WorldWideScience

Sample records for liner material collapse

  1. Thermoplastic liners for carbon steel pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Mehdi, Mauyed S.; AlDossary, Abdullah K. [Saudi Aramco, Dhahran (Saudi Arabia)

    2009-12-19

    Materials selection for pipe and fittings used to convey corrosive fluids has often been a challenge. Traditionally, exotic Corrosion Resistant Alloys (CRA) have been used in corrosive environments despite their high cost. Plastic lined carbon steel piping offers a cost effective alternative to the use of CRAs by eliminating corrosion, significantly reducing the use of toxic chemicals and the heavy metal usually present in CRAs. Thermoplastic Liners offer the combination of corrosion resistance and mechanical strength, which are unachievable with singular materials. Under pressure conditions, the liner is fully supported by the metalwork, while under vacuum conditions, the liner must be thick enough along with venting system to withstand the collapsing forces created by the negative pressure. Plastic liners have been used successfully to line and protect metallic pipelines for many years and have become an indispensable requirement of the oil and gas industry particularly with water injection and hydrocarbon services. In the case of internally corroded pipes, the use of thermoplastic liners for rehabilitation is an option to extend the lifetime of companies' assets, reduce maintenance cost and increase intervals between T and Is. For new construction, plastic liners in carbon steel pipes can compete technically and economically with pipelines of CRA materials and other corrosion inhibition systems. This paper describes various design features, installations of thermoplastic liners in comparison to other corrosion inhibition methods. (author)

  2. Composite-Material Tanks with Chemically Resistant Liners

    Science.gov (United States)

    DeLay, Thomas K.

    2004-01-01

    Lightweight composite-material tanks with chemically resistant liners have been developed for storage of chemically reactive and/or unstable fluids . especially hydrogen peroxide. These tanks are similar, in some respects, to the ones described in gLightweight Composite-Material Tanks for Cryogenic Liquids h (MFS-31379), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 58; however, the present tanks are fabricated by a different procedure and they do not incorporate insulation that would be needed to prevent boil-off of cryogenic fluids. The manufacture of a tank of this type begins with the fabrication of a reusable multisegmented aluminum mandrel in the shape and size of the desired interior volume. One or more segments of the mandrel can be aluminum bosses that will be incorporated into the tank as end fittings. The mandrel is coated with a mold-release material. The mandrel is then heated to a temperature of about 400 F (approximately equal to 200 C) and coated with a thermoplastic liner material to the desired thickness [typically approxiamtely equal to 15 mils (approximately equal to 0.38 mm)] by thermal spraying. In the thermal-spraying process, the liner material in powder form is sprayed and heated to the melting temperature by a propane torch and the molten particles land on the mandrel. The sprayed liner and mandrel are allowed to cool, then the outer surface of the liner is chemically and/or mechanically etched to enhance bonding of a composite overwrap. The etched liner is wrapped with multiple layers of an epoxy resin reinforced with graphite fibers; the wrapping can be done either by manual application of epoxy-impregnated graphite cloth or by winding of epoxy-impregnated filaments. The entire assembly is heated in an autoclave to cure the epoxy. After the curing process, the multisegmented mandrel is disassembled and removed from inside, leaving the finished tank. If the tank is to be used for storing hydrogen peroxide, then the liner material

  3. Utilization of sepiolite materials as a bottom liner material in solid waste landfills.

    Science.gov (United States)

    Guney, Yucel; Cetin, Bora; Aydilek, Ahmet H; Tanyu, Burak F; Koparal, Savas

    2014-01-01

    Landfill bottom liners are generally constructed with natural clay soils due to their high strength and low hydraulic conductivity characteristics. However, in recent years it is increasingly difficult to find locally available clay soils that satisfy the required engineering properties. Fine grained soils such as sepiolite and zeolite may be used as alternative materials in the constructions of landfill bottom liners. A study was conducted to investigate the feasibility of using natural clay rich in kaolinite, sepiolite, zeolite, and their mixtures as a bottom liner material. Unconfined compression tests, swell tests, hydraulic conductivity tests, batch and column adsorption tests were performed on each type of soil and sepiolite-zeolite mixtures. The results of the current study indicate that sepiolite is the dominant material that affects both the geomechanical and geoenvironmental properties of these alternative liners. An increase in sepiolite content in the sepiolite-zeolite mixtures increased the strength, swelling potential and metal adsorption capacities of the soil mixtures. Moreover, hydraulic conductivity of the mixtures decreased significantly with the addition of sepiolite. The utilization of sepiolite-zeolite materials as a bottom liner material allowed for thinner liners with some reduction in construction costs compared to use of a kaolinite-rich clay. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. CANMET Gasifier Liner Coupon Material Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Mark Fitzsimmons; Dave Grimmett; Bryan McEnerney

    2007-01-31

    This report provides detailed test results consisting of test data and post-test inspections from Task 1 ''Cooled Liner Coupon Development and Test'' of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources--Advanced Gasification Systems Development (AGSD)''. The primary objective of this development and test program is to verify that ceramic matrix composite (CMC) liner materials planned for use in an advanced gasifier pilot plant will successfully withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) designed and fabricated the cooled liner test assembly article that was tested in a slagging gasifier at CANMET Energy Technology Center (CETC-O) in Ottawa, Ontario, Canada. The test program conducted in 2006 met the objective of operating the cooled liner test article at slagging conditions in a small scale coal gasifier at CETC-O for over the planned 100 hours. The test hardware was exposed to at least 30 high temperature excursions (including start-up and shut-down cycles) during the test program. The results of the testing has provided valuable information on gasifier startup and required cooling controls in steady state operation of future advanced gasifiers using similar liners. The test program also provided a significant amount of information in the areas of CMC materials and processing for improved capability in a gasifier environment and insight into CMC liner fabrication that will be essential for near-term advanced gasifier projects.

  5. Design of steel-liners and their anchorage with regard to non-linear behaviour of liner-material and anchorage

    International Nuclear Information System (INIS)

    Oberpichler, R.

    1979-01-01

    The thin steel liner attached by studs or rib-type anchors to the interior wall of a Prestressed Concrete Reactor Pressure Vessel (PCRV) or a Concrete Containment Vessel (PCCV) has to provide the leak-tightness of the vessel. The liner also may serve as internal shuttering for placing concrete as well as a support for the cooling system or thermal isolation. Mainly strained by self-limited loads imposed on the liner by deformations of the vessel-wall or by heatup inside the vessel the liner predominantly will function in a compressive biaxially strained state like a membrane. The vessel-wall is assumed to be a rigid boundary without reactions caused by the liner-anchor-restraints. Furthermore it is assumed that the liner supported in a close-spaced pattern to the concrete with respect to self-limited loads and all effects of non-linear behaviour of liner-material and non-linear anchor-characteristics will not fail by instability, especially not by an effect of snapthrough. Only one essential mode of failure, the shear connector failure is assumed to be basis for all liner investigations. Design of the liner and its anchorage therefore is based on the analysis of large deformations with regard to elastic-plastic behaviour of liner-material and non-linear anchor characteristics. By this method both economical and safe sizing and spacing of the anchors can be calculated. (orig.)

  6. Correlating shaped charge performance with processing conditions and microstructure of an aluminum alloy 1100 liner enabled by a new method to arrest nascent jet formation

    Science.gov (United States)

    Scheid, James Eric

    Aluminum-lined shaped charges are used in special applications where jet and / or slug residue in the target is undesired. The three different microstructures of the aluminum liners studied herein resulted from three different manufacturing interpretations of the same design. One interpretation was completely machining the liners from best available annealed round stock. The second was to cold-forge the liners from annealed round-stock in an open-die forge to near-final dimensions, and then machine the liners to the final dimensions. The third variant in this study was to use the above forged liner, but with annealing after the machining. These three manufacturing choices resulted in significant variations in shaped charge performance. The goal of this research was to clarify the relationships between the liner metal microstructure and properties, and the corresponding shaped charge dynamic flow behavior. What began as an investigation into user-reported performance problems associated inherently with liner manufacturing processes and resultant microstructure, resolved into new understandings of the relationships between aluminum liner microstructure and shaped charge collapse kinetics. This understanding was achieved through an extensive literature review and the comprehensive characterization of the material properties of three variants of an 1100 aluminum shaped charge liner with a focus on collapse and nascent jet formation. The machined liner had a microstructure with large millimeter-sized grains and fine particles aligned in bands parallel to the charge axis. The forged liner microstructure consisted of very small one micrometer-sized (1 mum) subgrains and fine particles aligned largely in bands elongated parallel to the liner contour. The annealed liner was characterized by ten micrometer (10 mum) sized equiaxed grains with residual fine particles in the forged alignment. This characterization was enabled by the development, execution and validation of a

  7. Comprehensive review of geosynthetic clay liner and compacted clay liner

    Science.gov (United States)

    Shankar, M. Uma; Muthukumar, M.

    2017-11-01

    Human activity inevitably produces waste materials that must be managed. Some waste can be reused. However many wastes that cannot be used beneficially must be disposed of ensuring environmental safety. One of the common methods of disposal is landfilling. The most common problems of the landfill site are environmental degradation and groundwater contamination caused by leachate produced during the decomposition process of organic material and rainfall. Liner in a landfill is an important component which prevent leachate migration and prevent groundwater contamination. Earthen liners have been widely used to contain waste materials in landfill. Liners and covers for municipal and hazardous waste containment facilities are often constructed with the use of fine-grained, low plasticity soils. Because of low permeability geosynthetic clay liners and compacted clay liners are the main materials used in waste disposal landfills. This paper summaries the important geotechnical characteristics such as hydraulic conductivity, liquid limit and free swell index of geosynthetic clay liner and compacted clay liner based on research findings. This paper also compares geosynthetic clay liner and compacted clay liner based on certain criteria such as thickness, availability of materials, vulnerability to damage etc.

  8. Cracking investigation of Monju emergency generator C unit cylinder liner. Cylinder liner soundness confirmation by a fall cause of the materials strength of the cylinder liner and the supersonic wave speed

    International Nuclear Information System (INIS)

    Kobayashi, Takanori; Sakon, Miyoji; Takada, Osamu; Hatori, Masakazu; Sakamoto, Tsutomu; Sato, Toshiyuki; Kazama, Akihito; Ishizawa, Yoshihiro; Igawa, Katsuhisa; Nakae, Hideo

    2012-02-01

    I confirmed a leak of the effluent gas from cylinder part during a load examination after the check of the emergency generator C unit on December 28, 2010 of the facilities check average and confirmed crack in No.8 cylinder liner part. As a result, because it was not performed oil pressure management properly without attaching an oil pressure gauge when I removed cylinder liner about the cause, crack occurred by having been able to write excessive stress for the cylinder liner and reached damage. By a process of this investigation, a fall of the materials strength of some cylinder liner was confirmed, but because a lead ingredient got mixed with materials by a casting process at the time of the production of the cylinder liner, as for this, Widmannstaetten graphite occurred, and it became clear that materials strength fell. In addition, I performed inspection by the supersonic wave velocity measurement as technique to distinguish this Widmannstaetten graphite easily and confirmed that I was effective. Because this report was the knowledge that there were little inspection contents which modified soundness confirmation technique of the cylinder liner with the possibility of materials strength fall of the cylinder liner by the Widmannstaetten graphite outbreak and the mixture of lead for a report example in the field of cast iron, I gathered it in this report. (author)

  9. Radioactive wear tests of four cylinder liner materials

    International Nuclear Information System (INIS)

    Sylte, G.

    1976-01-01

    An investigation on the wear properties of various liner materials, financed by a research grant from NTNF (Royal Norwegian Council for Scientific and Industrial Research), is reported. The investigation was carried out by the Division of Internal Combustion Engines, Trondheim, Univ.,Norway, on a two-stroke, turbocharged, medium speed diesel engine (Wichmann 2ACAT, 280 by 420 mm). Thin pearlitic cast iron inserts of various compositions were pressed into the upper part of a specially machined cylinder liner. These inserts were activated in a nuclear reactor, and tracer techniques employed to measure the wear rate. Gas oil was used as a fuel throughout all tests. The insert technique employed, and the handling methods devised, were satisfactory. This part of the project must be characterised as being very successful. Originally, six different liner materials were specified, but due to misunderstandings duplications resulted in only four different materials finally being received at the laboratory. The engine tests disclosed that the wear rates of all four materials were low under laboratory conditions, and therefore difficult to measure accurately. Nevertheless, the wear properties of the inserts clearly fell into two distinct classes, which may be termed good and excellent. The relative values inside each group are, however, more uncertain due to the cumulative effects of errors, instrument drift, measurement statistics, etc. (Auth.)

  10. The effect of release liner materials on adhesive contaminants, paper recycling and recycled paper properties

    Science.gov (United States)

    Richard Venditti; Richard Gilbert; Andy Zhang; Said Abubakr

    2000-01-01

    Release liner waste material is found in post-consumer waste streams and is also a significant component of the preconsumer waste stream generated in the manufacturing of adhesive products. To date, very little has been reported pertaining to the behavior of release liner in paper recycling. In this study, the effect of the release liner material on the behavior of...

  11. Comparative parametric numerical simulations of materials used as liners in the explosively formed projectiles (EFPs)

    International Nuclear Information System (INIS)

    Hussain, G.; Sanaullah, K.

    2009-01-01

    A conventional shaped charge comprises a conical metal liner projecting a hyper velocity jet of metal that is able to penetrate to great depths into steel armour. However, misalignment problems exist in tandem with jet break up and spewing particles that greatly diminish its penetration power. An EFP, on the other hand, has a liner in the shape of a geometrical recess. The force of the blast molds the liner into a number of configurations, depending on the geometry and the explosive detonation characteristics. This paper presents comparative parametric numerical simulations of materials used as liners in the explosively formed projectiles EFPs. Numerical simulations are carried out using AUTODYN 2D hydrocode to study effects of liner's materials on the shape, velocity, traveled distance, time, pressure, internal energy, temperature, yield stress, divergence or stability, density, compression, and length to diameter (L/D) ratio of EFPs. These parameters are estimated at the instants of maximum as well as at stable velocities. The parametric study reveals that aluminum has maximum velocity in shortest time among the liner materials. From this reason, it was concluded effective standoff was greater for aluminum than more denser metals. Maximum velocity and traveled distance of Tantalum EFP is found to be minimum which may be due to low thermal softening exponent and larger hardening exponent. The simulated yield stress and pressure developed in the Fe EFP reaches at maximum. The L/D ratio for Copper is found to be maximum which supports maximum penetration. From the stability point of view, 1006 MS is found to be the most reliable liner material due to minimum divergence. Generally all liner materials have similar effects of all parameters like pressure, internal energy, temperature, yield stress, divergence or stability, density, compression at the instants of maximum as well as at stable velocities except L/D ratio of EFPs. At the instant of maximum velocity, L

  12. Comparative evaluation of liner materials for inactive uranium-mill-tailings piles

    International Nuclear Information System (INIS)

    Buelt, J.L.; Barnes, S.M.

    1981-01-01

    Under the funding of the Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Program, Pacific Northwest Laboratory (PNL) has completed the initial accelerated testing phase of eight candidate liner materials. The tests were designed to comparatively evaluate the long term effectiveness of liner materials as a radionuclide and hazardous chemical leachate barrier. The eight materials tested were selected from a technical review of published literature and industrial specialists. Conditions were then identified that would accelerate the aging processes expected in a uranium tailings environment for 1000 years. High calcium leachates were forced through thin layers of clay liners to accelerate the ion exchange rate of sodium and calcium. Asphalt and synthetic materials were accelerated by exposure to elevate temperatures, high concentrations of oxygen, and increased strengths of aqueous oxidizing agents. By comparing the changes of permeability with time of exposure, the most acceptable materials were then identified. These materials are a catalytically airblown asphalt membrane and natural soil amended with sodium bentonite. Both materials showed an increased resistance to leachate penetration throughout the exposure period with final permeabilities less than 10 -7 cm/s. In addition, the asphalt membrane and sodium bentonite are among the least expensive materials to install at a disposal site. Therefore based on their economic and technical merits, these two materials are being evaluated further in field tests at Grand Junction, Colorado

  13. Selection of Liner Materials and Design of Hazardous Water Facilities in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Sahel N. Abduljauwad

    2001-12-01

    Full Text Available Rapid development in Saudi Arabia has produced a broad spectrum of wastes.  In the last two decades, several refineries and petrochemical industries have been established. These industries have produced sludges and other toxic wastes which need proper planning for their handling and disposal. This paper covers design and selection of liner materials for two hazardous waste disposal sites. One of them is located in the Eastern Province of Saudi Arabia, while the second one is located in the Western part. The paper will present complete design details of the natural compacted and geosynthetic soil liners and the leachate collection and removal system for primary liners and leak detection/leachate collection and removal system for secondary liners.

  14. Stress analysis of liners for prestressed concrete reactor pressure vessels with regard to non-linear behaviour of liner material and of anchor-characteristics

    International Nuclear Information System (INIS)

    Oberpichler, R.; Schnellenbach, G.

    1975-01-01

    The thin liner attached by anchors like a membrane to the interior wall of a prestressed concrete reactor pressure vessel (PCRV) has to provide the leak-tightness of the vessel. Furthermore the liner may serve as internal shuttering for placing of concrete as well as a support for the cooling system. The two-dimensional behaviour of the liner is investigated with regard to non-linear anchor-characteristics and non-linear material behaviour of the liner. The analysis is based on a plane stress model under the assumption of a membrane state of the liner. Calculations are performed by the dynamic relaxation method. With the aid of available non-linear stress-strain diagrams, describing the post-buckling behaviour, individual panels are considered as buckled ones. The adjacent unbuckled panels are calculated on other non-linear diagrams. Strains and stresses in the liner and additional shear loads in the anchors can be calculated with arbitrary sizing and spacing of the anchors. With respect to the parameters they are easily controlled. Since actual loads on the liner are defined by the PCRV-behaviour, an economical and safe design is possible. Finally an extreme case is calculated to assess the maximum value of the shear-forces assuming zero post-buckling capacity for the buckled panel. (Auth.)

  15. Fabrication techniques of metal liner used for pressure vessels made by composite material

    International Nuclear Information System (INIS)

    Takahashi, W.K.; Al-Qureshi, H.A.

    1982-01-01

    Different viable techniques for the manufacturing of metal liner used for pressure vessels are presented. The aim of these metal liner is to avoid the fluid leakage from the pressurized vessel and to serve as a mandreal to be wound by composite material. The studied techniques are described and the practical results are illustrated. Finally a comparative study of the manufacturing techniques is made in order to define the process that furnishes the metal liner with the best characteristics. The advantages offered by these type of pressure vessels when compared with the conventional metallic vessels, are also presented. (Author) [pt

  16. Instruction manual: Fly ash stabilised sludge (FSS) as liner material; Vaegledning: Flygaskastabiliserat avloppsslam (FSA) som taetskikt

    Energy Technology Data Exchange (ETDEWEB)

    Carling, Maria; Haakansson, Karsten; Macsik, Josef; Mossakowska, Agnes; Rogbeck, Yvonne

    2007-06-15

    Several old waste sites are on the verge to be closed up during the next ten years. The function of a liner is to limit the amount of water that is infiltrated to the waste. This leads to high demand on a liner's permeability, shear strength and durability. Several pilot studies have been followed up where fly ash stabilised sewage sludge (FSS) was used as liner. The results show that FSS has low hydraulic conductivity (low permeability) and that it meets the demands put on a liner for non-hazardous wastes. Closure with FSS as liner puts special demands on the materials, the mixing action and during installation. The aim of this instruction manual is that it will work as an aid to manufacture and install liner, based on fly ash and sewage sludge, which fulfils functional demands. The manual contains a description of geotechnical and environmental demands to accomplish. This includes the following; manufacturing, storing, installation and follow up/control. This instruction manual is aimed for those who are planning closures of a landfill with FSS and need guidance to plan, carry out and control the liner construction. The manual can also be used by environmental agencies in order to control that the closure is done appropriately. Sewage sludge and fly ash from different producers can have varying properties. The quality of the used materials can change the FSS mixture's material properties and thereby also its permeability and durability. Both raw materials and mixtures should thereby be investigated according to material parameters. The mixtures dry solid content is a critical parameter as both shear strength and handling properties will be effected. In order to acquire sufficient amount of raw material storing is often required. Several aspects must then be counted on, as the properties of the raw materials can be altered. Manufacturing FSS must be done with the same material properties that have been investigated and evaluated in laboratory. Different

  17. Material Characterization and Real-Time Wear Evaluation of Pistons and Cylinder Liners of the Tiger 131 Military Tank

    OpenAIRE

    Saeed, Adil; Khan, Zulfiqar Ahmad; Hadfield, Mark; Davies, S.

    2013-01-01

    Material characterisation and wear evaluation of the original and replacement pistons and cylinder-liners of Tiger 131 is reported. Original piston and cylinder-liner were operative in the Tigers’ engine during WWII. The replacement piston and cylinder-liner were used as substitutes and were obtained after failure in two hours of operation in the actual engine. Material characterisation revealed that the original piston was aluminium silicon hypereutectic alloy whereas the replacement piston ...

  18. Inorganic material candidates to replace a metallic or non-metallic concrete containment liner

    Energy Technology Data Exchange (ETDEWEB)

    Seni, C [Atomic Energy of Canada Ltd., Mississauga, ON (Canada); Mills, R H [Toronto Univ., ON (Canada)

    1994-12-31

    Internal liners for concrete containments are generally organic or metals. They have to be able to inhibit radioactive leakage into the environment, but both types have shortcomings. The results of research to develop a better liner are published in this paper. The best material found was fibre-reinforced mortar. Of the fibres considered, steel, kevlar and glass were the best, each showing advantages and disadvantages. 1 ref., 9 tabs., 12 figs.

  19. Inorganic material candidates to replace a metallic or non-metallic concrete containment liner

    International Nuclear Information System (INIS)

    Seni, C.; Mills, R.H.

    1994-01-01

    Internal liners for concrete containments are generally organic or metals. They have to be able to inhibit radioactive leakage into the environment, but both types have shortcomings. The results of research to develop a better liner are published in this paper. The best material found was fibre-reinforced mortar. Of the fibres considered, steel, kevlar and glass were the best, each showing advantages and disadvantages. 1 ref., 9 tabs., 12 figs

  20. Influence of tanks liner material on water quality and growth of ...

    African Journals Online (AJOL)

    Three tank liner materials: polyvinylchloride (PVC), polyethylene and polyester were evaluated in a 93 days experiment for their influence on culture water quality and growth performance of Clarias gariepinus. Fish of average weight of 5.03±0.21g were stocked at 375 per m3 in tanks lined with the aforementioned materials.

  1. Ranking of Cylinder Liner Materials in Two Stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Pedersen, Michael Torben; Imran, Tajammal; Klit, Peder

    2009-01-01

    is made into a ring and the piston ring into a block. A short introduction of the test apparatus and its abilities is presented and discussed. Results from comparison and characterisation of five different cylinder liner materials run with a fixed piston ring material are presented. A preliminary ranking...... of the materials is given based on the materials tribological performance. The materials are evaluated on basis of friction force, oil film thickness variation, temperature variation and rotational speed....

  2. Standard test method for conducting friction tests of piston ring and cylinder liner materials under lubricated conditions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers procedures for conducting laboratory bench-scale friction tests of materials, coatings, and surface treatments intended for use in piston rings and cylinder liners in diesel or spark-ignition engines. The goal of this procedure is to provide a means for preliminary, cost-effective screening or evaluation of candidate ring and liner materials. A reciprocating sliding arrangement is used to simulate the contact that occurs between a piston ring and its mating liner near the top-dead-center position in the cylinder where liquid lubrication is least effective, and most wear is known to occur. Special attention is paid to specimen alignment, running-in, and lubricant condition. 1.2 This test method does not purport to simulate all aspects of a fired engine’s operating environment, but is intended to serve as a means for preliminary screening for assessing the frictional characteristics of candidate piston ring and liner material combinations in the presence of fluids that behave as u...

  3. SDU6 Interior Liner Testing & Evaluation

    International Nuclear Information System (INIS)

    Skidmore, T. E.

    2016-01-01

    Two liner materials (Marseal® M-3500 and REMA Chemoline® 4CN) proposed for use as a liner inside the Saltstone Disposal Unit 6 (SDU6) were subjected to specific ASTM tests (tensile and lap-shear) after immersion in 50% and 100% simulant solutions for 1000 hours at the Savannah River Ecology Laboratory. Both liner materials exhibited good resistance to the simulant chemistry, at least based on the tests performed and the test duration/conditions imposed. In lap-shear tests, both materials failed in the base material rather than peeling apart, confirming good adhesion. The REMA 4CN bromobutyl elastomer showed superior bonding characteristics and absence of warping or delamination at the conditions tested. The Marseal M-3500 material (PVC/EVA blend with polyester reinforcement) exhibited deformation and debonding in some locations. The cause of the deformation and delamination observed in the Marseal M-3500 material is not fully known, but possibly attributed to thermomechanical stress at immersion temperatures, and the thermoplastic nature of the material. The immersion temperature (68 °C) is slightly greater than the maximum use temperature limit quoted for the Marseal M- 3500 liner (65 °C), though the basis for the service limit is unknown. The testing performed was limited in scope and only for these two liner materials. These tests were primarily performed to screen for severe incompatibility or short-term degradation in Saltstone bleedwater simulants at bounding solution temperatures. Additional testing is recommended to assess long-term performance and the overall service life of the liner.

  4. SDU6 Interior Liner Testing & Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Skidmore, T. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-10-14

    Two liner materials (Marseal® M-3500 and REMA Chemoline® 4CN) proposed for use as a liner inside the Saltstone Disposal Unit 6 (SDU6) were subjected to specific ASTM tests (tensile and lap-shear) after immersion in 50% and 100% simulant solutions for 1000 hours at the Savannah River Ecology Laboratory. Both liner materials exhibited good resistance to the simulant chemistry, at least based on the tests performed and the test duration/conditions imposed. In lap-shear tests, both materials failed in the base material rather than peeling apart, confirming good adhesion. The REMA 4CN bromobutyl elastomer showed superior bonding characteristics and absence of warping or delamination at the conditions tested. The Marseal M-3500 material (PVC/EVA blend with polyester reinforcement) exhibited deformation and debonding in some locations. The cause of the deformation and delamination observed in the Marseal M-3500 material is not fully known, but possibly attributed to thermomechanical stress at immersion temperatures, and the thermoplastic nature of the material. The immersion temperature (68 °C) is slightly greater than the maximum use temperature limit quoted for the Marseal M- 3500 liner (65 °C), though the basis for the service limit is unknown. The testing performed was limited in scope and only for these two liner materials. These tests were primarily performed to screen for severe incompatibility or short-term degradation in Saltstone bleedwater simulants at bounding solution temperatures. Additional testing is recommended to assess long-term performance and the overall service life of the liner.

  5. Ageing of structural materials in tokamaks: TEXTOR liner study

    Science.gov (United States)

    Weckmann, A.; Petersson, P.; Rubel, M.; Fortuna-Zaleśna, E.; Zielinski, W.; Romelczyk-Baishya, B.; Grigore, E.; Ruset, C.; Kreter, A.

    2017-12-01

    After the final shut-down of the tokamak TEXTOR, all of its machine parts became accessible for comprehensive studies. This unique opportunity enabled the study of the Inconel 625 liner by a wide range of methods. The aim was to evaluate eventual alteration of surface and bulk characteristics from recessed wall elements that may influence the machine performance. The surface was covered with stratified layers consisting mainly of boron, carbon, oxygen, and in some cases also silicon. Wall conditioning and limiter materials hence predominantly define deposition on the liner. Deposited layers on recessed wall elements reach micrometre thickness within decades, peel off and may contribute to the dust inventory in tokamaks. Deuterium content was about 4,7 at% on average most probably due to wall conditioning with deuterated gas, and very low concentration in the Inconel substrate. Inconel 625 retained its mechanical strength despite 26 years of cyclic heating, stresses and particle bombardment.

  6. Extended liner performance for hydrodynamics and material properties experiments

    CERN Document Server

    Reinovsky, R E

    2001-01-01

    Summary form only given, as follows. Over the last few years a new application for high performance pulsed power, the production of high energy density environments for the study of material properties under extreme conditions and hydrodynamics in complex geometries has joined the traditional family of radiation source applications. The newly commissioned Atlas pulsed power system at Los Alamos has replaced its predecessor, Pegasus, and joined the Shiva Star system at AFRL, Albuquerque and a variety of flux compression systems, principally at the All Russian Scientific Research Institute of Experimental Physics (VNIIEF) as ultra high current drivers for the high precision, magnetically imploded, near-solid density liner that is used to create the needed environments. Three families of experiments: the production of ultra strong shocks (>10 Mbar), the production of strongly coupled plasmas by liner compression of an initially dense plasma of a few eV temperature, and the compression of a magnetized plasma for ...

  7. Flyash and sewage sludge as liner material - Preparations for a pilot test with fly-ash stabilised sewage sludge as landfill liner; Linermaterial med aska och roetslam - Underlag foer genomfoerande av pilotfoersoek med stabiliserat avloppsslam som taetskiktsmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Macsik, J.; Rogbeck, Y.; Svedberg, B.; Uhlander, O. [Scandiaconsult Sverige AB, Stockholm (Sweden); Mossakowska, A. [Stockholm Vatten AB (Sweden)

    2003-11-01

    The aim of this project was to develop a new liner material based on biofuel fly ash and sewage sludge and to plan for a pilot test with this new liner (FSA) on a landfill. The investigation shows that FSA has potential to fulfil technical and economical requirements as well as requirements of durability. This project constitutes part of a larger one, where the overall aim is to collect information/experience of FSA as a liner for presentation in a handbook. During the conducted laboratory work recipes for mixture proportions for application as landfill liner were controlled according to technical and environmental aspects. A recipe for FSA material has been prepared, which has permeability values lower than 10-9 m/s. This low permeability can assure a low percolation of precipitated water through the landfill liner, < 50 litre/m{sup 2}/year. FSA has sufficient un-drained shear strength and has an estimated slow bio-degradation, which can assure a long duration period. Based on results from tests conducted in this and other projects, where FSA materials were tested, necessary quality verifications has been conducted for the ingredients bio-fly-ash and sewage sludge and for the FSA-mixture. The FSA materials potential as liner increases with darker colour (bordering black). FSA-40 is a mixture of 40 % dry solid (DS) fly ash and 60 % DS sewage sludge, and FSA-60 is a mixture containing 60 % DS fly ash and 40 % DS sewage sludge and so on. Some important parameters of the ingredient materials are DS content (or water content) and pH and CaO content of the fly ash. A liner made of FSA should have surrounding layers of high water containing capacity in order to protect the FSA-liner from drying. The drainage and oxidation protection layers have to transport precipitated water as well as contain sufficient pore water in order to be an oxygen barrier above the liner (FSA). In addition, the investigation shows that a paddle blender should be used in order to guarantee a

  8. The compatibility of various polymeric liner and pipe materials with simulated double-shell slurry feed at 90 degree C

    International Nuclear Information System (INIS)

    Farnsworth, R.K.; Hymas, C.R.

    1989-08-01

    The purpose of this study was to evaluate the compatibility of various polymeric liner and pipe materials with a low-level radioactive waste slurry called double-shell slurry feed (DSSF). The evaluation was necessary as part of the permitting process authorized by the Resource Conservation and Recovery Act (RCRA), PL-94-580. Materials that were examined included five flexible membrane liners (Hytrel reg sign polyester, polyurethane, 8130 XR5 reg sign, polypropylene, and high-density polyethylene) and high-density polyethylene (HDPE) pipe. The liner and pipe samples were immersed for 120 days in the synthetic DSSE at 90 degree C, the maximum expected temperature in the waste disposal scenario. Physical properties of the liner and pipe samples were measured before immersion and every 30 days after immersion, in accordance with EPA Method 9090. In addition, some of the materials were exposed to four different radiation doses after 30 days of immersion. Physical properties of these materials were measured immediately after exposure and after an additional 90 days of immersion to determine each material's response to radiation, and whether radiation exposure affected the chemical compatibility of the material. 20 refs., 41 figs., 13 tabs

  9. Beneficial reuse of FGD material in the construction of low permeability liners: Impacts on inorganic water quality constituents

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, C.M.; Tu, W.; Zand, B.; Butalia, T.; Wolfe, W.; Walker, H. [Ohio State University, Columbus, OH (United States)

    2007-05-15

    In this paper, we examine the water quality impacts associated with the reuse of fixated flue gas desulfurization (FGD) material as a low permeability liner for agricultural applications. A 0.457-m-thick layer of fixated FGD material from a coal-fired power plant was utilized to create a 708 m{sup 2} swine manure pond at the Ohio Agricultural Research and Development Center Western Branch in South Charleston, Ohio. To assess the effects of the fixated FGD material liner, water quality samples were collected over a period of 5 years from the pond surface water and a sump collection system beneath the liner. Water samples collected from the sump and pond surface water met all Ohio nontoxic criteria, and in fact, generally met all national primary and secondary drinking water standards. Furthermore it was found that hazardous constituents (i.e., As, B, Cr, Cu, and Zn) and agricultural pollutants (i.e., phosphate and ammonia) were effectively retained by the FGD liner system. The retention of As, B, Cr, Cu, Zn, and ammonia was likely due to sorption to mineral components of the FGD liner, while Ca, Fe, and P retention were a result of both sorption and precipitation of Fe- and Ca-containing phosphate solids.

  10. Evaluation of inactive uranium mill tailings sites for liner requirements: Characterization and interaction of tailings, soil, and liner materials

    International Nuclear Information System (INIS)

    Relyea, J.F.; Martin, W.J.

    1982-01-01

    This paper summarizes the results of laboratory experiments using soils from Clive, Utah and tailings samples from three inactive uranium processing sites. The results are to be used to predict contaminant behavior for comparison with the regulatory criteria to decide whether a liner is needed. The interactions of leachates with soils and liner material were studied using both batch and column methods. It is determined that batch leaching tests are suitable for screening a large number of tailings samples for relative contaminant concentrations between samples but not for determining contaminant concentrations and release rates in tailings leachate. The results of column leaching tests on samples of tailings from inactive sites indicate that contaminant concentrations are highest in initial leachate from the columns and that concentrations decrease by an order of magnitude or more after one pore volume

  11. Composite liners protect ground water

    Energy Technology Data Exchange (ETDEWEB)

    Tatzky, R; August, H

    1987-12-01

    For about 10 years flexible membrane liners (FMLs) have been used as bottom liners to protect ground water in the vicinity of waste sites. But a permeation (absorption, diffusion, desorption) of chemical liquids, e.g. hydrocarbons (HC) and chlorinated hydrocarbons (CHC) will generally occur. The rates of permeation depend, first of all, on the chemical affinity, the thickness of the FML and the boundary conditions. In order to improve the barrier quality of polymeric membranes, it is necessary to study the transport processes of HC and CHC through the polymeric materials. Long-term tests with composite liners are additionally carried out. These are liners which consist of two components, flexible membrane and natural soil liner (recompacted clay, bentonite-soil mixtures). Laboratory studies show that with composite liners a perfect sealing of waste sites may be possible. Test methods for measuring permeation rates of HC and CHC through polymeric membranes and methods of testing for the development of composite liner systems are presented. (orig.)

  12. The high pH chemical and radiation compatibility of various liner materials

    International Nuclear Information System (INIS)

    Whyatt, G.A.; Farnsworth, R.K.

    1990-01-01

    This paper reports on a flexible membrane liner that has been proposed to line a concrete vault in which liquid low-level radioactive waste will be solidified. High-density polyethylene (HDPE) and polypropylene liners were tested at the Pacific Northwest Laboratory in an EPA method 9090 format to determine their chemical compatibility with the waste. Radiation effects were also investigated. The liners were immersed in a highly caustic (pH>14), primarily inorganic solution at 90 degrees C. The liners were subjected to radiation doses up to 38.9 Mrad, which was the expected dose the liner would receive over a 30-year life inside the vault. Recent changes have placed the liner outside the vault. The acceptance criteria for judging the compatibility of the liner with radiation would be different that those used for judging chemical compatibility. The radiation damage over the life of the liner can be simulated in a short-term test. Both HDPE and polypropylene liners were judged to be acceptable from a chemical and radiation standpoint when placed outside of the vault, while several other liners were not compatible. Radiation did not have a significant effect on chemical degradation rates

  13. The high pH chemical and radiation compatibility of various liner materials

    International Nuclear Information System (INIS)

    Whyatt, G.; Farnsworth, R.

    1990-01-01

    A flexible membrane liner has been proposed to line a concrete vault in which liquid low-level radioactive waste will be solidified. High-density polyethylene (HDPE) and polypropylene liners were tested at the Pacific Northwest Laboratory in an EPA method 9090 format to determine their chemical compatibility with the waste. Radiation effects were also investigated. The liners were immersed in a highly caustic (pH>14), primarily inorganic solution at 90 degrees C. The liners were subjected to radiation doses up to 38.9 Mrad, which was the expected dose the liner would receive over a 30-year life inside the vault. Recent changes have placed the liner outside the vault. The acceptance criteria for judging the compatibility of the liner with radiation should be different than those used for judging chemical compatibility. The radiation damage over the life of the liner can be simulated in a short-term test. Both HDPE and polypropylene liners were judged to be acceptable from a chemical and radiation standpoint when placed outside of the vault, while several other liners were not compatible. Radiation did not have a significant effect on chemical degradation rates

  14. Striation Formation in Cylindrical Liners Made of Various Materials Driven by a 1 MA Pulsed Power Generator

    Science.gov (United States)

    Atoyan, Levon; Byvank, Tom; Engelbrecht, Joseph; Greenly, John; Pikuz, Sergei; Potter, William; Shelkovenko, Tania; Kusse, Bruce; Hammer, David

    2016-10-01

    Peterson et al. found on the 20 MA Z machine that, without any applied external axial magnetic field, horizontal striations appear in radiographic images of a metal liner [Phys. Plasmas 19, 092701, 2012], a result that has been reproduced on other pulsed power machines since. In this work we present experimental results of horizontal striations on the 1 MA, 100-200 ns COBRA pulsed power generator [T. A. Shelkovenko et al., Rev. Sci. Instrum. 77, 10F521, 2006]. The pattern is observed in our experiments using extreme ultraviolet imaging, laser imaging, and X-ray backlighting. Using this combination of diagnostics, we were able to view simultaneously the pattern near the liner surface as well as in the higher density portion of the liner, displaying features with different wavelengths. Furthermore, materials such as Al, Cu, and Ti will be used for the liner to determine if the striation formation is affected by the nature of the material. This research is supported by the NNSA Stewardship Sciences Academic Programs under Department of Energy Cooperative Agreement DE-NA0001836 and DOE account DE-NA0002952.

  15. Simulation of LOCA and ageing effect with containment liner mockup for analysis of liner-concrete interaction

    International Nuclear Information System (INIS)

    Wienand, B.; Fila, A.; Hermann, N.; Mueller, M.

    2015-01-01

    The investigation of the pre-stressed concrete wall behavior including the liner during LOCA conditions is important for the assessment of the structural integrity of the structure and the leak tightness of the liner. In the frame of the NUGENIA ACCEPPT project WP1 G4 'Structural interaction of liner with the concrete', a load test on a reactor containment liner mockup was carried out. The pre-stressed mockup represents a cylindrical part of the liner, embedded in the concrete wall, but without the wall curvature which is not test relevant. It correlates in material and geometrical properties to the EPR containment. The purpose of the test was to check the liners structural behavior and its integrity for Loss of Coolant Accident (LOCA) load combination considering pre-stressing forces and ageing effects due to creep and shrinkage including liner buckling. The test was carried out at the Karlsruhe Institute of Technology (KIT) in September 2013. This article presents the measurement technology, the results and the development of a calculation method for the embedded liner structure. It appears that the liner deformation results are exemplarily shown at the locations of the imperfections, where the liner buckling is anticipated. The measured liner surface strains ranged between +2 and -10 per thousand. The compressive strains are higher than the tensile strains due to the compressive membrane strains caused by pre-stressing and heating. Although the liner got plastic deformations, the liner strains are still far below the elongation at rupture, which indicates that the liner integrity is ensured. We can conclude that the liner mockup test proceeded as planned. The evaluation results show that the purpose of the liner mockup to simulate LOCA + ageing conditions and liner buckling has fully been achieved

  16. High-resolution simulations of cylindrical void collapse in energetic materials: Effect of primary and secondary collapse on initiation thresholds

    Science.gov (United States)

    Rai, Nirmal Kumar; Schmidt, Martin J.; Udaykumar, H. S.

    2017-04-01

    Void collapse in energetic materials leads to hot spot formation and enhanced sensitivity. Much recent work has been directed towards simulation of collapse-generated reactive hot spots. The resolution of voids in calculations to date has varied as have the resulting predictions of hot spot intensity. Here we determine the required resolution for reliable cylindrical void collapse calculations leading to initiation of chemical reactions. High-resolution simulations of collapse provide new insights into the mechanism of hot spot generation. It is found that initiation can occur in two different modes depending on the loading intensity: Either the initiation occurs due to jet impact at the first collapse instant or it can occur at secondary lobes at the periphery of the collapsed void. A key observation is that secondary lobe collapse leads to large local temperatures that initiate reactions. This is due to a combination of a strong blast wave from the site of primary void collapse and strong colliding jets and vortical flows generated during the collapse of the secondary lobes. The secondary lobe collapse results in a significant lowering of the predicted threshold for ignition of the energetic material. The results suggest that mesoscale simulations of void fields may suffer from significant uncertainty in threshold predictions because unresolved calculations cannot capture the secondary lobe collapse phenomenon. The implications of this uncertainty for mesoscale simulations are discussed in this paper.

  17. Thermographic inspection of pipes, tanks, and containment liners

    Energy Technology Data Exchange (ETDEWEB)

    Renshaw, Jeremy B., E-mail: jrenshaw@epri.com; Muthu, Nathan [Electric Power Research Institute, 1300 West WT Harris Blvd., Charlotte, NC 28262 (United States); Lhota, James R.; Shepard, Steven M., E-mail: sshepard@thermalwave.com [Thermal Wave Imaging, 845 Livernois St., Ferndale, MI 48220 (United States)

    2015-03-31

    Nuclear power plants are required to operate at a high level of safety. Recent industry and license renewal commitments aim to further increase safety by requiring the inspection of components that have not traditionally undergone detailed inspected in the past, such as tanks and liners. NEI 09-14 requires the inspection of buried pipes and tanks while containment liner inspections are required as a part of license renewal commitments. Containment liner inspections must inspect the carbon steel liner for defects - such as corrosion - that could threaten the pressure boundary and ideally, should be able to inspect the surrounding concrete for foreign material that could be in contact with the steel liner and potentially initiate corrosion. Such an inspection requires a simultaneous evaluation of two materials with very different material properties. Rapid, yet detailed, inspection results are required due to the massive size of the tanks and containment liners to be inspected. For this reason, thermal NDE methods were evaluated to inspect tank and containment liner mockups with simulated defects. Thermographic Signal Reconstruction (TSR) was utilized to enhance the images and provide detailed information on the sizes and shapes of the observed defects. The results show that thermographic inspection is highly sensitive to the defects of interest and is capable of rapidly inspecting large areas.

  18. Interactions of tailings leachate with local liner materials found at Canonsburg, Pennsylvania

    International Nuclear Information System (INIS)

    Dodson, M.E.; Gee, G.W.; Serne, R.J.

    1984-04-01

    The mill tailings site at Canonsburg, Pennsylvania is the first mill site to receive remedial action under the Department of Energy's Uranium Mill Tailings Remedial Action Program. Part of this remedial action will require excavating the 53,500 m 3 (70,000 yd 3 ) of tailings on the site having a specific activity exceeding 100 pCi/g, and encapsulating these contaminated tailings in a clay-lined cell. As part of the remedial action effort, Pacific Northwest Laboratory has been studying the interactions of tailings and tailings leachate with locally occurring clays proposed for liner materials. These studies include physical and chemical characterization of amended and unamended local clays, chemical characterization of the tailings, column studies of tailings leached with deionized water, and column studies of clays contacted with tailings solutions to determine the attenuation properties of the proposed liner materials. Column studies of tailings leached with deionized water indicated that the Canonsburg tailings could represent a source of soluble radium-226 and uranium-238, several trace metals, cations, and the anions SO 4 , NO 3 , and Cl. Of these soluble contaminants, uranium-238, radium-226, the trace metals As and Mo, and the anions F and SO 4 were present at levels exceeding maximum concentration levels in the tailings leaching column effluents. However, local clays, both in amended and unamended form were effective in attenuating contaminant migration. The soil amendments tested failed to increase radium attenuation. The tailings leaching studies indicated that the tailings will produce leachates of neutral pH and relatively low contaminant levels for at least 200 years. We believe that compacting the tailings within the encapsulation cell will help to reduce leaching of contaminants from the liner system, since very low permeabilities ( -8 cm/s) were observed for even slightly compacted tailings materials

  19. Fusion power from fast imploding liners

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Moses, R.W.; Miller, R.L.; Germwin, R.A.

    1977-01-01

    An approach to fusion power is described which proposes magnetically driving a thin metal shell at high velocity (approximately 10 4 m/s) onto a warm (200 to 500 eV), dense (10 24 to 10 25 m -3 ) plasma. A description of the plasma/liner interaction by several analytic and numerical models is given. On the basis of theoretical scaling predictions, the advantages, disadvantages and uncertainties associated with a high-efficiency (recirculating power fraction less than or equal to 0.2) Fast-Liner Reactor (FLR) are described, quantified when possible, and summarized. The FLR approach is characterized by (1) a thin cylindrical nonrotating liner that would be magnetically accelerated by axial currents driven through the liner (no external coils or magnets), (2) axial and radial energy confinement would be provided by an azimuthal magnetic field associated either with axial currents driven through a hard core or through the plasma, (3) the plasma particle pressure would be supported directly by the liner surface and material end plugs, and (4) the liner and a portion of associated support structure would be destroyed at each implosion. A preliminary assessment of the technological implications of blast confinement, materials destruction and loss, energy transfer and storage requirements, and possible modes of FLR operation is presented

  20. Design and modeling of precision solid liner experiments on Pegasus

    International Nuclear Information System (INIS)

    Bowers, R.L.; Brownell, J.H.; Lee, H.; McLenithan, K.D.; Scannapieco, A.J.; Shanahan, W.R.

    1998-01-01

    Pulsed power driven solid liners may be used for a variety of physics experiments involving materials at high stresses. These include shock formation and propagation, material strain-rate effects, material melt, instability growth, and ejecta from shocked surfaces. We describe the design and performance of a cylindrical solid liner that can attain velocities in the several mm/μs regime, and that can be used to drive high-stress experiments. An approximate theoretical analysis of solid liner implosions is used to establish the basic parameters (mass, materials, and initial radius) of the driver. We then present one-dimensional and two-dimensional simulations of magnetically driven, liner implosions which include resistive heating and elastic endash plastic behavior. The two-dimensional models are used to study the effects of electrode glide planes on the liner close-quote s performance, to examine sources of perturbations of the liner, and to assess possible effects of instability growth during the implosion. Finally, simulations are compared with experimental data to show that the solid liner performed as predicted computationally. Experimental data indicate that the liner imploded from an initial radius of 2.4 cm to a target radius of 1.5 cm, and that it was concentric and cylindrical to better than the experimental resolution (60 μm) at the target. The results demonstrate that a precision solid liner can be produced for high-stress, pulsed power applications experiments. copyright 1998 American Institute of Physics

  1. Investigation on proper materials of a liner system for trench type disposal facilities of radioactive wastes from research, industrial and medical facilities

    International Nuclear Information System (INIS)

    Nakata, Hisakazu; Amazawa, Hiroya; Sakai, Akihiro; Arikawa, Masanobu; Sakamoto, Yoshiaki

    2011-08-01

    The Low-level Radioactive Waste Disposal Project Center of Japan Atomic Energy Agency will settle on near surface disposal facilities with and without engineered barriers for radioactive wastes from research, industrial and medical facilities. Both of them are so called 'concrete pit type' and 'trench type', respectively. The technical standard of constructing and operating a disposal facility based on 'Law for the Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors' have been regulated partly by referring to that of 'Waste Management and Public Cleansing Law'. This means that the concrete pit type and the trench type disposal facility resemble an isolated type for specified industrial wastes and a non leachate controlled type final disposal site for stable industrial wastes, respectively. On the other, We plan to design a disposal facility with a liner system corresponding to a leachate controlled type final disposal site on a crucial assumption that radioactive wastes other than stable industrial wastes to be disposed into the trench type disposal facility is generated. By current nuclear related regulations in Japan, There are no technical standard of constructing the disposal facility with the liner system referring to that of 'Waste Management and Public Cleansing Law'. We investigate the function of the liner system in order to design a proper liner system for the trench type disposal facility. In this report, We investigated liner materials currently in use by actual leachate controlled type final disposal sites in Japan. Thereby important items such as tensile strength, durability from a view point of selecting proper liner materials were studied. The items were classified into three categories according to importance. We ranked proper liner materials for the trench type disposal facility by evaluating the important items per material. As a result, high density polyethylene(HDPE) of high elasticity type polymetric sheet was selected

  2. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calcium hydroxide cavity liner. 872.3250 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a...

  3. Generation of a rotating liquid liner by tangential injection

    International Nuclear Information System (INIS)

    Burton, R.L.; Turchi, P.J.; Jenkins, D.J.; Lanham, R.E.; Cameron, J.; Cooper, A.L.

    1979-01-01

    Efficient compression of low mass-density payloads by the implosion of higher mass-density liquid cylinders or liners, as in the NRL LINUS concept for controlled thermonuclear fusion, requires rotation of the liner material to avoid Rayleigh--Taylor instabilities at the liner-payload interface. Experimentally, such implosions have been demonstrated with liners formed within rotating implosion chambers. The present work uses a scale-model experimental apparatus to investigate the possibility of creating liner rotation by tangential injection of the liquid liner material. Different modes of behavior are obtained depending on the fluid exhaust procedures. Right-circular, cylindrical free surfaces are achieved with axial exhaust of fluid at radii interior to the injection nozzles, for which the liner exhibits a combination of solid-body and free vortex flows in different regions. Measurements allow estimates of power losses to viscous shear, turbulence, etc. A simple model based on open-channel flow is then derived, which is in good agreement with experiment, and is used to extrapolate results to the scale of a possible LINUS fusion reactor

  4. 49 CFR 193.2187 - Nonmetallic membrane liner.

    Science.gov (United States)

    2010-10-01

    ... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Lng Storage Tanks § 193.2187 Nonmetallic membrane liner. A flammable nonmetallic membrane liner may not be used as an inner container in a storage tank...

  5. Metallographic examination of EPICOR-II liners from Three Mile Island

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Spaletta, H.W.

    1985-01-01

    Materials from selected EPICOR-II prefilter liners were collected and examined as part of the EPICOR and Waste Research and Disposition Program sponsored by the Department of Energy at the Idaho National Engineering Laboratory (INEL). The intent of that examination was to define the internal condition of liners and ensure that liners could be stored at INEL for ten years. This paper discusses the liner-integrity examination and presents the results of these examinations. Metallurgical examination of sections removed from the liners revealed no evidence of pitting or pitting-type corrosion. Measurements of wall thickness indicate that material was missing from the wall of PF-3 in an area where the protective coating had been removed to form a conductivity patch. If it is assumed that all thinning of the wall in that area is caused by corrosion, the liners will have a lifetime of approximately 50 years. 12 figures

  6. Conceptual design of imploding liner fusion reactors

    International Nuclear Information System (INIS)

    Turchi, P.J.; Robson, A.E.

    1976-01-01

    The basic new ingredient is the concept of rotationally stabilized liquid metal liners accelerated with free pistons. The liner motion is constrained on its outer surface by the pistons, laterally by channel walls, during acceleration, and on its inner surface, where megagauss field levels are attained by the centrifugal motion of the liner material. In this way, stable, reversible motion of the liner should be possible, permitting repetitive, pulsed operation at interior pressures far greater than can be allowed in static conductor systems. Such higher operating pressures permit the use of simple plasma geometries, such as theta pinches, with greatly reduced dimensions. Furthermore, the implosion of thick, lithium-bearing liners with large radial compression ratios inherently provides the plasma with a surrounding blanket of neutron absorbing liquid metal, thereby substantially reducing the problems of induced radioactivity and first wall damage that haunt conventional fusion reactor designs. The following article discusses the basic operation of liner reactors and several important features influencing their design

  7. Formation of imploding plasma liners for fundamental HEDP studies and MIF Standoff Driver Concept

    Energy Technology Data Exchange (ETDEWEB)

    Cassibry, Jason [Univ. of AL in Huntsville; Hatcher, Richard [Univ. of AL in Huntsville; Stanic, Milos [Univ. of AL in Huntsville

    2013-08-17

    The disciplines of High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF) are characterized by hypervelocity implosions and strong shocks. The Plasma Liner Experiment (PLX) is focused on reaching HEDP and/or ICF relevant regimes in excess of 1 Mbar peak pressure by the merging and implosion of discrete plasma jets, as a potentially efficient path towards these extreme conditions in a laboratory. In this work we have presented the first 3D simulations of plasma liner, formation, and implosion by the merging of discrete plasma jets in which ionization, thermal conduction, and radiation are all included in the physics model. The study was conducted by utilizing a smoothed particle hydrodynamics code (SPHC) and was a part of the plasma liner experiment (PLX). The salient physics processes of liner formation and implosion are studied, namely vacuum propagation of plasma jets, merging of the jets (liner forming), implosion (liner collapsing), stagnation (peak pressure), and expansion (rarefaction wave disassembling the target). Radiative transport was found to significantly reduce the temperature of the liner during implosion, thus reducing the thermal leaving more pronounced gradients in the plasma liner during the implosion compared with ideal hydrodynamic simulations. These pronounced gradients lead to a greater sensitivity of initial jet geometry and symmetry on peak pressures obtained. Accounting for ionization and transport, many cases gave higher peak pressures than the ideal hydrodynamic simulations. Scaling laws were developed accordingly, creating a non-dimensional parameter space in which performance of an imploding plasma jet liner can be estimated. It is shown that HEDP regimes could be reached with ~ 5 MJ of liner energy, which would translate to roughly 10 to 20 MJ of stored (capacitor) energy. This is a potentially significant improvement over the currently available means via ICF of achieving HEDP and nuclear fusion relevant parameters.

  8. Three-dimensional simulations of void collapse in energetic materials

    Science.gov (United States)

    Rai, Nirmal Kumar; Udaykumar, H. S.

    2018-03-01

    The collapse of voids in porous energetic materials leads to hot-spot formation and reaction initiation. This work advances the current knowledge of the dynamics of void collapse and hot-spot formation using 3D reactive void collapse simulations in HMX. Four different void shapes, i.e., sphere, cylinder, plate, and ellipsoid, are studied. For all four shapes, collapse generates complex three-dimensional (3D) baroclinic vortical structures. The hot spots are collocated with regions of intense vorticity. The differences in the vortical structures for the different void shapes are shown to significantly impact the relative sensitivity of the voids. Voids of high surface area generate hot spots of greater intensity; intricate, highly contorted vortical structures lead to hot spots of corresponding tortuosity and therefore enhanced growth rates of reaction fronts. In addition, all 3D voids are shown to be more sensitive than their two-dimensional (2D) counterparts. The results provide physical insights into hot-spot formation and growth and point to the limitations of 2D analyses of hot-spot formation.

  9. Diagnostics for the Plasma Liner Experiment

    International Nuclear Information System (INIS)

    Lynn, A. G.; Merritt, E.; Gilmore, M.; Hsu, S. C.; Witherspoon, F. D.; Cassibry, J. T.

    2010-01-01

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical ''plasma liners'' via merging high Mach number plasma jets to reach peak liner pressures of ∼0.1 Mbar using ∼1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n i ∼10 16 cm -3 , T e ≅T i ∼1 eV at the plasma gun mouth to n i >10 19 cm -3 , T e ≅T i ∼0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

  10. Removal of Cu(II) from leachate using natural zeolite as a landfill liner material.

    Science.gov (United States)

    Turan, N Gamze; Ergun, Osman Nuri

    2009-08-15

    All hazardous waste disposal facilities require composite liner systems to act as a barrier against migration of contaminated leachate into the subsurface environment. Removal of copper(II) from leachate was studied using natural zeolite. A serial of laboratory systems on bentonite added natural zeolite was conducted and copper flotation waste was used as hazardous waste. The adsorption capacities and sorption efficiencies were determined. The sorption efficiencies increased with increasing natural zeolite ratio. The pseudo-first-order, the pseudo-second-order, Elovich and the intra-particle diffusion kinetic models were used to describe the kinetic data to estimate the rate constants. The second-order model best described adsorption kinetic data. The results indicated that natural zeolite showed excellent adsorptive characteristics for the removal of copper(II) from leachate and could be used as very good liner materials due to its high uptake capacity and the abundance in availability.

  11. Removal of Cu(II) from leachate using natural zeolite as a landfill liner material

    International Nuclear Information System (INIS)

    Turan, N. Gamze; Ergun, Osman Nuri

    2009-01-01

    All hazardous waste disposal facilities require composite liner systems to act as a barrier against migration of contaminated leachate into the subsurface environment. Removal of copper(II) from leachate was studied using natural zeolite. A serial of laboratory systems on bentonite added natural zeolite was conducted and copper flotation waste was used as hazardous waste. The adsorption capacities and sorption efficiencies were determined. The sorption efficiencies increased with increasing natural zeolite ratio. The pseudo-first-order, the pseudo-second-order, Elovich and the intra-particle diffusion kinetic models were used to describe the kinetic data to estimate the rate constants. The second-order model best described adsorption kinetic data. The results indicated that natural zeolite showed excellent adsorptive characteristics for the removal of copper(II) from leachate and could be used as very good liner materials due to its high uptake capacity and the abundance in availability.

  12. Safety assessment of a multicavity prestressed concrete reactor vessel with hot liner

    Energy Technology Data Exchange (ETDEWEB)

    Lafitte, R.; Marchand, J. D. [Bonnard et Gardel, Ingenieurs-Conseil, Lausanne (Switzerland)

    1981-01-15

    The prestressed concrete reactor vessel of the high temperature reactor with helium turbine project differs from those realized up to this day by the important number of cavities, by the different cavity pressures and by a liner in contact with hot gas. For the cases of operating conditions, the computations can be based on an identical pressure in all the cavities. The overdimensioning of the vessel which results is not a determining factor at this stage of the project. The possible loss of leaktightness of the liner can introduce gas pressure into the walls of the vessel. The great thickness of the walls makes it impossible to withstand the resulting forces with prestressing in offering sufficient safety factor against collapse. It is thus important to design a drainage network largely dimensioned. The warm liner appears at this stage of the project too highly stressed by fatigue at the singularity points (ducts between cavities, angles). A solution is proposed which limits the variations of thermal stresses by using a steel with low coefficient of thermal expansion. The cavity closures, which are numerous and some with large dimensions are an important aspect of the vessel safety. A solution of reinforced concrete shell with independent liner is proposed.

  13. Safety assessment of a multicavity prestressed concrete reactor vessel with hot liner

    International Nuclear Information System (INIS)

    Lafitte, R.; Marchand, J.D.

    1981-01-01

    The prestressed concrete reactor vessel of the high temperature reactor with helium turbine project differs from those realized up to this day by the important number of cavities, by the different cavity pressures and by a liner in contact with hot gas. For the cases of operating conditions, the computations can be based on an identical pressure in all the cavities. The overdimensioning of the vessel which results is not a determining factor at this stage of the project. The possible loss of leaktightness of the liner can introduce gas pressure into the walls of the vessel. The great thickness of the walls makes it impossible to withstand the resulting forces with prestressing in offering sufficient safety factor against collapse. It is thus important to design a drainage network largely dimensioned. The warm liner appears at this stage of the project too highly stressed by fatigue at the singularity points (ducts between cavities, angles). A solution is proposed which limits the variations of thermal stresses by using a steel with low coefficient of thermal expansion. The cavity closures, which are numerous and some with large dimensions are an important aspect of the vessel safety. A solution of reinforced concrete shell with independent liner is proposed

  14. Creep and stress relaxation behavior of two soft denture liners.

    Science.gov (United States)

    Salloum, Alaa'a M

    2014-03-01

    Numerous investigators stated the indications of soft denture lining materials; but no one determined the indications of these materials according to their chemical structure. The purpose of this investigation was to evaluate the viscoelastic properties of acrylic and silicon lining materials. This study investigated and compared viscoelastic properties of two resilient denture lining materials. Tested materials were laboratory processed; one of them was silicone-based liner product (Molloplast-B), and the other was plasticized acrylic resin (Vertex™ Soft). Twenty cylindrical specimens (10-20 mm in length, 11.55 mm in diameter) were fabricated in an aluminum mold from each material for creep and stress relaxation testing (the study of viscoelastic properties). Tests were performed by using the universal testing machine DY-34. Collected data were analyzed with t test statistics for statistically significant differences at the 95 % confidence level. There was a clear difference in creep and stress relaxation behavior between acrylic and silicone liners. Statistical study of Young's moduli illustrated that Vertex™ Soft was softer than Molloplast-B. On the other hand, the results explained that the recovery of silicone material was better than of acrylic one. The creep test revealed that the plasticized acrylic resin lining material exhibited considerable creep, whereas silicone-based liner exhibited elastic behavior. Besides, the stress relaxation test showed that relaxation of the plasticized acrylic resin material was bigger than of the silicone-based liner.

  15. Ceramics Technology Project database: September 1991 summary report. [Materials for piston ring-cylinder liner for advanced heat/diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Keyes, B.L.P.

    1992-06-01

    The piston ring-cylinder liner area of the internal combustion engine must withstand very-high-temperature gradients, highly-corrosive environments, and constant friction. Improving the efficiency in the engine requires ring and cylinder liner materials that can survive this abusive environment and lubricants that resist decomposition at elevated temperatures. Wear and friction tests have been done on many material combinations in environments similar to actual use to find the right materials for the situation. This report covers tribology information produced from 1986 through July 1991 by Battelle columbus Laboratories, Caterpillar Inc., and Cummins Engine Company, Inc. for the Ceramic Technology Project (CTP). All data in this report were taken from the project's semiannual and bimonthly progress reports and cover base materials, coatings, and lubricants. The data, including test rig descriptions and material characterizations, are stored in the CTP database and are available to all project participants on request. Objective of this report is to make available the test results from these studies, but not to draw conclusions from these data.

  16. Optimisation of energy absorbing liner for equestrian helmets. Part II: Functionally graded foam liner

    International Nuclear Information System (INIS)

    Cui, L.; Forero Rueda, M.A.; Gilchrist, M.D.

    2009-01-01

    The energy absorbing liner of safety helmets was optimised using finite element modelling. In this present paper, a functionally graded foam (FGF) liner was modelled, while keeping the average liner density the same as in a corresponding reference single uniform density liner model. Use of a functionally graded foam liner would eliminate issues regarding delamination and crack propagation between interfaces of different density layers which could arise in liners with discrete density variations. As in our companion Part I paper [Forero Rueda MA, Cui L, Gilchrist MD. Optimisation of energy absorbing liner for equestrian helmets. Part I: Layered foam liner. Mater Des [submitted for publication

  17. Diagnostics for the plasma liner experiment.

    Science.gov (United States)

    Lynn, A G; Merritt, E; Gilmore, M; Hsu, S C; Witherspoon, F D; Cassibry, J T

    2010-10-01

    The goal of the Plasma Liner Experiment (PLX) is to explore and demonstrate the feasibility of forming imploding spherical "plasma liners" via merging high Mach number plasma jets to reach peak liner pressures of ∼0.1 Mbar using ∼1.5 MJ of initial stored energy. Such a system would provide HED plasmas for a variety of fundamental HEDLP, laboratory astrophysics, and materials science studies, as well as a platform for experimental validation of rad-hydro and rad-MHD simulations. It could also prove attractive as a potential standoff driver for magnetoinertial fusion. Predicted parameters from jet formation to liner stagnation cover a large range of plasma density and temperature, varying from n(i)∼10(16) cm(-3), T(e)≈T(i)∼1 eV at the plasma gun mouth to n(i)>10(19) cm(-3), T(e)≈T(i)∼0.5 keV at stagnation. This presents a challenging problem for the plasma diagnostics suite which will be discussed.

  18. Above-cutoff impedance measurements of pumping holes for the Collider Liner

    International Nuclear Information System (INIS)

    Walling, L.; Barts, T.; Ruiz, E.; Turner, W.; Spayd, N.

    1994-04-01

    A holed liner was considered for the Superconducting Super Collider (SSC) Collider Ring because of vacuum problems caused by photon-induced desorption. The liner would serve to shield the cold surface of the beam tube from the synchrotron radiation and the holes (or slots) would allow distributed pumping by gas-absorption material that could be placed between the liner and the beam tube. The impedance of holes and slots in a liner were studied by means of simulations using both MAFIA and HFSS, analytical modelling, wire measurements and electron beam measurements

  19. Experimental evaluation of cell liners

    International Nuclear Information System (INIS)

    Wierman, R.W.; Simmons, L.D.; Muhlestein, L.D.

    Cell liners may be used in breeder reactor sodium pipe ways, sodium cells, and lower cavity region to provide a leak-tight cell and to protect the concrete from sodium in the unlikely event of a sodium spill. The objectives of the HEDL liner verification test program are to evaluate the integrity of liner concepts under postulated accident conditions and to develop the experimental data base which will demonstrate that liners will not fail. Two specific tests are reported; a high temperature liner feature test, and a large-scale liner sodium spill test. In both tests no failures of the liners or tendencies toward failure were detected. The discussed liner designs appeared to be conservative, and the liner strength appeared to be more than adequate

  20. Manufacturing hollow obturator with resilient denture liner on post hemimaxillectomy

    Directory of Open Access Journals (Sweden)

    Michael Josef Kridanto Kamadjaja

    2006-03-01

    Full Text Available A resilient denture liner is placed in the part of the hollow obturator base that contacts to post hemimaxillectomy mucosa. Replacing the resilient denture liner can makes the hollow obturator has an intimate contact with the mucosa, so it can prevents the mouth liquid enter to the cavum nasi and sinus, also eliminates painful because of using the hollow obturator. Resilient denture liner is a soft and resilient material that applied to the fitting surface of a denture in order to allow a more distribution of load. A case was reported about using the hollow obturator with resilient denture liner on post hemimaxillectomy to overcome these problems.

  1. Aerogel Use as a Skin Protective Liner In Space Suits and Prosthetic Limbs Project

    Science.gov (United States)

    Roberson, Luke Bennett

    2014-01-01

    Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications for use in space suits and orthopedics. Three tests were performed on several types of aerogel to assess the properties of each material, and our initial findings demonstrated that these materrials would be excellent candidates for liner applications for prosthetics and space suits. The project is currently on hold until additional funding is obtained for application testing at the VH Hospitals in Tampa

  2. Accelerated aging tests of liners for uranium mill tailings disposal

    International Nuclear Information System (INIS)

    Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

    1981-11-01

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing

  3. Development of imploding liners with kinetic energies > 100 MJ and their applications

    International Nuclear Information System (INIS)

    Reinovsky, R.E.; Ekdahl, C.A.

    1996-01-01

    The Los Alamos program in High Energy Density Physics is developing high performance imploding liners as sources of high energy density environments for experimental physics applications. High performance liners are, for these purposes, liners with high velocity, 100 MJ or more kinetic energy at 20-50 MJ/cm of height. They must have sufficient azimuthal symmetry, axial uniformity and density to perform as high quality impactors on central, cylindrical targets. Scientific applications of such liners are numerous and varied. For example, the properties of materials at extreme energy densities can be assessed in such an experimental environment. The physics of plasmas near solid density can be studied and hydrodynamics experiments at high Mach number (above 5?) in materials that are near solid density and significantly ionized can be conducted. In addition, liners with substantial kinetic energy and good integrity at velocities of one to a few cm/microsec make good implosion drivers for fusion plasmas in the context of magnetized target fusion and MAGO

  4. Evaluation of Novel Liner Concepts for Fan and Airframe Noise Reduction

    Science.gov (United States)

    Jones, M. G.; Howerton, B. M.

    2016-01-01

    This paper presents a review of four novel liner concepts: soft vanes, over-the-rotor liners, external liners, and flap side-edge liners. A number of similarities in the design and evaluation of these concepts emerged during these investigations. Since these were the first attempts to study these particular liner concepts, there was limited information to guide the design process. In all cases, the target frequencies (or frequency range) were known, but the optimum acoustic impedance and optimum liner placement were typically not known. For these cases, the maximum available surface was used and a c-impedance was targeted based on the assumption the sound field impinges on the surface at normal incidence. This choice proved fruitful for every application. An impedance prediction model was used to design variable-depth liner configurations, and a graphical design code (ILIAD) was developed to aid in this process. The ability to build increasingly complex liner configurations via additive manufacturing was key, such that multiple designs could quickly be tested in a normal incidence impedance tube. The Two-Thickness Method was used to evaluate available bulk materials, such that bulk liners could also be considered for each application. These novel liner concepts provide sufficient noise reduction to warrant further investigations.

  5. Liner system design

    International Nuclear Information System (INIS)

    Hutchinson, I.P.G.; Ellison, R.D.

    1992-01-01

    This paper discusses one of the most important regulatory and design decisions which is determining the type of liner system. The liner system includes a combination of low hydraulic conductivity and leakage control materials to be provided beneath a mine waste management unit to avoid seepage losses, which could result in an unacceptable threat to beneficial uses of ground water. This is more difficult for mine wastes than for other types of waste disposal because: The physical and chemical properties of mine wastes vary widely; The sizes )volume and areal extent) of mine waste management units is often very large so that the costs of liners can impact economic feasibility of some operations. The U.S. Congress considered the differences between mine wastes and other types of wastes when it passed the Bevill amendment to the Resource Conservation and Recovery Act (RCRA) in 1980. That amendment exempted most mine wastes from hazardous waste regulation until the United States Environmental Protection Agency (EPA) conducted a study to determine the appropriate degree of regulation for mine wastes. In 1986, the EPA issued a report recognizing that, with a few exceptions for certain processed materials, mine wastes do not present the same level of threat as other wastes and therefore should be regulated differently. An additional important factor which differentiates mine waste disposal management units form other solid waste disposal units is that, except in unusual circumstances, mine and process facilities are located where the mineral resource is being extracted. Therefore, the location of the mine waste disposal facilities cannot solely be based upon a site selection study. as a result, some mines are located where the distance or depth to a valuable water resource is relatively small, while others are located in remote desert areas with no contiguous surface water resources, and deep ground water of limited quantity and/or quality

  6. Analytical study on the suitability of using bentonite coated gravel as a landfill liner material

    International Nuclear Information System (INIS)

    Roberts, Anel A.; Shimaoka, Takayuki

    2008-01-01

    This study investigates the feasibility of using bentonite coated gravel (BCG) as a liner material for waste landfills. BCG has proven to be a very effective capping material/method for the remediation of contaminated sediments in aquatic environments. The concept of BCG is similar to that of peanuts/almonds covered with chocolate; each aggregate particle has been covered with the clayey material. Laboratory tests were aimed at evaluating regulated and non-regulated factors for liner materials, i.e., permeability and strength. Tests included X-ray diffraction, methylene blue absorption, compaction, free swelling, permeability, 1D consolidation, triaxial compression and cone penetration. The compactive efforts used for this study were the reduced Proctor, standard Proctor, intermediate Proctor, modified Proctor and super modified Proctor. The compactive energy corresponding to each effort, respectively, is as follows: 355.5, 592.3, 1196.3, 2693.3, and 5386.4 kJ/m 3 . Results revealed that even though aggregate content represents 70% of the weight of the material, hydraulic conductivities as low as 6 x 10 -10 cm/s can be achieved when proper compactive efforts are used. Compressibility is very low for this material even at low (or no) compactive efforts. Results also demonstrated how higher compactive efforts can lower the permeability of BCG; however, over-compaction creates fractures in the aggregate core of BCG that could increase permeability. Moreover, higher compactive efforts create higher swelling pressures that could compromise the performance of a barrier constructed using BCG. As a result of this study, moderate compactive efforts, i.e., intermediate Proctor or modified Proctor, are recommended for constructing a BCG barrier. Using moderate compactive efforts, very low hydraulic conductivities, good workability and good trafficability are easily attainable

  7. Assessment of structural integrity of Monju steel liner against sodium leakage and combustion. Strain criterion of the liner material

    Energy Technology Data Exchange (ETDEWEB)

    Asayama, T.; Koi, M. [Japan Nuclear Cycle Development Institute, Ibaraki (Japan)

    2001-07-01

    In a postulated condition of sodium leakage and combustion in the secondary heat transfer system of the prototype Japanese fast breeder reactor Monju, thermal stresses raise in steel liners installed to prevent sodium from contacting to concrete. Excessive strain due to the thermal stresses leads to failure of the liner. This paper proposes a strain criterion below that the mechanical integrity of liner is assured. In-plane thermal expansion causes membrane strain and out-of-plane expansion causes bending strain. Therefore, failure modes to be taken into account are tensile fracture and bending fracture. The strain criterion can be determined based on tensile and bending tests. Tensile tests and three-point bending tests were performed at the temperature range from room temperature to 1000 C. Fracture elongation was measured in both tests. Uniform elongation was also measured in tensile tests. Various factors that can affect the above experimental results, multi-axiality, environmental effects, and creep were examined. Based on the above results, the strain criterion was determined. The criterion is 10% for membrane strain and 30% for membrane plus bending strain in the temperature range of 350 C to 1000 C. For the temperatures less than 350 C, the half of those values is used. (author)

  8. Effects of plasma jet parameters, ionization, thermal conduction, and radiation on stagnation conditions of an imploding plasma liner

    Science.gov (United States)

    Stanic, Milos

    The disciplines of High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF) are characterized by hypervelocity implosions and strong shocks. The Plasma Liner Experiment (PLX) is focused on reaching HEDP and/or ICF relevant regimes in excess of 1 Mbar peak pressure by the merging and implosion of discrete plasma jets, as a potentially efficient path towards these extreme conditions in a laboratory. In this work we have presented the first 3D simulations of plasma liner, formation, and implosion by the merging of discrete plasma jets in which ionization, thermal conduction, and radiation are all included in the physics model. The study was conducted by utilizing a smoothed particle hydrodynamics code (SPHC) and was a part of the plasma liner experiment (PLX). The salient physics processes of liner formation and implosion are studied, namely vacuum propagation of plasma jets, merging of the jets (liner forming), implosion (liner collapsing), stagnation (peak pressure), and expansion (rarefaction wave disassembling the target). Radiative transport was found to significantly reduce the temperature of the liner during implosion, thus reducing the thermal expansion rates and leaving more pronounced gradients in the plasma liner during the implosion compared with ideal hydrodynamic simulations. These pronounced gradients lead to a greater sensitivity of initial jet geometry and symmetry on peak pressures obtained. Accounting for ionization and transport, many cases gave higher peak pressures than the ideal hydrodynamic simulations. Scaling laws were developed accordingly, creating a non-dimensional parameter space in which performance of an imploding plasma jet liner can be estimated. It is shown that HEDP regimes could be reached with ≈ 5 MJ of liner energy, which would translate to roughly 10 to 20 MJ of stored (capacitor) energy. This is a potentially significant improvement over the currently available means via ICF of achieving HEDP and nuclear

  9. Liner mounting assembly

    Science.gov (United States)

    Halila, Ely E. (Inventor)

    1994-01-01

    A mounting assembly includes an annular supporting flange disposed coaxially about a centerline axis which has a plurality of circumferentially spaced apart supporting holes therethrough. An annular liner is disposed coaxially with the supporting flange and includes a plurality of circumferentially spaced apart mounting holes aligned with respective ones of the supporting holes. Each of a plurality of mounting pins includes a proximal end fixedly joined to the supporting flange through a respective one of the supporting holes, and a distal end disposed through a respective one of the liner mounting holes for supporting the liner to the supporting flange while unrestrained differential thermal movement of the liner relative to the supporting flange.

  10. Development of liner cutting method for stainless steel liner

    International Nuclear Information System (INIS)

    Takahata, Masato; Wignarajah, Sivakmaran; Kamata, Hirofumi

    2005-01-01

    The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in cells and fuel storage pools of nuclear facilities. The effects of basic laser cutting parameters such as cutting speed, assist gas flow etc. were first studied applying a 1 kW Nd:YAG laser to mock up concrete specimens lined with 3 mm thick stainless steel sheets. These initial studies were followed by studies on the effect of unevenness of the liner surface and on methods of confining contamination during the cutting process. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. In addition to the above results, this paper describes the design outline of a laser cutting system for cutting stainless liners at site and evaluates its merit and cost performance. (author)

  11. Evaluation of flexible membrane liners as long-term barriers for uranium mill tailings

    International Nuclear Information System (INIS)

    1984-07-01

    The National Uranium Tailings Program has commissioned a study to evaluate flexible membrane liners (geomembranes) as long-term barriers for Canadian uranium mill tailings. This study reviews the common liner type and addresses flexible liners (polymeric membranes and asphalt) in detail. Liner fabrication, design, installation, and performance are reviewed. Conceptual designs are presented for basins to accommodate 20 years accumulation of uranium tailings from mills in Elliot Lake and southeastern Athabasca. Nine polymeric and three asphalt liner types have been considered with respect to the physical and chemical environment in the uranium producing areas of Canada. All materials indicate good chemical resistance to uranium wastes but are subject to installation problems

  12. Generation of rotation and shear flow in an imploding liner

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, J H; Ryutov, D D [Lawrence Livermore National Lab., Livermore, CA (United States)

    1997-12-31

    There exist several techniques that can set the liner into rotation and/or excite an embedded shear flow at any desired depth of the liner material. A common element of all these techniques is the use of properly used left-right asymmetric structures, situated either on the liner surface or embedded in the shell. Both rotation and shear flow get enhanced in the course of the liner implosion because of the angular momentum conservation. While fast enough rotation should stabilize the Rayleigh-Taylor instability near the turn-around point, the shear flow can also have a stabilizing effect on the interface. The specific model presented in the paper shows that a strong enough shear causes stabilization of a broad class of Rayleigh-Taylor perturbations. Thus, the use of left-right asymmetric structure for generation of rotation and shear flow is an interesting new option for improvement of the quality of the liner implosions. (J.U.). 4 figs., 12 refs.

  13. Sanitary landfill liners

    DEFF Research Database (Denmark)

    Christiansen, Ole V.; Stentsøe, Steen; Petersen, Søren

    DS/INF 466 is the revised Danish recommendation for investigations, design and construction of landfill liners.......DS/INF 466 is the revised Danish recommendation for investigations, design and construction of landfill liners....

  14. Method for baking a liner in thermonuclear device

    International Nuclear Information System (INIS)

    Yamamoto, Keiichi.

    1978-01-01

    Purpose: To attain effective baking for liners in a tokamak device by connecting the narrow portions and the wide portions of the liners with dielectric materials and supplying a constant current to these portions. Method: Split type liners disposed in the vacuum vessel of a thermonuclear device are connected with dielectric materials at their wide portions and narrow portions and they are baked by supplying a constant current at a same density to the wide and narrow portions to rise their temperature uniformly. The wide portions are formed in such a way that the sum of their cross sectional areas is equal to the sum of the cross sectional areas of the narrow portions, and they form a parallel circuit. The parallel circuit consisting of the wide portions and the parallel circuit consisting of the narrow portions are connected in series to each other and connected to the constant current supply circuit, by which a constant current is supplied to the wide and the narrow portions. (Moriyama, K.)

  15. Sodium leak and combustion experiment-II report. Evaluation result of damage of mild steel liner

    Energy Technology Data Exchange (ETDEWEB)

    Aoto, K.; Hirakawa, Y.; Kuroda, T. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1996-09-01

    Several material analyses on damage of the floor liner made of a mild steel which was in the test cell of the second sodium leak and combustion experiment (Test-2) performed in OEC/PNC on June 7 in 1996 were carried out to clarify the following issues. (1) Difference of the corrosion mechanism of Test-2 liner to that of the first sodium leak and combustion experiment (Test-1) liner. (2) The vital factor which can desides corrosion mechanism and damage location. The following analyses were accomplished. (1) Microstructure observation, (2) EPMA for cross-section of vicinity of corroded area, (3) X-ray diffraction (XRD) for the interface between corrosion product-liner (mild steel). The differences between the corrosion mechanism of Test-1 liner which is seemed to be the same that of `MONJU` liner and that of Test-2 liner is discussed based on the results of these material analyses. As the result, the Na-Fe double oxidization with mechanical/chemical removal of reaction product can be occurred on the Test-1 and `MONJU` liner. On the other hand, a hot-corrosion, that is the molten salt type corrosion is subject to be thinning of the Test-2 liner. All failures of Test-2 liner surround at the halfway up a convex. Considering the above corrosion mechanism, that fact leads that significant damage is occurred at the molten salt level. (author)

  16. Optimization of deformations and hoop stresses in TSV liners to boost interconnect reliability in electronic appliances

    Science.gov (United States)

    Juma, Mary Atieno; Zhang, Xuliang; He, Song Bai; Abusabah, Ahmed I. A.

    2015-12-01

    Recently, there has been a lot of research with electronic products because more and different functions are integrated into devices and the final product sizes have to be small to meet the market demand. A lot of research has been done on the (TSVs) Through Silicon Vias. In this paper, through silicon via liners are investigated. The liners: silicon dioxide, polystyrene and polypropylene carbonate are exposed to pressure on their inner surfaces and this yielded hoop stresses within their thickness. Deflections too occurred and this is a proof that deformation really took place. In one of our papers, hoop stresses for the same materials were investigated. The values were a little higher but different for each material used. In this paper, we use global cylindrical, partial cylinder model with different theta in Analysis system 14 to model the through silicon via liners. The values are lower meaning the reliability of the liners have been optimized and boosted. However, silicon dioxide liner had the lowest hoop stress around its circumference and lowest deflection value meaning that it's still one of the most reliable materials in the manufacture of through silicon via liners in the industry; but overdependence can be avoided if the other liners are used too.

  17. Progress In Magnetized Target Fusion Driven by Plasma Liners

    Science.gov (United States)

    Thio, Francis Y. C.; Kirkpatrick, Ronald C.; Knapp, Charles E.; Cassibry, Jason; Eskridge, Richard; Lee, Michael; Smith, James; Martin, Adam; Wu, S. T.; Schmidt, George; hide

    2001-01-01

    Magnetized target fusion (MTF) attempts to combine the favorable attributes of magnetic confinement fusion (MCF) for energy confinement with the attributes of inertial confinement fusion (ICF) for efficient compression heating and wall-free containment of the fusing plasma. It uses a material liner to compress and contain a magnetized plasma. For practical applications, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC).

  18. Fracture-dissociation of ceramic liner.

    Science.gov (United States)

    Hwang, Sung Kwan; Oh, Jin-Rok; Her, Man Seung; Shim, Young Jun; Cho, Tae Yeun; Kwon, Sung Min

    2008-08-01

    The use of BIOLOX delta ceramic (CeramTec AG, Plochingen, Germany) has been increasing. This ceramic prevents cracking by restraining the phase transformation due to the insertion of nano-sized, yttria-stabilized tetragonal zirconia into the alumina matrix. This restrains the progress of cracking through the formation of platelet-like crystal or whiskers due to the addition of an oxide additive. We observed a case of BIOLOX delta ceramic liner (CeramTec AG) rim fracture 4 months postoperatively. Radiographs showed that the ceramic liner was subluxated from the acetabular cup. Scratches on the acetabular cup and femoral neck were seen, and the fracture was visible on the rim of the liner. Under electron microscope, metal particle coatings from the ceramic liner were identified. The ceramic liner, fracture fragments, and adjacent tissues were removed and replaced with a ceramic liner and femoral head of the same size and design. We believe the mechanism of the fracture-dissociation of the ceramic liner in this case is similar to a case of separation of the ceramic liner from the polyethylene shell in a sandwich-type ceramic-ceramic joint. To prevent ceramic liner fracture-dissociation, the diameter of the femoral neck needs to be decreased in a new design, while the diameter of the femoral head needs to be increased to ensure an increase in range of motion.

  19. The effect of liner hydraulic conductivity on disposal cell performance

    International Nuclear Information System (INIS)

    Yu, C.; Yuan, Y.C.; Chia, Y.P.

    1988-01-01

    Multilayered disposal cells are frequently used for the disposal of radioactive and hazardous wastes. These disposal cells consist of materials with different permeabilities that are placed in various thicknesses at the bottom as well as in the cover of the cell. Typically, a layer of permeable material is placed above a layer with low permeability; the permeable layer functions as a drainage/leachate collection system and the low-permeability layer functions as a migration barrier/liner. This paper analyzes the effects of infiltration through unsaturated soil liners on the long-term performance of the disposal cell. Based on the results of this study, it is concluded that the long-term performance of a disposal cell is dependent on a well-designed cell cover. The design should emphasize a cap with less permeable material to prevent water from infiltrating the disposal cell. An impermeable bottom liner is effective only in the short term; however, it can eventually result in saturation of the wastes and cause the bathtub effect over the long term

  20. Shaping the Microstructure of Cast Iron Automobile Cylinder Liners Aimed at Providing High Service Properties

    Directory of Open Access Journals (Sweden)

    Orłowicz A.W.

    2015-06-01

    Full Text Available The paper presents an analysis of factors affecting the wear of cylinder liners. The effect of the graphite precipitation morphology on the cylinder liner wear mechanism is presented. Materials used to cast cylinder liners mounted in a number of engines have been examined for their conformity with requirements set out in applicable Polish industrial standard. A casting for a prototype cylinder liner has been made with a microstructure guaranteeing good service properties of the part.

  1. Effect of plasma spraying modes on material properties of internal combustion engine cylinder liners

    Science.gov (United States)

    Timokhova, O. M.; Burmistrova, O. N.; Sirina, E. A.; Timokhov, R. S.

    2018-03-01

    The paper analyses different methods of remanufacturing worn-out machine parts in order to get the best performance characteristics. One of the most promising of them is a plasma spraying method. The mathematical models presented in the paper are intended to anticipate the results of plasma spraying, its effect on the properties of the material of internal combustion engine cylinder liners under repair. The experimental data and research results have been computer processed with Statistica 10.0 software package. The pare correlation coefficient values (R) and F-statistic criterion are given to confirm the statistical properties and adequacy of obtained regression equations.

  2. Waste Handling Shaft concrete liner degradation conclusions and recommendations

    International Nuclear Information System (INIS)

    1992-10-01

    The primary function of the Waste Handling Shaft (WHS) at the Waste Isolation Pilot Plant (WIPP) is to permit the transfer of radioactive waste from the surface waste handling building to the underground storage area. It also serves as an intake shaft for small volumes of air during normal storage operations and as an emergency escape route. Part of the construction was the placement of a concrete liner and steel reinforced key in 1984. During a routine shaft inspection in May 1990, some degradation of the WHS concrete liner was observed between the depths of 800 and 900 feet below the ground surface. Detailed investigations of the liner had been carried out by Sandia National Laboratories and by Westinghouse Electric Corporation Waste Isolation Division (WID) through Lankard Materials Laboratory. Observations, reports, and data support the conclusion that the concrete degradation, resulting from attack by chemically aggressive brine, is a localized phenomena. It is the opinion of the WID that the degradation is not considered an immediate or near term concern; this is supported by technical experts. WID recommendations have been made which, when implemented, will ensure an extended liner life. Based on the current assessment of available data and the proposed shaft liner monitoring program described in this report, it is reasonable to assume that the operational life of the concrete shaft liner can safely support the 25-year life of the WIPP. Analysis of data indicates that degradation of the shaft's concrete liner is attributed to chemically aggressive brine seeping through construction joints and shrinkage cracks from behind the liner in and around the 834-foot depth. Chemical and mechanical components of concrete degradation have been identified. Chemical attack is comprised of several stages of concrete alteration. The other component, mechanical degradation, results from the expansive forces of crystals forming in the concrete pore space

  3. Localized deformation of zirconium-liner tube

    International Nuclear Information System (INIS)

    Nagase, Fumihisa; Uchida, Masaaki

    1988-03-01

    Zirconium-liner tube has come to be used in BWR. Zirconium liner mitigates the localized stress produced by the pellet-cladding interaction (PCI). In this study, simulating the ridging, stresses were applied to the inner surfaces of zirconium-liner tubes and Zircaloy-2 tubes, and, to investigate the mechanism and the extent of the effect, the behavior of zirconium liner was examined. As the result of examination, stress was concentrated especially at the edge of the deformed region, where zirconium liner was highly deformed. Even after high stress was applied, the deformation of Zircaloy part was small, since almost the concentrated stress was mitigated by the deformation of zirconium liner. In addition, stress and strain distributions in the cross section of specimen were calculated with a computer code FEMAXI-III. The results also showed that zirconium liner mitigated the localized stress in Zircaloy, although the affected zone was restricted to the region near the boundary between zirconium liner and Zircaloy. (author)

  4. Liner used in tailings ponds

    International Nuclear Information System (INIS)

    Dinchak, W.G.

    1984-01-01

    A composite liner has been developed for use in hazardous waste impoundments and in tailings ponds where uranium is involved. The liner offers a high degree of reliability against seepage, is durable, and provides a firm working surface. The advantages of the liner are discussed

  5. Acoustic Liners for Turbine Engines

    Science.gov (United States)

    Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

    2016-01-01

    An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

  6. Effects of tacky mat contamination on bond degradation for Chemlok/liner and NBR/liner bonds

    Science.gov (United States)

    Padilla, A. M.

    1989-01-01

    Tacky mats are placed by the rubber lay-up areas for the solid rocket motor segments. These mats dust off the shoes prior to entering the platform where the lay-up work is performed. The possibility exists that a tacky mat could be touched with gloved hands prior to handling the uncured nitride butadiene rubber (NBR). Tests were run to determine if NBR were accidentally touched would there be any degradation of the liner/NBR bond. The tacky mats were judged solely on the basis of bond degradation caused by either direct or indirect contamination. Test results all indicate that there was no notable NBR/Chemlok or liner/NBR bond degradation on samples that came into contact with the tacky mat material. Testing procedures are described. The tacky mat adhesive composition does not contain fluorocarbons or release agents that would affect bonding.

  7. Preparations to ship EPICOR liners

    International Nuclear Information System (INIS)

    Queen, S.P.

    1983-06-01

    The sampling and analysis of the hydrogen rich atmosphere of the 49 EPICOR II ion-exchange prefilter liners generated in the decontamination of radioactive water at TMI-2 will provide data to ensure safe storage and shipment of highly loaded ion-exchange media. This report discusses the prototype gas sampling tool used to breech the containment of the liners, the tool support equipment for sampling and inerting the liners, and the characterization program used for determining the radiolytic hydrogen generation rates in the liners

  8. Plasma-driven liners

    International Nuclear Information System (INIS)

    Kilic, H.; Linhart, J.G.; Bortolotti, A.; Nardi, V.

    1992-01-01

    The deposition of thermal energy by laser or ion beams in an ablator is capable of producing a very large acceleration of the adjacent pusher - for power densities of 100 Terrawatts/cm 2 , ablator pressure in the range of 10 Mbar is attainable. In the case of a plasma drive such driving pressures and accelerations are not directly possible. When a snowplough (SP) is used to accelerate a thin liner, the driving pressure is that of the magnetic piston pushing the SP, i.e. at most 0.1 Mbar. However, the initial radius r 0 of the liner can be a few centimeters, instead of 1 (mm) as in the case in direct pellet implosions. In order to compete with the performance of the beam-driven liners, the plasma drive must demonstrate that a) thin liner retains a high density during the implosion (lasting a fraction of a μsec); b) radial compression ratio r 0 /r min of the order of 100 can be attained. It is also attractive to consider the staging of two or more liners in order to get sharpening and amplifications of the pressure and/or radiation pulse. If a) and b) are verified then the final pressures produced will be comparable with those of the beam-driven implosions. (author) 5 refs., 3 figs

  9. High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner For Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Ellis, David; Singh, Jogender

    2014-01-01

    Advanced high thermal conductivity materials research conducted at NASA Marshall Space Flight Center (MSFC) with state of the art combustion chamber liner material NARloy-Z showed that its thermal conductivity can be increased significantly by adding diamond particles and sintering it at high temperatures. For instance, NARloy-Z containing 40 vol. percent diamond particles, sintered at 975C to full density by using the Field assisted Sintering Technology (FAST) showed 69 percent higher thermal conductivity than baseline NARloy-Z. Furthermore, NARloy-Z-40vol. percent D is 30 percent lighter than NARloy-Z and hence the density normalized thermal conductivity is 140 percent better. These attributes will improve the performance and life of the advanced rocket engines significantly. By one estimate, increased thermal conductivity will directly translate into increased turbopump power up to 2X and increased chamber pressure for improved thrust and ISP, resulting in an expected 20 percent improvement in engine performance. Follow on research is now being conducted to demonstrate the benefits of this high thermal conductivity NARloy-Z-D composite for combustion chamber liner applications in advanced rocket engines. The work consists of a) Optimizing the chemistry and heat treatment for NARloy-Z-D composite, b) Developing design properties (thermal and mechanical) for the optimized NARloy-Z-D, c) Fabrication of net shape subscale combustion chamber liner, and d) Hot fire testing of the liner for performance. FAST is used for consolidating and sintering NARlo-Z-D. The subscale cylindrical liner with built in channels for coolant flow is also fabricated near net shape using the FAST process. The liner will be assembled into a test rig and hot fire tested in the MSFC test facility to determine performance. This paper describes the development of this novel high thermal conductivity NARloy-Z-D composite material, and the advanced net shape technology to fabricate the combustion

  10. Accurate control testing for clay liner permeability

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R J

    1991-08-01

    Two series of centrifuge tests were carried out to evaluate the use of centrifuge modelling as a method of accurate control testing of clay liner permeability. The first series used a large 3 m radius geotechnical centrifuge and the second series a small 0.5 m radius machine built specifically for research on clay liners. Two permeability cells were fabricated in order to provide direct data comparisons between the two methods of permeability testing. In both cases, the centrifuge method proved to be effective and efficient, and was found to be free of both the technical difficulties and leakage risks normally associated with laboratory permeability testing of fine grained soils. Two materials were tested, a consolidated kaolin clay having an average permeability coefficient of 1.2{times}10{sup -9} m/s and a compacted illite clay having a permeability coefficient of 2.0{times}10{sup -11} m/s. Four additional tests were carried out to demonstrate that the 0.5 m radius centrifuge could be used for linear performance modelling to evaluate factors such as volumetric water content, compaction method and density, leachate compatibility and other construction effects on liner leakage. The main advantages of centrifuge testing of clay liners are rapid and accurate evaluation of hydraulic properties and realistic stress modelling for performance evaluations. 8 refs., 12 figs., 7 tabs.

  11. Nuclear containment steel liner corrosion workshop : final summary and recommendation report.

    Energy Technology Data Exchange (ETDEWEB)

    Erler, Bryan A. (Erler Engineering Ltd., Chicago, IL); Weyers, Richard E. (Virginia Tech University, Blacksburg, VA); Sagues, Alberto (University of South Florida, Tampa, FL); Petti, Jason P.; Berke, Neal Steven (Tourney Consulting Group, LLC, Kalamazoo, MI); Naus, Dan J. (Oak Ridge National Laboratory, Oak Ridge, TN)

    2011-07-01

    This report documents the proceedings of an expert panel workshop conducted to evaluate the mechanisms of corrosion for the steel liner in nuclear containment buildings. The U.S. Nuclear Regulatory Commission (NRC) sponsored this work which was conducted by Sandia National Laboratories. A workshop was conducted at the NRC Headquarters in Rockville, Maryland on September 2 and 3, 2010. Due to the safety function performed by the liner, the expert panel was assembled in order to address the full range of issues that may contribute to liner corrosion. This report is focused on corrosion that initiates from the outer surface of the liner, the surface that is in contact with the concrete containment building wall. Liner corrosion initiating on the outer diameter (OD) surface has been identified at several nuclear power plants, always associated with foreign material left embedded in the concrete. The potential contributing factors to liner corrosion were broken into five areas for discussion during the workshop. Those include nuclear power plant design and operation, corrosion of steel in contact with concrete, concrete aging and degradation, concrete/steel non-destructive examination (NDE), and concrete repair and corrosion mitigation. This report also includes the expert panel member's recommendations for future research.

  12. Experimental plans for LMFBR cavity liner sodium spill test LT-1

    International Nuclear Information System (INIS)

    Hilliard, R.K.; Newell, G.A.

    1976-01-01

    Reinforced concrete is an important material of construction in LMFBR cavities and cells. Steel liners are often installed on the concrete surfaces to provide a gastight seal for minimizing air inleakage to inerted cell atmospheres and to protect the concrete from direct contact with sodium in the event of a sodium spill. In making safety assessment analyses, it is of interest to determine the adequacy of the liners to maintain their leaktightness during postulated accidents involving large sodium spills. However, data for basing analytical assessments of cell liners are very meager and an experimental program is underway at HEDL to provide some of the needed information. The HEDL cell liner evaluation program consists of both bench-scale feature tests and large-scale sodium spill demonstration tests. The plans for the first large-scale sodium spill test (LT-1) are the subject of this paper

  13. Use of x-ray radiographic methods in the study of clay liners

    International Nuclear Information System (INIS)

    Malone, P.G.; May, J.H.; Brown, K.W.; Thomas, J.C.

    1986-01-01

    X-ray radiography has been widely used in soil investigation to study the distribution of layers in soil cores and the effects of changing conditions (loading or impact) on soil structure. X-ray radiographic techniques also can be useful in studying clays or clay soils used in liners. Laboratory investigations were undertaken to demonstrate that X-ray radiographic techniques could be used to detect density and soil structure changes that usually accompany variations in hydraulic conductivity of clay liners. An example of a real-time test of a simulated bentonite and sand, liner attacked with acid lead nitrate and examples of radiographic examination of clay soil (non-calcareous smectite) samples that have been permeated by lead acetate or lead nitrate are presented. The changes in density and structure can be related to changes observed in hydraulic conductivity during permeation. X-ray radiography easily can be applied to field samples of soil or clay liner materials to detect density and structural changes that occur as the liner and permeating fluid interact. X-ray techniques have applications in both understanding failure mechanisms and forecasting liner performance

  14. Optimization in liner shipping

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Karsten, Christian Vad; Pisinger, David

    2017-01-01

    Seaborne trade is the lynchpin in almost every international supply chain, and about 90% of non-bulk cargo worldwide is transported by container. In this survey we give an overview of data-driven optimization problems in liner shipping. Research in liner shipping is motivated by a need for handling...... still more complex decision problems, based on big data sets and going across several organizational entities. Moreover, liner shipping optimization problems are pushing the limits of optimization methods, creating a new breeding ground for advanced modelling and solution methods. Starting from liner...... shipping network design, we consider the problem of container routing and speed optimization. Next, we consider empty container repositioning and stowage planning as well as disruption management. In addition, the problem of bunker purchasing is considered in depth. In each section we give a clear problem...

  15. Novel Tribotester for Cylinder Liner/Piston Ring Contacts of Two Stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Pedersen, Michael Torben; Imran, Tajammal; Klit, Peder

    2009-01-01

    A good tribological description for the cylinder liner and piston ring materials is always desired in order to achieve an improved combination of the materials. The piston ring package in a two-stroke-diesel engine operates in three lubrication regimes and the materials must be characterized...... in relation to this before a final selection is made. A tribo-test-apparatus is developed to study the tribological performance and to rank the different combinations of cylinder liner and piston ring materials of two stroke marine diesel engines. The test apparatus is based on the block-on-ring principle...

  16. Evaluation of liners for a uranium-mill tailings disposal site: a status report

    International Nuclear Information System (INIS)

    Buelt, J.L.; Hale, V.Q.; Barnes, S.M.; Silviera, D.J.

    1981-05-01

    The United States Department of Energy is conducting a program designed to reclaim or stabilize inactive uranium-mill tailings sites. This report presents the status of the Liner Evaluation Program. The purpose of the study was to identify eight prospective lining materials or composites for laboratory testing. The evaluation was performed by 1) reviewing proposed regulatory requirements to define the material performance criteria; 2) reviewing published literature and communicating with industrial and government experts experienced with lining materials and techniques; and 3) characterizing the tailings at three of the sites for calcium concentration, a selection of anions, radionuclides, organic solvents, and acidity levels. The eight materials selected for laboratory testing are: natural soil amended with sodium-saturated montmorillonite (Volclay); locally available clay in conjunction with an asphalt emulsion radon suppression cover; locally available clay in conjunction with a multibarrier radon suppression cover; rubberized asphalt membrane; hydraulic asphalt concrete; chlorosulfonated polyethylene (hypalon) or high-density polyethylene; bentonite, sand and gravel mixture; and catalytic airblown asphalt membrane. The materials will be exposed in test units now being constructed to conditions such as wet/dry cycles, temperature cycles, oxidative environments, ion-exchange elements, etc. The results of the tests will identify the best material for field study. The status report also presents the information gathered during the field studies at Grand Junction, Colorado. Two liners, a bentonite, sand and gravel mixture, and a catalytic airblown asphalt membrane, were installed in a prepared trench and covered with tailings. The liners were instrumented and are being monitored for migration of moisture, radionuclides, and hazardous chemicals. The two liner materials will also be subjected to accelerated laboratory tests for a comparative assessment

  17. Migration behavior of landfill leachate contaminants through alternative composite liners

    Energy Technology Data Exchange (ETDEWEB)

    Varank, Gamze, E-mail: gvarank@yildiz.edu.tr; Demir, Ahmet, E-mail: ahmetd@yildiz.edu.tr; Top, Selin, E-mail: stop@yildiz.edu.tr; Sekman, Elif, E-mail: esekman@yildiz.edu.tr; Akkaya, Ebru, E-mail: ekoca@yildiz.edu.tr; Yetilmezsoy, Kaan, E-mail: yetilmez@yildiz.edu.tr; Bilgili, M. Sinan, E-mail: mbilgili@yildiz.edu.tr

    2011-08-01

    Four identical pilot-scale landfill reactors with different alternative composite liners were simultaneously operated for a period of about 540 days to investigate and to simulate the migration behaviors of phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and heavy metals (Pb, Cu, Zn, Cr, Cd, Ni) from landfill leachate to the groundwater. Alternative landfill liners of four reactors consist of R1: Compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R2: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R3: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + bentonite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn), and R4: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + zeolite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn). Wastes representing Istanbul municipal solid wastes were disposed in the reactors. To represent bioreactor landfills, reactors were operated by leachate recirculation. To monitor and control anaerobic degradation in the reactors, variations of conventional parameters (pH, alkalinity, chloride, conductivity, COD, TOC, TKN, ammonia and alcaly metals) were also investigated in landfill leachate samples. The results of this study showed that about 35-50% of migration of organic contaminants (phenolic compounds) and 55-100% of migration of inorganic contaminants (heavy metals) to the model groundwater could be effectively reduced with the use of bentonite and zeolite materials in landfill liner systems. Although leachate contaminants can reach to the groundwater in trace concentrations, findings of this study concluded that the release of these compounds from landfill leachate to the groundwater may potentially be of an important environmental concern based on the experimental findings. - Research highlights: {yields} Migration of

  18. Stabilized imploding liner fusion systems

    International Nuclear Information System (INIS)

    Book, D.L.; Cooper, A.L.; Ford, R.; Gerber, K.A.; Hammer, D.A.; Jenkins, D.J.; Robson, A.E.; Turchi, P.J.

    1977-01-01

    A new concept in imploding liner plasma compression is described in which a liquid metal liner is imploded by pistons driven by high-pressure gas, and stability of the inner surface against Rayleigh-Taylor modes is achieved by rotation. The principle has been demonstrated by using a water liner to compress air. This 'captive liner' offers the possibility of stable, reversible implosion-expansion cycles in which the plasma energy is recovered into the driving system, leading to reactor cycles with low Q and, hence, small size. A new method of setting up closed-field confinement geometries inside a liner using a rotating electron beam is described. Plasma currents induced by the beam provide initial plasma heating and generate the containment geometry. Persistence of plasma currents 100 times longer than the beam duration has been observed. Development of these methods could lead to a very compact thermonuclear reactor operating in the manner of a reciprocating engine. (author)

  19. Comparative evaluation of 2% sodium fluoride iontophoresis and other cavity liners beneath silver amalgam restorations

    Directory of Open Access Journals (Sweden)

    Gupta M

    2010-06-01

    Full Text Available Background: This study was designed to compare 2% sodium fluoride (NaF iontophoresis with other cavity liners. Materials and Methods: This study was carried out in 30 patients in the age group 10-14 years with bilateral carious permanent first molars. The study evaluated the use of 2% NaF iontophoresis as a cavity liner and also compared its desensitizing effect with varnish and an adhesive bonded liner. Sensitivity gradings were done on a subjective verbal rating scale. Results: All the liner treatments decreased the sensitivity following liner application. However, decrease of sensitivity in the case of 2% NaF iontophoresis was more compared with that of varnish and adhesive bonded liner. The results were statistically significant. Conclusions: It was found that 2% NaF iontophoresis was more effective in reducing the postoperative sensitivity compared with that of varnish and scotchbond multipurpose.

  20. SEM Evaluation of Internal Adaptation of Bases and Liners under Composite Restorations

    Directory of Open Access Journals (Sweden)

    Dimitrios Dionysopoulos

    2014-04-01

    Full Text Available The aim of this study was to evaluate the interfacial microgaps generating between different materials and between materials and dentin after polymerization of the composite restorations, using SEM. Methods: The materials investigated were a composite, an adhesive, a RMGI, and a calcium hydroxide. Thirty third molars were selected and two circular class V cavities (5 mm × 3 mm for each tooth were made. The teeth were randomly assigned into six groups and restored with a combination of the materials. The specimens were subjected to thermocycling and each tooth was sectioned mesiodistally in two halves. Each half was sectioned along the longitudinal axis through the center of the restorations to obtain a slice of 2 mm. The specimens were examined under SEM. The interfaces between the liners, the liners and dentin, and between the liners and the composite were examined for microgaps. Results: The results showed that there was not any significant difference in the mean width of microgaps in the interfaces between Dycal-dentin and Vitrebond-dentin (p>0.05. However, the width of microgaps in the interfaces between dentin-Clearfil Tri-S Bond was significantly smaller (p<0.05. The use of Clearfil Tri-S Bond reduced the possibility of microgap formation between the bonded interface and the materials tested.

  1. Computational concept for the containment liner for a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Nagelstutz, Franz; Anders, Nils [Babcock Noell GmbH, Wuerzburg (Germany). Abt. Berechnung

    2010-05-15

    The determination of the optimal design of the Containment Liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. Several load cases for normal operation and accidental conditions as well as severe accidents have been analyzed. A realistic consideration of impacts by accidents was especially difficult. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. An integrated concept from planning, manufacturing and erection of this large component has been implemented, which is the topic of the speech 'ENGINEERING AND INNOVATIVE ERECTION CONCEPT FOR THE CONTAINMENT LINER FOR AN EPR trademark ' given by Dr. Rainer Goehring, Babcock Noell GmbH, Division Nuclear Technology Projects, Wuerzburg. He demonstrates that within the given time frame, with the required quality and within the required tolerances the containment liner can be erected. (orig.)

  2. Liner Shipping Fleet Repositioning

    DEFF Research Database (Denmark)

    Tierney, Kevin; Jensen, Rune Møller

    2011-01-01

    Liner shipping fleet repositioning consists of moving vessels between services in a liner ship- ping network in order to better orient the overall network to the world economy, and to ensure the proper maintenance of vessels. Thus, fleet repositioning involves sailing and loading activities subject...

  3. Characterization of EPICOR II Prefilter Liner 3

    International Nuclear Information System (INIS)

    Wynhoff, N.L.; Pasupathi, V.

    1983-04-01

    As part of the overall TMI-2 Information and Examination Program, EPICOR II Prefilter Liner 3 was examined to provide information to aid in the development of technology for safely processing highly loaded ion-exchange media. The characterization program included sampling and analyses of the liner contents, including ion-exchange media, liquids and gases, as well as examinations of the liner interior and exterior. This report details the handling of the liner, sampling and analysis of the contents, and the examinations of the liner

  4. Characterization of EPICOR II Prefilter Liner 16

    International Nuclear Information System (INIS)

    Yesso, J.D.; Pasupathi, V.; Lowry, L.

    1982-08-01

    As part of the overall TMI-2 Information and Examination Program, EPICOR II Prefilter Liner 16 was examined to provide information to aid in the development of technology for safely processing highly loaded ion-exchange media. The characterization program included sampling and analyses of the liner contents, including ion-exchange media, liquids and gases, as well as examinations of the liner interior and exterior. This report details the handling of the liner, sampling and analysis of the contents, and the examinations of the liner

  5. Megagauss-level magnetic field production in cm-scale auto-magnetizing helical liners pulsed to 500 kA in 125 ns

    Science.gov (United States)

    Shipley, G. A.; Awe, T. J.; Hutsel, B. T.; Slutz, S. A.; Lamppa, D. C.; Greenly, J. B.; Hutchinson, T. M.

    2018-05-01

    Auto-magnetizing (AutoMag) liners [Slutz et al., Phys. Plasmas 24, 012704 (2017)] are designed to generate up to 100 T of axial magnetic field in the fuel for Magnetized Liner Inertial Fusion [Slutz et al., Phys. Plasmas 17, 056303 (2010)] without the need for external field coils. AutoMag liners (cylindrical tubes) are composed of discrete metallic helical conduction paths separated by electrically insulating material. Initially, helical current in the AutoMag liner produces internal axial magnetic field during a long (100 to 300 ns) current prepulse with an average current rise rate d I / d t = 5 k A / n s . After the cold fuel is magnetized, a rapidly rising current ( 200 k A / n s ) generates a calculated electric field of 64 M V / m between the helices. Such field is sufficient to force dielectric breakdown of the insulating material after which liner current is reoriented from helical to predominantly axial which ceases the AutoMag axial magnetic field production mechanism and the z-pinch liner implodes. Proof of concept experiments have been executed on the Mykonos linear transformer driver to measure the axial field produced by a variety of AutoMag liners and to evaluate what physical processes drive dielectric breakdown. A range of field strengths have been generated in various cm-scale liners in agreement with magnetic transient simulations including a measured field above 90 T at I = 350 kA. By varying the helical pitch angle, insulator material, and insulator geometry, favorable liner designs have been identified for which breakdown occurs under predictable and reproducible field conditions.

  6. AREVA NP Liner Repair Strategy with Adhesive Technology

    International Nuclear Information System (INIS)

    Georg, Kraemer; Revoirard, Sebastien; McCann, James-E.

    2012-09-01

    inside the pools in nuclear power plants is pure water which contains no SCC promoting elements, such as Chloride. At the concrete side of the liner, all of those preconditions can be found in some areas. Therefore, the SCC starts from the concrete side and can be detected after penetrating through the liner sheet. When there are leakages known in a pool, there is either the need to locate those leaks or to carry out a prophylactic coating on all welding joints. The detection method can be carried out in 2 steps. First, a pre-detection made with cameras for the main parts of the liner (for big impacts) and ACFM sensors on each side of the welds to check for crossing cracks in the HAZ. Then, on the pre-detected areas, the leak detection equipment is placed to identify and also evaluate (if requested) the leaks. This can be achieved in air or underwater. The AREVA repair method can be roughly divided into two principles: Remote controlled application for use under water or in high radiation dose areas and manual application for use in dry and low radiation dose areas. Depending on the application area a suitable adhesive material is chosen. For dry applications and low dose areas mainly a silicone based material is applied, for underwater application, e.g. in a spent fuel pool (SFP) mainly an epoxy based material is applied. There are several advantages of this technology compared to repair by welding. The AREVA repair method is substantially faster and therefore more cost effective than a usual weld repair. Additionally the exact localization of the leakages is not necessary if all weld seams in a pool are getting covered. Neither is the base material negatively affected by the adhesive material nor is the liner exposed to additional heat stress, which may cause future leaks. Furthermore, this repair technique has been field proven for more than 20 years. (authors)

  7. Use of clays as liners in solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gerardo [Facultad de Ingenieria, Universidad Anahuac Mexico Norte, Huixquilucan, Edo. de Mexico 52786 (Mexico); Almanza, Rafael [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico D.F. 04510 (Mexico)

    2009-06-15

    An alternative to synthetic materials for use in solar pond liners is to select clayey soils as hydraulic barriers. This option reduces the cost of construction and the risk of contamination of subsoil and groundwater by hot brines. This paper deals with the physical, chemical and hydraulic properties of different soils tested mainly as compacted clay liners. The underdeveloped nations have the option to use this type of liner, but before doing so several tests are recommended, including those for soil and water composition, permeability, plasticity and X-ray diffraction analysis. In this investigation the following samples are analyzed: native clayey soils with illite, montmorillonite and halloysite, treated and non-treated bentonites in powder and granulated form, a mixture of zeolite and sodium bentonite, and industrial minerals composed largely of halloysite, kaolinite and attapulgite selected clays. Neutral salt aqueous solutions (NaCl and KCl) at different concentrations and under temperature gradients were used for compatibility testing conducted on these specimens. Experiment setup and particular testing procedures are also discussed. (author)

  8. Accelerating Thick Aluminum Liners Using Pulsed Power

    International Nuclear Information System (INIS)

    Kyrala, G.A.; Hammerburg, J.E.; Bowers, D.; Stokes, J.; Morgan, D.V.; Anderson, W.E.; Cochrane, J.C.

    1999-01-01

    The authors have investigated the acceleration of very thick cylindrical aluminum liners using the Pegasus II capacitory bank. These accelerated solid liners will be used to impact other objects at velocities below 1.5 km/sec, allowing one to generate and sustain shocks of a few 100 kilobar for a few microseconds. A cylindrical shell of 1100 series aluminum with an initial inner radius of 23.61 mm, an initial thickness of 3.0 mm, and a height of 20 mm, was accelerated using a current pulse of 7.15 MA peak current and a 7.4 microsecond quarter cycle time. The aluminum shell was imploded within confining copper glide planes with decreasing separation with an inward slope of 8 degrees. At impact with a cylindrical target of diameter 3-cm, the liner was moving at 1.4 km/sec and its thickness increased to 4.5 mm. Radial X-ray radiograms of the liner showed both the liner and the glide plane interface. The curvature of the inner surface of the liner was measured before impact with the 15-mm radius target. The radiograms also showed that the copper glide planes distorted as the liner radius decreased and that some axial stress is induced in the liner. The axial stresses did not affect the inner curvature significantly. Post-shot calculations of the liner behavior indicated that the thickness of the glide plane played a significant role in the distortion of the interface between the liner and the glide plane

  9. Long-term performance of geosynthetic clay liners in cappings

    International Nuclear Information System (INIS)

    Maubeuge, K.P. von; Fricke, A.

    1998-01-01

    Geosynthetic clay liners (GCLs) are relatively thin composite materials combining bentonite clay and geosynthesis (usually geotextiles). GCLs have been employed by the waste industry for well over a decade now, and their level of usage is rapidly increasing world-wide. In landfill facilities, GCLs are generally used to replace or augment compacted clay liners. Until recently, the decision to do so has primarily been based on the availability of clay material on site (i.e., economic considerations). However, the advantages in using a GCL over other sealing elements such as compacted clay are not only economic but technically based, and the economic benefits extend beyond the construction phase, as a thin GCL can increase the revenue earning potential of a facility. This paper will highlight the shear behaviour of GCLs and demonstrate the long-term stability. (orig.)

  10. The AGN nature of LINER nuclear sources

    Science.gov (United States)

    Márquez, Isabel; Masegosa, Josefa; González-Martin, Omaira; Hernández-Garcia, Lorena; Pović, Mirjana; Netzer, Hagai; Cazzoli, Sara; del Olmo, Ascensión

    2017-11-01

    Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2-10 keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN towards lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L_X(2-10 keV) > 10^{41} erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison with both

  11. The AGN Nature of LINER Nuclear Sources

    Energy Technology Data Exchange (ETDEWEB)

    Márquez, Isabel; Masegosa, Josefa [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain); González-Martin, Omaira [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia (Mexico); Hernández-Garcia, Lorena [Istituto di Astrofisica e Planetologia Spaziali, Rome (Italy); Pović, Mirjana [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain); Ethiopian Space Science and Technology Institute and Entoto Observatory and Research Center, Addis Ababa (Ethiopia); Netzer, Hagai [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy and the Wise Observatory, Tel-Aviv University, Tel Aviv (Israel); Cazzoli, Sara; Olmo, Ascensión del, E-mail: isabel@iaa.es [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain)

    2017-11-16

    Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2–10keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN toward lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L{sub X}(2–10 keV) > 10{sup 41} erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison

  12. The AGN Nature of LINER Nuclear Sources

    International Nuclear Information System (INIS)

    Márquez, Isabel; Masegosa, Josefa; González-Martin, Omaira; Hernández-Garcia, Lorena; Pović, Mirjana; Netzer, Hagai; Cazzoli, Sara; Olmo, Ascensión del

    2017-01-01

    Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2–10keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN toward lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L X (2–10 keV) > 10 41 erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison with

  13. Study of imploding liner-electrode wall interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chernyshev, V K; Zharinov, E I; Mokhov, V N [All-Russian Scientific Research Institute of Experimental Physics, Sarov (Russian Federation)

    1997-12-31

    Acceleration of solid aluminium liners and their interaction with electrodes is studied experimentally. One of the main goal of the experiments is to find the method of improving the contact between the liner and the electrode during the acceleration process. Two independent liners connected in series in one discharge circuit are used. This arrangement makes it possible to record two different liner positions simultaneously at one discharge current. As an energy source, a helical explosive magnetic generator of the length of 0.7 m and 100 mm in diameter is used. The shape of liners at various stages of acceleration is recorded by using a flash radiographic facility. The measured liner flight velocity and the compression radius are compared with the results of MHD model calculations. (J.U.). 21 figs., 7 refs.

  14. Variable volume combustor with a conical liner support

    Science.gov (United States)

    Johnson, Thomas Edward; McConnaughhay, Johnie Franklin; Keener, Chrisophter Paul; Ostebee, Heath Michael

    2017-06-27

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a conical liner support supporting the liner.

  15. Evaluation of the structural integrity of LMFBR equipment cell liners: results of preliminary investigations

    International Nuclear Information System (INIS)

    McAfee, W.J.; Sartory, W.K.

    1976-01-01

    The behavior of a plane wall segment of a prototype liquid-metal-cooled fast breeder reactor (LMFBR) cell under conditions of a postulated massive sodium spill was studied. Sodium-concrete reaction calculations were performed assuming an initial flaw existed in the liner such that high-temperature sodium could penetrate to the concrete underneath. Based on existing sodium-concrete reaction rate data, bounding values were established for the maximum energy release per unit volume of concrete. The potential effect of this energy release on the deformation of the liner material was determined. The temperature buildup in the liner and the pressure differential across the flaw in the liner were also studied. The transient thermal and structural responses of the steel liner and backup concrete were analyzed in detail using the inelastic computer code ANSYS. The literature on the mechanical, physical, and general behavior properties of concrete at high temperature was reviewed. This review emphasized the structural behavior of concrete and did not cover the sodium-concrete reaction

  16. Effect of long-time immersion of soft denture liners in water on viscoelastic properties.

    Science.gov (United States)

    Iwasaki, Naohiko; Yamaki, Chisato; Takahashi, Hidekazu; Oki, Meiko; Suzuki, Tetsuya

    2017-09-26

    Aim of this study was to investigate the effect of long-time immersion of soft denture liners in 37°C water on viscoelastic properties. Six silicone-based and two acrylic resin-based soft denture liners were selected. Cylindrical specimens were stored in distilled water at 37°C for 6 months. Viscoelastic properties, which were instantaneous and delayed elastic displacements, viscous flow, and residual displacement, were determined using a creep meter, and analyzed with 2-way analysis of variance and Tukey's comparison (α=0.05). Viscoelastic properties and their time-dependent changes were varied among materials examined. The observed viscoelastic properties of three from six silicone-based liners did not significantly change after 6-month immersion, but those of two acrylic resin-based liners significantly changed with the increase of immersion time. However, the sum of initial instantaneous elastic displacement and delayed elastic displacement of two acrylic resin-based liners during 6-month immersion changed less than 10%, which might indicate clinically sufficient elastic performance.

  17. Skin-Inspired Hydrogel-Elastomer Composite with Application in a Moisture Permeable Prosthetic Limb Liner

    Science.gov (United States)

    Ruiz, Esteban

    Recent advances in fields such as 3D printing, and biomaterials, have enabled the development of a moisture permeable prosthetic liner. This project demonstrates the feasibility of the invention by addressing the three primary areas of risk including the mechanical strength, the permeability, and the ability to manufacture. The key enabling technology which allows the liner to operate is the skin inspired hydrogel elastomer composite. The skin inspiration is reflected in the molecular arrangement of the double network of polymers which mimics collagen-elastin toughening in the natural epidermis. A custom formulation for a novel tough double network nanocomposite reinforced hydrogel was developed to improve manufacturability of the liner. The liner features this double network nanocomposite reinforced hydrogel as a permeable membrane which is reinforced on either side by perforated silicone layers manufactured by 3d printing assisted casting. Uniaxial compression tests were conducted on the individual hydrogels, as well as a representative sample of off the shelf prosthetic liners for comparison. Permeability testing was also done on the same set of materials and compared to literature values for traditional hydrogels. This work led to the manufacture of three generations of liner prototypes, with the second and third liner prototype being tested with human participants.

  18. Elastic-plastic cyclic deformation of the TEXTOR 94 modified liner under conditions of heating and plasma disruption

    International Nuclear Information System (INIS)

    Bohn, F.H.; Czymek, G.; Giesen, B.; Bondarchuk, E.; Doinikov, N.; Kozhukhovskaja, N.; Panin, A.

    2001-01-01

    The present liner of the TEXTOR 94 tokamak installed inside the vacuum vessel represents the thin toroidal shell that is rested on the vessel inner surface. In order to integrate the dynamic ergodic divertor into the tokamak the liner design has been drastically changed. The 120 deg. sector of the liner shell facing the ergodic coils system is removed and some additional holes in the liner are provisioned. This demands a new liner supporting system allowing for the liner thermal expansion and taking the electromagnetic load occurring in the liner during plasma disruption. The cyclic elasto-plastic deformations of the liner caused by the electromagnetic forces and temperature rise have been studied. It is shown that the local plastic deformations occur in the liner elements after the first heating and electromagnetic loading. The most thermal stresses take place in the reinforcing structures around the holes because of the thermal expansion difference of the inconel shell and the steel reinforcements. These stresses are coupled with the bending stress due to the electromagnetic loading. Subsequent repetitive loading does not lead to any significant increment of the plastic deformation. After the materials' hardening the structure cyclically works mostly in the elastic range

  19. Magnetized Target Fusion Driven by Plasma Liners

    Science.gov (United States)

    Thio, Y. C. Francis; Cassibry, Jason; Eskridge, Richard; Kirkpatrick, Ronald C.; Knapp, Charles E.; Lee, Michael; Martin, Adam; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    For practical applications of magnetized target fusion, standoff drivers to deliver the imploding momentum flux to the target plasma remotely are required. Quasi-spherically converging plasma jets have been proposed as standoff drivers for this purpose. The concept involves the dynamic formation of a quasi-spherical plasma liner by the merging of plasma jets, and the use of the liner so formed to compress a spheromak or a field reversed configuration (FRC). Theoretical analysis and computer modeling of the concept are presented. It is shown that, with the appropriate choice of the flow parameters in the liner and the target, the impact between the liner and the target plasma can be made to be shockless in the liner or to generate at most a very weak shock in the liner. Additional information is contained in the original extended abstract.

  20. Polybore : an innovative casing liner and patch technology

    Energy Technology Data Exchange (ETDEWEB)

    Hayward, C. [Trican Well Service Ltd., Calgary, AB (Canada)

    2003-07-01

    This PowerPoint presentation provided several images on how to install a polybore tight fitting wellbore liner developed by Trican Well Service. The high density polyethylene liner is spooled and rolled into a reducer well where weights are maintained until the liner is in place. The liner offers corrosion protection, corrosion control, chemical resistance, and wear resistance. The liner helps to optimize water injection, well disposal, as well as carbon dioxide injection. It can be placed at depths up to 2,000 m and is well suited to repair pin hole leaks or plug off existing perforations that were previously cemented. The liner can be used to repair and control wellbore corrosion at specific intervals. This presentation provides a brief history of the development of the wellbore liner along with some installation case studies. The thermal velocity liner developed by Trican insulates fluids from heat loss. It prevents liquid dropout and paraffin formation in gas wells. The liner can be used as a replacement for tubing or a loose fit liner. Erosion rates were illustrated. The system, however, is limited because the wellbore casing must be round and scraped and it cannot be used in highly deviated wells. The economic benefits of injection and disposal well applications include power savings, quick payback, corrosion resistance, and lower repair costs. The liners are more cost effective than conventional steel patch. 1 tab., 14 figs.

  1. Can the liner be landed on the well bottom?; Posso apoiar o liner no fundo do poco?

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Carlos Fernando Humbert [PETROBRAS, Rio de Janeiro, RJ (Brazil). Departamento de Perfuracao. Div. de Suporte Tecnico

    1994-07-01

    During the 7 in.liner run-in operation in well 1-BSS-65 with the shoe depth at 2400 m, the setting string broke and, as a result, the whole array fell from 2800 m high. Through a fishing operation, the liner (setting tool) was recovered and later a casing string sticking was detected. Full fluid circulation was obtained and the possibility was considered of cementing the liner in that position. At this point three questions were asked to assess the feasibility of such a cementing operation: were there significant damages inflicted on the liner string as a result of the fall?; if no damages resulted from the fall, would liner bucking prevent the running in of completion tools?; would the casing withstand the strains caused by buckling? This paper addresses the two latter questions through the theory of helical bucking of the tubing confined within a cylinder. Equations are introduced to calculate the helical pitch and the axial strain due to bending. A user-friendly computer program was developed to apply this theory to instances such as the above-mentioned one or to eliminate the use of hangers with short liners. The results of the analysis carried out on this particular well are presented and an assessment of the main parameters bearing on the issue is undertaken. These parameters are: well diameter and liner length. (author)

  2. Synthesis of new aluminum nano hybrid composite liner for energy saving in diesel engines

    International Nuclear Information System (INIS)

    Tiruvenkadam, N.; Thyla, P.R.; Senthilkumar, M.; Bharathiraja, M.; Murugesan, A.

    2015-01-01

    Highlights: • Nano hybrid composite cylinder liner (NL) was developed to replace cast iron liner. • NL improved engine performance, combustion and reduced emissions except NO x . • Teardown analysis provides the suitability of NL for diesel engine. • The developed aluminum NL saved 43.75% of weight than cast iron cylinder liner. - Abstract: This work aims to replace the conventional cast iron cylinder liner (CL) in diesel engine by introducing lightweight aluminum (Al) 6061 nano hybrid composite cylinder liner (NL) by analyzing the performance, combustion, and emission characteristics of an engine. NL was fabricated by bottom pouring stir casting technique with nano- and micro-reinforcement materials. Experimental results proved that the use of NL increased brake thermal efficiency, in-cylinder pressure, heat release rate, and reduced carbon monoxide, hydrocarbon, and smoke emission in comparison with CL. However, oxides of nitrogen slightly increased with the use of the new liner. No differences in wear or other issues were noted during the engine teardown after 1 year of operation and 2000 h of running. Thus, NL has been recommended to replace the CL to save the energy and to reap environmental benefits

  3. Liner evaluation for uranium mill tailings. Final report

    International Nuclear Information System (INIS)

    Buelt, J.L.

    1983-09-01

    The Liner Evaluation for Uranium Mill Tailings Program was conducted to evaluate the need for and performance of prospective lining materials for the long-term management of inactive uranium mill tailings piles. On the basis of program results, two materials have been identified: natural foundation soil amended with 10% sodium bentonite; catalytic airblown asphalt membrane. The study showed that, for most situations, calcareous soils typical of Western US sites adequately buffer tailings leachates and prevent groundwater contamination without additional liner materials or amendments. Although mathematical modeling of disposal sites is recommended on a site-specific basis, there appears to be no reason to expect significant infiltration through the cover for most Western sites. The major water source through the tailings would be groundwater movement at sites with shallow groundwater tables. Even so column leaching studies showed that contaminant source terms were reduced to near maximum contaminant levels (MCL's) for drinking water within one or two pore volumes; thus, a limited source term for groundwater contamination exists. At sites where significant groundwater movement or infiltration is expected and the tailings leachates are alkaline, however, the sodium bentonite or asphalt membrane may be necessary

  4. Investigation of a Bio-Inspired Liner Concept

    Science.gov (United States)

    Koch, L. Danielle

    2017-01-01

    Four samples of natural reeds, Phragmites australis, were tested in the NASA Langley and Glenn Normal Incidence Impedance Tubes in order to experimentally determine the acoustic absorption coefficients as a function of frequency from 400 to 3000 Hz. Six samples that mimicked the geometry of the assemblies of natural reeds were also designed and additively manufactured from ASA thermoplastic and tested. Results indicate that structures can be manufactured of synthetic materials that mimic the geometry and the low frequency acoustic absorption of natural reeds. This accomplishment demonstrates that a new class of structures can now be considered for a wide range of industrial products that need thin, lightweight, broadband acoustic absorption effective at frequencies below 1000 Hz. Aircraft engine acoustic liners and aircraft cabin acoustic liners, in particular, are two aviation applications that might benefit from further development of this concept.

  5. Dynamic stabilization of imploding liquid metal liner

    International Nuclear Information System (INIS)

    Itoh, Yasuyuki; Fujiie, Yoichi

    1979-01-01

    The rotational stabilization has been proposed against the Rayleigh-Taylor instability of the imploding liquid metal liner. In this paper, the discussion is made on the possibility of the dynamic stabilization by applying the oscillating azimuthal magnetic field in addition to the axial field. In contrast to the rotational stabilization, the required (field) energy for this stabilization is also used for the liner driving or the plasma confinement. In the analysis, the liner subjected to the acceleration is assumed to be infinitely long, at rest and have the situation at the start of the implosion or turnaround. At turnaround, the existence of the plasma is taken into account. The perturbed motion of the liner is discussed with a linear stability analysis. Results are as follows: (1) The dynamic stabilization at the start of the implosion is possible if the distance from the conducting wall to the liner outer surface is comparable with or less than the liner thickness. (2) At turnaround, the stability is improved with decreasing the ratio of the plasma radius to that of the liner inner surface however the kink mode (m = 1) cannot be suppressed. (author)

  6. Gravitational Waves from Gravitational Collapse.

    Science.gov (United States)

    Fryer, Chris L; New, Kimberly C B

    2011-01-01

    Gravitational-wave emission from stellar collapse has been studied for nearly four decades. Current state-of-the-art numerical investigations of collapse include those that use progenitors with more realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non-axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with ground-based and space-based interferometric observatories. This review covers the entire range of stellar collapse sources of gravitational waves: from the accretion-induced collapse of a white dwarf through the collapse down to neutron stars or black holes of massive stars to the collapse of supermassive stars. Supplementary material is available for this article at 10.12942/lrr-2011-1.

  7. HOST liner cyclic facilities: Facility description

    Science.gov (United States)

    Schultz, D.

    1982-01-01

    A quartz lamp box, a quartz lamp annular rig, and a low pressure liner cyclic can rig planned for liner cyclic tests are described. Special test instrumentation includes an IR-TV camera system for measuring liner cold side temperatures, thin film thermocouples for measuring liner hot side temperatures, and laser and high temperature strain gages for obtaining local strain measurements. A plate temperature of 2,000 F was obtained in an initial test of an apparatus with three quartz lamps. Lamp life, however, appeared to be limited for the standard commercial quartz lamps available. The design of vitiated and nonvitiated preheaters required for the quartz lamp annular rig and the cyclic can test rigs is underway.

  8. Hydrodynamic model experiments for stabilized liquid liners with annular piston drive

    International Nuclear Information System (INIS)

    Burton, R.L.; Turchi, P.J.; Jenkins, D.J.; Cooper, A.L.

    1977-01-01

    The achievement of megagauss-level magnetic fields by flux compression using controlled liquid liner implosions will be studied in the LINUS-O experiments. This paper reports on experimental studies of the rotating liquid liner at lower energy density, using a one-third scale model with water as the liner material. Radial implosion of the free inside surface of the liquid is achieved by axial displacement of an annular piston, driven by helium. Azimuthally symmetric, repetitive implosion-reexpansion cycles have been demonstrated, with area compressions of over a hundred. The apparatus has also been used to investigate other problems inherent in the annular piston geometry, including piston guidance, seals, z-dependence of the imploding free surface trajectory, and Rayleigh-Taylor instability of the free surface. Methods for r-z plane tailoring of the free surface to provide three-dimensional payload compression are considered

  9. The Compressibility and Swell of Mixtures for Sand-Clay Liners

    Directory of Open Access Journals (Sweden)

    Muawia A. Dafalla

    2017-01-01

    Full Text Available Sand-clay liners utilize expansive clay to act as a filler to occupy the voids in the sand and thus reduce the hydraulic conductivity of the mixture. The hydraulic conductivity and transfer of water and other substances through sand-clay mixtures are of prime concern in the design of liners and hydraulic barriers. Many successful research studies have been undertaken to achieve appropriate mixtures that satisfy hydraulic conductivity requirements. This study investigates compressibility and swelling properties of mixtures to ensure that they were acceptable for light structures, roads, and slabs on grade. A range of sand-expansive clay mixtures were investigated for swell and compression properties. The swelling and compressibility indices were found to increase with increasing clay content. The use of highly expansive material can result in large volume changes due to swell and shrinkage. The inclusion of less expansive soil material as partial replacement of bentonite by one-third to two-thirds is found to reduce the compressibility by 60% to 70% for 10% and 15% clay content, respectively. The swelling pressure and swell percent were also found significantly reduced. Adding less expansive natural clay to bentonite can produce liners that are still sufficiently impervious and at the same time less problematic.

  10. Geosynthetic clay liners shrinkage under simulated daily thermal cycles.

    Science.gov (United States)

    Sarabadani, Hamid; Rayhani, Mohammad T

    2014-06-01

    Geosynthetic clay liners are used as part of composite liner systems in municipal solid waste landfills and other applications to restrict the escape of contaminants into the surrounding environment. This is attainable provided that the geosynthetic clay liner panels continuously cover the subsoil. Previous case histories, however, have shown that some geosynthetic clay liner panels are prone to significant shrinkage and separation when an overlying geomembrane is exposed to solar radiation. Experimental models were initiated to evaluate the potential shrinkage of different geosynthetic clay liner products placed over sand and clay subsoils, subjected to simulated daily thermal cycles (60°C for 8 hours and 22°C for 16 hours) modelling field conditions in which the liner is exposed to solar radiation. The variation of geosynthetic clay liner shrinkage was evaluated at specified times by a photogrammetry technique. The manufacturing techniques, the initial moisture content, and the aspect ratio (ratio of length to width) of the geosynthetic clay liner were found to considerably affect the shrinkage of geosynthetic clay liners. The particle size distribution of the subsoil and the associated suction at the geosynthetic clay liner-subsoil interface was also found to have significant effects on the shrinkage of the geosynthetic clay liner. © The Author(s) 2014.

  11. High Thermal Conductivity NARloy-Z-Diamond Composite Liner for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar; Greene, Sandra

    2015-01-01

    NARloy-Z (Cu-3Ag-0.5Zr) alloy is state-of-the-art combustion chamber liner material used in liquid propulsion engines such as the RS-68 and RS-25. The performance of future liquid propulsion systems can be improved significantly by increasing the heat transfer through the combustion chamber liner. Prior work1 done at NASA Marshall Space Flight Center (MSFC) has shown that the thermal conductivity of NARloy-Z alloy can be improved significantly by embedding high thermal conductivity diamond particles in the alloy matrix to form NARloy-Z-diamond composite (fig. 1). NARloy-Z-diamond composite containing 40vol% diamond showed 69% higher thermal conductivity than NARloy-Z. It is 24% lighter than NARloy-Z and hence the density normalized thermal conductivity is 120% better. These attributes will improve the performance and life of the advanced rocket engines significantly. The research work consists of (a) developing design properties (thermal and mechanical) of NARloy-Z-D composite, (b) fabrication of net shape subscale combustion chamber liner, and (c) hot-fire testing of the liner to test performance. Initially, NARloy-Z-D composite slabs were made using the Field Assisted Sintering Technology (FAST) for the purpose of determining design properties. In the next step, a cylindrical shape was fabricated to demonstrate feasibility (fig. 3). The liner consists of six cylinders which are sintered separately and then stacked and diffusion bonded to make the liner (fig. 4). The liner will be heat treated, finish-machined, and assembled into a combustion chamber and hot-fire tested in the MSFC test facility (TF 115) to determine perform.

  12. Experimental Study of Magnetic Field Production and Dielectric Breakdown of Auto-Magnetizing Liners

    Science.gov (United States)

    Shipley, Gabriel; Awe, Thomas; Hutchinson, Trevor; Hutsel, Brian; Slutz, Stephen; Lamppa, Derek

    2017-10-01

    AutoMag liners premagnetize the fuel in MagLIF targets and provide enhanced x-ray diagnostic access and increased current delivery without requiring external field coils. AutoMag liners are composite liners made with discrete metallic helical conduction paths separated by insulating material. First, a low dI/dt ``foot'' current pulse (1 MA in 100 ns) premagnetizes the fuel. Next, a higher dI/dt pulse with larger induced electric field initiates breakdown on the composite liner's; surface, switching the current from helical to axial to implode the liner. Experiments on MYKONOS have tested the premagnetization and breakdown phases of AutoMag and demonstrate axial magnetic fields above 90 Tesla for a 550 kA peak current pulse. Electric fields of 17 MV/m have been generated before breakdown. AutoMag may enhance MagLIF performance by increasing the premagnetization strength significantly above 30 T, thus reducing thermal-conduction losses and mitigating anomalous diffusion of magnetic field out of hotter fuel regions, by, for example, the Nernst thermoelectric effect. This project was funded in part by Sandia's Laboratory Directed Research and Development Program (Projects No. 200169 and 195306).

  13. Separate effects testing to investigate liner tearing of the 1:6-scale reinforced concrete containment building

    International Nuclear Information System (INIS)

    Spletzer, B.L.; Lambert, L.D.

    1993-01-01

    The US Nuclear Regulatory Commission (NRC) is investigating the performance of containments subject to severe accidents. This work is being performed by Sandia National Laboratories (SNL). In 1987, a 1:6-scale Reinforced Concrete Containment (RCC) model was tested to failure. The failure mode was a liner tear. As a result, a separate effects test program has been conducted to investigate liner tearing. This paper discusses the design of test specimens and the results of the testing. The post-test examination of the 1:6-scale RCC model revealed that the large tear was not an isolated event. Other small tears in similar locations were also discovered. All tears occurred near the insert-to-liner transition which is also the region of closest stud spacing. Also, all tears propagated vertically, in response to the hoop strain. Finally, all tears were adjacent to a row of studs. The tears point to a mechanism which could involve the liner/insert transition, the liner anchorage, and the material properties. The separate effects tests investigated these effects. The program included the design of three types of specimens with each simulating some features of the 1:6-scale RCC model. The specimens were instrumented using strain gages and photoelastic materials

  14. The critical thickness of liners of Cu interconnects

    International Nuclear Information System (INIS)

    Jiang, Q; Zhang, S H; Li, J C

    2004-01-01

    A model for the size-dependence of activation energy is developed. With the model and Fick's second law, relationships among the liner thickness, the working life and the working temperature of a TaN liner for Cu interconnects are predicted. The predicted results of the TaN liner are in good agreement with the experimental results. Moreover, the critical thicknesses of liners of some elements are calculated

  15. Compression of toroidal plasma by imploding plasma-liner

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1979-07-01

    A new concept of compressing a plasma in a closed magnetic configuration by a version of liner implosion flux compression technique is considered. The liner consists of a dense plasma cylinder, i.e. the plasma-liner. Maximum compression ratio of toroidal plasma is determined just by the initial density ratio of the toroidal plasma to the liner plasma because of the Rayleigh-Taylor instability. A start-up senario of plasma-liner is also proposed with a possible application of this concept to the creation of a burning plasma in reversed field configurations, i.e. burning plasma vortex. (author)

  16. The Liner Shipping Fleet Repositioning Problem with Cargo Flows

    DEFF Research Database (Denmark)

    Tierney, Kevin; Jensen, Rune Møller

    2012-01-01

    We solve an important problem for the liner shipping industry called the Liner Shipping Fleet Repositioning Problem (LSFRP). The LSFRP poses a large financial burden on liner shipping firms. During repositioning, vessels are moved between services in a liner shipping network. Shippers wish...

  17. Composite Liner, Multi-Megabar Shock Driver Development

    International Nuclear Information System (INIS)

    Cochrane, J.C. Jr.; Bartsch, R.R.; Clark, D.A.; Morgan, D.V.; Anderson, W.E.; Lee, H.; Bowers, R.L.; Atchison, W.L.; Oona, H.; Stokes, J.L.; Veeser, L.R.; Broste, W.B.

    1998-01-01

    The multi-megabar shock driver development is a series of experiments in support of the Los Alamos High Energy Density Physics Experimental Program. Its purpose is to develop techniques to impact a uniform, stable, composite liner upon a high Z target to produce a multi-megabar shock for EOS studies. To date, experiments have been done on the Pegasus II capacitor bank with a current of approximately12MA driving the impactor liner. The driving field is approximately200 T at the target radius of 1cm. Data will be presented on the impactor liner. The driving field is approximately200 T at the target radius of 1 cm. Data will be presented on the stability and uniformity of the impactor liner when it impacts the target cylinder. Three experiments have been done with emphasis on liner development. Shock pressures greater than a megabar have been done with emphasis on liner development. Shock pressures greater than a megabar have been produced with an Al target cylinder. A Pt target cylinder should produce shock pressures in th e 5-megabar range

  18. Evaluation of corrosion attack of chimney liners

    Directory of Open Access Journals (Sweden)

    Blahetová M.

    2016-06-01

    Full Text Available The case study of chimney liner corrosion addresses three specific cases of damage of chimney systems from of stainless steels. These systems were used for flue of gas arising from the combustion of brown coal in small automatic boilers, which are used for heating. Detailed analyzes implied that the cause of devastating corrosion of the steel AISI 316 and 304 steel (CSN 17349, 17241 was particularly high content of halides (chlorides and fluorides, which caused a severe pitting corrosion, which led up to the perforation of the liner material. Simultaneous reduction of the thickness of the used sheets was due to by the general corrosion, which was caused by the sulfur in the solid fuel. The condensation then led to acid environment and therefore the corrosion below the dew point of the sulfuric acid has occurred. All is documented by metallographic analysis and microanalysis of the corrosion products.

  19. Liner Stability Experiments at Pegasus: Diagnostics and Experimental Results

    International Nuclear Information System (INIS)

    Clark, D.A.; Morgan, D.V.; Rodriguez, G.

    1998-01-01

    A series of experiments to compare imploding liner performance with magneto-hydrodynamic (MHD) modeling has been performed at the Los Alamos National Laboratory Pegasus II pulse power machine. Liner instability growth originating from initial perturbations machined into the liner has been observed with high resolution. Three major diagnostics were used: radiography, Velocity Interferometer for a Surface of Any Reflector (VISAR), and fiber optic impact pins. For radiography, three flash x-ray units were mounted radially to observe liner shape at three different times during the implosion. Liner velocity was measured continuously with the VISAR for the entire distance traveled in two experiments. Optical impact pins provide a high-resolution measure of liner symmetry and shape near the end of travel. Liner performance has compared well with predictions

  20. Solving the Liner Shipping Fleet Repositioning Problem with Cargo Flows

    DEFF Research Database (Denmark)

    Tierney, Kevin; Askelsdottir, Björg; Jensen, Rune Møller

    2015-01-01

    We solve a central problem in the liner shipping industry called the liner shipping fleet repositioning problem (LSFRP). The LSFRP poses a large financial burden on liner shipping firms. During repositioning, vessels are moved between routes in a liner shipping network. Liner carriers wish...

  1. Development of 1D Liner Compression Code for IDL

    Science.gov (United States)

    Shimazu, Akihisa; Slough, John; Pancotti, Anthony

    2015-11-01

    A 1D liner compression code is developed to model liner implosion dynamics in the Inductively Driven Liner Experiment (IDL) where FRC plasmoid is compressed via inductively-driven metal liners. The driver circuit, magnetic field, joule heating, and liner dynamics calculations are performed at each time step in sequence to couple these effects in the code. To obtain more realistic magnetic field results for a given drive coil geometry, 2D and 3D effects are incorporated into the 1D field calculation through use of correction factor table lookup approach. Commercial low-frequency electromagnetic fields solver, ANSYS Maxwell 3D, is used to solve the magnetic field profile for static liner condition at various liner radius in order to derive correction factors for the 1D field calculation in the code. The liner dynamics results from the code is verified to be in good agreement with the results from commercial explicit dynamics solver, ANSYS Explicit Dynamics, and previous liner experiment. The developed code is used to optimize the capacitor bank and driver coil design for better energy transfer and coupling. FRC gain calculations are also performed using the liner compression data from the code for the conceptual design of the reactor sized system for fusion energy gains.

  2. On decisive factors of liner anchorage behaviour

    International Nuclear Information System (INIS)

    Bucchardt, F.; Weber, M.; Yazdi, F.

    1984-01-01

    Design of reinforced and prestressed containments for nuclear power plants in the FRG shall be guided by DIN 25459; this also includes the structural behaviour of the liner. While the containment safety analysis is a more global matter, the liner and especially the liner anchorage behaviour concentrates on local effects which need a more refined local area description. Due to the predominant stiffness of the concrete structure liner failure analysis are performed by decoupling the steel membrane which is then only supported by anchorage springs. A comprehensive nonlinear analytical study is carried out to examine the anchorage behaviour. (Author) [pt

  3. LINER galaxy properties and the local environment

    Science.gov (United States)

    Coldwell, Georgina V.; Alonso, Sol; Duplancic, Fernanda; Mesa, Valeria

    2018-05-01

    We analyse the properties of a sample of 5560 low-ionization nuclear emission-line region (LINER) galaxies selected from SDSS-DR12 at low red shift, for a complete range of local density environments. The host LINER galaxies were studied and compared with a well-defined control sample of 5553 non-LINER galaxies matched in red shift, luminosity, morphology and local density. By studying the distributions of galaxy colours and the stellar age population, we find that LINERs are redder and older than the control sample over a wide range of densities. In addition, LINERs are older than the control sample, at a given galaxy colour, indicating that some external process could have accelerated the evolution of the stellar population. The analysis of the host properties shows that the control sample exhibits a strong relation between colours, ages and the local density, while more than 90 per cent of the LINERs are redder and older than the mean values, independently of the neighbourhood density. Furthermore, a detailed study in three local density ranges shows that, while control sample galaxies are redder and older as a function of stellar mass and density, LINER galaxies mismatch the known morphology-density relation of galaxies without low-ionization features. The results support the contribution of hot and old stars to the low-ionization emission although the contribution of nuclear activity is not discarded.

  4. Re-Use of Clean Coal Technology By-Products in the Construction of Low Permeability Liners. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, William E. [The Ohio State Univ., Columbus, OH (United States); Butalia, Tarunjit S. [The Ohio State Univ., Columbus, OH (United States); Walker, Harold [The Ohio State Univ., Columbus, OH (United States); Mitsch, William [The Ohio State Univ., Columbus, OH (United States)

    2005-07-15

    This final project report presents the results of a research program conducted at The Ohio State University from January 3, 2000 to June 30, 2005 to investigate the long-term use of stabilized flue gas desulfurization (FGD) materials in the construction of low permeability liners for ponds and wetlands. The objective of the research program was to establish long-term field-verified time-dependent relationships for the performance of liners constructed from stabilized FGD byproducts generated in Ohio. The project objective was accomplished with a coordinated program of testing and analyzing small-scale laboratory specimens under controlled conditions, mediumscale wetland experiments, and monitoring of a full-scale FGD-lined pond facility. Although the specific uses directly addressed by this report include liners for surface impoundments, the results presented in this study are also useful in other applications especially in the design of daily covers and liners for landfills, seepage cutoff walls and trenches, and for nutrient retention and pollution mitigation wetlands. The small-scale laboratory tests and monitoring of the full-scale FGD lined facility (capacity of one million gallons) shows that stabilized FGD materials can be used as low permeability liners in the construction of water and manure holding ponds. Actual long-term permeability coefficients in the range of 10-7 cm/sec (3 x 10-9 ft/sec) can be obtained in the field by compacting lime and fly ash enriched stabilized FGD materials. Leachate from the FGD material meets Ohio’s non-toxic criteria for coal combustion by-products, and for most potential contaminants the national primary and secondary drinking water standards are also met. The low permeability non-toxic FGD material investigated in this study poses very minimal risks, if any, for groundwater contamination. The FGD wetland experiments indicated no significant differences in phosphorus retention between the clay and FGD

  5. Liner failure around a tunnel or a storage cell in Callovo-Oxfordian clay

    International Nuclear Information System (INIS)

    Damjanac, Branko; Radakovic-Guzina, Zorica; Billaux, Daniel; Poutrel, A.

    2010-01-01

    Document available in extended abstract form only. In the framework of the feasibility studies for the storage of radioactive waste in a deep geological layer, the post-failure behaviour of the concrete liner of the galleries and storage cells may have a direct effect on long term safety. In fact, the failure of the liner will result in new loads on the canisters placed inside the works, and in the de-stressing of the Callovo-Oxfordian clays, which may lead to a change in the Excavation Damage Zone. These phenomenons are studied via numerical modelling, using properties derived from ANDRA's underground laboratory (CMHM) project. Two types of gallery geometries are analyzed: one with a thinner concrete liner and filled interior (the standard gallery); and another with a thick concrete liner filled with concrete canisters (the MAVL disposal cell). The Standard Gallery is filled with a Cam-Clay material after 100 years of creep, while the MAVL disposal cell is filled with 16 concrete canisters immediately after installation of the concrete liner. Progressive failure of the concrete liner due to time-dependent deformation of the surrounding rock (Callovo-Oxfordian clay) over a long period of time is analyzed. The analyses are carried out in two steps. In the initial simulations, the concrete liner is represented as a continuum strain-softening Mohr-Coulomb material. The locations of stress-induced fractures in the concrete are determined from this continuum model. The stress-induced fractures are then specified as pre-defined discontinuities in the concrete liner in subsequent dis-continuum simulations. In a dis-continuum model, the large deformations and movements of the concrete blocks as the liner disintegrates can be simulated without numerical problems. The Callovo-Oxfordian clay is represented as an elastic-plastic-viscous material using the Lemaitre constitutive relation. The majority of the simulations are carried out over 5,000 years of creep time, with a

  6. Numerical studies of cavitation erosion on an elastic-plastic material caused by shock-induced bubble collapse

    Science.gov (United States)

    Turangan, C. K.; Ball, G. J.; Jamaluddin, A. R.; Leighton, T. G.

    2017-09-01

    We present a study of shock-induced collapse of single bubbles near/attached to an elastic-plastic solid using the free-Lagrange method, which forms the latest part of our shock-induced collapse studies. We simulated the collapse of 40 μm radius single bubbles near/attached to rigid and aluminium walls by a 60 MPa lithotripter shock for various scenarios based on bubble-wall separations, and the collapse of a 255 μm radius bubble attached to aluminium foil with a 65 MPa lithotripter shock. The coupling of the multi-phases, compressibility, axisymmetric geometry and elastic-plastic material model within a single solver has enabled us to examine the impingement of high-speed liquid jets from the shock-induced collapsing bubbles, which imposes an extreme compression in the aluminium that leads to pitting and plastic deformation. For certain scenarios, instead of the high-speed jet, a radially inwards flow along the aluminium surface contracts the bubble to produce a `mushroom shape'. This work provides methods for quantifying which parameters (e.g. bubble sizes and separations from the solid) might promote or inhibit erosion on solid surfaces.

  7. Three Year RSA Evaluation of Vitamin E Diffused Highly Cross-linked Polyethylene Liners and Cup Stability

    DEFF Research Database (Denmark)

    Sillesen, Nanna H; Greene, Meridith E; Nebergall, Audrey K

    2015-01-01

    10-year RSA. This is the first evaluation of the multicenter cohort after 3-years. All patients received E-XLPE liners (E1, Biomet) and porous-titanium coated cups (Regenerex, Biomet). There was no difference (P=0.450) in median femoral head penetration into the E-XLPE liners at 3-years comparing...... cobalt-chrome heads (-0.028mm; inter-quartile range (IQR) - 0.065 to 0.047) with ceramic heads (-0.043mm, IQR - 0.143to0.042). The 3-year follow-up indicates minimal E-XLPE liner penetration regardless of head material and minimal early cup movement....

  8. Fast liner proposal

    International Nuclear Information System (INIS)

    Sherwood, A.R.; Freeman, B.L.; Gerwin, R.A.; Jarboe, T.R.; Krakowski, R.A.; Malone, R.C.; Marshall, J.; Miller, R.L.; Suydam, B.

    1977-08-01

    This is a proposal to study, both theoretically and experimentally, the possibility of making a fusion reactor by magnetically imploding a cylindrical metallic shell on a prepared plasma. The approach is characterized by the following features: (1) the nonrotating liner would be driven by an axial current, (2) the plasma would also carry an axial current that provides an azimuthal magnetic field for thermal insulation in both the radial and longitudinal directions, (3) solid end plugs would be utilized to prevent axial loss of particles, and (4) liner speeds would be in the 10 6 cm/s range. The preliminary calculations indicate (1) that the energetics are favorable (energy inputs of about 10 MJ might produce a machine in the break-even regime), (2) that radiation and heat losses could be made tolerable, (3) that alpha-particle heating could be made very effective, and (4) that Taylor instabilities in a fast liner might be harmless because of the large viscosities at high pressures. A preliminary conceptual design of the sort of fusion reactor that might result from such an approach is discussed, as are some of the relevant reactor scaling arguments

  9. Elastic Plastic Fracture Analysis of an Aluminum COPV Liner

    Science.gov (United States)

    Forth, Scott; Gregg, Bradley; Bailey, Nathaniel

    2012-01-01

    Onboard any space-launch vehicle, composite over-wrapped pressure vessels (COPVs) may be utilized by propulsion or environmental control systems. The failure of a COPV has the potential to be catastrophic, resulting in the loss of vehicle, crew or mission. The latest COPV designs have reduced the wall-thickness of the metallic liner to the point where the material strains plastically during operation. At this time, the only method to determine the damage tolerance lifetime (safe-life) of a plastically responding metallic liner is through full-scale COPV testing. Conducting tests costs substantially more and can be far more time consuming than performing an analysis. As a result of this cost, there is a need to establish a qualifying process through the use of a crack growth analysis tool. This paper will discuss fracture analyses of plastically responding metallic liners in COPVs. Uni-axial strain tests have been completed on laboratory specimens to collect elastic-plastic crack growth data. This data has been modeled with the crack growth analysis tool, NASGRO 6.20 to predict the response of laboratory specimens and subsequently the complexity of a COPV.

  10. Accreting CO material onto ONe white dwarfs towards accretion-induced collapse

    Science.gov (United States)

    Wu, Cheng-Yuan; Wang, Bo

    2018-03-01

    The final outcomes of accreting ONe white dwarfs (ONe WDs) have been studied for several decades, but there are still some issues that are not resolved. Recently, some studies suggested that the deflagration of oxygen would occur for accreting ONe WDs with Chandrasekhar masses. In this paper, we aim to investigate whether ONe WDs can experience accretion-induced collapse (AIC) or explosions when their masses approach the Chandrasekhar limit. Employing the stellar evolution code Modules for Experiments in Stellar Astrophysics (MESA), we simulate the long-term evolution of ONe WDs with accreting CO material. The ONe WDs undergo weak multicycle carbon flashes during the mass-accretion process, leading to mass increase of the WDs. We found that different initial WD masses and mass-accretion rates influence the evolution of central density and temperature. However, the central temperature cannot reach the explosive oxygen ignition temperature due to neutrino cooling. This work implies that the final outcome of accreting ONe WDs is electron-capture induced collapse rather than thermonuclear explosion.

  11. A Conventional Liner Acoustic/Drag Interaction Benchmark Database

    Science.gov (United States)

    Howerton, Brian M.; Jones, Michael G.

    2017-01-01

    The aerodynamic drag of acoustic liners has become a significant topic in the design of such for aircraft noise applications. In order to evaluate the benefits of concepts designed to reduce liner drag, it is necessary to establish the baseline performance of liners employing the typical design features of conventional configurations. This paper details a set of experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of a number of perforate-over-honeycomb liner configurations at flow speeds of M=0.3 and 0.5. These conventional liners are investigated to determine their resistance factors using a static pressure drop approach. Comparison of the resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 Hz at source sound pressure levels of 140 and 150 dB. Educed impedance and attenuation spectra are used to determine the interaction between acoustic performance and drag.

  12. Graphical Acoustic Liner Design and Analysis Tool

    Science.gov (United States)

    Howerton, Brian M. (Inventor); Jones, Michael G. (Inventor)

    2016-01-01

    An interactive liner design and impedance modeling tool comprises software utilized to design acoustic liners for use in constrained spaces, both regularly and irregularly shaped. A graphical user interface allows the acoustic channel geometry to be drawn in a liner volume while the surface impedance calculations are updated and displayed in real-time. A one-dimensional transmission line model may be used as the basis for the impedance calculations.

  13. Quantitative Analysis of Retrieved Glenoid Liners

    Directory of Open Access Journals (Sweden)

    Katelyn Childs

    2016-02-01

    Full Text Available Revision of orthopedic surgeries is often expensive and involves higher risk from complications. Since most total joint replacement devices use a polyethylene bearing, which serves as a weak link, the assessment of damage to the liner due to in vivo exposure is very important. The failures often are due to excessive polyethylene wear. The glenoid liners are complex and hemispherical in shape and present challenges while assessing the damage. Therefore, the study on the analysis of glenoid liners retrieved from revision surgery may lend insight into common wear patterns and improve future product designs. The purpose of this pilot study is to further develop the methods of segmenting a liner into four quadrants to quantify the damage in the liner. Different damage modes are identified and statistically analyzed. Multiple analysts were recruited to conduct the damage assessments. In this paper, four analysts evaluated nine glenoid liners, retrieved from revision surgery, two of whom had an engineering background and two of whom had a non-engineering background. Associated human factor mechanisms are reported in this paper. The wear patterns were quantified using the Hood/Gunther, Wasielewski, Brandt, and Lombardi methods. The quantitative assessments made by several observers were analyzed. A new, composite damage parameter was developed and applied to assess damage. Inter-observer reliability was assessed using a paired t-test. Data reported by four analysts showed a high standard deviation; however, only two analysts performed the tests in a significantly similar way and they had engineering backgrounds.

  14. Broadband Liner Optimization for the Source Diagnostic Test Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.

    2012-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

  15. Effects of varying the through silicon via liners thickness on their hoop stresses and deflections

    Directory of Open Access Journals (Sweden)

    Juma Mary Atieno

    2017-03-01

    Full Text Available Through silicon via (TSV interconnect reliability is a problem in electronic packaging. The authors address the insertion losses, deflections which can result to separation of TSV layers and hoop stresses. These problems are due to different coefficient of thermal expansion between materials. The authors propose a robust methodology for (TSV liners in this paper which in turn solves the reliability problem in (TSV. Silicon dioxide material is used in their paper as a TSV liner. First, they modelled the equivalent TSV circuit in advanced design systems (ADS. The authors then simulated it to obtain the TSV characterisation from which they obtained the S-parameter S21 which represents the insertion losses. Insertion losses have been described with changes in frequencies from 0 to 20 GHz with changes in TSV thickness from 7 to 8 µm. Later two different shapes of the TSV liner; the disc- and rod-shaped are modelled in analysis system 14 software. The two shapes with a radius of 5 µm each and a fixed pressure of 100 µPa developed changes in hoop stresses and deflections when the liners thicknesses are varied from 2 to 3 µm. The disc shape experienced least reliability problems so the authors propose its use in via structures.

  16. Modular liquid-cooled helmet liner for thermal comfort

    Science.gov (United States)

    Williams, B. A.; Shitzer, A.

    1974-01-01

    A modular liquid-cooled helmet liner made of eight form-fitting neoprene patches was constructed. The liner was integrated into the sweatband of an Army SPH-4 helicopter aircrew helmet. This assembly was tested on four subjects seated in a hot (47 C), humid (40%) environment. Results indicate a marked reduction in the rate of increase of physiological body functions. Rectal temperature, weight loss, heart rate, and strain indices are all reduced to approximately 50% of uncooled levels. The cooling liner removed from 10% to 30% of total metabolic heat produced. This study also demonstrated the technical feasilibity of using a cooling liner in conjunction with a standard hard helmet. Potential applications of the cooling liner in thermally stressful environments are numerous, notably for helicopter and other aircrews.

  17. Durability, Performance, and Emission of Diesel Engines Using Carbon Fiber Piston and Liner

    Science.gov (United States)

    Afify, E. M.; Roberts, W. L.

    1999-01-01

    This report summarizes the research conducted by NC State University in investigating the durability, performance and emission of a carbon fiber piston and liner in our single cylinder research Diesel engine. Both the piston and liner were supplied to NC State University by NASA LaRC and manufactured by C-CAT under a separate contract to NASA LaRC. The carbon-carbon material used to manufacture the piston and liner has significantly lower thermal conductivity, coefficient of thermal expansion, and superior strength characteristics at elevated temperatures when compared to conventional piston materials such as aluminum. The results of the carbon-carbon fiber piston testing were compared to a baseline configuration, which used a conventional aluminum piston in a steel liner. The parameters measured were the brake specific fuel consumption, ignition delay, frictional horsepower, volumetric efficiency, and durability characteristics of the two pistons. Testing was performed using a naturally aspirated Labeco Direct Injection single cylinder diesel engine. Two test cases were performed over a range of loads and speeds. The fixed test condition between the aluminum and carbon-carbon piston configurations was the brake mean effective pressure. The measured data was the fuel consumption rate, volumetric efficiency, load, speed, cylinder pressure, needle lift, and exhaust gas temperature. The cylinder pressure, and fuel consumption, exhaust gas temperature, and needle lift were recorded using a National Instruments DAQ board and a PC. All test cases used Diesel no. 2 for fuel.

  18. Influence of the mechanical properties of resilient denture liners on the retention of overdenture attachments.

    Science.gov (United States)

    Kubo, Keitaro; Koike, Takashi; Ueda, Takayuki; Sakurai, Kaoru

    2018-03-15

    Information is lacking about the selection criteria for silicone resilient denture liners applied as a matrix material for attachments on overdentures. The purpose of this in vitro study was to investigate the mechanical properties of silicone resilient denture liners and their influence on the initial retention force of overdenture attachments and the reduction in retention force over time. Nine types of silicone resilient denture liner were injected and fixed to the matrix section of an experimental denture base. They were then fitted to an epoxy resin model that simulated the residual ridge with a patrix ball attachment (n=10). The retention force of the denture was measured with a digital force gauge, and the maximum force of traction (N) was regarded as the initial retention force. The retention force reduction (N) after repeated insertion and removal (n=5) was calculated by subtracting the retention force after 3348 cycles (3-year simulated insertion and removal) from the initial retention force. The intaglio of the matrix was observed with a scanning electron microscope (SEM) before and after the 3348 cycles. Four mechanical properties (hardness, strain-in-compression, tensile strength, and arithmetic mean roughness) of the resilient denture liners were measured. One-way ANOVA of the initial retention force of each lining material was performed, followed by the Scheffe test (α=.05). Pearson correlation analysis was used (α=.05) to analyze correlations of the initial retention force with the retention force reduction after insertion and removal and the mechanical properties of each material. Multiple regression analysis with the stepwise method extracted the initial retention force and the retention force reduction as dependent variables, and the resilient denture liner mechanical properties as explanatory variables (α=.05). The initial retention force of the resilient denture liners was 1.3 to 5.4 N. Multiple comparisons showed significant differences in

  19. Re-Use of Clean Coal Technology By-Products in the Construction of Low Permeability Liners. Final report, 10/1/1996 - 3/31/2000

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, William E. [The Ohio State Univ., Columbus, OH (United States); Butalia, Tarunjit S. [The Ohio State Univ., Columbus, OH (United States); Whitlach, Jr., E. Earl [The Ohio State Univ., Columbus, OH (United States); Mitsch, William [The Ohio State Univ., Columbus, OH (United States)

    2000-12-31

    This final project report presents the results of a research program conducted at The Ohio State University from October 1, 1996 to March 31, 2000 to investigate the use of stabilized flue gas desulfurization (FGD) materials in the construction of low permeability liners. The objective of the research program was to establish field-verified time-dependent relationships for the performance of liners constructed from stabilized FGD by-products generated in Ohio. The project objective was accomplished with a coordinated program of testing and analyzing small scale laboratory specimens under controlled conditions, medium-scale wetland mesocosms, and a full-scale pond facility. Although the specific uses directly addressed by this report include liners for surface impoundments, the results presented in this study are also useful in other applications including design of daily cover and liners for landfills, seepage cutoff walls and trenches and for nutrient retention and pollution mitigation wetlands. The small scale laboratory tests, medium scale mesocosm wetland experiments, and construction and monitoring of a full-scale FGD lined facility (capacity of one million gallons) shows that stabilized FGD materials can be used as low permeability liners in the construction of water and manure holding ponds, and constructed wetlands for wastewater treatment. Actual permeability coefficients in the range of 10-7 cm/sec (3 x 10-9 ft/sec) can be obtained in the field by properly compacting lime and fly ash enriched stabilized FGD materials. Leachate from the FGD material meets Ohio’s non-toxic criteria for coal combustion by-products, and for most potential contaminants the national primary and secondary drinking water standards are also met. The low permeability non-toxic FGD material investigated in this study poses very minimal risks, if any, for groundwater contamination. Constructed FGD-lined wetlands offer the opportunity for increased phosphorous

  20. Mass ablation and magnetic flux losses through a magnetized plasma-liner wall interface

    Science.gov (United States)

    García-Rubio, F.; Sanz, J.

    2017-07-01

    The understanding of energy and magnetic flux losses in a magnetized plasma medium confined by a cold wall is of great interest in the success of magnetized liner inertial fusion (MagLIF). In a MagLIF scheme, the fuel is magnetized and subsonically compressed by a cylindrical liner. Magnetic flux conservation is degraded by the presence of gradient-driven transport processes such as thermoelectric effects (Nernst) and magnetic field diffusion. In previous publications [Velikovich et al., Phys. Plasmas 22, 042702 (2015)], the evolution of a hot magnetized plasma in contact with a cold solid wall (liner) was studied using the classical collisional Braginskii's plasma transport equations in one dimension. The Nernst term degraded the magnetic flux conservation, while both thermal energy and magnetic flux losses were reduced with the electron Hall parameter ωeτe with a power-law asymptotic scaling (ωeτe)-1/2. In the analysis made in the present paper, we consider a similar situation, but with the liner being treated differently. Instead of a cold solid wall acting as a heat sink, we model the liner as a cold dense plasma with low thermal conduction (that could represent the cryogenic fuel layer added on the inner surface of the liner in a high-gain MagLIF configuration). Mass ablation comes into play, which adds notably differences to the previous analysis. The direction of the plasma motion is inverted, but the Nernst term still convects the magnetic field towards the liner. Magnetization suppresses the Nernst velocity and improves the magnetic flux conservation. Thermal energy in the hot plasma is lost in heating the ablated material. When the electron Hall parameter is large, mass ablation scales as (ωeτe)-3/10, while both the energy and magnetic flux losses are reduced with a power-law asymptotic scaling (ωeτe)-7/10.

  1. Temporary abandonment cement plug on the liner top; Tampao de abandono temporario na boca do liner

    Energy Technology Data Exchange (ETDEWEB)

    Hiss Filho, Paulo Henrique; Costa Junior, Pedro Americo da; Viana, Jose Luis Rodrigues [PETROBRAS, Rio de Janeiro, RJ (Brazil). Distrito de Pefuracao do Sudeste. Div. de Tecnicas de Perfuracao

    1994-07-01

    In many instances wells are temporary abandoned just after cementing liner to be completed later or to have the BOP removed to change rams. In these cases, an additional volume of slurry is designed in order to bring the top of cement plug over the liner top, thus saving the time required for all full plugging operation. (author)

  2. Wheel liner design for improved sound and structural performances

    Science.gov (United States)

    Oltean, Alexandru; Diaconescu, Claudiu; Tabacu, Ştefan

    2017-10-01

    Vehicle noise is composed mainly of wheel-road noise and noise from the power unit. At low speeds power unit noise dominates while at high speeds wheel-road noise dominates as wheel-road noise level increases approximately logarithmically with speed. The wheel liner is designed as a component of the vehicle that has a multiple role. It has to prevent the dirt or water from the road surface that are engaged by the wheel to access the engine/front bay. Same time it has the important role to reduce perceived noised in the passenger’s compartment that comes from the wheel-road interaction. Progress in plastic injection moulding technology allowed for new structures to be developed - nonwoven materials in combination with a PP based carrier structure which benefits from a cell structure caused by MuCell injection moulding. The results are light parts with increased sound absorption performances. An adapted combination of materials and production processes can provide the solution for stiff yet soundproofing structures valued for modern vehicles. Sound absorption characteristics of materials used for wheel liners applications were reported in this study. Different polypropylene and polyester fibre-based thermally bonded nonwovens varying in weight and thickness were investigated. Having as a background the performances of the nonwoven material the microcellular structure was part of the analysis. Acoustical absorptive behaviour was explained by analysing the results obtained using the impedance tube and correlating with the knowledge of materials structure.

  3. Liquid metal liner implosion systems with blade lattice for fusion

    International Nuclear Information System (INIS)

    Itoh, Yasuyuki; Fujiie, Yoichi

    1980-01-01

    In this paper, the liquid liner implosion systems with the blade lattice is proposed for the rotational stabilization of the liner inner surface which is facing a plasma in a fusion reactor. The blades are electrically conducting and inclined to the radial direction. Its major function is either acceleration or deceleration of the liner in the azimuthal direction. This system enables us to exclude the rotary mechanism for the liner rotation. In this system, the liner is formed as an annular flow of a liquid metal (the waterfall concept). Results show that there is no significant difference of the energy cost for the stabilization compared with the earlier proposed system where a liner is rotated rigidly before implosion. Furthermore, the application of the rotating blade lattice makes it possible to reduce the rotational kinetic energy required for the stabilization at turnaround, where the lattice acts as an impeller in the initial liner rotation. There is an optimum blade angle to maximize the compressed magnetic field energy inside the liner for a given driving energy. (author)

  4. Developing the procedure of modifying the denture soft liner by silver nanoparticles.

    Science.gov (United States)

    Chladek, Grzegorz; Barszczewska-Rybarek, Izabela; Lukaszczyk, Jan

    2012-01-01

    Colonization of denture soft lining materials by fungi and denture plaque leads to infections of mucosa. Microorganisms such as Candida albicans colonize not only the surface of the soft liners, but they also penetrate inside those materials. Therefore the use of common disinfectants, e.g., surface active cleaners, is not a perfect solution for keeping a proper hygiene of soft linings. Modifying soft lining by silver nanoparticles (AgNP) seems to be a right way to overcome those problems. The procedure of modifying two-component silicone material by silver nanoparticles (AgNP) is presented in the article. The solubility tests for both material components have been carried out in the first stage of examinations. On the basis of test results, a solvent has been selected, being a dispersion medium for AgNPs and both soft liner components. The effective method for evaporating a solvent from the composition has been developed. Material components with various AgNP concentrations (10, 20, 40, 80, 120 and 200 ppm) have been obtained. Cured samples of the composites have been examined by SEM to confirm the effectiveness of the procedure.

  5. Evaluation of Skin Friction Drag for Liner Applications in Aircraft

    Science.gov (United States)

    Gerhold, Carl H.; Brown, Martha C.; Jasinski, Christopher M.

    2016-01-01

    A parameter that is gaining significance in the evaluation of acoustic liner performance is the skin friction drag induced by air flow over the liner surface. Estimates vary widely regarding the amount of drag the liner induces relative to a smooth wall, from less than a 20% increase to nearly 100%, and parameters such as face sheet perforate hole diameter, percent open area, and sheet thickness are expected to figure prominently in the skin friction drag. Even a small increase in liner drag can impose an economic penalty, and current research is focused on developing 'low drag' liner concepts, with the goal being to approach the skin friction drag of a smooth wall. The issue of skin friction drag takes on greater significance as airframe designers investigate the feasibility of putting sound absorbing liners on the non-lifting surfaces of the wings and fuselage, for the purpose of reducing engine noise reflected and scattered toward observers on the ground. Researchers at the NASA Langley Research Center have embarked on investigations of liner skin friction drag with the aims of: developing a systematic drag measurement capability, establishing the drag of current liners, and developing liners that produce reduced drag without compromising acoustic performance. This paper discusses the experimental procedures that have been developed to calculate the drag coefficient based on the change in momentum thickness and the companion research program being carried out to measure the drag directly using a force balance. Liner samples that are evaluated include a solid wall with known roughness and conventional liners with perforated facesheets of varying hole diameter and percent open area.

  6. In-situ studies on the performance of landfill caps (compacted soil liners, geomembranes, geosynthetic clay liners, capillary barriers)

    International Nuclear Information System (INIS)

    Melchior, S.

    1997-01-01

    Since 1986 different types of landfill covers have been studied in-situ on the Georgswerder landfill in Hamburg, Germany. Water balance data are available for eight years. The performance of different carriers has been measured by collecting the leakage on areas ranging from 100 m 2 to 500 m 2 . Composite liners with geomembranes performed best, showing no leakage. An extended capillary barrier also performed well. The performance of compacted soil liners, however, decreased severely within five years due to desiccation, shrinkage and plant root penetration (liner leakage now ranging from 150 mm/a to 200 mm/a). About 50 % of the water that reaches the surface of the liner is leaking through it. The maximum leakage rates have increased from 2 x 10 -10 m 3 m -2 s -1 to 4 x 10 -8 m 3 m -2 s -1 . Two types of geosynthetic clay liners (GCL) have been tested for two years now with disappointing results. The GCL desiccated during the first dry summer of the study. High percolation rates through the GCL were measured during the following winter (45 mm resp. 63 mm in four months). Wetting of the GCL did not significantly reduce the percolation rates

  7. The effects of crystalline Fe and Mn oxides on contaminant migration through soil liners

    International Nuclear Information System (INIS)

    Dodson, M.E.; Gee, G.W.; Serne, R.J.

    1984-01-01

    Tailings solution, produced from tailings excavated at the Canonsburg, Pennsylvania UMTRAP site, was used in liner material column flow studies to test the attenuation characteristics of local borrow pit soil found adjacent to the tailings area. The effluents from liner columns, under saturated conditions, were sampled at fractional pore volumes and analyzed for macro cation, anion, trace metal and radionuclide contents. Solution displacement was allowed to continue until three pore volumes of tailings solution had contacted the liner material. In addition, two amended liner mixtures were contacted with Canonsburg tailings solution to assess the effects of crystalline iron and manganese oxides in attenuating contaminants. The amended mixes represented Canonsburg soil plus either 2% (dry wt. basis) reagent grade iron oxide or 2% manganese saturated green sand zeolite. Attenuation of most trace metals and radionuclides was high in all three column studies, while macro ions, zinc, and the anions C1 and SO 4 showed limited signs of attenuation regardless of whether the soil was amended or not. In addition, there were no signs of excess leaching of Fe or Mn from the columns enriched with their oxides. General results indicate that the addition of iron and manganese oxides in their crystaline form is of little additional value compared to the attenuation of contaminants achieved with native iron and manganese oxides found as partial coatings on the silicate minerals of the unamended Canonsburg soil

  8. The photoionization mechanism of LINERs - Stellar and nonstellar

    Science.gov (United States)

    Ho, Luis C.; Filippenko, Alexei V.

    1993-01-01

    We present high quality spectroscopic observations of a sample of 14 LINERs. Starlight removal is achieved by the subtraction of a suitable absorption-line 'template' galaxy, allowing accurate measurements of emission lines. We use these line fluxes to examine the possible excitation mechanisms of LINERs. We suggest that LINERs with weak forbidden O I 6300-A emission may be H II regions photoionized by unusually hot O-type stars. LINERs with forbidden O I/H-alpha approximately greater than 1/6 may be powered by photoionization from a nonstellar continuum. This is supported by the detection of broad H-alpha emission, a correlation between line width and critical density, and pointlike X-ray emission in several of these objects.

  9. Melt Infiltrated Ceramic Matrix Composites for Shrouds and Combustor Liners of Advanced Industrial Gas Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Corman; Krishan Luthra; Jill Jonkowski; Joseph Mavec; Paul Bakke; Debbie Haught; Merrill Smith

    2011-01-07

    This report covers work performed under the Advanced Materials for Advanced Industrial Gas Turbines (AMAIGT) program by GE Global Research and its collaborators from 2000 through 2010. A first stage shroud for a 7FA-class gas turbine engine utilizing HiPerComp{reg_sign}* ceramic matrix composite (CMC) material was developed. The design, fabrication, rig testing and engine testing of this shroud system are described. Through two field engine tests, the latter of which is still in progress at a Jacksonville Electric Authority generating station, the robustness of the CMC material and the shroud system in general were demonstrated, with shrouds having accumulated nearly 7,000 hours of field engine testing at the conclusion of the program. During the latter test the engine performance benefits from utilizing CMC shrouds were verified. Similar development of a CMC combustor liner design for a 7FA-class engine is also described. The feasibility of using the HiPerComp{reg_sign} CMC material for combustor liner applications was demonstrated in a Solar Turbines Ceramic Stationary Gas Turbine (CSGT) engine test where the liner performed without incident for 12,822 hours. The deposition processes for applying environmental barrier coatings to the CMC components were also developed, and the performance of the coatings in the rig and engine tests is described.

  10. The impact of different types of textile liners used in protective footwear on the subjective sensations of firefighters.

    Science.gov (United States)

    Irzmańska, Emilia

    2015-03-01

    The paper presents ergonomic evaluation of footwear used with three types of textile liners differing in terms of design and material composition. Two novel textile composite liners with enhanced hygienic properties were compared with a standard liner used in firefighter boots. The study involved 45 healthy firefighters from fire and rescue units who wore protective footwear with one of the three types of liners. The study was conducted in a laboratory under a normal atmosphere. The ergonomic properties of the protective footwear and liners were evaluated according to the standard EN ISO 20344:2012 as well as using an additional questionnaire concerning the thermal and moisture sensations experienced while wearing the footwear. The study was conducted on a much larger group of subjects (45) than that required by the ISO standard (3) to increase the reliability of subjective evaluations. Some statistically significant differences were found between the different types of textile liners used in firefighter boots. It was confirmed that the ergonomic properties of protective footwear worn in the workplace may be improved by the use of appropriate textile components. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  11. Three Year RSA Evaluation of Vitamin E Diffused Highly Cross-linked Polyethylene Liners and Cup Stability.

    Science.gov (United States)

    Sillesen, Nanna H; Greene, Meridith E; Nebergall, Audrey K; Nielsen, Poul T; Laursen, Mogens B; Troelsen, Anders; Malchau, Henrik

    2015-07-01

    Vitamin E diffusion into highly cross-linked polyethylene (E-XLPE) is a method for enhancing oxidative stability of acetabular liners. The purpose of this study was to evaluate in vivo penetration of E-XLPE using radiostereometric analysis (RSA). Eighty-four hips were recruited into a prospective 10-year RSA. This is the first evaluation of the multicenter cohort after 3-years. All patients received E-XLPE liners (E1, Biomet) and porous-titanium coated cups (Regenerex, Biomet). There was no difference (P=0.450) in median femoral head penetration into the E-XLPE liners at 3-years comparing cobalt-chrome heads (-0.028mm; inter-quartile range (IQR) - 0.065 to 0.047) with ceramic heads (-0.043mm, IQR - 0.143to0.042). The 3-year follow-up indicates minimal E-XLPE liner penetration regardless of head material and minimal early cup movement. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Development of a Multifidelity Approach to Acoustic Liner Impedance Eduction

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.

    2017-01-01

    The use of acoustic liners has proven to be extremely effective in reducing aircraft engine fan noise transmission/radiation. However, the introduction of advanced fan designs and shorter engine nacelles has highlighted a need for novel acoustic liner designs that provide increased fan noise reduction over a broader frequency range. To achieve aggressive noise reduction goals, advanced broadband liner designs, such as zone liners and variable impedance liners, will likely depart from conventional uniform impedance configurations. Therefore, educing the impedance of these axial- and/or spanwise-variable impedance liners will require models that account for three-dimensional effects, thereby increasing computational expense. Thus, it would seem advantageous to investigate the use of multifidelity modeling approaches to impedance eduction for these advanced designs. This paper describes an extension of the use of the CDUCT-LaRC code to acoustic liner impedance eduction. The proposed approach is applied to a hardwall insert and conventional liner using simulated data. Educed values compare well with those educed using two extensively tested and validated approaches. The results are very promising and provide justification to further pursue the complementary use of CDUCT-LaRC with the currently used finite element codes to increase the efficiency of the eduction process for configurations involving three-dimensional effects.

  13. Engineering and innovative erection concept for the containment liner for an EPR trademark

    International Nuclear Information System (INIS)

    Goehring, Rainer

    2010-01-01

    The determination of the optimal design of the containment liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. The construction costs of a Nuclear Power Plant are also impacted by the erection time of components. Therefore, it is necessary to optimize the erection times and consequently essentially to shorten. One possibility has been demonstrated by Babcock Noell GmbH with the erection concept of a containment liner. The liner is preassembled on the pre-assembly place in rings of up to 12 meter height, with the nominal diameter of 47 meter and a weight of approximately up to 200 tonnes. These rings, as well as the containment cup and the dome, are lifted with a heavy load crane into the reactor building. Several load cases for normal operation and accidental conditions as well as severe accidents have been analysed. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. This is the topic of the speech '' Computational Concept for the Containment Liner for EPR trademark '', given by Mr. Franz Nagelstutz, Abt. Planning, Babcock Noell GmbH und Mr. Nils Anders, Babcock Noell GmbH, Abt. Planning. With this concept, the construction activities on the inner containment wall are only five times disrupted by the welding and coating of the circumferential weld (approx. 25 calendar days). In comparison with the common known erection concept of welding of liner shells in situ, at least 20 weeks are saved on the schedule. An integrated concept from planning, manufacturing and erection of this large component has been implemented. It could be demonstrated that within the given time frame, with the required quality and within the required tolerances the containment liner for the Nuclear Power Plant can be delivered to the Client. (orig.)

  14. Evaluation of hardness and colour change of soft liners after accelerated ageing.

    Science.gov (United States)

    Mancuso, Daniela Nardi; Goiato, Marcelo Coelho; Zuccolotti, Bruna Carolina Rossatti; Moreno, Amália; dos Santos, Daniela Micheline

    2009-07-01

    Soft liners have been developed to offer comfort to denture wearers. However, this comfort is compromised when there is a change in the properties of the material, causing colour change, solubility, absorption and hardening. These characteristics can compromise the longevity of soft liners. The aim of this in vitro study was to investigate the effect of ageing on both the hardness and colour change of two soft liners following accelerated ageing. Two denture liners, one resin based (Trusoft, Bosworth, Illinois, USA) and one silicone based (Ufi Gel P, Voco GMBH, Cuxhaven, Germany), were tested in this study for both hardness (using the Shore A scale) and colour change (using the CIE L*a*b* colour scale), initially and after 1008 hours (6 weeks) of accelerated ageing. Statistical analysis was performed using the unpaired t-test with the Welch correction. These indicated that both materials increased in hardness and underwent colour change after accelerated ageing. The initial hardness of Trusoft was far lower than that of Ufi Gel P (18.2 Shore A units vs 34.8 Shore A units). However, for Trusoft the changes for both hardness (from 18.2 to 52.1 Shore A units) and colour change (16.85 on the CIE L*a*b* colour scale) were greater than those for Ufi Gel P, for which hardness changed from 34.8 to 36.5 Shore A units and the colour change was 5.19 on the CIE L*a*b* colour scale. Ufi Gel P underwent less hardness and colour change after accelerated ageing than Trusoft. On the other hand, the use of Trusoft may be preferable in cases where initial softness is a major consideration, such as when relining an immediate denture after implant surgery.

  15. The magnetically driven imploding liner parameter space of the ATLAS capacitor bank

    CERN Document Server

    Lindemuth, I R; Faehl, R J; Reinovsky, R E

    2001-01-01

    Summary form only given, as follows. The Atlas capacitor bank (23 MJ, 30 MA) is now operational at Los Alamos. Atlas was designed primarily to magnetically drive imploding liners for use as impactors in shock and hydrodynamic experiments. We have conducted a computational "mapping" of the high-performance imploding liner parameter space accessible to Atlas. The effect of charge voltage, transmission inductance, liner thickness, liner initial radius, and liner length has been investigated. One conclusion is that Atlas is ideally suited to be a liner driver for liner-on-plasma experiments in a magnetized target fusion (MTF) context . The parameter space of possible Atlas reconfigurations has also been investigated.

  16. Advantages of floating covers with LLDPE Liners

    International Nuclear Information System (INIS)

    Munoz Gomez, J. M.

    2014-01-01

    Using floating covers in irrigation pounds and waste dam gives many advantages. It is a very interesting investment for those place with a high evaporation ratio. this is an easy system which improves several aspects in irrigation or drinkable water reservoirs, mainly it saves water and it saves clean-works (time and cost). It is also used in waste dam to deodorization. Time ago this application was developed with PVC liners and TPO liners, now the innovation is LLDPE liners which improve mechanical properties, durability and an easier installation. This paper develops the state of art of this design technology, and the back ground of our experience. (Author)

  17. Inductively Driven, 3D Liner Compression of a Magnetized Plasma to Megabar Energy Densities

    Energy Technology Data Exchange (ETDEWEB)

    Slough, John [MSNW LLC, Redmond, WA (United States)

    2015-02-01

    modules. The additional energy and switching capability proposed will thus provide for optimal utilization of the liner energy. The following tasks were outlined for the three year effort: (1) Design and assemble the foil liner compression test structure and chamber including the compression bank and test foils [Year 1]. (2) Perform foil liner compression experiments and obtain performance data over a range on liner dimensions and bank parameters [Year 2]. (3) Carry out compression experiments of the FRC plasma to Megagauss fields and measure key fusion parameters [Year 3]. (4) Develop numerical codes and analyze experimental results, and determine the physics and scaling for future work [Year 1-3]. The principle task of the project was to design and assemble the foil liner FRC formation chamber, the full compression test structure and chamber including the compression bank. This task was completed successfully. The second task was to test foils in the test facility constructed in year one and characterize the performance obtained from liner compression. These experimental measurements were then compared with analytical predictions, and numerical code results. The liner testing was completed and compared with both the analytical results as well as the code work performed with the 3D structural dynamics package of ANSYS Metaphysics®. This code is capable of modeling the dynamic behavior of materials well into the non-linear regime (e.g. a bullet hit plate glass). The liner dynamic behavior was found to be remarkably close to that predicted by the 3D structural dynamics results. Incorporating a code that can also include the magnetics and plasma physics has also made significant progress at the UW. The remaining test bed construction and assembly task is was completed, and the FRC formation and merging experiments were carried out as planned. The liner compression of the FRC to Megagauss fields was not performed due to not obtaining a sufficiently long lived FRC during the

  18. Construction experience on PCRV liners at Fort St. Vrain

    International Nuclear Information System (INIS)

    Cliff, J.O.; Wunderlich, R.G.

    1976-01-01

    The construction of the steel liners for the Fort St. Vrain prestressed concrete reactor vessel presented many unique problems for which techniques were developed to satisfy the rigid specification requirements. The PCRV cavity liner was fabricated from 1.9cm carbon steel plate. The liners were partially fabricated by Pittsburgh-Des Moines Steel Company at their Pittsburgh manufacturing facility. The liners were then shipped by rail to within approximately five miles of the jobsite and then trucked the remaining distance. The construction techniques, dimensional control, concrete support and testing utilized on the Fort St. Vrain project are presented in detail and demonstrate the flexibility of the PCRV for field construction. (author)

  19. Repairing liner of the reactor; Reparacion del liner del reactor

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-07-15

    Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

  20. Compact, Lightweight, Ceramic Matrix Composite (CMC) Based Acoustic Liners for Reducing Subsonic Jet Aircraft Engine Noise

    Science.gov (United States)

    Kiser, J. Douglas; Grady, Joseph E.; Miller, Christopher J.; Hultgren, Lennart S.; Jones, Michael G.

    2016-01-01

    Recent developments have reduced fan and jet noise contributions to overall subsonic aircraft jet-engine noise. Now, aircraft designers are turning their attention toward reducing engine core noise. The NASA Glenn Research Center and NASA Langley Research Center have teamed to investigate the development of a compact, lightweight acoustic liner based on oxide/oxide ceramic matrix composite (CMC) materials. The NASA team has built upon an existing oxide/oxide CMC sandwich structure concept that provides monotonal noise reduction. Oxide/oxide composites have good high temperature strength and oxidation resistance, which could allow them to perform as core liners at temperatures up to 1000C (1832F), and even higher depending on the selection of the composite constituents. NASA has initiated the evaluation of CMC-based liners that use cells of different lengths (variable-depth channels) or effective lengths to achieve broadband noise reduction. Reducing the overall liner thickness is also a major goal, to minimize the volume occupied by the liner. As a first step toward demonstrating the feasibility of our concepts, an oxide/oxide CMC acoustic testing article with different channel lengths was tested. Our approach, summary of test results, current status, and goals for the future are reported.

  1. Dynamics of heterogeneous liners with prolonged plasma creation

    International Nuclear Information System (INIS)

    Aleksandrov, V.V.; Branitskii, A.V.; Volkov, G.S.; Grabovskii, E.V.; Zurin, M.V.; Nedoseev, S.L.; Oleinik, G.M.; Samokhin, A.A.; Smirnov, V.P.; Fedulov, M.V.; Frolov, I.N.; Sasorov, P.V.

    2001-01-01

    Prolonged plasma creation in heterogeneous liners, in which the liner substance is separated into two phase states (a hot plasma and a cold skeleton), is investigated both experimentally and theoretically. This situation is typical of multiwire, foam, and even gas liners in high-current high-voltage facilities. The main mechanisms governing the rate at which the plasma is created are investigated, and the simplest estimates of the creation rate are presented. It is found that, during prolonged plasma creation, the electric current flows through the entire cross section of the produced plasma shell, whose thickness is comparable with the liner radius; in other words, a current skin layer does not form. During compression, such a shell is fairly stable because of its relatively high resilience. It is shown that, under certain conditions, even a thick plasma shell can be highly compressed toward the discharge axis. A simplified numerical simulation of the compression of a plasma shell in a liner with prolonged plasma creation is employed in order to determine the conditions for achieving regimes of fairly compact and relatively stable radial compression of the shell

  2. Dynamics of bubble collapse under vessel confinement in 2D hydrodynamic experiments

    Science.gov (United States)

    Shpuntova, Galina; Austin, Joanna

    2013-11-01

    One trauma mechanism in biomedical treatment techniques based on the application of cumulative pressure pulses generated either externally (as in shock-wave lithotripsy) or internally (by laser-induced plasma) is the collapse of voids. However, prediction of void-collapse driven tissue damage is a challenging problem, involving complex and dynamic thermomechanical processes in a heterogeneous material. We carry out a series of model experiments to investigate the hydrodynamic processes of voids collapsing under dynamic loading in configurations designed to model cavitation with vessel confinement. The baseline case of void collapse near a single interface is also examined. Thin sheets of tissue-surrogate polymer materials with varying acoustic impedance are used to create one or two parallel material interfaces near the void. Shadowgraph photography and two-color, single-frame particle image velocimetry quantify bubble collapse dynamics including jetting, interface dynamics and penetration, and the response of the surrounding material. Research supported by NSF Award #0954769, ``CAREER: Dynamics and damage of void collapse in biological materials under stress wave loading.''

  3. Construction and performance of a long-term earthen liner experiment

    Science.gov (United States)

    Cartwright, Keros; Krapac, Ivan G.; Bonaparte, Rudolph

    1990-01-01

    In land burial schemes, compacted soil barriers with low hydraulic conductivity are commonly used in cover and liner systems to control the movement of liquids and prevent groundwater contamination. An experimental liner measuring 8 x 15 x 0.9 m was constructed with design criteria and equipment to simulate construction of soil liners built at waste disposal facilities. The surface of the liner was flooded with a 29.5 cm deep pond on April 12, 1988. Infiltration of water into the liner has been monitored for two years using 4 large-ring (1.5 m OD) and 32 small-ring (0.28 m OD) infiltrometers, and a water-balance that accounts for total infiltration and evaporation. Average long-term infiltration fluxes based on two years of monitoring are 5.8 x 10-9 cm/s, 6.0 x 10-8 cm/s and 5.6 x 10-8 for the large-ring, small-ring, and water-balance data, respectively. The saturated hydraulic conductivity of the liner based on small-ring data, estimated using Darcy's Law and the Green-Ampt Approximation, is 3 x 10-8 and 4 x 10-8 cm/s, respectively. All sets of data indicate that the liner's performance exceed that which is required by the U.S. EPA.

  4. Symmetry of nonexploding cylindrical liner converging to the axis under magnetic field effects

    International Nuclear Information System (INIS)

    Chernyshev, V.K.; Grinevich, B.E.; Buzin, V.N.; Pogorelov, V.P.; Shertsov, V.A.; Petrukhin, A.A.; Demidov, V.A.; Zharinov, E.I.

    1990-01-01

    Liner acceleration, affected by magnetic pressure, is broadly used to yield megagauss magnetic fields and plasma compression. The progress of test conduction depends much on the state of liner subjected to Taylor instability while being accelerated. There is a number of methods permitting to reduce liner shape distortions, developing during its acceleration. The most simple method consists in that the aspect ratio (the ratio of liner placing radius to its thickness) is taken less than 10. To impart sufficient velocity to the liner of large thickness its density should be small. Therefore, liner is either a gas layer or explosion products of thin metal foil which passed to a vaporous state in early stage of acceleration. Acceleration of nonexploding liners may serve as the other method of asymmetry reduction. Strength and viscosity of liner will be used as stabilizing factors with respect to the development of Taylor instability. This will allow the aspect ratio increase, that is sometimes useful. Test results on acceleration of nonexploding aluminum liners 1 mm thick have been described. Aspect ratio amounted to 30-60 and the ratio of liner acceleration distance to its thickness (parameter, being of great importance when studying the development of Taylor instability) made up 20-40. Satisfactory azimuthal symmetry of liner convergence to the center was recorded. For more detailed investigation of Taylor instability influence on the symmetry of nonexploding liner, the experiments, when the ratio of liner acceleration length to its thickness would be increased up to 90-100 simultaneously with determination of azimuthal and axial symmetry of liner, are of interest. In this paper presents the results of experiments on acceleration of copper cylindrical liner 1.37 mm thick

  5. Optimization of Variable-Depth Liner Configurations for Increased Broadband Noise Reduction

    Science.gov (United States)

    Jones, M. G.; Watson, W. R.; Nark, D. M.; Schiller, N. H.; Born, J. C.

    2016-01-01

    This paper employs three acoustic propagation codes to explore variable-depth liner configurations for the NASA Langley Grazing Flow Impedance Tube (GFIT). The initial study demonstrates that a variable impedance can acceptably be treated as a uniform impedance if the spatial extent over which this variable impedance occurs is less than one-third of a wavelength of the incident sound. A constrained optimization study is used to design a variable-depth liner and to select an optimization metric. It also provides insight regarding how much attenuation can be achieved with variable-depth liners. Another optimization study is used to design a liner with much finer chamber depth resolution for the Mach 0.0 and 0.3 test conditions. Two liners are designed based on spatial rearrangement of chambers from this liner to determine whether the order is critical. Propagation code predictions suggest this is not the case. Both liners are fabricated via additive manufacturing and tested in the GFIT for the Mach 0.0 condition. Predicted and measured attenuations compare favorably across the full frequency range. These results clearly suggest that the chambers can be arranged in any order, thus offering the potential for innovative liner designs to minimize depth and weight.

  6. Modeling of Broadband Liners Applied to the Advanced Noise Control Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.

    2015-01-01

    The broadband component of fan noise has grown in relevance with an increase in bypass ratio and incorporation of advanced fan designs. Therefore, while the attenuation of fan tones remains a major factor in engine nacelle acoustic liner design, the simultaneous reduction of broadband fan noise levels has received increased interest. As such, a previous investigation focused on improvements to an established broadband acoustic liner optimization process using the Advanced Noise Control Fan (ANCF) rig as a demonstrator. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom liner designs were carried through design, fabrication, and testing. This paper addresses a number of areas for further research identified in the initial assessment of the ANCF study. Specifically, incident source specification and uncertainty in some aspects of the predicted liner impedances are addressed. This information is incorporated in updated predictions of the liner performance and comparisons with measurement are greatly improved. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of various liner designs. This study also provides further confidence in the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

  7. Engineering and innovative erection concept for the containment liner for a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Goehring, Rainer [Babcock Noell GmbH, Wuerzburg (Germany). Abt. Nukleare Projekte; Anders, Nils; Nagelstutz, Franz [Babcock Noell GmbH, Wuerzburg (Germany). Abt. Berechnung

    2010-04-15

    The determination of the optimal design of the containment liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. Several load cases for normal operation and accidental conditions as well as severe accidents have been analysed. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. The construction costs of a Nuclear Power Plant are also impacted by the erection time of components. Therefore, it is necessary to optimize the erection times and consequently essentially to shorten. One possibility has been demonstrated by Babcock Noell GmbH with the erection concept of a containment liner. The liner is preassembled on the pre-assembly place in rings of up to 12 meter height, with the nominal diameter of 47 meter and a weight of approximately up to 200 tonnes. These rings, as well as the containment cup and the dome, are lifted with a heavy load crane into the reactor building. With this concept, the construction activities on the inner containment wall are only five times disrupted by the welding and coating of the circumferential weld (approx. 25 calendar days). In comparison with the common known erection concept of welding of liner shells in situ, at least 20 weeks are saved on the schedule. An integrated concept from planning, manufacturing and erection of this large component has been implemented. It could be demonstrated that within the given time frame, with the required quality and within the required tolerances the containment liner for the Nuclear Power Plant can be delivered to the Client. (orig.)

  8. Engineering and innovative erection concept for the containment liner for a nuclear power plant

    International Nuclear Information System (INIS)

    Goehring, Rainer; Anders, Nils; Nagelstutz, Franz

    2010-01-01

    The determination of the optimal design of the containment liner considering amount of material, manufacturing and erection was the challenge for the engineering team of Babcock Noell GmbH. Several load cases for normal operation and accidental conditions as well as severe accidents have been analysed. The special load cases in the vicinity of penetrations and anchor plates have been calculated. The results of theses analyses have been considered in the actual design of the liner. The construction costs of a Nuclear Power Plant are also impacted by the erection time of components. Therefore, it is necessary to optimize the erection times and consequently essentially to shorten. One possibility has been demonstrated by Babcock Noell GmbH with the erection concept of a containment liner. The liner is preassembled on the pre-assembly place in rings of up to 12 meter height, with the nominal diameter of 47 meter and a weight of approximately up to 200 tonnes. These rings, as well as the containment cup and the dome, are lifted with a heavy load crane into the reactor building. With this concept, the construction activities on the inner containment wall are only five times disrupted by the welding and coating of the circumferential weld (approx. 25 calendar days). In comparison with the common known erection concept of welding of liner shells in situ, at least 20 weeks are saved on the schedule. An integrated concept from planning, manufacturing and erection of this large component has been implemented. It could be demonstrated that within the given time frame, with the required quality and within the required tolerances the containment liner for the Nuclear Power Plant can be delivered to the Client. (orig.)

  9. Investigation of friction characteristics in segmented piston ring liner assembly of IC engine

    Directory of Open Access Journals (Sweden)

    Tejaskumar Chaudhari

    2016-09-01

    Full Text Available The friction at the piston ring cylinder liner assembly (PRLA is a major contributor in the total friction losses in the I.C. engine. New materials, coatings and high-tech machining processes that previously were considered to be too expensive and therefore only used in complex applications are today becoming more affordable. A significant amount of the total power loss in a modern automotive engine is due to the Friction interaction between the top compression ring and the cylinder liner, especially at the TDC and BDC where boundary lubrication exists. The change in piston speed is accompanied with change the lubrication regime in the cylinder, which results change in friction between the ring and the liner during the entire stroke of the piston. Theoretical modelling of friction force from the various sources of friction will be compared to experimental results for analysing the tribological characteristics. The appropriate sample of piston ring and cylinder liner pair is developed for studying the different tribological parameters on Reciprocating Tribometer. The variable parameters are engine speed, oil viscosity, and load. The experimental results and observations are studied under different operating conditions in speed ranges from 300 rpm to 1500 rpm with constant load of 60 N. It can be seen that as speed increases, the friction force and friction coefficient also decreases.

  10. Degradation rate of sludge/fly ash mixture used as landfill liner; Nedbrytningshastigheten foer taetskikt uppbyggda av slam och aska

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, Karin; Berg, Magnus [AaF-Process AB, Stockholm (Sweden); Svensson, Malin; Ecke, Holger [Luleaa Univ. of Technology (Sweden)

    2005-10-01

    In order to be able to use mixtures of ash and sludge as landfill liner an important aspect is to demonstrate that the degradation of organic matter is slow enough. Therefore, the goal of this project has been to find out for how long a landfill liner material of sludge and ash will be stable and keep its function. The degradation of organic material in two different mixtures of sludge and ash has been studied in laboratory experiments. The rate of degradation was then estimated for barriers of sludge and ash, taking into account construction techniques (mixture, compaction, water content), climate conditions (freezing, drying) and biological processes (NaN{sub 3} additive). The effect of the degradation on the permeability has also been quantified. Organic material may disappear for the landfill liner material through 1) initial leaching of soluble organic material, 2) leaching of organic material after chemical reactions or 3) evaporation during biological degradation. Bacterial activity was not found in the sludge/ash mixtures during the experiments. Therefore, the organic material is probably reduced mainly though leaching according to 1) and 2). The leached amount of TOC (total organic carbon) was measured for all samples of sludge/ash in several experimental cycles. The leached amount of TOC was compared to the initial amount of TOC in the material. The results show a small initial reduction of organic material through leaching but the TOC content in the material is then stabilized. In relation to the total weight of the material the leaching of TOC was similar for the mixtures with 80 % ash and 20 % ash. However, this means that a larger amount of TOC was leached out from the mixtures with a high ash content since the initial amount of organic material was smaller. General conclusions about which ash-sludge ratio that is suitable for a landfill liner material could not be drawn from the experiments from a degradation point of view. If the initial

  11. Repairing liner of the reactor; Reparacion del liner del reactor

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-07-15

    Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

  12. USSR imploding liner program

    International Nuclear Information System (INIS)

    Shearer, J.W.

    1975-01-01

    A summary is given of the history and rationale of the USSR program to implode metallic liners for the fusion program. The explosive driven, magnetic drive, and compressed gas driven research is reviewed. (MOW)

  13. One-and-Two-Dimensional Simulations of Liner Performance at Atlas Parameters

    International Nuclear Information System (INIS)

    Keinigs, R.K.; Atchison, W.L.; Faehl, R.J.; Mclenithan, K.D.; Trainor, R.J.

    1998-01-01

    The authors report results of one-and-two-dimensional MHD simulations of an imploding heavy liner in Z-pinch geometry. The driving current has a pulse shape and peak current characteristic of the Atlas pulsed-power facility being constructed at Los Alamos National Laboratory. One-dimensional simulations of heavy composite liners driven by 30 MA currents can achieve velocities on the order of 14 km/sec. Used to impact a tungsten target, the liner produces shock pressures of ∼ fourteen megabars. The first 2-D simulations of imploding liners driven at Atlas current parameters are also described. These simulations have focused on the interaction of the liner with the glide planes, and the effect of realistic surface perturbations on the dynamics of the pinch. It is found that the former interaction does not seriously affect the inner liner surface. Results from the second problem indicate that a surface perturbation having amplitude as small as 0.2 microm can have a significant effect on the implosion dynamics

  14. Metallurgical examination of, and resin transfer from, Three Mile Island prefilter liners

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, Jr, J W; Spaletta, H W

    1984-08-01

    Metallurgical examinations were performed on two EPICOR-II prefilter liners at the Idaho National Engineering Laboratory (INEL) to determine conditions of the liners and identify the minimum expected lifetime of those and other liners stored at INEL. The research work was accomplished by EG and G Idaho, Inc. for the EPICOR-II Research and Disposition Program, which is funded by the US Department of Energy. The EPICOR-II prefilter liners were used to filter radionuclides from contaminated water during cleanup of Three Mile Island Unit 2 (TMI-2). The liners were constructed of carbon steel with a phenolic protective coating and contained organic and inorganic ion-exchange filtration media. Program plans call for interim storage of EPICOR-II prefilters at INEL for up to ten years, before final disposal in high integrity containers at the Hanford, Washington commercial disposal site. This report describes the (a) resin transfer process used to empty liners for examination, (b) removal of metallographic sections from those liners, (c) specimen preparation, and (d) findings from metallographic examination of those specimens. A minimum lifetime for the liners is determined and recommendations are given for storage of wastes from future TMI-2 activities.

  15. Metallurgical examination of, and resin transfer from, Three Mile Island prefilter liners

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Spaletta, H.W.

    1984-08-01

    Metallurgical examinations were performed on two EPICOR-II prefilter liners at the Idaho National Engineering Laboratory (INEL) to determine conditions of the liners and identify the minimum expected lifetime of those and other liners stored at INEL. The research work was accomplished by EG and G Idaho, Inc. for the EPICOR-II Research and Disposition Program, which is funded by the US Department of Energy. The EPICOR-II prefilter liners were used to filter radionuclides from contaminated water during cleanup of Three Mile Island Unit 2 (TMI-2). The liners were constructed of carbon steel with a phenolic protective coating and contained organic and inorganic ion-exchange filtration media. Program plans call for interim storage of EPICOR-II prefilters at INEL for up to ten years, before final disposal in high integrity containers at the Hanford, Washington commercial disposal site. This report describes the (a) resin transfer process used to empty liners for examination, (b) removal of metallographic sections from those liners, (c) specimen preparation, and (d) findings from metallographic examination of those specimens. A minimum lifetime for the liners is determined and recommendations are given for storage of wastes from future TMI-2 activities

  16. Advanced Computational and Experimental Techniques for Nacelle Liner Performance Evaluation

    Science.gov (United States)

    Gerhold, Carl H.; Jones, Michael G.; Brown, Martha C.; Nark, Douglas

    2009-01-01

    The Curved Duct Test Rig (CDTR) has been developed to investigate sound propagation through a duct of size comparable to the aft bypass duct of typical aircraft engines. The axial dimension of the bypass duct is often curved and this geometric characteristic is captured in the CDTR. The semiannular bypass duct is simulated by a rectangular test section in which the height corresponds to the circumferential dimension and the width corresponds to the radial dimension. The liner samples are perforate over honeycomb core and are installed on the side walls of the test section. The top and bottom surfaces of the test section are acoustically rigid to simulate a hard wall bifurcation or pylon. A unique feature of the CDTR is the control system that generates sound incident on the liner test section in specific modes. Uniform air flow, at ambient temperature and flow speed Mach 0.275, is introduced through the duct. Experiments to investigate configuration effects such as curvature along the flow path on the acoustic performance of a sample liner are performed in the CDTR and reported in this paper. Combinations of treated and acoustically rigid side walls are investigated. The scattering of modes of the incident wave, both by the curvature and by the asymmetry of wall treatment, is demonstrated in the experimental results. The effect that mode scattering has on total acoustic effectiveness of the liner treatment is also shown. Comparisons of measured liner attenuation with numerical results predicted by an analytic model based on the parabolic approximation to the convected Helmholtz equation are reported. The spectra of attenuation produced by the analytic model are similar to experimental results for both walls treated, straight and curved flow path, with plane wave and higher order modes incident. The numerical model is used to define the optimized resistance and reactance of a liner that significantly improves liner attenuation in the frequency range 1900-2400 Hz. A

  17. Polymerization shrinkage of different types of composite resins and microleakage with and without liner in class II cavities.

    Science.gov (United States)

    Karaman, E; Ozgunaltay, G

    2014-01-01

    To determine the volumetric polymerization shrinkage of four different types of composite resin and to evaluate microleakage of these materials in class II (MOD) cavities with and without a resin-modified glass ionomer cement (RMGIC) liner, in vitro. One hundred twenty-eight extracted human upper premolar teeth were used. After the teeth were divided into eight groups (n=16), standardized MOD cavities were prepared. Then the teeth were restored with different resin composites (Filtek Supreme XT, Filtek P 60, Filtek Silorane, Filtek Z 250) with and without a RMGIC liner (Vitrebond). The restorations were finished and polished after 24 hours. Following thermocycling, the teeth were immersed in 0.5% basic fuchsin for 24 hours, then midsagitally sectioned in a mesiodistal plane and examined for microleakage using a stereomicroscope. The volumetric polymerization shrinkage of materials was measured using a video imaging device (Acuvol, Bisco, Inc). Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U-tests. All teeth showed microleakage, but placement of RMGIC liner reduced microleakage. No statistically significant differences were found in microleakage between the teeth restored without RMGIC liner (p>0.05). Filtek Silorane showed significantly less volumetric polymerization shrinkage than the methacrylate-based composite resins (pcomposite resin restorations resulted in reduced microleakage. The volumetric polymerization shrinkage was least with the silorane-based composite.

  18. Liner of a thermonuclear pulse THETA-pinch reactor

    International Nuclear Information System (INIS)

    Baranov, G.A.; Izotov, E.N.; Karasev, B.G.; Komin, A.V.; Krivosheev, M.V.; Levashov, A.D.

    1975-01-01

    Some possible constructive solutions to the problem of fabrication of the theta-pinch reactor liner by the method of centrifugal casting in a casting mould are considered. A scheme for liner manufacturing is presented, which includes the following elements: 1) a casting mould of dielectric material presenting a hollow cylinder of 4 m in diam., 3 m in length and 12 t in weight, which rotates at 8 rps in the reactor chamber; 2) a system for heat protection of the casting mould; the volume heat of the mould is suggested to remove by gaseous helium flowing under pressure along axial cooling channels of 5 mm in diam.; the channels are evenly distributed throughout the thickness of the mould shell; 3) a system for preparation and supply of a liquid metal to the casting mould, the metal is being supplied into the casting mould from its both ends at a rate of 1.7 t of the melt per second; 4) a system for rotation of the mould, which comprises two gas turbines mounted on both ends of the mould and two main stop-radial slip supports with gas lubrication

  19. Effects of crystalline FE and MN oxides on contaminant migration through soil liners

    International Nuclear Information System (INIS)

    Dodson, M.E.; Serne, R.J.; Gee, G.W.

    1983-12-01

    Tailings solution, produced from tailings excavated at the Canonsburg, Pennsylvania UMTRAP site, was used in liner material column flow studies to test the attenuation characteristics of local borrow pit soil found adjacent to the tailings area. The effluents from linear columns, under saturated conditions, were sampled at fractional pore volumes and analyzed for macro cation, anion, trace metal and radionuclide contents. Solution displacement was allowed to continue until three pore volumes of tailings solution had contacted the liner material. In addition, two amended liner mixtures were contacted with Canonsburg tailings solution to assess the effects of crystalline iron and manganese oxides in attenuating contaminants. The amended mixes represented Canonsburg soil plus either 2% (dry wt basis) reagent grade iron oxide of 2% manganese saturated green sand zeolite. Attenuation of most trace metals and readionuclides was high in all three column studies, while macro ions, zinc, and the anions Cl and SO 4 showed limited signs of attenuation regardless of whether the soil was amended or not. In addition, there were no signs of excess leaching to Fe or Mn from the columns enriched with their oxides. General results indicate that the addition of iron and manganese oxides in their crystalline form is of little additional value compared to the attenuation of contaminants achieved with native iron and manganese oxides found as partial coatings on the silicate minerals of the unamended Canonsburg soil. 8 references, 3 figures, 3 tables

  20. Experimental Evaluation of Acoustic Engine Liner Models Developed with COMSOL Multiphysics

    Science.gov (United States)

    Schiller, Noah H.; Jones, Michael G.; Bertolucci, Brandon

    2017-01-01

    Accurate modeling tools are needed to design new engine liners capable of reducing aircraft noise. The purpose of this study is to determine if a commercially-available finite element package, COMSOL Multiphysics, can be used to accurately model a range of different acoustic engine liner designs, and in the process, collect and document a benchmark dataset that can be used in both current and future code evaluation activities. To achieve these goals, a variety of liner samples, ranging from conventional perforate-over-honeycomb to extended-reaction designs, were installed in one wall of the grazing flow impedance tube at the NASA Langley Research Center. The liners were exposed to high sound pressure levels and grazing flow, and the effect of the liner on the sound field in the flow duct was measured. These measurements were then compared with predictions. While this report only includes comparisons for a subset of the configurations, the full database of all measurements and predictions is available in electronic format upon request. The results demonstrate that both conventional perforate-over-honeycomb and extended-reaction liners can be accurately modeled using COMSOL. Therefore, this modeling tool can be used with confidence to supplement the current suite of acoustic propagation codes, and ultimately develop new acoustic engine liners designed to reduce aircraft noise.

  1. Time constrained liner shipping network design

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Brouer, Berit Dangaard; Desaulniers, Guy

    2017-01-01

    We present a mathematical model and a solution method for the liner shipping network design problem. The model takes into account coordination between vessels and transit time restrictions on the cargo flow. The solution method is an improvement heuristic, where an integer program is solved...... iteratively to perform moves in a large neighborhood search. Our improvement heuristic is applicable as a real-time decision support tool for a liner shipping company. It can be used to find improvements to the network when evaluating changes in operating conditions or testing different scenarios...

  2. Numerical Analysis on Heat Flux Distribution through the Steel Liner of the Ex-vessel Core Catcher

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Se Hong; Choi, Choeng Ryul [ELSOLTEC, Yongin (Korea, Republic of); Kim, Byung Jo; Lee, Kyu Bok [KEPCO, Gimcheon (Korea, Republic of); Hwang, Do Hyun [KHNP-CRI, Daejeon (Korea, Republic of)

    2016-05-15

    In order to prevent material failure of steel container of the core catcher system due to high temperatures, heat flux through the steel liner wall must be kept below the critical heat flux (CHF), and vapor dry-out of the cooling channel must be avoided. In this study, CFD methodology has been developed to simulate the heat flux distribution in the core catcher system, involving following physical phenomena: natural convection in the corium pool, boiling heat transfer and solidification/melting of the corium. A CFD methodology has been developed to simulate the thermal/hydraulic phenomena in the core catcher system, and a numerical analysis has been carried out to estimate the heat flux through the steel liner of the core catcher. High heat flux values are formed at the free surface of the corium pool. However, the heat flux through the steel liner is maintained below the critical heat flux.

  3. Survivorship of Total Hip Joint Replacements Following Isolated Liner Exchange for Wear.

    Science.gov (United States)

    Vadei, Leone; Kieser, David C; Frampton, Chris; Hooper, Gary

    2017-11-01

    Liner exchange for articular component wear in total hip joint replacements (THJRs) is a common procedure, often thought to be benign with reliable outcomes. Recent studies, however, suggest high failure rates of liner exchange revisions with significant complications. The primary aim of this study was, therefore, to analyze the survivorship of isolated liner exchange for articular component wear, and secondarily to assess the influence of patient demographics (gender, age, and American Society of Anaesthesiologists [ASA] ratings) on rerevisions following isolated liner exchange for wear. A retrospective review of the 15-year New Zealand Joint Registry (1999-2014) was performed, analyzing the outcomes of isolated liner exchange for articular component wear. The survivorship as defined as rerevision with component exchange was determined and 10-year Kaplan-Meier survivorship curves were constructed. These revision rates were compared to age, gender, and ASA rating groups using a log-rank test. The 10-year survivorship of THJR following liner exchange revision for liner wear was 75.3%. If a rerevision was required, the median time to rerevision was 1.33 years with a rerevision rate of 3.33 per 100 component years (95% confidence interval 2.68-4.08/100 component years). The principle reasons for rerevision were dislocation (48.4%) and acetabular component loosening (20.9%). There was no statistically significant difference in rerevision rates based on gender, age categories, or ASA scores. THJR isolated liner exchange for liner wear is not a benign procedure with a survivorship of 75.3% at 10 years. Surgeons contemplating liner exchange revisions should be cognisant of this risk and should adequately assess component position and stability preoperatively. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Obtaining off-Hugoniot equation of state data on solid metals at extreme pressures via pulsed-power driven cylindrical liner implosions

    Science.gov (United States)

    Lemke, Raymond

    2015-06-01

    The focus of this talk is on magnetically driven, liner implosion experiments on the Z machine (Z) in which a solid, metal tube is shocklessly compressed to multi-megabar pressure. The goal of the experiments is to collect velocimetry data that can be used in conjunction with a new optimization based analysis technique to infer the principal isentrope of the tube material over a range of pressures. For the past decade, shock impact and ramp loading experiments on Z have used planar platforms exclusively. While producing state-of-the-art results for material science, it is difficult to produce drive pressures greater than 6 Mbar in the divergent planar geometry. In contrast, a cylindrical liner implosion is convergent; magnetic drive pressures approaching 50 Mbar are possible with the available current on Z (~ 20 MA). In our cylindrical experiments, the liner comprises an inner tube composed of the sample material (e.g., Ta) of unknown equation of state, and an outer tube composed of aluminum (Al) that serves as the current carrying cathode. Internal to the sample are fielded multiple PDV (Photonic Doppler Velocimetry) probes that measure velocity of the inner free surface of the imploding sample. External to the composite liner, at much larger radius, is an Al tube that is the return current anode. VISAR (velocity interferometry system for any reflector) probes measure free surface velocity of the exploding anode. Using the latter, MHD and optimization codes are employed to solve an inverse problem that yields the current driving the liner implosion. Then, the drive current, PDV velocity, MHD and optimization codes, are used to solve another inverse problem that yields pressure vs. density on approximately the principal isentrope of the sample material. Results for Ta, Re, and Cu compressed to ~ 10 Mbar are presented. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin

  5. Imploding-liner reactor nucleonic studies: the LINUS blanket

    International Nuclear Information System (INIS)

    Dudziak, D.J.

    1977-09-01

    Scoping nucleonic studies have been performed for a small imploding-liner fusion reactor concept. Tritium breeding ratio and time-dependent energy deposition rates were the primary parameters of interest in the study. Alloys of Pb and LiPb were considered for the liquid liner (blanket), and tritium breeding was found to be more than adequate with blankets less than 1 m thick. However, neutron leakages into the solid cylinder block surrounding the liquid liner are generally quite high, so considerable effort was concentrated on minimizing these values. Time-dependent calculations reveal that 89% of the energy is deposited in the blanket within 2 μs. Thus, LINUS's blanket should remain intact for the requisite neutron and gamma-ray lifetimes

  6. A comparative evaluation of effect on water sorption and solubility of a temporary soft denture liner material when stored either in distilled water, 5.25% sodium hypochlorite or artificial saliva: An in vitro study

    Directory of Open Access Journals (Sweden)

    Aditi Garg

    2016-01-01

    Full Text Available Introduction: Soft denture liners have a key role in modern removable prosthodontics since they restore health to inflamed and abused mucosa by redistribution of forces transmitted to the edentulous ridges. The most common problems encountered using soft denture liners are water sorption and solubility when in contact with saliva or storage media. These problems are associated with swelling, distortion, support of Candida albicans growth, and stresses at the liner/denture base interface that reduces the bond strength. Objective: To evaluate the water sorption and solubility of commercially available acrylic based self cure soft denture lining material (GC RELINE™ Tissue Conditioner after immersion in three different storage media (distilled water, Shellis artificial saliva, 5.25% sodium hypochlorite disinfectant solution at time interval of 4, 7, 11, and 15 days. Material and Methods: The study involved preparation of artificial saliva using Shellis formula. A total 45 standardized samples of the material (GC RELINE™ were prepared in disk form (15 mm in diameter and 2 mm in thickness. The study was divided into three groups with storage in Control (distilled water, Shellis artificial saliva, and 5.25% sodium hypochlorite. Samples were dried in a desiccator and weighed in the analytical balance to measure the initial weight (mg/cm2 of the disks (W1. The first groups (15 samples were placed in 30 ml distilled water (Group A at 37΀C, second group 30 ml of artificial saliva (Group B and third group in 5.25% sodium hypochlorite (Group C. Disks were removed from disinfectant after 5 min and placed in 30 ml distilled water. On days 4, 7, 11, and 15, all samples were removed from their containers and reweighed to measure the weight (mg/cm2 of the disks after sorption (W2. The solubility was measured by placing the disks back in the desiccator after each sorption cycle and drying them to constant weight in the desiccator. These values were weight

  7. Design of the ZTH vacuum liner

    International Nuclear Information System (INIS)

    Prince, P.P.

    1987-01-01

    The current status of the ZTH vacuum liner design is covered by this report. ZTH will be the first experiment to be installed in the CPRF (Confinement Physics Research Facility) at the Los Alamos National Laboratory and is scheduled to be operational at 2 MA in 1990 and at the rated current of 4 MA in 1992. The vacuum vessel has a 2.4m major radius and a 40 cm minor radius. The vacuum vessel design features which satisfy the operating parameters are defined. The liner is constructed of Inconel 625 and has a geometry which alternates sections of thin walled bellows with rigid ribs. These composite sections span between pairs of the 16 diagnostic stations to complete the torus. The thin bellows sections maximize the liner toroidal resistance and the ribs provide support and positional accuracy for the armour in relation to the conducting shell. Heat transfer from the vessel is controlled by a blanket wrap of ceramic fiber insulation and the heat flux is dissipated to a water cooling jacket in the conducting shell. 7 figs., 1 tab

  8. Axial magnetic field injection in magnetized liner inertial fusion

    Science.gov (United States)

    Gourdain, P.-A.; Adams, M. B.; Davies, J. R.; Seyler, C. E.

    2017-10-01

    MagLIF is a fusion concept using a Z-pinch implosion to reach thermonuclear fusion. In current experiments, the implosion is driven by the Z-machine using 19 MA of electrical current with a rise time of 100 ns. MagLIF requires an initial axial magnetic field of 30 T to reduce heat losses to the liner wall during compression and to confine alpha particles during fusion burn. This field is generated well before the current ramp starts and needs to penetrate the transmission lines of the pulsed-power generator, as well as the liner itself. Consequently, the axial field rise time must exceed hundreds of microseconds. Any coil capable of being submitted to such a field for that length of time is inevitably bulky. The space required to fit the coil near the liner, increases the inductance of the load. In turn, the total current delivered to the load decreases since the voltage is limited by driver design. Yet, the large amount of current provided by the Z-machine can be used to produce the required 30 T field by tilting the return current posts surrounding the liner, eliminating the need for a separate coil. However, the problem now is the field penetration time, across the liner wall. This paper discusses why skin effect arguments do not hold in the presence of resistivity gradients. Numerical simulations show that fields larger than 30 T can diffuse across the liner wall in less than 60 ns, demonstrating that external coils can be replaced by return current posts with optimal helicity.

  9. Design and construction of the liner plate for the Arkansas and Midland containments

    International Nuclear Information System (INIS)

    Wiedner, K.; Shah, G.H.; Chang-Lo, P.

    1976-01-01

    This paper presents the design criteria and features of the containment liner plate systems utilized for the Arkansas and Midland Nuclear Power Plant. For the Arkansas project, the liner plate system was erected in circumferential rings approximately 3 m high, and the penetration assemblies were welded into the liner after erection. For the Midland project, the liner plate system was erected in vertical segments approximately 6 m wide x 24 m high, and the penetration assemblies were welded into the liner prior to erection. The differences between the schemes are discussed. (author)

  10. Routing and scheduling and fleet management for liner shipping

    DEFF Research Database (Denmark)

    Kjeldsen, Karina Hjortshøj

    2009-01-01

    The problem of routing, scheduling and fleet management in global liner shipping is presented. The developed model incorporates the ships' speed as a decision variable. Furthermore, the model must be able to handle problems of the size and complexity experienced by the global liner shipping...

  11. Leakage Performance of the GM + CCL Liner System for the MSW Landfill

    Directory of Open Access Journals (Sweden)

    Fan Jingjing

    2014-01-01

    Full Text Available The contaminants in the landfill leachate press pose a grave threat to environment of the soil and the groundwater beneath the landfill. Despite there being strict requirements in relevant provisions of both domestic and foreign countries for the design of the bottom liner system. Pollution of the soil and the groundwater still took place in a number of landfills because of the leakage. To investigate the leakage rate of the liner systems, the minimum design requirements of the liner systems are summarized according to the provisions of four countries, including China, USA, Germany, and Japan. Comparative analyses using one-dimensional transport model are conducted to study the leakage performance of these liner systems composed of geomembrance (GM and compacted clay layer (CCL meeting the relevant minimum design requirements. Then parametric analyses are conducted to study the effects of the hydraulic head, the thickness of GM, the hydraulic conductivity of CCL, and so forth on the leakage performance of the liner system. It is concluded that the liner system designed according to the minimum design requirements of Germany provide the best antileakage performance, while that of Japan performs the lowest. The key parameters affecting the failure time of the liner system are summarized. Finally, some suggestions for the design of the liner systems are made according to the analyses.

  12. Corrosion failure of a BWR embedded reactor containment liner

    International Nuclear Information System (INIS)

    Wegemar, B.

    2006-01-01

    Following sixteen fuel cycles, leakage through a BWR embedded reactor containment liner (carbon steel) was discovered. Leakage was located at a penetration for electrical conductors as a result of penetrating corrosion attack. During construction, porous cement structures and air pockets/cavities were formed due to erroneous injection of grout. Corrosion attacks on the CS steel liner were located at the relatively small, active surfaces in contact with the porous cement structure. The corrosion mechanism was supposed to be anodic dissolution of the steel liner in areas with insufficient passivation. The penetrations were restored according to original design requirements. (author)

  13. Liner Service Network Design

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard

    . The research field of liner shipping network design is relatively young and many open research questions exists. Among others, a unified and rich mathematical model formulating the main characteristics of the business domain has not been clearly described and exact methods for such mathematical models...... management is of great concern to liner shippers as 70-80% of vessel round trips experience delays in at least one port. A novel mathematical model for handling a disruption using a series of recovery techniques is presented as the The Vessel Schedule Recovery Problem. The model has been applied to four real...... is based upon improving the constructed solution by applying an IP model as a large scale neighbourhood to each service in the network. The IP is based on estimating the benefit of inserting and removing port calls within a predefined neighborhood of candidate ports. Furthermore, the heuristic applies...

  14. Modeling, measuring, and mitigating instability growth in liner implosions on Z

    Science.gov (United States)

    Peterson, Kyle

    2015-11-01

    Electro-thermal instabilities result from non-uniform heating due to temperature dependence in the conductivity of a material. In this talk, we will discuss the role of electro-thermal instabilities on the dynamics of magnetically accelerated implosion systems. We present simulations that show electro-thermal instabilities form immediately after the surface material of a conductor melts and can act as a significant seed to subsequent magneto-Rayleigh-Taylor (MRT) instability growth. We discuss measurement results from experiments performed on Sandia National Laboratories Z accelerator to investigate signatures of electro-thermal instability growth on well-characterized initially solid aluminum or beryllium rods driven with a 20 MA, 100 ns risetime current pulse. These measurements show good agreement with electro-thermal instability simulations and exhibit larger instability growth than can be explained by MRT theory alone. Recent experiments have confirmed simulation predictions of dramatically reduced instability growth in solid metallic rods when thick dielectric coatings are used to mitigate density perturbations arising from the electro-thermal instability. These results provide further evidence that the inherent surface roughness of the target is not the dominant seed for the MRT instability, in contrast with most inertial confinement fusion approaches. These results suggest a new technique for substantially reducing the integral MRT growth in magnetically driven implosions. Indeed, recent results on the Z facility with 100 km/s Al and Be liner implosions show substantially reduced growth. These new results include axially magnetized, CH-coated beryllium liner radiographs in which the inner liner surface is observed to be remarkably straight and uniform at a radius of about 120 microns (convergence ratio ~20). Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under

  15. DT ignition in a Z pinch compressed by an imploding liner

    International Nuclear Information System (INIS)

    Bilbao, L.; Bernal, L.; Linhart, J.G.; Verri, G.

    2001-01-01

    It has been shown that an m=0 instability of a Z pinch carrying a current of the order of 10 MA with a rise time of less than 10 ns can generate a spark capable of igniting a fusion detonation in the adjacent DT plasma channel. A possible method for generating such currents, necessary for the implosion of an initial large radius, low temperature Z pinch, can be a radial implosion of a cylindrical fast liner. The problem has been addressed in previous publications without considering the role played by an initially impressed m=0 perturbation, a mechanism indispensable for the generation of a spark. The liner-Z pinch dynamics can be solved at several levels of physical model completeness. The first corresponds to a zero dimensional model in which the liner has a given mass per unit length and a zero thickness, the plasma is compressed adiabatically and is isotropic, and there are no energy losses or Joule heating. The second level is one dimensional. The Z pinch plasma is described by the full set of MHD, two-fluid equations. The liner is treated first as thin and incompressible, and subsequently it is assumed that it has a finite thickness and is composed of a heavy ion plasma, having an artificial but realistic equation of state. Both plasma and liner are considered uniform in the Z direction and only DT reactions are considered. It is shown that, given sufficient energy and speed of the liner, the Z pinch can reach a volume ignition. The third level is two dimensional. Plasma and liner are treated as in the second level but either the Z pinch or the liner is perturbed by an m=0 non-uniformity. Provided the liner energy is high enough and the initial m=0 perturbation is correctly chosen, the final neck plasma can act as a spark for DT ignition. It is also shown that the liner energy required for generating a spark and the subsequent detonation propagation are considerably less than in the case of volume ignition. (author)

  16. Formation of Imploding Plasma Liners for HEDP and MIF Applications - Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, Mark [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering. Dept. of Physics and Astronomy; Hsu, Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Witherspoon, F. Douglas [HyperV Technologies Corp., Chantilly, VA (United States); Cassibry, Jason [Univ. of Alabama, Huntsville, AL (United States); Bauer, Bruno S. [Univ. of Nevada, Reno, NV (United States)

    2015-04-27

    The goal of the plasma liner experiment (PLX) was to explore and demonstrate the feasibility of forming imploding spherical plasma liners that can reach High Energy Density (HED)-relevant (~ 0.1 Mbar) pressures upon stagnation. The plasma liners were to be formed by a spherical array of 30 – 36 railgun-driven hypervelocity plasma jets (Mach 10 – 50). Due to funding and project scope reductions in year two of the project, this initial goal was revised to focus on studies of individual jet propagation, and on two jet merging physics. PLX was a collaboration between a number of partners including Los Alamos National Laboratory, HyperV Technologies, University of New Mexico (UNM), University of Alabama, Huntsville, and University of Nevada, Reno. UNM’s part in the collaboration was primary responsibility for plasma diagnostics. Though full plasma liner experiments could not be performed, the results of single and two jet experiments nevertheless laid important groundwork for future plasma liner investigations. Though challenges were encountered, the results obtained with one and two jets were overwhelmingly positive from a liner formation point of view, and were largely in agreement with predictions of hydrodynamic models.

  17. A Base Integer Programming Model and Benchmark Suite for Liner-Shipping Network Design

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Alvarez, Fernando; Plum, Christian Edinger Munk

    2014-01-01

    . The potential for making cost-effective and energy-efficient liner-shipping networks using operations research (OR) is huge and neglected. The implementation of logistic planning tools based upon OR has enhanced performance of airlines, railways, and general transportation companies, but within the field......The liner-shipping network design problem is to create a set of nonsimple cyclic sailing routes for a designated fleet of container vessels that jointly transports multiple commodities. The objective is to maximize the revenue of cargo transport while minimizing the costs of operation...... sources of liner shipping for OR researchers in general. We describe and analyze the liner-shipping domain applied to network design and present a rich integer programming model based on services that constitute the fixed schedule of a liner shipping company. We prove the liner-shipping network design...

  18. A Study of Market Structure in Liner Shipping Under the Influence of Government Policies

    OpenAIRE

    Wong, Peter Chi Chung; Bamford, Colin

    2012-01-01

    The peculiar operational mode and involvement of international carriers\\ud granted liner operators special exemption from Anti-trust regulations\\ud globally. The changes of policy from USA and EU in recent years forbidden\\ud liner operators to form Liner Conference (LC) which seems to possess\\ud oligopoly power in the trade. This paper use the freight rate to verified the\\ud change of Government policies cannot stop the liner operators to form in\\ud their natural formation - Liner Conference.

  19. Analysis of Dual Mobility Liner Rim Damage Using Retrieved Components and Cadaver Models.

    Science.gov (United States)

    Nebergall, Audrey K; Freiberg, Andrew A; Greene, Meridith E; Malchau, Henrik; Muratoglu, Orhun; Rowell, Shannon; Zumbrunn, Thomas; Varadarajan, Kartik M

    2016-07-01

    The objective of this study was to assess the retentive rim of retrieved dual mobility liners for visible evidence of deformation from femoral neck contact and to use cadaver models to determine if anterior soft tissue impingement could contribute to such deformation. Fifteen surgically retrieved polyethylene liners were assessed for evidence of rim deformation. The average time in vivo was 31.4 months, and all patients were revised for reasons other than intraprosthetic dislocation. Liner interaction with the iliopsoas was studied visually and with fluoroscopy in cadaver specimens using a dual mobility system different than the retrieval study. For fluoroscopic visualization, a metal wire was sutured to the iliopsoas and wires were also embedded into grooves on the outer surface of the liner and the inner head. All retrievals showed evidence of femoral neck contact. The cadaver experiments showed that liner motion was impeded by impingement with the iliopsoas tendon in low flexion angles. When observing the hip during maximum hyperextension, 0°, 15°, and 30° of flexion, there was noticeable tenting of the iliopsoas caused by impingement with the liner. Liner rim deformation resulting from contact with the femoral neck likely begins during early in vivo function. The presence of deformation is indicative of a mechanism inhibiting mobility of the liner. The cadaver studies showed that liner motion could be impeded because of its impingement with the iliopsoas. Such soft tissue impingement may be one mechanism by which liner motion is routinely inhibited, which can result in load transfer from the neck to the rim. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Calculation of anchor forces on penetration liners for the reactor vessel Schmehausen (Germany)

    International Nuclear Information System (INIS)

    Roennert, J.K.

    1976-01-01

    Penetrations through the walls of the single cavity PCPV Prestressed Concrete Pressure Vessel for the 300 MW(e) reactor are lined with steel penetration liners welded to the liner of the cavity. For gas-tightness of the system the penetrations are closed by covers. To secure their integration with the concrete, the liners are anchored to it by means of shear studs and/or angles. Being embedded in concrete, over the full width of the walls, the liners are exposed to lateral and longitudinal concrete deformations causing forces on the anchors. The axial blow-out force due to the pressure of the coolant on the closures must also be transferred through the anchors to the concrete. In the design of anchored penetration liners stress analyses are performed to determine anchor forces under different loading conditions and at several ages of the PCPV. The present paper deals with the mathematical estimation of the anchor forces on the basis of given concrete deformations, temperature of liners, and pressure in the vessel by the method of replacing the penetration liners and their anchors by a spring model with linear stiffness characteristics for both the liner and the anchors. An example of the computations on a digital computer is shown. (author)

  1. A three-dimensional rupture analysis of steel liners anchored to concrete pressure and containment vessels

    International Nuclear Information System (INIS)

    Bangash, Y.

    1987-01-01

    Steel liners or plates are anchored to concrete pressure and containment vessels for nuclear and offshore facilities. Due to extreme loading conditions a liner may buckle due to the pull-out or shearing of anchors from the base metal and concrete. Under certain conditions attributed to loadings, liner metal deterioration and cracking of concrete behind the liner, the liner may fail by rupture. This paper presents a three-dimensional analysis of steel-concrete elements, using finite elements analysis in which a provision is made for liner instability, anchor strength and stiffness, concrete cracking and finally liner rupture. The analysis is tested first on an octagonal slab with and without an anchored steel liner. It is then extended to concrete pressure and containment vessels. The analytical results obtained are compared well with those available from the experimental tests and other sources. (author)

  2. Consideration of liners and covers in performance assessments

    Energy Technology Data Exchange (ETDEWEB)

    Phifer, Mark A. [Savannah River National Laboratory, Aiken, SC (United States); Seitz, Robert R. [Savannah River National Laboratory, Aiken, SC (United States); Suttora, Linda C. [USDOE Enviromental Management, Washington, DC (United States)

    2014-09-18

    On-site disposal cells are in use and being considered at several United States Department of Energy (USDOE) sites as the final disposition for large amounts of waste associated with cleanup of contaminated areas and facilities. These disposal cells are typically regulated by States and/or the U.S. Environmental Protection Agency under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in addition to having to comply with requirements in DOE Order 435.1, Radioactive Waste Management due to the radioactive waste. The USDOE-Environmental Management Office of Site Restoration formed a working group to foster improved communication and sharing of information for personnel associated with these CERCLA disposal cells and work towards more consistent assumptions, as appropriate, for technical and policy considerations related to CERCLA risk assessments and DOE Order 435.1 performance assessments in support of a Record of Decision and Disposal Authorization Statement, respectively. One of the issues considered by the working group, which is addressed in this report, was how to appropriately consider the performance of covers and liners/leachate collections systems in the context of a DOE Order 435.1 performance assessment (PA). This same information may be appropriate for consideration within CERCLA risk assessments for these facilities. These OSDCs are generally developed to meet hazardous waste (HW) disposal design standards under the Resource Conservation and Recovery Act (RCRA) as well as the DOE Order 435.1 performance based standards for disposal of radioactive waste. To meet the standards for HW, the facilities typically include engineered covers and liner/leachate collection systems. Thus, when considering such facilities in the context of a DOE Order 435.1 PA, there is a need to address the evolution of performance of covers and liner/leachate collection systems in the context of meeting a performance standard considering time

  3. Strength analyses of containment steel liner at the plasticity instability

    International Nuclear Information System (INIS)

    Klyashchitskij, V.I.; Golyakov, V.I.; Kostylev, V.I.; Margolin, B.Z.

    2003-01-01

    The steel liner of NPP containment plays the important role of a leak-tight contour preventing the possible releases of radioactive substances beyond the boundaries of the reactor building. However, so far in many cases an assessment of strain-stress state of the liner having initial imperfections of the shape was made with approximate methods. A new methodology for the analysis of the liner at the plasticity instability was developed at Atomenergoproekt institute in cooperation with specialists from other agencies. The methodology is based on code 'Termit'. Assessment of the critical strain was made taking into account possible presence of one or two defects: construction undercut or crack-like defect in a weld. On the base of the real structure analyses under any combinations of quasi-static loads the algorithm was developed for the computation of the liner. (author)

  4. Tissue Friendly Pendulum: Soft Liner to prevent Tissue Irritation

    Directory of Open Access Journals (Sweden)

    Siddharth Shashidhar Revankar

    2014-01-01

    Full Text Available Palatal mucosal irritation is commonly encountered with the Pendulum appliance. The efficiency of soft liners in reducing tissue irritation has been well documented in the field of prosthodontics. The following article describes an innovative technique where soft liner can be used to reduce palatal mucosal irritation caused by pendulum appliance.

  5. Deuterium Liner and Multiparameter Investigation of the Inverse Z-Pinch Formation Process

    CERN Document Server

    Bystritskii, Vyach M; Grebenyuk, V M; Parzhitsky, S S; Penkov, F M; Stolupin, V A; Boznyak, J; Gula, E; Dudkin, G N; Nechaev, B A; Padalko, V M; Mesyats, G A; Ratakhin, N A; Sorokin, S A

    2001-01-01

    A description of the methods and results of the measurements of the ion energy distribution of the deuterium liner accelerated in the inverse Z-pinch configuration are presented - the liner plasma is radially accelerated from the outward small radius. The knowledge of the experiment deuteron energy distribution is crucially important for correct interpretation of the results on the study of the dd-reaction at infralow collision energies using the liner plasma. Experiments were fulfilled in the HCEI (Tomsk, Russia) at a nanosecond pulsed high current generator (I=950 kA, pulse duration \\tau=80 ns). The hollow deuterium liner of 20 mm length was accelerated from the initial radius of \\sim 15 mm to 45 mm. Measurement of the liner characteristics was produced by means of the light detectors (detection of H_\\alpha and H_\\beta deuterium lines) and magnetic B-dot probes, placed on the various radii of the expanding liner. Besides, the measurement of the neutron radiation intensity due to reaction d+d\\to^{3}He+n was ...

  6. Landing Gear Door Liners for Airframe Noise Reduction

    Science.gov (United States)

    Jones, Michael G. (Inventor); Howerton, Brian M. (Inventor); Van De Ven, Thomas (Inventor)

    2014-01-01

    A landing gear door for retractable landing gear of aircraft includes an acoustic liner. The acoustic liner includes one or more internal cavities or chambers having one or more openings that inhibit the generation of sound at the surface and/or absorb sound generated during operation of the aircraft. The landing gear door may include a plurality of internal chambers having different geometries to thereby absorb broadband noise.

  7. Competitive Liner Shipping Network Design

    DEFF Research Database (Denmark)

    Karsten, Christian Vad

    .The contributions of this thesis cover modeling, methodology, and applications.The developed methods address operational (cargo routing), tactical (speed optimization and service selection), and strategic (network design) planning problems faced by liner shipping companies. Ultimately, the proposed methods help...... take the container transportation times that can be realized in the network nor the number of transshipments into consideration. This is mainly because the optimization problem is based on other transportation networks where these constraints are not decisive to the quality of the network. Furthermore......, the problem in itself is challenging to optimize due to its size and complexity. However, the field has seen crucial progress and is mature to include handling of competitiveness in the actual design of the network.As a liner shipping network is an organic entity, which is constantly changed to reflect...

  8. Pining for home: Studying crew homesickness aboard a cruise liner ...

    African Journals Online (AJOL)

    Research in Hospitality Management ... Crew homesickness should be seen as important by both shipboard and liner company management because it can ultimately impact on customer service experiences, and can be ameliorated by ... Keywords: homesickness, cruise-liner, crewmembers, shipboard hotel services ...

  9. An Improved Lubrication Model between Piston Rings and Cylinder Liners with Consideration of Liner Dynamic Deformations

    Directory of Open Access Journals (Sweden)

    Guoxing Li

    2017-12-01

    Full Text Available The friction pair of piston rings and cylinder liner is one of the most important friction couplings in an internal combustion engine. It influences engine efficiency and service life. Under the excitation of piston slaps, the dynamic deformation of cylinder liner is close to the surface roughness magnitudes, which can affect the friction and lubrication performance between the piston rings and cylinder assemblies. To investigate the potential influences of structural deformations to tribological behaviours of cylinder assemblies, the dynamic deformation of the inner surface due to pistons slaps is obtained by dynamic simulations, and then coupled into an improved lubrication model. Different from the traditional lubrication model which takes the pressure stress factor and shear stress factor to be constant, the model proposed in this paper calculated these factors in real time using numerical integration to achieve a more realistic simulation. Based on the improved piston rings and cylinder liner lubrication model, the minimum oil film thickness and friction force curves are obtained for an entire work cycle. It shows that the friction force obtained from the improved model manifests clear oscillations in each stoke, which is different from the smoothed profiles predicted traditionally. Moreover, the average amplitude of the friction forces also shows clear reduction.

  10. Super-fast multi-wire liner implosion physics study at Angara-5-1

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrov, V V; Branitsky, A V; Volkov, G S; Fedulov, M V; Grabovsky, E V; Nedoseev, L; Oleinik, G M; Samokhin, A N; Sasorov, F P.V.; Smirnov, V P; Frolov, I N; Zaitzev, V I; Zurin, M V [GSC Troitsk Institute for Innovation and Fusion Research, Troitsk, Moscow region (Russian Federation); Spielman, R B; Deeney, C [Sandia National Labs., Albuquerque, NM (United States)

    2000-07-01

    The temporally dragged plasma production (TDPP) from dense substance of tungsten wire occurs during multi-wire-liner implosion. TDPP is the typical feature of wire liner implosion. In spite of plasma filling of the initial liner cavity, a narrow pulse (up to 6 ns) of X rays is radiated for an 0.3-mm inter-wire gap. (authors)

  11. Super-fast multi-wire liner implosion physics study at Angara-5-1

    International Nuclear Information System (INIS)

    Alexandrov, V.V.; Branitsky, A.V.; Volkov, G.S.; Fedulov, M.V.; Grabovsky, E.V.; Nedoseev, L.; Oleinik, G.M.; Samokhin, A.N.; Sasorov, F.P.V.; Smirnov, V.P.; Frolov, I.N.; Zaitzev, V.I.; Zurin, M.V.; Spielman, R.B.; Deeney, C.

    2000-01-01

    The temporally dragged plasma production (TDPP) from dense substance of tungsten wire occurs during multi-wire-liner implosion. TDPP is the typical feature of wire liner implosion. In spite of plasma filling of the initial liner cavity, a narrow pulse (up to 6 ns) of X rays is radiated for an 0.3-mm inter-wire gap. (authors)

  12. Simulating Ice Shelf Response to Potential Triggers of Collapse Using the Material Point Method

    Science.gov (United States)

    Huth, A.; Smith, B. E.

    2017-12-01

    Weakening or collapse of an ice shelf can reduce the buttressing effect of the shelf on its upstream tributaries, resulting in sea level rise as the flux of grounded ice into the ocean increases. Here we aim to improve sea level rise projections by developing a prognostic 2D plan-view model that simulates the response of an ice sheet/ice shelf system to potential triggers of ice shelf weakening or collapse, such as calving events, thinning, and meltwater ponding. We present initial results for Larsen C. Changes in local ice shelf stresses can affect flow throughout the entire domain, so we place emphasis on calibrating our model to high-resolution data and precisely evolving fracture-weakening and ice geometry throughout the simulations. We primarily derive our initial ice geometry from CryoSat-2 data, and initialize the model by conducting a dual inversion for the ice viscosity parameter and basal friction coefficient that minimizes mismatch between modeled velocities and velocities derived from Landsat data. During simulations, we implement damage mechanics to represent fracture-weakening, and track ice thickness evolution, grounding line position, and ice front position. Since these processes are poorly represented by the Finite Element Method (FEM) due to mesh resolution issues and numerical diffusion, we instead implement the Material Point Method (MPM) for our simulations. In MPM, the ice domain is discretized into a finite set of Lagrangian material points that carry all variables and are tracked throughout the simulation. Each time step, information from the material points is projected to a Eulerian grid where the momentum balance equation (shallow shelf approximation) is solved similarly to FEM, but essentially treating the material points as integration points. The grid solution is then used to determine the new positions of the material points and update variables such as thickness and damage in a diffusion-free Lagrangian frame. The grid does not store

  13. Contoured-gap coaxial guns for imploding plasma liner experiments

    Science.gov (United States)

    Witherspoon, F. D.; Case, A.; Brockington, S.; Cassibry, J. T.; Hsu, S. C.

    2014-10-01

    Arrays of supersonic, high momentum flux plasma jets can be used as standoff compression drivers for generating spherically imploding plasma liners for driving magneto-inertial fusion, hence the name plasma-jet-driven MIF (PJMIF). HyperV developed linear plasma jets for the Plasma Liner Experiment (PLX) at LANL where two guns were successfully tested. Further development at HyperV resulted in achieving the PLX goal of 8000 μg at 50 km/s. Prior work on contoured-gap coaxial guns demonstrated an approach to control the blowby instability and achieved substantial performance improvements. For future plasma liner experiments we propose to use contoured-gap coaxial guns with small Minirailgun injectors. We will describe such a gun for a 60-gun plasma liner experiment. Discussion topics will include impurity control, plasma jet symmetry and topology (esp. related to uniformity and compactness), velocity capability, and techniques planned for achieving gun efficiency of >50% using tailored impedance matched pulse forming networks. Mach2 and UAH SPH code simulations will be included. Work supported by US DOE DE-FG02-05ER54810.

  14. Laboratory tests of bentonite stabilization of bottom sediments from a dam reservoir in relation to their usage in municipal solid waste landfill liners

    Directory of Open Access Journals (Sweden)

    Karolina Koś

    2016-09-01

    Full Text Available Geotechnical parameters of bottom sediments from a dam reservoir (Rzeszowski Reservoir, Poland with bentonite addition are presented in the paper. Tests were carried out in the aspect of the possible usage of sediments as a material for soil liners in Municipal Solid Waste Landfill. Mentioned sediments did not fulfilled the permeability and plasticity criteria defined for soils that can be used in liners. The bentonite addition caused, among other things, a decrease in permeability coefficient and increase in plasticity index. Based on the carried out tests it was stated that sediments with 6% addition of bentonite fulfil all requirements and can be used for liners in MSWL.

  15. An integer programming model and benchmark suite for liner shipping network design

    DEFF Research Database (Denmark)

    Løfstedt, Berit; Alvarez, Jose Fernando; Plum, Christian Edinger Munk

    effective and energy efficient liner shipping networks using operations research is huge and neglected. The implementation of logistic planning tools based upon operations research has enhanced performance of both airlines, railways and general transportation companies, but within the field of liner......Maritime transportation is accountable for 2.7% of the worlds CO2 emissions and the liner shipping industry is committed to a slow steaming policy to provide low cost and environmentally conscious global transport of goods without compromising the level of service. The potential for making cost...... along with a rich integer programming model based on the services, that constitute the fixed schedule of a liner shipping company. The model may be relaxed as well as decomposed. The design of a benchmark suite of data instances to reflect the business structure of a global liner shipping network...

  16. Classification of Ship Routing and Scheduling Problems in Liner Shipping

    DEFF Research Database (Denmark)

    Kjeldsen, Karina Hjortshøj

    2011-01-01

    This article provides a classification scheme for ship routing and scheduling problems in liner shipping in line with the current and future operational conditions of the liner shipping industry. Based on the classification, the literature is divided into groups whose main characteristics...

  17. Acoustic Panel Liner for an Engine Nacelle

    Science.gov (United States)

    Jones, Michael G. (Inventor); Nark, Douglas M. (Inventor); Ayle, Earl (Inventor); Ichihashi, Fumitaka (Inventor)

    2016-01-01

    An acoustic panel liner includes a face sheet, back plate, and liner core positioned there-between, which may be used in an engine nacelle. Elongated chambers contain variable amounts of septa at a calibrated depth or depths. The septa may have varying DC flow resistance. The chambers may have a hexagonal or other polygonal cross sections. The septa, such as mesh caps, may be bonded to an inner wall of a corresponding chamber. The insertion depths may be the same or different. If different, the pattern of distribution of the depths may be randomized.

  18. A Finite Element Theory for Predicting the Attenuation of Extended-Reacting Liners

    Science.gov (United States)

    Watson, W. R.; Jones, M. G.

    2009-01-01

    A non-modal finite element theory for predicting the attenuation of an extended-reacting liner containing a porous facesheet and located in a no-flow duct is presented. The mathematical approach is to solve separate wave equations in the liner and duct airway and to couple these two solutions by invoking kinematic constraints at the facesheet that are consistent with a continuum theory of fluid motion. Given the liner intrinsic properties, a weak Galerkin finite element formulation with cubic polynomial basis functions is used as the basis for generating a discrete system of acoustic equations that are solved to obtain the coupled acoustic field. A state-of-the-art, asymmetric, parallel, sparse equation solver is implemented that allows tens of thousands of grid points to be analyzed. A grid refinement study is presented to show that the predicted attenuation converges. Excellent comparison of the numerically predicted attenuation to that of a mode theory (using a Haynes 25 metal foam liner) is used to validate the computational approach. Simulations are also presented for fifteen porous plate, extended-reacting liners. The construction of some of the porous plate liners suggest that they should behave as resonant liners while the construction of others suggest that they should behave as broadband attenuators. In each case the finite element theory is observed to predict the proper attenuation trend.

  19. Failure mechanisms and closed reduction of a constrained tripolar acetabular liner.

    Science.gov (United States)

    Robertson, William J; Mattern, Christopher J; Hur, John; Su, Edwin P; Pellicci, Paul M

    2009-02-01

    Unlike traditional bipolar constrained liners, the Osteonics Omnifit constrained acetabular insert is a tripolar device, consisting of an inner bipolar bearing articulating within an outer, true liner. Every reported failure of the Omnifit tripolar implant has been by failure at the shell-bone interface (Type I failure), failure at the shell-liner interface (Type II failure), or failure of the locking mechanism resulting in dislocation of the bipolar-liner interface (Type III failure). In this report we present two cases of failure of the Omnifit tripolar at the bipolar-femoral head interface. To our knowledge, these are the first reported cases of failure at the bipolar-femoral head interface (Type IV failure). In addition, we described the first successful closed reduction of a Type IV failure.

  20. Flap Side Edge Liners for Airframe Noise Reduction

    Science.gov (United States)

    Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

    2014-01-01

    One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

  1. Enhanced safety in the storage of fissile materials

    International Nuclear Information System (INIS)

    Williams, G.E.; Alvares, N.J.

    1978-01-01

    An inexpensive boron-loaded liner of epoxy resin for fissile-material storage containers was developed that can be easily fabricated of readily available, low-cost materials. Computer calculations indicate reactivity will be reduced substantially if this neutron-absorbing liner is added to containers in a typical storage array. These calculations compare favorably with neutron-attenuation experiments with thermal and fission neutron spectra, and tests at the Fire Test Facility indicate the epoxy resin will survive extreme environmental and accident conditions. The fire-resistant and insulating properties of the epoxy-resin liner further augment its ability to protect fissile materials. Boron-loaded epoxy resin is adaptable to many tasks but is particularly useful for providing enhanced criticality safety in the packaging and storage of fissile materials

  2. Improved Broadband Liner Optimization Applied to the Advanced Noise Control Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.; Ayle, Earl; Ichihashi, Fumitaka

    2014-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more desirable. This paper describes improvements to a previously established broadband acoustic liner optimization process using the Advanced Noise Control Fan rig as a demonstrator. Specifically, in-duct attenuation predictions with a statistical source model are used to obtain optimum impedance spectra over the conditions of interest. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom designs are carried through design, fabrication, and testing to validate the efficacy of the design process. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of these liner designs. This study also provides an application for demonstrating the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

  3. Characterization of the Migration of Hop Volatiles into Different Crown Cork Liner Polymers and Can Coatings.

    Science.gov (United States)

    Wietstock, Philip C; Glattfelder, Richard; Garbe, Leif-Alexander; Methner, Frank-Jürgen

    2016-04-06

    Absorption of hop volatiles by crown cork liner polymers and can coatings was investigated in beer during storage. All hop volatiles measured were prone to migrate into the closures, and the absorption kinetics was demonstrated to fit Fick's second law of diffusion well for a plane sheet. The extent and rate of diffusion were significantly dissimilar and were greatly dependent upon the nature of the volatile. Diffusion coefficients ranged from 1.32 × 10(-5) cm(2)/day (limonene) to 0.26 × 10(-5) cm(2)/day (α-humulene). The maximum amounts absorbed into the material at equilibrium were in the following order: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With the application of low-density polyethylene (LDPE) liners with oxygen-scavenging functionality, oxygen-barrier liners made up from high-density polyethylene (HDPE) or liner polymers from a different manufacturer had no significant effect on the composition of hop volatiles in beers after prolonged storage of 55 days; however, significantly higher amounts of myrcene and limonene were found in the oxygen-barrier-type crown cork, while all other closures behaved similarly. Can coatings were demonstrated to absorb hop volatiles in a similar pattern as crown corks but to a lesser extent. Consequently, significantly higher percentages of myrcene were found in the beers.

  4. Writing and Music: Album Liner Notes

    Directory of Open Access Journals (Sweden)

    Dean Leonard Biron

    2011-09-01

    Full Text Available A deceptive aspect of the ‘writing about music is like dancing about architecture’ cliché is the function of the preposition ‘about’. Literature and music, dance and architecture, painting and film – all are discrete aesthetic forms that nonetheless simultaneously feed off and provide nourishment for each other as part of art’s perpetual drive toward diversity and innovation. Nowhere is the aptness of the association between writing and music more obvious than in the phenomenon of album liner notes. Rather than merely an attempt at describing or translating musical experience, liner notes contribute to the dialogue between composer and listener and are a significant part of the culture of contemporary music.

  5. Key variables influencing patterns of lava dome growth and collapse

    Science.gov (United States)

    Husain, T.; Elsworth, D.; Voight, B.; Mattioli, G. S.; Jansma, P. E.

    2013-12-01

    Lava domes are conical structures that grow by the infusion of viscous silicic or intermediate composition magma from a central volcanic conduit. Dome growth can be characterized by repeated cycles of growth punctuated by collapse, as the structure becomes oversized for its composite strength. Within these cycles, deformation ranges from slow long term deformation to sudden deep-seated collapses. Collapses may range from small raveling failures to voluminous and fast-moving pyroclastic flows with rapid and long-downslope-reach from the edifice. Infusion rate and magma rheology together with crystallization temperature and volatile content govern the spatial distribution of strength in the structure. Solidification, driven by degassing-induced crystallization of magma leads to the formation of a continuously evolving frictional talus as a hard outer shell. This shell encapsulates the cohesion-dominated soft ductile core. Here we explore the mechanics of lava dome growth and failure using a two-dimensional particle-dynamics model. This meshless model follows the natural evolution of a brittle carapace formed by loss of volatiles and rheological stiffening and avoids difficulties of hour-glassing and mesh-entangelment typical in meshed models. We test the fidelity of the model against existing experimental and observational models of lava dome growth. The particle-dynamics model follows the natural development of dome growth and collapse which is infeasible using simple analytical models. The model provides insight into the triggers that lead to the transition in collapse mechasnism from shallow flank collapse to deep seated sector collapse. Increase in material stiffness due to decrease in infusion rate results in the transition of growth pattern from endogenous to exogenous. The material stiffness and strength are strongly controlled by the magma infusion rate. Increase in infusion rate decreases the time available for degassing induced crystallization leading to a

  6. Effect of liner non-uniformity on plasma instabilities in an inverse Z-pinch magnetized target fusion system: liner-on-plasma simulations and comparison with linear stability analysis

    International Nuclear Information System (INIS)

    Subhash, P V; Madhavan, S; Chaturvedi, S

    2008-01-01

    Two-dimensional (2D) magneto-hydrodynamic (MHD) liner-on-plasma computations have been performed to study the growth of instabilities in a magnetized target fusion system involving the cylindrical compression of an inverse Z-pinch target plasma by a metallic liner. The growth of modes in the plasma can be divided into two phases. During the first phase, the plasma continues to be Kadomtsev stable. The dominant mode in the liner instability is imposed upon the plasma in the form of a growing perturbation. This mode further transfers part of its energy to its harmonics. During the second phase, however, non-uniform implosion of the liner leads to axial variations in plasma quantities near the liner-plasma interface, such that certain regions of the plasma locally violate the Kadomtsev criteria. Further growth ofthe plasma modes is then due to plasma instability. The above numerical study has been complemented with a linear stability analysis for the plasma, the boundary conditions for this analysis being obtained from the liner-on-plasma simulation. The stability of axisymmetric modes in the first phase is found to satisfy the Kadomtsev condition Q 0 1 modes, using equilibrium profiles from the 2D MHD study, shows that their growth rates can exceed those for m=0 by as much as an order of magnitude

  7. Comparative evaluation of tensile bond strength of silicone-based denture liners after thermocycling and surface treatment

    Directory of Open Access Journals (Sweden)

    Harsimran Kaur

    2015-01-01

    Full Text Available Purpose: To examine, evaluate, and compare the tensile bond strength of two silicone-based liners; one autopolymerizing and one heat cured, when treated with different chemical etchants to improve their adhesion with denture base resin. Materials and Methods: Hundred and sixty test specimens of heat-cured polymethyl methacrylate (PMMA were fabricated; out of which 80 specimens were tested for tensile bond strength after bonding it to autopolymerizing resilient liner (Ufigel P and rest 80 to heat-cured resilient liner (Molloplast B. Each main group was further divided into four subgroups of 20 specimens each, one to act as a control and three were subjected to surface treatment with different chemical etchants namely dichloromethane, MMA monomer, and chloroform. The two silicone-based denture liners were processed between 2 PMMA specimens (10 mm × 10 mm × 40 mm in the space provided by a spacer of 3 mm, thermocycled (5-55°C for 500 cycles, and then their tensile strength measurements were done in the universal testing machine. Results: One-way ANOVA technique showed a highly significant difference in the mean tensile bond strength values for all the groups. The Student′s t-test computed values of statistics for the compared groups were greater than the critical values both at 5% and at 1% levels. Conclusion: Surface treatment of denture base resin with chemical etchants prior to the application of silicone-based liner (Ufigel P and Molloplast-B increased the tensile bond strength. The increase was the highest with specimens subjected to 180 s of MMA surface treatment and the lowest with control group specimens.

  8. Applied algorithm in the liner inspection of solid rocket motors

    Science.gov (United States)

    Hoffmann, Luiz Felipe Simões; Bizarria, Francisco Carlos Parquet; Bizarria, José Walter Parquet

    2018-03-01

    In rocket motors, the bonding between the solid propellant and thermal insulation is accomplished by a thin adhesive layer, known as liner. The liner application method involves a complex sequence of tasks, which includes in its final stage, the surface integrity inspection. Nowadays in Brazil, an expert carries out a thorough visual inspection to detect defects on the liner surface that may compromise the propellant interface bonding. Therefore, this paper proposes an algorithm that uses the photometric stereo technique and the K-nearest neighbor (KNN) classifier to assist the expert in the surface inspection. Photometric stereo allows the surface information recovery of the test images, while the KNN method enables image pixels classification into two classes: non-defect and defect. Tests performed on a computer vision based prototype validate the algorithm. The positive results suggest that the algorithm is feasible and when implemented in a real scenario, will be able to help the expert in detecting defective areas on the liner surface.

  9. Effect of radiation losses on the compression of hydrogen by imploding solid liners

    International Nuclear Information System (INIS)

    Hussey, T.W.; Kiuttu, G.F.; Degnan, J.H.; Peterkin, R.E.; Smith, G.A.; Turchi, P.J.

    1996-01-01

    Quasispherical solid liner implosions with little or no instability growth have been achieved experimentally. Applications for such implosions include the uniform, shock-free compression of some sort of on-axis target. One proposed means of obtaining such compression is to inject a 1 eV hydrogen plasma working fluid between the liner and the target, and imploding the liner around it. the high initial temperature assures that the sound speed within the liner is always greater than the inner surface implosion velocity of the liner, and the initial density is chosen so that the volume of the working fluid at peak compression is sufficiently large so that perfectly spherical convergence of the liner is not required. One concern with such an approach is that energy losses associated with ionization and radiation will degrade the effective gamma of the compression. To isolate and, therefore, understand these effects the authors have developed a simple zero-dimensional model for the liner implosion that accurately accounts for the shape and thickness of the liner as it implodes and compresses the working fluid. Based on simple considerations they make a crude estimate of the range of initial densities of interest for this technique. They then observe that within this density rage, for the temperatures of interest, the lines are strongly self-absorbed so that the transport of radiation is dominated by bound-free and free-free processes

  10. The Logistical Challenges of the SpaceLiner Concept

    OpenAIRE

    van Foreest, Arnold; Sippel, Martin

    2008-01-01

    The SpaceLiner concept developed at DLR combines extremely fast transport (90 minutes from Europe to Australia) with the experience of Space flight. As such it is different from the spaceflight which focuses exclusively on space tourism but it combines space tourism with for example business travel. The SpaceLiner is designed to carry 50 passengers in suborbital flight. The conceptual technical design presents some challenges which have already been partially investigated at DLR [1]. However,...

  11. Rehabilitation of underwater pipeline with liner; Reabilitacao de aqueduto submarino com liner: multiplas vantagens e aplicacoes

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Roberto S.; Oliveira, Jose N. de; Urtiga, Rogerio L.; Witt, R. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The system of water injection in XAREU oil production field has an water pipeline sizing 4'' of diameter, between the offshore platform PXA-1 and another PXA-2, that it transfers 165 m{sup 3}/d of salt water for pressurization of the reservoir through the injection well Xareu-23. This water pipeline always presented high degree of corrosion needing frequently installation of cramps to eliminate leakages. After evaluating the costs we conclude that the more attractive it would be the installation of a liner than the launching of a new water pipeline. For the installation of a new water pipeline we would need the approval of IBAMA and of a great number of resources for the substitution of that pipeline. In spite of treating of an unpublished service between two offshore platforms we chose for the installation of a liner, because we had a great technological domain in this service in onshore oil production facilities with many pipelines recovered with this technique. We had to revise all of the procedures so that there was not any surprise to make unfeasible this service. The installation of the system liner, consisted of an internal coating 'in situ' through the insert of plastic tubes(high density polyethylene-HDPE), that it forms a barrier between the pipeline and the transported fluid. (author)

  12. Design, engineering and evaluation of refractory liners for slagging gasifiers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    deTineo, B J; Booth, G; Firestone, R F; Greaves, M J; Hales, C; Lamoureux, J P; Ledford, R R

    1982-08-01

    The contract for this program was awarded at the end of September 1978. Work was started on 1 October 1978, on Tasks A, B, and E. Task A, Conceptual Liner Designs, and Task B, Test System Design and Construction, were completed. Task C, Liner Tests, and Task D, Liner Design Evaluation, were to begin upon completion of Task B. Task E, Liner Model Development, is inactive after an initial data compilation and theoretical model development effort. It was to be activated as soon as data were available from Task D. Task F, Liner Design Handbook, was active along with Task A since the reports of both tasks were to use the same format. At this time, Tasks C, D, and F are not to be completed since funding of this project was phased out by DOE directive. The refractory text facility, which was constructed, was tested and found to perform satisfactorily. It is described in detail, including a hazard analysis which was performed. (LTN)

  13. Risk assessment for the transportation of radioactive zeolite liners

    International Nuclear Information System (INIS)

    1982-01-01

    The risk is estimated for the shipment of radioactive zeolite liners in support of the Zeolite Vitrification Demonstration Program currently underway at Pacific Northwest Laboratory under the sponsorship of the US Department of Energy. This program will establish the feasibility of zeolite vitrification as an effective means of immobilizing high-specific-activity wastes. In this risk assessment, it is assumed that two zeolite liners, each loaded around July 1, 1981 to 60,000 Ci, will be shipped by truck around January 1, 1982. However, to provide a measure of conservatism, each liner is assumed to initially hole 70,000 Ci, with the major radioisotopes as follow: 90 Sr = 3000 Ci, 134 Cs = 7000 Ci, 137 Cs = 60,000 Ci. Should shipment take place with essentially no delay after initial loading (regardless of loading date), the shipment loading would be only 2.7% higher than that for the assumed six-month delay. This would negligibly affect the overall risk. As a result of this risk assessment, it is concluded that the transport of the radioactive zeolite liners from TMI to PNL by truck can be conducted at an insignificant level of risk to the public

  14. The effect of surface roughness on the performances of liner-piston ...

    African Journals Online (AJOL)

    The effect of surface roughness on the performances of liner-piston ring contact in internal combustion engine. ... The surface roughness between the liner and the piston rings, plays an ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  15. A new approach to the design of LMFBR liners

    International Nuclear Information System (INIS)

    Polentz, L.M.

    1980-01-01

    An advance in the state-of-the-art of LMFBR liners which permits notable savings in construction costs without any sacrifice of safety is described. The application of the new design concept to the rework of the upper reactor vault liner of the FFTF is discussed. Factors which affect the application of the new design approach to other LMFBRs are delineated and discussed. (author)

  16. Filling material for a buried cavity in a collapse area using light-weighted foam and active feldspar

    Science.gov (United States)

    Cho, Jin Woo; Lee, Ju-hyoung; Kim, Sung-Wook; Choi, Eun-Kyeong

    2017-04-01

    Concrete which is generally used as filling material for a buried cavity has very high strength but significantly high self-load is considered its disadvantage. If it is used as filling material, the second collapse due to additional load, causing irreversible damage. If light-weighted foam and active feldspar are used to solve this problem, the second collapse can be prevented by reducing of self-load of filling material. In this study, the specimen was produced by mixing light-weighted foam, active feldspar and cement, and changes in the density, unconfined compressive strength and hydraulic conductivity were analyzed. Using the light-weighted foam could enable the adjustment of density of specimen between 0.5 g/cm3 and 1.7 g/cm3, and if the mixing ratio of the light-weighted foam increases, the specimen has more pores and smaller range of cross-sectional area. It is confirmed that it has direct correlation with the density, and if the specimen has more pores, the density of the specimen is lowered. The density of the specimen influences the unconfined compressive strength and the hydraulic conductivity, and it was also confirmed that the unconfined compressive strength could be adjusted between 0.6 MPa and 8 MPa and the hydraulic conductivity could be adjusted between 10-9cm/sec and 10-3cm/sec. These results indicated that we can adjust unconfined compressive strength and hydraulic conductivity of filling materials by changing the mixing amount of lightweight-weighted foam according to the requirements of the field condition. Keywords: filling material, buried cavity, light-weighted foam, feldspar Acknowledgement This research was supported by a Grant from a Strategic Research Project (Horizontal Drilling and Stabilization Technologies for Urban Search and Rescue (US&R) Operation) funded by the Korea Institute of Civil Engineering and Building Technology.

  17. CT of lobar collapse

    International Nuclear Information System (INIS)

    Suh, D. C.; Im, J. G.; Park, J. H.; Han, M. C.

    1987-01-01

    The computed tomographic (CT) findings of labor collapse are analysed in an attempt to evaluate the patterns of labor collapse and to get the helpful signs in differentiation between benign and malignant causes of collapse. 43 cases of labor collapse with or without endobronchial obstruction were reviewed. In 29 of 43 cases the collapses were caused by lung cancer. Benign causes of labor collapse included tuberculosis(10), broncholith(2), organizing pneumonia(1) and hamartoma(1). The helpful signs favoring malignant cause of the labor collapse were proximal bulging of the collapsed lobe, low density mass within the collapsed lung, and endobronchial lesion. Above described differential findings were especially applicable in cases of upper lobe collapse

  18. Acoustic Liner Drag: Measurements on Novel Facesheet Perforate Geometries

    Science.gov (United States)

    Howerton, Brian M.; Jones, Michael G.

    2016-01-01

    Interest in characterization of the aerodynamic drag of acoustic liners has increased in the past several years. This paper details experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of several perforate-over-honeycomb liner configurations at flow speeds of centerline flow Mach number equals 0.3 and 0.5. Various perforate geometries and orientations are investigated to determine their resistance factors using a static pressure drop approach. Comparison of these resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 hertz at source sound pressure levels of 140 and 150 decibels. Educed impedance and attenuation spectra are used to determine the impact of variations in perforate geometry on acoustic performance.

  19. COVE-1: a finite difference creep collapse code for oval fuel pin cladding material

    International Nuclear Information System (INIS)

    Mohr, C.L.

    1975-03-01

    COVE-1 is a time-dependent incremental creep collapse code that estimates the change in ovality of a fuel pin cladding tube. It uses a finite difference method of solving the differential equations which describe the deflection of the tube walls as a function of time. The physical problem is nonlinear, both with respect to geometry and material properties, which requires the use of an incremental, analytical, path-dependent solution. The application of this code is intended primarily for tubes manufactured from Zircaloy. Therefore, provision has been made to include some of the effects of anisotropy in the flow equations for inelastic incremental deformations. 10 references. (U.S.)

  20. Field performance assessment of synthetic liners for uranium tailings ponds: a status report

    International Nuclear Information System (INIS)

    Mitchell, D.H.; Spanner, G.E.

    1984-03-01

    The objective of this study is to provide a database to support US Nuclear Regulatory Commission (NRC) licensing of uranium tailings leachate isolation impoundments. This objective is being accomplished by determining the effectiveness of design, installation, and quality assurance practices associated with uranium mill tailings impoundments with flexible membrane liners. The program includes testing of chemical resistance and physical performance of liners, leak detection systems, and seam inspection techniques. This report presents the status of the program through September 1983. The report addresses impoundment design, installation, and inspection techniques used by the uranium milling industry. To determine the relative successes of these techniques, information has been collected from consultants, mill operators, and the synthetic liner industry. Progress in experimental tasks on chemical resistance of liners, physical properties of liners, and nondestructive examination of seams is reported. 25 references, 9 figures, 13 tables

  1. Follow up of test areas with FSS liners. Gaerstad and Sofielund landfills; Uppfoeljning av provytor med taetskikt av FSA. Gaerstad deponi och Sofielunds deponi

    Energy Technology Data Exchange (ETDEWEB)

    Laendell, Maerta; Carling, Maria; Haakansson, Karsten; Myrhede, Elke; Svensson, Bo

    2009-03-19

    In the coming years, a large number of landfills will be closed as a result of new environmental legislation and more stringent requirements. The availability of suitable material for covering and sealing is limited, especially in large urban areas. Sludge and ash are potentially useful materials for this purpose. The project 'Covering landfill with sludge and ash' was carried out from 2003 to 2005. The project involved the establishment and monitoring of different test areas having liners (sealing layers) of sewage sludge and fly ash. The experience gained from this project has also been used in the development of guidelines for using fly-ash-stabilised sewage sludge (FSS) as a liner. In the current project, two test areas have been monitored for a three-year period. Investigations have focused on the permeability of the materials, chemical properties of both runoff water and percolating water, resistance to decomposition, subsidence/compaction, strength, etc. The project was financed by Vaermeforsk, Svensk Vatten Utveckling and the two participating facilities (Tekniska Verken in Linkoeping and SRV Aatervinning in Huddinge). The study was carried out by Geo Innova in collaboration with both facilities, and the Department for Water and Environmental Studies at Linkoeping University. The project involved sampling and analysis of water, pore gas and solid material. In the field, subsidence and water levels have been measured. The results have been compared with the guideline levels for surface water, between different sampling and measurement locations (above and below the liner, with and without drainage, steep and flat areas, etc), and at different times. The results show that the FSS liner is impermeable. The requirement for landfills for non-hazardous waste is satisfied; in some cases the permeability is on a par with the requirement for hazardous waste landfills. Some decomposition of the material occurs, as indicated by the detection of methane and

  2. Some features of liners convergence accelerated with the help of powerful EMGs

    Energy Technology Data Exchange (ETDEWEB)

    Grinevich, B E; Chernyshev, V K; Buzin, V N; Petrukhin, A A; Zarionov, E I [All-Russian Science and Research Institute of Experimental Physics, Sarov (Russian Federation)

    1997-12-31

    Described are experiments devoted to the convergence of condensed liners, non-exploding during the flight, under the influence of current. To feed the liners with a power of not less than 25 MJ, powerful explosive magnetic 1000 mm diameter generators were used. Interesting effects arising during the liners flight were observed. A comparison of experimental results and calculations carried out using the SMOG program, showed that the calculated current was 20% higher than the observed current. At the same time, the experimental speed exceeded the rated speed calculated according to the known current curve. The asymmetry of current distribution along the liners was defined depending on time. Some conclusions concerning the current spread symmetry are made. (author). 4 figs., 1 ref.

  3. Critical interfaces in geosynthetic multilayer liner system of a landfill

    Directory of Open Access Journals (Sweden)

    Qian Xuede

    2008-12-01

    Full Text Available This study is to identify the critical interface in a geosynthetic multilayer liner system by examining the effects of the interface shear strength of liner components, leachate level, leachate buildup cases, and peak and residual interface strengths. According to current landfill design procedures, conducting stability analysis along the same interface at both the back slope and base may result in a non-conservative result. The critical interfaces with the minimum factor of safety are generally found at different locations along the back slope and base. The critical interface for a multilayer liner system cannot simply be assumed during stability analysis. It can shift from one interface to another with changes in the leachate level and with different leachate buildup cases. The factor of safety for an interface with a high friction angle and low apparent cohesion generally drops much more quickly than it does under inverse conditions when the leachate level increases. The failure interface in a liner system under residual conditions is usually different from the failure interface under peak conditions.

  4. Engineering design of the LINUS-O prototype liner implosion system

    International Nuclear Information System (INIS)

    Turchi, P.J.; Jenkins, D.J.; Warnick, W.L.; Ford, R.D.; Lanham, R.; Cooper, A.L.; Burton, R.L.

    1977-01-01

    The development of imploding liner flux compression techniques for application to compact, pulsed fusion reactors has led to the concept of rotating liquid metal implosions driven by free-pistons. In hydrodynamic model tests, such implosions have been demonstrated to be stable and reversible, allowing serious consideration of a new class of pulsed fusion reactor. The next step is to demonstrate repetitive, controlled operation at high energy densities with liquid metal liners, for which peak magnetic field levels approaching a megagauss are possible. A prototype controlled liner implosion system, LINUS-O, has been designed and is under construction. During operation, the annular driving-piston surrounding the implosion chamber is displaced axially by the action of pulsed high pressure gas at several hundred atmospheres. The piston and chamber rotate at 2100 RPM, allowing the free inside surface of the liner to implode stably from 30 cm diameter to 1.0 cm at turnaround. The experimental facility is described and engineering problems associated with design and operation of controlled high energy implosion systems are discussed

  5. Design of the ZTH vacuum liner

    International Nuclear Information System (INIS)

    Prince, P.P.; Dike, R.S.

    1987-01-01

    The current status of the ZTH vacuum liner design is covered by this report. ZTH will be the first experiment to be installed in the CPRF (Confinement Physics Research Facility) at the Los Alamos National Laboratory and is scheduled to be operational at the rated current of 4 MA in 1992. The vacuum vessel has a 2.4 m major radius and a 40 cm minor radius. Operating parameters which drive the vacuum vessel mechanical design include a 300 C bakeout temperature, an armour support system capable of withstanding 25 kV, a high toroidal resistance, 1250 kPa magnetic loading, a 10 minute cycle time, and high positional accuracy with respect to the conducting shell. The vacuum vessel design features which satisfy the operating parameters are defined. The liner is constructed of Inconel 625 and has a geometry which alternates sections of thin walled bellows with rigid ribs. These composite sections span between pairs of the 16 diagnostic stations to complete the torus. The thin bellows sections maximize the liner toroidal resistance and the ribs provide support and positional accuracy for the armour in relation to the conducting shell. Heat transfer from the vessel is controlled by a blanket wrap of ceramic fiber insulation and the heat flux is dissipated to a water cooling jacket in the conducting shell

  6. Application of the Ta liner technique to produce Ca beams at INFN-Legnaro National Laboratories (INFN-LNL)

    Energy Technology Data Exchange (ETDEWEB)

    Galatà, A., E-mail: alessio.galata@lnl.infn.it; Sattin, M.; Manzolaro, M.; Martini, D.; Facco, A. [INFN-Legnaro National Laboratories, Legnaro (Pd) (Italy); Tinschert, K.; Spaedtke, P.; Lang, R. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Kulevoy, T. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

    2014-02-15

    The ECR ion sources are able to produce a wide variety of highly charged metallic ion beams thanks to the development of different techniques (ovens, sputtering, direct insertion, metal ions from volatile compounds (MIVOC)). In the case of the ovens, the sticking of the hot vapors on the surface of the plasma chamber leads to high material consumption rates. For elements like Ca, a tantalum liner inserted inside the chamber can be used to limit this phenomenon. The modeling of temperature distribution inside the chamber with and without the liner was carried out with COMSOL-multiphysics code. Results of simulation and the comparison with experiments performed at INFN-Legnaro National Laboratories with Ca beams are discussed.

  7. Development of laser cutting method for stainless steel liner

    International Nuclear Information System (INIS)

    Ishihara, Satoshi; Takahata, Masato; Wignarajah, Sivakumaran; Kamata, Hirofumi

    2007-01-01

    The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in nuclear facilities. The effect of basic laser cutting parameters such as energy, cutting speed, assist gas flow etc. were first studied through cutting experiments on mock-up concrete specimens lined with 3mm thick stainless steel sheets using a 1kW Nd:YAG laser. These initial studies were followed by further studies on the effect of unevenness of the liner surface and on a new method of confining contamination during the cutting process using a sliding evacuation hood attached to the laser cutting head. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. (author)

  8. Repairing liner of the reactor

    International Nuclear Information System (INIS)

    Aguilar H, F.

    2001-07-01

    Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

  9. Fabrication Process for Machined and Shrink-Fitted Impactor-Type Liners for the LOS Alamos Hedp Program

    Science.gov (United States)

    Randolph, B.

    2004-11-01

    Composite liners have been fabricated for the Los Alamos liner-driven High Energy Density Physics (HEDP) experiments using impactors formed by physical vapor deposition, and by machining and shrink fitting. Chemical vapor deposition has been proposed for some ATLAS liner applications. This paper describes the processes used to fabricate machined and shrink-fitted impactors; these processes have been used for copper impactors in 1100 aluminum liners and for 6061 T-6 aluminum impactors in 1100 aluminum liners. The most successful processes have been largely empirically developed and rely upon a combination of shrink-fitting and light press fitting. The processes used to date will be described along with some considerations for future composite liners for the HEDP Program.

  10. Use of fly ash, phosphogypsum and red mud as a liner material for the disposal of hazardous zinc leach residue waste.

    Science.gov (United States)

    Coruh, Semra; Ergun, Osman Nuri

    2010-01-15

    Increasing amounts of residues and waste materials coming from industrial activities in different processes have become an increasingly urgent problem for the future. The release of large quantities of heavy metals into the environment has resulted in a number of environmental problems. The present study investigated the safe disposal of the zinc leach residue waste using industrial residues such as fly ash, phosphogypsum and red mud. In the study, leachability of heavy metals from the zinc leach residue has been evaluated by mine water leaching procedure (MWLP) and toxicity characteristic leaching procedure (TCLP). Zinc removal from leachate was studied using fly ash, phosphogypsum and red mud. The adsorption capacities and adsorption efficiencies were determined. The adsorption rate data was analyzed according to the pseudo-second-order kinetic, Elovich kinetic and intra-particle diffusion kinetic models. The pseudo-second-order kinetic was the best fit kinetic model for the experimental data. The results show that addition of fly ash, phosphogypsum and red mud to the zinc leach residue drastically reduces the heavy metal content in the leachate and could be used as liner materials.

  11. One-dimensional MHD simulations of MTF systems with compact toroid targets and spherical liners

    Science.gov (United States)

    Khalzov, Ivan; Zindler, Ryan; Barsky, Sandra; Delage, Michael; Laberge, Michel

    2017-10-01

    One-dimensional (1D) MHD code is developed in General Fusion (GF) for coupled plasma-liner simulations in magnetized target fusion (MTF) systems. The main goal of these simulations is to search for optimal parameters of MTF reactor, in which spherical liquid metal liner compresses compact toroid plasma. The code uses Lagrangian description for both liner and plasma. The liner is represented as a set of spherical shells with fixed masses while plasma is discretized as a set of nested tori with circular cross sections and fixed number of particles between them. All physical fields are 1D functions of either spherical (liner) or small toroidal (plasma) radius. Motion of liner and plasma shells is calculated self-consistently based on applied forces and equations of state. Magnetic field is determined by 1D profiles of poloidal and toroidal fluxes - they are advected with shells and diffuse according to local resistivity, this also accounts for flux leakage into the liner. Different plasma transport models are implemented, this allows for comparison with ongoing GF experiments. Fusion power calculation is included into the code. We performed a series of parameter scans in order to establish the underlying dependencies of the MTF system and find the optimal reactor design point.

  12. A competing risk model for the reliability of cylinder liners in marine Diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Bocchetti, D. [Grimaldi Group, Naples (Italy); Giorgio, M. [Department of Aerospace and Mechanical Engineering, Second University of Naples, Aversa (Italy); Guida, M. [Department of Information Engineering and Electrical Engineering, University of Salerno, Fisciano (Italy); Pulcini, G. [Istituto Motori, National Research Council-CNR, Naples (Italy)], E-mail: g.pulcini@im.cnr.it

    2009-08-15

    In this paper, a competing risk model is proposed to describe the reliability of the cylinder liners of a marine Diesel engine. Cylinder liners presents two dominant failure modes: wear degradation and thermal cracking. The wear process is described through a stochastic process, whereas the failure time due to the thermal cracking is described by the Weibull distribution. The use of the proposed model allows performing goodness-of-fit test and parameters estimation on the basis of both wear and failure data. Moreover, it enables reliability estimates of the state of the liners to be obtained and the hierarchy of the failure mechanisms to be determined for any given age and wear level of the liner. The model has been applied to a real data set: 33 cylinder liners of Sulzer RTA 58 engines, which equip twin ships of the Grimaldi Group. Estimates of the liner reliability and of other quantities of interest under the competing risk model are obtained, as well as the conditional failure probability and mean residual lifetime, given the survival age and the accumulated wear. Furthermore, the model has been used to estimate the probability that a liner fails due to one of the failure modes when both of these modes act.

  13. Distinct Element modeling of geophysical signatures during sinkhole collapse

    Science.gov (United States)

    Al-Halbouni, Djamil; Holohan, Eoghan P.; Taheri, Abbas; Dahm, Torsten

    2017-04-01

    A sinkhole forms due to the collapse of rocks or soil near the Earth's surface into an underground cavity. Such cavities represent large secondary pore spaces derived by dissolution and subrosion in the underground. By changing the stress field in the surrounding material, the growth of cavities can lead to a positive feedback, in which expansion and mechanical instability in the surrounding material increases or generates new secondary pore space (e.g. by fracturing), which in turn increases the cavity size, etc. A sinkhole forms due to the eventual subsidence or collapse of the overburden that becomes destabilized and fails all the way to the Earth's surface. Both natural processes like (sub)surface water movement and earthquakes, and human activities, such as mining, construction and groundwater extraction, intensify such feedbacks. The development of models for the mechanical interaction of a growing cavity and fracturing of its surrounding material, thus capturing related precursory geophysical signatures, has been limited, however. Here we report on the advances of a general, simplified approach to simulating cavity growth and sinkhole formation by using 2D Distinct Element Modeling (DEM) PFC5.0 software and thereby constraining pre-, syn- and post-collapse geophysical and geodetic signatures. This physically realistic approach allows for spontaneous cavity development and dislocation of rock mass to be simulated by bonded particle formulation of DEM. First, we present calibration and validation of our model. Surface subsidence above an instantaneously excavated circular cavity is tracked and compared with an incrementally increasing dissolution zone both for purely elastic and non-elastic material.This validation is important for the optimal choice of model dimensions and particles size with respect to simulation time. Second, a cavity growth approach is presented and compared to a well-documented case study, the deliberately intensified sinkhole collapse at

  14. Development of Adaptive Acoustic Impedance Control Technologies of Acoustic Duct Liner

    Directory of Open Access Journals (Sweden)

    Hiroshi Kobayashi

    2011-01-01

    Full Text Available This paper describes the development of adaptive acoustic impedance control (AAC technologies to achieve a larger fan noise reduction, by adaptively adjusting reactance and resistance of the acoustic liner impedance. For the actual proof of the AAC technology III performance, the advanced fan noise absorption control duct liner II was made on trial basis, with the simple control system and the plain device. And, then, the duct liner II was examined for the AAC technology I, II, and III models, using the high speed fan test facility. The test results made clear that the duct liner II of the AAC technology III model could achieve the fan noise reduction higher than O.A. SPL 10 dB (A at the maximum fan speed 6000 rpm, containing the reduction of fundamental BPF tone of 18 dB and 2nd BPF tone of 10 dB in response to the fan peed change from 3000 to 6000 rpm.

  15. Comparison of Heavy-Duty Scuffing Behavior between Chromium-Based Ceramic Composite and Nickel-Chromium-Molybdenum-Coated Ring Sliding against Cast Iron Liner under Starvation

    Directory of Open Access Journals (Sweden)

    Yan Shen

    2017-10-01

    Full Text Available A running-in and starved lubrication experiment is designed to investigate the heavy-duty scuffing behavior of piston ring coatings against cast iron (Fe cylinder liner using the piston ring reciprocating liner test rig. The scuffing resistance of the piston ring with the chromium-based ceramic composite coating (CKS, and that with the thermally sprayed nickel-chromium-molybdenum coating (NCM is compared at different nominal pressures (40~100 MPa and temperatures (180~250 °C. With the failure time as a criterion, the rank order is as follows: NCM/Fe > CKS/Fe. Before the scoring occurs at the interface of the piston ring and cylinder liner (PRCL, the cast iron liner enters into a “polish wear” stage, and iron-based adhesive materials begin to form on the piston ring surface. With the macroscopic adhesion formation, the plastic shearing cycle causes surface damages mainly due to abrasive effects for the CKS/Fe pairs and adhesive effects for the NCM/Fe pairs.

  16. Computational models of stellar collapse and core-collapse supernovae

    International Nuclear Information System (INIS)

    Ott, Christian D; O'Connor, Evan; Schnetter, Erik; Loeffler, Frank; Burrows, Adam; Livne, Eli

    2009-01-01

    Core-collapse supernovae are among Nature's most energetic events. They mark the end of massive star evolution and pollute the interstellar medium with the life-enabling ashes of thermonuclear burning. Despite their importance for the evolution of galaxies and life in the universe, the details of the core-collapse supernova explosion mechanism remain in the dark and pose a daunting computational challenge. We outline the multi-dimensional, multi-scale, and multi-physics nature of the core-collapse supernova problem and discuss computational strategies and requirements for its solution. Specifically, we highlight the axisymmetric (2D) radiation-MHD code VULCAN/2D and present results obtained from the first full-2D angle-dependent neutrino radiation-hydrodynamics simulations of the post-core-bounce supernova evolution. We then go on to discuss the new code Zelmani which is based on the open-source HPC Cactus framework and provides a scalable AMR approach for 3D fully general-relativistic modeling of stellar collapse, core-collapse supernovae and black hole formation on current and future massively-parallel HPC systems. We show Zelmani's scaling properties to more than 16,000 compute cores and discuss first 3D general-relativistic core-collapse results.

  17. Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses

    International Nuclear Information System (INIS)

    Glowka, D.A.

    1990-09-01

    This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs

  18. Collapse of experimental capsules under external pressure

    International Nuclear Information System (INIS)

    Simonen, F.A.; Shippell, R.J. Jr.

    1980-01-01

    Stress analyses and developmental tests of capsules fabricated from thick-walled tubing were performed for an external pressure design condition. In the design procedure no credit was taken for the expected margin in pressure between yielding of the capsule wall and catastrophic collapse or flattening. In tests of AISI-1018 low carbon steel capsules, a significant margin was seen between yield and collapse pressure. However, the experimental yield pressures were significantly below predictions, essentially eliminating the safety margin present in the conservative design approach. The differences between predictions and test results are attributed to deficiencies in the plasticity theories commonly in use for engineering stress analyses. The results of this study show that the von Mises yield condition does not accurately describe the yield behavior of the AISI-1018 steel tubing material for the triaxial stress conditions of interest. Finite element stress analyses successfully predicted the transition between uniform inward plastic deformation and ovalization that leads to catastrophic collapse. After adjustments to correct for the unexpected yield behavior of the tube material, the predicted pressure-deflection trends were found to follow the experimental data

  19. Aging test results of an asphalt membrane liner

    International Nuclear Information System (INIS)

    Buelt, J.L.; Barnes, S.M.

    1983-07-01

    The objective of the asphalt aging study described in this report was to determine the expected performance lifetime of a catalytically airblown asphalt membrane as a seepage barrier for inactive uranium mill tailings. The study, conducted by Pacific Northwest Laboratory for the Department of Energy's Uranium Mill Tailings Remedial Action Program, showed through chemical compatibility tests that the asphalt membrane is well suited for this purpose. The chemical compatibility tests were designed to accelerate the aging reactions in the asphalt and to determine the accelerated aging effect. Higher temperatures and oxygen concentrations proved to be effective acceleration parameters. By infrared spectral analysis, the asphalt was determined to have undergone 7 years of equivalent aging in a 3-month period when exposed to 40 0 C and 1.7 atm oxygen pressure. However, the extent of aging was limited to a maximum penetration of 0.5% of the total liner thickness. It was concluded that the liner could be expected to be effective as a seepage barrier for at least 1000 years before the entire thickness of the liner would be degraded

  20. Liner velocity, current, and symmetry measurements on the 32 MA flux compression generator experiment ALT-1

    CERN Document Server

    Clark, D A; Rodríguez, G; Tabaka, L J

    2001-01-01

    Summary form only given, as follows. A flux compression generator based pulse power system, designed, built, and fielded by a Russian team at the All Russian Scientific Research Institute of Experimental Physics (VNIIEF), was used to successfully drive an aluminum liner to velocities greater than 10 km/sec. The experiment objective was to demonstrate performance of a precision liner implosion at Atlas current of 30 MA or greater. Diagnostics to measure liner performance were an essential part of the experiment. An experimental team from Los Alamos National Laboratory (LANL) provided a suite of diagnostics to measure liner performance. Three diagnostics were fielded. 1. a velocity interferometer (VISAR) to continuously measure the liner inner surface velocity from throughout the entire range of travel. 2. Two Faraday rotation devices to measure liner current during the implosion. 3. Sixteen fiber optic impact pins to record liner impact time and provide axial and azimuthal symmetry information. All diagnostics...

  1. Wear resistance of poly(2-methacryloyloxyethyl phosphorylcholine)-grafted carbon fiber reinforced poly(ether ether ketone) liners against metal and ceramic femoral heads.

    Science.gov (United States)

    Yamane, Shihori; Kyomoto, Masayuki; Moro, Toru; Hashimoto, Masami; Takatori, Yoshio; Tanaka, Sakae; Ishihara, Kazuhiko

    2018-04-01

    Younger, active patients who undergo total hip arthroplasty (THA) have increasing needs for wider range of motion and improved stability of the joint. Therefore, bearing materials having not only higher wear resistance but also mechanical strength are required. Carbon fiber-reinforced poly(ether ether ketone) (CFR-PEEK) is known as a super engineering plastic that has great mechanical strength. In this study, we focused on poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted CFR-PEEK and investigated the effects of PMPC grafting and the femoral heads materials on the wear properties of CFR-PEEK liners. Compared with untreated CFR-PEEK, the PMPC-grafted CFR-PEEK surface revealed higher wettability and lower friction properties under aqueous circumstances. In the hip simulator wear test, wear particles generated from the PMPC-grafted CFR-PEEK liners were fewer than those of the untreated CFR-PEEK liners. There were no significant differences in the size and the morphology of the wear particles between the differences of PMPC-grafting and the counter femoral heads. Zirconia-toughened alumina (ZTA) femoral heads had significantly smoother surfaces compared to cobalt-chromium-molybdenum alloy femoral heads after the hip simulator test. Thus, we conclude that the bearing combination of the PMPC-grafted CFR-PEEK liner and ZTA head is expected to be a lifelong bearing interface in THA. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1028-1037, 2018. © 2017 Wiley Periodicals, Inc.

  2. Molten core material holding device in a nuclear reactor

    International Nuclear Information System (INIS)

    Nakamura, Hisashi; Tanaka, Nobuo; Takahashi, Katsuro.

    1985-01-01

    Purpose: To improve the function of cooling to hold molten core materials in a molten core material holding device. Constitution: Plenum structures are formed into a pan-like configuration, in which liners made of metal having high melting point and relatively high heat conductivity such as tantalum, tungsten, rhenium or alloys thereof are integrally appended to hold and directly cool the molten reactor core materials. Further, a plurality of heat pipes, passing through the plenum structures, facing the cooling portion thereof to the coolants at the outer side and immersing the heating portion into the molten core materials fallen to deposit in the inner liners are disposed radially. Furthermore, heat pipes embodded in the plenum structure are disposed in the same manner below the liners. Thus, the plenum structures and the molten reactor core materials can be cooled at a high efficiency. (Seki, T.)

  3. Crystallite structure formation at the collapse pressure of fatty acid Langmuir films

    International Nuclear Information System (INIS)

    Valdes-Covarrubias, M A; Cadena-Nava, R D; Vasquez-MartInez, E; Valdez-Perez, D; Ruiz-GarcIa, J

    2004-01-01

    We report isotherm and atomic force microscopy studies of collapsed Langmuir monolayers of fatty acids. The Langmuir monolayers were overcompressed in the range 7-40 deg. C and transferred onto mica after the sharp pressure drop when the collapse pressure was reached. Collapsed material was observed by AFM, which revealed that the multilayers are indeed three-dimensional crystallites. We found that the shape of the crystallites depends on the collapse temperature, the phase from which the collapse occurs and/or the chain length. However, at higher temperatures the collapsed films no longer show a well defined crystallite formation, but rather a more heterogeneous melt-like pattern. We associated the crystallite formation with known bulk crystal phases of the fatty acids

  4. Assessment of the slowly-imploding liner (LINUS) fusion reactor concept

    International Nuclear Information System (INIS)

    Miller, R.L.; Krakowski, R.A.

    1980-01-01

    Prospects for the slowly-imploding liner (LINUS) fusion reactor concept are reviewed. The concept envisages the nondestructive, repetitive and reversible implosion of a liquid-metal cylindrical annulus (liner) onto field-reversed DT plasmoids. Adiabatic heating of the plasmoid to ignition at ultra-high magnetic fields results in a compact, high power density fusion reactor with unique solutions to several technological problems and potentially favorable economics

  5. Synergistic Integration of Liner Shipping and Economic Development

    Directory of Open Access Journals (Sweden)

    Edvard Roškar

    2008-07-01

    Full Text Available Liner shipping with all its specific features plays an importantrole in the economic development of a country whose portsare involved. In the strategic goals of maritime policy for the period2005-2009 the European Commission stresses the needfor a sustainable environmental development and economicgrowth. Besides, it points out the necessity for the fulfilment ofall maritime potentials. Yet, individual EU member states frequentlycreate the environment, which discourages the developmentof their own national maritime economy. Unfortunately,this applies also to the Republic of Slovenia. The current paperoffers a detailed analysis of the weaknesses and benefits of theclassical liner shipping in present day.

  6. Computational models of stellar collapse and core-collapse supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Ott, Christian D; O' Connor, Evan [TAPIR, Mailcode 350-17, California Institute of Technology, Pasadena, CA (United States); Schnetter, Erik; Loeffler, Frank [Center for Computation and Technology, Louisiana State University, Baton Rouge, LA (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ (United States); Livne, Eli, E-mail: cott@tapir.caltech.ed [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)

    2009-07-01

    Core-collapse supernovae are among Nature's most energetic events. They mark the end of massive star evolution and pollute the interstellar medium with the life-enabling ashes of thermonuclear burning. Despite their importance for the evolution of galaxies and life in the universe, the details of the core-collapse supernova explosion mechanism remain in the dark and pose a daunting computational challenge. We outline the multi-dimensional, multi-scale, and multi-physics nature of the core-collapse supernova problem and discuss computational strategies and requirements for its solution. Specifically, we highlight the axisymmetric (2D) radiation-MHD code VULCAN/2D and present results obtained from the first full-2D angle-dependent neutrino radiation-hydrodynamics simulations of the post-core-bounce supernova evolution. We then go on to discuss the new code Zelmani which is based on the open-source HPC Cactus framework and provides a scalable AMR approach for 3D fully general-relativistic modeling of stellar collapse, core-collapse supernovae and black hole formation on current and future massively-parallel HPC systems. We show Zelmani's scaling properties to more than 16,000 compute cores and discuss first 3D general-relativistic core-collapse results.

  7. Assessment of structural integrity of Monju steel liner against sodium leakage and combustion. Modeling of thinning process of liner due to corrosion in structural analysis

    International Nuclear Information System (INIS)

    Tsukimori, K.; Kato, T.; Furuhashi, I.; Iwata, K.; Akatsu, M.

    2001-01-01

    The lining structure of LMFBR (Liquid Metal cooled Fast Breeder Reactor) has an important role to prohibit leaking sodium from touching a concrete floor in a sodium leakage incident. JNC (Japan Nuclear Cycle Development Institute) experienced a sodium leakage incident in 1995 in the secondary heat transport system room of the prototype LMFBR MONJU. In this incident, a part of the liner was covered with a certain amount of high temperature leaked sodium and its compounds. Visible but small distortion and thinning of the liner were detected, which were due to heating by sodium fire and chemical corrosion, respectively. To simulate the MONJU incident, JNC conducted a series of sodium leakage tests, in one of which severer corrosion (molten salt type corrosion) than that in the MONJU incident was observed. In order to secure the conservativeness in the integrity assessment of the liner, consideration of a severest corrosion process was demanded. This means that the loss of parts of the structure with time should be considered in the structural analyses. In this study a modeling of thinning process of the liner was developed in order to realize reasonable analysis from the point of view of actual phenomena. The concept of the method is to release the stress of the lost region by using artificial creep and reducing Young's modulus. The necessity of this kind of model and the validity was verified through an application analysis of the liner in the secondary heat transport system room of MONJU. (authors)

  8. Uranium-mill-tailings remedial-action project (UMTRAP) cover and liner technology development project

    International Nuclear Information System (INIS)

    Hartley, J.N.; Gee, G.W.; Freeman, H.D.; Cline, J.F.; Beedlow, P.A.; Buelt, J.L.; Relyea, J.R.; Tamura, T.

    1982-01-01

    Cover and liner systems for uranium mill tailings in the United States must satisfy stringent requirements regarding long-term stability, radon control, and radionuclide and hazardous chemical migration. The cover placed over a tailings pile serves three basic purposes: (1) to reduce the release of radon, (2) to prevent the intrusion of plant roots and burrowing animals into the tailings, and (3) to limit surface erosion. The liner placed under a tailings pile prevents the migration of radionuclides and hazardous chemicals to groundwater. Pacific Northwest Laboratory is developing and evaluating cover and liner systems that meet these objectives and conform to federal standards. The cover and liner technology discussed in this paper involves: (1) single and multilayer earthen cover systems, (2) asphalt emulsion radon barrier systems, (3) biobarrier systems, (4) revegetation and rock covers, and (5) asphalt, clay, and synthetic liner systems. These systems have been tested at the Grand Junction, Colorado, tailings pile, where they have been shown to effectively reduce radon releases and radionuclide and chemical migration

  9. Tendency of spherically imploding plasma liners formed by merging plasma jets to evolve toward spherical symmetry

    International Nuclear Information System (INIS)

    Cassibry, J. T.; Stanic, M.; Hsu, S. C.; Witherspoon, F. D.; Abarzhi, S. I.

    2012-01-01

    We have performed three-dimensional (3D) simulations using smoothed particle hydrodynamics (SPH) in order to study the effects of discrete plasma jets on the processes of plasma liner formation, implosion on vacuum, and expansion. It was found that the pressure histories of the inner portion of the liner from 3D SPH simulations with a uniform liner and with 30 discrete plasma jets were qualitatively and quantitatively similar from peak compression through the complete stagnation of the liner. The 3D simulations with a uniform liner were first benchmarked against results from one-dimensional radiation-hydrodynamic simulations [T. J. Awe et al., Phys. Plasmas 18, 072705 (2011)]. Two-dimensional plots of the pressure field show that the discrete jet SPH case evolves towards a profile that is almost indistinguishable from the SPH case with a uniform liner, thus indicating that non-uniformities due to discrete jets are smeared out by late stages of the implosion. The processes of plasma liner formation and implosion on vacuum were shown to be robust against Rayleigh-Taylor instability growth. Finally, interparticle mixing for a liner imploding on vacuum was investigated. The mixing rate was found to be very small until after the peak compression for the 30 jet simulations.

  10. Helium High Pressure Tanks at EADS Space Transportation New Technology with Thermoplastic Liner

    National Research Council Canada - National Science Library

    Benedic, Fabien; Leard, Jean-Philippe; Lefloch, Christian

    2005-01-01

    .... In order to achieve the new target prices, a new disruptive technology has been performing for several years in using a thermoplastic liner instead the usual expensive concept of metallic forged liner...

  11. Plasma Liner Research for MTF at NASA Marshall Space Flight Center

    Science.gov (United States)

    Thio, Y. C. F.; Eskridge, R.; Lee, M.; Martin, A.; Smith, J.; Cassibry, J. T.; Wu, S. T.; Kirkpatrick, R. C.; Knapp, C. E.; Turchi, P. J.; hide

    2002-01-01

    The current research effort at NASA Marshall Space Flight Center (MSFC) in MTF is directed towards exploring the critical physics issues of potential embodiments of MTF for propulsion, especially standoff drivers involving plasma liners for MTF. There are several possible approaches for forming plasma liners. One approach consists of using a spherical array of plasma jets to form a spherical plasma shell imploding towards the center of a magnetized plasma, a compact toroid. Current experimental plan and status to explore the physics of forming a 2-D plasma liner (shell) by merging plasma jets are described. A first-generation coaxial plasma guns (Mark-1) to launch the required plasma jets have been built and tested. Plasma jets have been launched reproducibly with a low jitter, and velocities in excess of 50 km/s for the leading edge of the plasma jet. Some further refinements are being explored for the plasma gun, Successful completion of these single-gun tests will be followed by an experimental exploration of the problems of launching a multiple number of these jets simultaneously to form a cylindrical plasma liner.

  12. Friction Stir Welding of GR-Cop 84 for Combustion Chamber Liners

    Science.gov (United States)

    Russell, Carolyn K.; Carter, Robert; Ellis, David L.; Goudy, Richard

    2004-01-01

    GRCop-84 is a copper-chromium-niobium alloy developed by the Glenn Research Center for liquid rocket engine combustion chamber liners. GRCop-84 exhibits superior properties over conventional copper-base alloys in a liquid hydrogen-oxygen operating environment. The Next Generation Launch Technology program has funded a program to demonstrate scale-up production capabilities of GR-Cop 84 to levels suitable for main combustion chamber production for the prototype rocket engine. This paper describes a novel method of manufacturing the main combustion chamber liner. The process consists of several steps: extrude the GR-Cop 84 powder into billets, roll the billets into plates, bump form the plates into cylinder halves and friction stir weld the halves into a cylinder. The cylinder is then metal spun formed to near net liner dimensions followed by finish machining to the final configuration. This paper describes the friction stir weld process development including tooling and non-destructive inspection techniques, culminating in the successful production of a liner preform completed through spin forming.

  13. The basic design of the Krupp heat-insulating system with hot liner for PCPVs of HTRs

    International Nuclear Information System (INIS)

    Spandick, W.

    1979-01-01

    Presented is the design of a heat-insulating system incorporating a so called ''hot'' liner for use with high temperature reactors. The liner is in direct contact with the coolant, has a thickness of between 10 and 15 mm and is arc welded to anchors embedded in the concrete. Thermal cyclic tests were performed and incipient cracks were detected after about 5000 cycles; the liner is to be designed for between 800 and 1400 cycles. The liner design allows for internal inspection and, if necessary, repair at all times. Tests have shown the advantages of the design provided liner temperatures do not rise above 300 0 C

  14. Design report on the SSCL prototype 80 K Synchrotron Radiation Liner System

    International Nuclear Information System (INIS)

    Shu, Q.S.; Barts, T.; Chou, W.

    1993-09-01

    This report documents the effort to develop a viable design for an SSC prototype 80 K Synchrotron Radiation Liner System. This liner is designed to be tested in the Superconducting Super Collider Accelerator Systems String Test (ASST) facility. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum environment. Secondly, the liner is aimed at improving the Collider cryogenic thermal efficiency which would allow a potential luminosity upgrade. The SSC Collider is the first proton superconducting accelerator designed to operate at an energy of 20 TeV (each beam) and a beam current of 72 mA. The Collider will produce a synchrotron power of 0.14 W/m and a total of 18 kW into 4.2 K for the two rings. This radiated power may trigger a serious impact of photodesorbed gases on the operational availability of the Collider. The interaction between beam particle and photodesorbed gases may greatly reduce the beam lifetime and the scattered beam power may lead to quenching of the superconducting magnets. Collider availability may be unacceptable if this concern is not properly addressed. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum. Secondly, the liner is aimed improving the Collider's cryogenic thermal efficiency which would allow a potential luminosity upgrade. The ultimate goal is to require no more than one machine warm up per year for vacuum maintenance during operation of the SSC Collider

  15. Design report on the SSCL prototype 80 K Synchrotron Radiation Liner System

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Q.S.; Barts, T.; Chou, W. [and others

    1993-09-01

    This report documents the effort to develop a viable design for an SSC prototype 80 K Synchrotron Radiation Liner System. This liner is designed to be tested in the Superconducting Super Collider Accelerator Systems String Test (ASST) facility. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum environment. Secondly, the liner is aimed at improving the Collider cryogenic thermal efficiency which would allow a potential luminosity upgrade. The SSC Collider is the first proton superconducting accelerator designed to operate at an energy of 20 TeV (each beam) and a beam current of 72 mA. The Collider will produce a synchrotron power of 0.14 W/m and a total of 18 kW into 4.2 K for the two rings. This radiated power may trigger a serious impact of photodesorbed gases on the operational availability of the Collider. The interaction between beam particle and photodesorbed gases may greatly reduce the beam lifetime and the scattered beam power may lead to quenching of the superconducting magnets. Collider availability may be unacceptable if this concern is not properly addressed. The liner is one method under consideration to minimize the presence of photodesorbed gases in the particle beam line vacuum. Secondly, the liner is aimed improving the Collider`s cryogenic thermal efficiency which would allow a potential luminosity upgrade. The ultimate goal is to require no more than one machine warm up per year for vacuum maintenance during operation of the SSC Collider.

  16. A review of bias flow liners for acoustic damping in gas turbine combustors

    Science.gov (United States)

    Lahiri, C.; Bake, F.

    2017-07-01

    The optimized design of bias flow liner is a key element for the development of low emission combustion systems in modern gas turbines and aero-engines. The research of bias flow liners has a fairly long history concerning both the parameter dependencies as well as the methods to model the acoustic behaviour of bias flow liners under the variety of different bias and grazing flow conditions. In order to establish an overview over the state of the art, this paper provides a comprehensive review about the published research on bias flow liners and modelling approaches with an extensive study of the most relevant parameters determining the acoustic behaviour of these liners. The paper starts with a historical description of available investigations aiming on the characterization of the bias flow absorption principle. This chronological compendium is extended by the recent and ongoing developments in this field. In a next step the fundamental acoustic property of bias flow liner in terms of the wall impedance is introduced and the different derivations and formulations of this impedance yielding the different published model descriptions are explained and compared. Finally, a parametric study reveals the most relevant parameters for the acoustic damping behaviour of bias flow liners and how this is reflected by the various model representations. Although the general trend of the investigated acoustic behaviour is captured by the different models fairly well for a certain range of parameters, in the transition region between the resonance dominated and the purely bias flow related regime all models lack the correct damping prediction. This seems to be connected to the proper implementation of the reactance as a function of bias flow Mach number.

  17. A matheuristic for the liner shipping network design problem

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Desaulniers, Guy

    2012-01-01

    for revenue and transshipment of cargo along with in/decrease of vessel- and operational cost for the current solution. The evaluation functions may be used by heuristics in general to evaluate changes to a network design without solving a large scale multicommodity flow problem.......We present a matheuristic, an integer programming based heuristic, for the Liner Shipping Network Design Problem. The heuristic applies a greedy construction heuristic based on an interpretation of the liner shipping network design problem as a multiple quadratic knapsack problem. The construction...

  18. In the zone - first rotary steerable liner-while-drilling system; Drilling technology

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    Statoil recently successfully tested the world's first rotary steerable liner-while-drilling system from its Brage platform in the Norwegian sector of the North Sea. This innovative technology - with applications in new and mature fields - was jointly developed by Statoil and Baker Hughes Incorporated. The concept of a rotary steerable system that gives operators the ability to accurately drill and log three-dimensional well profiles with a liner attached directly to the drillstring is entirely new. The system is designed to withstand high circulation rates and high torque loads while providing liner connect and disconnect capabilities. (Author)

  19. Review of collapse triggering mechanism of collapsible soils due to wetting

    Directory of Open Access Journals (Sweden)

    Ping Li

    2016-04-01

    Full Text Available Loess soil deposits are widely distributed in arid and semi-arid regions and constitute about 10% of land area of the world. These soils typically have a loose honeycomb-type meta-stable structure that is susceptible to a large reduction in total volume or collapse upon wetting. Collapse characteristics contribute to various problems to infrastructures that are constructed on loess soils. For this reason, collapse triggering mechanism for loess soils has been of significant interest for researchers and practitioners all over the world. This paper aims at providing a state-of-the-art review on collapse mechanism with special reference to loess soil deposits. The collapse mechanism studies are summarized under three different categories, i.e. traditional approaches, microstructure approach, and soil mechanics-based approaches. The traditional and microstructure approaches for interpreting the collapse behavior are comprehensively summarized and critically reviewed based on the experimental results from the literature. The soil mechanics-based approaches proposed based on the experimental results of both compacted soils and natural loess soils are reviewed highlighting their strengths and limitations for estimating the collapse behavior. Simpler soil mechanics-based approaches with less parameters or parameters that are easy-to-determine from conventional tests are suggested for future research to better understand the collapse behavior of natural loess soils. Such studies would be more valuable for use in conventional geotechnical engineering practice applications.

  20. Evaluation Of Liner Back-pressure Due To Concrete Pore Pressure At Elevated Temperatures

    International Nuclear Information System (INIS)

    James, R.J.; Rashid, Y.R.; Liu, A.S.; Gou, B.

    2006-01-01

    GE's latest evolution of the boiling water reactor, the ESBWR, has innovative passive design features that reduce the number and complexity of active systems, which in turn provide economic advantages while also increasing safety. These passive systems used for emergency cooling also mean that the primary containment system will experience elevated temperatures with longer durations than conventional plants in the event of design basis accidents. During a Loss of Coolant Accident (LOCA), the drywell in the primary containment structure for the ESBWR will be exposed to saturated steam conditions for up to 72 hours following the accident. A containment spray system may be activated that sprays the drywell area with water to condense the steam as part of the recovery operations. The liner back-pressure will build up gradually over the 72 hours as the concrete temperatures increase, and a sudden cool down could cause excessive differential pressure on the liner to develop. For this analysis, it is assumed that the containment spray is activated at the end of the 72-hour period. A back-pressure, acting between the liner and the concrete wall of the containment, can occur as a result of elevated temperatures in the concrete causing steam and saturated vapor pressures to develop from the free water remaining in the pores of the concrete. Additional pore pressure also develops under the elevated temperatures from the non-condensable gases trapped in the concrete pores during the concrete curing process. Any buildup of this pore pressure next to the liner, in excess of the drywell internal pressure, will act to push the liner away from the concrete with a potential for tearing at the liner anchorages. This paper describes the methods and analyses used to quantify this liner back-pressure so that appropriate measures are included in the design of the liner and anchorage system. A pore pressure model is developed that calculates the pressure distribution across the concrete

  1. Evaluation of a stack: A concrete chimney with brick liner

    International Nuclear Information System (INIS)

    Joshi, J.R.; Amin, J.A.; Porthouse, R.A.

    1995-01-01

    A 200 ft. tall stack, consisting of a concrete chimney with an independent acid proof brick liner built in the 1950's, serving the Separations facility at the Savannah River Site (SRS), was evaluated for the performance category 3 (PC3) level of Natural Phenomena Hazards (NPH) effects. The inelastic energy absorption capacity of the concrete chimney was considered in the evaluation of the earthquake resistance, in particular, to compute the F μ factor. The calculated value of F μ exceeded 3.0, while the seismic demand for the PC3 level, using an F μ value of 1.5, was found to be less than the capacity of the concrete chimney. The capacity formulation of ACI 307 was modified to incorporate the effect of an after design opening on the tension side. There are considerable uncertainties in determining the earthquake resistance of the independent brick liner. The critical liner section, located at the bottom of the breeching opening, does not meet the current recommendations. A discussion is provided for the possible acceptable values for the ''Moment Reduction Factor'', R w or F μ for the liner. Comments are provided on the comparison of stack demands using response spectra (RS) versus time history (TH) analysis, with and without soil structure interaction (SSI) effects

  2. 75 FR 1596 - Grant of Authority for Subzone Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock...

    Science.gov (United States)

    2010-01-12

    ... Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock), Louisville, Kentucky Pursuant to its...-purpose subzone at the aluminum foil liner stock manufacturing and distribution facilities of Reynolds... manufacturing and distribution of aluminum foil liner stock and aluminum foil at the facilities of Reynolds...

  3. Types of collapse calderas

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre-Diaz, Gerardo J [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro., 76230 (Mexico)], E-mail: ger@geociencias.unam.mx

    2008-10-01

    Three main types of collapse calderas can be defined, 1) summit caldera: those formed at the top of large volcanoes, 2) classic caldera: semi-circular to irregular-shaped large structures, several km in diameter and related to relatively large-volume pyroclastic products, and 3) graben caldera: explosive volcano-tectonic collapse structures from which large-volume, ignimbrite-forming eruptions occurred through several fissural vents along the graben master faults and the intra-graben block faults. These in turn can collapse at least with three styles: 1) Piston: when the collapse occurs as a single crustal block; 2) Trap-door: when collapse occurs unevenly along one side while the opposite side remains with no collapse; 3) Piece-meal: when collapse occurs as broken pieces of the crust on top of the magma chamber.

  4. Candida albicans biofilms and MMA surface treatment influence the adhesion of soft denture liners to PMMA resin

    Directory of Open Access Journals (Sweden)

    Martinna de Mendonça e Bertolini

    2014-01-01

    Full Text Available The effect of Candida albicans biofilms and methyl methacrylate (MMA pretreatment on the bond strength between soft denture liners and polymethyl methacrylate (PMMA resin was analyzed. Specimens were prepared and randomly divided with respect to PMMA pretreatment, soft liner type (silicone-based or PMMA-based, and presence or absence of a C. albicans biofilm. Samples were composed of a soft denture liner bonded between two PMMA bars. Specimens (n = 10 were incubated to produce a C. albicans biofilm or stored in sterile PBS for 12 days. The tensile bond strength test was performed and failure type was determined using a stereomicroscope. Surface roughness (SR and scanning electron microscopy (SEM analysis were performed on denture liners (n = 8. Highest bond strength was observed in samples containing a silicone-based soft liner and stored in PBS, regardless of pretreatment (p < 0.01. Silicone-based specimens mostly underwent adhesive failures, while samples containing PMMA-based liners predominantly underwent cohesive failures. The silicone-based specimens SR decreased after 12 days of biofilm accumulation or PBS storage, while the SR of PMMA-based soft liners increased (p < 0.01. The PMMA-based soft liners surfaces presented sharp valleys and depressions, while silicone-based specimens surfaces exhibited more gentle features. In vitro exposure to C. albicans biofilms reduced the adhesion of denture liners to PMMA resin, and MMA pretreatment is recommended during relining procedures.

  5. Contestability of Container Liner Shipping Market in Alliance Era

    Directory of Open Access Journals (Sweden)

    Enna Hirata

    2017-03-01

    Full Text Available A cross section panel model is applied to estimate the effect that the Herfindahl-Hirschman Index (HHI has on container freight rates for a sample of six major container liner shipping routes during 2009 to 2011. The estimated coefficient of HHI is non-positive and statistically insignificant, indicating that higher concentration level does not lead to high price and the container liner shipping market is contestable for the period under consideration. The suggestion that efficiency can be achieved without actual competition in a contestable market is highly significant for policy makers.

  6. Micro-XRD Stress And Texture Study Of Inlaid Copper Lines - Influence Of ILD, Liner And Etch Stop Layer

    International Nuclear Information System (INIS)

    Prinz, H.; Zienert, I.; Rinderknecht, J.; Geisler, H.; Zschech, E.; Besser, P.

    2004-01-01

    The influence of ILD, liner and etch stop layer on the room temperature stress state of copper line test structures was examined by micro-XRD. Test structures consisted of large arrays of parallel lines with line widths of 0.18 μm and 1.8 μm. All these parameters have an influence on the room temperature stress state, whereas the variation of the liner and the ILD showed the largest effects. The change from a full low-k stack to a hybrid stack, where SiO2 ILD is use for the 'via layer' only and low-k material for the 'line layer' results in completely different parameter dependencies. The relationship between copper microstructure and the resulting stress in copper lines is discussed

  7. An Examination of the Causes and Effects of Building Collapse in Nigeria

    Directory of Open Access Journals (Sweden)

    Oke Ayodeji

    2011-12-01

    Full Text Available The research investigated the causes and consequence of building collapse in Nigeria using historical data from 1974 to 2006 and also proffers appropriate solutions. Relevant books, seminar papers, workshop papers, articles, etc. were reviewed so as to examine the general view of individuals that have worked on similar study. Data for the study were obtained through historical data of past building collapse in Nigeria. The data were presented and analysed using tables, bar graphs, Pearson moment correlation coefficient (r and linear regression analysis to generate a model. Sixty (60 buildings that collapsed in the country were gathered, upon which the analysis was carried out. The study revealed that poor maintenance culture, design error, poor quality of materials and workmanship, natural phenomenon and excessive loading contributed to about 7%, 15%, 52%, 7% and 20% respectively of building collapse in Nigeria with most of them being private residential buildings executed by indigenous contractors. The study finally recommended that Standard Organisation of Nigeria (SON should increase their effort in sanitizing building materials in the market. More so, construction professionals should ensure proper supervision of workmen and efficient checking of materials before incorporation into building works.

  8. Impact of landfill liner time-temperature history on the service life of HDPE geomembranes.

    Science.gov (United States)

    Rowe, R Kerry; Islam, M Z

    2009-10-01

    The observed temperatures in different landfills are used to establish a number of idealized time-temperature histories for geomembrane liners in municipal solid waste (MSW) landfills. These are then used for estimating the service life of different HDPE geomembranes. The predicted antioxidant depletion times (Stage I) are between 7 and 750 years with the large variation depending on the specific HDPE geomembrane product, exposure conditions, and most importantly, the magnitude and duration of the peak liner temperature. The higher end of the range corresponds to data from geomembranes aged in simulated landfill liner tests and a maximum liner temperature of 37 degrees C. The lower end of the range corresponds to a testing condition where geomembranes were immersed in a synthetic leachate and a maximum liner temperature of 60 degrees C. The total service life of the geomembranes was estimated to be between 20 and 3300 years depending on the time-temperature history examined. The range illustrates the important role that time-temperature history could play in terms of geomembrane service life. The need for long-term monitoring of landfill liner temperature and for geomembrane ageing studies that will provide improved data for assessing the likely long-term performance of geomembranes in MSW landfills are highlighted.

  9. Single string planning problem arising in liner shipping industries: A heuristic approach

    DEFF Research Database (Denmark)

    Gelareh, Shahin; Neamatian Monemi, Rahimeh; Mahey, Philippe

    2013-01-01

    We propose an efficient heuristic approach for solving instances of the Single String Planning Problem (SSPP) arising in the liner shipping industry. In the SSPP a Liner Service Provider (LSP) only revises one of its many operational strings, and it is assumed that the other strings are unchangea...

  10. Durability test of geomembrane liners presumed to avail near surface disposal facilities for low-level waste generated from research, industrial and medical facilities

    International Nuclear Information System (INIS)

    Nakata, Hisakazu; Amazawa, Hiroya; Sakai, Akihiro; Kurosawa, Ryohei; Sakamoto, Yoshiaki; Kanno, Naohiro; Kashima, Takahiro

    2014-02-01

    The Low-level Radioactive Waste Disposal Project Center will construct near surface disposal facilities for radioactive wastes from research, industrial and medical facilities. The disposal facilities consist of “concrete pit type” for low-level radioactive wastes and “trench type” for very low level radioactive wastes. As for the trench type disposal facility, two kinds of facility designs are on projects – one for a normal trench type disposal facility without any of engineered barriers and the other for a trench type disposal facility with geomembrane liners that could prevent from causing environmental effects of non radioactive toxic materials contained in the waste packages. The disposal facility should be designed taking basic properties of durability on geomembrane liners into account, for it is exposed to natural environment on a long-term basis. This study examined mechanical strength and permeability properties to assess the durability on the basis of an indoor accelerated exposure experiment targeting the liner materials presumed to avail the conceptual design so far. Its results will be used for the basic and detailed design henceforth by confirming the empirical degradation characteristic with the progress of the exposure time. (author)

  11. Epoxy-borax-coal tar composition for a radiation protective, burn resistant drum liner and centrifugal casting method

    International Nuclear Information System (INIS)

    Boyer, N.W.; Taylor, R.S.

    1980-01-01

    A boron containing burn resistant, low level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source. The material is basically composed of borax in the range of 25-50%, coal tar in the range of 25-37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications

  12. Plasma-Jet-Driven Magneto-Inertial Fusion (PJMIF): Physics and Design for a Plasma Liner Formation Experiment

    Science.gov (United States)

    Hsu, Scott; Cassibry, Jason; Witherspoon, F. Douglas

    2014-10-01

    Spherically imploding plasma liners are a potential standoff compression driver for magneto-inertial fusion, which is a hybrid of and operates in an intermediate density between those of magnetic and inertial fusion. We propose to use an array of merging supersonic plasma jets to form a spherically imploding plasma liner. The jets are to be formed by pulsed coaxial guns with contoured electrodes that are placed sufficiently far from the location of target compression such that no hardware is repetitively destroyed. As such, the repetition rate can be higher (e.g., 1 Hz) and ultimately the power-plant economics can be more attractive than most other MIF approaches. During the R&D phase, a high experimental shot rate at reasonably low cost (e.g., gun plasma-liner-formation experiment, which will provide experimental data on: (i) scaling of peak liner ram pressure versus initial jet parameters, (ii) liner non-uniformity characterization and control, and (iii) control of liner profiles for eventual gain optimization.

  13. Thermal asymmetry model of single slope single basin solar still with sponge liner

    Directory of Open Access Journals (Sweden)

    Shanmugan Sengottain

    2014-01-01

    Full Text Available An attempt has been made to propose a thermal asymmetry model for single slope basin type solar still with sponge liner of different thickness (3cm, 5cm, and 10cm in the basin. Two different color sponge liners have been used i.e., yellow and black. In the proposed design, a suitable dripping arrangement has been designed and used to pour water drop by drop over the sponge liner instead of sponge liner in stagnant saline water in the basin. The special arrangement overcomes the dryness of the sponge during peak sunny hours. The performance of the system with black color sponge of 3cm thickness shows better result with an output of 5.3 kg/m2 day and the proposed model have used to find the thermal asymmetries during the working hours of the still.

  14. Static end-expiratory and dynamic forced expiratory tracheal collapse in COPD

    International Nuclear Information System (INIS)

    O'Donnell, C.R.; Bankier, A.A.; O'Donnell, D.H.; Loring, S.H.; Boiselle, P.M.

    2014-01-01

    Aim: To determine the range of tracheal collapse at end-expiration among chronic obstructive pulmonary disease (COPD) patients and to compare the extent of tracheal collapse between static end-expiratory and dynamic forced-expiratory multidetector-row computed tomography (MDCT). Materials and methods: After institutional review board approval and obtaining informed consent, 67 patients meeting the National Heart, Lung, and Blood Institute (NHLBI)/World Health Organization (WHO) Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria for COPD were sequentially imaged using a 64-detector-row CT machine at end-inspiration, during forced expiration, and at end-expiration. Standardized respiratory coaching and spirometric monitoring were employed. Mean percentage tracheal collapse at end-expiration and forced expiration were compared using correlation analysis, and the power of end-expiratory cross-sectional area to predict excessive forced-expiratory tracheal collapse was computed following construction of receiver operating characteristic (ROC) curves. Results: Mean percentage expiratory collapse among COPD patients was 17 ± 18% at end-expiration compared to 62 ± 16% during forced expiration. Over the observed range of end-expiratory tracheal collapse (approximately 10–50%), the positive predictive value of end-expiratory collapse to predict excessive (≥80%) forced expiratory tracheal collapse was <0.3. Conclusion: COPD patients demonstrate a wide range of end-expiratory tracheal collapse. The magnitude of static end-expiratory tracheal collapse does not predict excessive dynamic expiratory tracheal collapse

  15. Design analysis report: high-integrity container for disposal of EPICOR-II prefilter liners

    International Nuclear Information System (INIS)

    Chapman, R.L.; Reno, H.W.

    1983-06-01

    A high-integrity container has been developed to (a) immobilize the EPIROC-II prefilter liners from Unit-2 of the Three Mile Island (TMI) Nuclear Power Station, and (b) protect possible future, inadvertent intruders from damaging radiation. The container is designed for disposal depths to 90 feet in either wet or dry subsurface conditions. A built-in vent system for each container will permit the release of gas and function as a water barrier at pressures reaching 45 psig. The container has outside dimensions of 62.5 inches diameter by 84 inches high, and is designed to ensure a 300-year functional life. Its design features multiple barriers that prevent corrosives from penetrating container walls. The multiple-barrier approach provides a 1204-year mean time to total failure, based on an assumed single-event-failure probability of 20%. The multiple-corrosion-barrier concept is supplemented by aluminum hydroxide, which reduces the chemical activity of corrosives potentially arising from chemical decomposition of organic resins in the EPICOR-II prefilter liner. Aluminum hydroxide, an effective amphoteric material, tends to neutralize both acids and bases. An epoxy seal between the lid and container body functions as a barrier against any loss of container contents. Two separate epoxy materials fill the space between the lid and container body; they form a seal, mechanically bonding the lid in place. After curing, this epoxy material has a greater strength than the concrete; thus, the concrete has to fail in order for the lid to loosen

  16. Automatic measuring system of zirconium thickness for zirconium liner cladding tubes

    International Nuclear Information System (INIS)

    Matsui, K.; Yamaguchi, H.; Hiroshima, T.; Sakamoto, T.; Murayama, R.

    1985-01-01

    An automatic system of pure zirconium liner thickness for zirconium-zircaloy cladding tubes has been successfully developed. The system consists of three parts. (1) An ultrasonic thickness measuring method for mother tubes before cold rolling. (2) An electromagnetic thickness measuring method for the manufactured tubes. (3) An image processing method for the cross sectional view of the manufactured cut tube samples. In Japanese nuclear industry, zirconium-zircaloy cladding tubes have been tested in order to realize load following operation in the atomic power plant. In order to provide for the practical use in the near future, Sumitomo Metal Industries, Ltd. has been studied and established the practical manufacturing process of the zirconium liner cladding tubes. The zirconium-liner cladding tube is a duplex tube comprising an inner layer of pure zirconium bonded to zircaloy metallurgically. The thickness of the pure zirconium is about 10 % of the total wall thickness. Several types of the automatic thickness measuring methods have been investigated instead of the usual microscopic viewing method in which the liner thickness is measured by the microscopic cross sectional view of the cut tube samples

  17. Development of Lightweight, Compact, Structurally-Integrated Acoustic Liners for Broadband Low-Frequency Noise Mitigation

    Science.gov (United States)

    Chambers, Andrew T.

    Airborne noise with a low dominant frequency content (scope of conventional acoustic noise mitigation techniques using liners, foams or claddings owing to mass and volume considerations. Its low evanescence contributes significantly to environmental noise pollution, and unwanted structural vibrations causing diminished efficiency, comfort, payload integrity and mission capabilities. An alternative approach using liner configurations with realistic mass and volume constraints having innovative 'folded' core geometries is investigated to ascertain its low-frequency noise absorption characteristics. In contrast to mass-driven approaches, the folded core approach relies on tailoring interactions between acoustic resonances to tune the liner's impedance to suit the dominant low-frequency content of the source. This allows to keep non-structural mass-addition to a minimum, while retaining an overall thickness comparable to conventional liners for these low-frequency liner designs. The relative acoustic performance of various candidate folded core designs is evaluated by means of a new composite metric termed the Low-Frequency Performance (LFP) factor, which is educed from the absorption coefficient spectrum obtained using Zwikker-Kosten Transmission Line (ZKTL) theory-based numerical studies. An LFP-based software tool is developed to determine optimal 3D cavity packing for a prescribed liner volume and target frequency range. ZKTL-based parametric studies on core dimensions and face sheet porosity are utilized for detailed design of test articles. Experimental verification of absorption coefficient spectra conducted using 3D printed test articles in a normal incidence acoustic impedance tube yield good correlation with simulations. More than 100 Hz of continuous bandwidth with an absorption coefficient greater than 0.6 is shown to be possible in the 300 to 400 Hz range with a 38.1-mm (1.5-inch) thick liner. Further, the influence of face sheet type, Mach number, and

  18. Development and application of a packer-type drilling-free liner hanger

    Directory of Open Access Journals (Sweden)

    Xin Tang

    2014-12-01

    Full Text Available In liner cementing, the upper cement plug and inner components of a common hanger needs to be drilled out after cementing, which will result in a poor cementing quality or even gas leakage at the flare opening. Therefore, a new packer-type drilling-free liner hanger has been developed, and a hydraulic setting-control packer, a flexible drilling-free seal box, and an auxiliary bearing back-off mechanism that go with the line hanger have been designed at the same time. Specific operation procedures include: (1 run in the liner string to the designed depth, then fully circulate the drilling fluid, finally drop the ball. When the tripping ball gets into the seat, the pressure will go up to cut off the hanging control pin and set the hanger; (2 continue to hold the pressure and cut off the ball seat pin to form circulation; (3 trip in the drill pipe to exert pressure on the hanger, back off to release the hanger from the running tool; (4 lower the drill pipe plug upon the completion of cement injection, cut off the releasing control pin of hollow casing plug, and run down further to bump with the bumping assembly; (5 remove the cementing head and connect the kelly driver, hold pressure again, then slowly pull up the drill tools, exert hydraulic pressure on the setting hydraulic cylinder of the packer assembly to cut off the setting control pin and set the packer; and (6 pull up the tools to the flare opening and wash out excessive cement slurry by circulating to realize free drilling of the whole hole. The successful application of the liner hanger in 127 mm diameter liner in Well BQ203-H1 indicates that the packer-type liner hanger has such advantages as easy hanging and back-off, accurate bumping, simple setting, and sound sealing performance.

  19. Performance evaluation of a newly developed variable rate sprayer for nursery liner applications

    Science.gov (United States)

    An experimental variable-rate sprayer designed for liner applications was tested by comparing its spray deposit, coverage, and droplet density inside canopies of six nursery liner varieties with constant-rate applications. Spray samplers, including water sensitive papers (WSP) and nylon screens, wer...

  20. Lining materials for waste disposal containment and waste storage facilities. (Latest citations from the NTIS bibliographic database). Published Search

    International Nuclear Information System (INIS)

    1993-11-01

    The bibliography contains citations concerning the design characteristics, performance, and materials used to make liners for the waste disposal and storage industry. Liners made of concrete, polymeric materials, compacted clays, asphalt, and in-situ glass are discussed. The use of these liners to contain municipal wastes, hazardous waste liquids, and both low-level and high-level radioactive wastes is presented. Liner permeability, transport, stability, construction, and design are studied. Laboratory field measurements for specific wastes are included. (Contains a minimum of 213 citations and includes a subject term index and title list.)

  1. Advances in the analysis and design of concrete structures, metal containments and liner plate for extreme loads

    International Nuclear Information System (INIS)

    Stevenson, J.D.; Eibl, J.; Curbach, M.; Johnson, T.E.; Daye, M.A.; Riera, J.D.; Nemet, J.; Iyengar, K.T.S.

    1992-01-01

    The material presented in this paper summarizes the progress that has been made in the analysis, design, and testing of concrete structures. The material is summarized in the following documents: Part I: Containment Design Criteria and Loading Combinations; Part II: Reinforced and Prestressed Concrete Behavior; Part III: Concrete Containment Analysis, Design and Related Testing; Part IV: Impact and Impulse Loading and Response Prediction; Part V: Metal Containments and Liner Plate Systems; Part VI: Prestressed Reactor Vessel Design, Testing and Analysis. (orig.)

  2. Image flows and one-liner graphical image representation.

    Science.gov (United States)

    Makhervaks, Vadim; Barequet, Gill; Bruckstein, Alfred

    2002-10-01

    This paper introduces a novel graphical image representation consisting of a single curve-the one-liner. The first step of the algorithm involves the detection and ranking of image edges. A new edge exploration technique is used to perform both tasks simultaneously. This process is based on image flows. It uses a gradient vector field and a new operator to explore image edges. Estimation of the derivatives of the image is performed by using local Taylor expansions in conjunction with a weighted least-squares method. This process finds all the possible image edges without any pruning, and collects information that allows the edges found to be prioritized. This enables the most important edges to be selected to form a skeleton of the representation sought. The next step connects the selected edges into one continuous curve-the one-liner. It orders the selected edges and determines the curves connecting them. These two problems are solved separately. Since the abstract graph setting of the first problem is NP-complete, we reduce it to a variant of the traveling salesman problem and compute an approximate solution to it. We solve the second problem by using Dijkstra's shortest-path algorithm. The full software implementation for the entire one-liner determination process is available.

  3. A Physics Exploratory Experiment on Plasma Liner Formation

    Science.gov (United States)

    Thio, Y. C. Francis; Knapp, Charles E.; Kirkpatrick, Ronald C.; Siemon, Richard E.; Turchi, Peter

    2002-01-01

    Momentum flux for imploding a target plasma in magnetized target fusion (MTF) may be delivered by an array of plasma guns launching plasma jets that would merge to form an imploding plasma shell (liner). In this paper, we examine what would be a worthwhile experiment to do in order to explore the dynamics of merging plasma jets to form a plasma liner as a first step in establishing an experimental database for plasma-jets driven magnetized target fusion (PJETS-MTF). Using past experience in fusion energy research as a model, we envisage a four-phase program to advance the art of PJETS-MTF to fusion breakeven Q is approximately 1). The experiment (PLX (Plasma Liner Physics Exploratory Experiment)) described in this paper serves as Phase I of this four-phase program. The logic underlying the selection of the experimental parameters is presented. The experiment consists of using twelve plasma guns arranged in a circle, launching plasma jets towards the center of a vacuum chamber. The velocity of the plasma jets chosen is 200 km/s, and each jet is to carry a mass of 0.2 mg - 0.4 mg. A candidate plasma accelerator for launching these jets consists of a coaxial plasma gun of the Marshall type.

  4. Performance of a Liner-on-Target Injector for Staged Z-Pinch Experiments

    Science.gov (United States)

    Conti, F.; Valenzuela, J. C.; Narkis, J.; Krasheninnikov, I.; Beg, F.; Wessel, F. J.; Ruskov, E.; Rahman, H. U.; McGee, E.

    2016-10-01

    We present the design and characterization of a compact liner-on-target injector, used in the Staged Z-pinch experiments conducted on the UNR-NTF Zebra Facility. Previous experiments and analysis indicate that high-Z gas liners produce a uniform and efficient implosion on a low-Z target plasma. The liner gas shell is produced by an annular solenoid valve and a converging-diverging nozzle designed to achieve a collimated, supersonic, Mach-5 flow. The on-axis target is produced by a coaxial plasma gun, where a high voltage pulse is applied to ionize neutral gas and accelerate the plasma by the J-> × B-> force. Measurements of the liner and target dynamics, resolved by interferometry in space and time, fast imaging, and collection of the emitted light, are presented. The results are compared to the predictions from Computational Fluid Dynamics and MHD simulations that model the injector. Optimization of the design parameters, for upcoming Staged Z-pinch experiments, will be discussed. Advanced Research Projects Agency - Energy, DE-AR0000569.

  5. Current state of knowledge on the behavior of steel liners in concrete containments subjected to overpressurization loads

    International Nuclear Information System (INIS)

    von Riesemann, W.A.; Parks, M.B.

    1993-01-01

    In the United States, concrete containment buildings for commercial nuclear power plants have steel liners that act as the intemal pressure boundary. The liner abuts the concrete, acting as the interior concrete form. The liner is attached to the concrete by either studs or by a continuous structural shape (such as a T-section or channel) that is either continuously or intermittently welded to the liner. Studs are commonly used in reinforced concrete containments, while prestressed containments utilize a structural element as the anchorage. The practice in some countries follows the US practice, while in other countries the containment does not have a steel liner. In this latter case, there is a true double containment, and the annular region between the two containments is vented. This paper will review the practice of design of the liner system prior to the consideration of severe accident loads (overpressurization loads beyond the design conditions)

  6. Filament wound pressure vessels with load sharing liners for space shuttle orbiter applications

    International Nuclear Information System (INIS)

    Ecord, G.M.

    1976-01-01

    Early in the development of orbiter propulsion and environmental control subsystems it was recognized that use of overwrapped pressure vessels with load sharing liners may provide significant weight savings for high pressure gas containment. A program is described which was undertaken by Rockwell International to assess the utility for orbiter applications of titanium 6Al--4V and Inconel 718 liners overwrapped with Kevlar fibers. Also briefly described are programs administered by the NASA Lewis Research Center to evaluate cryoformed steel liners overwrapped with Kevlar fibers and to establish a method that can guarantee cyclic life of the vessels

  7. Study of film boiling collapse behavior during vapor explosion

    International Nuclear Information System (INIS)

    Yagi, Masahiro; Yamano, Norihiro; Sugimoto, Jun; Abe, Yutaka; Adachi, Hiromichi; Kobayashi, Tomoyoshi.

    1996-06-01

    Possible large scale vapor explosions are safety concern in nuclear power plants during severe accident. In order to identify the occurrence of the vapor explosion and to estimate the magnitude of the induced pressure pulse, it is necessary to investigate the triggering condition for the vapor explosion. As a first step of this study, scooping analysis was conducted with a simulation code based on thermal detonation model. It was found that the pressure at the collapse of film boiling much affects the trigger condition of vapor explosion. Based on this analytical results, basic experiments were conducted to clarify the collapse conditions of film boiling on a high temperature solid ball surface. Film boiling condition was established by flooding water onto a high temperature stainless steel ball heated by a high frequency induction heater. After the film boiling was established, the pressure pulse generated by a shock tube was applied to collapse the steam film on the ball surface. As the experimental boundary conditions, materials and size of the balls, magnitude of pressure pulse and initial temperature of the carbon and stainless steel balls were varied. The transients of pressure and surface temperature were measured. It was found that the surface temperature on the balls sharply decreased when the pressure wave passed through the film on balls. Based on the surface temperature behavior, the film boiling collapse pattern was found to be categorized into several types. Especially, the pattern for stainless steel ball was categorized into three types; no collapse, collapse and reestablishment after collapse. It was thus clarified that the film boiling collapse behavior was identified by initial conditions and that the pressure required to collapse film boiling strongly depended on the initial surface temperature. The present results will provide a useful information for the analysis of vapor explosions based on the thermal detonation model. (J.P.N.)

  8. Prestressed concrete reactor vessel for the HHT-670 MW(e) demonstration plant. Pt.1. Design of the multi-cavity prestressed concrete reactor vessel with warm liner

    International Nuclear Information System (INIS)

    Lafitte, R.; Marchand, J.D.

    1979-01-01

    The design studies and tests described in this paper were undertaken as part of ''PROJECT HHT'', a German-Swiss joint effort for the development of high-temperature helium cooled reactors with direct-cycle turbine. The prestressed concrete reactor pressure vessel encloses the core of the reactor itself, the heat exchangers (coolers and recuperators), the helium turbine, the main helium circuit, all nuclear and thermal equipment, and auxiliary reactor cooling equipment. In order to make the liner accessible for inspection, no thermal insulation is provided between the coolant and the liner. The temperature of the helium in contact with the liner is limited to 200 0 C, under all normal operation conditions of the reactor. In the HHT reactor pressure vessel, the resisting structure is protected thermally by a layer of warm concrete between the liner and the structural prestressed concrete. The main features of this pressure vessel are the marked pressure differences in the cavities during normal operation, and the use of warm liner. The objectives of the reference design were chiefly related to the sizing up of the main structure, taking into account the modifications to be expected in the material characteristics as a result of the high temperatures developed

  9. Prevention of gravitational collapse

    International Nuclear Information System (INIS)

    Moffat, J.W.; Taylor, J.G.

    1981-01-01

    We apply a new theory of gravitation to the question of gravitational collapse to show that collapse is prevented in this theory under very reasonable conditions. This result also extends to prevent ultimate collapse of the Universe. (orig.)

  10. Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples.

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    Full Text Available The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In order to determine the rupture and reformulation positions of fluid film accurately, the Jacoboson-Floberg-Olsson (JFO cavitation boundary condition is applied to the mixed lubrication model for ensuring the mass-conservative law. On this basis, the minimum oil film thickness and average friction forces in the compression ring-cylinder liner system are investigated under the engine-like conditions by changing the dimple area density, radius, and depth. The wear load, average friction forces, and power loss of the compression ring-cylinder liner system with and without dimples are also compared for different compression ring face profiles. The results show that the spherical dimples can produce a larger reduction of friction in mixed lubrication region, and reduce power loss significantly in the middle of the strokes. In addition, higher reduction percentages of average friction forces and wear are obtained for smaller crown height or larger axial width.

  11. The Aerodynamic Performance of an Over-the-Rotor Liner With Circumferential Grooves on a High Bypass Ratio Turbofan Rotor

    Science.gov (United States)

    Bozak, Richard F.; Hughes, Christopher E.; Buckley, James

    2013-01-01

    While liners have been utilized throughout turbofan ducts to attenuate fan noise, additional attenuation is obtainable by placing an acoustic liner over-the-rotor. Previous experiments have shown significant fan performance losses when acoustic liners are installed over-the-rotor. The fan blades induce an oscillating flow in the acoustic liners which results in a performance loss near the blade tip. An over-the-rotor liner was designed with circumferential grooves between the fan blade tips and the acoustic liner to reduce the oscillating flow in the acoustic liner. An experiment was conducted in the W-8 Single-Stage Axial Compressor Facility at NASA Glenn Research Center on a 1.5 pressure ratio fan to evaluate the impact of this over-the-rotor treatment design on fan aerodynamic performance. The addition of a circumferentially grooved over-the-rotor design between the fan blades and the acoustic liner reduced the performance loss, in terms of fan adiabatic efficiency, to less than 1 percent which is within the repeatability of this experiment.

  12. Measurements of Magneto-Rayleigh-Taylor instability growth in solid liners on the 20 MA Z facility

    International Nuclear Information System (INIS)

    Bigman, Verle; Vesey, Roger Alan; Shores, Jonathon; Herrmann, Mark C.; Stamm, Robert; Killebrew, Korbie; Holt, Randy; Blue, Brent; Nakhleh, Charlie; McBride, Ryan D.; Leifeste, Gordon T.; Smith, Ian Craig; Stygar, William A.; Porter, John Larry Jr.; Cuneo, Michael Edward; Bennett, Guy R.; Schroen, Diana Grace; Sinars, Daniel Brian; Lopez, Mike R.; Slutz, Stephen A.; Atherton, Briggs W.; Tomlinson, Kurt; Edens, Aaron D.; Savage, Mark Edward; Peterson, Kyle J.

    2010-01-01

    The magneto-Rayleigh-Taylor (MRT) instability is the most important instability for determining whether a cylindrical liner can be compressed to its axis in a relatively intact form, a requirement for achieving the high pressures needed for inertial confinement fusion (ICF) and other high energy-density physics applications. While there are many published RT studies, there are a handful of well-characterized MRT experiments at time scales >1 (micro)s and none for 100 ns z-pinch implosions. Experiments used solid Al liners with outer radii of 3.16 mm and thicknesses of 292 (micro)m, dimensions similar to magnetically-driven ICF target designs (1). In most tests the MRT instability was seeded with sinusoidal perturbations (λ = 200, 400 (micro)m, peak-to-valley amplitudes of 10, 20 (micro)m, respectively), wavelengths similar to those predicted to dominate near stagnation. Radiographs show the evolution of the MRT instability and the effects of current-induced ablation of mass from the liner surface. Additional Al liner tests used 25-200 (micro)m wavelengths and flat surfaces. Codes being used to design magnetized liner ICF loads (1) match the features seen except at the smallest scales (<50 (micro)m). Recent experiments used Be liners to enable penetrating radiography using the same 6.151 keV diagnostics and provide an in-flight measurement of the liner density profile.

  13. Is the quality of cement a contributing factor for building collapse in Ghana?

    OpenAIRE

    Danso, Humphrey; Boateng, Isaac

    2013-01-01

    Sub-standard (poor quality) materials have been mentioned as one of the major causes of building collapse worldwide. The main materials mostly identified as sub-standard are cement, reinforcement bars, timber and aggregate. This Paper assesses whether the quality of Type I Portland cement use in Ghana - contribute to the recent building collapse in Accra and Kumasi. This was achieved through experimental study by comparing the properties of Ghana cement with that of UK cement. The study found...

  14. Gravitational Waves from Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    Chris L. Fryer

    2011-01-01

    Full Text Available Gravitational-wave emission from stellar collapse has been studied for nearly four decades. Current state-of-the-art numerical investigations of collapse include those that use progenitors with more realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non-axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with ground-based and space-based interferometric observatories. This review covers the entire range of stellar collapse sources of gravitational waves: from the accretion-induced collapse of a white dwarf through the collapse down to neutron stars or black holes of massive stars to the collapse of supermassive stars.

  15. Gravitational waves from gravitational collapse

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, Christopher L [Los Alamos National Laboratory; New, Kimberly C [Los Alamos National Laboratory

    2008-01-01

    Gravitational wave emission from stellar collapse has been studied for nearly four decades. Current state-of-the-art numerical investigations of collapse include those that use progenitors with more realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non-axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with ground-based and space-based interferometric observatories. This review covers the entire range of stellar collapse sources of gravitational waves: from the accretion induced collapse of a white dwarf through the collapse down to neutron stars or black holes of massive stars to the collapse of supermassive stars.

  16. Reliability-based condition assessment of steel containment and liners

    International Nuclear Information System (INIS)

    Ellingwood, B.; Bhattacharya, B.; Zheng, R.

    1996-11-01

    Steel containments and liners in nuclear power plants may be exposed to aggressive environments that may cause their strength and stiffness to decrease during the plant service life. Among the factors recognized as having the potential to cause structural deterioration are uniform, pitting or crevice corrosion; fatigue, including crack initiation and propagation to fracture; elevated temperature; and irradiation. The evaluation of steel containments and liners for continued service must provide assurance that they are able to withstand future extreme loads during the service period with a level of reliability that is sufficient for public safety. Rational methodologies to provide such assurances can be developed using modern structural reliability analysis principles that take uncertainties in loading, strength, and degradation resulting from environmental factors into account. The research described in this report is in support of the Steel Containments and Liners Program being conducted for the US Nuclear Regulatory Commission by the Oak Ridge National Laboratory. The research demonstrates the feasibility of using reliability analysis as a tool for performing condition assessments and service life predictions of steel containments and liners. Mathematical models that describe time-dependent changes in steel due to aggressive environmental factors are identified, and statistical data supporting the use of these models in time-dependent reliability analysis are summarized. The analysis of steel containment fragility is described, and simple illustrations of the impact on reliability of structural degradation are provided. The role of nondestructive evaluation in time-dependent reliability analysis, both in terms of defect detection and sizing, is examined. A Markov model provides a tool for accounting for time-dependent changes in damage condition of a structural component or system. 151 refs

  17. Azimuthal Current Density Distribution Resulting from a Power Feed Vacuum Gap in Metallic Liner Experiments at 1 MA

    Science.gov (United States)

    Bott-Suzuki, Simon; Cordaro, S. W.; Caballero Bendixsen, L. S.; Atoyan, L.; Byvank, T.; Potter, W.; Kusse, B. R.; Greenly, J. B.; Hammer, D. A.; Chittenden, J. P.; Jennings, C. A.

    2015-11-01

    We present a study investigating the initiation of plasma in solid, metallic liners where the liner thickness is large compared to the collisionless skin depth. A vacuum gap is introduced in the power feed and we investigate the effect of this on the azimuthal initiation of plasma in the liner. We present optical emission data from aluminum liners on the 1 MA, 100ns COBRA generator. We use radial and axial gated imaging and streak photography, which show a dependence of onset of emission with the size of a small power-feed vacuum gap. The evolution of ``hot-spots'' generated from breakdown vacuum gap evolves relatively slowly and azimuthal uniformity is not observed on the experimental time-scale. We also show measurements of the B-field both outside and inside the liner, using miniature Bdot probes, which show a dependence on the liner diameter and thickness, and a correlation to the details of the breakdown. These data will be compared to magneto-hydrodynamic simulations to infer how such non-uniformities may affect full liner implosion experiments.

  18. A semi-analytic model of magnetized liner inertial fusion

    Energy Technology Data Exchange (ETDEWEB)

    McBride, Ryan D.; Slutz, Stephen A. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2015-05-15

    Presented is a semi-analytic model of magnetized liner inertial fusion (MagLIF). This model accounts for several key aspects of MagLIF, including: (1) preheat of the fuel (optionally via laser absorption); (2) pulsed-power-driven liner implosion; (3) liner compressibility with an analytic equation of state, artificial viscosity, internal magnetic pressure, and ohmic heating; (4) adiabatic compression and heating of the fuel; (5) radiative losses and fuel opacity; (6) magnetic flux compression with Nernst thermoelectric losses; (7) magnetized electron and ion thermal conduction losses; (8) end losses; (9) enhanced losses due to prescribed dopant concentrations and contaminant mix; (10) deuterium-deuterium and deuterium-tritium primary fusion reactions for arbitrary deuterium to tritium fuel ratios; and (11) magnetized α-particle fuel heating. We show that this simplified model, with its transparent and accessible physics, can be used to reproduce the general 1D behavior presented throughout the original MagLIF paper [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)]. We also discuss some important physics insights gained as a result of developing this model, such as the dependence of radiative loss rates on the radial fraction of the fuel that is preheated.

  19. Manufacturing and testing of ITER divertor gas box liners

    International Nuclear Information System (INIS)

    Mazul, I.; Giniatulin, R.; Komarov, V.L.; Krylov, V.; Kuzmin, Ye.; Makhankov, A.; Odintsov, V.; Zhuk, A.

    1998-01-01

    Among a variety of R and D works performed by different ITER parties there are seven large projects which deal with the development, manufacturing and testing of most important complex reactor components. One of the projects is directed to produce a prototype of divertor cassette. In according with integration plan two full size liners with dummy armour are manufactured by RF Home Team. Except for liners with dummy armors the large - scale mock-up with real armour have to be manufactured in order to demonstrate the semi-industrial possibilities for joining of Be and W to CuCrZr heat - sink structure. The design of this liners, technological approaches to their manufacturing are presented. The description of brazing facility and joining technology which use a fast ohmic heating by 15 kA current is made. A mock-up of 800 mm in length and 90 mm in width was armored by 18 Be tiles (44 x 44 mm 2 in plane, 10 mm - thick) and 16 W-Cu tiles (44 x 44 mm 2 in plane, 3 mm - thick W). The preliminary results of high heat flux testing of the armored mock-ups are also presented. (author)

  20. Self-similar compression of a magnetized plasma filled liner

    International Nuclear Information System (INIS)

    Felber, F.S.; Liberman, M.A.; Velikovich, A.L.

    1985-01-01

    New analytic, one-dimensional, self-similar solutions of magnetohydrodynamic equations describing the compression of a magnetized plasma by a thin cylindrical liner are presented. The solutions include several features that have not been included in an earlier self-similar solution of the equations of ideal magnetohydrodynamics. These features are the effects of finite plasma electrical conductivity, induction heating, thermal conductivity and related thermogalvanomagnetic effects, plasma turbulence, and plasma boundary effects. These solutions have been motivated by recent suggestions for production of ultrahigh magnetic fields by new methods. The methods involve radially imploding plasmas in which axial magnetic fields have been entrained. These methods may be capable of producing controlled magnetic fields up to approx. = 100 MG. Specific methods of implosion suggested were by ablative radial acceleration of a liner by a laser and by a gas-puff Z pinch. The model presented here addresses the first of these methods. The solutions derived here are used to estimate magnetic flux losses out of the compression volume, and to indicate conditions under which an impulsively-accelerated, plasma-filled liner may compress an axial magnetic field to large magnitude

  1. HOST liner cyclic facilities

    Science.gov (United States)

    Schultz, D.

    1983-01-01

    The HOST Liner Cyclic Program is utilizing two types of test apparatus, rectangular box rigs and a full annular rig. To date two quartz lamp cyclic box rigs have been tested and a third is to begin testing in late October 1983. The box rigs are used to evaluate 5x8 inch rectangular linear samples. A 21 inch diameter outer liner simulator is also being built up for testing beginning in April 1984. All rigs are atmospheric rigs. The first box rig, a three 6-kVA lamp installation, was operated under adverse conditions to determine feasibility of using quartz lamps for cyclic testing. This work was done in December 1981 and looked promising. The second box rig, again using three 6-kVA lamps, was operated to obtain instrumentation durability information and initial data input to a Finite Element Model. This limited test program was conducted in August 1983. Five test plates were run. Instrumentation consisted of strain gages, thermocouples and thermal paint. The strain gages were found to fail at 1200 F as expected though plates were heated to 1700 F. The third box rig, containing four 6-kVA lamps, is in build up for testing to begin in late October 1983. In addition to 33 percent greater power input, this rig has provision for 400 F backside line cooling air and a viewing port suitable for IR camera viewing. The casing is also water cooled for extended durability.

  2. Current state of knowledge on the behavior of steel liners in concrete containments subjected to overpressurization loads

    International Nuclear Information System (INIS)

    Riesemann, W.A. von; Parks, M.B.

    1995-01-01

    In the US, concrete containment buildings for commercial nuclear power plants have steel liners that act as the internal pressure boundary. The liner abuts the concrete, acting as the interior concrete form. The liner is attached to the concrete by either studs or by a continuous structural shape (such as a T-section or channel) that is either continuously or intermittently welded to the liner. Studs are commonly used in reinforced concrete containments, while prestressed containments utilize a structural element as the anchorage. The practice in some countries follows the US practice, while in other countries the containment does not have a steel liner. In this latter case, there is a true double containment, and the annular region between the two containments is vented.This paper will review the practice of design of the liner system prior to the consideration of severe accident loads (overpressurization loads beyond the design conditions).An overpressurization test of a 1:6 scale reinforced concrete containment at Sandia National Laboratories resulted in a failure mechanism in the liner that was not fully anticipated. Post-test analyses and experiments have been conducted to understand the failure better. This work and the activities that followed the test are reviewed. Areas in which additional research should be conducted are given. (orig.)

  3. EFFECTS OF INORGANIC SALT SOLUTION ON SOME PROPERTIES OF COMPACTED CLAY LINERS

    Directory of Open Access Journals (Sweden)

    KHALID R. MAHMOOD AL-JANABI

    2017-12-01

    Full Text Available Processed and natural clays are widely used to create impermeable liners in solid waste disposal landfills. The engineering properties of clay liners can be significantly affected by the leachate from the waste mass. In this study, the effect of inorganic salt solutions will be investigated. These solutions used at different concentrations. Two type of inorganic salt MnSO4 and FeCl3 are used at different concentration 2%,5%, 10%. Clay used in this study was the CL- clay (kaolinite. The results show that the consistency limits and unconfined compressive strength increased as the concentration of salts increased. While the permeability tends to decrease as salt concentration increased. Also, the compression index decreases as the concentration increased from 2% to 5%. The swelling index tends to increase slightly as the concentration of MnSO4 increased, while its decrease as the concentration of FeCl3. In this paper, it is aimed to investigate the performance of compacted clay liner exposed to the certain chemicals generated by the leachate and their effects on the geotechnical properties of compacted clay liner such consistency limits, permeability coefficient, compressibility characteristics and unconfined compressive strength.

  4. Magnetic pressure effects in a plasma-liner interface

    Science.gov (United States)

    García-Rubio, F.; Sanz, J.

    2018-04-01

    A theoretical analysis of magnetic pressure effects in a magnetized liner inertial fusion-like plasma is presented. In previous publications [F. García-Rubio and J. Sanz, Phys. Plasmas 24, 072710 (2017)], the evolution of a hot magnetized plasma in contact with a cold unmagnetized plasma, aiming to represent the hot spot and liner, respectively, was investigated in planar geometry. The analysis was made in a double limit low Mach and high thermal to magnetic pressure ratio β. In this paper, the analysis is extended to an arbitrary pressure ratio. Nernst, Ettingshausen, and Joule effects come into play in the energy balance. The region close to the liner is governed by thermal conduction, while the Joule dissipation becomes predominant far from it when the pressure ratio is low. Mass ablation, thermal energy, and magnetic flux losses are reduced with plasma magnetization, characterized by the electron Hall parameter ω e τ e , until β values of order unity are reached. From this point forward, increasing the electron Hall parameter no longer improves the magnetic flux conservation, and mass ablation is enhanced due to the magnetic pressure gradients. A thoughtful simplification of the problem that allows to reduce the order of the system of governing equations while still retaining the finite β effects is presented and compared to the exact case.

  5. Geosynthetic clay liners - slope stability field study

    International Nuclear Information System (INIS)

    Carson, D.A.; Daniel, D.E.; Koerner, R.M.; Bonaparte, R.

    1997-01-01

    A field research project was developed to examine the internal shear performance of geosynthetic clay liners (GCLs). Several combinations of cross sections were assembled using GCL materials that were available at the time of project initiation. The cross sections utilized were intended to simulate landfill cover applications. Thirteen (13) resulting test plots were constructed on two different slope angles, and each plot is instrumented for physical displacement and soil moisture characteristics. Test plots were constructed in a manner that dictated the shear plane in the clay portion of the GCL product. The project purpose is to assess field performance and to verify design parameters associated with the application of GCLs in waste containment applications. Interim research data shows that test slopes on 2H:1V show global deformation, but little internal shear evidence, and the 3H:1V slopes show little deformation at approximately 650 days. The research is ongoing, and this paper presents the most recent information available from the project

  6. Extrapolation of creep behavior of high-density polyethylene liner in the Catch Basin of grout vaults

    International Nuclear Information System (INIS)

    Whyatt, G.A.

    1995-07-01

    Testing was performed to determine if gravel particles will creep into and puncture the high-density polyethylene (HDPE) liner in the catch basin of a grout vault over a nominal 30-year period. Testing was performed to support a design without a protective geotextile cover after the geotextile was removed from the design. Recently, a protective geotextile cover over the liner was put back into the design. The data indicate that the geotextile has an insignificant effect on the creep of gravel into the liner. However, the geotextile may help to protect the liner during construction. Two types of tests were performed to evaluate the potential for creep-related puncture. In the first type of test, a very sensitive instrument measured the rate at which a probe crept into HDPE over a 20-minute period at temperatures of 176 degrees F to 212 degrees F (80 degrees C to 100 degrees C). The second type of test consisted of placing the liner between gravel and mortar at 194 degrees F (90 degrees C) and 45.1 psi overburden pressure for periods up to 1 year. By combining data from the two tests, the long-term behavior of the creep was extrapolated to 30 years of service. After 30 years of service, the liner will be in a nearly steady condition and further creep will be extremely small. The results indicate that the creep of gravel into the liner will not create a puncture during service at 194 degrees F (90 degrees C). The estimated creep over 30 years is expected to be less than 25 mils out of the total initial thickness of 60 mils. The test temperature of 194 degrees F (90 degrees C) corresponds to the design basis temperature of the vault. Lower temperatures are expected at the liner, which makes the test conservative. Only the potential for failure of the liner resulting from creep of gravel is addressed in this report

  7. Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses; Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Glowka, D.A.

    1990-09-01

    This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs.

  8. Effect of Different Liners on Fracture Resistance of Premolars Restored with Conventional and Short Fiber-Reinforced Composite Resins.

    Science.gov (United States)

    Shafiei, Fereshteh; Doozandeh, Maryam; Ghaffaripour, Dordaneh

    2018-01-11

    To see whether applying four different liners under short fiber-reinforced composite (SFRC), everX Posterior, compared to conventional composite resin, Z250, affected their strengthening property in premolar MOD cavities. Mesio-occluso-distal (MOD) cavities were prepared in 120 sound maxillary premolars divided into 10 groups (n = 12) in terms of two composite resin types and 4 liners or no liner. For each composite resin, in 5 groups no liner, resin-modified glass ionomer (RMGI), conventional flowable composite (COFL), self-adhesive flowable composite resin (SAFL), and self-adhesive resin cement (SARC) were applied prior to restoring incrementally. After water storage and thermocycling, static fracture resistance was tested. Data (in Newtons) were analyzed using two-way ANOVA (α = 0.05). Fracture resistance was significantly affected by composite resin type (p = 0.02), but not by the liner (p > 0.05). The interaction of the two factors was not statistically significant (p > 0.05). SFRC exhibited higher fracture strength (1470 ± 200 N) compared to conventional composite resin (1350 ± 290), irrespective of the application of liners. Application of SARC and SAFL liners led to a higher number of restorable fractures for both composite resins. The four liners can be used without interfering with the higher efficacy of SFRC, compared to conventional composite resins, to improve the fracture strength of premolar MOD cavities. © 2018 by the American College of Prosthodontists.

  9. Plastic collapse of tubes submitted to a ring load by optimization

    International Nuclear Information System (INIS)

    Zouain, N.

    1982-05-01

    The limit analysis of a tube with finite lenght, made of a rigid - plastic material, is considered for the case of an internal load uniformely distributed in a cross section of the tube. The exact creep law is calculated for several qualitatively differents cases, namely different tube lenghts. The corresponding stress and collapse mechanisms are given so that they can be compared to the approximations developed here. The static and kinematic theorems on plastic collapse are used for establishing two numerical methods of resolution, specifically mathematical programming and finite element method. These mathematical methods are applied to collapse load for the considered tube. (E.G.) [pt

  10. A realistic structural analysis of the integrity of the liner of reinforced and prestressed concrete containments

    International Nuclear Information System (INIS)

    Buchhardt, F.; Brandl, P.

    1979-01-01

    The BWR Gundremmingen II is the first German nuclear power plant with a concrete containment having a thin steel plate liner directly attached to the interior concrete surface to provide an air-tight seal. Due to this monolithic way of anchorage a bonded system of concrete and metal liner membrane is obtained so that the same deformations of the loading or strain conditions are induced to the very stiff concrete hull as well as to the liner. Because of the complex structural behaviour of the bonded system the evaluation is carried out by the finite element method. The overall system is decoupled in several steps. Due to its considerable stiffness the concrete structure can be regarded as the liner supporting basis. The liner system itself might be subdivided into perfect and imperfect sections discretized by plain or curved elements which are supported by point-wise spring elements representing the stud anchors. (orig.)

  11. Elevated lip liner positions improving stability in total hip arthroplasty. An experimental study.

    Directory of Open Access Journals (Sweden)

    Suleman Qurashi

    2018-01-01

    Full Text Available Background: The use of elevated lip polyethylene liners with the acetabular component is relatively common in Total Hip Arthroplasty (THA. Elevated lip liners increase stability of the THA by increasing the jump distance in one direction. However, the elevated lip, conversely, also reduces the primary arc in the opposite direction and leads to early impingement of the neck on the elevated lip, potentially causing instability. The aim of the present study is to determine the total range of motion of the femoral head component within the acetabular component with the elevated lip liner in different orientations within the acetabular cup. Methods: We introduce a novel experimental (ex-vivo framework for studying the effects lip liner orientation on the range of motion of the femoral component. For constant acetabular cup orientation, the elevated lip liner was positioned superiorly and inferiorly. The femoral component range of motion in the coronal, sagittal and axial plane was measured. To avoid any confounding influences of out of plane motion, the femoral component was constrained to move in the tested plane. Results: This experimental set up introduces a rigorous framework in which to test the effects of elevated lip liner orientations on the range of motion of the femoral head component in abduction, adduction, flexion, extension and rotation. The movements of this experimental set-up are directly informative of patient’s maximum potential post-operative range of motion. Initial results show that an inferior placement of the elevated lip increases the effective superior lateral range of motion (abduction for the femoral component, whilst the anatomy of the patient (i.e. their other leg prevents the point of femoral component – acetabular lip impingement being reached (in adduction.

  12. Effect of Incorporation of Antifungal Agents on the Ultimate Tensile Strength of Temporary Soft Denture Liners.

    Science.gov (United States)

    Neppelenbroek, Karin Hermana; Lima, Jozely Francisca Mello; Hotta, Juliana; Galitesi, Lucas Lulo; Almeida, Ana Lucia Pompéia Fraga; Urban, Vanessa Migliorini

    2018-02-01

    To investigate the ultimate tensile strength of temporary soft denture liners modified by minimum inhibitory concentrations (MICs) of antifungal agents for Candida albicans biofilm (SC5314) determined in previous microbiological research. Dumbbell-shaped specimens (n = 7) with a central cross-sectional area of 6 × 3 × 33 mm were produced by Softone and Trusoft, without (control) or with incorporation of drugs in powder form at MICs for C. albicans biofilm (per g of material powder): nystatin (0.032 g), chlorhexidine diacetate (0.064 g), ketoconazole (0.128 g), miconazole (0.256 g), and itraconazole (0.256 g). After plasticization, specimens were immersed in distilled water at 37°C for 24 hours, 7 or 14 days, and then tested in tension in a universal testing machine at 40 mm/min. Data of tensile strength (MPa) and elongation percentage (%) were submitted to 3-way ANOVA and Tukey's test (α = 0.05). At the end of 14 days, the tensile strength for both materials was significantly lower in the groups modified by miconazole and itraconazole compared to the other groups (p 0.05). After 7 and 14 days in water, miconazole and itraconazole added into both materials resulted in significantly lower elongation percentages compared to the other antifungal agents and control (p 0.05). The addition of the nystatin, chlorhexidine, and ketoconazole at MICs for C. albicans biofilm resulted in no harmful effects on the tensile strength and elongation percentage of the temporary soft denture liner materials up to 14 days. © 2017 by the American College of Prosthodontists.

  13. Texture collapse

    International Nuclear Information System (INIS)

    Prokopec, T.; Sornborger, A.; Brandenberger, R.H.

    1992-01-01

    We study single-texture collapse using a leapfrog discretization method on a 30x30x30 spatial lattice. We investigate the influence of boundary conditions, physical size of the lattice, type of space-time background (flat, i.e., nonexpanding, vs radiation-dominated and matter-dominated universes), and spatial distribution of the initial texture configuration on collapse time and critical winding. For a spherically symmetric initial configuration of size equal to the horizon size on a lattice containing 12 (30) horizon volumes, the critical winding is found to be 0.621±0.001 (0.602±0.003) (flat case), 0.624±0.002 (0.604±0.005) (radiation era), 0.628±0.002 (0.612±0.003) (matter era). The larger the physical size of the lattice (in units of the horizon size), the smaller is the critical winding, and in the limit of an infinite lattice, we argue that the critical winding approaches 0.5. For radially asymmetric cases, contraction of one axis ( /Ipancake case) slightly reduces collapse time and critical winding, and contraction of two axes (d/Icigar case) reduces collapse time and critical winding significantly

  14. Collapsing stellar cores and supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, R J [Nordisk Inst. for Teoretisk Atomfysik, Copenhagen (Denmark); Noorgaard, H [Nordisk Inst. for Teoretisk Atomfysik, Copenhagen (Denmark); Chicago Univ., IL (USA). Enrico Fermi Inst.); Bond, J R [Niels Bohr Institutet, Copenhagen (Denmark); California Inst. of Tech., Pasadena (USA). W.K. Kellogg Radiation Lab.)

    1979-05-01

    The evolution of a stellar core is studied during its final quasi-hydrostatic contraction. The core structure and the (poorly known) properties of neutron rich matter are parametrized to include most plausible cases. It is found that the density-temperature trajectory of the material in the central part of the core (the core-center) is insensitive to nearly all reasonable parameter variations. The central density at the onset of the dynamic phase of the collapse (when the core-center begins to fall away from the rest of the star) and the fraction of the emitted neutrinos which are trapped in the collapsing core-center depend quite sensitively on the properties of neutron rich matter. We estimate that the amount of energy Ecm which is imparted to the core-mantle by the neutrinos which escape from the imploded core-center can span a large range of values. For plausible choices of nuclear and model parameters Ecm can be large enough to yield a supernova event.

  15. Effect of sealer coating and storage methods on the surface roughness of soft liners.

    Science.gov (United States)

    Usta Kutlu, Ilknur; Yanikoğlu, Nuran Dinckal; Kul, Esra; Duymuş, Zeynep Yesïl; Sağsöz, Nurdan Polat

    2016-03-01

    A soft lining is applied under a removable prosthesis for various reasons. The porosity of the lining material may increase colonization by microorganisms and cause tissue inflammation. The purpose of this in vitro study was to evaluate the effect of sealer coating on the surface roughness of soft lining materials under 4 different conditions. A total of 125 specimens were prepared. One high-temperature silicone-based soft lining material and 2 room-temperature-polymerized soft lining materials (1 silicone-based and 1 methacrylate-based) were used. Twenty-five specimens of each room-temperature soft lining material were coated with 2 layers of surface sealer. Additionally, 5 specimens of each material were stored in either distilled water, Coca-Cola, denture cleanser, saliva, or air. The surface roughness was measured at baseline and after 1, 7, 14, and 28 days. Surface roughness values were analyzed with repeated measures analysis of variance, and the Bonferroni multiple comparison test was performed using time-dependent groups and storage methods. In the time-dependent groups, methacrylate-based sealer-coated soft liners exhibited a significant increase in roughness (1.74-2.09 μm, P.05). Therefore, the sealer coating was not effective in reducing surface roughness. Among the time-dependent storage methods, the denture cleanser exhibited an almost significant increase in roughness (1.83-1.99 μm, P=.054). Coca-Cola and artificial saliva did not show a significant difference (P>.05). However, a significant decrease in roughness was found with distilled water (P=.02) and air (P<.001). Statistically significant differences in surface roughness were found among the different types of soft liners. The sealer coating had no significant effect, and denture cleanser slightly increased the surface roughness. Contrary to expectations, the roughness did not increase in all groups over time. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry

  16. Small-angle neutron scattering study of micropore collapse in amorphous solid water.

    Science.gov (United States)

    Mitterdorfer, Christian; Bauer, Marion; Youngs, Tristan G A; Bowron, Daniel T; Hill, Catherine R; Fraser, Helen J; Finney, John L; Loerting, Thomas

    2014-08-14

    Vapor-deposited amorphous solid water (ASW) is the most abundant solid molecular material in space, where it plays a direct role in both the formation of more complex chemical species and the aggregation of icy materials in the earliest stages of planet formation. Nevertheless, some of its low temperature physics such as the collapse of the micropore network upon heating are still far from being understood. Here we characterize the nature of the micropores and their collapse using neutron scattering of gram-quantities of D2O-ASW of internal surface areas up to 230 ± 10 m(2) g(-1) prepared at 77 K. The model-free interpretation of the small-angle scattering data suggests micropores, which remain stable up to 120-140 K and then experience a sudden collapse. The exact onset temperature to pore collapse depends on the type of flow conditions employed in the preparation of ASW and, thus, the specific surface area of the initial deposit, whereas the onset of crystallization to cubic ice is unaffected by the flow conditions. Analysis of the small-angle neutron scattering signal using the Guinier-Porod model suggests that a sudden transition from three-dimensional cylindrical pores with 15 Å radius of gyration to two-dimensional lamellae is the mechanism underlying the pore collapse. The rather high temperature of about 120-140 K of micropore collapse and the 3D-to-2D type of the transition unraveled in this study have implications for our understanding of the processing and evolution of ices in various astrophysical environments.

  17. Risk assessment for the transportation of radioactive zeolite liners

    International Nuclear Information System (INIS)

    Gallucci, R.H.V.

    1982-01-01

    The accident risk is estimated for the shipment of two zeolite liners containing radioactive cesium and strontium. Each liner, assumed to hold 68,200 Ci and sealed inside a CNS 1 to 13C, type-B shipping cask, is transported by truck over a 4200-km route. The risk to the population along the route is calculated for potential transportation accidents involving fire, impact, and puncture forces. The total risk is 5.3E-7 man-rem (50-year inhalation dose) and the maximum dose (from the least-likely accident) is 0.7 man-rem. Both estimates are less than 0.1% of comparable risk measures for natural background radiation and spent fuel shipment accidents

  18. Conceptual design of the Fast-Liner Reactor (FLR) for fusion power

    International Nuclear Information System (INIS)

    Moses, R.W.; Krakowski, R.A.; Miller, R.L.

    1979-02-01

    The generation of fusion power from the Fast-Liner Reactor (FLR) concept envisages the implosion of a thin (3-mm) metallic cylinder (0.2-m radius by 0.2-m length) onto a preinjected plasma. This plasma would be heated to thermonuclear temperatures by adiabatic compression, pressure confinement would be provided by the liner inertia, and thermal insulation of the wall-confined plasma would be established by an embedded azimuthal magnetic field. A 2- to 3-mu s burn would follow the approx. 10 4 m/s radial implosion and would result in a thermonuclear yield equal to 10 to 15 times the energy initially invested into the liner kinetic energy. For implosions occurring once every 10 s a gross thermal power of 430 MWt would be generated. The results of a comprehensive systems study of both physics and technology (economics) optima are presented. Despite unresolved problems associated with both the physics and technology of the FLR, a conceptual power plant design is presented

  19. Issues with Strong Compression of Plasma Target by Stabilized Imploding Liner

    Science.gov (United States)

    Turchi, Peter; Frese, Sherry; Frese, Michael

    2017-10-01

    Strong compression (10:1 in radius) of an FRC by imploding liquid metal liners, stabilized against Rayleigh-Taylor modes, using different scalings for loss based on Bohm vs 100X classical diffusion rates, predict useful compressions with implosion times half the initial energy lifetime. The elongation (length-to-diameter ratio) near peak compression needed to satisfy empirical stability criterion and also retain alpha-particles is about ten. The present paper extends these considerations to issues of the initial FRC, including stability conditions (S*/E) and allowable angular speeds. Furthermore, efficient recovery of the implosion energy and alpha-particle work, in order to reduce the necessary nuclear gain for an economical power reactor, is seen as an important element of the stabilized liner implosion concept for fusion. We describe recent progress in design and construction of the high energy-density prototype of a Stabilized Liner Compressor (SLC) leading to repetitive laboratory experiments to develop the plasma target. Supported by ARPA-E ALPHA Program.

  20. Vertical and horizontal liners. Expert seminar; Vertikale und horizontale Abdichtungssysteme. Fachseminar

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, M.; Schulz, T. [comps.

    2000-07-01

    The seminar presented new findings in the fields of surface coverings and alternative liners, vertical liners (with a contribution on developments in Great Britain), and basic constructive problems of liner systems. Another session discussed problems, experience and developments of sealing walls, especially quality assurance measures during sealing wall construction. Apart from presenting a status report, the seminar also intended to provide a basis for an exchange of experience between the attendants. [German] Ein Schwerpunkt des diesjaehrigen Deponieseminars ist die Darstellung von neuen Erkenntnissen und Erfahrungen mit Oberflaechenabdichtungen und mit alternativen Dichtungssystemen fuer Deponien. Weiterhin werden vertikale Abdichtungen behandelt, fuer die ein Beitrag ueber Entwicklungen in Grossbritannien vorliegt sowie grundsaetzliche konstruktive Fragen zu Abdichtungssystemen. Der weitere Seminarschwerpunkt behandelt Problemstellungen, Erfahrungen und Entwicklungen der Dichtwandtechnologie, insbesondere Qualitaetssicherungsmassnahmen waehrend des Dichtwandbaus. Das Ziel des Seminars ist es, einerseits den Stand der Technik und der Forschung darzustellen, andererseits aber die Moeglichkeit zu bieten, Erfahrungen und Informationen auszutauschen. (orig.)

  1. Simulation Study of Structure and Properties of Plasma Liners for the PLX- α Project

    Science.gov (United States)

    Samulyak, Roman; Shih, Wen; Hsu, Scott; PLX-Alpha Team

    2017-10-01

    Detailed numerical studies of the propagation and merger of high-Mach-number plasma jets and the formation and implosion of plasma liners have been performed using the FronTier code in support of the Plasma Liner Experiment-ALPHA (PLX- α) project. Physics models include radiation, physical diffusion, plasma-EOS models, and an anisotropic diffusion model that mimics deviations from fully collisional hydrodynamics in outer layers of plasma jets. Detailed structure and non-uniformity of plasma liners of due to primary and secondary shock waves have been studies as well as averaged quantities of ram pressure and Mach number. Synthetic data from simulations have been compared with available experimental data from a multi-chord interferometer and survey and high-resolution spectrometers. Numerical studies of the sensitivity of liner properties to experimental errors in the initial masses of jets and the synchronization of plasma gun valves have also been performed. Supported by the ARPA-E ALPHA program.

  2. Formation of metal and dielectric liners using a solution process for deep trench capacitors.

    Science.gov (United States)

    Ham, Yong-Hyun; Kim, Dong-Pyo; Baek, Kyu-Ha; Park, Kun-Sik; Kim, Moonkeun; Kwon, Kwang-Ho; Shin, Hong-Sik; Lee, Kijun; Do, Lee-Mi

    2012-07-01

    We demonstrated the feasibility of metal and dielectric liners using a solution process for deep trench capacitor application. The deep Si trench via with size of 10.3 microm and depth of 71 microm were fabricated by Bosch process in deep reactive ion etch (DRIE) system. The aspect ratio was about 7. Then, nano-Ag ink and poly(4-vinylphenol) (PVPh) were used to form metal and dielectric liners, respectively. The thicknesses of the Ag and PVPh liners were about 144 and 830 nm, respectively. When the curing temperature of Ag film increased from 120 to 150 degrees C, the sheet resistance decreased rapidly from 2.47 to 0.72 Omega/sq and then slightly decreased to 0.6 Omega/sq with further increasing the curing temperature beyond 150 degrees C. The proposed liner formation method using solution process is a simple and cost effective process for the high capacity of deep trench capacitor.

  3. Speed Optimization in Liner Shipping Network Design

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Karsten, Christian Vad; Pisinger, David

    In the Liner Shipping Network Design Problem (LSNDP) services sail at a given speed throughout a round trip. In reality most services operate with a speed differentiated head- and back-haul, or even individual speeds on every sailing between two ports. The speed of a service is decisive...

  4. Growth of Rayleigh-Taylor and bulk convective instabilities in dynamics of plasma liners and pinches

    International Nuclear Information System (INIS)

    Bud'ko, A.B.; Velikovich, A.L.; Liberman, M.A.; Felber, F.S.

    1989-01-01

    Perturbation growth is studied for the initial, linear stage of an instability development in the course of a cylindrically-symmetric compression and expansion of plasma liners and Z-pinches with a sharp boundary. The hydrodynamic instabilities are Rayleigh-Taylor and bulk convective ones, the former being the most dengerous. Classification of the instability modes developing in accelerated plasmas, inclusing the local and global Rayleigh-Taylor modes, is given. The spectra of the instability growth rates are calculated for plasma liners and Z-pinches. The properties of the spectra appear to explain the filamentation and stratification of plasmas observed in the experiments with liners and Z-pinches. An axial magnetic field is shown to create a window of stability in the space of the flow parameters, where th Rayleigh-Taylor modes are fully suppressed by the magnetic shear, and the bulk convective ones - to a considerable extent. The axial magnetic field required to stabilize the implosion of a liner is estimated as B z0 =(10-30 kG)I(MA)/R 0 (cm), where I is the average current, R 0 - the initial radius of the liner

  5. Mitigation of Ground Vibration due to Collapse of a Large-Scale Cooling Tower with Novel Application of Materials as Cushions

    Directory of Open Access Journals (Sweden)

    Feng Lin

    2017-01-01

    Full Text Available Ground vibration induced by the collapse of large-scale cooling towers in nuclear power plants (NPPs has recently been realized as a potential secondary disaster to adjacent nuclear-related facilities with demands for vibration mitigation. The previous concept to design cooling towers and nuclear-related facilities operating in a containment as isolated components in NPPs is inappropriate in a limited site which is the cases for inland NPPs in China. This paper presents a numerical study on the mitigation of ground vibration in a “cooling tower-soil-containment” system via a novel application of two materials acting as cushions underneath cooling towers, that is, foamed concrete and a “tube assembly.” Comprehensive “cooling tower-cushion-soil” models were built with reasonable cushion material models. Computational cases were performed to demonstrate the effect of vibration mitigation using seven earthquake waves. Results found that collapse-induced ground vibrations at a point with a distance of 300 m were reduced in average by 91%, 79%, and 92% in radial, tangential, and vertical directions when foamed concrete was used, and the vibrations at the same point were reduced by 53%, 32%, and 59% when the “tube assembly” was applied, respectively. Therefore, remarkable vibration mitigation was achieved in both cases to enhance the resilience of the “cooling tower-soil-containment” system against the secondary disaster.

  6. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin.

    Science.gov (United States)

    Ekren, Orhun; Ozkomur, Ahmet

    2016-08-01

    The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials.

  7. Skin friction on a flat perforated acoustic liner

    Science.gov (United States)

    Boldman, D. R.; Brinich, P. F.

    1976-01-01

    The report concerns the measurement of friction coefficients of a typical perforated acoustic liner installed in the side of a wind tunnel. The results are compared with measured friction coefficients of a smooth hard wall for the same mean flow velocities in a wind tunnel. At a velocity of 61 m/sec, an increase in the local skin coefficient of only a few percent was observed, but at the highest velocity of 213 m/sec an increase of about 20% was obtained. This velocity is a realistic velocity for turbo-machinery components utilizing such liners, so a loss in performance is to be expected. Some tests were also performed to see if changes in the mean boundary layer induced by imposed noise would result in friction increase, but only at low velocity levels was such an increase in friction noted.

  8. Long-term stability of earthen materials in contact with acidic tailings solutions

    International Nuclear Information System (INIS)

    Peterson, S.R.; Erikson, R.L.; Gee, G.W.

    1982-11-01

    The objectives of the studies documented in this report were to use experimental and geochemical computer modeling tools to assess the long-term environmental impact of leachate movement from acidic uranium mill tailings. Liner failure (i.e., an increase in the permeability of the liner material) was not found to be a problem when various acidic tailings solutions leached through liner materials for periods up to 3 years. On the contrary, materials that contained over 30% clay showed a decrease in permeability with time in the laboratory columns. The high clay materials tested appear suitable for lining tailings impoundment ponds. The decreases in permeability are attributed to pore plugging resulting from the precipitation of minerals and solids. This precipitation takes place due to the increase in pH of the tailings solution brought about by the buffering capacity of the soil. Geochemical modeling predicts, and x-ray characterization confirms, that precipitation of solids from solution is occurring in the acidic tailings solution/liner interactions studied. In conclusion the same mineralogical changes and contaminant reactions predicted by geochemical modeling and observed in laboratory studies were found at a drained evaporation pond (Lucky Mc in Wyoming) with a 4 year history of acid attack

  9. Collapse and erosion at the low-level radioactive-waste burial site near Sheffield, Illinois

    International Nuclear Information System (INIS)

    Gray, J.R.; McGovern, L.L.

    1986-01-01

    Collapse and erosion are the dominant landform-modification processes at the Sheffield, Illinois, low-level radioactive-waste burial site. Records on collapse have been collected by the site contractor since 1978 and include data of inspection, location, and cavity dimensions. Fluvial sediment yield was measured by the US Geological Survey beginning in July 1982 from three gaged areas which drained two-thirds of the 20-acre site, and from a gaged 3.5-acre area in undisturbed terrain 0.3 mile south of the site. A total of 302 collapse cavities were recorded from October 1978 through September 1985. Based on the weight of earth material equivalent to cavity volume, an annual average of 6 tons of sediment per acre of site area has moved downward due to collapse. Sixty-two percent of the collapses occurred in swales between waste-disposal trenches or near trench boundaries, while the remainder occurred in earth material covers over trench interiors. Two-thirds of the collapses occurred during the months of February, March, and April. On-site fluvial sediment yield averaged 2 tons per acre per year from July 1982 through July 1984. Although this yield was approximately 200 times that from the undisturbed area, it is about one-half the annual sediment yield expected from a 20-acre row-crop agricultural basin on an 8% slope near Sheffield

  10. Multi-shocks generation and collapsing instabilities induced by competing nonlinearities

    KAUST Repository

    Crosta, Matteo; Trillo, Stefano; Fratalocchi, Andrea

    2012-01-01

    We investigate dispersive shock dynamics in materials with competing cubic-quintic nonlinearities. Whitham theory of modulation, hydrodynamic analysis and numerics demonstrate a rich physical scenario, ranging from multi-shock generation to collapse.

  11. FORENSIC INVESTIGATION OF A GENERATION OLD CIPP LINER

    Science.gov (United States)

    There is limited information regarding the in-situ performance of rehabilitation methods used for prolonging the service life of buried municipal pipeline systems. With some CIPP liners nearly 30 years in service, municipalities are expressing a strong interest in the collection ...

  12. The f electron collapse revisited

    International Nuclear Information System (INIS)

    Bennett, B.I.

    1987-03-01

    A reexamination of the collapse of 4f and 5f electrons in the lanthanide and actinide series is presented. The calculations show the well-known collapse of the f electron density at the thresholds of these series along with an f 2 collapse between thorium and protactinium. The collapse is sensitive to the choice of model for the exchange-correlation potential and the behavior of the potential at large radius

  13. Modeling and Solving the Liner Shipping Service Selection Problem

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Balakrishnan, Anant

    We address a tactical planning problem, the Liner Shipping Service Selection Problem (LSSSP), facing container shipping companies. Given estimated demand between various ports, the LSSSP entails selecting the best subset of non-simple cyclic sailing routes from a given pool of candidate routes...... to accurately model transshipment costs and incorporate routing policies such as maximum transit time, maritime cabotage rules, and operational alliances. Our hop-indexed arc flow model is smaller and easier to solve than path flow models. We outline a preprocessing procedure that exploits both the routing...... requirements and the hop limits to reduce problem size, and describe techniques to accelerate the solution procedure. We present computational results for realistic problem instances from the benchmark suite LINER-LIB....

  14. Recyclability of mixed office waste papers containing pressure sensitive adhesives and silicone release liners

    Science.gov (United States)

    Julie Hess; Roberta Sena-Gomes; Lisa Davie; Marguerite Sykes

    2001-01-01

    Increased use of pressure sensitive adhesives for labels and stamps has introduced another contaminant into the office paper stream: silicone- coated release liners. This study examines methods and conditions for removal of contaminants, including these liners, from a typical batch of discarded office papers. Removal of contaminants contained in the furnish were...

  15. Collapse dynamics of ultrasound contrast agent microbubbles

    Science.gov (United States)

    King, Daniel Alan

    the size distributions of these UCAs, it is shown that the shell material has a large influence on the occurrence of postexcitation rebound at all tested frequencies while moderate alteration of the size distribution may only play a significant role within certain frequency ranges. Finally, the conditions which generate the experimental postexcitation signal are examined theoretically using several forms of single bubble models. Evidence is provided for the usefulness of modeling this large amplitude UCA behavior with a size-varying surface tension as described in the Marmottant model; better agreement for lipid-shelled Definity UCAs is obtained by considering the dynamic response with a rupturing shell rather than either a non-rupturing or nonexistent shell. Moreover, the modeling indicates that maximum radial expansion from the initial UCA size is a suitable metric to predict postexcitation collapse, and that both shell rupture and inertial cavitation are necessary conditions to generate this behavior. Postexcitation analysis is found to be a beneficial characterization metric for studying the destruction behaviors of single UCAs when measured with the double PCD setup. This work provides quantitative documentation of UCA collapse, exploration into UCA material properties which affect this collapse, and comparison of existing single bubble models with experimentally measured postexcitation signals.

  16. Technique for fabrication of ultrathin foils in cylindrical geometry for liner-plasma implosion experiments with sub-megaampere currents

    Science.gov (United States)

    Yager-Elorriaga, D. A.; Steiner, A. M.; Patel, S. G.; Jordan, N. M.; Lau, Y. Y.; Gilgenbach, R. M.

    2015-11-01

    In this work, we describe a technique for fabricating ultrathin foils in cylindrical geometry for liner-plasma implosion experiments using sub-MA currents. Liners are formed by wrapping a 400 nm, rectangular strip of aluminum foil around a dumbbell-shaped support structure with a non-conducting center rod, so that the liner dimensions are 1 cm in height, 6.55 mm in diameter, and 400 nm in thickness. The liner-plasmas are imploded by discharging ˜600 kA with ˜200 ns rise time using a 1 MA linear transformer driver, and the resulting implosions are imaged four times per shot using laser-shadowgraphy at 532 nm. This technique enables the study of plasma implosion physics, including the magneto Rayleigh-Taylor, sausage, and kink instabilities on initially solid, imploding metallic liners with university-scale pulsed power machines.

  17. Asymmetries in core-collapse supernovae from maps of radioactive 44Ti in Cassiopeia A

    DEFF Research Database (Denmark)

    Grefenstette, B W; Harrison, F A; Boggs, S E

    2014-01-01

    Asymmetry is required by most numerical simulations of stellar core-collapse explosions, but the form it takes differs significantly among models. The spatial distribution of radioactive (44)Ti, synthesized in an exploding star near the boundary between material falling back onto the collapsing...... core and that ejected into the surrounding medium, directly probes the explosion asymmetries. Cassiopeia A is a young, nearby, core-collapse remnant from which (44)Ti emission has previously been detected but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio...... and iron X-ray emission, the latter being visible only in shock-heated material. The observed spatial distribution rules out symmetric explosions even with a high level of convective mixing, as well as highly asymmetric bipolar explosions resulting from a fast-rotating progenitor. Instead...

  18. Instability behavior of stiffened dome liners under construction condition

    International Nuclear Information System (INIS)

    Jefts, A.R.; Guha-Majumdar, S.; Wanchoo, M.K.

    1977-01-01

    The purpose of this paper is to present techniques related to stability analysis, design concepts and behavior of dome liners. Various stiffening systems are examined from economy, schedule and constructablity point of view. The various failure modes can be classified as either buckling due to local instability or to an overall instability of the shell. Local instability may occur due to buckling of liner panel between a pair of rings and stringers or torsional and lateral buckling of the stiffeners. Methods are developed for proportioning stiffening system to preclude local buckling. Overall stability is a function of concrete pour height and thickness, loading distribution, time elapse between successive placements, rate of concrete placement, arrangement of stiffeners and other external supports. A computer program based on system energy minimization is used to study the overall instability of stiffened domes. Modelling techniques, effect of temperature and lack of bond, and their influence on results are discussed. Results for a self-standing stiffened hemispherical dome are presented in the form of mode shapes and buckling loads. Based on the results, a pouring scheme is recommended for an economical stiffening system. Recommendations are made to select the stiffening system and predict the buckling loads for preliminary analysis and design of the dome liner. Existing methods and code provisions related to tolerance, design criteria etc. are examined and recommendations made from practical considerations

  19. On the role of ambient environments in the collapse of Bonnor-Ebert spheres

    International Nuclear Information System (INIS)

    Kaminski, Erica; Frank, Adam; Carroll, Jonathan; Myers, Phil

    2014-01-01

    We consider the interaction between a marginally stable Bonnor-Ebert (BE) sphere and the surrounding ambient medium. In particular, we explore how the infall from an evolving ambient medium can trigger the collapse of the sphere using three-dimensional adaptive mesh refinement simulations. We find the resulting collapse dynamics to vary considerably with ambient density. In the highest ambient density cases, infalling material drives a strong compression wave into the cloud. It is the propagation of this wave through the cloud interior that triggers the subsequent collapse. For lower ambient densities, we find the main trigger of collapse to be a quasistatic adjustment of the BE sphere to gravitational settling of the ambient gas. In all cases, we find that the classic 'outside-in' collapse mode for super-critical BE spheres is recovered before a protostar (i.e., sink particle) forms. Our work supports scenarios in which BE dynamics naturally begins with either a compression wave or infall dominated phase, and only later assumes the usual outside-in collapse behavior.

  20. Pulsed power experiments in hydrodynamics and material properties

    CERN Document Server

    Reinovsky, R E

    1999-01-01

    A new application for high performance pulsed power program, the production of high energy density environments in materials for the study of material properties and hydrodynamics in complex geometries, has joined family of radiation source applications in the Stockpile Stewardship. The principle tool for producing high energy density environments is the high precision, magnetically imploded, near-solid density liner. The most attractive pulsed power system for driving such experiments is an ultra-high current, low impedance, microsecond time scale source that is economical both to build and operate. The 25-MJ Atlas capacitor bank system currently under construction at Los Alamos is the first system of its scale specifically designed to drive high precision solid liners. Delivering 30 MA, Atlas will provide liner velocities 12-15 km/sec and kinetic energies of 1-2 MJ /cm with extensive diagnostics and excellent reproducibility. Explosive flux compressor technology provides access to currents exceeding 100 MA ...

  1. Mechanisms and prevention of plant tissue collapse during dehydration: a critical review.

    Science.gov (United States)

    Prothon, Frédéric; Ahrné, Lilia; Sjöholm, Ingegerd

    2003-01-01

    The appearance and functional properties are primordial in the quality assessment of semifinished fruit and vegetable products. These properties are often associated with shrunken, shriveled, darkened materials of poor rehydration ability after been subjected to air-drying--the most used drying method in the food industry. Fruits and vegetables are cellular tissues containing gas-filled pores that tend to collapse when subjected to dehydration. Collapse is an overall term that has different meanings and scale-settings in the literature depending on whether the author is a plant physiologist, a food technologist, a chemical engineer, or a material scientist. Some clarifications are given in this particular but wide field. The purpose of this work was to make a state-of-the-art contribution to the structural and textural effects of different types of dehydration on edible plant products and give a basis for preventing this phenomenon. The plant tissue is described, and the primordial role of the cell wall in keeping the structural integrity is emphasized. Water and its functionality at macro and micro levels of the cellular tissue are reviewed as well as its transport during dehydration. The effects of both dehydration and rehydration are described in detail, and the term "textural collapse" is proposed as an alternative to structural collapse.

  2. Geotechnical properties of Egyptian collapsible soils

    Directory of Open Access Journals (Sweden)

    Khaled E. Gaaver

    2012-09-01

    Full Text Available The risk of constructing structures on collapsible soils presents significant challenges to geotechnical engineers due to sudden reduction in volume upon wetting. Identifying collapsible soils when encountered in the field and taking the needed precautions should substantially reduce the risk of such problems usually reported in buildings and highways. Collapsible soils are those unsaturated soils that can withstand relatively high pressure without showing significant change in volume, however upon wetting; they are susceptible to a large and sudden reduction in volume. Collapsible soils cover significant areas around the world. In Egypt, collapsible soils were observed within the northern portion of the western desert including Borg El-Arab region, and around the city of Cairo in Six-of-October plateau, and Tenth-of-Ramadan city. Settlements associated with development on untreated collapsible soils usually lead to expensive repairs. One method for treating collapsible soils is to densify their structure by compaction. The ongoing study presents the effect of compaction on the geotechnical properties of the collapsible soils. Undisturbed block samples were recovered from test pits at four sites in Borg El-Arab district, located at about 20 km west of the city of Alexandria, Egypt. The samples were tested in both unsoaked and soaked conditions. Influence of water inundation on the geotechnical properties of collapsible soils was demonstrated. A comparative study between natural undisturbed and compacted samples of collapsible soils was performed. An attempt was made to relate the collapse potential to the initial moisture content. An empirical correlation between California Bearing Ratio of the compacted collapsible soils and liquid limit was adopted. The presented simple relationships should enable the geotechnical engineers to estimate the complex parameters of collapsible soils using simple laboratory tests with a reasonable accuracy.

  3. The PLX- α project: demonstrating the viability of spherically imploding plasma liners as an MIF driver

    Science.gov (United States)

    Hsu, S. C.; Witherspoon, F. D.; Cassibry, J. T.; Gilmore, M.; Samulyak, R.; Stoltz, P.; the PLX-α Team

    2015-11-01

    Under ARPA-E's ALPHA program, the Plasma Liner Experiment-ALPHA (PLX- α) project aims to demonstrate the viability and scalability of spherically imploding plasma liners as a standoff, high-implosion-velocity magneto-inertial-fusion (MIF) driver that is potentially compatible with both low- and high- β targets. The project has three major objectives: (a) advancing existing contoured-gap coaxial-gun technology to achieve higher operational reliability/precision and better control/reproducibility of plasma-jet properties and profiles; (2) conducting ~ π / 2 -solid-angle plasma-liner experiments with 9 guns to demonstrate (along with extrapolations from modeling) that the jet-merging process leads to Mach-number degradation and liner uniformity that are acceptable for MIF; and (3) conducting 4 π experiments with up to 60 guns to demonstrate the formation of an imploding spherical plasma liner for the first time, and to provide empirical ram-pressure and uniformity scaling data for benchmarking our codes and informing us whether the scalings justify further development beyond ALPHA. This talk will provide an overview of the PLX- α project as well as key research results to date. Supported by ARPA-E's ALPHA program; original PLX construction supported by DOE Fusion Energy Sciences.

  4. Topographic stress and catastrophic collapse of volcanic islands

    Science.gov (United States)

    Moon, S.; Perron, J. T.; Martel, S. J.

    2017-12-01

    Flank collapse of volcanic islands can devastate coastal environments and potentially induce tsunamis. Previous studies have suggested that factors such as volcanic eruption events, gravitational spreading, the reduction of material strength due to hydrothermal alteration, steep coastal cliffs, or sea level change may contribute to slope instability and induce catastrophic collapse of volcanic flanks. In this study, we examine the potential influence of three-dimensional topographic stress perturbations on flank collapses of volcanic islands. Using a three-dimensional boundary element model, we calculate subsurface stress fields for the Canary and Hawaiian islands to compare the effects of stratovolcano and shield volcano shapes on topographic stresses. Our model accounts for gravitational stresses from the actual shapes of volcanic islands, ambient stress in the underlying plate, and the influence of pore water pressure. We quantify the potential for slope failure of volcanic flanks using a combined model of three-dimensional topographic stress and slope stability. The results of our analysis show that subsurface stress fields vary substantially depending on the shapes of volcanoes, and can influence the size and spatial distribution of flank failures.

  5. Mechanisms of cascade collapse

    International Nuclear Information System (INIS)

    Diaz de la Rubia, T.; Smalinskas, K.; Averback, R.S.; Robertson, I.M.; Hseih, H.; Benedek, R.

    1988-12-01

    The spontaneous collapse of energetic displacement cascades in metals into vacancy dislocation loops has been investigated by molecular dynamics (MD) computer simulation and transmission electron microscopy (TEM). Simulations of 5 keV recoil events in Cu and Ni provide the following scenario of cascade collapse: atoms are ejected from the central region of the cascade by replacement collision sequences; the central region subsequently melts; vacancies are driven to the center of the cascade during resolidification where they may collapse into loops. Whether or not collapse occurs depends critically on the melting temperature of the metal and the energy density and total energy in the cascade. Results of TEM are presented in support of this mechanism. 14 refs., 4 figs., 1 tab

  6. A matheuristic for the liner shipping network design problem

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Desaulniers, Guy; Pisinger, David

    We present a matheuristic, an integer programming based heuristic, for the liner shipping network design problem. This problem consists of finding a set of container shipping routes defining a capacitated network for cargo transport. The objective is to maximize the revenue of cargo transport...... the available fleet of container vessels. The cargo transports make extensive use of transshipments between routes and the number of transshipments of the cargo flow is decisive for network profitability. Computational results are reported for the benchmark suite LINER-LIB 2012 following the industry standard...... of weekly departures on every schedule. The heuristic shows overall good performance and is able to find high quality solutions within competitive execution times. The matheuristic can also be applied as a decision support tool to improve an existing network by optimizing on a designated subset...

  7. Milking performance and udder health of cows milked with two different liners

    DEFF Research Database (Denmark)

    Rasmussen, Morten D.; Frimer, Erik S.; Kaartinen, L.

    1998-01-01

    The effects of milking cows with two different liners were measured for a period of 8 months with 115 Danish Holstein cows divided into two groups. G-roup H and L animals were milked with liners with mouthpiece cavity]heights of 30 and 18 mm respectively (other dimensions also differed between...... the two liners). Aver age teat lengths of first lactation cows were 45 and 40 mm for front and rear teats. Older cows had teats similar to 10 min longer. There was no difference in milk yield or milk flow rates between the two groups. Average machine-on time was shorter for group L, and first lactation...... cows of group L were less restive. The frequency of red and blue discoloured teats immediately after milking was higher for group H, and teat length increased on average 5 mm during lactation with no increase for group L. The small overall differences in udder health between the two groups were...

  8. Estimation of exposure to sunlight of the liner under a tiled roof

    DEFF Research Database (Denmark)

    Holck, Ole; Rosenfeld, J.L.J.

    2005-01-01

    One construction for a pitched roof is to use tiles on battens, with a liner attached below the battens. The shape of some types of tiles is such that, at each corner where four tiles overlap, a small gap is formed. At certain positions of the sun solar radiation can penetrate through these gaps....... Simulations were carried out for a roof tilted at 25degrees, 35degrees or 45degrees, facing SE, S, SW or W. For the particular roof construction and gap studied, the maximum annual exposure of a 25 mm(2) piece of the liner placed 150 mm below the gap (corresponding to about 100 mm below the base of the tiles...... to the roof. Analytic expressions for the size of the illuminated area are obtained using a thick slit model. The accuracy of the model was assessed by some experimental measurements. The exposure over one year of the roof liner was calculated using the Design Reference Year for Copenhagen, Denmark...

  9. Effectiveness of a resin-modified glass ionomer liner in reducing hypersensitivity in posterior restorations: a study from the practitioners engaged in applied research and learning network.

    Science.gov (United States)

    Strober, Brad; Veitz-Keenan, Analia; Barna, Julie Ann; Matthews, Abigail G; Vena, Donald; Craig, Ronald G; Curro, Frederick A; Thompson, Van P

    2013-08-01

    The objectives of this randomized comparative effectiveness study conducted by members of the Practitioners Engaged in Applied Research and Learning (PEARL) Network were to determine whether using a resin-modified glass ionomer (RMGI) liner reduces postoperative hypersensitivity (POH) in dentin-bonded Class I and Class II resin-based composite (RBC) restorations, as well as to identify other factors (putative risk factors) associated with increased POH. PEARL Network practitioner-investigators (P-Is) (n = 28) were trained to assess sensitivity determination, enamel and dentin caries activity rankings, evaluation for sleep bruxism, and materials and techniques used. The P-Is enrolled 341 participants who had hypersensitive posterior lesions. Participants were randomly assigned to receive an RBC restoration with or without an RMGI liner before P-Is applied a one-step, self-etching bonding agent. P-Is conducted sensitivity evaluations at baseline, at one and four weeks after treatment, and at all visits according to patient-reported outcomes. P-Is collected complete data regarding 347 restorations (339 participants) at baseline, with 341 (98 percent) (333 participants) recalled at four weeks. Treatment groups were balanced across baseline characteristics and measures. RBC restorations with or without an RMGI liner had the same one-week and four-week POH outcomes, as measured clinically (by means of cold or air stimulation) and according to patient-reported outcomes. Use of an RMGI liner did not reduce clinically measured or patient-reported POH in moderate-depth Class I and Class II restorations. Cold and air clinical stimulation findings were similar between groups. Practical Implications. The time, effort and expense involved in placing an RMGI liner in these moderate-depth RBC restorations may be unnecessary, as the representative liner used did not improve hypersensitivity outcomes.

  10. The effect of rebonding and liner type on microleakage of Class V amalgam restorations

    Directory of Open Access Journals (Sweden)

    Moosavi H.

    2008-10-01

    Full Text Available Background and Aim: Application of varnish and dentin bonding agents can effectively reduce microleakage under amalgam restorations. Also rebonding may show some effects on microleakage and its complications. The aim of this study was to evaluate the effect of liner/ adhesives on microleakage of Class V amalgam restoration with or without rebonding. Materials and Methods: In this in vitro study Class V cavities were prepared on sixty sound human maxillary premolars with the gingival floor 1mm below the CEJ. Cases were divided into six groups of ten teeth each. Specimens in group 1 and 2 were lined with Copalite and Scotchbond Multi-Purpose (SBMP respectively. In the third group (control no liner was applied. The teeth were then restored with spherical amalgam. Specimens in group 4 to 6 received the same treatments but after filling, the interfaces of restorations and teeth were etched with 37% phosphoric acid gel, rinsed and dried. Adhesive resin of SBMP was applied over amalgam and tooth margins and polymerized (rebonding. Specimens were thermocycled, exposed to dye and sectioned. Microleakage was graded (0-3 using a stereomicroscope at X40 magnification. Data were analyzed with Kruskal-Wallis, Mann-Whitney and Wilcoxon pair wise statistical tests. P<0.05 was considered as the limit of significance. Results: The groups lined with SBMP showed the lowest and the groups without liner the highest microleakage (p= 0.001. Significant difference was observed in microleakage mean rank of enamel and dentin margins (p=0.048. Rebonding with resin did not improve the seal (p> 0.05. Conclusion: Based on the results of this study, total etch adhesive system had significant effect on microleakage of Class V amalgam restorations especially in cervical margin. Rebonding did not show a significant effect on microleakage.

  11. Eddy current and quench loads and stress of SSC collider 4-K liner and the bore tube during magnet quench

    International Nuclear Information System (INIS)

    Leung, K.K.; Shu, Q.S.

    1993-07-01

    This paper describes the response of the eddy current and quench loads on a proposed Superconducting SuperCollider 4-K liner system. The liner within a bore tube is designed to remove the radiated power and the photodesorbed gas that impair the beam tube vacuum. The bimetallic liner tube is subjected to cooldown and eddy current loads. The square liner tube is a two-shell laminated Nitronic-40 steel is used for strength and a copper inner layer for low impedance to the image currents. Perforated holes are used to remove the photodesorbed gases for vacuum maintenance. The holes are located in a low-stress area of the liner. Rectangular holes in a four-pole symmetry pattern are required for beam dynamic stability. The liner is conductivity cooled by the round steel bore tube with a 2-mm wall. The copper layer must not be stressed over the yield strength limit because copper properties such as conductivity are known to change when the copper is stressed over yield strength. This analysis will address liner system response under thermal, eddy current, and vaporized liquid helium loads in a quenching dipole magnet

  12. Dynamic Response and Residual Helmet Liner Crush Using Cadaver Heads and Standard Headforms.

    Science.gov (United States)

    Bonin, S J; Luck, J F; Bass, C R; Gardiner, J C; Onar-Thomas, A; Asfour, S S; Siegmund, G P

    2017-03-01

    Biomechanical headforms are used for helmet certification testing and reconstructing helmeted head impacts; however, their biofidelity and direct applicability to human head and helmet responses remain unclear. Dynamic responses of cadaver heads and three headforms and residual foam liner deformations were compared during motorcycle helmet impacts. Instrumented, helmeted heads/headforms were dropped onto the forehead region against an instrumented flat anvil at 75, 150, and 195 J. Helmets were CT scanned to quantify maximum liner crush depth and crush volume. General linear models were used to quantify the effect of head type and impact energy on linear acceleration, head injury criterion (HIC), force, maximum liner crush depth, and liner crush volume and regression models were used to quantify the relationship between acceleration and both maximum crush depth and crush volume. The cadaver heads generated larger peak accelerations than all three headforms, larger HICs than the International Organization for Standardization (ISO), larger forces than the Hybrid III and ISO, larger maximum crush depth than the ISO, and larger crush volumes than the DOT. These significant differences between the cadaver heads and headforms need to be accounted for when attempting to estimate an impact exposure using a helmet's residual crush depth or volume.

  13. Separate effects testing and analyses to investigate liner tearing of the 1:6-scale reinforced concrete containment building

    International Nuclear Information System (INIS)

    Spletzer, B.L.; Lambert, L.D.; Bergman, V.L.

    1995-06-01

    The overpressurization of a 1:6-scale reinforced concrete containment building demonstrated that liner tearing is a plausible failure mode in such structures under severe accident conditions. A combined experimental and analytical program was developed to determine the important parameters which affect liner tearing and to develop reasonably simple analytical methods for predicting when tearing will occur. Three sets of test specimens were designed to allow individual control over and investigation of the mechanisms believed to be important in causing failure of the liner plate. The series of tests investigated the effect on liner tearing produced by the anchorage system, the loading conditions, and the transition in thickness from the liner to the insert plate. Before testing, the specimens were analyzed using two- and three-dimensional finite element models. Based on the analysis, the failure mode and corresponding load conditions were predicted for each specimen. Test data and post-test examination of test specimens show mixed agreement with the analytical predictions with regard to failure mode and specimen response for most tests. Many similarities were also observed between the response of the liner in the 1:6-scale reinforced concrete containment model and the response of the test specimens. This work illustrates the fact that the failure mechanism of a reinforced concrete containment building can be greatly influenced by details of liner and anchorage system design. Further, it significantly increases the understanding of containment building response under severe conditions

  14. Mineralogical and chemical-physical effects of hydrocarbon permeation in composite liners and cut-off walls. Final report; Mineralogische und chemisch-physikalische Auswirkungen der Permeation von Kohlenwasserstoffen in Kombinationsdichtungen und -dichtwaenden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kalbe, U; Berger, W; Mueller, W; Brune, M; Eckardt, J; Tatzky-Gerth, R; Ache, W; Goebbels, J [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Breu, J; Kerzdoerfer, H [Regensburg Univ. (Germany). Inst. fuer Anorganische Chemie

    2000-05-31

    Composite liner systems (HDPE geomembrane and compacted mineral liner) are used in Germany in landfills and for the lining of contaminated sites according to the technical regulations. It is expected that these lining systems provide a highly efficient and reliable technical barrier for the long-term groundwater protection. To support these expectations and assess the performance of the liner system even under extreme conditions, various composite liner systems were exposed to a mixture of 9 liquid hydrocarbons and their permeation behaviour was studied in permeation cells over 12 years. The cells were now dismantled and changes in the liner materials were carefully measured and controlled. The following issues were pursued in the research project: - effect of long-term hydrocarbon permeation and immersion on the properties of the geomembrane, - determination of the vertical distribution of organic contaminants in the mineral liner, - changes in the mineralogical, micromorphological and soil mechanical properties of the mineral liner brought about by the contaminant mixture, - investigation of the influence of microbial activity on the mineral layer, - modelling of the pollutant transport in the composite liner system. Neither geomembrane nor most of the tested mineral liners exhibited significant changes. Hydrocarbon permeation was proved to have been substantially suppressed by the composite liner. (orig.) [German] Zur Sicherung von Deponien und Altlasten mit dem Ziel eines langfristig wirksamen Grundwasserschutzes werden seit Mitte der 80er Jahre Kombinationsdichtungen (Verbund aus Kunststoffdichtungsbahn und mineralischer Dichtschichten) eingesetzt. Um deren Langzeitbestaendigkeit auch unter extremen Bedingungen bewerten zu koennen, wurden Permeationsmesszellen, welche die Verhaeltnisse in der Deponie nachstellen und ueber einen Zeitraum von 12 Jahren mit einem Mehrkomponentengemisch konzentrierter organischer Verbindungen beaufschlagt worden waren, zerlegt und

  15. [Comparative study of the antimicrobial effect of various cavity liners used in conservative dentistry].

    Science.gov (United States)

    Pumarola Suñé, J; Espias Gómez, A; Canalda Sahli, C

    1989-01-01

    We have compared the microbiological activity of the following cavity liners: Life, Dycal II, Calcipulpe, Pure calcium hydroxide and Cavitec; against five different bacterial strains: Veillonella parvula, Bacteroides fragilis, Peptococcus s.p., Staphylococcus aureus, and Streptococcus beta hemolytic: The results demonstrate the higher antimicrobial activity of the manufactured cavity liners with calcium hydroxide base in comparison with the pure calcium hydroxide.

  16. Slope Stability of Geosynthetic Clay Liner Test Plots

    Science.gov (United States)

    Fourteen full-scale field test plots containing five types of geosynthetic clay liners (GCLs) were constructed on 2H:IV and 3H:IV slopes for the purpose of assessing slope stability. The test plots were designed to simulate typical final cover systems for landfill. Slides occurr...

  17. Basic processes and factors determining the evolution of collapse sinkholes: a sensitivity study

    Science.gov (United States)

    Romanov, Douchko; Kaufmann, Georg

    2017-04-01

    Collapse sinkholes appear as closed depressions at the surface. The origin of these karst features is related to the continuous dissolution of the soluble rock caused by a focussed sub-surface flow. Water flowing along a preferential pathway through fissures and fractures within the phreatic part of a karst aquifer is able to dissolve the rock (limestone, gypsum, anhydrite). With time, the dissolved void volume increases and part of the ceiling above the stream can become unstable, collapses, and accumulates as debris in the flow path. The debris partially blocks the flow and thus activates new pathways. Because of the low compaction of the debris (high hydraulic conductivity), the flow and the dissolution rates within this crushed zone remain high. This allows a relatively fast dissolutional and erosional removal of the crushed material and the development of new empty voids. The void volume expands upwards towards the surface until a collapse sinkhole is formed. The collapse sinkholes exhibit a large variety of shapes (cylindrical, cone-, bowl-shaped), depths (from few to few hundred meters) and diameters (meters up to hundreds of meters). Two major processes are responsible for this diversity: a) the karst evolution of the aquifer - responsible for the dissolutional and erosional removal of material; b) the mechanical evolution of the host rock and the existence of structural features, faults for example, which determine the stability and the magnitude of the subsequent collapses. In this work we demonstrate the influence of the host rock type, the hydrological and geological boundary conditions, the chemical composition of the flowing water, and the geometry and the scale of the crushed zone, on the location and the evolution of the growing sinkhole. We demonstrate the ability of the karst evolution models to explain, at least qualitatively, the growth and the morphology of the collapse sinkholes and to roughly predict their shape and location. Implementing

  18. Application of non-destructive liner thickness measurement technique for manufacturing and inspection process of zirconium lined cladding tube

    International Nuclear Information System (INIS)

    Nakazawa, Norio; Fukuda, Akihiro; Fujii, Noritsugu; Inoue, Koichi

    1986-01-01

    Recently, in order to meet the difference of electric power demand owing to electric power situation, large scale load following operation has become necessary. Therefore, the development of the cladding tubes which withstand power variation has been carried out, as the result, zirconium-lined zircaloy 2 cladding tubes have been developed. In order to reduce the sensitivity to stress corrosion cracking, these zirconium-lined cladding tubes require uniform liner thickness over the whole surface and whole length. Kobe Steel Ltd. developed the nondestructive liner thickness measuring technique based on ultrasonic flaw detection technique and eddy current flaw detection technique. These equipments were applied to the manufacturing and inspection processes of the zirconium-lined cladding tubes, and have demonstrated superiority in the control and assurance of the liner thickness of products. Zirconium-lined cladding tubes, the development of the measuring technique for guaranteeing the uniform liner thickness and the liner thickness control in the manufacturing and inspection processes are described. (Kako, I.)

  19. Competitive Liner Shipping Network Design

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Brouer, Berit Dangaard; Pisinger, David

    2017-01-01

    We present a solution method for the liner shipping network design problem which is a core strategic planning problem faced by container carriers. We propose the first practical algorithm which explicitly handles transshipment time limits for all demands. Individual sailing speeds at each service...... leg are used to balance sailing speed against operational costs, hence ensuring that the found network is competitive on both transit time and cost. We present a matheuristic for the problem where a MIP is used to select which ports should be inserted or removed on a route. Computational results...

  20. Competitive Liner Shipping Network Design

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Brouer, Berit Dangaard; Pisinger, David

    We present a solution method for the liner shipping network design problem which is a core strategic planning problem faced by container carriers. We propose the first practical algorithm which explicitly handles transshipment time limits for all demands. Individual sailing speeds at each service...... leg are used to balance sailings speed against operational costs, hence ensuring that the found network is competitive on both transit time and cost. We present a matheuristic for the problem where a MIP is used to select which ports should be inserted or removed on a route. Computational results...

  1. Spherical dust collapse in higher dimensions

    International Nuclear Information System (INIS)

    Goswami, Rituparno; Joshi, Pankaj S.

    2004-01-01

    We consider here whether it is possible to recover cosmic censorship when a transition is made to higher-dimensional spacetimes, by studying the spherically symmetric dust collapse in an arbitrary higher spacetime dimension. It is pointed out that if only black holes are to result as the end state of a continual gravitational collapse, several conditions must be imposed on the collapsing configuration, some of which may appear to be restrictive, and we need to study carefully if these can be suitably motivated physically in a realistic collapse scenario. It would appear, that, in a generic higher-dimensional dust collapse, both black holes and naked singularities would develop as end states as indicated by the results here. The mathematical approach developed here generalizes and unifies the earlier available results on higher-dimensional dust collapse as we point out. Further, the dependence of black hole or naked singularity end states as collapse outcomes on the nature of the initial data from which the collapse develops is brought out explicitly and in a transparent manner as we show here. Our method also allows us to consider here in some detail the genericity and stability aspects related to the occurrence of naked singularities in gravitational collapse

  2. Spherically symmetric radiation in gravitational collapse

    International Nuclear Information System (INIS)

    Bridy, D.J.

    1983-01-01

    This paper investigates a previously neglected mode by which a star may lose energy in the late stages of gravitational collapse to the black hole state. A model consisting of a Schwarzschild exterior matched to a Friedman interior of collapsing pressureless dust is studied. The matter of the collapsing star is taken as the source of a massive vector boson field and a detailed boundary value problem is carried out. Vector mesons are strongly coupled to all nucleons and will be radiated by ordinary matter during the collapse. The time dependent coupling between interior and exterior modes matched across the moving boundary of the collapsing star and the presence of the gravitational fields and their gradients in the field equations may give rise to a parametric amplification mechanism and permit the gravitational field to pump energy into the boson field, greatly enhancing the amount of boson radiation. The significance of a radiative mechanism driven by collapse is that it can react back upon the collapsing source and deprive it of some of the very mass that drives the collapse via its self gravitation. If the mass loss is great enough, this may provide a mechanism to slow or even halt gravitational collapse in some cases

  3. Experimental investigations concerning the suitability of channel systems for liner leak detection and drainage of a prestressed concrete vessel

    International Nuclear Information System (INIS)

    Nickel, M.; Breitbach, G.; Altes, J.; Escherich, K.H.; Wolters, J.

    1985-02-01

    The iternal surfaces of prestressed concrete pressure vessels are fitted with a steel liner to preserve the gas tightness of the primary circuit. Because of the high quality manufacture and the loading conditions a linear failure can be practically excluded. However, if it is hypothetically assumed, that a leak develops during reactor operation, it may be difficult to determine the position of the leak, because the linear area is very large. For tightness surveillance and for venting channel systems installed in close proximity to the linear are suitable. The suitability of such channels for leak detection, localisation and venting was investigated experimentally. A concrete wall (length 2.5 m, height 2.0 m, thickness 0.5 m) was constructed, covered on one side with a steel liner. Behind the liner two different channel systems have been installed. For the simulation of leaks holes were drilled into the liner. The experimental programm contained the following measurements: determination of gas flow rates into the different leaks, distribution of leakage gas over the array of channels and determination of pressures into the concrete and immediately behind the liner. The experiments have shown, that channel arrays immediately adjacent to the liner are the most suitable systems for localisation and controlled exhaust of leakage gas. The suitability decreases, if the channels are set into the concrete somewhat distant from the liner. (orig.) [de

  4. Spherical Collapse in Chameleon Models

    CERN Document Server

    Brax, Ph; Steer, D A

    2010-01-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse depends on the initial comoving size of the inhomogeneity.

  5. Spherical collapse in chameleon models

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Ph. [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Rosenfeld, R. [Instituto de Física Teórica, Universidade Estadual Paulista, Rua Dr. Bento T. Ferraz, 271, 01140-070, São Paulo (Brazil); Steer, D.A., E-mail: brax@spht.saclay.cea.fr, E-mail: rosenfel@ift.unesp.br, E-mail: daniele.steer@apc.univ-paris7.fr [APC, UMR 7164, CNRS, Université Paris 7, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

    2010-08-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse in principle depends on the initial comoving size of the inhomogeneity.

  6. Spherical collapse in chameleon models

    International Nuclear Information System (INIS)

    Brax, Ph.; Rosenfeld, R.; Steer, D.A.

    2010-01-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse in principle depends on the initial comoving size of the inhomogeneity

  7. Plastic collapse moment for pipe repaired with weld overlay

    International Nuclear Information System (INIS)

    Li, Yinsheng; Hasegawa, Kunio; Shibuya, Akira; Deardorff, Arthur

    2009-01-01

    The Weld Overlay has been used in several countries as an effective method to repair the stress corrosion cracks in nuclear power plant piping. However, the method to evaluate the plastic collapse stress for the pipe repaired with Weld Overlay has not been proposed and the limit load criterion for single uniform material has been used to design its structure by now. In this paper, the equations to evaluate the plastic collapse moment for the pipe repaired with Weld Overlay have been derived considering two layer materials. Moreover, several numerical examples are given to show the validity of Weld Overlay. The equations given in this paper are simple to use like the limit load criterion showed in present standards such as JSME Rules on Fitness-for-Service for Nuclear Power Plants or ASME Boiler and Pressure Vessel Code Section XI, and they can not only be used to evaluate the fracture of the pipe, but also be applied to design the weld structure. (author)

  8. Development And Characterization Of A Liner-On-Target Injector For Staged Z-Pinch Experiments

    Science.gov (United States)

    Valenzuela, J. C.; Conti, F.; Krasheninnikov, I.; Narkis, J.; Beg, F.; Wessel, F. J.; Rahman, H. U.

    2016-10-01

    We present the design and optimization of a liner-on-target injector for Staged Z-pinch experiments. The injector is composed of an annular high atomic number (e.g. Ar, Kr) gas-puff and an on-axis plasma gun that delivers the ionized deuterium target. The liner nozzle injector has been carefully studied using Computational Fluid Dynamics (CFD) simulations to produce a highly collimated 1 cm radius gas profile that satisfies the theoretical requirement for best performance on the 1 MA Zebra current driver. The CFD simulations produce density profiles as a function of the nozzle shape and gas. These profiles are initialized in the MHD MACH2 code to find the optimal liner density for a stable, uniform implosion. We use a simple Snowplow model to study the plasma sheath acceleration in a coaxial plasma gun to help us properly design the target injector. We have performed line-integrated density measurements using a CW He-Ne laser to characterize the liner gas and the plasma gun density as a function of time. The measurements are compared with models and calculations and benchmarked accordingly. Advanced Research Projects Agency - Energy, DE-AR0000569.

  9. Modelling Technique for Demonstrating Gravity Collapse Structures in Jointed Rock.

    Science.gov (United States)

    Stimpson, B.

    1979-01-01

    Described is a base-friction modeling technique for studying the development of collapse structures in jointed rocks. A moving belt beneath weak material is designed to simulate gravity. A description is given of the model frame construction. (Author/SA)

  10. Decision-tree approach to evaluating inactive uranium-processing sites for liner requirements

    International Nuclear Information System (INIS)

    Relyea, J.F.

    1983-03-01

    Recently, concern has been expressed about potential toxic effects of both radon emission and release of toxic elements in leachate from inactive uranium mill tailings piles. Remedial action may be required to meet disposal standards set by the states and the US Environmental Protection Agency (EPA). In some cases, a possible disposal option is the exhumation and reburial (either on site or at a new location) of tailings and reliance on engineered barriers to satisfy the objectives established for remedial actions. Liners under disposal pits are the major engineered barrier for preventing contaminant release to ground and surface water. The purpose of this report is to provide a logical sequence of action, in the form of a decision tree, which could be followed to show whether a selected tailings disposal design meets the objectives for subsurface contaminant release without a liner. This information can be used to determine the need and type of liner for sites exhibiting a potential groundwater problem. The decision tree is based on the capability of hydrologic and mass transport models to predict the movement of water and contaminants with time. The types of modeling capabilities and data needed for those models are described, and the steps required to predict water and contaminant movement are discussed. A demonstration of the decision tree procedure is given to aid the reader in evaluating the need for the adequacy of a liner

  11. Effect of Lithium Disilicate Reinforced Liner Treatment on Bond and Fracture Strengths of Bilayered Zirconia All-Ceramic Crown

    Directory of Open Access Journals (Sweden)

    Yong-Seok Jang

    2018-01-01

    Full Text Available This study was performed to evaluate the effect of a lithium-disilicate spray-liner application on both the bond strength between zirconia cores and heat-pressed lithium-disilicate glass-ceramic veneers, and the fracture strength of all-ceramic zirconia crowns. A lithium-disilicate reinforced liner was applied on the surface of a zirconia core and lithium-disilicate glass-ceramic was veneered on zirconia through heat press forming. Microtensile and crown fracture tests were conducted in order to evaluate, respectively, the bonding strength between the zirconia cores and heat pressed lithium-disilicate glass-ceramic veneers, and the fracture strength of bilayered zirconia all-ceramic crowns. The role of lithium-disilicate spray-liner at the interface between zirconia and lithium-disilicate glass-ceramic veneers was investigated through surface and cross-sectional analyses. We confirmed that both the mean bonding strength between the zirconia ceramics and lithium-disilicate glass-ceramic veneers and the fracture strength of the liner-treated groups were significantly higher than those of the untreated groups, which resulted, on the one hand, from the chemical bonding at the interface of the zirconia and lithium-disilicate liner, and, on the other, from the existence of a microgap in the group not treated with liner.

  12. Tracheal collapse in two cats

    International Nuclear Information System (INIS)

    Hendricks, J.C.; O'Brien, J.A.

    1985-01-01

    Two cats examined bronchoscopically to discover the cause of tracheal collapse were found to have tracheal obstruction cranial to the collapse. Cats with this unusual sign should be examined bronchoscopically to ascertain whether there is an obstruction, as the cause in these 2 cats was distinct from the diffuse airway abnormality that causes tracheal collapse in dogs

  13. Use of the gamma-ray absorption technique as a quality control procedure in the manufacture of powder metal shaped charge liners

    CSIR Research Space (South Africa)

    Lawrie, JJ

    2010-09-01

    Full Text Available The use of the gamma-ray absorption technique as a tool in evaluating the quality of manufactured powder metal liners was investigated. With powder metal liners, it is not only of interest to know whether the liner conforms geometrically...

  14. MTF Driven by Plasma Liner Dynamically Formed by the Merging of Plasma Jets: An Overview

    Science.gov (United States)

    Thio, Y. C. Francis; Eskridge, Richard; Martin, Adam; Smith, James; Lee, Michael; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    One approach for standoff delivery of the momentum flux for compressing the target in MTF consists of using a spherical array of plasma jets to form a spherical plasma shell imploding towards the center of a magnetized plasma, a compact toroid (Figure 1). A 3-year experiment (PLX-1) to explore the physics of forming a 2-D plasma liner (shell) by merging plasma jets is described. An overview showing how this 3-year project (PLX-1) fits into the program plan at the national and international level for realizing MTF for energy and propulsion is discussed. Assuming that there will be a parallel program in demonstrating and establishing the underlying physics principles of MTF using whatever liner is appropriate (e.g. a solid liner) with a goal of demonstrating breakeven by 2010, the current research effort at NASA MSFC attempts to complement such a program by addressing the issues of practical embodiment of MTF for propulsion. Successful conclusion of PLX-1 will be followed by a Physics Feasibility Experiment (PLX-2) for the Plasma Liner Driven MTF.

  15. FFTF in-containment cell liner design and installation experience

    International Nuclear Information System (INIS)

    Umek, A.M.; Swenson, L.D.

    1980-01-01

    Design features and liner construction techniques are discussed. Cell leak-rate tests and the methods used to locate and repair leaks are described. A brief analysis of the overall experience at FFTF is provided, with recommendations for future plant designs

  16. Voluntary Consensus Organization Standards for Nondestructive Evaluation of Thin-Walled Metallic Liners and Composite Overwraps in Composite Overwrapped Pressure Vessels

    Science.gov (United States)

    Waller, Jess; Saulsberry, Regor

    2012-01-01

    NASA fracture control requirements outlined in NASA-STD-5009 and NASA-STD-5014 are predicated on the availability and use of sensitive nondestructive evaluation (NDE) methods that can detect and monitor defects, thereby providing data that can be used to predict failure or reduce the risk of failure in fracture critical components. However, in the case of composite materials and components, including composite overwrapped pressure vessels (COPVs), the effect of defects is poorly understood, the NDE methods used to evaluate locate and size defects are typically at lower technical readiness level than analogous NDE methods used for metals, and demonstration studies to verify the probability of detection (POD) are generally lacking or unavailable. These factors together make failure prediction of fracture critical composite materials and components based on size, quantity, or orientation of defects nearly impossible. Also, when inspecting metal liners in as-manufactured COPVs, sensitivity is lost and only the inner surface of the liner is accessible. Also, NDE of COPVs as applied during manufacturing varies significantly from manufacturer to manufacturer and has not yet been standardized. Although requirements exist to perform NDE immediately after manufacturing to establish initial integrity of the parts, procedural detail for NDE of composites is still nonexistent or under development. For example, in practice, only a visual inspection of COPVs is performed during manufacturing and service, leaving in question whether defects of concern, for example, bridging, overwrap winding anomalies, impact damage below visible threshold, out-of-family strain growth, and liner buckling have been adequately detected and monitored. To address these shortcomings, in 2005 the NASA Nondestructive Evaluation Working Group (NNWG) began funding work to develop and adopt standards for nondestructive evaluation of aerospace composites in collaboration with the American Society for Testing

  17. State-of-the-Art-Review of Collapsible Soils

    Directory of Open Access Journals (Sweden)

    A. A. AL-Rawas

    2000-12-01

    Full Text Available Collapsible soils are encountered in arid and semi-arid regions. Such soils cause potential construction problems due to their collapse upon wetting. The collapse phenomenon is primarily related to the open structure of the soil. Several soil collapse classifications based on parameters such as moisture content, dry density, Atterberg limits and clay content have been proposed in the literature as indicators of the soil collapse potential. Direct measurement of the magnitude of collapse, using laboratory and/or field tests, is essential once a soil showed indications of collapse potential. Treatment methods such as soil replacement, compaction control and chemical stabilization showed significant reduction in the settlement of collapsible soils. The design of foundations on collapsible soils depends on the depth of the soil, magnitude of collapse and economics of the design. Strip foundations are commonly used when collapsing soil extends to a shallow depth while piles and drilled piers are recommended in cases where the soil extends to several meters. This paper provides a comprehensive review of collapsible soils. These include the different types of collapsible soils, mechanisms of collapse, identification and classification methods, laboratory and field testing, treatment methods and guidelines for foundation design.

  18. Development of ultrasonic testing technique to inspect containment liners embedded in concrete on nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, H.; Kurozumi, Y. [Inst. of Nuclear Safety System, Incorporated, Mihama, Fukui (Japan); Kaneshima, Y. [The Kansai Electric Power Company, Inc., Mihama, Fukui (Japan)

    2004-07-01

    The purpose of this study is development of ultrasonic testing technique to inspect containment liners embedded in concrete on nuclear power plants. Integrity of containment liners on nuclear power plants can be secured by suitable present operation and maintenance. Furthermore, non-destructive testing technique to inspect embedded liners will ensure the integrity of the containment further. In order to develop the non-destructive testing technique, ultrasonic transducers were made newly and ultrasonic testing data acquisition and evaluation were carried out by using a mock-up. We adopted the surface shear horizontal (SH) wave, low frequency (0.3-0.5MHz), to be able to detect an echo from a defect against attenuation of ultrasonic waves due to long propagation in the liners and dispersion into concrete. We made transducers with three large active elements (40mm x 40mm) in a line which were equivalent to a 120mm width active element. Artificial hollows, {phi}200mm - 19mm depth (1/2thickness) and {phi}200mm - 9.5mm depth (1/4thickness), were made on a surface of a mock-up: carbon steel plate, 38mm thickness, 2,000mm length, 1000mm width. The surfaces of the plate were covered with concrete in order to simulate liners embedded in concrete. As a result of the examinations, the surface SH transducers could detect clearly the echo from the hollows at a distance of 1500mm. We evaluate that the newly made surface SH transducers with three elements have ability of detection of defects such as corrosion on the liners embedded in concrete. (author)

  19. Collapse of large extra dimensions

    International Nuclear Information System (INIS)

    Geddes, James

    2002-01-01

    In models of spacetime that are the product of a four-dimensional spacetime with an 'extra' dimension, there is the possibility that the extra dimension will collapse to zero size, forming a singularity. We ask whether this collapse is likely to destroy the spacetime. We argue, by an appeal to the four-dimensional cosmic censorship conjecture, that--at least in the case when the extra dimension is homogeneous--such a collapse will lead to a singularity hidden within a black string. We also construct explicit initial data for a spacetime in which such a collapse is guaranteed to occur and show how the formation of a naked singularity is likely avoided

  20. Cylindrical collapse and gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, L [Escuela de FIsica, Faculdad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela (Venezuela); Santos, N O [Universite Pierre et Marie Curie, CNRS/FRE 2460 LERMA/ERGA, Tour 22-12, 4eme etage, BoIte 142, 4 place Jussieu, 75252 Paris Cedex 05 (France); Laboratorio Nacional de Computacao Cientifica, 25651-070 Petropolis RJ (Brazil); Centro Brasileiro de Pesquisas Fisicas, 22290-180 Rio de Janeiro RJ (Brazil)

    2005-06-21

    We study the matching conditions for a collapsing anisotropic cylindrical perfect fluid, and we show that its radial pressure is non-zero on the surface of the cylinder and proportional to the time-dependent part of the field produced by the collapsing fluid. This result resembles the one that arises for the radiation-though non-gravitational-in the spherically symmetric collapsing dissipative fluid, in the diffusion approximation.

  1. Attenuation of FJ44 Turbofan Engine Noise with a Foam-Metal Liner Installed Over-the-Rotor

    Science.gov (United States)

    Sutliff, Daniel L.; Elliott, Dave M.; Jones, Michael G.; Hartley, Thomas C.

    2009-01-01

    A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for a Foam-Metal Liner (FML) installed in close proximity to the fan. Two FML designs were tested and compared to the hardwall baseline. Traditional single degree-of-freedom liner designs were also evaluated to provide a comparison. Farfield acoustic levels and limited engine performance results are presented in this paper. The results show that the FML achieved up to 5 dB Acoustic Power Level (PWL) overall attenuation in the forward quadrant, equivalent to the traditional liner design. An earlier report presented the test set-up and conditions.

  2. Advantages of floating covers with LLDPE Liners; Ventajas del uso de geomembranas LLDPE en cubiertas flotantes

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Gomez, J. M.

    2014-02-01

    Using floating covers in irrigation pounds and waste dam gives many advantages. It is a very interesting investment for those place with a high evaporation ratio. this is an easy system which improves several aspects in irrigation or drinkable water reservoirs, mainly it saves water and it saves clean-works (time and cost). It is also used in waste dam to deodorization. Time ago this application was developed with PVC liners and TPO liners, now the innovation is LLDPE liners which improve mechanical properties, durability and an easier installation. This paper develops the state of art of this design technology, and the back ground of our experience. (Author)

  3. Collapse models with non-white noises

    International Nuclear Information System (INIS)

    Adler, Stephen L; Bassi, Angelo

    2007-01-01

    We set up a general formalism for models of spontaneous wavefunction collapse with dynamics represented by a stochastic differential equation driven by general Gaussian noises, not necessarily white in time. In particular, we show that the non-Schroedinger terms of the equation induce the collapse of the wavefunction to one of the common eigenstates of the collapsing operators, and that the collapse occurs with the correct quantum probabilities. We also develop a perturbation expansion of the solution of the equation with respect to the parameter which sets the strength of the collapse process; such an approximation allows one to compute the leading-order terms for the deviations of the predictions of collapse models with respect to those of standard quantum mechanics. This analysis shows that to leading order, the 'imaginary noise' trick can be used for non-white Gaussian noise

  4. Triggering Collapse of the Presolar Dense Cloud Core and Injecting Short-lived Radioisotopes with a Shock Wave. V. Nonisothermal Collapse Regime

    Energy Technology Data Exchange (ETDEWEB)

    Boss, Alan P., E-mail: aboss@carnegiescience.edu [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

    2017-08-01

    Recent meteoritical analyses support an initial abundance of the short-lived radioisotope (SLRI) {sup 60}Fe that may be high enough to require nucleosynthesis in a core-collapse supernova, followed by rapid incorporation into primitive meteoritical components, rather than a scenario where such isotopes were inherited from a well-mixed region of a giant molecular cloud polluted by a variety of supernovae remnants and massive star winds. This paper continues to explore the former scenario, by calculating three-dimensional, adaptive mesh refinement, hydrodynamical code (FLASH 2.5) models of the self-gravitational, dynamical collapse of a molecular cloud core that has been struck by a thin shock front with a speed of 40 km s{sup −1}, leading to the injection of shock front matter into the collapsing cloud through the formation of Rayleigh–Taylor fingers at the shock–cloud intersection. These models extend the previous work into the nonisothermal collapse regime using a polytropic approximation to represent compressional heating in the optically thick protostar. The models show that the injection efficiencies of shock front materials are enhanced compared to previous models, which were not carried into the nonisothermal regime, and so did not reach such high densities. The new models, combined with the recent estimates of initial {sup 60}Fe abundances, imply that the supernova triggering and injection scenario remains a plausible explanation for the origin of the SLRIs involved in the formation of our solar system.

  5. Influence of electric current intensity on the performance of electroformed copper liner for shaped charge application

    Directory of Open Access Journals (Sweden)

    Tamer Elshenawy

    2017-12-01

    Full Text Available Electrolytic Copper used in the shaped charge liner manufacturing can be produced from acid solution using electro-deposition technique. The intensity of the applied electric current controls the quality of the produced copper grade. The electric current intensity within the electrolytic acidic solution cell with the minimum oxygen and sulfur elements in the produced copper was optimized and found to be 30–40 A/Ft2. The elemental composition of the obtained electrolytic copper was determined using high-end stationary vacuum spectrometer, while the oxygen was determined precisely using ELTRA ONH-2000 apparatus. Besides, SEM was used to investigate the shape of the copper texture inside the deposited layers and to determine the average grain size. New relations have been obtained between the applied current intensity and both the oxygen and sulfur contents and the average grain size of the produced copper. Experimental result showed that when the applied current density increases to a certain limit, the oxygen and sulfur content in the electrolytic copper decreases. Performance of the produced copper liner was investigated by the static firing of a small caliber shaped charge containing an electro-formed copper liners, where the penetration depth of the optimized electrolytic liner was enhanced by 22.7% compared to that of baseline non-optimized liner.

  6. Writing and Music: Album Liner Notes

    OpenAIRE

    Biron, Dean Leonard

    2011-01-01

    A deceptive aspect of the ‘writing about music is like dancing about architecture’ cliché is the function of the preposition ‘about’. Literature and music, dance and architecture, painting and film – all are discrete aesthetic forms that nonetheless simultaneously feed off and provide nourishment for each other as part of art’s perpetual drive toward diversity and innovation. Nowhere is the aptness of the association between writing and music more obvious than in the phenomenon of album liner...

  7. Design and Analysis of Collapsible Scissor Bridge

    Directory of Open Access Journals (Sweden)

    Biro Mohamad Nabil Aklif

    2018-01-01

    Full Text Available Collapsible scissor bridge is a portable bridge that can be deployed during emergency state to access remote areas that are affected by disaster such as flood. The objective of this research is to design a collapsible scissor bridge which is able to be transported by a 4x4 vehicle and to be deployed to connect remote areas. The design is done by using Solidworks and numerical analysis for structural strength is conducted via ANSYS. The research starts with parameters setting and modelling. Finite element analysis is conducted to analyze the strength by determining the safety factor of the bridge. Kutzbach equation is also analyzed to ensure that the mechanism is able to meet the targeted degree of motion. There are five major components of the scissor structure; pin, deck, cross shaft and deck shaft. The structure is controlled by hydraulic pump driven by a motor for the motions. Material used in simulation is A36 structural steel due to limited library in ANSYS. However, the proposed material is Fiber Reinforced Polymer (FRP composites as they have a high strength to weight ratio. FRP also tends to be corrosion resistance and this characteristic is useful in flooded area.

  8. Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

    2016-01-01

    This paper describes the process development for fabricating a high thermal conductivity NARloy-Z-Diamond composite (NARloy-Z-D) combustion chamber liner for application in advanced rocket engines. The fabrication process is challenging and this paper presents some details of these challenges and approaches used to address them. Prior research conducted at NASA-MSFC and Penn State had shown that NARloy-Z-40%D composite material has significantly higher thermal conductivity than the state of the art NARloy-Z alloy. Furthermore, NARloy-Z-40 %D is much lighter than NARloy-Z. These attributes help to improve the performance of the advanced rocket engines. Increased thermal conductivity will directly translate into increased turbopump power, increased chamber pressure for improved thrust and specific impulse. Early work on NARloy-Z-D composites used the Field Assisted Sintering Technology (FAST, Ref. 1, 2) for fabricating discs. NARloy-Z-D composites containing 10, 20 and 40vol% of high thermal conductivity diamond powder were investigated. Thermal conductivity (TC) data. TC increased with increasing diamond content and showed 50% improvement over pure copper at 40vol% diamond. This composition was selected for fabricating the combustion chamber liner using the FAST technique.

  9. Containment liner plate anchors and steel embedments test results

    International Nuclear Information System (INIS)

    Chang-Lo, P.L.; Johnson, T.E.; Pfeifer, B.W.

    1977-01-01

    This paper summarizes test data on shear load and deformation capabilities for liner plate line anchors and structural steel embedments in reinforced and prestressed concrete nuclear containments. Reinforced and prestressed nuclear containments designed and constructed in the United States are lined with a minimum of 0.64 cm steel plate. The liner plates are anchored by the use of either studs or structural members (line anchors) which usually run in the vertical direction. This paper will only address line anchors. Static load versus displacement test data is necessary to assure that the design is adequate for the maximum loads. The test program for the liner anchors had the following major objectives: determine load versus displacement data for a variety of anchors considering structural tees and small beams with different weld configurations, from the preceding tests, determine which anchors would lead to an economical and extremely safe design and test these anchors for cyclic loads resulting from thermal fluctuations. Various concrete embeds in the containment and other structures are subjected to loads such as pipe rupture which results in shear. Since many of the loads are transient by nature, it is necessary to know the load-displacement relationship so that the energy absorption can be determined. The test program for the embeds had the following objectives: determine load-displacement relationship for various size anchors from 6.5 cm 2 to 26 cm 2 with maximum capacities of approximately 650 kN; determine the effect of various anchor width-to-thickness ratios for the same shear area

  10. Emission and Absorption in the M87 LINER

    Science.gov (United States)

    Sabra, Bassem M.; Shields, Joseph C.; Ho, Luis C.; Barth, Aaron J.; Filippenko, Alexei V.

    2003-02-01

    The nucleus of M87 displays a LINER spectrum at optical wavelengths, with a nuclear disk of nebulosity that is resolved by the Hubble Space Telescope (HST). We present new results from optical and ultraviolet spectra of the central ~40 pc as measured by HST. In contrast with previous results for the extended disk, the emission-line spectrum of the central region is best reproduced by a multicomponent photoionization scenario, rather than shock heating. The nebular properties as well as energetic considerations suggest a transition on scales of several tens of parsecs, from predominantly photoionization by a central accretion source to shock ionization within the disk. If this source is at all representative, it suggests that many LINERs may be composite in terms of the energetic processes that give rise to the emission spectrum. We also report measurements of resonance-line absorption for the nucleus. The absorption spectrum, like the emission lines, is characterized by low ionization. The absorption-line measurements coupled with independent constraints suggest a total hydrogen column density of 1019-1020 cm-2, outflowing from the galaxy center with a velocity of ~126 km s-1. The kinematic signature of an outflow, along with evidence that the absorber covers the power-law continuum source but not the emission-line clouds, suggests that the absorbing matter is related to accretion phenomena in the nucleus. The presence of such an outflow resembles similar behavior in luminous active galactic nuclei, although the low ionization that characterizes LINERs is probably indicative of a different mode of accretion in these sources. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  11. Casing and liners for drilling and completion

    CERN Document Server

    Byrom, Ted G

    2007-01-01

    The Gulf Drilling Series is a joint project between Gulf Publishing Company and the International Association of Drilling Contractors. The first text in this Series presents casing design and mechanics in a concise, two-part format. The first part focuses on basic casing design and instructs engineers and engineering students how to design a safe casing string. The second part covers more advanced material and special problems in casing design in a user-friendly format. Learn how to select sizes and setting depths to achieve well objectives, determine casing loads for design purposes, design casing properties to meet burst, collapse and tensile strength requirements and conduct casing running operations safely and successfully.

  12. Influence of flow stress choice on the plastic collapse estimation of axially cracked steam generator tubes

    International Nuclear Information System (INIS)

    Tonkovic, Zdenko; Skozrit, Ivica; Alfirevic, Ivo

    2008-01-01

    The influence of the choice of flow stress on the plastic collapse estimation of axially cracked steam generator (SG) tubes is considered. The plastic limit and collapse loads of thick-walled tubes with external axial semi-elliptical surface cracks are investigated by three-dimensional non-linear finite element (FE) analyses. The limit pressure solution as a function of the crack depth, length and tube geometry has been developed on the basis of extensive FE limit load analyses employing the elastic-perfectly plastic material behaviour and small strain theory. Unlike the existing solutions, the newly developed analytical approximation of the plastic limit pressure for thick-walled tubes is applicable to a wide range of crack dimensions. Further, the plastic collapse analysis with a real strain-hardening material model and a large deformation theory is performed and an analytical approximation for the estimation of the flow stress is proposed. Numerical results show that the flow stress, defined by some failure assessment diagram (FAD) methods, depends not only on the tube material, but also on the crack geometry. It is shown that the plastic collapse pressure results, in the case of deeper cracks obtained by using the flow stress as the average of the yield stress and the ultimate tensile strength, can become unsafe

  13. Stagnation morphology in Magnetized Liner Inertial Fusion experiments

    Science.gov (United States)

    Gomez, M. R.; Harding, E. C.; Ampleford, D. J.; Jennings, C. A.; Awe, T. J.; Chandler, G. A.; Glinsky, M. E.; Hahn, K. D.; Hansen, S. B.; Jones, B.; Knapp, P. F.; Martin, M. R.; Peterson, K. J.; Rochau, G. A.; Ruiz, C. L.; Schmit, P. F.; Sinars, D. B.; Slutz, S. A.; Weis, M. R.; Yu, E. P.

    2017-10-01

    In Magnetized Liner Inertial Fusion (MagLIF) experiments on the Z facility, an axial current of 15-20 MA is driven through a thick metal cylinder containing axially-magnetized, laser-heated deuterium fuel. The cylinder implodes, further heating the fuel and amplifying the axial B-field. Instabilities, such as magneto-Rayleigh-Taylor, develop on the exterior of the liner and may feed through to the inner surface during the implosion. Monochromatic x-ray emission at stagnation shows the stagnation column is quasi-helical with axial variations in intensity. Recent experiments demonstrated that the stagnation emission structure changed with modifications to the target wall thickness. Additionally, applying a thick dielectric coating to the exterior of the target modified the stagnation column. A new version of the x-ray self-emission diagnostic has been developed to investigate stagnation with higher resolution. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  14. Predicting mining collapse: Superjerks and the appearance of record-breaking events in coal as collapse precursors

    Science.gov (United States)

    Jiang, Xiang; Liu, Hanlong; Main, Ian G.; Salje, Ekhard K. H.

    2017-08-01

    The quest for predictive indicators for the collapse of coal mines has led to a robust criterion from scale-model tests in the laboratory. Mechanical collapse under uniaxial stress forms avalanches with a power-law probability distribution function of radiated energy P ˜E-ɛ , with exponent ɛ =1.5 . Impending major collapse is preceded by a reduction of the energy exponent to the mean-field value ɛ =1.32 . Concurrently, the crackling noise increases in intensity and the waiting time between avalanches is reduced when the major collapse is approaching. These latter criteria were so-far deemed too unreliable for safety assessments in coal mines. We report a reassessment of previously collected extensive collapse data sets using "record-breaking analysis," based on the statistical appearance of "superjerks" within a smaller spectrum of collapse events. Superjerks are defined as avalanche signals with energies that surpass those of all previous events. The final major collapse is one such superjerk but other "near collapse" events equally qualify. In this way a very large data set of events is reduced to a sparse sequence of superjerks (21 in our coal sample). The main collapse can be anticipated from the sequence of energies and waiting times of superjerks, ignoring all weaker events. Superjerks are excellent indicators for the temporal evolution, and reveal clear nonstationarity of the crackling noise at constant loading rate, as well as self-similarity in the energy distribution of superjerks as a function of the number of events so far in the sequence Es j˜nδ with δ =1.79 . They are less robust in identifying the precise time of the final collapse, however, than the shift of the energy exponents in the whole data set which occurs only over a short time interval just before the major event. Nevertheless, they provide additional diagnostics that may increase the reliability of such forecasts.

  15. Liner shipping hub network design in a competitive environment

    DEFF Research Database (Denmark)

    Gelareh, Shahin; Nickel, Stefan; Pisinger, David

    2010-01-01

    A mixed integer programming formulation is proposed for hub-and-spoke network design in a competitive environment. It addresses the competition between a newcomer liner service provider and an existing dominating operator, both operating on hub-and-spoke networks. The newcomer company maximizes i...

  16. Stress evolution during caldera collapse

    Science.gov (United States)

    Holohan, E. P.; Schöpfer, M. P. J.; Walsh, J. J.

    2015-07-01

    The mechanics of caldera collapse are subject of long-running debate. Particular uncertainties concern how stresses around a magma reservoir relate to fracturing as the reservoir roof collapses, and how roof collapse in turn impacts upon the reservoir. We used two-dimensional Distinct Element Method models to characterise the evolution of stress around a depleting sub-surface magma body during gravity-driven collapse of its roof. These models illustrate how principal stress orientations rotate during progressive deformation so that roof fracturing transitions from initial reverse faulting to later normal faulting. They also reveal four end-member stress paths to fracture, each corresponding to a particular location within the roof. Analysis of these paths indicates that fractures associated with ultimate roof failure initiate in compression (i.e. as shear fractures). We also report on how mechanical and geometric conditions in the roof affect pre-failure unloading and post-failure reloading of the reservoir. In particular, the models show how residual friction within a failed roof could, without friction reduction mechanisms or fluid-derived counter-effects, inhibit a return to a lithostatically equilibrated pressure in the magma reservoir. Many of these findings should be transferable to other gravity-driven collapse processes, such as sinkhole formation, mine collapse and subsidence above hydrocarbon reservoirs.

  17. Development of a model capable of predicting the performance of piston ring-cylinder liner-like tribological interfaces

    DEFF Research Database (Denmark)

    Felter, C.L.; Vølund, A.; Imran, Tajammal

    2010-01-01

    Friction in the piston ring package (piston, piston rings, and liner) is a major source of power consumption in large two-stroke marine diesel engines. In order to improve the frictional and wear performance, knowledge about the tribological interface between piston rings and liner is needed...

  18. Conjugated heat transfer and temperature distributions in a gas turbine combustion liner under base-load operation

    International Nuclear Information System (INIS)

    Kim, Kyung Min; Yun, Nam Geon; Jeon, Yun Heung; Lee, Dong Hyun; Cho, Yung Hee

    2010-01-01

    Prediction of temperature distributions on hot components is important in development of a gas turbine combustion liner. The present study investigated conjugated heat transfer to obtain temperature distributions in a combustion liner with six combustion nozzles. 3D numerical simulations using FVM commercial codes, Fluent and CFX were performed to calculate combustion and heat transfer distributions. The temperature distributions in the combustor liner were calculated by conjugation of conduction and convection (heat transfer coefficients) obtained by combustion and cooling flow analysis. The wall temperature was the highest on the attachment points of the combustion gas from combustion nozzles, but the temperature gradient was high at the after shell section with low wall temperature

  19. Analysis of Potential for Titanium Liner Buckling after Proof in a Large Kevlar/Epoxy COPV

    Science.gov (United States)

    Phoenix, S. Leigh; Kezirian, Michael T.

    2009-01-01

    We analyze the potential for liner buckling in a 40-in Kevlar49/epoxy overwrapped spherical pressure vessel (COPV) due to long, local depressions or valleys in the titanium liner, which appeared after proof testing (autofrettage). We begin by presenting the geometric characteristics of approximately 20 mil (0.02 in.) deep depressions measured by laser profilometry in several vessels. While such depths were more typical, depths of more than 40 mils (0.02 in.) were seen near the equator in one particular vessel. Such depressions are largely the result of overlap of the edges of overwrap bands (with rectangular cross-section prepreg tows) from the first or second wrap patterns particularly where they start and end. We then discuss the physical mechanisms of formation of the depressions during the autofrettage process in terms of uneven void compaction in the overwrap around the tow overlap lines and the resulting 10-fold increase in through-thickness stiffness of the overwrap. We consider the effects of liner plastic yielding mechanisms in the liner on residual bending moments and interface pressures with the overwrap both at the peak proof pressure (approx.6500 psi) and when reducing the pressure to 0 psi. During depressurization the Bauschinger phenomenon becomes very important whereby extensive yielding in tension reduces the magnitude of the yield threshold in compression by 30 to 40%, compared to the virgin annealed state of the liner titanium. In the absence of a depression, the liner is elastically stable in compression even at liner overwrap interface pressures nominally 6 times the approx. 1000 psi interface pressure that exists at 0 psi. Using a model based on a plate-on-an-elastic-foundation, we develop an extensive analysis of the possible destabilizing effects of a frozen-in valley. The analysis treats the modifying effects of the residual bending moments and interface pressures remaining after the proof hold as well as the Bauschinger effect on the

  20. Injector design for liner-on-target gas-puff experiments

    Science.gov (United States)

    Valenzuela, J. C.; Krasheninnikov, I.; Conti, F.; Wessel, F.; Fadeev, V.; Narkis, J.; Ross, M. P.; Rahman, H. U.; Ruskov, E.; Beg, F. N.

    2017-11-01

    We present the design of a gas-puff injector for liner-on-target experiments. The injector is composed of an annular high atomic number (e.g., Ar and Kr) gas and an on-axis plasma gun that delivers an ionized deuterium target. The annular supersonic nozzle injector has been studied using Computational Fluid Dynamics (CFD) simulations to produce a highly collimated (M > 5), ˜1 cm radius gas profile that satisfies the theoretical requirement for best performance on ˜1-MA current generators. The CFD simulations allowed us to study output density profiles as a function of the nozzle shape, gas pressure, and gas composition. We have performed line-integrated density measurements using a continuous wave (CW) He-Ne laser to characterize the liner gas density. The measurements agree well with the CFD values. We have used a simple snowplow model to study the plasma sheath acceleration in a coaxial plasma gun to help us properly design the target injector.

  1. Fire-induced collapses of steel structures

    DEFF Research Database (Denmark)

    Dondera, Alexandru; Giuliani, Luisa

    Single-story steel buildings such as car parks and industrial halls are often characterised by stiff beams and flexible columns and may experience an outward (sway) collapse during a fire, endangering people and properties outside the building. It is therefore a current interest of the research...... to investigate the collapse behaviour of single-story steel frames and identify relevant structural characteristics that influence the collapse mode. In this paper, a parametric study on the collapse a steel beam-column assembly with beam hinged connection and fixed column support is carried out under...... on the beam. By means of those tables, a simple method for the assessment and the countermeasure of unsafe collapse mode of single-story steel buildings can be derived....

  2. Granular Silo collapse: an experimental study

    Science.gov (United States)

    Clement, Eric; Gutierriez, Gustavo; Boltenhagen, Philippe; Lanuza, Jose

    2008-03-01

    We present an experimental work that develop some basic insight into the pre-buckling behavior and the buckling transition toward plastic collapse of a granular silo. We study different patterns of deformation generated on thin paper cylindrical shells during granular discharge. We study the collapse threshold for different bed height, flow rates and grain sizes. We compare the patterns that appear during the discharge of spherical beads, with those obtained in the axially compressed cylindrical shells. When the height of the granular column is close to the collapse threshold, we describe a ladder like pattern that rises around the cylinder surface in a spiral path of diamond shaped localizations, and develops into a plastic collapsing fold that grows around the collapsing silo.

  3. Wear of a 5 megarad cross-linked polyethylene liner: a 6-year RSA study.

    Science.gov (United States)

    Callary, Stuart A; Campbell, David G; Mercer, Graham; Nilsson, Kjell G; Field, John R

    2013-07-01

    One cross-linked polyethylene (XLPE) liner is manufactured using a lower dose of radiation, 5 Mrad, which may result in less cross-linking. The reported in vivo wear rate of this XLPE liner in patients undergoing THA has varied, and has included some patients in each reported cohort who had greater than 0.1 mm/year of wear, which is an historical threshold for osteolysis. Previous studies have measured wear on plain radiographs, an approach that has limited sensitivity. We therefore measured the amount and direction of wear at 6 years using Radiostereometric analysis (RSA) in patients who had THAs that included a cross-linked polyethylene liner manufactured using 5 Mrad radiation. We prospectively reviewed wear in 30 patients who underwent primary THAs with the same design of cross-linked acetabular liner and a 28-mm articulation. Tantalum markers were inserted during surgery and all patients had RSA radiographic examinations at 1 week, 6 months, 1, 2, and 6 years postoperatively. The mean proximal, two-dimensional (2-D) and three-dimensional (3-D) wear rates calculated between 1 year and 6 years were 0.014, 0.014, and 0.018 mm/per year, respectively. The direction of the head penetration recorded between 1 week and 6 years was in a proximal direction for all patients, proximolateral for 16 of 24 patients, and proximomedial for eight of 24 patients. The proximal, 2-D and 3-D wear of a XLPE liner produced using 5 Mrad of radiation was low but measurable by RSA after 6 years. No patients had proximal 2-D or 3-D wear rates exceeding 0.1 mm/year. Further followup is needed to evaluate the effect of XLPE wear particles on the development of long-term osteolysis.

  4. Assessment of structural materials inside the reactor pool of the Dalat research reactor

    International Nuclear Information System (INIS)

    Nguyen Nhi Dien; Luong Ba Vien; Nguyen Minh Tuan; Trang Cao Su

    2010-01-01

    Originally the Dalat Nuclear Research Reactor (DNRR) was a 250-kW TRIGA MARK II reactor, started building from early 1960s and achieved the first criticality on February 26, 1963. During the 1982-1984 period, the reactor was reconstructed and upgraded to 500kW, and restarted operation on March 20, 1984. From the original TRIGA reactor, only the pool liner, beam ports, thermal columns, and graphite reflector have been remained. The structural materials of pool liner and other components of TRIGA were made of aluminum alloy 6061 and aluminum cladding fuel assemblies. Some other parts, such as reactor core, irradiation rotary rack around the core, vertical irradiation facilities, etc. were replaced by the former Soviet Union's design with structural materials of aluminum alloy CAV-1. WWR-M2 fuel assemblies of U-Al alloy 36% and 19.75% 235 U enrichment and aluminum cladding have been used. In its original version, the reactor was setting upon an all-welded aluminum frame supported by four legs attached to the bottom of the pool. After the modification made, the new core is now suspended from the top of the pool liner by means of three aluminum concentric cylindrical shells. The upper one has a diameter of 1.9m, a length of 3.5m and a thickness of 10mm. This shell prevents from any visual access to the upper part of the pool liner, but is provided with some holes to facilitate water circulation in the 4cm gap between itself and the reactor pool liner. The lower cylindrical shells act as an extracting well for water circulation. As reactor has been operated at low power of 500 kW, it was no any problem with degradation of core structural materials due to neutron irradiation and thermal heat, but there are some ageing issues with aluminum liner and other structures (for example, corrosion of tightening-up steel bolt in the fourth beam port and flood of neutron detector housing) inside the reactor pool. In this report, the authors give an overview and assessment of

  5. Ultraviolet spectrophotometry of three LINERs

    Science.gov (United States)

    Goodrich, R. W.; Keel, W. C.

    1986-01-01

    Three galaxies known to be LINERs were observed spectroscopically in the ultraviolet in an attempt to detect the presumed nonthermal continuum source thought to be the source of photoionization in the nuclei. NGC 4501 was found to be too faint for study with the IUE spectrographs, while NGC 5005 had an extended ultraviolet light profile. Comparison with the optical light profile of NGC 5005 indicates that the ultraviolet source is distributed spatially in the same manner as the optical starlight, probably indicating that the ultraviolet excess is due to a component of hot stars in the nucleus. These stars contribute detectable absorption features longward of 2500 A; together with optical data, the IUE spectra suggest a burst of star formation about 1 billion yr ago, with a lower rate continuing to produce a few OB stars. In NGC 4579, a point source contributing most of the ultraviolet excess is found that is much different than the optical light distribution. Furthermore, the ultraviolet to X-ray spectral index in NGC 4579 is 1.4, compatible with the UV to X-ray indices found for samples of Seyfert galaxies. This provides compelling evidence for the detection of the photoionizing continuum in NGC 4579 and draws the research fields of normal galaxies and active galactic nuclei closer together. The emission-line spectrum of NGC 4579 is compared with calculations from a photoionization code, CLOUDY, and several shock models. The photoionization code is found to give superior results, adding to the increasing weight of evidence that the LINER phenomenon is essentially a scaled-down version of the Seyfert phenomenon.

  6. Geophysical observations at cavity collapse

    Science.gov (United States)

    Jousset, Philippe; Bazargan-Sabet, Behrooz; Lebert, François; Bernardie, Séverine; Gourry, Jean-Christophe

    2010-05-01

    In Lorraine region (France) salt layers at about 200 meters depth are exploited by Solvay using solution mining methodology which consists in extracting the salt by dissolution, collapsing the cavern overburden during the exploitation phase and finally reclaiming the landscape by creating a water area. In this process, one of the main challenges for the exploiting company is to control the initial 120-m diameter collapse so as to minimize possible damages. In order to detect potential precursors and understand processes associated with such collapses, a wide series of monitoring techniques including micro seismics, broad-band seismology, hydro-acoustic, electromagnetism, gas probing, automatic leveling, continuous GPS, continuous gravity and borehole extensometry was set-up in the frame of an in-situ study carried out by the "Research Group for the Impact and Safety of Underground Works" (GISOS, France). Equipments were set-up well before the final collapse, giving a unique opportunity to analyze a great deal of information prior to and during the collapse process which has been successfully achieved on February the 13th, 2009 by controlling the cavity internal pressure. In this work, we present the results of data recorded by a network of 3 broadband seismometers, 2 accelerometers, 2 tilt-meters and a continuously gravity meter. We relate the variations of the brine pumping rate with the evolutions of the induced geophysical signals and finally we propose a first mechanical model for describing the controlled collapse. Beyond the studied case, extrapolation of the results obtained might contribute to the understanding of uncontrolled cavity collapses, such as pit-craters or calderas at volcanoes.

  7. The construction of a PWR power station reactor building liner

    International Nuclear Information System (INIS)

    Skirving, N.; Goulding, J.S.; Gibson, J.A.

    1991-01-01

    Cleveland Bridge and Engineering Co Ltd (CBE) are constructing the Reactor Building Liner Plate containment of the Sizewell 'B' Power Station for Nuclear Electric Ltd. This has entailed extensive offsite prefabrication of components and their subsequent erection at Sizewell. It has been necessary to engineer temporary supporting mechanisms to enable manufacture and erection to proceed, yet also to withstand wet concrete forces during the progressive construction. The Reactor Building Liner Plate is a safety related system and as such, in addition to strict compliance with the ASME code, the Quality Assurance (QA) requirements of BS 5882 are applicable. A dedicated Project Team was established by CBE to control and direct the work. Equally important as satisfying the rigorous Q.A. requirements has been the need to meet programme and budget. This paper details CBE execution of the Project. (author)

  8. The liner shipping berth scheduling problem with transit times

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander; Plum, Christian E.M.; Pisinger, David

    2016-01-01

    In this paper speed optimization of an existing liner shipping network is solved by adjusting the port berth times. The objective is to minimize fuel consumption while retaining the customer transit times including the transhipment times. To avoid too many changes to the time table, changes of port...

  9. Transition duct system with arcuate ceramic liner for delivering hot-temperature gases in a combustion turbine engine

    Energy Technology Data Exchange (ETDEWEB)

    Wiebe, David J.

    2017-11-07

    A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include an arcuate connecting segment (36). An arcuate ceramic liner (60) may be inwardly disposed onto a metal outer shell (38) along the arcuate connecting segment of the exit piece. Structural arrangements are provided to securely attach the ceramic liner in the presence of substantial flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liner can be readily removed and replaced as needed.

  10. The effect of selected parameters of the honing process on cylinder liner surface topography

    International Nuclear Information System (INIS)

    Pawlus, P; Dzierwa, A; Michalski, J; Reizer, R; Wieczorowski, M; Majchrowski, R

    2014-01-01

    Many truck cylinder liners made from gray cast iron were machined. Ceramic and diamond honing stones were used in the last stages of operation: coarse honing and plateau honing. The effect of honing parameters on the cylinder liner surface topography was studied. Selected surface topography parameters were response variables. It was found that parameters from the Sq group were sensitive to honing parameter change. When plateau honing time varied, the Smq parameter increased, while the other parameters, Spq and Svq, were stable. (papers)

  11. Cross-hole fracture connectivity assessed using hydraulic responses during liner installations in crystalline bedrock boreholes

    Science.gov (United States)

    Persaud, Elisha; Levison, Jana; Pehme, Peeter; Novakowski, Kentner; Parker, Beth

    2018-01-01

    In order to continually improve the current understanding of flow and transport in crystalline bedrock environments, developing and improving fracture system characterization techniques is an important area of study. The presented research examines the installation of flexible, impermeable FLUTe™ liners as a means for assessing cross-hole fracture connectivity. FLUTe™ liners are used to generate a new style of hydraulic pulse, with pressure response monitored in a nearby network of open boreholes drilled in gneissic rock of the Canadian Shield in eastern Ontario, Canada. Borehole liners were installed in six existing 10-15 cm diameter boreholes located 10-35 m apart and drilled to depths ranging between 25-45 m. Liner installation tests were completed consecutively with the number of observation wells available for each test ranging between one and six. The collected pressure response data have been analyzed to identify significant groundwater flow paths between source and observation boreholes as well as to estimate inter-well transmissivity and storativity using a conventional type-curve analysis. While the applied solution relies on a number of general assumptions, it has been found that reasonable comparison can be made to previously completed pulse interference and pumping tests. Results of this research indicate areas where method refinement is necessary, but, nonetheless, highlight the potential for use in crystalline bedrock environments. This method may provide value to future site characterization efforts given that it is complementary to, and can be used in conjunction with, other currently employed borehole liner applications, such as the removal of cross-connection at contaminated sites and the assessment of discrete fracture distributions when boreholes are sealed, recreating natural hydraulic gradient conditions.

  12. Unifying Research on Social-Ecological Resilience and Collapse.

    Science.gov (United States)

    Cumming, Graeme S; Peterson, Garry D

    2017-09-01

    Ecosystems influence human societies, leading people to manage ecosystems for human benefit. Poor environmental management can lead to reduced ecological resilience and social-ecological collapse. We review research on resilience and collapse across different systems and propose a unifying social-ecological framework based on (i) a clear definition of system identity; (ii) the use of quantitative thresholds to define collapse; (iii) relating collapse processes to system structure; and (iv) explicit comparison of alternative hypotheses and models of collapse. Analysis of 17 representative cases identified 14 mechanisms, in five classes, that explain social-ecological collapse. System structure influences the kind of collapse a system may experience. Mechanistic theories of collapse that unite structure and process can make fundamental contributions to solving global environmental problems. Copyright © 2017. Published by Elsevier Ltd.

  13. Use of a Tantalum Liner to Reduce Bore Erosion and Increase Muzzle Velocity in Two-Stage Light Gas Guns

    Science.gov (United States)

    Bogdanoff, David W.

    2015-01-01

    Muzzle velocities and gun erosion predicted by earlier numerical simulations of two stage light gas guns with steel gun tubes were in good agreement with experimental values. In a subsequent study, simulations of high performance shots were repeated with rhenium (Re) gun tubes. Large increases in muzzle velocity (2 - 4 km/sec) were predicted for Re tubes. In addition, the hydrogen-produced gun tube erosion was, in general, predicted to be zero with Re tubes. Tantalum (Ta) has some mechanical properties superior to those of Re. Tantalum has a lower modulus of elasticity than Re for better force transmission from the refractory metal liner to an underlying thick wall steel tube. Tantalum also has greater ductility than Re for better survivability during severe stress/strain cycles. Also, tantalum has been used as a coating or liner in military powder guns with encouraging results. Tantalum has, however, somewhat inferior thermal properties to those of rhenium, with a lower melting point and lower density and thermal conductivity. The present study was undertaken to see to what degree the muzzle velocity gains of rhenium gun tubes (over steel tubes) could be achieved with tantalum gun tubes. Nine high performance shots were modeled with a new version of our CFD gun code for steel, rhenium and tantalum gun tubes. For all except the highest velocity shot, the results with Ta tubes were nearly identical with those for Re tubes. Even for the highest velocity shot, the muzzle velocity gain over a steel tube using Ta was 82% of the gain obtained using Re. Thus, the somewhat inferior thermal properties of Ta (when compared to those of Re) translate into only very slightly poorer overall muzzle velocity performance. When this fact is combined with the superior mechanical properties of Ta and the encouraging performance of Ta liners/coatings in military powder guns, tantalum is to be preferred over Re as a liner/coating material for two stage light gas guns to increase muzzle

  14. The Pore Collapse “Hot-Spots” Model Coupled with Brittle Damage for Solid Explosives

    Directory of Open Access Journals (Sweden)

    L. R. Cheng

    2014-01-01

    Full Text Available This paper is devoted to the building of a numerical pore collapse model with “hot-spots” formation for the impacted damage explosives. According to damage mechanical evolution of brittle material, the one-dimensional elastic-viscoplastic collapse model was improved to incorporate the impact damage during the dynamic collapse of pores. The damage of explosives was studied using the statistical crack mechanics (SCRAM. The effects of the heat conduction and the chemical reaction were taken into account in the formation of “hot-spots.” To verify the improved model, numerical simulations were carried out for different pressure states and used to model a multiple-impact experiment. The results show that repeated weak impacts can lead to the collapse of pores and the “hot-spots” may occur due to the accumulation of internal defects accompanied by the softening of explosives.

  15. Collapse settlement in compacted soils

    CSIR Research Space (South Africa)

    Booth, AR

    1977-01-01

    Full Text Available Research into collapse settlement in compacted soils is described, with special reference to recent cases in Southern Africa where collapse settlement occurred in road embankments following wetting of the soil. The laboratory work described...

  16. Spherically symmetric scalar field collapse

    Indian Academy of Sciences (India)

    2013-03-01

    Mar 1, 2013 ... The very recent interest in scalar field collapse stems from a cosmological ... The objective of the present investigation is to explore the collapsing modes of a simple ..... The authors thank the BRNS (DAE) for financial support.

  17. Progressive Collapse of High-Rise Buildings from Fire

    Directory of Open Access Journals (Sweden)

    Pershakov Valerii

    2016-01-01

    Full Text Available Considers ensuring the stability of structures of high-rise buildings against progressive collapse due to fire, proposed measures to ensure the stability of high-rise buildings due to progressive collapse. The analysis of large fires in high-rise buildings with progressive collapse and review of the literature on the issue of progressive collapse. The analysis of the Ukrainian normative documents on progressive collapse resistance.

  18. Comparative evaluation of tensile bond strength of silicone-based denture liners after thermocycling and surface treatment.

    Science.gov (United States)

    Kaur, Harsimran; Datta, Kusum

    2015-01-01

    To examine, evaluate, and compare the tensile bond strength of two silicone-based liners; one autopolymerizing and one heat cured, when treated with different chemical etchants to improve their adhesion with denture base resin. Hundred and sixty test specimens of heat-cured polymethyl methacrylate (PMMA) were fabricated; out of which 80 specimens were tested for tensile bond strength after bonding it to autopolymerizing resilient liner (Ufigel P) and rest 80 to heat-cured resilient liner (Molloplast B). Each main group was further divided into four subgroups of 20 specimens each, one to act as a control and three were subjected to surface treatment with different chemical etchants namely dichloromethane, MMA monomer, and chloroform. The two silicone-based denture liners were processed between 2 PMMA specimens (10 mm × 10 mm × 40 mm) in the space provided by a spacer of 3 mm, thermocycled (5-55°C) for 500 cycles, and then their tensile strength measurements were done in the universal testing machine. One-way ANOVA technique showed a highly significant difference in the mean tensile bond strength values for all the groups. The Student's t-test computed values of statistics for the compared groups were greater than the critical values both at 5% and at 1% levels. Surface treatment of denture base resin with chemical etchants prior to the application of silicone-based liner (Ufigel P and Molloplast-B) increased the tensile bond strength. The increase was the highest with specimens subjected to 180 s of MMA surface treatment and the lowest with control group specimens.

  19. A matheuristic for the liner shipping network design problem

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Desaulniers, Guy; Pisinger, David

    2014-01-01

    , while minimizing the cost of operating the network. Liner shipping companies publish a set of routes with a time schedule, and it is an industry standard to have a weekly departure at each port call on a route. A weekly frequency is achieved by deploying several vessels to a single route, respecting...

  20. Transition duct system with straight ceramic liner for delivering hot-temperature gases in a combustion turbine engine

    Science.gov (United States)

    Wiebe, David J.

    2017-05-16

    A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include a straight path segment (26) for receiving a gas flow from a respective combustor. A straight ceramic liner (40) may be inwardly disposed onto a metal outer shell (38) along the straight path segment of the exit piece. Structural arrangements are provided to securely attach the ceramic liner in the presence of substantial flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liner can be readily removed and replaced as needed.

  1. Collapse of tall granular columns in fluid

    Science.gov (United States)

    Kumar, Krishna; Soga, Kenichi; Delenne, Jean-Yves

    2017-06-01

    Avalanches, landslides, and debris flows are geophysical hazards, which involve rapid mass movement of granular solids, water, and air as a multi-phase system. In order to describe the mechanism of immersed granular flows, it is important to consider both the dynamics of the solid phase and the role of the ambient fluid. In the present study, the collapse of a granular column in fluid is studied using 2D LBM - DEM. The flow kinematics are compared with the dry and buoyant granular collapse to understand the influence of hydrodynamic forces and lubrication on the run-out. In the case of tall columns, the amount of material destabilised above the failure plane is larger than that of short columns. Therefore, the surface area of the mobilised mass that interacts with the surrounding fluid in tall columns is significantly higher than the short columns. This increase in the area of soil - fluid interaction results in an increase in the formation of turbulent vortices thereby altering the deposit morphology. It is observed that the vortices result in the formation of heaps that significantly affects the distribution of mass in the flow. In order to understand the behaviour of tall columns, the run-out behaviour of a dense granular column with an initial aspect ratio of 6 is studied. The collapse behaviour is analysed for different slope angles: 0°, 2.5°, 5° and 7.5°.

  2. A Path Based Model for a Green Liner Shipping Network Design

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Jepsen, Mads Kehlet; Plum, Christian Edinger Munk

    Liner shipping networks are the backbone of international trade providing low transportation cost, which is a major driver of globalization. These networks are under constant pressure to deliver capacity, cost eectiveness and environmentally conscious transport solutions. This article proposes...... a new path based MIP model for the Liner shipping Network Design Problem minimizing the cost of vessels and their fuel consumption facilitating a green network. The proposed model reduces problem size using a novel aggregation of demands. A decomposition method enabling delayed column generation...... is presented. The subproblems have similar structure to Vehicle Routing Problems, which can be solved using dynamic programming. An algorithm has been implemented for this model, unfortunately with discouraging results due to the structure of the subproblem and the lack of proper dominance criteria...

  3. Characterization and hardenability evaluation of gray cast iron used in the manufacture of diesel engine cylinder liners

    Directory of Open Access Journals (Sweden)

    Edgar L. Castellanos-Leal

    2017-09-01

    Full Text Available The increment of the mechanical properties (surface hardness of engine cylinder is one of the principal goals for foundry company, to increase the competitiveness of their products in the local and foreign market. This study focused on the characterization of the gray cast iron used in the production of engine cylinder liners and metallurgical parameters determination in the design of conventional quenching heat treatment. The characterization was performed by material hardenability evaluation using Grossmann method, and Jominy test; the austenitizing temperature and the severity of cooling medium to a proper hardening of material were selected. Results revealed that the excellent hardness value obtained is attributed to the suitable hardenability of the gray cast iron and adequate severity selection for hardening treatment.

  4. The correlation of defect distribution in collisional phase with measured cascade collapse probability

    International Nuclear Information System (INIS)

    Morishita, K.; Ishino, S.; Sekimura, N.

    1995-01-01

    The spatial distributions of atomic displacement at the end of the collisional phase of cascade damage processes were calculated using the computer simulation code MARLOWE, which is based on the binary collision approximation (BCA). The densities of the atomic displacement were evaluated in high dense regions (HDRs) of cascades in several pure metals (Fe, Ni, Cu, Ag, Au, Mo and W). They were compared with the measured cascade collapse probabilities reported in the literature where TEM observations were carried out using thin metal foils irradiated by low-dose ions at room temperature. We found that there exists the minimum or ''critical'' values of the atomic displacement densities for the HDR to collapse into TEM-visible vacancy clusters. The critical densities are generally independent of the cascade energy in the same metal. Furthermore, the material dependence of the critical densities can be explained by the difference in the vacancy mobility at the melting temperature of target materials. This critical density calibration, which is extracted from the ion-irradiation experiments and the BCA simulations, is applied to estimation of cascade collapse probabilities in the metals irradiated by fusion neutrons. (orig.)

  5. Passive afterheat removal in the HTGR with the liner cooling system as a heat sink

    International Nuclear Information System (INIS)

    Rehm, W.; Jahn, W.; Verfondern, K.

    1984-09-01

    The report deals with the transients of temperature and system pressure and the fission product behaviour in the primary circuit of an HTGR during passive afterheat removal, where the liner cooling system of the PCRV serves as a heat sink. The analysis has been made for the PNP-500-reactor representing nuclear plants with medium thermal power. The investigations show that the liner cooling system is able to control a core heatup. High temperature loads are encountered in the upper core region. In the case of a reactor under pressure the fuel elements and the primary circuit remain intact as the first and second barriers for fission products. In the case of a depressurized primary circuit the liner cooling system also keeps the PCRV at normal operating temperatures. The effects of a core heatup on component damage and release of fission products are thus limited. (orig.) [de

  6. Progress in the Design of the Stabilized Liner Compressor for MTF/MIF Plasma Target Development

    Science.gov (United States)

    Frese, Sherry; Frese, Michael; Turchi, Peter; Gale, Don

    2016-10-01

    The Stabilized Liner Compressor (SLC) seeks to extend concepts for repetitive, rotationally stabilized, liquid-metal liners driven by free-pistons to much higher drive pressures (25 vs 5 kpsi) and faster implosion speeds (2000 vs 100 m/s) than previously demonstrated. Such extension is needed to enable experiments with magnetized-plasma targets presently offering sizes and lifetimes of 10's cm diam and 10's microsec. SLC represents the confluence of several difficult technologies, including pulsed high pressures, high-speed rotating machinery and alkali-metal (Na, NaK) handling. Solution of the two-dimensional, unsteady, compressible flow of a rotating liquid-metal liner requires advanced numerical techniques. We report the use of the 2-1/2 dimensional MHD code MACH2 to explore flow options, including magnetic flux compression, and to provide pulsed pressure distributions for mechanical design. Supported by ARPA-E ALPHA Program.

  7. Collapse mechanisms of metal foam matrix composites under static and dynamic loading conditions

    Energy Technology Data Exchange (ETDEWEB)

    Linul, Emanoil, E-mail: emanoil.linul@upt.ro [Department of Mechanics and Strength of Materials, Politehnica University of Timisoara, 1 Mihai Viteazu Avenue, 300 222 Timisoara (Romania); Marsavina, Liviu [Department of Mechanics and Strength of Materials, Politehnica University of Timisoara, 1 Mihai Viteazu Avenue, 300 222 Timisoara (Romania); Kováčik, Jaroslav [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 13 Bratislava (Slovakia)

    2017-04-06

    The collapse mechanisms of metal foam matrix composites under static and dynamic loading conditions were experimentally and analytically investigated. Closed-cell aluminium foam AlSi10 with 325±10 kg/m{sup 3} density was used as core material, while stainless-steel-mesh is the faces materials. Prior to characterizing the composite sandwich structure, the stainless steel mesh face material and closed-cell aluminium foam were characterized by tensile testing and compression testing, respectively. Experimental tests were performed on sandwich beams using both High Speed Camera and Digital Image Correlation system for strain distribution. All experimental tests were performed at room temperature with constant crosshead speed of 1.67×10{sup −4} m/s for static tests and 2 m/s impact loading speed for dynamic tests. Two main deformation behaviours of investigated metal foam matrix composites were observed following post-failure collapse: face failure and core shear. It was showed that the initiation, propagation and interaction of failure modes depend on the type of loading, constituent material properties and geometrical parameters.

  8. Process and device for imploding a micro-area by means of a fast liner

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    The invention describes a process and a device for controlling a fast liner with hot plasma, in order to start or drive a structured micro-area to implode, in turn. In this way a natural pulse formation causes high implosion speeds for generating energy in the form of radiation, neutrons and/or alpha particles. By optimizing the extraordinarily powerful flow instability to heat the very dense plasma, the invention produces effective giving up of radiation energy to heat the plasma and to initiate the fast liner to implode the micro-area. (orig.) [de

  9. Black hole formation in perfect fluid collapse

    International Nuclear Information System (INIS)

    Goswami, Rituparno; Joshi, Pankaj S

    2004-01-01

    We construct here a special class of perfect fluid collapse models which generalizes the homogeneous dust collapse solution in order to include nonzero pressures and inhomogeneities into evolution. It is shown that a black hole is necessarily generated as the end product of continued gravitational collapse, rather than a naked singularity. We examine the nature of the central singularity forming as a result of endless collapse and it is shown that no nonspacelike trajectories can escape from the central singularity. Our results provide some insights into how the dynamical collapse works and into the possible formulations of the cosmic censorship hypothesis, which is as yet a major unsolved problem in black hole physics

  10. Gravitational collapse and the vacuum energy

    International Nuclear Information System (INIS)

    Campos, M

    2014-01-01

    To explain the accelerated expansion of the universe, models with interacting dark components (dark energy and dark matter) have been considered recently in the literature. Generally, the dark energy component is physically interpreted as the vacuum energy of the all fields that fill the universe. As the other side of the same coin, the influence of the vacuum energy on the gravitational collapse is of great interest. We study such collapse adopting different parameterizations for the evolution of the vacuum energy. We discuss the homogeneous collapsing star fluid, that interacts with a vacuum energy component, using the stiff matter case as example. We conclude this work with a discussion of the Cahill-McVittie mass for the collapsed object.

  11. Simple Analytic Models of Gravitational Collapse

    Energy Technology Data Exchange (ETDEWEB)

    Adler, R.

    2005-02-09

    Most general relativity textbooks devote considerable space to the simplest example of a black hole containing a singularity, the Schwarzschild geometry. However only a few discuss the dynamical process of gravitational collapse, by which black holes and singularities form. We present here two types of analytic models for this process, which we believe are the simplest available; the first involves collapsing spherical shells of light, analyzed mainly in Eddington-Finkelstein coordinates; the second involves collapsing spheres filled with a perfect fluid, analyzed mainly in Painleve-Gullstrand coordinates. Our main goal is pedagogical simplicity and algebraic completeness, but we also present some results that we believe are new, such as the collapse of a light shell in Kruskal-Szekeres coordinates.

  12. On the Induced Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    M. Becerra Laura

    2018-01-01

    Full Text Available The induced gravitational collapse (IGC paradigm has been applied to explain the long gamma ray burst (GRB associated with type Ic supernova, and recently the Xray flashes (XRFs. The progenitor is a binary systems of a carbon-oxygen core (CO and a neutron star (NS. The CO core collapses and undergoes a supernova explosion which triggers the hypercritical accretion onto the NS companion (up to 10-2 M⊙s-1. For the binary driven hypernova (BdHNe, the binary system is enough bound, the NS reach its critical mass, and collapse to a black hole (BH with a GRB emission characterized by an isotropic energy Eiso > 1052 erg. Otherwise, for binary systems with larger binary separations, the hypercritical accretion onto the NS is not sufficient to induced its gravitational collapse, a X-ray flash is produced with Eiso < 1052 erg. We’re going to focus in identify the binary parameters that limits the BdHNe systems with the XRFs systems.

  13. Gravity induced wave function collapse

    Science.gov (United States)

    Gasbarri, G.; Toroš, M.; Donadi, S.; Bassi, A.

    2017-11-01

    Starting from an idea of S. L. Adler [in Quantum Nonlocality and Reality: 50 Years of Bell's Theorem, edited by M. Bell and S. Gao (Cambridge University Press, Cambridge, England 2016)], we develop a novel model of gravity induced spontaneous wave function collapse. The collapse is driven by complex stochastic fluctuations of the spacetime metric. After deriving the fundamental equations, we prove the collapse and amplification mechanism, the two most important features of a consistent collapse model. Under reasonable simplifying assumptions, we constrain the strength ξ of the complex metric fluctuations with available experimental data. We show that ξ ≥10-26 in order for the model to guarantee classicality of macro-objects, and at the same time ξ ≤10-20 in order not to contradict experimental evidence. As a comparison, in the recent discovery of gravitational waves in the frequency range 35 to 250 Hz, the (real) metric fluctuations reach a peak of ξ ˜10-21.

  14. Nonlinear wave collapse and strong turbulence

    International Nuclear Information System (INIS)

    Robinson, P.A.

    1997-01-01

    The theory and applications of wave self-focusing, collapse, and strongly nonlinear wave turbulence are reviewed. In the last decade, the theory of these phenomena and experimental realizations have progressed rapidly. Various nonlinear wave systems are discussed, but the simplest case of collapse and strong turbulence of Langmuir waves in an unmagnetized plasma is primarily used in explaining the theory and illustrating the main ideas. First, an overview of the basic physics of linear waves and nonlinear wave-wave interactions is given from an introductory perspective. Wave-wave processes are then considered in more detail. Next, an introductory overview of the physics of wave collapse and strong turbulence is provided, followed by a more detailed theoretical treatment. Later sections cover numerical simulations of Langmuir collapse and strong turbulence and experimental applications to space, ionospheric, and laboratory plasmas, including laser-plasma and beam-plasma interactions. Generalizations to self-focusing, collapse, and strong turbulence of waves in other systems are also discussed, including nonlinear optics, solid-state systems, magnetized auroral and astrophysical plasmas, and deep-water waves. The review ends with a summary of the main ideas of wave collapse and strong-turbulence theory, a collection of open questions in the field, and a brief discussion of possible future research directions. copyright 1997 The American Physical Society

  15. Prospects for x-ray polarimetry measurements of magnetic fields in magnetized liner inertial fusion plasmas.

    Science.gov (United States)

    Lynn, Alan G; Gilmore, Mark

    2014-11-01

    Magnetized Liner Inertial Fusion (MagLIF) experiments, where a metal liner is imploded to compress a magnetized seed plasma may generate peak magnetic fields ∼10(4) T (100 Megagauss) over small volumes (∼10(-10)m(3)) at high plasma densities (∼10(28)m(-3)) on 100 ns time scales. Such conditions are extremely challenging to diagnose. We discuss the possibility of, and issues involved in, using polarimetry techniques at x-ray wavelengths to measure magnetic fields under these extreme conditions.

  16. Concrete protection from sodium spills by intentionally defected liners, small-scale tests S9 and S10

    International Nuclear Information System (INIS)

    Hilliard, R.K.; Boehmer, W.D.

    1975-07-01

    Two small scale tests were performed to determine the protection against sodium attack afforded to a concrete surface by a defected steel liner. An inert atmosphere was maintained over the sodium pool, which was heated electrically to 1600 0 F for 2--6 hrs in one test, to 1380 0 F for 19 hrs in the other. The 10 inch diameter vertical concrete surface was separated from the sodium by a liner plate in which small defects had been drilled. The plates provided significant protection against direct chemical attack, but most of the water was released from the concrete through the defects to react in the sodium pool region. The liners were corroded significantly in the defect areas. (U.S.)

  17. Non-destructive electrochemical techniques applied to the corrosion evaluation of the liner structures in nuclear power plants

    International Nuclear Information System (INIS)

    Martinez, I.; Castillo, A.; Andrade, C.

    2008-01-01

    The liner structure in nuclear power plants provides containment for the operation and therefore the study of its durability and integrity during its service life is an important issue. There are several causes for the deterioration of the liner, which in general involve corrosion due to its metallic nature. The present paper is aimed at describing the assessment of corrosion problems of two liners from two different nuclear power plants, which were evaluated using non-destructive electrochemical techniques. In spite of the testing difficulties arisen, from the results extracted it can be concluded that the electrochemical techniques applied are adequate for the corrosion evaluation. They provide important information about the integrity of the structure and allow for its evolution with time to be assessed

  18. Neutrinos and supernova collapse

    International Nuclear Information System (INIS)

    Colgate, S.A.; Petschek, A.G.

    1980-01-01

    The neutrino emission resulting from stellar collapse and supernova formation is reviewed. The electron capture and consequent neutronization of the collapsing stellar matter at the end of evolution determines both the initial adiabat of core collapse as well as the trapped lepton fraction. The initial lepton fraction, Y/sub l/ = .48 supplies the pressure for neutral support of the star at the Chandrasekhar limit. High trapping values, Y/sub l/ = .4, lead to soft core collapses; low values to harder collapses. The value of Y/sub l/ is presently in dispute. The neutrino emission from initial electron capture is relatively small. A strong core-bounce shock releases both electron neutrino as well as thermal muon and tau neutrinos. Subsequent neutrino emission and cooling can sometimes lead to an unstable buoyancy gradient in the core in which case unstable core overturn is expected. Calculations have already shown the importance of the largest possible eddy or equivalently the lowest mode of overturn. Present models of low lepton trapping ratio lead to high entropy creation by the reflected shock and the stabilization of the core matter against overturn. In such cases the exterior matter must cool below an entropy of approximately s/k approx. = 2 to become unstable. This may require too long a time approximately one second for neutrino cooling from a neutrinosphere at rho approx. = 2 x 10 12 g cm -3 . On the other hand, high values of Y/sub l/ such as .4 lead to softer bounces at lower density and values of the critical stabilizing entropy of 3 or higher. Under such circumstances, core overturn can still occur

  19. Investigation of piston ring – cylinder liner dry wear using a block-on-ring test rig

    DEFF Research Database (Denmark)

    Bihlet, Uffe; Klit, Peder; Felter, Christian L.

    Characterization of the wear of piston rings and cylinder liner is an important aspect of large two stroke diesel engine design. Two major wear mechanisms exist; corrosive wear and mechanical wear. This paper deals with the most aggressive form of the latter, which is known as scuffing. Different...... that ceramic coating on the piston ring decreases the dry wear rate of both piston ring and liner, while the coefficient of friction is increased....

  20. Conceptual design of the Purdue compact torus/passive liner fusion reactor

    International Nuclear Information System (INIS)

    Terry, W.K.

    1981-01-01

    This proposal describes a program for the conceptual development of a novel fusion reactor design, the Purdue Compact Torus/Passive Liner Reactor. The key features of the concept are described and a comparison is made with a conventional tokamak

  1. Optical fiber Bragg grating-instrumented silicone liner for interface pressure measurement within prosthetic sockets of lower-limb amputees

    Science.gov (United States)

    Al-Fakih, Ebrahim; Arifin, Nooranida; Pirouzi, Gholamhossein; Mahamd Adikan, Faisal Rafiq; Shasmin, Hanie Nadia; Abu Osman, Noor Azuan

    2017-08-01

    This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction.

  2. Green vessel scheduling in liner shipping: Modeling carbon dioxide emission costs in sea and at ports of call

    Directory of Open Access Journals (Sweden)

    Maxim A. Dulebenets

    2018-03-01

    Full Text Available Considering a substantial increase in volumes of the international seaborne trade and drastic climate changes due to carbon dioxide emissions, liner shipping companies have to improve planning of their vessel schedules and improve energy efficiency. This paper presents a novel mixed integer non-linear mathematical model for the green vessel scheduling problem, which directly accounts for the carbon dioxide emission costs in sea and at ports of call. The original non-linear model is linearized and then solved using CPLEX. A set of numerical experiments are conducted for a real-life liner shipping route to reveal managerial insights that can be of importance to liner shipping companies. Results indicate that the proposed mathematical model can serve as an efficient planning tool for liner shipping companies and may assist with evaluation of various carbon dioxide taxation schemes. Increasing carbon dioxide tax may substantially change the design of vessel schedules, incur additional route service costs, and improve the environmental sustainability. However, the effects from increasing carbon dioxide tax on the marine container terminal operations are found to be very limited.

  3. Karst collapse in cities and mining areas, China

    International Nuclear Information System (INIS)

    Jian Chen

    1988-01-01

    Karst collapse is a dynamic geological phenomenon, in which the rock mass or deposits overlying the karstified zone subsides down along the karst cavity, resulting in a collapse pit or sinkhole. After discussing the typical examples of collapse emerging in the karst cities and mines in provinces and regions of South China, such as Guangdong, Guangxi, Hunan, Hubei, Zhejiang, Yunnan, Guizhou, and Jiangxi, it is considered that human activities of economy and production have become a major effect in causing karst collapse. Man-made collapses make 66.4 percent of the total, whereas natural ones 33.6 percent. Most of the collapses occurred to the area with soil overburden (96.7 percent), only a few in areas of bedrock overburden (3.3 percent). The karst collapses have a close relationship with the extent of karst development, the character and the thickness of overburden, and the dynamic condition of underground water. Collapse usually occurs in those parts of an area that are more intensely karstified, with soil thickness less than 5 m and a high amplitude of water table fluctuation. Many kinds of mechanical effects are caused by pumping or draining on the over-burden and destroying its equilibrium, leading to the collapse. These effects included the support loss and load-added effect, penetrating suffusion, gas explosion, water-hammer, suction pressure erosion, and liquefaction effects. The collapses are the result of varied comprehensive effects, particularly the support loss and load-added, and penetrating suffusion

  4. Material-Point-Method Analysis of Collapsing Slopes

    DEFF Research Database (Denmark)

    Andersen, Søren; Andersen, Lars

    2009-01-01

    To understand the dynamic evolution of landslides and predict their physical extent, a computational model is required that is capable of analysing complex material behaviour as well as large strains and deformations. Here, a model is presented based on the so-called generalised-interpolation mat......To understand the dynamic evolution of landslides and predict their physical extent, a computational model is required that is capable of analysing complex material behaviour as well as large strains and deformations. Here, a model is presented based on the so-called generalised......, a deformed material description is introduced, based on time integration of the deformation gradient and utilising Gauss quadrature over the volume associated with each material point. The method has been implemented in a Fortran code and employed for the analysis of a landslide that took place during...

  5. Improvement of journal bearing operation at heavy misalignment using bearing flexibility and compliant liners

    DEFF Research Database (Denmark)

    Thomsen, Kim; Klit, Peder

    2012-01-01

    A flexure journal bearing design is proposed that will improve operational behaviour of a journal bearing at pronounced misalignment. Using a thermoelastohydrodynamic model, it is shown that the proposed flexure journal bearing has vastly increased the hydrodynamic performance compared to the stiff...... bearing when misaligned. The hydrodynamic performance is evaluated on lubricant film thickness, pressure and temperature. Furthermore, the influence of a compliant bearing liner is investigated and it is found that it increases the hydrodynamic performance when applied to a stiff bearing, whereas...... the liner has practically no influence on the flexure journal bearing's performance....

  6. A novel numerical model for estimating the collapse pressure of flexible pipes

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Victor P.P.; Antoun Netto, Theodoro [Universidade Federal do Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao em Engenharia], e-mail: victor@lts.coppe.ufrj.br

    2009-07-01

    As the worldwide oil and gas industry operational environments move to ultra-deep waters, failure mechanisms in flexible pipes such as instability of the armor layers under compression and hydrostatic collapse are more likely to occur. Therefore, it is important to develop reliable numerical tools to reproduce the failure mechanisms that may occur in flexible pipes. This work presents a representative finite element model of flexible pipe capable to reproduce its pre and post-collapse behavior under hydrostatic pressure. The model, developed in the scope of this work, uses beam elements and includes nonlinear kinematics and material behavior influences. The dependability of the numerical results is assessed in light of experimental tests on flexible pipes with 4 inches and 8 inches nominal diameter available in the literature (Souza, 2002). The applied methodology provided coherent values regarding the estimation of the collapse pressures and results have shown that the proposed model is capable to reproduce experimental results. (author)

  7. Pineapple Fruit Collapse: Newly Emerging Disease of Pineapple Fruit in Lampung, Indonesia

    Directory of Open Access Journals (Sweden)

    Joko Prasetyo

    2014-03-01

    Full Text Available ABSTRACT Pineapple fruit collapse: newly emerging disease of pineapple fruit in Lampung, Indonesia Recently, a new disease on pineapple fruit has occurred in Lampung. Symptoms of the disease are complex. Fruits rotted and exuded copious liquid from the inter- fruitlet tissues accompanied by gas bubbles. Open spaces were formed inside the rotten fruit. Dissection of diseased fruit showed many cavities within its sceletal fibres and bad odour was exerted from the rotten tissues. A bacterial entity was isolated  from the diseased materials. In a pathogenicity test, the isolated bacteria caused the same symptom as mentioned. In the growing-on test the crown of the heavily infected fruit  showed  heart rot symptom.  Those  indicated that the disease was pineapple fruit collapse. Both symptoms were known related to the same causal agent, Erwinia chrysanthemi (pineapple strain Dickeya sp.. In our opinion, this is the first report of pineapple fruit collapse in Indonesia.

  8. Neutrinos from gravitational collapse

    International Nuclear Information System (INIS)

    Mayle, R.; Wilson, J.R.; Schramm, D.N.

    1986-05-01

    Detailed calculations are made of the neutrino spectra emitted during gravitational collapse events (Type II supernovae). Those aspects of the neutrino signal which are relatively independent of the collapse model and those aspects which are sensitive to model details are discussed. The easier-to-detect high energy tail of the emitted neutrinos has been calculated using the Boltzmann equation which is compared with the result of the traditional multi-group flux limited diffusion calculations. 8 figs., 28 refs

  9. Developing empirical collapse fragility functions for global building types

    Science.gov (United States)

    Jaiswal, K.; Wald, D.; D'Ayala, D.

    2011-01-01

    Building collapse is the dominant cause of casualties during earthquakes. In order to better predict human fatalities, the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) program requires collapse fragility functions for global building types. The collapse fragility is expressed as the probability of collapse at discrete levels of the input hazard defined in terms of macroseismic intensity. This article provides a simple procedure for quantifying collapse fragility using vulnerability criteria based on the European Macroseismic Scale (1998) for selected European building types. In addition, the collapse fragility functions are developed for global building types by fitting the beta distribution to the multiple experts’ estimates for the same building type (obtained from EERI’s World Housing Encyclopedia (WHE)-PAGER survey). Finally, using the collapse probability distributions at each shaking intensity level as a prior and field-based collapse-rate observations as likelihood, it is possible to update the collapse fragility functions for global building types using the Bayesian procedure.

  10. Key enabling design features of the ITER HNB Duct Liner

    Energy Technology Data Exchange (ETDEWEB)

    Chuilon, Ben, E-mail: ben.chuilon@ccfe.ac.uk; Mistry, Sanjay; Andrews, Rodney; Verhoeven, Roel; Xue, Yongkuan

    2015-10-15

    Highlights: • Key engineering design details of the ITER HND Duct Liner are presented. • A standardised CuCrZr water cooled panel that can be remotely handled is detailed. • Bolts are protected from beam power by means of a tungsten cap to radiate heat away. • Water connections placed coaxially are protected from beam power by a tungsten ring. • Explosion-bonded CuCrZr-316L panels result in a tenfold disruption torque reduction. - Abstract: The Duct Liner (DL) for the ITER Heating Neutral Beam (HNB) is a key component in the beam transport system. Duct Liners installed into equatorial ports 4 and 5 of the Vacuum Vessel (VV) will protect the port extension from power deposition due to re-ionisation and direct interception of the HNB. Furthermore, the DL contributes towards the shielding of the VV and superconducting coils from plasma photons and neutrons. The DL incorporates a 316L(N)-IG, deep-drilled and water cooled Neutron Shield (NS) whose internal walls are lined with actively cooled CuCrZr Duct Liner Modules (DLMs). These Remote Handling Class 2 and 3 panels provide protection from neutral beam power. This paper provides an overview of the preliminary design for the ITER HNB DL and focusses on critical features that ensure compatibility with: high heat flux requirements, remote maintenance procedures, and transient magnetic fields arising from major plasma disruptions. The power deposited on a single DLM can reach 300 kW with a peak power density of 2.4 MW/m{sup 2}. Feeding coolant to the DLMs is accomplished via welded connections to the internal coolant network of the NS. These are placed coaxially to allow for thermal expansion of the DLMs without the use of deformable connections. Critically, the remote maintenance of individual DLMs necessitates access to water connections and bolts from the beam facing surface, thus subjecting them to high heat flux loads. This design challenge will become more prevalent as fusion devices become more powerful

  11. The effect of thermocycling on tensile bond strength of two soft liners.

    Science.gov (United States)

    Geramipanah, Farideh; Ghandari, Masoumeh; Zeighami, Somayeh

    2013-09-01

    Failure of soft liners depends mostly on separation from the denture base resin; therefore measurement of the bond strength is very important. The purpose of this study was to compare the tensile bond strength of two soft liners (Acropars, Molloplast-B) to denture base resin before and after thermocycling. Twenty specimens fromeach of the two different soft liners were processed according to the manufacturer's instructions between two polymethyl methacrylate (PMMA) sheets. Ten specimens in each group were maintained in 37°C water for 24 hours and 10 were thermocycled (5000 cycles) among baths of 5° and 55°C. The tensile bond strength was measured using a universal testing machine at a crosshead speed of 5 mm/min. Mode of failure was determined with SEM (magnification ×30). Two-way ANOVA was used to analyze the data. The mean and standard deviation of tensile bond strength of Acropars and Molloplast-B before thermocycling were 6.59±1.85 and1.51±0.22 MPa, respectively and 5.89±1.52 and1.37±0.18 MPa, respectively after thermocycling. There was no significant difference before and after thermocycling. Mode of failure in Acropars and Molloplast-B were adhesive and cohesive, respectivley. The bond strength of Acropars was significantly higher than Molloplast-B (P<0.05).

  12. Effect of Cylinder Liner Oil Grooves Shape on Two-Stroke Marine Diesel Engine's Piston Ring Friction Force

    Directory of Open Access Journals (Sweden)

    Salaheldin A. Mohamad

    2015-02-01

    Full Text Available The dimensions, area densities, and geometry of macroscale surface textures may affect the performance of hydrodynamic lubrication interface. Reported in this paper are the investigations of the effect of surface textures bottom shapes on the friction forces between piston ring and cylinder liner for two-stroke marine diesel engine, using numerically generated textures and average Reynolds equation. These textures are on the cylinder liner surface in the form of circumferential oil grooves with different aspect ratios and different area densities. The hydrodynamic pressure distribution is also calculated using Reynolds boundary condition. The results revealed that the bottom shape could positively affect the friction between moving surfaces, as it could provide a microwedge or microstep bearing that tends to enhance the lubrication condition between piston ring and cylinder liner.

  13. The Liner Shipping Routing and Scheduling Problem Under Environmental Considerations

    DEFF Research Database (Denmark)

    Dithmer, Philip; Reinhardt, Line Blander; Kontovas, Christos

    2017-01-01

    This paper deals with the Liner Shipping Routing and Scheduling Problem (LSRSP), which consists of designing the time schedule for a vessel to visit a fixed set of ports while minimizing costs. We extend the classical problem to include the external cost of ship air emissions and we present some...

  14. Four tails problems for dynamical collapse theories

    Science.gov (United States)

    McQueen, Kelvin J.

    2015-02-01

    The primary quantum mechanical equation of motion entails that measurements typically do not have determinate outcomes, but result in superpositions of all possible outcomes. Dynamical collapse theories (e.g. GRW) supplement this equation with a stochastic Gaussian collapse function, intended to collapse the superposition of outcomes into one outcome. But the Gaussian collapses are imperfect in a way that leaves the superpositions intact. This is the tails problem. There are several ways of making this problem more precise. But many authors dismiss the problem without considering the more severe formulations. Here I distinguish four distinct tails problems. The first (bare tails problem) and second (structured tails problem) exist in the literature. I argue that while the first is a pseudo-problem, the second has not been adequately addressed. The third (multiverse tails problem) reformulates the second to account for recently discovered dynamical consequences of collapse. Finally the fourth (tails problem dilemma) shows that solving the third by replacing the Gaussian with a non-Gaussian collapse function introduces new conflict with relativity theory.

  15. The Effect of Casting Ring Liner Length and Prewetting on the Marginal Adaptation and Dimensional Accuracy of Full Crown Castings.

    Science.gov (United States)

    Haralur, Satheesh B; Hamdi, Osama A; Al-Shahrani, Abdulaziz A; Alhasaniah, Sultan

    2017-01-01

    To evaluate the effect of varying cellulose casting ring liner length and its prewetting on the marginal adaptation and dimensional accuracy of full veneer metal castings. The master die was milled in stainless steel to fabricate the wax pattern. Sixty wax patterns were fabricated with a uniform thickness of 1.5 mm at an occlusal surface and 1 mm axial surface, cervical width at 13.5 mm, and 10 mm cuspal height. The samples were divided into six groups ( n = 10). Groups I and II samples had the full-length cellulose prewet and dry ring liner, respectively. The groups III and IV had 2 mm short prewet and dry cellulose ring liner, respectively, whereas groups V and VI were invested in 6 mm short ring liner. The wax patterns were immediately invested in phosphate bonded investment, and casting procedure was completed with nickel-chrome alloy. The castings were cleaned and mean score of measurements at four reference points for marginal adaption, casting height, and cervical width was calculated. The marginal adaption was calculated with Imaje J software, whereas the casting height and cervical width was determined using a digital scale. The data was subjected to one-way analysis of varaince and Tukey post hoc statistical analysis with Statistical Package for the Social Sciences version 20 software. The group II had the best marginal adaption with a gap of 63.786 μm followed by group I (65.185 μm), group IV (87.740 μm), and group III (101.455 μm). A large marginal gap was observed in group V at 188.871 μm. Cuspal height was more accurate with group V (10.428 mm), group VI (10.421 mm), and group II (10.488 mm). The cervical width was approximately similar in group I, group III, and group V. Statistically significant difference was observed in Tukey post hoc analysis between group V and group VI with all the other groups with regards to marginal adaptation. The dry cellulose ring liners provided better marginal adaptation in comparison to prewet cellulose ring

  16. Long-term efficacy of denture cleansers in preventing Candida spp. biofilm recolonization on liner surface

    Directory of Open Access Journals (Sweden)

    Ana Paula Coelho Vieira

    2010-09-01

    Full Text Available This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min, 0.5% sodium hypochlorite (10 min or distilled water (control; 15 min. After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL. Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05. Results of cell count estimation showed significant differences in cleanliness among the treatments (p 0.05 was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p < 0.001. Sodium hypochlorite was the only treatment that removed biofilm efficiently, since no viable cells were found after its use. In conclusion, alkaline peroxide denture cleansers were not effective in removing Candida spp. biofilm from denture liner surfaces and preventing biofilm recolonization.

  17. The collapse of interstellar gas clouds

    International Nuclear Information System (INIS)

    McNally, D.; Settle, J.J.

    1980-01-01

    The stability of spherically symmetric free-fall collapse to small radial perturbations is examined for non-uniform clouds. It is concluded that fragmentation of the central region of a collapsing gas cloud is possible if: (a) the density distribution is sufficiently smooth; and (b) the collapse is nearly free fall. Generally, perturbations enjoy only finite amplification during the collapse, and the amplification tends to decrease with increasing distance from the centre of the cloud. Unlimited amplification occurs only for uniform density clouds. Fragmentation is therefore unlikely to result from dynamical instability in the outer parts of a non-uniform cloud. Isothermal clouds are also briefly considered and, while it is argued that an earlier suggestion of their instability to fragmentation is unfounded, no general conclusion on the instability of such clouds could be drawn. (author)

  18. Creep collapse of TAPS fuel cladding

    International Nuclear Information System (INIS)

    Chaudhry, S.M.; Anand, A.K.

    1975-01-01

    Densification of UO 2 can cause axial gaps between fuel pelets and cladding in unsupported (internally) at these regions. An analysis is carried out regarding the possibility of creep collapse in these regions. The analysis is based on Timoshenko's theory of collapse. At various times during the residence of fuel in reactor following parameters are calculated : (1) inelastic collapse of perfectly circular tubes (2) plastic instability in oval tubes (3) effect of creep on ovality. Creep is considered to be a non-linear combination of the following : (a) thermal creep (b) intresenic creep (c) stress aided radiation enhanced (d) stress free growth (4) Critical pressure ratio. The results obtained are compared with G.E. predictions. The results do not predict collapse of TAPS fuel cladding for five year residence time. (author)

  19. Comparative study of multistage cemented liner and openhole system completion technologies in the Montney resource play

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Brad; Lui, David; Klim, James [Murphy Oil Company Ltd (United States); Kenyon, Mike [Society of Petroleum Engineers (Canada); McCaffrey, Matt [Packers Plus Energy Services (Canada)

    2011-07-01

    This work highlights hydraulic fracturing technologies implemented in the Lower Montney formation. The goal of the study is to compare two multistage hydraulic fracturing techniques: the cemented liner and the open hole multistage system (OHMS) and to investigate the effects each has on production rates and performance in general. The overall field was separated into two geographical areas and a total of 15 wells were investigated, some of which were subjected to cemented liner fracturing and others to OHMS. Various physical, mechanical, and financial data were collected. These data included: oil production rates, well spacing, pumping rates, stage times, and operational costs. In general, it was shown that OHMS proved to be the more suitable fracturing technique for the Montney formation, yielding higher initial and cumulative production rates. Moreover, average fracturing costs per stage were lower and time to complete was less than with the cemented liner technique.

  20. Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

    2018-01-01

    Corrosive wear of cylinder liners in large two-stroke marine diesel engines that burn heavy fuel oil containing sulfur is coupled to the formation of gaseous sulfur trioxide (SO3) and subsequent combined condensation of sulfuric acid (H2SO4) and water (H2O) vapor. The present work seeks to address...... vapor liquid equilibrium. By assuming homogenous cylinder gas mixtures condensation is modeled using a convective heat and mass transfer analogy combined with realistic liner temperature profiles. Condensation of water is significantly altered by the liner temperature and charge air humidity while...... how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...