WorldWideScience

Sample records for hybrid mica seals

  1. A hermetic sealing process for large irregularly shaped hybrid microcircuit enclosures

    Science.gov (United States)

    Stahler, M. R.

    1977-01-01

    A system for sealing vacuum baked hybrids in a dry inert atmosphere using an overlapping spot resistance weld is described. A unique electrode configuration and fixturing that permits sealing of large and irregularly shaped gold plated Kovar packages to the hermeticity requirements of MIL-STD-883 was discussed. Metallurgical considerations and comparisons to laser sealing were made. Problems encountered during the development and optimization of the process were highlighted. Solutions to plating, fixturing, warpage, weld splatter and cracked bead problems are presented.

  2. Hydrodynamics of a hybrid circulating fluidized bed reactor with a partitioned loop seal system

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Dal-Hee; Moon, Jong-Ho; Jin, Gyoung Tae; Shun, Dowon [Korea Institute of Energy Research, Daejeon (Korea, Republic of); Yun, Minyoung; Park, Chan Seung; Norbeck, Joseph M. [University of California, Riverside (United States)

    2015-07-15

    A circulating fluidized bed (CFB) with a hybrid design has been developed and optimized for steam hydrogasification. The hybrid CFB is composed of a bubbling fluidized bed (BFB) type combustor and a fast fluidized bed (FB) type gasifier. Char is burnt in the combustor and the generated heat is supplied to the gasifier along with the bed materials. Two different types of fluidized beds are connected to each other with a newly developed partitioned loop seal to avoid direct contact between two separate gas streams flowing in each fluidized bed. Gas mixing tests were carried out with Air and Argon in a cold model hybrid CFB to test the loop seal efficiency. Increase in solid inventory in the loop seal can improve the gas separation efficiency. It can be realized at higher gas velocity in fast bed and with higher solid inventory in the loop seal system. In addition, bed hydrodynamics was investigated with varying gas flow conditions and particle sizes in order to obtain a full understanding of changes of solid holdup in the FB. The solid holdup in the FB increased with increasing gas velocity in the BFB. Conversely, increase in gas velocity in the FB contributed to reducing the solid holdup in the FB. It was observed that changing the particle size of bed material does not have a big impact on hydrodynamic parameters.

  3. Hybrid Feature Selection for Myoelectric Signal Classification Using MICA

    Science.gov (United States)

    Naik, Ganesh R.; Kumar, Dinesh K.

    2010-03-01

    This paper presents a novel method to enhance the performance of Independent Component Analysis (ICA) of myoelectric signal by decomposing the signal into components originating from different muscles. First, we use Multi run ICA (MICA) algorithm to separate the muscle activities. Pattern classification of the separated signal is performed in the second step with a back propagation neural network. The focus of this work is to establish a simple, yet robust system that can be used to identify subtle complex hand actions and gestures for control of prosthesis and other computer assisted devices. Testing was conducted using several single shot experiments conducted with five subjects. The results indicate that the system is able to classify four different wrist actions with near 100% accuracy.

  4. EFFECT OF SURFACE SEALING ON STAIN RESISTANCE OF A NANO-HYBRID RESIN COMPOSITE*

    Directory of Open Access Journals (Sweden)

    Günçe SAYGI

    2015-04-01

    Full Text Available Purpose: This study investigated the influence of sealant application on stain resistance of a nanohybrid resin composite compared to the efficacy of a bonding agent used as a surface sealant on prolonging color stability of the resin composite. Materials and Methods: 28 disc-shaped materials were prepared from a nano-hybrid resin composite Filtek Z550 and assigned to four groups: G1K: nonsealed; G2:Adper Single Bond; G3: Fortify ; G4: Biscover LV. After 24 h storage in distilled water at 37˚C, all specimens were subjected to thermocycling and immersed into coffee solution. Color measurements were performed using spectrophotometer (VITA Easyshade; Vident according to CIEL*a*b* system. Results: Color change values were significantly different among the groups in each evaluation period except for after thermocycling (p<0.05. For 7 days evaluation period, the difference between G3 and G4 group was statistically significant while G4 exhibited statistically significant differences (p<0.05 and p<0.0001 respectively compared to control (G1 in 14 day whereas no significant difference was found between GI and GII in 28-day evaluation period. However, ΔE values of sealed specimens (GIII, GIV differed significantly from non-sealed (GI specimens after 28 days of immersion in coffee solution (p<0.05 and p<0.0001 respectively. Conclusion: It may be concluded that using a bonding agent as a surface sealant does not increase stain resistance of resin composites of the sealants evaluated. Biscover LV showed the highest efficacy to prolong color stability of the resin composite.

  5. PLASMA SPRAYED Al₂O₃-13 WT.%TiO₂ COATING SEALED WITH ORGANIC-INORGANIC HYBRID AGENT AND ITS CORROSION RESISTANCE IN ACID ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Zehua Zhou

    2016-07-01

    Full Text Available A novel organic-inorganic hybrid material of γ-methacryloxypropyltrime-thoxysilane (KH570 -SiO₂ was fabricated by Sol-Gel method. The hybrid material was used as the sealing agent for the plasma sprayed Al₂O₃-13 wt.% TiO₂ coating. Infrared spectrum and grafted mechanism of the hybrid agent (HA were studied. Moreover, morphology and porosity, as well as characteristics of immersion plus electrochemical corrosion in acid environment of the coating with and without sealing treatment were evaluated, compared with those of the coating sealed with the conventional silicone resin agent (SRA. The results reveal that KH570 was successfully grafted onto the surface of SiO₂. The HA film sealed on the surface of the coating presents a little better quality than the SRA film. The porosities of the coatings after the sealing treatment decreased. Furthermore, the sealing treatment can improve efficiently the corrosion resistance of the coating in 5 vol.% HCl solution. The hybrid sealing agent can become a candidate for the plasma sprayed Al₂O₃-13 wt.% TiO₂ coating used in acid environment to overcome some disadvantages of organic agents such as severely environmental pollution.

  6. Hybrid Finite-Discrete Element Simulation of the EDZ Formation and Mechanical Sealing Process Around a Microtunnel in Opalinus Clay

    Science.gov (United States)

    Lisjak, Andrea; Tatone, Bryan S. A.; Mahabadi, Omid K.; Grasselli, Giovanni; Marschall, Paul; Lanyon, George W.; Vaissière, Rémi de la; Shao, Hua; Leung, Helen; Nussbaum, Christophe

    2016-05-01

    The analysis and prediction of the rock mass disturbance around underground excavations are critical components of the performance and safety assessment of deep geological repositories for nuclear waste. In the short term, an excavation damaged zone (EDZ) tends to develop due to the redistribution of stresses around the underground openings. The EDZ is associated with an increase in hydraulic conductivity of several orders of magnitude. In argillaceous rocks, sealing mechanisms ultimately lead to a partial reduction in the effective hydraulic conductivity of the EDZ with time. The goal of this study is to strengthen the understanding of the phenomena involved in the EDZ formation and sealing in Opalinus Clay, an indurated claystone currently being assessed as a host rock for a geological repository in Switzerland. To achieve this goal, hybrid finite-discrete element method (FDEM) simulations are performed. With its explicit consideration of fracturing processes, FDEM modeling is applied to the HG-A experiment, an in situ test carried out at the Mont Terri underground rock laboratory to investigate the hydro-mechanical response of a backfilled and sealed microtunnel. A quantitative simulation of the EDZ formation process around the microtunnel is first carried out, and the numerical results are compared with field observations. Then, the re-compression of the EDZ under the effect of a purely mechanical loading, capturing the increase of swelling pressure from the backfill onto the rock, is considered. The simulation results highlight distinctive rock failure kinematics due to the bedded structure of the rock mass. Also, fracture termination is simulated at the intersection with a pre-existing discontinuity, representing a fault plane oblique to the bedding orientation. Simulation of the EDZ re-compression indicates an overall reduction of the total fracture area as a function of the applied pressure, with locations of ineffective sealing associated with self

  7. Seals and sealing handbook

    CERN Document Server

    Flitney, Robert K

    2014-01-01

    Seals and Sealing Handbook, 6th Edition provides comprehensive coverage of sealing technology, bringing together information on all aspects of this area to enable you to make the right sealing choice. This includes detailed coverage on the seals applicable to static, rotary and reciprocating applications, the best materials to use in your sealing systems, and the legislature and regulations that may impact your sealing choices. Updated in line with current trends this updated reference provides the theory necessary for you to select the most appropriate seals for the job and with its 'Failur

  8. Juxtarenal Inflammatory Aneurysm Treated with Bilateral Iliac-Renal Bypass Using the Gore Hybrid Device and Total Sealing of the Aneurysmal Sac with a Nellix Device.

    Science.gov (United States)

    Martinelli, Ombretta; Malaj, Alban; Gattuso, Roberto; Irace, Luigi; Gossetti, Bruno

    2017-01-01

    The aim of this study is to present the treatment of a juxtarenal inflammatory aneurysm using a Nellix device (Endologix, Inc., Irvine, CA) to seal the entire aneurysmatic aorta combined with bilateral iliac-renal bypass using the Gore hybrid vascular graft (W. L. Gore & Associates, Inc., Flagstaff, AZ). A 63-year-old man was diagnosed with a 6-cm juxtarenal inflammatory aneurysm. It was initially decided to treat him with an aorto-aortic bypass and to revascularize the 2 renal arteries with "graft to renal artery bypass" using Gore hybrid vascular grafts. Due to the high intraoperative bleeding preparing the proximal neck and the tight adhesion of the aorta to the adjacent structures, we decided to change our plans and to treat the patient using the Nellix system combined with bilateral iliac-renal bypass using the Gore hybrid vascular grafts. Contrast computed tomography control at 1 month showed complete sealing of the aneurysm sac and patent iliac renal bypasses. The reported case demonstrated that the Nellix Endovascular Aneurysm Sealing system combined with Gore hybrid vascular grafts for bilateral iliac-renal bypass showed that it can be an effective modality for the treatment of juxtarenal, inflammatory aortic aneurysm and revascularization of the renal arteries from the distal iliac arteries. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Seals and sealing handbook

    CERN Document Server

    Flitney, Robert K

    2007-01-01

    Wherever machinery operates there will be seals of some kind ensuring that the machine remains lubricated, the fluid being pumped does not leak, or the gas does not enter the atmosphere. Seals are ubiquitous, in industry, the home, transport and many other places. This 5th edition of a long-established title covers all types of seal by application: static, rotary, reciprocating etc. The book bears little resemblance to its predecessors, and Robert Flitney has re-planned and re-written every aspect of the subject. No engineer, designer or manufacturer of seals can afford to be without this uniq

  10. Performance Study of Dynamic-hydrostatic Hybrid Gas Seal%动静压混合式气体密封的特性分析

    Institute of Scientific and Technical Information of China (English)

    李双喜; 张树强; 蔡纪宁; 张秋翔

    2011-01-01

    Based on the principles of dynamic gas seal and hydrostatic gas seal,a new kind of gas seal,namely dynamic-hydrostatic hybrid gas seal(DHHGS),was proposed.Gas film pressure distribution between the two faces of dynamic seal,hydrostatic seal and DHHGS were obtained by solving the Reynolds equation of the gas film numerically.The sealing performance parameters,i.e.opening force,steady-state stiffness,leakage rate and frictional power were evaluated.Operating characteristics of DHHGS were investigated by comparing the sealing performances of different structure of seal end faces of DHHGS,hydrostatic seal and dynamic seal.Specifically sealing performances of DHHGS and hydrostatic seal without initial gas pressure were analyzed.Results showed that the opening force of DHHGS was larger in the same gas film thickness and the stiffness of DHHGS was still greater when the gas film thickness increased,compared with dynamic seal.Static opening and dynamic running could be well achieved with DHHGS.As it has both the hydrodynamic effect and hydrostatic effect simultaneously,DHHGS could find more applications in engineering.In addition the sealing performance,parameters of DHHGS could be changed through gas source pressure adjustment online.%基于气体动压式和静压式密封原理,提出了新型的动静压混合式气体密封(简称混合式密封),介绍了该密封的工作原理.采用有限元法,利用Matlab数值软件,求解了混合式密封及动压式密封和静压式密封端面间气膜的Reynolds方程,得到气膜的压力分布,进而求得了密封的性能参数,如开启力、稳态刚度、泄漏率、摩擦功耗等.比较了不同端面结构的混合式密封与静压式和动压式密封的密封性能,并分析了混合式密封及静压式密封在失去气源情况下的密封性能.结果表明:与动压式密封相比,在同一气膜厚度下混合式密封获得的开启力更大,气膜厚度增加时仍具有

  11. A study of the Chinese organic-inorganic hybrid sealing material used in 'Huaguang No.1' ancient wooden ship

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Shiqiang [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014 (China); Zhang, Hui [Department of Cultural Heritage and Museology, Zhejiang University, Hangzhou 310028 (China); Zhang, Bingjian, E-mail: zhangbiji@zju.edu.cn [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Department of Cultural Heritage and Museology, Zhejiang University, Hangzhou 310028 (China); Wei, Guofeng [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Li, Guoqing [Museum of Overseas Communication History Quanzhou, Fujian 362000 (China); Zhou, Yang [China National Silk Museum, Hangzhou 310002 (China)

    2013-01-10

    Highlights: Black-Right-Pointing-Pointer The composition of ancient sealing material was analyzed. Black-Right-Pointing-Pointer The excellent performance of this sealing material comes from the compact structure. Black-Right-Pointing-Pointer This structure is established through coordination and oxidative polymerization. Black-Right-Pointing-Pointer Conservation of ancient relies to a knowledge on their materials and crafts. - Abstracts: Chu-nam putty is a special organic-inorganic hybrid material invented by ancient Chinese people. It was prepared by mixing tung-oil, lime and oakum (plant fibers like jute, ramie and so on) with excellent sealing performance. The invention and application of Chu-nam putty in wooden ship lead to improvement in sailing technology and ship safety issue. In this paper, the analytical results of a piece of chu-nam putty which was discovered in 'Huaguang No.1' ancient ship are presented. The results show that the components of chu-nam putty are calcite, carboxylate and unsaturated esters by means of FT-IR, XRD and TGA/DSC. And the FT-IR and cross-section microscopic analysis confirm that the oakum was from jute. Comparing with the modeling putty samples it is found that the outstanding sealing performance of chu-nam putty comes from the coordination reaction of Ca{sup 2+} from the Ca(OH){sub 2} and the oxidation aggregation reaction of C=C double bonds in unsaturated fatty acid.

  12. Glass sealing

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  13. 新型动静压混合润滑机械密封流场数值研究%Numerical Study on Flow Field of New-type Hydrostatic-dynamic Hybrid Lubrication Seal

    Institute of Scientific and Technical Information of China (English)

    王彬; 郝木明

    2009-01-01

    A three-dimensional model of the new-type hydrostatic-dynamic hybrid lubrication seals was developed based on fluid film. The pressure and velocity distribution of fluid film was simulated by using the software of computational fluid dynamics. The law of influence of operating parameters (sealant pressure, rotating speed) on sealing performance was ana-lyzed by comparing with hydrostatic seals and dynamic seals. The results show that this type of seal has the characteristics of hydrostatic seals and dynamic seals, it has low leakage and high film stiffness, and is suitable for low speed non-contac-ting seals.%以流体膜为研究对象,建立了新型动静压混合润滑密封端面的三维模型,并利用流体力学软件FLUENT对端面流场进行数值模拟,得出端面液膜的压力分布及速度分布.通过与静压和动压式密封对比,分析了操作参数(如封液压力、转速)对密封性能的影响规律.结果表明,该密封兼有动压与静压两种密封形式的特点,泄漏量小,液膜刚度大,适合于低速非接触密封.

  14. Mechanical seals

    CERN Document Server

    Mayer, E

    1977-01-01

    Mechanical Seals, Third Edition is a source of practical information on the design and use of mechanical seals. Topics range from design fundamentals and test rigs to leakage, wear, friction and power, reliability, and special designs. This text is comprised of nine chapters; the first of which gives a general overview of seals, including various types of seals and their applications. Attention then turns to the fundamentals of seal design, with emphasis on six requirements that must be considered: sealing effectiveness, length of life, reliability, power consumption, space requirements, and c

  15. Ceramic Seal.

    Energy Technology Data Exchange (ETDEWEB)

    Smartt, Heidi A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Romero, Juan A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Custer, Joyce Olsen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hymel, Ross W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Krementz, Dan [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Gobin, Derek [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Harpring, Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martinez-Rodriguez, Michael [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Varble, Don [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); DiMaio, Jeff [Tetramer Technologies, Pendleton, SC (United States); Hudson, Stephen [Tetramer Technologies, Pendleton, SC (United States)

    2016-11-01

    Containment/Surveillance (C/S) measures are critical to any verification regime in order to maintain Continuity of Knowledge (CoK). The Ceramic Seal project is research into the next generation technologies to advance C/S, in particular improving security and efficiency. The Ceramic Seal is a small form factor loop seal with improved tamper-indication including a frangible seal body, tamper planes, external coatings, and electronic monitoring of the seal body integrity. It improves efficiency through a self-securing wire and in-situ verification with a handheld reader. Sandia National Laboratories (SNL) and Savannah River National Laboratory (SRNL), under sponsorship from the U.S. National Nuclear Security Administration (NNSA) Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D), have previously designed and have now fabricated and tested Ceramic Seals. Tests have occurred at both SNL and SRNL, with different types of tests occurring at each facility. This interim report will describe the Ceramic Seal prototype, the design and development of a handheld standalone reader and an interface to a data acquisition system, fabrication of the seals, and results of initial testing.

  16. Ferrules seals

    Science.gov (United States)

    Smith, J.L.

    1984-07-10

    A device is provided for sealing an inner tube and an outer tube without excessively deforming the tubes. The device includes two ferrules which cooperate to form a vacuum-tight seal between the inner tube and outer tube and having mating surfaces such that overtightening is not possible. 3 figs.

  17. 自加压式动静压混合式气体润滑密封的性能分析%Study on Self-pressurized Hydrostatic-dynamic Hybrid Lubrication Gas Seal

    Institute of Scientific and Technical Information of China (English)

    扈中平; 李双喜; 蔡纪宁; 张秋翔

    2011-01-01

    介绍自加压动静压混合润滑气体密封的工作原理,分析其密封特性.采用流体计算软件FLUENT建立不同自加压动静压混合气体润滑密封端面间气膜的数值计算流场,求得气膜的压力和速度分布,得到密封的性能参数,如开启力、刚度、泄漏量.分析该密封在稳定运转状态和启停工作状态的运行特点,与流体动压型气体密封的工作特性进行对比.结果表明:自加压动静压混合密封在运转时具有更大的开启力和泄漏量以及较高的刚度,表现出更好的启停性能;静压引入孔的位置以及均压槽结构对密封开启力及泄漏量有较大影响,静压引人孔在坝区使气膜刚度增大,在动压槽区则使气膜刚度减小.%The operating principle of the self-pressurized hydrostatic-dynamic hybrid lubrication gas seal (SHDHLGS)was introduced and its seal characteristic was analyzed. Different numerical calculated flow field of the gas film between the seal faces of self-pressurized hydrostatic-dynamic hybrid lubrication gas seal and dynamic pressure gas seal was established by software FLUENT. The distributions of pressure and velocity and the performance parameters of the seal such as the opening force, stiffness, and leakage distribution were obtained. The operating characteristics of this seal under stable condition and working status of the start and stop running were analyzed and compared with the operating characteristics of fluid dynamic pressure gas seal. The results show that better start and stop performance is ensured and there is a higher opening force and leakage in SHDHLGS when operating;the location of pressure introduction hole and pressure groove structure influences the opening force and leakage obviously. The gas film stiffness will increases when the pressure introduction hole locates in the dam area, and it will reduces when the pressure introduction hole locates in the pressure groove area.

  18. Hybrid density functional based study on the band structure of trioctahedral mica and its dependence on the variation of Fe(2+) content.

    Science.gov (United States)

    Timón, V; Praveen, C S; Escamilla-Roa, E; Valant, M

    2013-07-01

    A hybrid density functional based study of a phyllosilicate (PS) is presented here for the first time. Using all-electron electronic structure calculations with the B3LYP hybrid functional, we have investigated the electronic and structural properties of a series of trioctahedral 1M-polytype K-bearing micas starting from phlogopite (the Mg-end member), ending with the annite (the Fe-end member), and passing through the biotite (a solid solution of the end members). Electronic band gap is calculated for all the compositions and nature of the electronic transition is discussed with the aid of band structure and density of states plots. An excellent agreement with the available experimental data has been observed. An insulator to semiconductor transition is explained on the basis of orbital hybridization. A further comparison is made using the pure GGA functional. For the completeness of the study, the dielectric properties of phlogopite are calculated using the coupled perturbed Kohn-Sham scheme, as implemented within the CRYSTAL09 code.

  19. Seal Counts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Database of seal counts from aerial photography. Counts by image, site, species, and date are stored in the database along with information on entanglements and...

  20. Python fiber optic seal

    Energy Technology Data Exchange (ETDEWEB)

    Ystesund, K.; Bartberger, J.; Brusseau, C.; Fleming, P.; Insch, K.; Tolk, K.

    1993-08-01

    Sandia National Laboratories has developed a high security fiber optic seal that incorporates tamper resistance features that are not available in commercial fiber optic seals. The Python Seal is a passive fiber optic loop seal designed to give indication of unauthorized entry. The seal includes a fingerprint feature that provides seal identity information in addition to the unique fiber optic pattern created when the seal is installed. The fiber optic cable used for the seal loop is produced with tamper resistant features that increase the difficulty of attacking that component of a seal. A Seal Reader has been developed that will record the seal signature and the fingerprint feature of the seal. A Correlator software program then compares seal images to establish a match or mismatch. SNL is also developing a Polaroid reader to permit hard copies of the seal patterns to be obtained directly from the seal.

  1. Turbine with radial acting seal

    Energy Technology Data Exchange (ETDEWEB)

    Eng, Darryl S; Ebert, Todd A

    2016-11-22

    A floating brush seal in a rim cavity of a turbine in a gas turbine engine, where the floating brush seal includes a seal holder in which the floating brush seal floats, and a expandable seal that fits within two radial extending seal slots that maintains a seal with radial displacement of the floating brush seal and the seal holder.

  2. Regenerator seal

    Science.gov (United States)

    Davis, Leonard C.; Pacala, Theodore; Sippel, George R.

    1981-01-01

    A method for manufacturing a hot side regenerator cross arm seal assembly having a thermally stablilized wear coating with a substantially flat wear surface thereon to seal between low pressure and high pressure passages to and from the hot inboard side of a rotary regenerator matrix includes the steps of forming a flat cross arm substrate member of high nickel alloy steel; fixedly securing the side edges of the substrate member to a holding fixture with a concave surface thereacross to maintain the substrate member to a slightly bent configuration on the fixture surface between the opposite ends of the substrate member to produce prestress therein; applying coating layers on the substrate member including a wear coating of plasma sprayed nickel oxide/calcium flouride material to define a wear surface of slightly concave form across the restrained substrate member between the free ends thereon; and thereafter subjecting the substrate member and the coating thereon to a heat treatment of 1600.degree. F. for sixteen hours to produce heat stabilizing growth in the coating layers on the substrate member and to produce a thermally induced growth stress in the wear surface that substantially equalizes the prestress in the substrate whereby when the cross arm is removed from the fixture surface following the heat treatment step a wear face is formed on the cross arm assembly that will be substantially flat between the ends.

  3. Seal design alternatives study

    Energy Technology Data Exchange (ETDEWEB)

    Van Sambeek, L.L. [RE/SPEC Inc., Rapid City, SD (US); Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D. [Parsons Brinckerhoff Quade & Douglas, Inc., San Francisco, CA (US)

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information.

  4. Magnetically Actuated Seal

    Science.gov (United States)

    Pinera, Alex

    2013-01-01

    This invention is a magnetically actuated seal in which either a single electromagnet, or multiple electromagnets, are used to control the seal's position. This system can either be an open/ close type of system or an actively controlled system.

  5. Magnetically Actuated Seal Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT proposes development of a magnetically actuated dynamic seal. Dynamic seals are used throughout the turbopump in high-performance, pump-fed, liquid rocket...

  6. Seal Out Tooth Decay

    Science.gov (United States)

    ... Decay (Caries) > Seal Out Tooth Decay Seal Out Tooth Decay Main Content What are dental sealants? How are ... fix decayed teeth. Back to Top What causes tooth decay? Germs in the mouth use the sugar in ...

  7. Turbomachine Interface Sealing

    Science.gov (United States)

    Hendricks, Robert C.; Chupp, Raymond E.; Lattime, Scott B.; Steinetz, Bruce M.

    2005-01-01

    Sealing interfaces and coatings, like lubricants, are sacrificial, giving up their integrity for the benefit of the component. Clearance control is a major issue in power systems turbomachine design and operational life. Sealing becomes the most cost-effective way to enhance system performance. Coatings, films, and combined use of both metals and ceramics play a major role in maintaining interface clearances in turbomachine sealing and component life. This paper focuses on conventional and innovative materials and design practices for sealing interfaces.

  8. Seals For Cryogenic Turbomachines

    Science.gov (United States)

    Hendricks, Robert C.; Tam, L. T.; Braun, M. J.; Vlcek, B. L.

    1988-01-01

    Analysis considers effects of seals on stability. Report presents method of calculation of flows of cryogenic fluids through shaft seals. Key to stability is local average velocity in seal. Local average velocity strongly influenced by effects of inlet and outlet and injection of fluid.

  9. Low Cost, Durable Seal

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, George; Parsons, Jason; Friedman, Jake

    2010-12-17

    Seal durability is critical to achieving the 2010 DOE operational life goals for both stationary and transportation PEM fuel cell stacks. The seal material must be chemically and mechanically stable in an environment consisting of aggressive operating temperatures, humidified gases, and acidic membranes. The seal must also be producible at low cost. Currentlyused seal materials do not meet all these requirements. This project developed and demonstrated a high consistency hydrocarbon rubber seal material that was able to meet the DOE technical and cost targets. Significant emphasis was placed on characterization of the material and full scale molding demonstrations.

  10. Características agronômicas e composição química de oito híbridos de sorgo [Sorghum bicolor (L. Moench] Agronomic characteristics and chemical composition of eight sorghum hybrids [Sorghum bicolor (L. Moench

    Directory of Open Access Journals (Sweden)

    Márcio dos Santos Pedreira

    2003-10-01

    Full Text Available O experimento foi conduzido com o objetivo de avaliar as características agronômicas, composição química das frações e da planta inteira de oito híbridos de sorgo, semeados em março de 2000, no sentido de contribuir para os programas de seleção de germoplamas resistentes aos efeitos das estiagens prolongadas e, ao mesmo tempo, apropriados ao processo de ensilagem. Utilizou-se o delineamento em blocos ao acaso com oito tratamentos e três repetições, para avaliar os híbridos AG-2005, BR-700, MASSA-03, 498111, 65E3, 698005, 698007 e 699005. Não houve diferenças significativas entre produção de matéria seca (PMS e proporção de folhas dos híbridos avaliados. A maior proporção de colmo (41,3% foi observada no 498111 e a menor no MASSA-03 (28,9%. O híbrido 65E3 apresentou a maior proporção de panícula (43,2% e o 498111 a menor (28,9%. Quanto à composição química da planta inteira, não foram observadas diferenças significativas entre os híbridos quanto aos teores de matéria seca, matéria mineral, hemicelulose, nitrogênio insolúvel em detergente neutro, nitrogênio insolúvel em detergente ácido e nutrientes digestíveis totais (NDT. Os teores de proteína bruta variaram de 6,5 a 8,8%, fibra em detergente neutro de 57,0 a 70,3%, fibra em detergente ácido de 29,8 a 36,2%, celulose de 25,3 a 31,2% e lignina de 3,6 a 5,5%, sendo estatisticamente diferentes entre os híbridos. O 699005 apresentou o maior teor de carboidratos solúveis (14,5%, diferindo estatisticamente apenas do híbrido 698007 (9,6%. Os híbridos também mostraram diferenças na composição química das frações folhas, colmo e panícula. De forma geral, todos os híbridos apresentaram teores de matéria seca e carboidratos solúveis adequados ao processo de ensilagem. As produções médias de matéria seca dos híbridos (6,2 t/ha, foram altas considerando-se a baixa precipitação ocorrida durante o período experimental. A análise de Cluster

  11. Zero leakage sealings

    Science.gov (United States)

    Kotesovec, Bernhard; Steinrück, Herbert

    2010-11-01

    The piston rod of a reciprocating compressor is sealed with elastic cylindrical sealing elements. Across the sealings the pressure drops from the operating pressure to the ambient pressure. The lubrication gap between the elastic sealing and reciprocating piston rod is studied with the aim to find conditions of a leakage free sealing. The flow in the lubrication gap and the elastic deformation of the sealing are determined simultaneously. The net-flow during one cycle of the reciprocating piston rod is calculated. It turns out that maintaining zero leakage is very sensible. Indeed the outbound flow during out-stroke has to be equal the inbound flow during the in-stroke. By prescribing a special shape of the undeformed sealing zero leakage can be attained - at least theoretically for certain operating conditions. It turns out that temperature dependent material data and a model for cavitation is necessary. The model, its numerical implementation and results will be discussed.

  12. Ormocer: An aesthetic direct restorative material; An in vitro study comparing the marginal sealing ability of organically modified ceramics and a hybrid composite using an ormocer-based bonding agent and a conventional fifth-generation bonding agent

    Directory of Open Access Journals (Sweden)

    Sarika Kalra

    2012-01-01

    Full Text Available Aims and Objectives : To compare the marginal sealing ability of ormocer with a hybrid composite using an ormocer based bonding agent and a conventional fifth generation bonding agent. Materials and Methods : Fifty four human premolars were randomly distributed into four test groups of 12 teeth each and two control groups of 3 teeth each. Class I occlusal preparation of 1.5 mm depth were made in each tooth. These were restored using the adhesive and restorative material according to the group. The restorations were finished using a standard composite finishing and polishing kit. Thermocycling between 5 o C and 55 o C was carried out. Having blocked the root apex and the entire tooth surface except 1 mm around the restoration margin, the teeth were immersed in 2% methylene blue for 48 hours, after which the dye penetration through the margins of each sample was studied under a stereomicroscope. Results and Discussion : Group IV (Admira with Admira Bond showed the minimum marginal leakage with a mean of 0.200 mm. Four samples in this group showed no microleakage at all and a maximum of 0.400 mm was seen in one sample. Group II (Spectrum TPH with Admira Bond showed the maximum leakage with a mean of 0.433 mm. One sample showed as much as 1.00 mm of microleakage. Admira when used with Admira Bond showed lesser microleakage than Spectrum TPH used with Prime & Bond NT, the difference being statistically insignificant.

  13. Tenacidade à fratura translaminar dinâmica de um laminado híbrido metal-fibra para uso em elevadas temperaturas Translaminar dynamic fracture toughness of a hybrid fiber-metal laminate devised to high-temperature applications

    Directory of Open Access Journals (Sweden)

    José R. Tarpani

    2010-01-01

    Full Text Available A tenacidade à fratura translaminar dinâmica do laminado híbrido metal-fibra titânio-grafite com matriz termoplástica foi determinada sob as velocidades de impacto de 2,25 e 5,52 m/s, no intervalo de temperaturas de -196 a +180 °C, e comparada à de laminados compósitos convencionais de fibras de carbono e resina epóxi. Constatou-se que o laminado híbrido exibe uma tenacidade à iniciação da fratura inferior à dos compósitos tradicionais com fibras na forma de fita unidirecional, porém superior à dos laminados convencionais com fibras na forma de tecido bidirecional. Os ensaios de impacto revelaram que, comparativamente ao desempenho mecânico dos laminados carbono-epóxi, o emprego do laminado híbrido metal-fibra se justifica mais pela sua resistência à propagação do que à iniciação da fratura dinâmica.The translaminar dynamic fracture toughness of titanium-graphite hybrid fiber-metal laminate with thermoplastic matrix has been determined at the impact velocities of 2.25 and 5.52 m/s, within the temperature range from -196 to +180 ºC, and compared to that of conventional carbon-epoxy composite laminates. The hybrid laminate exhibits lower initiation fracture toughness than traditional unidirectional tape composites though it is tougher than conventional woven fabric laminates. Impact tests revealed that, if compared to the mechanical performance of conventional carbon-epoxy laminates, the fiber-metal laminate application must rely on its resistance to dynamic fracture propagation rather than on fracture initiation.

  14. Dynamic sealing principles

    Science.gov (United States)

    Zuk, J.

    1976-01-01

    The fundamental principles governing dynamic sealing operation are discussed. Different seals are described in terms of these principles. Despite the large variety of detailed construction, there appear to be some basic principles, or combinations of basic principles, by which all seals function, these are presented and discussed. Theoretical and practical considerations in the application of these principles are discussed. Advantages, disadvantages, limitations, and application examples of various conventional and special seals are presented. Fundamental equations governing liquid and gas flows in thin film seals, which enable leakage calculations to be made, are also presented. Concept of flow functions, application of Reynolds lubrication equation, and nonlubrication equation flow, friction and wear; and seal lubrication regimes are explained.

  15. Caracterização agronômica e composição química de híbridos de milho = Agronomic evaluation and chemical composition of corn hybrid

    Directory of Open Access Journals (Sweden)

    Ulysses Cecato

    2007-04-01

    Full Text Available O trabalho teve por objetivo avaliar a produção de matéria seca total (MST, de colmo (MSc, de folhas (MSf, de espigas (MSe, teores de proteína bruta (PB, fibra em detergente ácido (FDA, altura de planta (AP e relação colmo/folha (C/F de híbridos (Zea mays L. AG 122, AG 519, C 525, C 805, D 170, D 771, G 600, G 1328, P 3041, P 3069, XL 520, XL 530, OC 705, FO 01. Utilizou-se o delineamento experimental inteiramente casualizado, com 10 repetições. O híbrido FO 01 apresentou maior produção de matéria seca, maior altura de planta e maior produção de colmo, porém com menor percentagemde espigas e folhas, prejudicando a qualidade do material original. A maior produtividade apresentada pelos híbridos está associada a maior altura da planta e maior proporção de colmos na matéria seca total. Em geral, uma boa produção de matéria seca, com equilíbrio na relação folhas/colmo/espigas, foi apresentado pelo híbrido G 1328.The objective of this work was to evaluate the total dry matter production (TDMP of stem (DMs, leaves (DMl, ear (DMe, crude protein content (CPC, acid detergent fiber (ADF, plant height (PH and stem/leaves relation (S/L of the hybrids (Zea mays L. AG 122, AG 519, C 525, C 805, D 170, D 771, G 600, G 1328, P 3041, P 3069, XL 520, XL 530, OC 705, FO 01. The results indicated that the hybrid FO 01 showed the highest dry matter production, the highest plant and stem production, but the smallest ear and leaves percentage, decreasing the quality of the original material. The higher productivity of hybrids was associated with a higher plant height and stem production on total dry matter. The hybrid G 1328 showed a good dry matter production with equilibrium in the relation leaves/stem/corn cob.

  16. Repository seals requirements study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-03

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. This report presents the results of a repository sealing requirements study. Sealing is defined as the permanent closure of the shafts, ramps, and exploratory boreholes. Sealing includes those components that would reduce potential inflows above the repository, or that would divert flow near the repository horizon to allow vertical infiltration to below the repository. Sealing of such features as emplacement drifts was not done in this study because the current capability to calculate fracture flow into the drifts is not sufficiently mature. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

  17. Applications of quantum message sealing

    CERN Document Server

    Worley, G G

    2005-01-01

    In 2003, Bechmann-Pasquinucci introduced the concept of quantum seals, a quantum analogue to wax seals used to close letters and envelopes. Since then, some improvements on the method have been found. We first review the current quantum sealing techniques, then introduce and discuss potential applications of quantum message sealing, and conclude with some discussion of the limitations of quantum seals.

  18. High Test Peroxide High Sealing Conical Seal Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High Test Peroxide (HTP) Highly Compatible High Sealing Conical Seals are necessary for ground test operations and space based applications. Current conical seals...

  19. Saving Seal Cutting

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    On April 20, the graduation ceremony of China’s seal-cutting art postgraduates and visiting experts from the Institute of Seal Cutting Art under the China Art Academy was held in Beijing. On the same day, the exhibition of the works of the teachers and graduates of the institute was also held.

  20. Dinâmica floral e abortamento de flores em híbridos de canola e mostarda castanha Floral dynamics and flower abortion in hybrids of canola and Indian mustard

    Directory of Open Access Journals (Sweden)

    Rafael Battisti

    2013-02-01

    Full Text Available O objetivo deste trabalho foi avaliar a dinâmica floral e determinar o índice de abortamento de flores de híbridos de canola (Brassica napus e de mostarda castanha (Brassica juncea, bem como determinar suas relações com as condições meteorológicas do Sul do Brasil. Durante a floração, dez híbridos de canola e dois de mostarda foram avaliados a cada três dias quanto ao número de flores abertas, de síliquas e de flores abortadas. O número acumulado e relativo de flores foi usado para avaliação da dinâmica floral. A relação desses números com a soma térmica acumulada durante a floração foi determinada por meio de modelo logístico. A partir dos coeficientes desse modelo, identificaram-se grupos de genótipos com diferentes taxas de emissão de flores. O abortamento de flores entre híbridos variou de 10,53 a 45,96% e correlacionou-se com a temperatura e a demanda evaporativa da atmosfera. Genótipos com maiores tempos térmicos entre o período de máxima emissão de flores e o final da floração geralmente apresentam maiores percentagens de abortamento de flores. O ajuste dos dados de emissão de flores aos de soma térmica do período da floração, por meio de modelo logístico, permite simular a dinâmica floral de híbridos de canola e mostarda castanha.The objective of this work was to evaluate the floral dynamics and to determine the index of flower abortion in canola (Brassica napus and Indian mustard (Brassica juncea hybrids, as well as to determine their relation with meteorological conditions of southern Brazil. During flowering, ten hybrids of canola and two of Indian mustard were evaluated every three days as to the number of open flowers, pods, and aborted flowers. The cumulative and the relative number of flowers were used to evaluate floral dynamics. The relation of these numbers with the accumulated thermal sum during flowering was determined with a logistic model. Groups of genotypes with different

  1. Sealing device for providing a seal in a turbomachine

    Science.gov (United States)

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Porter, Christopher Donald; Schick, David Edward; Weber, David Wayne

    2016-08-16

    Sealing device for providing seals between adjacent components, and turbomachines utilizing such sealing devices, are provided. A sealing device includes a seal plate insertable between the adjacent components, the seal plate comprising a first face and an opposing second face. The sealing device further includes a plurality of pins extending from one of the first face or the second face, the plurality of pins configured to space the one of the first face or the second face from contact surfaces of the adjacent components.

  2. Caracterização morfoanatômica do colmo de híbridos de milho para avaliar a qualidade de silagem = Morphoanatomical characterization of corn hybrids stems, in order to evaluate silage quality

    Directory of Open Access Journals (Sweden)

    Geane Dias Gonçalves Ferreira

    2007-07-01

    Full Text Available O objetivo foi avaliar a caracterização morfoanatômica e suas possíveis correlações com a digestibilidade da parede celular e com a lignina de dez híbridos de milho (DK265bm3, DK265, HS5, HS6, HTV2, HTV27, Anjou285, Mexxal, Pistache e Buxxil, plantados no INRA (Unité de Génétique et d’Amélioration dês Plantes Fourragères, Lusignan-França, em parcelas de 150 m². O delineamento utilizado foi inteiramente casualizado com cinco repetições por tratamento. Comexceção ao comprimento do córtex, verificou-se que os híbridos apresentaram diferenças significativas (p The objective was to evaluate morphoanatomical characteristics andpossible correlations with cell wall digestibility and with lignin of ten corn hybrids (DK265bm3, DK265, HS5, HS6, HTV2, HTV27, Anjou285, Mexxal, Pistachio and Buxxil planted at INRA (Unité of Génétique Amélioration des Plant Fourragères, Lusignan, France in 150 m² areas. A completely randomized experimental design with five replications was used. With exception for cortical length, significant differences were verified as for the evaluated morphoanatomical aspects, with hybrid DK265bm3 being characterized by lower counts of lignified cells in the medullar parenchyma and cortical areas, lower percentage of medullar parenchyma and higherpercentage of cortex in relation to other hybrids. However, DK265bm3 did not differ from other hybrids in regards to vascular bundle surface and cell wall thickness of the vascular bundle. Usingcorrelation analysis a positive correlation was observed between the levels of Klason lignin and lignin in acid detergent with the number of lignified cells in the parenchyma and cortex. IVCNDF showed a negative correlation with the proportion of lignified cells in medullar parenchyma and lignified cells in the cortex.

  3. Caracterização físico-química de novos híbridos de abacaxi resistentes à fusariose Physico-chemical characterization of new hybrids pineapple resistant to fusariosis

    Directory of Open Access Journals (Sweden)

    Eliseth de Souza Viana

    2013-01-01

    Full Text Available Cinco genótipos de abacaxi (Gold, Pérola, Smooth Cayenne, BRS Vitória, BRS Imperial e quatro novos híbridos (SC x PRI-21, SC48 x PRI-02, PE x SC-73 e PA x PE-01 foram avaliados quanto às suas características físico-químicas. A cultivar 'Gold' apresentou os maiores teores de carotenoides totais (7,82µg g-1 e vitamina C (51,0mg 100g-1, enquanto que a cultivar 'BRS' Imperial destacou-se pelos elevados teores de açúcares redutores (5,12%, açúcares totais (15,23%, sólidos solúveis (18,41°Brix, pH (3,96 e ratio (35,28. Os híbridos SC 48 x PRI-02, PE x SC-73 e PA x PE-01 apresentaram teores de sólidos solúveis, açúcares totais e redutores superiores aos das cultivares Smooth Cayenne, Pérola e BRS Vitória, destacando-se o híbrido PE x SC-73 por apresentar polpa amarela mais intensa, doçura elevada, elevado teor de carotenoides totais e vitamina C, sendo, portanto, um híbrido promissor para substituição de cultivares comerciais.Five pineapple genotypes (Gold, Pérola, Smooth Cayenne, BRS Vitória and BRS Imperial and four new hybrids - SC x PRI-21, SC48 x PRI-02, PE x SC-73 and PA x PE-01, were evaluated for their physicochemical characteristics. The 'Gold' cultivar presented the highest contents of total carotenoids (7.82mg g-1 and vitamin C (51.0mg 100g-1, whereas the 'BRS' Imperial stood out for its high levels of reducing (5.12% and total (15.23% sugars, soluble solids (18.41°Brix, pH (3.96 and ratio (35.28. Improved hybrids SC 48 x PRI-02, PE x SC-73 and PA x PE-01 had the soluble solids, reducing and total sugars contents higher than those of cultivars 'Smooth Cayenne', 'BRS Vitória' and 'Pérola', highlighting the 'PE x SC-73' hybrid for its pulp of intense yellow color, high sweetness, high content of total carotenoids and vitamin C and which was considered as a promising hybrid to replace commercial cultivars.

  4. Fur seal investigations, 1966

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Annually a report is made on the fur seal investigations carried on by the Bureau of Commercial Fisheries on the Pribilof Islands and at sea. Investigations on the...

  5. Bearded Seal Distribution Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains GIS layers that depict the known spatial distributions (i.e., ranges) of the two subspecies of bearded seals (Erignathus barbatus). It was...

  6. Spotted Seal Distribution Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains GIS layers that depict the known spatial distributions (i.e., ranges) and reported breeding areas of spotted seals (Phoca largha). It was...

  7. Ribbon Seal Distribution Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains GIS layers that depict the known spatial distributions (i.e., ranges) and reported breeding areas of ribbon seals (Histriophoca fasciata). It...

  8. Ringed Seal Distribution Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains GIS layers that depict the known spatial distributions (i.e., ranges) of the five subspecies of ringed seals (Phoca hispida). It was produced...

  9. Agronomic traits and chemical composition of single hybrids of sweet corn Caracteres agronômicos e composição química de híbridos simples de milho doce

    Directory of Open Access Journals (Sweden)

    Angela Kwiatkowski

    2011-12-01

    Full Text Available In Brazil, the greengrocery market of sweet corn has been expanding along the country. In contrast, there have been few agri-industries canning sweet corn (Zea mays because of the lack of cultivars with agronomic characteristics proper to industrial purposes. The purpose of this study was to evaluate the general combining ability (GCA of seven inbred lines of sweet corn, and the specific combining ability (SCA of their hybrid combinations based on their agronomic traits, and the chemical composition of the grain. In the growing season 2006/2007, twenty-one single hybrids were evaluated in the Iguatemi Research Station, Maringá County, Northwestern Paraná, in Brazil using a complete randomized block design with four replications. Data were subjected to the analysis of variance and the genotypes were clustered by the Scott-Knott test. We estimated the GCA and SCA effects using the Griffing's method IV with the fixed model for plant height (PH, height of ear (EH, dehusked ears yield (DEY, reducing (RS and total sugars (TS, starch (ST, proteins (PTN, ether extract (EE and fibers (FB. The inbred line L4, which was originated from the 'Doce de Cuba', had the best GCA for crop yield and grain quality and therefore should be used in the next hybrid combinations. The hybrids L4xL5 and L3xL7 were the most promising with regard to crop yield and grain quality.No Brasil, poucas indústrias envazam o milho doce (Zea mays por causa da falta de cultivares para o processamento industrial. Em compensação, o mercado de milho verde doce aumentou. O objetivo deste estudo foi avaliar a capacidade geral de combinação (CGC de sete linhagens de milho doce e da capacidade específica de combinação (CEC das combinações híbridas, com base em características agronômicas e composição química dos grãos. Os vinte e um híbridos simples foram avaliados em blocos casualizados, com quatro repetições, durante o ano agrícola 2006/2007, no distrito de Iguatemi

  10. Nuclear instrumentation cable end seal

    Science.gov (United States)

    Cannon, Collins P.; Brown, Donald P.

    1979-01-01

    An improved coaxial end seal for hermetically sealed nuclear instrumentation cable exhibiting an improved breakdown pulse noise characteristic under high voltage, high temperature conditions. A tubular insulator body has metallized interior and exterior surface portions which are braze sealed to a center conductor and an outer conductive sheath. The end surface of the insulator body which is directed toward the coaxial cable to which it is sealed has a recessed surface portion within which the braze seal material terminates.

  11. Sliding seal for mining machine power transmission

    Energy Technology Data Exchange (ETDEWEB)

    Levenstein, V.M.

    1993-07-06

    A generally tubular sealing mechanism is described for use in the power train of a mining machine to seal between an annular seal face on one of two spaced apart units in the power train and a sealing ring surface on the other of said units for sealed protection of a drive shaft connected between said two units, said sealing mechanism including a tubular seal carrier with a first end portion having a cylindrical sealing surface for being telescoped with said sealing ring surface, an annular seal element mountable on said cylindrical sealing surface for sealing engagement between said sealing ring surface and said cylindrical sealing surface, said carrier further having a second end portion with a radially extending face, a clamp connectable between said one unit and said carrier for urging said radially extending face toward said annular seal face, and a sealing member mountable in sealing engagement between said annular seal face and said radially extending face.

  12. THE ORIGINS OF SEALS AND SEALING IN CHINA

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    The origin of Chinese seals remains obscure in modern research. Most publications, influenced by the traditional point of view, have dealt with the seals handed down from the Eastern Zhou (771-256 B.C.). Only a few studies have discussed seals from their earliest-and still neglected-history. There have even been some suggestions, based on the idea of using a seal and using it on clay first developed in Mesopotamia, that the seal was introduced to China from the Near East. This proposed foreign origin makes the history of Chinese seals more complicated.

  13. Forged seal detection based on the seal overlay metric.

    Science.gov (United States)

    Lee, Joong; Kong, Seong G; Lee, Young-Soo; Moon, Ki-Woong; Jeon, Oc-Yeub; Han, Jong Hyun; Lee, Bong-Woo; Seo, Joong-Suk

    2012-01-10

    This paper describes a method for verifying the authenticity of a seal impression imprinted on a document based on the seal overlay metric, which refers to the ratio of an effective seal impression pattern and the noise in the neighborhood of the reference impression region. A reference seal pattern is obtained by taking the average of a number of high-quality impressions of a genuine seal. A target seal impression to be examined, often on paper with some background texts and lines, is segmented out from the background by an adaptive threshold applied to the histogram of color components. The segmented target seal impression is then spatially aligned with the reference by maximizing the count of matching pixels. Then the seal overlay metric is computed for the reference and the target. If the overlay metric of a target seal is below a predetermined limit for the similarity to the genuine, then the target is classified as a forged seal. To further reduce the misclassification rate, the seal overlay metric is adjusted by the filling rate, which reflects the quality of inked pattern of the target seal. Experiment results demonstrate that the proposed method can detect elaborate seal impressions created by advanced forgery techniques such as lithography and computer-aided manufacturing. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. HMSRP Hawaiian Monk Seal Master Identification Records (seal)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records of all individually identified Hawaiian monk seals since 1981. These seals were identified by PSD personnel and cooperating scientists...

  15. Sealing coupling. [LMFBR

    Science.gov (United States)

    Pardini, J.A.; Brubaker, R.C.; Rusnak, J.J.

    1982-09-20

    Disclosed is a remotely operable releasable sealing coupling which provides fluid-tight joinder of upper and a lower conduit sections. Each conduit section has a concave conical sealing surface adjacent its end portion. A tubular sleeve having convex spherical ends is inserted between the conduit ends to form line contact with the concave conical end portions. An inwardly projecting lip located at one end of the sleeve cooperates with a retaining collar formed on the upper pipe end to provide swivel capture for the sleeve. The upper conduit section also includes a tapered lower end portion which engages the inside surface of the sleeve to limit misalignment of the connected conduit sections.

  16. Static seal for turbine engine

    Science.gov (United States)

    Salazar, Santiago; Gisch, Andrew

    2014-04-01

    A seal structure for a gas turbine engine, the seal structure including first and second components located adjacent to each other and forming a barrier between high and low pressure zones. A seal cavity is defined in the first and second components, the seal cavity extending to either side of an elongated gap extending generally in a first direction between the first and second components. A seal member is positioned within the seal cavity and spans across the elongated gap. The seal member includes first and second side edges extending into each of the components in a second direction transverse to the first direction, and opposing longitudinal edges extending between the side edges generally parallel to the first direction. The side edges include a groove formed therein for effecting a reduction of gas flow around the seal member at the side edges.

  17. Ceramic to metal seal

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Gary S. (Albuquerque, NM); Wilcox, Paul D. (Albuquerque, NM)

    1976-01-01

    Providing a high strength, hermetic ceramic to metal seal by essentially heating a wire-like metal gasket and a ceramic member, which have been chemically cleaned, while simultaneously deforming from about 50 to 95 percent the metal gasket against the ceramic member at a temperature of about 30 to 75 percent of the melting temperature of the metal gasket.

  18. GOLD PRESSURE VESSEL SEAL

    Science.gov (United States)

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  19. Mechanical Face Seal Dynamics.

    Science.gov (United States)

    1985-12-01

    These liquids range from lubricants to highly toxic chemicals and acids. The applications range from helicopter transmissions to nuclear reactor... Analit ~is., N ,iontat ting lame St-ak"ts fnn. ASXIE namin Behaioir ni Nonmmuiam ing (knied-Fate Mechanikal Seals:* SL /I ub In h. 104. 1. 111 *)6ii-414

  20. Four Sided Seal Tester

    Science.gov (United States)

    2009-07-01

    The Center for Advanced Food Technology School of Enviromental and Biological Sciences New Brunswick, NJ 08903 FTR 216 Defense Logistics Agency...specification for four sided seal tester as function of confinement plate distance” The following modifications were issued :  Jul 18, 2007 0013/01

  1. Detection of grey seal

    NARCIS (Netherlands)

    van Bleijswijk, J.; Begeman, L.; Witte, H.J.; IJsseldijk, L.L.; Brasseur, S.M.J.M.; Gröne, A.; Leopold, M.F.

    2014-01-01

    DNA was analysed from external wounds on 3 dead harbour porpoises Phocoena phocoena that were stranded in the Netherlands. Puncture wounds as well as the edges of large open wounds were sampled with sterile cotton swabs. With specific primers that target the mtDNA control region of grey seal Halicho

  2. Detection of grey seal

    NARCIS (Netherlands)

    van Bleijswijk, J.; Begeman, L.; Witte, H.J.; IJsseldijk, L.L.; Brasseur, S.M.J.M.; Gröne, A.; Leopold, M.F.

    2014-01-01

    DNA was analysed from external wounds on 3 dead harbour porpoises Phocoena phocoena that were stranded in the Netherlands. Puncture wounds as well as the edges of large open wounds were sampled with sterile cotton swabs. With specific primers that target the mtDNA control region of grey seal

  3. Regenerator cross arm seal assembly

    Science.gov (United States)

    Jackman, Anthony V.

    1988-01-01

    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  4. Seals Having Textured Portions for Protection in Space Environments

    Science.gov (United States)

    Daniels, Christopher (Inventor); Garafolo, Nicholas (Inventor)

    2016-01-01

    A sealing construct for a space environment includes a seal-bearing object, a seal on the seal-bearing object, and a seal-engaging object. The seal includes a seal body having a sealing surface, and a textured pattern at the sealing surface, the textured pattern defining at least one shaded channel surface. The seal-engaging object is selectively engaged with the seal-bearing object through the seal. The seal-engaging object has a sealing surface, wherein, when the seal-engaging object is selectively engaged with the seal-bearing object, the sealing surface of the seal-engaging object engages the sealing surface of the seal, and the seal is compressed between the seal-bearing object and the seal-engaging object such that at least one shaded channel surface engages the sealing surface of the seal-engaging object.

  5. Sealing the Mitochondrial Respirasome

    OpenAIRE

    Winge, Dennis R.

    2012-01-01

    The mitochondrial respiratory chain is organized within an array of supercomplexes that function to minimize the generation of reactive oxygen species (ROS) during electron transfer reactions. Structural models of supercomplexes are now known. Another recent advance is the discovery of non-OXPHOS complex proteins that appear to adhere to and seal the individual respiratory complexes to form stable assemblages that prevent electron leakage. This review highlights recent advances in our underst...

  6. A sealing element

    Energy Technology Data Exchange (ETDEWEB)

    Obi, F.; Takada, K.

    1983-09-22

    A sealing lining made of a mixture of polyethylene or polypropylene with an additive which prevents destruction of the lining is used in the element. The content of the additive in the mixture is 10 to 30 percent by mass. The additive basically consists of polyethylene. Carboxyl groups are introduced into the polymer as an anion and sodium, potassium and molybdenum are introduced as the cation.

  7. Composição química e energia metabolizável de híbridos de milho para frangos de corte Chemical composition and metabolizable energy of corn hybrids for broilers

    Directory of Open Access Journals (Sweden)

    Rodrigo de Oliveira Vieira

    2007-08-01

    Full Text Available Determinaram-se a composição química e os valores energéticos de 45 híbridos de milho em quatro ensaios de metabolismo com pintos em crescimento. Foram utilizados 1.225 pintos machos com 19 dias de idade (350 nos ensaios 1, 2 e 3 e 175 no ensaio 4. Os ensaios 1, 2 e 3 foram compostos de 14 tratamentos, constituídos, cada um, de 13 dietas-teste com híbridos de milho e uma dieta-referência. O ensaio 4 foi composto de sete tratamentos, constituídos de seis dietas-teste e uma dieta-referência. Em todos os ensaios, os milhos substituíram 40% da dieta-referência. Adotou-se delineamento inteiramente casualizado, com cinco repetições de 5 aves/parcela. As dietas e a água foram fornecidas à vontade durante sete dias (quatro de adaptação e três de coleta total de excretas. Os valores percentuais de PB variaram em 32% (7,79% vs 11,45%, expressos na MS e os de energia bruta (EB, em 5,2%. O menor valor foi 4.425 kcal e o maior, 4.668 kcal/kg de MS. O valor médio de energia metabolizável aparente corrigida (EMAn foi de 3.744 kcal/kg e apresentou variação de 15,15% entre os híbridos testados (3.405 a 4.013 kcal/kg. Entretanto, os dois híbridos que apresentaram esta variação de 608 kcal/kg de MS na EMAn tiveram valores de EB semelhantes, diferentes em apenas 0,36% (3.914 e 3.931 kcal de EB/kg de MS, o que possivelmente resultou do coeficiente de metabolizabilidade da EB, que foi de 75% para o híbrido de menor EMAn e de 88% para o de maior EMAn. Apesar de ser um alimento energético, os valores protéicos e energéticos dos diferentes híbridos variaram consideravelmente.The values of chemical composition and metabolizable energy of 45 hybrid corns were determined in four trials with growing chickens. A total of 1,225, nineteen days old male chicks were used: 350 in the trials 1, 2 and 3 and 175 in trial 4. In the trials 1, 2 and 3 the treatments consisted of 13 test diets, being 13 corn varieties, and the reference diet in each trial

  8. Navy GTE seal development activity

    Science.gov (United States)

    Grala, Carl P.

    1993-10-01

    Under the auspices of the Integrated High Performance Turbine Engine Technology Initiative, the Naval Air Warfare Center conducts advanced development programs for demonstration in the next generation of air-breathing propulsion systems. Among the target technologies are gas path and lube oil seals. Two development efforts currently being managed by NAWCAD are the High Performance Compressor Discharge Film-Riding Face Seal and the Subsonic Core High Speed Air/Oil Seal. The High Performance Compressor Discharge Film-Riding Face Seal Program aims at reducing parasitic leakage through application of a film-riding face sea concept to the compressor discharge location of a Phase 2 IHPTET engine. An order-of-magnitude leakage reduction relative to current labyrinth seal configurations is expected. Performance goals for these seals are (1) 1200 F air temperature, (2) 800 feet-per-second surface velocity, and (3) 600 SPI differential pressure. The two designs chosen for fabrication and rig test are a spiral groove and a Rayleigh step seal. Rig testing is currently underway. The Subsonic Core High Speed Air/Oil Seal Program is developing shaft-to-ground seals for next-generation propulsion systems that will minimize leakage and provide full life. Significantly higher rotor speeds and temperatures will be experienced. Technologies being exploited include, hydrodynamic lift assist features, ultra light weight designs, and improved cooling schemes. Parametric testing has been completed; a final seal design is entering the endurance test phase.

  9. Closure and Sealing Design Calculation

    Energy Technology Data Exchange (ETDEWEB)

    T. Lahnalampi; J. Case

    2005-08-26

    The purpose of the ''Closure and Sealing Design Calculation'' is to illustrate closure and sealing methods for sealing shafts, ramps, and identify boreholes that require sealing in order to limit the potential of water infiltration. In addition, this calculation will provide a description of the magma that can reduce the consequences of an igneous event intersecting the repository. This calculation will also include a listing of the project requirements related to closure and sealing. The scope of this calculation is to: summarize applicable project requirements and codes relating to backfilling nonemplacement openings, removal of uncommitted materials from the subsurface, installation of drip shields, and erecting monuments; compile an inventory of boreholes that are found in the area of the subsurface repository; describe the magma bulkhead feature and location; and include figures for the proposed shaft and ramp seals. The objective of this calculation is to: categorize the boreholes for sealing by depth and proximity to the subsurface repository; develop drawing figures which show the location and geometry for the magma bulkhead; include the shaft seal figures and a proposed construction sequence; and include the ramp seal figure and a proposed construction sequence. The intent of this closure and sealing calculation is to support the License Application by providing a description of the closure and sealing methods for the Safety Analysis Report. The closure and sealing calculation will also provide input for Post Closure Activities by describing the location of the magma bulkhead. This calculation is limited to describing the final configuration of the sealing and backfill systems for the underground area. The methods and procedures used to place the backfill and remove uncommitted materials (such as concrete) from the repository and detailed design of the magma bulkhead will be the subject of separate analyses or calculations. Post

  10. TECHNOLOGY ROADMAPPING FOR IAEA SEALS.

    Energy Technology Data Exchange (ETDEWEB)

    HOFFHEINS,B.; ANNESE,C.; GOODMAN,M.; OCONNOR,W.; GUSHUE,S.; PEPPER,S.

    2003-07-13

    In the fall of 2002, the U.S. Support Program (USSP) initiated an effort to define a strategy or ''roadmap'' for future seals technologies and to develop a generalized process for planning safeguards equipment development, which includes seals and other safeguards equipment. The underlying objectives of the USSP include becoming more proactive than reactive in addressing safeguards equipment needs, helping the IAEA to maintain an inventory of cost-effective, reliable, and effective safeguards equipment, establishing a long-term planning horizon, and securing IAEA ownership in the process of effective requirements definition and timely transitioning of new or improved systems for IAEA use. At an initial workshop, seals, their functions, performance issues, and future embodiments were discussed in the following order: adhesive seals, metal seals, passive and active loop seals, ultrasonic seals, tamper indicating enclosures (including sample containers, equipment enclosures, and conduits). Suggested improvements to these technologies focused largely on a few themes: (1) The seals must be applied quickly, easily, and correctly; (2) Seals and their associated equipment should not unduly add bulk or weight to the inspectors load; (3) Rapid, in-situ verifiability of seals is desirable; and (4) Seal systems for high risk or high value applications should have two-way, remote communications. Based upon these observations and other insights, the participants constructed a skeletal approach for seals technology planning. The process begins with a top-level review of the fundamental safeguards requirements and extraction of required system features, which is followed by analysis of suitable technologies and identification of technology gaps, and finally by development of a planning schedule for system improvements and new technology integration. Development of a comprehensive procedure will require the partnership and participation of the IAEA. The

  11. PLANT DENSITY AND AGRONOMIC TRAITS OF MAIZE HYBRIDS IN NARROW ROW SPACING DENSIDADE DE PLANTAS E CARACTERÍSTICAS AGRONÔMICAS DE HÍBRIDOS DE MILHO SOB ESPAÇAMENTO REDUZIDO ENTRE LINHAS

    Directory of Open Access Journals (Sweden)

    Cleber Morais Guimarães

    2007-09-01

    Full Text Available

    The objective of this study was to evaluate the behavior of maize hybrids cultivated under different population densities in narrow row spacing (0.45 m. Two field experiments were installed to evaluate six commercial hybrids (A 2555, A 2288, AG 9010, AG 6690, P 30F88 and Valent grown in five plant densities (40,000; 53,000; 71,000; 84,000; and 97,000 plants per hectare, in Goiânia and Jataí, Goiás State, during the growing season of 2002/2003. The experimental design was a randomized complete blocks, arranged in a 6x5 factorial design with four replicates. In the Goiânia experiment, the treatments were carried out using a split plot design. In the experiment of Goiânia, the treatments were carried out using a split plot design. The means of ear insertion, plant height, stalk lodging, ear length, ear diameter, corncob diameter, kernels per ear, weight of 100 kernels and grain yield was significantly influenced by plant density in both experiments. Grain yield was increased for plant densities higher than 70,000 plants per hectare, indicating that the use of narrow row spacing associated to the presence of shorter plant stature hybrids, favors enhancements in plant density. The grain yield was significantly affected by the interaction between hybrid and plant density in both fields. This indicates that, depending of the hybrid, the reduction of row spacing to 0.45 m is a managing practice that allows an increment in the sowing density.

    KEY-WORDS: Zea mays; cultivar; plant arrangement; agronomic trait; grain yield.

    O objetivo deste trabalho foi avaliar o comportamento de híbridos de milho (A 2555, A 2288, AG 9010, AG 6690, P 30F88 e Valent, cultivados em diferentes densidades populacionais (40 mil, 53 mil, 71 mil, 84 mil e 97 mil plantas por hectare e sob espaçamento reduzido

  12. Composição química, vitreosidade e digestibilidade de diferentes híbridos de milho para suínos Chemical composition, vitreousity endosperm and digestibility of different hybrids of corn for growing pigs

    Directory of Open Access Journals (Sweden)

    Vinícius de Souza Cantarelli

    2007-06-01

    Full Text Available Objetivou-se avaliar a composição química, vitreosidade e valores nutricionais de diferentes híbridos de milho através de análises laboratoriais e de um ensaio de metabolismo com suínos em crescimento. Foram utilizados 24 suínos em fase de crescimento (35,6 Kg ±± 3,05 kg de PV machos castrados mestiços (LD x LW, os quais foram mantidos em gaiolas de metabolismo e distribuídos em um delineamento inteiramente ao acaso totalizando 24 parcelas. Os tratamentos experimentais consistiram de 6 rações com os seguintes híbridos de milho: milho óleo (Móleo, milho QPM (MQPM, milho dentado (Mdent, milho semidentado (Msemi e dois milhos duros (Mdur1 e (Mdur2. Os valores obtidos de vitreosidade, coeficiente de digestibilidade da proteína bruta (CDPB e energia digestível (ED para Móleo, MQPM, Mdent, Msemi, Mdur1 e Mdur2 foram 78,5%; 71,7%; 57,2%; 68,2%; 75,9%; 82,8%; 81,68%; 80,14%; 82,35%; 69,71%; 76,98%; 75,61%; 3680; 3426; 3597; 3441; 3340 e 3469 Kcal/Kg, respectivamente. Foram observadas diferenças significativas (PThis study was conducted in order to evaluate the chemical composition, vitreousity endosperm and nutritional values of different hybrids of corn through of chemical analysis and a metabolism assay with growing pigs. The metabolism assay were conducted by utilizing 24 crossbred (LD x.LW barrows with 35,6Kg+- 3,05Kg keept in metabolism cages . The experimental treatments were formed by six (6 diets formulated with hybrids of corn: "corn oil", corn QPM, corn-dent, semi-dent, and two corns-flints. The values obtained Vitreousity, Digestibility Coefficients of the Crude Protein, and Energy Digestible for corns high oil, QPM, dent, semi-dent, hard 1 and hard 2 were 78,5%; 71,7%; 57,2%; 68,2%; 75,9%; 82,8%; 80,14%; 82,35%; 69,71%; 76,98%; 75,61%; 3680, 3426; 3597; 3441; 3340 and 3469 Kcal/Kg, respectively. The data shown significant differences (P<0,005 for the values of vitreousity (P<0,005 among the corns studied. Corns varieties

  13. Sealing the mitochondrial respirasome.

    Science.gov (United States)

    Winge, Dennis R

    2012-07-01

    The mitochondrial respiratory chain is organized within an array of supercomplexes that function to minimize the generation of reactive oxygen species (ROS) during electron transfer reactions. Structural models of supercomplexes are now known. Another recent advance is the discovery of non-OXPHOS complex proteins that appear to adhere to and seal the individual respiratory complexes to form stable assemblages that prevent electron leakage. This review highlights recent advances in our understanding of the structures of supercomplexes and the factors that mediate their stability.

  14. Características agronômicas e estruturais de híbridos de sorgo em função de diferentes densidades de plantio Agronomic characteristics of sorghum hybrids cultivated with different plant populations

    Directory of Open Access Journals (Sweden)

    Poliana Mendes Avelino

    2011-06-01

    Full Text Available Foram avaliadas as características agronômicas dos híbridos de sorgo, AG-2005 (duplo propósito e VOLUMAX (forrageiro para produção de silagem, cultivados nos espaçamentos de 1,00; 0,75; e 0,50 m entre linhas em Neossolo Quartzarênico Órtico, resultando nas densidades de 140.000; 186.666 e 280.000 plantas por hectares, respectivamente. Para tais avaliações foi utilizado o delineamento experimental de blocos ao acaso num arranjo fatorial (2 x 3. Foram determinadas as produções de matéria seca total (PMST, de lâmina foliar (PMLF, de caule (PMSC e de panícula (PMSP, bem como suas proporções na planta inteira. Ocorreu interação significativa entre híbrido de sorgo e espaçamento para as características PMST, PMSLF e PMSP. O híbrido VOLUMAX apresentou produções semelhantes nos três espaçamentos testados. O AG-2005 apresentou maior PMST (9.474,59 vs 6.842,91 kg ha-1 e PMSP (6.355,77 vs 3.032,40 kg ha-1 em relação ao VOLUMAX no espaçamento 0,50 m. O AG-2005 foi superior ao VOLUMAX no percentual de panícula nos espaçamentos 1,00 m (57,06 vs 40,22% e 0,50 m (66,99 vs 43,55% e o VOLUMAX foi superior no percentual de colmo nos espaçamentos 1,00 e 0,50 m. Recomenda-se o uso do híbrido AG-2005 cultivado sob espaçamento de 0,50 m para produção de silagem, em virtude da maior produção de MS por área, maior percentual de panícula e menor percentual de colmo na composição da planta em comparação ao híbrido VOLUMAX.The objective of the experiment was to evaluate the agronomic characteristics of two sorghum hybrids for silage production, AG-2005 (double purpose and VOLUMAX (forage cultivated with different row spacing 1; 0.75 and 0.50 m, on Orthic Quartzarenic Neosol, resulting in 140,000; 186,666 e 280,000 plants per ha, respectively. A randomized block design with four replicates was used and the treatments consisted on a factorial arrangement 2 x 3. Were determined the total dry matter production (PMST, of leaves

  15. Gulf and Dilmun Type seals

    DEFF Research Database (Denmark)

    Laursen, Steffen

    2011-01-01

    these Gulf Type‘ seals drew heavily on Indus Valley iconography and Indus script was occasionally employed in a pidgin-like manner. While the earliest circular seals incorporate features from Mesopotamian glyptic only to a lesser extent, this becomes a more important source of inspiration for later Dilmun...

  16. Face-Sealing Butterfly Valve

    Science.gov (United States)

    Tervo, John N.

    1992-01-01

    Valve plate made to translate as well as rotate. Valve opened and closed by turning shaft and lever. Interactions among lever, spring, valve plate, and face seal cause plate to undergo combination of translation and rotation so valve plate clears seal during parts of opening and closing motions.

  17. Seals. Grades 3-6.

    Science.gov (United States)

    New England Aquarium, Boston, MA.

    Explanations of a marine mammal rescue program and information on seals and sea lions are presented in this curriculum package for intermediate grade teachers. Activities are highlighted which focus on the natural history of harbor seals. This unit contains: (1) pre-trip activities (including fact sheets and worksheets on the different types of…

  18. High temperature autoclave vacuum seals

    Science.gov (United States)

    Hoffman, J. R.; Simpson, W. G.; Walker, H. M.

    1971-01-01

    Aluminum sheet forms effective sealing film at temperatures up to 728 K. Soft aluminum wire rings provide positive seal between foil and platen. For applications at temperatures above aluminum's service temperature, stainless steel is used as film material and copper wire as sealant.

  19. Aerodynamic seals for rotary machine

    Energy Technology Data Exchange (ETDEWEB)

    Bidkar, Rahul Anil; Cirri, Massimiliano; Thatte, Azam Mihir; Williams, John Robert

    2016-02-09

    An aerodynamic seal assembly for a rotary machine includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward-shoe section and an aft-shoe section having multiple labyrinth teeth therebetween facing the rotor. The sealing device segment also includes multiple flexures connected to the shoe plate and to a top interface element, wherein the multiple flexures are configured to allow the high pressure fluid to occupy a forward cavity and the low pressure fluid to occupy an aft cavity. Further, the sealing device segments include a secondary seal attached to the top interface element at one first end and positioned about the flexures and the shoe plate at one second end.

  20. Gas-path seal technology

    Science.gov (United States)

    Zuk, J.

    1976-01-01

    Improved gas-path seals are needed for better fuel economy, longer performance retention, and lower maintenance, particularly in advanced, high-performance gas turbine engines. Problems encountered in gas-path sealing are described, as well as new blade-tip sealing approaches for high-pressure compressors and turbines. These include a lubricant coating for conventional, porous-metal, rub-strip materials used in compressors. An improved hot-press metal alloy shows promise to increase the operating surface temperatures of high-pressure-turbine, blade-tip seals to 1450 K (2150 F). Three ceramic seal materials are also described that have the potential to allow much higher gas-path surface operating temperatures than are possible with metal systems.

  1. Turbine and Structural Seals Team Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — Seals Team Facilities conceive, develop, and test advanced turbine seal concepts to increase efficiency and durability of turbine engines. Current projects include...

  2. Turbine and Structural Seals Team Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — Seals Team Facilities conceive, develop, and test advanced turbine seal concepts to increase efficiency and durability of turbine engines. Current projects include...

  3. Aerodinámica

    OpenAIRE

    Da Riva de la Cavada, Ignacio

    1991-01-01

    La Aerodinámica estudia las fuerzas que un viento relativo ejerce sobre un obstáculo sumergido en él. Desde este punto de vista tan general las aplicaciones de la Aerodinámica no se reducen exclusivamente al estudio de las fuerzas sobre aviones más o menos clásicos sino que trascienden a otros muchos campos por el efecto de arrastre que es característico de ciencias y técnicas avanzadas. La conferencia, dentro de un ciclo sobre Ingeniería Aeroespacial, se centra en la aerodinámica de...

  4. Research on new-style seal-filling hydrogel material for coalmine fire zone

    Institute of Scientific and Technical Information of China (English)

    LUO Zhen-min; GE Ling-mei; DENG Jun; ZHANG Yan-ni; YANG Yong-bin

    2006-01-01

    The present seal form is restricted by itself, so pilot study in new-style seal-filling hydrogel by choosing acrylamide as absorb-water performance monomer with binary solution hybrid method was carried out. The feasibility of using new-style seal-filling hydrogel to build hermetic wall rapidly was indicated from results. Gelling time of seal-filling hydrogel was influenced by gelling temperature, initiator concentration and accelerator content. Gelling time decreased by 1/3~1/2 times as gelling temperature increased by each 10 ℃. Gelling time was proportional to 1/2 power of initiator concentration, and was linear of accelerator content with one power. Addition, deformation rate of seal-filling hydrogel depended on monomer content, cross linking agent concentration, accelerator content. And staggered change of elastic modulus was come forth, its demarcation points generally appeared at the value of 50% of vertical deformation.

  5. Rim seal arrangement having pumping feature

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ching-Pang; Myers, Caleb

    2017-04-25

    A rim seal arrangement for a gas turbine engine includes a first seal face on a rotor component, and a second seal face on a stationary annular rim centered about a rotation axis of the rotor component. The second seal face is spaced from the first seal face along an axial direction to define a seal gap. The seal gap is located between a radially outer hot gas path and a radially inner rotor cavity. The first seal face has a plurality of circumferentially spaced depressions, each having a depth in an axial direction and extending along a radial extent of the first seal face. The depressions influence flow in the seal gap such that during rotation of the rotor component, fluid in the seal gap is pumped in a radially outward direction to prevent ingestion of a gas path fluid from the hot gas path into the rotor cavity.

  6. Friction Characteristics of Mechanical Seals with Laser-textured Seal Faces

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Heat generated by friction between faces of mechanica l seals is a major factor that causes deterioration of the seals and shortens th eir service life. Excessive temperature rise can greatly alter the seal geometry and vaporize the sealing fluid, resulting in friction of boundary lubrication. These effects on face seals usually lead to excessive leakage and ultimately ren der the seal inoperable. In order to maintain the reliability of seals, high fri ction and unwanted wear must be avoided. Using the l...

  7. 7 CFR 29.35 - Lot seal.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots...

  8. 7 CFR 29.34 - Sample seal.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Sample seal. 29.34 Section 29.34 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.34 Sample seal. A seal approved by the Director for sealing...

  9. Northern Fur Seal Food Habits

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains food habits samples, usually scats, collected opportunistically on northern fur seal rookeries and haulouts in Alaska from 1987 to present....

  10. Alaska Harbor Seal Glacial Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Floating glacial ice serves as a haul-out substrate for a significant number (10-15%) of Alaskan harbor seals, and thus surveying tidewater glacial fjords is an...

  11. Seal device for ferromagnetic containers

    Science.gov (United States)

    Meyer, Ross E.; Jason, Andrew J.

    1994-01-01

    A temporary seal or patch assembly prevents the escape of contents, e.g., fluids and the like, from within a container having a breach therethrough until the contents can be removed and/or a repair effected. A frame that supports a sealing bladder can be positioned over the breach and the frame is then attached to the container surface, which must be of a ferromagnet material, by using switchable permanent magnets. The permanent magnets are designed to have a first condition that is not attracted to the ferromagnetic surface and a second conditions whereby the magnets are attracted to the surface with sufficient force to support the seal assembly on the surface. Latching devices may be attached to the frame and engage the container surface with hardened pins to prevent the lateral movement of the seal assembly along the container surface from external forces such as fluid drag or gravity.

  12. Quantum String Seal Is Insecure

    CERN Document Server

    Chau, H F

    2006-01-01

    A quantum string seal encodes the value of a (bit) string as a quantum state in such a way that everyone can extract a non-negligible amount of information on the string by a suitable measurement. Moreover, such measurement must disturb the quantum state and is likely to be detected by an authorized verifier. In this way, the intactness of the encoded quantum state plays the role of a wax seal in the digital world. Here I analyze the security of quantum string seal by studying the information disturbance tradeoff of a measurement. This information disturbance tradeoff analysis extends the earlier results of Bechmann-Pasquinucci et al. and Chau by concluding that all quantum string seals are insecure. Specifically, I find a way to obtain non-trivial information on the string that escapes the verifier's detection with probability at least one half.

  13. Self Sealing Magmas

    Science.gov (United States)

    von Aulock, Felix W.; Wadsworth, Fabian B.; Kennedy, Ben M.; Lavallee, Yan

    2015-04-01

    During ascent of magma, pressure decreases and bubbles form. If the volume increases more rapidly than the relaxation timescale, the magma fragments catastrophically. If a permeable network forms, the magma degasses non-violently. This process is generally assumed to be unidirectional, however, recent studies have shown how shear and compaction can drive self sealing. Here, we additionally constrain skin formation during degassing and sintering. We heated natural samples of obsidian in a dry atmosphere and monitored foaming and impermeable skin formation. We suggest a model for skin formation that is controlled by diffusional loss of water and bubble collapse at free surfaces. We heated synthetic glass beads in a hydrous atmosphere to measure the timescale of viscous sintering. The beads sinter at drastically shorter timescales as water vapour rehydrates an otherwise degassed melt, reducing viscosity and glass transition temperatures. Both processes can produce dense inhomogeneities within the timescales of magma ascent and effectively disturb permeabilities and form barriers, particularly at the margins of the conduit, where strain localisation takes place. Localised ash in failure zones (i.e. Tuffisite) then becomes associated with water vapour fluxes and alow rapid rehydration and sintering. When measuring permeabilities in laboratory and field, and when discussing shallow degassing in volcanoes, local barriers for degassing should be taken into account. Highlighting the processes that lead to the formation of such dense skins and sintered infills of cavities can help understanding the bulk permeabilities of volcanic systems.

  14. Status of Understanding for Seal Materials

    Science.gov (United States)

    Brown, P. F.

    1984-01-01

    Material selection for mainshaft face and ring seals, labyrinth seals, accessory gearbox face seals, and lip seals are discussed in light of tribology requirements and a given seal application. Carbon graphite has been found to be one of the best sealing materials and it is widely used in current gas turbine mainshaft and accessory gearbox seals. Its popularity is due to its unique combination of properties which consists of dimensional stability, corrosion resistance, low friction, good self lubricating characteristics, high thermal conductivity and low thermal expansion, the latter two properties combining to provide good thermal shock resistance. A brief description of the seals and the requirements they must meet are discussed to provide insight into the limitations and advantages of the seals in containing the lubricant. A forecast is made of the operational requirements of main shaft and gearbox seals for advanced engines and candidate materials and coatings that may satisfy these advanced engine requirements.

  15. Brush Seals for Improved Steam Turbine Performance

    Science.gov (United States)

    Turnquist, Norman; Chupp, Ray; Baily, Fred; Burnett, Mark; Rivas, Flor; Bowsher, Aaron; Crudgington, Peter

    2006-01-01

    GE Energy has retrofitted brush seals into more than 19 operating steam turbines. Brush seals offer superior leakage control compared to labyrinth seals, owing to their compliant nature and ability to maintain very tight clearances to the rotating shaft. Seal designs have been established for steam turbines ranging in size from 12 MW to over 1200 MW, including fossil, nuclear, combined-cycle and industrial applications. Steam turbines present unique design challenges that must be addressed to ensure that the potential performance benefits of brush seals are realized. Brush seals can have important effects on the overall turbine system that must be taken into account to assure reliable operation. Subscale rig tests are instrumental to understanding seal behavior under simulated steam-turbine operating conditions, prior to installing brush seals in the field. This presentation discusses the technical challenges of designing brush seals for steam turbines; subscale testing; performance benefits of brush seals; overall system effects; and field applications.

  16. Novel B19-like parvovirus in the brain of a harbor seal.

    Directory of Open Access Journals (Sweden)

    Rogier Bodewes

    Full Text Available Using random PCR in combination with next-generation sequencing, a novel parvovirus was detected in the brain of a young harbor seal (Phoca vitulina with chronic non-suppurative meningo-encephalitis that was rehabilitated at the Seal Rehabilitation and Research Centre (SRRC in the Netherlands. In addition, two novel viruses belonging to the family Anelloviridae were detected in the lungs of this animal. Phylogenetic analysis of the coding sequence of the novel parvovirus, tentatively called Seal parvovirus, indicated that this virus belonged to the genus Erythrovirus, to which human parvovirus B19 also belongs. Although no other seals with similar signs were rehabilitated in SRRC in recent years, a prevalence study of tissues of seals from the same area collected in the period 2008-2012 indicated that the Seal parvovirus has circulated in the harbor seal population at least since 2008. The presence of the Seal parvovirus in the brain was confirmed by real-time PCR and in vitro replication. Using in situ hybridization, we showed for the first time that a parvovirus of the genus Erythrovirus was present in the Virchow-Robin space and in cerebral parenchyma adjacent to the meninges. These findings showed that a parvovirus of the genus Erythrovirus can be involved in central nervous system infection and inflammation, as has also been suspected but not proven for human parvovirus B19 infection.

  17. Novel B19-like parvovirus in the brain of a harbor seal.

    Science.gov (United States)

    Bodewes, Rogier; Rubio García, Ana; Wiersma, Lidewij C M; Getu, Sarah; Beukers, Martijn; Schapendonk, Claudia M E; van Run, Peter R W A; van de Bildt, Marco W G; Poen, Marjolein J; Osinga, Nynke; Sánchez Contreras, Guillermo J; Kuiken, Thijs; Smits, Saskia L; Osterhaus, Albert D M E

    2013-01-01

    Using random PCR in combination with next-generation sequencing, a novel parvovirus was detected in the brain of a young harbor seal (Phoca vitulina) with chronic non-suppurative meningo-encephalitis that was rehabilitated at the Seal Rehabilitation and Research Centre (SRRC) in the Netherlands. In addition, two novel viruses belonging to the family Anelloviridae were detected in the lungs of this animal. Phylogenetic analysis of the coding sequence of the novel parvovirus, tentatively called Seal parvovirus, indicated that this virus belonged to the genus Erythrovirus, to which human parvovirus B19 also belongs. Although no other seals with similar signs were rehabilitated in SRRC in recent years, a prevalence study of tissues of seals from the same area collected in the period 2008-2012 indicated that the Seal parvovirus has circulated in the harbor seal population at least since 2008. The presence of the Seal parvovirus in the brain was confirmed by real-time PCR and in vitro replication. Using in situ hybridization, we showed for the first time that a parvovirus of the genus Erythrovirus was present in the Virchow-Robin space and in cerebral parenchyma adjacent to the meninges. These findings showed that a parvovirus of the genus Erythrovirus can be involved in central nervous system infection and inflammation, as has also been suspected but not proven for human parvovirus B19 infection.

  18. Grease lubrication mechanisms in bearing seals

    OpenAIRE

    2011-01-01

    Rolling bearings contain seals to keep lubricant inside and contaminants outside the bearing system. These systems are often lubricated with grease; the grease acts as a lubricant for the bearing and seal and improves the sealing efficiency. In this thesis, the influence of lubricating grease on bearing seal performance is studied. Rheological properties of the grease, i.e. shear stress and normal stress difference, are evaluated and related to the lubricating and sealing performance of the s...

  19. Harbour seals (Phoca vitulina and rehabilitation

    Directory of Open Access Journals (Sweden)

    Nynke Osinga

    2010-09-01

    Full Text Available Throughout the past few decades, rehabilitation of seals has become an activity that is anchored in the present day society of many countries. Seals are primarily rehabilitated to help individual animals in distress. At the same time, the release of seals which would have otherwise died can be considered as a contribution to the population. Most rehabilitated seals are animals under one year of age. They are mainly orphans, weaned seals with complications and seals with a parasiticbronchopneumonia. For the optimal handling of seals and their diseases, centralised operations with quality standards are essential. Rehabilitation provides an instrument to monitor the health of the seal population and its ecosystem. Changes in stranding trends or the appearance of new diseases can be monitored. Moreover, rehabilitation is important to show the general public thestate of the marine environment. In the Netherlands there is significant social support for the rehabilitation of seals. Experience obtained with seal care is of importance in countries where urgent help of threatened seal species is required. Here individual seals are also ambassadors to raise support for the protection of this species in general. Given that the anthropogenic impact on the seals and their environment is extensive in the Wadden Sea, rehabilitation centres can compensate the consequences of this impact on individual seals as well as the population as a whole.

  20. Sealing Performance of Labyrinth Seals against Small Oil Particles in HDDs

    Science.gov (United States)

    Miyatake, Masaaki; Yoshimoto, Shigeka; Dambara, Shinsuke; Nakamura, Taichi; Tanaka, Katsuhiko

    Small oil particles generated from lubricant for ball bearings in HDDs sometimes cause fatal problems such as head crashes. A labyrinth seal is often used to prevent oil particles from scattering onto the disk surfaces. In this paper, the sealing performance of labyrinth seals for small oil particles is investigated numerically and experimentally. Two types of labyrinth seal are considered, one a straight-type and the other a bent-type seal. It was found that the sealing capability of the labyrinth seal is generated by the centrifugal force exerted on oil particles due to disk rotation when they pass through the seal gap.

  1. Tamper-Indicating Quantum Seal*

    Science.gov (United States)

    Williams, Brian P.; Britt, Keith A.; Humble, Travis S.

    2016-01-01

    Technical means for identifying when tampering occurs is a critical part of many containment and surveillance technologies. Conventional fiber-optic seals provide methods for monitoring enclosed inventories, but they are vulnerable to spoofing attacks based on classical physics. We address these vulnerabilities with the development of a quantum seal that offers the ability to detect the intercept-resend attack using quantum integrity verification. Our approach represents an application of entanglement to provide guarantees in the authenticity of the seal state by verifying it is transmitted coherently. We implement these ideas using polarization-entangled photon pairs that are verified after passing through a fiber-optic-channel test bed. Using binary-detection theory, we find the probability of detecting inauthentic signals is greater than 0.9999 with a false-alarm chance of 1 0-9 for a 10-s sampling interval. In addition, we show how the Hong-Ou-Mandel effect concurrently provides a tight bound on redirection attack, in which tampering modifies the shape of the seal. Our measurements limit the tolerable path-length change to submillimeter disturbances. These tamper-indicating features of the quantum seal offer unprecedented security for unattended monitoring systems.

  2. Gas Path Sealing in Turbine Engines

    Science.gov (United States)

    Ludwig, L. P.

    1978-01-01

    A survey of gas path seals is presented with particular attention given to sealing clearance effects on engine component efficiency. The effects on compressor pressure ratio and stall margin are pointed out. Various case-rotor relative displacements, which affect gas path seal clearances, are identified. Forces produced by nonuniform sealing clearances and their effect on rotor stability are discussed qualitatively, and recent work on turbine-blade-tip sealing for high temperature is described. The need for active clearance control and for engine structural analysis is discussed. The functions of the internal-flow system and its seals are reviewed.

  3. Mechanical seal with textured sidewall

    Energy Technology Data Exchange (ETDEWEB)

    Khonsari, Michael M.; Xiao, Nian

    2017-02-14

    The present invention discloses a mating ring, a primary ring, and associated mechanical seal having superior heat transfer and wear characteristics. According to an exemplary embodiment of the present invention, one or more dimples are formed onto the cylindrical outer surface of a mating ring sidewall and/or a primary ring sidewall. A stationary mating ring for a mechanical seal assembly is disclosed. Such a mating ring comprises an annular body having a central axis and a sealing face, wherein a plurality of dimples are formed into the outer circumferential surface of the annular body such that the exposed circumferential surface area of the annular body is increased. The texture added to the sidewall of the mating ring yields superior heat transfer and wear characteristics.

  4. Cryogenic Flange and Seal Evaluation

    Science.gov (United States)

    Ramirez, Adrian

    2014-01-01

    The assembly of flanges, seals, and pipes are used to carry cryogenic fluid from a storage tank to the vehicle at launch sites. However, after a certain amount of cycles these raised face flanges with glass-filled Teflon gaskets have been found to have torque relaxation and are as a result susceptible to cryogenic fluid leakage if not re-torqued. The intent of this project is to identify alternate combinations of flanges and seals which may improve thermal cycle performance and decrease re-torque requirements. The general approach is to design a test fixture to evaluate leak characteristics between spiral and concentric serrations and to test alternate flange and seal combinations. Due to insufficient time, it was not possible to evaluate these different types of combinations for the combination that improved thermal cycle performance the most. However, the necessary drawings for the test fixture were designed and assembled along with the collection of the necessary parts.

  5. Desempenho de híbridos de linhagens parcialmente endogâmicas de milho em regiões dos estados de Roraima e Minas Gerais Performance of hybrids of partially endogamic lines s2 of maize in regions of the states of Roraima and Minas Gerais

    Directory of Open Access Journals (Sweden)

    Agnaldo Donizete Ferreira de Carvalho

    2003-10-01

    Full Text Available Entre as alternativas de tipos de híbridos de milho (Zea mays L., os que envolvem linhagens parcialmente endogâmicas (LPE S2 possuem a vantagem de maior rapidez na obtenção, se comparados com linhagens de endogamia completa. Essas LPE S2 podem ser obtidas a partir de qualquer tipo de população, porém, uma boa opção seria aquelas derivadas de híbridos simples comerciais, que associam produtividade e grande proporção de locos segregantes. Com esse intuito, o presente trabalho foi conduzido visando à avaliação de híbridos de LPE S2 derivados de três híbridos simples comerciais. Para obtenção dos híbridos, foram selecionados 30 LPE S2 de três populações distintas das cultivares híbridas comerciais: AG-9012, C-333B e Z-8392. Os cruzamentos foram realizados em esquema de dialelo circulante, em que cada LPE S2 de uma população foi cruzada com outras três LPE S2 de outra população. Para os cruzamentos, as LPE S2 foram semeadas em linha com dez metros cada uma. No aparecimento das primeiras espigas, as mesmas foram protegidas e, por ocasião da polinização, uma mistura de pólen de cada LPE S2 foi utilizada para polinizar pelo menos dez plantas de uma outra população LPE S2. Os híbridos obtidos foram avaliados em Boa Vista, Roraima e em Lavras, Minas Gerais, utilizando-se o delineamento látice simples 12x12, envolvendo os 135 híbridos LPE S2 obtidos e mais nove testemunhas, sendo elas as gerações F1 dos híbridos simples AG-9012, C-333B e Z-8392, um híbrido duplo (C 435 e cinco outros híbridos intervarietais. A parcela experimental foi constituída por uma linha de três metros de comprimento, espaçada de 90 cm entre linhas e permanecendo um total de cinco plantas por metro linear após o desbaste. As seguintes variáveis foram avaliadas: peso de espiga despalhada (PESP, altura de planta (ALTP e altura de espiga (ALTE. Para a PESP, 81% dos híbridos S2 foram superiores às médias das testemunhas. Observou-se que

  6. Stabilizing geometry for hydrodynamic rotary seals

    Science.gov (United States)

    Dietle, Lannie L.; Schroeder, John E.

    2010-08-10

    A hydrodynamic sealing assembly including a first component having first and second walls and a peripheral wall defining a seal groove, a second component having a rotatable surface relative to said first component, and a hydrodynamic seal comprising a seal body of generally ring-shaped configuration having a circumference. The seal body includes hydrodynamic and static sealing lips each having a cross-sectional area that substantially vary in time with each other about the circumference. In an uninstalled condition, the seal body has a length defined between first and second seal body ends which varies in time with the hydrodynamic sealing lip cross-sectional area. The first and second ends generally face the first and second walls, respectively. In the uninstalled condition, the first end is angulated relative to the first wall and the second end is angulated relative to the second wall. The seal body has a twist-limiting surface adjacent the static sealing lip. In the uninstalled condition, the twist-limiting surface is angulated relative to the peripheral wall and varies along the circumference. A seal body discontinuity and a first component discontinuity mate to prevent rotation of the seal body relative to the first component.

  7. Legacy HMSRP Hawaiian Monk Seal Ultrasound Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ultrasounds measuring the condition of juvenile seals at Laysan Island during 2009-2010, collected when seals were handled as part of the De-Worming Project

  8. HMSRP Hawaiian Monk Seal Entanglement data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set contains records of all entanglements of Hawaiian monk seals in marine debris. The data set comprises records of seals entangled by derelict fishing...

  9. Film riding seals for rotary machines

    Energy Technology Data Exchange (ETDEWEB)

    Bidkar, Rahul Anil; Sarawate, Neelesh Nandkumar; Wolfe, Christopher Edward; Ruggiero, Eric John; Raj Mohan, Vivek Raja

    2017-03-07

    A seal assembly for a rotary machine is provided. The seal assembly includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward-shoe section and an aft-shoe section having one or more labyrinth teeth therebetween facing the rotor. The sealing device includes a stator interface element having a groove or slot for allowing disposal of a spline seal for preventing segment leakages. The sealing device segment also includes multiple bellow springs or flexures connected to the shoe plate and to the stator interface element. Further, the sealing device segments include a secondary seal integrated with the stator interface element at one end and positioned about the multiple bellow springs or flexures and the shoe plate at the other end.

  10. Legacy HMSRP Hawaiian Monk Seals Observers

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set documents observers that have collected monk seal data as part of the ongoing monk seal population assessment efforts by PSD personnel and cooperating...

  11. HMSRP Hawaiian Monk Seal Crittercam video

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project investigates foraging behavior of Hawaiian monk seals by conducting telemetry studies. During these studies, live seals are instrumented with dive...

  12. HMSRP Hawaiian Monk Seal Handling Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records for all handling and measurement of Hawaiian monk seals since 1981. Live seals are handled and measured during a variety of events...

  13. Non Destructive Seal Testing Polymeric Tray

    Science.gov (United States)

    2006-10-01

    School of Enviromental and Biological Science Rutgers, The State University of New Jersey New Brunswick, New Jersey 08903 Principal Investigator...strength, tack seals and seal creep. The following modifications were issued : Jan 20, 2004 0008/01 Add incremental funding to increase total...Technologies”. Most of the “commercial off the shelf” systems are designed to detect seal integrity issues , such as seal contamination, cuts and holes. A

  14. Multi-layer seal for electrochemical devices

    Science.gov (United States)

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-09-14

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  15. Multi-layer seal for electrochemical devices

    Science.gov (United States)

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-11-16

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  16. Pre-sealing risk analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ensminger, D.A.; Hough, M.E.; Oston, S.G.

    1980-01-07

    This report describes studies of accidents involving high-level radioactive waste before sealing the waste into a repository. The report summarizes work done in this area during Fiscal Year 1978 and supplements previous work. Models of accident probability, severity, and consequences are refined and extended.

  17. Predicting Leakage in Labyrinth Seals

    Science.gov (United States)

    Morrison, G. L.; Rhode, D. L.; Cogan, K. C.; Chi, D.; Demko, J.

    1985-01-01

    Analytical and empirical methods evaluated. 264-page report presents comprehensive information on leakage in labyrinth seals. Summarizes previous analyses of leakage, reviews leakage tests conducted by authors and evaluates various analytical and experimental methods of determining leakage and discusses leakage prediction techniques.

  18. Aerodynamic seal assemblies for turbo-machinery

    Energy Technology Data Exchange (ETDEWEB)

    Bidkar, Rahul Anil; Wolfe, Christopher; Fang, Biao

    2015-09-29

    The present application provides an aerodynamic seal assembly for use with a turbo-machine. The aerodynamic seal assembly may include a number of springs, a shoe connected to the springs, and a secondary seal positioned about the springs and the shoe.

  19. Piston rod seal for a Stirling engine

    Science.gov (United States)

    Shapiro, Wilbur

    1984-01-01

    In a piston rod seal for a Stirling engine, a hydrostatic bearing and differential pressure regulating valve are utilized to provide for a low pressure differential across a rubbing seal between the hydrogen and oil so as to reduce wear on the seal.

  20. Ergonomics and safety of manual bag sealing.

    NARCIS (Netherlands)

    Groot, M.D. de; Bosch, T.; Eikhout, S.M.; Vink, P.

    2005-01-01

    A variety of seals is used to close bags. Each seal has advantages and disadvantages. For shop assistants sealing bags could be a repetitive physically demanding action. Opening and closing the bags again can cause some discomfort or annoyance for consumers. Besides, it is an activity which can enda

  1. Annular Pressure Seals and Hydrostatic Bearings

    Science.gov (United States)

    2006-11-01

    affecting the rotordynamics of liquid turbopumps, in particular those handling large density fluids. Highlights on the bulk-flow analysis of annular seals... rotordynamic stability. Hydrostatic bearings rely on external fluid pressurization to generate load support and large centering stiffnesses, even in...SEALS IN PUMP APPLICATIONS Seal rotordynamic characteristic have a primary influence on the stability response of high-performance turbomachinery [1

  2. Characteristics of a magnetic fluid seal and its motion in an axial variable seal gap

    Institute of Scientific and Technical Information of China (English)

    QIAN Ji-guo; YANG Zhi-yi

    2008-01-01

    With suitable assumptions a hydrodynamic model for the magnetic fluid motion in an axial variable gap seal was constructed, and the solution to the equations of the model was deduced. The characteristics of a magnetic fluid seal and its motion,including the speed and pressure distribution, and the seal capacity of a magnetic fluid rotating seal were systematically described.The factors affecting seal capacity and ways to improve seal capacity based on the hydrodynamic model are discussed. The basic condition for dynamic seal availability is presented. The rotating speed and radius of the shafts should be decreased. The work can provide proof of a seal design or suggest ways to improve the seal capacity of magnetic fluid seals.

  3. Potencial produtivo e composição das frações anatômicas de quatro híbridos de sorgo sob doses de nitrogênio Production and composition of anatomical fractions of four sorghum hybrids under nitrogen dosages

    Directory of Open Access Journals (Sweden)

    Eduardo Rodrigues de Carvalho

    2010-09-01

    Full Text Available Objetivou-se nesse trabalho avaliar a produção e composição das frações anatômicas de quatro híbridos de sorgo sob doses de nitrogênio (N. O delineamento experimental foi em blocos ao acaso em esquema fatorial 4x3 (quatro híbridos de sorgo e três doses de N. Os híbridos de sorgo testados oram os seguintes: 1F 305, 0369 267, 0369 255 e BR 700, enquanto que as doses de N foram 0, 60 e 120kg/ha. Foram determinadas a produção de matéria natural (PMN, teor de matéria seca (MS, produção de matéria seca (PMS, produção total de matéria seca (PTMS, porcentagem de rebrota e composição das frações da planta (folhas, colmo e panículas. No primeiro e segundo cortes a PMN e PMS foram maiores na dose de 120kg/ha de N. O teor de MS foi influenciado tanto pelos híbridos quanto pelas doses de N apenas no primeiro corte, mas não no segundo. O híbrido 0369 255 e a dose de 120 kg/ha de N apresentaram maiores rendimentos de PTMS. O híbrido 1F 305 diferiu dos demais em relação à proporção de folhas no primeiro corte, enquanto que no segundo, os híbridos 1F 305 e BR 700 apresentaram maior porcentagem de folhas em relação aos demais. Obteve-se maior proporção de folhas na dose de 120kg/ha de N nos dois cortes. A utilização do híbrido 0369 255 adubado com 120kg/ha de N é a melhor recomendação para obtenção de altos rendimentos de sorgo forrageiro.The objective of this study was to evaluate the production and composition of anatomical fractions of four forage sorghum hybrids under three N (nitrogen dosages. The experimental design was in randomized blocks in a factorial scheme 4x3 (four sorghum hybrids and three N dosages. The sorghum hybrids were the following: 1F 305, 0369 267, 0369 255 and BR 700, and N dosages were 0, 60 and 120 kg/ha. It was determined the NMP (natural matter production, DM (dry matter contents, DMP (dry matter production, TDMP (total dry matter production, regrowth percentage and composition of the

  4. Symmetries in Images on Ancient Seals

    CERN Document Server

    Sparavigna, Amelia

    2008-01-01

    In this paper, we discuss the presence of symmetries in images engraved on ancient seals, in particular on stamp seals. Mainly used to secure the containers from tampering and for owner's identification, these objects appeared during the 5th millennium BC in Mesopotamia. Usually the seals were engraved with simple images, suitable to communicate an immediate information. Rotational symmetries are already displayed by the most ancient stamp seals, whose images reach a quasi-perfect symmetry in their small circular or ovoid spaces. Bilateral symmetries are quite common in Egyptian scarab seals.

  5. Repository Sealing Program Plan: repository in salt

    Energy Technology Data Exchange (ETDEWEB)

    Kelsall, P.C.; Coons, W.E.; Meyer, D.

    1983-01-01

    The isolation of nuclear wastes in deep, mined repositories will require the sealing of all penetrations such as shafts, tunnels, or boreholes into or nearby the repository. This Repository Sealing Program Plan describes the technical programs required to complete seal designs for a repository in salt prior to license application in 1988. The plan examines the current schematic seal designs for a repository in salt and identifies seven major technical programs which are required to advance the designs to the status required for licensing: (1) update designs to incorporate site-specific geologic and hydrologic characteristics; (2) reference designs to site-specific repository designs; (3) develop site-specific performance requirements; (4) salt consolidation testing and modeling; (5) materials development; (6) design analyses; (7) verification testing. Scedules for each of these programs are keyed to governing seal design and ONWI milestones. Conceptual seal designs will be completed in FY 84 and preliminary seal designs in FY 87.

  6. Air riding seal with purge cavity

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, Thomas D; Mills, Jacob A

    2017-08-15

    An air riding seal for a turbine in a gas turbine engine, where an annular piston is axial moveable within an annular piston chamber formed in a stator of the turbine and forms a seal with a surface on the rotor using pressurized air that forms a cushion in a pocket of the annular piston. A purge cavity is formed on the annular piston and is connected to a purge hole that extends through the annular piston to a lower pressure region around the annular piston or through the rotor to an opposite side. The annular piston is sealed also with inner and outer seals that can be a labyrinth seal to form an additional seal than the cushion of air in the pocket to prevent the face of the air riding seal from overheating.

  7. Rotary seal with improved film distribution

    Energy Technology Data Exchange (ETDEWEB)

    Dietle, Lannie Laroy; Schroeder, John Erick

    2015-09-01

    The present invention is a generally circular rotary seal that establishes sealing between relatively rotatable machine components for lubricant retention and environmental exclusion, and incorporates seal geometry that interacts with the lubricant during relative rotation to distribute a lubricant film within the dynamic sealing interface. The features of a variable inlet size, a variable dynamic lip flank slope, and a reduction in the magnitude and circumferentially oriented portion of the lubricant side interfacial contact pressure zone at the narrowest part of the lip, individually or in combination thereof, serve to maximize interfacial lubrication in severe operating conditions, and also serve to minimize lubricant shear area, seal torque, seal volume, and wear, while ensuring retrofitability into the seal grooves of existing equipment.

  8. Rotary seal with improved film distribution

    Science.gov (United States)

    Dietle, Lannie Laroy; Schroeder, John Erick

    2013-10-08

    The present invention is a generally circular rotary seal that establishes sealing between relatively rotatable machine components for lubricant retention and environmental exclusion, and incorporates seal geometry that interacts with the lubricant during relative rotation to distribute a lubricant film within the dynamic sealing interface. The features of a variable inlet size, a variable dynamic lip flank slope, and a reduction in the magnitude and circumferentially oriented portion of the lubricant side interfacial contact pressure zone at the narrowest part of the lip, individually or in combination thereof, serve to maximize interfacial lubrication in severe operating conditions, and also serve to minimize lubricant shear area, seal torque, seal volume, and wear, while ensuring retrofitability into the seal grooves of existing equipment.

  9. Seal dynamics on the Swedish west coast: Scenarios of competition as Baltic grey seal intrude on harbour seal territory

    Science.gov (United States)

    Svensson, Carl Johan

    2012-07-01

    The Kattegat-Skagerrak region on the Swedish west coast is home to an abundant harbour seal population (Phoca vitulina) and a small scattered grey seal population (Halichoerus grypus). In addition, grey seal from the growing population in the Baltic Sea frequently migrate into the Kattegat-Skagerrak. Harbour seals on the west coast of Sweden show relatively high population growth (approximately 9%) compared to the Baltic grey seal in ice-free habitats (approximately 6%), which, in theory, makes harbour seal the stronger competitor of the two in this region. However, incidents of disease in harbour seals that lower population growth are becoming more frequent. These epidemics are primarily caused by the Phocine Distemper Virus (PDV), and may reduce population size with up to 70%. This study models the average development under potential scenarios of competing harbour- and Baltic grey seal populations using Leslie matrices and the Lotka-Volterra model of inter-specific competition. The model is parameterised with previously published data, and resource overlap is incorporated through density dependent pup survival. Using numerical methods short- and long-term abundances are simulated under weak, moderate and strong competition and for different frequencies of PDV epidemics. Results show that the harbour seals are resilient to competition while exerting a negative effect on grey seal abundance under moderate to strong competition. Hence Baltic grey seal benefit from weaker levels of competition. Under moderate and strong competition grey seal abundance is a direct function of the PDV frequency as this reduces the competitive strength of harbour seals. Theoretically this means that higher frequencies of PDV or other pathogens epidemics could facilitate an expansion of Baltic grey seal into Kattegat-Skagerrak. Independent of interaction strength and frequency of epidemics the projected changes to abundances are slow (50-100 years), and even in exceedingly stable

  10. Mechanical Deformation of Ship Stern-Shaft Mechanical Face Seals

    Institute of Scientific and Technical Information of China (English)

    朱汉华; 刘正林; 温诗铸; 严新平

    2004-01-01

    In ship propeller shaft systems, the shaft seal is a mechanical face seal, which includes a stationary metal seal ring and a rotating ring.The seal faces are deformed with different loads.The deformation of the seal faces affects the performance of mechanical face seals, which leads to water leakage, so the seal face deformation must be analyzed.A mechanics model with deformation equations was developed to describe ship stern-shaft seals.An example was given to verify the deformation equations.The solution of the deformation equations gives a theoretical basis for the analysis of seal leakage and improvements of seal structures.

  11. Seal designing of theodolite used in seaside environment

    Science.gov (United States)

    Jin, Humin; Yan, Xiaoxu; Hao, Wei; Zhou, Sizhong

    2014-08-01

    Based on the environment requirements in seaside there exists static and dynamic seal designing for the photoelectric Theodolite. Static seal designing emphatically includes the designing of o-ring size and mechanical property analysis of o-ring seal, which is difficult to adopt conventional dynamic seal to meet the requirements. According to practical application, the combination of the radial labyrinth seal and high quality felt seal are designed. The combination seal which better solves the seal problem of narrow radial size is a good way of dynamic seal. At the same time, there is engineering practice needing to proof the radial labyrinth seal.

  12. Hermetic seal for a shaft

    Science.gov (United States)

    Lombardi, F. (Inventor)

    1982-01-01

    An hermetic seal for a linear rod having a portion thereof projected axially through a port defined in a wall for a pressure chamber and supported thereby for omni-directional motion is described. The seal is characterized by a resilient, impervious, cylindrical body having a first section concentrically related to the shaft and integrally affixed thereto comprising a linear ordered array of annular flutes. A second section integrally is affixed to the wall of the chamber and concentrically related to the port comprising a second linear ordered array of annular flutes. A third section is interposed between the first and second sections and integrally affixed in coaxial alignment therewith comprising an annular ordered array of linear flutes concentrically related to the shaft, whereby axial, angular, and pivotal motion of the rod is accommodated.

  13. Caracterização agronômica e composição química de híbridos de milho - DOI: 10.4025/actascianimsci.v29i2.206 Agronomic evaluation and chemical composition of corn hybrid - DOI: 10.4025/actascianimsci.v29i2.206

    Directory of Open Access Journals (Sweden)

    Augusto Manoel Rodrigues

    2007-11-01

    Full Text Available O trabalho teve por objetivo avaliar a produção de matéria seca total (MST, de colmo (MSc, de folhas (MSf, de espigas (MSe, teores de proteína bruta (PB, fibra em detergente ácido (FDA, altura de planta (AP e relação colmo/folha (C/F de híbridos (Zea mays L. AG 122, AG 519, C 525, C 805, D 170, D 771, G 600, G 1328, P 3041, P 3069, XL 520, XL 530, OC 705, FO 01. Utilizou-se o delineamento experimental inteiramente casualizado, com 10 repetições. O híbrido FO 01 apresentou maior produção de matéria seca, maior altura de planta e maior produção de colmo, porém com menor percentagem de espigas e folhas, prejudicando a qualidade do material original. A maior produtividade apresentada pelos híbridos está associada a maior altura da planta e maior proporção de colmos na matéria seca total. Em geral, uma boa produção de matéria seca, com equilíbrio na relação folhas/colmo/espigas, foi apresentado pelo híbrido G 1328.The objective of this work was to evaluate the total dry matter production (TDMP of stem (DMs, leaves (DMl, ear (DMe, crude protein content (CPC, acid detergent fiber (ADF, plant height (PH and stem/leaves relation (S/L of the hybrids (Zea mays L. AG 122, AG 519, C 525, C 805, D 170, D 771, G 600, G 1328, P 3041, P 3069, XL 520, XL 530, OC 705, FO 01. The results indicated that the hybrid FO 01 showed the highest dry matter production, the highest plant and stem production, but the smallest ear and leaves percentage, decreasing the quality of the original material. The higher productivity of hybrids was associated with a higher plant height and stem production on total dry matter. The hybrid G 1328 showed a good dry matter production with equilibrium in the relation leaves/stem/corn cob.

  14. Caracterização imuno-histoquímica de lesão híbrida de ameloblastoma desmoplásico e convencional "Hybrid" lesion of desmoplastic and conventional ameloblastoma: immunohistochemical aspects

    Directory of Open Access Journals (Sweden)

    Jean Nunes dos Santos

    2006-10-01

    Full Text Available O ameloblastoma é uma neoplasia odontogênica benigna comumente encontrada nos ossos maxilares. Histologicamente, mostra diversos padrões, incluindo a ameloblastoma plexiforme e folicular. Quando estes padrões histológicos coexistem com um ameloblastoma que exibe abundante desmoplasia, são então denominados de lesão ‘híbrida" de ameloblastoma desmoplásico e convencional. No presente trabalho, nos propomos a relatar um caso de lesão híbrida de ameloblastoma desmoplásico e convencional destacando os aspectos imuno-histoquímicos relativos a expressão das proteínas da matriz extracelular (tenascina, fibronectina e colágeno I.Ameloblastoma is a benign epithelial odontogenic tumor and is the most commonly encountered odontogenic tumor in the jaws. Histologically, ameloblastomas occur in different patterns, including plexiform pattern and follicular pattern. "Hybrid " lesion of ameloblastoma is a tumor variant in which histologically, areas of follicular or plexiform ameloblastoma coexist with characteristic areas of ameloblastoma exhibiting pronounced stromal desmoplasia (desmoplastic ameloblastoma. The purpose of this article is to present a case of "hybrid" lesion of desmoplastic ameloblastoma (AD and conventional, and investigate extracellular matrix proteins such as tenascin, fibronectin, and type I collagen.

  15. Design optimization of seal structure for sealing liquid by magnetic fluids

    Science.gov (United States)

    Liu, Tonggang; Cheng, Yusheng; Yang, Zhiyi

    2005-03-01

    The durability of the magnetic fluid seal clearly decreases when sealing another liquid because of the interface instability caused by the applied magnetic field and the velocity difference of the two liquids. With an intention to establish a stable interface during sealing liquid, a new magnetic fluid seal was developed in this paper. The parameters of the structure were optimized by a simulation apparatus. And the magnetic fluid seal designed based on the optimum parameters shows good performance and long life for sealing lubricating oil.

  16. Numerical Analysis of Magnetic Fluid Sealing Performance

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The sealing performance of magnetic fluid is related to the magnetic fluid itself. Many factors can influence the magnetic field and the seal pressure differences of magnetic fluid seals, such as the sealing gap, the shaft eccentricity, the shaft diameter, the volume of the magnetic fluid and the centrifugal force. These factors are analyzed by numerical computation . When the seal material and structure are the same, the seal pressure difference is directly proportional to the magnetic field intensity and the saturation magnetization of the magnetic fluid. The sealing performance of the magnetic fluid will reduce with the increase of the sealing gap and shaft eccentricity. The sealing performance will increase with the volume of the magnetic fluid and decrease with the increase of the shaft diameter taking gravity into account. The increase of the shaft diameter is the same as the reduction of the volume of the magnetic fluid. The magnetic fluid cross-section can change because of the centrifugal force. Some improvements can reduce the influence of the centrifugal force. The centrifugal force can be utilized to improve the sealing performance.

  17. Hybrid slab-microchannel gel electrophoresis system

    Science.gov (United States)

    Balch, Joseph W.; Carrano, Anthony V.; Davidson, James C.; Koo, Jackson C.

    1998-01-01

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  18. Avaliação agronômica de parentais e híbridos de maracujazeiro- amarelo Agronomic evalution of parental and hybrid of yellow passion fruit

    Directory of Open Access Journals (Sweden)

    Cláudia Garcia Neves

    2013-03-01

    Full Text Available O presente trabalho objetiva determinar o potencial agronômico de genótipos de maracujazeiro-amarelo, visando a identificar e selecionar híbridos promissores. O experimento foi conduzido em área de produção no município de Cruz das Almas (BA, em delineamento de blocos casualizados, com três repetições, 41 genótipos (30 híbridos e 11 parentais, com parcela de 4 plantas. As características avaliadas foram: produtividade; número de frutos; massa média de frutos; espessura de casca; rendimento de suco; produtividade de suco e teor de sólidos solúveis totais. Houve diferença significativa entre os genótipos a 1% de probabilidade pelo teste F, para todas as variáveis em estudo, exceto para a característica rendimento de suco (pThe present study aims to determine the agronomic potential of genotypes of yellow passion fruit, to identify and select promising hybrid. The experiment was conducted in the production area in Cruz das Almas (BA in a randomized block design with three replications, 41 genotypes (30 hybrids and 11 parents, in a share of four plants. The characteristics evaluated were: yield, number of fruits, average mass fruit, peel thickness, juice yield, and total soluble solids. There were significant differences between genotypes for the F test for all variables studied, except for juice yield (p<0.06. High amplitudes for all traits were observed, showing favorable situation to select the best genotypes for recommendation. However, it was observed that the most suitable traits for a good yellow passion fruit cultivar are presented in different genotypes, with existence of some undesirable correlations. Among the positive genotypic correlation of greater importance are yield x number of fruits (0.78 and yield x juice productivity (0.81. However, the use of the selection indexes of Mulamba & Mock (MM and genotype-ideotype distance, allowed the appointment of three hybrids (H09-10, H09-14 and H09-20 with high average and

  19. Características agronômica de híbridos diploides de bananeira em três ciclos de produção em Cruz das Almas, Bahia Agronomic traits of banana diploid hybrids in three cycle of production in Cruz das Almas, Bahia

    Directory of Open Access Journals (Sweden)

    Lauro Saraiva Lessa

    2010-03-01

    Full Text Available O objetivo deste trabalho foi avaliar agronomicamente híbridos diploides de bananeira, em três ciclos de produção, visando à seleção de genótipos para utilização em programas de melhoramento. O experimento foi conduzido entre os anos de 2005 e 2007, em blocos casualizados, no esquema de parcela subdividida no tempo, com quatro repetições, em Cruz das Almas, Bahia. Os híbridos diploides 4279-06, TH03-01, 8987-01, 0323-03, 1318-01, 0116-01, 8694-20, 1304-06 e 9179-03 foram avaliados quanto à altura de plantas, diâmetro do pseudocaule, número de folhas vivas na floração e na colheita, presença de pólen, período de formação do cacho, número de pencas e frutos, e massa média dos frutos. O híbrido 1304-06 apresentou a maior altura nos três ciclos estudados, enquanto o 0323-03 e o 1318-01 apresentaram porte intermediário. À exceção des 8987-01, 0323-03, 1304-06 e 9179-03, os demais híbridos apresentaram número de folhas, na floração, superior a oito. Na colheita, 0323-03, 1318-01, 0116-01, 1304-06 e 9179-03 destacaram-se com os maiores números de folhas. Existe variabilidade genética entre os híbridos diploides de bananeira estudados. Os híbridos 4279-06, 0323-03, 1318-01, 0116-01, 1304-06 e 9179-03 apresentaram características agronômicas favoráveis e podem ser utilizados como genitores em programas de melhoramento genético da bananeira.Objective this work was to evaluate agronomic traits of banana diploid hybrids, in three production cycles, seeking the selection of genotypes for use in banana breeding programs. Experiment was conducted between years 2005 and 2007, at complete randomized block in split plot design, with four replicates, in Cruz das Almas, Bahia, Brazil. Diploids hybrids 4279-06, TH03-01, 8987-01, 0323-03, 1318-01, 0116-01, 8694-20, 1304-06 and 9179-03, were evaluated regarding the characters plant height, pseudostem diameter, number of fresh leaves in flowering and harvest, pollen presence

  20. Air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Jacob A; Brown, Wesley D; Sexton, Thomas D; Jones, Russell B

    2016-07-19

    An air riding seal between a rotor and a stator in a turbine of a gas turbine engine, where an annular piston is movable in an axial direction within a housing that extends from the stator, and a bellows is secured to the annular piston to form a flexible air passageway from a compressed air inlet through the annular piston and into a cushion cavity that forms an air riding seal between the annular piston and the rotor sealing surface. In another embodiment, a flexible seal secured to and extending from the annular piston forms a sealing surface between the annular piston chamber and the annular piston to provide a seal and allow for axial movement.

  1. Coalbed methane reservoir boundaries and sealing mechanism

    Institute of Scientific and Technical Information of China (English)

    SU Xianbo; LIN Xiaoying; LIU Shaobo; SONG Yan

    2005-01-01

    It is important to investigate the coalbed methane reservoir boundaries for the classification, exploration, and development of the coalbed methane reservoir.Based on the investigation of the typical coalbed methane reservoirs in the world, the boundaries can be divided into four types: hydrodynamic boundary, air altered boundary,permeability boundary, and fault boundary. Hydrodynamic and air altered boundaries are ubiquitous boundaries for every coalbed methane reservoir. The four types of the fault sealing mechanism in the petroleum geological investigation (diagen- esis, clay smear, juxtaposition and cataclasis) are applied to the fault boundary of the coalbed methane reservoir. The sealing mechanism of the open fault boundary is the same with that of the hydrodynamic sealing boundary.The sealing mechanism of the permeability boundary is firstly classified into capillary pressure sealing and hydrocarbon concentration sealing. There are different controlling boundaries in coalbed methane reservoirs that are in different geological backgrounds. Therefore, the coalbed methane reservoir is diversiform.

  2. NEW POLIMER SEALING FLUID STOPS MUD LOSS

    Directory of Open Access Journals (Sweden)

    Stanislaw Stryczek

    1989-12-01

    Full Text Available This paper deals with a composition of sealing fluid, prepared from acrylic acid salt water solution Solakryl M. Laboratory test results of technological properties of its modifications with mineral agents are shown. A new method of sealing mud loss operations with given sealing liquid is discussed along with comments on effects of its use for stopping mud loss in case of freeze-well drilling is described (the paper is published in Croatian.

  3. Face seal assembly for rotating drum

    Science.gov (United States)

    Morgan, J. Giles; Rennich, Mark J.; Whatley, Marvin E.

    1982-01-01

    A seal assembly comprises a tube rotatable about its longitudinal axis and having two longitudinally spaced flanges projecting radially outwardly from the outer surface thereof. Slidably positioned against one of the flanges is a seal ring, and disposed between this seal ring and the other flange are two rings that are forced apart by springs, one of the latter rings being attached to a flexible wall.

  4. económica

    Directory of Open Access Journals (Sweden)

    Rodrigo Gómez

    2004-01-01

    Full Text Available En este artículo se analiza el papel ejercido por TV Azteca en el sistema televisivo mexicano desde su aparición en 1993. La investigación se centra en las políticas y estrategias que ha establecido la empresa, tanto en el ámbito económico-financiero como en el de su programación y producción. El análisis que proponemos se enmarca principalmente dentro del contexto de la liberalización económica, la desregulación y la integración regional de México con Estados Unidos y Canadá. El enfoque que utilizamos es desde la perspectiva de la economía política de la comunicación.

  5. Byzantine seals from the Ras fortress

    Directory of Open Access Journals (Sweden)

    Ivanišević Vujadin

    2013-01-01

    Full Text Available In this paper, seals found at the location of the Ras fortress (Tvrđava Ras have been published. Inscriptions on these seals show that they used to belong to persons which could be identified with certain military commanders who served under Alexios I Komnenos. The seals in question are: the seals of protonobelissimos Eustathios Kamytzes, Constantine Dalassenos Doukas, protoproedros and doux Constantine Kekaumenos and a certain person called Alexios. [Projekat Ministarstva nauke Republike Srbije, br. 177021 i br. 177032

  6. Ductile alloys for sealing modular component interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Marra, John J.; Wessell, Brian J.; James, Allister W.; Marsh, Jan H.; Gear, Paul J.

    2017-08-08

    A vane assembly (10) having: an airfoil (12) and a shroud (14) held together without metallurgical bonding there between; a channel (22) disposed circumferentially about the airfoil (12), between the airfoil (12) and the shroud (14); and a seal (20) disposed in the channel (22), wherein during operation of a turbine engine having the vane assembly (10) the seal (20) has a sufficient ductility such that a force generated on the seal (20) resulting from relative movement of the airfoil (12) and the shroud (14) is sufficient to plastically deform the seal (20).

  7. A reliable sealing method for microbatteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuxing; Cartmell, Samuel; Li, Qiuyan; Xiao, Jie; Li, Huidong; Deng, Zhiqun Daniel; Zhang, Ji-Guang

    2017-02-01

    With continuous downsizing of electronic devices, lithium batteries of traditional shapes cannot meet the demand where small-size high energy density batteries are needed. Conventional sealing methods become increasingly difficult to apply and impose high processing cost as the size of batteries decreases. In this report, a facile sealing method is proposed and demonstrated in CFx/Li mini-batteries. The method employs a temporary barrier to liquid electrolytes while relies on the epoxies/cell casings bond for the hermetic sealing. Cells sealed by this method show no degradation for an extended period of storage time.

  8. Sealing Occlusal Dentin Caries in Permanent Molars

    DEFF Research Database (Denmark)

    Qvist, Vibeke; Borum, Mette Kit; Møller, Kirsten Dynes

    2017-01-01

    /renewed and 20% were still functioning. No endodontics was performed. Kaplan–Meier and Cox regression survival analyses were performed on 341 sealings and 152 restorations in first and second molar teeth. The 7-y survival was 37% (CI, 29% to 45%) for sealings and 91% (CI, 85% to 96%) for restorations (P ....001). The median survival time for sealings not replaced by restorations was 7.3 y (CI, 6.4 y to NA). Survival of sealings was increased in patients with low caries risk and/or excellent oral hygiene, second molars compared with first molars, and lesions not extending the middle one-third of the dentin. Survival...

  9. Self-acting geometry for noncontact seals

    Science.gov (United States)

    Allen, G. P.

    1981-01-01

    Performance ot two self acting seal designs for a liquid oxygen (LOX) turbopump was predicted over ranges of pressure differential and speed. Predictions were compared with test results. Performance of a radial face seal for LOX was predicted up to 448 N/cu cm and 147 m/sec. Performance of a segmented circumferential seal for helium was predicted up to 69 N/cu cm and 189 m/sec. Results confirmed predictions of noncontact operation. Qualitative agreement between test and analysis was found. The LOX face seal evidently operated with mostly liquid in the self acting geometry and mostly gas across the dam.

  10. Ceramic/metal seals. [refractory materials for hermetic seals for lighium-metal sulfide batteries

    Science.gov (United States)

    Bredbenner, A. M.

    1977-01-01

    Design criteria are discussed for a hermetic seal capable of withstanding the 450 C operating temperature of a lithium-metal sulfide battery system. A mechanical seal consisting of two high strength alloy metal sleeves welded or brazed to a conductor assembly and pressed onto a ceramic is described. The conductor center passes through the ceramic but is not sealed to it. The seal is effected on the outside of the taper where the tubular part is pressed down over and makes contact.

  11. Influence of Rocket Engine Characteristics on Shaft Sealing Technology Needs

    Science.gov (United States)

    Keba, John E.

    1999-01-01

    This paper presents viewgraphs of The Influence of Rocket Engine Characteristics on Shaft Sealing Technology Needs. The topics include: 1) Rocket Turbomachinery Shaft Seals (Inter-Propellant-Seal (IPS) Systems, Lift-off Seal Systems, and Technology Development Needs); 2) Rocket Engine Characteristics (Engine cycles, propellants, missions, etc., Influence on shaft sealing requirements); and 3) Conclusions.

  12. Sealed nickel-cadmium battery

    Energy Technology Data Exchange (ETDEWEB)

    1989-08-15

    Overcharge protection, and especially the chargeability of a sealed Ni/Cd battery with high currents is improved by rolling a carbon-containing powdered material into the surface of the negative electrode, which material catalyzes the reduction of oxygen. Wetting of the electrode with a Tylose dispersion prior to application of the powder (by powdering, vibration or in an agitator) improves the adhesion of the powder. The cadmium electrode thus prepared combines in itself the functions of a negative principal electrode and of an auxiliary oxygen electrode.

  13. Well sealing via thermite reactions

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, William Edward; Dunn, Sandra Dalvit

    2016-11-15

    A platform is formed in a well below a target plug zone by lowering a thermite reaction charge into the well and igniting it, whereby the products of the reaction are allowed to cool and expand to form a platform or support in the well. A main thermite reaction charge is placed above the platform and ignited to form a main sealing plug for the well. In some embodiments an upper plug is formed by igniting an upper thermite reaction charge above the main thermite reaction charge. The upper plug confines the products of ignition of the main thermite reaction charge.

  14. Magnetohydrodynamic (MHD) channel corner seal

    Science.gov (United States)

    Spurrier, Francis R.

    1980-01-01

    A corner seal for an MHD duct includes a compressible portion which contacts the duct walls and an insulating portion which contacts the electrodes, sidewall bars and insulators. The compressible portion may be a pneumatic or hydraulic gasket or an open-cell foam rubber. The insulating portion is segmented into a plurality of pieces of the same thickness as the electrodes, insulators and sidewall bars and aligned therewith, the pieces aligned with the insulator being of a different size from the pieces aligned with the electrodes and sidewall bars to create a stepped configuration along the corners of the MHD channel.

  15. Seals at sea: modelling seal distribution in the German bight based on aerial survey data

    NARCIS (Netherlands)

    Herr, H.; Scheidat, M.; Lehnert, K.; Siebert, U.

    2009-01-01

    The Wadden Sea is an important habitat for harbour seals and grey seals. They regularly haul-out on sandbanks and islands along the coast. Comparably little is known about the time seals spend at sea and how they use the remainder of the North Sea. Yet, human activity in offshore waters is increasin

  16. Albinistic common seals (Phoca vitulina) and melanistic grey seals (Halichoerus grypus) rehabilitated in the Netherlands

    NARCIS (Netherlands)

    Osinga, Nynke; 't Hart, Pieter; Vader, Pieter C. van Voorst

    2010-01-01

    The Seal Rehabilitation and Research Centre (SRRC) in Pieterburen, The Netherlands, rehabilitates seals from the waters of the Wadden Sea, North Sea and Southwest Delta area. Incidental observations of albinism and melanism in common and grey seals are known from countries surrounding the North Sea.

  17. Corkscrew Seals: Grey Seal (Halichoerus grypus) Infanticide and Cannibalism May Indicate the Cause of Spiral Lacerations in Seals

    Science.gov (United States)

    2016-01-01

    Large numbers of dead seals with characteristic spiral lesions have been washing ashore around the North Atlantic over the past two decades. Interactions with ship propellers and shark predation have been suggested as the likely causal mechanisms. However, new evidence points towards a more likely candidate: grey seal predation. An adult male grey seal was observed and recorded catching, killing and eating five weaned grey seal pups over a period of one week on the Isle of May, Scotland. A further 9 carcasses found in the same area exhibited similar injuries. Post mortem analysis of lesions indicated the wound characteristics were similar to each other and in 12 of the 14 carcasses analysed, were indistinguishable from carcasses previously attributed to propeller interaction. We therefore propose that most of the seal carcasses displaying spiral lacerations in the UK are caused by grey seal predation. Cases in other locations should be re-evaluated using the scoring system presented here to identify whether grey seal predation is a major cause of mortality in phocid seals. PMID:27254025

  18. Corkscrew Seals: Grey Seal (Halichoerus grypus Infanticide and Cannibalism May Indicate the Cause of Spiral Lacerations in Seals.

    Directory of Open Access Journals (Sweden)

    Andrew Brownlow

    Full Text Available Large numbers of dead seals with characteristic spiral lesions have been washing ashore around the North Atlantic over the past two decades. Interactions with ship propellers and shark predation have been suggested as the likely causal mechanisms. However, new evidence points towards a more likely candidate: grey seal predation. An adult male grey seal was observed and recorded catching, killing and eating five weaned grey seal pups over a period of one week on the Isle of May, Scotland. A further 9 carcasses found in the same area exhibited similar injuries. Post mortem analysis of lesions indicated the wound characteristics were similar to each other and in 12 of the 14 carcasses analysed, were indistinguishable from carcasses previously attributed to propeller interaction. We therefore propose that most of the seal carcasses displaying spiral lacerations in the UK are caused by grey seal predation. Cases in other locations should be re-evaluated using the scoring system presented here to identify whether grey seal predation is a major cause of mortality in phocid seals.

  19. Corkscrew Seals: Grey Seal (Halichoerus grypus) Infanticide and Cannibalism May Indicate the Cause of Spiral Lacerations in Seals.

    Science.gov (United States)

    Brownlow, Andrew; Onoufriou, Joseph; Bishop, Amanda; Davison, Nicholas; Thompson, Dave

    2016-01-01

    Large numbers of dead seals with characteristic spiral lesions have been washing ashore around the North Atlantic over the past two decades. Interactions with ship propellers and shark predation have been suggested as the likely causal mechanisms. However, new evidence points towards a more likely candidate: grey seal predation. An adult male grey seal was observed and recorded catching, killing and eating five weaned grey seal pups over a period of one week on the Isle of May, Scotland. A further 9 carcasses found in the same area exhibited similar injuries. Post mortem analysis of lesions indicated the wound characteristics were similar to each other and in 12 of the 14 carcasses analysed, were indistinguishable from carcasses previously attributed to propeller interaction. We therefore propose that most of the seal carcasses displaying spiral lacerations in the UK are caused by grey seal predation. Cases in other locations should be re-evaluated using the scoring system presented here to identify whether grey seal predation is a major cause of mortality in phocid seals.

  20. Características agronômicas e bromatológicas de híbridos de milho para produção de silagem Agronomic and nutritional characteristics of the corn hybrids for silage production

    Directory of Open Access Journals (Sweden)

    Solidete de Fátima Paziani

    2009-03-01

    Full Text Available Objetivou-se estabelecer correlações entre características quantitativas e qualitativas e avaliar a influência dessas características sobre a produção e a qualidade do milho para silagem. Utilizaram-se dados do Programa de Avaliação de Cultivares de Milho para Silagem IAC/APTA/ESALQ para cálculo das correlações de Pearson entre as variáveis. A produção de matéria seca (MS digestível foi afetada tanto pelas produções de massa e de grãos quanto pelas digestibilidades da planta e do colmo. A produção de matéria seca digestível apresentou os maiores coeficientes de correlação com a produção de MS (0,85; com as produções de grãos na ensilagem (0,60 e na maturidade (0,68; com produção de matéria verde (0,47; e com o índice de espigas (0,48. Os coeficientes de correlação entre a produção de matéria seca digestível e a digestibilidade da planta inteira (0,44 e da fração colmo (0,38 foram inferiores aos obtidos para a produção de matéria seca. A digestibilidade da planta dependeu principalmente da digestibilidade do colmo (0,60 e dos parâmetros relacionados aos grãos. Na ausência de informações específicas sobre os cultivares de milho para silagem, pode-se optar por aqueles de maior produção de grãos à maturidade, em razão da elevada correlação dessa característica com produção de matéria seca e com produção de matéria seca digestível.The objective of this work was to establish correlations between quantitative and qualitative variables and to evaluate their influence on the corn quality for ensilage production. Data from the Corn Hybrids for Silage Evaluation Program were used (IAC/APTA/ESALQ. Pearson correlations between the variables were calculated. The digestible dry matter (DM production was affected not only by forage and grain productions, but also by the whole plant and stem digestibility. The digestible dry matter production presented the highest correlation coefficients with

  1. Beta testing of MTI seal codes

    Science.gov (United States)

    Scharrer, Joseph

    1994-01-01

    An evaluation of MTI seal codes is made by comparing cylindrical air and water seals. Results are presented in viewgraph format and show that: ICYL and GCYL geometry variations are desirable; load and direct stiffness calculations are good; damping and cross-coupled stiffness predictions are poor; added mass coefficients should be calculated; and variation in inlet tangential velocity is critical to design.

  2. Seal Technology in Gas Turbine Engines

    Science.gov (United States)

    1978-08-01

    high speeds; b) the pressure, temperature and flow rate of the sealing and coolant fluid should be in dependently varied; c) various sealing media ...been determined from the geometricA Input data. Tne thermal moments are evaluated by regarding thermal stresses as equivalent to distributed body

  3. Earlier pupping in harbour seals, Phoca vitulina

    NARCIS (Netherlands)

    Reijnders, P.J.H.; Brasseur, S.M.J.M.; Meesters, H.W.G.

    2010-01-01

    The annual reproductive cycle of most seal species is characterized by a tight synchrony of births. Typically, timing of birth shows little inter-annual variation. Here, however we show that harbour seals Phoca vitulina from the Wadden Sea (southeast North Sea) have shortened their yearly cycle, mov

  4. 19 CFR 101.7 - Customs seal.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Customs seal. 101.7 Section 101.7 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY GENERAL PROVISIONS § 101.7 Customs seal. (a) Design. According to the design furnished by the...

  5. Space Environment Effects on Silicone Seal Materials

    Science.gov (United States)

    deGroh, Henry C., III; Daniels, Christopher C.; Dever, Joyce A.; Miller, Sharon K.; Waters, Deborah L.; Finkbeiner, Joshua R.; Dunlap, Patrick H.; Steinetz, Bruce M.

    2010-01-01

    A docking system is being developed by the NASA to support future space missions. It is expected to use redundant elastomer seals to help contain cabin air during dockings between two spacecraft. The sealing surfaces are exposed to the space environment when vehicles are not docked. In space, the seals will be exposed to temperatures between 125 to -75 C, vacuum, atomic oxygen, particle and ultraviolet radiation, and micrometeoroid and orbital debris (MMOD). Silicone rubber is the only class of space flight-qualified elastomeric seal material that functions across the expected temperature range. NASA Glenn has tested three silicone elastomers for such seal applications: two provided by Parker (S0899-50 and S0383-70) and one from Esterline (ELA-SA-401). The effects of atomic oxygen (AO), UV and electron particle radiation, and vacuum on the properties of these three elastomers were examined. Critical seal properties such as leakage, adhesion, and compression set were measured before and after simulated space exposures. The S0899-50 silicone was determined to be inadequate for extended space seal applications due to high adhesion and intolerance to UV, but both S0383-70 and ELA-SA-401 seals were adequate.

  6. Space Environment's Effects on Seal Materials

    Science.gov (United States)

    deGroh, Henry C., III; Daniels, Christopher C.; Dunlap, Patrick; Miller, Sharon; Dever, Joyce; Waters, Deborah; Steinetz, Bruce M.

    2007-01-01

    A Low Impact Docking System (LIDS) is being developed by the NASA Johnson Space Center to support future missions of the Crew Exploration Vehicle (CEV). The LIDS is androgynous, such that each system half is identical, thus any two vehicles or modules with LIDS can be coupled. Since each system half is a replica, the main interface seals must seal against each other instead of a conventional flat metal surface. These sealing surfaces are also expected to be exposed to the space environment when vehicles are not docked. The NASA Glenn Research Center (NASA GRC) is supporting this project by developing the main interface seals for the LIDS and determining the durability of candidate seal materials in the space environment. In space, the seals will be exposed to temperatures of between 50 to 50 C, vacuum, atomic oxygen, particle and ultraviolet radiation, and micrometeoroid and orbital debris (MMOD). NASA GRC is presently engaged in determining the effects of these environments on our candidate elastomers. Since silicone rubber is the only class of seal elastomer that functions across the expected temperature range, NASA GRC is focusing on three silicone elastomers: two provided by Parker Hannifin (S0-899-50 and S0-383-70) and one from Esterline Kirkhill (ELA-SA-401). Our results from compression set, elastomer to elastomer adhesion, and seal leakage tests before and after various simulated space exposures will be presented.

  7. Active Infrared Thermography for Seal Contamination Detection in Heat-Sealed Food Packaging

    Directory of Open Access Journals (Sweden)

    Karlien D’huys

    2016-11-01

    Full Text Available Packaging protects food products from environmental influences, assuring quality and safety throughout shelf life if properly performed. Packaging quality depends on the quality of the packaging material and of the closure or seal. A common problem possibly jeopardizing seal quality is the presence of seal contamination, which can cause a decreased seal strength, an increased packaging failure risk and leak formation. Therefore, early detection and removal of seal contaminated packages from the production chain is crucial. In this work, a pulsed-type active thermography method using the heated seal bars as an excitation source was studied for detecting seal contamination. Thermal image sequences of contaminated seals were recorded shortly after sealing. The detection performances of six thermal image processing methods, based on a single frame, a fit of the cooling profiles, thermal signal reconstruction, pulsed phase thermography, principal component thermography and a matched filter, were compared. High resolution digital images served as a reference to quantify seal contamination, and processed thermal images were mapped to these references. The lowest detection limit (equivalent diameter 0.60 mm was obtained for the method based on a fit of the cooling profiles. Moreover, the detection performance of this method did not depend strongly on the time after sealing at which recording of the thermal images was started, making it a robust and generally applicable method.

  8. Grey seal (Halichoerus grypus) predation on harbour seals (Phoca vitulina) on the island of Helgoland, Germany

    Science.gov (United States)

    van Neer, Abbo; Jensen, Lasse Fast; Siebert, Ursula

    2015-03-01

    The prey spectrum of grey seals has to date been described as largely consisting of different fish, cephalopod and shrimp species. On the German island of Helgoland Düne, where harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) co-occur, a young male grey seal was observed in 2013 and again in 2014 preying upon young harbour seals. A harbour seal carcass with severe traumatic lesions was retrieved and post-mortem examinations were performed. In the following weeks several carcasses showing similar lesions were found. Sightings of grey seals assumed to be preying on harbour porpoises have increased around the North Sea. Increased competition as well as individualised behaviour could explain the increased number of observations, but former cases of abnormal lesions of marine mammals attributed to for example predation by sharks or mechanical processes should be revisited with regard to the emerging knowledge.

  9. [Methods for sealing of corneal perforations].

    Science.gov (United States)

    Samoilă, O; Totu, Lăcrămioara; Călugăru, M

    2012-01-01

    A variety of corneal pathology can lead to corneal ulcers and perforations. A deep corneal ulcer may need surgical treatment to allow good volume restoration and reepithelisation. Corneal perforation must be sealed and when the perforation is large, the task of repairing the defect can be underwhelming. The elegant solution is the corneal transplant, but this is not always readily available, especially in undeveloped countries. We present here two cases with different solutions to seal the perforated cornea: the first one has a large peripheral defect and it is successfully sealed with scleral patch and the second one is central with small perforation and is successfully sealed with multilayered amniotic membrane. Both cases are followed for over 12 months and demonstrate good corneal restoration (both on clinical examination and corneal topography). Sclera and amniotic membrane can be used to seal corneal defects when corneal transplant is not readily available.

  10. Film riding seal assembly for turbomachinery

    Energy Technology Data Exchange (ETDEWEB)

    Bidkar, Rahul Anil; Giametta, Andrew Paul; Gibson, Nathan Evan McCurdy; Cleveland, Nicolas Joseph

    2016-06-07

    An aerodynamic seal assembly for a rotary machine includes multiple sealing segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward load-bearing section and an aft load-bearing section configured to generate an aerodynamic force between the shoe plate and the rotor. The shoe plate includes at least one labyrinth teeth facing the rotor and positioned between the forward load-bearing section and the aft load-bearing section. The sealing segment also includes at least one spring connected to a pedestal located about midway of an axial length of the shoe plate and to a stator interface element. Further, the sealing segment includes a rigid segmented secondary seal attached to the stator interface element at one first end and in contact with the pedestal of the shoe plate at one second end.

  11. A reliable sealing method for microbatteries

    Science.gov (United States)

    Wang, Yuxing; Cartmell, Samuel; Li, Qiuyan; Xiao, Jie; Li, Huidong; Deng, Zhiqun Daniel; Zhang, Ji-Guang

    2017-02-01

    As electronic devices continue to become smaller, their energy sources (i.e., batteries) also need to be smaller. Typically, energy densities of batteries decrease as the battery size decreases due to the relative increase of parasitic weight such as packaging materials. In addition, the sealing methods in conventional batteries are difficult to apply to microbatteries. In this work, we developed a facile sealing method for microbatteries. The method employs a dual-sealing concept: a first rubber barrier temporally confines the organic electrolytes and a second adhesive barrier forms a hermetic seal with the battery case. With this innovative sealing approach, excellent shelf life and operation life of the batteries have been demonstrated. A minimal amount of packing materials is employed resulting in high energy densities.

  12. electroquímica

    Directory of Open Access Journals (Sweden)

    HÉCTOR FABIÁN RESTREPO

    2005-01-01

    Full Text Available En este trabajo se estudió el efecto de la temperatura y la concentración inicial de la anilina sobre la morfología y la conductividad de polianilina obtenida por electropolimerización con voltametría cíclica en soportes de carbón vítreo. La sal de anilina inicial se caracterizó mediante análisis infrarrojo (I.R. La morfología de la polianilina obtenida se analizó por medio de microscopio electrónico (S.E.M., y la conductividad mediante impedancia electroquímica (E.I.S.. Los resultados mostraron un aumento en la velocidad de polimerización y cambios en la morfología del polímero con el aumento de la temperatura y de la concentración del monómero. Los análisis S.E.M. mostraron tres tipos de formaciones poliméricas para los diferentes parámetros de polimerización: lentejuelas, filamentos y gránulos. Los resultados de EIS muestran mayor conductividad y alta capacitancia del polímero a mayores temperaturas y concentraciones.

  13. Radiation Safety of Sealed Radioactive Sources

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, Kathryn H.

    2015-01-01

    Sealed radioactive sources are used in a wide variety of occupational settings and under differing regulatory/licensing structures. The definition of a sealed radioactive source varies between US regulatory authorities and standard-setting organizations. Potential problems with sealed sources cover a range of risks and impacts. The loss of control of high activity sealed sources can result in very high or even fatal doses to members of the public who come in contact with them. Sources that are not adequately sealed, and that fail, can cause spread of contamination and potential intake of radioactive material. There is also the possibility that sealed sources may be (or threatened to be) used for terrorist purposes and disruptive opportunities. Until fairly recently, generally-licensed sealed sources and devices received little, if any, regulatory oversight, and were often forgotten, lost or unaccounted for. Nonetheless, generally licensed devices can contain fairly significant quantities of radioactive material and there is some potential for exposure if a device is treated in a way that it was never designed. Industrial radiographers use and handle high activity and/or high-dose rate sealed sources in the field with a high degree of independence and minimal regulatory oversight. Failure to follow operational procedures and properly handle radiography sources can and has resulted in serious injuries and death. Industrial radiographers have experienced a disproportionately large fraction of incidents that result in unintended exposure to radiation. Sources do not have to contain significant quantities of radioactive material to cause problems in the event of their failure. A loss of integrity can cause the spread of contamination and potential exposure to workers and members of the public. The NCRP has previously provided recommendations on select aspects of sealed source programs. Future efforts to provide recommendations for sealed source programs are discussed.

  14. Does the seal licensing system in Scotland have a negative impact on seal welfare?

    Directory of Open Access Journals (Sweden)

    Laetitia Nunny

    2016-08-01

    Full Text Available This study examined the licensing system that permits seal shooting in Scotland, which was established under Part 6 Conservation of Seals of the Marine (Scotland Act 2010. Four approaches were used: data were collated and analyzed from both the Scottish Government and Scottish Marine Animal Stranding Scheme; a survey was sent to current license holders and informal interviews were conducted with key stakeholder types. Between February 2011 and the end of October 2015, 1229 gray seals and 275 common seals were reported shot under license to the Scottish Government. The numbers of seals reported as shot has reduced year-on-year since the licensing system was put in place. While some license holders, notably fish farms, were using some non-lethal forms of deterrent to reduce seal-related damage, these were often used alongside seal shooting. Of the seals reported as shot to the Scottish Government, only a small percentage were also reported to the Scottish Marine Animal Stranding Scheme, despite this being a licensing requirement. Only 2.3% of the shot gray seals and 4.5% of the shot common seals were necropsied. There is evidence from these necropsies that some seals had not died instantly or had not been shot in the manner recommended by the Scottish Seal Management Code of Practice. These preliminary results show that more carcasses need to be recovered and necropsied if the welfare implications of current seal shooting practice are to be properly assessed. The current legislation does not specify closed seasons to protect breeding seals and thirty-five per cent of necropsied seals were pregnant gray seals. Seals have also been shot during their lactation periods when pups are dependent on their mothers. This raises significant welfare concerns. The re-introduction of closed seasons specific to each species of seal is recommended along with greater effort to deploy non-lethal methods. Independent assessment of the number of seals being killed

  15. Spacecraft/Rover Hybrids for the Exploration of Small Solar System Bodies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The actuation of the hybrids relies on spinning three internal flywheels, which allows all subsystems to be packaged in one sealed enclosure and enables the...

  16. Caracterização morfoanatômica do colmo de híbridos de milho para avaliar a qualidade de silagem - DOI: 10.4025/actascianimsci.v29i3.550 Morphoanatomical characterization of corn hybrids stems, in order to evaluate silage quality - DOI: 10.4025/actascianimsci.v29i3.550

    Directory of Open Access Journals (Sweden)

    Jean-Claude Emile

    2007-12-01

    Full Text Available O objetivo foi avaliar a caracterização morfoanatômica e suas possíveis correlações com a digestibilidade da parede celular e com a lignina de dez híbridos de milho (DK265bm3, DK265, HS5, HS6, HTV2, HTV27, Anjou285, Mexxal, Pistache e Buxxil, plantados no INRA (Unité de Génétique et d’Amélioration dês Plantes Fourragères, Lusignan-França, em parcelas de 150 m². O delineamento utilizado foi inteiramente casualizado com cinco repetições por tratamento. Com exceção ao comprimento do córtex, verificou-se que os híbridos apresentaram diferenças significativas (p bm3 se caracterizou por apresentar menor quantidade de células lignificadas, tanto na região medular quanto na região do córtex, menor porcentagem de parênquima medular e maior porcentagem do córtex em relação aos demais híbridos. Porém, o híbrido DK265bm3 não diferiu dos demais quanto à superfície do feixe vascular e espessura da parede celular do feixe vascular. Por meio de análises de correlação, verificou-se correlação positiva entre os teores de lignina klason e lignina em detergente ácido com as quantidades de células lignificadas no parênquima e córtex. A DIVFDN apresentou correlação negativa com a proporção de células lignificadas no parênquima medular e células lignificadas no córtex.The objective was to evaluate morphoanatomical characteristics and possible correlations with cell wall digestibility and with lignin of ten corn hybrids (DK265bm3, DK265, HS5, HS6, HTV2, HTV27, Anjou285, Mexxal, Pistachio and Buxxil planted at INRA (Unité of Génétique Amélioration des Plant Fourragères, Lusignan, France in 150 m² areas. A completely randomized experimental design with five replications was used. With exception for cortical length, significant differences were verified as for the evaluated morphoanatomical aspects, with hybrid DK265bm3 being characterized by lower counts of lignified cells in the medullar parenchyma and

  17. Ocean climate and seal condition

    Directory of Open Access Journals (Sweden)

    Crocker Daniel E

    2005-03-01

    Full Text Available Abstract Background The condition of many marine mammals varies with fluctuations in productivity and food supply in the ocean basin where they forage. Prey is impacted by physical environmental variables such as cyclic warming trends. The weaning weight of northern elephant seal pups, Mirounga angustirostris, being closely linked to maternal condition, indirectly reflects prey availability and foraging success of pregnant females in deep waters of the northeastern Pacific. The aim of this study was to examine the effect of ocean climate on foraging success in this deep-diving marine mammal over the course of three decades, using cohort weaning weight as the principal metric of successful resource accrual. Results The mean annual weaning weight of pups declined from 1975 to the late 1990s, a period characterized by a large-scale, basin-wide warm decadal regime that included multiple strong or long-duration El Niños; and increased with a return to a cool decadal regime from about 1999 to 2004. Increased foraging effort and decreased mass gain of adult females, indicative of reduced foraging success and nutritional stress, were associated with high ocean temperatures. Conclusion Despite ranging widely and foraging deeply in cold waters beyond coastal thermoclines in the northeastern Pacific, elephant seals are impacted significantly by ocean thermal dynamics. Ocean warming redistributes prey decreasing foraging success of females, which in turn leads to lower weaning mass of pups. Annual fluctuations in weaning mass, in turn, reflect the foraging success of females during the year prior to giving birth and signals changes in ocean temperature cycles.

  18. Tamper-indicating quantum optical seals

    Energy Technology Data Exchange (ETDEWEB)

    Humble, Travis S [ORNL; Williams, Brian P [ORNL

    2015-01-01

    Confidence in the means for identifying when tampering occurs is critical for containment and surveillance technologies. Fiber-optic seals have proven especially useful for actively surveying large areas or inventories due to the extended transmission range and flexible layout of fiber. However, it is reasonable to suspect that an intruder could tamper with a fiber-optic sensor by accurately replicating the light transmitted through the fiber. In this contribution, we demonstrate a novel approach to using fiber-optic seals for safeguarding large-scale inventories with increased confidence in the state of the seal. Our approach is based on the use of quantum mechanical phenomena to offer unprecedented surety in the authentication of the seal state. In particular, we show how quantum entangled photons can be used to monitor the integrity of a fiber-optic cable - the entangled photons serve as active sensing elements whose non-local correlations indicate normal seal operation. Moreover, we prove using the quantum no-cloning theorem that attacks against the quantum seal necessarily disturb its state and that these disturbances are immediately detected. Our quantum approach to seal authentication is based on physical principles alone and does not require the use of secret or proprietary information to ensure proper operation. We demonstrate an implementation of the quantum seal using a pair of entangled photons and we summarize our experimental results including the probability of detecting intrusions and the overall stability of the system design. We conclude by discussing the use of both free-space and fiber-based quantum seals for surveying large areas and inventories.

  19. Floating air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Todd A

    2016-08-16

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber formed in the stator, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, where the axial moveable annular piston includes an inlet scoop on a side opposite to the annular cavity that scoops up the swirling cooling air and directs the cooling air to the annular cavity to form an air cushion with the seal surface of the rotor.

  20. Compliant Glass Seals for SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Y. S.; Choi, Jung-Pyung; Xu, Wei; Stephens, Elizabeth V.; Koeppel, Brian J.; Stevenson, Jeffry W.; Lara-Curzio, Edgar

    2014-04-01

    This report summarizes results from experimental and modeling studies performed by participants in the Solid-State Energy Conversion Alliance (SECA) Core Technology Program, which indicate that compliant glass-based seals offer a number of potential advantages over conventional seals based on de-vitrifying glasses, including reduced stresses during stack operation and thermal cycling, and the ability to heal micro-damage induced during thermal cycling. The properties and composition of glasses developed and/or investigated in these studies are reported, along with results from long-term (up to 5,800h) evaluations of seals based on a compliant glass containing ceramic particles or ceramic fibers.

  1. Compliant Glass Seals for SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong -Shyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Choi, Jung-Pyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephens, Elizabeth V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Koeppel, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stevenson, Jeffry W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lara-Curzio, Edgar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-04-30

    This report summarizes results from experimental and modeling studies performed by participants in the Solid-State Energy Conversion Alliance (SECA) Core Technology Program, which indicate that compliant glass-based seals offer a number of potential advantages over conventional seals based on de-vitrifying glasses, including reduced stresses during stack operation and thermal cycling, and the ability to heal micro-damage induced during thermal cycling. The properties and composition of glasses developed and/or investigated in these studies are reported, along with results from long-term (up to 5,800h) evaluations of seals based on a compliant glass containing ceramic particles or ceramic fibers.

  2. Vacuum-sealed casting process under pressure

    Institute of Scientific and Technical Information of China (English)

    LI Chen-xi; GUO Tai-ming; WU Chun-jing; WANG Hong

    2006-01-01

    A new casting method, the vacuum-sealed mold casting under pressure, has been developed, and thin wall iron castings with high precision and smooth surface have been produced successfully with this casting method. The experimental results show that the liquid iron has a very excellent filling ability because a high negative pressure is formed in the mold cavity during filling process. The vacuum-sealed mold under pressure has very high compressive strength greater than 650 kPa, which is 3-4 times as high as that of the molds produced by high-pressure molding process or vacuum-sealed molding process.

  3. Composição química, digestibilidade e cinética de degradação ruminal das silagens de híbridos de girassol em diferentes épocas de semeadura Effects of sowing dates on chemical composition, digestibility and ruminal degradation kinetics of silages from sunflower hybrids

    Directory of Open Access Journals (Sweden)

    Renius Mello

    2006-08-01

    Full Text Available Objetivou-se estimar o valor nutritivo das silagens de quatro híbridos de girassol - Rumbosol-91 (forrageiro, M-734 (duplo-propósito, C-11 (duplo-propósito e BRS-191 (granífero - semeados em três épocas: outubro (antecipada, novembro (normal e dezembro (tardia - por meio de análises químicas, da digestibilidade e da cinética de degradação ruminal. O delineamento experimental foi em blocos ao acaso, com arranjo fatorial 4 x 3 (quatro híbridos x três épocas de semeadura e três repetições. Os teores de MS variaram de 23,2 a 43,0%; o pH, de 4,0 a 5,1; e o N-NH3%/NT, de 5,3 a 16,8%. Os teores de CZ oscilaram de 6,8 a 8,8% e aumentaram da semeadura em outubro para dezembro. O Rumbosol-91 apresentou teores menores de EE e maiores de N na parede celular, de N indisponível e de carboidratos totais (CHOT. Os teores de PB aumentaram e os de CHOT diminuíram de outubro para dezembro. A semeadura de novembro e o C-11 apresentaram menores teores de FDN, FDNcp e FDA. O C-11 semeado em novembro apresentou menor teor de LDA. A semeadura de outubro e o Rumbosol-91 tiveram maior proporção de LDA%/FDN. O Rumbosol-91 apresentou maior DIVMS e DIVFDN. A semeadura de novembro e os híbridos C-11 e M-734 apresentaram maior teor de NDT. O desaparecimento da MS pode ser representado por um único perfil de degradação. A proporção de FDN indegradável (I aumentou da semeadura em outubro para dezembro, com maiores valores para o BRS-191 semeado em dezembro. A extensão (Vf1 e a taxa (k1 de degradação da fração solúvel de rápida digestão diminuíram da semeadura em outubro para dezembro, com maiores valores para o Rumbosol-91 semeado em outubro. A relação entre análise química, digestibilidade, NDT e cinética de degradação ruminal foi melhor para os híbridos M-734 e C-11 semeados em novembro.The objective of this trial was to estimate chemical composition, digestibility and ruminal degradation kinetics of silages from four sunflower

  4. Effect of bar sealing parameters on OPP/MCPP heat seal strength

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available The effect of bar sealing parameters on the heat seal strength of oriented polypropylene (OPP/metallic cast polypropylene (MCPP laminate film was investigated. Based on the results obtained from the parametric study, a bar sealing process window was developed. All points drop within the process window are combinations of platen temperature and dwell time that produce acceptable heat seal. Optimum combinations are indicated by the lower border of the window. The plateau initiation temperature, Tpi of OPP/MCPP laminate film used in the present study occurred before the final melting temperature, Tmf of the sealant material. The highest achievable heat seal strength was at the plateau region, and the corresponding failure modes were delaminating, tearing or combine failure modes (delaminating and tearing. Minimum pressure level of 1.25 bars is necessary to bring the laminate interface into intimate contact in order to effect sealing.

  5. Investigating the sealing capacity of a seal system in rock salt (DOPAS project)

    Energy Technology Data Exchange (ETDEWEB)

    Jantschik, Kyra; Moog, Helge C.; Czaikowski, Oliver; Wieczorek, Klaus [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Braunschweig (Germany)

    2016-11-15

    This paper describes research and development work on plugging and sealing repositories, an issue of fundamental importance for the rock salt option which represents one of the three European repository options, besides the clay rock and the crystalline rock options. The programme aims at providing experimental data needed for the theoretical analysis of the long-term sealing capacity of concrete- based sealing materials. In order to demonstrate hydro-mechanical material stability under representative load scenarios, a comprehensive laboratory testing programme is carried out. This comprises investigation of the sealing capacity of the combined seal system and impact of the so-called excavation-damaged zones (EDZ) as well as investigation of the hydro-chemical long-term stability of the seal in contact with different brines under diffusive and advective conditions. This paper presents experimental approaches and preliminary results from laboratory investigations on salt concrete and combined systems as obtained to date.

  6. Finite Element Analysis of Elastomeric Seals for LIDS

    Science.gov (United States)

    Oswald, Jay J.; Daniels, Christopher C.

    2007-01-01

    Objective: Create a means of evaluating seals w/o prototypes. Motivation: Cost Prototype 54" seal approx.$100k per seal pair FEA license + high end workstation approx. $30k per year. Development time: 6 months lead time for a new seal design Many designs per day (solution time <1 minute) Understanding: Difficult to experimentally measure strains, contact pressure profile, stresses, displacements

  7. Properties of Sealing Materials in Groundwater Wells

    DEFF Research Database (Denmark)

    Köser, Claus

    on the maximum swelling pressure; i) the bulk density of the sample, and ii) whether the sample is sorted or unsorted. CT scans (Computed Tomography) have been used to evaluate certain properties of bentonite seals in a limited volume. In this context, a set of algorithms to convert CT numbers (HU unit......) into densities for clay/water systems has been developed. This method has successfully been used to evaluate e.g., macroporosity, homogenization of the bentonite seal during the hydration of water, hydraulic conductivity and the creation of channels in the bentonite seals. Based on the results obtained...... in this Ph.D. thesis, a number of recommendations has been offered; i) a change regarding the production of pellets and ii) how sealing material must be treated in the actual construction of groundwater wells....

  8. Epoxy resins used to seal brachytherapy seed

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos, E-mail: nccf@cdtn.br, E-mail: ferrazw@cdtn.br, E-mail: reissc@cdtn.br, E-mail: amms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, BH (Brazil)

    2013-07-01

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  9. HMSRP Hawaiian Monk Seal Photo Identification Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This photo collection contains identification and other images and video of Hawaiian monk seals taken by PSD personnel and cooperating scientists as part of the...

  10. HMSRP Hawaiian Monk Seal Tag Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records for all tags applied to Hawaiian monk seals since 1981. These tags were applied by PSD personnel and cooperating scientists as part of...

  11. HMSRP Hawaiian Monk Seal Necropsy Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains information on Hawaiian monk seal gross necropsy (in some cases only field notes or minimal information) and histopathology results beginning...

  12. HMSRP Hawaiian Monk Seals on Social Media

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — As social media platforms develop, they potentially provide valuable information for wildlife researchers and managers. NOAA’s Hawaiian Monk Seal Research Program...

  13. HMSRP Hawaiian Monk Seal Survey Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records of Hawaiian monk seal and green turtle sightings in the Northwestern Hawaiian Islands (NWHI) since 1982 at Lisianski Island, and since...

  14. HMSRP Hawaiian Monk Seal Survival Factors

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records of survival factors recorded by PSD personnel and cooperating scientists as part of the ongoing monk seal population assessment...

  15. Improved Gas Seal for Electrolytic Cells

    Science.gov (United States)

    Richter, R.

    1984-01-01

    Breakage by differential thermal expansion reduced. Cells for hot electrolysis of gases improved by design that reduces vulnerability of gas seals to breakage at operating temperature of about 1000 degrees C.

  16. HMSRP Hawaiian Monk Seal Fisheries Interactions data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set contains records of all documented hookings and/or entanglements of Hawaiian monk seals with actively fished gear, both commercial and recreational. The...

  17. Contamination and potential impacts to monk seals

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — There are six main Hawaiian monk seal breeding colonies (French Frigate Shoals, Kure Atoll, Laysan Island, Lisianski Island, Pearl and Hermes Reef and Midway Atoll)...

  18. HMSRP Hawaiian Monk Seal Microsatellite Genotypes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Currently ~2,400 Hawaiian monk seal specimens have been analyzed genetically, providing genotypes at 18 microsatellite loci. These data are organized by individual,...

  19. Reactor coolant pump shaft seal stability during station blackout

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, D B; Hill, R C; Wensel, R G

    1987-05-01

    Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries.

  20. Departamento de química

    OpenAIRE

    Universidad Nacional, colombia

    2010-01-01

    Reseña histórica del Departamento. Profesorado. Laboratorios. Sumarios de los programas de los cursos: Química General, Química Biológica, Mineralogía y Geología, Laboratorio de Aguas, Química I y II, Química Orgánica, Química Analítica Cualitativa. Pénsum de los estudios de Ciencias Químicas. Distribución general de materias y de las Facultades a que corresponden.

  1. Mineral resource of the month: mica

    Science.gov (United States)

    Hedrick, J.B.

    2008-01-01

    Humans have been using mica for millennia. Mica was first mined in India about 4,000 years ago, where it was used primarily in medicines, and some Hindu physicians still incorporate biotite mica into medicines today. Early civilizations also used mica for decorations, as windows and as surfaces on which to draw or paint. Maya temples were decorated with mica pigments, which were incorporated into the stucco to make it sparkle in the sun. In North America, ancient inhabitants adorned gravesites and burial mounds with animal figures made of mica.

  2. Troubleshooting ProSeal LMA

    Directory of Open Access Journals (Sweden)

    Bimla Sharma

    2009-01-01

    Full Text Available Supraglottic devices have changed the face of the airway management. These devices have contributed in a big way in airway management especially, in the difficult airway scenario significantly decreasing the pharyngolaryngeal morbidity. There is a plethora of these devices, which has been well matched by their wider acceptance in clinical practice. ProSeal laryngeal mask airway (PLMA is one such frequently used device employed for spontaneous as well as controlled ventilation. However, the use of PLMAat tunes maybe associated with certain problems. Some of the problems related with its use are unique while others are akin to the classic laryngeal mask airway (eLMA. However, expertise is needed for its safe and judicious use, correct placement, recognition and management of its various malpositions and complications. The present article describes the tests employed for proper confirmation of placementto assess the ventilatooy and the drain tube functions of the mask, diagnosis of various malpositions and the management of these aspects. All these areas have been highlighted under the heading of troubleshooting PLMA. Many problems can be solved by proper patient and procedure selection, maintaining adequate depth of anaesthesia, diagnosis and management of malpositions. Proper fixation of the device and monitoring cuff pressure intraopera-tively may bring down the incidence of airway morbidity.

  3. Aerodynamical sealing by air curtains

    Science.gov (United States)

    Frank, Daria; Linden, Paul

    2015-11-01

    Air curtains are artificial high-velocity plane turbulent jets which are installed in a doorway in order to reduce the heat and the mass exchange between two environments. The performance of an air curtain is assessed in terms of the sealing effectiveness E, the fraction of the exchange flow prevented by the air curtain compared to the open-door situation. The main controlling parameter for air curtain dynamics is the deflection modulus Dm representing the ratio of the momentum flux of the air curtain and the transverse forces acting on it due to the stack effect. In this talk, we examine the influence of two factors on the performance of an air curtain: the presence of an additional ventilation pathway in the room, such as a small top opening, and the effects of an opposing buoyancy force which for example arises if a downwards blowing air curtain is heated. Small-scale experiments were conducted to investigate the E (Dm) -curve of an air curtain in both situations. We present both experimental results and theoretical explanations for our observations. We also briefly illustrate how simplified models developed for air curtains can be used for more complex phenomena such as the effects of wind blowing around a model building on the ventilation rates through the openings.

  4. Inteligencia económica

    Directory of Open Access Journals (Sweden)

    José Ricardo Hernández Gómez

    2011-07-01

    Full Text Available La inteligencia económica y la contrainteligencia económica deben considerarse como funciones propias y exclusivas del Estado, provienen directamente de las ciencias tanto formales como empíricas y de todos los componentes que se les derivan, convirtiéndola en una sistémica congruenciade disciplinas científicas que procuran interpretar las realidades de los actores, factores, fenómenos y escenarios de contenido económico. Sus competencias y relaciones con los factores de desarrollo, la hacen necesaria para garantizar la pervivencia del Estado, el cumplimiento de sus fines esenciales y la realización consecuente de los Objetivos y fines Nacionales. Además de relacionarse con otras ciencias, sus estructuras teleológicas, fenomenológicas y deontológicas, le señalan unas dimensiones que circunscriben su objeto y su alcance.

  5. Repairing sealing surfaces on aluminum castings

    Science.gov (United States)

    Hanna, T. L.

    1980-01-01

    Approach using stylus nickel plating instead of copper and cadmium plating has simplified repair procedure. Damaged sealing surfaces are stylus nickelplated in one step. Superficial scratches and porous areas are removed more easily from repaired surface by simply lapping sealing areas to required finish. Although method is aimed for aerospace components, it may be easily incorporated into conventional aluminumcasting technology. One-step repair can be considered for cast-aluminum automobile and aircraft engines to reduce time and costs.

  6. Design, construction and testing of underground seals

    CSIR Research Space (South Africa)

    Cook, AP

    2000-01-01

    Full Text Available extend into the workings and there cause bodily harm. If this does not happen it is still possible for the atmospheric by-products of the explosion, like lethal carbon monoxide, to filter into the workings through damaged seals. The most practical.... FOSROC. Installation guideline for Fosroc tekseal permanent ventilation seals, Company brochure. Foster-Miller Associates Inc. 1975. Design of reusable explosion proof bulkheads for a cross cut refuge chamber. USBM Contract Report H0133050, Pittsburgh...

  7. The Advantage of Sensor Sealing Laser Welding

    Institute of Scientific and Technical Information of China (English)

    YAN Yezhi; XU yu

    2007-01-01

    @@ Laser Welding Inevitably Applied in Sen sor Production Certain kinds of sensors such as pressure sensor,temperature sensor, optic-electronic sensor etc. utilize welding seal according to different application environment. With precision components and IC which is isolated by inert gas inside, these sensors should be sealed and able to resist the pressure. So the welding process must avoid distortion and harm to the components and IC.

  8. Anodizing And Sealing Aluminum In Nonchromated Solutions

    Science.gov (United States)

    Emmons, John R.; Kallenborn, Kelli J.

    1995-01-01

    Improved process for anodizing and sealing aluminum involves use of 5 volume percent sulfuric acid in water as anodizing solution, and 1.5 to 2.0 volume percent nickel acetate in water as sealing solution. Replaces process in which sulfuric acid used at concentrations of 10 to 20 percent. Improved process yields thinner coats offering resistance to corrosion, fatigue life, and alloy-to-alloy consistency equal to or superior to those of anodized coats produced with chromated solutions.

  9. Some Aspects of Sealed Nickel Cadmium Cells

    Directory of Open Access Journals (Sweden)

    P. K. Saha

    1967-11-01

    Full Text Available Sealed Nickel Cadmium Cell system is termed till today as the most reliable power pack for electronic apparatus specially in low temperature use. This paper brings out the development and production of sealed nickel cadmium cells of pocket plate construction. The author who has gained experience in production of Ni-Cd cells in East Germany discusses also the major problems faced by the battery manufactures of to-day.

  10. Application study of magnetic fluid seal in hydraulic turbine

    Science.gov (United States)

    Yu, Z. Y.; Zhang, W.

    2012-11-01

    The waterpower resources of our country are abundant, and the hydroelectric power is developed, but at present the main shaft sealing device of hydraulic turbine is easy to wear and tear and the leakage is great. The magnetic fluid seal has the advantages of no contact, no wear, self-healing, long life and so on. In this paper, the magnetic fluid seal would be used in the main shaft of hydraulic turbine, the sealing structure was built the model, meshed the geometry, applied loads and solved by using MULTIPHYSICS in ANSYS software, the influence of the various sealing structural parameters such as tooth width, height, slot width, sealing gap on the sealing property were analyzed, the magnetic fluid sealing device suitable for large-diameter shaft and sealing water was designed, the sealing problem of the hydraulic turbine main shaft was solved effectively which will bring huge economic benefits.

  11. Emergency sacrificial sealing method in filters, equipment, or systems

    Science.gov (United States)

    Brown, Erik P

    2014-09-30

    A system seals a filter or equipment component to a base and will continue to seal the filter or equipment component to the base in the event of hot air or fire. The system includes a first sealing material between the filter or equipment component and the base; and a second sealing material between the filter or equipment component and the base and proximate the first sealing material. The first sealing material and the second seal material are positioned relative to each other and relative to the filter or equipment component and the base to seal the filter or equipment component to the base and upon the event of fire the second sealing material will be activated and expand to continue to seal the filter or equipment component to the base in the event of hot air or fire.

  12. Emergency sacrificial sealing method in filters, equipment, or systems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Erik P.

    2017-02-28

    A system seals a filter or equipment component to abase and will continue to seal the filter or equipment component to the base in the event of hot air or fire. The system includes a first sealing material between the filter or equipment component and the base; and a second sealing material between the filter or equipment component and the base and proximate the first sealing material. The first sealing material and the second seal material are positioned relative to each other and relative to the filter or equipment component and the base to seal the filter or equipment component to the base and upon the event of fire the second sealing material will be activated and expand to continue to seal the filter or equipment component to the base in the event of hot air or fire.

  13. Predicting edge seal performance from accelerated testing

    Science.gov (United States)

    Hardikar, Kedar; Vitkavage, Dan; Saproo, Ajay; Krajewski, Todd

    2014-10-01

    Degradation in performance of a PV module attributable to moisture ingress has received significant attention in PV reliability research. Assessment of field performance of PV modules against moisture ingress through product-level testing in temperature-humidity control chambers poses challenges. Development of a meaningful acceleration factor model is challenging due to different rates of degradation of components embedded in a PV module, when exposed to moisture. Test results are typically a convolution of moisture barrier performance of the edge seal and degradation of laminated components when exposed to moisture. It is desirable to have an alternate method by which moisture barrier performance of the edge seal in its end product form can be assessed in any given field conditions, independent of particular cell design. In this work, a relatively inexpensive test technique was developed to test the edge seal in its end product form in a manner that is decoupled from other components of the PV module. A theoretical framework was developed to assess moisture barrier performance of edge seal with desiccants subjected to different conditions. This framework enables the analysis of test results from accelerated tests and prediction of the field performance of the edge seal. Results from this study lead to the conclusion that the edge seal on certain Miasole glass-glass modules studied is effective for the most aggressive weather conditions examined, beyond the intended service.

  14. Adhesive sealing of the pulp chamber.

    Science.gov (United States)

    Belli, S; Zhang, Y; Pereira, P N; Pashley, D H

    2001-08-01

    The purpose of this in vitro study was to evaluate quantitatively the ability of four different filling materials to seal the orifices of root canals as a secondary seal after root canal therapy. Forty extracted human molar teeth were used. The top of pulp chambers and distal halves of the roots were removed using an Isomet saw. The canal orifices were temporarily sealed with a gutta-percha master cone without sealer. The pulp chambers were then treated with a self-etching primer adhesive system (Clearfil SE Bond), a wet bonding system (One-Step), a 4-methacryloyloxyethyl trimellitate anhydride adhesive system (C&B Metabond), or a reinforced zinc oxide-eugenol (IRM). The specimens were randomly divided into four groups of 10 each. A fluid filtration method was used for quantitative evaluation of leakage. Measurements of fluid movement were made at 2-min intervals for 8 min. The quality of the seal of each specimen was measured by fluid filtration immediately and after 1 day, 1 wk, and 1 month. Even after 1 month the resins showed an excellent seal. Zinc oxide-eugenol had significantly more leakage when compared with the resin systems (p < 0.05). Adhesive resins should be considered as a secondary seal to prevent intraorifice microleakage.

  15. Hybrid Baryons

    CERN Document Server

    Page, P R

    2003-01-01

    We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.

  16. Esclerosis sistémica

    OpenAIRE

    Méndez Rodriguez, Alexis

    2013-01-01

    La esclerosis sistémica es una conectivopatía crónica, multisistémica, con un amplio espectro de manifestaciones clínicas y cuya morbimortalidadestá determinada por el grado de compromiso visceral. La patogenia es desconocida, pero se plantea una interacción entre factores genéticospredisponentes y desencadenantes ambientales.Su presentación clínica más frecuente es la conocida como Síndrome de CREST, acrónimo de calcinosis, fenómeno de Raynaud, trastornode motilidad esofágica, esclerodactili...

  17. Self-balancing air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Jacob A.

    2017-08-15

    A turbine of a gas turbine engine has an air riding seal that forms a seal between a rotor and a stator of the turbine, the air riding seal including an annular piston movable in an axial direction under the influence of a pressure on one side with a pressure acting on an opposite side that self-balances the air riding seal during the steady state condition of the engine and lifts off the seal during engine transients.

  18. Sealing device and method for sealing fractures or leaks in wall or formation surrounding tube-shaped channel

    DEFF Research Database (Denmark)

    2014-01-01

    (11) arranged between the second annular flow barrier (8) and a third annular flow barrier (12) and including a sealing fluid activation device (13) adapted to at least initiate or accelerate curing of the sealing fluid (17). In operation, the elongated body may be displaced along the tube......-shaped channel until the sealing fluid activation section is placed at a position where sealing fluid has been ejected by the sealing fluid placement section, and the sealing fluid activation device may be activated. Thereby, sealing fluid may be cured at selected locations along the tube-shaped channel after...

  19. INDUSTRIAL YIELD AND CHEMICAL COMPOSITION OF HIGH QUALITY PROTEIN MAIZE AS COMPARED TO COMMERCIAL HYBRIDS RENDIMENTO INDUSTRIAL E COMPOSIÇÃO QUÍMICA DE MILHO DE ALTA QUALIDADE PROTÉICA EM RELAÇÃO A HÍBRIDOS COMERCIAIS

    Directory of Open Access Journals (Sweden)

    Luciana de Oliveira Froes

    2009-09-01

    Full Text Available

    The hardness of corn endosperm is an essential attribute for farmers and industries that use this cereal as a raw material. However, Quality Protein Maize (QPM presents alterations in the grain texture, which hinder its commercial use. This study evaluated the industrial yield in the kernel degerming and endosperm fractionation, and chemical composition of a QPM variety, regarding commercial common corn hybrids. QPM and common corn genotypes were processed using the dry degerming method, and the resulting yield was expressed as the ratio of the weight of fractions obtained to the initial weight of the whole corn. Compared to commercial corn hybrids, QPM presented lower endosperm yield, higher germ and fine fraction (< 0.425 mm yield and the same hominy yield in endosperm fractionation. QPM showed similar protein, lipid, and ash levels and higher levels of dietary fiber and iron in the germ, when compared to common corn hybrids. QPM and its fractions have potential as a nutritious raw material for use by the food industry.

    KEY-WORDS: QPM corn; corn germ; degermed corn yield; corn chemical composition; corn nutrients.

  20. DEVELOPMENT OF A CERAMIC TAMPER INDICATING SEAL: SRNL CONTRIBUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Krementz, D.; Brinkman, K.; Martinez-Rodriguez, M.; Mendez-Torres, A.; Weeks, G.

    2013-06-03

    Savannah River National Laboratory (SRNL) and Sandia National Laboratories (SNL) are collaborating on development of a Ceramic Seal, also sometimes designated the Intrinsically Tamper Indicating Ceramic Seal (ITICS), which is a tamper indicating seal for international safeguards applications. The Ceramic Seal is designed to be a replacement for metal loop seals that are currently used by the IAEA and other safeguards organizations. The Ceramic Seal has numerous features that enhance the security of the seal, including a frangible ceramic body, protective and tamper indicating coatings, an intrinsic unique identifier using Laser Surface Authentication, electronics incorporated into the seal that provide cryptographic seal authentication, and user-friendly seal wire capture. A second generation prototype of the seal is currently under development whose seal body is of Low Temperature Co-fired Ceramic (LTCC) construction. SRNL has developed the mechanical design of the seal in an iterative process incorporating comments from the SNL vulnerability review team. SRNL is developing fluorescent tamper indicating coatings, with recent development focusing on optimizing the durability of the coatings and working with a vendor to develop a method to apply coatings on a 3-D surface. SRNL performed a study on the effects of radiation on the electronics of the seal and possible radiation shielding techniques to minimize the effects. SRNL is also investigating implementation of Laser Surface Authentication (LSA) as a means of unique identification of each seal and the effects of the surface coatings on the LSA signature.

  1. Heartworm (Acanthocheilonema spirocauda) and seal louse (Echinophthirius horridus) infections in harbour seals (Phoca vitulina) from the North and Baltic Seas

    Science.gov (United States)

    Lehnert, Kristina; Schwanke, Eva; Hahn, Kerstin; Wohlsein, Peter; Siebert, Ursula

    2016-07-01

    The seal louse (Echinophthirius [E.] horridus) and the heartworm (Acanthocheilonema [A.] spirocauda) are parasites of harbour seal (Phoca vitulina). Little is known about the role of the seal louse as a potential vector and its role for the development and transmission of heartworm larvae to their final host, the harbour seal. The life-cycle of the heartworm is still not fully understood. For the presented study, findings of 1191 stranded harbour seals collected along the North- and Baltic Sea coast between 1996 and 2013 were examined. 4.4% (n = 53) of these harbour seals were infected with adult heartworms and 3.4% (n = 40) harbour seals carried seal lice. The highest prevalence and level of infection with adult heartworms (A. spirocauda) (9.3%) and seal lice (E. horridus) (8.9%) were found on yearling harbour seals (7-18 months) compared to neonate and adult seals. Investigating seal lice (n = 35) for larval heartworm stages one larvae was encountered in an ethanol-fixated seal louse. During a health monitoring survey of live harbour seals, 109 animals were captured and examined during spring and autumn between 2008 and 2014. Blood samples were taken and microfilariae were discovered in blood smears in 41% (n = 45) of the examined harbour seals. Yearling seals (n = 21) showed higher prevalence (86%) and level of infection with microfilariae than adults. Microfilariae were identified as A. spirocauda by sequencing the species-specific COI gene in 24 blood samples. The high prevalence of microfilariae of A. spirocauda in blood samples (41%) is in contrast to the low prevalence of mature infections/adult specimens in stranded seals (4.4%) investigated. Although rare parasites of seals, the recent increase in prevalence of heartworm and seal lice in stranded seals and the relatively high occurrence of microfilaria in the free-ranging population underscore the importance of further studies investigating the immunology of infections and their transmission pathways, as

  2. MEDICINA GENÓMICA

    Directory of Open Access Journals (Sweden)

    Ignacio Briceño Balcázar

    2011-03-01

    reporte de ancestría con el objeto de interpretar los resultados de acuerdo con la etnia de origen. Esta conducta es por ahora la más adecuada considerando que pasará mucho tiempo antes de que se pueda realizar estudios de validación.Como todos los grandes avances de la medicina, la genómica abre un camino que traerá inmensos beneficios mientras se consideren los criterios de la buena práctica médica.

  3. Effects of rejuvenator seal and fog seal on performance of open-graded friction course pavement

    Directory of Open Access Journals (Sweden)

    Nadeem A. Qureshi

    2013-05-01

    Full Text Available An open-graded friction course (OGFC is a special-purpose surface layer of hot-mix asphalt (HMA pavement that is increasingly being used around the world. Owing to its numerous benefits, OGFC is being regularly used as a final riding surface on interstate and high-traffic expressways by different highway agencies in the United States. However, some OGFC sections have experienced premature failure due to ravelling only after 6-8 years of service life. To maintain an effective, longer service life and enhanced performance of OGFC, preventive maintenance has been considered essential. There are several approaches to maintaining OGFC, one of which is the application of a fog seal and rejuvenator seal. A fog seal can reduce ravelling and extend the service life of OGFC while a rejuvenator seal can revitalise the existing aged asphalt binder in the top OGFC layer. This research focuses on optimising the fog and rejuvenator seal application rates by evaluating their effectiveness in terms of surface friction and durability. Three types of seal material were evaluated: Pavegaard (PG and Pavepreserve (PP asphalt rejuvenators and a cationic slow-setting asphalt emulsion (CSS-1H as a fog seal. Improvement in abrasion resistance of OGFC pavement was observed on application of fog and rejuvenator seals but surface friction was reduced to some extent. Hamburg test clearly shows a trend that the medium application rate of 0.10 gallon/square yard is better in enhancing resistance to rutting/moisture susceptibility of OGFC.

  4. Development of sprayed ceramic seal systems for turbine gas path sealing

    Science.gov (United States)

    Bill, R. C.; Shiembob, L. T.; Stewart, O. L.

    1978-01-01

    A ceramic seal system is reported that employs plasma-sprayed graded metal/ceramic yttria stabilized zirconium oxide (YSZ). The performance characteristics of several YSZ configurations were determined through rig testing for thermal shock resistance, abradability, and erosion resistance. Results indicate that this type of sealing system offers the potential to meet operating requirements of future gas turbine engines.

  5. Development of a Whole Container Seal

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Michael J [ORNL; Pickett, Chris A [ORNL; Stinson, Brad J [ORNL; Rowe, Nathan C [ORNL

    2014-01-01

    This paper outlines a technique for utilizing electrically conductive textiles as a whole container seal. This method has the potential to provide more robustness for ensuring that the container has not been breached versus conventional sealing methods that only provide tamper indication at the area used for normal access. The conductive textile is used as a distributed sensor for detecting and localizing container tamper or breach. For sealing purposes, the conductive fabric represents a bounded, near-infinite grid of resistors. The well-known infinite resistance grid problem was used to model and confirm the expected accuracy and validity of this approach. An experimental setup was built that uses a multiplexed Wheatstone bridge measurement to determine the resistances of a coarse electrode grid across the conductive fabric. Non-uniform resistance values of the grid infer the presence of damage or tears in the fabric. Results suggest accuracy proportional to the electrode spacing in determining the presence and location of disturbances in conductive fabric samples. Current work is focused on constructing experimental prototypes for field and environmental testing to gauge the performance of these whole container seals in real world conditions. We are also developing software and hardware to interface with the whole container seals. The latest prototypes are expected to provide more accuracy in detecting and localizing events, although detection of a penetration should be adequate for most sealing applications. We are also developing smart sensing nodes that integrate digital hardware and additional sensors (e.g., motion, humidity) into the electrode nodes within the whole container seal.

  6. Mechanical seal having a single-piece, perforated mating ring

    Science.gov (United States)

    Khonsari, Michael M.; Somanchi, Anoop K.

    2007-08-07

    A mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) with reduced contact surface temperature, reduced contact surface wear, or increased life span. The mechanical seal comprises a rotating ring and a single-piece, perforated mating ring, which improves heat transfer by controllably channeling coolant flow through the single-piece mating ring such that the coolant is in substantially uniform thermal contact with a substantial portion of the interior surface area of the seal face, while maintaining the structural integrity of the mechanical seal and minimizing the potential for coolant flow interruptions to the seal face caused by debris or contaminants (e.g., small solids and trash) in the coolant.

  7. Solid oxide fuel cell having a glass composite seal

    Science.gov (United States)

    De Rose, Anthony J.; Mukerjee, Subhasish; Haltiner, Jr., Karl Jacob

    2013-04-16

    A solid oxide fuel cell stack having a plurality of cassettes and a glass composite seal disposed between the sealing surfaces of adjacent cassettes, thereby joining the cassettes and providing a hermetic seal therebetween. The glass composite seal includes an alkaline earth aluminosilicate (AEAS) glass disposed about a viscous glass such that the AEAS glass retains the viscous glass in a predetermined position between the first and second sealing surfaces. The AEAS glass provides geometric stability to the glass composite seal to maintain the proper distance between the adjacent cassettes while the viscous glass provides for a compliant and self-healing seal. The glass composite seal may include fibers, powders, and/or beads of zirconium oxide, aluminum oxide, yttria-stabilized zirconia (YSZ), or mixtures thereof, to enhance the desirable properties of the glass composite seal.

  8. Method and system to facilitate sealing in gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Victor John; Foster, Gregory Thomas; Sarawate, Neelesh Nandkumar

    2017-09-12

    A method and system for sealing between components within a gas turbine is provided. A first recess defined in a first component receives a seal member. A second recess defined in a second component adjacent the first component also receives the seal member. The first and second recesses are located proximate a hot gas path defined through the gas turbine, and define circumferential paths about the turbine axis. The seal member includes a sealing face that extends in a direction substantially parallel to the turbine axis. The seal member also includes a plurality of seal layers, wherein at least one of the seal layers includes at least one stress relief region for facilitating flexing of the first seal member.

  9. Advanced helium purge seals for Liquid Oxygen (LOX) turbopumps

    Science.gov (United States)

    Shapiro, Wilbur; Lee, Chester C.

    1989-01-01

    Program objectives were to determine three advanced configurations of helium buffer seals capable of providing improved performance in a space shuttle main engine (SSME), high-pressure liquid oxygen (LOX) turbopump environment, and to provide NASA with the analytical tools to determine performance of a variety of seal configurations. The three seal designs included solid-ring fluid-film seals often referred to as floating ring seals, back-to-back fluid-film face seals, and a circumferential sectored seal that incorporated inherent clearance adjustment capabilities. Of the three seals designed, the sectored seal is favored because the self-adjusting clearance features accommodate the variations in clearance that will occur because of thermal and centrifugal distortions without compromising performance. Moreover, leakage can be contained well below the maximum target values; minimizing leakage is important on the SSME since helium is provided by an external tank. A reduction in tank size translates to an increase in payload that can be carried on board the shuttle. The computer codes supplied under this program included a code for analyzing a variety of gas-lubricated, floating ring, and sector seals; a code for analyzing gas-lubricated face seals; a code for optimizing and analyzing gas-lubricated spiral-groove face seals; and a code for determining fluid-film face seal response to runner excitations in as many as five degrees of freedom. These codes proved invaluable for optimizing designs and estimating final performance of the seals described.

  10. Molecular characterization of mycobacteria isolated from seals.

    Science.gov (United States)

    Zumárraga, M J; Bernardelli, A; Bastida, R; Quse, V; Loureiro, J; Cataldi, A; Bigi, F; Alito, A; Castro Ramos, M; Samper, S; Otal, I; Martin, C; Romano, M I

    1999-09-01

    Tuberculosis (TB) was diagnosed in 10 seals from three species (Arctocephalus australis, Arctocephalus tropicalis and Otaria flavescens) found in South America. The mycobacteria isolated from these cases belonged to the Mycobacterium tuberculosis complex, as determined by RFLP using an IS6110 probe, spoligotyping, analysis of the 16S rRNA gene sequence and by PCR-restriction analysis of hsp65. Polymorphisms in gyrA, katG, oxyR and pncA were investigated in some of the isolates, as well as the presence of the MPB70 antigen. The insertion sequence IS6110 was present in three to seven copies in the genome of the mycobacteria isolated from seals. Using the IS6110 probe, six patterns (designated A, B, C, D, E and F) were identified from 10 different isolates. Patterns A and B were found for the mycobacteria isolated from two and four seals, respectively, indicating an epidemiological relationship between isolates grouped according to their IS6110 RFLP. The mycobacteria isolated from seals shared the majority of their IS6110 DNA-containing restriction fragments, and nine isolates had an identical spoligotype; only one isolate showed a minor difference in its spoligotype. In addition, none of these spoligotypes were found in other M. tuberculosis complex strains. These results suggest that the isolates from seals constitute a unique group of closely related strains. The mycobacteria isolated from seals showed polymorphisms at gyrA codon 95 and katG codon 463, as do group 1 M. tuberculosis, and M. bovis. Group 1 mycobacteria are associated with cluster cases. The spoligotypes found in the mycobacteria isolated from seals lack spacers 39-43, as does M. bovis, but the MPB70 antigen, which is highly expressed in M. bovis and minimally expressed in M. tuberculosis, was not detected in these mycobacteria. The mycobacteria isolated from seals also showed oxyR and pncA polymorphisms specific to M. tuberculosis. In conclusion, the mycobacteria that cause TB in seals in the South

  11. Tribological Studies of Dynamic Thermal Seal Materials

    Science.gov (United States)

    DeMange, Jeffrey J.; Taylor, Shawn C.

    2016-01-01

    Thermal seals are required on high-speed vehicles in many dynamic applications such as variable inlets in propulsion systems and control surfaces. These seals, often referred to as dynamic thermal seals, must not only mitigate inboard heat transfer, but must also exhibit sufficient durability when scrubbed against mating surfaces. For high-temperature high-speed vehicle applications, the mating surfaces are often made from thermal protection system (TPS) materials, which are typically rougher and more abrasive than TPS materials used at lower temperatures. The high-temperature TPS materials used can include non-ablative (e.g., lightweight porous oxides, ceramic matrix composites) andor ablative systems (e.g., phenolic systems). Due to the increased need for durable high-temperature dynamic seals, researchers working with the NASA Glenn Research Center embarked on an effort to (a) characterize the tribological performance of state-of-the-art thermal seal materials against a variety of TPS materials and (b) develop approaches for improved wear resistance. Tests were conducted using a recently upgraded high-temperature tribometer to assess wear resistance for a variety of tribopairs under multiple conditions. This data will begin to frame the challenges of using these materials and eventually permit an improved ability to design and implement these critical TPS components.

  12. Apical sealing ability of two novel root canal sealers: An ex-vivo study

    Directory of Open Access Journals (Sweden)

    Priyanka Setia

    2013-01-01

    Full Text Available Objective: The objective was to compare the sealing ability of two root canal sealers viz.: Hybrid Root SEAL (Sun Medical, Tokyo, Japan and iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada. Materials and Methods: A sample of 60 permanent single rooted, human maxillary central incisors of similar sizes was selected for the study. The teeth were decoronated and randomly divided into two groups viz.: Group A and Group B, comprising of thirty teeth each. In Group A, Hybrid Root SEAL and Group B, iRoot SP were used as root canal sealers along with Gutta-percha cones using lateral condensation technique to obturate the canals. After obturation roots were covered with nail paint except 2.0 mm of root and stored in 0.5% methylene blue dye for 1 week. The teeth were immersed in 10 ml of 65% nitric acid for complete dissolution and subsequently subjected to UV spectrophotometer to quantify the concentration of the dye in each sample. The data were analyzed using the unpaired t-test. Results: The mean dye leakage value in Group B (0.368 was less as compared to Group A (0.408. However, statistically the difference was nonsignificant (P = 0.053. Conclusion: There was no statistically significant difference among the two groups.

  13. Seal assembly with anti-rotation pin for high pressure supercritical fluids

    Science.gov (United States)

    Wright, Steven A.; Fuller, Robert L.

    2014-08-05

    A seal assembly for sealing a machine with a first chamber and a second chamber is provided. A rotating shaft extends through the first and second chambers, and rotates therein. The seal assembly has a seal housing, a seal ring and a seal pin. The seal housing is positionable in the machine housing. The seal housing has a seal pocket extending into a fluid side thereof, and a housing receptacle extending into an inner diameter thereof at the seal pocket. The seal ring is positionable in the seal pocket of the seal housing for forming a seal therewith. The seal ring has a ring receptacle extending into an outer diameter thereof. The ring receptacle is positionable adjacent to the housing receptacle for defining a pin hole therebetween. The seal pin is loosely positionable in the pin hole whereby movement about the seal ring is accommodated while preventing rotation thereof.

  14. Híbridos de sorgo (Sorghum bicolor (L. Moench cultivados sob níveis crescentes de adubação: características agronômicas, carboidratos solúveis e estruturais da planta Sorghum (Sorghum bicolor (L. Moench hybrids cultivated under increasing fertilization levels: agronomic characteristics, soluble and structural carbohydrates of the plant

    Directory of Open Access Journals (Sweden)

    Miguel Marques Gontijo Neto

    2004-12-01

    Full Text Available Foram avaliadas características agronômicas, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA e carboidratos solúveis e estruturais de cinco híbridos de sorgo forrageiro (AG-2002, AG-2005E, AGX-202, AGX-213 e AGX-215, cultivados sob quatro níveis de adubação NPK. Utilizou-se o delineamento em blocos casualizados, em esquema fatorial 5 x 4, com quatro repetições. As médias dos fatores qualitativos foram comparadas pelo teste de Tukey a 5 e 1% de probabilidade. Os híbridos avaliados apresentaram diferentes proporções de colmos (29,01 a 53,38%, de folhas (16,70 a 22,64% e de panículas (29,91 a 52,43%, sendo colmos e panículas fortemente correlacionadas com altura, 0,79** e -0,82**, respectivamente. O teor de matéria seca (MS da planta inteira foi fortemente influenciado pelas proporções de colmos e panículas, tendo as panículas apresentado os maiores teores de MS (48,79 a 56,80% e colmos as menores (18,86 a 22,54%. O aumento nos níveis de adubação proporcionou acréscimo na produção de panículas, que refletiu na diminuição da relação colmo + folha/panícula, no acréscimo da proporção de panículas e no teor de MS da planta inteira. Os teores de carboidratos solúveis totais, com base na matéria seca, variaram entre os híbridos avaliados (12,24 a 19,80% e apresentaram aumento com a elevação dos níveis de adubação. Os híbridos avaliados apresentaram diferenças significativas entre os teores de fibra em detergente neutro (57,38 a 62,30%, fibra em detergente ácido (25,29 a 31,56%, hemicelulose (28,56 a 33,87%, celulose (19,20 a 24,34% e lignina (6,04 a 6,51%. O avanço nos níveis de adubação resultou em queda nos teores de FDN e hemicelulose.The agronomic characteristics, neutral detergent fiber (NDF, acid detergent fiber (ADF and total soluble and structural carbohydrates contents of five hybrid sorghum (AG-2002, AG-2005E, AGX-212, AGX-213 e AGX-215, cultivated under different fertilization

  15. Cylindrical electrochemical cells with a diaphragm seal

    Energy Technology Data Exchange (ETDEWEB)

    Georgopoulos, P.

    1993-07-13

    A cylindrical electrochemical cell is described comprising an anode, a cathode and electrolyte contained in a cylindrical container, the container having an open end and a closed end; wherein the open end of the container is sealed with a seal assembly comprising: (a) a disc-shaped seal member, made from an electrically insulative material, having an outer edge wall connected via a base to a centrally located cylindrical hub that defines an orifice; which base has a ventable diaphragm portion and a nonventable diaphragm portion that is thicker than the ventable diaphragm portion; and wherein the ventable diaphragm portion joins the hub at an interface and becomes gradually thicker in the direction away from the interface toward the outer edge wall so that the ventable diaphragm portion is thinnest at the interface; and (b) a current collector extending through the orifice defined by the hub into the cell's interior to contact one of the cell's electrodes.

  16. Pore-lining composition and capillary breakthrough pressure of mudstone caprocks : sealing efficiency at geologic CO2 storage sites.

    Energy Technology Data Exchange (ETDEWEB)

    Heath, Jason E.; Nemer, Martin B.; McPherson, Brian J. O. L. (University of Utah, Salt Lake City, UT); Dewers, Thomas A.; Kotula, Paul Gabriel

    2010-12-01

    Subsurface containment of CO2 is predicated on effective caprock sealing. Many previous studies have relied on macroscopic measurements of capillary breakthrough pressure and other petrophysical properties without direct examination of solid phases that line pore networks and directly contact fluids. However, pore-lining phases strongly contribute to sealing behavior through interfacial interactions among CO2, brine, and the mineral or non-mineral phases. Our high resolution (i.e., sub-micron) examination of the composition of pore-lining phases of several continental and marine mudstones indicates that sealing efficiency (i.e., breakthrough pressure) is governed by pore shapes and pore-lining phases that are not identifiable except through direct characterization of pores. Bulk X-ray diffraction data does not indicate which phases line the pores and may be especially lacking for mudstones with organic material. Organics can line pores and may represent once-mobile phases that modify the wettability of an originally clay-lined pore network. For shallow formations (i.e., < {approx}800 m depth), interfacial tension and contact angles result in breakthrough pressures that may be as high as those needed to fracture the rock - thus, in the absence of fractures, capillary sealing efficiency is indicated. Deeper seals have poorer capillary sealing if mica-like wetting dominates the wettability. We thank the U.S. Department of Energy's National Energy Technology Laboratory and the Office of Basic Energy Sciences, and the Southeast and Southwest Carbon Sequestration Partnerships for supporting this work.

  17. Intracoronal sealing ability of two dental cements.

    Science.gov (United States)

    Wells, John D; Pashley, David H; Loushine, Robert J; Weller, R Norman; Kimbrough, W Frank; Pereira, Patricia N

    2002-06-01

    The purpose of this study was to compare the efficacy of sealing the coronal 2-mm of the root canals versus covering the entire pulpal floor with one of two dental-resin cements (Principle or C&B Metabond). Sixty-two molars with the occlusal half of the crowns and the apical half of the roots removed were used. Each canal was enlarged by using a #3 Gates Glidden bur and obturated with unsealed gutta-percha cones. The teeth were randomly assigned to four groups, each containing 15 teeth, plus a negative and a positive control. In group 1, 2 mm of Principle were placed over the entire pulpal floor. In group 2, Principle was placed 2 mm into each canal orifice. Groups 3 and 4 were the same as groups 1 and 2, except C&B Metabond cement was used. After the cement set, the gutta-percha was removed and the integrity of the seal was tested by fluid filtration at a pressure of 20 cm H2O at 1 h and at 1, 2, and 4 weeks. The data were analyzed by a three-way ANOVA and the Student-Newman-Keuls tests at alpha = 0.05. The controls behaved as expected. Results showed that there were no statistically significant differences among the materials used or the location (p > 0.05), but there was a significant difference with respect to time. Principle leaked significantly more than C&B Metabond at 1 h (p < 0.05), but the seal became tighter over time. C&B Metabond leaked less early (p < 0.05) but increased in leakage at 4 weeks. Both materials sealed well over the 4-week study. Principle was easier to use, and sealing the entire pulpal floor was easier than sealing only the canal orifice.

  18. Dynamic analysis of C/C composite finger seal

    Institute of Scientific and Technical Information of China (English)

    Chen Guoding; Wang Li’na; Yu Qiangpeng; Su Hua

    2014-01-01

    A seal device as an important component of aeroengines has decisive influence on per-formance, reliability, and working life of aeroengines. With the development of aeroengines, demands on the performance characteristics of seal devices are made strictly. Finger seal as a novel kind of sealing device, recently attracts more and more attentions in academic circles and engineer-ing fields at home and abroad. Research on finger seals has been extensively developed, especially on leakage and wear performances under dynamic conditions. However, it is a pity that the work on finger seals has been limited with a single approach that is improving the performance by structural optimization;in addition, the technology of dynamic analysis on finger seals is weak. Aiming at the problems mentioned above, a distributed mass equivalent dynamic model of finger seals considering the coupling effect of overlaid laminates is established in the present paper, the dynamic perfor-mance of 2.5 dimension C/C composite finger seal is analyzed with the model, and then the effects of fiber bundle density and fiber bundle preparation direction on finger seal’s dynamic performance are discussed, as well as compared with those of Co-based alloy finger seal. The current work is about dynamic analysis of finger seals and application of C/C composite in this paper may have much academic significance and many engineering values for improving research level of finger seal dynamics and exploring feasibility of C/C composite being used for finger seals.

  19. Dynamic analysis of C/C composite finger seal

    Directory of Open Access Journals (Sweden)

    Chen Guoding

    2014-06-01

    Full Text Available A seal device as an important component of aeroengines has decisive influence on performance, reliability, and working life of aeroengines. With the development of aeroengines, demands on the performance characteristics of seal devices are made strictly. Finger seal as a novel kind of sealing device, recently attracts more and more attentions in academic circles and engineering fields at home and abroad. Research on finger seals has been extensively developed, especially on leakage and wear performances under dynamic conditions. However, it is a pity that the work on finger seals has been limited with a single approach that is improving the performance by structural optimization; in addition, the technology of dynamic analysis on finger seals is weak. Aiming at the problems mentioned above, a distributed mass equivalent dynamic model of finger seals considering the coupling effect of overlaid laminates is established in the present paper, the dynamic performance of 2.5 dimension C/C composite finger seal is analyzed with the model, and then the effects of fiber bundle density and fiber bundle preparation direction on finger seal’s dynamic performance are discussed, as well as compared with those of Co-based alloy finger seal. The current work is about dynamic analysis of finger seals and application of C/C composite in this paper may have much academic significance and many engineering values for improving research level of finger seal dynamics and exploring feasibility of C/C composite being used for finger seals.

  20. Cadmium Toxicity to Ringed Seals (Phoca hispida)

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, R.; Riget, F. F.

    Cadmium concentrations in kidneys from ringed seals (Phoca hispida) from North West Greenland (Qaanaaq) are high. Concentrations range at level known to induce renal toxic effects (mainly tubulopathy) and demineralisation (osteopenia) of the skeletal system (Fanconi's Syndrome) in humans as well...... as laboratory mammals. We have studied possible cadmium induced histopathological changes in the kidneys as well as a demineralisation of the skeletal system (DXA-scanning of lumbal vertebraes). No obvious cadmium induced toxic changes were found. Food composition and physiological adaptations may explain...... the absence of toxic effects of cadmium in ringed seal...

  1. Vacuum-sealed silicon micromachined pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Esashi, Masayoshi [Tohoku Univ., Aobaku, Sendai (Japan); Sugiyama, Susumu [Ritsumeikan Univ., Kusatsu, Shiga (Japan); Ikeda, Kyoichi [Yokogawa Electric Corp., Nagano (Japan); Wang, Y. [Zhejian Univ., Hangzhou (China); Miyashita, Haruzo [Anelva Corp., Yamanashi (Japan)

    1998-08-01

    Considerable progress in silicon pressure sensors has been made in recent years. This paper discusses three types of vacuum-sealed silicon micromachined pressure sensors that represent the present state of the art in this important area. The devices are a capacitive vacuum sensor, a surface-micromachined microdiaphragm pressure sensor, and a resonant pressure sensor. Vacuum sealing for these devices is accomplished using anodic bonding, films deposited using low-pressure chemical vapor deposition, and thermal out-diffusion of hydrogen, respectively. These sensors emphasize high sensitivity; small size, and excellent stability, respectively. The silicon-diaphragm vacuum sensor uses electrostatic force balancing to achieve a wide pressure measurement range.

  2. Fluid seals technology at BHR Group Ltd.

    Science.gov (United States)

    Leefe, Simon

    1991-01-01

    A mathematical model was developed for ESA, which couples the rigid body dynamics in four degrees of freedom of a flexibly mounted stator (with Coulomb damping) of a turbopump face seal with the fluid film behavior. The interfacial film is assumed gaseous, and the model incorporates laminar/turbulent flow, inertia and sonic choking. Seal faces may be wavy and coned, while the rotating ring can be eccentrically mounted, misaligned with the shaft and oscillate axially at arbitrary frequency. The model is currently being coded into software. An experimental program using a high speed cryogenic/hot gas test rig is being conducted to verify the output of the computer program.

  3. Space Shuttle Orbiter AFT heat shield seal

    Science.gov (United States)

    Walkover, L. J.

    1979-01-01

    The evolution of the orbiter aft heat shield seal (AHSS) design, which involved advancing mechanical seal technology in severe thermal environment is discussed. The baseline design, various improvements for engine access, and technical problem solution are presented. It is a structure and mechanism at the three main propulsion system (MPS) engine interfaces to the aft compartment structure. Access to each MPS engine requires disassembly and removal of the AHSS. Each AHSS accommodates the engine movement, is exposed to an extremely high temperature environment, and is part of the venting control of the aft compartment.

  4. Study on a new type of sealing - regeneration-labyrinth sealing for displacer in cryocoolers: Part I - Theoretical study

    Science.gov (United States)

    Liu, L. Q.; Zhang, L.

    2000-02-01

    A new concept of sealing structure - regeneration-labyrinth sealing has been put forward to substitute for sealing rings that influence seriously the performance of cryocoolers. A program, which can simulate the thermophysical process occurring in the sealing structure, is developed consequently. Using numerical simulation, the reasonable structure of the regeneration-labyrinth sealing has been determined. The influences of some parameters, such as the heat transfer coefficient of forced convection, the cylinder-displacer gap, the diameter and length of cylinder on the losses of cooling capacity have been studied numerically. As a result, the designing principle of the new type of sealing is obtained.

  5. Hybrid microcircuit technology handbook materials, processes, design, testing and production

    CERN Document Server

    Licari, James J

    1998-01-01

    The Hybrid Microcircuit Technology Handbook integrates the many diverse technologies used in the design, fabrication, assembly, and testing of hybrid segments crucial to the success of producing reliable circuits in high yields. Among these are: resistor trimming, wire bonding, die attachment, cleaning, hermetic sealing, and moisture analysis. In addition to thin films, thick films, and assembly processes, important chapters on substrate selections, handling (including electrostatic discharge), failure analysis, and documentation are included. A comprehensive chapter of design guidelines will

  6. Fissure seal or fluoride varnish?

    Science.gov (United States)

    Deery, Christopher

    2016-09-01

    Data sourcesCochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, the US National Institutes of Health Trials Register and the World Health Organization (WHO) Clinical Trials Registry PlatformStudy selectionRandomised controlled trials (RCTs) with at least 12 months follow-up, in which fissure sealants, or fissure sealants together with fluoride varnishes, were compared with fluoride varnishes alone for preventing caries in occlusal surfaces of permanent teeth of children and adolescents.Data extraction and synthesisTwo reviewers independently screened search results, extracted data and assessed risk of bias of included studies. Studies were grouped and analysed on the basis of sealant material type (resin-based sealant and glass ionomer-based sealant, glass ionomer and resin-modified glass ionomer) and different follow-up periods. Odds ratio were calculated for caries or no caries on occlusal surfaces of permanent molar teeth. Mean differences were calculated for continuous outcomes and data. Evidence quality was assessed using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods.ResultsEight RCTs involving a total of 1747 children aged five to ten years of age were included. Three trials compared resin-based fissure sealant versus fluoride varnish. Results from two studies (358 children) after two years were combined. Sealants prevented more caries, pooled odds ratio (OR) = 0.69 (95%CI; 0.50 to 0.94). One trial with follow-up at four and nine years found that the caries-preventive benefit for sealants was maintained, with 26% of sealed teeth and 55.8% of varnished teeth having developed caries at nine years. Evidence for glass-ionomer sealants was of low quality. One split-mouth trial analysing 92 children at two-year follow-up found a significant difference in favour of resin-based fissure sealant together with fluoride varnish compared with fluoride varnish only (OR

  7. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  8. Relação entre a composição química e a degradabilidade in situ da matéria seca e da fibra em detergente neutro da fração volumosa de híbridos de milho Correlation between chemical composition and dry matter and neutral detergent fiber in situ degradation of corn hybrids bulky fraction

    Directory of Open Access Journals (Sweden)

    Luís Felipe Prada e Silva

    2000-02-01

    Full Text Available RESUMO - A composição química e a degradação in situ da matéria seca (MS e fibra em detergente neutro (FDN da fração volumosa (haste + folhas de 28 híbridos de milho, em 1996, e 21 híbridos, em 1997, foram estudadas para estabelecer as correlações existentes entre os parâmetros analisados. Dos 21 híbridos de milho selecionados em 1997, 13 fizeram parte do experimento em 1996. O modelo para avaliar a cinética de degradação in situ da MS (Mcdonald, 1981 e o modelo para analisar a cinética de degradação in situ da FDN (Mertens e Loften ,1980 foram usados. Os dados dos dois anos (1996, 1997 foram analisados em separado ou em conjunto. A degradação efetiva da MS da porção volumosa mostrou-se fortemente relacionada com os teores de fibra em detergente ácido (FDA e FDN, mas não com o teor de lignina. Nenhuma análise química se mostrou correlacionada com o tempo de retenção da FDN, ou com as taxas de degradação da fração insolúvel potencialmente degradável da MS ou da FDN. O teor de FDA mostrou-se altamente correlacionado (R²=0,86 com a degradabilidade efetiva da MS, quando os anos foram analisados em conjunto, e pode ser utilizado como indicador da degradação da MS da fração volumosa de híbridos de milho.ABSTRACT - The chemical composition and in situ dry matter (DM and neutral detergent fiber (NDF of bulky fraction (stall and sheets degradation of 28 corn hybrids in 1996, and 21 hybrids, in 1997, were studied to establish the correlation among the analyzed factors. From the 21 hybrids selected in 1997, 13 were part of the experiment in 1996. The model for the evaluation of in situ DM degradation kinetics (McDonald, 1981, and the model to analyze the in situ NDF degradation kinetics (Mertens and Loften, 1980 were used. Data from both 1966 and 1977 years were analyzed separated or as a set. The bulky fraction effective DM degradation was strongly correlated with the acid detergent fiber (ADF and NDF content, but

  9. HMSRP Hawaiian Monk Seal Cell Phone Tag Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project investigates foraging behavior of Hawaiian monk seals by conducting telemetry studies. During these studies, live seals are instrumented with dive...

  10. Evaluation of Subterranean Subsidence at Seal Beach National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this study was to determine the amount of subsurface subsidence at Naval Weapons Station Seal Beach (NWSSB) areas which include Seal Beach National...

  11. Reactor coolant pump shaft seal behavior during station blackout

    Energy Technology Data Exchange (ETDEWEB)

    Kittmer, C.A.; Wensel, R.G.; Rhodes, D.B.; Metcalfe, R.; Cotnam, B.M.; Gentili, H.; Mings, W.J.

    1985-04-01

    A testing program designed to provide fundamental information pertaining to the behavior of reactor coolant pump (RCP) shaft seals during a postulated nuclear power plant station blackout has been completed. One seal assembly, utilizing both hydrodynamic and hydrostatic types of seals, was modeled and tested. Extrusion tests were conducted to determine if seal materials could withstand predicted temperatures and pressures. A taper-face seal model was tested for seal stability under conditions when leaking water flashes to steam across the seal face. Test information was then used as the basis for a station blackout analysis. Test results indicate a potential problem with an elastomer material used for O-rings by a pump vendor; that vendor is considering a change in material specification. Test results also indicate a need for further research on the generic issue of RCP seal integrity and its possible consideration for designation as an unresolved safety issue.

  12. Forming a Turbomachinery Seals Working Group: An Overview and Discussion

    Science.gov (United States)

    Proctor, Margaret P.

    2007-01-01

    Purose: Identify technical challenges to improving turbomachinery seal leakage and wear performance, reliability and cost effectiveness. Develop a coordinated effort to resolve foundational issues for turbomachinery seal technologies. Identify and foster opportunities for collaboration. Advocate for funding.

  13. HMSRP Hawaiian Monk Seal Master Identification Records (annual)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records of all individually identified Hawaiian monk seals since 1981. These seals were identified by PSD personnel and cooperating scientists...

  14. Bentonite as a waste isolation pilot plant shaft sealing material

    Energy Technology Data Exchange (ETDEWEB)

    Daemen, J.; Ran, Chongwei [Univ. of Nevada, Reno, NV (United States)

    1996-12-01

    Current designs of the shaft sealing system for the Waste Isolation Pilot Plant (WIPP) propose using bentonite as a primary sealing component. The shaft sealing designs anticipate that compacted bentonite sealing components can perform through the 10,000-year regulatory period and beyond. To evaluate the acceptability of bentonite as a sealing material for the WIPP, this report identifies references that deal with the properties and characteristics of bentonite that may affect its behavior in the WIPP environment. This report reviews published studies that discuss using bentonite as sealing material for nuclear waste disposal, environmental restoration, toxic and chemical waste disposal, landfill liners, and applications in the petroleum industry. This report identifies the physical and chemical properties, stability and seal construction technologies of bentonite seals in shafts, especially in a saline brine environment. This report focuses on permeability, swelling pressure, strength, stiffness, longevity, and densification properties of bentonites.

  15. Comparative analysis of the fecal bacterial community of five harbor seals (Phoca vitulina).

    Science.gov (United States)

    Numberger, Daniela; Herlemann, Daniel P R; Jürgens, Klaus; Dehnhardt, Guido; Schulz-Vogt, Heide

    2016-10-01

    The gut microbiota has many beneficial effects on host metabolism and health, and its composition is determined by numerous factors. It is also assumed that there was a co-evolution of mammals and the bacteria inhabiting their gut. Current knowledge of the mammalian gut microbiota mainly derives from studies on humans and terrestrial animals, whereas those on marine mammals are sparse. However, they could provide additional information on influencing factors, such as the role of diet and co-evolution with the host. In this study, we investigated and compared the bacterial diversity in the feces of five male harbor seals (Phoca vitulina). Because this small population included two half-brother pairs, each sharing a common father, it allowed an evaluation of the impact of host relatedness or genetic similarity on the gut microbial community. Fresh feces obtained from the seals by an enema were analyzed by fluorescence in situ hybridization and amplicon sequencing of 16S rRNA genes. The results showed that the bacterial communities in the seals' feces mainly consisted of the phyla Firmicutes (19-43%), Bacteroidetes (22-36%), Fusobacteria (18-32%), and Proteobacteria (5-17%) . Twenty-one bacterial members present in the fecal samples of the five seals contributed an average relative abundance of 93.7 + 8.7% of the total fecal microbial community. Contrary to all expectations based on previous studies a comparison of the fecal community between individual seals showed a higher similarity between unrelated than related individuals.

  16. 2000 NASA Seal/Secondary Air System Workshop. Volume 1

    Science.gov (United States)

    Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)

    2001-01-01

    The 2000 NASA Seal/Secondary Air System Workshop covered four main areas: (1) overviews of NASA-sponsored Ultra-Efficient Engine Technology (UEET) and Access to Space Programs, with emphasis on program goals and seal needs; (2) review of turbine engine seal issues from the perspective of end users such as United Airlines; (3) reviews of sealing concepts, test results, experimental facilities, and numerical predictions; and (4) reviews of material development programs relevant to advanced seals development. The NASA UEET overview illustrates for the reader the importance of advanced technologies, including seals, in meeting future engine system efficiency and emission goals. GE, Pratt & Whitney, and Honeywell presented advanced seal development work being performed within their organizations. The NASA-funded GE/Stein Seal team has successfully demonstrated a large (3-ft. diam) aspirating seal that can withstand all anticipated pressures, speeds, and rotor runouts anticipated for a GE90 L.P. turbine balance piston location. GE/Stein Seal are fabricating a full-scale seal to be tested in a GE-90 ground test engine in early 2002. Pratt & Whitney and Stein Seal are investigating carbon seals to accommodate large radial movements anticipated in future geared-fan gearbox locations. Honeywell presented a finger seal design being considered for a high-temperature static combustor location incorporating ceramic finger elements. Successful demonstration of the braided carbon rope thermal barriers to extreme temperatures (5500 F) for short durations provide a new form of very high temperature thermal barrier for future Shuttle solid rocket motor nozzle joints. The X-37, X-38, and future highly reusable launch vehicles pose challenging control surface seal demands that require new seal concepts made from emerging high temperature ceramics and other materials.

  17. Non-contacting shaft seals for gas and steam turbines

    OpenAIRE

    2012-01-01

    Improvements upon current gas turbine sealing technology performance are essential for decreasing specific fuel consumption to meet stringent future efficiency targets. The clearances between rotating and static components of a gas turbine, which need to be sealed, vary over a flight cycle. Hence, a seal which can passively maintain an optimum clearance, whilst preventing contact between itself and the rotor, is extremely desirable. Various configurations of a Rolls Royce (RR) seal concep...

  18. Automatic Inspection Of Heat Seals Between Plastic Sheets

    Science.gov (United States)

    Rai, Kula R.; Lew, Thomas M.; Sinclair, Robert B.

    1995-01-01

    Automatic inspection apparatus detects flaws in heat seals between films of polyethylene or other thermoplastic material. Heat-sealed strip in multilayer plastic sheet continuously moved lengthwise over illuminators. Variations in light transmitted through sheet interpreted to find flaws in heat seal. Site of flaw marked to facilitate subsequent manual inspection. Heat sealing used to join plastic films in manufacturing of variety of products, including inflatable toys and balloons carrying scientific instruments to high altitudes.

  19. Measure Guideline: Guide to Attic Air Sealing

    Energy Technology Data Exchange (ETDEWEB)

    Lstiburek, J.

    2014-09-01

    The Guide to Attic Air Sealing was completed in 2010 and although not in the standard Measure Guideline format, is intended to be a Measure Guideline on Attic Air Sealing. The guide was reviewed during two industry stakeholders meetings held on December 18th, 2009 and January 15th, 2010, and modified based on the comments received. Please do not make comments on the Building America format of this document. The purpose of the Guide to Attic Air Sealing is to provide information and recommendations for the preparation work necessary prior to adding attic insulation. Even though the purpose of this guide is to save energy - health, safety and durability should not be compromised by energy efficiency. Accordingly, combustion safety and ventilation for indoor air quality are addressed first. Durability and attic ventilation then follow. Finally, to maximize energy savings, air sealing is completed prior to insulating. The guide is intended for home remodelers, builders, insulation contractors, mechanical contractors, general contractors who have previously done remodeling and homeowners as a guide to the work that needs to be done.

  20. A morbillivirus causing mass mortality in seals.

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert)

    1989-01-01

    textabstractDuring an outbreak of a serious apparently infectious disease among harbour seals (Phoca vitulina), which started in the Kattegat area in April 1988 and rapidly spread to the North sea, the Wadden sea and the Baltic sea, greater than 17,000 animals died within a period of eight months. I

  1. Sealing materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, P.H.

    1999-02-01

    A major obstacle in the achievement of high electrical efficiency for planar solid oxide fuel cell stacks (SOFC) is the need for long term stable seals at the operational temperature between 850 and 1000 deg. C. In the present work the formation and properties of sealing materials for SOFC stacks that fulfil the necessary requirements were investigated. The work comprises analysis of sealing material properties independently, in simple systems as well as tests in real SOFC stacks. The analysed sealing materials were based on pure glasses or glass-ceramic composites having B{sub 2}O{sub 3}, P{sub 2}O{sub 5} or siO{sub 2} as glass formers, and the following four glass systems were investigated: MgO/caO/Cr{sub 2}O{sub 3}-Al{sub 2}O{sub 3}B{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}-SiO{sub 2} and BaO/Na{sub 2}O-Al{sub 2}O{sub 3}-SiO{sub 2}. (au) 32 tabs., 106 ills., 107 refs.

  2. A morbillivirus causing mass mortality in seals.

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert)

    1989-01-01

    textabstractDuring an outbreak of a serious apparently infectious disease among harbour seals (Phoca vitulina), which started in the Kattegat area in April 1988 and rapidly spread to the North sea, the Wadden sea and the Baltic sea, greater than 17,000 animals died within a period of eight months.

  3. Infiltrating/sealing proximal caries lesions

    DEFF Research Database (Denmark)

    Martignon, S; Ekstrand, K R; Gomez, J

    2012-01-01

    proximal lesions identified radiographically around the enamel-dentin junction to the outer third of the dentin, were included. Lesions were randomly allocated for treatment to test-A (Infiltration: ICON-pre-product; DMG), test-B (Sealing: Prime-Bond-NT; Dentsply), or control-C (Placebo). Primary outcome...

  4. On the lubrication of mechanical face seals

    NARCIS (Netherlands)

    Lubbinge, Hans

    1999-01-01

    Hence, in this thesis, a model is presented which is able to calculate a complete Stribeck curve for a mechanical face seal and, as a consequence, the transition from full film to mixed lubrication as a function of the operational conditions. This model is based on a combination of a contact model a

  5. Bearings and Seals. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on bearings and seals is one of a series of power mechanics texts and visual aids for use in training for the servicing of automotive and off-the-road farm and industrial machines. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. Focusing on…

  6. 14 CFR 1221.102 - Establishment of the NASA Seal.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Establishment of the NASA Seal. 1221.102 Section 1221.102 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION THE NASA SEAL AND OTHER DEVICES, AND THE CONGRESSIONAL SPACE MEDAL OF HONOR NASA Seal, NASA Insignia, NASA Logotype,...

  7. 14 CFR 1221.109 - Use of the NASA Seal.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Use of the NASA Seal. 1221.109 Section 1221.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION THE NASA SEAL AND OTHER DEVICES, AND THE CONGRESSIONAL SPACE MEDAL OF HONOR NASA Seal, NASA Insignia, NASA Logotype, NASA...

  8. Test of Seal System for Flexible Pipe End Fitting

    DEFF Research Database (Denmark)

    Banke, Lars; Jensen, Thomas Gregers

    1999-01-01

    by compression of the gaskets, thus using the geometry to establish a seal towards the inner liner of the pipe and the steel sleeve of the end fitting. This paper describes how the seal system of an end fitting can be tested using an autoclave. By regulating temperature and pressure, the seal system can...

  9. Analyses toward factors influencing sealing clearance of a metal rubber seal and derivation of a calculation formula

    Institute of Scientific and Technical Information of China (English)

    Yan Hui; Zhao Yalei; Liu Jianguo; Jiang Hongyuan

    2016-01-01

    Sealing clearance is a key factor for a metal rubber seal’s sealability. The expansion coef-ficient and expansion deformation in the radial direction of metal rubber have been obtained through a thermal expansion experiment of metal rubber. The influence of the elastic modulus to the sealing clearance has been analyzed theoretically. By combining the temperature and elasticity factors of metal rubber with the elastic mechanics theory, the calculation formula of the sealing clearance has been derived, and the values of the sealing clearance and the leakage rate in certain working conditions have been calculated. Experimental results are consistent with calculation results in a high degree. The calculation formula of the sealing clearance can explain the influences of the temperature and elastic modulus factors of metal rubber on the sealing clearance. It can pro-vide guidance for the study of sealing mechanism of metal rubber seals.

  10. Analyses toward factors influencing sealing clearance of a metal rubber seal and derivation of a calculation formula

    National Research Council Canada - National Science Library

    Yan Hui Zhao Yalei Liu Jianguo Jiang Hongyuan

    2016-01-01

    .... By combining the temperature and elasticity factors of metal rubber with the elastic mechanics theory, the calculation formula of the sealing clearance has been derived, and the values of the sealing...

  11. ITER lip seal welding and cutting developments

    Energy Technology Data Exchange (ETDEWEB)

    Levesy, B.; Cordier, J.J.; Jokinen, T. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Kujanpää, V.; Karhu, M. [VTT Technical Research Centre of Finland (Finland); Le Barbier, R. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Määttä, T. [VTT Technical Research Centre of Finland (Finland); Martins, J.P.; Utin, Y. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2015-10-15

    Highlights: • Different TIG and Laser welding techniques are tested. • Twin spot laser welding techniques is the best. • Limited heat input gives a stable weld pool in all positions. • Penetrations is achieved. • Lip seal welding and cutting with a robotic arm is successfully performed on a representative mock-up. - Abstract: The welded lip seals form part of the torus primary vacuum boundary in between the port plugs and the vacuum vessel, and are classified as Protection Important Component. In order to refurbish the port plugs or the in-vessel components, port plugs have to be removed from the machine. The lip seal design must enable up to ten opening of the vacuum vessel during the life time operation of the ITER machine. Therefore proven, remote reliable cutting and re-welding are essential, as these operations need to be performed in the port cells in a nuclear environment, where human presence will be restricted. Moreover, the combination of size of the components to be welded (∼10 m long vacuum compatible thin welds) and the congested environment close to the core of the machine constraint the type and size of tools to be used. This paper describes the lip seal cutting and welding development programme performed at the VTT Technical Research Centre, Finland. Potential cutting and welding techniques are analyzed and compared. The development of the cutting, TIG and laser welding techniques on samples are presented. Effects of lip seal misalignments and optimization of the 2 welding processes are discussed. Finally, the manufacturing and test of the two 1.2 m × 1 m representative mock-ups are presented. The set-up and use of a robotic arm for the mock-up cutting and welding operations are also described.

  12. Sealed source dismantling hot cell - startup

    Energy Technology Data Exchange (ETDEWEB)

    Dellamano, Jose Claudio; Ferreira, Robson de Jesus, E-mail: jcdellam@ipen.br, E-mail: rojefer@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Rejeitos radioativos

    2013-07-01

    Sealed radioactive sources are widely used in many applications of nuclear technology and at the end of the useful life, most sources become radioactive waste. In Brazil, this waste is received by the Institutes of the National Nuclear Energy Commission and kept under centralized storage. The Waste Management Department at the Nuclear and Energy Research Institute is the main storage center, having received around 20,000 disused sources. A hot cell was designed and constructed to manage Co-60 spent sealed sources with activity up to 3.7 10{sup 1}0 Bq and other sources with equivalent activities. In the hot cell the sources are withdraw from their original shielding and transferred to a standard shielding for further disposal off. The original shielding disassembling is made outside the hot cell and after opening, it is transferred inside the hot cell and the sealed source is removed remotely. The source is checked in relation to external contamination and its activity is checked. After this, the source is positioned in the standard shielding located inside an overpack at the bottom of the hot cell. This paper describes some pre-operational tests carried out in it, that include: opening and closing doors and locks, checking of all electrical and pneumatic controls, the original shielding movement inside the hot-cell, dose rate measurements outside the hot-cell, insertion of the sealed sources inside the activity meter chamber, transferring the sealed source to the standard shielding, movement of the overpack with the standard shielding to outside of the hot-cell and plugging of the standard shielding. (author)

  13. Angel wing seals for blades of a gas turbine and methods for determining angel wing seal profiles

    Science.gov (United States)

    Wang, John Zhiqiang

    2003-01-01

    A gas turbine has buckets rotatable about an axis, the buckets having angel wing seals. The seals have outer and inner surfaces, at least one of which, and preferably both, extend non-linearly between root radii and the tip of the seal body. The profiles are determined in a manner to minimize the weight of the seal bodies, while maintaining the stresses below predetermined maximum or allowable stresses.

  14. A bioquímica na sociedade

    OpenAIRE

    Aureliano, M.

    2014-01-01

    A Química Biológica, também conhecida por Bioquímica, é uma área do conhecimento que é cada vez mais importante nas sociedades contemporâneas. A Bioquímica, é uma ciência interdisciplinar que utiliza estratégias e métodos de muitas outras, desde a Física à Farmacologia.

  15. Mica surfaces stabilize pentavalent uranium.

    Science.gov (United States)

    Ilton, Eugene S; Haiduc, Anca; Cahill, Christopher L; Felmy, Andrew R

    2005-05-02

    High-resolution X-ray photoelectron spectroscopy was used to demonstrate that reduction of aqueous U6+ at ferrous mica surfaces at 25 degrees C preserves U5+ as the dominant sorbed species over a broad range of solution compositions. Polymerization of sorbed U5+ with sorbed U6+ and U4+ is identified as a possible mechanism for how mineral surfaces circumvent the rapid disproportionation of aqueous U5+. The general nature of this mechanism suggests that U5+ could play an important, but previously unidentified, role in the low-temperature chemistry of uranium in reducing, heterogeneous aqueous systems.

  16. Investigation of seal technology for Francis turbine

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Wei

    2012-06-01

    Leakage loss and disk friction loss caused by the clearance gap flow at the back of a runner have a major impact on the efficiency of hydraulic turbines. Accordingly, it is extremely important to develop and improve the seal technology by investigating the gap flow. Generally, there are two types of the gap flow: axial gap flow between a rotating disk and a stator (e.g. the flow at the back of a runner) and the annular gap flow (e.g. the flow at an annular seal). Firstly, the overview of previous researches on labyrinth seal, rotating disk flow and Taylor-Couette flow are summarized. Labyrinth seals are the primary type of seals for turbo machinery. However, most researchers studied it for compressible flow only. It is also found that the enclosed rotating disk flow with through-flow can be studied instead of the gap flow in a hydraulic machine. Furthermore, the above mentioned annular gap flow is similar to the Taylor-Couette flow. The Taylor-vortices are formed in the annular gap due to the rotation of disk, which could be used as a resistance of flow. Therefore, in the present work, three parts are investigated. The first part is the investigation of the labyrinth seal for Francis turbines. The second part is the investigation of the gap flow between two stationary walls. The third part is investigation of the annular gap flow between one stationary and one rotating wall, based on the theory of Taylor-Couette flow. Afterwards, the theoretical formulas for leakage flow of a traditional labyrinth seal used in high head Francis turbine is derived and is verified to give acceptable results. The theoretical model is useful to predict the leakage flow by the measurements of Francis turbine at the Aabjoera Power plant. For straight-through labyrinth seal, the effects of cavity dimensions, numbers and locations on the leakage flow are investigated numerically. Smaller cavity depth, longer cavity length and fewer cavity numbers are required in order to reduce leakage

  17. Experimental toxoplasma gondii infection in grey seals (Halichoerus grypus)

    DEFF Research Database (Denmark)

    Gajadhar, A. A.; Measures, L.; Forbes, L. B.;

    2004-01-01

    changes were observed in all inoculated seals but not in control animals. A modified agglutination test revealed the presence of antibodies to T. gondii in sera collected from inoculated seals and mice inoculated as controls. No evidence of the parasite was found on an extensive histological examination......Laboratory-reared animals were used to assess the susceptibility of seals (Halichoerus grypus) to Toxoplasma gondii infection. Four seals were each orally inoculated with 100 or 10,000 oocysts of T. gondii (VEG strain), and another 4 seals served as negative controls. Occasionally, mild behavioral...

  18. Method of making hermetic seals for hermetic terminal assemblies

    Science.gov (United States)

    Hsu, John S.; Marlino, Laura D.; Ayers, Curtis W.

    2010-04-13

    This invention teaches methods of making a hermetic terminal assembly comprising the steps of: inserting temporary stops, shims and jigs on the bottom face of a terminal assembly thereby blocking assembly core open passageways; mounting the terminal assembly inside a vacuum chamber using a temporary assembly perimeter seal and flange or threaded assembly interfaces; mixing a seal admixture and hardener in a mixer conveyor to form a polymer seal material; conveying the polymer seal material into a polymer reservoir; feeding the polymer seal material from the reservoir through a polymer outlet valve and at least one polymer outlet tube into the terminal assembly core thereby filling interstitial spaces in the core adjacent to service conduits, temporary stop, and the terminal assembly casing; drying the polymer seal material at room temperature thereby hermetically sealing the core of the terminal assembly; removing the terminal assembly from the vacuum chamber, and; removing the temporary stops, shims.

  19. Low torque hydrodynamic lip geometry for rotary seals

    Energy Technology Data Exchange (ETDEWEB)

    Dietle, Lannie L.; Schroeder, John E.

    2015-07-21

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  20. Dimensional Analysis on Resistance Characteristics of Labyrinth Seals

    Institute of Scientific and Technical Information of China (English)

    HU Dongxu; JIA Li; YANG Lixin

    2014-01-01

    Experimental investigation of stepped and straight-through labyrinth seals was designed to study the sealing performance of two different typical labyrinth seals.In order to facilitate dimensional analysis on the flow resistance characteristics of labyrinth seals,the variable cross-section of the flow channels are considered as constant cross-section flow.The mechanical energy loss of flow caused by throttle turbulence intensity is considered as caused by friction along the way.The friction coefficient of stepped labyrinth seals is bigger than that of straight-through labyrinth seals by more than 40% for the same Reynolds number and the ratio of equivalent diameter and the seal length.The expression of friction coefficient f and fRe are obtained from experimental data.The verifications indicate that the expressions are highly accurate.The contribution to the total pressure drop of each tooth cavity gradually becomes less along the flow direction.

  1. Apparatus and method for inspecting a sealed container

    Science.gov (United States)

    Harmon, J Frank [Pocatello, ID; Jones, James L [Idaho Falls, ID; Hunt, Alan W [Pocatello, ID; Spaulding, Randy J [Pocatello, ID; Smith, Michael [Phoenix, AZ

    2009-03-24

    An apparatus for inspecting a sealed container is disclosed and which includes a pulsed electron accelerator which is positioned in spaced relation relative to a first side of the sealed container, and which produces a pulsed beam of photons which passes through the sealed container and any contents enclosed within the sealed container; a detector positioned in spaced relation relative to a second, opposite side of the sealed container, and which receives the pulsed beam of photons which passes through the contents of the sealed container, and which produces an output signal; and a computer for developing a visible image from the output signal of the detector which depicts the contents of the sealed container.

  2. Seals/Secondary Fluid Flows Workshop 1997; Volume I

    Science.gov (United States)

    Hendricks, Robert C. (Editor)

    2006-01-01

    The 1997 Conference provided discussions and data on (a) program overviews, (b) developments in seals and secondary air management systems, (c) interactive seals flows with secondary air or fluid flows and powerstream flows, (d) views of engine externals and limitations, (e) high speed engine research sealing needs and demands, and (f) a short course on engine design development margins. Sealing concepts discussed include, mechanical rim and cavity seals, leaf, finger, air/oil, rope, floating-brush, floating-T-buffer, and brush seals. Engine externals include all components of engine fluid systems, sensors and their support structures that lie within or project through the nacelle. The clean features of the nacelle belie the minefield of challenges and opportunities that lie within. Seals; Secondary air flows; Rotordynamics; Gas turbine; Aircraft; CFD; Testing; Turbomachinery

  3. Manifold seal structure for fuel cell stack

    Science.gov (United States)

    Collins, William P.

    1988-01-01

    The seal between the sides of a fuel cell stack and the gas manifolds is improved by adding a mechanical interlock between the adhesive sealing strip and the abutting surface of the manifolds. The adhesive is a material which can flow to some extent when under compression, and the mechanical interlock is formed providing small openings in the portion of the manifold which abuts the adhesive strip. When the manifolds are pressed against the adhesive strips, the latter will flow into and through the manifold openings to form buttons or ribs which mechanically interlock with the manifolds. These buttons or ribs increase the bond between the manifolds and adhesive, which previously relied solely on the adhesive nature of the adhesive.

  4. Advanced Bristle Seals for Gas Turbine Engines

    Science.gov (United States)

    1993-01-28

    test sequence I retained the .003 inch shim and added a positive seal between the shim stock and the housing using Room Temperature Vulcanizing (RTV...113.4 200 6 1.131 1.040 175.142 0.219 * STANDARD CUBIC FOOT PER MINUTE u FLOW(cfm) OF AIR 2 70F/14.7psil TABLE C-8. TESI SEQUENCE H DATA "H. STATIC

  5. Shrink-Fit Solderable Inserts Seal Hermetically

    Science.gov (United States)

    Croucher, William C.

    1992-01-01

    Shrink-fit stainless-steel insert in aluminum equipment housing allows electrical connectors to be replaced by soldering, without degrading hermeticity of housing or connector. Welding could destroy electrostatic-sensitive components and harm housing and internal cables. Steel insert avoids problems because connector soldered directly to it rather than welded to housing. Seals between flange and housing, and between connector and flange resistant to leaks, even after mechanical overloading and thermal shocking.

  6. Sealed silica pressure ampoules for crystal growth

    Science.gov (United States)

    Holland, L. R.

    1984-01-01

    The properties of vitreous silica and the mechanics of thick walled pressure vessels are reviewed with regard to the construction of sealed silica crucibles such as are used in the growth of mercury-cadmium telluride crystals. Data from destructive rupture tests are reported, failure modes discussed, and recommendations for design given. Ordinary commercial clear vitreous silica from flame fused quartz can withstand a surface stress of 20 MPa or more in this application.

  7. Possible origin of life between mica sheets: does life imitate mica?

    Science.gov (United States)

    Hansma, Helen Greenwood

    2013-01-01

    The mica hypothesis for the origin of life proposes that life originated between the sheets of muscovite mica. This paper elaborates on two ways that life resembles what might have originated between mica sheets. First, enzymes: The configurations and dynamics of enzymes, with their substrates, cofactors, and sometimes transition metal ions, often resemble mica sheets, with their open-and-shut motions, acting on small molecules between them, sometimes assisted by transition metal ions. Second, organisms: Mica world had the potential to be a community or ecosystem of prebiotic organisms in a way unlike other models for the origin of life.

  8. How do seal whiskers suppress vortex shedding

    Science.gov (United States)

    Rinehart, Aidan; Flaherty, Justin; Bunjavick, Joseph; Shyam, Vikram; Zhang, Wei

    2016-11-01

    Certain seal whiskers possess a unique geometry that significantly reduces the vortex-induced vibration; which has attracted great attention to understand how the unique shape re-organizes the wake structure and its potential for passive flow control. The shape of the whiskers can be described as an elliptical cross-section that is lofted along the length of the whisker. Along the entire length of the whisker the ellipse varies in major and minor axis as well as angle of incidence with respect to the axis of the whisker. Of particular interest in this study is to identify what effect the angle of incidence has on the flow structure around the whisker, which has been overlooked in the past. The study will analyze the wake structure behind various scaled-up whisker models using particle image velocimitry (PIV). These whisker models share common geometry dimensions except for the angle of incidence. Flow conditions are created in a water channel and a wind tunnel, covering a wide range of Reynolds number (a few hundreds to thousands), similar to the ambient flow environment of seals and to the targeted aero-propulsion applications. This study will help address knowledge gaps in understanding of how certain geometry features of seal whiskers influence the wake and establish best practices for its application as effective passive flow control strategy.

  9. CENTRIFUGAL PUMP AND SHAFT SEALING MEANS

    Science.gov (United States)

    Rushing, F.C.

    1960-09-01

    A description is given of sealing means between a hollow rotatable shaft and a stationary member surrounding the shaft which defines therewith a sealing space of annular cross-section, comprising a plurality of axially spaced rings held against seats by ring springs which serve to subdivide the sealing space- into a plurality of zones. Process gas introduced into the hollow shaft through a port communicating with a centrally located zone which iu turn communicates with a bore in the sleeve, is removed from the shaft through a second port communicating with an adjacent central zone and discharged through a second bore. A sealant gas is supplied to an end zone under a pressure sufficient to cause it to flow axially into adjacent zones and then maintained at a lower pressure than either the sealant gas source or the process gas inlet zone, preventing the sealant gas from entering the shaft and allowing gases leaking into the sealant gas to be withdrawn and led to a separator.

  10. Management of disused plutonium sealed sources

    Energy Technology Data Exchange (ETDEWEB)

    Whitworth, Julia Rose [Los Alamos National Laboratory; Pearson, Michael W [Los Alamos National Laboratory; Abeyta, Cristy [Los Alamos National Laboratory

    2010-01-01

    The Global Threat Reduction Initiative's (GTRI) Offsite Source Recovery Project (OSRP) has been recovering excess and unwanted radioactive sealed sources since 1999, including more than 2,400 Plutonium (Pu)-238 sealed sources and 653 Pu-239-bearing sources that represent more than 10% of the total sources recovered by GTRI/OSRP to date. These sources have been recovered from hundreds of sites within the United States (US) and around the world. OSRP grew out of early efforts at the Los Alamos National Laboratory (LANL) to recover and disposition excess Plutonium-239 (Pu-239) sealed sources that were distributed in the 1960s and 1970s under the Atoms for Peace Program, a loan-lease program that serviced 31 countries, as well as domestic users. In the conduct of these recovery operations, GTRI/OSRP has been required to solve problems related to knowledge-of-inventory, packaging and transportation of fissile and heat-source materials, transfer of ownership, storage of special nuclear material (SNM) both at US Department of Energy (DOE) facilities and commercially, and disposal. Unique issues associated with repatriation from foreign countries, including end user agreements required by some European countries and denials of shipment, will also be discussed.

  11. Numerical and experimental evaluation of performance of centrifugal seals

    Indian Academy of Sciences (India)

    T V SANAND; P PRADEEP KUMAR; P UNNIKRISHNAN NAIR; PAUL P GEORGE

    2017-04-01

    ‘Centrifugal seals’ or ‘Slinger seals’ offer an attractive choice as non-contact-type sealing in fluid machinery. These seals utilize the radial pressure gradient caused by centrifugal forces in a rotating fluid ring, to create a sealing of the working fluid. Basic construction of a typical seal consists of a rotating disc inside astationary casing; one side of the disc (sealing side) is provided with a set of slots (Type-1) or vanes (Type-2) to enhance the tangential velocity of the fluid. The other side of the disk (back side) in both the configurations is exposed to high pressure liquid being sealed. Both numerical and experimental investigations of the performance of Type-1 seal (with slots) have been carried out so as to optimize the seal configuration to achieve maximum sealing capacity, with minimum power consumption. A comparison of the performance of Type-1 seal has been made with that of conventional one (Type-2) in view of economy of construction and better sealing with minimal expense of power consumption. A test rig that allows for varying the major geometrical and operating parameters was designed and tests were conducted with water as the medium. Influence of major geometric parameters like dimensions and number of slots, axial/radial clearances and major operating parameters like rotational speed, inlet pressure and sealing fluid bypass flow rate has been investigated. Apart from variouspressure, temperature, flow and torque measurements, the interface between the sealing and working fluid for the experiments was captured and recorded using a high speed camera at 26,000 frames per second. Geometrical configuration for the slots that maximizes the sealing capacity is arrived through 3D numerical simulations using commercial CFD solver ANSYS Fluent®. A good agreement is obtained with respect to experimental results. In view of economy of construction and better sealing with minimal expense of operating power, a modified version of Type-1 seal

  12. Sealed Crawl Spaces with Integrated Whole-House Ventilation in a Cold Climate

    Energy Technology Data Exchange (ETDEWEB)

    Zoeller, William [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Williamson, James [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-07-01

    One method of code-compliance for crawlspaces is to seal and insulate the crawlspace, rather than venting to the outdoors. However, codes require mechanical ventilation; either via conditioned supply air from the HVAC system, or a continuous exhaust ventilation strategy. As the CARB's building partner, Ithaca Neighborhood Housing Services, intended to use the unvented crawlspace in a recent development, CARB was interested in investigating a hybrid ventilation method that includes the exhaust air from the crawlspace as a portion of an ASHRAE 62.2 compliant whole-house ventilation strategy. This hybrid ventilation method was evaluated through a series of long-term monitoring tests that observed temperature, humidity, and pressure conditions through the home and crawlspace.

  13. A química da vida

    OpenAIRE

    2014-01-01

    A Bioquímica ou Química da Vida é uma ciência interdisciplinar que utiliza estratégias e métodos de todas as Ciências Exactas e Naturais. Nos últimos 10 anos, foram catorze os prémios Nobel da Química, Fisiologia e Medicina que foram atribuídos na área da Bioquímica o que reflecte a importância desta área de conhecimento nas Sociedades contemporâneas. A Química da Vida não se reduz apenas ao estudo dos compostos orgânicos, tais como os açúcares, lipidos ou proteínas mas tamb...

  14. Bipolar electrosurgical vessel-sealing device with compressive force monitoring.

    Science.gov (United States)

    Chen, Roland K; Chastagner, Matthew W; Geiger, James D; Shih, Albert J

    2014-06-01

    Bipolar electrosurgical vessel sealing is commonly used in surgery to perform hemostasis. The electrode compressive force is demonstrably an important factor affecting the vessel seal burst pressure, an index of the seal quality. Using a piezoresistive force sensor attached to the handle of a laparoscopic surgical device, applied handle force was measured and used to predict the electrosurgical vessel compressive force and the pressure at the electrode. The sensor enables the monitoring of vessel compressive force during surgery. Four levels of compressive force were applied to seal three types of porcine vessels (carotid artery, femoral artery, and jugular vein). The burst pressure of the vessel seal was tested to evaluate the seal quality. Compressive pressure was found to be a statistically significant factor affecting burst pressure for femoral arteries and jugular veins. Vessels sealed with low compressive pressure (<300 kPa) have a higher failure rate (burst pressure<100 mm Hg) than vessels sealed with high compressive pressure. An adequate compressive force is required to generate the compressive pressure needed to form a seal with high burst pressure. A laparoscopic surgical device with compressive force monitoring capability can help ensure adequate compressive pressure, vessel burst pressure, and quality of seal.

  15. Failure of Magnetic Fluid Seals Operating in Water: Preliminary Conclusions

    Directory of Open Access Journals (Sweden)

    Matuszewski Leszek

    2017-06-01

    Full Text Available The article analyses properties of magnetic fluid seals installed in rotary sealing nodes which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals exposed to longterm utility water loads, at different water pressures and shaft revolutions. The basic seal durability criterion was the number of revolutions made by the sealing node shaft until the appearance of water tightness loss (leakage. It was found that the main factor leading to the wear of the seal is the relative speed of the magnetic fluid with respect to that of the utility water, and this process is heavily affected by the pressure acting on the seal. The reported test results are presented in the form of diagrams showing the seal durability (time until water tightness loss as a function of rotational speed. The curves shown in the diagrams are regular, with two different rotational speed ranges: the highspeed range, when the tightness loss is relatively fast, and the low-speed range, with a clear tendency to prolong the seal lifetime. These diagrams were given the name of durability curves of the MF seal operating in water. The results of the performed tests suggest formal similarity between the experimental data distribution concerning tightness loss processes occurring in magnetic fluid seals operating in water environment and metal fatigue processes. The article proposes a preliminary simplified durability model to describe the examined phenomenon.

  16. 自适应接触式机械密封性能研究%Sealing Performance of Adaptive Contacting Mechanical Seal

    Institute of Scientific and Technical Information of China (English)

    赵星宇; 刘莹; 高志; 黄伟锋; 刘向锋; 王玉明

    2015-01-01

    The mechanism of a kind of adaptive contacting mechanical seal which is applied in pressurized water reactor nuclear coolant pumps in different operating conditions is investigated by the hybrid lubrication model coupled with thermal and elastic deformation and elastic hydrodynamic lubrication model. The floating structure of static ring with O-ring is given, and its performance is compared with interferential structure applied in import product. A full-scale vertical experiment rig for adaptive contacting mechanical seal is set up. The seal performance of the adaptive contacting mechanical seal in two statuses is obtained from the experiments which prove the two theoretical models. The feasibility and reliability of floating structure of static ring is verified by the experiments also. These results are beneficial to the domestic design and manufacturing of mechanical seals in nuclear coolant pump.%以压水堆核主泵静压轴封系统中具有自适应性的接触式机械密封为对象,分别采用热流固耦合混合润滑和流固耦合流体润滑模型,研究了不同工况下密封性能演变规律;提出了具有更好工艺性能的静环组件浮动安装结构并与国外产品采用的镶装结构密封性能进行了比较。自行研制了立式、全尺寸自适应接触式机械密封性能试验系统,获得自适应接触式机械密封在核主泵密封两种典型工作状态下的密封性能,验证了理论分析模型。同时,通过试验验证了静环组件浮动安装结构的可行性与性能,为国产化设计与制造提供了理论和实践基础。

  17. Sharks shape the geometry of a selfish seal herd: experimental evidence from seal decoys.

    Science.gov (United States)

    De Vos, Alta; O'Riain, M Justin

    2010-02-23

    Many animals respond to predation risk by forming groups. Evolutionary explanations for group formation in previously ungrouped, but loosely associated prey have typically evoked the selfish herd hypothesis. However, despite over 600 studies across a diverse array of taxa, the critical assumptions of this hypothesis have remained collectively untested, owing to several confounding problems in real predator-prey systems. To solve this, we manipulated the domains of danger of Cape fur seal (Arctocephalus pusillus pusillus) decoys to provide evidence that a selfish reduction in a seals' domain of danger results in a proportional reduction in its predation risk from ambush shark attacks. This behaviour confers a survival advantage to individual seals within a group and explains the evolution of selfish herds in a prey species. These findings empirically elevate Hamilton's selfish herd hypothesis to more than a 'theoretical curiosity'.

  18. Fluorine uptake into the human enamel surface from fluoride-containing sealing materials during cariogenic pH cycling

    Science.gov (United States)

    Yasuhiro, Matsuda; Katsushi, Okuyama; Hiroko, Yamamoto; Hisanori, Komatsu; Masashi, Koka; Takahiro, Sato; Naoki, Hashimoto; Saiko, Oki; Chiharu, Kawamoto; Hidehiko, Sano

    2015-04-01

    To prevent the formation of caries and reduce dentin hypersensitivity, sealing materials, either with or without fluoride, are generally applied on the tooth in clinical practice. Application of fluoride-free sealing materials results in the formation of an acid-resistant layer on the tooth surface. On the other hand, fluoride-containing sealing materials might not only form an acid-resistant layer but could possibly further provide fluoride to enhance remineralization and reduce demineralization. In this study, the demineralization prevention ability and fluorine uptake rate in human enamel of fluoride-containing sealing materials ["MS coats F" (MSF)] and fluoride-free sealing materials ("hybrid coats 2" [HI]) were evaluated using an automatic pH cycling system. Each material was applied to the original tooth surface, the cut surfaces were covered with sticky wax, and the automatic pH-cycling system simulated daily acid changes (pH 6.8-4.5) occurring in the oral cavity for 4 weeks. Caries progression was analyzed using transverse microradiography (TMR) taken pre and post the 4 weeks of pH cycling. The fluorine and calcium distributions in the carious lesion in each specimen were evaluated using the proton-induced gamma emission (PIGE) and proton-induced X-ray (PIXE) techniques, respectively. TMR analysis showed that both MSF and HI had a caries-preventing effect after 4 weeks of pH cycling. PIGE/PIXE analysis demonstrated that only MSF resulted in fluoride uptake in the enamel surface. Therefore, MSF can help to form an acid-resistant layer and provide fluoride to the enamel surface. The presence of fluoride on the enamel surface suggested that MSF could prevent demineralization, even if the acid-resistant layer was removed, in clinical settings. The data obtained using the PIGE and PIXE techniques are useful for understanding the benefits of the use of a fluoride-containing sealing material for preventing caries.

  19. Influence of ensiling temperature, simulated rainfall, and delayed sealing on fermentation characteristics and aerobic stability of corn silage.

    Science.gov (United States)

    Kim, S C; Adesogan, A T

    2006-08-01

    The aim of this study was to determine how delayed silo sealing, high ensiling temperatures, and rainfall at harvest affect the fermentation and aerobic stability of corn silage. One-half of each of 4 replicated, 6 x 1.5 m plots of a corn hybrid was harvested at 35% dry matter (Dry), and each of the other halves was harvested after they were sprinkled with sufficient water to simulate 4 mm of rainfall (Wet). Six representative (2 kg) subsamples were taken from the Wet and Dry forage piles and ensiled immediately (Prompt). Three hours later, 6 additional representative (2 kg) samples were taken from each pile and ensiled (Delay). Half of the bags from each moisture x sealing time treatment combination were stored for 82 d in a 40 degrees C incubator (Hot) and the other half were stored in a 20 degrees C air-conditioned room (Cool). A 2 (moisture treatments) x 2 (sealing times) x 2 (ensiling temperatures) factorial design with 3 replicates per treatment was used for the study. Wetting the corn silage increased concentrations of NH(3)-N, ethanol, and acetic acid. Ensiling at 40 instead of 20 degrees C increased pH, in vitro digestibility, and concentrations of NH(3)-N, residual water-soluble carbohydrates and acid detergent insoluble crude protein. The higher ensiling temperature also reduced concentrations of neutral and acid detergent fiber and lactic and acetic acid. Delayed sealing reduced concentrations of NH(3)-N and total volatile fatty acids. Wetting, high temperature ensiling, and delayed sealing each reduced yeast counts slightly, and marginally (8 h) increased aerobic stability. Hot-Wet-Delay silages were more stable than other silages but had the lowest lactic to acetic acid ratio, and total volatile fatty acid concentration. This study indicates that the fermentation of corn silage is adversely affected by wet conditions at harvest and high ensiling temperatures, whereas delayed silo sealing for 3 h caused no adverse effects.

  20. Hybrid Metaheuristics

    CERN Document Server

    2013-01-01

    The main goal of this book is to provide a state of the art of hybrid metaheuristics. The book provides a complete background that enables readers to design and implement hybrid metaheuristics to solve complex optimization problems (continuous/discrete, mono-objective/multi-objective, optimization under uncertainty) in a diverse range of application domains. Readers learn to solve large scale problems quickly and efficiently combining metaheuristics with complementary metaheuristics, mathematical programming, constraint programming and machine learning. Numerous real-world examples of problems and solutions demonstrate how hybrid metaheuristics are applied in such fields as networks, logistics and transportation, bio-medical, engineering design, scheduling.

  1. Phocid seals, seal lice and heartworms: a terrestrial host-parasite system conveyed to the marine environment.

    Science.gov (United States)

    Leidenberger, Sonja; Harding, Karin; Härkönen, Tero

    2007-10-15

    Adaptation of pinnipeds to the marine habitat imposed parallel evolutions in their parasites. Ancestral pinnipeds must have harboured sucking lice, which were ancestors of the seal louse Echinophthirius horridus. The seal louse is one of the few insects that successfully adjusted to the marine environment. Adaptations such as keeping an air reservoir and the ability to hold on to and move on the host were necessary, as well as an adjustment of their life cycle to fit the diving habits of their host. E. horridus are confined to the Northern Hemisphere and have been reported from 9 species of northern phocids belonging to 4 genera, including land-locked seal species. The transmission from seal to seal is only possible when animals are hauled-out on land or ice. Lice are rarely found on healthy adult seals, but frequently on weak and young animals. The seal louse is suggested to play an important role as an intermediate host transmitting the heartworm Acanthocheilonema spirocauda among seals. However, the evidence is restricted to a single study where the first 3 larval stages of the heartworm were shown to develop in the louse. The fourth-stage larvae develop in the blood system of seals and eventually transform into the adult stage that matures in the heart. Since all other studies failed to confirm the presence of heartworm larvae in seal lice, other unknown intermediate hosts could be involved in the transmission of the heartworm. Transplacental transmission of microfilariae in seals has been suggested as an additional possibility, but is not likely to be important since the occurrence of heartworms in adult seals is very rare compared with juveniles. Furthermore, there are no findings of the first 3 larval stages in seals. This review shows that the heartworm infects nearly the same species of seals as the seal louse, except for the grey seal Halichoerus grypus, where the heartworm is absent. Prevalence and intensity of infection differ among regions in the

  2. Apartment Compartmentalization With an Aerosol-Based Sealing Process

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Berger, D. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Harrington, C. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-03-01

    Air sealing of building enclosures is a difficult and time-consuming process. Current methods in new construction require laborers to physically locate small and sometimes large holes in multiple assemblies and then manually seal each of them. The innovation demonstrated under this research study was the automated air sealing and compartmentalization of buildings through the use of an aerosolized sealant, developed by the Western Cooling Efficiency Center at University of California Davis. CARB sought to demonstrate this new technology application in a multifamily building in Queens, NY. The effectiveness of the sealing process was evaluated by three methods: air leakage testing of overall apartment before and after sealing, point-source testing of individual leaks, and pressure measurements in the walls of the target apartment during sealing.

  3. Field Trial of an Aerosol-Based Enclosure Sealing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Curtis [Univ. of California, Davis, CA (United States); Springer, David [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2015-09-01

    This report presents the results from several demonstrations of a new method for sealing building envelope air leaks using an aerosol sealing process developed by the Western Cooling Efficiency Center at UC Davis. The process involves pressurizing a building while applying an aerosol sealant to the interior. As air escapes through leaks in the building envelope, the aerosol particles are transported to the leaks where they collect and form a seal that blocks the leak. Standard blower door technology is used to facilitate the building pressurization, which allows the installer to track the sealing progress during the installation and automatically verify the final building tightness. Each aerosol envelope sealing installation was performed after drywall was installed and taped, and the process did not appear to interrupt the construction schedule or interfere with other trades working in the homes. The labor needed to physically seal bulk air leaks in typical construction will not be replaced by this technology.

  4. Characterizing fluidic seals for on-board reagent delivery

    Science.gov (United States)

    Inamdar, Tejas; Anthony, Brian W.

    2013-03-01

    The reagent delivery mechanism in a point-of-care, HIV diagnostic, microfluidic device is studied. Reagents held in an aluminum blister pack are released on the opening of a fluidic seal. The fluidic seals, controlling the flow of reagents, are characterized to reduce anomalies in the desired flow pattern. The findings of this research can be divided into three categories - 1) bonding phenomenon 2) influence of seal pattern on flow and rupture mechanics and 3) process parameters which minimize flow anomalies. Four seal patterns - line hemisphere, line flat, chevron hemisphere and chevron flat were created and tested for reagent delivery using a flow sensor and a force gauge. Experiments suggest that one of the patterns - line-flat - inducted the fewest flow anomalies. A parameter scoping exercise of the seal manufacturing process parameters (temperature, time, pressure) was performed for the line flat seal. Temperature, time, pressure / gap and distance settings which minimize flow anomalies were found.

  5. Pressure actuated film riding seals for turbo machinery

    Energy Technology Data Exchange (ETDEWEB)

    Bidkar, Rahul Anil; Thatte, Azam Mihir; Gibson, Nathan Evan McCurdy; Giametta, Andrew Paul

    2015-08-25

    A seal assembly for a rotary machine is provided. The seal assembly includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the sealing device segments includes a stator interface element, a shoe plate having an extended portion having one or more labyrinth teeth facing the rotor and a load bearing portion, wherein the shoe plate is configured to generate an aerodynamic force between the shoe plate and the rotor. The sealing device segment further includes a secondary seal configured to be in contact with the stator interface element at a radially outer end and configured to be in contact with an elevated nose section of the extended portion of the shoe plate on a radially inner end; and multiple flexible elements attached to the shoe plate and to the stator interface element.

  6. A New Design of Magnetic Fluid Seal for Liquids

    Institute of Scientific and Technical Information of China (English)

    LIU Tong-gang; YANG Zhi-yi

    2005-01-01

    Direct contract between the sealed liquid and the magnetic fluid in a dynamic system under magnetic field may lead to an unstable interface, consequently, break down the seal. Aiming at this problem, a new magnetic fluid seal (MFS) was developed. In this new MFS, a soft iron bushing with high permeability was introduced on the shaft and nonferrous shields were installed beside the bushing and the pole pieces. The parameters of the bushing and the shields were optimized in a seal simulation facility. The results show that the bushing with a thickness of 7 mm and shields with a width of 8 mm are best for sealing a shaft 20 mm in diameter. The MFS designed based on the optimum parameters shows good performance and long life span for sealing lubricating oil.

  7. Condition monitoring of reciprocating seal based on FBG sensors

    Science.gov (United States)

    Zhao, Xiuxu; Zhang, Shuanshuan; Wen, Pengfei; Zhen, Wenhan; Ke, Wei

    2016-07-01

    The failure of hydraulic reciprocating seals will seriously affect the normal operation of hydraulic reciprocating machinery, so the potential fault condition monitoring of reciprocating seals is very important. However, it is extremely difficult because of the limitation of reciprocating motion and the structure constraints of seal groove. In this study, an approach using fiber Bragg grating (FBG) sensors is presented. Experimental results show that the contact strain changes of a reciprocating seal can be detected by FBG sensors in the operation process of the hydraulic cylinders. The failure condition of the reciprocating seal can be identified by wavelet packet energy entropy, and the center frequency of power spectrum analysis. It can provide an effective solution for the fault prevention and health management of reciprocating hydraulic rod seals.

  8. Method of forming shrink-fit compression seal

    Science.gov (United States)

    Podgorski, T. J. (Inventor)

    1977-01-01

    A method for making a glass-to-metal seal is described. A domed metal enclosure having a machined seal ring is fitted to a glass post machined to a slight taper and to a desired surface finish. The metal part is then heated by induction in a vacuum. As the metal part heats and expands relative to the glass post, the metal seal ring, possessing a higher coefficient of expansion than the glass post, slides down the tapered post. Upon cooling, the seal ring crushes against the glass post forming the seal. The method results in a glass-to-metal seal possessing extremely good leak resistance, while the parts are kept clean and free of the contaminants.

  9. Manufacturing of aluminium nano hybrid composites: a state of review

    Science.gov (United States)

    Madhukar, P.; Selvaraj, N.; Rao, CSP

    2016-09-01

    This paper gives the details of hybrid composites, their fabrication methods and evaluation of mechanical, tribological behaviour and machining characteristics. Investigations on the various aspects of Hybrid composites furnish several conclusions regarding the influence of various parameters on the performance of the composites. Mostly micro structures of the hybrid composites fabricated through casting routes have been found to be stable with the distribution of uniformed reinforce particles. therefore, the hybrid composites can be constructed with various combinations of reinforcements to carry out desirable mechanical properties. The density of Hybrid composites increases with increasing reinforcements such as SiC, TiC, B4C....etc, while incorporation of partial reinforcements like fly ash, mica, rice husk, etc. reduces the density of composites. The study also reports that the hybrid composites can be treated as a replacement for regular composite materials in different advanced applications.

  10. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  11. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available effect was observed for the elongation at break of the hybrid composites. The impact strength of the hybrid composites increased with the addition of glass fibres. The tensile and impact properties of thermoplastic natural rubber reinforced short... panels made from conventional structural materials. Figure 3 illustrates the performance of cellular biocomposite panels against conventional systems used for building and residential construction, namely a pre- cast pre-stressed hollow core concrete...

  12. Sealing of temporary cements in endodontics

    Directory of Open Access Journals (Sweden)

    Eduardo Gomes Ferraz

    2009-10-01

    Full Text Available Objective: The aim of this study was to assess the coronal leakage of three temporary cements in endodontics: Bioplic® (Biodinâmica, Londrina, Brazil, IRM® (Dentsply, Petrópolis, Brazil and Coltosol® (Vigodent, Bonsucesso, Brazil. Methods: Forty human pre-molars were divided into four groups: I (Bioplic® + adhesive system, II (Bioplic®, Biodinâmica, Londrina, Brasil, III (IRM®, Dentsply, Petrópolis, Brasil, and IV (Coltosol®, Vigodent, Bonsucesso, Brasil. The teeth were immersed in 1% Rodamine and kept at 37°C for 24h. They were then thermal cycled for seven days. Temperatures ranged between 5, 37 and 50°C. After longitudinal sectioning the leakage was measured in mm and statistical analysis was performed using the ANOVA and Tukey tests with a level of significance of 5%.Results: In the group in which Bioplic® was used with adhesive, a lower level of leakage was detected (0.37 ± 0.24. There was significant difference (p<0.05 between groups I and III, I and IV, II and III. Conclusion: It was concluded that all the tested material showed coronal leakage and that the use of the (Bioplic® Biodinâmica, Londrina, Brasilplus adhesive system showed the lowest level of leakage.

  13. Apartment Compartmentalization With an Aerosol-Based Sealing Process

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Sean [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Berger, David [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Harrington, Curtis [Univ. of California, Davis, CA (United States)

    2015-03-01

    The U.S. Department of Energy Building America Team, Consortium for Advanced Residential Buildings, sought to demonstrate this new technology application in a new construction multifamily building in Queens, New York. The effectiveness of the sealing process was evaluated by three methods: air leakage testing of overall apartment before-and-after sealing, point-source testing of individual leaks, and pressure measurements in the walls of an apartment during sealing.

  14. Hydraulic forces caused by annular pressure seals in centrifugal pumps

    Science.gov (United States)

    Iino, T.; Kaneko, H.

    1980-01-01

    The hydraulic forces caused by annular pressure seals were investigated. The measured inlet and exit loss coefficients of the flow through the seals were much smaller than the conventional values. The results indicate that the damping coefficient and the inertia coefficient of the fluid film in the seal are not affected much by the rotational speed or the eccentricity of the rotor, though the stiffness coefficient seemed to be influenced by the eccentricity.

  15. Hardness testing of some fissure-sealing materials.

    Science.gov (United States)

    Ulvestad, H

    1977-11-01

    The mechanical properties of fissure-sealing materials are of significant importance for their durability, i.e. their wear resistance. One of the methods of evaluating a material's resistance to attrition is to apply a hardness test. In the present investigation, the surface hardness of some fissure-sealing materials was tested. Sealants made from diluted composite materials and with inclusion of inorganic filler particles appeared to have a considerable higher surface hardness than the other sealing materials tested.

  16. Forming a Turbomachinery Seals Working Group - An Overview and Discussion

    Science.gov (United States)

    Proctor, Margaret P.

    2007-01-01

    A proposal to form a Turbomachinery Seals Working Group is discussed. Survey responses regarding the purpose, membership, and meeting frequency are presented as well as the areas of expertise and experience of the respondents. The types of seals used, designed, or sold, current work, and technical challenges of turbomachinery seals, their materials, analysis, geometry, manufacturing, maintenance, testing, and incorporation into engine systems are also presented.

  17. Develop Efficient Leak Proof M1 Abrams Plenum Seal

    Science.gov (United States)

    2014-05-07

    UNCLASSIFIED UNCLASSIFIED ER-GLSV11389-001.docx Develop Efficient Leak Proof M1 Abrams Plenum Seal SBIR Phase I: Topic A13-061...Leak Proof M1 Abrams Plenum Seal Christian Muehfeld Steve Pennala Great Lakes Sound & Vibration, Inc. 47140 North Main Street Houghton, MI 49931 ER...061. The purpose of this report is to show the feasibility of developing an efficient, leak proof plenum seal for the M1 Abrams . It also shows the

  18. Integral edge seals for phosphoric acid fuel cells

    Science.gov (United States)

    Granata, Jr., Samuel J. (Inventor); Woodle, Boyd M. (Inventor); Dunyak, Thomas J. (Inventor)

    1992-01-01

    A phosphoric acid fuel cell having integral edge seals formed by an elastomer permeating an outer peripheral band contiguous with the outer peripheral edges of the cathode and anode assemblies and the matrix to form an integral edge seal which is reliable, easy to manufacture and has creep characteristics similar to the anode, cathode and matrix assemblies inboard of the seals to assure good electrical contact throughout the life of the fuel cell.

  19. Twist seal for high-pressure vessels such as space shuttle rocket motors

    Science.gov (United States)

    von Pragenau, George L. (Inventor)

    1989-01-01

    Seals for sealing clevis and flange joints (14) of a solid rocket booster motor, and more particularly to a seal (30) which is twisted upon application of expansion forces to an edge seal (36). This twisting motion initially causes a leading edge seal (44) to be urged into sealing engagement with a surface (48) of an adjacent member (20) and thereafter, increasing fluid pressure on a pressurized side (64) of a seal (30) drives a broad sealing region (46) into sealing engagement with a surface (48).

  20. Influence analysis of secondary O-ring seals in dynamic behavior of spiral groove gas face seals

    Science.gov (United States)

    Hu, Songtao; Huang, Weifeng; Liu, Xiangfeng; Wang, Yuming

    2016-05-01

    The current research on secondary O-ring seals used in mechanical seals has begun to focus on their dynamic properties. However, detailed analysis of the dynamic properties of O-ring seals in spiral groove gas face seals is lacking. In particular a transient study and a difference analysis of steady-state and transient performance are imperative. In this paper, a case study is performed to gauge the effect of secondary O-ring seals on the dynamic behavior (steady-state performance and transient performance) of face seals. A numerical finite element method (FEM) model is developed for the dynamic analysis of spiral groove gas face seals with a flexibly mounted stator in the axial and angular modes. The rotor tilt angle, static stator tilt angle and O-ring damping are selected to investigate the effect of O-ring seals on face seals during stable running operation. The results show that the angular factor can be ignored to save time in the simulation under small damping or undamped conditions. However, large O-ring damping has an enormous effect on the angular phase difference of mated rings, affecting the steady-state performance of face seals and largely increasing the possibility of face contact that reduces the service life of face seals. A pressure drop fluctuation is carried out to analyze the effect of O-ring seals on the transient performance of face seals. The results show that face seals could remain stable without support stiffness and O-ring damping during normal stable operation but may enter a large-leakage state when confronting instantaneous fluctuations. The oscillation-amplitude shortening effect of O-ring damping on the axial mode is much greater than that on the angular modes and O-ring damping prefers to cater for axial motion at the cost of angular motion. This research proposes a detailed dynamic-property study of O-ring seals in spiral groove gas face seals, to assist in the design of face seals.

  1. An ideal sealed source life-cycle

    Energy Technology Data Exchange (ETDEWEB)

    Tompkins, Joseph Andrew [Los Alamos National Laboratory

    2009-01-01

    In the last 40 years, barriers to compliant and timely disposition of radioactive sealed sources have become apparent. The story starts with the explosive growth of nuclear gauging technologies in the 1960s. Dozens of companies in the US manufactured sources and many more created nuclear solutions to industrial gauging problems. Today they do not yet know how many Cat 1, 2, or 3 sources there are in the US. There are, at minimum, tens of thousands of sources, perhaps hundreds of thousands of sources. Affordable transportation solutions to consolidate all of these sources and disposition pathways for these sources do not exist. The root problem seems to be a lack of necessary regulatory framework that has allowed all of these problems to accumulate with no national plan for solving the problem. In the 1960s, Pu-238 displaced Pu-239 for most neutron and alpha source applications. In the 1970s, the availability of inexpensive Am-241 resulted in a proliferation of low energy gamma sources used in nuclear gauging, well logging, pacemakers, and X-ray fluorescence applications for example. In the 1980s, rapid expansion of worldwide petroleum exploration resulted in the expansion of Am-241 sources into international locations. Improvements of technology and regulation resulted in a change in isotopic distribution as Am-241 made Pu-239 and Pu-238 obsolete. Many early nuclear gauge technologies have been made obsolete as they were replaced by non-nuclear technoogies. With uncertainties in source end of life disposition and increased requirements for sealed source security, nuclear gauging technology is the last choice for modern process engineering gauging solutions. Over the same period, much was learned about licensing LLW disposition facilities as evident by the closure of early disposition facilities like Maxey Flats. The current difficulties in sealed source disposition start with adoption of the NLLW policy act of 1985, which created the state LLW compact system they

  2. Taller de Química Espectacular

    OpenAIRE

    Alonso Felipe, Jose Vicente

    2015-01-01

    En el Taller de Química Espectacular se describen y desarrollan distintos experimentos visualmente muy atractivos que permiten observar reacciones químicas con reactivos de propiedades opuestas, percibir desde el punto de vista sensorial las características de la reacción y en general, apreciar aspectos que se relacionan con conceptos de química tales como velocidad de reacción y catálisis, reacciones exotérmicas y endotérmicas, reacciones redox, equilibrios de precipitación, cristalizaciones...

  3. Biocerâmicas em Endodontia

    OpenAIRE

    Oliveira, Pedro Miguel da Silva

    2014-01-01

    Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária Introdução e Objectivos: Biocerâmicas incluem materiais cerâmicos projetados especificamente para uso em Medicina e Medicina Dentária. O objetivo deste trabalho é efetuar uma revisão bibliográfica em que demonstre a avaliação das propriedades físico-químicas das biocerâmicas e o seu uso em Endodontia. Radiopacidade, Fluid...

  4. STUDY ON RECIPROCATING SEALS FOR A LARGER DIAMETER AXIAL PISTON

    Institute of Scientific and Technical Information of China (English)

    Yang Jian; Yang Huayong; Xu Bing

    2004-01-01

    Sealing performance of the reciprocating seals on a larger diameter (100 mm in diameter ) axial piston is theoretically investigated.Based on the characteristics of the clearance flow between the seal and the piston, reasonable boundary conditions for Navier-Stokes equations are determined and the equations are modified, so that the final equations can describe the real flow state of the clearance flow.Through combining the final equations with finite element method, the pressure distributions within the clearance field during the reciprocating motion of the piston and the leakage rate with the pressure are studied.The deflections of the seal which affect sealing performance are calculated as well.Sealing performance of piston seals using oil as the working liquid is compared with using water.It is concluded that the seal using water as the working liquid is under dry friction, which cannot be dealt with the theory of fluid mechanics.The seal structure is only acceptable using oil as the working liquid..

  5. Reactor coolant pump shaft seal behavior during blackout conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mings, W.J.

    1985-01-01

    The United States Nuclear Regulatory Commission has classified the problem of reactor coolant pump seal failures as an unresolved safety issue. This decision was made in large part due to experimental results obtained from a research program developed to study shaft seal performance during station blackout and reported in this paper. Testing and analysis indicated a potential for pump seal failure under postulated blackout conditions leading to a loss of primary coolant with a concomitant danger of core uncovery. The work to date has not answered all the concerns regarding shaft seal failure but it has helped scope the problem and focus future research needed to completely resolve this issue.

  6. Split ring floating air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Jacob A

    2015-11-03

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, and a central passage connecting the annular cavity to the annular piston chamber to supply compressed air to the seal face, where the annular piston assembly is a split piston assembly to maintain a tight seal as coning of the rotor disk occurs.

  7. Investigation and Improvement of the Staggered Labyrinth Seal

    Institute of Scientific and Technical Information of China (English)

    LIN Zhirong; WANG Xudong; YUAN Xin; SHIBUKAWANaoki; NOGUCHI Taro

    2015-01-01

    Recent studies on staggered labyrinth seals have focused on the effects of different parameters, such as the pressure ratio and rotational speed on the leakage flow rate. However, few investigations pay sufficient attention to flow details and the sealing mechanism, which would be of practical importance in designing seals having higher performance. This paper establishes a theoretical model to study the seal mechanism, thus revealing that leakage is determined by the pressure ratio and geometric structure. Numerical simulation is implemented to illustrate details of the flow field within the seal structure. Viscous dissipation is used to quantitatively investigate the contribution that each location makes to the seal performance, revealing that orifices and stagnation points are the most important positions in the seal structure, generating the most dissipation. The orifice is carefully studied by using the theoretical model. Experiments for different pressure ratios are conducted and the results match well with those of the theoretical model and numerical simulation, verifying the theoretical model and analysis of the seal mechanism. Three new designs, based on a good understanding of the seal mechanism, are presented, with one reducing leakage by 24.5%.

  8. Soft Wire Seals For High Temperatures And Pressures

    Science.gov (United States)

    Tsou, Peter

    1996-01-01

    Soft metal wires used to make O-ring and similar seals for vessels, flanges, and fittings subject to pressures equal to or greater than 1,000 psi and temperatures equal to or greater than 100 degrees C. Seals containing soft metal wires made inexpensively because fabricated to looser tolerances like those of lower-temperature, lower-pressure elastomeric-O-ring seals, which they resemble. Seals also made with noncircular grooves and with soft metals other than aluminum. For example, gold performs well, though expensive. For other applications, silver good choice.

  9. Numerical Analysis of Nonlinear Rotor-bearing-seal System

    Institute of Scientific and Technical Information of China (English)

    CHENG Mei; MENG Guang; JING Jian-ping

    2008-01-01

    The system state trajectory, Poincaré maps, largest Lyapunov exponents, frequency spectra and bifurcation diagrams were used to investigate the non-linear dynamic behaviors of a rotor-bearing-seal coupled system and to analyze the influence of the seal and bearing on the nonlinear characteristics of the rotor system. Various nonlinear phenomena in the rotor-bearing-seal system, such as periodic motion, double-periodicmotion, multi-periodic motion and quasi-periodic motion were investigated. The results may contribute to a further understanding of the non-linear dynamics of the rotor-bearing-seal coupled system.

  10. Reducing Seal Adhesion in Low Impact Docking Systems

    Science.gov (United States)

    Banks, Bruce A.; Miller, Sharon K.

    2010-01-01

    Silicone elastomers, used in seals for airlocks or other sealing surfaces in space, are sticky in their as-received condition. Because of the sticking, a greater force may be needed to separate the mating surfaces. If the adhesion is sufficiently high, a sudden unpredicted movement of the spacecraft during undocking, vibration, or uneven release could pull off the seal, resulting in a damage that would have to be repaired before another docking. The damaged seal can result in significant gas leakage and possibly in a catastrophic mishap impacting the safety of the crew. It is also possible that a compromised seal could result in a delayed but sudden gas leak that could put the crew at unexpected risk. This is especially of concern for androgynous seals, which have identical mating surfaces on both sides for interchangeability and redundancy. Such seals typically have elastomer-on-elastomer sealing surfaces. To reduce sticking, one could use release agents such as powders and lubricants, but these can be easily removed and transferred to other surfaces, causing uneven sealing and contamination. Modification of the elastomer surface to make a more slippery and less sticky surface that is integral with the bulk elastomer would be more desirable.

  11. Rotordynamic and leakage characteristics of a 4-stage brush seal

    Science.gov (United States)

    Conner, K. J.; Childs, D. W.

    1992-12-01

    Experimental results are presented for the direct and cross-coupled stiffness and damping coefficients as well as the leakage performance for a 4-stage brush seal. Variable test parameters include the inlet pressure, pressure ratio, shaft speed, fluid prerotation, and seal spacing. Direct damping is shown to increase with running speed; otherwise, the rotordynamic coefficients are relatively insensitive to changes in the test parameters. Cross-coupled stiffness is generally unchanged by increasing the inlet tangential velocity to the seals, suggesting that the brush seal is not affected by inlet swirl. Direct stiffness is shown to increase with frequency; however, the magnitudes of direct stiffness are always positive. Cross-coupled stiffness increases slightly with frequency; yet not as drastically as direct stiffness. Comparisons of test results for the 4-stage brush seal with an 8-cavity labyrinth showed superior rotordynamics performance for the brush seal; viz., large values for direct stiffness and lower values for the (destabilizing) cross-coupled stiffness coefficient. The damping for brush seals is smaller, but comparable to labyrinth seals. The whirl-frequency ratio is always smaller for the brush seal.

  12. Low Leakage Turbine Shaft Seals for Advanced Combined Cycle Systems.

    Science.gov (United States)

    1984-11-01

    Study of Shaft Face Seal With Self-Acting Lift Augmentation", N71- 11579, Nov. 1970 29p. Povinelli , V.P. and McKibbin, A. H., "Development of...34, N73-24086, May 1973, 28p. Povinelli , V. P. and McKibbin, A. H., "Development of Mainshaft Seals for Advanced Air Breathing Propulsion Systems... Povinelli , V. P., "Current Seal Designs and Future Requirements for Turbine Engine Seals and Bearings", Journal of Aircraft, Vol. 12, No. 4, April 1975

  13. Measure Guideline: Guide to Attic Air Sealing

    Energy Technology Data Exchange (ETDEWEB)

    Lstiburek, Joseph [Building Science Corporation, Westford, MA (United States)

    2014-09-01

    The purpose of this measure guideline is to provide information and recommendations for the preparation work necessary prior to adding attic insulation. Even though the purpose of this guide is to save energy, health, safety, and durability should not be compromised by energy efficiency. Accordingly, combustion safety and ventilation for indoor air quality are addressed first. Durability and attic ventilation then follow. Finally, to maximize energy savings, air sealing is completed prior to insulating. The guide is intended for home remodelers, builders, insulation contractors, mechanical contractors, general contractors who have previously done remodeling and homeowners as a guide to the work that needs to be done.

  14. Compatibility testing of vacuum seal materials

    Science.gov (United States)

    Foster, P. A.; Rodin, W. A.

    1993-05-01

    Small scale materials compatibility testing was conducted for three elastomers considered for use as vacuum seal materials: Adiprene MOCA-cured; Adiprene Cyanacured; and Sylgard silastic rubber. The tests were conducted using orthogonal array designed experiments for each of the elastomers placed in contact with three materials commonly used during weapon disassembly operations: Duxseal, Sylgard 186 grease, and 2-propyl alcohol. The test results indicated that only the 2-propyl alcohol had a significant effect on the elastomer hardness and physical properties. The alcohol had the largest effect on the two Adiprene materials, and the silastic rubber was the least affected.

  15. Cadmium Toxicity to Ringed Seals (Phoca hispida)

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, R.; Riget, F. F.;

    as laboratory mammals. We have studied possible cadmium induced histopathological changes in the kidneys as well as a demineralisation of the skeletal system (DXA-scanning of lumbal vertebraes). No obvious cadmium induced toxic changes were found. Food composition and physiological adaptations may explain......Cadmium concentrations in kidneys from ringed seals (Phoca hispida) from North West Greenland (Qaanaaq) are high. Concentrations range at level known to induce renal toxic effects (mainly tubulopathy) and demineralisation (osteopenia) of the skeletal system (Fanconi's Syndrome) in humans as well...

  16. Ceramic-to-metal sealing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gates, W.G.

    1977-03-01

    Ceramic-to-metal sealing was accomplished by brazing a metallized alumina insulator to a Kovar (Carpenter Technology Corporation) pin and header. A braze alloy wetting evaluation and a braze joint tensile strength evaluation were completed by brazing the specimens in a hydrogen atmosphere. From these evaluations the best braze alloy and brazing cycle were selected. Twelve braze alloys were evaluated and Nicusil 3 (Western Gold and Platinum Company) braze alloy was found to have good wetting characteristics and optimum strength. Assemblies brazed with this alloy were vacuum leak tight and metallurgically sound.

  17. Remote video registration of seals at Rødsand seal sanctuary

    DEFF Research Database (Denmark)

    Edren, Susi M.C.; Teilmann, J.; Dietz, R.

    This report describes the preliminary use of a remote-controlled webbased camera system in the Rødsand seal sanctuary. The camera system powered by solar and wind energy is designed to operate under extreme weather conditions. Live images and still photos are transmitted to a land station, from...

  18. Influenza virus infection in seal (Phocidae) : seroepidemiological survey of influenza virus in Caspian seals(Phoca caspica)

    OpenAIRE

    OHISHI, Kazue; NINOMIYA, Ai; Kida, Hiroshi; Maruyama, Tadashi; Arai, Takaomi; Miyazaki, Nobuyuki

    2003-01-01

    In the last a few decades, several viral diseases in marine mammals such as seals and cetaceans were characterized. Influenza virus causes a worldwide zoonosis, influenza, and was shown to be involved in mass mortality in seals. Several influenza virus strains have been isolated from the sick seals. Because interspecies transmission of influenza virus plays a crucial role in the introduction of pandemic influenza disease in humans, it is important to monitor the virus distribution in wild ani...

  19. An entrance region friction factor model applied to annular seal analysis - Theory versus experiment for smooth and honeycomb seals

    Science.gov (United States)

    Elrod, D.; Nelson, C.; Childs, D.

    1989-01-01

    A friction factor model is developed for the entrance-region of a duct. The model is used in an annular gas seal analysis similar to Nelson's (1984). Predictions of the analysis are compared to experimental results for a smooth-stator/smooth-rotor seal and three honeycomb-stator/smooth-rotor seals. The model predicts a leakage and direct damping well. The model overpredicts the dependence of cross-coupled stiffness on fluid prerotation. The model predicts direct stiffness poorly.

  20. Bioactivity of mica/apatite glass ceramics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The bioactivity of mica/apatite glass ceramic composites, including the in vitro behavior in simulated body fluid and the histological appearance of the interface between the mica/apatite glass ceramics and the rabbit mandible defect in vivo under a dynamic condition. The results show that biological apatite layer forms on the surface of the mica/apatite glass ceramics after 1 d of immersion in the simulated body fluid, and becomes dense after 14 d. In vivo tests indicate that bone formation occurs after implantation for 14 d, and strong bonding of bone to the implant occurs after 42 d. No aseptic loosening occurs during 42 d of implantation. The finding shows that mica/apatite glass ceramics have good bioactivity and osteoconductivity for constructing bone graft, and can be promising for biomedical application.

  1. breve panorámica

    Directory of Open Access Journals (Sweden)

    Sandra M. Camelo Roa

    2005-01-01

    Full Text Available Desde los terrenos de la psicoinmunología, la presente revisión se propone una mirada panorámica a sus principales postulados, líneas de investigación, resultados y perspectivas. Para ello, inicialmente se abordaron algunos aspectos históricos de la relación entre la vida psíquica y la salud; posteriormente, se revisaron aspectos como la fisiología del sistema inmune especificando los tipos de inmunidad adquirida e inmunidad natural. Temas como las interacciones entre el sistema inmune y cerebro fueron revisados desde la evidencia experimental y resumidos en cuatro grupos: condicionamiento de la respuesta inmune, lesiones cerebrales, estrés e inmunidad y emociones e inmunidad. Finalmente, se contemplaron algunos métodos para el estudio del sistema inmune como los ensayos in vitro, citometría de flujo y ensayos in vivo. Como observaciones finales, toda la literatura sugiere que existe relación entre el sistema inmune y diversos estados psíquicos. Pero aún surgen preguntas de esta indiscutible relación sin tener una respuesta satisfactoria.

  2. Three-step cylindrical seal for high-performance turbomachines

    Science.gov (United States)

    Hendricks, Robert C.

    1987-01-01

    A three-step cylindrical seal configuration representing the seal for a high performance turbopump (e.g., the space shuttle main engine fuel pump) was tested under static (nonrotating) conditions. The test data included critical mass flux and pressure profiles over a wide range of inlet temperatures and pressures for fluid nitrogen and fluid hydrogen with the seal in concentric and fully eccentric positions. The critical mass flux (leakage rate) was 70% that of an equivalent straight cylindrical seal with a correspondingly higher pressure drop based on the same flow areas of 0.3569 sq cm but 85% that of the straight seal based on the third-step flow area of 0.3044 sq cm. The mass flow rates for the three step cylindrical seal in the fully eccentric and concentric positions were essentially the same, and the trends in flow coefficient followed those of a simple axisymmetric inlet configuration. However, for inlet stagnation temperatures less than the thermodynamic critical temperature the pressure profiles exhibited a flat region throughout the third step of the seal, with the pressure magnitude dependent on the inlet stagnation temperature. Such profiles represent an extreme positive direct stiffness. These conditions engendered a crossover in the pressure profile upstream of the postulated choke that resulted in a local negative stiffness. Flat and crossover profiles resulting from choking within the seal are practically unknown to the seal designer. However, they are of critical importance to turbomachine stability and must be integrated into any dynamic analysis of a seal of this configuration. In addition, choking is highly dependent on geometry, inlet-to-backpressure ratio, and inlet temperature and can occur within the seal even though the backpressure is above the critical pressure.

  3. Analysis of physical demands during bulk bag closing and sealing.

    Science.gov (United States)

    Nasarwanji, Mahiyar F; Reardon, Leanna M; Heberger, John R; Dempsey, Patrick G

    2016-05-01

    Several tools are sold and recommended for closing and sealing flexible intermediate bulk containers (bulk bags) which are used to transport product that has been mined and processed. However, there is limited information on the risks, physical demands, or the benefits of using one tool over another. The purpose of this study was to evaluate the physical demands involved with two closing methods and several sealing tools in order to provide recommendations for selecting tools to reduce exposure to risk factors for work-related musculoskeletal disorders. In this study, twelve participants completed bag closing and sealing tasks using two different closing methods and eight sealing tools on two types of bulk bags. Physical demands and performance were evaluated using muscle activity, perceived exertion, subjective ratings of use, and time. Results indicate that using the "flowering" method to close bags required on average 32% less muscle activity, 30% less perceived exertion, 42% less time, and was preferred by participants compared to using the "snaking" method. For sealing, there was no single method significantly better across all measures; however, using a pneumatic cable tie gun consistently had the lowest muscle activity and perceived exertion ratings. The pneumatic cable tie gun did require approximately 33% more time to seal the bag compared to methods without a tool, but the amount of time to seal the bag was comparable to using other tools. Further, sealing a spout bulk bag required on average 13% less muscle activity, 18% less perceived exertion, 35% less time, and was preferred by participants compared to sealing a duffle bulk bag. The current results suggest that closing the spout bag using the flowering method and sealing the bag using the pneumatic cable tie gun that is installed with a tool balancer is ergonomically advantageous. Our findings can help organizations select methods and tools that pose the lowest physical demands when closing and

  4. Brush seal shaft wear resistant coatings

    Science.gov (United States)

    Howe, Harold

    1995-03-01

    Brush seals suffer from high wear, which reduces their effectiveness. This work sought to reduce brush seal wear by identifying and testing several industry standard coatings. One of the coatings was developed for this work. It was a co-sprayed PSZ with boron-nitride added for a high temperature dry lubricant. Other coatings tested were a PSZ, chrome carbide and a bare rotor. Testing of these coatings included thermal shocking, tensile testing and wear/coefficient of friction testing. Wear testing consisted of applying a coating to a rotor and then running a sample tuft of SiC ceramic fiber against the coating. Surface speeds at point of contact were slightly over 1000 ft/sec. Rotor wear was noted, as well as coefficient of friction data. Results from the testing indicates that the oxide ceramic coatings cannot withstand the given set of conditions. Carbide coatings will not work because of the need for a metallic binder, which oxidizes in the high heat produced by friction. All work indicated a need for a coating that has a lubricant contained within itself and the coating must be resistant to an oxidizing environment.

  5. Sealed joint structure for electrochemical device

    Science.gov (United States)

    Tucker, Michael C; Jacobson, Craig P; De Jonghe, Lutgard C; Visco, Steven J

    2013-05-21

    Several members make up a joint in a high-temperature electrochemical device, wherein the various members perform different functions. The joint is useful for joining multiple cells (generally tubular modules) of an electrochemical device to produce a multi-cell segment-in-series stack for a solid oxide fuel cell, for instance. The joint includes sections that bond the joining members to each other; one or more seal sections that provide gas-tightness, and sections providing electrical connection and/or electrical insulation between the various joining members. A suitable joint configuration for an electrochemical device has a metal joint housing, a first porous electrode, a second porous electrode, separated from the first porous electrode by a solid electrolyte, and an insulating member disposed between the metal joint housing and the electrolyte and second electrode. One or more brazes structurally and electrically connects the first electrode to the metal joint housing and forms a gas tight seal between the first electrode and the second electrode.

  6. Evaluation of Polymer Hermetically Sealed Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander A.

    2014-01-01

    Polymer cathode tantalum capacitors have lower ESR (equivalent series resistance) compared to other types of tantalum capacitors and for this reason have gained popularity in the electronics design community. Their use allows improved performance of power supply systems along with substantial reduction of size and weight of the components used. However, these parts have poor thermal stability and can degrade in humid environments. Polymer hermetically sealed (PHS) capacitors avoid problems related to environmental degradation of molded case parts and can potentially replace current wet and solid hermetically sealed capacitors. In this work, PHS capacitors manufactured per DLA LAM DWG#13030 are evaluated for space applications. Several lots of capacitors manufactured over period from 2010 to 2014 were tested for the consistency of performance, electrical and thermal characteristics, highly accelerated life testing, and robustness under reverse bias and random vibration conditions. Special attention was given to analysis of leakage currents and the effect of long-term high temperature storage on capacitors in as is condition and after hermeticity loss. The results show that PHS capacitors might be especially effective for low-temperature applications or for system requiring a cold start-up. Additional screening and qualification testing have been recommended to assure the necessary quality of capacitors for space projects.

  7. Mineral resource of the month: Mica

    Science.gov (United States)

    Willett, Jason C.

    2014-01-01

    The mica mineral group includes 34 phyllosilicate minerals, all with a layered, platy texture. The mineral has been known for millennia: Mica was first mined in India about 4,000 years ago, where it was used primarily in medicines. The Mayans used it for decorative effect in stucco to make their temples sparkle in the sun. Today it is used in everything from electrical products to makeup.

  8. Propriedades dinâmicas de fluidos por simulação computacional: métodos híbridos atomístico-contínuo Computer simulations of dynamical properties of fluids: atomistic-continuum hybrid methods

    Directory of Open Access Journals (Sweden)

    Luciano T. Costa

    2010-01-01

    Full Text Available Computational methods for the calculation of dynamical properties of fluids might consider the system as a continuum or as an assembly of molecules. Molecular dynamics (MD simulation includes molecular resolution, whereas computational fluid dynamics (CFD considers the fluid as a continuum. This work provides a review of hybrid methods MD/CFD recently proposed in the literature. Theoretical foundations, basic approaches of computational methods, and dynamical properties typically calculated by MD and CFD are first presented in order to appreciate the similarities and differences between these two methods. Then, methods for coupling MD and CFD, and applications of hybrid simulations MD/CFD, are presented.

  9. Vacuum Packaging of MEMS With Multiple Internal Seal Rings

    Science.gov (United States)

    Hayworth, Ken; Yee, Karl; Shcheglov, Kirill; Bae, Youngsam; Wiberg, Dean; Peay, Chris; Challoner, Anthony

    2008-01-01

    A proposed method of design and fabrication of vacuum-packaged microelectromechanical systems (MEMS) and of individual microelectromechanical devices involves the use of multiple internal seal rings (MISRs) in conjunction with vias (through holes plated with metal for electrical contacts). The proposed method is compatible with mass production in a wafer-level fabrication process, in which the dozens of MEMS or individual microelectromechanical devices on a typical wafer are simultaneously vacuum packaged by bonding a capping wafer before the devices are singulated (cut apart by use of a dicing saw). In addition to being compatible with mass production, the proposed method would eliminate the need for some complex and expensive production steps and would yield more reliable vacuum seals. Conventionally, each MEMS or individual microelectromechanical device is fabricated as one of many identical units on a device wafer. Vacuum packaging is accomplished by bonding the device wafer to a capping wafer with metal seal rings (one ring surrounding each unit) that have been formed on the capping wafer. The electrical leads of each unit are laid out on what would otherwise be a flat surface of the device wafer, against which the seal ring is to be pressed for sealing. The resulting pattern of metal lines and their insulating oxide coverings presents a very rough and uneven surface, upon which it is difficult to pattern the sealing metal. Consequently, the seal is prone to leakage unless additional costly and complex planarization steps are performed before patterning the seal ring and bonding the wafers.

  10. 77 FR 73263 - Organization and Functions, and Seal

    Science.gov (United States)

    2012-12-10

    ... Federal Housing Enterprise Oversight 12 CFR Part 1700 RIN 2590-AA54 Organization and Functions, and Seal... Federal home loan banks, Organization and functions (Government agencies). 12 CFR Part 1200 Organization and functions (Government agencies), Seals and insignia. 12 CFR Part 1700 Organization and...

  11. 10 CFR 36.21 - Performance criteria for sealed sources.

    Science.gov (United States)

    2010-01-01

    ... or wet-source-change irradiator; (4) Must be encapsulated in a material resistant to general... resistance if the sources are for use in irradiator pools; and (5) In prototype testing of the sealed source... 10 Energy 1 2010-01-01 2010-01-01 false Performance criteria for sealed sources. 36.21 Section 36...

  12. Plastic ingestion by harbour seal (Phoca vitulina) in the Netherlands

    NARCIS (Netherlands)

    Bravo Rebolledo, E.; Franeker, van J.A.; Jansen, O.E.; Brasseur, S.M.J.M.

    2013-01-01

    Abundance of ingested debris by seals has been mentioned as a potential indicator of marine litter in the European Marine Strategy Framework Directive (MSFD). A sample of 107 stomachs, 100 intestines and 125 scats of harbour seals from the Netherlands was analysed for the presence of plastics. Incid

  13. Analog Video Authentication and Seal Verification Equipment Development

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Lancaster

    2012-09-01

    Under contract to the US Department of Energy in support of arms control treaty verification activities, the Savannah River National Laboratory in conjunction with the Pacific Northwest National Laboratory, the Idaho National Laboratory and Milagro Consulting, LLC developed equipment for use within a chain of custody regime. This paper discussed two specific devices, the Authentication Through the Lens (ATL) analog video authentication system and a photographic multi-seal reader. Both of these devices have been demonstrated in a field trial, and the experience gained throughout will also be discussed. Typically, cryptographic methods are used to prove the authenticity of digital images and video used in arms control chain of custody applications. However, in some applications analog cameras are used. Since cryptographic authentication methods will not work on analog video streams, a simple method of authenticating analog video was developed and tested. A photographic multi-seal reader was developed to image different types of visual unique identifiers for use in chain of custody and authentication activities. This seal reader is unique in its ability to image various types of seals including the Cobra Seal, Reflective Particle Tags, and adhesive seals. Flicker comparison is used to compare before and after images collected with the seal reader in order to detect tampering and verify the integrity of the seal.

  14. 46 CFR 59.10-30 - Seal welding.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated...

  15. Building America Top Innovations 2012: Attic Air Sealing Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-01-01

    This Building America Top Innovations profile describes the DOE-sponsored Guide to Attic Air Sealing by Building America research partner Building Science Corporation, which provides best practices for attic air sealing. The guide has had 21,000 views and 13,000 downloads since it was posted.

  16. 10 CFR 835.1202 - Accountable sealed radioactive sources.

    Science.gov (United States)

    2010-01-01

    ... radioactive material shall be controlled in a manner that minimizes the spread of radioactive contamination. ... 10 Energy 4 2010-01-01 2010-01-01 false Accountable sealed radioactive sources. 835.1202 Section 835.1202 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Sealed Radioactive Source...

  17. Sealing occlusal caries lesions in adults referred for restorative treatment

    DEFF Research Database (Denmark)

    Bakhshandeh, Azam; Qvist, Vibeke; Ekstrand, Kim R

    2012-01-01

    treatment by senior lecturers at School of Dentistry, Copenhagen, Denmark were included. In case the patient had more than one occlusal caries lesion, randomization between sealing and restoration was made; otherwise, the lesion was sealed. In total, 60 resin sealants and 12 composite restorations were made...

  18. Modelling prey consumption and switching by UK grey seals

    DEFF Research Database (Denmark)

    Smout, Sophie; Rindorf, Anna; Hammond, Philip S.

    2014-01-01

    Grey seals (Halichoerus grypus) are adaptable generalist predatorswhose diet includes commercial fish species such as cod. Consumption by the seals may reduce the size of some fish stocks or have an adverse effect on stock recovery programmes, especially because predation may trap sparse prey pop...

  19. 27 CFR 72.68 - Sale on sealed, competitive bids.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Sale on sealed, competitive bids. 72.68 Section 72.68 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... PROPERTY Administrative Sale or Disposition of Personal Property § 72.68 Sale on sealed, competitive...

  20. Mercury and selenium in wild and experimental seals

    NARCIS (Netherlands)

    Ven, van de W.S.M.; Koeman, J.H.; Svenson, A.

    1979-01-01

    This paper describes the tissue distribution of inorganic mercury, organic mercury selenium in Dutch and British seals as well as in seals which were dosed with methylmercury under experimental conditions. In the experimental animals, a time-related increase of both mercury and selenium was found in

  1. Unification of reactor elastomeric sealing based on material

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, N.K., E-mail: nksinha@igcar.gov.in [Indira Gandhi Centre for Atomic Research (IGCAR), Department of Atomic Energy (DAE), Kalpakkam, Tamilnadu 603102 (India); Raj, Baldev [Indira Gandhi Centre for Atomic Research (IGCAR), Department of Atomic Energy (DAE), Kalpakkam, Tamilnadu 603102 (India)

    2012-02-15

    The unification of elastomeric sealing applications of Indian nuclear reactors based on a few qualified fluoroelastomer/perfluoroelastomer compounds and standardized approaches for finite element analysis (FEA) based design, manufacturing process and antifriction coatings is discussed. It is shown that the advance polymer architecture based Viton{sup Registered-Sign} formulation developed for inflatable seals of 500 MWe Prototype Fast Breeder Reactor (PFBR) and its four basic variations can encompass other sealing applications of PFBR with minimum additional efforts on development and validation. Changing the blend ratio of Viton{sup Registered-Sign} GBL 200S and 600S in inflatable seal formulation could extend its use to Pressurized Heavy Water Reactors (PHWRs). The higher operating temperature of Advanced Heavy Water Reactor (AHWR) seals expands the choice to perfluoroelastomers. FEA based on plane-strain/axisymmetric modeling (with Mooney-Rivlin as the basic constitutive model), seal manufacture by cold feed extrusion and injection molding as well as plasma Teflon-like coating belonging to two variations obtained from the development of inflatable seals provide the necessary standardization for unification. The gains in simplification of design, development and operation of seals along with the enhancements of safety and reliability are expected to be substantial.

  2. Rapid recovery of Dutch gray seal colonies fueled by immigration

    NARCIS (Netherlands)

    Brasseur, S.M.J.M.; Polanen Petel, van T.; Gerrodette, T.; Meesters, E.; Reijnders, P.J.H.; Aarts, G.M.

    2015-01-01

    Gray seals were first observed breeding in the Dutch Wadden Sea in 1985, after centuries of absence. The breeding colony there is now the largest on the European continent. We describe the changes in gray seal numbers and their geographical expansion, and estimate how these processes were influenced

  3. Mercury and selenium in wild and experimental seals

    NARCIS (Netherlands)

    Ven, van de W.S.M.; Koeman, J.H.; Svenson, A.

    1979-01-01

    This paper describes the tissue distribution of inorganic mercury, organic mercury selenium in Dutch and British seals as well as in seals which were dosed with methylmercury under experimental conditions. In the experimental animals, a time-related increase of both mercury and selenium was found in

  4. Stirling engine or heat pump having an improved seal

    Science.gov (United States)

    White, Maurice A.; Riggle, Peter; Emigh, Stuart G.

    1985-01-01

    A Stirling Engine or Heat Pump having two relatively movable machine elements for power transmission purposes includes a hermetic seal bellows interposed between the elements for separating a working gas from a pressure compensating liquid that balances pressure across the bellows to reduce bellows stress and to assure long bellows life. The volume of pressure compensating liquid displaced due to relative movement between the machine elements is minimized by enclosing the compensating liquid within a region exposed to portions of both machine elements at one axial end of a slidable interface presented between them by a clearance seal having an effective diameter of the seal bellows. Pressure equalization across the bellows is achieved by a separate hermetically sealed compensator including a movable enclosed bellows. The interior of the compensator bellows is in communication with one side of the seal bellows, and its exterior is in communication with the remaining side of the seal bellows. A buffer gas or additional liquid region can be provided at the remaining axial end of the clearnace seal, along with valved arrangements for makeup of liquid leakage through the clearance seal.

  5. Dry compliant seal for phosphoric acid fuel cell

    Science.gov (United States)

    Granata, Jr., Samuel J. (Inventor); Woodle, Boyd M. (Inventor)

    1990-01-01

    A dry compliant overlapping seal for a phosphoric acid fuel cell preformed f non-compliant Teflon to make an anode seal frame that encircles an anode assembly, a cathode seal frame that encircles a cathode assembly and a compliant seal frame made of expanded Teflon, generally encircling a matrix assembly. Each frame has a thickness selected to accommodate various tolerances of the fuel cell elements and are either bonded to one of the other frames or to a bipolar or end plate. One of the non-compliant frames is wider than the other frames forming an overlap of the matrix over the wider seal frame, which cooperates with electrolyte permeating the matrix to form a wet seal within the fuel cell that prevents process gases from intermixing at the periphery of the fuel cell and a dry seal surrounding the cell to keep electrolyte from the periphery thereof. The frames may be made in one piece, in L-shaped portions or in strips and have an outer perimeter which registers with the outer perimeter of bipolar or end plates to form surfaces upon which flanges of pan shaped, gas manifolds can be sealed.

  6. Laboratory Testing of Aerosol for Enclosure Air Sealing

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Curtis [Building Industry Research Alliance (BIRA), Stockton, CA (United States); Modera, Mark [Building Industry Research Alliance (BIRA), Stockton, CA (United States)

    2012-05-01

    This report presents a process for improving the air tightness of a building envelope by sealing shell leaks with an aerosol sealing technology. Both retrofit and new construction applications are possible through applying this process either in attics and crawlspaces or during rough-in stage.

  7. Brush Seal Arrangement for the RS-68 Turbopump Set

    Science.gov (United States)

    Nunez, D.; Ransom, D.; Prueger, G.

    2006-01-01

    The nature of the RS-68 turbopumps requires that the hydrogen seals separating the pump from the turbine must have extremely low levels of leakage and be contained in small packages. Conventional seal technologies are not able to reasonably satisfy such design requirements. A review of experimental measurements and analysis publications suggests that brush seals are well suited for the design requirements. Brush seals are shown to have less leakage than conventional labyrinth and damper seals and have no adverse effects on the rotordynamics of the machine. The bulk-flow analysis presented by Hendricks et al. is used as a guideline to create a spreadsheet that provides mass flow through the seal and heat generated by the rubbing contact of the bristles on the shaft. The analysis is anchored to published data for LN2 and LH2 leakage tests. Finally, the analysis is used to design seals for both applications. It is observed that the most important analysis parameter is the thickness of the bristle pack and its relationship to seal clearance, lay angle and pressure drop.

  8. Performance assessment of sealing systems. Conceptual and integrated modelling of plugs and seals

    Energy Technology Data Exchange (ETDEWEB)

    Ruebel, Andre; Buhmann, Dieter; Kindlein, Jonathan; Lauke, Thomas

    2016-08-15

    The long-time isolation of radionuclides from the biosphere is the goal of the storage of radioactive waste in deep geological repositories. For repositories in rock salt, this goal is achieved on the one hand by the impermeable undisturbed part of the salt host rock formation and on the other hand by crushed salt, which is used to backfill the mine openings in the emplacement areas and galleries created during the construction of the repository. The crushed salt backfill is compacted over time and achieves a sufficiently high hydraulic resistance to avoid inflow of brines into the emplacement areas of the repository in the long-term. Plugs and seals must additionally provide their sealing function during the early post closure phase, until the compaction of the backfill is adequate and the permeability of the backfill is sufficiently low. To assess the future development of the waste repository, an adequate knowledge of the material behaviour is necessary and related mathematical models must be developed to be able to perform predictions on the long-term safety of the repository. An integrated performance assessment model was formulated that describes the long-term behaviour of a sealing built from salt concrete. The average permeability of the sealing changes with time after its emplacement from various processes of which two were regarded in a constitutive model: first, the healing of the EDZ in the host rock around the sealing, and second, the corrosion of the salt concrete material resulting from brine attack. Empirical parameter model functions were defined for both processes to reflect the actual behaviour. The mathematical model was implemented in the integrated performance assessment model LOPOS which is used by GRS as near-field model for repositories in salt. Deterministic and probabilistic calculations were performed with realistic parameters showing how the permeability of the sealing decreases during the first 2 000 years due to the healing of the EDZ

  9. Seal with integrated shroud for androgenous docking and berthing in contaminated environments

    Science.gov (United States)

    Daniels, Christopher C. (Inventor)

    2012-01-01

    The present invention is directed to a specially configured seal system which provides a barrier to gas leakage flow between a pressurized module and its external environment. The seal includes a shroud covering which protects the sealing interface from its environment when not in use, and retracts to expose the sealing interface when mated. The seal system is constructed and arranged to mate with a seal of identical construction and arrangement or to mate with a flat surface.

  10. Asphalt emulsion sealing of uranium mill tailings. 1980 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, J.N.; Koehmstedt, P.L; Esterl, D.J.; Freeman, H.D.; Buelt, J.L.; Nelson, D.A.; Elmore, M.R.

    1981-05-01

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.

  11. FE Simulation of SMA Seal for Mars Sample Return

    Science.gov (United States)

    Bao, Xiaoqi; Younse, Paulo; Bhandari, Pradeep

    2013-01-01

    Several NASA rovers and landers have been on Mars and performed successful in-situ exploration. Returning Martian samples to Earth for extensive analysis is of great interest to the planetary science community. Current Mars sample return architecture would require leaving the acquired samples on Mars for years before being retrieved by subsequent mission. Each sample would be sealed securely to keep its integrity. A reliable seal technique that does not affect the integrity of the samples and uses a simple low-mass tool is required. The shape memory alloy (SMA) seal technique is a promising candidate. A study of the thermal performances of several primary designs of a SMA seal for sample tubes by finite element (FE) simulation are presented in this paper. The results show sealing the sample tube by SMA plugs and controlling the sample temperature below the allowed temperature level are feasible.

  12. Grey seal predation on forage fish in the Baltic Sea

    DEFF Research Database (Denmark)

    Eero, Aro; Neuenfeldt, Stefan; Aho, Teija;

    has increased accordingly. The diet of grey seal in the Baltic consists of ca. 20 fish species. The most abundant prey items in the Baltic proper are Baltic herring, sprat, and cod, and in the Bothnian Sea and Bothnian Bay Baltic herring, Coregonus sp., Baltic salmon, and sea trout. An adult seal...... consumes on average round 4.5 kg fish per day, of which 55% are clupeoids in the Baltic Main basin and 70% in the Bothnian Sea and Bothnian Bay. According to acoustic estimates, predator– prey distribution patterns, migration patterns, and multispecies analysis (SMS), the predation effect of grey seals...... on Baltic herring and sprat stocks is still at a very low level. Hence, with present grey seal stock sizes, the impact of seal predation can be ignored in whole Baltic‐scale herring and sprat stock management considerations. Locally, however, grey seal–fishery interactions play an important role and should...

  13. Application of hydrophilic magnetic fluid to oil seal

    Science.gov (United States)

    Kim, Y. S.; Nakatsuka, K.; Fujita, T.; Atarashi, T.

    1999-07-01

    Bearing and gear are important components in machines. Lubricant for bearing or gear is usually confined in working space by rubber retainer or mechanical seal, and its lifetime which is determined by the friction wear of sealing material is important. In this report, the basic characteristics of magnetic fluid seal applied to lubricant retainer is studied. The fluid used for this purpose is ethyleneglycol-based magnetic fluid in which silica-coated iron particles are dispersed. The lubricant oil seal set consisting of six stages of pole piece and Nd-permanent magnets (4.0 Wb/m 2) in seal housing showed an excellent pressure resistance of 618 kPa under a rotating speed of 1800 rpm.

  14. Microfabrication of hybrid fluid membrane for microengines

    Science.gov (United States)

    Chutani, R.; Formosa, F.; de Labachelerie, M.; Badel, A.; Lanzetta, F.

    2015-12-01

    This paper describes the microfabrication and dynamic characterization of thick membranes providing a technological solution for microengines. The studied membranes are called hybrid fluid-membrane (HFM) and consist of two thin membranes that encapsulate an incompressible fluid. This work details the microelectromechanical system (MEMS) scalable fabrication and characterization of HFMs. The membranes are composite structures based on Silicon spiral springs embedded in a polymer (RTV silicone). The anodic bonding of multiple stacks of Si/glass structures, the fluid filling and the sealing have been demonstrated. Various HFMs were successfully fabricated and their dynamic characterization demonstrates the agreement between experimental and theoretical results.

  15. Experimental and Simulation Studies on Cold Welding Sealing Process of Heat Pipes

    Science.gov (United States)

    Li, Yong; Chen, Shengle; Huang, Jinlong; Yan, Yuying; Zeng, Zhixin

    2017-03-01

    Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bonding mechanism of the cold welding sealing process (CWSP) is investigated and compared with the experimental results obtained from the bonding interface analysis. An orthogonal experiment is conducted to observe the effects of various parameters, including the sealing gap, sealing length, sealing diameter, and sealing velocity on bonding strength. A method with the utilization of saturated vapor pressure inside a copper tube is proposed to evaluate bonding strength. A corresponding finite element model is developed to investigate the effects of sealing gap and sealing velocity on plastic deformation during the cold welding process. Effects of various parameters on the bonding strength are determined and it is found that the sealing gap is the most critical factor and that the sealing velocity contributes the least effect. The best parameter combination (A 1 B 3 C 1 D 3, with a 0.5 mm sealing gap, 6 mm sealing length, 3.8 mm sealing diameter, and 50 mm/s sealing velocity) is derived within the experimental parameters. Plastic deformation results derived from the finite element model are consistent with those from the experiment. The instruction for the CWSP of heat pipes and the design of sealing dies of heat pipes are provided.

  16. Mathematical model of the Beta Rand Cam{trademark} engine vane seals

    Energy Technology Data Exchange (ETDEWEB)

    Braden, C.H.; Thompson, G.J.; Smith, J.E.; Mucino, V.H. [West Virginia Univ., Morgantown, WV (United States)

    1996-12-31

    A mathematical model of the vane sealing mechanism is presented to determine how the loading on the seals will affect the performance of the Rand Cam{trademark} engine. Within the Rand Cam{trademark} engine, sacrificial linear seals in the vane are used as the main sealing mechanism to prevent blowby from one chamber to the next. Throughout this investigation a kinetostatic analysis, based upon Yamamoto`s Wankel apex seal analysis, is extended into three dimensions. The input data to the model can be varied to study the effects of seal dimensions, seal material, seal dynamics, and friction.

  17. Interaction between Monk Seals, Monachus monachus (Hermann, 1779), and artisanal fisheries in the Foca Pilot Monk Seal conservation area, Turkey

    NARCIS (Netherlands)

    Guclusoy, H.

    2008-01-01

    The present study examines some aspects of the interaction between critically endangered Monk Seals Monachus monachus and artisanal fisheries in the Foc¿a Pilot Monk Seal Conservation Area, Turkey, between 1994 and 2002. One to four permanent researchers collected the data on this interaction during

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT-A AND A ENVIRONMENTAL SEALS, INC., SEAL ASSIST SYSTEM (SAS) PHASE II REPORT

    Science.gov (United States)

    The Environmental Technology Verification report discusses the technology and performance of Seal Assist System (SAS) for natural gas reciprocating compressor rod packing manufactured by A&A Environmental Seals, Inc. The SAS uses a secondary containment gland to collect natural g...

  19. La coyuntura económica nacional

    Directory of Open Access Journals (Sweden)

    Arturo Huerta González

    2003-01-01

    Full Text Available El objetivo de este artículo es analizar los problemas de contracción económica que enfrenta nuestro país como resultado de la política económica predominante, que lo ha llevado a depender de la economía estadounidense. Cuando ésta enfrentó problemas de crecimiento también frenó el crecimiento de la economía nacional. El gobierno mexicano no instrumenta política fiscal anticíclica (expansión del gasto para contrarrestar la caída de exportaciones y recuperar la dinámica económica por considerar que ello originaría presiones sobre precios y el sector externo y pudiera llevar a un contexto de especulación y crisis. Es por esto que se opta por seguir priorizando políticas contraccionistas para evitar la inflación, como si éste fuese el principal problema del país. Asimismo, el gobierno insiste en las reformas estructurales (apertura eléctrica, petrolera, reforma fiscal y laboral para ampliar la esfera de influencia del sector privado nacional y extranjero y para consolidar el saneamiento fiscal y abaratar el costo de la fuerza de trabajo, impulsando así la dinámica económica. Sin embargo, tales reformas ya las hemos vivido —desde el gobierno de Salinas de Gortari a la fecha— y sus resultados han sido crecimientos espurios que han desembocado en crisis y en el actual estancamiento. Mientras prosiga la actual política económica seguirá deteriorándose la esfera productiva y aumentando el desempleo, sin que se logre un crecimiento sostenido y menos vulnerable de la economía

  20. Environmental contaminants in the food chain, NWS Seal Beach and Seal Beach NWR

    Energy Technology Data Exchange (ETDEWEB)

    Ohlendorf, H.M.; Byron, E.R. [CH2M Hill, Sacramento, CA (United States); Freas, K.E. [CH2M Hill, San Jose, CA (United States); Casados, E.M.; Kidwell, J.J. [Naval Facilities Engineering Command, San Diego, CA (United States). SW Division

    1994-12-31

    The authors conducted a study to determine whether environmental contaminants occurred in fish and invertebrates at concentrations that could be harmful to birds feeding in the estuarine salt marsh at Seal Beach National Wildlife Refuge (NWR), which is part of Naval Weapons Station (NWS) Seal Beach. Management of the refuge is focused primarily on endangered species, especially the light-footed clapper rail and the California least tern. Important food-chain organisms taken by rails (e.g., crabs and snails) and least terns (small fish) were sampled and analyzed for inorganic and organic contaminants that might be related to Navy activities at the Station. Results indicated that those contaminants are not likely to have lethal effects on rails or terns, although some chemicals (including cadmium, chromium, copper, lead, zinc and DDE) occurred at elevated concentrations in portions of the marsh. Possible sublethal effects also were evaluated and will be discussed.

  1. Sliding seal materials for adiabatic engines

    Science.gov (United States)

    Lankford, J.

    1985-01-01

    The sliding friction coefficients and wear rates of promising carbide, oxide, and nitride materials were measured under temperature, environmental, velocity, loading conditions that are representative of the adiabatic engine environment. In order to provide guidance needed to improve materials for this application, the program stressed fundamental understanding of the mechanisms involved in friction and wear. Microhardness tests were performed on the candidate materials at elevated temperatures, and in atmospheres relevant to the piston seal application, and optical and electron microscopy were used to elucidate the micromechanisms of wear following wear testing. X-ray spectroscopy was used to evaluate interface/environment interactions which seemed to be important in the friction and wear process. Electrical effects in the friction and wear processes were explored in order to evaluate the potential usefulness of such effects in modifying the friction and wear rates in service. However, this factor was found to be of negligible significance in controlling friction and wear.

  2. ChipSeal Inorganic Sealing Technology for Hermetic-Like Integrated Circuits. Volume 1

    Science.gov (United States)

    2000-09-01

    formation (Kerkendall voiding ) and is more susceptible to corrosive attack under adverse conditions. • Degradation of the metallization stack from...processed devices in standard and flip-chip formats, both with and without epoxy encapsulants or underfills . 17 4. Phase I - ChipSeal Process...significant number of bumps exhibited internal voids (Figure 24). A second reflow eliminated the voids open to the surface (Figure 25), but some

  3. Remote video registration of seals at Rødsand seal sanctuary

    DEFF Research Database (Denmark)

    Edren, Susi M.C.; Teilmann, J.; Dietz, R.

    This report describes the preliminary use of a remote-controlled webbased camera system in the Rødsand seal sanctuary. The camera system powered by solar and wind energy is designed to operate under extreme weather conditions. Live images and still photos are transmitted to a land station, from...... where it is streamed to the Internet. The cameras are operated remotely and pictures are stored every 5 - 10 seconds....

  4. Turbomachine Sealing and Secondary Flows. Part 1; Review of Sealing Performance, Customer, Engine Designer, and Research Issues

    Science.gov (United States)

    Hendricks, R. C.; Steinetz, B. M.; Braun, M. J.

    2004-01-01

    Although forces outside our control shape our industry, turbomachine sealing research, design, and customer agendas established in 1978 by Ludwig, Campbell, and Smith in terms of specific fuel consumption and performance remain as objectives today. Advances have been made because failures of the space shuttle main engine turbomachinery ushered in a new understanding of sealing in high-power-density systems. Further, it has been shown that changes in sealing, especially for high-pressure rotors, dramatically change the performance of the entire engine or turbomachine. Maintaining seal leakages and secondary flows within engine design specifications remains the most efficient and cost effective way to enhance performance and minimize maintenance costs. This three-part review summarizes experiences, ideas, successes, and failures by NASA and the U.S. aerospace industry in secondary flow management in advanced turbomachinery. Part 1 presents system sealing, part 2 system rotordynamics, and part 3 modeling, with some overlap of each part.

  5. Sealing of investigation boreholes, Phase 4 - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Drawrite AB, Luleaa Technical University, Luleaa (Sweden); Ramqvist, Gunnar [El-Tekno AB, Figeholm (Sweden); Bockgaard, Niclas [Golder Associates, Goeteborg (Sweden); Ekman, Lennart [LE Geokonsult AB, Baelinge (Sweden)

    2011-09-15

    The report describes the outcome of Phase 4 of the project 'Sealing of investigation boreholes', which deals with 1) characterization and planning of borehole sealing, 2) performance and quality assessment, 3) sealing of large diameter holes, and 4) interaction of clay and concrete plugs. A specific goal was to find ways to characterize, plan and seal of boreholes so that their impact on the overall hydraulic performance of the repository rock can predicted and controlled. The work comprised selection of representative 'reference holes' at the Laxemar and Forsmark sites for development of a general programme for planning and simulating implementation of borehole plugging campaigns, considering also cost issues. A second aim was to define and quantify the role of seals in the reference holes for finding out how important sealing really is. A third was to test a practical way to seal large diameter boreholes and a fourth to find out how concrete matures and performs in contact with smectite clay. The study demonstrated, in conclusion, the need for developing techniques for preparing deep boreholes before lasting seals are installed in them, since poor sealing can short-circuit hydraulically important fracture zones intersected by the holes. The practically oriented sealing activities showed that the technique developed for tight sealing of large-diameter boreholes is practical and feasible. The issue of chemical stability was investigated by testing the performance and constitution of a plug consisting of CBI concrete in contact with smectite-rich seals for almost three years. This study showed that none of them underwent substantial degradation in this period of time, but chemical reactions and thereby generated changes in physical behaviour of the plug components had taken place, particularly in the clay. The rate of degradation is, however, not yet known. It was concluded from this study that it is suitable to carry out a corresponding

  6. QUÍMICA VERDE: UN NUEVO RETO

    Directory of Open Access Journals (Sweden)

    Nerlis Paola Pájaro Castro

    2011-01-01

    Full Text Available En la actualidad, existe un enorme deterioro del medio ambiente que ha generado la necesidad de buscar alternativas que conduzcan a la sostenibilidad ambiental. Una de estas herramientas es la ¿química verde¿, concepto que contempla el diseño de productos y procesos que reduzcan la generación de sustancias peligrosas y maximicen la eficiencia en la utilización de recursos materiales y energéticos. El empleo de tecnologías menos contaminantes, permitirá a las empresas químicas mitigar los efectos ambientales asociados a su actividad, reduciendo el consumo de materiales e incrementando la participación de recursos renovables. Para alcanzar estas metas, se han propuesto 12 principios básicos de química verde, aplicables en diferentes campos, tales como la medicina, la agricultura, la industria química y farmacéutica. Esta revisión detalla los principios y usos principales de la química verde, y su aplicación como una filosofía de trabajo para avanzar hacia un verdadero desarrollo sostenible.

  7. Petrography and mineral chemistry of carbonatites and mica-rich rocks from the Araxa Complex (Alto Paranaiba Province, Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Traversa, Gianbosco; Morbidelli, Lucio; Ronca, Sara [Roma Univ. (Italy). Dipt. di Scienze della Terra; Gomes, Celso B.; Ruberti, Excelso [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias].E-mail: cgomes@usp.br; Brotzu, Piero [Napoli Univ. (Italy). Dipt. di Scienze della Terra; Buraglini, Nicoletta [Catania Univ. (Italy). Dipt. di Scienza della Terra; Principato, Maria Speranza [Milano Univ. (Italy). Dipt. di Scienza della Terra

    2001-03-01

    The Araxa complex (16 km{sup 2}) comprises carbonatites forming a central core and a complex network of concentric and radial dykes as well as small veins; additionally, it includes mica-rich rocks, phoscorities and lamprophyres. Fenites also occur and rare represented by Proterozoic quartzites and schists of the Araxa Group. The petrographic study of 130 borehole samples indicates that the complex is basically made up by two rock-types, carbonatites and mica-rich rocks, and subordinately by a third unit of hybrid composition. Carbonatites range chemically in composition, the most abundant type being magnesio-carbonatites. Dolomite and calcite correspond to the chief constituents, but other carbonate phases, including the Ce-group RE minerals, are also recognized. phosphates and oxides are widespread accessories whereas silicate minerals consist of olivine, clinopyroxene, mica and amphibole. Mica-rich rocks are represented by abundant glimmeritic rocks and scare cumulitic phlogopite-, olivine-and diopside-bearing pyroxenites. Hybrid rocks mainly contain phlogopite and tetraferriphlopite as cumulus and intercumulus phases, respectively; carbonate minerals may also be found. Chemical data indicate that the carbonatities are strongly enriched in REE and have lower contents of Nb, Zr, V, Cr, Ni and Rb compared to the mica-rich rocks. The higher K, Nb and Zr contents of the latter rocks are believed to be related to metasomatic processes (glimmeritization) of the pyroxenites. Similar REE patterns for carbonatites and mica-rich rocks seem to suggest that they are related to a single parental magma, possibly of ijolitic composition. Steep LREE/HREE fractionation and high {sigma}REE content of some carbonatite samples would be explained by hydrothermal and supergenic processes. (author)

  8. Carbon Dioxide Sealing Capacity: Textural or Compositional Controls?

    Energy Technology Data Exchange (ETDEWEB)

    Cranganu, Constantin; Soleymani, Hamidreza; Sadiqua, Soleymani; Watson, Kieva

    2013-11-30

    This research project is aiming to assess the carbon dioxide sealing capacity of most common seal-rocks, such as shales and non-fractured limestones, by analyzing the role of textural and compositional parameters of those rocks. We hypothesize that sealing capacity is controlled by textural and/or compositional pa-rameters of caprocks. In this research, we seek to evaluate the importance of textural and compositional parameters affecting the sealing capacity of caprocks. The conceptu-al framework involves two testable end-member hypotheses concerning the sealing ca-pacity of carbon dioxide reservoir caprocks. Better understanding of the elements controlling sealing quality will advance our knowledge regarding the sealing capacity of shales and carbonates. Due to relatively low permeability, shale and non-fractured carbonate units are considered relatively imper-meable formations which can retard reservoir fluid flow by forming high capillary pres-sure. Similarly, these unites can constitute reliable seals for carbon dioxide capture and sequestration purposes. This project is a part of the comprehensive project with the final aim of studying the caprock sealing properties and the relationship between microscopic and macroscopic characteristics of seal rocks in depleted gas fields of Oklahoma Pan-handle. Through this study we examined various seal rock characteristics to infer about their respective effects on sealing capacity in special case of replacing reservoir fluid with super critical carbon dioxide (scCO{sub 2}). To assess the effect of textural and compositional properties on scCO{sub 2} maximum reten-tion column height we collected 30 representative core samples in caprock formations in three counties (Cimarron, Texas, Beaver) in Oklahoma Panhandle. Core samples were collected from various seal formations (e.g., Cherokee, Keys, Morrowan) at different depths. We studied the compositional and textural properties of the core samples using several techniques

  9. Three-step labyrinth seal for high-performance turbomachines

    Science.gov (United States)

    Hendricks, Robert C.

    1987-01-01

    A three-step labyrinth seal with 12, 11, and 10 labyrinth teeth per step, respectively, was tested under static (nonrotating) conditions. The configuration represented the seal for a high-performance turbopump (e.g., the space shuttle main engine fuel pump). The test data included critical mass flux and pressure profiles over a wide range of fluid conditions at concentric, partially eccentric, and fully eccentric seal positions. The seal mass fluxes (leakage rates) were lower over the entire range of fluid conditions tested than those for data collected for similar straight and three-step cylindrical seals, and this conformed somewhat to expectations. However, the pressure profiles for the eccentric positions indicated little, if any, direct stiffness for this configuration in contrast to significant direct stiffness reported for the straight and three-step cylindrical seals over the range of test conditions. Seal dynamics depend on geometric configuration, inlet and exit parameters, fluid phase, and rotation. The method of corresponding states was applied to the mass flux data, which were found to have a pressure dependency for helium.

  10. Field Trial of an Aerosol-Based Enclosure Sealing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Curtis [Univ. of California, Davis, CA (United States); Springer, David [Univ. of California, Davis, CA (United States)

    2015-09-01

    This report presents the results from several demonstrations of a new method for sealing building envelope air leaks using an aerosol sealing process developed by the Western Cooling Efficiency Center at UC Davis. The process involves pressurizing a building while applying an aerosol sealant to the interior. As air escapes through leaks in the building envelope, the aerosol particles are transported to the leaks where they collect and form a seal that blocks the leak. Standard blower door technology is used to facilitate the building pressurization, which allows the installer to track the sealing progress during the installation and automatically verify the final building tightness. Each aerosol envelope sealing installation was performed after drywall was installed and taped, and the process did not appear to interrupt the construction schedule or interfere with other trades working in the homes. The labor needed to physically seal bulk air leaks in typical construction will not be replaced by this technology. However, this technology is capable of bringing the air leakage of a building that was built with standard construction techniques and HERS-verified sealing down to levels that would meet DOE Zero Energy Ready Homes program requirements. When a developer is striving to meet a tighter envelope leakage specification, this technology could greatly reduce the cost to achieve that goal by providing a simple and relatively low cost method for reducing the air leakage of a building envelope with little to no change in their common building practices.

  11. Leakage predictions for Rayleigh-step, helium-purge seals

    Science.gov (United States)

    Proctor, Margaret P.

    1988-01-01

    Rayleigh-step, helium purge, annular shaft seals, studied for use in liquid oxygen turbopumps, generate a hydrodynamic force that enables the seal to follow shaft perturbations. Hence, smaller clearances can be used to reduce seal leakage. FLOWCAL, a computer code developed by Mechanical Technology Incorporated, predicts gas flow rate through an annular seal with an axial pressure gradient. Analysis of a 50-mm Rayleigh-step, helium-purge, annular seal showed the flow rate increased axial pressure gradient, downstream pressure, and eccentricity ratio. Increased inlet temperature reduced leakage. Predictions made at maximum and minimum clearances (due to centrifugal and thermal growths, machining tolerances and + or - 2 percent uncertainty in the clearance measurement) placed wide boundaries on expected flow rates. The widest boundaries were set by thermal growth conditions. Predicted flow rates for a 50-mm Rayleigh-step, helium-purge, annular seal underestimated measured flow rates by three to seven times. However, the analysis did accurately predict flow rates for choked gas flow through annular seals when compared to flow rates measured in two other independent studies.

  12. Basis of property limits for inflatable seal fluoroelastomers

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, N.K., E-mail: nksinha@igcar.gov.in [Indira Gandhi Centre for Atomic Research (IGCAR), Department of Atomic Energy (DAE), Kalpakkam, Tamilnadu 603102 (India); Raj, Baldev, E-mail: dr.baldev@psg.org.in [Indira Gandhi Centre for Atomic Research (IGCAR), Department of Atomic Energy (DAE), Kalpakkam, Tamilnadu 603102 (India)

    2012-03-15

    Identification of a set of governing physico-mechanical properties for inflatable seals of Prototype Fast Breeder Reactor (PFBR) and specification of their limits is described based on operating requirements, design practices and results from seal development. The limits of tensile strength, elongation at break, hardness, tear strength, fluid compatibility, compression set and specific gravity defined for the Viton GBL 200S/600S based inflatable seal formulation provide a standardized framework for regular production of reactor seals and a streamlined approach for compounding, design, manufacture and quality control. This assures significant reduction of efforts during the envisaged unification of Fast Breeder Reactor sealing based on four variations of inflatable seal compound which could result in a universal design code apart from significant gains in safety, reliability and life. The property set has potential use in Pressurized Heavy Water Reactor and Advanced Heavy Water Reactor. Inclusion of factors such as batch-to-batch variations of compound properties and their reproducibility during laboratory measurements, hot tensile behavior of fluoroelastomer, long term ageing effects and the margin of safety at the end of seal design life ensures the utility of property set in attaining its intended objective.

  13. Travelling waves and fold localization in hovercraft seals

    Science.gov (United States)

    Wiggins, Andrew; Zalek, Steve; Perlin, Marc; Ceccio, Steve

    2013-11-01

    The seal system on hovercraft consists of a series of open-ended fabric cylinders that contact the free surface and, when inflated, form a compliant pressure barrier. Due to a shortening constraint imposed by neighboring seals, bow seals operate in a post-buckled state. We present results from large-scale experiments on these structures. These experiment show the hydroelastic response of seals to be characterized by striking stable and unstable post-buckling behavior. Using detailed 3-d measurements of the deformed seal shape, dominant response regimes are identified. These indicate that mode number decreases with wetted length, and that the form of the buckling packet becomes localized with increased velocity and decreased bending stiffness. Eventually, at a critical pressure, travelling waves emerge. To interpret the wide range of observed behavior, a 2-d nonlinear post-buckling model is developed and compared with the experimental studies. The model shows the importance of seal shortening and the buckling length, which is driven by the balance of hydrodynamic and bending energies. Preliminary scaling laws for the fold amplitude and mode number are presented. The experiments may ultimately provide insight into the bedeviling problem of seal wear. Sponsored by the Office of Naval Research under grant N00014-10-1-0302, Ms. Kelly B. Cooper, program manager.

  14. The ringed seal (Phoca hispida in the western Russian Arctic

    Directory of Open Access Journals (Sweden)

    Stanislav E Belikov

    1998-06-01

    Full Text Available This paper presents a review of available published and unpublished material on the ringed seal (Phoca hispida in the western part of the Russian Arctic, including the White, Barents and Kara seas. The purpose of the review is to discuss the status of ringed seal stocks in relation to their primary habitat, the history of sealing, and a recent harvest of the species in the region. The known primary breeding habitats for this species are in the White Sea, the south-western part of the Barents Sea, and in the coastal waters of the Kara Sea, which are seasonally covered by shore-fast ice. The main sealing sites are situated in the same areas. Female ringed seals become mature by the age of 6, and males by the age of 7. In March-April a female gives birth to one pup in a breeding lair constructed in the shore-fast ice. The most important prey species for ringed seals in the western sector of the Russian Arctic are pelagic fish and crustaceans. The maximum annual sealing level for the region was registered in the first 70 years of the 20th century: the White Sea maximum (8,912 animals was registered in 1912; the Barents Sea maximum (13,517 animals was registered in 1962; the Kara Sea maximum (13,200 animals was registered in 1933. Since the 1970s, the number of seals harvested has decreased considerably. There are no data available for the number of seals harvested annually by local residents for their subsistence.

  15. Design and development of seal components fatigue tester

    Directory of Open Access Journals (Sweden)

    P. Czop

    2008-09-01

    Full Text Available Purpose: The aim of the paper is research and development concerning a fatigue tester of shock absorber seal systems.Design/methodology/approach: Analytical approach has been applied to get an understanding of a heat exchange process. The mathematical model has been formulated and validated based on the available measurements. Numerical simulation has been carried out to illustrate a heat exchange process performance.Findings: It is possible to control a seal temperature and mechanical friction related to the rod movement into the seal at the specified velocity. The model accuracy is sufficient to perform sensitivity analysis and optimize the design.Research limitations/implications: The components of a fatigue tester have to withstand the significant temperature differences in the range 30; +140˚C, e.g. hydraulic hoses, fittings, and pumps.Practical implications: We combine the analytical and experimental approach to provide customized and reliable engineering solution in the area of damper component seal development. A typical seal has a lip-like design protecting the moving parts against the leakage. It can be tested in a shock absorber or externally with use of a customized test rigs. Seal tests inside a shock absorber have numerous disadvantages. A shock absorber temperature rises during longer tests and cooling phase is required. This dramatically increases tests duration performed with the use of an expensive general-purpose hydraulic testing machinery. A compressed air or water jacket is used to accelerate the cooling process. Nevertheless, there are limitations related to the physics behind the cooling process. A seal component fatigue tester allows to perform the seal component tests out of the shock absorber.Originality/value: A new testing method provides possibility to quantify the main contributors of seal usage.

  16. Supercement for Annular Seal and Long-Term Integrity in Deep, Hot Wells "DeepTrek"

    Energy Technology Data Exchange (ETDEWEB)

    CSI Technologies

    2007-08-31

    The purpose of this project is to formulate a 'Supercement' designed for improving the long-term sealing integrity in HPHT wells. Phase I concentrated on chemistry studies and screening tests to design and evaluate Portland-based, hybrid Portland, and non-Portland-based cement systems suitable for further scale-up testing. Phase II work concentrated on additional lab and field testing to reduce the candidate materials list to two systems, as well as scaleup activities aimed at verifying performance at the field scale. Phase II was extended thorough a proposal to develop additional testing capabilities aimed at quantifying cementing material properties and performance that were previously not possible. Phase III focused on bringing the material(s) developed in previous Phases to commercialization, through Field Trials, Cost/Benefit Analysis, and Technology Transfer. Extensive development and testing work throughout the project led to Phase III commercialization of two very different materials: (1) Highly-expansive cement (Portland-based), patent pending as 'PRESTRESSED CEMENT'; and (2) Epoxy Resin (non-Portland-based), patent pending. Trade name is Ultra Seal-R. In Phase III, work concentrated on application of the Supercement materials in various increasingly-challenging wells. Previous testing revealed that PRESTRESSED CEMENT, when applied in weak or unconsolidated formations, tends to expand away from the central pipe, restricting the applicability of this material to competent formations. Tests were devised to quantify this effect so the material could be applied in appropriate wells. Additionally, the testing was needed because of industry resistance to expansive cements, due to previous marketing attempts with other materials that were less than successful. Field trials with the Epoxy Resin currently numbers in the hundreds of jobs at up to 295 deg F, with a large percentage being completely successful. Both the PRESTRESSED CEMENT as well

  17. Validation of numerical models for flow simulation in labyrinth seals

    Science.gov (United States)

    Frączek, D.; Wróblewski, W.

    2016-10-01

    CFD results were compared with the results of experiments for the flow through the labyrinth seal. RANS turbulence models (k-epsilon, k-omega, SST and SST-SAS) were selected for the study. Steady and transient results were analyzed. ANSYS CFX was used for numerical computation. The analysis included flow through sealing section with the honeycomb land. Leakage flows and velocity profiles in the seal were compared. In addition to the comparison of computational models, the divergence of modeling and experimental results has been determined. Tips for modeling these problems were formulated.

  18. Eddy-Current Inspection Of Tab Seals On Beverage Cans

    Science.gov (United States)

    Bar-Cohen, Yoseph

    1994-01-01

    Eddy-current inspection system monitors tab seals on beverage cans. Device inspects all cans at usual production rate of 1,500 to 2,000 cans per minute. Automated inspection of all units replaces visual inspection by microscope aided by mass spectrometry. System detects defects in real time. Sealed cans on conveyor pass near one of two coils in differential eddy-current probe. Other coil in differential eddy-current probe positioned near stationary reference can on which tab seal is known to be of acceptable quality. Signal of certain magnitude at output of probe indicates defective can, automatically ejected from conveyor.

  19. Engineered glass seals for solid-oxide fuel cells

    Science.gov (United States)

    Surdoval, Wayne; Lara-Curzio, Edgar; Stevenson, Jeffry; Muth, Joseph Thomas; Armstrong, Beth L.; Shyam, Amit; Trejo, Rosa M.; Wang, Yanli; Chou, Yeong Shyung; Shultz, Travis Ray

    2017-02-07

    A seal for a solid oxide fuel cell includes a glass matrix having glass percolation therethrough and having a glass transition temperature below 650.degree. C. A deformable second phase material is dispersed in the glass matrix. The second phase material can be a compliant material. The second phase material can be a crushable material. A solid oxide fuel cell, a precursor for forming a seal for a solid oxide fuel cell, and a method of making a seal for a solid oxide fuel cell are also disclosed.

  20. Growth and reproduction in the Icelandic grey seal

    OpenAIRE

    2013-01-01

    Growth and reproduction in grey seals (Halichoerus grypus Fabricius, 1791) from Iceland were examined. The oldest Icelandic grey seals obtained were a 36 year old female and a 23 year old male. The longest animals were a 255 cm 13 year old male, and a 230 cm 20 year old female. The heaviest grey seal was an 11 year old male weighing 310 kg. The heaviest female was a 20 year old female that weighed 240 kg. Females reached an asymptotic standard length and weight of 200 (95% CI 196 - 204) cm an...

  1. Engineered glass seals for solid-oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Surdoval, Wayne; Lara-Curzio, Edgar; Stevenson, Jeffry; Muth, Joseph Thomas; Armstrong, Beth L.; Shyam, Amit; Trejo, Rosa M.; Wang, Yanli; Chou, Yeong Shyung; Shultz, Travis Ray

    2017-02-07

    A seal for a solid oxide fuel cell includes a glass matrix having glass percolation therethrough and having a glass transition temperature below 650.degree. C. A deformable second phase material is dispersed in the glass matrix. The second phase material can be a compliant material. The second phase material can be a crushable material. A solid oxide fuel cell, a precursor for forming a seal for a solid oxide fuel cell, and a method of making a seal for a solid oxide fuel cell are also disclosed.

  2. Flexible edge seal for vacuum insulating glazing units

    Science.gov (United States)

    Bettger, Kenneth J.; Stark, David H.

    2012-12-11

    A flexible edge seal is provided for a vacuum insulating glazing unit having a first glass pane and a second glass pane spaced-apart from the first. The edge seal comprises a seal member formed of a hermetically bondable material and having a first end, a second end and a center section disposed therebetween. The first end is hermetically bondable to a first glass pane. The second end is hermetically bondable to a second glass pane. The center section comprises a plurality of convolutes.

  3. Experimental study on a magnetofluid sealing liquid for propeller shaft

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chang-fa; SUN Rong-hua; ZHENG Jin-xing

    2003-01-01

    The selecting and preparing method of the basic material of magnetic fluid was introduced. By using a chemical method, the magnetic micropowder Fe3O4 was successfully yielded, and an oil-base as a working carrier and dispersing agent was determined. The preparation process of the magnetic fluid and prescription of the oil-base magnetic fluid were discussed. The simulation experimental rig of magnetic fluid sealing for propeller shaft was designed. The sealing ability experiment was conducted and results were analyzed. The pressure of sealing is up to 2 Mpa.

  4. Study and Application of Sealing Material for Coke Oven Chamber

    Institute of Scientific and Technical Information of China (English)

    GAN Feifang; TAI Li

    2005-01-01

    A kind of dry refractory sealing material has been developed to repair the fine cracks in coke oven chamber. With silica sand as the main raw material, the sealing material is blown into coke oven chamber by compressed air while being applied, and bonded to brick surface or filled in fine cracks of chamber under right pressure. The physical properties of the material are similar to those of silica bricks during its application. So it can be adapted to conditions of coke oven and has good service life. The study and application results of the sealing material are described in this paper.

  5. Hybrid microelectronic technology

    Science.gov (United States)

    Moran, P.

    Various areas of hybrid microelectronic technology are discussed. The topics addressed include: basic thick film processing, thick film pastes and substrates, add-on components and attachment methods, thin film processing, and design of thick film hybrid circuits. Also considered are: packaging hybrid circuits, automating the production of hybrid circuits, application of hybrid techniques, customer's view of hybrid technology, and quality control and assurance in hybrid circuit production.

  6. Proteómica da paramiloidose

    OpenAIRE

    Guerreiro, Ana Catarina Leite

    2010-01-01

    Tese de mestrado, Bioquímica (Bioquímica Médica), Universidade de Lisboa, Faculdade de Ciências, 2010 A Polineuropatia Amiloidótica Familiar (PAF) é uma doença neurodegenerativa, com manifestações clínicas entre a terceira e a quarta década de vida, associada à deposição de agregados amilóides de transtirretina (TTR) em diversos tecidos. A TTR é produzida maioritariamente pelo fígado. A PAF está associada a mutações pontuais na TTR, desestabilizadoras da sua estrutura tetramérica, levando ...

  7. Farmacogenômica e psiquiatria

    OpenAIRE

    2009-01-01

    A farmacogenética é o ramo da ciência que investiga as variações genéticas relacionadas a respostas individuais ao uso de medicamentos ou substâncias. Com o avanço das descobertas nessa área e a possibilidade de sua aplicabilidade clínica, o conceito da farmacogenética clássica expandiu e o termo farmacogenômica passou a ser usado. O presente trabalho tem como objetivo apresentar um histórico do desenvolvimento da farmacogenômica na Psiquiatria, discutir as principais descobertas na área bem ...

  8. AUDITORÍA ACADÉMICA

    OpenAIRE

    Egúsquiza Pereda, Carlos Alfonso; Facultad de Ciencias Contables, Universidad Nacional Mayor de San Marcos

    2014-01-01

    Mediante la presente investigación sobre Auditoría Académica hemos podido fijar las bases para la evaluación o auditoría integral de empresas o instituciones educativas, dirigida, sobre todo, al corazón del negocio, en un ambiente de alta competitividad y donde campea, también, la mediocridad y la improvisación. En este trabajo se ha abordado la naturaleza, amplitud y características del trabajo de auditoría integral: Auditoría Académica, verificándose que no existen trabajos de esta nat...

  9. La dinámica marina

    OpenAIRE

    2003-01-01

    En este trabajo se realiza una revisión general de los aspectos generales de la dinámica marina, especialmente centrado en playas y la parte más cercana a la costa de la plataforma. Es evidente que la dinámica de erosión, transporte y depósito de sedimentos, jugará un papel fundamental en la removilización de contaminantes. Formas de acumulación más profundas, jugarán un papel fundamental como reservónos de contaminantes. También es importante, ...

  10. Review Article: recent advances in metal-ceramic brazing Artigo Revisão: avanços recentes em brasagem metal-cerâmica

    Directory of Open Access Journals (Sweden)

    R. M. do Nascimento

    2003-12-01

    Full Text Available Metal-ceramic joining has slowly but steadily become an important manufacturing step. The evolution of joining processes has allowed ceramics to be used in combination with metals in a number of hybrid devices from traditional light bulbs and seals to improved cutting tools and modern monitoring and measuring electronic devices. New joining methods and newer approaches to conventional methods have been developed aiming at joints characterized by improved reliability, and interfaces capable of withstanding high-temperature resistance with minimum residual stresses. A summary of recent improvements on alternative approaches to ceramic-metal joining as well as new developments on brazing are presented herein. The present review also focuses on recent advances towards brazing metallized ceramics and the selection of filler alloys, since in a scenario that includes joining by laser and direct bonding with liquid transient phases, brazing continues to be by far the most widely used approach to joining as a result of its low-cost and possibility to join intricate geometries for large-scale production. Finally, methods to evaluate the mechanical strength and residual thermal stresses are presented in addition to alternative approaches to minimize residual stresses and, consequently, improve joint reliability.O interesse no estudo de métodos de junção-cerâmica para aplicações industriais tem crescido gradativamente ao longo dos anos. A evolução dos processos de união tem permitido a utilização de cerâmicas em conjunto com metais na fabricação de diversos componentes híbridos incluindo lâmpadas tradicionais, juntas para vácuo, ferramentas de corte de alto desempenho e modernos dispositivos eletrônicos de medição e monitoramento. Novos métodos de união e aprimoramentos de métodos convencionais têm sido estudados com o intuito de produzir-se juntas com alta confiabilidade e interfaces capazes de suportar altas temperaturas de

  11. Contribution of electron microscopy to the study of sealing processes in oxalic anodised aluminium

    Directory of Open Access Journals (Sweden)

    Bartolomé, Mª J.

    2007-06-01

    Full Text Available Transmission electron microscopy (TEM of anodic coatings reveals a substructure in which three regions are clearly differentiated: a very thin band at the hexagonal cell boundaries; the cell walls contaminated with anions from the anodising bath; and the hydrated alumina that fills the pores with a certain amount of retained water. Scanning electron microscopy (SEM appears to be a highly suitable tool to observe, at the surface and at more internal levels, the structural changes associated with each sealing degree. Both types of electron microscopy allow the possibility to visualise the different stages of the very complex sealing and ageing mechanisms indirectly determined by gravimetric and electrochemical techniques

    La microscopía electrónica de transmisión (MET de los recubrimientos anódicos revela una subestructura en la cual se diferencian claramente tres regiones: una banda muy delgada en los límites de las celdas hexagonales; las paredes de las celdas contaminadas con los aniones procedentes del baño de anodización; y la alúmina hidratada que llena los poros con una cierta cantidad de agua retenida. La microscopía electrónica de barrido (MEB parece ser una herramienta muy adecuada para observar, tanto en la superficie como en los níveles más internos, los cambios estructurales asociados con cada grado de sellado. Ambos tipos de microscopía electrónica permiten la posibilidad de visualizar las diferentes etapas de los muy complejos mecanismos de sellado y envejecimiento indirectamente determinados por técnicas gravimétricas y electroquímicas.

  12. Nitrogen fertilization impact on agronomic traits of maize hybrids released at different decades Impacto da fertilização nitrogenada sobre características agronômicas de híbridos de milho lançados em diferentes décadas

    Directory of Open Access Journals (Sweden)

    Luís Sangoi

    2001-05-01

    Full Text Available Genetic selection of maize hybrids is often conducted using high N rates during the breeding cycle. This procedure may either lead to the release of genotypes that present nitrogen luxury consumption or require a stronger N input to accomplish their yield potential. This work was carried out to evaluate the effects of N rates on grain yield and N use efficiency of hybrids cultivated in different decades in Southern Brazil. The trial was performed in Lages, Santa Catarina State. A split plot design was used. Hybrids Ag 12, Ag 28, Ag 303 and Ag 9012, released during the 60's, 70's, 80's and 90's, respectively, were evaluated in the main plots. Nitrogen rates equivalent to 0, 50, 100 and 200 kg ha-1 were side-dressed in the split-plots when each hybrid had six fully expanded leaves. Modern-day hybrid Ag 9012 had higher grain yield than hybrids of earlier eras, regardless of N rates. Under high doses of N, the older hybrids Ag 12 and Ag 28 took up more N and presented higher values of shoot dry matter at flowering than Ag 9012. Nonetheless, they set less grains per ear which contributed to decrease their grain yield and N use efficiency.Novos híbridos de milho são normalmente desenvolvidos utilizando-se altas doses de N durante o ciclo de seleção. Isto pode favorecer o lançamento de genótipos que apresentem consumo de luxo de N ou requeiram altas doses deste nutriente para expressarem o seu potencial produtivo. Este trabalho foi conduzido para avaliar os efeitos de doses de N sobre o rendimento de grãos e eficiência de uso do N de híbridos cultivados em diferentes épocas no sul do Brasil. O ensaio foi conduzido em Lages, Santa Catarina. Os híbridos Ag 12, Ag 28, Ag 303 e Ag 9012, lançados comercialmente nas décadas de 60, 70, 80 e 90, respectivamente, foram avaliados na parcela principal. Doses de N de 0, 50, 100 e 200 kg ha-1 foram aplicadas em cobertura nas subparcelas. O híbrido moderno Ag 9012 expressou maior rendimento de gr

  13. Wellbore Seal Repair Using Nanocomposite Materials

    Energy Technology Data Exchange (ETDEWEB)

    Stormont, John [Univ. of New Mexico, Albuquerque, NM (United States)

    2016-08-31

    Nanocomposite wellbore repair materials have been developed, tested, and modeled through an integrated program of laboratory testing and numerical modeling. Numerous polymer-cement nanocomposites were synthesized as candidate wellbore repair materials using various combinations of base polymers and nanoparticles. Based on tests of bond strength to steel and cement, ductility, stability, flowability, and penetrability in opening of 50 microns and less, we identified Novolac epoxy reinforced with multi-walled carbon nanotubes and/or alumina nanoparticles to be a superior wellbore seal material compared to conventional microfine cements. A system was developed for testing damaged and repaired wellbore specimens comprised of a cement sheath cast on a steel casing. The system allows independent application of confining pressures and casing pressures while gas flow is measured through the specimens along the wellbore axis. Repair with the nanocomposite epoxy base material was successful in dramatically reducing the flow through flaws of various sizes and types, and restoring the specimen comparable to an intact condition. In contrast, repair of damaged specimens with microfine cement was less effective, and the repair degraded with application of stress. Post-test observations confirm the complete penetration and sealing of flaws using the nanocomposite epoxy base material. A number of modeling efforts have supported the material development and testing efforts. We have modeled the steel-repair material interface behavior in detail during slant shear tests, which we used to characterize bond strength of candidate repair materials. A numerical model of the laboratory testing of damaged wellbore specimens was developed. This investigation found that microannulus permeability can satisfactorily be described by a joint model. Finally, a wellbore model has been developed that can be used to evaluate the response of the wellbore system (casing, cement, and microannulus

  14. Measurement and theoretical analysis of the under-seal pressure of rotary engine apex seals. Rotary engine no apex seal no haiatsu no sokutei to kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, K.; Terasaki, K. (Aoyama gakuin Univ., Tokyo (Japan). School of Science and Technology)

    1991-08-25

    A fundamental structure of an experimental rotary engine, which satisfies the conditions for the actual machine and can provide the phenomena on the rotor in multichannel electrical signals, and a method of taking out the signals have been developed. The pressures under two apex seals at medium speed and up to high load were measured to obtain some new knowledges. The pressure under the apex seal of 6mm thickness decreased considerably than that of the working chamber when the rotation speed increased with high loads. On the other hand, the decrease was little with the apex seal of 3mm thickness. The temperature of the gas flowing into the underseal chamber, temperature of the sealing groove wall, and the values of the pressures in the working chamber before and after apex seals measured by a pressure sensor provided in the housing were compared with the values calculated by theoretical analysis method for the underseal pressure to clarify the effect of each factor on the underseal pressure. 13 refs., 18 figs., 1 tab.

  15. Sealing ability of a new polydimethylsiloxane-based root canal filling material

    NARCIS (Netherlands)

    Ozok, Ahmet R.; van der Sluis, Lucas W. M.; Wu, Min-Kai; Wesselink, Paul R.

    2008-01-01

    We tested the null hypothesis that there is no difference in the sealing ability of GuttaFlow, RoekoSeal, and AH26 in root canals. Sixty extracted mandibular premolars were filled with AH26 (lateral compaction), RoekoSeal, or GuttaFlow (modified single-cone). The sealing ability of the root canal fi

  16. 10 CFR 35.500 - Use of sealed sources for diagnosis.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Use of sealed sources for diagnosis. 35.500 Section 35.500 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Sealed Sources for Diagnosis § 35.500 Use of sealed sources for diagnosis. A licensee shall use only sealed sources for...

  17. DDT plus PCB's in blubber of harbor seals

    Energy Technology Data Exchange (ETDEWEB)

    Anas, R.E.

    1974-06-01

    Total amounts of DDT plus pcb's ranged from 380.7-2350.0 ppm in San Miguel Island seals; 459.4-1620.0 ppm in Puget Sound seals; 27.7-109.9 ppm in Columbia River seals; and 6.8-27.8 ppm in Pribilof Island seals sampled in 1971. (1 table)

  18. 19 CFR 24.13 - Car, compartment, and package seals; kind, procurement.

    Science.gov (United States)

    2010-04-01

    ... Inspection, Ottowa, Canada, for approval and forwarding to the manufacturer. An order for green strap-in bond... such sealing. (b) Red in-bond and high security red in-bond seals used for sealing imported merchandise shipped between ports in the United States shall be stamped “U.S. Customs in Bond.” Uncolored seals used...

  19. 76 FR 55332 - Federal Bureau of Investigation Anti-Piracy Warning Seal Program

    Science.gov (United States)

    2011-09-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE 41 CFR Part 128-1 RIN 1110-AA32 Federal Bureau of Investigation Anti-Piracy Warning Seal Program AGENCY...- Piracy Warning Seal (APW Seal). The proposed rule will provide access to the APW Seal to all...

  20. Ultra-High Temperature Metallic Seal/Energizer Development for Aero Propulsion and Gas Turbine Applications

    Science.gov (United States)

    Cornett, Ken; Newman, Jesse; Datta, Amit

    2009-01-01

    The industry is requiring seals to operate at higher and higher temperatures. Traditional static seal designs and materials experience stress relaxation, losing their ability to maintain contact with moving flanges. Ultra High Temperature seal development program is a multiphase program with incremental increases in seal operating temperatures.

  1. The isolation and partial characterization of a highly pathogenic herpesvirus from the harbor seal (Phoca vitulina).

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert); H. Yang (Hong); H.E.M. Spijkers (Ine); J. Groen (Jan); J.S. Teppema; G. van Steenis (Bert)

    1985-01-01

    textabstractThis report describes the first isolation and partial characterization of a herpesvirus from the harbor seal (Phoca vitulina). The virus was isolated during a disease outbreak in a group of young seals nursed in a seal orphanage in The Netherlands. Almost half of the seals died with symp

  2. 7 CFR 201.36c - Hermetically-sealed containers.

    Science.gov (United States)

    2010-01-01

    ... allow water vapor penetration through any wall, including the seals, greater than 0.05 grams of water... percent and on the other side of 0 percent. Water vapor penetration or WVP is measured by the standards...

  3. Extreme Environment Ceramic-to-Metal Seal Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase 1 program will demonstrate the feasibility of large ceramic to metal joints/seals that can tolerate extreme environments. The immediate...

  4. Recovering and Mining Asteroids with a Gas-Sealed Enclosure

    Science.gov (United States)

    Jenniskens, P.; Damer, B.; Norkus, R.; Pilotz, S.; Grigsby, B.; Adams, C.; Blair, B. R.

    2015-01-01

    The internal structure of weakly consolidated rubble piles and primitive asteroids can be studied closer to home, and such asteroids can be mined, if it is possible to create a gas-sealed enclosure around the asteroid.

  5. Evaluation of seals for high-performance cryogenic turbomachines

    Science.gov (United States)

    Hendricks, R. C.; Tam, L. T.; Braun, M. J.; Vlcek, B. L.

    1987-01-01

    An approach to computing flow and dynamic characteristics for seals or bearings is discussed. The local average velocity was strongly influenced by inlet and exit effects and fluid injection, which in turn drove zones of secondary flow. For the restricted three-dimensional model considered, the integral averaged results were in reasonable agreement with selected data. Unidirectional pressure measurements alone were insufficient to define such flow variations. However, for seal and bearing leakage correlations the principles of corresponding states were found to be useful. Also discussed are three phenomena encountered during testing of three eccentric nonrotating seal configurations for the Space Shuttle Main Engine (SSME) Program. Fluid injection, choking within a seal, and pressure profile crossover are related to postulated zones of secondary flow or separation and to direct stiffness.

  6. The Trail Inventory of Seal Beach NWR [Cycle 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on Seal Beach National Wildlife Refuge. Trails in this inventory are...

  7. Analysis of automotive liftgate seals using finite element analysis

    Directory of Open Access Journals (Sweden)

    Rafael H. T Ueda

    2010-01-01

    Full Text Available Seals have wide application in automotive products. They are responsible for sealing the car in several parts such as the doors, the air intake cowl seal, and air intake lights seal. Strain and stress studies are very important in order to understand the behavior of polymeric materials, which are generally submitted to great workload variation and environmental influence. This study of EPDM rubber was carried out to define the strain, stress and yield stress. Tensile and compression tests were carried out on workpieces with 100 mm of length. The data were acquired using the Qmat software. A Finite Element Analysis using the MSC Marc MentatTM was conducted and compared with experimental tests. The results showed an increase of effort proportional to bulb thickness. The proportional increase of compression effort for different displacements was significant. Moreover, physical parameters such as length, thickness, and friction coefficient changed the strain and stress rate.

  8. LEGACY - EOP CRITTERCAM Deployments on French Frigate Shoals monk seals

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRITTERCAMs, were deployed on a 42 monk seals at French Frigate Shoals Hawaii. Sixty nine hours of video comprised of 3192 recording segments collected at...

  9. Aerial Survey Units for Harbor Seals in Coastal Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aerial surveys of coastal Alaska are the primary method for estimating abundance of harbor seals. A particular challenge associated with aerial surveys of harbor...

  10. Seal assembly for materials with different coefficients of thermal expansion

    Science.gov (United States)

    Minford, Eric

    2009-09-01

    Seal assembly comprising (a) two or more seal elements, each element having having a coefficient of thermal expansion; and (b) a clamping element having a first segment, a second segment, and a connecting segment between and attached to the first and second segments, wherein the two or more seal elements are disposed between the first and second segments of the clamping element. The connecting segment has a central portion extending between the first segment of the clamping element and the second segment of the clamping element, and the connecting segment is made of a material having a coefficient of thermal expansion. The coefficient of thermal expansion of the material of the connecting segment is intermediate the largest and smallest of the coefficients of thermal expansion of the materials of the two or more seal elements.

  11. Seal Beach National Wildlife Refuge: Final Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Seal Beach NWR for the next 15 years. This plan outlines the Refuge vision and purpose...

  12. Northern fur seal pup weights, Pribilof Islands, Alaska, 1957-present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database contains northern fur seal pup mass and length data by date, island, rookery and sex on the Pribilof Islands, Alaska, collected between 1957-2012. Mass...

  13. Seal Out Tooth Decay: A Fact Sheet for Parents

    Science.gov (United States)

    ... Institute of Dental and Craniofacial Research Seal Out Tooth Decay A Fact Sheet for Parents What are dental ... important reason for getting sealants is to avoid tooth decay. • Fluoride in toothpaste and in drinking water protects ...

  14. End crop sealing method for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, Kiyoshi

    1998-12-04

    End crops of spent nuclear fuels and glass materials are sealed in a corrosion and heat resistant vessel having an upper portion opened, and the corrosion and heat resistant vessel is heated from outside to melt the glass materials and they are solidified to form glass solidification products in which the end crops and radioactive materials deposited on the end crops are sealed. Then, the opened portion is closed. Since the end crops and radioactive materials deposited on end crops are sealed as glass solidification products in the vessel, sealing property for radioactive materials can be enhanced. Accordingly, radioactive materials can be prevented from transferring to the outside upon storing wastes or processing them into underground. In addition, since a large quantity of end crops can be filled into the corrosion and heat resistant vessel to form high level wastes, the space for the storage of wastes and processing facilities can be reduced. (T.M.)

  15. An application of small-gap equations in sealing devices

    Science.gov (United States)

    Vionnet, Carlos A.; Heinrich, Juan C.

    1993-01-01

    The study of a thin, incompressible Newtonian fluid layer trapped between two almost parallel, sliding surfaces has been actively pursued in the last decades. This subject includes lubrication applications such as slider bearings or the sealing of non-pressurized fluids with rubber rotary shaft seals. In the present work we analyze numerically the flow of lubricant fluid through a micro-gap of sealing devices. The first stage of this study is carried out assuming that a 'small-gap' parameter delta attains an extreme value in the Navier-Stokes equations. The precise meaning of small-gap is achieved by the particular limit delta = 0 which, within the bounds of the hypotheses, predicts transport of lubricant through the sealed area by centrifugal instabilities. Numerical results obtained with the penalty function approximation in the finite element method are presented. In particular, the influence of inflow and outflow boundary conditions, and their impact in the simulated flow, are discussed.

  16. WEAR AND SEALING CHARACTERISTICS OF ENGINE VALVE GUIDE

    Institute of Scientific and Technical Information of China (English)

    Qu Shengguan; Xia Wei; Han Lifa; Xiao Zhiyu; Chen Weiping; Li Yuanyuan

    2005-01-01

    A novel powder metallurgy (P/M) material with high wear resistance is developed in order to decrease the wear and lubricant-leakage of a diesel engine valve guide. The friction and wear tests of this material are conducted. It indicates that the wear resistance of the newly developed P/M material has been improved and much better than that of the formerly used alloy steel. Moreover, three different sealing structures are designed and theoretically analyzed with respect to the characteristic of hydrodynamic sealing. Through comparative experiments of component leakage and engine run-in for different valve guide structures, it proves that the structure with a machined sealing groove but not installed with a seal-ring cannot only reduce the specific lubricant consumption (SLC) of cylinder head, but also decrease the wear of valve stem and valve guide.

  17. Optical properties of end-sealed hollow fibers.

    Science.gov (United States)

    Mohri, Shintaro; Kasai, Takao; Abe, Yukio; Shi, Yi-Wei; Matsuura, Yuji; Miyagi, Mitsunobu

    2002-03-01

    We propose sealing techniques for medical hollow fibers to protect the inner surface of fibers from debris or water that scatters from targets. First, hollow fibers are sealed with a film of polymer that is easily formed by use of a dipping technique. The transmission loss of 20-microm-thick sealing film was 0.2 dB for Er:YAG laser light, and the maximum energy that is available for the film was 180 mJ. Second, a sealed glass cap was applied to the output end of hollow fiber. The silica-glass cap with a wall thickness of 400 microm shows a transmission loss of 0.5 dB and was not damaged by radiation of 400-mJ energy pulses.

  18. Northern Fur Seal Captures and Tag Sightings Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains information regarding the capture, tagging and re-sighting of northern fur seals on the Pribilof Islands and Bogoslof Island, Alaska, from 1986...

  19. Legacy HMSRP Hawaiian Monk Seal Scat-spew data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project investigates the dietary consumption of Hawaiian monk seals using traditional dietary analysis of fecal and regurgitate samples. Samples are collected...

  20. Hiatal hernia in a harbor seal (Phoca vitulina) pup.

    Science.gov (United States)

    Biancani, Barbara; Field, Cara L; Dennison, Sophie; Pulver, Robert; Tuttle, Allison D

    2012-06-01

    A 2-wk-old stranded harbor seal (Phoca vitulina) rescued by Mystic Aquarium showed signs of the presence of a hiatal hernia during rehabilitation. Contrast radiographs of esophagus and stomach revealed an intrathoracic radiodensity that contains filling defects typical of stomach, consistent with gastric rugal folds. Mural thickening was observed at the level of the cardia consistent with a diagnosis of a hiatal hernia. Although clinical improvement was noted with medical therapy and tube feeding, surgical correction of the hiatal hernia was considered necessary for full resolution. However, owing to the animal's low body weight, the corrective hernia surgery was postponed until the body condition improved. The seal needed to be surgically treated for a corneal ulcer, and while anesthetized with isoflurane, the seal became dyspneic and developed cardiac arrhythmias; ultimately cardiac arrest ensued. Resuscitation was unsuccessfully attempted and the seal was euthanized. Necropsy confirmed the radiographic diagnosis and further characterized a paraesophageal hiatal hernia.

  1. Gamma-ray computed tomography to characterize soil surface sealing

    Energy Technology Data Exchange (ETDEWEB)

    Pires, L.F.Luiz F. E-mail: lfpires@cena.usp.br; Macedo, Jose R. de; Souza, Manoel D. de; Bacchi, Osny O.S.; Reichardt, Klaus

    2002-09-01

    The application of sewage sludge as a fertilizer on soils may cause compacted surface layers (surface sealing), which can promote changes on soil physical properties. The objective of this work was to study the use of gamma-ray computed tomography, as a diagnostic tool for the evaluation of this sealing process through the measurement of soil bulk density distribution of the soil surface layer of samples subjected to sewage sludge application. Tomographic images were taken with a first generation tomograph with a resolution of 1 mm. The image analysis opened the possibility to obtain soil bulk density profiles and average soil bulk densities of the surface layer and to detect the presence of soil surface sealing. The sealing crust thickness was estimated to be in the range of 2-4 mm.

  2. 49 CFR 236.553 - Seal, where required.

    Science.gov (United States)

    2010-10-01

    .... Seal shall be maintained on any device other than brake-pipe cut-out cock (double-heading cock), by means of which the operation of the pneumatic portion of automatic train-stop or train-control...

  3. Remarks on modeling the flexible seal ring housing

    Science.gov (United States)

    Kundera, C.; Martsynkovskyy, V.; Zahorulko, A.

    2017-08-01

    When formulating models of dynamic face seals, two issues are of essential importance. The first concerns the determination of the forces formed in the medium film in the gap formed by the faces of two rings, while the second refers to the model of the flexible housing of one of the seal rings. The first issue includes the analysis of the medium flow through a narrow slit, taking thermal phenomena and deformations of slit-forming surfaces into account. The second issue concerns the modeling of properties of seal structural components, especially the modeling of elastic-damping properties of the flexible seal ring housing. This paper presents the results of simple relaxation tests of elastomeric rings and the procedure for analyzing these results and evaluating the elastic-damping properties of the rings tested. Finally, experimental results will be compared with theory.

  4. Seal Island and Franklin Island National Wildlife Refuges Trip Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of visits to both Seal Island National Wildlife Refuge and Franklin Island National Wildlife Refuge on August 14, 15, 16, 1982.

  5. Inflatable Module Seal Interface Development and Testing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Inflatable structures will require low permeable bladder to metallic seal interface.  Cold flow of bladder materials over time is not acceptable for long term...

  6. Vacuum sealing and cooling as methods to preserve surgical specimens

    DEFF Research Database (Denmark)

    Kielsgaard Kristensen, Thomas; Engvad, Birte; Nielsen, Ole

    2011-01-01

    Recently, vacuum-based preservation of surgical specimens has been proposed as a safe alternative to formalin fixation at the surgical theater. The method seems feasible from a practical point of view, but no systematic study has examined the effect of vacuum sealing alone with respect to tissue...... preservation. In this study, we therefore subjected tissue samples from 5 different organs to treatments with and without vacuum sealing and cooling at 4°C to study the effect of vacuum sealing of surgical specimens with respect to tissue preservation and compare it with the effect of cooling. No preserving...... effect of vacuum sealing was observed with respect to cellular morphology, detection of immunohistochemical epitopes, or RNA integrity. In contrast, storage at 4°C was shown to preserve tissue to a higher degree than storage at room temperature for all included endpoints, independently of whether...

  7. Measure Guideline: Sealing and Insulating of Ducts in Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Puttagunta, S.

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  8. Measure Guideline. Sealing and Insulating Ducts in Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, S. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  9. The sidebar template and extraction of invariant feature of calligraphy and painting seal

    Science.gov (United States)

    Hu, Zheng-kun; Bao, Hong; Lou, Hai-tao

    2009-07-01

    The paper propose a novel seal extract method through template matching based on the characteristics of the external contour of the seal image in Chinese Painting and Calligraphy. By analyzing the characteristics of the seal edge, we obtain the priori knowledge of the seal edge, and set up the outline template of the seals, then design a template matching method by computing the distance difference between the outline template and the seal image edge which can extract seal image from Chinese Painting and Calligraphy effectively. This method is proved to have higher extraction rate by experiment results than the traditional image extract methods.

  10. Ecotoxicological diagnosis of a sealed municipal landfill.

    Science.gov (United States)

    Hernández, A J; Bartolomé, C; Pérez-Leblic, M I; Rodríguez, J; Alvarez, J; Pastor, J

    2012-03-01

    Assessing the environmental impact of a soil-topped landfill requires an accurate ecotoxicological diagnosis. This paper describes various diagnostic protocols for this purpose and their application to a real case: the urban solid waste (USW) municipal landfill of Getafe (Madrid, Spain). After their initial sealing with soil from the surroundings about 20 years ago, most USW landfills in the autonomous community of Madrid have continued to receive waste. This has hindered precise assessment of their impact on their environment and affected ecosystems. The procedure proposed here overcomes this problem by assessing the situation in edaphic, aquatic and ecological terms. The present study focused on the most influential soil variables (viz. salinity due largely to the presence of anions, and heavy metals and organic compounds). These variables were also determined in surface waters of the wetland most strongly affected by leachates running down landfill slopes. Determinations included the characterization of plant communities and microbial biodiversity. The study was supplemented with a bioassay under controlled conditions in pots containing soil contaminated with variable concentrations of Zn (as ZnCl(2)) intended to assess ecochemical actions in a population of Bromus rubens, which grows profusely in the landfill. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Radioactivity Confinement Studies Within the SEAL Program

    Science.gov (United States)

    Collén, Jan; Matsugu, Ron; Natalizio, Antonio; Shen, Kecheng

    1997-09-01

    In the framework of the European SEAL program, investigations have been performed with the aim of optimizing the second confinement function and plant layout with respect to normal operation as well as abnormal operation, including accident conditions. This has been done for two conceptual fusion reactor designs: one using water as the coolant and the other using helium. The starting point of these investigations was the SEAFP project design. For the water-cooled reactor design the studies were focused on design options such as pressure suppression spray system, pressure suppression pool with closed containment or with venting to gravel bed filter and stack, and separate expansion volume optionally operated with a vacuum and equipped with spray system. Similar analyses were performed for the helium-cooled reactor design. The analyses were focused on design options comprising a single, large confinement volume or a vent duct connected to an expansion volume operated at vacuum in comparison with the SEAFP Model 1. The thermal-hydraulic analyses performed with the MELCOR code provide an integrated assessment of the cooling loop and confinement system dynamics.

  12. Toward a predictive model for elastomer seals

    Science.gov (United States)

    Molinari, Nicola; Khawaja, Musab; Sutton, Adrian; Mostofi, Arash

    Nitrile butadiene rubber (NBR) and hydrogenated-NBR (HNBR) are widely used elastomers, especially as seals in oil and gas applications. During exposure to well-hole conditions, ingress of gases causes degradation of performance, including mechanical failure. We use computer simulations to investigate this problem at two different length and time-scales. First, we study the solubility of gases in the elastomer using a chemically-inspired description of HNBR based on the OPLS all-atom force-field. Starting with a model of NBR, C=C double bonds are saturated with either hydrogen or intramolecular cross-links, mimicking the hydrogenation of NBR to form HNBR. We validate against trends for the mass density and glass transition temperature for HNBR as a function of cross-link density, and for NBR as a function of the fraction of acrylonitrile in the copolymer. Second, we study mechanical behaviour using a coarse-grained model that overcomes some of the length and time-scale limitations of an all-atom approach. Nanoparticle fillers added to the elastomer matrix to enhance mechanical response are also included. Our initial focus is on understanding the mechanical properties at the elevated temperatures and pressures experienced in well-hole conditions.

  13. Retrograde seal in ultrasonically prepared canals.

    Science.gov (United States)

    Sutimuntanakul, S; Worayoskowit, W; Mangkornkarn, C

    2000-08-01

    The sealing ability of various retrofilling materials was compared. The root canals of 85 single-rooted teeth were cleansed and obturated with gutta-percha without sealer using lateral condensation. The apical 3 mm of the roots were resected and divided into positive control, negative control, and five experimental groups. The experimental teeth received root-end cavity preparation to 3 mm depth using an ultrasonic retroprep tip. The retrocavities were dried and divided into five groups to receive the following materials: amalgam with varnish, amalgam with Clearfil Liner Bond II, thermoplasticized gutta-percha (TGP) with sealer, Ketac-fil, and Super-EBA. After immersion in India ink for 7 days, the roots were demineralized, cleared, and evaluated for dye leakage under a stereomicroscope. Statistical analysis showed that Super-EBA, Ketac-fil, and TGP with sealer demonstrated less leakage than amalgam with varnish and amalgam with Clearfil Liner Bond II (p fil or TGP sealer (p fil and TGP or between the two groups filled with amalgam (p > 0.05).

  14. Measure Guideline: Air Sealing Attics in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Otis, C.; Maxwell, S.

    2012-06-01

    This Building America Measure Guideline is intended for owners, builders, contractors, homeowners, and other stakeholders in the multifamily building industry, and focuses on challenges found in existing buildings for a variety of housing types. It explains why air sealing is desirable, explores related health and safety issues, and identifies common air leakage points in multifamily building attics. In addition, it also gives an overview of materials and techniques typically used to perform air sealing work.

  15. Measure Guideline. Air Sealing Attics in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Otis, Casey [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Maxwell, Sean [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2012-06-01

    This Building America Measure Guideline is intended for owners, builders, contractors, homeowners, and other stakeholders in the multifamily building industry, and focuses on challenges found in existing buildings for a variety of housing types. It explains why air sealing is desirable, explores related health and safety issues, and identifies common air leakage points in multifamily building attics. In addition, it also gives an overview of materials and techniques typically used to perform air sealing work.

  16. Filled glass composites for sealing of solid oxide fuel cells.

    Energy Technology Data Exchange (ETDEWEB)

    Tandon, Rajan; Widgeon, Scarlett Joyce; Garino, Terry J.; Brochu, Mathieu; Gauntt, Bryan D.; Corral, Erica L.; Loehman, Ronald E.

    2009-04-01

    Glasses filled with ceramic or metallic powders have been developed for use as seals for solid oxide fuel cells (SOFC's) as part of the U.S. Department of Energy's Solid State Energy Conversion Alliance (SECA) Program. The composites of glass (alkaline earth-alumina-borate) and powders ({approx}20 vol% of yttria-stabilized zirconia or silver) were shown to form seals with SOFC materials at or below 900 C. The type and amount of powder were adjusted to optimize thermal expansion to match the SOFC materials and viscosity. Wetting studies indicated good wetting was achieved on the micro-scale and reaction studies indicated that the degree of reaction between the filled glasses and SOFC materials, including spinel-coated 441 stainless steel, at 750 C is acceptable. A test rig was developed for measuring strengths of seals cycled between room temperature and typical SOFC operating temperatures. Our measurements showed that many of the 410 SS to 410 SS seals, made using silver-filled glass composites, were hermetic at 0.2 MPa (2 atm.) of pressure and that seals that leaked could be resealed by briefly heating them to 900 C. Seal strength measurements at elevated temperature (up to 950 C), measured using a second apparatus that we developed, indicated that seals maintained 0.02 MPa (0.2 atm.) overpressures for 30 min at 750 C with no leakage. Finally, the volatility of the borate component of sealing glasses under SOFC operational conditions was studied using weight loss measurements and found by extrapolation to be less than 5% for the projected SOFC lifetime.

  17. Sealing and anti-corrosive action of tannin rust converters

    Energy Technology Data Exchange (ETDEWEB)

    Gust, J.; Bobrowicz, J. (Building Research Inst., Warsaw (Poland))

    1993-01-01

    A possibility of the application of mercury porosimetry in the investigation on porosity in corrosion products of the carbon steel along with the degree of sealing by the use of tannin rust converters is presented. The effect of the atmospheric humidity on the rust conversion including the time of that conversion on the degree of rust sealing is discussed. The results of the corrosion investigation of carbon steel covered with a layer of the rust converted with tannin-containing agents are presented.

  18. Adhesion of Silicone Elastomer Seals for NASA's Crew Exploration Vehicle

    Science.gov (United States)

    deGroh, Henry C., III; Miller, Sharon K. R.; Smith, Ian M.; Daniels, Christopher C.; Steinetz, Bruce M

    2008-01-01

    Silicone rubber seals are being considered for a number of interfaces on NASA's Crew Exploration Vehicle (CEV). Some of these joints include the docking system, hatches, and heat shield-to-back shell interface. A large diameter molded silicone seal is being developed for the Low Impact Docking System (LIDS) that forms an effective seal between the CEV and International Space Station (ISS) and other future Constellation Program spacecraft. Seals between the heat shield and back shell prevent high temperature reentry gases from leaking into the interface. Silicone rubber seals being considered for these locations have inherent adhesive tendencies that would result in excessive forces required to separate the joints if left unchecked. This paper summarizes adhesion assessments for both as-received and adhesion-mitigated seals for the docking system and the heat shield interface location. Three silicone elastomers were examined: Parker Hannifin S0899-50 and S0383-70 compounds, and Esterline ELA-SA-401 compound. For the docking system application various levels of exposure to atomic oxygen (AO) were evaluated. Moderate AO treatments did not lower the adhesive properties of S0899-50 sufficiently. However, AO pretreatments of approximately 10(exp 20) atoms/sq cm did lower the adhesion of S0383-70 and ELA-SA-401 to acceptable levels. For the heat shield-to-back shell interface application, a fabric covering was also considered. Molding Nomex fabric into the heat shield pressure seal appreciably reduced seal adhesion for the heat shield-to-back shell interface application.

  19. Gas impermeable glaze for sealing a porous ceramic surface

    Science.gov (United States)

    Reed, Scott T.; Stone, Ronald G.; Nenoff, Tina M.; Trudell, Daniel E.; Thoma, Steven G.

    2004-04-06

    A process for fabricating a gas impermeable seal on a porous ceramic surface using a thin, glass-based, pinhole free glaze. The process can be used to fabricate gas impermeable end seals on porous alumina tubes used as filter media. The porous alumina tubes can have an inorganic microporous thin film separation membrane on the inner surface, which can be used for high temperature gas separation processes.

  20. Experimental study of ceramic coated tip seals for turbojet engines

    Science.gov (United States)

    Biesiadny, T. J.; Klann, G. A.; Lassow, E. S.; Mchenry, M.; Mcdonald, G.; Hendricks, R. C.

    1985-01-01

    Ceramic gas-path seals were fabricated and successfully operated over 1000 cycles from flight idle to maximum power in a small turboshaft engine. The seals were fabricated by plasma spraying zirconia over a NiCoCrAlX bond boat on the Haynes 25 substrate. Coolant-side substrate temperatures and related engine parameters were recorded. Post-test inspection revealed mudflat surface cracking with penetration to the ceramic bond-coat interface.

  1. INEL storage facility for sealed sources from the commercial sector

    Energy Technology Data Exchange (ETDEWEB)

    Kingsford, C.O.; Satterthwaite, B.C.

    1994-08-01

    Commercially owned sealed radiation sources determine by the US Nuclear Regulatory Commission to be a public health or safety hazard are accepted by the US Department of Energy, under the Atomic Energy Act of 1954, as material for reuse of recycle. To implement this policy, the sealed sources must be stored until proper disposition is determined. This report documents the investigation and selection process undertaken to locate a suitable storage facility at the Idaho National Engineering Laboratory.

  2. Infection studies in mink with seal-derived morbillivirus

    DEFF Research Database (Denmark)

    Blixenkrone-Møller, M; Svansson, V; Have, P.

    1989-01-01

    Morbillivirus derived from diseased harbour seals (Phoca vitulina) has characteristics of acute virulent canine distemper virus infection in mink. The infection induced a disease resembling the acute systemic and nervous form of canine distemper.......Morbillivirus derived from diseased harbour seals (Phoca vitulina) has characteristics of acute virulent canine distemper virus infection in mink. The infection induced a disease resembling the acute systemic and nervous form of canine distemper....

  3. Laboratory Testing of Aerosol for Enclosure Air Sealing

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, C.; Modera, M.

    2012-05-01

    Space conditioning energy use can be significantly reduced by addressing uncontrolled infiltration and exfiltration through the envelope of a building. A process for improving the air tightness of a building envelope by sealing shell leaks with an aerosol sealing technology is presented. Both retrofit and new construction applications are possible through applying this process either in attics and crawlspaces or during rough-in stage.

  4. Rotordynamics of Turbine Labyrinth Seals with Rotor Axial Shifting

    OpenAIRE

    Jinxiang Xi; Rhode, David L.

    2006-01-01

    Rotors in high-performance steam turbines experience a significant axial shifting during starting and stopping processes due to thermal expansion, for example. This axial shifting could significantly alter the flow pattern and the flow-induced rotordynamic forces in labyrinth seals, which in turn, can considerably affect the rotor-seal system performance. This paper investigates the influence of the rotor axial shifting on leakage rate as well as rotordynamic forces in hi...

  5. Experimental Study on Leakage Flow in Labyrinth Seals with Asymmetric Geometries

    Science.gov (United States)

    Nishii, Kazufumi; Furukawa, Akinori; Watanabe, Satoshi; Miyake, Kunihiro

    2010-06-01

    The labyrinth seal is one of non-contact seals, which is used as a seal device of rotary machines from reasons of the lubrication free and small losses. So far, many researchers have investigated the characteristics and suitable geometries of labyrinth seals, though only one directional flow of the seal has been focused up to now. As flow direction in the seal becomes changeable depending on the gas-purge system and the inner pressure variation of machines for recent applications, a guideline of designing labyrinth seal with changeable flow directions is required. In the present report, effects of seal characteristics and internal flow behaviors on various shapes of asymmetric convexity in labyrinth seals are experimentally investigated and relations between pressure loss and convexity geometries are discussed for designing a suitable seal.

  6. Dielectric relaxation of gamma irradiated muscovite mica

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Navjeet [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Singh, Mohan, E-mail: mohansinghphysics@gmail.com [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Singh, Lakhwant [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Awasthi, A.M. [Thermodynamics Laboratory, UGC-DAE Consortium for Scientific Research, Indore 452001 (India); Lochab, S.P. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-03-15

    Highlights: • The present article reports the effect of gamma irradiation on the dielectric relaxation characteristics of muscovite mica. • Dielectric and electrical relaxations have been analyzed in the framework of dielectric permittivity, electric modulus and Cole–Cole formalisms. • The frequency dependent electrical conductivity has been rationalized using Johnsher’s universal power law. • The experimentally measured electric modulus and conductivity data have been fitted using Havriliak–Negami dielectric relaxation function. - Abstract: In the present research, the dielectric relaxation of gamma irradiated muscovite mica was studied in the frequency range of 0.1 Hz–10 MHz and temperature range of 653–853 K, using the dielectric permittivity, electric modulus and conductivity formalisms. The dielectric constants (ϵ′ and ϵ′′) are found to be high for gamma irradiated muscovite mica as compared to the pristine sample. The frequency dependence of the imaginary part of complex electric modulus (M′′) and dc conductivity data conforms Arrhenius law with single value of activation energy for pristine sample and two values of activation energy for gamma irradiated mica sample. The experimentally assessed electric modulus and conductivity information have been interpreted by the Havriliak–Negami dielectric relaxation explanation. Using the Cole–Cole framework, an analysis of real and imaginary characters of the electric modulus for pristine and gamma irradiated sample was executed which reflects the non-Debye relaxation mechanism.

  7. mica – music information center austria

    OpenAIRE

    2010-01-01

    1994 wurde das österreichische Musikinformationszentrum (mica) im Auftrag des österreichischen Bundesministers für Unterricht und Kunst (Rudolf Scholten) von den Bundeskuratoren für Musik (L. Knessl, Christian Scheib) gegründet (Geschäftsführer 1994–99 Matthias Finkentey, 1999–09 Peter Rantasa, ab 2009 Sabine Reiter).

  8. APRENDIENDO ELECTROQUÍMICA. UN ESTUDIO COMPARATIVO

    Directory of Open Access Journals (Sweden)

    Maria I. Vera

    2011-01-01

    Full Text Available Se realizó un seguimiento del proceso de enseñanza y aprendizaje de Electroquímica y se compararon los resultados obtenidos en evaluaciones parciales, con el objetivo de analizar si existen diferencias significativas en la apropiación de contenidos entre alumnos de carreras con diferentes perfiles. Se trabajó en los años 2009 y 2010 con dos grupos de alumnos en cada año, pertenecientes a carreras químicas y no químicas respectivamente. En ambos grupos se desarrollaron, con la misma carga horaria, contenidos conceptuales y procedimentales en clases teóricas con prácticas de resolución de problemas y de laboratorio. Para la evaluación se presentaron idénticas situaciones problemáticas, cuyos resultados muestran diferencias no significativas entre ambos grupos en la identificación del cátodo y del ánodo y cálculo de la fem estándar de la celda; en cambio en la aplicación de la Ecuación de Nernst y la identificación de especies químicas que reaccionan en los electrodos, hay diferencias significativas en las respuestas dadas.

  9. MeV fullerene impacts on mica

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.

  10. mica – music information center austria

    OpenAIRE

    2011-01-01

    1994 wurde das österreichische Musikinformationszentrum (mica) im Auftrag des österreichischen Bundesministers für Unterricht und Kunst (Rudolf Scholten) von den Bundeskuratoren für Musik (L. Knessl, Christian Scheib) gegründet (Geschäftsführer 1994–99 Matthias Finkentey, 1999–09 Peter Rantasa, ab 2009 Sabine Reiter).

  11. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  12. Hybrid Qualifications

    DEFF Research Database (Denmark)

    has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...... masters», i.e. by producing skills for the labour market and enabling individuals to progress more or less directly to higher education. The specific focus of this book is placed on conditions, structures and processes which help to combine VET with qualifications leading into higher education...

  13. Tags and seals to strengthen arms control verification

    Energy Technology Data Exchange (ETDEWEB)

    DeVolpi, A.

    1990-10-03

    Tags and seals have long been recognized as important tools in arms control. The trend in control of armaments is to limit militarily significant equipment that is capable of being verified through direct and cooperative means, chiefly on-site inspection or monitoring. Although this paper will focus on the CFE treaty, the role of tags and seals for other treaties will also be addressed. Published technology and concepts will be reviewed, based on open sources. Arms control verification tags are defined as unique identifiers designed to be tamper-revealing; in that respect, seals are similar, being used as indicators of unauthorized access. Tamper-revealing tags are intended as single-point markers, seals for two-point couplings, and nets for volume containment. Seals usually bind two separate components, such as a hatch or flange that provides access to a secure compartment or a valve that controls fluid flow. A tamper-revealing net might be comprised of a coupled fiberoptic bundle wrapped around an object. Sometimes the term ``seal`` is used to denote the tamper-revealing feature of a tag that is attached to a surface, but in this paper the tamper-indicating connection is considered to be part of the tag concept itself.

  14. Catch history of ringed seals (Phoca hispida in Canada

    Directory of Open Access Journals (Sweden)

    Randall R Reeves

    1998-06-01

    Full Text Available The ringed seal (Phoca hispida has always been a staple in the diet and household economy of Inuit in Canada. The present paper was prepared at the request of the NAMMCO Scientific Committee to support their assessment of ringed seal stocks in the North Atlantic Basin and adjacent arctic and subarctic waters. Specifically, our objective was to evaluate recent and current levels of use of ringed seals by Canadian Inuit. Annual removals probably were highest (possibly greater than 100,000 in the 1960s and 1970s, a period when sealskin prices were particularly strong. Catches declined substantially in the 1980s following a collapse in sealskin prices, presumably related to the European trade ban on skins from newborn harp and hooded seals (Phoca groenlandica and Cystophora cristata, respectively. Recent catch levels throughout Canada (1980s and early 1990s are believed to be in the order of 50,000 to 65,000 ringed seals, with a total average annual kill (including hunting loss in the high tens of thousands. No reliable system is in place to monitor catches of ringed seals, so any estimate must be derived from a heterogeneous array of sources.

  15. Could seals prevent cod recovery in the Baltic Sea?

    Directory of Open Access Journals (Sweden)

    Brian R MacKenzie

    Full Text Available Fish populations are increasingly affected by multiple human and natural impacts including exploitation, eutrophication, habitat alteration and climate change. As a result many collapsed populations may have to recover in ecosystems whose structure and functioning differ from those in which they were formerly productive and supported sustainable fisheries. Here we investigate how a cod (Gadus morhua population in the Baltic Sea whose biomass was reduced due to a combination of high exploitation and deteriorating environmental conditions might recover and develop in the 21st century in an ecosystem that likely will change due to both the already started recovery of a cod predator, the grey seal Halichoerus grypus, and projected climate impacts. Simulation modelling, assuming increased seal predation, fishing levels consistent with management plan targets and stable salinity, shows that the cod population could reach high levels well above the long-term average. Scenarios with similar seal and fishing levels but with 15% lower salinity suggest that the Baltic will still be able to support a cod population which can sustain a fishery, but biomass and yields will be lower. At present knowledge of cod and seal interactions, seal predation was found to have much lower impact on cod recovery, compared to the effects of exploitation and salinity. These results suggest that dual management objectives (recovery of both seal and cod populations are realistic but success in achieving these goals will also depend on how climate change affects cod recruitment.

  16. 21 CFR 73.350 - Mica-based pearlescent pigments.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Mica-based pearlescent pigments. 73.350 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.350 Mica-based pearlescent pigments. (a... color additive mixtures for coloring food. (b) Specifications. Mica-based pearlescent pigments...

  17. Acústica, fluidos y termodinámica

    OpenAIRE

    Beléndez Vázquez, Augusto

    1992-01-01

    Acústica. Estática de fluidos. Dinámica de fluidos y fluidos reales. Temperatura y propagación del calor. Primer principio de la Termodinámica. Gases ideales. Segundo principio de la Termodinámica.

  18. Development of a resilient mechanical sealing solution to resist electro corrosion in ultrapure feedwater applications

    Energy Technology Data Exchange (ETDEWEB)

    Loenhout, Gerard van [Flowservice Flow Solutions Division, Etten-Leur (Netherlands); Enders, Klaus; Schmerberg, Rainer [Vattenfall Europe Generation AG, Peitz (Germany)

    2012-11-01

    Ever since the introduction of mechanical seals on high speed boiler feed pumps in the sixties, mechanical seals have proven to be a reliable, cost effective sealing method. However, since the introduction of combined water treatment chemistry used in today's modern fossil-fuelled power stations, keeping mechanical seal reliability high, became a challenge. A pragmatic approach is presented. A resilient sealing solution was developed to resist electro corrosion for such critical feed water pumps. (orig.)

  19. Shape memory alloy seals for geothermal applications. Final report. Report ESG-82-14

    Energy Technology Data Exchange (ETDEWEB)

    Friske, Warren H.; Schwartzbart, Harry

    1982-07-30

    A novel temperature-actuated seal for geothermal applications is under development. This program uses the shape memory property of nickel-titanium (Nitinol) alloys to achieve an improved seal in geothermal downhole pumps. Nitinol flange face seals and pump shaft seals have been designed, fabricated, and tested. It has been demonstrated that the shape memory effect of Nitinol alloys can be utilized to activate and maintain a leaktight seal in geothermal environments.

  20. Nitrogen determination in micas of metamorphic rocks

    Energy Technology Data Exchange (ETDEWEB)

    Ager, F.J. [Depto. Fisica Aplicada I, Escuela Universitaria Politecnica, Universidad de Sevilla, C. Virgen de Africa 7, E-41011 Sevilla (Spain) and Centro Nacional de Aceleradores, Av. Thomas A. Edison, E-41092 Sevilla (Spain)]. E-mail: fjager@us.es; Mata, M.P. [Depto. Geologia, Fac. Ciencias del Mar y Ambientales, Campus Rio San Pedro, s/n, E-11510 Puerto Real, Cadiz (Spain); Ynsa, M.D. [Centre d' Etudes Nucleaires de Bordeaux-Gradignan, IN2P3-CNRS, BP 120, 33175 Gradignan Cedex (France); Respaldiza, M.A. [Centro Nacional de Aceleradores, Av. Thomas A. Edison, E-41092 Sevilla (Spain); Goffe, B. [UMR 8538, Lb. Geologie, ENS, 24, Rue Lhomond, F-75231 Paris Cedex 05 (France); Nieto, F. [Dpto. Mineralogia y Petrologia, Fac. Ciencias, Av. Fuentenueva s/n, E-18002 Granada (Spain)

    2006-08-15

    Micas are minerals that provide large amounts of information regarding geological processes, because of the sensitivity of their chemical composition to temperature, pressure and deformation of rocks in which they form. Rocks under analysis are formed of different minerals with variable grain size. Mica grain size may vary between 5 and 10 {mu}m and approximately correspond to the chemical formula (Si{sub 3.2}Al{sub 0.8})O{sub 10}(Al{sub 1.9}Fe{sub 0.05}Mg{sub 0.1})(OH){sub 2}(K{sub 0.75}Na{sub 0.05}), being distinguishable from other minerals because of their composition and their morphology in secondary electron images and specially backscattered electron (BSE) images. NH{sub 4}, when present, would partially substitute K in the previous formula. In some cases NH{sub 4}-rich micas (tobelites) have been described coexisting with the corresponding K-rich micas, but the actual NH{sub 4} content of normal K-rich micas is still unknown. Low N content makes necessary to use nuclear reactions such as {sup 14}N(d, p{gamma}){sup 15}N at 1.4 MeV and its cascade of intense {gamma}-rays. For the quantification and localization of nitrogen on the surface of the samples, PIGE analysis was carried out in the vacuum microprobe line of the CNA, together with simultaneous micro-RBS and micro-PIXE analyses, giving a more comprehensive picture of sample structure and composition.

  1. The physiology and life-history parameters of reproduction in Steller sea lions, spotted seals and ribbon seals from the coastal waters of Hokkaido

    National Research Council Canada - National Science Library

    Tsuyoshi Ishinazaka

    2002-01-01

    .... This study was designed to better understand the physiology and life-history parameters of reproduction in Steller sea lions (Eumetopias jubatus), spotted seals (Phoca largha) and ribbon seals (Phoca fasciata...

  2. Final report of the rock sealing project. Sealing of zones disturbed by blasting and stress release

    Energy Technology Data Exchange (ETDEWEB)

    Boergesson, L.; Pusch, R.; Fredriksson, A.; Hoekmark, H.; Karnland, O.; Sanden, T. (Clay Technology AB, Lund (Sweden))

    1992-04-01

    Test 2 and 3 of the rock sealing project comprised determination of the hydraulic properties of the disturbed rock around tunnels and drifts and the possibilities of decreasing the hydraulic conductivity of the disturbed zones by an attempt to seal the very fine excavation-induced fractures that cause an increase in conductivity. This report deals with the grouting procedures and their effect while the hydraulic testing before grouting is described in volume 2. The macro flow test of the BMT drift before grouting showed that the disturbed zone around the drift has a highly increased hydraulic conductivity reaching more than 1 m into the rock from the periphery of the drift. The most conductive shallow part of this zone was grouted by 350 1 m long 'hedgehog' holes. The holes were injected with cement using dynamic as well as static techniques. The injections were preceded by laboratory investigations of the rheological properties of different cement mixtures, by theoretical modelling of grout penetration in factures, and by full scale injections in an artificial fracture. The macro flow test was repeated after the grouting and the results evaluated by using the same finite element models as before the grouting. The conclusion was that the effect of the grouting was very small. Excavation of the rock after grouting showed that the grout penetration has been very poor into chlorite-coated fractures and a conclusion was that such fractures are hardly groutable due to debris hindering the grout from penetrating. (au).

  3. Replacement of nickel sealing rings by expanded graphite sealing rings -upgrading of SG primary collector flange connection

    Energy Technology Data Exchange (ETDEWEB)

    Cikryt, F.; Bednarek, L.; Kusyn, L. [Vitkovice, Ostrava (Switzerland)

    1997-12-31

    One of the most loaded parts of a steam generator of VVER 440 MW type are the bolts and thread holes of the primary collector cover sealing set. The strength calculations and tensometric measurings performed during operation proved the high degree of a load on the bolts. The conditions of the stress limitation are not met in some cases according to the pertinent standards. The untightnesses at nickel rings occurred during putting the units of Jaslovske Bohunice and Dukovany nuclear power stations into operation. With regard to improve the reliability, the producer has taken measures to improve the quality of the rings and users have introduced more strict regulations for bolts tightening. Due to these measures the high reliability of the set has been obtained from point of view of the tightness, but substantial reduction of bolts and holes threads loading have not been obtained. Several years operation experience proved relatively low service of bolts, damage of thread holes and sealing grooves. As the degree of mechanical load is one of the vital parameters influencing the damage of sealing set, in 1996 we started with the works aimed at a possibility of nickel sealing rings replacement for a more modern type of sealing which assure the higher reliability and service life of the individual part of sealing set under the reduced load.

  4. Comparison of two ultrasonic coagulating shears in sealing pulmonary vessels

    Directory of Open Access Journals (Sweden)

    Raghavan D

    2013-03-01

    Full Text Available Devanathan Raghavan,1 John A Howington,2 Duan Broughton,1 Cortney E Henderson,1 Jeffrey W Clymer1 1Preclinical Research, Ethicon Endo-Surgery, Cincinnati, OH, USA; 2NorthShore University HealthSystem, Chicago, IL, USA Abstract: Ultrasonic cutting and coagulating devices have been used successfully in thoracic applications such as pulmonary resection or artery harvesting, but few studies have evaluated their use in sealing pulmonary vessels. In this study we compared two commercially available devices, Harmonic Ace+ (HAR, Ethicon Endo-Surgery, Inc., Cincinnati OH, USA and SonoSurg (SS, Olympus America, Center Valley, PA, USA, in a canine preclinical model. There were three sections to the study: acute, survival, and ex vivo (burst pressure. Hemostasis of sealed pulmonary arteries and veins was assessed for the initial application and during a simulated hypertensive crisis, both immediately after vessel sealing and after a survival period of 30 days. Other intraoperative measures were also evaluated, including transection time, tissue sticking, tissue tags, and char on the seal. Histological evaluation was performed both after initial sealing and after the survival period. Burst pressure of sealed vessels was measured ex vivo. For both devices, hemostasis was excellent, including those measurements made under simulated hypertensive crisis. There were no differences in any of the intraoperative measures or thermal damage evaluated histologically. Wound healing was normal. The burst pressures for ex vivo vessels sealed by HAR (median 619.2 mmHg were significantly higher than those of SS (350.3 mmHg, P = 0.022. Both devices displayed acceptable characteristics in sealing canine pulmonary arteries and veins. The only difference observed was that HAR produced burst pressures 76.8% greater than SS, which may lead to a lower percentage of failures in the region of physiological interest. Use of ultrasonic devices in thoracic applications provides a high

  5. Fluorine uptake into the human enamel surface from fluoride-containing sealing materials during cariogenic pH cycling

    Energy Technology Data Exchange (ETDEWEB)

    Yasuhiro, Matsuda, E-mail: matsuda@den.hokudai.ac.jp [Department of Restorative Dentistry, Graduate School of Dental Medicine Hokkaido University (Japan); Katsushi, Okuyama [Department of Restorative Dentistry, Graduate School of Dental Medicine Hokkaido University (Japan); Hiroko, Yamamoto [Graduate School of Dentistry, Osaka University (Japan); Hisanori, Komatsu [Department of Restorative Dentistry, Graduate School of Dental Medicine Hokkaido University (Japan); Masashi, Koka; Takahiro, Sato [Takasaki Advanced Radiation Research Institute, JAEA (Japan); Naoki, Hashimoto; Saiko, Oki; Chiharu, Kawamoto; Hidehiko, Sano [Department of Restorative Dentistry, Graduate School of Dental Medicine Hokkaido University (Japan)

    2015-04-01

    To prevent the formation of caries and reduce dentin hypersensitivity, sealing materials, either with or without fluoride, are generally applied on the tooth in clinical practice. Application of fluoride-free sealing materials results in the formation of an acid-resistant layer on the tooth surface. On the other hand, fluoride-containing sealing materials might not only form an acid-resistant layer but could possibly further provide fluoride to enhance remineralization and reduce demineralization. In this study, the demineralization prevention ability and fluorine uptake rate in human enamel of fluoride-containing sealing materials [“MS coats F” (MSF)] and fluoride-free sealing materials (“hybrid coats 2” [HI]) were evaluated using an automatic pH cycling system. Each material was applied to the original tooth surface, the cut surfaces were covered with sticky wax, and the automatic pH-cycling system simulated daily acid changes (pH 6.8–4.5) occurring in the oral cavity for 4 weeks. Caries progression was analyzed using transverse microradiography (TMR) taken pre and post the 4 weeks of pH cycling. The fluorine and calcium distributions in the carious lesion in each specimen were evaluated using the proton-induced gamma emission (PIGE) and proton-induced X-ray (PIXE) techniques, respectively. TMR analysis showed that both MSF and HI had a caries-preventing effect after 4 weeks of pH cycling. PIGE/PIXE analysis demonstrated that only MSF resulted in fluoride uptake in the enamel surface. Therefore, MSF can help to form an acid-resistant layer and provide fluoride to the enamel surface. The presence of fluoride on the enamel surface suggested that MSF could prevent demineralization, even if the acid-resistant layer was removed, in clinical settings. The data obtained using the PIGE and PIXE techniques are useful for understanding the benefits of the use of a fluoride-containing sealing material for preventing caries.

  6. Intuitionistic hybrid logic

    DEFF Research Database (Denmark)

    Braüner, Torben

    2011-01-01

    Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area.......Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area....

  7. Continuity Controlled Hybrid Automata

    OpenAIRE

    Bergstra, J. A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of hybrid automata as timed transition systems. We also relate the synchronized product operator on hybrid automata to the parallel composition operator of the process algebra. It turns out that the f...

  8. Development of Mechanical Sealing and Laser Welding Technology to Instrument Thermocouple for Nuclear Fuel Test Rod

    Energy Technology Data Exchange (ETDEWEB)

    Joung, Chang-Young; Ahn, Sung-Ho; Hong, Jin-Tae; Kim, Ka-Hye; Huh, Sung-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Zircaloy-4 of the nuclear fuel test rod, AISI 316L of the mechanical sealing parts, and the MI (mineral insulated) cable at a thermocouple instrumentation are hetero-metals, and are difficult to weld to dissimilar materials. Therefore, a mechanical sealing method to instrument the thermocouple should be conducted using two kinds of sealing process as follows: One is a mechanical sealing process using Swagelok, which is composed of sealing components that consists of an end-cap, a seal tube, a compression ring and a Swagelok nut. The other is a laser welding process used to join a seal tube, and an MI cable, which are made of the same material. The mechanical sealing process should be sealed up with the mechanical contact compressed by the strength forced between a seal tube and an end-cap, and the laser welding process should be conducted to have no defects on the sealing area between a seal tube and an MI cable. Therefore, the mechanical sealing and laser welding techniques need to be developed to accurately measure the centerline temperature of the nuclear fuel test rod in an experimental reactor. The mechanical sealing and laser welding tests were conducted to develop the thermocouple instrumentation techniques for the nuclear fuel test rod. The optimum torque value of a Swagelok nut to seal the mechanical sealing part between the end-cap and seal tube was established through various torque tests using a torque wrench. The optimum laser welding conditions to seal the welding part between a seal tube and an MI cable were obtained through various welding tests using a laser welding system.

  9. Molecular epidemiology of seal parvovirus, 1988-2014.

    Directory of Open Access Journals (Sweden)

    Rogier Bodewes

    Full Text Available A novel parvovirus was discovered recently in the brain of a harbor seal (Phoca vitulina with chronic meningo-encephalitis. Phylogenetic analysis of this virus indicated that it belongs to the genus Erythroparvovirus, to which also human parvovirus B19 belongs. In the present study, the prevalence, genetic diversity and clinical relevance of seal parvovirus (SePV infections was evaluated in both harbor and grey seals (Halichoerus grypus that lived in Northwestern European coastal waters from 1988 to 2014. To this end, serum and tissue samples collected from seals were tested for the presence of seal parvovirus DNA by real-time PCR and the sequences of the partial NS gene and the complete VP2 gene of positive samples were determined. Seal parvovirus DNA was detected in nine (8% of the spleen tissues tested and in one (0.5% of the serum samples tested, including samples collected from seals that died in 1988. Sequence analysis of the partial NS and complete VP2 genes of nine SePV revealed multiple sites with nucleotide substitutions but only one amino acid change in the VP2 gene. Estimated nucleotide substitution rates per year were 2.00 × 10(-4 for the partial NS gene and 1.15 × 10(-4 for the complete VP2 gene. Most samples containing SePV DNA were co-infected with phocine herpesvirus 1 or PDV, so no conclusions could be drawn about the clinical impact of SePV infection alone. The present study is one of the few in which the mutation rates of parvoviruses were evaluated over a period of more than 20 years, especially in a wildlife population, providing additional insights into the genetic diversity of parvoviruses.

  10. Molecular epidemiology of seal parvovirus, 1988-2014.

    Science.gov (United States)

    Bodewes, Rogier; Hapsari, Rebriarina; Rubio García, Ana; Sánchez Contreras, Guillermo J; van de Bildt, Marco W G; de Graaf, Miranda; Kuiken, Thijs; Osterhaus, Albert D M E

    2014-01-01

    A novel parvovirus was discovered recently in the brain of a harbor seal (Phoca vitulina) with chronic meningo-encephalitis. Phylogenetic analysis of this virus indicated that it belongs to the genus Erythroparvovirus, to which also human parvovirus B19 belongs. In the present study, the prevalence, genetic diversity and clinical relevance of seal parvovirus (SePV) infections was evaluated in both harbor and grey seals (Halichoerus grypus) that lived in Northwestern European coastal waters from 1988 to 2014. To this end, serum and tissue samples collected from seals were tested for the presence of seal parvovirus DNA by real-time PCR and the sequences of the partial NS gene and the complete VP2 gene of positive samples were determined. Seal parvovirus DNA was detected in nine (8%) of the spleen tissues tested and in one (0.5%) of the serum samples tested, including samples collected from seals that died in 1988. Sequence analysis of the partial NS and complete VP2 genes of nine SePV revealed multiple sites with nucleotide substitutions but only one amino acid change in the VP2 gene. Estimated nucleotide substitution rates per year were 2.00 × 10(-4) for the partial NS gene and 1.15 × 10(-4) for the complete VP2 gene. Most samples containing SePV DNA were co-infected with phocine herpesvirus 1 or PDV, so no conclusions could be drawn about the clinical impact of SePV infection alone. The present study is one of the few in which the mutation rates of parvoviruses were evaluated over a period of more than 20 years, especially in a wildlife population, providing additional insights into the genetic diversity of parvoviruses.

  11. Molecular Epidemiology of Seal Parvovirus, 1988–2014

    Science.gov (United States)

    Bodewes, Rogier; Hapsari, Rebriarina; Rubio García, Ana; Sánchez Contreras, Guillermo J.; van de Bildt, Marco W. G.; de Graaf, Miranda; Kuiken, Thijs; Osterhaus, Albert D. M. E.

    2014-01-01

    A novel parvovirus was discovered recently in the brain of a harbor seal (Phoca vitulina) with chronic meningo-encephalitis. Phylogenetic analysis of this virus indicated that it belongs to the genus Erythroparvovirus, to which also human parvovirus B19 belongs. In the present study, the prevalence, genetic diversity and clinical relevance of seal parvovirus (SePV) infections was evaluated in both harbor and grey seals (Halichoerus grypus) that lived in Northwestern European coastal waters from 1988 to 2014. To this end, serum and tissue samples collected from seals were tested for the presence of seal parvovirus DNA by real-time PCR and the sequences of the partial NS gene and the complete VP2 gene of positive samples were determined. Seal parvovirus DNA was detected in nine (8%) of the spleen tissues tested and in one (0.5%) of the serum samples tested, including samples collected from seals that died in 1988. Sequence analysis of the partial NS and complete VP2 genes of nine SePV revealed multiple sites with nucleotide substitutions but only one amino acid change in the VP2 gene. Estimated nucleotide substitution rates per year were 2.00×10−4 for the partial NS gene and 1.15×10−4 for the complete VP2 gene. Most samples containing SePV DNA were co-infected with phocine herpesvirus 1 or PDV, so no conclusions could be drawn about the clinical impact of SePV infection alone. The present study is one of the few in which the mutation rates of parvoviruses were evaluated over a period of more than 20 years, especially in a wildlife population, providing additional insights into the genetic diversity of parvoviruses. PMID:25390639

  12. Environmental predictors of ice seal presence in the Bering Sea.

    Science.gov (United States)

    Miksis-Olds, Jennifer L; Madden, Laura E

    2014-01-01

    Ice seals overwintering in the Bering Sea are challenged with foraging, finding mates, and maintaining breathing holes in a dark and ice covered environment. Due to the difficulty of studying these species in their natural environment, very little is known about how the seals navigate under ice. Here we identify specific environmental parameters, including components of the ambient background sound, that are predictive of ice seal presence in the Bering Sea. Multi-year mooring deployments provided synoptic time series of acoustic and oceanographic parameters from which environmental parameters predictive of species presence were identified through a series of mixed models. Ice cover and 10 kHz sound level were significant predictors of seal presence, with 40 kHz sound and prey presence (combined with ice cover) as potential predictors as well. Ice seal presence showed a strong positive correlation with ice cover and a negative association with 10 kHz environmental sound. On average, there was a 20-30 dB difference between sound levels during solid ice conditions compared to open water or melting conditions, providing a salient acoustic gradient between open water and solid ice conditions by which ice seals could orient. By constantly assessing the acoustic environment associated with the seasonal ice movement in the Bering Sea, it is possible that ice seals could utilize aspects of the soundscape to gauge their safe distance to open water or the ice edge by orienting in the direction of higher sound levels indicative of open water, especially in the frequency range above 1 kHz. In rapidly changing Arctic and sub-Arctic environments, the seasonal ice conditions and soundscapes are likely to change which may impact the ability of animals using ice presence and cues to successfully function during the winter breeding season.

  13. Environmental predictors of ice seal presence in the Bering Sea.

    Directory of Open Access Journals (Sweden)

    Jennifer L Miksis-Olds

    Full Text Available Ice seals overwintering in the Bering Sea are challenged with foraging, finding mates, and maintaining breathing holes in a dark and ice covered environment. Due to the difficulty of studying these species in their natural environment, very little is known about how the seals navigate under ice. Here we identify specific environmental parameters, including components of the ambient background sound, that are predictive of ice seal presence in the Bering Sea. Multi-year mooring deployments provided synoptic time series of acoustic and oceanographic parameters from which environmental parameters predictive of species presence were identified through a series of mixed models. Ice cover and 10 kHz sound level were significant predictors of seal presence, with 40 kHz sound and prey presence (combined with ice cover as potential predictors as well. Ice seal presence showed a strong positive correlation with ice cover and a negative association with 10 kHz environmental sound. On average, there was a 20-30 dB difference between sound levels during solid ice conditions compared to open water or melting conditions, providing a salient acoustic gradient between open water and solid ice conditions by which ice seals could orient. By constantly assessing the acoustic environment associated with the seasonal ice movement in the Bering Sea, it is possible that ice seals could utilize aspects of the soundscape to gauge their safe distance to open water or the ice edge by orienting in the direction of higher sound levels indicative of open water, especially in the frequency range above 1 kHz. In rapidly changing Arctic and sub-Arctic environments, the seasonal ice conditions and soundscapes are likely to change which may impact the ability of animals using ice presence and cues to successfully function during the winter breeding season.

  14. Fine-scale variability in harbor seal foraging behavior.

    Directory of Open Access Journals (Sweden)

    Kenady Wilson

    Full Text Available Understanding the variability of foraging behavior within a population of predators is important for determining their role in the ecosystem and how they may respond to future ecosystem changes. However, such variability has seldom been studied in harbor seals on a fine spatial scale (<30 km. We used a combination of standard and Bayesian generalized linear mixed models to explore how environmental variables influenced the dive behavior of harbor seals. Time-depth recorders were deployed on harbor seals from two haul-out sites in the Salish Sea in 2007 (n = 18 and 2008 (n = 11. Three behavioral bout types were classified from six dive types within each bout; however, one of these bout types was related to haul-out activity and was excluded from analyses. Deep foraging bouts (Type I were the predominant type used throughout the study; however, variation in the use of bout types was observed relative to haul-out site, season, sex, and light (day/night. The proportional use of Type I and Type II (shallow foraging/traveling bouts differed dramatically between haul-out sites, seasons, sexes, and whether it was day or night; individual variability between seals also contributed to the observed differences. We hypothesize that this variation in dive behavior was related to habitat or prey specialization by seals from different haul-out sites, or individual variability between seals in the study area. The results highlight the potential influence of habitat and specialization on the foraging behavior of harbor seals, and may help explain the variability in diet that is observed between different haul-out site groups in this population.

  15. Hybridized tetraquarks

    Directory of Open Access Journals (Sweden)

    A. Esposito

    2016-07-01

    Full Text Available We propose a new interpretation of the neutral and charged X,Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h-tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs0π± channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X,Z particles. Considerations on a state with the same quantum numbers as the X(5568 are also made.

  16. Hybridized Tetraquarks

    CERN Document Server

    Esposito, A.; Polosa, A.D.

    2016-01-01

    We propose a new interpretation of the neutral and charged X, Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules. The latter would require a negative or zero binding energy whose counterpart in h-tetraquarks is a positive quantity. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs pi+- channel by the D0 collaboration and the negative result presented subsequently by the LHCb collaboration are understood in this scheme, together with a considerable portion of available data on X, Z particles. Considerations on a state with the same quantum numbers as the X(5568) are also made.

  17. Carbon Dioxide Sealing Capacity: Textural or Compositional Controls?

    Energy Technology Data Exchange (ETDEWEB)

    Cranganu, Constantin; Soleymani, Hamidreza; Sadiqua, Soleymani; Watson, Kieva

    2013-11-30

    This research project is aiming to assess the carbon dioxide sealing capacity of most common seal-rocks, such as shales and non-fractured limestones, by analyzing the role of textural and compositional parameters of those rocks. We hypothesize that sealing capacity is controlled by textural and/or compositional pa-rameters of caprocks. In this research, we seek to evaluate the importance of textural and compositional parameters affecting the sealing capacity of caprocks. The conceptu-al framework involves two testable end-member hypotheses concerning the sealing ca-pacity of carbon dioxide reservoir caprocks. Better understanding of the elements controlling sealing quality will advance our knowledge regarding the sealing capacity of shales and carbonates. Due to relatively low permeability, shale and non-fractured carbonate units are considered relatively imper-meable formations which can retard reservoir fluid flow by forming high capillary pres-sure. Similarly, these unites can constitute reliable seals for carbon dioxide capture and sequestration purposes. This project is a part of the comprehensive project with the final aim of studying the caprock sealing properties and the relationship between microscopic and macroscopic characteristics of seal rocks in depleted gas fields of Oklahoma Pan-handle. Through this study we examined various seal rock characteristics to infer about their respective effects on sealing capacity in special case of replacing reservoir fluid with super critical carbon dioxide (scCO{sub 2}). To assess the effect of textural and compositional properties on scCO{sub 2} maximum reten-tion column height we collected 30 representative core samples in caprock formations in three counties (Cimarron, Texas, Beaver) in Oklahoma Panhandle. Core samples were collected from various seal formations (e.g., Cherokee, Keys, Morrowan) at different depths. We studied the compositional and textural properties of the core samples using several techniques

  18. Multiple internal seal ring micro-electro-mechanical system vacuum packaging method

    Science.gov (United States)

    Hayworth, Ken J. (Inventor); Yee, Karl Y. (Inventor); Shcheglov, Kirill V. (Inventor); Bae, Youngsam (Inventor); Wiberg, Dean V. (Inventor); Challoner, A. Dorian (Inventor); Peay, Chris S. (Inventor)

    2008-01-01

    A Multiple Internal Seal Ring (MISR) Micro-Electro-Mechanical System (MEMS) vacuum packaging method that hermetically seals MEMS devices using MISR. The method bonds a capping plate having metal seal rings to a base plate having metal seal rings by wafer bonding the capping plate wafer to the base plate wafer. Bulk electrodes may be used to provide conductive paths between the seal rings on the base plate and the capping plate. All seals are made using only metal-to-metal seal rings deposited on the polished surfaces of the base plate and capping plate wafers. However, multiple electrical feed-through metal traces are provided by fabricating via holes through the capping plate for electrical connection from the outside of the package through the via-holes to the inside of the package. Each metal seal ring serves the dual purposes of hermetic sealing and providing the electrical feed-through metal trace.

  19. Method and apparatus for detecting flaws and defects in heat seals

    Science.gov (United States)

    Rai, Kula R. (Inventor); Lew, Thomas M. (Inventor); Sinclair, Robert B. (Inventor)

    1993-01-01

    Flaws and defects in heat seals formed between sheets of translucent film are identified by optically examining consecutive lateral sections of the seal along the seal length. Each lateral seal section is illuminated and an optical sensor array detects the intensity of light transmitted through the seal section for the purpose of detecting and locating edges in the heat seal. A line profile for each consecutive seal section is derived having an amplitude proportional to the change in light intensity across the seal section. Instances in the derived line profile where the amplitude is greater than a threshold level indicate the detection of a seal edge. The detected edges in each derived line profile are then compared to a preset profile edge standard to identify the existence of a flaw or defect.

  20. Simulation Analysis of Spherical Mechanical Seal Property of Marine Stern Shaft

    Directory of Open Access Journals (Sweden)

    Zhou Xu Hui

    2016-01-01

    Full Text Available The finite element model of spherical mechanical seal wasestablished with ANSYS, and the influence of seawater pressure, shaft speed and other factors on the sealing performance was discussed. The study results show that local contact situation of the spherical mechanical seal is in the outside of the seal rings, and both maximum contact pressure and temperature appearat the same position. As sea water pressure and stern shaft rotary speed are increased, the contact pressure and temperature of the spherical seal surface are raised, and when the contact pressure of seal surface is 0, the spherical seal surface forms two zones including contact one and clearance zone. The former is near the outside of the seal ring, the lateris close to the inside of one. These research results are of important theoretical significance and engineering application value for the development of new kinds of mechanical seals, and improvement of both safety and survivability of underwater vehicles.