth and educate them about the potential dangers of these behaviors. Copyright © 2017 by the American Academy of Pediatrics.

  16. Gonadal shield.

    Science.gov (United States)

    Purdy, J A; Stiteler, R D; Glasgow, G P; Mill, W B

    1975-10-01

    A secondary gonadal shield for use in the pelvic irradiation of males was designed and built using material and apparatus available with the Cerrobend blocking system. The gonadal dose was reduced to approximately 1.5 to 2.5% of the given dose.

  17. Radiation shielding

    International Nuclear Information System (INIS)

    Yue, D.D.

    1979-01-01

    Details are given of a cylindrical electric penetration assembly for carrying instrumentation leads, used in monitoring the performance of a nuclear reactor, through the containment wall of the reactor. Effective yet economical shielding protection against both fast neutron and high-energy gamma radiation is provided. Adequate spacing within the assembly allows excessive heat to be efficiently dissipated and means of monitoring all potential radiation and gas leakage paths are provided. (UK)

  18. 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

  19. Longevity of shallow subsurface drip irrigation tubing under three tillage practices

    Science.gov (United States)

    Shallow Sub-Surface drip irrigation (S3DI) has drip tubing buried about 2-in below the soil surface. It is unknown how long drip tubing would be viable at this shallow soil depth using strip- or no-tillage systems. The objectives were to determine drip tube longevity, resultant crop yield, and parti...

  20. Hot rotating fp shell Fe isotopes near proton drip line

    International Nuclear Information System (INIS)

    Aggarwal, Mamta

    2003-01-01

    F p shell 44-58 Fe nuclei have been investigated in highly excited state using the statistical theory of hot rotating nucleus. Effects of thermal and rotational excitation at drip line nuclei are studied

  1. Method of constructing shielding wall

    International Nuclear Information System (INIS)

    Nagao, Tetsuya.

    1990-01-01

    For instance, surfaces of lead particles each formed into a sphere of about 0.5 to 0.3 mm grain size are coated with a coating material of a synthetic resin comprising a polymeric material such as teflon. Subsequently, the floated lead particle are kneaded with concrete materials and then poured into a molding die by way of a hose. After coagulation, the molding die is removed to complete shielding walls in which lead particles are scattered substantially at an equal distance. In this way, since the lead particles are mixed into the shielding walls, shielding effects can be improved by so much as the lead particles are mixed, thereby enabling to reduce the thickness of the shielding walls. Further, since the lead particles are coated with the coating material, the lead particles are insulated from the concrete materials, thereby enabling to prevent the corrosion of the lead particles. Furthermore, since the lead particles and the concrete materials can be transported with ease, operation labors can be reduced. (T.M.)

  2. ASPECTS OF DRIP IRRIGATION ON SLOPES

    Directory of Open Access Journals (Sweden)

    Oprea Radu

    2010-01-01

    Full Text Available Nowadays, water and its supply raise problems of strategic importance, of great complexity, being considered one of the keys to sustainable human development. Drip irrigation consists in the slow and controlled administration of water in the area of the root system of the plants for the purposes of fulfilling their physiological needs and is considered to be one of the variants of localized irrigation. Water is distributed in a uniform and slow manner, drop by drop, in a quantity and with a frequency that depend on the needs of the plant, thanks to the exact regulation of the water flow rate and pressure, as well as to the activation of the irrigation based on the information recorded by the tensiometer with regard to soil humidity. This method enables the exact dosage of the water quantity necessary in the various evolution stages of the plant, thus eliminating losses. By applying the irrigation with 5 liters of water per linear meter, at a 7 days interval, in the month of august, for a vine cultivated on a slope, in layers covered with black film and irrigated via dropping, soil humidity immediately after irrigation reaches its highest level, but within the limits of active humidity, on the line of the irrigation band. Three days later, the water content of the soil in the layer is relatively uniform, and, after this interval, it is higher in the points situated at the basis of the film. This technology of cultivation on slopes favors the accumulation, in the soil, of the water resulted from heavy rains and reduces soil losses as a result of erosion.

  3. Corrosion cracking

    International Nuclear Information System (INIS)

    Goel, V.S.

    1985-01-01

    This book presents the papers given at a conference on alloy corrosion cracking. Topics considered at the conference included the effect of niobium addition on intergranular stress corrosion cracking, corrosion-fatigue cracking in fossil-fueled-boilers, fracture toughness, fracture modes, hydrogen-induced thresholds, electrochemical and hydrogen permeation studies, the effect of seawater on fatigue crack propagation of wells for offshore structures, the corrosion fatigue of carbon steels in seawater, and stress corrosion cracking and the mechanical strength of alloy 600

  4. Blood drop size in passive dripping from weapons.

    Science.gov (United States)

    Kabaliuk, N; Jermy, M C; Morison, K; Stotesbury, T; Taylor, M C; Williams, E

    2013-05-10

    Passive dripping, the slow dripping of blood under gravity, is responsible for some bloodstains found at crime scenes, particularly drip trails left by a person moving through the scene. Previous work by other authors has established relationships, under ideal conditions, between the size of the stain, the number of spines and satellite stains, the roughness of the surface, the size of the blood droplet and the height from which it falls. To apply these relationships to infer the height of fall requires independent knowledge of the size of the droplet. This work aims to measure the size of droplets falling from objects representative of hand-held weapons. Pig blood was used, with density, surface tension and viscosity controlled to fall within the normal range for human blood. Distilled water was also tested as a reference. Drips were formed from stainless steel objects with different roughnesses including cylinders of diameter between 10 and 100 mm, and flat plates. Small radius objects including a knife and a wrench were also tested. High speed images of the falling drops were captured. The primary blood drop size ranged from 4.15±0.11 mm up to 6.15±0.15 mm (depending on the object), with the smaller values from sharper objects. The primary drop size correlated only weakly with surface roughness, over the roughness range studied. The number of accompanying droplets increased with the object size, but no significant correlation with surface texture was observed. Dripping of blood produced slightly smaller drops, with more accompanying droplets, than dripping water. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. A comparative study on drip and furrow irrigation methods

    International Nuclear Information System (INIS)

    Babar, M.M.; Shaikh, A.

    2008-01-01

    This study was conducted at Field Laboratory of the IIDE-MUET (Institute of lrrigation and Drainage Engineering, Mehran University of Engineering and Technology), Jamshoro in April 2007 and completed in October 2007. The soil was out-wash of the surrounding hilly tracts. Thus, the texture of the soil was sandy loam mixed with various sizes of gravels. Consequently, its water holding capacity was low and drainability high. The field capacity, wilting point and available moisture of the soil were found to be 10.35, 5.56 and 4.79%, respectively. The soil was moderate (ECe 8-16 dS/m) to strongly saline (ECe> 16 dS/m) and slightly sodic in nature in drip and furrow irrigated plots under study before start of vegetable crops. Three summer vegetables, i.e. okra, long gourd and ridge gourd were cultivated under drip and furrow systems of irrigation. Tap water was used for irrigation, which was class-I quality water i.e. nonsaline and non-sodic. Yields of the three respective vegetables were 25, 16.5 and 7.9% higher than the yields obtained from furrow method. Likewise, WUE (Water Use Efficiency) was higher in drip at 1.27, 3.19 and 2.28 Kg/m/sup 3/ against 0.59, 1.46 and 1.16 Kg/m/sup 3/ in furrow for the respective vegetables. The water saving in drip over furrow method for okra, long gourd and ridge gourd was estimated at 42.2, 46.9 and 45.0%, respectively. The soil salinity and sodicity decreased and did not develop within wetted zone under drip irrigation method and at furrow beds. However the same increased at the wetted periphery and at tops of the ridges under drip and furrow methods of irrigation respectively. (author)

  6. About the Scythian Shields

    Directory of Open Access Journals (Sweden)

    About the Scythian Shields

    2017-10-01

    Full Text Available Shields played major role in the armament system of the Scythians. Made from organic materials, they are poorly traced on the materials of archaeological excavations. Besides, scaly surface of shields was often perceived in practice as the remnants of the scaly armor. E. V. Chernenko was able to discern the difference between shields’ scaly plates and armor scales. The top edge of the scales was bent inwards, and shield plates had a wire fixation. These observations let significantly increase the number of shields, found in the burial complexes of the Scythians. The comparison of archaeological materials and the images of Scythian warriors allow distinguishing the main forms of Scythian shields. All shields are divided into fencing shields and cover shields. The fencing shields include round wooden shields, reinforced with bronze sheet, and round moon-shaped shields with a notch at the top, with a metal scaly surface. They came to the Scythians under the Greek influence and are known in the monuments of the 4th century BC. Oval shields with scaly surface (back cover shields were used by the Scythian cavalry. They protected the rider in case of frontal attack, and moved back in case of maneuver or closein fighting. Scythian battle tactics were based on rapid approaching the enemy and throwing spears and further rapid withdrawal. Spears stuck in the shields of enemies, forcing them to drop the shields, uncover, and in this stage of the battle the archers attacked the disorganized ranks of the enemy. That was followed by the stage of close fight. Oval form of a wooden shield with leather covering was used by the Scythian infantry and spearmen. Rectangular shields, including wooden shields and the shields pleached from rods, represented a special category. The top of such shield was made of wood, and a pleached pad on leather basis was attached to it. This shield could be a reliable protection from arrows, but it could not protect against javelins

  7. Systematic study of shell effect near drip-lines

    International Nuclear Information System (INIS)

    Adhikari, S.; Samanta, C.

    2004-01-01

    The variation of nuclear shell effects with nucleon numbers is evaluated using the modified Bethe–Weizsaecker mass formula (BWM) and the measured atomic masses. The shell effects at magic neutron numbers N=8, 20, 28, 50, 82 and 126 and magic proton numbers Z=8, 20, 28, 50 and 82 are found to vary rapidly approaching the drip-lines. The shell effect due to one magic number increases on approaching another magic number. Thus, shell effects are not always negligible near the drip-lines. (author)

  8. Stroke mimics under the drip-and-ship paradigm.

    Science.gov (United States)

    Mehta, Sonal; Vora, Nirav; Edgell, Randall C; Allam, Hesham; Alawi, Aws; Koehne, Jennifer; Kumar, Abhay; Feen, Eliahu; Cruz-Flores, Salvador; Alshekhlee, Amer

    2014-01-01

    Recent reports suggested better outcomes associated with the drip-and-ship paradigm for acute ischemic stroke (AIS) treated with thrombolysis. We hypothesized that a higher rate of stroke mimics (SM) among AIS treated in nonspecialized stroke centers that are transferred to comprehensive centers is responsible for such outcomes. Consecutive patients treated with thrombolysis according to the admission criteria were reviewed in a single comprehensive stroke center over 1 academic year (July 1, 2011 to June 30, 2012). Information on the basic demographic, hospital complications, psychiatric diagnoses, and discharge disposition was collected. We identified those patients who were treated at a facility and then transferred to the tertiary center (ie, drip-and-ship paradigm). In addition to comparative and adjusted analysis to identify predictors for SM, a stratified analysis by the drip-and-ship status was performed. One hundred twenty patients were treated with thrombolysis for AIS included in this analysis; 20 (16.7%) were discharged with the final diagnosis of SM; 14 of those had conversion syndrome and 6 patients had other syndromes (seizures, migraine, and hypoglycemia). Patients with SM were younger (55.6 ± 15.0 versus 69.4 ± 14.9, P = .0003) and more likely to harbor psychiatric diagnoses (45% versus 9%; P ≤ .0001). Eighteen of 20 SM patients (90%) had the drip-and-ship treatment paradigm compared with 65% of those with AIS (P = .02). None of the SM had hemorrhagic complications, and all were discharged to home. Predictors of SM on adjusted analysis included the drip-and-ship paradigm (odds ratio [OR] 12.8, 95% confidence interval [CI] 1.78, 92.1) and history of any psychiatric illness (OR 12.08; 95% CI 3.14, 46.4). Eighteen of 83 drip-and-ship patients (21.7%) were diagnosed with SM compared with 2 of 37 patients (5.4%) presented directly to the hub hospital (P = .02). The drip-and-ship paradigm and any psychiatric history predict the diagnosis of

  9. Corrosion engineering

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, M.G.

    1986-01-01

    This book emphasizes the engineering approach to handling corrosion. It presents corrosion data by corrosives or environments rather than by materials. It discusses the corrosion engineering of noble metals, ''exotic'' metals, non-metallics, coatings, mechanical properties, and corrosion testing, as well as modern concepts. New sections have been added on fracture mechanics, laser alloying, nuclear waste isolation, solar energy, geothermal energy, and the Statue of Liberty. Special isocorrosion charts, developed by the author, are introduced as a quick way to look at candidates for a particular corrosive.

  10. Evaluation of mulched drip irrigation for cotton in arid Northwest China

    NARCIS (Netherlands)

    Wang, Z.; Jin, M.; Simunek, J.; van Genuchten, M.T.

    2014-01-01

    Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control

  11. Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

    NARCIS (Netherlands)

    Benouniche, M.; Kuper, M.; Hammani, A.; Boesveld, H.

    2014-01-01

    The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured

  12. Implementation of Localized Corrosion in the Performance Assessment Model for Yucca Mountain

    International Nuclear Information System (INIS)

    Jain, V.; SEVOUGIAN, D.S.; MATTIE, P.D.; MACKINNON, R.J.

    2005-01-01

    A total system performance assessment (TSPA) model has been developed to analyze the ability of the natural and engineered barriers of the Yucca Mountain repository to isolate nuclear waste for the 10,000-year period following repository closure. The principal features of the engineered barrier system (EBS) are emplacement tunnels (or ''drifts'') containing a two-layer waste package (WP) for waste containment and a titanium drip shield to protect the waste package from seeping water and falling rock. The 20-mm-thick outer shell of the WP is composed of Alloy 22, a highly corrosion-resistant nickel-based alloy, while the 50-mm inner shell is composed of 316 stainless steel (modified with lower carbon and nitrogen compositions), whose primary purpose is to provide structural strength. The barrier function of the EBS is to isolate the waste from the migrating water with its associated chemical conditions that eventually lead to degradation of the waste packages and mobilization of the radionuclides within the packages

  13. Shielding benchmark problems

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi; Sasamoto, Nobuo; Oka, Yoshiaki; Kawai, Masayoshi; Nakazawa, Masaharu.

    1978-09-01

    Shielding benchmark problems were prepared by the Working Group of Assessment of Shielding Experiments in the Research Comittee on Shielding Design of the Atomic Energy Society of Japan, and compiled by the Shielding Laboratory of Japan Atomic Energy Research Institute. Twenty-one kinds of shielding benchmark problems are presented for evaluating the calculational algorithm and the accuracy of computer codes based on the discrete ordinates method and the Monte Carlo method and for evaluating the nuclear data used in the codes. (author)

  14. Radiation shielding device

    International Nuclear Information System (INIS)

    Nakagawa, Takahiro; Yamagami, Makoto.

    1996-01-01

    A fixed shielding member made of a radiation shielding material is constituted in perpendicular to an opening formed on radiation shielding walls. The fixed shielding member has one side opened and has other side, the upper portion and the lower portion disposed in close contact with the radiation shielding walls. Movable shielding members made of a radiation shielding material are each disposed openably on both side of the fixed shielding member. The movable shielding member has a shaft as a fulcrum on one side thereof for connecting it to the radiation shielding walls. The other side has a handle attached for opening/closing the movable shielding member. Upon access of an operator, when each one of the movable shielding members is opened/closed on every time, leakage of linear or scattered radiation can be prevented. Even when both of the movable shielding members are opened simultaneously, the fixed shielding member and the movable shielding members form labyrinth to prevent leakage of linear radioactivity. (I.N.)

  15. Sensitivity of the engineered barrier system (EBS) release rate to alternative conceptual models of advective release from waste packages under dripping fractures

    International Nuclear Information System (INIS)

    Lee, J.H.; Atkins, J.E.; McNeish, J.A.; Vallikat, V.

    1996-01-01

    The first model assumed that dripping water directly contacts the waste form inside the ''failed'' waste package and radionuclides are released from the EBS by advection. The second model assumed that dripping water is diverted around the package (because of corrosion products plugging the perforations), thereby being prevented from directly contacting the waste form. In the second model, radionuclides were assumed to diffuse through the perforations, and, once outside the waste package, to be released from the EBS by advection. For the case with the second EBS release model, most radionuclides had lower peak EBS release rates than with the first model. Impacts of the alternative EBS release models were greater for the radionuclides with low solubility. The analysis indicated that the EBS release model representing advection through a ''failed'' waste package (the first model) may be too conservative; thus a ''failed'' waste package container with multiple perforations may still be an important barrier to radionuclide release

  16. APPLICATION OF DRIP IRRIGATION ON COTTON PLANT GROWTH (Gossypium sp.

    Directory of Open Access Journals (Sweden)

    Syahruni Thamrin

    2017-12-01

    Full Text Available The condition of cotton planting in South Sulawesi is always constrained in the fulfillment of water. All plant growth stages are not optimal to increase production, so it is necessary to introduce good water management technology, such as through water supply with drip irrigation system. This study aims to analyze the strategy of irrigation management in cotton plants using drip irrigation system. Model of application by designing drip irrigation system and cotton planting on land prepared as demonstration plot. Observations were made in the germination phase and the vegetative phase of the early plants. Based on the result of drip irrigation design, the emitter droplet rate (EDR was 34.266 mm/hour with an operational time of 4.08 min/day. From the observation of cotton growth, it is known that germination time lasted from 6 to 13 days after planting, the average plant height reached 119.66 cm, with the number of leaves averaging 141.93 pieces and the number of bolls averaging 57.16 boll.

  17. A field performance evaluation of drip emitters: pressure versus ...

    African Journals Online (AJOL)

    Field evaluation of irrigation systems (drip) can form a basis for decision making as to whether the irrigation system needs rehabilitation, overhaul or even dismantling if found to be very uneconomical. A comprehensive field evaluation of irrigation systems involves determining the overall efficiency of the system, for example, ...

  18. Yield response and economics of shallow subsurface drip irrigation systems

    Science.gov (United States)

    Field tests were conducted using shallow subsurface drip irrigation (S3DI) on cotton (Gossypium hirsutum, L.), corn (Zea mays, L.), and peanut (Arachis hypogeae, L.) in rotation to investigate yield potential and economic sustainability of this irrigation system technique over a six year period. Dri...

  19. Potassium and calcium nutrition improves potato production in drip ...

    African Journals Online (AJOL)

    The response of Spunta potato (Solanum tuberosum L.) plants to different rates of potassium (60 and 120 kg Fed-1 ) in presence or absence of Ca nutrition was studied. The study was performed in sandy-loam soil under a drip-irrigation system during fall seasons of 1996 and 1997 years. Plants fertilised with high rate of K ...

  20. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings Evaluation of Corrosion Resistance FY05 HPCRM Annual Report No. Rev. 1DOE-DARPA Co-Sponsored Advanced Materials Program

    International Nuclear Information System (INIS)

    Farmer, J C; Haslam, J J; Day, S D

    2007-01-01

    or inhibitor. Comparable metallic alloys such as SAM2X5 and SAM1651 may also experience crevice corrosion under sufficiently harsh conditions. Accelerated crevice corrosion tests are now being conducted to intentionally induce crevice corrosion, and to determine those environmental conditions where such localized attack occurs. Such materials are extremely hard, and provide enhanced resistance to abrasion and gouges (stress risers) from backfill operations, and possibly even tunnel boring. The hardness of Type 316L Stainless Steel is approximately 150 VHN, that of Alloy C-22 is approximately 250 VHN, and that of HVOF SAM2X5 ranges from 1100-1300 VHN. These new materials provide a viable coating option for repository engineers. SAM2X5 and SAM1651 coatings can be applied with thermal spray processes without any significant loss of corrosion resistance. Both Alloy C-22 and Type 316L stainless lose their resistance to corrosion during thermal spraying. Containers for the transportation, storage and disposal of spent nuclear fuel (SNF) and high-level radioactive waste (HLW) with corrosion resistant coatings are envisioned. For example, an enhanced multi-purpose container (MPC) could be made with such coatings, leveraging existing experience in the fabrication of such containers. These coating materials could be used to protect the final closure weld on SNF/HLW disposal containers, eliminate need for stress mitigation. Integral drip shield could be produced by directly spraying it onto the disposal container, thereby eliminating the need for an expensive titanium drip shield. In specific areas where crevice corrosion is anticipated, such as the contact point between the disposal container and pallet, HVOF coatings could be used to buildup thickness, thereby selectively adding corrosion life where it is needed. Both SAM2X5 and SAM1651 have high boron content which enable them to absorb neutrons and therefore be used for criticality control in baskets. Alloy C-22 and 316L

  1. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings

    International Nuclear Information System (INIS)

    Farmer, J; Choi, J; Haslam, J; Day, S; Yang, N; Headley, T; Lucadamo, G; Yio, J; Chames, J; Gardea, A; Clift, M; Blue, G; Peters, W; Rivard, J; Harper, D; Swank, D; Bayles, R; Lemieux, E; Brown, R; Wolejsza, T; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Lavernia, E; Schoenung, J; Ajdelsztajn, L; Dannenberg, J; Graeve, O; Lewandowski, J; Perepezko, J; Hildal, K; Kaufman, L; Boudreau, J

    2007-01-01

    or inhibitor. Comparable metallic alloys such as SAM2X5 and SAM1651 may also experience crevice corrosion under sufficiently harsh conditions. Accelerated crevice corrosion tests are now being conducted to intentionally induce crevice corrosion, and to determine those environmental conditions where such localized attack occurs. Such materials are extremely hard, and provide enhanced resistance to abrasion and gouges (stress risers) from backfill operations, and possibly even tunnel boring. The hardness of Type 316L Stainless Steel is approximately 150 VHN, that of Alloy C-22 is approximately 250 VHN, and that of HVOF SAM2X5 ranges from 1100-1300 VHN. These new materials provide a viable coating option for repository engineers. SAM2X5 and SAM1651 coatings can be applied with thermal spray processes without any significant loss of corrosion resistance. Both Alloy C-22 and Type 316L stainless lose their resistance to corrosion during thermal spraying. Containers for the transportation, storage and disposal of spent nuclear fuel (SNF) and high-level radioactive waste (HLW) with corrosion resistant coatings are envisioned. For example, an enhanced multi-purpose container (MPC) could be made with such coatings, leveraging existing experience in the fabrication of such containers. These coating materials could be used to protect the final closure weld on SNF/HLW disposal containers, eliminate need for stress mitigation. Integral drip shield could be produced by directly spraying it onto the disposal container, thereby eliminating the need for an expensive titanium drip shield. In specific areas where crevice corrosion is anticipated, such as the contact point between the disposal container and pallet, HVOF coatings could be used to buildup thickness, thereby selectively adding corrosion life where it is needed. Both SAM2X5 and SAM1651 have high boron content which enable them to absorb neutrons and therefore be used for criticality control in baskets. Alloy C-22 and 316L

  2. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Choi, J; Haslam, J; Day, S; Yang, N; Headley, T; Lucadamo, G; Yio, J; Chames, J; Gardea, A; Clift, M; Blue, G; Peters, W; Rivard, J; Harper, D; Swank, D; Bayles, R; Lemieux, E; Brown, R; Wolejsza, T; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Lavernia, E; Schoenung, J; Ajdelsztajn, L; Dannenberg, J; Graeve, O; Lewandowski, J; Perepezko, J; Hildal, K; Kaufman, L; Boudreau, J

    2007-09-20

    or inhibitor. Comparable metallic alloys such as SAM2X5 and SAM1651 may also experience crevice corrosion under sufficiently harsh conditions. Accelerated crevice corrosion tests are now being conducted to intentionally induce crevice corrosion, and to determine those environmental conditions where such localized attack occurs. Such materials are extremely hard, and provide enhanced resistance to abrasion and gouges (stress risers) from backfill operations, and possibly even tunnel boring. The hardness of Type 316L Stainless Steel is approximately 150 VHN, that of Alloy C-22 is approximately 250 VHN, and that of HVOF SAM2X5 ranges from 1100-1300 VHN. These new materials provide a viable coating option for repository engineers. SAM2X5 and SAM1651 coatings can be applied with thermal spray processes without any significant loss of corrosion resistance. Both Alloy C-22 and Type 316L stainless lose their resistance to corrosion during thermal spraying. Containers for the transportation, storage and disposal of spent nuclear fuel (SNF) and high-level radioactive waste (HLW) with corrosion resistant coatings are envisioned. For example, an enhanced multi-purpose container (MPC) could be made with such coatings, leveraging existing experience in the fabrication of such containers. These coating materials could be used to protect the final closure weld on SNF/HLW disposal containers, eliminate need for stress mitigation. Integral drip shield could be produced by directly spraying it onto the disposal container, thereby eliminating the need for an expensive titanium drip shield. In specific areas where crevice corrosion is anticipated, such as the contact point between the disposal container and pallet, HVOF coatings could be used to buildup thickness, thereby selectively adding corrosion life where it is needed. Both SAM2X5 & SAM1651 have high boron content which enable them to absorb neutrons and therefore be used for criticality control in baskets. Alloy C-22 and 316L have

  3. Shielding modefication and safety review on Mutsu

    International Nuclear Information System (INIS)

    Osanai, Masao

    1978-01-01

    The Japan Atomic Energy Commission requests strongly to repair the shielding and make general safety inspection on Mutsu after an accident of radiation leakage from the reactor. The content and procedure of this repair of shielding and general safety inspection are outlined. The neutron leakage location in the reactor proper, technical shielding investigation, conceptual design of relating shielding repair, the mock up test of the shielding on the neutron streaming, the final conceptual design of repair, the relating research and development experiment and the detailed basic design of repair are explained, comparing the original design and the modified one. The modified design depends on the experimental results of neutron streaming test between the reactor vessel and the primary shield. As for the general safety inspection, the functional test of control rod driving mechanism and other main components, the flaw detection for heat transfer tubes of the steam generator and primary cooling pipings are carried out in hardwares, and the integrity analysis of fuel assemblies, stress corrosion cracking of fuel claddings and primary cooling pipings, the natural circulation analysis of primary cooling system, and integrity check of the heat transfer tubes of steam generator are carried out in softwares. The burst test and the strength test after high temperature oxidation for fuel claddings made of stainless steel were carried out. (Nakai, Y.)

  4. Effect of gamma irradiation on the amino acid contents of seafood cooking drips

    International Nuclear Information System (INIS)

    Lee, Ju Woon; Kim, Yeon Joo; Choi, Jong Il; Kim, Yun Joo; Kim, Jae Hun; Kim, Jin Kyu; Byun, Myung Woo; Kwon, Joong Ho; Ahn, Dong Hyun; Chun, Byung Soo

    2008-01-01

    In this study, the effects of gamma irradiation on the change of structural and free amino acids contents of cooking drips from Hizikia fusiformis (HF) and Enteroctopus dofleini (ED) were investigated. The main structural amino acids were glutamic acid in HF cooking drip, and glutamic acid, glycine, arginine and aspartic acid in ED cooking drip, respectively. The concentrations of structural amino acids in both cooking drip extracts were decreased by the gamma irradiation at the dose of 10 kGy. Especially, the sulfur-containing amino acids were severely degraded by the irradiation. In free amino acid, ED cooking drip extract was contained the larger amount of free amino acid than that of HF cooking drip affecting its rich flavor. The free amino acid concentrations of cooking drips extracts from HF and ED were both increased by irradiation, and it explained the higher protein content by the irradiation

  5. Handout on shielding calculation

    International Nuclear Information System (INIS)

    Heilbron Filho, P.F.L.

    1991-01-01

    In order to avoid the difficulties of the radioprotection supervisors in the tasks related to shielding calculations, is presented in this paper the basic concepts of shielding theory. It also includes exercises and examples. (author)

  6. Design of emergency shield

    International Nuclear Information System (INIS)

    Soliman, S.E.

    1993-01-01

    Manufacturing of an emergency movable shield in the hot laboratories center is urgently needed for the safety of personnel in case of accidents or spilling of radioactive materials. In this report, a full design for an emergency shield is presented and the corresponding dose rates behind the shield for different activities (from 1 mCi to 5 Ci) was calculated by using micro shield computer code. 4 figs., 1 tab

  7. Electromagnetically shielded building

    International Nuclear Information System (INIS)

    Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

    1992-01-01

    This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs

  8. Electromagnetically shielded building

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T; Nakamura, M; Yabana, Y; Ishikawa, T; Nagata, K

    1992-04-21

    This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs.

  9. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

    2015-01-01

    The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P......, K, Mg and micronutrients, and in addition 120 kg N/ha in the gun irrigated treatments and 36 kg N/ha in the drip-fertigated. For the latter, portion of 20 kg N/ha was applied whenever plant N concentration approached a critical value as simulated by the Daisy model. As a result differences in soil...

  10. Strange Stars: Can Their Crust Reach the Neutron Drip Density?

    Institute of Scientific and Technical Information of China (English)

    Hai Fu; Yong-Feng Huang

    2003-01-01

    The electrostatic potential of electrons near the surface of static strange stars at zero temperature is studied within the frame of the MIT bag model. We find that for QCD parameters within rather wide ranges, if the nuclear crust on the strange star is at a density leading to neutron drip, then the electrostatic potential will be insufficient to establish an outwardly directed electric field, which is crucial for the survival of such a crust. If a minimum gap width of 200 fm is brought in as a more stringent constraint, then our calculations will completely rule out the possibility of such crusts. Therefore, our results argue against the existence of neutron-drip crusts in nature.

  11. Variation of nuclear radii in the drip line regions

    CERN Document Server

    Beiner, M; Mas, D

    1976-01-01

    The authors are concerned with predictions of the energy density method with respect to the nuclear sizes (RMS radii). It is known that the commonly accepted A/sup 1/3/-type laws are only approximative and deviations are expected to grow significantly as one goes away from the beta -stability region. Particular attention is paid to the variation of nuclear radii in the drip line regions. Implications of the resulting large total Coulomb energy variations between neighbouring nuclei will be emphasized.

  12. Electromagnetic shielding formulae

    International Nuclear Information System (INIS)

    Dahlberg, E.

    1979-02-01

    This addendum to an earlier collection of electromagnetic shielding formulae (TRITA-EPP-75-27) contains simple transfer matrices suitable for calculating the quasistatic shielding efficiency for multiple transverse-field and axial-field cylindrical and spherical shields, as well as for estimating leakage fields from long coaxial cables and the normal-incidence transmission of a plane wave through a multiple plane shield. The differences and similarities between these cases are illustrated by means of equivalent circuits and transmission line analogies. The addendum also includes a discussion of a possible heuristic improvement of some shielding formulae. (author)

  13. Shielding benchmark problems, (2)

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi; Sasamoto, Nobuo; Oka, Yoshiaki; Shin, Kazuo; Tada, Keiko.

    1980-02-01

    Shielding benchmark problems prepared by Working Group of Assessment of Shielding Experiments in the Research Committee on Shielding Design in the Atomic Energy Society of Japan were compiled by Shielding Laboratory in Japan Atomic Energy Research Institute. Fourteen shielding benchmark problems are presented newly in addition to twenty-one problems proposed already, for evaluating the calculational algorithm and accuracy of computer codes based on discrete ordinates method and Monte Carlo method and for evaluating the nuclear data used in codes. The present benchmark problems are principally for investigating the backscattering and the streaming of neutrons and gamma rays in two- and three-dimensional configurations. (author)

  14. The Active Muon Shield

    CERN Document Server

    Bezshyiko, Iaroslava

    2016-01-01

    In the SHiP beam-dump of the order of 1011 muons will be produced per second. An active muon-shield is used to magnetically deflect these muons out of the acceptance of the spectrom- eter. This note describes how this shield is modelled and optimized. The SHiP spectrometer is being re-optimized using a conical decay-vessel, and utilizing the possibility to magnetize part of the beam-dump shielding iron. A shield adapted to these new conditions is presented which is significantly shorter and lighter than the shield used in the Technical Proposal (TP), while showing a similar performance.

  15. Corrosion Engineering.

    Science.gov (United States)

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  16. Wake Shield Target Protection

    International Nuclear Information System (INIS)

    Valmianski, Emanuil I.; Petzoldt, Ronald W.; Alexander, Neil B.

    2003-01-01

    The heat flux from both gas convection and chamber radiation on a direct drive target must be limited to avoid target damage from excessive D-T temperature increase. One of the possibilities of protecting the target is a wake shield flying in front of the target. A shield will also reduce drag force on the target, thereby facilitating target tracking and position prediction. A Direct Simulation Monte Carlo (DSMC) code was used to calculate convection heat loads as boundary conditions input into ANSYS thermal calculations. These were used for studying the quality of target protection depending on various shapes of shields, target-shield distance, and protective properties of the shield moving relative to the target. The results show that the shield can reduce the convective heat flux by a factor of 2 to 5 depending on pressure, temperature, and velocity. The protective effect of a shield moving relative to the target is greater than the protective properties of a fixed shield. However, the protective effect of a shield moving under the drag force is not sufficient for bringing the heat load on the target down to the necessary limit. Some other ways of diminishing heat flux using a protective shield are discussed

  17. Genotoxicological safety of the ethanol extract from seafood cooking drips by gamma irradiation

    International Nuclear Information System (INIS)

    Kim, Hyun Joo; Choi, Jong Il; Lee, Hee Sub; Kim, Jae Hun; Byun, Myung Woo; Chun, Byung Soo; Ahn, Dong Hyun; Yook, Hong Sun; Kim, Kee Hyuk

    2008-01-01

    Although seafood cooking drips were the byproducts from the fishery industry it was known that the cooking drips had many nutrients and could be used as functional materials. Previously, the physiological properties of cooking drips were shown to be increased by a gamma irradiation. But, there was no report on the safe for the genotoxicity on the irradiation. In this study, the genotoxicity of the cooking drips from Hizikia fusiformis, Enteroctopus dofleni and Thunnus thynnus was evaluated by the Ames test (Salmonella typhimurium reversion assay) and the SOS chromotest. The results from all samples were negative in the bacterial reversion assay with S. typhimurium TA98, TA100. No mutagenicity was detected in the assay, both with and without metabolic activation. The SOS chromotest also indicated that the gamma-irradiated seafood cooking drips did not show any mutagenicity. Therefore, this study indicated that gamma irradiation could be used for the hygiene, functional properties and processibility of seafood cooking drips

  18. Localized Corrosion Behavior of Type 304SS with a Silica Layer Under Atmospheric Corrosion Environments

    International Nuclear Information System (INIS)

    E. Tada; G.S. Frankel

    2006-01-01

    The U.S. Department of Energy (DOE) has proposed a potential repository for spent nuclear fuel and high-level radioactive waste at the Yucca Mountain site in Nevada. [I] The temperature could be high on the waste packages, and it is possible that dripping water or humidity could interact with rock dust particulate to form a thin electrolyte layer with concentrated ionic species. Under these conditions, it is possible that highly corrosion-resistant alloys (CRAs) used as packages to dispose the nuclear waste could suffer localized corrosion. Therefore, to better understand long-term corrosion performance of CRAs in the repository, it is important to investigate localized corrosion under a simulated repository environment. We measured open circuit potential (OCP) and galvanic current (i g ) for silica-coated Type 304SS during drying of salt solutions under controlled RH environments to clarify the effect of silica layer as a dust layer simulant on localized corrosion under atmospheric environments. Type 304SS was used as a relatively susceptible model CRA instead of the much more corrosion resistant alloys, such as Alloy 22, that are being considered as, waste package materials

  19. Space Shielding Materials for Prometheus Application

    Energy Technology Data Exchange (ETDEWEB)

    R. Lewis

    2006-01-20

    At the time of Prometheus program restructuring, shield material and design screening efforts had progressed to the point where a down-selection from approximately eighty-eight materials to a set of five ''primary'' materials was in process. The primary materials were beryllium (Be), boron carbide (B{sub 4}C), tungsten (W), lithium hydride (LiH), and water (H{sub 2}O). The primary materials were judged to be sufficient to design a Prometheus shield--excluding structural and insulating materials, that had not been studied in detail. The foremost preconceptual shield concepts included: (1) a Be/B{sub 4}C/W/LiH shield; (2) a Be/B{sub 4}C/W shield; (3) and a Be/B{sub 4}C/H{sub 2}O shield. Since the shield design and materials studies were still preliminary, alternative materials (e.g., {sup nal}B or {sup 10}B metal) were still being screened, but at a low level of effort. Two competing low mass neutron shielding materials are included in the primary materials due to significant materials uncertainties in both. For LiH, irradiation-induced swelling was the key issue, whereas for H{sub 2}O, containment corrosion without active chemistry control was key, Although detailed design studies are required to accurately estimate the mass of shields based on either hydrogenous material, both are expected to be similar in mass, and lower mass than virtually any alternative. Unlike Be, W, and B{sub 4}C, which are not expected to have restrictive temperature limits, shield temperature limits and design accommodations are likely to be needed for either LiH or H{sub 2}O. The NRPCT focused efforts on understanding swelting of LiH, and observed, from approximately fifty prior irradiation tests, that either casting ar thorough out-gassing should reduce swelling. A potential contributor to LiH swelling appears to be LiOH contamination due to exposure to humid air, that can be eliminated by careful processing. To better understand LiH irradiation performance and

  20. Sensitivity of the engineered barrier system (EBS) release rate to alternative conceptual models of advective release from waste packages under dripping fractures

    International Nuclear Information System (INIS)

    Lee, J.H.; Atkins, J.E.; McNeish, J.A.; Vallikat, V.

    1996-01-01

    Simulations were conducted to analyze the sensitivity of the engineered barrier system (EBS) release rate to alternative conceptual models of the advective release from waste packages under dripping fractures. The first conceptual model assumed that dripping water directly contacts the waste form inside the 'failed' waste package, and radionuclides are released from the EBS by advection. The second conceptual model assumed that dripping water is diverted around the 'failed' waste package (because of the presence of corrosion products plugging the perforations) and dripping water is prevented from directly contacting the waste form. In the second model, radionuclides were assumed to transport through the perforations by diffusion, and, once outside the waste package, to be released from the EBS by advection. The second model was to incorporate more realism into the EBS release calculations. For the case with the second EBS release model, most radionuclides had significantly lower peak EBS release rates (from at least one to several orders of magnitude) than with the first EBS release model. The impacts of the alternative EBS release models were greater for the radionuclides with a low solubility (or solubility-limited radionuclides) than for the radionuclides with a high solubility (or waste form dissolution-limited radionuclides). The analyses indicated that the EBS release model representing advection through a 'failed' waste package (the first EBS release model) may be too conservative in predicting the EBS performance. One major implication from this sensitivity study was that a 'failed' waste package container with multiple perforations may still be able to perform effectively as an important barrier to radionuclide release. (author)

  1. Radiation shielding concrete

    International Nuclear Information System (INIS)

    Kunishima, Shigeru.

    1990-01-01

    The radiation shielding concretes comprise water, cement, fine aggregates consisting of serpentines and blown mist slags, coarse aggregates consisting of serpentines and kneading materials. Since serpentines containing a relatively great amount of water of crystallization in rocks as coarse aggregates and fine aggregates, the hydrogen content in the radiation shielding concretes is increased and the neutron shielding effect is improved. In addition, since serpentines are added as the fine aggregates and blown mists slags of a great specific gravity are used, the specific gravity of the shielding concretes is increased to improve the γ-ray shielding effect. Further, by the use of the kneading material having a water reducing effect and fluidizing effect, and by the bearing effect of the spherical blown mist slags used as the fine aggregates, concrete fluidity can be increased. Accordingly, workability of the radiation shielding concretes can be improved. (T.M.)

  2. Accelerator shielding benchmark problems

    International Nuclear Information System (INIS)

    Hirayama, H.; Ban, S.; Nakamura, T.

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  3. INTOR radiation shielding for personnel access

    International Nuclear Information System (INIS)

    Gohar, Y.; Abdou, M.

    1981-01-01

    The INTOR reactor shield system consists of the blanket, bulk shield, penetration shield, component shield, and biological shield. The bulk shield consists of two parts: (a) the inboard shield; and (b) the outboard shield. The distinction between the different components of the shield system is essential to satisfy the different design constraints and achieve various objectives

  4. Shielded regenerative neutron detector

    International Nuclear Information System (INIS)

    Terhune, J.H.; Neissel, J.P.

    1978-01-01

    An ion chamber type neutron detector is disclosed which has a greatly extended lifespan. The detector includes a fission chamber containing a mixture of active and breeding material and a neutron shielding material. The breeding and shielding materials are selected to have similar or substantially matching neutron capture cross-sections so that their individual effects on increased detector life are mutually enhanced

  5. Radiation shielding plate

    International Nuclear Information System (INIS)

    Kobayashi, Torakichi; Sugawara, Takeo.

    1983-01-01

    Purpose: To reduce the weight and stabilize the configuration of a radiation shielding plate which is used in close contact with an object to be irradiated with radiation rays. Constitution: The radiation shielding plate comprises a substrate made of lead glass and a metallic lead coating on the surface of the substrate by means of plating, vapor deposition or the like. Apertures for permeating radiation rays are formed to the radiation shielding plate. Since the shielding plate is based on a lead glass plate, a sufficient mechanical strength can be obtained with a thinner structure as compared with the conventional plate made of metallic lead. Accordingly, if the shielding plate is disposed on a soft object to be irradiated with radiation rays, the object and the plate itself less deform to obtain a radiation irradiation pattern with distinct edges. (Moriyama, K.)

  6. Evaluation of dripper clogging using magnetic water in drip irrigation

    Science.gov (United States)

    Khoshravesh, Mojtaba; Mirzaei, Sayyed Mohammad Javad; Shirazi, Pooya; Valashedi, Reza Norooz

    2018-06-01

    This study was performed to investigate the uniformity of distribution of water and discharge variations in drip irrigation using magnetic water. Magnetic water was achieved by transition of water using a robust permanent magnet connected to a feed pipeline. Two main factors including magnetic and non-magnetic water and three sub-factor of salt concentration including well water, addition of 150 and 300 mg L-1 calcium carbonate to irrigation water with three replications were applied. The result of magnetic water on average dripper discharge was significant at ( P ≤ 0.05). At the final irrigation, the average dripper discharge and distribution uniformity were higher for the magnetic water compared to the non-magnetic water. The magnetic water showed a significant effect ( P ≤ 0.01) on distribution uniformity of drippers. At the first irrigation, the water distribution uniformity was almost the same for both the magnetic water and the non-magnetic water. The use of magnetic water for drip irrigation is recommended to achieve higher uniformity.

  7. Farmers’ Logics in Engaging With Projects Promoting Drip Irrigation Kits in Burkina Faso

    NARCIS (Netherlands)

    Wanvoeke, J.; Venot, J.-P.; Zwarteveen, M.; de Fraiture, C.

    2016-01-01

    Development agencies enthusiastically promote micro-drip irrigation as an affordable water and labor-saving device, yet most farmers stop using it as soon as development projects end. This article analyzes why farmers engage in projects promoting drip irrigation kits, even though they appear not to

  8. Low cost drip irrigation in Burkina Faso : unravelling actors, networks and practices

    NARCIS (Netherlands)

    Wanvoeke, M.J.V.

    2015-01-01

    Title: Low cost drip irrigation in Burkina Faso: Unravelling Actors, Networks and Practices

    In Burkina Faso, there is a lot of enthusiasm about Low Cost Drip Irrigation (LCDI) as a tool to irrigate vegetables, and thus improve food security,

  9. Farmers’ Logics in Engaging With Projects Promoting Drip Irrigation Kits in Burkina Faso

    NARCIS (Netherlands)

    Wanvoeke, Jonas; Venot, Jean Philippe; Zwarteveen, Margreet; Fraiture, de Charlotte

    2016-01-01

    Development agencies enthusiastically promote micro-drip irrigation as an affordable water and labor-saving device, yet most farmers stop using it as soon as development projects end. This article analyzes why farmers engage in projects promoting drip irrigation kits, even though they appear not

  10. 40 CFR 270.26 - Special part B information requirements for drip pads.

    Science.gov (United States)

    2010-07-01

    ... residuals. (14) A description of how each drip pad, including appurtenances for control of run-on and run..., detailed plans and an engineering report describing how the requirements of § 264.90(b)(2) of this chapter will be met. (c) Detailed plans and an engineering report describing how the drip pad is or will be...

  11. Corn yield and economic return with nitrogen applied through drip tubing

    Science.gov (United States)

    A two year project was established to determine corn (Zea mays, L) yield response to subsurface (SSDI) and surface (SDI) drip irrigation systems at various nitrogen fertilizer rates. Nitrogen was applied through the drip system at two nitrogen levels in three split applications. Supplemental dry N ...

  12. Bricolage as innovation: opening the black box of drip irrigation systems

    NARCIS (Netherlands)

    Benouniche, M.; Zwarteveen, M.; Kuper, M.

    2014-01-01

    In Morocco, many farmers enthusiastically use drip irrigation. However, few drip irrigation systems conform to engineering standards. In a process they refer to as bricolage, farmers modify and adapt standard designs, thus creating their own technical standards. We document three instances of

  13. Bricolage as innovation: opening the black box of Drip Irrigation Systems

    NARCIS (Netherlands)

    Benouniche, M.; Zwarteveen, M.Z.; Kuper, M.

    2014-01-01

    In Morocco, many farmers enthusiastically use drip irrigation. However, few drip irrigation systems conform to engineering standards. In a process they refer to as bricolage, farmers modify and adapt standard designs, thus creating their own technical standards. We document three instances of

  14. Study on the physiological activities of gamma-irradiated seafood cooking drips

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Eu Ri; Kim, Yeon Joo; Choi, Jong Il; Sung, Nak Yun; Jung, Pil Moon; Kim, Jae Hun; Song, Beom Seok; Yoon, Yo Han; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Lee, Ju Yeoun [Chonbuk National University, Jeonju (Korea, Republic of)

    2010-03-15

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment.

  15. Study on the physiological activities of gamma-irradiated seafood cooking drips

    International Nuclear Information System (INIS)

    Jo, Eu Ri; Kim, Yeon Joo; Choi, Jong Il; Sung, Nak Yun; Jung, Pil Moon; Kim, Jae Hun; Song, Beom Seok; Yoon, Yo Han; Lee, Ju Woon; Lee, Ju Yeoun

    2010-01-01

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment

  16. Corrosion in airframes

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    The introductory chapter provides a brief reference to the issue of corrosion and corrosion damage to aircraft structures. Depending on the nature and dimensions of this non uniformity, three different categories of corrosion are defined: uniform, selective and localized corrosion. The following chapters present the forms of corrosion that can occur in three defined categories of corrosion. Conditions that cause certain types of corrosion in various corrosive environments are discussed. Examp...

  17. HPGe detector shielding adjustment

    International Nuclear Information System (INIS)

    Trnkova, L.; Rulik, P.

    2008-01-01

    Low-level background shielding of HPGe detectors is used mainly for environmental samples with very low content of radionuclides. National Radiation Protection Institute (SURO) in Prague is equipped with 14 HPGe detectors with relative efficiency up to 150%. The detectors are placed in a room built from materials with low content of natural radionuclides and equipped with a double isolation of the floor against radon. Detectors themselves are placed in lead or steel shielding. Steel shielding with one of these detectors with relative efficiency of 100% was chosen to be rebuilt to achieve lower minimum detectable activity (MDA). Additional lead and copper shielding was built up inside the original steel shielding to reduce the volume of the inner space and filled with nitrogen by means of evaporating liquid nitrogen. The additional lead and copper shielding, consequent reduction of the inner volume and supply of evaporated nitrogen, caused a decrease of the background count and accordingly MDA values as well. The effect of nitrogen evaporation on the net areas of peaks belonging to radon daughters is significant. The enhanced shielding adjustment has the biggest influence in low energy range, what can be seen in collected data. MDA values in energy range from 30 keV to 400 keV decreased to 0.65-0.85 of original value, in energy range from 400 keV to 2 MeV they fell to 0.70-0.97 of original value. (authors)

  18. Shielding in experimental areas

    International Nuclear Information System (INIS)

    Stevens, A.; Tarnopolsky, G.; Thorndike, A.; White, S.

    1979-01-01

    The amount of shielding necessary to protect experimental detectors from various sources of background radiation is discussed. As illustrated an experiment has line of sight to sources extending approx. 90 m upstream from the intersection point. Packing a significant fraction of this space with shielding blocks would in general be unacceptable because primary access to the ring tunnel is from the experimental halls. (1) From basic machine design considerations and the inherent necessity to protect superconducting magnets it is expected that experimental areas in general will be cleaner than at any existing accelerator. (2) Even so, it will likely be necessary to have some shielding blocks available to protect experimental apparatus, and it may well be necessary to have a large amount of shielding available in the WAH. (3) Scraping will likely have some influence on all halls, and retractable apparatus may sometimes be necessary. (4) If access to any tunnel is needed to replace a magnet, one has 96 h (4 days) available to move shielding away to permit access without additional downtime. This (the amount of shielding one can shuffle about in 96 h) is a reasonable upper limit to shielding necessary in a hall

  19. Engineering considerations for corrosion monitoring of gas gathering pipeline systems

    Energy Technology Data Exchange (ETDEWEB)

    Braga, T.G.; Asperger, R.G.

    1987-01-01

    Proper corrosion monitoring of gas gathering pipelines requires a system review to determine the appropriate monitor locations and types of monitoring techniques. This paper develops and discusses a classification of conditions such as flow regime and gas composition. Also discussed are junction categories which, for corrosion monitoring, need to be considered from two points of view. The first is related to fluid flow in the line and the second is related corrosion inhibitor movement along the pipeline. The appropriate application of the various monitoring techniques such as coupons, hydrogen detectors, electrical resistance probe and linear polarization probes are discussed in relation to flow regime and gas composition. Problems caused by semi-conduction from iron sulfide are considered. Advantages and disadvantages of fluid gathering methods such as pots and flow-through drips are discussed in relation to their reliability as on-line monitoring locations.

  20. Shielding member for thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masanori

    1997-06-30

    In a thermonuclear device for shielding fast neutrons by shielding members disposed in a shielding vessel (vacuum vessel and structures such as a blanket disposed in the vacuum vessel), the shielding member comprises a large number of shielding wires formed fine and short so as to have elasticity. The shielding wires are sealed in a shielding vessel together with water, and when the width of the shielding vessel is changed, the shielding wires follow after the change of the width while elastically deforming in the shielding vessel, so that great stress and deformation are not formed thereby enabling to improve reliability. In addition, the length, the diameter and the shape of each of the shielding wires can be selected in accordance with the shielding space of the shielding vessel. Even if the shape of the shielding vessel is complicated, the shielding wires can be inserted easily. Accordingly, the filling rate of the shielding members can be changed easily. It can be produced more easily compared with a conventional spherical pebbles. It can be produced more easily than existent spherical shielding pebbles thereby enabling to reduce the production cost. (N.H.)

  1. Estimating ISABELLE shielding requirements

    International Nuclear Information System (INIS)

    Stevens, A.J.; Thorndike, A.M.

    1976-01-01

    Estimates were made of the shielding thicknesses required at various points around the ISABELLE ring. Both hadron and muon requirements are considered. Radiation levels at the outside of the shield and at the BNL site boundary are kept at or below 1000 mrem per year and 5 mrem/year respectively. Muon requirements are based on the Wang formula for pion spectra, and the hadron requirements on the hadron cascade program CYLKAZ of Ranft. A muon shield thickness of 77 meters of sand is indicated outside the ring in one area, and hadron shields equivalent to from 2.7 to 5.6 meters in thickness of sand above the ring. The suggested safety allowance would increase these values to 86 meters and 4.0 to 7.2 meters respectively. There are many uncertainties in such estimates, but these last figures are considered to be rather conservative

  2. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    Olson, R.E.; Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  3. Corrosion inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, A O

    1965-12-29

    An acid corrosion-inhibiting composition consists essentially of a sugar, and an alkali metal salt selected from the group consisting of iodides and bromides. The weight ratio of the sugar to the alkali metal salt is between 2:1 and about 20,000:1. Also, a corrosion- inhibited phosphoric acid composition comprising at least about 20 wt% of phosphoric acid and between about 0.1 wt% and about 10 wt% of molasses, and between about 0.0005 wt% and about 1 wt% of potassium iodide. The weight ratio of molasses to iodide is greater than about 2:1. (11 claims)

  4. Shields for nuclear reactors

    International Nuclear Information System (INIS)

    Aspden, G.J.

    1984-01-01

    The patent concerns shields for nuclear reactors. The roof shield comprises a normally fixed radial outer portion, a radial inner portion rotatable about a vertical axis, and a connection between the inner and outer portions. In the event of hypothecal core disruption conditions, a cantilever system on the inner wall allows the upward movement of the inner wall, in order to prevent loss of containment. (UK)

  5. Radiation shielding curtain

    International Nuclear Information System (INIS)

    Winkler, N.T.

    1976-01-01

    A radiation shield is described in the form of a stranded curtain made up of bead-chains whose material and geometry are selected to produce a cross-sectional density that is the equivalent of 0.25 mm or more of lead and which curtain may be mounted on various radiological devices to shield against scattered radiation while offering a minimum of obstruction to the radiologist

  6. Shielded cells transfer automation

    International Nuclear Information System (INIS)

    Fisher, J.J.

    1984-01-01

    Nuclear waste from shielded cells is removed, packaged, and transferred manually in many nuclear facilities. Radiation exposure is absorbed by operators during these operations and limited only through procedural controls. Technological advances in automation using robotics have allowed a production waste removal operation to be automated to reduce radiation exposure. The robotic system bags waste containers out of glove box and transfers them to a shielded container. Operators control the system outside the system work area via television cameras. 9 figures

  7. Clustering and correlations at the neutron drip-line

    Energy Technology Data Exchange (ETDEWEB)

    Orr, N.A.; Marques, F.M

    2003-03-01

    Some recent experimental studies of clustering and correlations within very neutron-rich light nuclei are reviewed. In particular, the development of the novel probes of neutron-neutron interferometry and Dalitz-plot analyses is presented through the example of the dissociation of the two-neutron halo system {sup 14}Be. The utility of high-energy proton radiative capture is illustrated using a study of the {sup 6}He(p,{gamma}) reaction. A new approach to the production and detection of bound neutron clusters is also described, and the observation of events with the characteristics expected for tetraneutrons ({sup 4}n) liberated in the breakup of {sup 14}Be is discussed. The prospects for future work, including systems beyond the neutron drip-line, are briefly outlined. (authors)

  8. Predicting deep percolation with eddy covariance under mulch drip irrigation

    Science.gov (United States)

    Ming, Guanghui; Tian, Fuqiang; Hu, Hongchang

    2016-04-01

    Water is essential for the agricultural development and ecological sustainability of the arid and semi-arid oasis with rare precipitation input and high evaporation demand. Deep percolation (DP) defined as excess irrigation water percolating below the plant root zone will reduce irrigation water use efficiency (WUE). But the DP was often ignored in mulch drip irrigation (MDI) which has reached the area of 1.6 million hectares in Xinjiang, the northwest of China. In this study DP experiments were conducted at an agricultural experiment station located within an irrigation district in the Tarim River Basin for four cotton growing periods. First it was detected the irrigation water infiltrated into the soil layers below 100cm and the groundwater level responded to the irrigation events well. Then DP below 100cm soil layers was calculated using the soil water balance method with the aid of eddy covariance (with the energy balance closure of 0.72). The negative DP (groundwater contribution to the crop-water use through capillary rising) at the seedling and harvesting stages can reach 77mm and has a good negative correlation with the groundwater level and positive correlation with potential evaporation. During the drip irrigation stage approximately 45% of the irrigation became DP and resulted in the low irrigation WUE of 0.6. The DP can be 164mm to 270mm per year which was positive linearly correlated to irrigation depth and negative linear correlated to irrigation interval. It is better to establish the irrigation schedule with small irrigation depth and given frequently to reduce deep percolation and meet crop needs.

  9. Corrosion inhibitors

    International Nuclear Information System (INIS)

    El Ashry, El Sayed H.; El Nemr, Ahmed; Esawy, Sami A.; Ragab, Safaa

    2006-01-01

    The corrosion inhibition efficiencies of some triazole, oxadiazole and thiadiazole derivatives for steel in presence of acidic medium have been studied by using AM1, PM3, MINDO/3 and MNDO semi-empirical SCF molecular orbital methods. Geometric structures, total negative charge on the molecule (TNC), highest occupied molecular energy level (E HOMO ), lowest unoccupied molecular energy level (E LUMO ), core-core repulsion (CCR), dipole moment (μ) and linear solvation energy terms, molecular volume (V i ) and dipolar-polarization (π *), were correlated to corrosion inhibition efficiency. Four equations were proposed to calculate corrosion inhibition efficiency. The agreement with the experimental data was found to be satisfactory; the standard deviations between the calculated and experimental results ranged between ±0.03 and ±4.18. The inhibition efficiency was closely related to orbital energies (E HOMO and E LUMO ) and μ. The correlation between quantum parameters and experimental inhibition efficiency has been validated by single point calculations for the semi-empirical AM1 structures using B3LYP/6-31G** as a higher level of theory. The proposed equations were applied to predict the corrosion inhibition efficiency of some related structures to select molecules of possible activity from a presumable library of compounds

  10. Patient Selection for Drip and Ship Thrombolysis in Acute Ischemic Stroke.

    Science.gov (United States)

    Lyerly, Michael J; Albright, Karen C; Boehme, Amelia K; Shahripour, Reza Bavarsad; Donnelly, John P; Houston, James T; Rawal, Pawan V; Kapoor, Niren; Alvi, Muhammad; Sisson, April; Alexandrov, Anne W; Alexandrov, Andrei V

    2015-07-01

    The drip and ship model is a method used to deliver thrombolysis to acute stroke patients in facilities lacking onsite neurology coverage. We sought to determine whether our drip and ship population differs from patients treated directly at our stroke center (direct presenters). We retrospectively reviewed consecutive patients who received thrombolysis at an outside facility with subsequent transfer to our center between 2009 and 2011. Patients received thrombolysis after telephone consultation with a stroke specialist. We examined demographics, vascular risk factors, laboratory values, and stroke severity in drip and ship patients compared with direct presenters. Ninety-six patients were identified who received thrombolysis by drip and ship compared with 212 direct presenters. The two groups did not differ with respect to sex, ethnicity, vascular risk factors, or admission glucose. The odds ratio (OR) of arriving at our hospital as a drip and ship for someone 80 years or older was 0.31 (95% confidence interval [CI] 0.15-0.61, P < 0.001). Only 21% of drip and ship patients were black versus 38% of direct presenters (OR 0.434, 95% CI 0.25-0.76, P = 0.004). Even after stratifying by age (<80 vs ≥80), a smaller proportion of drip and ship patients were black (OR 0.44, 95% CI 0.24-0.81, P = 0.008). Furthermore, we found that fewer black patients with severe strokes arrived by drip and ship (OR 0.33, 95% CI 0.11-0.98, P = 0.0028). Our study showed that a smaller proportion of blacks and older adults arrived at our center by the drip and ship model. This may reflect differences in how patients are selected for thrombolysis and transfer to a higher level of care.

  11. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  12. Corrosion/95 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The papers in this conference represent the latest technological advances in corrosion control and prevention. The following subject areas are covered: cathodic protection in natural waters; materials for fossil fuel combustion and conversion systems; modern problems in atmospheric corrosion; innovative ideas for controlling the decaying infrastructure; deposits and their effects on corrosion in industry; volatile high temperature and non aqueous corrosion inhibitors; corrosion of light-weight and precoated metals for automotive application; refining industry corrosion; corrosion in pulp and paper industry; arctic/cold weather corrosion; materials selection for waste incinerators and associated equipment; corrosion measurement technology; environmental cracking of materials; advancing technology in the coating industry; corrosion in gas treating; green inhibition; recent advances in corrosion control of rail equipment; velocity effects and erosion corrosion in oil and gas production; marine corrosion; corrosion of materials in nuclear systems; underground corrosion control; corrosion in potable and industrial water systems in buildings and its impact on environmental compliance; deposit related boiler tube failures; boiler systems monitoring and control; recent developments and experiences in reactive metals; microbiologically influenced corrosion; corrosion and corrosion control for steel reinforced concrete; international symposium on the use of 12 and 13 Cr stainless steels in oil and gas production environments; subsea corrosion /erosion monitoring in production facilities; fiberglass reinforced pipe and tubulars in oilfield service; corrosion control technology in power transmission and distribution; mechanisms and methods of scale and deposit control; closing the loop -- results oriented cooling system monitoring and control; and minimization of aqueous discharge

  13. Neutron shielding material

    International Nuclear Information System (INIS)

    Nodaka, M.; Iida, T.; Taniuchi, H.; Yosimura, K.; Nagahama, H.

    1993-01-01

    From among the neutron shielding materials of the 'kobesh' series developed by Kobe Steel, Ltd. for transport and storage packagings, silicon rubber base type material has been tested for several items with a view to practical application and official authorization, and in order to determine its adaptability to actual vessels. Silicon rubber base type 'kobesh SR-T01' is a material in which, from among the silicone rubber based neutron shielding materials, the hydrogen content is highest and the boron content is most optimized. Its neutron shielding capability has been already described in the previous report (Taniuchi, 1986). The following tests were carried out to determine suitability for practical application; 1) Long-term thermal stability test 2) Pouring test on an actual-scale model 3) Fire test The experimental results showed that the silicone rubber based neutron shielding material has good neutron shielding capability and high long-term fire resistance, and that it can be applied to the advanced transport packaging. (author)

  14. Concrete radiation shielding

    International Nuclear Information System (INIS)

    Kaplan, M.F.

    1989-01-01

    The increased use of nuclear energy has given rise to a growth in the amount of artificially produced radiation and radioactive materials. The design and construction of shielding to protect people, equipment and structures from the effects of radiation has never been more important. Experience has shown that concrete is an effective, versatile and economical material for the construction of radiation shielding. This book provides information on the principles governing the interaction of radiation with matter and on relevant nuclear physics to give the engineer an understanding of the design and construction of concrete shielding. It covers the physical, mechanical and nuclear properties of concrete; the effects of elevated temperatures and possible damage to concrete due to radiation; basic procedures for the design of concrete radiation shields and finally the special problems associated with their construction and cost. Although written primarily for engineers concerned with the design and construction of concrete shielding, the book also reviews the widely scattered data and information available on this subject and should therefore be of interest to students and those wishing to research further in this field. (author)

  15. Method for dismantling shields

    International Nuclear Information System (INIS)

    Fukuzawa, Rokuro; Kondo, Nobuhiro; Kamiyama, Yoshinori; Kawasato, Ken; Hiraga, Tomoaki.

    1990-01-01

    The object of the present invention is to enable operators to dismantle shieldings contaminated by radioactivity easily and in a short period of time without danger of radiation exposure. A plurality of introduction pipes are embedded previously to the shielding walls of shielding members which contain a reactor core in a state where both ends of the introduction pipes are in communication with the outside. A wire saw is inserted into the introduction pipes to cut the shieldings upon dismantling. Then, shieldings can be dismantled easily in a short period of time with no radiation exposure to operator's. Further, according to the present invention, since the wire saw can be set easily and a large area can be cut at once, operation efficiency is improved. Further, since remote control is possible, cutting can be conducted in water and complicated places of the reactor. Biting upon starting the wire saw in the introduction pipe is reduced to facilitate startup for the rotation. (I.S.)

  16. Mechanical shielded hot cell

    International Nuclear Information System (INIS)

    Higgy, H.R.; Abdel-Rassoul, A.A.

    1983-01-01

    A plan to erect a mechanical shielded hot cell in the process hall of the Radiochemical Laboratory at Inchas is described. The hot cell is designed for safe handling of spent fuel bundles, from the Inchas reactor, and for dismantling and cutting the fuel rods in preparation for subsequent treatment. The biological shielding allows for the safe handling of a total radioactivity level up to 10,000 MeV-Ci. The hot cell consists of an α-tight stainless-steel box, connected to a γ-shielded SAS, through an air-lock containing a movable carriage. The α-box is tightly connected with six dry-storage cavities for adequate storage of the spent fuel bundles. Both the α-box, with the dry-storage cavities, and the SAS are surrounded by 200-mm thick biological lead shielding. The α-box is equipped with two master-slave manipulators, a lead-glass window, a monorail crane and Padirac and Minirag systems. The SAS is equipped with a lead-glass window, tong manipulator, a shielded pit and a mechanism for the entry of the spent fuel bundle. The hot cell is served by adequate ventilation and monitoring systems. (author)

  17. Localized corrosion of Alloy C22 nuclear waste canister material under limiting conditions

    International Nuclear Information System (INIS)

    Lee, S.G.; Solomon, A.A.

    2006-01-01

    Localized corrosion behavior of Alloy C22 in simulated Yucca Mountain (YM) repository environments was studied at the highest achievable but realistic temperatures under boiling and dripping scenarios. Temperatures measured in concentrated boiling solutions of KCl and NaNO 3 were found to be stable at 140 deg. C, although transient boiling before dryout was observed at temperatures as high as 160 deg. C, as the electrolyte became progressively more concentrated. Experiments that simulated a dripping scenario with simulated J13 well water confirmed the existence of concentrated solutions stable at 142 ± 3 deg. C under controlled drip conditions leading to pit initiation in Alloy C22 after only a few hours. The polarization experiments conducted at 140 deg. C in a solution with 0.5 mol L -1 chloride concentration showed that the critical potential for localized corrosion was 250 mV (versus Ag/AgCl). Potentiostatic tests confirmed that active metal dissolution occurred only in the crevice region at this potential. The crevice corrosion of Alloy C22 required an incubation time to develop a critical crevice solution, and it was triggered by severe local chemistry (enrichment of Cl - and H + ) aided by the high temperature

  18. Specification for corrosion-resisting chromium and chromium-nickel steel covered welding electrodes

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    This specification prescribes requirements for covered corrosion-resisting chromium and chromium-nickel steel electrodes. These electrodes normally are used for shielded metal arc welding, and include those alloy steels designated as corrosion or heat-resisting chromium-nickel steels in which chromium exceeds 4.0 percent and nickel does not exceed 50.0 percent

  19. Specification for corrosion-resisting chromium and chromium-nickel steel covered welding electrodes

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    This specification prescribes requirements for covered corrosion-resisting chromium and chromium-nickel steel electrodes. These electrodes are normally used for shielded metal arc welding, and include those alloy steels designated as corrosion or heat-resisting chromium and chromium-nickel steels, in which chromium exceeds 4.0% and nickel does not exceed 50.0%

  20. Specification for corrosion-resisting chromium and chromium-nickel steel covered welding electrodes

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    This specification prescribes requirements for covered corrosion-resisting chromium and chromium-nickel steel electrodes. These electrodes are normally used for shielded metal arc welding, and include those alloy steels designated as corrosion or heat-resisting chromium and chromium-nickel steels, in which chromium exceeds 4.0 percent and nickel does not exceed 50.0 percent

  1. Shield support frame. Schildausbaugestell

    Energy Technology Data Exchange (ETDEWEB)

    Plaga, K.

    1981-09-17

    A powered shield support frame for coal sheds is described comprising of two bottom sliding shoes, a large area gob shield and a larg area roof assembly, all joined movable together. The sliding shoes and the gob shield are joined by a lemniscate guide. Two hydraulic props are arranged at the face-side at one third of the length of the sliding shoes and at the goaf-side at one third of the length of the roof assembly. A nearly horizontal lying pushing prop unit joins the bottom wall sliding shoes to the goaf-side lemniscate guide. This assembly can be applied to seams with a thickness down to 45 cm. (OGR).

  2. Radiation shielding material

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Isobe, Eiji.

    1976-01-01

    Purpose: To increase the shielding capacity of the radiation shielding material having an abundant flexibility. Constitution: A mat consisting of a lead or lead alloy fibrous material is covered with a cloth, and the two are made integral by sewing in a kilted fashion by using a yarn. Thereafter, the system is covered with a gas-tight film or sheet. The shielding material obtained in this way has, in addition to the above merits, advantages in that (1) it is free from restoration due to elasticity so that it can readily seal contaminants, (2) it can be used in a state consisting of a number of overlapped layers, (3) it fits the shoulder well and is readily portable and (4) it permits attachment of fasteners or the like. (Ikeda, J.)

  3. Hybrid Magnetic Shielding

    Science.gov (United States)

    Royal, Kevin; Crawford, Christopher; Mullins, Andrew; Porter, Greg; Blanton, Hunter; Johnstone, Connor; Kistler, Ben; Olivera, Daniela

    2017-09-01

    The search for the electric dipole moment of the neutron requires the ambient magnetic field to be on the pT scale which is accomplished with large magnetic shielding rooms. These rooms are fitted with large mu-metal sheets to allow for passive cancellation of background magnetic fields. Active shielding technology cannot uniformly cancel background magnetic fields. These issues can be remedied by combining the methods into a hybrid system. The design used is composed of panels that have an active layer of cancellation between two sheets of mu-metal. The panels form a cube and draw in magnetic fields perpendicular to the surface which can then be reduced using active shielding. This work is supported by the Department of Energy under Contract DE-SC0008107.

  4. Reactor head shielding apparatus

    International Nuclear Information System (INIS)

    Schukei, G.E.; Roebelen, G.J.

    1992-01-01

    This patent describes a nuclear reactor head shielding apparatus for mounting on spaced reactor head lifting members radially inwardly of the head bolts. It comprises a frame of sections for mounting on the lifting members and extending around the top central area of the head, mounting means for so mounting the frame sections, including downwardly projecting members on the frame sections and complementary upwardly open recessed members for fastening to the lifting members for receiving the downwardly projecting members when the frame sections are lowered thereto with lead shielding supported thereby on means for hanging lead shielding on the frame to minimize radiation exposure or personnel working with the head bolts or in the vicinity thereof

  5. Double-layer neutron shield design as neutron shielding application

    Science.gov (United States)

    Sariyer, Demet; Küçer, Rahmi

    2018-02-01

    The shield design in particle accelerators and other high energy facilities are mainly connected to the high-energy neutrons. The deep penetration of neutrons through massive shield has become a very serious problem. For shielding to be efficient, most of these neutrons should be confined to the shielding volume. If the interior space will become limited, the sufficient thickness of multilayer shield must be used. Concrete and iron are widely used as a multilayer shield material. Two layers shield material was selected to guarantee radiation safety outside of the shield against neutrons generated in the interaction of the different proton energies. One of them was one meter of concrete, the other was iron-contained material (FeB, Fe2B and stainless-steel) to be determined shield thicknesses. FLUKA Monte Carlo code was used for shield design geometry and required neutron dose distributions. The resulting two layered shields are shown better performance than single used concrete, thus the shield design could leave more space in the interior shielded areas.

  6. low cost constant low cost constant – head drip irrigation emitter

    African Journals Online (AJOL)

    eobe

    manufacturer's coefficient of variation and distribution uniformity of discharge were 0.098 and ... The system operates under low pressure (87.9 mbar) and can deliver the daily crop .... The concept underlining the design is to develop a drip.

  7. Study on the changes in phyicochemical properties of seafood cooking drips by gamma ray irradiation

    International Nuclear Information System (INIS)

    Choi, Jong Il; Kim, Yeon Joo; Kim, Jae Hun; Yoon, Yo Han; Song, Beom Seok; Lee, Ju Woon; Chun, Byung Soo; Ahn, Dong Hyun; Lee, Ju Yeoun

    2010-01-01

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lots of proteins, carbohydrates, and other functional materials. But, the seafood cooking drips are easily contaminated because of its rich nutrients, and their color are very dark. This study was conducted to investigate the effect of gamma irradiation on the quality of seafood cooking drips including Hizikia fusiformis, Enteroctopus dofleini, and Thunnus thynnus. The Hunter's color values (L, Brightness) of H. fusiformis, and T.thynnus, were increased with increasing irradiation doses, showing becoming bright. The crude protein content and crude lipid content were increased by gamma irradiation. These results indicated that gamma irradiation increased extraction efficiency of available compounds in cooking drips

  8. Shielding research in France

    Energy Technology Data Exchange (ETDEWEB)

    Lafore, P

    1964-10-01

    Shielding research as an independent subject in France dates from 1956. The importance of these studies has been reflected in the contribution which they have made to power reactor design and in the resultant savings in expenditure for civil engineering and machinery for the removal of mobile shields. The Reactor Shielding Research Division numbers approximately 60 persons and uses several experimental facilities. These include: NAIADE I, installed near the ZOE reactor and operating with a natural uranium slab 2 cm thick (an effective diameter of 60 cm is the one most commonly used); the TRITON pool-type reactor, mainly used in shielding studies, includes an active-water loop, by means of which the secondary shields required for light-water reactors can be studied; core, NEREIDE, which is situated near a 2 m x 2 m aluminium window enables a large neutron source to be placed in a compartment without water in which large-scale mock-ups can be mounted for the study, in particular, of neutron diffusion in large cavities, and of reactor shielding of greater thickness than that in NAIADE I; SAMES 600 keV accelerator is used for monoenergetic neutron studies. Instrumentation studies are an important part of the work, mainly in the measurement of fast neutrons and their spectra by activation detectors. Of late, attention has been directed towards the use of (n, n') (rhodium) reactions and of heavy detectors for low-flux measurements. The simultaneous use of a large number of detectors poses automation problems. With our installation we can count 16 detectors simultaneously. Neutron spectrum studies are conducted with nuclear emulsions and a lithium-6 semiconductor spectrometer. As to the materials used, the research carried out in France involves chiefly graphite, iron and concrete at various temperatures up to 800 deg C. Different compounds, borated and non-borated and of densities up to between 1 and 9 are under consideration. Problems connected with applications are

  9. Aircraft Corrosion

    Science.gov (United States)

    1981-08-01

    attribud au choix de traitements et de rev~tements spproprids. Au contrairo, dens d’sutros structures des corrosions iirportsntea se sont msnifestdes...au traitement . micaniqus qui provoque une compression de surface - h1l’spplication i1’une double protection comportant oxydation snodique et...chlore mais dans une proportion semblable b cells d’une eau de vil)e ; - lea solides, d’aprbs lea analyses chimique et criatallographique, paraissaiont

  10. Radiation shielding bricks

    International Nuclear Information System (INIS)

    Crowe, G.J.W.

    1983-01-01

    A radiation shielding brick for use in building dry walls to form radiation proof enclosures and other structures is described. It is square in shape and comprises a sandwich of an inner layer of lead or similar shielding material between outer layers of plastics material, for structural stability. The ability to mechanically interlock adjacent bricks is provided by shaping the edges as cooperating external and internal V-sections. Relatively leak-free joints are ensured by enlarging the width of the inner layer in the edge region. (author)

  11. Grey mould development in greenhouse tomatoes under drip and furrow irrigation

    OpenAIRE

    Aissat , Kamel; Nicot , Philippe ,; Guechi , Abdelhadi; Bardin , Marc; Chibane , Mohamed

    2008-01-01

    Several methods can be used to provide water to plants in cropping systems where irrigation is necessary. For instance, drip irrigation has recently received much attention due to its advantages for water conservation. The type of irrigation can also impact the development of several pathogens responsible for soilborne diseases. Here, we studied the effect of drip irrigation and furrow irrigation on the development of grey mould, caused by the airborne fungus Botrytis cinerea, on tomato plant...

  12. Farmers' logics in engaging with projects promoting drip irrigation kits in Burkina Faso

    OpenAIRE

    Wanvoeke, J.; Venot, Jean-Philippe; Zwarteveen, M.; de Fraiture, C.

    2016-01-01

    Development agencies enthusiastically promote micro-drip irrigation as an affordable water and labor-saving device, yet most farmers stop using it as soon as development projects end. This article analyzes why farmers engage in projects promoting drip irrigation kits, even though they appear not to be interested in their water and labor-saving attributes. We combine practice-based theories of innovation with insights from the anthropology of development to explain that in development project ...

  13. Safety and Time Course of Drip-and-Ship in Treatment of Acute Ischemic Stroke.

    Science.gov (United States)

    Ishihara, Hideyuki; Oka, Fumiaki; Oku, Takayuki; Shinoyama, Mizuya; Suehiro, Eiichi; Sugimoto, Kazutaka; Suzuki, Michiyasu

    2017-11-01

    The drip-and-ship approach allows intravenous tissue plasminogen activator therapy and adjuvant endovascular treatment in acute ischemic stroke, even in rural areas. Here, we examined the safety and time course of the drip-and-ship approach. Fifty consecutive cases treated with the drip-and-ship approach (drip-and-ship group) in June 2009 to March 2016 were retrospectively examined. Changes in mean blood pressure, systemic complications, and neurological complications were compared according to method of transportation. Time courses were compared between drip-and-ship and direct admission groups during the same period. In the drip-and-ship group, 33 and 17 patients were transferred to hospital by ambulance and helicopter, respectively. One patient suffered hemorrhagic infarction during transportation by ambulance. Mean blood pressure change was lower in patients transferred by helicopter than ambulance (<5 mmHg versus 12.2 mmHg, respectively). The mean onset-to-door times in the drip-and-ship and direct admission groups were 71 and 64 minutes, respectively, and mean door-to-needle times were 70 and 47 minutes, respectively (P =.002). Although mean transportation time from the primary stroke hospital to our hospital was 32 minutes, the entry-to-exit time from the primary stroke hospital was 113 minutes. Thereafter, there was an average delay of 100 minutes until reperfusion compared with the direct admission group. Drip-and-ship was relatively safe in this small series. Transportation by helicopter was less stressful for acute ischemic stroke patients. It is important to reduce door-to-needle time and needle-to-departure time in the primary stroke hospital to minimize the time until treatment in cases of acute ischemic stroke. Copyright © 2017. Published by Elsevier Inc.

  14. Hybrid Active-Passive Radiation Shielding System

    Data.gov (United States)

    National Aeronautics and Space Administration — A radiation shielding system is proposed that integrates active magnetic fields with passive shielding materials. The objective is to increase the shielding...

  15. Influence of Flame Retardants on the Melt Dripping Behaviour of Thermoplastic Polymers

    Directory of Open Access Journals (Sweden)

    Melissa Matzen

    2015-08-01

    Full Text Available Melt flow and dripping of the pyrolysing polymer melt can be both a benefit and a detriment during a fire. In several small-scale fire tests addressing the ignition of a defined specimen with a small ignition source, well-adjusted melt flow and dripping are usually beneficial to pass the test. The presence of flame retardants often changes the melt viscosity crucially. The influence of certain flame retardants on the dripping behaviour of four commercial polymers, poly(butylene terephthalate (PBT, polypropylene (PP, polypropylene modified with ethylene-propylene rubber (PP-EP and polyamide 6 (PA 6, is analysed based on an experimental monitoring of the mass loss due to melt dripping, drop size and drop temperature as a function of the furnace temperature applied to a rod-shaped specimen. Investigating the thermal transition (DSC, thermal and thermo-oxidative decomposition, as well as the viscosity of the polymer and collected drops completes the investigation. Different mechanisms of the flame retardants are associated with their influence on the dripping behaviour in the UL 94 test. Reduction in decomposition temperature and changed viscosity play a major role. A flow limit in flame-retarded PBT, enhanced decomposition of flame-retarded PP and PP-EP and the promotion of dripping in PA 6 are the salient features discussed.

  16. Usage of drip drops as stimuli in an auditory P300 BCI paradigm.

    Science.gov (United States)

    Huang, Minqiang; Jin, Jing; Zhang, Yu; Hu, Dewen; Wang, Xingyu

    2018-02-01

    Recently, many auditory BCIs are using beeps as auditory stimuli, while beeps sound unnatural and unpleasant for some people. It is proved that natural sounds make people feel comfortable, decrease fatigue, and improve the performance of auditory BCI systems. Drip drop is a kind of natural sounds that makes humans feel relaxed and comfortable. In this work, three kinds of drip drops were used as stimuli in an auditory-based BCI system to improve the user-friendness of the system. This study explored whether drip drops could be used as stimuli in the auditory BCI system. The auditory BCI paradigm with drip-drop stimuli, which was called the drip-drop paradigm (DP), was compared with the auditory paradigm with beep stimuli, also known as the beep paradigm (BP), in items of event-related potential amplitudes, online accuracies and scores on the likability and difficulty to demonstrate the advantages of DP. DP obtained significantly higher online accuracy and information transfer rate than the BP ( p  < 0.05, Wilcoxon signed test; p  < 0.05, Wilcoxon signed test). Besides, DP obtained higher scores on the likability with no significant difference on the difficulty ( p  < 0.05, Wilcoxon signed test). The results showed that the drip drops were reliable acoustic materials as stimuli in an auditory BCI system.

  17. Spatially dense drip hydrological monitoring and infiltration behaviour at the Wellington Caves, South East Australia

    Directory of Open Access Journals (Sweden)

    Jex Catherine N.

    2012-07-01

    Full Text Available Despite the fact that karst regions are recognised as significant groundwater resources, the nature of groundwater flow paths in the unsaturated zone of such fractured rock is at present poorly understood. Many traditional methods for constraining groundwater flow regimes in karst aquifers are focussed on the faster drainage components and are unable to inform on the smaller fracture or matrix-flow components of the system. Caves however, offer a natural inception point to observe both the long term storage and the preferential movement of water through the unsaturated zone of such fractured carbonate rock by monitoring of drip rates of stalactites, soda straws and seepage from fractures/micro fissures that emerge in the cave ceiling. Here we present the largest spatial survey of automated cave drip rate monitoring published to date with the aim of better understanding both karst drip water hydrogeology and the relationship between drip hydrology and surface climate. By the application of cross correlation functions and multi-dimensional scaling, clustered by k-means technique, we demonstrate the nature of the relationships between drip behaviour and initial surface infiltration and similarity amongst the drip rate time series themselves that may be interpreted in terms of flow regimes and cave chamber morphology and lithology.

  18. Organic characterisation of cave drip water by LC-OCD and fluorescence analysis

    Science.gov (United States)

    Rutlidge, Helen; Andersen, Martin S.; Baker, Andy; Chinu, Khorshed J.; Cuthbert, Mark O.; Jex, Catherine N.; Marjo, Christopher E.; Markowska, Monika; Rau, Gabriel C.

    2015-10-01

    Cathedral Cave, Wellington, Australia, is a natural laboratory for studying water movement and geochemical processes in the unsaturated zone by using artificial irrigation to activate drip sites within the cave. Water sampled from two drip sites activated by irrigations carried out in summer 2014 was analysed for dissolved inorganic ions and fluorescent organic matter. The analysis allowed the development of a conceptual flow path model for each drip site. DOM analysis was further complemented by liquid chromatography with organic carbon detection (LC-OCD), applied for the first time to karst drip waters, allowing the characterisation of six organic matter fractions. The differences in organic matter fractions at each drip site are interpreted as a signature of the proposed flow paths. LC-OCD was also compared with parallel factor analysis (PARAFAC) of the fluorescence and good correlations were observed for high molecular weight organic matter. Strong positive correlations were also observed for high molecular weight matter and Cu and Ni. This is suggestive of colloidal transport of Cu and Ni by organic matter with high molecular weight, while small molecular weight colloids were not efficient transporters. LC-OCD uniquely provides information on non-fluorescent organic matter and can be used to further quantify drip water organic matter composition.

  19. Corrosion Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Corrosion Testing Facility is part of the Army Corrosion Office (ACO). It is a fully functional atmospheric exposure site, called the Corrosion Instrumented Test...

  20. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Sayenko, S.Yu.; Dovbnya, A.N.; Shkuropatenko, V.A.; Tarasov, R.V.; Rybka, A.V.; Zakharchenko, A.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

    2015-07-15

    Highlights: • It incorporates all suggestions by the reviewers. • Explanation to each new term is provided and suitable references are given. • Sample identities have been streamlined by revising the text and the tables. • Some figures have been redrawn. - Abstract: Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete’s tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

  1. Propofol drip infusion anesthesia for MRI scanning: two case reports.

    Science.gov (United States)

    Sasao-Takano, Mami; Misumi, Kan; Suzuki, Masayuki; Kamiya, Yoko; Noguchi, Izumi; Kawahara, Hiroshi

    2013-01-01

    The magnetic resonance imaging (MRI) room is a special environment. The required intense magnetic fields create unique problems with the use of standard anesthesia machines, syringe pumps, and physiologic monitors. We have recently experienced 2 oral maxillofacial surgery cases requiring MRI: a 15-year-old boy with developmental disability and a healthy 5-year-old boy. The patients required complete immobilization during the scanning for obtaining high-quality images for the best diagnosis. Anesthesia was started in the MRI scanning room. An endotracheal intubation was performed after induction with intravenous administration of muscle relaxant. Total intravenous anesthesia via propofol drip infusion (4-7 mg/kg/h) was used during the scanning. Standard physiologic monitors were used during scan pauses, but special monitors were used during scanning. In MRI scanning for oral maxillofacial surgery, general anesthesia, with the added advantage of having a secured airway, is recommended as a safe alternative to sedation especially in cases of patients with disability and precooperative chidren.

  2. Radiation shielding cloth

    International Nuclear Information System (INIS)

    Ijiri, Yasuo; Fujinuma, Tadashi; Tamura, Shoji.

    1989-01-01

    Radiation shielding cloth having radiation shielding layers comprising a composition of inorganic powder of high specific gravity and rubber are excellentin flexibility and comfortable to put on. However, since they are heavy in the weight, operators are tired upon putting them for a long time. In view of the above, the radiation ray shielding layers are prepared by calendering sheets obtained by preliminary molding of the composition to set the variation of the thickness within a range of +15% to -0% of prescribed thickness. Since the composition of inorganic powder at high specific gravity and rubber used for radiation ray shielding comprises a great amount of inorganic powder at high specific gravity blended therein, it is generally poor in fabricability. Therefor, it is difficult to attain fine control for the sheet thickness by merely molding a composition block at once. Then, the composition is at first preliminarily molded into a sheet-like shape which is somewhat thickener than the final thickness and then finished by calendering, by which the thickness can be reduced in average as compared with conventional products while keeping the prescribed thickness and reducing the weight reduce by so much. (N.H.)

  3. Electrostatic shielding of transformers

    Energy Technology Data Exchange (ETDEWEB)

    De Leon, Francisco

    2017-11-28

    Toroidal transformers are currently used only in low-voltage applications. There is no published experience for toroidal transformer design at distribution-level voltages. Toroidal transformers are provided with electrostatic shielding to make possible high voltage applications and withstand the impulse test.

  4. Penetration portion shielding structure

    International Nuclear Information System (INIS)

    Hayashi, Katsumi; Narita, Hitoshi; Handa, Hiroyuki; Takeuchi, Jun; Tozuka, Fumio.

    1994-01-01

    Openings of a plurality of shieldings for penetration members are aligned to each other, and penetration members are inserted from the openings. Then, the openings of the plurality of shielding members are slightly displaced with each other to make the penetration portions into a helical configuration, so that leakage of radiation is reduced. Upon removal of the members, reverse operation is conducted. When a flowable shielding material is used, the penetration portions are constituted with two plates having previously formed openings and pipes for connecting the openings with each other and a vessel covering the entire of them. After passing the penetration members such as a cable, the relative position of the two plates is changed by twisting, to form a helical configuration which reduces radiation leakage. Since they are bent into the helical configuration, shielding performance is extremely improved compared with a case that radiation leakage is caused from an opening of a straight pipe. In addition, since they can be returned to straight pipes, attachment, detachment and maintenance can be conducted easily. (N.H.)

  5. Dosimetry and shielding

    International Nuclear Information System (INIS)

    Farinelli, U.

    1977-01-01

    Today, reactor dosimetry and shielding have wide areas of overlap as concerns both problems and methods. Increased interchange of results and know-how would benefit both. The areas of common interest include calculational methods, sensitivity studies, theoretical and experimental benchmarks, cross sections and other nuclear data, multigroup libraries and procedures for their adjustment, experimental techniques and damage functions. This paper reviews the state-of-the-art and the latest development in each of these areas as far as shielding is concerned, and suggests a number of interactions that could be profitable for reactor dosimetry. Among them, re-evaluation of the potentialities of calculational methods (in view of the recent developments) in predicting radiation environments of interest; the application of sensitivity analysis to dosimetry problems; a common effort in the field of theoretical benchmarks; the use of the shielding one-material propagation experiments as reference spectra for detector cross sections; common standardization of the detector nuclear data used in both fields; the setting up of a common (or compatible) multigroup structure and library applicable to shielding, dosimetry and core physics; the exchange of information and experience in the fields of cross section errors, correlations and adjustment; and the intercomparison of experimental techniques

  6. Radiation shielding glass

    International Nuclear Information System (INIS)

    Kido, Kazuhiro; Ueda, Hajime.

    1997-01-01

    It was found that a glass composition comprising, as essential ingredients, SiO 2 , PbO, Gd 2 O 3 and alkali metal oxides can provide a shielding performance against electromagnetic waves, charged particles and neutrons. The present invention provides radiation shielding glass containing at least from 16 to 46wt% of SiO 2 , from 47 to 75wt% of PbO, from 1 to 10wt% of Gd 2 O 3 , from 0 to 3wt% of Li 2 O, from 0 to 7wt% of Na 2 O, from 0 to 7wt% of K 2 O provided that Li 2 O + Na 2 O + K 2 O is from 1 to 10wt%, B 2 O 3 is from 0 to 10wt%, CeO 2 is from 0 to 3wt%, As 2 O 3 is from 0 to 1wt% and Sb 2 O 3 is from 0 to 1wt%. Since the glass can shield electromagnetic waves, charged particles and neutrons simultaneously, radiation shielding windows can be designed and manufactured at a reduced thickness and by less constitutional numbers in a circumstance where they are present altogether. (T.M.)

  7. Corrosion technology. V. 1

    International Nuclear Information System (INIS)

    Khan, I.H.

    1989-01-01

    This book has been produced for dissemination of information on corrosion technology, corrosion hazards and its control. Chapter one of this book presents an overall view of the subject and chapter 2-5 deals with electrochemical basics, types of corrosion, pourbaix diagrams and form of corrosion. The author explains polarization/kinetics of corrosion, passivity, aqueous corrosion and corrosion testing and monitoring in 6-11 chapters. The author hopes it will provide incentive to all those interested in the corrosion technology. (A.B.)

  8. Corrosion/94 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The approximately 500 papers from this conference are divided into the following sections: Rail transit systems--stray current corrosion problems and control; Total quality in the coatings industry; Deterioration mechanisms of alloys at high temperatures--prevention and remediation; Research needs and new developments in oxygen scavengers; Computers in corrosion control--knowledge based system; Corrosion and corrosivity sensors; Corrosion and corrosion control of steel reinforced concrete structures; Microbiologically influenced corrosion; Practical applications in mitigating CO 2 corrosion; Mineral scale deposit control in oilfield-related operations; Corrosion of materials in nuclear systems; Testing nonmetallics for life prediction; Refinery industry corrosion; Underground corrosion control; Mechanisms and applications of deposit and scale control additives; Corrosion in power transmission and distribution systems; Corrosion inhibitor testing and field application in oil and gas systems; Decontamination technology; Ozone in cooling water applications, testing, and mechanisms; Corrosion of water and sewage treatment, collection, and distribution systems; Environmental cracking of materials; Metallurgy of oil and gas field equipment; Corrosion measurement technology; Duplex stainless steels in the chemical process industries; Corrosion in the pulp and paper industry; Advances in cooling water treatment; Marine corrosion; Performance of materials in environments applicable to fossil energy systems; Environmental degradation of and methods of protection for military and aerospace materials; Rail equipment corrosion; Cathodic protection in natural waters; Characterization of air pollution control system environments; and Deposit-related problems in industrial boilers. Papers have been processed separately for inclusion on the data base

  9. Investigating Liquid Leak from Pre-Filled Syringes upon Needle Shield Removal: Effect of Air Bubble Pressure.

    Science.gov (United States)

    Chan, Edwin; Maa, Yuh-Fun; Overcashier, David; Hsu, Chung C

    2011-01-01

    This study is to investigate the effect of headspace air pressure in pre-filled syringes on liquid leak (dripping) from the syringe needle upon needle shield removal. Drip tests to measure drip quantity were performed on syringes manually filled with 0.5 or 1.0 mL of various aqueous solutions. Parameters assessed included temperature (filling and test), bulk storage conditions (tank pressure and the type of the pressurized gas), solution composition (pure water, 0.9% sodium chloride, and a monoclonal antibody formulation), and testing procedures. A headspace pressure analyzer was used to verify the drip test method. Results suggested that leakage is indeed caused by headspace pressure increase, and the temperature effect (ideal gas expansion) is a major, but not the only, factor. The dissolved gases in the liquid bulk prior to or during filling may contribute to leakage, as these gases could be released into the headspace due to solubility changes (in response to test temperature and pressure conditions) and cause pressure increase. Needle shield removal procedures were found to cause dripping, but liquid composition played little role. Overall, paying attention to the processing history (pressure and temperature) of the liquid bulk is the key to minimize leakage. The headspace pressure could be reduced by decreasing liquid bulk storage pressure, filling at a higher temperature, or employing lower solubility gas (e.g., helium) for bulk transfer and storage. Leakage could also be mitigated by simply holding the syringe needle pointing upward during needle shield removal. Substantial advances in pre-filled syringe technology development, particularly in syringe filling accuracy, have been made. However, there are factors, as subtle as how the needle shield (or tip cap) is removed, that may affect dosing accuracy. We recently found that upon removal of the tip cap from a syringe held vertically with needle pointed downwards, a small amount of solution, up to 3-4% of

  10. Gonad shielding in diagnostic radiology

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The use of gonad shielding is an important radiation protection technique, intended to reduce unnecessary x-ray exposure of the gonads of patients from diagnostic x-ray procedures. The types of gonad shields in use are discussed as are the types of diagnostic examinations that should include gonad shielding. It was found that when properly used, most shields provided substantial gonad dose reductions

  11. Hydrological characterization of cave drip waters in a porous limestone: Golgotha Cave, Western Australia

    Science.gov (United States)

    Mahmud, Kashif; Mariethoz, Gregoire; Baker, Andy; Treble, Pauline C.

    2018-02-01

    Cave drip water response to surface meteorological conditions is complex due to the heterogeneity of water movement in the karst unsaturated zone. Previous studies have focused on the monitoring of fractured rock limestones that have little or no primary porosity. In this study, we aim to further understand infiltration water hydrology in the Tamala Limestone of SW Australia, which is Quaternary aeolianite with primary porosity. We build on our previous studies of the Golgotha Cave system and utilize the existing spatial survey of 29 automated cave drip loggers and a lidar-based flow classification scheme, conducted in the two main chambers of this cave. We find that a daily sampling frequency at our cave site optimizes the capture of drip variability with the least possible sampling artifacts. With the optimum sampling frequency, most of the drip sites show persistent autocorrelation for at least a month, typically much longer, indicating ample storage of water feeding all stalactites investigated. Drip discharge histograms are highly variable, showing sometimes multimodal distributions. Histogram skewness is shown to relate to the wetter-than-average 2013 hydrological year and modality is affected by seasonality. The hydrological classification scheme with respect to mean discharge and the flow variation can distinguish between groundwater flow types in limestones with primary porosity, and the technique could be used to characterize different karst flow paths when high-frequency automated drip logger data are available. We observe little difference in the coefficient of variation (COV) between flow classification types, probably reflecting the ample storage due to the dominance of primary porosity at this cave site. Moreover, we do not find any relationship between drip variability and discharge within similar flow type. Finally, a combination of multidimensional scaling (MDS) and clustering by k means is used to classify similar drip types based on time series

  12. Hydrological characterization of cave drip waters in a porous limestone: Golgotha Cave, Western Australia

    Directory of Open Access Journals (Sweden)

    K. Mahmud

    2018-02-01

    Full Text Available Cave drip water response to surface meteorological conditions is complex due to the heterogeneity of water movement in the karst unsaturated zone. Previous studies have focused on the monitoring of fractured rock limestones that have little or no primary porosity. In this study, we aim to further understand infiltration water hydrology in the Tamala Limestone of SW Australia, which is Quaternary aeolianite with primary porosity. We build on our previous studies of the Golgotha Cave system and utilize the existing spatial survey of 29 automated cave drip loggers and a lidar-based flow classification scheme, conducted in the two main chambers of this cave. We find that a daily sampling frequency at our cave site optimizes the capture of drip variability with the least possible sampling artifacts. With the optimum sampling frequency, most of the drip sites show persistent autocorrelation for at least a month, typically much longer, indicating ample storage of water feeding all stalactites investigated. Drip discharge histograms are highly variable, showing sometimes multimodal distributions. Histogram skewness is shown to relate to the wetter-than-average 2013 hydrological year and modality is affected by seasonality. The hydrological classification scheme with respect to mean discharge and the flow variation can distinguish between groundwater flow types in limestones with primary porosity, and the technique could be used to characterize different karst flow paths when high-frequency automated drip logger data are available. We observe little difference in the coefficient of variation (COV between flow classification types, probably reflecting the ample storage due to the dominance of primary porosity at this cave site. Moreover, we do not find any relationship between drip variability and discharge within similar flow type. Finally, a combination of multidimensional scaling (MDS and clustering by k means is used to classify similar drip

  13. Shielding experiments for accelerator facilities

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Hiroshi; Tanaka, Susumu; Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2000-06-01

    A series of shielding experiments was carried out by using AVF cyclotron accelerator of TIARA at JAERI in order to validate shielding design methods for accelerator facilities in intermediate energy region. In this paper neutron transmission experiment through thick shields and radiation streaming experiment through a labyrinth are reported. (author)

  14. Shielding experiments for accelerator facilities

    International Nuclear Information System (INIS)

    Nakashima, Hiroshi; Tanaka, Susumu; Sakamoto, Yukio

    2000-01-01

    A series of shielding experiments was carried out by using AVF cyclotron accelerator of TIARA at JAERI in order to validate shielding design methods for accelerator facilities in intermediate energy region. In this paper neutron transmission experiment through thick shields and radiation streaming experiment through a labyrinth are reported. (author)

  15. Shielding Design and Radiation Shielding Evaluation for LSDS System Facility

    International Nuclear Information System (INIS)

    Kim, Younggook; Kim, Jeongdong; Lee, Yongdeok

    2015-01-01

    As the system characteristics, the target in the spectrometer emits approximately 1012 neutrons/s. To efficiently shield the neutron, the shielding door designs are proposed for the LSDS system through a comparison of the direct shield and maze designs. Hence, to guarantee the radiation safety for the facility, the door design is a compulsory course of the development of the LSDS system. To improve the shielding rates, 250x250 covering structure was added as a subsidiary around the spectrometer. In this study, the evaluations of the suggested shielding designs were conducted using MCNP code. The suggested door design and covering structures can shield the neutron efficiently, thus all evaluations of all conditions are satisfied within the public dose limits. From the Monte Carlo code simulation, Resin(Indoor type) and Tungsten(Outdoor type) were selected as the shielding door materials. From a comparative evaluation of the door thickness, In and Out door thickness was selected 50 cm

  16. Linkage between canopy water storage and drop size distributions of leaf drips

    Science.gov (United States)

    Nanko, Kazuki; Watanabe, Ai; Hotta, Norifumi; Suzuki, Masakazu

    2013-04-01

    Differences in drop size distribution (DSD) of leaf drips among tree species have been estimated and physically interpreted to clarify the leaf drip generation process. Leaf drip generation experiments for nine species were conducted in an indoor location without foliage vibration using an automatic mist spray. Broad-leaved species produced a similar DSD among species whose leaves had a matte surface and a second similar DSD among species whose leaves had a coated surface. The matte broad leaves produced a larger and wider range of DSDs than the coated broad leaves. Coated coniferous needles had a wider range of DSDs than the coated broad leaves and different DSDs were observed for different species. The species with shorter dense needles generated a larger DSD. The leaf drip diameter was calculated through the estimation of a state of equilibrium of a hanging drop on the leaves based on physical theory. The calculations indicated that the maximum diameter of leaf drips was determined by the contact angle, and the range of DSDs was determined by the variation in contact length and the contact diameter at the hanging points. The results revealed that leaf drip DSD changed due to variations in leaf hydrophobicity, leaf roughness, leaf geometry and leaf inclination among the different tree species. This study allows the modelization of throughfall DSD. Furthermore, it indicates the possibility of interpreting canopy water processes from canopy water storage to drainage through the contact angle and leaf drip DSD. The part of this study is published in Nanko et al. (2013, Agric. Forest. Meteorol. 169, 74-84).

  17. Surface films and corrosion of copper

    International Nuclear Information System (INIS)

    Hilden, J.; Laitinen, T.; Maekelae, K.; Saario, T.; Bojinov, M.

    1999-03-01

    In Sweden and Finland the spent nuclear fuel is planned to be encapsulated in cast iron canisters that have an outer shield made of copper. The copper shield is responsible for the corrosion protection of the canister construction. General corrosion of the copper is not expected to be the limiting factor in the waste repository environment when estimating the life-time of the canister construction. However, different forms of localised corrosion, i.e. pitting, stress corrosion cracking, or environmentally assisted creep fracture may cause premature failure of the copper shield. Of the probable constituents in the groundwater, nitrites, chlorides, sulphides and carbonates have been suggested to promote localised corrosion of copper. The main assumption made in planning this research program is that the surface films forming on copper in the repository environment largely determine the susceptibility of copper to the different forms of localised corrosion. The availability of reactants, which also may become corrosion rate limiting, is investigated in several other research programs. This research program consists of a set of successive projects targeted at characterising the properties of surface films on copper in repository environment containing different detrimental anions. A further aim was to assess the significance of the anion-induced changes in the stability of the oxide films with regard to localised corrosion of copper. This report summarises the results from a series of investigations on properties of surface films forming on copper in water of pH = 8.9 at temperature of 80 deg C and pressure of 2 MPa. The main results gained so far in this research program are as follows: The surface films forming on copper in the thermodynamic stability region of monovalent copper at 80 deg C consist of a bulk part (about 1 mm thick) which is a good ionic and electronic conductor, and an outer, interfacial layer (0.001 - 0.005 mm thick) which shows p-type semiconductor

  18. Phosphorus distribution in sandy soil profile under drip irrigation system

    International Nuclear Information System (INIS)

    El-Gendy, R.W.; Rizk, M.A.; Abd El Moniem, M.; Abdel-Aziz, H.A.; Fahmi, A.E.

    2009-01-01

    This work aims at to studying the impact of irrigation water applied using drip irrigation system in sandy soil with snap bean on phosphorus distribution. This experiment was carried out in soils and water research department farm, nuclear research center, atomic energy authority, cairo, Egypt. Snap bean was cultivated in sandy soil and irrigated with 50,37.5 and 25 cm water in three water treatments represented 100, 75 and 50% ETc. Phosphorus distribution and direction of soil water movement had been detected in three sites on the dripper line (S1,S2 and S3 at 0,12.5 and 25 cm distance from dripper). Phosphorus fertilizer (super phosphate, 15.5% P 2 O 5 in rate 300 kg/fed)was added before cultivation. Neutron probe was used to detect the water distribution and movement at the three site along soil profile. Soil samples were collected before p-addition, at end developing, mid, and late growth stages to determine residual available phosphorus. The obtained data showed that using 50 cm water for irrigation caused an increase in P-concentration till 75 cm depth in the three sites of 100% etc treatment, and covered P-requirements of snap bean for all growth stages. As for 37.5 and 25 cm irrigation water cannot cover all growth stages for P-requirements of snap bean. It could be concluded that applied irrigation water could drive the residual P-levels till 75 cm depth in the three sites. Yield of the crop had been taken as an indicator as an indicator profile. Yield showed good response according to water quantities and P-transportation within the soil profile

  19. External dosimetry sources and shielding

    International Nuclear Information System (INIS)

    Calisto, Washington

    1994-01-01

    A definition of external dosimetry r external sources dosimetry,physical and mathematical treatment of the interaction of gamma radiation with a minimal area in that direction. Concept of attenuation coefficient, cumulated effect by polyenergetic sources, exposition rate, units, cumulated dose,shielding, foton shielding, depth calculation, materials used for shielding.Beta shielding, consideration of range and maximum β energy , low stopping radiation by use of low Z shielding. Tables for β energy of β emitters, I (tau) factor, energy-range curves for β emitters in aqueous media, gamma attenuation factors for U, W and Pb. Y factor for bone tissue,muscle and air, build-up factors

  20. Radiation shielding calculation using MCNP

    International Nuclear Information System (INIS)

    Masukawa, Fumihiro

    2001-01-01

    To verify the Monte Carlo code MCNP4A as a tool to generate the reference data in the shielding designs and the safety evaluations, various shielding benchmark experiments were analyzed using this code. These experiments were categorized in three types of the shielding subjects; bulk shielding, streaming, and skyshine. For the variance reduction technique, which is indispensable to get meaningful results with the Monte Carlo shielding calculation, we mainly used the weight window, the energy dependent Russian roulette and spitting. As a whole, our analyses performed enough small statistical errors and showed good agreements with these experiments. (author)

  1. Shielding benchmark test

    International Nuclear Information System (INIS)

    Kawai, Masayoshi

    1984-01-01

    Iron data in JENDL-2 have been tested by analyzing shielding benchmark experiments for neutron transmission through iron block performed at KFK using CF-252 neutron source and at ORNL using collimated neutron beam from reactor. The analyses are made by a shielding analysis code system RADHEAT-V4 developed at JAERI. The calculated results are compared with the measured data. As for the KFK experiments, the C/E values are about 1.1. For the ORNL experiments, the calculated values agree with the measured data within an accuracy of 33% for the off-center geometry. The d-t neutron transmission measurements through carbon sphere made at LLNL are also analyzed preliminarily by using the revised JENDL data for fusion neutronics calculation. (author)

  2. Neutron shielding material

    International Nuclear Information System (INIS)

    Suzuki, Shigenori; Iimori, Hiroshi; Kobori, Junzo.

    1980-01-01

    Purpose: To provide a neutron shielding material which incorporates preferable shielding capacity, heat resistance, fire resistance and workability by employing a mixture of thermosetting resin, polyethylene and aluminium hydroxide in special range ratio and curing it. Constitution: A mixture containing 20 to 60% by weight of thermosetting resin having preferable heat resistance, 10 to 40% by weight of polyethylene powder having high hydrogen atom density and 1000 to 60000 of molecular weight, and 15 to 55% by weight of Al(OH) 3 for imparting fire resistance and self-fire extinguishing property thereto is cured. At this time approx. 0.5 to 5% of curing catalyst of the thermosetting resin is contained in 100 parts by weight of the mixture. (Sekiya, K.)

  3. Radiation shielding wall structure

    International Nuclear Information System (INIS)

    Nishimura, Yoshitaka; Oka, Shinji; Kan, Toshihiko; Misato, Takeshi.

    1990-01-01

    A space between a pair of vertical steel plates laterally disposed in parallel at an optional distance has a structure of a plurality of vertically extending tranks partitioned laterally by vertically placed steel plates. Then, cements are grouted to the tranks. Strip-like steel plates each having a thickness greater than the gap between the each of the vertically placed steel plates and the cement are bonded each at the surface for each of the vertically placed steel plates opposing to the cements. A protrusion of a strip width having radiation shielding performance substantially identical with that by the thickness of the cement is disposed in the strip-like steel plates. With such a constitution, a safety radiation shielding wall structure with no worry of radiation intrusion to gaps, if formed, between the steel plates and the grouted cements due to shrinkage of the cements. (I.N.)

  4. Radiation shielding material

    International Nuclear Information System (INIS)

    Kawakubo, Takamasa; Yamada, Fumiyuki; Nakazato, Kenjiro.

    1976-01-01

    Purpose: To provide a material, which is used for printing a samples name and date on an X-ray photographic film at the same time an X-ray radiography. Constitution: A radiation shielding material of a large mass absorption coefficient such as lead oxide, barium oxide, barium sulfate, etc. is added to a solution of a radiation permeable substance capable of imparting cold plastic fluidity (such as microcrystalline wax, paraffin, low molecular polyethylene, polyvinyl chloride, etc.). The resultant system is agitated and then cooled, and thereafter it is press fitted to or bonded to a base in the form of a film of a predetermined thickness. This radiation shielding layer is scraped off by using a writing tool to enter information to be printed in a photographic film, and then it is laid over the film and exposed to X-radiation to thereby print the information on the film. (Seki, T.)

  5. Multilayer radiation shield

    Science.gov (United States)

    Urbahn, John Arthur; Laskaris, Evangelos Trifon

    2009-06-16

    A power generation system including: a generator including a rotor including a superconductive rotor coil coupled to a rotatable shaft; a first prime mover drivingly coupled to the rotatable shaft; and a thermal radiation shield, partially surrounding the rotor coil, including at least a first sheet and a second sheet spaced apart from the first sheet by centripetal force produced by the rotatable shaft. A thermal radiation shield for a generator including a rotor including a super-conductive rotor coil including: a first sheet having at least one surface formed from a low emissivity material; and at least one additional sheet having at least one surface formed from a low emissivity material spaced apart from the first sheet by centripetal force produced by the rotatable shaft, wherein each successive sheet is an incrementally greater circumferential arc length and wherein the centripetal force shapes the sheets into a substantially catenary shape.

  6. Light shielding apparatus

    Science.gov (United States)

    Miller, Richard Dean; Thom, Robert Anthony

    2017-10-10

    A light shielding apparatus for blocking light from reaching an electronic device, the light shielding apparatus including left and right support assemblies, a cross member, and an opaque shroud. The support assemblies each include primary support structure, a mounting element for removably connecting the apparatus to the electronic device, and a support member depending from the primary support structure for retaining the apparatus in an upright orientation. The cross member couples the left and right support assemblies together and spaces them apart according to the size and shape of the electronic device. The shroud may be removably and adjustably connectable to the left and right support assemblies and configured to take a cylindrical dome shape so as to form a central space covered from above. The opaque shroud prevents light from entering the central space and contacting sensitive elements of the electronic device.

  7. Shielding container for radioactive isotopes

    International Nuclear Information System (INIS)

    Sumi, Tetsuo; Tosa, Masayoshi; Hatogai, Tatsuaki.

    1975-01-01

    Object: To effect opening and closing bidirectional radiation used particularly for a gamma densimeter or the like by one operation. Structure: This device comprises a rotatable shielding body for receiving radioactive isotope in the central portion thereof and having at least two radiation openings through which radiation is taken out of the isotope, and a shielding container having openings corresponding to the first mentioned radiation openings, respectively. The radioactive isotope is secured to a rotational shaft of the shielding body, and the shielding body is rotated to register the openings of the shielding container with the openings of the shielding body or to shield the openings, thereby effecting radiation and cut off of gamma ray in the bidirection by one operation. (Kamimura, M.)

  8. Primary shield displacement and bowing

    International Nuclear Information System (INIS)

    Scott, K.V.

    1978-01-01

    The reactor primary shield is constructed of high density concrete and surrounds the reactor core. The inlet, outlet and side primary shields were constructed in-place using 2.54 cm (1 in) thick steel plates as the forms. The plates remained as an integral part of the shields. The elongation of the pressure tubes due to thermal expansion and pressurization is not moving through the inlet nozzle hardware as designed but is accommodated by outward displacement and bowing of the inlet and outlet shields. Excessive distortion of the shields may result in gas seal failures, intolerable helium gas leaks, increased argon-41 emissions, and shield cooling tube failures. The shield surveillance and testing results are presented

  9. Shielding calculations using FLUKA

    International Nuclear Information System (INIS)

    Yamaguchi, Chiri; Tesch, K.; Dinter, H.

    1988-06-01

    The dose equivalent on the surface of concrete shielding has been calculated using the Monte Carlo code FLUKA86 for incident proton energies from 10 to 800 GeV. The results have been compared with some simple equations. The value of the angular dependent parameter in Moyer's equation has been calculated from the locations where the values of the maximum dose equivalent occur. (author)

  10. Shielding Benchmark Computational Analysis

    International Nuclear Information System (INIS)

    Hunter, H.T.; Slater, C.O.; Holland, L.B.; Tracz, G.; Marshall, W.J.; Parsons, J.L.

    2000-01-01

    Over the past several decades, nuclear science has relied on experimental research to verify and validate information about shielding nuclear radiation for a variety of applications. These benchmarks are compared with results from computer code models and are useful for the development of more accurate cross-section libraries, computer code development of radiation transport modeling, and building accurate tests for miniature shielding mockups of new nuclear facilities. When documenting measurements, one must describe many parts of the experimental results to allow a complete computational analysis. Both old and new benchmark experiments, by any definition, must provide a sound basis for modeling more complex geometries required for quality assurance and cost savings in nuclear project development. Benchmarks may involve one or many materials and thicknesses, types of sources, and measurement techniques. In this paper the benchmark experiments of varying complexity are chosen to study the transport properties of some popular materials and thicknesses. These were analyzed using three-dimensional (3-D) models and continuous energy libraries of MCNP4B2, a Monte Carlo code developed at Los Alamos National Laboratory, New Mexico. A shielding benchmark library provided the experimental data and allowed a wide range of choices for source, geometry, and measurement data. The experimental data had often been used in previous analyses by reputable groups such as the Cross Section Evaluation Working Group (CSEWG) and the Organization for Economic Cooperation and Development/Nuclear Energy Agency Nuclear Science Committee (OECD/NEANSC)

  11. Muon shielding for PEP

    International Nuclear Information System (INIS)

    Jenkins, T.M.; Thomas, R.H.

    1974-01-01

    The first stage of construction of PEP will consist of electron and positron storage rings. At a later date a 200 GeV proton storage ring may be added. It is judicious therefore, to ensure that the first and second phases of construction are compatible with each other. One of several factors determining the elevation at which the storage rings will be constructed is the necessity to provide adequate radiation shielding. The overhead shielding of PEP is determined by the reproduction of neutrons in the hadron cascade generated by primary protons lost from the storage ring. The minimum overburden planned for PEP is 5.5 meters of earth (1100 gm cm/sup /minus/2/). To obtain a rough estimate of the magnitude of the muon radiation problem this note presents some preliminary calculations. Their purpose is intended merely to show that the presently proposed design for PEP will present no major shielding problems should the protons storage ring be installed. More detailed calculations will be made using muon yield computer codes developed at CERN and NAL and muon transport codes developed at SLAC, when details of the proton storage ring become settled. 9 refs., 4 figs

  12. Shielding calculations for NET

    International Nuclear Information System (INIS)

    Verschuur, K.A.; Hogenbirk, A.

    1991-05-01

    In the European Fusion Technology Programme there is only a small activity on research and development for fusion neutronics. Never-the-less, looking further than blanket design now, as ECN is getting involved in design of radiation shields for the coils and biological shields, it becomes apparent that fusion neutronics as a whole still needs substantial development. Existing exact codes for calculation of complex geometries like MCNP and DORT/TORT are put over the limits of their numerical capabilities, whilst approximate codes for complex geometries like FURNACE and MERCURE4 are put over the limits of their modelling capabilities. The main objective of this study is just to find out how far we can get with existing codes in obtaining reliable values for the radiation levels inside and outside the cryostat/shield during operation and after shut-down. Starting with a 1D torus model for preliminary parametric studies, more dimensional approximation of the torus or parts of it including the main heterogeneities should follow. Regular contacts with the NET-Team are kept, to be aware of main changes in NET design that might affect our calculation models. Work on the contract started 1 July 1990. The technical description of the contract is given. (author). 14 refs.; 4 figs.; 1 tab

  13. Drip Loss Assessment by Different Analytical Methods and Their Relationships with Pork Quality Classification

    Directory of Open Access Journals (Sweden)

    Robledo de Almeida Torres Filho

    2017-01-01

    Full Text Available We analyzed drip loss in pork by comparing the standard bag (DL, filter-paper wetness (FPW, and EZ-DripLoss methods by weighing the meat juice container and dabbed sample after 24 h and 48 h. Samples were classified into quality categories based on pH, color, and drip loss. The relationship between DL and FPW revealed the cut-off of 5% DL as corresponding to FPW of 139 mg; 1.89% when analyzed by weighing meat juice container or dabbed sample after 24 h; and 3.18% and 3.74% for those analyzed by weighing both meat juice container and dabbed sample after 48 h, respectively. Highest correlations were observed between DL and EZ when the meat juice container was weighed after 48 h (r=0.86. The EZ-DripLoss method in which the meat juice container was weighed after 24 h was able to distinguish drip loss into meat-quality categories in accordance with the bag method. Therefore, this method is recommended for meat categorization because of its greater standardization and ease of application.

  14. Accelerated Corrosion Testing

    Science.gov (United States)

    1982-12-01

    Treaty Organization, Brussels, 1971), p. 449. 14. D. 0. Sprowls, T. J. Summerson, G. M. Ugianski, S. G. Epstein, and H. L. Craig , Jr., in Stress...National Association of Corrosion Engineers Houston, TX, 1972). 22. H. L. Craig , Jr. (ed.), Stress Corrosion-New Approaches, ASTM-STP- 610 (American...62. M. Hishida and H. Nakada, Corrosion 33 (11) 403 (1977). b3. D. C. Deegan and B. E. Wilde, Corrosion 34 (6), 19 (1978). 64. S. Orman, Corrosion Sci

  15. A contribution to shielding effectiveness analysis of shielded tents

    Directory of Open Access Journals (Sweden)

    Vranić Zoran M.

    2004-01-01

    Full Text Available An analysis of shielding effectiveness (SE of the shielded tents made of the metallised fabrics is given. First, two electromagnetic characteristic fundamental for coupling through electrically thin shield, the skin depth break frequency and the surface resistance or transfer impedance, is defined and analyzed. Then, the transfer function and the SE are analyzed regarding to the frequency range of interest to the Electromagnetic Compatibility (EMC Community.

  16. Oxide induced corrosion on the welded stainless steels SS 2352 and 2353

    International Nuclear Information System (INIS)

    Stroem, S.; Li Huiqin.

    1991-01-01

    The pitting corrosion properties have been investigated in welded and unwelded condition by polarization tests in sodium chloride solutions. The two steels were TIG welded without adding welding material and as shielding on the bottom side argon gas containing 2, 26 or 99 ppm oxygen was used. In some tests low breakthrough potentials were received, without discovering any pitting corrosion in the specimen surfaces. The unwelded SS 2352 steel had a critical (lowest) pitting temperature (CPT) of 5 degrees C in the more concentrated solution. For the same steel with weld pitting corrosion was obtained at 5 degrees C, which was the lowest temperature for the tests. Thus the CPT value was lower than 5 degrees C, but by looking at the pitting corrosion potentials the following conclusion could be drawn: Welding with higher oxygen content in the shielding gas implied lower pitting corrosion resistance. For the SS 2353 steel the CPT values were 25 and 27.5 degrees C for material without weld, in contact with the more concentrated and the more dilute solution respectively. Welded material was all through more sensitive to pitting corrosion, and the CPT values were 15-17.5, 15 and 5-10 degrees C for welded areas which had been gas shielded with argon containing 2, 26 and 99 ppm oxygen respectively. The result thus showed that welding with shielding gas containing maximum about 30 ppm oxygen does not substantially affect the pitting corrosion properties. Post treatment of the welding areas increased the pitting corrosion resistance. Acid pickling implied the highest pitting corrosion resistance with 15 degrees C as CPT value for the 2353 steel in the more concentrated solution. Steel brushing implied an obvious increase to the pitting corrosion resistance compared to untreated weld areas and the same statement could be done for sand blasted surfaces. (10 refs., 16 tabs., 11 figs.)

  17. Corrosion/96 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Topics covered by this conference include: cathodic protection in natural waters; cleaning and repassivation of building HVAC systems; worldwide opportunities in flue gas desulfurization; advancements in materials technology for use in oil and gas service; fossil fuel combustion and conversion; technology of corrosion inhibitors; computers in corrosion control--modeling and information processing; recent experiences and advances of austenitic alloys; managing corrosion with plastics; corrosion measurement technology; corrosion inhibitors for concrete; refining industry; advances in corrosion control for rail and tank trailer equipment; CO 2 corrosion--mechanisms and control; microbiologically influenced corrosion; corrosion in nuclear systems; role of corrosion in boiler failures; effects of water reuse on monitoring and control technology in cooling water applications; methods and mechanisms of scale and deposit control; corrosion detection in petroleum production lines; underground corrosion control; environmental cracking--relating laboratory results and field behavior; corrosion control in reinforced concrete structures; corrosion and its control in aerospace and military hardware; injection and process addition facilities; progress reports on the results of reinspection of deaerators inspected or repaired per RP0590 criteria; near 100% volume solids coating technology and application methods; materials performance in high temperature environments containing halides; impact of toxicity studies on use of corrosion/scale inhibitors; mineral scale deposit control in oilfield related operations; corrosion in gas treating; marine corrosion; cold climate corrosion; corrosion in the pulp and paper industry; gaseous chlorine alternatives in cooling water systems; practical applications of ozone in recirculating cooling water systems; and water reuse in industry. Over 400 papers from this conference have been processed separately for inclusion on the data base

  18. Deep subsurface drip irrigation using coal-bed sodic water: part II. geochemistry

    Science.gov (United States)

    Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.

    2013-01-01

    Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm-1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation(SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5-1.2) are only slightly increased over non-irrigated soils (0.1-0.5). Only 8-15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values >12, measured by 1:1 water-soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (-1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1-1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to 14 and decreasing EC in soil water to 3.2 mS cm-1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters.

  19. Seasonal variation of fatty acids from drip water in Heshang Cave, central China

    International Nuclear Information System (INIS)

    Li Xiuli; Wang Canfa; Huang Junhua; Hu Chaoyong; Xie Shucheng

    2011-01-01

    Research highlights: → A 2-year monitoring to investigate the seasonal variation of fatty acids in cave drip water. → Microbes are the dominant source for fatty acids in drip water. → The relative abundance of mono-unsaturated responds negatively with external air temperature. - Abstract: In order to investigate how lipids in cave water respond to seasonal climate change, drip water samples were collected from 2006 to 2008 in Heshang Cave, central China for fatty acid analysis. These lipids are abundant in the drip water. Their compositions are dominated by lower-molecular-weight nC16:0, nC18:0 and nC14:0 acids, together with mono-unsaturated nC18:1, nC16:1 and nC14:1. Analysis of one water sample revealed marked differences between the dissolved and particulate fractions. The dissolved fraction contains total fatty acids one order of magnitude higher than that of the particulate fraction. The distributional patterns of the fatty acids suggest that microbes living in the overlying soils and/or groundwater system contribute most fatty acids to the drip water. This 2-a monitoring experiment reveals that the abundance of mono-unsaturated fatty acids relative to the saturated homologues (nC16:1/nC16:0 and nC18:1/nC18:0) relate inversely to the changes of synchronous external air temperature. Higher values occur under cold conditions (winter/spring), while lower values appear in warm intervals (summer). Further studies are needed to elucidate the dynamic processes by which the external temperature affects fatty acids in drip water and to confirm the potential application of fatty acid ratios such as nC16:1/nC16:0 and nC18:1/nC18:0 in paleotemperature reconstructions.

  20. Radiation shielding quality assurance

    Science.gov (United States)

    Um, Dallsun

    For the radiation shielding quality assurance, the validity and reliability of the neutron transport code MCNP, which is now one of the most widely used radiation shielding analysis codes, were checked with lot of benchmark experiments. And also as a practical example, follows were performed in this thesis. One integral neutron transport experiment to measure the effect of neutron streaming in iron and void was performed with Dog-Legged Void Assembly in Knolls Atomic Power Laboratory in 1991. Neutron flux was measured six different places with the methane detectors and a BF-3 detector. The main purpose of the measurements was to provide benchmark against which various neutron transport calculation tools could be compared. Those data were used in verification of Monte Carlo Neutron & Photon Transport Code, MCNP, with the modeling for that. Experimental results and calculation results were compared in both ways, as the total integrated value of neutron fluxes along neutron energy range from 10 KeV to 2 MeV and as the neutron spectrum along with neutron energy range. Both results are well matched with the statistical error +/-20%. MCNP results were also compared with those of TORT, a three dimensional discrete ordinates code which was developed by Oak Ridge National Laboratory. MCNP results are superior to the TORT results at all detector places except one. This means that MCNP is proved as a very powerful tool for the analysis of neutron transport through iron & air and further it could be used as a powerful tool for the radiation shielding analysis. For one application of the analysis of variance (ANOVA) to neutron and gamma transport problems, uncertainties for the calculated values of critical K were evaluated as in the ANOVA on statistical data.

  1. Radiolysis and corrosion aspects of the aqueous self-cooled blanket concept

    International Nuclear Information System (INIS)

    Bruggeman, A.; Snykers, M.; Bogaerts, W.F.; Waeben, R.; Embrechts, M.J.; Steiner, D.

    1989-01-01

    Corrosion and radiolysis aspects of the Aqueous Self-Cooled Blanket concept, proposed as a potential shielding breeding blanket for near term fusion devices and fusion reactors, have been investigated. On the basis of preliminary results for selected aqueous solutions of lithium compounds, no particular corrosion problems have been revealed for the low-temperature concept envisaged for NET and radiolysis effects might be controlled by appropriate countermeasures. For the reactor-relevant high-temperature concept particular attention has to be paid to intergranular stress-corrosion and to the synergistic radiolysis-corrosion effects. Further information is needed from tests performed in relevant operational conditions. (orig.)

  2. Neutronic reactor thermal shield

    International Nuclear Information System (INIS)

    Lowe, P.E.

    1976-01-01

    A shield for a nuclear reactor includes at least two layers of alternating wide and narrow rectangular blocks so arranged that the spaces between blocks in adjacent layers are out of registry, each block having an opening therein equally spaced from the sides of the blocks and nearer the top of the block than the bottom, the distance from the top of the block to the opening in one layer being different from this distance in adjacent layers, openings in blocks in adjacent layers being in registry. 1 claim, 7 drawing figures

  3. A shield against distraction

    OpenAIRE

    Halin, N.; Marsh, J.E.; Hellman, A.; Hellstrom, I.; Sörqvist, Patrik

    2014-01-01

    In this paper, we apply the basic idea of a trade-off between the level of concentration and distractibility to test whether a manipulation of task difficulty can shield against distraction. Participants read, either in quiet or with a speech noise background, texts that were displayed either in an easy-to-read or a hard-to-read font. Background speech impaired prose recall, but only when the text was displayed in the easy-to-read font. Most importantly, recall was better in the background sp...

  4. Multi-component Lattice Boltzmann simulation of the hydrodynamics in drip emitters

    Directory of Open Access Journals (Sweden)

    Giacomo Falcucci

    2017-09-01

    Full Text Available In this paper, we propose a fast and efficient numerical technique based on the Lattice Boltzmann method (LBM to model the flow through a reference drip emitter geometry. The aim of the study is to demonstrate the applicability of the LBM as a reliable simulation tool for the hydraulic optimisation of irrigation systems. Results for the water flow through a rectangular drip emitter are in good agreement with literature numerical and experimental data. Furthermore, we demonstrate the feasibility of the proposed model to simulate a multi-component flow that could be used to simulate the presence of additives, contaminants, and suspended particles.

  5. Nuclear vorticity and the low-energy nuclear response. Towards the neutron drip line

    International Nuclear Information System (INIS)

    Papakonstantinou, P.; Athens Univ.; Wambach, J.; Ponomarev, V.Y.; Mavrommatis, E.

    2004-01-01

    The transition density and current provide valuable insight into the nature of nuclear vibrations. Nuclear vorticity is a quantity related to the transverse transition current. In this work, we study the evolution of the strength distribution, related to density fluctuations, and the vorticity strength distribution, as the neutron drip line is approached. Our results on the isoscalar, natural-parity multipole response of Ni isotopes, obtained by using a self-consistent Skyrme-Hartree-Fock+continuum RPA model, indicate that, close to the drip line, the low-energy response is dominated by L > 1 vortical transitions. (orig.)

  6. Measuring space radiation shielding effectiveness

    OpenAIRE

    Bahadori Amir; Semones Edward; Ewert Michael; Broyan James; Walker Steven

    2017-01-01

    Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles ...

  7. Selective shielding device for scintiphotography

    International Nuclear Information System (INIS)

    Harper, J.W.; Kay, T.D.

    1976-01-01

    A selective shielding device to be used in combination with a scintillation camera is described. The shielding device is a substantially oval-shaped configuration removably secured to the scintillation camera. As a result of this combination scanning of preselected areas of a patient can be rapidly and accurately performed without the requirement of mounting any type of shielding paraphernalia on the patient. 1 claim, 2 drawing figures

  8. Tax Shield, Insolvenz und Zinsschranke

    OpenAIRE

    Arnold, Sven; Lahmann, Alexander; Schwetzler, Bernhard

    2010-01-01

    Dieser Beitrag analysiert den Wertbeitrag fremdfinanzierungsbedingter Steuervorteile (Tax Shield) unter realistischen Bedingungen (keine Negativsteuer; mögliche Insolvenz) für unterschiedliche Finanzierungspolitiken. Zusätzlich wird der Effekt der sogenannten Zinsschranke auf den Wert des Tax Shield ermittelt. Die Bewertung des Tax Shield mit und ohne Zinsschranke findet im einperiodigen Fall auf der Basis von Optionspreismodellen und im mehrperiodigen Fall auf der Basis von Monte Carlo Simul...

  9. Management of irrigation frequency and nitrogen fertilization to mitigate GHG and NO emissions from drip-fertigated crops

    NARCIS (Netherlands)

    Abalos, D.; Sanchez-Martin, L.; Garcia-Torres, L.; Groenigen, van J.W.; Vallejo, A.

    2014-01-01

    Drip irrigation combined with split application of fertilizer nitrogen (N) dissolved in the irrigation water (i.e. drip fertigation) is commonly considered best management practice for water and nutrient efficiency. As a consequence, its use is becoming widespread. Some of the main factors

  10. Transformations accompanying a shift from surface to drip irrigation in the Cànyoles Watershed, Valencia, Spain

    NARCIS (Netherlands)

    Sese-Minguez, Saioa; Boesveld, Harm; Asins-Velis, Sabina; Kooij, van der Saskia; Maroulis, Jerry

    2017-01-01

    Drip irrigation is widely promoted in Spain to increase agricultural production and to save water. In the Cànyoles watershed, Valencia, we analysed the consequences of change from surface irrigation to drip irrigation over the past 25 years. There were a number of transformations resulting from,

  11. Analysis of components from drip tests with ATM-10 glass

    International Nuclear Information System (INIS)

    Fortner, J.A.; Bates, J.K.; Gerding, T.J.

    1996-09-01

    Waste package assemblies consisting of actinide-doped West Valley ATM-10 reference glass and sensitized 304L stainless steel have been reacted with simulated repository groundwater using the Unsaturated Test Method. Analyses of surface corrosion and reaction products resulting from tests that were terminated at scheduled intervals between 13 and 52 weeks are reported. Analyses reveal complex interactions between the groundwater, the sensitized stainless steel waste form holder, and the glass. Alteration phases form that consist mainly of smectite clay, brockite, and an amorphous thorium iron titanium silicate, the latter two incorporating thorium, uranium, and possibly transuranics. The results from the terminated tests, combined with data from tests that are still ongoing, will help determine the suitability of glass waste forms in the proposed high-level repository at the Yucca Mountain Site

  12. SHIELD verification and validation report

    International Nuclear Information System (INIS)

    Boman, C.

    1992-02-01

    This document outlines the verification and validation effort for the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system code. Along with its predecessors, SHIELD has been in use at the Savannah River Site (SRS) for more than ten years. During this time the code has been extensively tested and a variety of validation documents have been issued. The primary function of this report is to specify the features and capabilities for which SHIELD is to be considered validated, and to reference the documents that establish the validation

  13. Multifunctional Hot Structure Heat Shield

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is performing preliminary development of a Multifunctional Hot Structure (HOST) heat shield for planetary entry. Results of this development will...

  14. Radiation shield for nuclear reactors

    International Nuclear Information System (INIS)

    Weissenfluh, J.A.

    1978-01-01

    A shield for use with nuclear reactor systems to attenuate radiation resulting from reactor operation is described. The shield comprises a container preferably of a thin, flexible or elastic material, which may be in the form of a bag, a mattress, a toroidal segment or toroid or the like filled with radiation attenuating liuid. Means are provided in the container for filling and draining the container in place. Due to its flexibility, the shield readily conforms to irregularities in surfaces with which it may be in contact in a shielding position

  15. Medication and volume delivery by gravity-driven micro-drip intravenous infusion: potential variations during "wide-open" flow.

    Science.gov (United States)

    Pierce, Eric T; Kumar, Vikram; Zheng, Hui; Peterfreund, Robert A

    2013-03-01

    Gravity-driven micro-drip infusion sets allow control of medication dose delivery by adjusting drops per minute. When the roller clamp is fully open, flow in the drip chamber can be a continuous fluid column rather than discrete, countable, drops. We hypothesized that during this "wide-open" state, drug delivery becomes dependent on factors extrinsic to the micro-drip set and is therefore difficult to predict. We conducted laboratory experiments to characterize volume delivery under various clinically relevant conditions of wide-open flow in an in vitro laboratory model. A micro-drip infusion set, plugged into a bag of normal saline, was connected to a high-flow stopcock at the distal end. Vertically oriented IV catheters (gauges 14-22) were connected to the stopcock. The fluid meniscus height in the bag was fixed (60-120 cm) above the outflow point. The roller clamp on the infusion set was in fully open position for all experiments resulting in a continuous column of fluid in the drip chamber. Fluid volume delivered in 1 minute was measured 4 times with each condition. To model resistive effects of carrier flow, volumetric infusion pumps were used to deliver various flow rates of normal saline through a carrier IV set into which a micro-drip infusion was "piggybacked." We also compared delivery by micro-drip infusion sets from 3 manufacturers. The volume of fluid delivered by gravity-driven infusion under wide-open conditions (continuous fluid column in drip chamber) varied 2.9-fold (95% confidence interval, 2.84-2.96) depending on catheter size and fluid column height. Total model resistance of the micro-drip with stopcock and catheter varied with flow rate. Volume delivered by the piggybacked micro-drip decreased up to 29.7% ± 0.8% (mean ± SE) as the carrier flow increased from 0 to 1998 mL/min. Delivery characteristics of the micro-drip infusion sets from 3 different manufacturers were similar. Laboratory simulation of clinical situations with gravity

  16. New Toroid shielding design

    CERN Multimedia

    Hedberg V

    On the 15th of June 2001 the EB approved a new conceptual design for the toroid shield. In the old design, shown in the left part of the figure above, the moderator part of the shielding (JTV) was situated both in the warm and cold areas of the forward toroid. It consisted both of rings of polyethylene and hundreds of blocks of polyethylene (or an epoxy resin) inside the toroid vacuum vessel. In the new design, shown to the right in the figure above, only the rings remain inside the toroid. To compensate for the loss of moderator in the toroid, the copper plug (JTT) has been reduced in radius so that a layer of borated polyethylene can be placed around it (see figure below). The new design gives significant cost-savings and is easier to produce in the tight time schedule of the forward toroid. Since the amount of copper is reduced the weight that has to be carried by the toroid is also reduced. Outgassing into the toroid vacuum was a potential problem in the old design and this is now avoided. The main ...

  17. SHIELDS Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Jordanova, Vania Koleva [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-03

    Predicting variations in the near-Earth space environment that can lead to spacecraft damage and failure, i.e. “space weather”, remains a big space physics challenge. A new capability was developed at Los Alamos National Laboratory (LANL) to understand, model, and predict Space Hazards Induced near Earth by Large Dynamic Storms, the SHIELDS framework. This framework simulates the dynamics of the Surface Charging Environment (SCE), the hot (keV) electrons representing the source and seed populations for the radiation belts, on both macro- and micro-scale. In addition to using physics-based models (like RAM-SCB, BATS-R-US, and iPIC3D), new data assimilation techniques employing data from LANL instruments on the Van Allen Probes and geosynchronous satellites were developed. An order of magnitude improvement in the accuracy in the simulation of the spacecraft surface charging environment was thus obtained. SHIELDS also includes a post-processing tool designed to calculate the surface charging for specific spacecraft geometry using the Curvilinear Particle-In-Cell (CPIC) code and to evaluate anomalies' relation to SCE dynamics. Such diagnostics is critically important when performing forensic analyses of space-system failures.

  18. Radiation shielding analysis

    International Nuclear Information System (INIS)

    Moon, S.H.; Ha, C.W.; Kwon, S.K.; Lee, J.K.; Choi, H.S.

    1982-01-01

    The theoretical bases of radiation streaming analysis in power reactors, such as ducts or reactor cavity, have been investigated. Discrete ordinates-Monte Carlo or Monte Carlo-Monte Carlo coupling techniques are suggested for the streaming analysis of ducts or reactor cavity. Single albedo scattering approximation code (SINALB) has been developed for simple and quick estimation of gamma-ray ceiling scattering, where the ceiling is assumed to be semi-infinite medium. This code has been employed to calculate the gamma-ray ceiling scattering effects in the laboratory containing a Co-60 source. The SINALB is applicable to gamma-ray scattering, only where the ceiling is thicker than Σsup(-1) and the height is at least twice higher than the shield wall. This code can be used for the purpose of preliminary radiation shield design. The MORSE code has been improved to analyze the gamma-ray scattering problem with on approximation method in respect to the random walk and estimation processes. This improved MORSE code has been employed to the gamma-ray ceiling scattering problem. The results of the improved MORSE calculation are in good agreement with the SINALB and standard MORSE. (Author)

  19. Cerium oxide as conversion coating for the corrosion protection of aluminum

    Directory of Open Access Journals (Sweden)

    JELENA GULICOVSKI

    2013-11-01

    Full Text Available CeO2 coatings were formed on the aluminum after Al surface preparation, by dripping the ceria sol, previously prepared by forced hydrolysis of Ce(NO34. The anticorrosive properties of ceria coatings were investigated by the electrochemical impedance spectroscopy (EIS during the exposure to 0.03 % NaCl. The morphology of the coatings was examined by the scanning electron microscopy (SEM. EIS data indicated considerably larger corrosion resistance of CeO2-coated aluminum than for bare Al. The corrosion processes on Al below CeO2 coating are subjected to more pronounced diffusion limitations in comparison to the processes below passive aluminum oxide film, as the consequence of the formation of highly compact protective coating. The results show that the deposition of ceria coatings is an effective way to improve corrosion resistance for aluminum.

  20. Radiation shield for PWR reactors

    International Nuclear Information System (INIS)

    Esenov, Amra; Pustovgar, Andrey

    2013-01-01

    One of the chief structures of a reactor pit is a 'dry' shield. Setting up a 'dry' shield includes the technologically complex process of thermal processing of serpentinite concrete. Modern advances in the area of materials technology permit avoiding this complex and demanding procedure, and this significantly decreases the duration, labor intensity, and cost of setting it up. (orig.)

  1. Nuclear data for radiation shielding

    International Nuclear Information System (INIS)

    Miyasaka, Shunichi; Takahashi, Hiroshi.

    1976-01-01

    The third shielding expert conference was convened in Paris in Oct. 1975 for exchanging informations about the sensitivity evaluation of nuclear data in shielding calculation and integral bench mark experiment. The requirements about nuclear data presented at present from the field of nuclear design do not reflect sufficiently the requirements of shielding design, therefore it was the object to gather the requirements about nuclear data from the field of shielding. The nuclides used for shielding are numerous, and the nuclear data on these isotopes are required. Some of them cannot be ignored as the source of secondary γ-ray or in view of the radioactivation of materials. The requirements for the nuclear data of neutrons in the field of shielding are those concerning the reaction cross sections producing secondary γ-ray, the reaction cross sections including the production of secondary neutrons, elastic scattering cross sections, and total cross sections. The topics in the Paris conference about neutron shielding data are described, such as the methodology of sensitivity evaluation, the standardization of group constant libraries, the bench mark experiment on iron and sodium, and the cross section of γ-ray production. In the shielding of nuclear fission reactors, the γ-ray production owing to nuclear fission reaction is also important. In (d, t) fusion reactors, high energy neutrons are generated, and high energy γ-ray is emitted through giant E1 resonance. (Kako, I.)

  2. Concrete shielding exterior to iron

    International Nuclear Information System (INIS)

    Yurista, P.; Cossairt, D.

    1983-08-01

    A rule of thumb at Fermilab has been to use 3 feet of concrete exterior to iron shielding. A recent design of a shield with a severe dimensional constraint has prompted a re-evaluation of this rule of thumb and has led to the following calculations of the concrete thickness required to nullify this problem. 4 references, 4 figures

  3. Gonad shielding in diagnostic radiology

    International Nuclear Information System (INIS)

    1975-06-01

    The use of gonad shielding is an important radiation protection technique, intended to reduce unnecessary x-ray exposure of the gonads of patients from diagnostic x-ray procedures. This pamphlet will provide physicians and radiologic technologists with information which will aid their appropriate use of gonad shielding

  4. Drip irrigation emitter clogging in Dutch greenhouses as affected by methane and organic acids

    NARCIS (Netherlands)

    Kreij, de C.; Burg, van der A.M.M.; Runia, W.T.

    2003-01-01

    It is believed that the serious clogging of drip irrigation emitters in the Dutch greenhouse industry is caused by methane-oxidising bacteria and/or organic acids used as anti-clogging agents. In this study greenhouses with moderate to severe emitter clogging have been examined. High methane

  5. Performing drip irrigation by the farmer managed Seguia Khrichfa irrigation system, Morocco

    NARCIS (Netherlands)

    Kooij, van der S.

    2016-01-01

    Drip irrigation is represented in literature and agricultural policies as a modern and water saving technology. Because this technology is often associated with ‘modern’ agriculture and development, it seems out-of-place in ‘traditional’ farmer managed irrigation systems (FMIS). Thinking along

  6. Sprinkler and drip irrigation in the organic tomato for single crops and when intercropped with coriander

    Directory of Open Access Journals (Sweden)

    Waldir Aparecido Marouelli

    Full Text Available The objective of this study was to evaluate the influence of both sprinkler and drip irrigation systems on the organic production of the tomato, cultivar Duradouro, when cultivated both as a single crop and intercropped with coriander. The experiment was carried out in the Distrito Federal, Brazil, using a randomized block design with six replications and a 2 x 2 factorial arrangement for the treatments. There was no significant interaction between the factors of irrigation system and cropping system. The productivity and mass of the tomato fruits were not affected by the treatments, but for the coriander, productivity was higher under the sprinkler system. Drip irrigation hindered the development of late blight (Phytophthora infestans and reduced the percentage of rotten fruit, whereas the incidence of powdery mildew (Leveillula taurica and infestation by the tomato leafminer (Tuta absoluta were higher under the sprinkler system. The volume of soil exploited by the roots of tomato plants was higher with the sprinkler system, while the water productivity index with the drip system was 47% higher than with the sprinkler system. Firmer fruits were produced under drip irrigation. The cultivation system had a significant effect on the occurrence of insect pests, with the tomato intercropped with coriander showing a lower percentage of damaged fruit due to the Tomato Leafminer and to Spodoptera eridania.

  7. The effects of drip line depths and irrigation levels on yield, quality ...

    African Journals Online (AJOL)

    sefer bozkurt

    2011-04-25

    Apr 25, 2011 ... yield, quality and water use characteristics of lettuce ... agriculture in greenhouse has increased in recent years. (Kadayifci et al., 2004). ... Well-managed subsurface drip irrigation (SDI) systems save water ... water was 1.486 dS m-1 and had no serious harmful effect on plant growth. .... Leaf areas (LA) were.

  8. D-Area Drip Irrigation/Phytoremediation Project: SRTC Report on Phase 1

    International Nuclear Information System (INIS)

    Wilde, E.W.

    2001-01-01

    The overall objective of this project is to evaluate a novel drip irrigation-phytoremediation process for remediating volatile organic contaminants (VOCs), primarily trichloroethylene (TCE), from groundwater in D-Area at the Savannah River Site (SRS). The process is expected to be less expensive and more beneficial to the environment than alternative TCE remediation technologies

  9. The effects of drip line depths and irrigation levels on yield, quality ...

    African Journals Online (AJOL)

    This study was conducted to investigate the effects of different drip irrigation methods and different irrigation levels on yield, quality and water use characteristics of lettuce (Lactuca sativa var. longifolia cv. Lital) cultivated in a solar greenhouse from 07 October 2009 to 03 December 2009 in the Eastern Mediterranean region ...

  10. Obstruction and uniformity in drip irrigation systems by applying treated wastewater

    Directory of Open Access Journals (Sweden)

    Patrícia Ferreira da Silva

    Full Text Available ABSTRACT The use of wastewater in agriculture is an alternative to control surface water pollution, and helps to promote the rational use of water. Therefore, the objective of this study was to evaluate the obstruction and uniformity of application of treated wastewater in drip irrigation systems. The study was conducted in a greenhouse at the Universidade Federal de Campina Grande. The treatments were composed by the factorial combination of two factors: three types of water (supply water-ABAST, effluent of a constructed wetland system -WETLAND and upflow of anaerobic reactor effluent followed by constructed wetland system -UASB + WETLAND, and two drip irrigation systems (surface and subsurface, set in a completely randomized design, with four replications. The results indicated that the pH, suspended solids, total iron and coliforms of the WETLAND and UASB + WETLAND treatments represented a severe risk of clogging of drippers; the flow of the emitters increased as the service pressure was increased; values of CUC and CUD in surface and subsurface drip were classified as excellent in ABAST and WETLAND treatments. The degree of clogging reduced as pressure under surface and subsurface drip was increased.

  11. The effects of three techniques that change the wetting patterns over subsurface drip-irrigated potatoes

    Energy Technology Data Exchange (ETDEWEB)

    Elnesr, M.N.; Alazba, A.A.

    2015-07-01

    Wetting pattern enhancement is one of the goals of irrigation designers and researchers. In this study, we addressed three techniques (dual-lateral drip, intermittent flow and physical barrier methods) that change the wetting pattern of subsurface drip irrigation. To study their effect on the yield and water-use efficiency (WUE) of potatoes, field experiments were conducted for four seasons, during which the soil-water balance was continuously monitored using a set of capacitance probes. The results of the soil water patterns showed that both the dual-lateral and intermittent techniques increased lateral water movement and eliminated deep percolation, whereas the physical barrier had a limited effect on the top soil layer. The crop results indicated that the yield and WUE increased significantly in response to the application of the dual-lateral drip (up to 30%); the intermittent application also positively affected the yield (~10%) and the WUE (~14%), but these effects were not statistically significant according to the statistical model. The physical barrier showed a non-significant negative effect on the yield and WUE. These findings suggest the following recommended practices: the use of dual-lateral drip technique due to its beneficial results and its potential for increasing yields and reducing water consumption; the application of intermittent flow with more than three surges; and restricting the use of physical barriers to soils with high permeability. (Author)

  12. Helium Isotopes and Noble Gas Abundances of Cave Dripping Water in Three Caves in East Asia

    Science.gov (United States)

    Chen, A. T.; Shen, C. C.; Tan, M.; Li, T.; Uemura, R.; Asami, R.

    2015-12-01

    Paleo-temperature recorded in nature archives is a critical parameter to understand climate change in the past. With advantages of unique inert chemical characteristics and sensitive solubilities with temperature, dissolved noble gases in speleothem inclusion water were recently proposed to retrieve terrestrial temperature history. In order to accurately apply this newly-developed speleothem noble gas temperature (NGT) as a reliable proxy, a fundamental issue about behaviors of noble gases in the karst should be first clarified. In this study, we measured noble gas contents in air and dripping water to evaluate any ratio deviation between noble gases. Cave dripping water samples was collected from three selected caves, Shihua Cave in northern China, Furong Cave in southwestern, and Gyukusen Cave in an island located in the western Pacific. For these caves are characterized by a thorough mixing and long-term storage of waters in a karst aquifer by the absence of seasonal oxygen isotope shifts. Ratios of dripping water noble gases are statistically insignificant from air data. Helium isotopic ratios in the dripping water samples match air value. The results indicate that elemental and isotopic signatures of noble gases from air can be frankly preserved in the epikarst and support the fidelity of NGT techniques.

  13. Cotton, tomato, corn, and onion production with subsurface drip irrigation – a review

    Science.gov (United States)

    The usage of subsurface drip irrigation (SDI) has increased by 89% in the USA during the last ten years according to USDA NASS estimates and over 93% of the SDI land area is located in just ten states. Combining public entity and private industry perceptions of SDI in these ten states, the major cro...

  14. The crop water stress index (CWSI) for drip irrigated cotton in a semi ...

    African Journals Online (AJOL)

    The crop water stress index (CWSI) for drip irrigated cotton in a semi-arid region of Turkey. ... Four irrigation treatments designated as full (I100) with no water stress and slight (DI70), moderate (DI50) and strong water ... from 32 Countries:.

  15. Performing the success of an innovation: the case of smallholder drip irrigation in Burkina Faso

    NARCIS (Netherlands)

    Wanvoeke, M.J.V.; Venot, J.P.J.N.; Zwarteveen, M.Z.; Fraiture, de C.M.S.

    2015-01-01

    Over the last 15 years, smallholder drip irrigation has gained almost unanimous popularity as an effective tool to achieve the combined goals of sustainable water use, food security and poverty alleviation in the developing world. Based on a study in Sub-Saharan Africa, this article shows that this

  16. Catastrophes caused by corrosion

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    For many years, huge attention has been paid to the problem of corrosion damage and destruction of metallic materials. Experience shows that failures due to corrosion problems are very important, and statistics at the world level shows that the damage resulting from the effects of various forms of corrosion is substantial and that, for example, in industrialized countries it reaches 4-5% of national incomes. Significant funds are determined annually for the prevention and control of corrosion...

  17. Modelling of Corrosion Cracks

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed.......Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed....

  18. The Imperial Shield

    DEFF Research Database (Denmark)

    Mortensen, Simon Valentin

    2006-01-01

      The title of this Ph.d. dissertation is "The Imperial Shield: Imperial Overstretch, Assured Destruction, and the ban on nationwide ABM-defense with particular emphasis on the Johnson and the Nixon Administration". The dissertation set out to explain the origins of the ABM Treaty's central meaning....... Domestic spending continued to increase by more in real terms than the GDP, and the Democratically controlled Congress also made some very expensive modifications in Nixon tax bill in the fall of 1969, once again plunging the budget into the red.The economic crisis was partly caused by, and partly...... the Administration debated the deployment of new ABM-sites in early 1970, Kissinger could not prevail against these forces, but had to settle for a compromise, which he regarded as less than a definite commitment to nationwide ABM-defense.The political developments were of even greater importance. A strong link has...

  19. Shielded Canister Transporter

    International Nuclear Information System (INIS)

    Eidem, G.G. Jr.; Fages, R.

    1993-01-01

    The Hanford Waste Vitrification Plant (HWVP) will produce canisters filled with high-level radioactive waste immobilized in borosilicate glass. This report discusses a Shielded Canister Transporter (SCT) which will provide the means for safe transportation and handling of the canisters from the Vitrification Building to the Canister Storage Building (CSB). The stainless steel canisters are 0.61 meters in diameter, 3.0 meters tall, and weigh approximately 2,135 kilograms, with a maximum exterior surface dose rate of 90,000 R/hr. The canisters are placed into storage tubes to a maximum of three tall (two for overpack canisters) with an impact limiter placed at the tube bottom and between each canister. A floor plug seals the top of the storage tube at the operating floor level of the CSB

  20. ITER shielding blanket

    Energy Technology Data Exchange (ETDEWEB)

    Strebkov, Yu [ENTEK, Moscow (Russian Federation); Avsjannikov, A [ENTEK, Moscow (Russian Federation); Baryshev, M [NIAT, Moscow (Russian Federation); Blinov, Yu [ENTEK, Moscow (Russian Federation); Shatalov, G [KIAE, Moscow (Russian Federation); Vasiliev, N [KIAE, Moscow (Russian Federation); Vinnikov, A [ENTEK, Moscow (Russian Federation); Chernjagin, A [DYNAMICA, Moscow (Russian Federation)

    1995-03-01

    A reference non-breeding blanket is under development now for the ITER Basic Performance Phase for the purpose of high reliability during the first stage of ITER operation. More severe operation modes are expected in this stage with first wall (FW) local heat loads up to 100-300Wcm{sup -2}. Integration of a blanket design with protective and start limiters requires new solutions to achieve high reliability, and possible use of beryllium as a protective material leads to technologies. The rigid shielding blanket concept was developed in Russia to satisfy the above-mentioned requirements. The concept is based on a copper alloy FW, austenitic stainless steel blanket structure, water cooling. Beryllium protection is integrated in the FW design. Fabrication technology and assembly procedure are described in parallel with the equipment used. (orig.).

  1. Welding shield for coupling heaters

    Science.gov (United States)

    Menotti, James Louis

    2010-03-09

    Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

  2. Penetration shielding applications of CYLSEC

    International Nuclear Information System (INIS)

    Dexheimer, D.T.; Hathaway, J.M.

    1985-01-01

    Evaluation of penetration and discontinuity shielding is necessary to meet 10CFR20 regulations for ensuring personnel exposures are as low as reasonably achievable (ALARA). Historically, those shielding evaluations have been done to some degree on all projects. However, many early plants used conservative methods due to lack of an economical computer code, resulting in costly penetration shielding programs. With the increased industry interest in cost effectively reducing personnel exposures to meet ALARA regulations and with the development of the CYLSEC gamma transport computer code at Bechtel, a comprehensive effort was initiated to reduce penetration and discontinuity shielding but still provide a prudent degree of protection for plant personnel from radiation streaming. This effort was more comprehensive than previous programs due to advances in shielding analysis technology and increased interest in controlling project costs while maintaining personnel exposures ALARA. Methodology and resulting cost savings are discussed

  3. Shield calculations, optimization vs. paradigm

    International Nuclear Information System (INIS)

    Cornejo D, N.; Hernandez S, A.; Martinez G, A.

    2006-01-01

    Many shieldings have been designed under the criteria of 'Maximum dose rates of project'. It has created the paradigm of those 'low dose rates', for the one which not few specialists would consider unacceptable levels of dose rate superior to the units of μSv.h -1 , independently of the exposure times. At the present time numerous shieldings are being designed considering dose restrictions in real times of exposure. After these new shieldings, the dose rates could be notably superior to those after traditional shieldings, without it implies inadequate designs or constructive errors. In the work significant differences in levels of dose rates and thickness of shieldings estimated by both methods for some typical facilities. It was concluded that the use of real times of exposure is more adequate for the optimization of the Radiological Protection, although this method demands bigger care in its application. (Author)

  4. Modular reactor head shielding system

    International Nuclear Information System (INIS)

    Jacobson, E. B.

    1985-01-01

    An improved modular reactor head shielding system is provided that includes a frame which is removably assembled on a reactor head such that no structural or mechanical alteration of the head is required. The shielding system also includes hanging assemblies to mount flexible shielding pads on trolleys which can be moved along the frame. The assemblies allow individual pivoting movement of the pads. The pivoting movement along with the movement allowed by the trolleys provides ease of access to any point on the reactor head. The assemblies also facilitate safe and efficient mounting of the pads directly to and from storage containers such that workers have additional shielding throughout virtually the entire installation and removal process. The flexible shielding pads are designed to interleave with one another when assembled around the reactor head for substantially improved containment of radiation leakage

  5. Parameters calculation of shielding experiment

    International Nuclear Information System (INIS)

    Gavazza, S.

    1986-02-01

    The radiation transport methodology comparing the calculated reactions and dose rates for neutrons and gama-rays, with experimental measurements obtained on iron shield, irradiated in the YAYOI reactor is evaluated. The ENDF/B-IV and VITAMIN-C libraries and the AMPX-II modular system, for cross sections generation collapsed by the ANISN code were used. The transport calculations were made using the DOT 3.5 code, adjusting the boundary iron shield source spectrum to the reactions and dose rates, measured at the beginning of shield. The neutron and gamma ray distributions calculated on the iron shield presented reasonable agreement with experimental measurements. An experimental arrangement using the IEA-R1 reactor to determine a shielding benchmark is proposed. (Author) [pt

  6. Erosion-corrosion

    International Nuclear Information System (INIS)

    Aghili, B.

    1999-05-01

    A literature study on erosion-corrosion of pipings in the nuclear industry was performed. Occurred incidents are reviewed, and the mechanism driving the erosion-corrosion is described. Factors that influence the effect in negative or positive direction are treated, as well as programs for control and inspection. Finally, examples of failures from databases on erosion-corrosion are given in an attachment

  7. Microbiological corrosion of metals

    International Nuclear Information System (INIS)

    Vladislavlev, V.V.

    1992-01-01

    Problems is considered of development of the microbiological corrosion of the NPP equipment. The main attention is paid to the selective character of microbiological corrosion in zones of welded joints of austenitic steels. It is noted that the presence of technological defects promotes growth of corrosional damages. Methods for microbiological corrosion protection are discussed

  8. Management of Reinforcement Corrosion

    DEFF Research Database (Denmark)

    Küter, André; Geiker, Mette Rica; Møller, Per

    Reinforcement corrosion is the most important cause for deterioration of reinforced concrete structures, both with regard to costs and consequences. Thermodynamically consistent descriptions of corrosion mechanisms are expected to allow the development of innovative concepts for the management...... of reinforcement corrosion....

  9. Design experience: CRBRP radiation shielding

    International Nuclear Information System (INIS)

    Disney, R.K.; Chan, T.C.; Gallo, F.G.; Hedgecock, L.R.; McGinnis, C.A.; Wrights, G.N.

    1978-11-01

    The Clinch River Breeder Reactor Plant (CRBRP) is being designed as a fast breeder demonstration project in the U.S. Liquid Metal Fast Breeder Reactor (LMFBR) program. Radiation shielding design of the facility consists of a comprehensive design approach to assure compliance with design and government regulatory requirements. Studies conducted during the CRBRP design process involved the aspects of radiation shielding dealing with protection of components, systems, and personnel from radiation exposure. Achievement of feasible designs, while considering the mechanical, structural, nuclear, and thermal performance of the component or system, has required judicious trade-offs in radiation shielding performance. Specific design problems which have been addressed are in-vessel radial shielding to protect permanent core support structures, flux monitor system shielding to isolate flux monitoring systems for extraneous background sources, reactor vessel support shielding to allow personnel access to the closure head during full power operation, and primary heat transport system pipe chaseway shielding to limit intermediate heat transport system sodium system coolant activation. The shielding design solutions to these problems defined a need for prototypic or benchmark experiments to provide assurance of the predicted shielding performance of selected design solutions and the verification of design methodology. Design activities of CRBRP plant components an systems, which have the potential for radiation exposure of plant personnel during operation or maintenance, are controlled by a design review process related to radiation shielding. The program implements design objectives, design requirements, and cost/benefit guidelines to assure that radiation exposures will be ''as low as reasonably achievable''

  10. Zirconium alloy barrier having improved corrosion resistance

    International Nuclear Information System (INIS)

    Adamson, R.B.; Rosenbaum, H.S.

    1983-01-01

    A nuclear fuel element for use in the core of a nuclear reactor has a composite cladding container having a substrate and a dilute zirconium alloy liner bonded to the inside surface of the substrate. The dilute zirconium alloy liner forms about 1 to about 20 percent of the thickness of the cladding and is comprised of zirconium and a metal selected from the group consisting of iron, chromium, iron plus chromium, and copper. The dilute zirconium alloy liner shields the substrate from impurities or fission products from the nuclear fuel material and protects the substrate from stress corrosion and stress cracking. The dilute zirconium alloy liner displays greater corrosion resistance, especially to oxidation by hot water or steam than unalloyed zirconium. The substrate material is selected from conventional cladding materials, and preferably is a zirconium alloy. (author)

  11. Solar-forced diurnal regulation of cave drip rates via phreatophyte evapotranspiration

    Directory of Open Access Journals (Sweden)

    K. Coleborn

    2016-11-01

    Full Text Available We present results of a detailed study of drip rate variations at 12 drip discharge sites in Glory Hole Cave, New South Wales, Australia. Our novel time series analysis, using the wavelet synchrosqueezed transform, reveals pronounced oscillations at daily and sub-daily frequencies occurring in 8 out of the 12 monitored sites. These oscillations were not spatially or temporally homogenous, with different drip sites exhibiting such behaviour at different times of year in different parts of the cave. We test several hypotheses for the cause of the oscillations, including variations in pressure gradients between karst and cave due to cave breathing effects or atmospheric and earth tides, variations in hydraulic conductivity due to changes in viscosity of water with daily temperature oscillations, and solar-driven daily cycles of vegetative (phreatophytic transpiration. We conclude that the only hypothesis consistent with the data and hydrologic theory is that daily oscillations are caused by solar-driven pumping by phreatophytic trees which are abundant at the site. The daily oscillations are not continuous and occur sporadically in short bursts (2–14 days throughout the year due to non-linear modification of the solar signal via complex karst architecture. This is the first indirect observation leading to the hypothesis of tree water use in cave drip water. It has important implications for karst hydrology in regards to developing a new protocol to determine the relative importance of trends in drip rate, such as diurnal oscillations, and how these trends change over timescales of weeks to years. This information can also be used to infer karst architecture. This study demonstrates the importance of vegetation on recharge dynamics, information that will inform both process-based karst models and empirical estimation approaches. Our findings support a growing body of research exploring the impact of trees on speleothem paleoclimate proxies.

  12. Safety of a "drip and ship" intravenous thrombolysis protocol for patients with acute ischemic stroke.

    Science.gov (United States)

    Mansoor, Simin; Zand, Ramin; Al-Wafai, Ameer; Wahba, Mervat N; Giraldo, Elias A

    2013-10-01

    The "drip and ship" approach for intravenous thrombolysis (IVT) is becoming the standard of care for patients with acute ischemic stroke (AIS) in communities without direct access to a stroke specialist. We aimed to demonstrate the safety of our "drip and ship" IVT protocol. This was a retrospective study of patients with AIS treated with IVT between January 2003 and January 2011. Information on patients' baseline characteristics, neuroimaging, symptomatic intracerebral hemorrhage (sICH), and mortality was obtained from our stroke registry. A group of patients were treated with IVT by an emergency physician in phone consultation with a board-certified vascular neurologist (BCVN) at 1 of our 3 stroke network-affiliated hospitals (SNAHs). These patients were subsequently transferred to our Joint Commission-certified primary stroke center (CPSC) after completion of IVT ("drip and ship" protocol). The other patients were treated directly by a BCVN at the CPSC. We studied 201 patients treated with IVT. Of them, 14% received IVT at a SNAH ("drip and ship" protocol) and 86% were treated at the CPSC. There were no significant differences between the 2 groups with regard to age, National Institutes of Health Stoke Scale score, stroke symptom onset-to-needle time, sICH, or in-hospital mortality. Our "drip and ship" protocol for IVT is safe. The protocol was not associated with an excess of sICH or in-hospital mortality compared with patients who received IVT at the CPSC. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  13. Estimation of deep infiltration in unsaturated limestone environments using cave lidar and drip count data

    Science.gov (United States)

    Mahmud, K.; Mariethoz, G.; Baker, A.; Treble, P. C.; Markowska, M.; McGuire, E.

    2016-01-01

    Limestone aeolianites constitute karstic aquifers covering much of the western and southern Australian coastal fringe. They are a key groundwater resource for a range of industries such as winery and tourism, and provide important ecosystem services such as habitat for stygofauna. Moreover, recharge estimation is important for understanding the water cycle, for contaminant transport, for water management, and for stalagmite-based paleoclimate reconstructions. Caves offer a natural inception point to observe both the long-term groundwater recharge and the preferential movement of water through the unsaturated zone of such limestone. With the availability of automated drip rate logging systems and remote sensing techniques, it is now possible to deploy the combination of these methods for larger-scale studies of infiltration processes within a cave. In this study, we utilize a spatial survey of automated cave drip monitoring in two large chambers of Golgotha Cave, south-western Western Australia (SWWA), with the aim of better understanding infiltration water movement and the relationship between infiltration, stalactite morphology, and unsaturated zone recharge. By applying morphological analysis of ceiling features from Terrestrial LiDAR (T-LiDAR) data, coupled with drip time series and climate data from 2012 to 2014, we demonstrate the nature of the relationships between infiltration through fractures in the limestone and unsaturated zone recharge. Similarities between drip rate time series are interpreted in terms of flow patterns, cave chamber morphology, and lithology. Moreover, we develop a new technique to estimate recharge in large-scale caves, engaging flow classification to determine the cave ceiling area covered by each flow category and drip data for the entire observation period, to calculate the total volume of cave discharge. This new technique can be applied to other cave sites to identify highly focussed areas of recharge and can help to better

  14. Transparent fast neutron shielding material and shielding method

    International Nuclear Information System (INIS)

    Nashimoto, Tetsuji; Katase, Haruhisa.

    1993-01-01

    Polyisobutylene having a viscosity average molecular weight of 20,000 to 80,000 and a hydrogen atom density of greater than 7.0 x 10 22 /cm 3 is used as a fast neutron shielding material. The shielding material is excellent in the shielding performance against fast neutrons, and there is no worry of leakage even when holes should be formed to a vessel. Further, it is excellent in fabricability, relatively safe even upon occurrence of fire and, in addition, it is transparent to enable to observe contents easily. (T.M.)

  15. Initial data release of regular blood drip stain created by varying fall height, angle of impact and source dimension

    Directory of Open Access Journals (Sweden)

    Nabanita Basu

    2016-09-01

    Full Text Available The dataset developed consists of 108 blood drip stains developed with fresh porcine blood, blood admixed with different dosage of Warfarin and Heparin, respectively. For each particular blood type (i.e. fresh blood, blood admixed with Warfarin at different dosage and blood admixed with Heparin at varied dosage stain patterns were created by passive dripping of blood from a 2.5 cm3 subcutaneous syringe with needle filled to capacity, at 30°, 60° and 90° angle of impact with corresponding fall height of 20, 40 and 60 cm respectively. In the other dataset of 162 datapoints, 81 regular drip stains were formed from blood that had dripped passively from a subcutaneous syringe without needle at the aforementioned angle of impact and fall height, while the other stains were formed as a result of dripping of blood from a subcutaneous syringe with needle. In order to compare stains formed, all stains were recorded on the same representative, non-porous, smooth target surface under similar physical conditions. The interpretations relevant to the dataset are available in the article titled ‘2D Source Area prediction based on physical characteristics of a regular, passive blood drip stain’ (Basu and Bandyopadhyay, 2016 [7]. An image pre-processing algorithm for extracting ROI has also been incorporated in this article. Keywords: Drip stain, Bloodstain Pattern Analysis, Source Dimension prediction

  16. Corrosion of metallic materials. Dry corrosion, aqueous corrosion and corrosion by liquid metal, methods of protection

    International Nuclear Information System (INIS)

    Helie, Max

    2015-01-01

    This book is based on a course on materials given in an engineering school. The author first gives an overview of metallurgy issues: metallic materials (pure metals, metallic alloys), defects of crystal lattices (point defects, linear defects or dislocations), equilibrium diagrams, steels and cast, thermal processing of steels, stainless steels, aluminium and its alloys, copper and its alloys. The second part addresses the properties and characterization of surfaces and interfaces: singularity of a metal surface, surface energy of a metal, energy of grain boundaries, adsorption at a material surface, metal-electrolyte interface, surface oxide-electrolyte interface, techniques of surface analysis. The third chapter addresses the electrochemical aspects of corrosion: description of the corrosion phenomenon, free enthalpy of a compound and free enthalpy of a reaction, case of dry corrosion (thermodynamic aspect, Ellingham diagram, oxidation mechanisms, experimental study, macroscopic modelling), case of aqueous corrosion (electrochemical thermodynamics and kinetics, experimental determination of corrosion rate). The fourth part addresses the different forms of aqueous corrosion: generalized corrosion (atmospheric corrosion, mechanisms and tests), localized corrosion (galvanic, pitting, cracking, intergranular, erosion and cavitation), particular cases of stress cracking (stress corrosion, fatigue-corrosion, embrittlement by hydrogen), and bi-corrosion (of non alloyed steels, of stainless steels, and of aluminium and copper alloys). The sixth chapter addresses the struggle and the protection against aqueous corrosion: methods of prevention, scope of use of main alloys, geometry-based protection of pieces, use of corrosion inhibitors, use of organic or metallic coatings, electrochemical protection. The last chapter proposes an overview of corrosion types in industrial practices: in the automotive industry, in the oil industry, in the aircraft industry, and in the

  17. Lead corrosion evaluation in high activity nuclear waste container (Argentina)

    International Nuclear Information System (INIS)

    Guasp, R.; Lanzani, L.; Bruzzoni, P.; Cufre, W.; Semino, C.J.

    2000-01-01

    This report describes a study of high activity nuclear waste canister corrosion in a deep geological disposal. In this canister design, the vitrified nuclear waste stainless steel container is shielded by a 100 mm thick lead wall. For mechanical resistance, the canister will also have a thin carbon steel external liner. Experimental and mathematical modeling studies are aimed to asses the corrosion kinetics of the carbon steel liner in first instance and then, once this liner has been corroded away, the corrosion kinetics of the main lead barrier. Being that oxygen reduction is the main cathodic reaction that supports the anodic oxidation of iron, a model is described predicting the rate of oxygen consumption in a sealed deep nuclear waste disposal vault as a result of the canister corrosion. Oxidation processes other than container corrosion, and that can account also for oxygen depletion, are not taken into consideration. Corrosion experimental studies on lead and its alloys in groundwater are also reported. These experiments are aimed to improve the corrosion resistance of commercial lead in groundwater. (author)

  18. Radiation shielding for fusion reactors

    International Nuclear Information System (INIS)

    Santoro, R.T.

    2000-01-01

    Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel. (author)

  19. Morphometry of terrestrial shield volcanoes

    Science.gov (United States)

    Grosse, Pablo; Kervyn, Matthieu

    2018-03-01

    Shield volcanoes are described as low-angle edifices built primarily by the accumulation of successive lava flows. This generic view of shield volcano morphology is based on a limited number of monogenetic shields from Iceland and Mexico, and a small set of large oceanic islands (Hawaii, Galápagos). Here, the morphometry of 158 monogenetic and polygenetic shield volcanoes is analyzed quantitatively from 90-meter resolution SRTM DEMs using the MORVOLC algorithm. An additional set of 24 lava-dominated 'shield-like' volcanoes, considered so far as stratovolcanoes, are documented for comparison. Results show that there is a large variation in shield size (volumes from 0.1 to > 1000 km3), profile shape (height/basal width (H/WB) ratios mostly from 0.01 to 0.1), flank slope gradients (average slopes mostly from 1° to 15°), elongation and summit truncation. Although there is no clear-cut morphometric difference between shield volcanoes and stratovolcanoes, an approximate threshold can be drawn at 12° average slope and 0.10 H/WB ratio. Principal component analysis of the obtained database enables to identify four key morphometric descriptors: size, steepness, plan shape and truncation. Hierarchical cluster analysis of these descriptors results in 12 end-member shield types, with intermediate cases defining a continuum of morphologies. The shield types can be linked in terms of growth stages and shape evolution, related to (1) magma composition and rheology, effusion rate and lava/pyroclast ratio, which will condition edifice steepness; (2) spatial distribution of vents, in turn related to the magmatic feeding system and the tectonic framework, which will control edifice plan shape; and (3) caldera formation, which will condition edifice truncation.

  20. Fighting corrosion in India

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopalan, K S; Rangaswamy, N S

    1979-03-01

    A survey covers the cost of corrosion in India; methods of preventing corrosion in industrial plants; some case histories, including the prevention of corrosion in pipes through which fuels are pumped to storage and the stress-corrosion cracking of evaporators in fertilizer plants; estimates of the increase in demand in 1979-89 for anticorrosion products and processes developed by the Central Electrochemical Research Institute (CECRI) at Karaikudi, India; industries that may face corrosion problems requiring assistance from CECRI, including the light and heavy engineering structural, and transport industries and the chemical industry; and some areas identified for major efforts, including the establishment of a Corrosion Advisory Board with regional centers and the expansion of the Tropical Corrosion Testing Station at Mandapam Camp, Tamil Nadu.

  1. A study of gamma shielding

    International Nuclear Information System (INIS)

    Roogtanakait, N.

    1981-01-01

    Gamma rays have high penetration power and its attenuation depends upon the thickness and the attenuation coefficient of the shield, so it is necessary to use the high density shield to attenuate the gamma rays. Heavy concrete is considered to be used for high radiation laboratory and the testing of the shielding ability and compressibility of various types of heavy concrete composed of baryte, hematite, ilmenite and galena is carried out. The results of this study show that baryte-ilmenite concrete is the most suitable for high radiation laboratory in Thailand

  2. Radiation protection/shield design

    International Nuclear Information System (INIS)

    Disney, R.K.

    1977-01-01

    Radiation protection/shielding design of a nuclear facility requires a coordinated effort of many engineering disciplines to meet the requirements imposed by regulations. In the following discussion, the system approach to Clinch River Breeder Reactor Plant (CRBRP) radiation protection will be described, and the program developed to implement this approach will be defined. In addition, the principal shielding design problems of LMFBR nuclear reactor systems will be discussed in realtion to LWR nuclear reactor system shielding designs. The methodology used to analyze these problems in the U.S. LMFBR program, the resultant design solutions, and the experimental verification of these designs and/or methods will be discussed. (orig.) [de

  3. Influence of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel welding joints

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhiqiang; Jing, Hongyang [School of Materials Science and Engineering, Tianjin University, Tianjin 300350 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300350 (China); Xu, Lianyong, E-mail: xulianyong@tju.edu.cn [School of Materials Science and Engineering, Tianjin University, Tianjin 300350 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300350 (China); Han, Yongdian; Zhao, Lei [School of Materials Science and Engineering, Tianjin University, Tianjin 300350 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300350 (China); Zhang, Jianli [Welding laboratory, Offshore Oil Engineering (Qing Dao) Company, Qing Dao 266520 (China)

    2017-02-01

    Highlights: • N{sub 2}-supplemented shielding gas promoted nitrogen solid-solution in the austenite. • Secondary austenite had higher Ni but lower Cr and Mo than primary austenite. • Pitting corrosion preferentially occurred at secondary austenite and Cr{sub 2}N. • Adding N{sub 2} in shielding gas improved pitting corrosion resistance of GTAW joint. • E2209T{sub 1} weld metal had very poor pitting corrosion resistance due to inclusions. - Abstract: The influences of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel joints welded by gas tungsten arc welding (GTAW) and flux-cored arc welding (FCAW) with different shielding gas compositions were studied by optical microscopy, electron backscatter diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, electron probe microanalysis, and potentiostatic and potentiodynamic polarization methods The adding 2% N{sub 2} in shielding gas facilitated primary austenite formation in GTAW weld metal (WM) and suppressed Cr{sub 2}N precipitation in GTAW weld root. In the HAZ, the banded microstructure disappeared while the coarse ferrite grains maintained same orientation as the banded ferrite in the BM. In the WM, the ferrite had one single orientation throughout a grain, whereas several families of austenite appeared. The austenite both in BM and WM enriched in Ni and nitrogen, while Cr and Mo were concentrated in the ferrite and thus no element showed clear dendritic distribution in the WM (ER2209 and E2209T{sub 1}). In addition, the secondary austenite had higher Ni content but lower Cr and Mo content than the primary austenite. The N{sub 2}-supplemented shielding gas promoted nitrogen solid-solution in the primary and secondary austenite. Furthermore, the secondary austenite had relatively lower pitting resistance equivalent number (PREN) than the ferrite and primary austenite, thereby resulting in its preferential

  4. Shielding synchrotron light sources: Advantages of circular shield walls tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.L. [Design and Accelerator Operations Consulting, 568 Wintergreen Ct Ridge, NY 11961 (United States); Ghosh, V.J.; Breitfeller, M. [NSLS-II, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2016-08-11

    Third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produce significantly higher neutron component dose to the experimental floor than lower energy injection and ramped operations. High energy neutrons produced in the forward direction from thin target beam losses are a major component of the dose rate outside the shield walls of the tunnel. The convention has been to provide thicker 90° ratchet walls to reduce this dose to the beam line users. We present an alternate circular shield wall design, which naturally and cost effectively increases the path length for this forward radiation in the shield wall and thereby substantially decreasing the dose rate for these beam losses. This shield wall design will greatly reduce the dose rate to the users working near the front end optical components but will challenge the beam line designers to effectively utilize the longer length of beam line penetration in the shield wall. Additional advantages of the circular shield wall tunnel are that it's simpler to construct, allows greater access to the insertion devices and the upstream in tunnel beam line components, as well as reducing the volume of concrete and therefore the cost of the shield wall.

  5. Survivor shielding. Part C. Improvements in terrain shielding

    International Nuclear Information System (INIS)

    Egbert, Stephen D.; Kaul, Dean C.; Roberts, James A.; Kerr, George D.

    2005-01-01

    A number of atomic-bomb survivors were affected by shielding provided by terrain features. These terrain features can be a small hill, affecting one or two houses, or a high mountain that shields large neighborhoods. In the survivor dosimetry system, terrain shielding can be described by a transmission factor (TF), which is the ratio between the dose with and without the terrain present. The terrain TF typically ranges between 0.1 and 1.0. After DS86 was implemented at RERF, the terrain shielding categories were examined and found to either have a bias or an excessive uncertainty that could readily be removed. In 1989, an improvement in the terrain model was implemented at RERF in the revised DS86 code, but the documentation was not published. It is now presented in this section. The solution to the terrain shielding in front of a house is described in this section. The problem of terrain shielding of survivors behind Hijiyama mountain at Hiroshima and Konpirasan mountain at Nagasaki has also been recognized, and a solution to this problem has been included in DS02. (author)

  6. Radiation shielding member

    International Nuclear Information System (INIS)

    Nemezawa, Isao; Kimura, Tadahiro; Mizuochi, Akira; Omori, Tetsu

    1998-01-01

    A single body of a radiation shield comprises a bag prepared by welding or bonding a polyurethane sheet which is made flat while interposing metal plates at the upper and the lower portion of the bag. Eyelet fittings are disposed to the upper and the lower portions of the bag passing through the metal plates and the flat portion of the bag. Water supplying/draining ports are disposed to two upper and lower places of the bag at a height where the metal plates are disposed. Reinforcing walls welded or bonded to the inner wall surface of the bag are elongated in vertical direction to divide the inside of the bag to a plurality of cells. The bag is suspended and supported from a frame with S-shaped hooks inserted into the eyelet fittings as connecting means. A plurality of bags are suspended and supported from the frame at a required height by way of the eyelets at the lower portion of the suspended and supported bag and the eyelet fittings at the upper portion of the bag below the intermediate connection means. (I.N.)

  7. Self-shielding factors

    International Nuclear Information System (INIS)

    Kaul, D.C.

    1982-01-01

    Throughout the last two decades many efforts have been made to estimate the effect of body self-shielding on organ doses from externally incident neutrons and gamma rays. These began with the use of simple geometry phantoms and have culminated in the use of detailed anthropomorphic phantoms. In a recent effort, adjoint Monte Carlo analysis techniques have been used to determine dose and dose equivalent to the active marrow as a function of energy and angle of neutron fluence externally incident on an anthropomorphic phantom. When combined with fluences from actual nuclear devices, these dose-to-fluence factors result in marrow dose values that demonstrate great sensitivity to variations in device type, range, and body orientation. Under a state-of-the-art radiation transport analysis demonstration program for the Japanese cities, sponsored by the Defense Nuclear Agency at the request of the National Council on Radiation Protection and Measurements, the marrow dose study referred to above is being repeated to obtain spectral distributions within the marrow for externally incident neutrons and gamma rays of arbitrary energy and angle. This is intended to allow radiobiologists and epidemiologists to select and to modify numbers of merit for correlation with health effects and to permit a greater understanding of the relationship between human and laboratory subject dosimetry

  8. Shielding plug device

    International Nuclear Information System (INIS)

    Orii, Shoichi; Hasegawa, Satoshi; Makishima, Kenji.

    1976-01-01

    Object: To reduce the size of and extend the life of a revolving bearing and facilitate the laying of driving cables and duct lines, this being accomplished by providing plug raising means of a fast breeder on a stationary plug mounting base so as to prevent the shearing force of sodium from acting upon the revolving bearing. Structure: The shield plug means comprises a stationary plug secured to the open end of the reactor container, a rotary plug rotatable with respect to the stationary plug, an annular base formed on top of the stationary plug so as to cover the rotary plug, a bearing secured to the rotary plug edge lower face and upper and lower locking plates. At the time of the rotation of the rotary plug, the upper locking plate is withdrawn, the stationary plug is raised to release the seal structure, and the lower locking plate is inserted between the bearing and stationary plug. In this way, smooth rotation of the rotary plug can be obtained. (Horiuchi, T.)

  9. A Framework for the Analysis of Localized Corrosion at the Proposed Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Payer, J H; Carroll, S A; Gdowski, G E; Rebak, R B; Michels, T C; Miller, M C; Henson, V E

    2006-01-01

    The proposed Repository presents a familiar materials performance application that is regularly encountered in energy, transportation and other industries. The widely accepted approach to dealing with materials performance is to identify the performance requirements, to determine the operating conditions to which materials will be exposed and to select materials of construction that perform well in those conditions. A special feature of the proposed Yucca Mountain Repository is the extremely long time frame of interest, i.e. 10,000's of years and longer. Thus, the time evolution of the environment in contact with waste package surfaces and the time evolution of corrosion damage that may result are of primary interest in the determination of expected performance. An approach is presented to the analysis of localized corrosion during a time period when it is possible for waters from drips and seepage to contact the waste package surfaces, and the analysis is demonstrated for the water chemistry of mixed salt solutions and a set of time-temperature-relative humidity profiles for a hot, mid and cool temperature waste package. Based on the analysis, there are large time periods when localized corrosion can not be supported, and no corrosion damage will occur. Further analysis can then focus on time periods when it is possible for localized corrosion to occur and the determination of the evolution of any corrosion damage

  10. SNF shipping cask shielding analysis

    International Nuclear Information System (INIS)

    Johnson, J.O.; Pace, J.V. III.

    1996-01-01

    The Waste Management and Remedial Action Division has planned a modification sequence for storage facility 7827 in the Solid Waste Storage Area (SWSA). The modification cycle is: (1) modify an empty caisson, (2) transfer the spent nuclear fuel (SNF) of an occupied caisson to a hot cell in building 3525 for inspection and possible repackaging, and (3) return the package to the modified caisson in the SWSA. Although the SNF to be moved is in the solid form, it has different levels of activity. Thus, the following 5 shipping casks will be available for the task: the Loop Transport Carrier, the In- Pile Loop LITR HB-2 Carrier, the 6.5-inch HRLEL Carrier, the HFIR Hot Scrap Carrier, and the 10-inch ORR Experiment Removal Shield Cask. This report describes the shielding tasks for the 5 casks: determination of shielding characteristics, any streaming avenues, estimation of thermal limits, and shielding calculational uncertainty for use in the transportation plan

  11. Active Radiation Shield, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — DEC-Shield technology offers the means to generate electric power from cosmic radiation sources and fuse dissimilar systems and functionality into a structural...

  12. Gonad shielding in computerized tomography

    International Nuclear Information System (INIS)

    Rockstroh, G.

    1984-01-01

    The reduction of gonadal dose by shielding of the gonads was investigated for a Somatom 2 using an anthropomorphic phantom. For small distances from the slice examined the gonadal dose results from intracorporal secondary radiation and is only insignificantly reduced by shielding. For greater distances shielding is relatively more effective, the gonadal dose however is small because of the approximately exponential decay. Shielding of the gonads therefore does not seem adequate for the reduction of gonadal dose. From dose measurements in cylinder phantoms of several diameters it appears that no different results would be obtained for children and young adults. An effective reduction of gonadal dose is only possible with lead capsules for males. (author)

  13. Radiation shielding for neutron guides

    International Nuclear Information System (INIS)

    Ersez, T.; Braoudakis, G.; Osborn, J.C.

    2005-01-01

    Full text: Models of the neutron guide shielding for the out of bunker guides on the thermal and cold neutron beam lines of the OPAL Reactor (ANSTO) were constructed using the Monte Carlo code MCNP 4B. The neutrons that were not reflected inside the guides but were absorbed by the supermirror (SM) layers were noted to be a significant source of gammas. Gammas also arise from neutrons absorbed by the B, Si, Na and K contained in the glass. The proposed shielding design has produced compact shielding assemblies. These arrangements are consistent with safety requirements, floor load limits, and cost constraints. To verify the design a prototype was assembled consisting of 120mm thick Pb(96%)Sb(4%) walls resting on a concrete block. There was good agreement between experimental measurements and calculated dose rates for bulk shield regions. (authors)

  14. Shielding calculations. Optimization vs. Paradigms

    International Nuclear Information System (INIS)

    Cornejo Diaz, Nestor; Hernandez Saiz, Alejandro; Martinez Gonzalez, Alina

    2005-01-01

    Many radiation shielding barriers in Cuba have been designed according to the criterion of Maxi-mum Projected Dose Rates. This fact has created the paradigm of low dose rates. Because of this, dose rate levels greater than units of Sv.h-1 would be considered unacceptable by many specialists, regardless of the real exposure times. Nowadays many shielding barriers are being designed using dose constraints in real exposure times. Behind the new barriers, dose rates could be notably greater than those behind the traditional ones, and it does not imply inadequate designs or constructive errors. In this work were obtained significant differences in dose rate levels and shield-ing thicknesses calculated by both methods for some typical installations. The work concludes that real exposure time approach is more adequate in order to optimise Radiation Protection, although this method should be carefully applied

  15. Radiation shielding for neutron guides

    International Nuclear Information System (INIS)

    Ersez, T.; Braoudakis, G.; Osborn, J.C.

    2006-01-01

    Models of the neutron guide shielding for the out of bunker guides on the thermal and cold neutron beam lines of the OPAL Reactor (ANSTO) were constructed using the Monte Carlo code MCNP 4B. The neutrons that were not reflected inside the guides but were absorbed by the supermirror (SM) layers were noted to be a significant source of gammas. Gammas also arise from neutrons absorbed by the B, Si, Na and K contained in the glass. The proposed shielding design has produced compact shielding assemblies. These arrangements are consistent with safety requirements, floor load limits, and cost constraints. To verify the design a prototype was assembled consisting of 120 mm thick Pb(96%)Sb(4%) walls resting on a concrete block. There was good agreement between experimental measurements and calculated dose rates for bulk shield regions

  16. Shielding modification and safety review on the nuclear ship 'Mutsu'

    International Nuclear Information System (INIS)

    Osanai, Masao

    1978-01-01

    The Japan Atomic Energy Commission (JAEC) called on the Japan Nuclear Ship Development Agency (JNSDA) for shielding modification and safety review on the nuclear ship ''Mutsu'', and JNSDA has conducted the research and development (R and D) to meet the request of JAEC for the above two items. Concerning the shield modification, the following matters are described: the study on the cause of radiation leakage which was concluded to the fast neutron streaming, the conceptual design for this modification, the mock up experiment for shielding utilizing JRR-4, the basic design following on the conceptual design, including the detailed drawings of the modified construction and the shielding analysis using RADHEAT-V3 code, and the relating experiments such as the heat transfer test of the primary shielding structure and the test of strength in stranding. As for the safety review, the survey of the troubles and the technical problems having been experienced in the light water reactor plants of land use, for example, fuel integrity, stress corrosion cracking and the leakage of steam generator tubes, the revision of the design so as to adapt to current safety standards and regulations, for example, in-service inspection, the setting of additional leak detectors in the primary cooling system, the modification of emergeney filters, etc., and the review of the design and construction corresponding to recent R and D works, such as re-evaluation of the core design, cooling capability of natural circulation, thermal stress analysis of main pipings, and the evaluation of ECCS performance are presented . (Nakai, Y.)

  17. Corrosion principles and surface modification

    International Nuclear Information System (INIS)

    Kruger, J.

    1982-01-01

    This chapter examines the important strategies provided by the newer ideas of corrosion science and engineering that surface modification techniques must utilize to help prevent corrosion, especially the most damaging kind of aqueous corrosion, localized corrosion. Provides a brief introduction to the principles underlying the phenomenon of corrosion in order to use them to discuss surface modification strategies to combat corrosion. Discusses the electrochemistry of corrosion; the thermodynamics of corrosion; the kinetics of corrosion; thermodynamic strategies; and kinetic strategies (formation of more protective passive films; resistance to breakdown; ductility; repassivation)

  18. Measuring space radiation shielding effectiveness

    Directory of Open Access Journals (Sweden)

    Bahadori Amir

    2017-01-01

    Full Text Available Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

  19. Measuring space radiation shielding effectiveness

    Science.gov (United States)

    Bahadori, Amir; Semones, Edward; Ewert, Michael; Broyan, James; Walker, Steven

    2017-09-01

    Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

  20. The conundrum of low-cost drip irrigation in Burkina Faso : Why development interventions that have little to show continue

    NARCIS (Netherlands)

    Wanvoeke, J.; Venot, J.-P.; Zwarteveen, M.; de Fraiture, C.; Venot, J.-P.; Kuper, M.; Zwarteveen, M.

    2017-01-01

    Research and development efforts concerning drip irrigation have traditionally been oriented toward intensive commercial farming in developed economies, focusing on ways to improve efficiencies and productivities. From the mid-1990s onward, an increasing number of research institutes and

  1. Estimation of soil salinity in a drip irrigation system by using joint inversion of multicoil electromagnetic induction measurements

    KAUST Repository

    Jadoon, Khan Zaib; Moghadas, Davood; Jadoon, Aurangzeb; Missimer, Thomas M.; Al-Mashharawi, Samir K.; McCabe, Matthew

    2015-01-01

    -Explorer) is used for subsurface characterization of soil salinity in a drip irrigation system via a joint inversion approach of multiconfiguration EMI measurements. EMI measurements were conducted across a farm where Acacia trees are irrigated with brackish water

  2. The transfer of seasonal isotopic variability between precipitation and drip water at eight caves in the monsoon regions of China

    Science.gov (United States)

    Duan, Wuhui; Ruan, Jiaoyang; Luo, Weijun; Li, Tingyong; Tian, Lijun; Zeng, Guangneng; Zhang, Dezhong; Bai, Yijun; Li, Jilong; Tao, Tao; Zhang, Pingzhong; Baker, Andy; Tan, Ming

    2016-06-01

    This study presents new stable isotope data for precipitation (δ18Op) and drip water (δ18Od) from eight cave sites in the monsoon regions of China (MRC), with monthly to bi-monthly sampling intervals from May-2011 to April-2014, to investigate the regional-scale climate forcing on δ18Op and how the isotopic signals are transmitted to various drip sites. The monthly δ18Op values show negative correlation with surface air temperature at all the cave sites except Shihua Cave, which is opposite to that expected from the temperature effect. In addition, although the monthly δ18Op values are negatively correlated with precipitation at all the cave sites, only three sites are significant at the 95% level. These indicate that, due to the various vapor sources, a large portion of variability in δ18Op in the MRC cannot be explained simply by either temperature or precipitation alone. All the thirty-four drip sites are classified into three types based on the δ18Od variability. About 82% of them are static drips with little discernable variation in δ18Od through the whole study period, but the drip rates of these drips are not necessary constant. Their discharge modes are site-specific and the oxygen isotopic composition of the stalagmites growing from them may record the average of multi-year climatic signals, which are modulated by the seasonality of recharge and potential effects of evaporation, and in some cases infiltration from large rainfall events. About 12% of the thirty-four drip sites are seasonal drips, although the amplitude of δ18Od is narrower than that of δ18Op, the monthly response of δ18Od to coeval precipitation is not completely damped, and some of them follow the seasonal trend of δ18Op very well. These drips may be mainly recharged by present-day precipitation, mixing with some stored water. Thus, the stalagmites growing under them may record portions of the seasonal climatic signals embedded in δ18Op. About 6% of the thirty-four drip sites

  3. Properties of Fe, Ni and Zn isotope chains near the drip-line

    International Nuclear Information System (INIS)

    Tarasov, V.N.; Tarasov, D.V.; Kuprikov, V.I.; Gridnev, K.A.; Gridnev, D.K.; Gridnev, K.A.; Gridnev, D.K.; Kartavenko, V.G.; Greiner, W.; Kartavenko, V.G.

    2007-01-01

    The location of proton and neutron drip-lines and the characteristics of the neutron-deficient and the neutron-rich isotopes Fe, Ni and Zn on the basis of Hartree-Fock method with Skyrme forces (Ska, SkM * , Sly4) taking into account deformation was investigated. The calculations predict a big jump of deformation parameter up to β ∼ 0.4 for Ni isotopes in the neighborhood of N ∼ 62. The manifestation of magic numbers for isotopes 48 Ni, 56 Ni, 78 Ni and also for the stable isotope in the respect to neutron emission 110 Ni which is situated beyond the neutron drip-line is discussed

  4. Study of capillary experiments and hydrologic factors under subsurface drip irrigation with fractal theory

    International Nuclear Information System (INIS)

    Zhou, W; Cao, L

    2012-01-01

    Soil spatial variability is one of the primary environmental factors that influences the hydraulic factors and technical indicators of subsurface drip irrigation (SDI), whose emitters are buried in the soil. This paper aimed at evaluating these effects of soil spatial variability on hydrologic factors under SDI. And some SDI emitter and capillary experiments were designed to obtain test data and distribution of pressure and emitter discharge. First, The results of labyrinth non-turbulent mosaic drip emitter test and fractal theory were used to research the fractal and quantitative relationship between single emitter hydrologic factors and soil physical parameters; and then, the capillary experiments and the relationship among hydrologic factors of capillary were used to analyze the fractal and quantitative relationship between hydrologic factors of capillary and soil physical parameters, which explained the inner relationship between spatial variability of soil and hydrologic factors of filed pipeline network under SDI, and provide theory support for the plan, design, management and production of SDI.

  5. Monitoring Microbially Influenced Corrosion

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    and diffusional effects and unreliable corrosion rates, when biofilm and ferrous sulphide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 by electrochemical techniques. Weight loss coupons and ER are recommended as necessary basic monitoring techniques......Abstract Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria (SRB). The applicability and reliability of a number of corrosion monitoring techniques for monitoring MIC has been evaluated in experiments....... EIS might be used for detection of MIC as the appearance of very large capacitances can be attributed to the combined ferrous sulphide and biofilm formation. Capacitance correlates directly with sulphide concentration in sterile sulphide media. Keywords: Corrosion monitoring, carbon steel, MIC, SRB...

  6. SRB seawater corrosion project

    Science.gov (United States)

    Bozack, M. J.

    1991-01-01

    The corrosion behavior of 2219 aluminum when exposed to seawater was characterized. Controlled corrosion experiments at three different temperatures (30, 60 and 100 C) and two different environments (seawater and 3.5 percent salt solution) were designed to elucidate the initial stages in the corrosion process. It was found that 2219 aluminum is an active catalytic surface for growth of Al2O3, NaCl, and MgO. Formation of Al2O3 is favored at lower temperatures, while MgO is favored at higher temperatures. Visible corrosion products are formed within 30 minutes after seawater exposure. Corrosion characteristics in 3.5 percent salt solution are different than corrosion in seawater. Techniques utilized were: (1) scanning electron microscopy, (2) energy dispersive x-ray spectroscopy, and (3) Auger electron spectroscopy.

  7. Deep subsurface drip irrigation using coal-bed sodic water: part I. water and solute movement

    Science.gov (United States)

    Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.; Hammack, Richard

    2013-01-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300-480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  8. The Application of Drip Irrigation System on Tomato (Lycopersicum Esculentum Mill)

    OpenAIRE

    Setyaningrum, Diah Ayu

    2014-01-01

    This study aimed to analyze the performance of drip irrigation systems, determine performance of tomato treated under the irrigation systems.Field research was conducted at the Laboratory of Land and Water Resources Engineering; and at the Laboratory ofintegrated field, Faculty of Agriculture, University of Lampung in August 2013 to December 2013.Irrigation systems consisted of main componens: water supplies, Polythilene lateral tube, and emitters. Emitter on every pot, were made of Polythile...

  9. Control of soil moisture with radio frequency in a photovoltaic-powered drip irrigation system

    OpenAIRE

    DURSUN, Mahir; ÖZDEN, Semih

    2015-01-01

    Solar-powered irrigation systems are becoming increasingly widespread. However, the initial setup costs of these systems are very high. To reduce these costs, both the energy usage and the prevention of losses from irrigation systems are very important. In this study, a drip irrigation control system of 1000 dwarf cherry trees was controlled using soil moisture sensors in order to prevent excessive water consumption and energy losses in a solar-powered irrigation system. The control sys...

  10. Stalagmite water content as a proxy for drip water supply in tropical and subtropical areas

    Directory of Open Access Journals (Sweden)

    N. Vogel

    2013-01-01

    Full Text Available In this pilot study water was extracted from samples of two Holocene stalagmites from Socotra Island, Yemen, and one Eemian stalagmite from southern continental Yemen. The amount of water extracted per unit mass of stalagmite rock, termed "water yield" hereafter, serves as a measure of its total water content. Based on direct correlation plots of water yields and δ18Ocalcite and on regime shift analyses, we demonstrate that for the studied stalagmites the water yield records vary systematically with the corresponding oxygen isotopic compositions of the calcite (δ18Ocalcite. Within each stalagmite lower δ18Ocalcite values are accompanied by lower water yields and vice versa. The δ18Ocalcite records of the studied stalagmites have previously been interpreted to predominantly reflect the amount of rainfall in the area; thus, water yields can be linked to drip water supply. Higher, and therefore more continuous drip water supply caused by higher rainfall rates, supports homogeneous deposition of calcite with low porosity and therefore a small fraction of water-filled inclusions, resulting in low water yields of the respective samples. A reduction of drip water supply fosters irregular growth of calcite with higher porosity, leading to an increase of the fraction of water-filled inclusions and thus higher water yields. The results are consistent with the literature on stalagmite growth and supported by optical inspection of thin sections of our samples. We propose that for a stalagmite from a dry tropical or subtropical area, its water yield record represents a novel paleo-climate proxy recording changes in drip water supply, which can in turn be interpreted in terms of associated rainfall rates.

  11. Nuclear structure near the particle drip-lines and explosive nucleosynthesis processes

    International Nuclear Information System (INIS)

    Kratz, K.L.; Pfeiffer, B.; Moeller, P.; Thielemann, F.K.; Wiescher, M.

    1999-01-01

    In this paper, we discuss the nuclear physics input for a selected set of explosive nucleosynthesis scenarios leading to rapid proton-- and neutron--capture processes. Observables (like e.g. luminosity curves or elemental abundance distributions) witness the interplay between nuclear structure aspects near the particle drip-lines and the appropriate astrophysical environments, and can give guidance to and constraints on stellar conditions and the associated nucleosynthesis. (authors)

  12. Hydraulic performance evaluation of pressure compensating (pc) emitters and micro-tubing for drip irrigation system

    International Nuclear Information System (INIS)

    Mangrio, A.G.; Asif, M.; Jahangir, I.

    2013-01-01

    Drip irrigation system is necessary for those areas, where the water scarcity issues are present. The present study was conducted at the field station of Climate Change, Alternate Energy and Water Resources Institute (CAEWRI), National Agricultural Research Center (NARC), Islamabad, during 2013, regarding drip irrigation system. Drip irrigation system depends on uniform emitter application flow. All the emitters were tested and replicated thrice at pressure head (34 to 207Kpa) with an increment of 34 Kpa. The minimum and maximum discharges were 1.32 - 3.52, 3.36 - 5.42, and 43.22 - 100.99 Lph, with an average of 2.42, 4.63 and 73.66 Lph, for Bow Smith, RIS and Micro-tubing, respectively. It indicates that more than 90% of emission uniformity (EU) and uniformity coefficient (CU) for all Emitters, which shows excellent water application with least standard deviation, ranging 0.12 to 2.37, throughout the operating pressure heads in all emitters. An average coefficient of variation (CV) of all emitters were behaving less than 0.07, indicating an excellent class at all operating pressure heads between 34 to 207 Kpa. Moreover, the relationship of discharge and pressure of emitters indicates that discharge increased with the increase of pressure head. The Q-H curve plays key role in the selection of emitters. (author)

  13. Effect of fabric mounting method and backing material on bloodstain patterns of drip stains on textiles.

    Science.gov (United States)

    Chang, J Y M; Michielsen, S

    2016-05-01

    Textiles may provide valuable bloodstain evidence to help piece together events or activities at violent crime scenes. However, in spite of over 75 years of research, there are still difficulties encountered in many cases in the interpretation and identification of bloodstains on textiles. In this study, we dripped porcine blood onto three types of fabric (plain woven, single jersey knit, and denim) that are supported in four different ways (hard, taut, loose, and semi-hard, i.e., fabric laid on denim). These four mounting methods represent different ways in which a textile may be present when blood from a violent act lands on it. This study investigates how the fabric mounting method and backing material affect the appearance of drip stains on textiles. We found that bloodstain patterns formed on fabric lying flat on a hard surface were very different from when the same fabric was suspended loosely. We also found that bloodstains formed on the technical back of single jersey knit were vastly different from those on the technical face. Interestingly, some drip stains showed blood passing through the textile and leaving a stain behind it that resembled insect stains. By observing, recording, and describing how a blood stained textile is found or presented at the scene, the analyst may be able to better understand bloodstains and bloodstain patterns on textiles, which could be useful to confirm or refute a witness's account of how blood came to be where it was found after a bloodshed event.

  14. [Effect of compound Danshen dripping pills combined with atorvastatin on restenosis after angioplasty in rabbits].

    Science.gov (United States)

    Song, Jieli; Zeng, Jinpei; Zhang, Yongxia; Li, Pengfei; Zhang, Lihong; Chen, Cibin

    2014-08-01

    To study the effect of compound Danshen dripping pills and atorvastatin on restenosis after abdominal aorta angioplasty in rabbits. Rabbit models of abdominal aorta restenosis after angioplasty were established and treated with saline (group A), compound Danshen dripping pills (group B), atorvastatin (group C), or compound Danshen dripping pills plus atorvastatin (group D). HE staining was used to determine the thickness of arterial intimal hyperplasia and assess the morphological changes of the narrowed artery. Immunohistochemistry was employed to detect the expression of nuclear factor-κB (NF-κB) and monocyte chemoattractant protein-1 (MCP-1). Compared with group A, the 3 treatment groups showed significant increased vascular cavity area and reduced intimal area and percentage of intimal hyperplasia (Ppills combined with atorvastatin produces better effects than the drugs used alone in inhibiting vascular smooth muscle cell proliferation in rabbits after abdominal aorta angioplasty possibly due to a decreased expression of MCP-1 as a result of NF-κB inhibition.

  15. Influence of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel welding joints

    Science.gov (United States)

    Zhang, Zhiqiang; Jing, Hongyang; Xu, Lianyong; Han, Yongdian; Zhao, Lei; Zhang, Jianli

    2017-02-01

    The influences of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel joints welded by gas tungsten arc welding (GTAW) and flux-cored arc welding (FCAW) with different shielding gas compositions were studied by optical microscopy, electron backscatter diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, electron probe microanalysis, and potentiostatic and potentiodynamic polarization methods The adding 2% N2 in shielding gas facilitated primary austenite formation in GTAW weld metal (WM) and suppressed Cr2N precipitation in GTAW weld root. In the HAZ, the banded microstructure disappeared while the coarse ferrite grains maintained same orientation as the banded ferrite in the BM. In the WM, the ferrite had one single orientation throughout a grain, whereas several families of austenite appeared. The austenite both in BM and WM enriched in Ni and nitro`gen, while Cr and Mo were concentrated in the ferrite and thus no element showed clear dendritic distribution in the WM (ER2209 and E2209T1). In addition, the secondary austenite had higher Ni content but lower Cr and Mo content than the primary austenite. The N2-supplemented shielding gas promoted nitrogen solid-solution in the primary and secondary austenite. Furthermore, the secondary austenite had relatively lower pitting resistance equivalent number (PREN) than the ferrite and primary austenite, thereby resulting in its preferential corrosion. The Cr2N precipitation led to relatively poor resistance to pitting corrosion in three HAZs and pure Ar shielding GTAW weld root. The N2-supplemented shielding gas improved pitting corrosion resistance of GTAW joint by increasing PREN of secondary austenite and suppressing Cr2N precipitation. In addition, the FCAW WM had much poorer resistance to pitting corrosion than the GTAW WM due to many O-Ti-Si-Mn inclusions. In the BM, since the austenite with lower PREN compared

  16. Corrosion control. 2. ed.

    International Nuclear Information System (INIS)

    Bradford, S.A.

    2001-01-01

    The purpose of this text is to train engineers and technologists not just to understand corrosion but to control it. Materials selection, coatings, chemical inhibitors, cathodic and anodic protection, and equipment design are covered in separate chapters. High-temperature oxidation is discussed in the final two chapters ne on oxidation theory and one on controlling oxidation by alloying and with coatings. This book treats corrosion and high-temperature oxidation separately. Corrosion is divided into three groups: (1) chemical dissolution including uniform attack, (2) electrochemical corrosion from either metallurgical or environmental cells, and (3) stress-assisted corrosion. Corrosion is logically grouped according to mechanisms rather than arbitrarily separated into different types of corrosion as if they were unrelated. For those university students and industry personnel who approach corrosion theory very hesitantly, this text will present the electrochemical reactions responsible for corrosion summed up in only five simple half-cell reactions. When these are combined on a polarization diagram, which is also explained in detail, the electrochemical processes become obvious. For those who want a text stripped bare of electrochemical theory, several noted sections can be omitted without loss of continuity. However, the author has presented the material in such a manner that these sections are not beyond the abilities of any high school graduate who is interested in technology

  17. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  18. Electrodynamic Dust Shield Demonstrator

    Science.gov (United States)

    Stankie, Charles G.

    2013-01-01

    The objective of the project was to design and manufacture a device to demonstrate a new technology developed by NASA's Electrostatics and Surface Physics Laboratory. The technology itself is a system which uses magnetic principles to remove regolith dust from its surface. This project was to create an enclosure that will be used to demonstrate the effectiveness of the invention to The Office of the Chief Technologist. ONE of the most important challenges of space exploration is actually caused by something very small and seemingly insignificant. Dust in space, most notably on the moon and Mars, has caused many unforeseen issues. Dirt and dust on Earth, while a nuisance, can be easily cleaned and kept at bay. However, there is considerably less weathering and erosion in space. As a result, the microscopic particles are extremely rough and abrasive. They are also electrostatically charged, so they cling to everything they make contact with. This was first noted to be a major problem during the Apollo missions. Dust would stick to the spacesuits, and could not be wiped off as predicted. Dust was brought back into the spacecraft, and was even inhaled by astronauts. This is a major health hazard. Atmospheric storms and other events can also cause dust to coat surfaces of spacecraft. This can cause abrasive damage to the craft. The coating can also reduce the effectiveness of thermal insulation and solar panels.' A group of engineers at Kennedy Space Center's Electrostatics and Surface Physics Laboratory have developed a new technology, called the Electrodynamic Dust Shield, to help alleviate these problems. It is based off of the electric curtain concept developed at NASA in 1967. "The EDS is an active dust mitigation technology that uses traveling electric fields to transport electrostatically charged dust particles along surfaces. To generate the traveling electric fields, the EDS consists of a multilayer dielectric coating with an embedded thin electrode grid

  19. Corrosion in the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Brondel, D [Sedco Forex, Montrouge (France); Edwards, R [Schlumberger Well Services, Columbus, OH (United States); Hayman, A [Etudes et Productions Schlumberger, Clamart (France); Hill, D [Schlumberger Dowell, Tulsa, OK (United States); Mehta, S [Schlumberger Dowell, St. Austell (United Kingdom); Semerad, T [Mobil Oil Indonesia, Inc., Sumatra (Indonesia)

    1994-04-01

    Corrosion costs the oil industry billions of dollars a year, a fact that makes the role of the corrosion engineer an increasingly important one. Attention is paid to how corrosion affects every aspect of exploration and production, from offshore rigs to casing. Also the role of corrosion agents such as drilling and production fluids is reviewed. Methods of control and techniques to monitor corrosion are discussed, along with an explanation of the chemical causes of corrosion. 21 figs., 32 refs.

  20. Radiation shielding in dental radiography

    International Nuclear Information System (INIS)

    Stenstroem, B.; Rehnmark-Larsson, S.; Julin, P.; Richter, S.

    1983-01-01

    The protective effect in the thyroid region from different types of radiation shieldings at intraoral radiography has been studied as well as the reduction of the absorbed dose to the sternal and the gonadal regions. The shieldings tested were five different types of leaded aprons, of which three had an attached leaded collar and the other two were used in combination with separate soft leaded collars. Furthermore one of the soft leaded collars and an unflexible horizontal leaded shield were tested separately. Two dental x-ray machines of 60 and 65 kVp with rectangular and circular tube collimators were used. The exposure time corresponded to speed group E film. The absorbed doses were measured with two ionization chambers. No significant difference in the protective effect in the thyroid gland could be found between the different types of radiation shieldings. There was a dose reduction by approximately a factor of 2 to the thyroid region down to 0.08 mGy per full survey using parallelling technique, and below 0.001 mGy per single bitewing exposure. The shieldings reduced the thyroid dose using bisecting-angle technique by a factor of 5 down to 0.15 mGy per full survey (20 exposures). In the sternal region the combinations of apron and collar reduced the absorbed dose from a full survey to below 2 μGy compared with 18 μGy (parallelling) and 31 μGy (biscting-angle) without any shielding. With the horizontal leaded shield a reduction by a factor of 6 was obtained but no significant sternal dose reduction could be detected from the soft collar alone. The gonadal dose could be reduced by a factor of 10 with the horizontal leaded shield, parallelling technique and circular collimator. Using leaded aprons the gonadal dose was approximately one per cent of the dose without any shielding, i.e. below 0.01 μGy per single intraoral exposure. (Authors)

  1. Drip irrigation and fertigation of potato under light-textured soils of cappadocia region

    International Nuclear Information System (INIS)

    Halitgil, M. B.; Onaran, H.; Munsuz, N.; Kislal, H.; Akin, A.; Unlenen, A. L.; Cayci, G.; Kutuk, C.

    2002-01-01

    In order to evaluate potato response to drip irrigation and N fertigation; and also to improve nitrogen and water use efficiencies of potato and eventually to obtain less nitrogen polluted surface and water, 10 field experiments were carried out at three different locations in Cappadocia Region of Turkey in 1997, 1998, 1999 and 2000 growing seasons. Nitrogen as ammonium sulphate ((NH 4 ) 2 So 4 ), was supplied by drip irrigation water (fertigation) at rates of 0, 30, 60 and 90 kg N/da. Also, soil N application treatment equivalent to the fertigation treatment of 60kg N/da was included. These five treatments were investigated in a completely randomized block design with four replicants. Agria potato variety was used in all experiments and potato was planted in mid May and harvested at the end of October.''1''5N-labelled ammonium sulphate fertilizer were applied in isotope-sub plots within the macroplots for each treatment, in order to determine the amount of nitrogen taken up by the plant, nitrogen use efficiency and the distribution of residual nitrogen at different depths in the soil profile. Each year, during the growth period, total 12 irrigations were done and 50 mm of water was applied at each irrigation. At harvest, plant samples (tuber and leaf+vein) and soil samples were taken from each plot and N%, ''1''5N% atom excess (''1''5N% a.e.) and Ndff% determinations were done. Soil water contents at differrent soil depths were determined by soil moisture neutron probe at plantingand at harvest period so that water contents at different soil layers and water use efficiencies were calculated for each treatment. The results obtained showed that 3350 kg/da mean total marketable tuber yield was obtained with application of 600 mm irrigation water. Also,it was found that water did not move below 90 cm of soil layer in drip irrigation-fertigation system, which showed clearly that no nitrogen movement occured beyond 90 cm soil depth. Tuber yields and %Ndff increased when

  2. Shielding features of quarry stone

    International Nuclear Information System (INIS)

    Hernandez V, C.; Contreras S, H.; Hernandez A, L.; Baltazar R, A.; Escareno J, E.; Mares E, C. A.; Vega C, H. R.

    2010-10-01

    Quarry stone lineal attenuation coefficient for gamma-rays has been obtained. In Zacatecas, quarry stone is widely utilized as a decorative item in buildings, however its shielding features against gamma-rays unknown. The aim of this work is to determine the shielding properties of quarry stone against γ-rays using Monte Carlo calculations where a detailed model of a good geometry experimental setup was carried out. In the calculations 10 pieces 10 X 10 cm 2 of different thickness were utilized to evaluate the photons transmission as the quarry stone thickness is increased. It was noticed that transmitted photons decay away as the shield thickness is increased, these results were fitted to an exponential function were the linear attenuation coefficient was estimated. Also, using XCOM code the linear attenuation coefficient from several keV up to 100 MeV was estimated. From the comparison between Monte Carlo results and XCOM calculations a good agreement was found. For 0.662 MeV γ-rays the attenuation coefficient of quarry stone, whose density is 2.413 g-cm -3 , is 0.1798 cm -1 , this mean a X 1/2 = 3.9 cm, X 1/4 = 7.7 cm, X 1/10 = 12.8 cm, and X 1/100 = 25.6 cm. Having the information of quarry stone performance as shielding give the chance to use this material to shield X and γ-ray facilities. (Author)

  3. Radiation Shielding Materials and Containers Incorporating Same

    Energy Technology Data Exchange (ETDEWEB)

    Mirsky, Steven M.; Krill, Stephen J.; and Murray, Alexander P.

    2005-11-01

    An improved radiation shielding material and storage systems for radioactive materials incorporating the same. The PYRolytic Uranium Compound (''PYRUC'') shielding material is preferably formed by heat and/or pressure treatment of a precursor material comprising microspheres of a uranium compound, such as uranium dioxide or uranium carbide, and a suitable binder. The PYRUC shielding material provides improved radiation shielding, thermal characteristic, cost and ease of use in comparison with other shielding materials. The shielding material can be used to form containment systems, container vessels, shielding structures, and containment storage areas, all of which can be used to house radioactive waste. The preferred shielding system is in the form of a container for storage, transportation, and disposal of radioactive waste. In addition, improved methods for preparing uranium dioxide and uranium carbide microspheres for use in the radiation shielding materials are also provided.

  4. MMW [multimegawatt] shielding design and analysis

    International Nuclear Information System (INIS)

    Olson, A.P.

    1988-01-01

    Reactor shielding for multimegawatt (MMW) space power must satisfy a mass constraint as well as performance specifications for neutron fluence and gamma dose. A minimum mass shield is helpful in attaining the launch mass goal for the entire vehicle, because the shield comprises about 1% to 2% of the total vehicle mass. In addition, the shield internal heating must produce tolerable temperatures. The analysis of shield performance for neutrons and gamma rays is emphasized. Topics addressed include cross section preparation for multigroup 2D S/sub n/-transport analyses, and the results of parametric design studies on shadow shield performance and mass versus key shield design variables such as cone angle, number, placement, and thickness of layers of tungsten, and shield top radius. Finally, adjoint methods are applied to the shield in order to spatially map its relative contribution to dose reduction, and to provide insight into further design optimization. 7 refs., 2 figs., 3 tabs

  5. Magnetic shielding for superconducting RF cavities

    Science.gov (United States)

    Masuzawa, M.; Terashima, A.; Tsuchiya, K.; Ueki, R.

    2017-03-01

    Magnetic shielding is a key technology for superconducting radio frequency (RF) cavities. There are basically two approaches for shielding: (1) surround the cavity of interest with high permeability material and divert magnetic flux around it (passive shielding); and (2) create a magnetic field using coils that cancels the ambient magnetic field in the area of interest (active shielding). The choice of approach depends on the magnitude of the ambient magnetic field, residual magnetic field tolerance, shape of the magnetic shield, usage, cost, etc. However, passive shielding is more commonly used for superconducting RF cavities. The issue with passive shielding is that as the volume to be shielded increases, the size of the shielding material increases, thereby leading to cost increase. A recent trend is to place a magnetic shield in a cryogenic environment inside a cryostat, very close to the cavities, reducing the size and volume of the magnetic shield. In this case, the shielding effectiveness at cryogenic temperatures becomes important. We measured the permeabilities of various shielding materials at both room temperature and cryogenic temperature (4 K) and studied shielding degradation at that cryogenic temperature.

  6. Superconducting magnetic shields production. Realisation d'ecrans magnetiques supraconducteurs

    Energy Technology Data Exchange (ETDEWEB)

    Lainee, F; Kormann, R [Thomson-CSF, Domaine de Corbeville, 91 - Orsay (FR); Lainee, F [Ecole des Mines de Paris, 91 - Evry (FR)

    1992-02-01

    Low fields and low frequency shielding properties of YBCO magnetic shields are measured at 77 K. They compare favourably with shielding properties of mumetal shields. Therefore high-T{sub c} superconducting magnetic shields can already be used to shield small volumes. The case of magnetic shields for large volumes is also discussed. 3 refs; 6 figs; 4 tabs.

  7. Radiation shielding for fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Yoshiaki [Tokyo Univ., Nuclear Engineering Research Laboratory, Tokyo (Japan)

    2000-03-01

    Radiation shielding aspects relating fission reactors have been reviewed. Domestic activities in the past five years have been mainly described concerning nuclear data, calculation methods, shielding and skyshine experiments, Advanced Boiling Water Reactor (ABWR), Advanced Pressurized Water Reactor (APWR), High Temperature Engineering Test Reactor (HTTR), Experimental and Prototype Fast Reactors (JOYO, MONJU), Demonstration FBR, core shroud replacement of BWR, and spent fuel transportation cask and vessel. These studies have valuable information in safety and cost reduction issues of fission reactor design for not only existing reactors but also new reactor concepts in the next century. It has been concluded that we should maintain existing shielding technologies and improve these data and methods for coming generations in the next millennium. (author)

  8. Shield cost minimization using SWAN

    International Nuclear Information System (INIS)

    Watkins, E.F.; Annese, C.E.; Greenspan, E.

    1993-01-01

    The common approach to the search for minimum cost shield designs is open-quotes trial-and-errorclose quotes; it proceeds as follows: 1. Based on prior experience and intuition, divide the shield into zones and assume their composition. 2. Solve the transport equation and calculate the relevant performance characteristics. 3. Change the composition or the geometry of one or a few of the zones and repeat step 2. 4. Repeat step 3 many times until the shield design appears to be optimal. 5. Select a different set of constituents and repeat steps 2,3, and 4. 6. Repeate step 5 a few or many times until the designer can point to the most cost-effective design

  9. Radiation shield for nuclear reactors

    International Nuclear Information System (INIS)

    Weissenfluh, J.A.

    1980-01-01

    A reusable radiation shield for use in a reactor installation comprises a thin-walled, flexible and resilient container, made of plastic or elastomeric material, containing a hydrogenous fluid with boron compounds in solution. The container can be filled and drained in position and the fluid can be recirculated if required. When not in use the container can be folded and stored in a small space. The invention relates to a shield to span the top of the annular space between a reactor vessel and the primary shield. For this purpose a continuous toroidal container or a series of discrete segments is used. Other forms can be employed for different purposes, e.g. mattress- or blanket-like forms can be draped over potential sources of radiation or suspended from a mobile carrier and placed between a worker and a radiation source. (author)

  10. Corrosion evaluation technology

    International Nuclear Information System (INIS)

    Kim, Uh Chul; Han, Jeong Ho; Nho, Kye Ho; Lee, Eun Hee; Kim, Hong Pyo; Hwang, Seong Sik; Lee, Deok Hyun; Hur, Do Haeng; Kim, Kyung Mo.

    1997-09-01

    A multifrequency ACPD system was assembled which can measure very small crack. Stress corrosion cracking test system with SSRT operating high temperature was installed. Stress corrosion cracking test of newly developed alloy 600 and existing alloy 600 was carried out in steam atmosphere of 400 deg C. No crack was observed in both materials within a test period of 2,000 hrs. Corrosion fatigue test system operating at high temperature was installed in which fatigue crack was measured by CDPD. Lead enhanced the SCC of the Alloy 600 in high temperature water, had a tendency to modify a cracking morphology from intergranular to transgranular. Pit initiation preferentially occurred at Ti-rich carbide. Resistance to pit initiation decreased with increasing temperature up to 300 deg C. Test loop for erosion corrosion was designed and fabricated. Thin layer activation technique was very effective in measuring erosion corrosion. Erosion corrosion of a part of secondary side pipe was evaluated by the Check Family Codes of EPRI. Calculated values of pipe thickness by Check Family Codes coincided with the pipe thickness measured by UT with an error of ± 20%. Literature review on turbine failure showed that failure usually occurred in low pressure turbine rotor disc and causes of failure are stress corrosion cracking and corrosion fatigue. (author). 12 refs., 20 tabs., 77 figs

  11. Aluminum Corrosion and Turbidity

    International Nuclear Information System (INIS)

    Longtin, F.B.

    2003-01-01

    Aluminum corrosion and turbidity formation in reactors correlate with fuel sheath temperature. To further substantiate this correlation, discharged fuel elements from R-3, P-2 and K-2 cycles were examined for extent of corrosion and evidence of breaking off of the oxide film. This report discusses this study

  12. Demystifying Controlling Copper Corrosion

    Science.gov (United States)

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  13. Archaeological analogs and corrosion

    International Nuclear Information System (INIS)

    David, D.

    2008-01-01

    In the framework of the high level and long life radioactive wastes disposal deep underground, the ANDRA built a research program on the material corrosion. In particular they aim to design containers for a very long time storage. Laboratory experiments are in progress and can be completed by the analysis of metallic archaeological objects and their corrosion after hundred years. (A.L.B.)

  14. Outcome of the 'Drip-and-Ship' Paradigm among Patients with Acute Ischemic Stroke: Results of a Statewide Study.

    Science.gov (United States)

    Qureshi, Adnan I; Chaudhry, Saqib A; Rodriguez, Gustavo J; Suri, M Fareed K; Lakshminarayan, Kamakshi; Ezzeddine, Mustapha A

    2012-01-01

    BACKGROUND: The 'drip-and-ship' paradigm denotes a treatment regimen in patients in whom intravenous (IV) recombinant tissue plasminogen activator (rt-PA) is initiated at the emergency department (ED) of a community hospital, followed by transfer within 24 h to a comprehensive stroke center. Although the drip-and-ship paradigm has the potential to increase the number of patients who receive IV rt-PA, comparative outcomes have not been assessed at a population-based level. METHODS: Statewide estimates of thrombolysis, associated in-hospital outcomes, and hospitalization charges were obtained from 2008-2009 Minnesota Hospital Association data for all patients hospitalized with a primary diagnosis of ischemic stroke. Patients who were assigned the drip-and-ship code [International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) V45.88] were classified under the drip-and-ship paradigm. Patients who underwent thrombolysis (ICD-9-CM code 99.10) without drip-and-ship code were classified as primary ED arrival. Patient outcomes were analyzed after stratification into patients treated with IV rt-PA through primary ED arrival or drip-and-ship paradigm. RESULTS: Of the 21,024 admissions, 602 (2.86%) received IV rt-PA either through primary ED arrival (n = 473) or the drip-and-ship paradigm (n = 129). IV rt-PA was administered in 30 hospitals, of which 13 hospitals used the drip-and-ship paradigm; the number of patients treated with the drip-and-ship paradigm varied from 1 to 40 between the 13 hospitals. The rates of secondary intracerebral or subarachnoid hemorrhage were higher in patients treated with IV rt-PA through primary ED arrival compared with those treated with the drip-and-ship paradigm (8.5 vs. 3.1%, respectively; p = 0.038). The in-hospital mortality rate was similar among ischemic stroke patients receiving IV rt-PA through primary ED arrival or the drip-and-ship paradigm (5.9 vs. 7.0%, respectively). The mean hospital charges were USD

  15. Erosion and erosion-corrosion

    International Nuclear Information System (INIS)

    Isomoto, Yoshinori

    2008-01-01

    It is very difficult to interpret the technical term of erosion-corrosion' which is sometimes encountered in piping systems of power plants, because of complicated mechanisms and several confusing definitions of erosion-corrosion phenomena. 'FAC (flow accelerated corrosion)' is recently introduced as wall thinning of materials in power plant systems, as a representative of 'erosion-corrosion'. FAC is, however, not necessarily well understood and compared with erosion-corrosion. This paper describes firstly the origin, definition and fundamental understandings of erosion and erosion-corrosion, in order to reconsider and reconfirm the phenomena of erosion, erosion-corrosion and FAC. Next, typical mapping of erosion, corrosion, erosion-corrosion and FAC are introduced in flow velocity and environmental corrosiveness axes. The concept of damage rate in erosion-corrosion is finally discussed, connecting dissolution rate, mass transfer of metal ions in a metal oxide film and film growth. (author)

  16. Exploratory shaft liner corrosion estimate

    International Nuclear Information System (INIS)

    Duncan, D.R.

    1985-10-01

    An estimate of expected corrosion degradation during the 100-year design life of the Exploratory Shaft (ES) is presented. The basis for the estimate is a brief literature survey of corrosion data, in addition to data taken by the Basalt Waste Isolation Project. The scope of the study is expected corrosion environment of the ES, the corrosion modes of general corrosion, pitting and crevice corrosion, dissimilar metal corrosion, and environmentally assisted cracking. The expected internal and external environment of the shaft liner is described in detail and estimated effects of each corrosion mode are given. The maximum amount of general corrosion degradation was estimated to be 70 mils at the exterior and 48 mils at the interior, at the shaft bottom. Corrosion at welds or mechanical joints could be significant, dependent on design. After a final determination of corrosion allowance has been established by the project it will be added to the design criteria. 10 refs., 6 figs., 5 tabs

  17. Corrosion fatigue of steels

    International Nuclear Information System (INIS)

    Spaehn, H.; Wagner, G.H.

    1976-01-01

    Corrosion fatigue phenomena can be classified into two main groups according to the electrochemical state of the metal surface in the presence of electrolytes: the active and the passive state with an important sub-group of corrosion fatigue in the unstable passive state. The allowable stress for structures exposed to the conjoint action of corrosion and fatigue is influenced by many factors: kind of media, number of cycles, frequency, mean stress, size, notches, loading mode, alloy composition and mechanical strength. A critical literature review shows contradictory results if a classification by the electrochemical surface state is not applied. Case histories and counter measures illustrate the practical importance of corrosion fatigue in many branches of industry as well as the urgent need for a better knowledge about the mutual influence of the phenomena to get rules by which the engineer can appraise the risk of corrosion fatigue. (orig.) [de

  18. Shielding walls against ionizing radiation

    International Nuclear Information System (INIS)

    1993-05-01

    Hot-cell shielding walls consist of building blocks made of lead according to DIN 25407 part 1, and of special elements according to DIN 25407 part 2. Alpha-gamma cells can be built using elements for protective contamination boxes according to DIN 25480 part 1. This standards document intends to provide planning engineers, manufacturers, future users and the competent authorities and experts with a basis for the design of hot cells with lead shielding walls and the design of hot-cell equipment. (orig./HP) [de

  19. Nuclear steam generator tubesheet shield

    International Nuclear Information System (INIS)

    Nickerson, J.H.D.; Ruhe, A.

    1982-01-01

    The invention involves improvements to a nuclear steam generator of the type in which a plurality of U-shaped tubes are connected at opposite ends to a tubesheet and extend between inlet and outlet chambers, with the steam generator including an integral preheater zone adjacent to the downflow legs of the U-shaped tubes. The improvement is a thermal shield disposed adjacent to an upper face of the tubesheet within the preheater zone, the shield including ductile cladding material applied directly to the upper face of the tubesheet, with the downflow legs of the U-shaped tubes extending through the cladding into the tubesheet

  20. Shielding structure analysis for LSDS facility

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hong Yeop; Kim, Jeong Dong; Lee, Yong Deok; Kim, Ho Dong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The nuclear material (Pyro, Spent nuclear fuel) itself and the target material to generate neutrons is the LSDS system for isotopic fissile assay release of high intensity neutron and gamma rays. This research was performed to shield from various strong radiation. A shielding evaluation was carried out with a facilities model of LSDS system. The MCNPX 2.5 code was used and a shielding evaluation was performed for the shielding structure and location. The radiation dose based on the hole structure and location of the wall was evaluated. The shielding evaluation was performed to satisfy the safety standard for a normal person (1 μSv/h) and to use enough interior space. The MCNPX2.5 code was used and a dose evaluation was performed for the location of the shielding material, shielding structure, and hole structure. The evaluation result differs according to the shielding material location. The dose rate was small when the shielding material was positioned at the center. The dose evaluation result regarding the location of the shielding material was applied to the facility and the shielding thickness was determined (In 50 cm + Borax 5 cm + Out 45cm). In the existing hole structure, the radiation leak is higher than the standard. A hole structure model to prevent leakage of radiation was proposed. The general public dose limit was satisfied when using the concrete reinforcement and a zigzag structure. The shielding result will be of help to the facility shielding optimization.

  1. Concrete shielding for nuclear ship 'Mutsu'

    International Nuclear Information System (INIS)

    Nagase, Tetsuo; Saito, Tetsuo

    1983-01-01

    The repair works of the shielding for the nuclear ship ''Mutsu'' were completed in August, 1982. For the primary shielding, serpentine concrete was adopted as it contains a large quantity of water required for neutron shielding, and in the secondary shielding at the upper part of the reactor containment vessel, the original shielding was abolished, and the heavy concrete (high water content, high density concrete) which is effective for neutron and gamma-ray shielding was newly adopted. In this report, the design and construction using these shielding concrete are outlined. In September, 1974, Mutsu caused radiation leak during the test, and the cause was found to be the fast neutrons streaming through a gap between the reactor pressure vessel and the primary shielding. The repair works were carried out in the Sasebo Shipyard. The outline of the repair works of the shielding is described. The design condition for the shielding, the design standard for the radiation dose outside and inside the ship, the method of shielding analysis and the performance required for shielding concrete are reported. The selection of materials, the method of construction and mixing ratio, the evaluation of the soundness and properties of concrete, and the works of placing the shielding concrete are outlined. (Kako, I.)

  2. Shielding structure analysis for LSDS facility

    International Nuclear Information System (INIS)

    Choi, Hong Yeop; Kim, Jeong Dong; Lee, Yong Deok; Kim, Ho Dong

    2014-01-01

    The nuclear material (Pyro, Spent nuclear fuel) itself and the target material to generate neutrons is the LSDS system for isotopic fissile assay release of high intensity neutron and gamma rays. This research was performed to shield from various strong radiation. A shielding evaluation was carried out with a facilities model of LSDS system. The MCNPX 2.5 code was used and a shielding evaluation was performed for the shielding structure and location. The radiation dose based on the hole structure and location of the wall was evaluated. The shielding evaluation was performed to satisfy the safety standard for a normal person (1 μSv/h) and to use enough interior space. The MCNPX2.5 code was used and a dose evaluation was performed for the location of the shielding material, shielding structure, and hole structure. The evaluation result differs according to the shielding material location. The dose rate was small when the shielding material was positioned at the center. The dose evaluation result regarding the location of the shielding material was applied to the facility and the shielding thickness was determined (In 50 cm + Borax 5 cm + Out 45cm). In the existing hole structure, the radiation leak is higher than the standard. A hole structure model to prevent leakage of radiation was proposed. The general public dose limit was satisfied when using the concrete reinforcement and a zigzag structure. The shielding result will be of help to the facility shielding optimization

  3. Automated Methods Of Corrosion Measurements

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers; Andersen, Jens Enevold Thaulov; Reeve, John Ch

    1997-01-01

    The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell.......The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell....

  4. The role of nitrogen in improving pitting corrosion resistance of high-alloy austenitic and duplex stainless steel welds

    International Nuclear Information System (INIS)

    Vilpas, M.; Haenninen, H.

    1999-01-01

    The effects of nitrogen alloyed shielding gas on weld nitrogen content and pitting corrosion resistance of super austenitic (6%Mo) and super duplex stainless steels have been studied with special emphasis on microsegregation behaviour of Cr, Mo and N. The measurements performed with the 6%Mo steel indicate that all these elements segregate interdendritically in the fully austenitic weld metal. With nitrogen addition to the shielding gas the enrichment of nitrogen to the interdendritic regions is more pronounced than to the dendrite cores due to which the pitting corrosion resistance of the dendrite cores increases only marginally. In the super duplex steel welds nitrogen enriches in austenite increasing its pitting corrosion resistance more effectively. In these welds the pitting corrosion resistance of the ferrite phase remains lower. (orig.)

  5. Reduced Nitrous Oxide Emissions in Tomato Cropping Systems under Drip Irrigation and Fertigation

    Science.gov (United States)

    Kennedy, T.; Suddick, E. C.; Six, J. W.

    2011-12-01

    In California, agriculture and forestry account for 8% of the total greenhouse gas (GHG) emissions, of which 50% is accounted for by nitrous oxide (N2O). Furrow irrigation and high temperatures in the Central Valley, together with conventional fertilization, are ideal for the production of food, but also N2O. These conditions lead to high N2O fluxes, but also mean there is great potential to reduce N2O emissions by optimizing fertilizer use and irrigation practices. Improving fertilizer use by better synchronizing nitrogen (N) availability and crop demand can reduce N losses and fertilizer costs. Smaller, more frequent fertilizer applications can increase the synchrony between available soil N and crop N uptake. Fertigation allows for more control over how much N is being added and can therefore allow for better synchrony throughout the growing season. In our study, we determined how management practices, such as fertilization, irrigation, tillage and harvest, affect direct N2O emissions in typical tomato cropping systems. We evaluated two contrasting irrigation managements and their associated fertilizer application method, i.e. furrow irrigation and knife injection versus drip irrigation and fertigation. Across two tomato-growing seasons, we found that shifts in fertilizer and irrigation water management directly affect GHG emissions. Seasonal N2O fluxes were 3.4 times lower under drip versus furrow irrigation. In 2010, estimated losses of fertilizer N as N2O were 0.60 ± 0.06 kg N2O-N ha-1 yr-1 in the drip system versus 2.06 ± 0.11 N2O-N kg ha-1 yr-1 in the furrow system, which was equivalent to 0.29% and 0.87% of the added fertilizer, respectively. Carbon dioxide (CO2) emissions were also lower in the drip system (2.21 ± 0.16 Mg CO2-C ha-1 yr-1) than the furrow system (4.65 ± 0.23 Mg CO2-C ha-1 yr-1). Soil mineral N, dissolved organic carbon and soil moisture also varied between the two systems and correlated positively with N2O and CO2 emissions, depending

  6. Investigation of factors influencing the efficacy of electromagnetic shielding in X band frequency range

    Directory of Open Access Journals (Sweden)

    Vida Zaroushani

    2016-12-01

    Full Text Available Introduction: Due to the importance of engineering controls for prevention of microwave exposure, this study was conducted to design and constract a novel electromagnetic shielding and also to examine the factors influencing shielding efficacy in X band frequency range. Material and Method: This study used Resin Epoxy as matrix and nano-Nickel Oxide as filler to prepare the composite plates with three different thicknesses (2,4, and 6 mm and four different weight percentages (5,7,9 and 11. The fabricated composites characterized using X-ray diffraction and Field Emission Scanning Electron microscopy. Shielding effectiveness, percolation depth, and percolation threshold were measured using Vector Network Analyzers. Thermal Gravimetric Analysis was conducted to study the temperature influence on weight loss for fabricated composites. Result: A maximum shielding effectiveness value of 84.18% was obtained for the 11%-6mm composite at 8.01 GHz and the 7%-4mm composite exhibits a higher average of shielding effectiveness of 66.72% at X- band frequency range. The 4mm thickness was optimum and critical diameter for composite plates; and percolation depth was obtained greater than thickness of composites. However, increasing the nickel oxide content did not show noticeable effect on the shielding effectiveness. Thermal Gravimetric Analysis showed that the study shields were resistant to temperature up to 150 °C without experiencing weight loss. What is more, the results indicated that Nickel oxide Nano particles had desirable distribution and dispersion in epoxy matrix and percolation threshold was appeared in low content of nickel oxide nanoparticles. Conclusion: A novel electromagnetic shield using low thickness and few content of nanoparticle with noticeable efficacy was properly designed and constructed in the field of occupational health. In addition, this shield has low cost, easy to manufacture, resistance to wet/corrosion, and low weight. Epoxy

  7. Shielding Effectiveness of a Thin Film Window

    National Research Council Canada - National Science Library

    Johnson, Eric

    1998-01-01

    .... The predicted shielding effectiveness was 29 dB based on theoretical calculations. The error analysis of the shielding effectiveness showed that this predicted value was within the measurement error...

  8. Gonadal Shielding in Radiography: A Best Practice?

    Science.gov (United States)

    Fauber, Terri L

    2016-11-01

    To investigate radiation dose to phantom testes with and without shielding. A male anthropomorphic pelvis phantom was imaged with thermoluminescent dosimeters (TLDs) placed in the right and left detector holes corresponding to the testes. Ten exposures were made of the pelvis with and without shielding. The exposed TLDs were packaged securely and mailed to the University of Wisconsin Calibration Laboratory for reading and analysis. A t test was calculated for the 2 exposure groups (no shield and shielded) and found to be significant, F = 8.306, P shield was used during pelvic imaging. Using a flat contact shield during imaging of the adult male pelvis significantly reduces radiation dose to the testes. Regardless of the contradictions in the literature on gonadal shielding, the routine practice of shielding adult male gonads during radiographic imaging of the pelvis is a best practice. © 2016 American Society of Radiologic Technologists.

  9. Infinite slab-shield dose calculations

    International Nuclear Information System (INIS)

    Russell, G.J.

    1989-01-01

    I calculated neutron and gamma-ray equivalent doses leaking through a variety of infinite (laminate) slab-shields. In the shield computations, I used, as the incident neutron spectrum, the leakage spectrum (<20 MeV) calculated for the LANSCE tungsten production target at 90 degree to the target axis. The shield thickness was fixed at 60 cm. The results of the shield calculations show a minimum in the total leakage equivalent dose if the shield is 40-45 cm of iron followed by 20-15 cm of borated (5% B) polyethylene. High-performance shields can be attained by using multiple laminations. The calculated dose at the shield surface is very dependent on shield material. 4 refs., 4 figs., 1 tab

  10. Using glass as a shielding material

    International Nuclear Information System (INIS)

    Yousef, S.

    2002-04-01

    Different theoretical and technological concepts and problems in using glass as a shielding material was discussed, some primarily designs for different types of radiation shielding windows were illustrated. (author)

  11. Using glass as a shielding material

    International Nuclear Information System (INIS)

    Yousef, S.

    2003-01-01

    Different theoretical and technological concepts and problems in using glass as a shielding material was discussed, some primarily designs for different types of radiation shielding windows were illustrated. (author)

  12. The effects of compound danshen dripping pills and human umbilical cord blood mononuclear cell transplant after acute myocardial infarction.

    Science.gov (United States)

    Jun, Yi; Chunju, Yuan; Qi, Ai; Liuxia, Deng; Guolong, Yu

    2014-04-01

    The low frequency of survival of stem cells implanted in the myocardium after acute myocardial infarction may be caused by inflammation and oxidative stress in the myocardial microenvironment. We evaluated the effects of a traditional Chinese medicine, Compound Danshen Dripping Pills, on the cardiac microenvironment and cardiac function when used alone or in combination with human umbilical cord blood mononuclear cell transplant after acute myocardial infarction. After surgically induced acute myocardial infarction, rabbits were treated with Compound Danshen Dripping Pills alone or in combination with human umbilical cord blood mononuclear cell transplant. Evaluation included histology, measurement of left ventricular ejection fraction and fractional shortening, leukocyte count, count of green fluorescent protein positive cells, superoxide dismutase activity, and malondialdehyde content. Combination treatment with Compound Danshen Dripping Pills and human umbilical cord blood mononuclear cell transplant significantly increased the survival of implanted cells, inhibited cardiac cell apoptosis, decreased oxidative stress, decreased the inflammatory response, and improved cardiac function. Rabbits treated with either Compound Danshen Dripping Pills or human umbilical cord blood mononuclear cells alone had improvement in these effects compared with untreated control rabbits. Combination therapy with Compound Danshen Dripping Pills and human umbilical cord blood mononuclear cells may improve cardiac function and morphology after acute myocardial infarction.

  13. Cloud shading and fog drip influence the metabolism of a coastal pine ecosystem.

    Science.gov (United States)

    Carbone, Mariah S; Park Williams, A; Ambrose, Anthony R; Boot, Claudia M; Bradley, Eliza S; Dawson, Todd E; Schaeffer, Sean M; Schimel, Joshua P; Still, Christopher J

    2013-02-01

    Assessing the ecological importance of clouds has substantial implications for our basic understanding of ecosystems and for predicting how they will respond to a changing climate. This study was conducted in a coastal Bishop pine forest ecosystem that experiences regular cycles of stratus cloud cover and inundation in summer. Our objective was to understand how these clouds impact ecosystem metabolism by contrasting two sites along a gradient of summer stratus cover. The site that was under cloud cover ~15% more of the summer daytime hours had lower air temperatures and evaporation rates, higher soil moisture content, and received more frequent fog drip inputs than the site with less cloud cover. These cloud-driven differences in environmental conditions translated into large differences in plant and microbial activity. Pine trees at the site with greater cloud cover exhibited less water stress in summer, larger basal area growth, and greater rates of sap velocity. The difference in basal area growth between the two sites was largely due to summer growth. Microbial metabolism was highly responsive to fog drip, illustrated by an observed ~3-fold increase in microbial biomass C with increasing summer fog drip. In addition, the site with more cloud cover had greater total soil respiration and a larger fractional contribution from heterotrophic sources. We conclude that clouds are important to the ecological functioning of these coastal forests, providing summer shading and cooling that relieve pine and microbial drought stress as well as regular moisture inputs that elevate plant and microbial metabolism. These findings are important for understanding how these and other seasonally dry coastal ecosystems will respond to predicted changes in stratus cover, rainfall, and temperature. © 2012 Blackwell Publishing Ltd.

  14. Shielding and grounding in large detectors

    International Nuclear Information System (INIS)

    Radeka, V.

    1998-09-01

    Prevention of electromagnetic interference (EMI), or ''noise pickup,'' is an important design aspect in large detectors in accelerator environments. Shielding effectiveness as a function of shield thickness and conductivity vs the type and frequency of the interference field is described. Noise induced in transmission lines by ground loop driven currents in the shield is evaluated and the importance of low shield resistance is emphasized. Some measures for prevention of ground loops and isolation of detector-readout systems are discussed

  15. Corrosion in power industry

    International Nuclear Information System (INIS)

    Ventakeshwarlu, K.S.

    1979-01-01

    A brief account of the problem areas encountered as a result of corrosion in the electrical power industry including nuclear power industry is given and some of the measures contemplated and/or implemented to control corrosion are outlined. The corrosion problems in the steam generators and cladding tubes of the nuclear power plant have an added dimension of radioactivation which leads to contamination and radiation field. Importance of monitoring water quality and controlling water chemistry by addition of chemicals is emphasised. (M.G.B.)

  16. Corrosion of reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-01-15

    Much operational experience and many experimental results have accumulated in recent years regarding corrosion of reactor materials, particularly since the 1958 Geneva Conference on the Peaceful Uses of Atomic Energy, where these problems were also discussed. It was, felt that a survey and critical appraisal of the results obtained during this period had become necessary and, in response to this need, IAEA organized a Conference on the Corrosion of Reactor Materials at Salzburg, Austria (4-9 June 1962). It covered many of the theoretical, experimental and engineering problems relating to the corrosion phenomena which occur in nuclear reactors as well as in the adjacent circuits

  17. Simulated oxygen isotopes in cave drip water and speleothem calcite in European caves

    Directory of Open Access Journals (Sweden)

    A. Wackerbarth

    2012-11-01

    Full Text Available Interpreting stable oxygen isotope (δ18O records from stalagmites is still one of the complex tasks in speleothem research. Here, we present a novel model-based approach, where we force a model describing the processes and modifications of δ18O from rain water to speleothem calcite (Oxygen isotope Drip water and Stalagmite Model – ODSM with the results of a state-of-the-art atmospheric general circulation model enhanced by explicit isotope diagnostics (ECHAM5-wiso. The approach is neither climate nor cave-specific and allows an integrated assessment of the influence of different varying climate variables, e.g. temperature and precipitation amount, on the isotopic composition of drip water and speleothem calcite.

    First, we apply and evaluate this new approach under present-day climate conditions using observational data from seven caves from different geographical regions in Europe. Each of these caves provides measured δ18O values of drip water and speleothem calcite to which we compare our simulated isotope values. For six of the seven caves modeled δ18O values of drip water and speleothem calcite are in good agreement with observed values. The mismatch of the remaining caves might be caused by the complexity of the cave system, beyond the parameterizations included in our cave model.

    We then examine the response of the cave system to mid-Holocene (6000 yr before present, 6 ka climate conditions by forcing the ODSM with ECHAM5-wiso results from 6 ka simulations. For a set of twelve European caves, we compare the modeled mid-Holocene-to-modern difference in speleothem calcite δ18O to available measurements. We show that the general European changes are simulated well. However, local discrepancies are found, and might be explained either by a too low model resolution, complex local soil-atmosphere interactions affecting evapotranspiration or by cave specific factors

  18. Drip Sealing Grouting of Tunnels in Crystalline Rock: Conceptualisation and Technical Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Butron, Christian

    2012-07-01

    A conceptual model of the groundwater hydraulic conditions around the tunnel contour in ancient brittle crystalline rocks has been developed and verified. The general aim has been to reach an understanding of the groundwater conditions in and close to the tunnel roof where dripping takes place and to propose technical and practical strategies for waterproofing. Dripping is accompanied by ice growth and icicle formation in cold regions, creating additional problems such as shotcrete fall-outs, icicle fall-outs, damage to vehicles, damage to trains, etc. The methodology for the development of the conceptual model is based mainly on transmissivity determinations from short-duration hydraulic tests and analyses of the connectivity of the fracture structure by means of semi-variogram analysis. The determination of the dimensionality of the flow in the fractures has also been found to be essential in order to describe the conductive system. This conceptual model describes the fracture systems as a combination of transmissive patches (2D-flow fractures) connected by less pervious channels (1D-flow fractures). It provides an understanding of the heterogeneity and connectivity of the fracture network and thus the groundwater conditions, not only in the roof but also around the tunnel contour. The pre-excavation grouting design process used in the tunnelling projects followed a structured approach and the evaluation showed that the grouting design reduced the inflow and fulfilled the environmental demands. However, dripping remained, making its characterisation very important when proposing a possible solution for its control. It is proposed that the remaining dripping comes from a channelised system that has been left unsealed and which would be extremely difficult to intersect with future boreholes, as well as from some ungrouted fractures with inconvenient orientations. Geomembrane lining and post-excavation grouting are possible solutions, although particular attention

  19. Modelling reinforcement corrosion in concrete

    DEFF Research Database (Denmark)

    Michel, Alexander; Geiker, Mette Rica; Stang, Henrik

    2012-01-01

    A physio-chemical model for the simulation of reinforcement corrosion in concrete struc-tures was developed. The model allows for simulation of initiation and subsequent propaga-tion of reinforcement corrosion. Corrosion is assumed to be initiated once a defined critical chloride threshold......, a numerical example is pre-sented, that illustrates the formation of corrosion cells as well as propagation of corrosion in a reinforced concrete structure....

  20. Corrosion of PWR steam generators

    International Nuclear Information System (INIS)

    Garnsey, R.

    1979-01-01

    Some designs of pressurized water reactor (PWR) steam generators have experienced a variety of corrosion problems which include stress corrosion cracking, tube thinning, pitting, fatigue, erosion-corrosion and support plate corrosion resulting in 'denting'. Large international research programmes have been mounted to investigate the phenomena. The operational experience is reviewed and mechanisms which have been proposed to explain the corrosion damage are presented. The implications for design development and for boiler and feedwater control are discussed. (author)

  1. Pretinning Nickel-Plated Wire Shields

    Science.gov (United States)

    Igawa, J. A.

    1985-01-01

    Nickel-plated copper shielding for wires pretinned for subsequent soldering with help of activated rosin flux. Shield cut at point 0.25 to 0.375 in. (6 to 10 mm) from cut end of outer jacket. Loosened end of shield straightened and pulled toward cut end. Insulation of inner wires kept intact during pretinning.

  2. Computed tomography shielding methods: a literature review.

    Science.gov (United States)

    Curtis, Jessica Ryann

    2010-01-01

    To investigate available shielding methods in an effort to further awareness and understanding of existing preventive measures related to patient exposure in computed tomography (CT) scanning. Searches were conducted to locate literature discussing the effectiveness of commercially available shields. Literature containing information regarding breast, gonad, eye and thyroid shielding was identified. Because of rapidly advancing technology, the selection of articles was limited to those published within the past 5 years. The selected studies were examined using the following topics as guidelines: the effectiveness of the shield (percentage of dose reduction), the shield's effect on image quality, arguments for or against its use (including practicality) and overall recommendation for its use in clinical practice. Only a limited number of studies have been performed on the use of shields for the eyes, thyroid and gonads, but the evidence shows an overall benefit to their use. Breast shielding has been the most studied shielding method, with consistent agreement throughout the literature on its effectiveness at reducing radiation dose. The effect of shielding on image quality was not remarkable in a majority of studies. Although it is noted that more studies need to be conducted regarding the impact on image quality, the currently published literature stresses the importance of shielding in reducing dose. Commercially available shields for the breast, thyroid, eyes and gonads should be implemented in clinical practice. Further research is needed to ascertain the prevalence of shielding in the clinical setting.

  3. BRH Gonad Shielding Program: where it has led

    International Nuclear Information System (INIS)

    Arcarese, J.S.

    1975-01-01

    Some topics discussed are: Bureau of Radiological Health guidelines; types of gonad shields; specific area shielding; gonad shielding guidelines; and publication of pamphlet on types of shields and circumstances under which they should be used

  4. Fire-side corrosion in power-station boilers

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, A J.B.; Flatley, T; Hay, K A

    1978-10-01

    The steel tubing of a modern power-station boiler operates at up to 650/sup 0/C (a dull red heat) in the very corrosive environment produced by the combustion gases and ash particles. Within the tubes, whose walls are around 5mm thick, 2000 tons of steam are generated per hour at temperatures up to 565/sup 0/C and pressures up to 170 bar. Several forms of metal corrosion may occur on the fireside surface of these tubes and on other boiler components. The designed 20-year operating life of the stainless-steel superheater and reheater tubes can be much reduced at temperatures above 600/sup 0/C by attack from molten salts formed beneath the deposited ash on the upstream tube surfaces. Mild steel evaporator tubes lining the furnace wall may suffer similarly if flame impingement allows the local release of volatile chlorine compounds from coal particles on the tube surface. Uncooled metal components supporting and aligning the boiler tubes may reach 1000/sup 0/C and are particularly susceptible to corrosion. CEGB research effort has been applied to quantify the rate of corrosion and to obtain an understanding of the complex corrosion mechanisms, so that ways of minimizing or preventing their occurrence may be found. These include the optimization of the combustion chemistry, design modifications such as shielding certain vulnerable tubes, and the selection of improved alloys and the use of ''co-extruded'' tubing.

  5. Survivor shielding. Part A. Nagasaki factory worker shielding

    International Nuclear Information System (INIS)

    Santoro, Robert T.; Barnes, John M.; Azmy, Yousry Y.; Kerr, George D.; Egbert, Stephen D.; Cullings, Harry M.

    2005-01-01

    Recent investigations based on conventional chromosome aberration data by the RERF suggest that the DS86 doses received by many Nagasaki factory workers may have been overestimated by as much as 40% relative to those for other survivors in Japanese-type houses and other shielding configurations (Kodama et al. 2001). Since the factory workers represent about 25% of the Nagasaki survivors with DS86 doses in excess of 0.5 Gy (50 rad), systematic errors in their dose estimates can have a major impact on the risk coefficients from RERF studies. The factory worker doses may have been overestimated for a number of reasons. The calculation techniques, including the factory building modeling, weapon source spectra and cross-section data used in the DS86 shielding calculations were not detailed enough to replicate actual conditions. The models used did not take into account local shielding provided by machinery, tools, and the internal structure in the buildings. In addition, changes in the disposition of shielding following collapse of the building by the blast wave were not considered. The location of large factory complexes may be uncertain, causing large numbers of factory survivors, correctly located relative to each other, to be uniformly too close to the hypocenter. Any or all of these reasons are sufficient to result in an overestimate of the factory worker doses. During the DS02 studies, factory worker doses have been reassessed by more carefully modeling the factory buildings, incorporating improved radiation transport methods and cross-section data and using the most recent bomb leakage spectra (Chapter 2). Two-dimensional discrete ordinates calculations were carried out initially to estimate the effects of workbenches and tools on worker doses to determine if the inclusion of these components would, in fact, reduce the dose by amounts consistent with the RERF observations (Kodama et al. 2001). (author)

  6. Characteristics and influencing factors of crop coefficient for drip-irrigated cotton under plastic mulch conditions in arid environment

    DEFF Research Database (Denmark)

    Ai, Zhipin; Yang, Yonghui; Wang, Qinxue

    2017-01-01

    agronomy practice such as plastic mulching and drip irrigation in arid environments. This study calculated and analyzed Kc of a drip-irrigated and plastic-mulched cotton field in Aksu Oasis of the arid Tarim River Basin, China, and its relationships with several crop-, soil- and management variables......-mulched condition already published, the Kc of mulched cotton for the entire growth season decreased by 16 to 39%. The largest reductions in Kc due to plastic mulch were found in the initial and developmental growth stage. Kc could be calculated by a third-degree polynomial model in relation to RGD, which...... significantly increased Kc, i.e., 29% on average, partly due to arid advection. This study provided up-to-date and detailed information on cotton crop coefficient under plastic mulching and drip irrigation conditions in arid environment, and it is useful for improved management of agricultural water resources....

  7. Pairing in exotic neutron-rich nuclei near the drip line and in the crust of neutron stars

    Science.gov (United States)

    Pastore, A.; Margueron, J.; Schuck, P.; Viñas, X.

    2013-09-01

    Exotic and drip-line nuclei as well as nuclei immersed in a low-density gas of neutrons in the inner crust of neutron stars are systematically investigated with respect to their neutron pairing properties. This is done using Skyrme density-functional and different pairing forces such as a density-dependent contact interaction and a separable form of a finite-range Gogny interaction. Hartree-Fock-Bogoliubov (HFB) and Bardeen-Cooper-Schrieffer (BCS) theories are compared. It is found that neutron pairing is reduced towards the drip line while overcast by strong shell effects. Furthermore, resonances in the continuum can have an important effect counterbalancing the tendency of reduction and leading to a persistence of pairing at the drip line. It is also shown that in these systems the difference between HFB and BCS approaches can be quantitatively large.

  8. Corrosion of valve metals

    International Nuclear Information System (INIS)

    Draley, J.E.

    1976-01-01

    A general survey related to the corrosion of valve metals or film-forming metals. The way these metals corrode with some general examples is described. Valve metals form relatively perfect oxide films with little breakdown or leakage when anodized

  9. Corrosion in Electronics

    DEFF Research Database (Denmark)

    Ambat, Rajan; Gudla, Helene Virginie Conseil; Verdingovas, Vadimas

    2017-01-01

    Electronic control units, power modules, and consumer electronics are used today in a wide variety of varying climatic conditions. Varying external climatic conditions of temperature and humidity can cause an uncontrolled local climate inside the device enclosure. Uncontrolled humidity together...... and high density packing combined with the use of several materials, which can undergo electrochemical corrosion in the presence of water film formed due to humidity exposure and bias conditions on the PCBA surface. This article provides a short review of the corrosion reliability issues of electronics due...... to the use of electronics under varying humidity conditions. Important PCBA aspects, which are fundamental to the corrosion cell formation under humid conditions, are discussed. Effect of hygroscopic residues from the process and service and their role in assisting water film build up and corrosion...

  10. Microbiologically Influenced Corrosion

    Science.gov (United States)

    2009-01-01

    species grow as multicel- lular filaments called hyphae forming a mycelium, some fungal species also grow as single cells. Sexual and asexual...reinforced fluorinated 18 MICROBIOLOGICALLY INFLUENCED CORROSION polyimide composites due to hyphae penetration into resin interiors. The

  11. Carbon Dioxide Corrosion:

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup

    2008-01-01

    CO2 corrosion is a general problem in the industry and it is expensive. The focus of this study is an oil gas production related problem. CO2 corrosion is observed in offshore natural gas transportation pipelines. A general overview of the problem is presented in chapter 1. The chemical system...... with the basic thermodynamics of electrolytes in chapter 2, the extension and general description of electrolyte mass transport in chapter 3, and the electrochemical kinetics of corrosion in chapter 4. A literature overview of CO2 corrosion is shown in chapter 5 and possible extensions of the models...... and validated against heat capacity data. The model is also fitted to experimental data produced and shown in chapter 8 for SLE in the Na2CO3-NaHCO3-MEG-H2O system. The application of the above model is shown in chapter 9. Here the thermodynamic correction factors are calculated. These show how the diffusion...

  12. BWR steel containment corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C.P.; Bagchi, G.

    1996-04-01

    The report describes regulatory actions taken after corrosion was discovered in the drywell at the Oyster Creek Plant and in the torus at the Nine Mile Point 1 Plant. The report describes the causes of corrosion, requirements for monitoring corrosion, and measures to mitigate the corrosive environment for the two plants. The report describes the issuances of generic letters and information notices either to collect information to determine whether the problem is generic or to alert the licensees of similar plants about the existence of such a problem. Implementation of measures to enhance the containment performance under severe accident conditions is discussed. A study by Brookhaven National Laboratory (BNL) of the performance of a degraded containment under severe accident conditions is summarized. The details of the BNL study are in the appendix to the report.

  13. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  14. Corrosion of beryllium

    International Nuclear Information System (INIS)

    Mueller, J.J.; Adolphson, D.R.

    1987-01-01

    The corrosion behavior of beryllium in aqueous and elevated-temperature oxidizing environments has been extensively studied for early-intended use of beryllium in nuclear reactors and in jet and rocket propulsion systems. Since that time, beryllium has been used as a structural material in les corrosive environments. Its primary applications include gyro systems, mirror and reentry vehicle structures, and aircraft brakes. Only a small amount of information has been published that is directly related to the evaluation of beryllium for service in the less severe or normal atmospheric environments associated with these applications. Despite the lack of published data on the corrosion of beryllium in atmospheric environments, much can be deduced about its corrosion behavior from studies of aqueous corrosion and the experiences of fabricators and users in applying, handling, processing, storing, and shipping beryllium components. The methods of corrosion protection implemented to resist water and high-temperature gaseous environments provide useful information on methods that can be applied to protect beryllium for service in future long-term structural applications

  15. Development, yield and quality attributes of sugarcane cultivars fertigated by subsurface drip irrigation

    Directory of Open Access Journals (Sweden)

    André L. B. de O. Silva

    2016-06-01

    Full Text Available ABSTRACT The present study aimed to evaluate the development, yield and quality of four sugarcane cultivars fertigated by subsurface drip system. The experiment was carried out in Campinas-SP, Brazil, from January 2012 to November 2013, with the cultivars SP79-1011, IACSP94-2101, IACSP94-2094 and IACSP95-5000 subjected to daily irrigations. The irrigations depths were applied to bring soil moisture to field capacity. Soil moisture was monitored using soil moisture probes. Samples were collected along the crop cycle in order to evaluate crop development and yield, at the end of the first and second ratoons. Stalk height showed good correlation for the estimation of crop yield, with R2 equal to or higher than 0.96. The cultivar IACSP95-5000 showed the highest yield in the first ratoon. In the second ratoon the highest yield was observed in IACSP94-2101, followed by IACSP95-5000 and SP79-1011. Considering the yield results associated with the technological analysis, such as soluble solids content and apparent sucrose, the cultivar IACSP95-5000 excelled the others in the cultivation under subsurface drip irrigation.

  16. Properties of Fe, Ni and Zn isotopes near the drip-lines

    International Nuclear Information System (INIS)

    Tarasov, V.N.; Tarasaov, D.V.; Gridnev, K.A.; Gridnev, D.K.; Kartavenko, V.G.; Greiner, W.

    2008-01-01

    The position of the neutron and proton drip-lines as well as properties of the isotopes Fe, Ni and Zn with neutron excess and neutron deficit are studied within the Hartree–Fock approach with the Skyrme interaction (Ska, SkM*, Sly4). The pairing is taken into account on the basis of the BCS approach with the pairing constant G = (19.5/A)[1 ± 0.51(N-Z)/A]. Our calculations predict that for Ni isotopes around N = 62 there appears a sudden increase of the deformation parameter up to β = 0.4. The zone with such big deformation, where Ni isotopes are stable against one neutron emission stretches up to N = 78. The magic numbers effects for the isotopes 48 Ni, 56 Ni, 78 Ni, 110 Ni are discussed. The universality of the reasons standing behind the enhancement of stability of the isotopes 40 O and 110 Ni which are beyond the drip-line is demonstrated. Calculated values of the two-neutron separation energy, and proton and neutron root mean square radii for the chain of Ni isotopes show a good agreement with existing Hartree–Fock–Bogoliubov calculations of these values. (author)

  17. Distribution of the root system of peach palm under drip irrigation

    Directory of Open Access Journals (Sweden)

    Adriano da Silva Lopes

    2014-07-01

    Full Text Available The incorporation of technologies has resulted in increased productivity and the more rational management of peach palm, with irrigation being an important tool for certain regions. Thus, studies leading to proper crop management are extremely important, such as the estimate of the effective depth of the root system, which is indispensable for proper irrigation management. The objective of this study was to evaluate the effects of different irrigation depths, as applied by drip irrigation, on the distribution of the root system of peach palm. This experiment was conducted in Ilha Solteira, São Paulo State, Brazil, with drip irrigation, with the two systems (flow of 0.0023 m3 h-1 consisting of four irrigation treatments corresponding to 0, 50, 100 and 150% of Class ‘A’ pan evaporation. After five years, an analysis of the Bactris gasipaes root system was performed at a distance of 0.0, 0.5 and 1.0 meters from the trunk, collecting sampling at two depths (0.0 to 0.3 m and 0.3 to 0.6 m via the auger method (volumetric analysis. We concluded that the effective depth of the root system used for irrigation management should be a maximum of 0.3 meters.

  18. A Wireless Low Power Valve Controller for Drip Irrigation Control Systems

    Directory of Open Access Journals (Sweden)

    Haijiang Tai

    2014-03-01

    Full Text Available Drip irrigation control systems in fields generally include a large number of sensors and valves; controlling these devices efficiently can be achieved by using distributed irrigation control (DIC, which has the advantages of reduced wiring and piping costs and easier installation and maintenance. In this study, a wireless low power valve controller for drip irrigation control systems was developed and tested. The specific tasks included the controller design (hardware and software, energy consumption tests, and field tests. The controller uses the highly integrated JN5139 module, which is based on IEEE802.15.4, for hardware design; low power consumption sleep algorithms for software design; and two alkaline batteries for supply of power to the valve controller. Results of laboratory and field tests show continuous working days of the valve controller powered by two alkaline batteries are at least 3 months under different sleep periods and frequencies of valve control. The controller described here is characterized as reliable, low cost, easy to install, and having low power consumption.

  19. Reactions and single-particle structure of nuclei near the drip lines

    International Nuclear Information System (INIS)

    Hansen, P.G.; Sherrill, B.M.

    2001-01-01

    The techniques that have allowed the study of reactions of nuclei situated at or near the neutron or proton drip line are described. Nuclei situated just inside the drip line have low nucleon separation energies and, at most, a few bound states. If the angular momentum in addition is small, large halo states are formed where the wave function of the valency nucleon extends far beyond the nuclear radius. We begin with examples of the properties of nuclear halos and of their study in radioactive-beam experiments. We then turn to the continuum states existing above the particle threshold and also discuss the possibility of exciting them from the halo states in processes that may be thought of as 'collateral damage'. Finally, we show that the experience from studies of halo states has pointed to knockout reactions as a new way to perform spectroscopic studies of more deeply bound non-halo states. Examples are given of measurements of l values and spectroscopic factors

  20. Evaluation of different methods of measuring evapotranspiration as a scheduling guide for drip-irrigated cotton

    International Nuclear Information System (INIS)

    Rawitz, E.; Marani, A.; Mahrer, Y.; Berkovich, D.

    1983-01-01

    Evapotranspiration in a drip-irrigated cotton field was estimated by the energy balance method, net radiation, standard evaporation pan, evaporation pan in the field at canopy height, and by the Penman equation, and the results were compared with the soil-water balance based on neutron meter and tensiometer data from seven observation sites. Evapotranspiration according to the soil-water balance was only about 85% of that determined by the energy balance method, and this is attributed to the fact that irrigation laterals were placed every second row, and the soil-water balance was determined in the irrigated rows. The crop also utilized moisture stored from winter rains in the unirrigated inter-row spaces, which was detected by the energy balance method. Actual evapotranspiration (ET) was 96% of potential ET (Penman), and the latter equalled 98% of net radiation energy. The actual ET equalled 90% of free water evaporation from the pan in the field at canopy height, and 88% of net radiation. The high-frequency drip regime maintained ET very close to potential ET, and under these conditions the field-installed evaporation pan, or the net radiometer, are good indicators of crop water use, with the latter being adaptable to computer-controlled irrigation. (author)

  1. Drip and Surface Irrigation Water Use Efficiency of Tomato Crop Using Nuclear Techniques

    International Nuclear Information System (INIS)

    Mellouli, H.J.; Askri, H.; Mougou, R.

    2003-01-01

    Nations in the arid and semi-arid regions, especially the Arab countries, will have to take up an important challenge at the beginning of the 21 st century: increasing food production in order to realise food security for growing population, wile optimising the use of limited water resources. Using and adapting management techniques like the drip irrigation system could obtain the later. This would allow reduction in water losses by bare soil evaporation and deep percolation. Consequently improved water use efficiency could be realised. In this way, this work was conducted as a contribution on the Tunisian national programs on the optimisation of the water use. By mean a field study at Cherfech Experimental Station (30 km from Tunis), the effect of the irrigation system on the water use efficiency (WUE)-by a season tomato crop-was monitored by comparing three treatments receiving equivalent quantities of fertiliser: Fertigation, Drip irrigation and Furrow irrigation. Irrigation was scheduled by mean calculation of the water requirement based on the agro meteorological data, the plant physiological stage and the soil water characteristics (Clay Loam). The plant water consumption (ETR) was determined by using soil water balance method, where rainfall and amount of irrigation water readily measured

  2. Dynamic plant uptake model applied for drip irrigation of an insecticide to pepper fruit plants.

    Science.gov (United States)

    Legind, Charlotte N; Kennedy, Coleen M; Rein, Arno; Snyder, Nathan; Trapp, Stefan

    2011-05-01

    Drip application of insecticides is an effective way to deliver the chemical to the plant that avoids off-site movement via spray drift and minimizes applicator exposure. The aim of this paper is to present a cascade model for the uptake of pesticide into plants following drip irrigation, its application for a soil-applied insecticide and a sensitivity analysis of the model parameters. The model predicted the measured increase and decline of residues following two soil applications of an insecticide to peppers, with an absolute error between model and measurement ranging from 0.002 to 0.034 mg kg fw(-1). Maximum measured concentrations in pepper fruit were approximately 0.22 mg kg fw(-1). Temperature was the most sensitive component for predicting the peak and final concentration in pepper fruit, through its influence on soil and plant degradation rates. Repeated simulations of pulse inputs with the cascade model adequately describe soil pesticide applications to an actual cropped system and reasonably mimic it. The model has the potential to be used for the optimization of practical features, such as application rates and waiting times between applications and before harvest, through the integrated accounting of soil, plant and environmental influences. Copyright © 2011 Society of Chemical Industry.

  3. Sorption of pathogens during sub-surface drip irrigation with wastewater

    Science.gov (United States)

    Levi, Laillach; Gillerman Gillerman, Leonid; Kalavrouziotis, Ioannis; Oron, Gideon

    2017-04-01

    Water scarcity continues to be one of the major threats to human survival in many regions worldwide, such as Africa, the Mediterranean Basin, the State of California in the US. Due to a mixture of factors such as population growth, reduction in water resources availability and higher demand for high quality waters in these regions these countries face water shortage issues that stem from overuse, extensive extraction of groundwater, and frequent drought events. In addition, there are increases in environmental and health awareness that have led to intensive efforts in the treatment and reuse of nonconventional water sources, mainly wastewater and greywater. One approach to water shortages issues is to use wastewater as means to close the gap between supply and demand. However, the need to treat wastewater and to disinfect it forces additional economic burden on the users, primarily for agricultural irrigation. A possible solution might be to use the soil as a sorbent for the contained pathogens. Under sub-surface drip irrigation, not allowing the wastewater to reach the soil surface, the pathogens will remain in the soil. It was as well shown in field experiments that the opening size of roots will not allow pathogens to penetrate into the plants. Additional advantages such as water saving, protection of the pipe systems and others are also important. Field experiments in commercial fields just emphasize the main advantages of sub-surface drip irrigation.

  4. Design development and testing of a solar PV pump based drip system for orchards

    Energy Technology Data Exchange (ETDEWEB)

    Pande, P.C.; Singh, A.K.; Ansari, S.; Vyas, S.K.; Dave, B.K. [Central Arid Zone Research Inst., Jodhpur (India)

    2003-03-01

    A Solar Photovoltaic (PV) pump operated drip irrigation system has been designed and developed for growing orchards in arid region considering different design parameters like pumps size, water requirements, the diurnal variation in the pressure of the pump due to change in irradiance and pressure compensation in the drippers. The system comprising a PV pump with 900 W{sub p} PV array and 800 W dc motor-pump mono-block, microfilter, main and sub-mains and three open-able low-pressure compensating drippers on each plant was field tested. The emission uniformity was observed to be 92-94% with discharge of 3.8 l/h in the pressure range of 70-100 kPa provided by the pump and thus the system could irrigate some 1 ha area within 2 h. Based on the performance of the PV pump and the drip system, it was inferred that about 5 ha area of orchard could be covered. The projected benefit-cost ratio for growing pomegranate orchards with such a system was evaluated to be above 2 even with the costly PV pump and therefore the system was considered to be an appropriate technology for the development of arid region. (Author)

  5. Drip Irrigation Aided Phytoremediation for Removal of TCE FR-om Groundwater

    International Nuclear Information System (INIS)

    Wilde, E.W.

    2003-01-01

    Groundwater in D-Area at the Savannah River Site (SRS) is contaminated with trichloroethylene (TCE) and by-products resulting FR-om discharges of this organic solvent during past disposal practices. This contaminated groundwater occurs primarily at depths of 9 meters to 15 meters below ground surface, well below the depths that are typically penetrated by plant roots. The process investigated in this study involved pumping water FR-om the contaminated aquifer and discharging the water into overlying test plots two inches below the surface using drip irrigation. The field treatability study was conducted FR-om 8/31/00 to 4/18/02 using six 0.08 hectare test plots, two each containing pines, cottonwoods, and no vegetation (controls). The primary objective was to determine the overall effectiveness of the process for TCE removal and to determine the principal biotic and abiotic pathways for its removal. Results demonstrated that the process provides a viable method to remove TCE-contaminated groundwater. The data clearly showed that the presence of trees reduced volatilization of TCE FR-om the drip irrigation system to the atmosphere. Influent groundwater TCE concentrations averaging 89 mg/L were reduced to non-detectable levels (less than 5 mg/L) within the upper two feet of soil (rhizosphere)

  6. Developing a Hybrid Solar/Wind Powered Drip Irrigation System for Dragon Fruit Yield

    Science.gov (United States)

    Widiastuti, I.; Wijayanto, D. S.

    2017-03-01

    Irrigation operations take a large amount of water and energy which impact to total costs of crop production. Development of an efficient irrigation supplying precise amount of water and conserving the use of energy can have benefits not only by reducing the operating costs but also by enhancing the farmland productivity. This article presents an irrigation method that promotes sustainable use of water and energy appropriate for a developing tropical country. It proposes a drip irrigation system supported by a combined solar-wind electric power generation system for efficient use of water in dragon fruit cultivation. The electric power generated is used to drive a water pump filling a storage tank for irrigating a 3000 m2 dragon fruit yield in Nguntoronadi, Wonogiri, Indonesia. In designing the irrigation system, the plant’s water requirement was identified based on the value of reference evapotranspiration of the area. A cost/benefit analysis was performed to evaluate the economic feasibility of the proposed scheme. The installation of this solar and wind drip irrigation helps provide sufficient quantity of water to each plant using renewable energy sources which reduce dependence on fossil fuel.

  7. Monitoring corrosion rates and localised corrosion in low conductivity water

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2006-01-01

    Monitoring of low corrosion rates and localised corrosion in a media with low conductivity is a challenge. In municipal district heating, quality control may be improved by implementing on-line corrosion monitoring if a suitable technique can be identified to measure both uniform and localised...... corrosion. Electrochemical techniques (LPR, EIS, crevice corrosion current) as well as direct measurement techniques (high-sensitive electrical resistance, weight loss) have been applied in operating plants. Changes in the corrosion processes are best monitored in non-aggressive, low conductivity media...

  8. New facility shield design criteria

    International Nuclear Information System (INIS)

    Howell, W.P.

    1981-07-01

    The purpose of the criteria presented here is to provide standard guidance for the design of nuclear radiation shields thoughout new facilities. These criteria are required to assure a consistent and integrated design that can be operated safely and economically within the DOE standards. The scope of this report is confined to the consideration of radiation shielding for contained sources. The whole body dose limit established by the DOE applies to all doses which are generally distributed throughout the trunk of the body. Therefore, where the whole body is the critical organ for an internally deposited radionuclide, the whole body dose limit applies to the sum of doses received must assure control of the concentration of radionuclides in the building atmosphere and thereby limit the dose from internal sources

  9. INERT GAS SHIELD FOR WELDING

    Science.gov (United States)

    Jones, S.O.; Daly, F.V.

    1958-10-14

    S>An inert gas shield is presented for arc-welding materials such as zirconium that tend to oxidize rapidly in air. The device comprises a rectangular metal box into which the welding electrode is introduced through a rubber diaphragm to provide flexibility. The front of the box is provided with a wlndow having a small hole through which flller metal is introduced. The box is supplied with an inert gas to exclude the atmosphere, and with cooling water to promote the solidification of the weld while in tbe inert atmosphere. A separate water-cooled copper backing bar is provided underneath the joint to be welded to contain the melt-through at the root of the joint, shielding the root of the joint with its own supply of inert gas and cooling the deposited weld metal. This device facilitates the welding of large workpieces of zirconium frequently encountered in reactor construction.

  10. Facility target insert shielding assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mocko, Michal [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-06

    Main objective of this report is to assess the basic shielding requirements for the vertical target insert and retrieval port. We used the baseline design for the vertical target insert in our calculations. The insert sits in the 12”-diameter cylindrical shaft extending from the service alley in the top floor of the facility all the way down to the target location. The target retrieval mechanism is a long rod with the target assembly attached and running the entire length of the vertical shaft. The insert also houses the helium cooling supply and return lines each with 2” diameter. In the present study we focused on calculating the neutron and photon dose rate fields on top of the target insert/retrieval mechanism in the service alley. Additionally, we studied a few prototypical configurations of the shielding layers in the vertical insert as well as on the top.

  11. Transient shielded liquid hydrogen containers

    International Nuclear Information System (INIS)

    Varghese, A.P.; Herring, R.H.

    1990-01-01

    The storage of hydrogen in the liquid phase has been limited in duration due to the thermal performance constraints of conventional Liquid Hydrogen containers available. Conventional Liquid Hydrogen containers lose hydrogen because of their relatively high heat leak and variations in usage pattern of hydrogen due to shutdowns. Local regulations also discourage venting of hydrogen. Long term storage of Liquid Hydrogen without product loss was usually accomplished using Liquid Nitrogen sacrificial shields. This paper reports on a new low heat leak container developed and patented that will extend the storage time of liquid hydrogen by five hundred percent. The principle of operation of the Transient Shields which makes the extraordinary performance of this container feasible is described in this paper. Also covered are the impact of this new container on present applications of hydrogen and the new opportunities afforded to Liquid hydrogen in the world hydrogen market

  12. Shielding calculational system for plutonium

    International Nuclear Information System (INIS)

    Zimmerman, M.G.; Thomsen, D.H.

    1975-08-01

    A computer calculational system has been developed and assembled specifically for calculating dose rates in AEC plutonium fabrication facilities. The system consists of two computer codes and all nuclear data necessary for calculation of neutron and gamma dose rates from plutonium. The codes include the multigroup version of the Battelle Monte Carlo code for solution of general neutron and gamma shielding problems and the PUSHLD code for solution of shielding problems where low energy gamma and x-rays are important. The nuclear data consists of built in neutron and gamma yields and spectra for various plutonium compounds, an automatic calculation of age effects and all cross-sections commonly used. Experimental correlations have been performed to verify portions of the calculational system. (23 tables, 7 figs, 16 refs) (U.S.)

  13. Radiation-shielding transparent material

    International Nuclear Information System (INIS)

    Kusumeki, Asao.

    1983-01-01

    Purpose : To obtain radiation-shielding transparent material having a high resistivity to the radioactive rays or light irradiation which is greater at least by two digits as compared with lead glass. Constitution : The shielding material is composed of a saturated aqueous solution zinc iodide. Zinc iodide (specific gravity of 4.2) is dissolved by 430 g into 100 cc of water at a temperature of 20 0 C and forms a heavy liquid with a specific gravity of 2.80. The radiation length of the heavy liquid is 3.8 cm which is 1.5 times as large as lead glass. The light transmission is greater than 95% in average. Furthermore, by adding hypophosphorous acid as a reducing agent to the aqueous solution of the lead iodide, the material is stabilized against the irradiation of light or radioactive rays and causes no discoloration for a long time. (Moriyama, K.)

  14. Installation of a shielded SIMS in CEA Cadarache

    International Nuclear Information System (INIS)

    Desgranges, L.; Pasquet, B.; Rasser, B.

    2002-01-01

    A shielded SIMS 6f has been installed in the LECA in 1999 and will examine nuclear fuels before the end of this year. Meanwhile several studies have been realised to test its technical performance for nuclear materials analysis. After a brief presentation of the design of the shielded SIMS, five examples of preliminary results will be underlined. In the nuclear field, SIMS is currently used for the analysis of Zircaloy cladding corrosion because it can detect light elements like boron or lithium. More than a quantitative measurement of isotopes, it was possible with our SIMS to produce a two dimension image of the corrosion layer focusing on the protective layer. SIMS has also the advantage to detect isotopes with a low concentration. This property will be enlightened with some results obtained on sulphur in UO 2 . Because SIMS uses the erosion of the sample surface, it is possible to make depth profile. This possibility will be demonstrated on water altered glass samples on which the altered layer will be evidenced on depth profile. The last application of SIMS presented in the paper is addressed to nuclear fuel with detection of xenon. Fission gases release is indeed of first importance for nuclear fuel because it affects fuel swelling, rod internal pressure, fuel thermal conductivity via the formation of pores etc. We have demonstrated that it was possible to measure xenon on an unirradiated UO 2 sample implanted with xenon. It was also proved that xenon could be measured in gaseous state, which would make possible the measurement of xenon filling pores. (author)

  15. Radiation shield vest and skirt

    International Nuclear Information System (INIS)

    Maine, G.J.

    1982-01-01

    A two-piece garment is described which provides shielding for female workers exposed to radiation. The upper part is a vest, overlapping and secured in the front by adjustable closures. The bottom part is a wraparound skirt, also secured by adjustable closures. The two parts overlap, thus providing continuous protection from shoulder to knee and ensuring that the back part of the body is protected as well as the front

  16. Handbook of radiation shielding data

    International Nuclear Information System (INIS)

    Courtney, J.C.

    1976-07-01

    This handbook is a compilation of data on units, conversion factors, geometric considerations, sources of radiation, and the attenuation of photons, neutrons, and charged particles. It also includes related topics in health physics. Data are presented in tabular and graphical form with sufficient narrative for a least first-approximation solutions to a variety of problems in nuclear radiation protection. Members of the radiation shielding community contributed the information in this document from unclassified and uncopyrighted sources, as referenced

  17. Corrosion and anticorrosion. Industrial practice

    International Nuclear Information System (INIS)

    Beranger, G.; Mazille, H.

    2002-01-01

    This book comprises 14 chapters written with the collaboration of about 50 French experts of corrosion. It is complementary to another volume entitled 'corrosion of metals and alloys' and published by the same editor. This volume comprises two parts: part 1 presents the basic notions of corrosion phenomena, the properties of surfaces, the electrochemical properties of corrosion etc.. Part 2 describes the most frequent forms of corrosion encountered in industrial environments and corresponding to specific problems of protection: marine environment, atmospheric corrosion, galvanic corrosion, tribo-corrosion, stress corrosion etc.. The first 8 chapters (part 1) treat of the corrosion problems encountered in different industries and processes: oil and gas production, chemical industry, phosphoric acid industry, PWR-type power plants, corrosion of automobile vehicles, civil engineering and buildings, corrosion of biomaterials, non-destructive testing for the monitoring of corrosion. The other chapters (part 2) deal with anticorrosion and protective coatings and means: choice of materials, coatings and surface treatments, thick organic coatings and enamels, paints, corrosion inhibitors and cathodic protection. (J.S.)

  18. Shielding wall for thermonuclear device

    International Nuclear Information System (INIS)

    Uchida, Takaho.

    1989-01-01

    This invention concerns shielding walls opposing to plasmas of a thermonuclear device and it is an object thereof to conduct reactor operation with no troubles even if a portion of shielding wall tiles should be damaged. That is, the shielding wall tiles are constituted as a dual layer structure in which the lower base tiles are connected by means of bolts to first walls. Further, the upper surface tiles are bolt-connected to the layer base tiles. In this structure, the plasma thermal loads are directly received by the surface layer tiles and heat is conducted by means of conduction and radiation to the underlying base tiles and the first walls. Even upon occurrence of destruction accidents to the surface layer tiles caused by incident heat or electromagnetic force upon elimination of plasmas, since the underlying base tiles remain as they are, the first walls constituted with stainless steels, etc. are not directly exposed to the plasmas. Accordingly, the integrity of the first walls having cooling channels can be maintained and sputtering intrusion of atoms of high atom number into the plasmas can be prevented. (I.S.)

  19. Design of ITER shielding blanket

    International Nuclear Information System (INIS)

    Furuya, Kazuyuki; Sato, Satoshi; Hatano, Toshihisa; Tokami, Ikuhide; Kitamura, Kazunori; Miura, Hidenori; Ito, Yutaka; Kuroda, Toshimasa; Takatsu, Hideyuki

    1997-05-01

    A mechanical configuration of ITER integrated primary first wall/shield blanket module were developed focusing on the welded attachment of its support leg to the back plate. A 100 mm x 150 mm space between the legs of adjacent modules was incorporated for the working space of welding/cutting tools. A concept of coolant branch pipe connection to accommodate deformation due to the leg welding and differential displacement of the module and the manifold/back plate during operation was introduced. Two-dimensional FEM analyses showed that thermal stresses in Cu-alloy (first wall) and stainless steel (first wall coolant tube and shield block) satisfied the stress criteria following ASME code for ITER BPP operation. On the other hand, three-dimensional FEM analyses for overall in-vessel structures exhibited excessive primary stresses in the back plate and its support structure to the vacuum vessel under VDE disruption load and marginal stresses in the support leg of module No.4. Fabrication procedure of the integrated primary first wall/shield blanket module was developed based on single step solid HIP for the joining of Cu-alloy/Cu-alloy, Cu-alloy/stainless steel, and stainless steel/stainless steel. (author)

  20. Photonic Bandgap (PBG) Shielding Technology

    Science.gov (United States)

    Bastin, Gary L.

    2007-01-01

    Photonic Bandgap (PBG) shielding technology is a new approach to designing electromagnetic shielding materials for mitigating Electromagnetic Interference (EM!) with small, light-weight shielding materials. It focuses on ground planes of printed wiring boards (PWBs), rather than on components. Modem PSG materials also are emerging based on planar materials, in place of earlier, bulkier, 3-dimensional PBG structures. Planar PBG designs especially show great promise in mitigating and suppressing EMI and crosstalk for aerospace designs, such as needed for NASA's Constellation Program, for returning humans to the moon and for use by our first human visitors traveling to and from Mars. Photonic Bandgap (PBG) materials are also known as artificial dielectrics, meta-materials, and photonic crystals. General PBG materials are fundamentally periodic slow-wave structures in I, 2, or 3 dimensions. By adjusting the choice of structure periodicities in terms of size and recurring structure spacings, multiple scatterings of surface waves can be created that act as a forbidden energy gap (i.e., a range of frequencies) over which nominally-conductive metallic conductors cease to be a conductor and become dielectrics. Equivalently, PBG materials can be regarded as giving rise to forbidden energy gaps in metals without chemical doping, analogous to electron bandgap properties that previously gave rise to the modem semiconductor industry 60 years ago. Electromagnetic waves cannot propagate over bandgap regions that are created with PBG materials, that is, over frequencies for which a bandgap is artificially created through introducing periodic defects

  1. Reactor vessel head permanent shield

    International Nuclear Information System (INIS)

    Hankinson, M.F.; Leduc, R.J.; Richard, J.W.; Malandra, L.J.

    1989-01-01

    A nuclear reactor is described comprising: a nuclear reactor pressure vessel closure head; control rod drive mechanisms (CRDMs) disposed within the closure head so as to project vertically above the closure head; cooling air baffle means surrounding the control rod drive mechanisms for defining cooling air paths relative to the control rod drive mechanisms; means defined within the periphery of the closure head for accommodating fastening means for securing the closure head to its associated pressure vessel; lifting lugs fixedly secured to the closure head for facilitating lifting and lowering movements of the closure head relative to the pressure vessel; lift rods respectively operatively associated with the plurality of lifting lugs for transmitting load forces, developed during the lifting and lowering movements of the closure head, to the lifting lugs; upstanding radiation shield means interposed between the cooling air baffle means and the periphery of the enclosure head of shielding maintenance personnel operatively working upon the closure head fastening means from the effects of radiation which may emanate from the control rod drive mechanisms and the cooling air baffle means; and connecting systems respectively associated with each one of the lifting lugs and each one of the lifting rods for connecting each one of the lifting rods to a respective one of each one of the lifting lugs, and for simultaneously connecting a lower end portion of the upstanding radiation shield means to each one of the respective lifting lugs

  2. ATLAS Award for Shield Supplier

    CERN Multimedia

    2004-01-01

    ATLAS technical coordinator Dr. Marzio Nessi presents the ATLAS supplier award to Vojtech Novotny, Director General of Skoda Hute.On 3 November, the ATLAS experiment honoured one of its suppliers, Skoda Hute s.r.o., of Plzen, Czech Republic, for their work on the detector's forward shielding elements. These huge and very massive cylinders surround the beampipe at either end of the detector to block stray particles from interfering with the ATLAS's muon chambers. For the shields, Skoda Hute produced 10 cast iron pieces with a total weight of 780 tonnes at a cost of 1.4 million CHF. Although there are many iron foundries in the CERN member states, there are only a limited number that can produce castings of the necessary size: the large pieces range in weight from 59 to 89 tonnes and are up to 1.5 metres thick.The forward shielding was designed by the ATLAS Technical Coordination in close collaboration with the ATLAS groups from the Czech Technical University and Charles University in Prague. The Czech groups a...

  3. Concrete shielding for nuclear ship 'Mutsu'

    International Nuclear Information System (INIS)

    Nagase, Tetsuo; Nakajima, Tadao; Okumura, Tadahiko; Saito, Tetsuo

    1983-01-01

    The nuclear ship ''Mutsu'' was constructed in 1970 as the fourth in the world. On September 1, 1974, during the power raising test in the Pacific Ocean, radiation leak was detected. As the result of investigation, it was found that the cause was the fast neutrons streaming through the gap between the reactor pressure vessel and the primary shield. In order to repair the shielding facility, the Japan Nuclear Ship Research Development Agency carried out research and development and shielding design. It was decided to adopt serpentine concrete for the primary shield, which is the excellent moderator of fast neutrons even at high temperature, and heavy concrete for the secondary shield, which is effective for shielding both gamma ray and neutron beam. The repair of shielding was carried out in the Sasebo Shipyard, and completed in August, 1982. The outline of the repair work is reported. The weight increase was about 300 t. The conditions of the shielding design, the method of shielding analysis, the performance required for the shielding concrete, the preliminary experiment on heavy concrete and the construction works of serpentine concrete and heavy concrete are described. (Kako, I.)

  4. Evaluation of corrosive behavior of SAE 5155 by corrosion environment

    International Nuclear Information System (INIS)

    An, Jae Pil; Park, Keyung Dong

    2005-01-01

    In this study, the influence of shot peening and corrosive condition for corrosion property was investigated on immersed in 3.5% NaCl, 10% HNO 3 + 3% HF, 6% FeCl 3 . The immersion test was performed on two kinds of specimen. The immersion periods was performed 30days. Corrosion potential, weight loss were investigated from experimental results. From test results, the effect of shot peening on the corrosion was evaluated

  5. Long term testing of materials for tube shielding, stage 2; Laangtidsprovning av tubskyddsmaterial, etapp 2

    Energy Technology Data Exchange (ETDEWEB)

    Norling, Rikard; Hjoernhede, Anders; Mattsson, Mattias

    2012-02-15

    Circulating Fluidized Bed (CFB) boilers are commonly used for combustion of biomass and are used to some extent for Waste-to-Energy (WtE) plants as well. The superheaters of the latter are for obvious reasons more prone to suffer from high temperature corrosion caused by the corrosive species in the fuel, mainly chlorides. Frequently the final (hottest) superheater is positioned in the loop seal, where the circulating bed material is returned to the furnace after being separated from the flue gas by a cyclone. The environment in the loop seal is relatively free of chlorides, since these primarily follow the flue gas into the convection pass. Hence, higher steam temperature can be allowed without excessive damage to the final superheater. On the other hand the superheaters, which are located in the convection pass, are more exposed to the corrosive species of the flue gas. Further, they are eroded by particles entrained in the gas flow. Particles and condensing gaseous species are to a large extent deposited on the superheaters, which limits the heat transfer and promotes corrosion. The deposits are regularly removed e.g. by soot blowers. The pressurized steam from soot blowers causes additional erosion damage to that caused by entrained particles. It shall be noted that the actual damage is caused by a combined mechanism of erosion and corrosion denoted erosion-corrosion, which usually results in dramatically accelerated wear. To avoid excessive erosion damage on the superheater tubes the first tube row of each bundle is protected by tube shielding. In its simplest form the shields are made from a steel sheet that has been bent into a semi-circular half-cylinder shell. These shields are attached onto the wind-side of the tubes by hangers. A typical material for tube shielding is the austenitic high temperature resistant stainless steel 253MA. Life of tube shielding depends on numerous factors such as boiler design, superheater location, fuel and operating

  6. A review on the effect of welding on the corrosion of magnesium alloys

    Science.gov (United States)

    Mohamed, N. S.; Alias, J.

    2017-10-01

    Welding is an important joining technique for lightweight alloys with their increasing applications in aerospace, aircraft, automotive, electronics and other industries. The applications of lightweight alloys particularly magnesium alloys increased rapidly due to their beneficial properties such as low density, high strength-to-mass ratio, good dimensional stability, electromagnetic shielding and good recyclability. The effect of welding on the corrosion of magnesium alloys are reviewed in this paper, which closely related to the developed microstructure by the welding process. The paper focuses particularly on friction stir and laser welding. The basic principles of friction stir and laser welding are discussed, to present the likelihood of defects which significantly affect the corrosion of magnesium alloy. The finding in corrosion demonstrated the morphology of corrosion occurrence on each welded region, and observation on the potential and current values are also included.

  7. Microbiologically induced corrosion

    International Nuclear Information System (INIS)

    Stein, A.A.

    1988-01-01

    Biological attack is a problem that can affect all metallic materials in a variety of environments and systems. In the power industry, corrosion studies have focused on condensers and service water systems where slime, barnacles, clams, and other macro-organisms are easily detected. Efforts have been made to eliminate the effect of these organisms through the use of chlorination, backflushing, organic coating, or thermal shock. The objective is to maintain component performance by eliminating biofouling and reducing metallic corrosion. Recently, corrosion of power plant components by micro-organisms (bacteria) has been identified even in very clean systems. A system's first exposure to microbiologically induced corrosion (MIC) occurs during its first exposure to an aqueous environment, such as during hydrotest or wet layup. Corrosion of buried pipelines by sulfate-reducing bacteria has been studied by the petrochemical industry for years. This paper discusses various methods of diagnosing, monitoring, and controlling MIC in a variety of systems, as well as indicates areas where further study is needed

  8. Calibration Curve of Neutron Moisture Meter for Sandy Soil under Drip Irrigation System

    International Nuclear Information System (INIS)

    Mohammad, Abd El- Moniem M.; Gendy, R. W.; Bedaiwy, M. N.

    2004-01-01

    The aim of this work is to construct a neutron calibration curve in order to be able to use the neutron probe in sandy soils under drip irrigation systems. The experimental work was conducted at the Soil and Water Department of the Nuclear Research Center, Atomic Energy Authority. Three replicates were used along the lateral lines of the drip irrigation system. For each dripper, ten neutron access tubes were installed to 100-cm depth at distances of 5, 15 and 25 cm from the dripper location around the drippers on the lateral line, as well as between lateral lines. The neutron calibrations were determined at 30, 45, and 60-cm depths. Determining coefficients as well as t-test in pairs were employed to detect the accuracy of the calibrations. Results indicated that in order for the neutron calibration curve to express the whole wet area around the emitter; three-access tubes must be installed at distances of 5, 15, and 25 cm from the emitter. This calibration curve will be correlating the average count ratio (CR) at the studied soil depth of the three locations (5, 15, and 25-cm distances from the emitter) to the average moisture content (θ) for this soil depth of the entire wetted area. This procedure should be repeated at different times in order to obtain different θ and C.R values, so that the regression equation of calibration curve at this soil depth can be obtained. To determine the soil moisture content, the average CR of the three locations must be taken and substituted into the regression equation representing the neutron calibration curve. Results taken from access tubes placed at distances of 15 cm from the emitter, showed good agreement with the average calibration curve both for the 45- and the 60-cm depths, suggesting that the 15-cm distance may provide a suitable substitute for the simultaneous use of the three different distances of 5, 15 and 25 cm. However, the obtained results show also that the neutron calibration curves of the 30-cm depth for

  9. Corrosion failure analysis as related to prevention of corrosion failures

    International Nuclear Information System (INIS)

    Suss, H.

    1977-10-01

    The factors and conditions which have contributed to many of the corrosion related service failures are discussed based on a review of actual case histories. The anti-corrosion devices which developed as a result of these failure analyses are reviewed, and the method which must be adopted and used to take advantage of the available corrosion prevention techniques is discussed

  10. Beyond the drip-line: a high-resolution open-air Holocene hunter-gatherer sequence from highland Lesotho

    CSIR Research Space (South Africa)

    Mitchell, P

    2011-03-01

    Full Text Available the drip-line: a high-resolution open-air Holocene hunter-gatherer sequence from highland Lesotho Peter Mitchell1, Ina Plug2, Geoff Bailey3, Ruth Charles4, Amanda Esterhuysen5, Julia Lee Thorp6, Adrian Parker7 & Stephan Woodborne8 The activities...

  11. assessment of injection of liquid rhizobial inoculum and traditional inoculation of soybean under furrow and drip irrigation

    International Nuclear Information System (INIS)

    Janat, M.; Kurdali, F.

    2008-01-01

    Soybean in naturally N 2 -fixing legume, but it needs artificial inoculation with appropriate strains of rhizobia when introduced to land not previously cultivated to the crop. As soybean is being introduced to Syria, inoculation with Bradyrhizobium japonicum is essential to ensure effective biological nitrogen fixation by the crop. The question is: what is the most effective mean of inoculation?. As Syria is a water-short country, we examined the possibility of applying the rhizobial inoculant in irrigation system (Biofertigation) in contrast with the conventional seed pelleting application. In a 2 year experiment at a research station near Damascus, we compared seed pelleting of the inoculant under furrow and drip irrigation, with repeated inoculation by injection of a liquid culture rhizobial inoculum through the drip system. Drip irrigation enhanced N 2 fixation by soybean regardless of inoculation technique ad repeated inoculation. Injection of the liquid rhizobial inoculum through drip irrigation system was shown to enhances the acquisition of atmospheric N 2 and improve N 2 fixation by soybean.(author)

  12. Development of fine and coarse roots of Thuja occidentalis 'Brabant' in non-irrigated and drip irrigated field plots

    NARCIS (Netherlands)

    Pronk, A.A.; Willigen, de P.; Heuvelink, E.; Challa, H.

    2002-01-01

    Aboveground dry mass, total root dry mass and root length density of the fine roots of Thuja occidentalis `Brabant' were determined under non- and drip-irrigated field conditions. Two-dimensional diffusion parameters for dynamic root growth were estimated based on dry mass production of the fine

  13. Study of high-spin structure of the nuclei around A∼120 near proton-drip line

    International Nuclear Information System (INIS)

    Ray, I; Datta Pramanik, U.; Banerjee, P.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Mukherjee, A.; Mukherjee, B.; Saha Sarkar, M.; Basu, S.K.; Bhowmik, R.K.; Rakesh Kumar; Muralithar, S.; Singh, R.P.; Mandal, S.; Ranjet

    2005-01-01

    It would be interesting to explore the shell structure for nuclei near proton-drip line. The nuclei around A∼ 110-130 region show a wide range of interesting features in high spin states which reflect different types of symmetry breaking mechanisms as well as maintaining symmetries

  14. Variation in post mortem rate of glycolyis does not necessarily affect drip loss of non-stimulated veal

    NARCIS (Netherlands)

    Hertog-Meischke, den M.J.; Klont, R.E.; Smulders, F.J.M.; Logtestijn, van J.G.

    1997-01-01

    In this study the effect of the rate of post mortem pH fall on the water-holding capacity of meat from moderately chilled veal carcasses was investigated. Also the relationship between muscle protein denaturation and drip loss of veal was examined. Three groups of 10 Friesian Holstein male veal

  15. The usefulness of levin tube inserted drip infusion spiral CT: comparison with conventional method in subtotal gastrectomy patients

    International Nuclear Information System (INIS)

    Park, Young Jin; Kim, Young Hwan; Yoon, Jung Hee; Cha, Soon Joo; Kim, Jeong Sook; Kim, Sung Rok; Hur, Gham; Rhim, Hyun Chul

    1998-01-01

    The purpose of this study is to access the usefulness of newly designed Levin tube inserted drip infusion spiral CT for the evaluation of remnant stomach and anastomosis site in patients who have undergone subtotal gastrectomy for stomach cancer. A new technique named Levin tube inserted drip infusion spiral CT was used to prospectively study 23 patients. A 16Fr Levin tube was inserted into the remnant stomach; 500 ml of tap water was drip infused just before CT scanning and an additional 500 ml of water was infused during IV contrast injection. Water was infused by gravity, using a water bottle suspended at a height of 90 cm (Group A). The 31 patients who underwent conventional spiral CT scanning immediately after the divided ingestion of 900 ml diluted gastrografin were selected as a control group (Group B). The anatomic delineation of the anastomosis site was graded by two radiologists as excellent (3), good(2), fair (1) or poor (0). To evaluate the degree of distension, the maximal diameters of remnant stomach and the anastomosis site, and the thickness of the stomach wall, were also measured. In patients who had undergone subtobal gastrectomy, Levin tube inserted drip infusion spiral CT showed excellent anatomic delineation of the site of anastomosis and remnant stomach. We found that because it increases the distension of remnant stomach and the anastomosis site, this technique is effective for the evaluation of postoperative stomach. (author). 10 refs., 2 tabs., 3 figs

  16. Corrosion testing facilities in India

    International Nuclear Information System (INIS)

    Viswanathan, R.; Subramanian, Venu

    1981-01-01

    Major types of corrosion tests, establishment of specifications on corrosion testing and scope of their application in practice are briefly described. Important organizations in the world which publish specifications/standards are listed. Indian organizations which undertake corrosion testing and test facilities available at them are also listed. Finally in an appendix, a comprehensive list of specifications relevant to corrosion testing is given. It is arranged under the headings: environmental testing, humidity tests, salt spray/fog tests, immersion tests, specification corrosion phenomena, (tests) with respect to special corrosion media, (tests) with respect to specific corrosion prevention methods, and specific corrosion tests using electrical and electrochemical methods (principles). Each entry in the list furnishes information about: nature of the test, standard number, and its specific application. (M.G.B.)

  17. Hexavalent Chrome Free Coatings for Electronics: Electromagnetic Interference (EMI) Shielding Effectiveness (SE)

    Science.gov (United States)

    Kessel, Kurt R.

    2016-01-01

    Determine the suitability of trivalent chromium conversion coatings that meet the requirements of MIL-DTL-5541, Type II, for use in applications where high-frequency electrical performance is important. Evaluate the ability of hexavalent chrome free pretreated aluminum to form adequate EMI seals, and maintain that seal while being subjected to harsh environmental conditions. Assess the performance of trivalent chromium pretreatments against a known control hexavalent chrome pretreatment before and after they have been exposed to a set of environmental conditions. It is known that environmental testing causes a decrease in shielding effectiveness when hexavalent chrome pretreatments are used (Alodine 1200s). Need to determine how shielding effectiveness will be affected with the use of hexavalent chrome free pretreatments. Performance will be assessed by evaluating shielding effectiveness (SE) test data from a variety of test samples comprised of different aluminum types and/or conversion coatings. The formation of corrosion will be evaluated between the mating surfaces and gasket to assess the corrosion resistant properties of the pretreatments, comparing the hexavalent control to the hexavalent chrome free pretreatments.

  18. Seasonal variations of {sup 14}C and δ{sup 13}C for cave drip waters in Ryugashi Cave, Shizuoka Prefecture, central Japan

    Energy Technology Data Exchange (ETDEWEB)

    Minami, Masayo, E-mail: minami@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); Kato, Tomomi [Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601 (Japan); Horikawa, Keiji [Department of Environmental Biology and Chemistry, Toyama University, Toyama 930-8555 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan)

    2015-11-01

    Speleothem {sup 14}C has recently emerged as a potentially powerful proxy for hydrology changes in comparison with atmospheric {sup 14}C calibration curve, rather than as a direct dating tool, apart from a time marker using bomb peak of {sup 14}C. Some possible causes for the relationship between speleothem {sup 14}C content (or dead carbon fraction: DCF) and karst hydrology have been proposed, such as changes in temperature, precipitation, drip water flow dynamics, cave air ventilation, soil air pCO{sub 2}. In this study, we investigated seasonal variation in {sup 14}C and δ{sup 13}C of drip water in Ryugashi Cave, Shizuoka Prefecture, central Japan, to examine the causes of the {sup 14}C and δ{sup 13}C variations in a speleothem. The results show that different {sup 14}C concentrations and δ{sup 13}C values of drip water from the Ryugashi Cave, were exhibited at different sites of the Caves No. 1, No. 3, and No. 4, which have different temperature, air pCO{sub 2}, and flow paths. Further, the {sup 14}C and δ{sup 13}C of drip waters showed seasonal variations at all sites, which were lower in fall and winter, and higher in spring and summer, though the extent of the variations was different among the sites. The {sup 14}C in drip waters tended to be correlated with the drip rates: {sup 14}C tended to be higher in drip waters with higher drip rates, and also correlated with rainfall amount around the Ryugashi Cave, especially for the drip waters in Cave No. 3, which are considered to have simpler flow paths. The increase in rainfall amount could bring the increase in drip rate of drip water, and then the decrease in interaction between solution and karst, resulting in {sup 14}C increase (DCF decrease) in drip water. Accordingly, the reconstruction of precipitation could be performed using {sup 14}C variation in a speleothem formed by drip water with simple flow dynamics.

  19. Acid corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, N G

    1964-04-28

    An acid corrosion inhibitor is prepared by a 2-stage vacuum evaporation of effluents obtained from the ammonia columns of the coking oven plant. The effluent, leaving a scrubber in which the phenols are removed at a temperature of 98$C, passes through a quartz filter and flows into a heated chamber in which it is used for preheating a solution circulating through a vacuum unit, maintaining the temperature of the solution at 55$ to 60$C. The effluent enters a large tank in which it is boiled at 55$ to 60$C under 635 to 640 mm Hg pressure. Double evaporation of this solution yields a very effective acid corrosion inhibitor. Its corrosion-preventing effect is 97.9% compared with 90.1% for thiourea and 88.5% for urotropin under identical conditions.

  20. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  1. Corrosion Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Russ Braunling

    2004-10-31

    The Corrosion Monitoring System (CMS) program developed and demonstrated a continuously on-line system that provides real-time corrosion information. The program focused on detecting pitting corrosion in its early stages. A new invention called the Intelligent Ultrasonic Probe (IUP) was patented on the program. The IUP uses ultrasonic guided waves to detect small defects and a Synthetic Aperture Focusing Technique (SAFT) algorithm to provide an image of the pits. Testing of the CMS demonstrated the capability to detect pits with dimensionality in the sub-millimeter range. The CMS was tested in both the laboratory and in a pulp and paper industrial plant. The system is capable of monitoring the plant from a remote location using the internet.

  2. Stochastic theory of fatigue corrosion

    Science.gov (United States)

    Hu, Haiyun

    1999-10-01

    A stochastic theory of corrosion has been constructed. The stochastic equations are described giving the transportation corrosion rate and fluctuation corrosion coefficient. In addition the pit diameter distribution function, the average pit diameter and the most probable pit diameter including other related empirical formula have been derived. In order to clarify the effect of stress range on the initiation and growth behaviour of pitting corrosion, round smooth specimen were tested under cyclic loading in 3.5% NaCl solution.

  3. Corrosion-resistant metal surfaces

    Science.gov (United States)

    Sugama, Toshifumi [Wading River, NY

    2009-03-24

    The present invention relates to metal surfaces having thereon an ultrathin (e.g., less than ten nanometer thickness) corrosion-resistant film, thereby rendering the metal surfaces corrosion-resistant. The corrosion-resistant film includes an at least partially crosslinked amido-functionalized silanol component in combination with rare-earth metal oxide nanoparticles. The invention also relates to methods for producing such corrosion-resistant films.

  4. Shielded room measurements, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stanton, J.S.

    1949-02-22

    The attenuation of electro-statically and electro-magnetically shielded rooms in the ``E,`` ``R,`` ``I,`` and ``T`` Buildings was measured so that corrective measure could be taken if the attenuation was found to be low. If remedial measures could not be taken, the shortcomings of the rooms would be known. Also, the men making the measurements should oversee construction and correct errors at the time. The work was performed by measuring the attenuation at spot frequencies over the range of from 150 kilocycles to 1280 megacycles with suitable equipment mounted in small rubber-tried trucks. The attenuation was determined by ``before and after`` shielding and/or ``door open and door closed`` measurements after installation of copper shielding. In general, attenuation in the frequency range of approximately 10 to 150 mc. was good and was of the order expected. At frequencies in the range of 150 mc. to 1280 mc., the attenuation curve was more erratic; that is, at certain frequencies a severe loss of attenuation was noted, while at others, the attenuation was very good. This was mainly due to poor or faulty seals around doors and pass windows. These poor seals existed in the ``T,`` ``E,`` and ``I`` Buildings because the doors were fitted improperly and somewhat inferior material was used. By experience from these difficulties, both causes were corrected in the ``R`` Building, which resulted in the improvement of the very high frequency (v.h.f.) range in this building. In some specific cases, however, the results were about the same. For the range of frequencies below approximately 10 mc., the attenuation, in almost all cases, gradually decreased as the frequency decreased and reached a minimum at .3 to 1.0 mc. This loss of attenuation was attributed to multiple grounding caused by moisture in the insulating timbers and will gradually decrease as the wood dries out.

  5. Radiation shielding activities at IDOM

    Energy Technology Data Exchange (ETDEWEB)

    Ordóñez, César Hueso; Gurpegui, Unai Cano; Valiente, Yelko Chento; Poveda, Imanol Zamora, E-mail: cesar.hueso@idom.com [IDOM, Consulting, Engineering and Architecture, S.A.U, Vizcaya (Spain)

    2017-07-01

    When human activities have to be performed under ionising radiation environments the safety of the workers must be guaranteed. Usually three principles are used to accomplish with ALARA (As Low As Reasonably Achievable) requirements: the more distance between the source term and the worker, the better; the less time spent to arrange any task, the better; and, once the previous principles are optimized should the exposure of the workers continues being above the regulatory limits, shielding has to be implemented. Through this paper some different examples of IDOM's shielding design activities are presented. Beginning with the gamma collimators for the Jules Horowitz Reactor, nuclear fuel's behaviour researching facility, where the beam path crosses the reactor's containment walls and is steered up to a gamma detector where the fuel spectrum is analysed and where the beam has to be attenuated several orders of magnitude in a short distance. Later it is shown IDOM’s approach for the shielding of the Emergency Control Management Center of Asociación Nuclear Ascó-Vandellòs-II NPPs, a bunker designed to withstand severe accident conditions and to support the involved staff during 30 days, considering the outside radioactive cloud and the inside source term that filtering units become as they filter the incoming air. And finally, a general approach to this kind of problems is presented, since the study of the source term considering all the possible contributions, passing through the material selection and the thicknesses calculation until the optimization of the materials. (author)

  6. Magnetic shielding of a limiter

    International Nuclear Information System (INIS)

    Brevnov, N.N.; Stepanov, S.B.; Khimchenko, L.N.; Matthews, G.F.; Goodal, D.H.J.

    1991-01-01

    Localization of plasma interaction with material surfaces in a separate chamber, from where the escape of impurities is hardly realized, i.e. application of magnetic divertors or pump limiters, is the main technique for reduction of the impurity content in a plasma. In this case, the production of a divertor configuration requires a considerable power consumption and results in a less effective utilization of the magnetic field volume. Utilization of a pump limiter, for example the ICL-type, under tokamak-reactor conditions would result in the extremely high and forbidden local heat loadings onto the limiter surface. Moreover, the magnetically-shielded pump limiter (MSL) was proposed to combine positive properties of the divertor and the pump limiter. The idea of magnetic shielding is to locate the winding with current inside the limiter head so that the field lines of the resultant magnetic field do not intercept the limiter surface. In this case the plasma flows around the limiter leading edges and penetrates into the space under the limiter. The shielding magnetic field can be directed either counter the toroidal field or counter the poloidal one of a tokamak, dependent on the concrete diagram of the device. Such a limiter has a number of advantages: -opportunity to control over the particle and impurity recycling without practical influence upon the plasma column geometry, - perturbation of a plasma column magnetic configuration from the side of such a limiter is less than that from the side of the divertor coils. The main deficiency is the necessity to locate active windings inside the discharge chamber. (author) 5 refs., 3 figs

  7. Radiation shielding activities at IDOM

    International Nuclear Information System (INIS)

    Ordóñez, César Hueso; Gurpegui, Unai Cano; Valiente, Yelko Chento; Poveda, Imanol Zamora

    2017-01-01

    When human activities have to be performed under ionising radiation environments the safety of the workers must be guaranteed. Usually three principles are used to accomplish with ALARA (As Low As Reasonably Achievable) requirements: the more distance between the source term and the worker, the better; the less time spent to arrange any task, the better; and, once the previous principles are optimized should the exposure of the workers continues being above the regulatory limits, shielding has to be implemented. Through this paper some different examples of IDOM's shielding design activities are presented. Beginning with the gamma collimators for the Jules Horowitz Reactor, nuclear fuel's behaviour researching facility, where the beam path crosses the reactor's containment walls and is steered up to a gamma detector where the fuel spectrum is analysed and where the beam has to be attenuated several orders of magnitude in a short distance. Later it is shown IDOM’s approach for the shielding of the Emergency Control Management Center of Asociación Nuclear Ascó-Vandellòs-II NPPs, a bunker designed to withstand severe accident conditions and to support the involved staff during 30 days, considering the outside radioactive cloud and the inside source term that filtering units become as they filter the incoming air. And finally, a general approach to this kind of problems is presented, since the study of the source term considering all the possible contributions, passing through the material selection and the thicknesses calculation until the optimization of the materials. (author)

  8. Core test reactor shield cooling system analysis

    International Nuclear Information System (INIS)

    Larson, E.M.; Elliott, R.D.

    1971-01-01

    System requirements for cooling the shield within the vacuum vessel for the core test reactor are analyzed. The total heat to be removed by the coolant system is less than 22,700 Btu/hr, with an additional 4600 Btu/hr to be removed by the 2-inch thick steel plate below the shield. The maximum temperature of the concrete in the shield can be kept below 200 0 F if the shield plug walls are kept below 160 0 F. The walls of the two ''donut'' shaped shield segments, which are cooled by the water from the shield and vessel cooling system, should operate below 95 0 F. The walls of the center plug, which are cooled with nitrogen, should operate below 100 0 F. (U.S.)

  9. Highly heat removing radiation shielding material

    International Nuclear Information System (INIS)

    Asano, Norio; Hozumi, Masahiro.

    1990-01-01

    Organic materials, inorganic materials or metals having excellent radiation shielding performance are impregnated into expanded metal materials, such as Al, Cu or Mg, having high heat conductivity. Further, the porosity of the expanded metals and combination of the expanded metals and the materials to be impregnated are changed depending on the purpose. Further, a plurality of shielding materials are impregnated into the expanded metal of the same kind, to constitute shielding materials. In such shielding materials, impregnated materials provide shielding performance against radiation rays such as neutrons and gamma rays, the expanded metals provide heat removing performance respectively and they act as shielding materials having heat removing performance as a whole. Accordingly, problems of non-informity and discontinuity in the prior art can be dissolved be provide materials having flexibility in view of fabrication work. (T.M.)

  10. Shielding design of ITER pressure suppression system

    International Nuclear Information System (INIS)

    Yamauchi, Michinori; Sato, Satoshi; Nishitani, Takeo; Kawasaki, Hiromitsu

    2006-01-01

    The duct shield from streaming D-T neutrons has been designed for the ITER pressure suppression system. Streaming calculations are performed with the DUCT-III code for the region from the inlet of the pressure relief line to the rupture disk. Next, the neutron permeation through the shield is studied by Monte Carlo calculations with the MCNP code. It is found that 0.15 m thick iron shield is enough to suppress the permeating component from the outside. In addition, it is suggested that the volume of the shield can be reduced by about 30% if the optimized iron shield structure having localized thickness across intense permeation paths is employed to shield the pressure suppression line. (T.I.)

  11. Stalk yield of sugarcane cultivars under different water regimes by subsurface drip irrigation

    Directory of Open Access Journals (Sweden)

    Aderson S. de Andrade Junior

    Full Text Available ABSTRACT This study aimed to evaluate the stalk yield of ten sugarcane cultivars (RB962962, RB931011, RB931530, RB98710, RB92579, RB867515, RB863129, SP791011, RB72545 and VAT90212 subjected to water deficit, full irrigation and water surplus by subsurface drip irrigation, during three cropping seasons (2011-2014. The experiment was conducted at the Experimental Field of Embrapa Meio-Norte, Teresina, Piauí State, Brazil, in dystrophic Red Yellow Argisol. The cultivars RB962962 (162.3 Mg ha-1 and RB867515 (158.5 Mg ha-1 have better stalk yield compared with other cultivars in all water regimes and cropping seasons.

  12. Continuous Drip Flow System to Develop Biofilm of E. faecalis under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Ana Maria Gonzalez

    2014-01-01

    Full Text Available Purpose. To evaluate a structurally mature E. faecalis biofilm developed under anaerobic/dynamic conditions in an in vitro system. Methods. An experimental device was developed using a continuous drip flow system designed to develop biofilm under anaerobic conditions. The inoculum was replaced every 24 hours with a fresh growth medium for up to 10 days to feed the system. Gram staining was done every 24 hours to control the microorganism purity. Biofilms developed under the system were evaluated under the scanning electron microscope (SEM. Results. SEM micrographs demonstrated mushroom-shaped structures, corresponding to a mature E. faecalis biofilm. In the mature biofilm bacterial cells are totally encased in a polymeric extracellular matrix. Conclusions. The proposed in vitro system model provides an additional useful tool to study the biofilm concept in endodontic microbiology, allowing for a better understanding of persistent root canal infections.

  13. A Computer Program for Drip Irrigation System Design for Small Plots

    Science.gov (United States)

    Philipova, Nina; Nicheva, Olga; Kazandjiev, Valentin; Chilikova-Lubomirova, Mila

    2012-12-01

    A computer programhas been developed for design of surface drip irrigation system. It could be applied for calculation of small scale fields with an area up to 10 ha. The program includes two main parts: crop water requirements and hydraulic calculations of the system. It has been developed in Graphical User Interface in MATLAB and gives opportunity for selecting some parameters from tables such as: agro- physical soil properties, characteristics of the corresponding crop, climatic data. It allows the user of the program to assume and set a definite value, for example the emitter discharge, plot parameters and etc. Eight cases of system layout according to the water source layout and the number of plots of the system operation are laid into hydraulic section of the program. It includes the design of lateral, manifold, main line and pump calculations. The program has been compiled to work in Windows.

  14. Soil salinity under deficit drip irrigation of potato and millet in in an arid environment

    Directory of Open Access Journals (Sweden)

    Kamel Nagaz

    2017-06-01

    Full Text Available The influence of deficit irrigation (DI with saline water on soil salinity in a drip-irrigated potato and millet fields was investigated. We had compared proportional soil salinity developed under Full and DI under drip irrigation. For both experiments, the treatments were (1 Full, control treatment where rooting zone soil water content was increased to field capacity at each irrigation; (2 DI80; (3 DI60 and DI40; 20, 40 and 60% deficit irrigation compared to Full treatment were applied, respectively. Soil salinity was assessed using the isosalinity maps constructed with grid soil sampling of plant root zone at harvest. Results show that high spatial variability was observed in salinity along soil profiles when applying saline water with drip irrigation for potato. For the DI40 and DI60 treatments, high soil salinity was recorded in the upper soil layer close to the emitter. Increase of soil salinity within soil depths of 30 cm or below was also observed under DI60 and DI40 treatments. The lowest increase was noted under the full treatment. Surface soil salinity was somewhat higher under DI60 and DI40 compared with that of full and DI80 irrigation treatments. The distribution of salts around the dripper changes during the crop season according to applied irrigation treatments, with overall higher concentrations between the drippers and towards the margin of wetted band. Iso-salinity maps at harvest of potato showed that the surface layer of 30 cm depth had the lowest salinity which gradually increased at deeper zones irrespective of the treatment. Salt accumulation essentially occurred at wetting front between the drippers and the plant row. Although salt accumulation was relatively highest along the row under DI treatments, the area of accumulation was relatively shifted toward the center between the rows and the drip line. The results also show the importance of the potato cropping season to benefit from the leaching of soluble salts with the

  15. Influence of the impact energy on the pattern of blood drip stains

    Science.gov (United States)

    Smith, F. R.; Nicloux, C.; Brutin, D.

    2018-01-01

    The maximum spreading diameter of complex fluid droplets has been extensively studied and explained by numerous physical models. This research focuses therefore on a different aspect, the bulging outer rim observed after evaporation on the final dried pattern of blood droplets. A correlation is found between the inner diameter, the maximum outer diameter, and the impact speed. This shows how the drying mechanism of a blood drip stain is influenced by the impact energy, which induces a larger spreading diameter and thus a different redistribution of red blood cells inside the droplet. An empirical relation is established between the final dried pattern of a passive bloodstain and its impact speed, yielding a possible forensic application. Indeed, being able to relate accurately the energy of the drop with its final pattern would give a clue to investigators, as currently no such simple and accurate tool exists.

  16. Nuclear spectroscopy in the rare earth region near the proton drip line

    International Nuclear Information System (INIS)

    Toth, K.S.; Nitschke, J.M.; Wilmarth, P.A.; Vierinen, K.S.

    1989-01-01

    We have used the isotope separator facility OASIS, on-line at the Lawrence Berkeley Laboratory SuperHILAC, to investigate rare earth nuclei close to the proton drip line. Single-particle states near the 82-neutron shell have been examined and their excitation energies determined. Numerous new isotopes, isomers, and β-delayed proton emitters have been discovered. In addition, the α-decay properties of nuclides with N ≥ 84 have been reexamined; this has led to the discovery of several previously unobserved α transitions. The overall experimental program is summarized and some recently obtained results on 145 Dy, 147 Er, 147 Tm, 153 Lu, 155 Lu, and 157 Lu are discussed. 20 refs., 11 figs., 11 tabs

  17. Spectroscopy of N approximately 82 nuclei near the proton drip line

    International Nuclear Information System (INIS)

    Daly, P.J.

    1984-01-01

    The yrast spectroscopy of Z>64 nuclei close to the proton drip line is discussed. This is a region of shell model nuclei in which high-spin excitations are accessible with heavy ion beams, and the occurrence of many isomers will facilitate future spectroscopic study of these nuclei to much higher spins that were observed in these investigations. The study of πhsub(11/2)sup(n) excitations in n=82 nuclei above 146 Gd provided particularly interesting results, since in certain respects their properties match shell model predictions better than those of jsup(n) states near traditional doubly magic nuclei. First results for N=81 nuclei above Z=64 were also reported, but much work remains to be done in the Z>64, N<82 quadrant

  18. Low salinity hydrocarbon water disposal through deep subsurface drip irrigation: leaching of native selenium

    Science.gov (United States)

    Bern, Carleton R.; Engle, Mark A.; Boehlke, Adam R.; Zupancic, John W.; Brown, Adrian; Figueroa, Linda; Wolkersdorfer, Christian

    2013-01-01

    A subsurface drip irrigation system is being used in Wyoming’s Powder River Basin that treats high sodium, low salinity, coal bed methane (CBM) produced water with sulfuric acid and injects it into cropped fields at a depth of 0.92 m. Dissolution of native gypsum releases calcium that combats soil degradation that would otherwise result from high sodium water. Native selenium is leached from soil by application of the CBM water and traces native salt mobilization to groundwater. Resulting selenium concentrations in groundwater at this alluvial site were generally low (0.5–23 μg/L) compared to Wyoming’s agricultural use suitability standard (20 μg/L).

  19. Effect of ionizing radiation on the physiological activities of ethanol extract from hizikia fusiformis cooking drips

    International Nuclear Information System (INIS)

    Kim, Hyun-Joo; Choi, Jong-il; Kim, Duk-Jin; Kim, Jae-Hun; Soo Chun, Byeong; Hyun Ahn, Dong; Sun Yook, Hong; Byun, Myung-Woo; Kim, Mi-Jung; Shin, Myung-Gon; Lee, Ju-Woon

    2009-01-01

    Although the byproduct from Hizikia fusiformis industry had many nutrients, it is being wasted. In this study, the physiological activities of cooking drip extracts from H. fusiformis (CDHF) were determined to investigate the effect of a gamma and an electron beam irradiations. DPPH radical scavenging activity and tyrosinase and ACE inhibition effects of the gamma and electron beam irradiated CDHF extracts were increased with increasing irradiation dose. These were reasoned by the increase in the content of the total polyphenolic compound of CDHF by the gamma and electron beam irradiation. There were no differences for the radiation types. These results show that ionizing radiation could be used for enhancing the functional activity of CDHF which is a major by-product in Hizikia fusiformis processing, in various applications.

  20. Pharmacokinetic evaluation of Shenfu Injection in beagle dogs after intravenous drip administration

    Directory of Open Access Journals (Sweden)

    Yuqiao Zhang

    2016-10-01

    Full Text Available Shenfu Injection (SFI is a well-defined Chinese herbal formulation that is obtained from red ginseng and processed aconite root. The main active constituents in SFI are ginsenosides and aconitum alkaloids. In this work, ginsenosides (ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Rc and aconitum alkaloids (benzoylmesaconine and fuziline were used as the index components to explore the pharmacokinetic behavior of SFI. A selective and sensitive HPLC–MS/MS method was developed for the quantification of ginsenosides and aconitum alkaloids in dog plasma and was used to characterize the pharmacokinetics of the five index components after intravenous drip of three different dosages of SFI in beagle dogs. The pharmacokinetic properties of the index components were linear over the dose range of 2–8 mL/kg.

  1. Onion crop yield submitted to water and nitrogen levels by drip system

    Directory of Open Access Journals (Sweden)

    Renato Carvalho Vilas Boas

    2014-02-01

    Full Text Available The aim this work was evaluate the effects of water and nitrogen (N levels, supplied by drip system, on yield and water use efficiency of onion crop (Allium cepa L.. The experiment was carried at the experimental area of DEG/UFLA, in a randomized block statistical design was used, in a factorial scheme 4 x 4, with three replicates. Four irrigation depths based on Class A evaporation tanks (50, 100, 150 and 200% and four N doses (0, 60, 120 and 180 kg ha-1 were supplied through irrigation water (fertigation. It can be concluded that higher yields (total bulbs and of marketable bulbs and higher average marketable bulbs mass were obtained with the irrigation depth of 512.7 mm (100% Class A and 180 kg ha-1 of N. Water use efficiency decreased linearly as irrigation depths increased and N rate decreased.

  2. Dripping and jetting in microfluidic multiphase flows applied to particle and fiber synthesis

    Science.gov (United States)

    Nunes, J K; Tsai, S S H; Wan, J; Stone, H A

    2013-01-01

    Dripping and jetting regimes in microfluidic multiphase flows have been investigated extensively, and this review summarizes the main observations and physical understandings in this field to date for three common device geometries: coaxial, flow-focusing and T-junction. The format of the presentation allows for simple and direct comparison of the different conditions for drop and jet formation, as well as the relative ease and utility of forming either drops or jets among the three geometries. The emphasis is on the use of drops and jets as templates for microparticle and microfiber syntheses, and a description is given of the more common methods of solidification and strategies for achieving complex multicomponent microparticles and microfibers. PMID:23626378

  3. Spectroscopy at the two-proton drip line: Excited states in 158W

    Directory of Open Access Journals (Sweden)

    D.T. Joss

    2017-09-01

    Full Text Available Excited states have been identified in the heaviest known even-Z N=84 isotone 158W, which lies in a region of one-proton emitters and the two-proton drip line. The observation of γ-ray transitions feeding the ground state establishes the excitation energy of the yrast 6+ state confirming the spin-gap nature of the α-decaying 8+ isomer. The 8+ isomer is also expected to be unbound to two-proton emission but no evidence for this decay mode was observed. An upper limit for the two-proton decay branch has been deduced as b2p≤ 0.17% at the 90% confidence level. The possibility of observing two-proton emission from multiparticle isomers in nearby nuclides is considered.

  4. Safe household water treatment and storage using ceramic drip filters: a randomised controlled trial in Bolivia.

    Science.gov (United States)

    Clasen, T; Brown, J; Suntura, O; Collin, S

    2004-01-01

    A randomised controlled field trial was conducted to evaluate the effectiveness of ceramic drip filters to improve the microbiological quality of drinking water in a low-income community in rural Bolivia. In four rounds of water sampling over five months, 100% of the samples were free of thermotolerant (faecal) coliforms (TTC) compared to an arithmetic mean TTC count of 1517, 406, 167 and 245 among control households which continued to use their customary sources of drinking water. The filter systems produced water that consistently met WHO drinking-water standards despite levels of turbidity that presented a challenge to other low-cost POU treatment methods. The filter systems also demonstrated an ability to maintain the high quality of the treated water against subsequent re-contamination in the home.

  5. Spectroscopy at the two-proton drip line: Excited states in 158W

    Science.gov (United States)

    Joss, D. T.; Page, R. D.; Herzán, A.; Donosa, L.; Uusitalo, J.; Carroll, R. J.; Darby, I. G.; Andgren, K.; Cederwall, B.; Eeckhaudt, S.; Grahn, T.; Greenlees, P. T.; Hadinia, B.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Leino, M.; Leppanen, A.-P.; Nyman, M.; O'Donnell, D.; Pakarinen, J.; Rahkila, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Seweryniak, D.; Simpson, J.; Sorri, J.

    2017-09-01

    Excited states have been identified in the heaviest known even-Z N = 84 isotone 158W, which lies in a region of one-proton emitters and the two-proton drip line. The observation of γ-ray transitions feeding the ground state establishes the excitation energy of the yrast 6+ state confirming the spin-gap nature of the α-decaying 8+ isomer. The 8+ isomer is also expected to be unbound to two-proton emission but no evidence for this decay mode was observed. An upper limit for the two-proton decay branch has been deduced as b2p ≤ 0.17% at the 90% confidence level. The possibility of observing two-proton emission from multiparticle isomers in nearby nuclides is considered.

  6. The decay modes of proton drip-line nuclei with A between 42 and 47

    International Nuclear Information System (INIS)

    Borrel, V.; Dogny, S.; Guillemaud-Mueller, D.; Mueller, A.C.; Pougheon, F.; Sorlin, O.; Bazin, D.; Del Moral, R.; Dufour, J.P.; Faux, L.; Fleury, A.; Hubert, F.; Marchand, C.; Pravikoff, M.S.; Chubarian, G.G.

    1992-01-01

    Neutron-deficient isotopes with Z = 21 to 26 have been produced as projectile-like fragments of an intense 58 Ni GANIL beam of 69 MeV/nucleon. The nuclei selected by the upgraded LISE3 spectrometer were identified and implanted in a silicon detector telescope. The 43 Cr, 47 Fe and 46 Fe isotopes were identified for the first time whereas 45 Fe, 45 Mn, 44 Mn and 42 V were not observed, indicating probable instability of these nuclei against particle emission. Measurements of the half-lives of 43 Cr and 46 Mn have been performed and the analysis of their measured beta-delayed proton spectra has given, through the Isobaric Multiplet Mass Equation, an empirical estimation of their masses. Half-lives of 44 Cr, 43 V, 47 Fe and 46 Fe have also been measured. A discussion of various mass predictions for nuclei at the proton drip-line is given

  7. Rhenium corrosion in chloride melts

    International Nuclear Information System (INIS)

    Stepanov, A.D.; Shkol'nikov, S.N.; Vetyukov, M.M.

    1989-01-01

    The results investigating rhenium corrosion in chloride melts containing sodium, potassium and chromium ions by a gravimetry potentials in argon atmosphere in a sealing quarth cell are described. Rhenium corrosion is shown to be rather considerable in melts containing CrCl 2 . The value of corrosion rate depending on temperature is determined

  8. Irrigoscopy - irrigography method, dosimetry and radiation shielding

    International Nuclear Information System (INIS)

    Zubanov, Z.; Kolarevic, G.

    1999-01-01

    Use of patient's radiation shielding during radiology diagnostic procedures in our country is insufficiently represent, so patients needlessly receive very high entrance skin doses in body areas which are not in direct x-ray beam. During irrigoscopy, patient's radiation shielding is very complex problem, because of the organs position. In the future that problem must be solved. We hope that some of our suggestions about patient's radiation shielding during irrigoscopy, can be a small step in that way. (author)

  9. Cage for shield-type support. Schildausbaugestell

    Energy Technology Data Exchange (ETDEWEB)

    Harryers, W; Blumenthal, G; Irresberger, H

    1981-08-13

    A cage for shield-type support containing a fracture shield supported by a hydraulic stamp and a projecting roof bar was constructed in such a way that no cellular shirt is needed to timber the caved room. The roof bar which is linked at a joint axis at the face-side end of the fracture shield is formed at the face side as a multiply foldable bar. (HGOE).

  10. Accelerated cyclic corrosion tests

    Directory of Open Access Journals (Sweden)

    Prošek T.

    2016-06-01

    Full Text Available Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.

  11. Soil water movement in the unsaturated zone of an inland arid region: Mulched drip irrigation experiment

    Science.gov (United States)

    Han, Dongmei; Zhou, Tiantian

    2018-04-01

    Agricultural irrigation with trans-basin water diversion can effectively relieve the water paucity in arid and semi-arid regions, however, this may be accompanied by eco-environmental problems (e.g., saline soils, rising groundwater levels, water quality problems). The mechanism of soil water movement under irrigation in the unsaturated zone of arid regions is a key scientific problem that should be solved in order to evaluate agricultural water management and further improve current irrigation practices. This study investigated the impact of drip irrigation on soil water movement in the unsaturated zone of a cotton field in an inland arid region (the Karamay Agricultural Development Area), northwest China. Combining in situ observational physical data with temporal variation in stable isotopic compositions of soil water, we described the soil water flow system and mechanism in severe (Plot 1) and mild (Plot 2) saline-alkali cotton fields. The infiltration depths are 0-150 cm for both plots. Drip irrigation scheduling makes no significant contribution to local groundwater recharge, however, groundwater can move into the unsaturated zone through capillary rise during cotton flowering and boll periods. Plot 2 is less prone to having secondary soil salinization than Plot 1 due to the existence of a middle layer (approximately 100 cm thick), which elongated the distance between the root zone and aquifer. Rise in the water table (approximately 60 cm for Plot 1 and 50 cm for Plot 2) could be caused by lateral groundwater flow instead of vertical infiltration. We estimated the soil water storage changes in the unsaturated zone and proposed a conceptual model for deciphering the movement process of soil water. This study provides a scientific basis for determining the rise of groundwater levels and potential development of saline soils and improving agricultural water management in arid regions.

  12. Effect of soil properties on Hydraulic characteristics under subsurface drip irrigation

    Science.gov (United States)

    Fan, Wangtao; Li, Gang

    2018-02-01

    Subsurface drip irrigation (SDI) is a technique that has a high potential in application because of its high efficiency in water-saving. The hydraulic characteristics of SDI sub-unit pipe network can be affected by soil physical properties as the emitters are buried in soils. The related research, however, is not fully explored. The laboratory tests were carried out in the present study to determine the effects of hydraulic factors including operating pressure, initial soil water content, and bulk density on flow rate and its sensitivity to each hydraulic factor for two types of SDI emitters (PLASSIM emitter and Heping emitter). For this purpose, three soils with contrasting textures (i.e., light sand, silt loam, and light clay) were repacked with two soil bulk density (1.25 and1.40 g cm-3) with two initial soil water content (12% and 18%) in plexiglass columns with 40 cm in diameter and 40 cm in height. Drip emitters were buried at depth of 20 cm to measure the flow rates under seven operating pressures (60, 100, 150, 200, 250, 300, and 370 kPa). We found that the operating pressure was the dominating factor of flow rate of the SDI emitter, and flow rate increased with the increase of operating pressure. The initial soil water content and bulk density also affected the flow rate, and their effects were the most notable in the light sand soil. The sensitivity of flow rate to each hydraulic factor was dependent on soil texture, and followed a descending order of light sand>silt loam>light clay for both types of emitters. Further, the sensitivity of flow rate to each hydraulic factor decreased with the increase of operating pressure, initial soil water content, and bulk density. This study may be used to guide the soil specific-design of SDI emitters for optimal water use and management.

  13. Achievments of corrosion science and corrosion protection technology

    International Nuclear Information System (INIS)

    Fontana, M.; Stehjl, R.

    1985-01-01

    Problems of corrosion-mechanical strength of metals, effect of corrosive media on creep characteristics are presented. New concepts of the mechanism of corrosion cracking and its relation to hydrogen embrittlement are described. Kinetics and mechanism of hydrogen embrittlement effect on the process of corrosion cracking of different steels and alloys are considered. The dependence of such types of failure on various structural factors is shown. Data on corrosion cracking of high-strength aluminium and titanium alloys, mechanism of the processes and protective methods are given

  14. Shielded scanning electron microscope for radioactive samples

    International Nuclear Information System (INIS)

    Crouse, R.S.; Parsley, W.B.

    1977-01-01

    A small commercial SEM had been successfully shielded for examining radioactive materials transferred directly from a remote handling facility. Relatively minor mechanical modifications were required to achieve excellent operation. Two inches of steel provide adequate shielding for most samples encountered. However, samples reading 75 rad/hr γ have been examined by adding extra shielding in the form of tungsten sample holders and external lead shadow shields. Some degradation of secondary electron imaging was seen but was adequately compensated for by changing operating conditions

  15. Problems of the power plant shield optimization

    International Nuclear Information System (INIS)

    Abagyan, A.A.; Dubinin, A.A.; Zhuravlev, V.I.; Kurachenko, Yu.A.; Petrov, Eh.E.

    1981-01-01

    General approaches to the solution of problems on the nuclear power plant radiation shield optimization are considered. The requirements to the shield parameters are formulated in a form of restrictions on a number of functionals, determined by the solution of γ quantum and neutron transport equations or dimensional and weight characteristics of shield components. Functional determined by weight-dimensional parameters (shield cost, mass and thickness) and functionals, determined by radiation fields (equivalent dose rate, produced by neutrons and γ quanta, activation functional, radiation functional, heat flux, integral heat flux in a particular part of the shield volume, total energy flux through a particular shield surface are considered. The following methods of numerical solution of simplified optimization problems are discussed: semiempirical methods using radiation transport physical leaks, numerical solution of approximate transport equations, numerical solution of transport equations for the simplest configurations making possible to decrease essentially a number of variables in the problem. The conclusion is drawn that the attained level of investigations on the problem of nuclear power plant shield optimization gives the possibility to pass on at present to the solution of problems with a more detailed account of the real shield operating conditions (shield temperature field account, its strength and other characteristics) [ru

  16. Thermal design of top shield for PFBR

    International Nuclear Information System (INIS)

    Gajapathy, R.; Jalaludeen, S.; Selvaraj, A.; Bhoje, S.B.

    1988-01-01

    India's Liquid Metal Cooled Fast Breeder Reactor programme started with the construction of loop type 13MW(e) Fast Breeder Test Reactor (FBTR) which attained criticality in October 1985. With the experience of FBTR, the design work on pool type 500 MW(e) Prototype Fast Breeder Reactor (PFBR) which will be a forerunner for future commercial fast breeder reactors, has been started. The Top Shield forms the cover for the main vessel which contains the primary circuit. Argon cover gas separates the Top Shield from the free level of hot sodium pool (803K). The Top Shield which is of box type construction consists of control plug, two rotatable plugs and roof slab, assembled together, which provide biological shielding, thermal shielding and leak tight containment at the top of the main vessel. Heat is transferred from the sodium pool to the Top Shield through argon cover gas and through components supported by it and dipped in the sodium pool. The Top Shield should be maintained at the desired operating temperature by incorporating a cooling system inside it. Insulation may be provided below the bottom plate to reduce the heat load to the cooling system, if required. The thermal design of Top Shield consists of estimation of heat transfer to the Top Shield, selection of operating temperature, assessment of insulation requirement, design of cooling system and evaluation of transient temperature changes

  17. Neutron shielding for a 252 Cf source

    International Nuclear Information System (INIS)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Eduardo Gallego, Alfredo Lorente

    2006-01-01

    To determine the neutron shielding features of water-extended polyester a Monte Carlo study was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through inelastic collisions and absorption reactions. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide production induced by neutron activation must be considered. In this investigation the Monte Carlo method was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a 252 Cf isotopic neutron source. During calculations a detailed model for the 252 Cf and the shield was utilized. To compare the shielding features of water extended polyester, the calculations were also made for the bare 252 Cf in vacuum, air and the shield filled with water. For all cases the calculated neutron spectra was utilized to determine the ambient equivalent neutron dose at four sites around the shielding. In the case of water extended polyester and water shielding the calculations were extended to include the prompt gamma rays produced during neutron interactions, with this information the Kerma in air was calculated at the same locations where the ambient equivalent neutron dose was determined. (Author)

  18. Hot Cell Window Shielding Analysis Using MCNP

    International Nuclear Information System (INIS)

    Pope, Chad L.; Scates, Wade W.; Taylor, J. Todd

    2009-01-01

    The Idaho National Laboratory Materials and Fuels Complex nuclear facilities are undergoing a documented safety analysis upgrade. In conjunction with the upgrade effort, shielding analysis of the Fuel Conditioning Facility (FCF) hot cell windows has been conducted. This paper describes the shielding analysis methodology. Each 4-ft thick window uses nine glass slabs, an oil film between the slabs, numerous steel plates, and packed lead wool. Operations in the hot cell center on used nuclear fuel (UNF) processing. Prior to the shielding analysis, shield testing with a gamma ray source was conducted, and the windows were found to be very effective gamma shields. Despite these results, because the glass contained significant amounts of lead and little neutron absorbing material, some doubt lingered regarding the effectiveness of the windows in neutron shielding situations, such as during an accidental criticality. MCNP was selected as an analysis tool because it could model complicated geometry, and it could track gamma and neutron radiation. A bounding criticality source was developed based on the composition of the UNF. Additionally, a bounding gamma source was developed based on the fission product content of the UNF. Modeling the windows required field inspections and detailed examination of drawings and material specifications. Consistent with the shield testing results, MCNP results demonstrated that the shielding was very effective with respect to gamma radiation, and in addition, the analysis demonstrated that the shielding was also very effective during an accidental criticality.

  19. Radiation shielding application of lead glass

    International Nuclear Information System (INIS)

    Nathuram, R.

    2017-01-01

    Nuclear medicine and radiotherapy centers equipped with high intensity X-ray or teletherapy sources use lead glasses as viewing windows to protect personal from radiation exposure. Lead is the main component of glass which is responsible for shielding against photons. It is therefore essential to check the shielding efficiency before they are put in use. This can be done by studying photon transmission through the lead glasses. The study of photon transmission in shielding materials has been an important subject in medical physics and is potential useful in the development of radiation shielding materials

  20. Radiation dose reduction by water shield

    International Nuclear Information System (INIS)

    Zeb, J.; Arshed, W.; Ahmad, S.S.

    2007-06-01

    This report is an operational manual of shielding software W-Shielder, developed at Health Physics Division (HPD), Pakistan Institute of Nuclear Science and Technology (PINSTECH), Pakistan Atomic Energy Commission. The software estimates shielding thickness for photons having their energy in the range 0.5 to 10 MeV. To compute the shield thickness, self absorption in the source has been neglected and the source has been assumed as a point source. Water is used as a shielding material in this software. The software is helpful in estimating the water thickness for safe handling, storage of gamma emitting radionuclide. (author)

  1. Combating corrosion in biomass and waste fired plant

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Pamela [Vattenfall AB, Stockholm (Sweden). Research and Development; Hjoernhede, Anders [Vattenfall AB, Gothenburg (Sweden). Power Consultant

    2010-07-01

    Many biomass- or waste-fired plants have problems with high temperature corrosion especially if the steam temperature is greater than 500 C. An increase in the combustion of waste fuels means that an increasing number of boilers have had problems. Therefore, there is great interest in reducing the costs associated with high temperature corrosion and at the same time there exists a desire to improve the electrical efficiency of a plant by the use of higher steam temperatures. Assuming that the fuel is well-mixed and that there is good combustion control, there are in addition a number of other measures which can be used to reduce superheater corrosion in biomass and waste fired plants, and these are described in this paper. These include the use of fuel additives, specifically sulphur-containing ones; design aspects like placing superheaters in less corrosive positions in a boiler, using tube shielding, a wider pitch between the tubes; operational considerations such as more controlled soot-blowing and the use of better materials. (orig.)

  2. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.

    1994-01-01

    Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially of planned decommissioning operations. Thus lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for contaminated lead is removing the superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a scaled-off area. The slurry of abrasive and particles of lead falls through a floor and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

  3. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.W.

    1993-01-01

    Lead used for shielding is often surface contaminated with radionuclides and is therefore a Resource Conservation and Recovery Act (RCRA) D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Lab. decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 100 metric tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 280 kPa (40 psig) rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a pump. A pump sends the slurry mixture back to the spray gun, creating a continuous process

  4. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.W.

    1993-01-01

    Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium trader pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of contaminated lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

  5. TPX remote maintenance and shielding

    International Nuclear Information System (INIS)

    Rennich, M.J.; Nelson, B.E.

    1994-01-01

    The Tokamak Physics Experiment machine design incorporates comprehensive planning for efficient and safe component maintenance. Three programmatic decisions have been made to insure the successful implementation of this objective. First, the tokamak incorporates radiation shielding to reduce activation of components and limit the dose rate to personnel working on the outside of the machine. This allows most of the ex-vessel equipment to be maintained through conventional ''hands-on'' procedures. Second, to the maximum extent possible, low activation materials will be used inside the shielding volume. This resulted in the selection of Titanium (Ti-6Al-4V) for the vacuum vessel and PFC structures. The third decision stipulated that the primary in-vessel components will be replaced or repaired via remote maintenance tools specifically provided for the task. The component designers have been given the responsibility of incorporating maintenance design and for proving the maintainability of the design concepts in full-scale mockup tests prior to the initiation of final fabrication. Remote maintenance of the TPX machine is facilitated by general purpose tools provided by a special purpose design team. Major tools will include an in-vessel transporter, a vessel transfer system and a large component transfer container. In addition, tools such as manipulators and remotely operable impact wrenches will be made available to the component designers by this group. Maintenance systems will also provide the necessary controls for this equipment

  6. Isotope effects on nuclear shielding

    International Nuclear Information System (INIS)

    Hansen, P.E.

    1983-01-01

    This review concentrates upon empirical trends and practical uses of mostly secondary isotope effects, both of the intrinsic and equilibrium types. The text and the tables are arranged in the following fashion. The most 'popular' isotope effect is treated first, deuterium isotope effects on 13 C nuclear shielding, followed by deuterium on 1 H nuclear shieldings, etc. Focus is thus on the isotopes producing the effect rather than on the nuclei suffering the effect. After a brief treatment of each type of isotope effect, general trends are dealt with. Basic trends of intrinsic isotope effects such as additivity, solvent effects, temperature effects, steric effects, substituent effects and hyperconjugation are discussed. Uses of isotope effects for assignment purposes, in stereochemical studies, in hydrogen bonding and in isotopic tracer studies are dealt with. Kinetic studies, especially of phosphates, are frequently performed by utilizing isotope effects. In addition, equilibrium isotope effects are treated in great detail as these are felt to be new and very important and may lead to new uses of isotope effects. Techniques used to obtain isotope effects are briefly surveyed at the end of the chapter. (author)

  7. Continuous electrodeionization through electrostatic shielding

    International Nuclear Information System (INIS)

    Dermentzis, Konstantinos

    2008-01-01

    We report a new continuous electrodeionization cell with electrostatically shielded concentrate compartments or electrochemical Faraday cages formed by porous electronically and ionically conductive media, instead of permselective ion exchange membranes. Due to local elimination of the applied electric field within the compartments, they electrostatically retain the incoming ions and act as 'electrostatic ion pumps' or 'ion traps' and therefore concentrate compartments. The porous media are chemically and thermally stable. Electrodeionization or electrodialysis cells containing such concentrate compartments in place of ion exchange membranes can be used to regenerate ion exchange resins and produce deionized water, to purify industrial effluents and desalinate brackish or seawater. The cells can work by polarity reversal without any negative impact to the deionization process. Because the electronically and ionically active media constituting the electrostatically shielded concentrate compartments are not permselective and coions are not repelled but can be swept by the migrating counterions, the cells are not affected by the known membrane associated limitations, such as concentration polarization or scaling and show an increased current efficiency

  8. Development of sulfuric acid dew point corrosion resistant stainless steel for smokestacks and its ducts. Entotsu endoyo tairyusan roten fushoku stainless ko no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, E.; Matsuhashi, R.; Koseki, T. (Nippon Steel Corp., Tokyo (Japan)); Ebara, R.; Nakamoto, H. (Mitsubishi Heavy Industries, Ltd., Tokyo (Japan))

    1993-05-20

    A new corrosion resistant steel was developed as a metal system lining material to prevent sulfuric acid dew point corrosion in smokestacks and ducts. SO3 in stack gas turns to sulfuric acid as a result of reacting with coexistent moisture in non-steady conditions during boiler actuation and shutdown when smokestack walls have low temperatures. When sulfuric acid thus generated contacts with metallic materials at temperatures lower than the sulfuric acid dew point temperature, sulfuric acid dew point corrosion occurs. During boiler steady operation, localized corrosion develops at clearance between salt deposits and the metallic materials. In order to improve the corrosion resistance, Mo, Cu and N were added in a reasonable range of amount. Entire surface corrosion resistance and local corrosion resistance were experimented in aqueous solutions simulating the smokestack environments to derive relational formulas with steel compositions. The new corrosion resistant steel met the the entire surface and local corrosion resistance requirements and was found economical. Low torsional velocity tensile and U-bend tests proved the steel satisfying the stress corrosion resistance requirement. Semi-automatic CO2 welding and shielded are welding provided good workability with no cracking, and impact strength and corrosion resistance in joints equivalent to those in the base material. 3 refs., 4 figs., 4 tabs.

  9. General and Localized corrosion of Austenitic and Borated Stainless Steels in Simulated Concentrated Ground Waters

    International Nuclear Information System (INIS)

    Fix, D.; Estill, J.; Wong, L.; Rebak, R.

    2004-01-01

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water

  10. Corrosion resistant cemented carbide

    International Nuclear Information System (INIS)

    Hong, J.

    1990-01-01

    This paper describes a corrosion resistant cemented carbide composite. It comprises: a granular tungsten carbide phase, a semi-continuous solid solution carbide phase extending closely adjacent at least a portion of the grains of tungsten carbide for enhancing corrosion resistance, and a substantially continuous metal binder phase. The cemented carbide composite consisting essentially of an effective amount of an anti-corrosion additive, from about 4 to about 16 percent by weight metal binder phase, and with the remaining portion being from about 84 to about 96 percent by weight metal carbide wherein the metal carbide consists essentially of from about 4 to about 30 percent by weight of a transition metal carbide or mixtures thereof selected from Group IVB and of the Periodic Table of Elements and from about 70 to about 96 percent tungsten carbide. The metal binder phase consists essentially of nickel and from about 10 to about 25 percent by weight chromium, the effective amount of an anti-corrosion additive being selected from the group consisting essentially of copper, silver, tine and combinations thereof

  11. Corrosion resistant steel

    International Nuclear Information System (INIS)

    Zubchenko, A.S.; Borisov, V.P.; Latyshev, V.B.

    1980-01-01

    Corrosion resistant steel for production of sheets and tubes containing C, Mn, Cr, Si, Fe is suggested. It is alloyed with vanadium and cerium for improving tensile properties and ductility. The steel can be melted by a conventional method in electric-arc or induction furnaces. The mentioned steel is intended to be used as a substitute for nickel-bearing austenitic steels

  12. Corrosion in seawater systems

    International Nuclear Information System (INIS)

    Henrikson, S.

    1988-01-01

    Highly alloyed stainless steels have been exposed to natural chlorinated and chlorine-free seawater at 35 deg. C. Simulated tube-tubesheet joints, weld joints and galvanic couples with titanium, 90/10 CuNi and NiAl bronze were tested and evaluated for corrosion. The corrosion rates of various anode materials - zinc, aluminium and soft iron - were also determined. Finally the risk of hydrogen embrittlement of tubes of ferritic stainless steels and titanium as a consequence of cathodic protection was studied. An attempt was also made to explain the cracking mechanism of the ferritic steels by means of transmission electron microscopy. One important conclusion of the project is that chlorinated seawater is considerably more corrosive to stainless steels than chlorine-free water, whereas chlorination reduces the rate of galvanic corrosion of copper materials coupled to stainless steels. Hydrogen embrittlement of ferritic stainless steels and titanium as a consequence of cathodic protection of carbon steel or cast iron in the same structure can be avoided by strict potentiostatic control of the applied potential. (author)

  13. Corrosion resistant composite materials

    International Nuclear Information System (INIS)

    Ul'yanin, E.A.

    1986-01-01

    Foundations for corrosion-resistant composite materials design are considered with account of components compatibility. Fibrous and lamellar composites with metal matrix, dispersion-hardened steels and alloys, refractory metal carbides-, borides-, nitrides-, silicides-based composites are described. Cermet compositions and fields of their application, such as protective coatings for operation in agressive media at high temperatures, are presented

  14. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  15. Corrosion potential analysis system

    Science.gov (United States)

    Kiefer, Karl F.

    1998-03-01

    Many cities in the northeastern U.S. transport electrical power from place to place via underground cables, which utilize voltages from 68 kv to 348 kv. These cables are placed in seamless steel pipe to protect the conductors. These buried pipe-type-cables (PTCs) are carefully designed and constantly pressurized with transformer oil to prevent any possible contamination. A protective coating placed on the outside diameter of the pipe during manufacture protects the steel pipe from the soil environment. Notwithstanding the protection mechanisms available, the pipes remain vulnerable to electrochemical corrosion processes. If undetected, corrosion can cause the pipes to leak transformer oil into the environment. These leaks can assume serious proportions due to the constant pressure on the inside of the pipe. A need exists for a detection system that can dynamically monitor the corrosive potential on the length of the pipe and dynamically adjust cathodic protection to counter local and global changes in the cathodic environment surrounding the pipes. The northeastern United States contains approximately 1000 miles of this pipe. This milage is critical to the transportation and distribution of power. So critical, that each of the pipe runs has a redundant double running parallel to it. Invocon, Inc. proposed and tested a technically unique and cost effective solution to detect critical corrosion potential and to communicate that information to a central data collection and analysis location. Invocon's solution utilizes the steel of the casing pipe as a communication medium. Each data gathering station on the pipe can act as a relay for information gathered elsewhere on the pipe. These stations must have 'smart' network configuration algorithms that constantly test various communication paths and determine the best and most power efficient route through which information should flow. Each network station also performs data acquisition and analysis tasks that ultimately

  16. Mobile evaporator corrosion test results

    International Nuclear Information System (INIS)

    Rozeveld, A.; Chamberlain, D.B.

    1997-05-01

    Laboratory corrosion tests were conducted on eight candidates to select a durable and cost-effective alloy for use in mobile evaporators to process radioactive waste solutions. Based on an extensive literature survey of corrosion data, three stainless steel alloys (304L, 316L, AL-6XN), four nickel-based alloys (825, 625, 690, G-30), and titanium were selected for testing. The corrosion tests included vapor phase, liquid junction (interface), liquid immersion, and crevice corrosion tests on plain and welded samples of candidate materials. Tests were conducted at 80 degrees C for 45 days in two different test solutions: a nitric acid solution. to simulate evaporator conditions during the processing of the cesium ion-exchange eluant and a highly alkaline sodium hydroxide solution to simulate the composition of Tank 241-AW-101 during evaporation. All of the alloys exhibited excellent corrosion resistance in the alkaline test solution. Corrosion rates were very low and localized corrosion was not observed. Results from the nitric acid tests showed that only 316L stainless steel did not meet our performance criteria. The 316L welded interface and crevice specimens had rates of 22.2 mpy and 21.8 mpy, respectively, which exceeds the maximum corrosion rate of 20 mpy. The other welded samples had about the same corrosion resistance as the plain samples. None of the welded samples showed preferential weld or heat-affected zone (HAZ) attack. Vapor corrosion was negligible for all alloys. All of the alloys except 316L exhibited either open-quotes satisfactoryclose quotes (2-20 mpy) or open-quotes excellentclose quotes (<2 mpy) corrosion resistance as defined by National Association of Corrosion Engineers. However, many of the alloys experienced intergranular corrosion in the nitric acid test solution, which could indicate a susceptibility to stress corrosion cracking (SCC) in this environment

  17. Improvements in or relating to nuclear shields

    International Nuclear Information System (INIS)

    Hawkins, R.J.; Riley, K.; Powell, C.

    1981-01-01

    A nuclear radiation shield comprises two pieces of steel held together edge to edge by a weld, the depth of which is less than the thickness of either of the edges. As the radiaion shielding effect of the weld will be less than the steel, an insert is bolted or welded over the weld. (U.K.)

  18. Shielding effectiveness of superconductive particles in plastics

    International Nuclear Information System (INIS)

    Pienkowski, T.; Kincaid, J.; Lanagan, M.T.; Poeppel, R.B.; Dusek, J.T.; Shi, D.; Goretta, K.C.

    1988-09-01

    The ability to cool superconductors with liquid nitrogen instead of liquid helium has opened the door to a wide range of research. The well known Meissner effect, which states superconductors are perfectly diamagnetic, suggests shielding applications. One of the drawbacks to the new ceramic superconductors is the brittleness of the finished material. Because of this drawback, any application which required flexibility (e.g., wire and cable) would be impractical. Therefore, this paper presents the results of a preliminary investigation into the shielding effectiveness of YBa 2 Cu 3 O/sub 7-x/ both as a composite and as a monolithic material. Shielding effectiveness was measured using two separate test methods. One tested the magnetic (near field) shielding, and the other tested the electromagnetic (far field) shielding. No shielding was seen in the near field measurements on the composite samples, and only one heavily loaded sample showed some shielding in the far field. The monolithic samples showed a large amount of magnetic shielding. 5 refs., 5 figs

  19. Preliminary radiation shielding design for BOOMERANG

    International Nuclear Information System (INIS)

    Donahue, Richard J.

    2002-01-01

    Preliminary radiation shielding specifications are presented here for the 3 GeV BOOMERANG Australian synchrotron light source project. At this time the bulk shield walls for the storage ring and injection system (100 MeV Linac and 3 GeV Booster) are considered for siting purposes

  20. Actively shielded low level gamma - spectrometric system

    International Nuclear Information System (INIS)

    Mrdja, D.; Bikit, I.; Forkapic, S.; Slivka, J.; Veskovic, M.

    2005-01-01

    The results of the adjusting and testing of the actively shielded low level gamma-spectrometry system are presented. The veto action of the shield reduces the background in the energy region of 50 keV to the 2800 keV for about 3 times. (author) [sr

  1. Optimization of multi-layered metallic shield

    International Nuclear Information System (INIS)

    Ben-Dor, G.; Dubinsky, A.; Elperin, T.

    2011-01-01

    Research highlights: → We investigated the problem of optimization of a multi-layered metallic shield. → The maximum ballistic limit velocity is a criterion of optimization. → The sequence of materials and the thicknesses of layers in the shield are varied. → The general problem is reduced to the problem of Geometric Programming. → Analytical solutions are obtained for two- and three-layered shields. - Abstract: We investigate the problem of optimization of multi-layered metallic shield whereby the goal is to determine the sequence of materials and the thicknesses of the layers that provide the maximum ballistic limit velocity of the shield. Optimization is performed under the following constraints: fixed areal density of the shield, the upper bound on the total thickness of the shield and the bounds on the thicknesses of the plates manufactured from every material. The problem is reduced to the problem of Geometric Programming which can be solved numerically using known methods. For the most interesting in practice cases of two-layered and three-layered shields the solution is obtained in the explicit analytical form.

  2. Alignment modification for pencil eye shields

    International Nuclear Information System (INIS)

    Evans, M.D.; Pla, M.; Podgorsak, E.B.

    1989-01-01

    Accurate alignment of pencil beam eye shields to protect the lens of the eye may be made easier by means of a simple modification of existing apparatus. This involves drilling a small hole through the center of the shield to isolate the rayline directed to the lens and fabricating a suitable plug for this hole

  3. Several problems in accelerator shielding study

    International Nuclear Information System (INIS)

    Nakamura, Takashi; Hirayama, Hideo; Ban, Shuichi.

    1980-01-01

    Recently, the utilization of accelerators has increased rapidly, and the increase of accelerating energy and beam intensity is also remarkable. The studies on accelerator shielding have become important, because the amount of radiation emitted from accelerators increased, the regulation of the dose of environmental radiation was tightened, and the cost of constructing shielding rose. As the plans of constructing large accelerators have been made successively, the survey on the present state and the problems of the studies on accelerator shielding was carried out. Accelerators are classified into electron accelerators and proton accelerators in view of the studies on shielding. In order to start the studies on accelerator shielding, first, the preparation of the cross section data is indispensable. The cross sections for generating Bremsstrahlung, photonuclear reactions generating neutrons, generation of neutrons by hadrons, nuclear reaction of neutrons and generation of gamma-ray by hadrons are described. The generation of neutrons and gamma-ray as the problems of thick targets is explained. The shielding problems are complex and diversified, but in this paper, the studies on the shielding, by which basic data are obtainable, are taken up, such as beam damping and side wall shielding. As for residual radioactivity, main nuclides and the difference of residual radioactivity according to substances have been studied. (J.P.N.)

  4. Collection shield for ion separation apparatus

    International Nuclear Information System (INIS)

    Ford, K.L.; Pugh, R.A.

    1981-01-01

    The ion separation electrodes in isotope separation apparatus are provided with removable collection shields to collect neutral particles which would normally pass through the ionization region. A preferred collection shield comprises a u-shaped section for clipping onto the leading edge of an electrode and a pair of flanges projecting substantially perpendicular to the clipping section for collecting neutral particles

  5. Current status of methods for shielding analysis

    International Nuclear Information System (INIS)

    Engle, W.W.

    1980-01-01

    Current methods used in shielding analysis and recent improvements in those methods are discussed. The status of methods development is discussed based on needs cited at the 1977 International Conference on Reactor Shielding. Additional areas where methods development is needed are discussed

  6. Thermal neutron shield and method of manufacture

    Science.gov (United States)

    Brindza, Paul Daniel; Metzger, Bert Clayton

    2013-05-28

    A thermal neutron shield comprising concrete with a high percentage of the element Boron. The concrete is least 54% Boron by weight which maximizes the effectiveness of the shielding against thermal neutrons. The accompanying method discloses the manufacture of Boron loaded concrete which includes enriching the concrete mixture with varying grit sizes of Boron Carbide.

  7. Shielding augmentation of roll-on shield from NAPS to Kaiga-2

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Kumar, A.N.

    2000-01-01

    Extensive radiation field surveys were conducted in NAPS and KAPS reactor buildings as a part of commissioning checks on radiation shielding. During such surveys, dose rate higher than the expected values were noticed in fuelling machine service areas. A movable shield, separating high field area fuelling machine vault and low field area fuelling machine service area, known as roll-on shield was identified as one of the causes of high field in fuelling machine service area along with weaker end-shield. This paper discusses systematic approach adopted in bringing down the dose rates in fuelling machine service area by augmentation of roll-on shield. (author)

  8. Management of irrigation frequency and nitrogen fertilization to mitigate GHG and NO emissions from drip-fertigated crops

    Energy Technology Data Exchange (ETDEWEB)

    Abalos, Diego, E-mail: diego.abalos@upm.es [ETSI Agronomos, Technical University of Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Sanchez-Martin, Laura; Garcia-Torres, Lourdes [ETSI Agronomos, Technical University of Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Groenigen, Jan Willem van [Department of Soil Quality, Wageningen University, PO Box 47, 6700 AA Wageningen (Netherlands); Vallejo, Antonio [ETSI Agronomos, Technical University of Madrid, Ciudad Universitaria, 28040 Madrid (Spain)

    2014-08-15

    Drip irrigation combined with split application of fertilizer nitrogen (N) dissolved in the irrigation water (i.e. drip fertigation) is commonly considered best management practice for water and nutrient efficiency. As a consequence, its use is becoming widespread. Some of the main factors (water-filled pore space, NH{sub 4}{sup +} and NO{sub 3}{sup −}) regulating the emissions of greenhouse gases (i.e. N{sub 2}O, CO{sub 2} and CH{sub 4}) and NO from agroecosystems can easily be manipulated by drip fertigation without yield penalties. In this study, we tested management options to reduce these emissions in a field experiment with a melon (Cucumis melo L.) crop. Treatments included drip irrigation frequency (weekly/daily) and type of N fertilizer (urea/calcium nitrate) applied by fertigation. Crop yield, environmental parameters, soil mineral N concentrations and fluxes of N{sub 2}O, NO, CH{sub 4} and CO{sub 2} were measured during 85 days. Fertigation with urea instead of calcium nitrate increased N{sub 2}O and NO emissions by a factor of 2.4 and 2.9, respectively (P < 0.005). Daily irrigation reduced NO emissions by 42% (P < 0.005) but increased CO{sub 2} emissions by 21% (P < 0.05) compared with weekly irrigation. We found no relation between irrigation frequency and N{sub 2}O emissions. Based on yield-scaled Global Warming Potential as well as NO cumulative emissions, we conclude that weekly fertigation with a NO{sub 3}{sup −}-based fertilizer is the best option to combine agronomic productivity with environmental sustainability. Our study shows that adequate management of drip fertigation, while contributing to the attainment of water and food security, may provide an opportunity for climate change mitigation. - Highlights: • The effect of fertigation management techniques on GHG and NO emissions was studied. • Fertigation with urea instead of calcium nitrate increased N{sub 2}O by a factor of 2.4. • Daily irrigation reduced NO (42%) but increased CO

  9. Simulation of Salinity Distribution in Soil Under Drip Irrigation Tape with Saline Water Using SWAP Model

    Directory of Open Access Journals (Sweden)

    M. Tabei

    2016-02-01

    Full Text Available Introduction: The to be limited available water amount from one side and to be increased needs of world population from the other side have caused increase of cultivation for products. For this reason, employing new irrigation ways and using new water resources like using the uncommon water (salty water, water drainage are two main strategies for regulating water shortage conditions. On the other side, accumulation of salts on the soil surface in dry regions having low rainfall and much evaporation, i.e. an avoidable case. As doing experiment for determining moisture distribution form demands needs a lot of time and conducting desert experiments are costly, stimulator models are suitable alternatives in answering the problem concerning moving and saltiness distribution. Materials and Methods: In this research, simulation of soil saltiness under drip irrigation was done by the SWAP model and potency of the above model was done in comparison with evaluated relevant results. SWAP model was performed based on measured data in a corn field equipped with drip irrigation system in the farming year 1391-92 in the number one research field in the engineering faculty of water science, ShahidChamran university of Ahvaz and hydraulic parameters of soil obtained from RETC . Statistical model in the form of a random full base plan with four attendants for irrigating water saltiness including salinity S1 (Karoon River water with salinity 3 ds/m as a control treatment, S2 (S1 +0/5, S3 (S1 +1 and S4 (S1 +1/5 dS/m, in 3 repetition and in 3 intervals of 10 cm emitter, 20 cm emitters on the stack, at a depth of 0-90 cm (instead of each 30 cm from soil surface and intervals of 30, 60 and 90 days after modeling cultiviation was done. The cultivation way was done handheld in plots including four rows of 3 m in distance of 75 cm rows and with denseness of 80 bushes in a hectar. Drip irrigation system was of type strip with space of 20 cm pores. Results and Discussion

  10. Radiation Shielding Systems Using Nanotechnology

    Science.gov (United States)

    Chen, Bin (Inventor); McKay, Christoper P. (Inventor)

    2011-01-01

    A system for shielding personnel and/or equipment from radiation particles. In one embodiment, a first substrate is connected to a first array or perpendicularly oriented metal-like fingers, and a second, electrically conducting substrate has an array of carbon nanostructure (CNS) fingers, coated with an electro-active polymer extending toward, but spaced apart from, the first substrate fingers. An electric current and electric charge discharge and dissipation system, connected to the second substrate, receives a current and/or voltage pulse initially generated when the first substrate receives incident radiation. In another embodiment, an array of CNSs is immersed in a first layer of hydrogen-rich polymers and in a second layer of metal-like material. In another embodiment, a one- or two-dimensional assembly of fibers containing CNSs embedded in a metal-like matrix serves as a radiation-protective fabric or body covering.

  11. Radiation shielding and safety design

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Ouk; Gil, C. S.; Cho, Y. S.; Kim, D. H.; Kim, H. I.; Kim, J. W.; Lee, C. W.; Kim, K. Y.; Kim, B. H. [KAERI, Daejeon (Korea, Republic of)

    2011-07-15

    A benchmarking for the test facility, evaluations of the prompt radiation fields, evaluation of the induced activities in the facility, and estimation of the radiological impact on the environment were performed in this study. and the radiation safety analysis report for nuclear licensing was written based on this study. In the benchmark calculation, the neutron spectra was measured in the 20 Mev test facility and the measurements were compared with the computational results to verify the calculation system. In the evaluation of the prompt radiation fields, the shielding design for 100 MeV target rooms, evaluations of the leakage doses from the accidents and skyshine analysis were performed. The evaluation of the induced activities were performed for the coolant, inside air, structural materials, soil and ground-water. At last, the radiation safety analysis report was written based on results from these studies

  12. Shield verification and validation action matrix summary

    International Nuclear Information System (INIS)

    Boman, C.

    1992-02-01

    WSRC-RP-90-26, Certification Plan for Reactor Analysis Computer Codes, describes a series of action items to be completed for certification of reactor analysis computer codes used in Technical Specifications development and for other safety and production support calculations. Validation and verification are integral part of the certification process. This document identifies the work performed and documentation generated to satisfy these action items for the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system, it is not certification of the complete SHIELD system. Complete certification will follow at a later date. Each action item is discussed with the justification for its completion. Specific details of the work performed are not included in this document but can be found in the references. The validation and verification effort for the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system computer code is completed

  13. Practical radiation shielding for biomedical research

    International Nuclear Information System (INIS)

    Klein, R.C.; Reginatto, M.; Party, E.; Gershey, E.L.

    1990-01-01

    This paper reports on calculations which exist for estimating shielding required for radioactivity; however, they are often not applicable for the radionuclides and activities common in biomedical research. A variety of commercially available Lucite shields are being marketed to the biomedical community. Their advertisements may lead laboratory workers to expect better radiation protection than these shields can provide or to assume erroneously that very weak beta emitters require extensive shielding. The authors have conducted a series of shielding experiments designed to simulate exposures from the amounts of 32 P, 51 Cr and 125 I typically used in biomedical laboratories. For most routine work, ≥0.64 cm of Lucite covered with various thicknesses of lead will reduce whole-body occupational exposure rates of < 1mR/hr at the point of contact

  14. PC based temporary shielding administrative procedure (TSAP)

    International Nuclear Information System (INIS)

    Olsen, D.E.; Pederson, G.E.; Hamby, P.N.

    1995-01-01

    A completely new Administrative Procedure for temporary shielding was developed for use at Commonwealth Edison's six nuclear stations. This procedure promotes the use of shielding, and addresses industry requirements for the use and control of temporary shielding. The importance of an effective procedure has increased since more temporary shielding is being used as ALARA goals become more ambitious. To help implement the administrative procedure, a personal computer software program was written to incorporate the procedural requirements. This software incorporates the useability of a Windows graphical user interface with extensive help and database features. This combination of a comprehensive administrative procedure and user friendly software promotes the effective use and management of temporary shielding while ensuring that industry requirements are met

  15. A perturbation technique for shield weight minimization

    International Nuclear Information System (INIS)

    Watkins, E.F.; Greenspan, E.

    1993-01-01

    The radiation shield optimization code SWAN (Ref. 1) was originally developed for minimizing the thickness of a shield that will meet a given dose (or another) constraint or for extremizing a performance parameter of interest (e.g., maximizing energy multiplication or minimizing dose) while maintaining the shield volume constraint. The SWAN optimization process proved to be highly effective (e.g., see Refs. 2, 3, and 4). The purpose of this work is to investigate the applicability of the SWAN methodology to problems in which the weight rather than the volume is the relevant shield characteristic. Such problems are encountered in shield design for space nuclear power systems. The investigation is carried out using SWAN with the coupled neutron-photon cross-section library FLUNG (Ref. 5)

  16. Mars Exploration Rover Heat Shield Recontact Analysis

    Science.gov (United States)

    Raiszadeh, Behzad; Desai, Prasun N.; Michelltree, Robert

    2011-01-01

    The twin Mars Exploration Rover missions landed successfully on Mars surface in January of 2004. Both missions used a parachute system to slow the rover s descent rate from supersonic to subsonic speeds. Shortly after parachute deployment, the heat shield, which protected the rover during the hypersonic entry phase of the mission, was jettisoned using push-off springs. Mission designers were concerned about the heat shield recontacting the lander after separation, so a separation analysis was conducted to quantify risks. This analysis was used to choose a proper heat shield ballast mass to ensure successful separation with low probability of recontact. This paper presents the details of such an analysis, its assumptions, and the results. During both landings, the radar was able to lock on to the heat shield, measuring its distance, as it descended away from the lander. This data is presented and is used to validate the heat shield separation/recontact analysis.

  17. Technology development for radiation shielding analysis

    International Nuclear Information System (INIS)

    Ha, Jung Woo; Lee, Jae Kee; Kim, Jong Kyung

    1986-12-01

    Radiation shielding analysis in nuclear engineering fields is an important technology which is needed for the calculation of reactor shielding as well as radiation related safety problems in nuclear facilities. Moreover, the design technology required in high level radioactive waste management and disposal facilities is faced on serious problems with rapidly glowing nuclear industry development, and more advanced technology has to be developed for tomorrow. The main purpose of this study is therefore to build up the self supporting ability of technology development for the radiation shielding analysis in order to achieve successive development of nuclear industry. It is concluded that basic shielding calculations are possible to handle and analyze by using our current technology, but more advanced technology is still needed and has to be learned for the degree of accuracy in two-dimensional shielding calculation. (Author)

  18. PC based temporary shielding administrative procedure (TSAP)

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D.E.; Pederson, G.E. [Sargent & Lundy, Chicago, IL (United States); Hamby, P.N. [Commonwealth Edison Co., Downers Grove, IL (United States)

    1995-03-01

    A completely new Administrative Procedure for temporary shielding was developed for use at Commonwealth Edison`s six nuclear stations. This procedure promotes the use of shielding, and addresses industry requirements for the use and control of temporary shielding. The importance of an effective procedure has increased since more temporary shielding is being used as ALARA goals become more ambitious. To help implement the administrative procedure, a personal computer software program was written to incorporate the procedural requirements. This software incorporates the useability of a Windows graphical user interface with extensive help and database features. This combination of a comprehensive administrative procedure and user friendly software promotes the effective use and management of temporary shielding while ensuring that industry requirements are met.

  19. Repository Waste Package Transporter Shielding Weight Optimization

    International Nuclear Information System (INIS)

    C.E. Sanders; Shiaw-Der Su

    2005-01-01

    The Yucca Mountain repository requires the use of a waste package (WP) transporter to transport a WP from a process facility on the surface to the subsurface for underground emplacement. The transporter is a part of the waste emplacement transport systems, which includes a primary locomotive at the front end and a secondary locomotive at the rear end. The overall system with a WP on board weights over 350 metric tons (MT). With the shielding mass constituting approximately one-third of the total system weight, shielding optimization for minimal weight will benefit the overall transport system with reduced axle requirements and improved maneuverability. With a high contact dose rate on the WP external surface and minimal personnel shielding afforded by the WP, the transporter provides radiation shielding to workers during waste emplacement and retrieval operations. This paper presents the design approach and optimization method used in achieving a shielding configuration with minimal weight

  20. The use of nipple shields: A review

    Directory of Open Access Journals (Sweden)

    Selina Chow

    2016-11-01

    Full Text Available A nipple shield is a breastfeeding aid with a nipple-shaped shield that is positioned over the nipple and areola prior to nursing. Nipple shields are usually recommended to mothers with flat nipples or in cases in which there is a failure of the baby to effectively latch onto the breast within the first two days postpartum. The use of nipple shields is a controversial topic in the field of lactation. Its use has been an issue in the clinical literature since some older studies discovered reduced breast milk transfer when using nipple shields, while more recent studies reported successful breastfeeding outcomes. The purpose of this review was to examine the evidence and outcomes with nipple shield use. Methods: A literature search was conducted in Ovid MEDLINE, OLDMEDLINE, EMBASE Classic, EMBASE, Cochrane Central Register of Controlled Trials and CINAHL. The primary endpoint was any breastfeeding outcome following nipple shield use. Secondary endpoints included the reasons for nipple shield use and the average/median length of use. For the analysis, we examined the effect of nipple shield use on physiological responses, premature infants, mothers’ experiences, and health professionals’ experiences. Results: The literature search yielded 261 articles, 14 of which were included in this review. Of these 14 articles, three reported on physiological responses, two reported on premature infants, eight reported on mothers’ experiences, and one reported on health professionals’ experiences. Conclusion: Through examining the use of nipple shields, further insight is provided on the advantages and disadvantages of this practice, thus allowing clinicians and researchers to address improvements on areas that will benefit mothers and infants the most.