WorldWideScience

Sample records for sealed air filled

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Highly efficient isolation of waterborne sound by an air-sealed metasurface

    CERN Document Server

    Bai, Xiaoxue; Wen, Xinhua; Peng, Shasha; Ke, Manzhu; Liu, Zhengyou

    2016-01-01

    Underwater sound isolation has been a long-standing fundamental issue in industry and military fields. Starting from a simple theoretical model, here an air-sealed metasurface is proposed to overcome this problem. Comparing with the sample without filling air, the effective impedance of the air-sealed one is greatly reduced and strikingly mismatch with water, accompanying another merit of low sound speed. Deeply suppressed sound transmission (~10-5) through such a metasurface is observed experimentally over a wide range of ultrasonic frequencies and incident angles.

  8. Air filled porosity in composting processes

    Energy Technology Data Exchange (ETDEWEB)

    Ruggieri, L.; Gea, T.; Artola, A.; Sanchez, A.

    2009-07-01

    As it is widely known, the composting process consists in the aerobic decomposition of the biodegradable organic matter present in different types of solid wastes. Water and oxygen are necessary for the biological activity of microorganisms involved in the composting process and their availability is directly related to the total and the air filled porosity (AFP). Maintaining adequate AFP level satisfies the oxygen content requirement to achieve the desired composting conditions and thus, tho enhance biological activity. (Author)

  9. Split ring floating air riding seal for a turbine

    Science.gov (United States)

    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.

  10. 2006 NASA Seal/Secondary Air System Workshop; Volume 1

    Science.gov (United States)

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

    2007-01-01

    The 2006 NASA Seal/Secondary Air System workshop covered the following topics: (i) Overview of NASA s new Exploration Initiative program aimed at exploring the Moon, Mars, and beyond; (ii) Overview of NASA s new fundamental aeronautics technology project; (iii) Overview of NASA Glenn Research Center s seal project aimed at developing advanced seals for NASA s turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts including tip clearance control, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing seal leakages as well as high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Several organizations presented development efforts aimed at developing faster clearance control systems and associated technology to meet future engine needs. The workshop also covered several programs NASA is funding to develop technologies for the Exploration Initiative and advanced reusable space vehicle technologies. NASA plans on developing an advanced docking and berthing system that would permit any vehicle to dock to any on-orbit station or vehicle. Seal technical challenges (including space environments, temperature variation, and seal-on-seal operation) as well as plans to develop the necessary "androgynous" seal technologies were reviewed. Researchers also reviewed seal technologies employed by the Apollo command module that serve as an excellent basis for seals for NASA s new Crew Exploration Vehicle (CEV).

  11. 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.

  12. 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.

  13. Sealing efficacy of a single-cone root filling after post space preparation

    NARCIS (Netherlands)

    Sungur, D.D.; Moinzadeh, A.T.; Wesselink, P.R.; Tarhan, S.C.; Özok, A.R.

    2016-01-01

    Objectives The aim of the present study was to compare the sealing efficacy of root fillings made by a single-cone technique with three different sealers and a cold lateral compaction technique with an epoxy sealer. Materials and methods Eighty extracted single-rooted human teeth were assigned to

  14. A hermetically sealed, fluid-filled surgical enclosure for microgravity.

    Science.gov (United States)

    Hayden, Jennifer A; Pantalos, George M; Burgess, James E; Burgess, James E

    2013-12-01

    Expeditionary spaceflight is fraught with significant risks to human health, including trauma and other emergency medical events. To address several of the basic challenges of surgical care in reduced gravity, we are developing the Aqueous Immersion Surgical System (AISS), an optically clear enclosure pressurized by a fluid medium. The AISS is designed to prevent contamination of the spacecraft with blood and tissue debris, reduce intraoperative blood loss, and maintain visualization of the operative field. An early prototype of the AISS was tested in reduced gravity during parabolic flight. A clear, aqueous field was created in a watertight chamber containing a mock vascular network. Hemorrhage was simulated by severing several of the analogue vessels. Experiments were performed to evaluate the benefits of surrounding a surgical cavity with fluid medium, as compared to an air environment, with respect to maintaining a clear view and achieving hemostasis. Qualitative evaluation of audio and video recorded during parabolic flight confirm AISS capacity to maintain visualization of the surgical field during a hemorrhage situation and staunch bleeding by raising interchamber pressure. Evaluation of the AISS in reduced gravity corroborates observations in the literature regarding the difficulty in maintaining visualization of the surgical field when performing procedures in an air environment. By immersing the surgical field in fluid we were able to apply suction directly to the hemorrhage and also achieve hemostasis.

  15. 2008 NASA Seal/Secondary Air System Workshop

    Science.gov (United States)

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

    2009-01-01

    The 2008 NASA Seal/Secondary Air System Workshop covered the following topics: (i) Overview of NASA s new Orion project aimed at developing a new spacecraft that will fare astronauts to the International Space Station, the Moon, Mars, and beyond; (ii) Overview of NASA s fundamental aeronautics technology project; (iii) Overview of NASA Glenn s seal project aimed at developing advanced seals for NASA s turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing seal leakage as well as high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Turbine seal development topics covered include a method for fast-acting HPT blade tip clearance control, noncontacting low-leakage seals, intershaft seals, and a review of engine seal performance requirements for current and future Army engine platforms.

  16. 2007 NASA Seal/Secondary Air System Workshop. Volume 1

    Science.gov (United States)

    Steinetz, Bruce M.; Hendricks, Robert C.; Delgado, Irebert

    2008-01-01

    The 2007 NASA Seal/Secondary Air System workshop covered the following topics: (i) Overview of NASA's new Orion project aimed at developing a new spacecraft that will fare astronauts to the International Space Station, the Moon, Mars, and beyond; (ii) Overview of NASA's fundamental aeronautics technology project; (iii) Overview of NASA Glenn s seal project aimed at developing advanced seals for NASA's turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing seal leakage as well as high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Turbine seal development topics covered include a method for fast-acting HPT blade tip clearance control, noncontacting low-leakage seals, intershaft seals, and a review of engine seal performance requirements for current and future Army engine platforms.

  17. 2005 NASA Seal/Secondary Air System Workshop, Volume 1

    Science.gov (United States)

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

    2006-01-01

    The 2005 NASA Seal/Secondary Air System workshop covered the following topics: (i) Overview of NASA s new Exploration Initiative program aimed at exploring the Moon, Mars, and beyond; (ii) Overview of the NASA-sponsored Propulsion 21 Project; (iii) Overview of NASA Glenn s seal project aimed at developing advanced seals for NASA s turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts including tip clearance control, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Several organizations presented development efforts aimed at developing faster clearance control systems and associated technology to meet future engine needs. The workshop also covered several programs NASA is funding to develop technologies for the Exploration Initiative and advanced reusable space vehicle technologies. NASA plans on developing an advanced docking and berthing system that would permit any vehicle to dock to any on-orbit station or vehicle. Seal technical challenges (including space environments, temperature variation, and seal-on-seal operation) as well as plans to develop the necessary "androgynous" seal technologies were reviewed. Researchers also reviewed tests completed for the shuttle main landing gear door seals.

  18. The sealing ability of novel Kryptonite adhesive bone cement as a retrograde filling material

    Directory of Open Access Journals (Sweden)

    İsmail Uzun

    2016-08-01

    Full Text Available Background. This study evaluated the ability of Kryptonite bone cement in sealing retrograde cavities. Methods. The root canals of one hundred extracted human maxillary incisor teeth were instrumented up to master apical file #40 using Mtwo rotary system and obturated with gutta-percha and AH Plus sealer by cold lateral compaction method. The specimens were assigned to one control group and four experimental groups based on the retrograde filling materials (n=20. The specimens were immersed in 0.5% Rhodamine B solution for 48h. Then the specimens were divided longitudinally into two parts and the depth of dye penetration was assessed under ×10 magnification. Data were analyzed using one-way ANOVA and Bonferroni tests. Results. There were statistically significant difference between the experimental groups and the control group (P0.05. Conclusion. Kryptonite cement provided optimal apical seal in a manner similar to MTA, amalgam and IRM when used as a retrograde filling cement.

  19. Solubility and bacterial sealing ability of MTA and root-end filling materials

    Directory of Open Access Journals (Sweden)

    Camila Galletti ESPIR

    2016-04-01

    Full Text Available ABSTRACT Objective To evaluate solubility and sealing ability of Mineral Trioxide Aggregate (MTA and root-end filling materials. Material and Methods The materials evaluated were: MTA, Calcium Silicate Cement with zirconium oxide (CSC/ZrO2, and zinc oxide/eugenol (ZOE. Solubility test was performed according to ANSI/ADA. The difference between initial and final mass of the materials was analyzed after immersion in distilled water for 7 and 30 days. Retrograde cavities in human teeth with single straight root canal were performed by using ultrasonic tip CVD 9.5107-8. The cavities were filled with the evaluated materials to evaluate sealing ability using the bacterial leakage test with Enterococcus faecalis. Bacterial leakage was evaluated every 24 hours for six weeks observing the turbidity of Brain Heart infusion (BHI medium in contact with root apex. Data were submitted to ANOVA followed by Tukey tests (solubility, and Kruskal-Wallis and Dunn tests (sealing ability at a 5% significance level. Results For the 7-day period, ZOE presented highest solubility when compared with the other groups (p<0.05. For the 30-day period, no difference was observed among the materials. Lower bacterial leakage was observed for MTA and CSC/ZrO2, and both presented better results than ZOE (p<0.05. Conclusion MTA and CSC/ZrO2 presented better bacterial sealing capacity, which may be related to lower initial solubility observed for these materials in relation to ZOE.

  20. Sealing ability, water sorption, solubility and toothbrushing abrasion resistance of temporary filling materials.

    Science.gov (United States)

    Pieper, C M; Zanchi, C H; Rodrigues-Junior, S A; Moraes, R R; Pontes, L S; Bueno, M

    2009-10-01

    To evaluate marginal seal, water sorption, solubility and loss of mass after brushing of several temporary filling materials. For marginal seal, Class I cavities, including endodontic access preparations, were made in human molar teeth and restored using one or other of several temporary filling materials (n = 10): zinc oxide/calcium sulphate-based cement (Cavit, 3M,ESPE, St. Paul, MN, USA), zinc oxide/eugenol cement (IRM, Dentsply Caulk, Milford, DE, USA), glass ionomer cement (Vidrion R, SSWhite, Rio de Janeiro, RJ, Brazil) or a dimethacrylate-based filling (Bioplic, Biodinâmica, Londrina, PR, Brazil). Dye penetration was assessed after thermocycling and immersion in 0.5% basic fuchsine solution. For water sorption, solubility and loss of mass analyses, disc-shaped specimens were made. Water sorption and solubility were evaluated by mass alteration after storage in distilled water for 7 days (n = 7). Loss of mass was calculated based on the difference of mass after abrasion with a toothbrush (n = 5), and surfaces were analysed by SEM. Data of water sorption, solubility and loss of mass were submitted to anova and Tukey's test, and marginal sealing data to Kruskal-Wallis test (P Cavit had the greatest water sorption and solubility. Vidrion R and Bioplic had the lowest solubility. Loss of mass after brushing was higher for Cavit, followed by Bioplic, IRM and Vidrion R. Cavit and Vidrion R were worn aggressively by brushing. The resin-based temporary filling Bioplic produced the best marginal seal, and was associated with the lowest water sorption, solubility and loss of mass.

  1. Effect of hygroscopic expansion of resin filling on interfacial gap and sealing: a confocal microscopy study.

    Science.gov (United States)

    Rosales-Leal, Juan I; Castillo-Salmerón, Ramón Del; Molino-Serrano, María A; González-Moreira, Humberto; Cabrerizo-Vílchez, Miguel A

    2013-10-01

    To measure dimensional changes due to hygroscopic expansion and their effect on interface gaps and sealing in four light-cured restorative materials using an original confocal microscopic methodology. The materials tested were an ormocer (Admira [Voco]), a compomer (Dyract AP [Dentsply]), a hybrid composite (Spectrum [Dentsply]), and a nanohybrid composite (Esthet·X [Dentsply]). Water sorption was evaluated by weighing material disks after immersion. Hygroscopic expansion was measured from volumetric variations of material fillings in cylindrical cavities in dentin slices; the interfacial gap size was obtained from the same cavities using a novel confocal microscopic method. Microleakage was evaluated in cavities prepared in extracted third molars. Measurements followed water immersion for 24 h, 1 week, 4 weeks, and 8 weeks. A factorial ANOVA, the Student Newman Keuls test for post-hoc comparisons, the Student's t-test, and the Pearson test were used for the statistical analysis (p hygroscopic expansion, and sealing. Hygroscopic expansion reduced post-polymerization interfacial gaps and improved cavity sealing. Dyract AP and Admira showed the highest water sorption, hygroscopic expansion, and gap size reduction. 1. The proposed methodology is valid to measure hygroscopic expansion and interfacial gap. 2. Water sorption and hygroscopic expansion are positively correlated, and hygroscopic expansion, gap size, and sealing are also positively correlated. 3. The adhesive influences the interfacial gap size and its variation after hygroscopic expansion. 4. Hygroscopic expansion reduces the interfacial gaps generated by polymerization shrinkage and improves cavity sealing.

  2. Effect of bleaching agents on sealing properties of different intraorifice barriers and root filling materials

    Science.gov (United States)

    Canoglu, Ebru; Gulsahi, Kamran; Sahin, Cem; Altundasar, Emre

    2012-01-01

    Objective: To evaluate the effect of intracoronal bleaching agents on the sealing properties of different intraorifice barriers and root filling materials. Study Design: The root canals of extracted human premolars (n=180) were prepared by using System GT rotary files and filled with either gutta-percha+AH Plus or Resilon+Epiphany sealer. In both groups, the coronal 3mm of root filling was removed and replaced with one of the following materials applied as intraorifice barriers (n=30/group): 1. ProProot-MTA; 2. Conventional Glass ionomer cement; and 3. Hybrid resin composite. In each subgroup, intracoronal bleaching was performed using either sodium perborate with distilled water or 35% hydrogen peroxide gel for 3 weeks. The leakage of specimens was measured using fluid-filtration and dye penetration tests. The data were analyzed statistically with One-way ANOVA, Repeated Measures t-test and Independent Samples t-test (p=0.05). Results: The fluid conductance values of the test groups were not influenced by the type of the bleaching agent, the intraorifice barrier, or the root filling material (all p>0.05). However, the extent of dye leakage was significantly affected by the type of intraorifice barrier material (p resin composite > ProRoot-MTA (psodium perborate/distilled water on the sealing properties of tested intraorifice barriers and root filling materials varied conforming leakage assessment. These properties were not affected by using fluid filtration test, while the glass ionomer barrier showed the greatest amount of dye leakage in both gutta-percha and Resilon root-filled teeth. Key words:Tooth Bleaching, root canal filling materials, glass ionomer cement, mineral trioxide aggregate, micro leakage PMID:22322509

  3. Bacterial leakage in roots filled with different medicaments and sealed with Cavit.

    Science.gov (United States)

    Barthel, Claudia R; Zaritzki, Felix F; Raab, Wolfgang H-M; Zimmer, Stefan

    2006-02-01

    The aim of this study was to evaluate the time required by four different root canal medications coupled with the temporary filling material Cavit (ESPE, Seefeld, Germany) to prevent penetration of bacteria into the root canal. There were 145 roots prepared in a standardized manner. Four groups with 15 samples each were dressed with calcium hydroxide (Ca(OH)(2)), a 5% chlorhexidine gel (CHX), a chloromono-campherphenolic compound (ChKM), and Ledermix (LM), respectively, and sealed with Cavit. Four control groups contained identical medications but the roots were left unsealed. The 25 remaining roots served as additional controls. A standard setup for bacterial leakage studies was chosen with Staphylococcus epidermidis as test strain. Cavit application resulted in a significantly better seal compared with the unsealed groups. In the Cavit-sealed groups, all groups differed significantly from one another except for the CHX and the ChKM groups. The Ca(OH)(2) medicated roots provided the longest protection (median of 36 days), followed by the Ledermix-group (27 days) and the CHX (18 days) or ChKM groups (19 days). It may be concluded that Cavit-sealed and medicated root canals do not provide adequate protection against bacterial leakage for more than 1 month.

  4. Air quality in tightly sealed and passive homes

    Energy Technology Data Exchange (ETDEWEB)

    Scott, L.A.

    1981-09-01

    Indoor air quality has attracted increasing attention during the past few yars. Pollutants generated from combustion, building materials, and human activities may reach significant levels in the indoor environment to produce adverse health effects. This report deals with the classes of pollutants and their sources, and the significance of reported levels, possible health effects, and control strategies in relation to tightly sealed and passive solar construction techniques. In tightly sealed homes, residential air-to-air heat exchangers, whose design and performance are discussed, offer one method of improving air quality at reasonable cost. It is recommended that further research be implemented to identify hazardous concentrations of pollutants and set standards to minimize health impacts in the search for new energy innovations.

  5. 2004 NASA Seal/Secondary Air System Workshop, Volume 1

    Science.gov (United States)

    2005-01-01

    The 2004 NASA Seal/Secondary Air System workshop covered the following topics: (1) Overview of NASA s new Exploration Initiative program aimed at exploring the Moon, Mars, and beyond; (2) Overview of the NASA-sponsored Ultra-Efficient Engine Technology (UEET) program; (3) Overview of NASA Glenn s seal program aimed at developing advanced seals for NASA s turbomachinery, space, and reentry vehicle needs; (4) Reviews of NASA prime contractor and university advanced sealing concepts including tip clearance control, test results, experimental facilities, and numerical predictions; and (5) Reviews of material development programs relevant to advanced seals development. The NASA UEET overview illustrated for the reader the importance of advanced technologies, including seals, in meeting future turbine engine system efficiency and emission goals. For example, the NASA UEET program goals include an 8- to 15-percent reduction in fuel burn, a 15-percent reduction in CO2, a 70-percent reduction in NOx, CO, and unburned hydrocarbons, and a 30-dB noise reduction relative to program baselines. The workshop also covered several programs NASA is funding to develop technologies for the Exploration Initiative and advanced reusable space vehicle technologies. NASA plans on developing an advanced docking and berthing system that would permit any vehicle to dock to any on-orbit station or vehicle, as part of NASA s new Exploration Initiative. Plans to develop the necessary mechanism and androgynous seal technologies were reviewed. Seal challenges posed by reusable re-entry space vehicles include high-temperature operation, resiliency at temperature to accommodate gap changes during operation, and durability to meet mission requirements.

  6. Root Cause Investigation of Rubber Seal Cracking in Pre-filled Cartridges: Ozone and Packaging Effects.

    Science.gov (United States)

    Chan, Edwin K; Hubbard, Aaron; Hsu, Chung C; Vedrine, Lionel; Maa, Yuh-Fun

    2011-01-01

    Pre-filled syringes/cartridges as primary packaging for parenterally delivered biopharmaceutical liquids consist of multiple components, including containers made of glass or plastic, and stoppers/plungers and disk seals (septa) made of rubber materials. Cracking of rubber components may be cosmetically unacceptable and in extreme cases may compromise enclosure integrity. The purpose of this study was to investigate the root cause of septum cracking and evaluate parameters/solutions to delay or prevent cracking from occurring. Custom-made chambers capable of tightly controlling ozone levels were assembled to deliberately create septum cracks. Cracks were qualitatively assessed by optical microscopy and quantified using image analysis by ImageJ. The results confirmed that ozone attack is the root cause of septum cracking during storage, and the stress-the result of crimping on the glass cartridge by the aluminum lined seal-made the septum particularly vulnerable to ozone attack. Ozone concentration as low as 10-40 ppb (levels routinely detected on a busy street) could crack the stressed septum in hours while days of ozone exposure at 50 ppm could not cause the unstressed septum to crack. Under ozone attack cracks initially grow in length and width uniformly across the stressed area and then stop progressing, perhaps due to residual stress release. Although the use of impermeable barriers could prevent cracking completely, this study suggested that any form of packaging barriers, including a highly permeable Tyvek® sheet, could postpone cracking by slowing down ozone diffusion and convection. We demonstrate that simple double packaging-placing the Tyvek®-lidded blister tray in a cardboard carton-could sufficiently protect the stressed septum for years in a surrounding environment with ozone at normal indoor levels (≤2 ppb). Pre-filled syringes/cartridges as primary packaging for parenterally delivered biopharmaceutical liquids contain multiple components

  7. Application of I-structure though-glass interconnect filled with submicron gold particles to a hermetic sealing device

    Science.gov (United States)

    Nomura, Kazuya; Okada, Akiko; Shoji, Shuichi; Ogashiwa, Toshinori; Mizuno, Jun

    2016-10-01

    We propose hermetic sealing of a glass-to-glass structure with an I-structure through-glass interconnect via (TGV) filled with submicron Au particles. The top and bottom bumps and the TGV were formed by a simple filling process with a bump-patterned dry film resist. The sealing devices consisting of two glass substrates were bonded via Au interlayers. Vacuum ultraviolet irradiation in the presence of oxygen gas (VUV/O3) pretreatment was used for low-temperature Au-Au bonding at 200 °C. The bonded samples showed He leakage rates of less than 1.3  ×  10-9 Pa m3 s-1. The cross-sectional scanning electron microscope images of the fabricated I-structure TGV showed perfect adhesion between the I-structure TGV and glass substrate. These results indicate that the proposed I-structure TGV is suitable for hermetic sealing devices.

  8. Portable optical frequency standard based on sealed gas-filled hollow-core fiber using a novel encapsulation technique

    DEFF Research Database (Denmark)

    Triches, Marco; Brusch, Anders; Hald, Jan

    2015-01-01

    A portable stand-alone optical frequency standard based on a gas-filled hollow-core photonic crystal fiber is developed to stabilize a fiber laser to the 13C2H2 P(16) (ν1 + ν3) transition at 1542 nm using saturated absorption. A novel encapsulation technique is developed to permanently seal...

  9. Cavity air flow behavior during filling in microinjection molding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.

    2011-01-01

    valuable information about the process dynamics and also about the filling of a cavity by a polymer melt. In this paper, a novel experimental setup is proposed to monitor maximum air flow and air flow work as an integral of the air flow over time by employing a microelectromechanical system gas sensor...... mounted inside the mold. The influence of four μIM parameters, melt temperature, mold temperature, injection speed, and resistance to air evacuation, on two air flow-related output parameters is investigated by carrying out a design of experiment study. The results provide empirical evidences about...... the effects of process parameters on cavity air evacuation, and the influence of air evacuation on the part flow length. © 2011 American Society of Mechanical Engineers....

  10. Measure Guideline: Air Sealing Mechanical Closets in Slab-On-Grade Homes

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, B.

    2012-02-01

    This measure guideline describes covers two fundamental retrofit strategies for air sealing around air handling systems that are located within the living space in an enclosed closet: one in which all of the equipment is removed and being replaced, and a closet where the equipment is to remain and existing conditions are sealed. It includes the design and installation details necessary to effectively seal the air handler closet and central return system to maximize the efficiency and safety of the space conditioning system.

  11. Measure Guideline. Air Sealing Mechanical Closets in Slab-on-Grade Homes

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Bruce [IBACOS, Inc., Pittsburgh, PA (United States)

    2012-02-01

    This measure guideline describes two fundamental retrofit strategies for air sealing around air handling systems that are located within the living space in an enclosed closet: one in which all of the equipment is removed and being replaced, and a closet where the equipment is to remain and existing conditions are sealed. It includes the design and installation details necessary to effectively seal the air handler closet and central return system to maximize the efficiency and safety of the space conditioning system.

  12. Controlled-force end seal arrangement for an air press of a papermaking machine

    Science.gov (United States)

    Beck, David A.

    2003-07-08

    An air press for pressing a fiber web includes a plurality of rolls and a pair of end seal arrangements. Of the plurality of rolls, each pair of adjacent rolls forms a nip therebetween. Further, each roll has a pair of roll ends, the plurality of rolls together forming two sets of roll ends. Each end seal arrangement coacts with one set of roll ends, the plurality of rolls and the pair of end seal arrangements together defining an air press chamber having an air chamber pressure. Each end seal arrangement is composed of at least one roll seal, including a first roll seal, and an adjustable bias mechanism. Each roll seal forms a seal with at least one roll end, and one side of the first roll seal being exposed to the air chamber pressure. The adjustable bias mechanism is configured for controlling a position of each roll seal relative to a respective at least one roll end and for adjusting a seal force between the roll seal and the respective at least one roll end.

  13. Continuous microbiological air monitoring for aseptic filling lines.

    Science.gov (United States)

    Scherwing, Claudia; Golin, Franco; Guenec, Olivier; Pflanz, Karl; Dalmaso, Gilberto; Bini, Manuela; Andone, Francesca

    2007-01-01

    Pharmaceutical aseptic filling lines are used to fill sterile biotechnology products without affecting their quality by a terminal sterilization step. Standard grade A filling environments are required to have meter (m3) of air. Aseptic filling is the production cycle with one of the highest contamination risks. A typical method of contamination monitoring is to actively draw air and filter it through special gelatin filters. The study aims to establish whether continuous sampling provides effective monitoring for the entire production process by determining whether trapped organisms can withstand long-term drying stress with unaltered recovery. In two experimental phases, the study examined microbial recovery in long-term air-stressed membranes as well as the viability of microorganisms on gelatin filters during 8-hour runs of filtration with high-efficiency particulate air-filtered air from a laminar flow hood using the MD 8 Airscan system. Stressed and unstressed filters were compared with parallel-run reference filters as controls. The CFUs were counted and the genus of the identified microorganism populations determined to examine any changes in microbiological flora occurring during continuous long-term sampling. Compared to the unstressed reference filters, neither total recovery nor recovered bacterial diversity changed. No statistically significant differences in CFUs were found between test filters and reference filters, nor were any statistically significant differences found in the microbiological flora between test filters and reference filters. CFU populations were comparable in both experiments. Eight hours of continuous air sampling on gelatin filters with the MD 8 Airscan system did not affect total recovery or change the diversity of recovered microorganisms compared to the controls.

  14. A comparative evaluation of sealing ability of four root end filling materials using fluid filtration method: Anin vitrostudy.

    Science.gov (United States)

    Shetty, Shilpa; Hiremath, Geeta; Yeli, Mahantesh

    2017-01-01

    The aim of this study was to compare and evaluate the sealing ability of four root end filling materials mineral trioxide aggregate (MTA)-Plus, Biodentine, MTA (MTA Angelus) and glass ionomer cement (GIC) using fluid filtration method. Forty-four extracted, human single-rooted teeth were collected. The crown of each tooth was decoronated 2 mm above the cementoenamel junction. Canals were negotiated, instrumented, obturated using lateral compaction method. The access cavities were sealed with Cavit. Root end resection and apical root end cavity preparations of 4 mm were made in each specimen. The selected roots were then randomly divided into four groups ( n = 11) and restored as follows. Group 1 - GIC, Group 2 - MTA (MTA Angelus), Group 3 - Biodentine, and Group 4 - MTA Plus. The apical microleakage of each specimen was assessed using fluid filtration method at 72 h, 1 month and 3 months. Microleakage in each specimen was recorded in mm (millimeter) and converted to μl/min/cm H 2 O. MTA Angelus showed least microleakage followed by Biodentine and MTA Plus. Least sealing ability was seen with GIC. There was statistically significant difference between all the materials at various time intervals. MTA Angelus showed superior sealing ability as a retrograde filling material followed by Biodentine and MTA Plus.

  15. Air-filled vs water-filled intragastric balloon: a prospective randomized study.

    Science.gov (United States)

    Giardiello, Cristiano; Borrelli, Alessandro; Silvestri, Eufemia; Antognozzi, Valentina; Iodice, Giuseppe; Lorenzo, Michele

    2012-12-01

    The positioning of an intragastric saline-filled balloon has been developed as temporary and reversible therapeutic option for treatment of morbid obesity. Recently, an air-filled balloon was also developed. The aim of this study is to prospectively compare these two devices in terms of weight loss parameters, safety, and tolerance. Sixty patients were randomized into two groups: group A (Bioenterics Intragastric Balloon-BIB; n = 30; 20 F/10 M, mean age 36.7 ± 10.9; mean BMI 46.5 ± 5.9) and group B (Endobag-Heliosphere; n = 30; 20 F/10 M, mean age 37.8 ± 10.6; mean BMI 46.1 ± 5.6). All patients of both groups were sedated with midazolam (5 mg) + Propofol (2 mg/kg i.v.). The Heliosphere Bag was air-filled with 950 ml while BIB® was inflated with 500 ml of saline and 10 ml of methylene blue. Percentage of excess weight loss (%EWL) and body mass index (BMI) were evaluated. Student t test, Fisher exact test, and χ(2) test were used for statistical analysis. Similar weight loss parameters were observed in patients treated with liquid or air-filled balloon at time of removal: mean BMI was 40.8 ± 6.2 and 41.9 ± 6.5(p = ns), and mean %EWL was 20 ± 12 and 18 ± 14 (p = ns) in groups A and B, respectively. Significant longer extraction time, with high patient discomfort, was observed in group B due to difficult passage through the cardia and the lower pharynx. Air-filled balloon can be another valid therapeutic option in the temporary treatment of obesity, but at this time, the quality of the device must be improved to ameliorate the patient compliance at removal and avoid the spontaneous deflations.

  16. Bacterial microleakage of temporary filling materials used for endodontic access cavity sealing

    Directory of Open Access Journals (Sweden)

    Igor Križnar

    2016-12-01

    Conclusion: None of the tested materials were able to completely prevent bacterial microleakage. Adhesively bonded composites and Cavit offer better sealing compared with glass ionomer cements, resin modified glass ionomer cements, and composites without the use of an adhesive system.

  17. Heat and Pressure Seal for Doors

    Science.gov (United States)

    Gillespie, C. A.

    1982-01-01

    Proposed tubular gasket for doors performs dual function: seals in pressure, and seals out heat. Composed of quartz fabric filled with alumina matting, gasket is bonded with room-temperature-vulcanizing material to periphery of door. When door is closed, gasket is compressed like O-ring: fills gap between door and frame; and prevents leakage of air and heat.

  18. Macrobending loss properties of photonic crystal fibres with different air filling fractions

    DEFF Research Database (Denmark)

    Sørensen, Thorkild; Broeng, Jes; Bjarklev, Anders Overgaard

    2001-01-01

    We present experimental and theoretical analysis of macrobending losses of photonic crystal fibres with various air filling fractions. A scalar, effective-index method provides a good description of the losses for fibres with limited air filling fractions, whereas the method overestimates...... the losses for fibres with larger air filling fractions....

  19. Earth-Fill Dam Monitored by EIS Method during Application of Nutrient Aqueous Solution used in BioSealing Method

    Science.gov (United States)

    Pařílková, J.; Gjunsburgs, B.; Zachoval, Z.; Veselý, J.; Műnsterová, Z.

    2017-10-01

    The paper gives short information about the results of monitoring the electrical properties of an earth-fill dam during the application of a nutrient aqueous solution used in the method BioSealing. Monitoring is carried out using a Z-meter device when applying the method of electrical impedance spectrometry and, in some cases, is part of a system of monitoring seepage through the earth-fill dam of the water reservoir by its administrator. Information about the changes that take place in the body of the dam during the movement of the water level in the reservoir or after the influence of weather changes or human activity are given through the monitored changes in the electrical parameters of the soil of the dam with time.

  20. In vitro Study on Apical Sealing Ability of Nano-Hydroxyapatite-Filled Epoxy Resin Based Endodontic Sealer

    Science.gov (United States)

    Masudi, S. M.; Luddin, N.; Mohamad, D.; Alkashakhshir, J. J.; Adnan, R.; Ramli, R. A.

    2010-03-01

    The objectives of this in vitro study were to evaluate the apical sealing ability of experimental nano hydroxyapatite (HA)-filled epoxy resin based endodontic sealer and to compare it with the commercial AH26 sealant. A total of 76 extracted human anterior teeth were instrumented using NiTi files and randomly divided into two groups of 33 teeth each and two control groups of 5 teeth each. The first group was obturated using gutta-percha with AH26 sealer. The second group was obturated with the nano HA-filled epoxy resin based sealer. All teeth were coated with nail polish except 2 mm from foramen apical and then suspended in 2% methylene blue for 7 days. All teeth were sectioned longitudinally for measuring penetration of the dye using stereo-microscope (x36). The result showed that there was no statistically significant difference (p>0.05) in apical sealing ability between AH26 silver-free sealer and nano HA sealer.

  1. The Effect of Thickness on the Sealing Ability of CEM Cement as a Root-end Filling Material

    Science.gov (United States)

    Rahimi, Saeed; Asgary, Saeed; Samiei, Mohammad; Bahari, Mahmoud; Vahid Pakdel, Seyyed Mahdi; Mahmoudi, Rasoul

    2015-01-01

    Background and aims. Different materials have been used for root-end filling during surgical endodontic treatment. The aim of this in vitro study was to evaluate the dye penetration in different thicknesses of calcium enriched mixture (CEM) cement as root-end filling material. Materials and methods. Following root canal filling in 70 extracted human single-rooted premolar teeth, the apical 3 mm of their root-ends was resected; the root-end cavities with depths of 1, 2 and 3 mm were prepared by ultrasonic retrotips and filled with CEM cement. After setting of cement, the roots were immersed in 2% Rhodamine B and the dye leakage was measured under stereomicroscope (×16) using Image J software. The data were analyzed by one-way ANOVA and Bonferroni post hoc tests at 5% significance level. Results. The means and standard deviations of dye penetration in the 1, 2, and 3 mm groups were 3395.5±1893.4, 3410.4±1440.5, and 2581.6±1852.9 μm, respectively. The one-way ANOVA analysis indicated significant differences (P post hoc test revealed that only the positive control group differed significantly from the experimental groups (P < 0.001). Conclusion. The findings demonstrated CEM cement to have an adequate root-end sealing ability in 3-mm thickness. PMID:25973147

  2. Wave intensity analysis in air-filled flexible vessels.

    Science.gov (United States)

    Clavica, Francesco; Parker, Kim H; Khir, Ashraf W

    2015-02-26

    Wave intensity analysis (WIA) is an analytical technique generally used to investigate the propagation of waves in the cardiovascular system. Despite its increasing usage in the cardiovascular system, to our knowledge WIA has never been applied to the respiratory system. Given the analogies between arteries and airways (i.e. fluid flow in flexible vessels), the aim of this work is to test the applicability of WIA with gas flow instead of liquid flow. The models employed in this study are similar to earlier studies used for arterial investigations. Simultaneous pressure (P) and velocity (U) measurements were initially made in a single tube and then in several flexible tubes connected in series. Wave speed was calculated using the foot-to-foot method (cf), which was used to separate analytically the measured P and U waveforms into their forward and backward components. Further, the data were used to calculate wave intensity, which was also separated into its forward and backward components. Although the measured wave speed was relatively high, the results showed that the onsets and the nature of reflections (compression/expansion) derived with WIA, corresponded well to those anticipated using the theory of waves in liquid-filled elastic tubes. On average the difference between the experimental and theoretical arrival time of reflection was 6.1% and 3.6% for the single vessel and multivessel experiment, respectively. The results suggest that WIA can provide relatively accurate information on reflections in air-filled flexible tubes, warranting further studies to explore the full potential of this technique in the respiratory system. Copyright © 2015. Published by Elsevier Ltd.

  3. Measure Guideline: Wall Air Sealing and Insulation Methods in Existing Homes; An Overview of Opportunity and Process

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, S.; Stephenson, R.

    2012-09-01

    This guide provides renovators and retrofit contractors an overview of considerations when including wall air sealing and insulation in an energy retrofit project. It also outlines the potential project risks, various materials for insulating, possible field inspections needed, installation procedures, as well as the benefits and drawbacks. The purpose of this document is to provide the outline of the overview and process of insulating and air sealing walls so that home retrofit professionals can identify approaches to air sealing and insulation measures.

  4. Thermal Cyclability of Reactive Air Braze Seals in Anode Supported Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, John S.; Darsell, Jens T.; Coyle, Christopher A.; Birnbaum, Jerome C.; Weil, K. Scott

    2004-12-31

    The popularity of anode-supported solid oxide fuel cells (SOFC) has increased in tandem with the ability to fabricate thinner gas-tight yttrium-stabilized zirconia (YSZ) electrolyte layers, which can now be routinely produced on the order of 7 to 10 μm thick. While this has significantly improved power output and decreased the required fuel cell operating temperatures, the ability to reliably seal fuel cells remains a concern. The seals must be hermetic and be robust enough to retain their hermeticity even under the extreme operating conditions of SOFCs. Perhaps the largest contributor to stresses experienced by the seal is the fact that the SOFC is an assembly of many different materials with different thermal expansion properties. Although every effort is made to minimize thermal expansion mismatches across the seals, the stresses developed during thermal cycling still jeopardize seal integrity. Reactive air brazing (RAB), a method of joining that employs a metallic, and therefore non-brittle, seal material has been used to seal electrolyte/anode bilayers, such as those in anode-supported SOFCs, to Crofer-22 alloy. The results of rupture strength testing will be reported for as-brazed and thermally cycled samples and the effect of thermal cycling on the RAB seal microstructure will be shown

  5. Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study

    Directory of Open Access Journals (Sweden)

    Paulo Leal MEDEIROS

    2016-04-01

    Full Text Available ABSTRACT Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05. Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05. No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

  6. In-Air Evoked Potential Audiometry of Grey Seals (Halichoerus grypus) from the North and Baltic Seas

    NARCIS (Netherlands)

    Ruser, A.; Daehne, M.; Sundermeyer, J.; Lucke, K.; Houser, D.S.; Finneran, J.J.; Driver, J.; Pawliczka, I.; Rosenberger, T.; Siebert, U.

    2014-01-01

    In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear

  7. Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A. [ABT Systems, LLC, Annville, PA (United States); Prahl, D. [IBACOS, Inc., Pittsburgh, PA (United States)

    2014-12-01

    IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

  8. Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.; Prahl, D.

    2014-12-01

    IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are (1) the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and (2) the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

  9. Building America Best Practices Series, Volume 10: Retrofit Techniques and Technologies: Air Sealing

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, Michael C.; Gilbride, Theresa L.; Hefty, Marye G.; Cole, Pamala C.; Williamson, Jennifer L.; Love, Pat M.

    2010-04-12

    This report was prepared by PNNL for the U.S. Department of Energy Building America Program. The report provides information to home owners who want to make their existing homes more energy efficient by sealing leaks in the building envelope (ceiling, walls, and floors) that let in drafts and let conditioned air escape. The report provides descriptions of 19 key areas of the home where air sealing can improve home performance and energy efficiency. The report includes suggestions on how to find a qualified weatherization or home performance contractor, what to expect in a home energy audit, opportune times for performing air sealing, and what safety and health concerns to be aware of. The report describes some basic building science concepts and topics related to air sealing including ventilation, diagnostic tools, and code requirements. The report will be available for free download from the DOE Building America website. It is a suitable consumer education tool for home performance and weatherization contractors to share with customers to describe the process and value of home energy retrofits.

  10. Regulated tailored suction vs regulated seal: a prospective randomized trial on air leak duration.

    Science.gov (United States)

    Brunelli, Alessandro; Salati, Michele; Pompili, Cecilia; Refai, Majed; Sabbatini, Armando

    2013-05-01

    The objective of this study was to compare the air leak duration of two regulated chest tube modes following pulmonary lobectomy. This is a prospective randomized trial on 100 consecutive pulmonary lobectomies (2010-11) performed for lung cancer. A single 24-French chest tube was connected to an electronic system capable of maintaining the pleural pressure within preset values (regulated suction mode) or within a physiological range (regulated seal mode). Patients were randomized to two groups: Group 1, regulated individualized suction (range: -11 to -20 cmH2O, according to lobectomy type); Group 2, regulated seal (-2 cmH2O). The main endpoint was the duration of air leak (h) calculated from the end of the operation to a value consistently below 20 ml/min. Patients with prolonged air leak (>168 h) were connected to a portable device before discharge. Their air leak duration was considered as 192 h. The sample size was calculated to detect 1-day difference in air leak duration with a statistical power of 80%. The two groups were well matched for several baseline and surgical characteristics. No crossovers occurred between groups. The average air leak duration (Group 1: 28 vs Group 2: 22.2, P = 0.6), and the number of patients with prolonged air leak (Group 1: 5 vs Group 2: 4, P = 0.7) and with other complications (Group 1: 6 patients vs Group 2: 7 patients, P = 0.9) were similar between the groups. Sixteen patients of Group 1 and 21 of Group 2 had an air leak present immediately after extubation. Among them, patients of Group 2 (regulated seal) had an air leak lasting 34.5 h less than those of Group 1 (regulated suction) (52.9 vs 87.4, P = 0.07). Regulated seal is as effective and safe as regulated suction in managing chest tubes following lobectomy. This information demonstrates with objective data the non-superiority of regulated suction vs regulated seal and may assist in future investigations on regulated pleural pressure.

  11. Air-Filled porosity and permeability relationships during solid-waste fermentation

    NARCIS (Netherlands)

    Richard, T.L.; Veeken, A.H.M.; Wilde, de V.; Hamelers, H.V.M.

    2004-01-01

    An experimental apparatus was constructed to measure the structural parameters of organic porous media, i.,e. mechanical strength, air-filled porosity, air permeability, and the Ergun particle size. These parameters are critical to the engineering of aerobic bioconversion systems and were measured

  12. Differences in physical characteristics and sealing ability of three tricalcium silicate-based cements used as root-end-filling materials.

    Science.gov (United States)

    Kollmuss, Maximilian; Preis, Carolina Elisabeth; Kist, Stefan; Hickel, Reinhard; Huth, Karin Christine

    2017-08-01

    To evaluate differences in physical characteristics and sealing ability of root-end-fillings made with these materials compared to the gold standard (ProRoot MTA). The physical characteristics of ProRoot MTA, Medcem MTA and Biodentine were evaluated regarding setting time, flow, film thickness, solubility and radiopacity according to the German Institute for Standardization (EN-ISO 6878). To investigate their sealing ability as root-end-fillings, a glucose penetration model was used. 60 human extracted single-rooted teeth were endodontically treated, root-end resections performed and divided in three groups of 20 teeth, using either ProRoot MTA, Medcem MTA or Biodentine as root-end-filling material. After 30 days, glucose concentrations were determined photometrically, followed by statistical analysis (Kruskal-Wallis test, Mann-Whitney U-test). Biodentine showed the fastest setting time (Biodentine showed lower leakage than ProRoot MTA (P= 0.031). As Medcem MTA showed significantly lower leakage than the other materials tested, it may be an alternative for root-end-fillings with comparable physical characteristics to the current gold standard. With the exception of the high solubility, Biodentine performed well regarding leakage and setting time.

  13. Controlling a rabbet load and air/oil seal temperatures in a turbine

    Science.gov (United States)

    Schmidt, Mark Christopher

    2002-01-01

    During a standard fired shutdown of a turbine, a loaded rabbet joint between the fourth stage wheel and the aft shaft of the machine can become unloaded causing a gap to occur due to a thermal mismatch at the rabbet joint with the bearing blower turned on. An open or unloaded rabbet could cause the parts to move relative to each other and therefore cause the rotor to lose balance. If the bearing blower is turned off during a shutdown, the forward air/oil seal temperature may exceed maximum design practice criterion due to "soak-back." An air/oil seal temperature above the established maximum design limits could cause a bearing fire to occur, with catastrophic consequences to the machine. By controlling the bearing blower according to an optimized blower profile, the rabbet load can be maintained, and the air/oil seal temperature can be maintained below the established limits. A blower profile is determined according to a thermodynamic model of the system.

  14. MATHEMATICAL MODELLING OF QUAZISTEADY MODE OF BEARING AIR BUFFER FILLING

    Directory of Open Access Journals (Sweden)

    E. D. Chertov

    2014-01-01

    Full Text Available Summary. Today the only way to eliminate contact with the product during the manufacturing process is to provide a support surface under its support surface air buffer layer formed due to the expiration of the working environment through holes perforated gas distribution grids forms. There proposed the method of contactless formation of products consisting of composite materials by the means of air buffer in the article. The results of theoretical and experimental investigations of hydro-gas-dynamic processes occurring when casting of organic- mineral composite material onto the bearing air buffer expressed in the form of mathematical description realizing original hypotheses reflected in the choice of transformation algorithm and limiting conditions are presented. On the base of obtained mathematical model the algorithm of calculation of optimum parameters of transporting systems with discretely powered gas buffer is developed. The method of deduction of a semi-finished product on the gas buffer, which allows to level the pressure field under the bearing surface of the deduction object due to the usage of devices of pseudo fluidized granular material in pneumatic chambers is offered. The application of this method allows to eliminate the possibility of contact between the composite material and the working surface of the equipment and also to reduce the cost of production of pneumatic devices, to improve operational characteristics of this equipment. Submitted depending allowed to develop the methodology and implementation of engineering calculation device for non-contact casting composite materials on air buffer, semi-industrial and industrial variants were created and put into production.

  15. Challenges of Achieving 2012 IECC Air Sealing Requirements in Multifamily Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Klocke, S. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Faakye, O. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, S. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2014-10-01

    While previous versions of the International Energy Conservation Code (IECC) have included provisions to improve the air tightness of dwellings, for the first time, the 2012 IECC mandates compliance verification through blower door testing. Simply completing the Air Barrier and Insulation Installation checklist through visual inspection is no longer sufficient by itself. In addition, the 2012 IECC mandates a significantly stricter air sealing requirement. In Climate Zones 3 through 8, air leakage may not exceed 3 ACH50, which is a significant reduction from the 2009 IECC requirement of 7 ACH50. This requirement is for all residential buildings, which includes low-rise multifamily dwellings. While this air leakage rate requirement is an important component to achieving an efficient building thermal envelope, currently, the code language doesn't explicitly address differences between single family and multifamily applications. In addition, the 2012 IECC does not provide an option to sample dwellings for larger multifamily buildings, so compliance would have to be verified on every unit. With compliance with the 2012 IECC air leakage requirements on the horizon, several of Consortium for Advanced Residential Building's (CARB’s) multifamily builder partners are evaluating how best to comply with this requirement. Builders are not sure whether it is more practical or beneficial to simply pay for guarded testing or to revise their air sealing strategies to improve compartmentalization to comply with code requirements based on unguarded blower door testing. This report summarizes CARB's research that was conducted to assess the feasibility of meeting the 2012 IECC air leakage requirements in 3 multifamily buildings.

  16. Challenges of Achieving 2012 IECC Air Sealing Requirements in Multifamily Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Klocke, S.; Faakye, O.; Puttagunta, S.

    2014-10-01

    ​While previous versions of the International Energy Conservation Code (IECC) have included provisions to improve the air tightness of dwellings, for the first time, the 2012 IECC mandates compliance verification through blower door testing. Simply completing the Air Barrier and Insulation Installation checklist through visual inspection is no longer sufficient by itself. In addition, the 2012 IECC mandates a significantly stricter air sealing requirement. In Climate Zones 3 through 8, air leakage may not exceed 3 ACH50, which is a significant reduction from the 2009 IECC requirement of 7 ACH50. This requirement is for all residential buildings, which includes low-rise multifamily dwellings. While this air leakage rate requirement is an important component to achieving an efficient building thermal envelope, currently, the code language doesn't explicitly address differences between single family and multifamily applications. In addition, the 2012 IECC does not provide an option to sample dwellings for larger multifamily buildings, so compliance would have to be verified on every unit. With compliance with the 2012 IECC air leakage requirements on the horizon, several of CARB's multifamily builder partners are evaluating how best to comply with this requirement. Builders are not sure whether it is more practical or beneficial to simply pay for guarded testing or to revise their air sealing strategies to improve compartmentalization to comply with code requirements based on unguarded blower door testing. This report summarizes CARB's research that was conducted to assess the feasibility of meeting the 2012 IECC air leakage requirements in 3 multifamily buildings.

  17. The frequency response of the vibrissae of harp seal, Pagophilus Groenlandicus, to sound in air and water.

    Directory of Open Access Journals (Sweden)

    Lisa F Shatz

    Full Text Available The motion of isolated seal vibrissae due to low frequency sound in air has been measured using a microscope with a video camera and modeled using an FEM method with good agreement between the measurements and the model; the model has also been used to predict the motion of seal vibrissae in water. The shape of the seal vibrissae is that of a tapered right rectangular prism, unlike that of the previously studied rat vibrissae which are conical in shape. Moreover, unlike rat vibrissae which oscillate in the direction of the sound stimulus, two different modes of vibration of seal vibrissae were observed - one corresponding to the wider side being stimulated and one with the narrow side stimulated. The tuning of the seal vibrissae was much sharper than those of rat vibrissae, with quality factors about three times as large as those of rat vibrissae. As shown by the model, this increased sharpness is caused by the larger cross-sectional areas (by more than a factor of ten of the seal vibrissae. This increased sharpness may be necessary for seal vibrissae so that they can have tuning in water, where the drag more heavily dampens the tuning than in air. The results suggest that vibrissae tuning may be important in the seal's ability to track the wake of its prey.

  18. Air-filled porosity and permeability relationships during solid-state fermentation.

    Science.gov (United States)

    Richard, Tom L; Veeken, Adrie H M; de Wilde, Vinnie; Hamelers, H V M Bert

    2004-01-01

    An experimental apparatus was constructed to measure the structural parameters of organic porous media, i.,e. mechanical strength, air-filled porosity, air permeability, and the Ergun particle size. These parameters are critical to the engineering of aerobic bioconversion systems and were measured for a straw--manure mixture before and after 13 days of in-vessel composting. Porosity was measured using air pycnometry at four (day 0) and five (day 13) moisture levels, with each moisture level tested at a range of different densities. Tested wet bulk densities varied with moisture level, but dry bulk densities generally ranged from 100 to 200 kg m(-3). At each moisture/density combination, pressure drop was measured at airflow rates ranging from 0.001 to 0.05 m sec(-1), representing the range of airflow rates found in both intensive and extensive composting. Measured air-filled porosities were accurately predicted from measurements of bulk density, moisture, and organic matter content. Reductions in air-filled porosity at increasing moisture content were accompanied by an increase in permeability, apparently due to aggregations of fines. This aggregation was quantified by calculating an effective particle size from the Ergun permeability relationship, which increased from 0.0002 m at 50% moisture to 0.0021 m at 79% moisture. The range of airflow velocities reported in composting systems requires consideration of the second-order drag force term, particularly at velocities approaching 0.05 m s(-1) for the higher moisture treatments tested. Calculated permeabilities for the matrix ranged from 10(-10) to 10(-7) m2, varying with both air-filled porosity and moisture. Mechanical strength characterization provided a means to predict the effects of compaction on air-filled porosity and permeability of porous media beds. The results of this investigation extend porous media theory to the organic matrices common in solid-state fermentations and help build a framework for

  19. Numerical two-dimensional natural convection in an air filled square ...

    African Journals Online (AJOL)

    Numerical two-dimensional natural convection in an air filled square enclosure, tilted (25° and 65°) in relation to the horizontal plane, heated from two opposite sides for rayleigh numbers ranging between 10 3 and 2.10 6.

  20. Airtightness Results of Roof-Only Air Sealing Strategies on 1-1/2 Story Homes in Cold Climates

    Energy Technology Data Exchange (ETDEWEB)

    Ojczyk, C.; Murry, T.; Mosiman, G.

    2014-07-01

    In this second study on solutions to ice dams in 1-1/2 story homes, five test homes located in both cold and very cold climates were analyzed for air leakage reduction rates following modifications by independent contractors on owner-occupied homes. The reason for choosing this house type was they are very common in our area and very difficult to air seal and insulate effectively. Two projects followed a roof-only Exterior Thermal Moisture Management System (ETMMS) process. One project used an interior-only approach to roof air sealing and insulation. The remaining two projects used a deep energy retrofit approach for whole house (foundation wall, above grade wall, roof) air leakage and heat loss reduction. All were asked to provide information regarding project goals, process, and pre and post-blower door test results. Additional air leakage reduction data was provided by several NorthernSTAR Building America industry partners for interior-applied, roof-only modifications on 1-1/2 story homes. The data represents homes in the general market as well as homes that were part of the state of Minnesota weatherization program. A goal was to compare exterior air sealing methods with interior approaches. This pool of data enabled us to compare air tightness data from over 220 homes using similar air seal methods.

  1. Airtightness Results of Roof-Only Air Sealing Strategies on 1 ½-Story Homes in Cold Climates

    Energy Technology Data Exchange (ETDEWEB)

    Ojczyk, C.; Murry, T.; Mosiman, G.

    2014-07-01

    In this second study on solutions to ice dams in 1-1/2 story homes, the NorthernSTAR Building America Partnership team analyzed five test homes located in both cold and very cold climates for air leakage reduction rates following modifications by independent contractors on owner-occupied homes. These homes were chosen for testing as they are common in Minnesota and very difficult to air seal and insulate effectively. Two projects followed a roof-only Exterior Thermal Moisture Management System (ETMMS) process. One project used an interior-only approach to roof air sealing and insulation. The remaining two projects used a deep energy retrofit approach for whole house (foundation wall, above grade wall, roof) air leakage and heat loss reduction. All were asked to provide information regarding project goals, process, and pre and post-blower door test results. Additional air leakage reduction data was provided by several NorthernSTAR industry partners for interior-applied, roof-only modifications on 1-1/2 story homes. The data represents homes in the general market as well as homes that were part of the state of Minnesota weatherization program. A goal was to compare exterior air sealing methods with interior approaches. This pool of data enabled the team to compare air tightness data from over 220 homes using similar air seal methods.

  2. Hydraulic Transients Caused by Air Expulsion During Rapid Filling of Undulating Pipelines

    Directory of Open Access Journals (Sweden)

    Ciro Apollonio

    2016-01-01

    Full Text Available One of the main issues arising during the rapid filling of a pipeline is the pressure transient which originates after the entrapped air has been expelled at the air release valve. Because of the difference in density between water and air, a pressure transient originates at the impact of the water column. Many authors have analyzed the problem, both from the theoretical and the experimental standpoint. Nevertheless, mainly vertical or horizontal pipelines have been analyzed, whereas in real field applications, the pipe profile is a sequence of ascending and descending pipes, with air release/vacuum valves at high points. To overcome lack of knowledge regarding this latter case, laboratory experiments were carried out to simulate the filling of an undulating pipeline, initially empty at atmospheric pressure. The pipe profile has a high point where an orifice is installed for air venting, so as to simulate the air release valve at intermediate high point of a supply pipeline. In the experiments, the diameter of the orifice and the opening degree of both upstream and downstream valves were varied, in order to analyze their effect on the pressure transient. The experiments were also carried out with a longer descending pipe, in order to assess the effects on the pressure surge of the air volume downstream of the orifice.

  3. Liquid- and air-filled catheters without balloon as an alternative to the air-filled balloon catheter for measurement of esophageal pressure.

    Directory of Open Access Journals (Sweden)

    Alessandro Beda

    Full Text Available BACKGROUND: Measuring esophageal pressure (Pes using an air-filled balloon catheter (BC is the common approach to estimate pleural pressure and related parameters. However, Pes is not routinely measured in mechanically ventilated patients, partly due to technical and practical limitations and difficulties. This study aimed at comparing the conventional BC with two alternative methods for Pes measurement, liquid-filled and air-filled catheters without balloon (LFC and AFC, during mechanical ventilation with and without spontaneous breathing activity. Seven female juvenile pigs (32-42 kg were anesthetized, orotracheally intubated, and a bundle of an AFC, LFC, and BC was inserted in the esophagus. Controlled and assisted mechanical ventilation were applied with positive end-expiratory pressures of 5 and 15 cmH2O, and driving pressures of 10 and 20 cmH2O, in supine and lateral decubitus. MAIN RESULTS: Cardiogenic noise in BC tracings was much larger (up to 25% of total power of Pes signal than in AFC and LFC (<3%. Lung and chest wall elastance, pressure-time product, inspiratory work of breathing, inspiratory change and end-expiratory value of transpulmonary pressure were estimated. The three catheters allowed detecting similar changes in these parameters between different ventilation settings. However, a non-negligible and significant bias between estimates from BC and those from AFC and LFC was observed in several instances. CONCLUSIONS: In anesthetized and mechanically ventilated pigs, the three catheters are equivalent when the aim is to detect changes in Pes and related parameters between different conditions, but possibly not when the absolute value of the estimated parameters is of paramount importance. Due to a better signal-to-noise ratio, and considering its practical advantages in terms of easier calibration and simpler acquisition setup, LFC may prove interesting for clinical use.

  4. Heat loss in air of an Antarctic marine mammal, the Weddell seal.

    Science.gov (United States)

    Mellish, Jo-Ann; Hindle, Allyson; Skinner, John; Horning, Markus

    2015-01-01

    The conflicting needs of homeostasis in air versus water complicate our understanding of thermoregulation in marine mammals. Large-scale modeling efforts directed at predicting the energetic impact of changing sea ice conditions on polar ecosystems require a better understanding of thermoregulation in air of free-ranging animals. We utilized infrared imaging as an indirect approach to determine surface temperatures of dry, hauled-out Weddell seals (Leptonychotes weddellii, n = 35) of varying age and body condition during the Antarctic summer. The study groups provided a fivefold range in body mass and a threefold range in blubber depth. Surface temperature (T s) did not vary by body region (head, shoulder, axilla, torso, hip, flippers). Average seal T s (mean 13.9 ± 11.2 °C) was best described through a combination of the physical traits of body mass and environmental variables of ambient temperature T air, and wind speed. Additional factors of ice temperature (T ice), relative humidity and cloud cover did not improve the model. Heat transfer model estimates suggested that radiation contributed 56.6 ± 7.7 % of total heat loss. Convection and conduction accounted for the remaining 15.7 ± 12.3 and 27.7 ± 9.3 %, respectively. Heat loss by radiation was primarily influenced by body mass and wind speed, whereas convective heat loss was influenced primarily by blubber depth and wind speed. Conductive heat loss was modeled largely as a function of physical traits of mass and blubber depth rather than any environmental covariates, and therefore was substantially higher in animals in leaner condition.

  5. In-air evoked potential audiometry of grey seals (Halichoerus grypus from the North and Baltic Seas.

    Directory of Open Access Journals (Sweden)

    Andreas Ruser

    Full Text Available In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR on sedated grey seals exposed to 5-cycle (2-1-2 tone pips. Thresholds were measured at 10 frequencies between 1-20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL between 4-20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal.

  6. In-air evoked potential audiometry of grey seals (Halichoerus grypus) from the North and Baltic Seas.

    Science.gov (United States)

    Ruser, Andreas; Dähne, Michael; Sundermeyer, Janne; Lucke, Klaus; Houser, Dorian S; Finneran, James J; Driver, Jörg; Pawliczka, Iwona; Rosenberger, Tanja; Siebert, Ursula

    2014-01-01

    In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. Thresholds were measured at 10 frequencies between 1-20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test) and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL) between 4-20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal.

  7. The hydrodynamics of air-filled bags for wave energy conversion

    DEFF Research Database (Denmark)

    Greaves, Deborah; Hann, Martyn; Kurniawan, Adi

    The search for an economic means to harness energy from ocean waves continues. This paper aims to summarise the findings from our recent studies of novel wave energy devices in which flexible, deformable structures are used in place of conventional rigid structures. The devices utilise a flexible...... air-filled bag to capture energy from the waves and three different configurations are compared. In each of the three device configurations, expansion and contraction of the bag in waves create a reciprocating air flow via a turbine between the bag and another volume. The bags are all in the form...

  8. Effect of timing and method of post space preparation on sealing ability of remaining root filling material: in vitro microbiological study.

    Science.gov (United States)

    Grecca, Fabiana Soares; Rosa, Angela Rezende Gomes; Gomes, Maximiliano Schünke; Parolo, Clarissa Fatturi; Bemfica, Jules Renan Dutra; Frasca, Luis Carlos da Fontoura; Maltz, Marisa

    2009-10-01

    To evaluate the effect of timing (immediate versus delayed) and technique of post space preparation on the ability of the residual root canal obturation to prevent coronal bacterial leakage. Sixty-six single-rooted teeth were decoronated at the cementoenamel junction. The canals were prepared according to a step-back technique and were filled with thermoplasticized gutta-percha and AH Plus endodontic sealer (Dentsply De Trey). The root segments were randomly assigned to 8 groups. The positive controls (n = 3) were instrumented but not obturated. The negative controls (n = 3) were instrumented, obturated and sealed with Cavit (3M ESPE). In the other 6 groups (n = 10 each), the post space was prepared either immediately after obturation or 7 days later using LA Axxess burs (SybronEndo) (groups 1 and 2), heated pluggers (groups 3 and 4) or solvent delivered with a hand file (groups 5 and 6). The external surface of all roots was rendered waterproof with nail varnish. Custom-made dual-chamber devices were used to evaluate leakage. The coronal third of the prepared root canal was kept in contact with artificial saliva contaminated with Enterococcus faecalis, and the root apex was submerged in tryptic soy agar medium. The root assemblies were stored at 37 degrees C and were monitored daily over a 90-day period. The occurrence of turbidity in the medium was deemed to indicate bacterial leakage, from which failure of the seal was inferred. Throughout the experimental period, there was no significant difference (p = 0.094) among the preparation techniques, either immediate or delayed, in terms of bacterial leakage. Immediate and delayed post space preparation yielded similar outcomes in terms of the canal seal. Regardless of the timing and the technique of post space preparation, coronal bacterial leakage occurred over time.

  9. Design issues for compressed air energy storage in sealed underground cavities

    Directory of Open Access Journals (Sweden)

    P. Perazzelli

    2016-06-01

    Full Text Available Compressed air energy storage (CAES systems represent a new technology for storing very large amount of energy. A peculiarity of the systems is that gas must be stored under a high pressure (p = 10–30 MPa. A lined rock cavern (LRC in the form of a tunnel or shaft can be used within this pressure range. The rock mass surrounding the opening resists the internal pressure and the lining ensures gas tightness. The present paper investigates the key aspects of technical feasibility of shallow LRC tunnels or shafts under a wide range of geotechnical conditions. Results show that the safety with respect to uplift failure of the rock mass is a necessary but not a sufficient condition for assessing feasibility. The deformation of the rock mass should also be kept sufficiently small to preserve the integrity of the lining and, especially, its tightness. If the rock is not sufficiently stiff, buckling or fatigue failure of the steel lining becomes more decisive when evaluating the feasible operating air pressure. The design of the concrete plug that seals the compressed air stored in the container is another demanding task. Numerical analyses indicate that in most cases, the stability of the rock mass under the plug loading is not a decisive factor for plug design.

  10. Measure Guideline. Wall Air Sealing and Insulation Methods in Existing Homes; An Overview of Opportunity and Process

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, S. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Stephenson, R. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

    2012-09-01

    This guide provides renovators and retrofit contractors an overview of considerations when including wall air sealing and insulation in an energy retrofit project. It also outlines the potential project risks, various materials for insulating, possible field inspections needed, installation procedures, as well as the benefits and drawbacks.

  11. High-voltage leak detection of a parenteral proteinaceous solution product packaged in form-fill-seal plastic laminate bags. Part 1. Method development and validation.

    Science.gov (United States)

    Damgaard, Rasmus; Rasmussen, Mats; Buus, Peter; Mulhall, Brian; Guazzo, Dana Morton

    2013-01-01

    In Part 1 of this three-part research series, a leak test performed using high-voltage leak detection (HVLD) technology, also referred to as an electrical conductivity and capacitance leak test, was developed and validated for container-closure integrity verification of a small-volume laminate plastic bag containing an aqueous solution for injection. The sterile parenteral product is the rapid-acting insulin analogue, insulin aspart (NovoRapid®/NovoLog®, by Novo Nordisk A/S, Bagsværd, Denmark). The aseptically filled and sealed package is designed to preserve product sterility through expiry. Method development and validation work incorporated positive control packages with a single hole laser-drilled through the laminate film of each bag. A unique HVLD method characterized by specific high-voltage and potentiometer set points was established for testing bags positioned in each of three possible orientations as they are conveyed through the instrument's test zone in each of two possible directions-resulting in a total of six different test method options. Validation study results successfully demonstrated the ability of all six methods to accurately and reliably detect those packages with laser-drilled holes from 2.5-11.2 μm in nominal diameter. Part 2 of this series will further explore HVLD test results as a function of package seal and product storage variables. The final Part 3 will report the impact of HVLD exposure on product physico-chemical stability. In this Part 1 of a three-part research series, a leak test method based on electrical conductivity and capacitance, called high voltage leak detection (HVLD), was used to find leaks in small plastic bags filled with an insulin pharmaceutical solution for human injection by Novo Nordisk A/S (Bagsværd, Denmark). To perform the test, the package is electrically grounded while being conveyed past an electrode linked to a high-voltage, low-amperage transformer. The instrument measures the current that passes

  12. Rotary shaft sealing assembly

    Science.gov (United States)

    Dietle, Lannie L.; Schroeder, John E.; Kalsi, Manmohan S.; Alvarez, Patricio D.

    2010-09-21

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  13. Pulsed neutron generators based on the sealed chambers of plasma focus design with D and DT fillings

    Science.gov (United States)

    Yurkov, D. I.; Dulatov, A. K.; Lemeshko, B. D.; Golikov, A. V.; Andreev, D. A.; Mikhailov, Yu V.; Prokuratov, I. A.; Selifanov, A. N.

    2015-11-01

    Development of neutron generators using plasma focus (PF) chambers is being conducted in the All-Russia Scientific Research Institute of Automatics (VNIIA) during more than 25 years. PF is a source of soft and hard x-rays and neutrons 2.5 MeV (D) or 14 MeV (DT). Pulses of x-rays and neutrons have a duration of about several tens of nanoseconds, which defines the scope of such generators—the study of ultrafast processes. VNIIA has developed a series of pulse neutron generators covering the range of outputs 107-1012 n/pulse with resources on the order of 103-104 switches, depending on purposes. Generators have weights in the range of 30-700 kg, which allows referring them to the class of transportable generators. Generators include sealed PF chambers, whose manufacture was mastered by VNIIA vacuum tube production plant. A number of optimized PF chambers, designed for use in generators with a certain yield of neutrons has been developed. The use of gas generator based on gas absorber of hydrogen isotopes, enabled to increase the self-life and resource of PF chambers. Currently, the PF chambers withstand up to 1000 switches and have the safety of not less than 5 years. Using a generator with a gas heater, significantly increased security of PF chambers, because deuterium-tritium mixture is released only during work, other times it is in a bound state in the working element of the gas generator.

  14. Novel use of an air-filled breast prosthesis to allow radiotherapy to recurrent colonic cancer.

    LENUS (Irish Health Repository)

    O'Duffy, F

    2012-02-01

    AiM: The authors present the novel and successful use of an air-filled breast prosthesis for extra pelvic exclusion of small bowel to facilitate adjuvant radiotherapy following resection of recurrent adenocarcinoma of the ascending bowel. The therapeutic use of radiotherapy in colon cancer can cause acute or chronic radiation enteropathy. Mobile small bowel can be sequestered in \\'dead space\\' or by adhesions exposing it to adjuvant radiotherapy. A variety of pelvic partitioning methods have been described to exclude bowel from radiation fields using both native and prosthetic materials. METHOD: In this case a 68 year old presented with ascending colon adenocarcinoma invading the peritoneum and underwent en bloc peritoneal resection. Thirty-seven months later surveillance CT identified a local recurrence. Subsequent resection resulted in a large iliacus muscle defect which would sequester small bowel loops thus exposing the patient to radiation enteropathy. The lateral position of the defect precluded the use of traditional pelvic partitioning methods which would be unlikely to remain in place long enough to allow radiotherapy. A lightweight air-filled breast prosthesis (Allergan 133 FV 750 cms) secured in place with an omentoplasty was used to fill the defect. RESULTS: Following well tolerated radiotherapy the prosthesis was deflated under ultrasound guidance and removed via a 7-cm transverse incision above the right iliac crest. The patient is disease free 18 months later with no evidence of treatment related morbidity. CONCLUSION: The use of a malleable air-filled prosthesis for pelvic partitioning allows specific tailoring of the prosthesis size and shape for individual patient defects. It is also lightweight enough to be secured in place using an omentoplasty to prevent movement related prosthesis migration. In the absence of adequate omentum a mesh sling may be considered to allow fixation. In this case the anatomy of the prosthesis position allowed for its

  15. Sealing ability of three root-end filling materials prepared using an erbium: Yttrium aluminium garnet laser and endosonic tip evaluated by confocal laser scanning microscopy

    Science.gov (United States)

    Nanjappa, A Salin; Ponnappa, KC; Nanjamma, KK; Ponappa, MC; Girish, Sabari; Nitin, Anita

    2015-01-01

    Aims: (1) To compare the sealing ability of mineral trioxide aggregate (MTA), Biodentine, and Chitra-calcium phosphate cement (CPC) when used as root-end filling, evaluated under confocal laser scanning microscope using Rhodamine B dye. (2) To evaluate effect of ultrasonic retroprep tip and an erbium:yttrium aluminium garnet (Er:YAG) laser on the integrity of three different root-end filling materials. Materials and Methods: The root canals of 80 extracted teeth were instrumented and obturated with gutta-percha. The apical 3 mm of each tooth was resected and 3 mm root-end preparation was made using ultrasonic tip (n = 30) and Er:YAG laser (n = 30). MTA, Biodentine, and Chitra-CPC were used to restore 10 teeth each. The samples were coated with varnish and after drying, they were immersed in Rhodamine B dye for 24 h. The teeth were then rinsed, sectioned longitudinally, and observed under confocal laser scanning microscope. Statistical Analysis Used: Data were analyzed using one-way analysis of variance (ANOVA) and a post-hoc Tukey's test at P ultrasonics, the difference was found to be statistically significant (P ultrasonics. PMID:26180420

  16. Analysis of Incomplete Filling Defect for Injection-Molded Air Cleaner Cover Using Moldflow Simulation

    Directory of Open Access Journals (Sweden)

    Hyeyoung Shin

    2013-01-01

    Full Text Available A large-sized cover part for air cleaner was injection molded with ABS resin, and its incomplete filling defect was analyzed using commercial Moldflow software. To investigate the effect of processing temperature on incomplete filling defect, tensile properties, weight loss, and phase separation behavior of ABS resin were evaluated. The tensile properties of dumbbell samples were not changed up to 250°C and decreased significantly thereafter. SEM micrographs indicated no significant changes in the status of polybutadiene rubber phase below 250°C. These different test results indicated that ABS resin little affected the thermal decomposition in processing temperature range. The Moldflow simulation was performed using measured thickness of molded cover and actual mold design with the defects. As expected, the cover part showed unbalanced filling and incomplete sections. To improve these defects, two possible cases of hot runner system have been simulated. When applying modified 5-gate system, the maximum injection pressure was decreased approximately 5.5% more than that of actual gate system. In case of 6-gate system, the maximum injection pressure reduced by 23%, and the injection pressure required to fill is well within the range of the molding equipment. The maximum clamping force of 6-gate system was also significantly reduced than that of actual and 5-gate system.

  17. Correlation Between Endotracheal Tube Cuff Pressure and Tracheal Wall Pressure Using Air and Saline Filled Cuffs

    Science.gov (United States)

    2017-01-31

    Pressures within air-filled tracheal cuffs at altitude--an in vivo study. Anaesthesia . 2004;59(3):252-254. 5. Smith RP, McArdle BH. Pressure in the...cuffs of tracheal tubes at altitude. Anaesthesia . 2002; 57(4):374-378. 6. Britton T, Blakeman TC, Eggert J, Rodriquez D, Ortiz H, Branson RD. Managing...a comparison of three different in vitro techniques. Anaesthesia . 2008; 63(4):418-422. 15. Li Bassi G, Ranzani OT, Marti JD, Giunta V, Luque N, et

  18. Novel use of an air-filled breast prosthesis to allow radiotherapy to recurrent colonic cancer.

    LENUS (Irish Health Repository)

    O'Duffy, F

    2011-03-01

    AiM: The authors present the novel and successful use of an air-filled breast prosthesis for extra pelvic exclusion of small bowel to facilitate adjuvant radiotherapy following resection of recurrent adenocarcinoma of the ascending bowel. The therapeutic use of radiotherapy in colon cancer can cause acute or chronic radiation enteropathy. Mobile small bowel can be sequestered in \\'dead space\\' or by adhesions exposing it to adjuvant radiotherapy. A variety of pelvic partitioning methods have been described to exclude bowel from radiation fields using both native and prosthetic materials.

  19. Vitreoretinal surgery through multifocal intraocular lenses compared with monofocal intraocular lenses in fluid-filled and air-filled rabbit eyes.

    Science.gov (United States)

    Lim, J I; Kuppermann, B D; Gwon, A; Gruber, L

    2000-06-01

    To compare vitrectomy procedures and visualization of posterior segment structures through multifocal silicone intraocular lenses (IOLs) with the same procedures through monofocal silicone IOLs in rabbit eyes. Experimental study. Twelve eyes of six rabbits. Each rabbit eye underwent phacoemulsification of the lens and posterior chamber implantation of a silicone multifocal or silicone monofocal IOL. The type of IOL (monofocal vs. multifocal) implanted in the first eye of each rabbit was randomly decided. The fellow eye then received the other IOL type. Vitrectomy procedures were performed through the IOLs by using a flat contact lens (part 1) or wide-angled contact lens (part 2) for visualization through fluid-filled (parts 1 and 2) and air-filled (part 2) eyes. Image quality, stereopsis, and contrast were subjectively graded on a scale of 0 (none) to 4 (excellent) for each eye by each surgeon. In part 1, image quality averaged 4 for the monofocal IOL and 3.6 for the multifocal IOL. Stereopsis averaged 4 for the monofocal IOL and 4 for the multifocal IOL. Contrast averaged 4 for the monofocal IOL and 3.9 for the multifocal IOL. Vitrectomy with retinal surface maneuvers was successfully performed in both pigmented and nonpigmented rabbit eyes through both IOL types. In part 2, image quality, stereopsis, and contrast were rated as 4 for both multifocal and monofocal silicone IOLs. Air-fluid exchange was performed without difficulty. Image quality, stereopsis, and contrast were rated as 4 for air-filled eyes. Visualization of posterior segment structures through multifocal silicone IOLs was sufficient for retinal surface maneuvers during vitrectomy procedures in both fluid-filled and air-filled rabbit eyes.

  20. Measurement of the response-ratio of an ionization chamber filled with dry air to that filled with P-10 gas in the calibration of gas monitors.

    Science.gov (United States)

    Yunoki, Akira; Kawada, Yasushi; Hino, Yoshio

    2017-11-13

    We developed a new method to determine the response ratio of an ionization chamber (Ohkura ionization chamber: type I-4096 01/06) filled with dry air to that filled with P-10 gas. The response-ratio was obtained by comparing the output currents of the ionization chamber after introduction of radioactive gasses of identical activities contained in two small vessels. The obtained ratio was 0.690 ± 0.003, which agreed with the results obtained by other methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Apical adaptation, sealing ability and push-out bond strength of five root-end filling materials

    Directory of Open Access Journals (Sweden)

    Pablo Andrés AMOROSO-SILVA

    2014-08-01

    Full Text Available This study compared the fluid filtration, adaptation to the root canal walls, and the push-out bond strength of two resin-based sealers and three calcium silicate-based retrograde filling materials. Fifty maxillary canines were shaped using manual instruments and the apical portion was sectioned. Retrograde cavities of 3-mm depth were prepared. The specimens were divided into five groups (n = 10: Sealer 26 (S26; MBPc (experimental; MTA; Portland cement with 20% zirconium oxide (PC/ZO, and Portland cement with 20% calcium tungstate (PC/CT. The fluid filtration was measured at 7 and 15 days. To evaluate the interfacial adaptation, sections of the teeth, 1 and 2 mm from the apex, were prepared and the percentage of gaps was calculated. The push-out bond strength at 2 mm from the apex was evaluated. Statistical analysis was performed using the ANOVA/Tukey’s test (p < 0.05. At 7 and 15 days (p = 0.0048, p = 0.006, the PC/CT group showed higher fluid filtration values when compared to other groups. At 1 mm from the apex, no statistical differences in the adaptation were found among the cements (p = 0.44. At 2 mm from the apex, the PC/ZO group presented statistically lower percentage of gaps than S26, MBPc, and MTA (p = 0.0007. The MBPc group showed higher push-out bond strength than other cements evaluated (p = 0.0008. The fluid filtration and interfacial adaptation of the calcium silicate-based cements were similar to those of the resin-based cements. The resinous cement MBPc showed superior push-out bond strength.

  2. Comparison of the sealing ability of two root-end filling materials (MTA and CEM cement following retropreparation with ultrasonic or Er,Cr:YSGG laser

    Directory of Open Access Journals (Sweden)

    Razmi H

    2010-01-01

    Full Text Available "nBackground and Aims: Considering advantages and disadvantages of mineral trioxide aggregate (MTA, Calcium Enriched Mixture (CEM cement has been developed recently. The purpose of this study was to compare the apical microleakage of the root-end cavities prepared by ultrasonic or Er,Cr:YSGG laser and filled with MTA or CEM cement. "nMaterials and Methods: Eighty single-rooted, extracted human teeth were instrumented and obturated. Root-end resection was made by removing 3 mm of the apex. The teeth were randomly divided into two experimental (n=30 and two positive and negative control (n=10 groups. After that, the retrograde cavities were prepared using ultrasonic or Er,Cr: YSGG Laser. According to the root-end filling materials (MTA or CEM cement, each group was then divided into two subgroups. Finally, specimens were cleared for assessing the amount of apical dye (Indian ink penetration. The data were analyzed using Kruskall-Wallis and Dunn tests. "nResults: Laser/CEM cement group showed significantly the lowest mean apical dye penetration. There were no statistically significant differences between Laser/MTA, ultrasonic/MTA and ultrasonic/CEM cement groups. "nConclusion: Based on the findings of this study, CEM cement demonstrated lower rate of apical leakage compared with MTA, when the root-end cavities prepared with Er,Cr:YSGG Laser. The sealing ability of MTA was not different following root-end preparation by ultrasonic or Er,Cr:YSGG Laser.

  3. Filling a Conical Cavity

    Science.gov (United States)

    Nye, Kyle; Eslam-Panah, Azar

    2016-11-01

    Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

  4. 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

  5. A micro-gap, air-filled ionisation chamber as a detector for criticality accident dosimetry.

    Science.gov (United States)

    Murawski, Ł; Zielczyński, M; Golnik, N; Gryziński, M A

    2014-10-01

    A micro-gap air-filled ionisation chamber was designed for criticality dosimetry. The special feature of the chamber is its very small gap between electrodes of only 0.3 mm. This prevents ion recombination at high dose rates and minimises the influence of gas on secondary particles spectrum. The electrodes are made of polypropylene because of higher content of hydrogen in this material, when compared with soft tissue. The difference between neutron and gamma sensitivity in such chamber becomes practically negligible. The chamber's envelope contains two specially connected capacitors, one for polarising the electrodes and the other for collecting the ionisation charge. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Air filled ionization chambers and their response to high LET radiation

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    Background Air filled ionization chambers (ICs) are widely used for absolute dosimetry, not only in photon beams but also in beams of heavy charged particles. Within the IC, electron hole pairs are generated by the energy deposition originating from incoming radiation. High-LET particles create...... a high density of charge carriers in the core of particle tracks. As a consequence an increased (so called "initial") recombination of the charge carriers takes place, besides of the general (volume) recombination described by the Boag theory. A theory for a sub-type of initial recombination ("columnar......" recombination) is the Jaffe theory, which was developed in 1913 by Jaffe. He solved a differential equation by applying several simplifications and approximations such as a Gaussian shaped track whose width serves as free parameter. These simplifications and the use of an simplified charge carrier distribution...

  7. Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber.

    Science.gov (United States)

    Schmidt, Oliver A; Euser, Tijmen G; Russell, Philip St J

    2013-12-02

    We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems.

  8. MeV ion beam extraction into air with a glass capillary filled with He

    Science.gov (United States)

    Asamura, Moemi; Masatsugu, Misaki; Ishii, Kunikazu; Ogawa, Hidemi

    2017-11-01

    In order to obtain an intense ion beam, we have newly developed He-capillary optics, which is a tapered glass capillary filled with low pressure He gas to extract ion beam into atmospheric air. We have measured the energy spectra of an ion beam extracted from the He-capillary as a function of He gas pressure. We have observed that the intensity of the extracted ion beam is enhanced by using the He-capillary with He gas, although peak energy is shifted to a lower energy. Furthermore, in order to evaluate the performance of the He-capillary in detail, we have measured the intensity distribution of the ion beam via the He-capillary by using a 25 µm pinhole slit and have found that the He-capillary optics provides an intense ion beam without further spread of the extracted ion beam. Here, we discuss transmission properties of the ion beam via the He- capillary.

  9. Effect of Nd:YAG and Diode Lasers on Apical Seal of Root Canals Filled with AH Plus and Mineral Trioxide Aggregate-Based Sealers

    Directory of Open Access Journals (Sweden)

    Elham Khoshbin

    2018-01-01

    Full Text Available Objectives: Laser irradiation, as an adjunct to root canal preparation, may increase the success rate of endodontic treatments. This study aimed to assess the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG and diode lasers on the apical seal of the root canals filled with AH Plus® and mineral trioxide aggregate (MTA-based sealers.Materials and Methods: This in-vitro experimental study was conducted on 96 single-rooted, single-canal extracted human teeth with closed apices. The root canals were prepared by using ProTaper® rotary instruments and were randomly divided into six groups (n=16: 940-nm diode laser and AH Plus® sealer (group 1, Nd:YAG laser and AH Plus® sealer (group 2, AH Plus® sealer (group 3, 940-nm diode laser and MTA-based sealer (group 4, Nd:YAG laser and MTA-based sealer (group 5, MTA-based sealer (group 6, as well as positive and negative control groups. A bacterial leakage model was used for microleakage assessment. Qualitative assessment was done by using a scanning electron microscope (SEM. Data were analyzed by two-way analysis of variance (ANOVA at the significance level of 0.05.Results: There were statistically significant differences between the experimental and control groups (P=0.002. The laser-treated groups showed a lower apical microleakage compared to the non-laser-treated groups, although the difference was not statistically significant (P>0.05. No significant differences were noted between the two lasers in terms of the apical microleakage, irrespective of the type of sealer (P>0.05.Conclusions: Laser irradiation, as an adjunct to root canal preparation, has no significant effect on the level of apical microleakage.

  10. Bubble absorption by an air-filled helically-supported capillary channel

    Science.gov (United States)

    Beheshtipour, Negar; Thiessen, David

    2016-11-01

    Gas-liquid phase separation under microgravity conditions where buoyancy is not active represents a challenge for two-phase liquid-continuous space systems. Similar challenges are present in micro-scale electrochemical systems on Earth that generate gas bubbles in geometries where surface tension prevails over gravity. A possible ground-based application would be the removal of carbon dioxide bubbles from large aspect ratio channels in a direct-methanol fuel cell that could otherwise occlude the channel. In this study we use a 3-mm diameter stretched stainless-steel spring coated with a superhydrophobic layer to create a helically-supported capillary channel. Such a channel that is submerged in water and filled with air while vented to the atmosphere was found to absorb a stream of 2.5-mm diameter air bubbles at a rate of at least 36 bubbles/s. An optical detector and high-speed imaging system have been used to study bubble absorption dynamics. A significant finding is that the initial attachment of the bubble to the channel that involves the rupture of a thin film of water happens in less than 1 ms. The rapid rupture of the water film separating the bubble from the channel might be attributed to the roughness of the hydrophobic coating.

  11. Design and analysis of stepped impedance transformer from air filled waveguide to dielectric filled waveguide for high power microwave window applications

    Science.gov (United States)

    Sindam, Bashaiah; Sharma, P. K.; Raju, K. C. James

    2014-03-01

    This paper describes a design to achieve good microwave power transmission from an air filled rectangular waveguide to a narrow dielectric filled waveguide using a stepped impedance transformer. A novel material Ba(Zn1/3Ta2/3)O3 (BZT) having high dielectric constant and low dielectric loss has been proposed as a microwave window. The advantages of using such dielectric resonator materials for these applications is that they make the size reduction of such microwave components possible without unleashing microwave dissipation. A high density (more than 97%) and good microwave dielectric properties are obtained for BZT samples through the solid state reaction method. The obtained dielectric parameters are used to calculate the dimensions of the narrow dielectric window section in waveguide geometry and the resulting dielectric window structure is simulated using the IMST Empire simulator. The maximum power transmission is obtained by the simulated structure with a dielectric filled waveguide window of thickness 7.4 mm at 3.7 GHz with bandwidth of 780 MHz, which corresponds to an insertion loss (S21) magnitude of 0.008 dB, and the return loss (S11) obtained at the same frequency is -43 dB. The microwave dielectric properties of the material used as well as the simulated results for the BZT based window are studied and compared with those of a conventional window.

  12. Autonomous generation of a thermoacoustic solitary wave in an air-filled tube

    Science.gov (United States)

    Shimizu, Dai; Sugimoto, Nobumasa

    2016-10-01

    Experiments are performed to demonstrate the autonomous generation of an acoustic solitary wave in an air-filled, looped tube with an array of Helmholtz resonators. The solitary wave is generated spontaneously due to thermoacoustic instability by a pair of stacks installed in the tube and subject to a temperature gradient axially. No external drivers are used to create initial disturbances. Once the solitary wave is generated, it keeps on propagating to circulate along the loop endlessly. The stacks, which are made of ceramics and of many pores of square cross section, are placed in the tube diametrically on exactly the opposite side of the loop, and they are sandwiched by hot and cold (ambient) heat exchangers. When the temperature gradient along both stacks is appropriate, pulses of smooth profiles are generated and propagated in both directions of the tube. From good agreements of not only the pressure profile measured but also the propagation speed with the theory, the pulse is identified as the acoustic solitary wave, and it can be called thermoacoustic solitary wave or thermoacoustic soliton corresponding to the soliton solution of the K-dV equation in one limit.

  13. Effects of the Nd:YAG laser, air-abrasion, and acid-etchant on filling materials.

    Science.gov (United States)

    Türkmen, C; Sazak, H; Günday, M

    2006-01-01

    The purpose of this study was to determine any inadvertent effects of the neodymium: yttrium-aluminium-garnet (Nd:YAG) laser, air-abrasion, and ortho-phosphoric acid on some conventionally used dental filling materials [amalgam, composite resin, compomer, glass-ionomer cement (GIC), and ceromer], when they were used for purposes of margin etching and assessed according to standard enamel etching parameters using a total of five fillings. The surfaces of the filling materials were polished. One sample from each material group was exposed to laser (at 0.75 J, 15 pps) and air abrasion (with Al-oxide powder, 60 psi) for 2 s and to the 37% ortho-phosphoric acid for 60 s. The exposed materials were examined under Scanning Electron Microscopy (SEM). After laser treatment most specimens showed recrystallized areas, the GIC surface being the most affected. There were some pores and cavities on the amalgam surface following laser treatment. The abraded surfaces showed mechanical abrasions. The acid etchant showed the least effect. During the application of laser or air-abrasion, the adjacent tooth or filling surface must be protected or the dentist must be careful.

  14. 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

  15. Stability and Agreement of a Microtransducer and an Air-Filled Balloon Esophageal Catheter in the Monitoring of Esophageal Pressure.

    Science.gov (United States)

    Augusto, Renan Maloni; Albuquerque, André Luis Pereira; Jaeger, Thomas; de Carvalho, Carlos Roberto Ribeiro; Caruso, Pedro

    2017-02-01

    The use of esophageal catheters with microtransducer promises advantages over traditional catheters with air-filled balloons. However, performance comparisons between these 2 types of catheters are scarce and incomplete. A catheter with a 9.5-cm air-filled balloon at the distal tip and a catheter with a microtransducer mounted within a flexible silicone rubber were tested in vitro and in vivo. In vitro, the response times of both catheters were compared, and the drift of the baseline pressure of the microtransducer catheter was evaluated over a 6-h period. In vivo, 11 healthy volunteers had both catheters inserted, and the drift of the baseline esophageal pressure was measured over a 3-h period. Also, the correlation and agreement of the baseline and changes in the esophageal pressure of both catheters were evaluated. In vitro, the microtransducer catheter had a response time significantly higher (262 × 114 Hz, P pressure stability, with a mean baseline pressure drift of 1.4 cm H2O. In vivo, both catheters presented a small and similar baseline esophageal pressure drift (P = 0.08). For measurements of baseline and changes in esophageal pressure, the correlation and agreement between the catheters were poor, with a large bias between them. The catheter with the microtransducer had a small baseline pressure drift, similar to the air-filled balloon catheter. The low agreement between the catheters does not allow the microtransducer catheter to be used as a surrogate for the traditional air-filled balloon catheter. Copyright © 2017 by Daedalus Enterprises.

  16. Analysis of marginal seal of ProRoot MTA, MTA Angelus biodentine, and glass ionomer cement as root-end filling materials: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sakshi Malhotra

    2015-01-01

    Conclusion: Microleakage was present in all the samples. Least amount of apical dye microleakage was seen in biodentine with mean value of 0.16 mm followed by ProRoot MTA 0.68 mm, MTA Angelus 0.74 mm, and GIC 1.53 mm. The best sealing ability was seen in biodentine, and this difference was statistically significant.

  17. Air-filled postcranial bones in theropod dinosaurs: physiological implications and the 'reptile'-bird transition.

    Science.gov (United States)

    Benson, Roger B J; Butler, Richard J; Carrano, Matthew T; O'Connor, Patrick M

    2012-02-01

    Pneumatic (air-filled) postcranial bones are unique to birds among extant tetrapods. Unambiguous skeletal correlates of postcranial pneumaticity first appeared in the Late Triassic (approximately 210 million years ago), when they evolved independently in several groups of bird-line archosaurs (ornithodirans). These include the theropod dinosaurs (of which birds are extant representatives), the pterosaurs, and sauropodomorph dinosaurs. Postulated functions of skeletal pneumatisation include weight reduction in large-bodied or flying taxa, and density reduction resulting in energetic savings during foraging and locomotion. However, the influence of these hypotheses on the early evolution of pneumaticity has not been studied in detail previously. We review recent work on the significance of pneumaticity for understanding the biology of extinct ornithodirans, and present detailed new data on the proportion of the skeleton that was pneumatised in 131 non-avian theropods and Archaeopteryx. This includes all taxa known from significant postcranial remains. Pneumaticity of the cervical and anterior dorsal vertebrae occurred early in theropod evolution. This 'common pattern' was conserved on the line leading to birds, and is likely present in Archaeopteryx. Increases in skeletal pneumaticity occurred independently in as many as 12 lineages, highlighting a remarkably high number of parallel acquisitions of a bird-like feature among non-avian theropods. Using a quantitative comparative framework, we show that evolutionary increases in skeletal pneumaticity are significantly concentrated in lineages with large body size, suggesting that mass reduction in response to gravitational constraints at large body sizes influenced the early evolution of pneumaticity. However, the body size threshold for extensive pneumatisation is lower in theropod lineages more closely related to birds (maniraptorans). Thus, relaxation of the relationship between body size and pneumatisation preceded

  18. Compensating For Shrinkage In A Cryogenic Seal

    Science.gov (United States)

    Hill, Arnold E.

    1993-01-01

    Proposed design for seals in liquid-hydrogen plumbing eliminates leaks caused by contraction of seals at low operating temperature. Each seal consists of rubber, polytetrafluorethylene, or lead O-ring including hollow core filled with water. At temperature of liquid hydrogen, anomalous expansion of water keeps seal gland filled and leaktight despite shrinkage of surrounding O-ring material. Design also used in systems using cryogenic fluids other than liquid hydrogen.

  19. Effects of Thermal Cycling and Thermal Aging on the Hermeticity and Strength of Silver-Copper Oxide Air-Brazed Seals

    Energy Technology Data Exchange (ETDEWEB)

    Weil, K. Scott; Coyle, Christopher A.; Darsell, Jens T.; Xia, Gordon; Hardy, John S.

    2005-12-01

    Thermal cycle and exposure tests were conducted on ceramic-to-metal joints prepared by a new sealing technique. Known as reactive air brazing, this joining method is currently being considered for use in sealing various high-temperature solid-state electrochemical devices, including planar solid oxide fuel cells (pSOFC). In order to simulate a typical pSOFC application, test specimens were prepared by joining ceramic anode/electrolyte bilayers to washers, of the same composition as the common frame materials employed in pSOFC stacks, using a filler metal composed of 4mol% CuO in silver. The brazed samples were exposure tested at 750°C for 200, 400, and 800hrs in both simulated fuel and air environments and thermally cycled at rapid rate (75°C/min) between room temperature and 750°C for as many as fifty cycles. Subsequent joint strength testing and microstructural analysis indicated that the samples exposure tested in air displayed little degradation with respect to strength, hermeticity, or microstructure out to 800hrs of exposure. Those tested in fuel showed no change in rupture strength or loss in hermeticity after 800hrs of high-temperature exposure, but did undergo microstructural change due to the dissolution of hydrogen into the silver-based braze material. Air brazed specimens subjected to rapid thermal cycling exhibited no loss in joint strength or hermeticity, but displayed initial signs of seal delamination along the braze/electrolyte interface after 50 cycles.

  20. SU-E-T-297: Dosimetric Assessment of An Air-Filled Balloon Applicator in HDR Vaginal Cuff Brachytherapy Using the Monte Carlo Method

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, H; Lee, Y; Pokhrel, D; Badkul, R [University of Kansas Hospital, Kansas City, KS (United States)

    2015-06-15

    Purpose: As an alternative to cylindrical applicators, air inflated balloon applicators have been introduced into HDR vaginal cuff brachytherapy treatment to achieve sufficient dose to vagina mucosa as well as to spare rectum and bladder. In general, TG43 formulae based treatment planning systems do not take into account tissue inhomogeneity, and air in the balloon applicator can cause higher delivered dose to mucosa than treatment plan reported. We investigated dosimetric effect of air in balloon applicator using the Monte Carlo method. Methods: The thirteen-catheter Capri applicator with a Nucletron Ir-192 seed was modeled for various balloon diameters (2cm to 3.5cm) using the MCNP Monte Carlo code. Ir-192 seed was placed in both central and peripheral catheters to replicate real patient situations. Existence of charged particle equilibrium (CPE) with air balloon was evaluated by comparing kerma and dose at various distances (1mm to 70mm) from surface of air-filled applicator. Also mucosa dose by an air-filled applicator was compared with by a water-filled applicator to evaluate dosimetry accuracy of planning system without tissue inhomogeneity correction. Results: Beyond 1mm from air/tissue interface, the difference between kerma and dose was within 2%. CPE (or transient CPE) condition was deemed existent, and in this region no electron transport was necessary in Monte Carlo simulations. At 1mm or less, the deviation of dose from kerma became more apparent. Increase of dose to mucosa depended on diameter of air balloon. The increment of dose to mucosa was 2.5% and 4.3% on average for 2cm and 3.5cm applicators, respectively. Conclusion: After introduction of air balloon applicator, CPE fails only at the proximity of air/tissue interface. Although dose to mucosa is increased, there is no significant dosimetric difference (<5%) between air and water filled applicators. Tissue inhomogeneity correction is not necessary for air-filled applicators.

  1. Corrosion sealing of amalgam restorations in vitro.

    Science.gov (United States)

    Mahler, David B; Pham, Bao V; Adey, Jerry D

    2009-01-01

    Amalgam restorations, when first placed, have been shown to exhibit a gap at the amalgam/tooth interface. With time in service, this gap fills with corrosion products that have the potential to "seal" the restoration. With the advent of high-copper, more corrosion-resistant amalgams, there has been concern that the time required to create this seal would be increased significantly when compared with low-copper traditional amalgams. The current study was designed to address this concern. Amalgam was condensed into a MACOR mold, simulating a Class I cavity form and then immersed into a 1.0% NaCl solution to simulate oral conditions. Using an air pressure test, the sealing was monitored over time. The results showed that the sealing was influenced by the size of the initial gap prior to immersion as well as corrosion resistance of the amalgam and that a corrosion-resistant amalgam with a small initial gap size can seal as quickly as a corrosion-prone amalgam. Therefore, it is not possible to predict sealing behavior based on corrosion resistance, alone. Furthermore, the presence of zinc in the amalgam alloy has been shown to result in the formation of zinc corrosion products in the amalgam/mold margin, which contributes to more rapid sealing. Analysis of a tooth extracted after 16 years of clinical service that had been restored with an amalgam-containing zinc was also shown to contain zinc corrosion products in the occlusal marginal area. This could explain the reported reduction in marginal fracture of clinically placed amalgam restorations made from zinc-containing alloys.

  2. Thermo-Hydraulic Analysis of Heat Storage Filled with the Ceramic Bricks Dedicated to the Solar Air Heating System.

    Science.gov (United States)

    Nemś, Magdalena; Nemś, Artur; Kasperski, Jacek; Pomorski, Michał

    2017-08-12

    This article presents the results of a study into a packed bed filled with ceramic bricks. The designed storage installation is supposed to become part of a heating system installed in a single-family house and eventually to be integrated with a concentrated solar collector adapted to climate conditions in Poland. The system's working medium is air. The investigated temperature ranges and air volume flow rates in the ceramic bed were dictated by the planned integration with a solar air heater. Designing a packed bed of sufficient parameters first required a mathematical model to be constructed and heat exchange to be analyzed, since heat accumulation is a complex process influenced by a number of material properties. The cases discussed in the literature are based on differing assumptions and different formulas are used in calculations. This article offers a comparison of various mathematical models and of system operating parameters obtained from these models. The primary focus is on the Nusselt number. Furthermore, in the article, the thermo-hydraulic efficiency of the investigated packed bed is presented. This part is based on a relationship used in solar air collectors with internal storage.

  3. 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.

  4. Development of helicopter engine seals

    Science.gov (United States)

    Lynwander, P.

    1973-01-01

    An experimental evaluation of main shaft seals for helicopter gas turbine engines was conducted with shaft speeds to 213 m/s(700 ft/sec), air pressures to 148 N/sq cm (215 psia), and air temperatures to 645 K (675 F). Gas leakage test results indicate that conventional seals will not be satisfactory for high-pressure sealing because of excessive leakage. The self-acting face seal, however, had significantly lower leakage and operated with insignificant wear during a 150-hour endurance test at sliding speeds to 145 m/s (475 ft/sec), air pressures to 124 N/sq cm (180 psia), and air temperatures to 408 K (275 F). Wear measurements indicate that noncontact operation was achieved at shaft speeds of 43,000 rpm. Evaluation of the self-acting circumferential seal was inconclusive because of seal dimensional variations.

  5. The influence of temporally varying noise from seismic air guns on the detection of underwater sounds by seals.

    Science.gov (United States)

    Sills, Jillian M; Southall, Brandon L; Reichmuth, Colleen

    2017-02-01

    Standard audiometric data are often applied to predict how noise influences hearing. With regard to auditory masking, critical ratios-obtained using tonal signals and flat-spectrum maskers-can be combined with noise spectral density levels derived from 1/3-octave band levels to predict signal amplitudes required for detection. However, the efficacy of this conventional model of masking may vary based on features of the signal and noise in question. The ability of resource managers to quantify masking from intermittent seismic noise is relevant due to widespread geophysical exploration. To address this, spotted and ringed seals with previously measured critical ratios were trained to detect low-frequency tonal signals within seismic pulses recorded 1 and 30 km from an operational air gun array. The conventional model of masking accurately predicted the extent of masking only in certain cases. When noise amplitude varied significantly in time, the results suggested that detection was driven by higher signal-to-noise ratios within time windows shorter than the full signal duration. This study evaluates when it is appropriate to use average noise levels and critical ratios to predict auditory masking experienced by marine mammals, and suggests how masking models can be improved by incorporating time-based analyses of signals and noise.

  6. Atmospheric pressure as a force that fills developing bones with marrow and air.

    Science.gov (United States)

    Kurbel, Sven; Radić, Radivoje; Kristek, Branka; Ivezić, Zdravko; Selthofer, Robert; Kotromanović, Zeljko

    2004-01-01

    Many theories try to explain the existence and function of paranasal sinuses. This paper is an attempt to correlate process of paranasal sinus development in human with bone pneumatization processes in animals. It is here proposed that this mechanism starts in utero and continues after birth. During endochondral development, a solid hyaline cartilage model transforms into long bones. Central chondrocytes hypertrophy and their lacunae become confluent. Dissolving of the cartilage intercellular matrix forms a primitive marrow cavity. It is soon invaded by the periostal bud. Once circulation is established in the developing bone, the dissolved hyaline matrix can be slowly washed away from the bone cavity. Circulation in the bone cavity can develop slight subatmospheric pressures, similar to negative interstitial pressures in subcutaneous tissues. The amniotic fluid conducts atmospheric pressure to the fetal body. The pressure is trying to fill enlarging bone cavities through the existing vascular openings, or to create new openings. Bone walls of developing paranasal bones are to weak to resist the pressure gradient on their walls. New openings form on the weakest spots allowing airway mucosa to form initial paranasal sinuses. The enlarging cavities of long bones that are remote from the body surface and airway also develop a slightly subatmospheric pressure that fills them with cellular elements. These elements enter bone through the feeding vessels and form bone marrow. During after birth skeletal growth, bone remodeling shapes paranasal sinuses in a process of slow evolution that do not require measurable pressure gradients. When two sinuses come in vicinity, their growth rate declines, since the remaining thin and fragile bone lamella between them does not retract anymore.

  7. Laparoscopic Toupet Fundoplication using an Air Seal Intelligent Flow System and Anchor Port in a 1.8-kg infant: A Technical Report.

    Science.gov (United States)

    Miyano, Go; Morita, Keiichi; Kaneshiro, Masakatsu; Miyake, Hiromu; Nouso, Hiroshi; Yamoto, Masaya; Koyama, Mariko; Nakano, Reiji; Tanaka, Yasuhiko; Fukumoto, Koji; Urushihara, Naoto

    2015-08-01

    We report a case of a 1.8-kg infant who had laparoscopic Toupet fundoplication (LTF) using the AirSeal Intelligent Flow System and Anchor Port (AP). Our case had severe gastroesophageal reflux in association with genetic and cardiac anomalies. Despite the patient being continuously fed, persistent vomiting caused failure to thrive, and LTF was performed at 4 months of age when he weighed 1.8 kg. The AirSeal Intelligent Flow System is a novel laparoscopic CO2 insufflation system that improves the visual field by constantly evacuating smoke and providing a more stable pneumoperitoneum. The AP is a recently developed, stretchable, elastomeric, low-profile cannula. Three 5-mm AP were inserted: one subumbilically for the scope and one in both the right and left upper abdomen for the surgeon. A 5-mm AirSeal trocar was inserted in the left lower abdomen for the assistant. The gastrosplenic ligament was dissected free, and the intra-abdominal esophagus was prepared. A posterior hiatoplasty was performed, followed by the 270° fundoplication. During the fundoplication, the esophagus was fixed to the crus and then the right and left wraps were fixed to the esophagus. Pneumoperitoneum was maintained stably throughout the LTF procedure, with optimal operative field. Total operating time for LTF was 90 min. Body temperature dropped from 37.4°C to 35.7°C during pneumoperitoneum but resolved once pneumoperitoneum was ceased. Postoperative progress was uneventful, and an upper gastrointestinal study on postoperative day 2 showed no residual gastroesophageal reflux. We believe the AirSeal Intelligent Flow System and AP contributed to the successful completion of LTF in a 1.8-kg infant. © 2015 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

  8. Purging of an air-filled vessel by horizontal injection of steam

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.L.; Andreani, M

    2000-07-01

    Reported here are results from an idealised 2D problem in which cold air is purged from a large vessel by a steam jet. The focus of the study is the prediction of the evolution of the flow regimes resulting from changes in the relative importance of buoyancy and inertia forces, and time histories of the temperature and concentration fields. Global parameters of interest are the mixture concentration at the vessel outlet and the total time taken to purge the air. The Computational Fluid Dynamics (CFD) code CFX-4 has been used to perform calculations for different inlet velocities, covering a range of (densimetric) Froude numbers from Fr=0.8 (buoyancy dominated) to Fr=7.1 (inertia dominated). Animations have been used to help understand the dynamics of the flow transitions, and temperature and concentration histories at specific monitoring points have been compared with coarse-mesh predictions obtained using the containment code GOTHIC. (authors)

  9. Rebound tonometry over an air-filled anterior chamber in the supine child after intraocular surgery.

    Science.gov (United States)

    Davis, Ryan; Jiramongkolchai, Kim; Silverstein, Evan; Freedman, Sharon F

    2016-04-01

    Intracameral air is a critical component of multiple ophthalmic surgical procedures and is frequently used in pediatric intraocular surgery. Among other benefits, it helps to facilitate postoperative examination in uncooperative children by allowing quick confirmation of a formed anterior chamber. The purpose of this study was to evaluate the usefulness and accuracy of a position-independent rebound tonometer (Icare PRO) in measuring intraocular pressure (IOP) intraoperatively in pediatric eyes with intracameral air compared to a commonly used handheld applanation tonometer (Tono-Pen XL). In this prospective study of sequential children undergoing intraocular surgery, IOP was measured immediately following general anesthesia induction using both Icare PRO rebound tonometry and Tono-Pen XL tonometry, with instrument order randomized, in the supine child's eye(s). At completion of surgery after standard placement of intracameral air IOP was again measured using both instruments. A total of 42 eyes of 30 children were included. Surgeries included glaucoma (25), cataract-related (16), and both (1). Mean preoperative IOP by Tono-Pen XL was 23.52 ± 9.76 mm Hg; by Icare PRO, 20.94 ± 10.01 mm Hg (P = 0.0012). Mean IOP over intracameral air at surgery conclusion by Tono-Pen XL (n = 41) was 12.66 ± 4.90; by Icare PRO (n = 42), 12.96 ± 5.10 mm Hg (P = 0.46). One eye had postoperative IOP unrecordable by Tono-Pen XL but 7.9 mm Hg by Icare PRO. Bland-Altman analysis, which included only paired measurements, showed a preoperative mean difference in IOP (ΔIOPT-I) of 2.58 mm Hg (95% CI, -6.86 to 12.02); postoperative mean ΔIOPT-I of -0.42 mm Hg [95% CI, -7.57 to 6.73]. Position-independent rebound tonometry (Icare PRO) accurately measured IOP in supine children's eyes postoperatively in the presence of intracameral air. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  10. Prospective comparison between two different magnetic resonance defecography techniques for evaluating pelvic floor disorders: air-balloon versus gel for rectal filling

    Energy Technology Data Exchange (ETDEWEB)

    Francesca, Maccioni; Najwa, Al Ansari; Valeria, Buonocore; Fabrizio, Mazzamurro; Carlo, Catalano [Sapienza University of Rome, Department of Radiological Sciences, Oncology and Pathology, Policlinico Umberto I Hospital, Rome (Italy); Marileda, Indinnimeo; Massimo, Mongardini [Sapienza University of Rome, Department of Surgical Sciences, Policlinico Umberto I Hospital, Rome (Italy)

    2016-06-15

    to prospectively compare two rectal filling techniques for dynamic MRI of pelvic floor disorders (PFD). Twenty-six patients with PFD underwent the two techniques during the same procedure, one based on rectal placement of a balloon-catheter filled with saline and air insufflation (air-balloon technique or AB); another based on rectal filling with 180 cc of gel (gel-filling technique or GF). The examinations were compared for assessment and staging of PFD, including rectal-descent, rectocele, cystocele, colpocele, enterocele, rectal invagination. Surgery and clinical examinations were the gold standard. AB showed sensitivity of 96 % for rectal descent, 100 % for both rectocele and colpocele, 86 % for rectal invagination and 100 % for enterocele; understaged 11 % of rectal descents and 19 % of rectoceles. GF showed sensitivity of 100 % for rectal descent, 91 % for rectocele, 83 % for colpocele, 100 % for rectal invagination and 73 % for enterocele; understaged 3.8 % of rectal descent and 11.5 % of rectoceles. Both techniques showed 100 % of specificity. Agreement between air-balloon and gel filling was 84 % for rectal descent, 69 % for rectocele, 88 % for rectal invagination, 84 % for enterocele, 88 % for cystocele and 92 % for colpocele. Both techniques allowed a satisfactory evaluation of PFD. The gel filling was superior for rectal invagination, the air-balloon for rectocele and anterior/middle compartment disorders. (orig.)

  11. 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

  12. Wheel traffic effect on air-filled porosity and air permeability in a soil catena across the wheel rut

    DEFF Research Database (Denmark)

    Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

    The impact of wheel traffic on soil physical properties is usually quantified by randomly collecting soil cores at specific depths below the wheeled surface. However, modeling studies as well as few measurements indicated a non-uniform stress distribution in a catena across the wheel rut, which...... might induce different effects on soil physical properties. The objective of this study was to investigate the impact of vehicle traffic on soil physical properties and air permeability by systematic collection of samples in a transect running from the center to the outside of the wheel rut. A field...... experiment was conducted on a clay loam soil at Suberg, Switzerland, in 2010. Four repeated wheeling were performed by driving a forage harvester (wheel load of 6100 kg and a tyre width of 0.8 m) forward and rearward in the same track. We sampled 100 cm3 intact cores at 10, 30 and 50 cm depth in a soil...

  13. Numerical modeling of turbulence mixed convection heat transfer in air filled enclosures by finite volume method

    Directory of Open Access Journals (Sweden)

    M Safaei

    2016-09-01

    Full Text Available In the present study, first the turbulent natural convection and then laminar mixed convection of air flow was solved in a room and the calculated outcomes are compared with results of other scientists and after showing validation of calculations, aforementioned flow is solved as a turbulent mixed convection flow, using the valid turbulence models Standard k-ε, RNG k-ε and RSM. To solve governing differential equations for this flow, finite volume method was used. This method is a specific case of residual weighting method. The results show that at high Richardson Numbers, the flow is rather stationary at the center of the enclosure. Moreover, it is distinguished that when Richardson Number increases the maximum of local Nusselt decreases. Therefore, it can be said that less number of Richardson Number, more rate of heat transfer.

  14. Step-Wise Velocity of an Air Bubble Rising in a Vertical Tube Filled with a Liquid Dispersion of Nanoparticles.

    Science.gov (United States)

    Cho, Heon Ki; Nikolov, Alex D; Wasan, Darsh T

    2017-03-21

    The motion of air bubbles in tubes filled with aqueous suspensions of nanoparticles (nanofluids) is of practical interest for bubble jets, lab-on-a-chip, and transporting media. Therefore, the focus of this study is the dynamics of air bubbles rising in a tube in a nanofluid. Many authors experimentally and analytically proposed that the velocity of rising air bubbles is constant for long air bubbles suspended in a vertical tube in common liquids (e.g. an aqueous glycerol solution) when the capillary number is larger than 10-4. For the first time, we report here a systematic study of an air bubble rising in a vertical tube in a nanofluid (e.g. an aqueous silica dioxide nanoparticle suspension, nominal particle size, 19 nm). We varied the bubble length scaled by the diameter of the tubes (L/D), the concentration of the nanofluid (10 and 12.5 v %), and the tube diameter (0.45, 0.47, and 0.50 cm). The presence of the nanoparticles creates a significant change in the bubble velocity compared with the bubble rising in the common liquid with the same bulk viscosity. We observed a novel phenomenon of a step-wise increase in the air bubble rising velocity versus bubble length for small capillary numbers less than 10-7. This step-wise velocity increase versus the bubble length was not observed in a common fluid. The step-wise velocity increase is attributed to the nanoparticle self-layering phenomenon in the film adjacent to the tube wall. To elucidate the role of the nanoparticle film self-layering on the bubble rising velocity, the effect of the capillary number, the tube diameter (e.g. the capillary pressure), and nanofilm viscosity are investigated. We propose a model that takes into consideration the nanoparticle layering in the film confinement to explain the step-wise velocity phenomenon versus the length of the bubble. The oscillatory film interaction energy isotherm is calculated and the Frenkel approach is used to estimate the film viscosity.

  15. Air atmospheric-pressure plasma-jet treatment enhances the attachment of human gingival fibroblasts for early peri-implant soft tissue seals on titanium dental implant abutments.

    Science.gov (United States)

    Lee, Jung-Hwan; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2015-01-01

    Although dental implants are commonly used for tooth restoration, there is a lack of studies of treatment regimens for preventing extra-oral infection and decreasing osseointegration failures by establishing early peri-implant soft tissue seals on titanium dental implant abutments. In this study, air atmospheric-pressure plasma-jet (AAPPJ) treatment was applied to titanium disks to assay the potential for early peri-implant soft tissue seals on titanium dental implant abutment. After titanium disks were treated with AAPPJ for 10 s at 250, 500, 1000 and 1500 sccm, surface analysis was performed; the control group received air only or no treatment. Human gingival fibroblasts (HGF) were seeded onto the specimens for evaluating cell attachment and proliferation and adherent-cell morphology was visualized via confocal microscopy. In AAPPJ-treated specimens, the water contact angle decreased according to increased flow rate. Oxygen composition increased in XPS, but no topographical changes were detected. The effect of AAPPJ treatment at 1000 sccm was apparent 2 mm from the treated spot, with a 20% increase in early cell attachment and proliferation. Adherent HGF on AAPPJ-treated specimens displayed a stretched phenotype with more vinculin formation than the control group. Within the limitations of this study, the results indicate that AAPPJ treatment may enhance the early attachment and proliferation of HGF for establishing early peri-implant soft tissue seals on titanium dental implant abutments with possible favorable effects of osseointegration of dental implant.

  16. Effects of thermal cycling and thermal aging on the hermeticity and strength of silver-copper oxide air-brazed seals

    Energy Technology Data Exchange (ETDEWEB)

    Scott Weil, K.; Coyle, Christopher A.; Hardy, John S. [Energy Science and Technology Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Darsell, Jens T. [School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States); Xia, Gordon G. [Environmental Technology Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2005-12-01

    Thermal cycle and exposure tests were conducted on ceramic-to-metal joints prepared by a new sealing technique. Known as reactive air brazing, this joining method is currently being considered for use in sealing various high-temperature solid-state electrochemical devices, including planar solid oxide fuel cells (pSOFC). In order to simulate a typical pSOFC application, test specimens were prepared by joining ceramic anode/electrolyte bilayers to metal washers, of the same composition as the common frame materials employed in pSOFC stacks, using a filler metal composed of 4mol% CuO in silver. The brazed samples were exposure tested at 750{sup o}C for 200, 400, and 800h in both simulated fuel and air environments and thermally cycled at rapid rate (75{sup o}Cmin{sup -1}) between room temperature and 750{sup o}C for as many as 50 cycles. Subsequent joint strength testing and microstructural analysis indicated that the samples exposure tested in air displayed little degradation with respect to strength, hermeticity, or microstructure out to 800h of exposure. Those tested in fuel showed no change in rupture strength or loss in hermeticity after 800h of high-temperature exposure, but did undergo microstructural change due to the dissolution of hydrogen into the silver-based braze material. Air-brazed specimens subjected to rapid thermal cycling exhibited no loss in joint strength or hermeticity, but displayed initial signs of seal delamination along the braze-electrolyte interface after 50 cycles. (author)

  17. Preliminary study of cyclic thermal shock resistance of plasma-sprayed zirconium oxide turbine outer air seal shrouds

    Science.gov (United States)

    Bill, R. C.; Wisander, D. W.

    1977-01-01

    Several experimental concepts representing potential high pressure turbine seal material systems were subjected to cyclic thermal shock exposures similar to those that might be encountered under severe engine start-up and shut-down sequences. All of the experimental concepts consisted of plasma-sprayed yttria stabilized ZrO2 on the high temperature side of the blade tip seal shroud. Between the ZrO2 and a cooled, dense metal backing, various intermediate layer concepts intended to mitigate thermal stresses were incorporated. Performance was judged on the basis of the number of thermal shock cycles required to cause loss of seal material through spallation. The most effective approach was to include a low modulus, sintered metal pad between the ZrO2 and the metallic backing. It was also found that reducing the density of the ZrO2 layer significantly improved the performance of specimens with plasma-sprayed metal/ceramic composite intermediate layers.

  18. Low Pressure Robot-assisted Radical Prostatectomy With the AirSeal System at OLV Hospital: Results From a Prospective Study.

    Science.gov (United States)

    La Falce, Sabrina; Novara, Giacomo; Gandaglia, Giorgio; Umari, Paolo; De Naeyer, Geert; D'Hondt, Frederiek; Beresian, Jean; Carette, Rik; Penicka, Martin; Mo, Yujiing; Vandenbroucke, Geert; Mottrie, Alexandre

    2017-12-01

    Limited studies examined effects of pneumoperiotneum during robot-assisted radical prostatectomy (RARP) and with AirSeal. The aim of this study was to assess the effect on hemodynamics of a lower pressure pneumoperitoneum (8 mmHg) with AirSeal, during RARP in steep Trendelenburg 45° (ST). This is an institutional review board-approved, prospective, interventional, single-center study including patients treated with RARP at OLV Hospital by one extremely experienced surgeon (July 2015-February 2016). Intraoperative monitoring included: arterial pressure, central venous pressure, cardiac output, heart rate, stroke volume, systemic vascular resistance, intrathoracic pressure, airways pressures, left ventricular end-diastolic and end-systolic areas/volumes and ejection fraction, by transesophageal echocardiography, an esophageal catheter, and FloTrac/Vigileo system. Measurements were performed after induction of anesthesia with patient in horizontal (T0), 5 minutes after 8 mmHg pneumoperitoneum (TP), 5 minutes after ST (TT1) and every 30 minutes thereafter until the end of surgery (TH). Parameters modification at the prespecified times was assessed by Wilcoxon and Friedman tests, as appropriate. All analyses were performed by SPSS v. 23.0. A total of 53 consecutive patients were enrolled. The mean patients age was 62.6 ± 6.9 years. Comorbidity was relatively limited (51% with Charlson Comorbidity Index as low as 0). Despite the ST, working always at 8 mmHg with AirSeal, only central venous pressure and mean airways pressure showed a statistically significant variation during the operative time. Although other significant hemodynamic/respiratory changes were observed adding pneumoperitoneum and then ST, all variables remained always within limits safely manageable by anesthesiologists. The combination of ST, lower pressure pneumoperitoneum and extreme surgeon's experience enables to safely perform RARP. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Soil–water content and air-filled porosity affect height growth of Scots pine in afforested arable land in Finland

    National Research Council Canada - National Science Library

    Wall, Antti; Heiskanen, Juha

    2009-01-01

    We examined the soil-water content (SWC) and air-filled porosity (AFP) of afforested arable land in situ and related them with tree growth, which was expressed as the total length of 5-year-height growth above 2.5m stem height...

  20. Bismuth alloy potting seals aluminum connector in cryogenic application

    Science.gov (United States)

    Flower, J. F.; Stafford, R. L.

    1966-01-01

    Bismuth alloy potting seals feedthrough electrical connector for instrumentation within a pressurized vessel filled with cryogenic liquids. The seal combines the transformation of high-bismuth content alloys with the thermal contraction of an external aluminum tube.

  1. Single-mode pumped high air-fill fraction photonic crystal fiber taper for high-power deep-blue supercontinuum sources

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Larsen, Casper; Jakobsen, Christian

    2014-01-01

    Dispersion control with axially nonuniform photonic crystal fibers (PCFs) permits supercontinuum (SC) generation into the deep-blue from an ytterbium pump laser. In this Letter, we exploit the full degrees of freedom afforded by PCFs to fabricate a fiber with longitudinally increasing air-fill fr......-fill fraction and decreasing diameter directly on the draw-tower. We demonstrate SC generation extending down to 375 nm in one such monolithic fiber device that is single-mode at 1064 nm at the input end....

  2. 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.

  3. 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.

  4. Thermo-Hydraulic Analysis of Heat Storage Filled with the Ceramic Bricks Dedicated to the Solar Air Heating System

    National Research Council Canada - National Science Library

    Magdalena Nemś; Artur Nemś; Jacek Kasperski; Michał Pomorski

    2017-01-01

    ... to climate conditions in Poland. The system’s working medium is air. The investigated temperature ranges and air volume flow rates in the ceramic bed were dictated by the planned integration with a solar air heater...

  5. High-performance temperature sensing using a selectively filled solid-core photonic crystal fiber with a central air-bore.

    Science.gov (United States)

    Ma, J; Yu, H H; Jiang, X; Jiang, D S

    2017-04-17

    A high-performance temperature sensor based on mode-coupling principle is proposed using a selectively filled, solid-core photonic crystal fiber with a central air-bore. The fibers are fabricated using the "stack-and-draw" method, with a micro scale central bore deliberately kept during the drawing procedure. The addition of the central air-bore enhances the mode-coupling efficiency between the fundamental core mode and modes in the high-index liquid-filled holes in the fiber cladding, therefore, the fiber can be used for a novel sensing architecture, when cladding holes are selectively filled with temperature sensitive liquids. Based on this concept, numerical analyses are accomplished using finite element method, showing that this fiber-based temperature sensor possesses high sensitivity of -6.02 nm/°C, with a resolution of 3.32 × 10-3 °C, in the temperature range from -80 to 90 °C. The selective hole-filling is verified by a multi-step infiltration technique. A particularly designed probe with improved sensitivity and manipulation is also proposed for this system.

  6. Towards a liquid Argon TPC without evacuation filling of a 6$m^3$ vessel with argon gas from air to ppm impurities concentration through flushing

    CERN Document Server

    Curioni, A; Gendotti, A; Knecht, L; Lussi, D; Marchionni, A; Natterer, G; Resnati, F; Rubbia, A; Coleman, J; Lewis, M; Mavrokoridis, K; McCormick, K; Touramanis, C

    2010-01-01

    In this paper we present a successful experimental test of filling a volume of 6 $m^3$ with argon gas, starting from normal ambient air and reducing the impurities content down to few parts per million (ppm) oxygen equivalent. This level of contamination was directly monitored measuring the slow component of the scintillation light of the Ar gas, which is sensitive to $all$ sources of impurities affecting directly the argon scintillation.

  7. Single-mode pumped high air-fill fraction photonic crystal fiber taper for high-power deep-blue supercontinuum sources.

    Science.gov (United States)

    Sørensen, Simon T; Larsen, Casper; Jakobsen, Christian; Thomsen, Carsten L; Bang, Ole

    2014-02-15

    Dispersion control with axially nonuniform photonic crystal fibers (PCFs) permits supercontinuum (SC) generation into the deep-blue from an ytterbium pump laser. In this Letter, we exploit the full degrees of freedom afforded by PCFs to fabricate a fiber with longitudinally increasing air-fill fraction and decreasing diameter directly on the draw-tower. We demonstrate SC generation extending down to 375 nm in one such monolithic fiber device that is single-mode at 1064 nm at the input end.

  8. 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...

  9. [Christmas seals].

    Science.gov (United States)

    Loytved, G

    2006-11-01

    Christmas seals, i. e., special stamps used to decorate or seal Christmas and New Year's mail, were created by the Danish post office clerk E. Holboell. The proceeds from the sale of the stickers were meant to alleviate the suffering of children sick with tuberculosis. The first Christmas seal, showing a portrait of Queen Louise of Denmark, was issued on December 10, 1904. The demand at the post office was enormous. The funds raised exceeded all expectations and made it possible to finance the construction of a sanatorium for tuberculosis children. The idea of Christmas seals spread quickly around the world and ended up being copied in 130 countries. At the beginning of the 20 (th) century, the small stamp with the red double-barred cross became a banner for the crusade against tuberculosis. For many patients, it also represented a symbol of hope for recovery even though this hope, given the cure rates of a sanatorium treatment, only became a reality for a few. Worldwide, Christmas seals were and are colourful and imaginatively designed, mostly with Christmas symbols or motives relating to the fight against tuberculosis. The funds raised through the sale of the seals initially helped to build hospitals and were later also used to screen persons at risk for tuberculosis, to improve housing conditions of patients and for other measures of support. With the decrease of tuberculosis, some organisations discontinued fundraising through Christmas seals while others widened their intended purpose and supported, for example, the prevention of and research on lung diseases. In Germany, Christmas seals are closely connected with the German Central Committee against Tuberculosis. Today the "Kuratorium Tuberkulose in der Welt" is the only organisation in this country that still raises funds by this means. The funds are mostly used to assist developing countries with a high burden of tuberculosis.

  10. Sealing a Loosely Fitting Valve Assembly

    Science.gov (United States)

    Goff, L.; Tellier, G.

    1986-01-01

    Double-ring seal avoids expense of remachining or redesigning valve parts. Mating fittings on valve sealed by pair of rings - one O-ring and backup ring. Backup ring fills relatively large gap between parts. Prevents softer O-ring from being pushed into and through gap.

  11. Characterization of bacterial and archaeal communities in air-cathode microbial fuel cells, open circuit and sealed-off reactors

    KAUST Repository

    Chehab, Noura A.

    2013-06-18

    A large percentage of organic fuel consumed in a microbial fuel cell (MFC) is lost as a result of oxygen transfer through the cathode. In order to understand how this oxygen transfer affects the microbial community structure, reactors were operated in duplicate using three configurations: closed circuit (CC; with current generation), open circuit (OC; no current generation), and sealed off cathodes (SO; no current, with a solid plate placed across the cathode). Most (98 %) of the chemical oxygen demand (COD) was removed during power production in the CC reactor (maximum of 640 ± 10 mW/m 2), with a low percent of substrate converted to current (coulombic efficiency of 26.5 ± 2.1 %). Sealing the cathode reduced COD removal to 7 %, but with an open cathode, there was nearly as much COD removal by the OC reactor (94.5 %) as the CC reactor. Oxygen transfer into the reactor substantially affected the composition of the microbial communities. Based on analysis of the biofilms using 16S rRNA gene pyrosequencing, microbes most similar to Geobacter were predominant on the anodes in the CC MFC (72 % of sequences), but the most abundant bacteria were Azoarcus (42 to 47 %) in the OC reactor, and Dechloromonas (17 %) in the SO reactor. Hydrogenotrophic methanogens were most predominant, with sequences most similar to Methanobacterium in the CC and SO reactor, and Methanocorpusculum in the OC reactors. These results show that oxygen leakage through the cathode substantially alters the bacterial anode communities, and that hydrogenotrophic methanogens predominate despite high concentrations of acetate. The predominant methanogens in the CC reactor most closely resembled those in the SO reactor, demonstrating that oxygen leakage alters methanogenic as well as general bacterial communities. © 2013 Springer-Verlag Berlin Heidelberg.

  12. Investigations of Shuttle Main Landing Gear Door Environmental Seals

    Science.gov (United States)

    Finkbeiner, Joshua; Dunlap, Pat; Steinetz, Bruce; DeMango, Jeff; Newswander, Daniel

    2005-01-01

    The environmental seals for the main landing gear doors of the Shuttle Orbiters were raised by the Columbia Accident Investigation Board as a potential safety concern. Inspections of seals installed on the Shuttle Discovery revealed that they were permanently deformed and no longer met certified seal compression requirements. Replacement of the seals led to the inability to fully close the main landing gear doors. Johnson Space Center requested that Glenn Research Center conduct tests on the main landing gear door environmental seals to assist in installing the seals in a manner to allow the main landing gear doors to fully close. Further testing was conducted to fill out the seal performance database. Results from the testing indicated that the method of bonding the seals was important in reducing seal loads on the main landing gear doors. Also, the replacement seals installed in Shuttle Discovery were found to have leakage performance sufficient to meet the certification requirements.

  13. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

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

    Science.gov (United States)

    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.

  15. Wet powder seal for gas containment

    Science.gov (United States)

    Stang, Louis G.

    1982-01-01

    A gas seal is formed by a compact layer of an insoluble powder and liquid filling the fine interstices of that layer. The smaller the particle size of the selected powder, such as sand or talc, the finer will be the interstices or capillary spaces in the layer and the greater will be the resulting sealing capacity, i.e., the gas pressure differential which the wet powder layer can withstand. Such wet powder seal is useful in constructing underground gas reservoirs or storage cavities for nuclear wastes as well as stopping leaks in gas mains buried under ground or situated under water. The sealing capacity of the wet powder seal can be augmented by the hydrostatic head of a liquid body established over the seal.

  16. Exploring nonlinear pulse propagation, Raman frequency conversion and near octave spanning supercontinuum generation in atmospheric air-filled hollow-core Kagomé fiber

    Science.gov (United States)

    Abokhamis Mousavi, Seyedmohammad; Mulvad, Hans Christian Hansen; Wheeler, Natalie; Horak, Peter; Bradley, Thomas D.; Alam, Shaif-ul; Hayes, John; Sandoghchi, Seyed Reza; Richardson, David; Poletti, Francesco

    2017-02-01

    We have demonstrated Raman frequency conversion and supercontinuum light generation in a hollow core Kagomé fiber filled with air at atmospheric pressure, and developed a numerical model able to explain the results with good accuracy. A solid-state disk laser was used to launch short pulses ( 6ps) at 1030nm into an in-house fabricated hollow core Kagomé fiber with negative core curvature and both ends were open to the atmosphere. The fiber had a 150 THz wide transmission window and a record low loss of 12 dB/km at the pump wavelength. By gradually increasing the pulse energy up to 250 μJ, we observed the onset of different Kerr and Raman based optical nonlinear processes, resulting in a supercontinuum spanning from 850 to 1600 nm at maximum input power. In order to study the pulse propagation dynamics of the experiment, we used a generalized nonlinear Schrödinger equation (GNLSE). Our simulations showed that the use of a conventional damping oscillator model for the time-dependent response of the rotational Raman component of air was not accurate enough at such high intensities and large pulse widths. Therefore, we adopted a semiquantum Raman model for air, which included the full rotational and vibrational response, and their temperature-induced broadening. With this, our GNLSE results matched well the experimental data, which allowed us to clearly identify the nonlinear phenomena involved in the process. Aside from the technological interest in the high spectral density of the supercontinuum demonstrated, the validated numerical model can provide a valuable optimization tool for gas based nonlinear processes in air-filled fibers.

  17. 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.

  18. A Hot Dynamic Seal Rig for Measuring Hypersonic Engine Seal Durability and Flow Performance

    Science.gov (United States)

    Miller, Jeffrey H.; Steinetz, Bruce M.; Sirocky, Paul J.; Kren, Lawrence A.

    1993-01-01

    A test fixture for measuring the dynamic performance of candidate high-temperature engine seal concepts was installed at NASA Lewis Research Center. The test fixture was designed to evaluate seal concepts under development for advanced hypersonic engines, such as those being considered for the National Aerospace Plane (NASP). The fixture can measure dynamic seal leakage performance from room temperature up to 840 C (1550 F) and air pressure differentials up to 690 kPa (100 psi). Performance of the seals can be measured while sealing against flat or distorted walls. In the fixture two seals are preloaded against the sides of a 30 cm (1 ft) long saber that slides transverse to the axis of the seals, simulating the scrubbing motion anticipated in these engines. The capabilities of this test fixture along with preliminary data showing the dependence of seal leakage performance on high temperature cycling are addressed.

  19. 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.

  20. 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.

  1. Espacios aéreos pulmonares anormales por TCAR Abnormal air-filled spaces in the lung with HRCT

    Directory of Open Access Journals (Sweden)

    Juan Carlos Spina (h

    2008-06-01

    Full Text Available Objetivo: El propósito de este trabajo es revisar y dar claves para el diagnóstico de las distintas entidades que se presentan como espacios aéreos pulmonares anormales. Material y métodos: Se analizaron en forma retrospectiva los archivos de TCAR de nuestra institución con diagnóstico de espacios aéreos pulmonares anormales. En todos los casos se evaluó la localización, número (único o múltiples, grosor parietal y alteraciones parenquimatosas y mediastínicas asociadas y se los agrupo de acuerdo con su asociación con distintas enfermedades. Resultados: En base a las características topográficas, los espacios aéreos anormales fueron agrupados en: etiología infecciosa (tuberculosis, neumonía por Pneumocistis jiroveci, aspergilosis, hidatidosis, neumonía cavitada, absceso y neumatocele, enfermedades que producen bronquiectasias (fibrosis quística, síndrome de Kartagener, aspergilosis broncopulmonar alérgica, vasculitis ( granulomatosis de wegener y artritis reumatoidea, enfisema, neoplasias no primitivas (metástasis cavitadas, tumores primarios (carcinoma epidermoide y bronquioloalveolar y otras (linfangioleiomiomatosis, histiocitosis de células de Langerhans, secuestro pulmonar y malformación adenoidea quística. Conclusión: Los espacios aéreos pulmonares anormales son un hallazgo frecuente en los estudios por TCAR. Teniendo en cuenta cierta característica de los mismos, es posible arribar a un diagnóstico probable en la mayoría de los casos.Objetive: The purpose of this paper is to review and give some clues for the diagnosis of the many entities that present as abnormal air spaces at HRCT. Materials and methods: We retrospectively reviewed the archives of HRCT of our institution with diagnosis of different entities that presented with abnormal air spaces. In all cases we evaluated the location, number (unique o multiple, parietal thickness and concomitant compromise of parenchyma or mediastinum and we clustered

  2. Triple acting radial seal

    Science.gov (United States)

    Ebert, Todd A [West Palm Beach, FL; Carella, John A [Jupiter, FL

    2012-03-13

    A triple acting radial seal used as an interstage seal assembly in a gas turbine engine, where the seal assembly includes an interstage seal support extending from a stationary inner shroud of a vane ring, the interstage seal support includes a larger annular radial inward facing groove in which an outer annular floating seal assembly is secured for radial displacement, and the outer annular floating seal assembly includes a smaller annular radial inward facing groove in which an inner annular floating seal assembly is secured also for radial displacement. A compliant seal is secured to the inner annular floating seal assembly. The outer annular floating seal assembly encapsulates the inner annular floating seal assembly which is made from a very low alpha material in order to reduce thermal stress.

  3. Damper Spring For Omega Seal

    Science.gov (United States)

    Maclaughlin, Scott T.; Montgomery, Stuart K.

    1993-01-01

    Damper spring reduces deflections of omega-cross-section seal, reducing probability of failure and extending life of seal. Spring is split ring with U-shaped cross section. Placed inside omega seal and inserted with seal into seal cavity. As omega seal compressed into cavity, spring and seal make contact near convolution of seal, and spring becomes compressed also. During operation, when seal dynamically loaded, spring limits deflection of seal, reducing stress on seal.

  4. A Comparison of Candidate Seal Designs for Future Docking Systems

    Science.gov (United States)

    Dunlap, Patrick, H., Jr.; Steinetz, Bruce, M.

    2012-01-01

    NASA is developing a new docking system to support future space exploration missions to low Earth orbit, the Moon, and other destinations. A key component of this system is the seal at the main docking interface which inhibits the loss of cabin air once docking is complete. Depending on the mission, the seal must be able to dock in either a seal-on-flange or seal-on-seal configuration. Seal-on-flange mating would occur when a docking system equipped with a seal docks to a system with a flat metal flange. This would occur when a vehicle docks to a node on the International Space Station. Seal-on-seal mating would occur when two docking systems equipped with seals dock to each other. Two types of seal designs were identified for this application: Gask-O-seals and multi-piece seals. Both types of seals had a pair of seal bulbs to satisfy the redundancy requirement. A series of performance assessments and comparisons were made between the candidate seal designs indicating that they meet the requirements for leak rate and compression and adhesion loads under a range of operating conditions. Other design factors such as part count, integration into the docking system tunnel, seal-on-seal mating, and cost were also considered leading to the selection of the multi-piece seal design for the new docking system. The results of this study can be used by designers of future docking systems and other habitable volumes to select the seal design best-suited for their particular application.

  5. Indium seals for low-temperature and moderate-pressure applications

    Science.gov (United States)

    Lim, C. C.

    1986-01-01

    Some ideas as to what the important factors are that will produce a reliable indium O-ring seal are discussed. Four novel indium seal designs which are based on these ideas are presented. Three of these seals have been incorporated in a Brillouin cell. They include a simple sapphire window seal, a filling line union, and a flange seal. All of them have withstood low temperatures down to 77 K and moderate pressures up to 177 bar. The fourth seal described is a Pyrex tube seal for a Raman cell.

  6. Pond sealing

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson, G.; Laborde, M.

    1980-09-16

    A method of providing a substantially impermeable lining to the bottom of an earthen pond using native soil. Such soil is classified and formed into a slurry containing fine particles of predominately five or less micron size. The pond bottom is covered with a first layer of the slurry which is allowed to dry to a point where large crack patterns develop. The cracks are filled with a second layer of the slurry. More layers may be applied to form a final lining having the desired permeability for the particular application.

  7. Flexible sliding seal

    Science.gov (United States)

    Wallenhorst, E. L.

    1980-01-01

    Circular seal both slides and flexes to accomodate relative motion between two sealed members. Originally developed for Space Shuttle orbiter, it contains sliding seal to accommodate engine gimbaling and flexible seal that absorbs forward motion at high thrust of engine heat shield relative to airframe. Other possible applications are in support structures of heavy machinery and vehicle engines. Flexible sliding seal is ring about 7 feet in diameter and can withstand temperatures up to 1,600 F.

  8. Numerical Investigation on Windback Seals Used in Aero Engines

    Directory of Open Access Journals (Sweden)

    Michael Flouros

    2018-01-01

    Full Text Available Seals are considered one of the most important flow elements in turbomachinery applications. The most traditional and widely known seal is the labyrinth seal but in recent years other types like the brush or carbon seals were introduced since they considerably reduce the sealing air consumption. When seals are used for sealing of aero engine bearing chambers they are subjected to high “bombardment” through oil particles which are present in the bearing chamber. These particles mainly result from the bearings as a consequence of the high rotational speeds. Particularly when carbon or brush seals are used, problems with carbon formation (coking may arise when oil gets trapped in the very tight gap of these seals. In order to prevent oil migration into the turbomachinery, particularly when the pressure difference over a seal is small or even negligible, significant improvement can be achieved through the introduction of so called windback seals. This seal has a row of static helical teeth (thread and below this thread a scalloped or smooth shaft section is rotating. Depending on the application, a windback seal can be used alone or as a combination with another seal (carbon, brush or labyrinth seal. A CFD analysis carried out with ANSYS CFX version 11 is presented in this paper with the aim to investigate this seal type. The simulations were performed by assuming a two-phase flow of air and oil in the bearing compartment. Design parameters like seal clearance, thread size, scallop width, were investigated at different operating conditions.

  9. Rechargeability of Li-air cathodes pre-filled with discharge products using an ether-based electrolyte solution: implications for cycle-life of Li-air cells.

    Science.gov (United States)

    Meini, Stefano; Tsiouvaras, Nikolaos; Schwenke, K Uta; Piana, Michele; Beyer, Hans; Lange, Lukas; Gasteiger, Hubert A

    2013-07-21

    The instability of currently used electrolyte solutions and of the carbon support during charge-discharge in non-aqueous lithium-oxygen cells can lead to discharge products other than the desired Li2O2, such as Li2CO3, which is believed to reduce cycle-life. Similarly, discharge in an O2 atmosphere which contains H2O and CO2 impurities would lead to LiOH and Li2CO3 discharge products. In this work we therefore investigate the rechargeability of model cathodes pre-filled with four possible Li-air cell discharge products, namely Li2O2, Li2CO3, LiOH, and Li2O. Using Online Electrochemical Mass Spectrometry (OEMS), we determined the charge voltages and the gases evolved upon charge of pre-filled electrodes, thus determining the reversibility of the formation/electrooxidation reactions. We show that Li2O2 is the only reversible discharge product in ether-based electrolyte solutions, and that the formation of Li2CO3, LiOH, or Li2O is either irreversible and/or reacts with the electrolyte solution or the carbon during its oxidation.

  10. Nuclear reactor sealing system

    Science.gov (United States)

    McEdwards, James A.

    1983-01-01

    A liquid metal-cooled nuclear reactor sealing system. The nuclear reactor includes a vessel sealed at its upper end by a closure head. The closure head comprises at least two components, one of which is rotatable; and the two components define an annulus therebetween. The sealing system includes at least a first and second inflatable seal disposed in series in an upper portion of the annulus. The system further includes a dip seal extending into a body of insulation located adjacent a bottom portion of the closure head. The dip seal comprises a trough formed by a lower portion of one of the components, and a seal blade pendently supported from the other component and extending downwardly into the trough. A body of liquid metal is contained in the trough which submerges a portion of the seal blade. The seal blade is provided with at least one aperture located above the body of liquid metal for providing fluid communication between the annulus intermediate the dip seal and the inflatable seals, and a body of cover gas located inside the vessel. There also is provided means for introducing a purge gas into the annulus intermediate the inflatable seals and the seal blade. The purge gas is introduced in an amount sufficient to substantially reduce diffusion of radioactive cover gas or sodium vapor up to the inflatable seals. The purge gas mixes with the cover gas in the reactor vessel where it can be withdrawn from the vessel for treatment and recycle to the vessel.

  11. Inboard seal mounting

    Science.gov (United States)

    Hayes, John R. (Inventor)

    1983-01-01

    A regenerator assembly for a gas turbine engine has a hot side seal assembly formed in part by a cast metal engine block having a seal recess formed therein that is configured to supportingly receive ceramic support blocks including an inboard face thereon having a regenerator seal face bonded thereto. A pressurized leaf seal is interposed between the ceramic support block and the cast metal engine block to bias the seal wear face into sealing engagement with a hot side surface of a rotary regenerator matrix.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. Dampers for Stationary Labyrinth Seals

    Science.gov (United States)

    El-Aini, Yehia; Mitchell, William; Roberts, Lawrence; Montgomery, Stuart; Davis, Gary

    2011-01-01

    Vibration dampers have been invented that are incorporated as components within the stationary labyrinth seal assembly. These dampers are intended to supplement other vibration-suppressing features of labyrinth seals in order to reduce the incidence of high-cycle-fatigue failures, which have been known to occur in the severe vibratory environments of jet engines and turbopumps in which labyrinth seals are typically used. A vibration damper of this type includes several leaf springs and/or a number of metallic particles (shot) all held in an annular seal cavity by a retaining ring. The leaf springs are made of a spring steel alloy chosen, in conjunction with design parameters, to maintain sufficient preload to ensure effectiveness of damping at desired operating temperatures. The cavity is vented via a small radial gap between the retaining ring and seal housing. The damping mechanism is complex. In the case of leaf springs, the mechanism is mainly friction in the slippage between the seal housing and individual dampers. In the case of a damper that contains shot, the damping mechanism includes contributions from friction between individual particles, friction between particles and cavity walls, and dissipation of kinetic energy of impact. The basic concept of particle/shot vibration dampers has been published previously; what is new here is the use of such dampers to suppress traveling-wave vibrations in labyrinth seals. Damping effectiveness depends on many parameters, including, but not limited to, coefficient of friction, mode shape, and frequency and amplitude of vibrational modes. In tests, preloads of the order of 6 to 15 lb (2.72 to 6.8 kilograms) per spring damper were demonstrated to provide adequate damping levels. Effectiveness of shot damping of vibrations having amplitudes from 20 to 200 times normal terrestrial gravitational acceleration (196 to 1,960 meters per square second) and frequencies up to 12 kHz was demonstrated for shot sizes from 0.032 to

  17. Skew resisting hydrodynamic seal

    Science.gov (United States)

    Conroy, William T.; Dietle, Lannie L.; Gobeli, Jeffrey D.; Kalsi, Manmohan S.

    2001-01-01

    A novel hydrodynamically lubricated compression type rotary seal that is suitable for lubricant retention and environmental exclusion. Particularly, the seal geometry ensures constraint of a hydrodynamic seal in a manner preventing skew-induced wear and provides adequate room within the seal gland to accommodate thermal expansion. The seal accommodates large as-manufactured variations in the coefficient of thermal expansion of the sealing material, provides a relatively stiff integral spring effect to minimize pressure-induced shuttling of the seal within the gland, and also maintains interfacial contact pressure within the dynamic sealing interface in an optimum range for efficient hydrodynamic lubrication and environment exclusion. The seal geometry also provides for complete support about the circumference of the seal to receive environmental pressure, as compared the interrupted character of seal support set forth in U.S. Pat. Nos. 5,873,576 and 6,036,192 and provides a hydrodynamic seal which is suitable for use with non-Newtonian lubricants.

  18. Seals in motion

    NARCIS (Netherlands)

    Brasseur, Sophie Marie Jacqueline Michelle

    2017-01-01

    The harbour seal Phoca vitulina and the grey seal Halichoerus grypus have been inhabitants of the Wadden Sea since millennia. Prehistoric findings indicate the presence of both species around 5000 BC. This changed dramatically in the mid Middle-Ages as around 1500 AC, the grey seal disappeared from

  19. Detection of seal contamination in heat-sealed food packaging based on active infrared thermography

    Science.gov (United States)

    D'huys, Karlien; Saeys, Wouter; De Ketelaere, Bart

    2015-05-01

    In the food industry packaging is often applied to protect the product from the environment, assuring quality and safety throughout shelf life if properly performed. Packaging quality depends on the material used and the closure (seal). The material is selected based on the specific needs of the food product to be wrapped. However, proper closure of the package is often harder to achieve. One problem possibly jeopardizing seal quality is the presence of food particles between the seal. Seal contamination can cause a decreased seal strength and thus an increased packaging failure risk. It can also trigger the formation of microchannels through which air and microorganisms can enter and spoil the enclosed food. Therefore, early detection and removal of seal-contaminated packages from the production chain is essential. In this work, a pulsed-type active thermography method using the heat of the sealing bars as an excitation source was studied for detecting seal contamination. The cooling profile of contaminated seals was recorded. The detection performance of four processing methods (based on a single frame, a fit of the cooling profile, pulsed phase thermography and a matched filter) was compared. High resolution digital images served as a reference to quantify contamination. The lowest detection limit (equivalent diameter of 0.63 mm) and the lowest processing time (0.42 s per sample) were obtained for the method based on a single frame. Presumably, practical limitations in the recording stage prevented the added value of active thermography to be fully reflected in this application.

  20. Comparison of apical sealing ability of resected mineral trioxide ...

    African Journals Online (AJOL)

    Administrator

    2011-09-07

    Sep 7, 2011 ... filling were checked by radiography. Then, a damp cotton pellet was placed into the canal over the MTA. The access cavity was sealed with Cavit (ESPE Dental, Seefeld, Germany). In negative control of group 3, the canals were filled with MTA using the earlier mentioned process. The canals in the positive ...

  1. 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.

  2. MICROBIAL LEAKAGE AND APICAL INFLAMMATORY RESPONSE IN DOG’S TEETH AFTER ROOT CANAL FILLING WITH DIFFERENT SEALERS, POST SPACE PREPARATION AND EXPOSURE TO THE ORAL ENVIRONMENT

    Science.gov (United States)

    Gomes, Maximiliano Schünke; Barletta, Fernando Branco; Bona, Alvaro Della; Vanni, José Roberto; Pereira, Charles da Cunha; de Figueiredo, José Antônio Poli

    2007-01-01

    Coronal leakage is an important factor affecting the outcome of endodontic therapy. This study evaluated the microbial leakage (ML) and the apical inflammatory response (AIR) in dog’s teeth after root canal filling with three endodontic sealers, post preparation and exposure to the oral environment, testing the hypothesis that there is a positive correlation between these two histological parameters (ML and AIR). Sixty-four root canals of 8 mongrel dogs were cleaned, shaped and randomly distributed into groups according to the sealer to be used: Sealer 26 (n=18); AH Plus (n=18); RoekoSeal (n=19); no sealer – control group (n=9). Root canals were filled by the lateral condensation technique. Post space preparation left 4 mm of filling material in the apical root third, and specimens were exposed to the oral environment for 90 days. The dogs were killed and jaw blocks were histologically processed using Brown & Brenn and HE staining techniques. ML and AIR were scored from 1 to 4. Results were analyzed statistically using ANOVA, Duncan’s post-hoc test and Spearman’s correlation. ML and AIR score means were: Sealer 26 - 2.44±0.98 and 2.50±0.70; AH Plus - 2.50±0.78 and 2.22±0.54; RoekoSeal - 1.84±0.95 and 2.63±0.83; Control - 2.56±1.23 and 3.11±0.60. Statistically significant differences in AIR scores were found between the AH Plus and control groups (p<0.05). Although RoekoSeal had the lowest ML means, and AH Plus, the lowest AIR means after 90-day exposure to the oral environment, no statistically significant differences were found between the three sealers under study, and no correlation was found between ML and AIR. PMID:19089174

  3. Soil methane oxidation in both dry and wet temperate eucalypt forests shows a near-identical relationship with soil air-filled porosity

    Science.gov (United States)

    Fest, Benedikt J.; Hinko-Najera, Nina; Wardlaw, Tim; Griffith, David W. T.; Livesley, Stephen J.; Arndt, Stefan K.

    2017-01-01

    Well-drained, aerated soils are important sinks for atmospheric methane (CH4) via the process of CH4 oxidation by methane-oxidising bacteria (MOB). This terrestrial CH4 sink may contribute towards climate change mitigation, but the impact of changing soil moisture and temperature regimes on CH4 uptake is not well understood in all ecosystems. Soils in temperate forest ecosystems are the greatest terrestrial CH4 sink globally. Under predicted climate change scenarios, temperate eucalypt forests in south-eastern Australia are predicted to experience rapid and extreme changes in rainfall patterns, temperatures and wild fires. To investigate the influence of environmental drivers on seasonal and inter-annual variation of soil-atmosphere CH4 exchange, we measured soil-atmosphere CH4 exchange at high-temporal resolution (< 2 h) in a dry temperate eucalypt forest in Victoria (Wombat State Forest, precipitation 870 mm yr-1) and in a wet temperature eucalypt forest in Tasmania (Warra Long-Term Ecological Research site, 1700 mm yr-1). Both forest soil systems were continuous CH4 sinks of -1.79 kg CH4 ha-1 yr-1 in Victoria and -3.83 kg CH4 ha-1 yr-1 in Tasmania. Soil CH4 uptake showed substantial temporal variation and was strongly controlled by soil moisture at both forest sites. Soil CH4 uptake increased when soil moisture decreased and this relationship explained up to 90 % of the temporal variability. Furthermore, the relationship between soil moisture and soil CH4 flux was near-identical at both forest sites when soil moisture was expressed as soil air-filled porosity (AFP). Soil temperature only had a minor influence on soil CH4 uptake. Soil nitrogen concentrations were generally low and fluctuations in nitrogen availability did not influence soil CH4 uptake at either forest site. Our data suggest that soil MOB activity in the two forests was similar and that differences in soil CH4 exchange between the two forests were related to differences in soil moisture and

  4. 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.

  5. Feasibility Assessment of Thermal Barrier Seals for Extreme Transient Temperatures

    Science.gov (United States)

    Steinetz, Bruce M.; Dunlap, Patrick H., Jr.

    1998-01-01

    The assembly joints of modem solid rocket motor cases are generally sealed using conventional O-ring type seals. The 5500+ F combustion gases produced by rocket motors are kept a safe distance away from the seals by thick layers of phenolic insulation. Special compounds are used to fill insulation gaps leading up to the seals to prevent a direct flowpath to them. Design criteria require that the seals should not experience torching or charring during operation, or their sealing ability would be compromised. On limited occasions, NASA has observed charring of the primary O-rings of the Space Shuttle solid rocket nozzle assembly joints due to parasitic leakage paths opening up in the gap-fill compounds during rocket operation. NASA is investigating different approaches for preventing torching or charring of the primary O-rings. One approach is to implement a braided rope seal upstream of the primary O-ring to serve as a thermal barrier that prevents the hot gases from impinging on the O-ring seals. This paper presents flow, resiliency, and thermal resistance for several types of NASA rope seals braided out of carbon fibers. Burn tests were performed to determine the time to burn through each of the seals when exposed to the flame of an oxyacetylene torch (5500 F), representative of the 5500 F solid rocket motor combustion temperatures. Rope seals braided out of carbon fibers endured the flame for over six minutes, three times longer than solid rocket motor burn time. Room and high temperature flow tests are presented for the carbon seals for different amounts of linear compression. Room temperature compression tests were performed to assess seal resiliency and unit preloads as a function of compression. The thermal barrier seal was tested in a subscale "char" motor test in which the seal sealed an intentional defect in the gap insulation. Temperature measurements indicated that the seal blocked 2500 F combustion gases on the upstream side with very little temperature

  6. Sealing materials seals for arctic applications

    OpenAIRE

    Eichstaedt, Joanna Anna

    2016-01-01

    This thesis is about exploring the performance of rubber O-ring seals made of materials such as: ELAST-O-LION 101, base HNBR and HNBR 50 CB, under cold temperatures and compressions equal to 10% and 20%. Initially a test apparatus with cooling chamber was built to evaluate seal performance at different temperatures and contact pressures. This part of the project included building the environmental chamber in which the mechanical compression rig is located, as well as connecting the circulatin...

  7. Inflatable traversing probe seal

    Science.gov (United States)

    Trimarchi, Paul A.

    1991-01-01

    An inflatable seal acts as a pressure-tight zipper to provide traversing capability for instrumentation rakes and probes. A specially designed probe segment with a teardrop cross-section in the vicinity of the inflatable seal minimizes leakage at the interface. The probe is able to travel through a lengthwise slot in a pressure vessel or wind tunnel section, while still maintaining pressure integrity. The design uses two commercially available inflatable seals, opposing each other, to cover the probe slot in a wind tunnel wall. Proof-of-concept tests were conducted at vessel pressures up to 30 psig, with seals inflated to 50 psig, showing no measurable leakage along the seal's length or around the probe teardrop cross-section. This seal concept can replace the existing technology of sliding face plate/O-ring systems in applications where lengthwise space is limited.

  8. Sodium sulfur battery seal

    Science.gov (United States)

    Mikkor, Mati

    1981-01-01

    This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

  9. Foil Face Seal Testing

    Science.gov (United States)

    Munson, John

    2009-01-01

    In the seal literature you can find many attempts by various researchers to adapt film riding seals to the gas turbine engine. None have been successful, potential distortion of the sealing faces is the primary reason. There is a film riding device that does accommodate distortion and is in service in aircraft applications, namely the foil bearing. More specifically a foil thrust bearing. These are not intended to be seals, and they do not accommodate large axial movement between shaft & static structure. By combining the 2 a unique type of face seal has been created. It functions like a normal face seal. The foil thrust bearing replaces the normal primary sealing surface. The compliance of the foil bearing allows the foils to track distortion of the mating seal ring. The foil seal has several perceived advantages over existing hydrodynamic designs, enumerated in the chart. Materials and design methodology needed for this application already exist. Also the load capacity requirements for the foil bearing are low since it only needs to support itself and overcome friction forces at the antirotation keys.

  10. 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...

  11. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  12. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    OpenAIRE

    Chuanjun Han; Han Zhang; Jie Zhang

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficie...

  13. 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.

  14. Rotary shaft seal

    Science.gov (United States)

    Langebrake, C.O.

    1984-01-01

    The invention is a novel rotary shaft seal assembly which provides positive-contact sealing when the shaft is not rotated and which operates with its sealing surfaces separated by a film of compressed ambient gas whose width is independent of the speed of shaft rotation. In a preferred embodiment, the assembly includes a disc affixed to the shaft for rotation therewith. Axially movable, non-rotatable plates respectively supported by sealing bellows are positioned on either side of the disc to be in sealing engagement therewith. Each plate carries piezoelectric transucer elements which are electrically energized at startup to produce films of compressed ambient gas between the confronting surfaces of the plates and the disc. Following shutdown of the shaft, the transducer elements are de-energized. A control circuit responds to incipient rubbing between the plate and either disc by altering the electrical input to the transducer elements to eliminate rubbing.

  15. Root canal filling evaluation using optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Hughes, Michael; Bradu, Adrian; Todea, Carmen; Balabuc, Cosmin I.; Filip, Laura M.; Podoleanu, Adrian Gh.

    2008-04-01

    The root canal fillings are destined to seal the root canal especially in the apical areea. Invasive techniques are known which are used to assess the quality of the seal. These lead to the destruction of the probes and often no conclusion could be drawn in respect to the existence of any microleakage in the investigated areas of interest. Optical coherence tomography (OCT) is a relatively novel non-invasive imaging technique which presents potential in assessing the microleakage of the apical area in the root canal fillings with micron depth resolution. 3D reconstruction allows a complete view with obvious display of gaps in the apical root canal filling. For this study, 30 monoradicular teeth were prepared by conventional and rotative methods. Afterwards, root canal fillings were produced in each tooth. The images obtained show some microleakage in all the investigated root canal fillings. The advantages of the OCT method consist in non-invasiveness and high resolution.

  16. Performance evaluation of fog seals on chip seals and verification of fog seal field tests

    National Research Council Canada - National Science Library

    Kim, Y. Richard; Im, Jeong Hyuk

    2015-01-01

    .... To mitigate a major problem with chip seals, i.e., the loose aggregate particles, fog seals, which are composed of an emulsified product placed on top of the chip seal, can be used to help control the loose aggregate...

  17. Sealing of polymer micro-structures by over-moulding

    DEFF Research Database (Denmark)

    Vingaard, Mathias; Christiansen, Jesper de Claville

    2012-01-01

    A concept for sealing of polymer micro-structures by over-moulding with polystyrene was devised and investigated by both experiments and simulations. The depth to which the melt filled the structure, i.e. a groove in the surface of the insert, before solidification was compared with results from...... on filling depth in the narrowest grooves. Around the experimental groove widths, there was good agreement between experiments and simulations. It was concluded that sealing by over-moulding is feasible if the depth/width ratio of the structure is large enough which in this paper is larger than six, i.e. up...

  18. Air

    Science.gov (United States)

    ... and your health: Green living Sun Water Air Health effects of air pollution How to protect yourself from air pollution Chemicals Noise Quizzes Links to more information girlshealth glossary girlshealth. ...

  19. SEALING SIMULATED LEAKS

    Energy Technology Data Exchange (ETDEWEB)

    Michael A. Romano

    2004-09-01

    This report details the testing equipment, procedures and results performed under Task 7.2 Sealing Simulated Leaks. In terms of our ability to seal leaks identified in the technical topical report, Analysis of Current Field Data, we were 100% successful. In regards to maintaining seal integrity after pigging operations we achieved varying degrees of success. Internal Corrosion defects proved to be the most resistant to the effects of pigging while External Corrosion proved to be the least resistant. Overall, with limitations, pressure activated sealant technology would be a viable option under the right circumstances.

  20. Sealing device for providing a seal in a turbomachine

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Selective filling of Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Noordegraaf, Danny; Sørensen, Thorkild

    2005-01-01

    A model for calculating the time necessary for filling one or more specific holes in a photonic crystal fibre is made. This model is verified for water, and its enabling potential is illustrated by a polymer application. Selective filling of the core in an air-guide photonic crystal fibre is demo...

  2. Ingestion resistant seal assembly

    Science.gov (United States)

    Little, David A [Chuluota, FL

    2011-12-13

    A seal assembly limits gas leakage from a hot gas path to one or more disc cavities in a gas turbine engine. The seal assembly includes a seal apparatus associated with a blade structure including a row of airfoils. The seal apparatus includes an annular inner shroud associated with adjacent stationary components, a wing member, and a first wing flange. The wing member extends axially from the blade structure toward the annular inner shroud. The first wing flange extends radially outwardly from the wing member toward the annular inner shroud. A plurality of regions including one or more recirculation zones are defined between the blade structure and the annular inner shroud that recirculate working gas therein back toward the hot gas path.

  3. 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...

  4. 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...

  5. Turbine seal assembly

    Science.gov (United States)

    Little, David A.

    2013-04-16

    A seal assembly that limits gas leakage from a hot gas path to one or more disc cavities in a turbine engine. The seal assembly includes a seal apparatus that limits gas leakage from the hot gas path to a respective one of the disc cavities. The seal apparatus comprises a plurality of blade members rotatable with a blade structure. The blade members are associated with the blade structure and extend toward adjacent stationary components. Each blade member includes a leading edge and a trailing edge, the leading edge of each blade member being located circumferentially in front of the blade member's corresponding trailing edge in a direction of rotation of the turbine rotor. The blade members are arranged such that a space having a component in a circumferential direction is defined between adjacent circumferentially spaced blade members.

  6. 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...

  7. 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...

  8. Damping Seals for Turbomachinery

    Science.gov (United States)

    Von Pragenau, G. L.

    1984-01-01

    Seals with rough surfaces proposed for stabilizing shaft motion and preventing leakage along shaft in machines such as turbopumps. Applicable to turbomachinery with speed limits raised and bearing life extended, avoiding costly shutdowns.

  9. An Overview of Advanced Elastomeric Seal Development and Testing Capabilities at NASA Glenn Research Center

    Science.gov (United States)

    Dunlap, Patrick H.

    2014-01-01

    NASA is developing advanced space-rated elastomeric seals to support future space exploration missions to low Earth orbit, the Moon, near Earth asteroids, and other destinations. This includes seals for a new docking system and vehicle hatches. These seals must exhibit extremely low leak rates to ensure that astronauts have sufficient breathable air for extended missions. Seal compression loads must be below prescribed limits so as not to overload the mechanisms that compress them, and seal adhesion forces must be low to allow the sealed interface to be separated when required (e.g., during undocking or hatch opening). NASA Glenn Research Center has developed a number of unique test fixtures to measure the leak rates and compression and adhesion loads of candidate seal designs under simulated thermal, vacuum, and engagement conditions. Tests can be performed on full-scale seals with diameters on the order of 50 in., subscale seals that are about 12 in. in diameter, and smaller specimens such as O-rings. Test conditions include temperatures ranging from -238 to 662 F (-150 to 350 C), operational pressure gradients, and seal-on-seal or seal-on-flange mating configurations. Nominal and off-nominal conditions (e.g., incomplete seal compression) can also be simulated. This paper describes the main design features and capabilities of each type of test apparatus and provides an overview of advanced seal development activities at NASA Glenn.

  10. Sealing ability of three single-cone obturation systems: An in-vitro glucose leakage study

    National Research Council Canada - National Science Library

    El Sayed, Mohamed Abdel Aziz Mohamed; Taleb, Ahmed Abdel Aziz; Balbahaith, Mohammed Sulaiman Mubarak

    2013-01-01

    ...; Group 3, single-cone Gutta-percha/and GuttaFlow2; Group 4, single-cone Resilon/RealSeal SE after 7 days, the sealing ability of root canal fillings was tested at different time intervals using glucose leakage model...

  11. Filling patterns in contrast ventriculography

    Science.gov (United States)

    Ferguson, Lawrence

    1974-01-01

    The filling patterns of a negative contrast material (air), a positive contrast water soluble material (Conray), and a positive contrast water insoluble material (Myodil) were examined in 60 normal ventriculograms. Using a scoring system developed for this study, Conray was found effective for outlining the ipsilateral (injected) lateral ventricle, the third ventricle, the aqueduct of Sylvius, and the fourth ventricle. Air was the most effective for the noninjected lateral ventricle, while Myodil was best for A-P demonstration of the aqueduct. The clinical implications of these findings are discussed. PMID:4545798

  12. Hot dynamic test rig for measuring hypersonic engine seal flow and durability

    Science.gov (United States)

    Miller, Jeffrey H.; Steinetz, Bruce M.; Sirocky, Paul J.; Kren, Lawrence A.

    1994-01-01

    A test fixture for measuring the dynamic performance of candidate high-temperature engine seal concepts was developed. The test fixture was developed to evaluate seal concepts under development for advanced hypersonic engines, such as those being considered for the National Aerospace Plane (NASP). The fixture can measure dynamic seal leakage performance from room temperature up to 840 C and air pressure differentials of to 0.7 MPa. Performance of the seals can be measured while sealing against flat or engine-simulated distorted walls. In the fixture, two seals are preloaded against the sides of a 0.3 m long saber that slides transverse to the axis of the seals, simulating the scrubbing motion anticipated in these engines. The capabilities of this text fixture along with preliminary data showing the dependence of seal leakage performance on high temperature cycling are covered.

  13. Method for filling a reactor with a catalyst

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a method for filling a reactor with a catalyst for the carbonylation of carbonylated compounds in the gas phase. According to said method, a SILP catalyst is covered with a filling agent which is liquid under normal conditions and is volatile under carbonylation reaction...... conditions, and a thus-treated catalyst is introduced into the reactor and the reactor is sealed....

  14. Comparison of seal materials for use in Stirling engines

    Science.gov (United States)

    Lundholm, G.

    1983-01-01

    In a dry, reciprocating sliding test, rods of 12 different surface materials rubbed against a glass filled PTFE gas seal. To simulate operation in a Stirling engine a gas (N2) pressure of 1 MPa differential pressure was applied across the seal. Gas leakage rates, rods surface temperatures, changes in the surface finish of the rod, surface hardness of the rod and wear rate of the seals were measured. The rod surface materials that produced the least seal were: plasma sprayed molybdenum (75 Mo 18 Ni 4 Cr), gas nitrided steel, and plasma sprayed aluminum oxide (94 Al2O3 6 TiO2). In contrast to almost all other mating surfaces, the surface roughness of the rods coated with Mo did not decrease during wear. This property is very important for the formation of a PTFE transfer film on the mating surface. The presence of a stable transfer film gives a low PTFE wear rate.

  15. Thermal Barrier/Seal for Extreme Temperature Applications

    Science.gov (United States)

    Steinetz, Bruce M.; Dunlap, Patrick H., Jr.; Phelps, Jack; Bauer, Paul; Bond, Bruce; McCool, Alex (Technical Monitor)

    2002-01-01

    Large solid rocket motors, as found on the Space Shuttle, are fabricated in segments for manufacturing considerations, bolted together, and sealed using conventional Viton O-ring seals. Similarly the nine large solid rocket motor nozzles are assembled from several different segments, bolted together, and sealed at six joint locations using conventional O-ring seals. The 5500 F combustion gases are generally kept a safe distance away from the seals by thick layers of phenolic or rubber insulation. Joint-fill compounds, including RTV (room temperature vulcanized compound) and polysulfide filler, are used to fill the joints in the insulation to prevent a direct flow-path to the O-rings. Normally these two stages of protection are enough to prevent a direct flow-path of the 900-psi hot gases from reaching the temperature-sensitive O-ring seals. However, in the current design 1 out of 15 Space Shuttle solid rocket motors experience hot gas effects on the Joint 6 wiper (sacrificial) O-rings. Also worrisome is the fact that joints have experienced heat effects on materials between the RTV and the O-rings, and in two cases O-rings have experienced heat effects. These conditions lead to extensive reviews of the post-flight conditions as part of the effort to monitor flight safety. We have developed a braided carbon fiber thermal barrier to replace the joint fill compounds in the Space Shuttle solid rocket motor nozzles to reduce the incoming 5500 F combustion gas temperature and permit only cool (approximately 100 F) gas to reach the temperature-sensitive O-ring seals. Implementation of this thermal barrier provides more robust, consistent operation with shorter turn around times between Shuttle launches.

  16. High-birefringence photonic crystal fiber polarization filter with gold-coated and liquid-filled air holes based on surface plasmon resonance

    Science.gov (United States)

    Lou, Junbo; Li, Shuguang; Cheng, Tonglei; Yan, Xin; Zhang, Xuenan

    2018-01-01

    A high-birefringence photonic crystal fiber polarization filter is proposed. The coupling theory is used to explain full and incomplete couplings. The resonance point can be adjusted to the communication band by optimizing the fiber structure parameters. Numerical simulation results indicate that the resonance strength can reach 924.96 and 710.28 dB.cm-1 at the communication wavelength of 1.31 and 1.55 μm in x- and y-polarized directions, respectively. By filling liquid analyte, the confinement loss can reach 804.52 dB.cm-1 at the wavelength of 1.55 μm. Furthermore, when the fiber length of L equals 500 μm, the peak value of the cross talk (CT) can reach 389.15 and -280.52 dB, respectively. When the length of the fiber L equals 200 μm, the bandwidth of the CT better than 20 dB is up to 120 nm at the wavelength of 1.31 μm, and the bandwidth of the CT<-20 dB is up to 140 nm at the wavelength of 1.55 μm. These properties make it a good candidate for designing types of polarization filter devices.

  17. Taper-seal type metal sealing system and available applications

    Science.gov (United States)

    Kurokouchi, Satoshi; Okabe, Masayuki; Morita, Shinsaku

    2001-01-01

    A conventional disk (flat ring) gasket for ConFlat ® sealing system has been commonly applied to commercially available equipments for ultrahigh vacuum systems. However, its large redundant part which wastes the tightening force makes its handling and seal reliability problematic. We examine a taper-seal type gasket, which is newly designed to improve the inefficiency of ConFlat mechanism using conventional disk gaskets. It is remarked that the obtained seal area on a taper-seal type gasket is 1.6˜3.7 times larger than that of a conventional disk gasket. Our numencal results on stress distributions in a tightened gasket indicate that taper-seal gasket realizes highly stable seal pressure even under a lower tightening torque. High sealing reliability is thus achieved as expected which is mainly due to the wide seal area and stable seal pressure realized even for rather hard gasket material. Taper-seal type gasket also has some practical advantages. The most important of them may be that it enables to construct new edgeless metal sealing systems without a welded heavy flange. Here, edgeless sealing systems are composed of highly flexible incorporating viewports, bellows, feedthroughs, and blank-off covers, as well as any other conventional vacuum components.

  18. Seal system with integral detector

    Science.gov (United States)

    Fiarman, Sidney

    1985-01-01

    There is disclosed a seal system for materials where security is of the essence, such as nuclear materials, which is tamper-indicating, which indicates changes in environmental conditions that evidence attempts to by-pass the seal, which is unique and cost effective, said seal system comprised of a seal where an optical signal is transmitted through a loop, with a detector to read said signal, and one or more additional detectors designed to detect environmental changes, these detectors being operatively associated with the seal so that detection of a break in the optical signal or detection of environmental changes will cause an observable change in the seal.

  19. 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...

  20. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring.

    Science.gov (United States)

    Han, Chuanjun; Zhang, Han; Zhang, Jie

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal.

  1. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    Directory of Open Access Journals (Sweden)

    Chuanjun Han

    2015-01-01

    Full Text Available In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal.

  2. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    Science.gov (United States)

    Han, Chuanjun

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  3. 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.

  4. Chip seal design and specifications : final report.

    Science.gov (United States)

    2016-12-01

    Chip seals or seal coats, are a pavement preservation method constructed using a layer of asphalt binder that is covered by a uniformly graded aggregate. The benefits of chip seal include: sealing surface cracks, keeping water from penetrating the su...

  5. 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

  6. 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)

  7. Gas path seal

    Science.gov (United States)

    Bill, R. C.; Johnson, R. D. (Inventor)

    1979-01-01

    A gas path seal suitable for use with a turbine engine or compressor is described. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor bades. A compliant backing surrounds the shroud. The backing is a yieldingly deformable porous material covered with a thin ductile layer. A mounting fixture surrounds the backing.

  8. 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

  9. Seal for sodium sulfur battery

    Science.gov (United States)

    Topouzian, Armenag; Minck, Robert W.; Williams, William J.

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which the sealing is accomplished by a radial compression seal made on a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  10. Environmental Impact Assessment of Petrol and Gas Filling Stations ...

    African Journals Online (AJOL)

    Environmental Impact Assessment of Petrol and Gas Filling Stations on Air Quality in Umuahia, Nigeria. ... Hence a conclusion was drawn from the findings that the primary pollutant to consider when building filling station are the VOCs and methane and that the minimum safe distance to site a filling station is a distance of ...

  11. Advanced Seal Sessions I and II

    Science.gov (United States)

    Steinetz, Bruce M.; Dunlap, Patrick H.; Sarawate, Neelesh

    2013-01-01

    As aircraft operators continue to seek higher fuel efficiency, lower emissions, and longer on-wing performance, turbine engine designers are scrutinizing all components for areas of improvement. To achieve overall goals, turbine pressure ratios and by-pass ratios continue to climb. Also, designers are seeking to minimize parasitic and cooling flows to extract the most useful work out of the flow stream, placing a renewed interest on seal technology and secondary flow path management. In the area of future manned spacecraft, advancements are being examined for both habitat seals and re-entry thermal protection system thermal barrierseals. For long duration space craft, designers are continuing to look for savings in parasitic losses to reduce the amount of cabin re-supply air that needs to be brought along. This is placing greater demands on seal designs and materials to exhibit low leakage and be resistant to space environments. For future missions to and from distant planets, the re-entry heating will be higher than for low-earth orbit or lunar return motivating advanced thermal barrier development. This presentation will provide an overview of the seal challenges and opportunities in these diverse areas.

  12. Gulf and Dilmun Type seals

    DEFF Research Database (Denmark)

    Laursen, Steffen

    2011-01-01

    From around 2100 BC a glyptic tradition emerges in the Arabian Gulf, which is dependant on the well-established schools of the Indus Valley seal cutters. These circular hybrids of classic Harappan seals rapidly became popular amongst the merchants of Dilmun, centered on Bahrain Island. At first...... 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...... Type seals....

  13. Non-Contacting Finger Seals Static Performance Test Results at Ambient and High Temperatures

    Science.gov (United States)

    Proctor, Margaret P.

    2016-01-01

    The non-contacting finger seal is an advanced seal concept with potential to reduce specific fuel consumption in gas turbine engines by 2 to 3 with little to no wear of the seal or rotor. Static performance tests and bind-up tests of eight different non-contacting finger seal configurations were conducted in air at pressure differentials up to 689.4 kPa and temperatures up to 922 K. Four of the seals tested were designed to have lift pads concentric to a herringbone-grooved rotor which generates hydrodynamic lift when rotating. The remaining seals were tested with a smooth rotor; one seal had a circumferential taper and one had an axial taper on the lift pad inner diameter to create hydrodynamic lift during rotation. The effects of the aft finger axial thickness and of the forward finger inner diameter on leakage performance were investigated as well and compared to analytical predictions.

  14. Hermetic Seal Leak Detection Apparatus

    Science.gov (United States)

    Kelley, Anthony R. (Inventor)

    2013-01-01

    The present invention is a hermetic seal leak detection apparatus, which can be used to test for hermetic seal leaks in instruments and containers. A vacuum tight chamber is created around the unit being tested to minimize gas space outside of the hermetic seal. A vacuum inducing device is then used to increase the gas chamber volume inside the device, so that a slight vacuum is pulled on the unit being tested. The pressure in the unit being tested will stabilize. If the stabilized pressure reads close to a known good seal calibration, there is not a leak in the seal. If the stabilized pressure reads closer to a known bad seal calibration value, there is a leak in the seal. The speed of the plunger can be varied and by evaluating the resulting pressure change rates and final values, the leak rate/size can be accurately calculated.

  15. Microleakage of Cavit temporary filling material in endodontic access cavities in monkey teeth.

    Science.gov (United States)

    Lamers, A C; Simon, M; van Mullem, P J

    1980-06-01

    Sealing properties of Cavit-W temporary filling material were tested in vivo in the control group of a usage experiment in which root canal disinfectants were studied. Histologic examination (Brown and Brenn staining) of the root canals showed a statistical significance in the occurrence of microorganisms with increase in time. Microleakage past the filling material was considered to be responsible.

  16. Porosity distribution in root canals filled with gutta percha and calcium silicate cement

    NARCIS (Netherlands)

    Moinzadeh, A.T.; Zerbst, W.; Boutsioukis, C.; Shemesh, H.; Zaslansky, P.

    2015-01-01

    Objective Gutta percha is commonly used in conjunction with a sealer to produce a fluid-tight seal within the root canal fillings. One of the most commonly used filling methods is lateral compaction of gutta percha coupled with a sealer such as calcium silicate cement. However, this technique may

  17. Gas turbine sealing apparatus

    Science.gov (United States)

    Wiebe, David J; Wessell, Brian J; Ebert, Todd; Beeck, Alexander; Liang, George; Marussich, Walter H

    2013-02-19

    A gas turbine includes forward and aft rows of rotatable blades, a row of stationary vanes between the forward and aft rows of rotatable blades, an annular intermediate disc, and a seal housing apparatus. The forward and aft rows of rotatable blades are coupled to respective first and second portions of a disc/rotor assembly. The annular intermediate disc is coupled to the disc/rotor assembly so as to be rotatable with the disc/rotor assembly during operation of the gas turbine. The annular intermediate disc includes a forward side coupled to the first portion of the disc/rotor assembly and an aft side coupled to the second portion of the disc/rotor assembly. The seal housing apparatus is coupled to the annular intermediate disc so as to be rotatable with the annular intermediate disc and the disc/rotor assembly during operation of the gas turbine.

  18. Rotordynamic Analysis of Textured Annular Seals With Multiphase (Bubbly Flow

    Directory of Open Access Journals (Sweden)

    Gérard PINEAU

    2011-09-01

    Full Text Available For some applications it must be considered that the flow in the annular seal contains a mixture of liquid and gas. The multiphase character of the flow is described by the volume fraction of gas (usually air contained in the liquid under the form of bubbles.The fluid is then a homogenous mixture of air and liquid all thru the annular seal. Its local gas volume fraction depends on the pressure field and is calculated by using a simplified form of the Rayleigh-Plesset equation.The influence of such of a multiphase (bubbly flow on the dynamic characteristics of a straight annular seal is minimal because the volume of the fluid is reduced.The situation is quite different for textured annular (damper seals provided with equally spaced deep cavities intended to increase the damping capabilities and to reduce the leakage flow rate.As a by-product, the volume of the fluid in the seal increases drastically and the compressibility effects stemming from the bubbly nature of the flow are largely increased even for a low gas volume fraction. The present work depicts the influence of the gas volume fraction on the dynamic characteristics of a textured annular seal. It is shown that variations of the gas volume fraction between 1% and 0.1% can lead to frequency dependent stiffness, damping and added mass coefficients.

  19. Glass composition and process for sealing void spaces in electrochemical devices

    Science.gov (United States)

    Meinhardt, Kerry D [Richland, WA; Kirby, Brent W [Kennewick, WA

    2012-05-01

    A glass foaming material and method are disclosed for filling void spaces in electrochemical devices. The glass material includes a reagent that foams at a temperature above the softening point of the glass. Expansion of the glass fills void spaces including by-pass and tolerance channels of electrochemical devices. In addition, cassette to cassette seals can also be formed while channels and other void spaces are filled, reducing the number of processing steps needed.

  20. Seal Out Tooth Decay

    Science.gov (United States)

    ... and Deadlines Grant Application Forms Application Receipt Dates Electronic Submission of Applications Grants 101 (How to Write ... before they decay will also save time and money in the long run by avoiding fillings, crowns, ...

  1. Technology Solutions for New and Existing Homes Case Study: Field Trial of an Aerosol-Based Enclosure Sealing Technology

    Energy Technology Data Exchange (ETDEWEB)

    D. Springer and C. Harrington

    2016-05-01

    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.

  2. The Mechanical Performance of Subscale Candidate Elastomer Docking Seals

    Science.gov (United States)

    Bastrzyk, Marta B.; Daniels, Christopher C.

    2010-01-01

    The National Aeronautics and Space Administration is developing a Low Impact Docking System (LIDS) for future exploration missions. The mechanism is a new state-of-the-art device for in-space assembly of structures and rendezvous of vehicles. At the interface between two pressurized modules, each with a version of the LIDS attached, a composite elastomer-metal seal assembly prevents the breathable air from escaping into the vacuum of space. Attached to the active LIDS, this seal mates against the passive LIDS during docking operation. The main interface seal assembly must exhibit low leak and outgas values, must be able to withstand various harsh space environments, must remain operational over a range of temperatures from -50 C to 75 C, and perform after numerous docking cycles. This paper presents results from a comprehensive study of the mechanical performance of four candidate subscale seal assembly designs at -50, 23, 50, and 75 C test temperatures. In particular, the force required to fully compress the seal during docking, and that which is required for separation during the undocking operation were measured. The height of subscale main interface seal bulbs, as well as the test temperature, were shown to have a significant effect on the forces the main interface seal of the LIDS may experience during docking and undocking operations. The average force values required to fully compress each of the seal assemblies were shown to increase with test temperature by approximately 50% from -50 to 75 C. Also, the required compression forces were shown to increase as the height of the seal bulb was increased. The seal design with the tallest elastomer seal bulb, which was 31% taller than that with the shortest bulb, required force values approximately 45% higher than those for the shortest bulb, independent of the test temperature. The force required to separate the seal was shown to increase with decreasing temperature after 15 hours of simulated docking. No adhesion

  3. An assessment of coronal leakage of permanent filling materials in endodontically treated teeth: An in vitro study

    National Research Council Canada - National Science Library

    Shetty, Kishore; Habib, V Ashiq; Shetty, S Vidhyadhara; Khed, Jaishri N; Prabhu, Vishnudas Dinesh

    2015-01-01

    The present in vitro study was undertaken to evaluate and compare the sealing ability of hybrid composite, glass ionomer cement type II, silver amalgam and Ketac molar as permanent filling material...

  4. High temperature performance evaluation of a hypersonic engine ceramic wafer seal

    Science.gov (United States)

    Steinetz, Bruce M.

    1991-01-01

    Leakage rates of an innovative hypersonic engine seal were measured using a specially developed static high temperature seal test fixture at NASA Lewis Research Center. The three foot long structural panel-edge seal is designed to minimize leakage of high temperature, high pressure gases past the movable panels of advanced ramjet/scramjet engines. The seal is made of a stack of precision machined ceramic wafer pieces that are inserted into a closely conforming seal channel in the movable engine panel. The wafer seal accommodates the significant distortions in the adjacent engine walls through relative sliding between adjacent wafers. Seal leakage rates are presented for engine simulated air temperatures up to 1350 F and for engine pressures up to 100 psi. Leakage rates are also presented for the seal, sealing both a flat wall condition, and an engine simulated distorted wall condition in which the distortion was 0.15 in. in only an 18 in. span. Seal leakage rates were low, meeting an industry-established tentative leakage limit for all combinations of temperature, pressure, and wall conditions considered. Comparisons are made between the measured leakage rates and leakage rates predicted using a seal leakage model developed from externally-pressurized gas film bearing theory.

  5. Aft outer rim seal arrangement

    Science.gov (United States)

    Lee, Ching-Pang; Tham, Kok-Mun; Schroeder, Eric; Meeroff, Jamie; Miller, Jr., Samuel R; Marra, John J; Campbell, Christian X

    2015-04-28

    An outer rim seal arrangement (10), including: an annular rim (70) centered about a longitudinal axis (30) of a rotor disc (31), extending fore and having a fore-end (72), an outward-facing surface (74), and an inward-facing surface (76); a lower angel wing (62) extending aft from a base of a turbine blade (22) and having an aft end (64) disposed radially inward of the rim inward-facing surface to define a lower angel wing seal gap (80); an upper angel wing (66) extending aft from the turbine blade base and having an aft end (68) disposed radially outward of the rim outward-facing surface to define a upper angel wing seal gap (80, 82); and guide vanes (100) disposed on the rim inward-facing surface in the lower angel wing seal gap. Pumping fins (102) may be disposed on the upper angel wing seal aft end in the upper angel wing seal gap.

  6. Fiber Optic Safeguards Sealing System

    Science.gov (United States)

    1978-01-01

    an intergrity check of a seal than to photograph the seal’s fingerprints and to match positive/negative overlays. The seal identification time and...INSTALLATIONS, LOGISTICS fi FINANCIAL MANAGEMENT) DEPARTMENT OF THE ARMY WASHINGTON, DC 20310 ATTN OASA-IL&FM-DSM&T, E. A. ORSINI ATTK OASA-IL&FM, COL K...W, GOOCH OFFICE, DEPUTY CHIEF OF STAFF FOR LOGISTICS DEPARTMENT OF THE ARMY WASHINGTON, DC 20310 ATTN DALO-SMS, T. C. UECKERT OFFICE, DEPUTY

  7. Fluidtight Seal for a Container

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Edward F.

    1999-03-31

    A fluidtight seal for a container is formed by abutting a metal ring with a step machined in a convexo-concave container closure device and inserting this assembly into an open end of the container. Under compressive force, the closure device deforms causing the metal ring to pivot about the step on the closure device and interact with symmetrically tapered inner walls of the container to form a fluidtight seal between the container and the closure device. The compressive force is then withdrawn without affecting the fluidtight characteristic of the seal. A destructive force against the container closure device is necessary to destroy the fluidtight seal.

  8. Crack sealer fill characteristics.

    Science.gov (United States)

    2010-06-01

    Laboratory testing was conducted to determine the extent of crack fill for crack sealers composed of methyl methacrylate, : epoxy, urethane, and high molecular weight methacrylate. The test specimens consisted of eight-inch long concrete : cylinders ...

  9. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...... state-facilitated way of bridging/altering the tension-filled relationship between legitimation and fiscal accumulation in Western European liberal-capitalist democratic polities....

  10. Intermontane valley fills

    OpenAIRE

    Mey, Jürgen (Diplom-Geologe)

    2017-01-01

    Sedimentary valley fills are a widespread characteristic of mountain belts around the world. They transiently store material over time spans ranging from thousands to millions of years and therefore play an important role in modulating the sediment flux from the orogen to the foreland and to oceanic depocenters. In most cases, their formation can be attributed to specific fluvial conditions, which are closely related to climatic and tectonic processes. Hence, valley-fill deposits constitute v...

  11. Development of new sealed UV sensitive gaseous detectors and their applications

    CERN Document Server

    Periale, L; Di Mauro, Antonio; Martinengo, P; Picchi, P; Pietropaolo, F; Sipilä, H; Peskov, A

    2007-01-01

    We have developed prototypes of sealed gaseous detectors combined with CsI photocathodes or filled with photosensitive vapors for commercial applications. The first results with these devices for the detection of flames in daylight conditions and of scintillation lights from noble liquids are presented. They show that sealed UV sensitive gaseous detectors can have better performance (higher practical quantum efficiency and a better signal to noise ratio) than existing commercial UV sensitive detectors at lower production cost.

  12. Building America Case Study: Field Trial of an Aerosol-Based Enclosure Sealing Technology, Clovis, California

    Energy Technology Data Exchange (ETDEWEB)

    2016-05-01

    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.

  13. Seal between metal and ceramic conduits

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Richard Paul; Tentarelli, Stephen Clyde

    2015-02-03

    A seal between a ceramic conduit and a metal conduit of an ion transport membrane device consisting of a sealing surface of ceramic conduit, a sealing surface of ceramic conduit, a single gasket body, and a single compliant interlayer.

  14. leonina and Cape fur seals Arctocephalus pusillus

    African Journals Online (AJOL)

    Namibia, was observed catching, killing and attempting copulation with female fur seals Arc- tocephalus pusillus, as well as catching and occasionally kill- ing fur seal pups and participating in territorial disputes with fur seal bulls. Previous and ...

  15. Toward an Improved Hypersonic Engine Seal

    Science.gov (United States)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange,Jeffrey J.; Taylor, Shawn C.

    2003-01-01

    High temperature, dynamic seals are required in advanced engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures from 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA s Glenn Research Center (GRC) is developing advanced seals to overcome these shortfalls. Two seal designs and two types of seal preloading devices were evaluated in a series of compression tests at room temperature and 2000 F and flow tests at room temperature. Both seals lost resiliency with repeated load cycling at room temperature and 2000 F, but seals with braided cores were significantly more flexible than those with cores composed of uniaxial ceramic fibers. Flow rates for the seals with cores of uniaxial fibers were lower than those for the seals with braided cores. Canted coil springs and silicon nitride compression springs showed promise conceptually as potential seal preloading devices to help maintain seal resiliency.

  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. 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.

  18. Conical O-ring seal

    Science.gov (United States)

    Chalfant, Jr., Gordon G.

    1984-01-01

    A shipping container for radioactive or other hazardous materials which has a conical-shaped closure containing grooves in the conical surface thereof and an O-ring seal incorporated in each of such grooves. The closure and seal provide a much stronger, tighter and compact containment than with a conventional flanged joint.

  19. Initial field testing definition of subsurface sealing and backfilling tests in unsaturated tuff; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Tyburski, J.R. [I. T. Corp., Albuquerque, NM (United States)

    1993-05-01

    This report contains an initial definition of the field tests proposed for the Yucca Mountain Project repository sealing program. The tests are intended to resolve various performance and emplacement concerns. Examples of concerns to be addressed include achieving selected hydrologic and structural requirements for seals, removing portions of the shaft liner, excavating keyways, emplacing cementitious and earthen seals, reducing the impact of fines on the hydraulic conductivity of fractures, efficient grouting of fracture zones, sealing of exploratory boreholes, and controlling the flow of water by using engineered designs. Ten discrete tests are proposed to address these and other concerns. These tests are divided into two groups: Seal component tests and performance confirmation tests. The seal component tests are thorough small-scale in situ tests, the intermediate-scale borehole seal tests, the fracture grouting tests, the surface backfill tests, and the grouted rock mass tests. The seal system tests are the seepage control tests, the backfill tests, the bulkhead test in the Calico Hills unit, the large-scale shaft seal and shaft fill tests, and the remote borehole sealing tests. The tests are proposed to be performed in six discrete areas, including welded and non-welded environments, primarily located outside the potential repository area. The final selection of sealing tests will depend on the nature of the geologic and hydrologic conditions encountered during the development of the Exploratory Studies Facility and detailed numerical analyses. Tests are likely to be performed both before and after License Application.

  20. Airfoil seal system for gas turbine engine

    Science.gov (United States)

    None, None

    2013-06-25

    A turbine airfoil seal system of a turbine engine having a seal base with a plurality of seal strips extending therefrom for sealing gaps between rotational airfoils and adjacent stationary components. The seal strips may overlap each other and may be generally aligned with each other. The seal strips may flex during operation to further reduce the gap between the rotational airfoils and adjacent stationary components.

  1. Case Study of Envelope Sealing in Existing Multiunit Structures

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, Jordan [ARIES Collaborative, New York, NY (United States); Conlin, Francis [ARIES Collaborative, New York, NY (United States); Podorson, David [ARIES Collaborative, New York, NY (United States)

    2012-10-01

    This report describes envelope air sealing that was included in the retrofit of a 244 unit low-rise multifamily housing complex in Durham, N.C. On average, total leakage was reduced by nearly half, from 19.7 ACH50 to 9.4 ACH50. Important air leakage locations identified included plumbing and electrical penetrations, dropped ceilings/soffits, windows, ducts and wall-to-floor intersections. Specifications and a pictorial guide were developed for contractors performing the work.

  2. Aerodynamic seals for rotary machine

    Science.gov (United States)

    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.

  3. Root canal filling using Resilon: a review.

    LENUS (Irish Health Repository)

    Shanahan, D J

    2011-07-01

    Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material \\'entombs\\' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as a result other materials such as Resilon have been investigated as alternatives. The aim of this review was to analyse the literature to consider whether Resilon is a suitable root canal filling material. A MEDLINE and Cochrane library search including various keyword searches identified several papers which investigated or discussed Resilon or RealSeal\\/Epiphany. Analysis of the literature demonstrated that the bulk of the literature is in vitro in nature, based largely on leakage-type studies, and demonstrates a wide variety of methodologies with conflicting findings; as a result meaningful conclusions are difficult. Within the limit of these in vitro studies Resilon appears to perform adequately in comparison to gutta-percha, however, as a result of the questionable merit of such studies, it cannot presently be considered an evidence-based alternative to the current gold standard gutta-percha. It is imperative that before Resilon is considered as a replacement material, a better understanding of the physical properties of the resin sealer and the reality of the adhesive \\'monoblock\\' are elucidated. The literature also demonstrates a paucity of quality long-term clinical outcome studies which will need to be addressed before firm conclusions can be reached.

  4. 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...

  5. Determinação de volumes e pressões de balonetes de tubos traqueais insuflados com ar ambiente ou óxido nitroso Determinación de volúmenes y presiones de balones de tubos traqueales insuflados con aire ambiente u óxido nitroso Volume and pressure of tracheal tube cuffs filled with air or nitrous oxide

    Directory of Open Access Journals (Sweden)

    Ernesto Leonardo Cárpio Peña

    2004-06-01

    balanceada con entubación orotraqueal. El balón fue insuflado conforme criterios clínicos. Las medidas de base fueron realizadas después de 15 minutos del inicio de la anestesia con un manómetro aneróide calibrado en cm de H2O y dieron los valores iniciales de presión y volumen. Los pacientes fueron divididos en dos grupos: balón reinsuflado con aire ambiente, grupo A, o con óxido nitroso, grupo B. Las medidas de presión fueron obtenidas en intervalos hasta la primera hora y los resultados comparados. RESULTADOS: Los grupos se mostraron comparables para edad y sexo. En ambos grupos los valores basales medios para presión fueron próximos de 40 cmH2O con 8 ml de volumen. En el grupo con aire ambiente, las presiones aumentaron hasta 36 cmH2O en una hora. En el grupo de balón insuflado con N2O, las presiones cayeron abajo de 20 cmH2O entre 20 y 30 minutos de anestesia. CONCLUSIONES: El uso de N2O a 100% para insuflación del balón de sonda traqueal no constituye método seguro, acarreando progresiva pérdida de la capacidad de vedación. El uso de aire ambiente promueve aumento de volumen y de presión en el balón, aumentando la posibilidad de lesión de la mucosa traqueal.BACKGROUND AND OBJECTIVES: Tracheal tube cuff pressure against tracheal wall should to prevent air leaked or pulmonary aspiration, allowing adequate capillary blood flow. This study aimed at determining pressure variations of tracheal tube cuffs filled with air or 100% nitrous oxide. METHODS: Participated in this study 30 patients submitted to balanced general anesthesia with tracheal intubation. Cuff was inflated according to clinical criteria. The intracuff pressure measurements were undertaken after 15 minutes of anesthesia by means of an aneroid manometer gaged in cm of H2O and have provided initial pressure and volume values. The patients was allocated in two groups: cuff inflated with air, group A, and with nitrous oxide, group B. Measurements were recorded during one hour and results were

  6. Rim seal arrangement having pumping feature

    Science.gov (United States)

    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.

  7. High contrast ultrasound images of defects in food package seals.

    Science.gov (United States)

    Frazier, C H; Tian, Q; Ozguler, A; Morris, S A; O'Brien, W R

    2000-01-01

    Previous work to detect defects in food packaging seals using pulse-echo ultrasound inspired the backscattered amplitude integral (BAI) imaging technique, which could reliably identify channels with diameters 38 microm or larger at a center frequency of 17.3 MHz (lambda=86 microm). The current study presents two new processing techniques that more reliably reveal smaller channels ( approximately 6 microm in diameter). The RF sampling technique (RFS) displays a single, time-gated, pressure value from the received (not envelope-detected) RF waveform at each transducer position. The RF correlation technique (RFC) calculates the correlation coefficients of the RF signals with a reference signal that does not pass through a channel. The correlation coefficient can be calculated for the entire RF signal (RFCE) or over a short segment of the RF signal (RFCS). The performance of these imaging methods for detecting channel defects is investigated for plastic and aluminum foil trilaminate films with 6, 10, 15, 38, and 50 microm channels filled with water or air. Data are collected with a focused ultrasound transducer (17.3 MHz, 6.35 mm in diameter, f/2, 173 microm -6 dB pulse-echo lateral beamwidth at the focus) scanned over a rectangular grid, keeping the package in the focus. Performance is measured using detection rates, image contrast, and contrast-to-noise ratio (CNR). Both RFS and RFCS have improved detection rates relative to BAI for channels 15 microm or smaller. The RFCS technique is the most effective at smoothing the background, leading to the greatest CNR improvements.

  8. Cyclic tests of P-bulb end-seal designs for a shuttle-type wing-elevon cove membrane seal

    Science.gov (United States)

    Hunt, L. R.

    1979-01-01

    Four P-bulb end seal designs were tested at room temperature in a cyclic seal test apparatus. Test results show that all the P-bulb end seals have the durability required for a 100 mission life (neglecting possible elevated-temperature effects) and three of the four P-bulbs provide an adequate seal against a 7.0-kPa air pressure differential. Antifriction material attached to the P-bulb rub surface reduced friction slightly but could degrade the sealing effectiveness. A flat rub surface molded into the P-bulb discouraged wrinkling and rolling and thereby reduced leakage. However, the P-bulbs lacked resilience, as indicated by increased leakage when P-bulb compression was reduced. The best P-bulb design tested included an antifriction interface bonded to a flat surface molded into the P-bulb.

  9. Interaction between clay-based sealing components and crystalline host rock

    Science.gov (United States)

    Priyanto, D. G.; Dixon, D. A.; Man, A. G.

    The results of hydraulic-mechanical (H-M) numerical simulation of a shaft seal installed at a fracture zone (FZ) in a crystalline host rock using the finite element method are presented. The primary function of a shaft seal is to limit short-circuiting of the groundwater flow regime via the shaft in a deep geological repository. Two different stages of system evolution were considered in this numerical modelling. Stage 1 simulates the groundwater flow into an open shaft, prior to seal installation. Stage 2 simulates the groundwater flow into the shaft seal after seal installation. Four different cases were completed to: (i) evaluate H-M response due to the interaction between clay-based sealing material and crystalline host rock in the shaft seal structure; (ii) quantify the effect of the different times between the completion of the shaft excavation and the completion of shaft seal installation on the H-M response; and (iii) define the potential effects of different sealing material configurations. Shaft sealing materials include the bentonite-sand mixture (BSM), dense backfill (DBF), and concrete plug (CP). The BSM has greater swelling capacity and lower hydraulic conductivity ( K) than the DBF. The results of these analyses show that the decrease of the pore water pressure is concentrated along the fracture zone (FZ), which has the greatest K. As the time increases, the greatest decrease in pore water pressure is found around the FZ. Following FZ isolation and the subsequent filling of the shaft with water as it floods, the pore water pressure profile tends to recover back to the initial conditions prior to shaft excavation. The majority of the fluids that ultimately saturate the centre of the shaft seal flow radially inwards from the FZ. The time between the completion of the shaft excavation and the completion of shaft seal installation has a significant effect on the saturation time. A shorter time can reduce the saturation time. Since most of the inflow

  10. Space-filling Curves

    Indian Academy of Sciences (India)

    mathematics and computer applications for the last 20 years. He has been a National Science. Talent awardee of. NCERT in mathematics. GENERAL I ARTICLE. Space-filling Curves. ReMittal. In this article some Peano curves are exhibited and some of their recent applications are dis- cussed. A C++ program to draw the ...

  11. Optimization of material and production to develop fluoroelastomer inflatable seals for sodium cooled fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

    Research highlights: Production of thin fluoroelastomer profiles by cold feed extrusion and continuous cure involving microwave and hot air heating. Use of peroxide curing in air during production. Use of fluoroelastomers based on advanced polymer architecture (APA) for the production of profiles. Use of the profiles in inflatable seals for critical application of Prototype Fast Breeder Reactor. Tailoring of material formulation by synchronized optimization of material and production technologies to ensure that the produced seal ensures significant gains in terms of performance and safety in reactor under synergistic influences of temperature, radiation, air and sodium aerosol. - Abstract: The feasibility of producing thin-walled fluoroelastomer profiles under continuous, atmospheric-pressure vulcanization conditions in air has been demonstrated by successful manufacture of {approx}2 m diameter test inflatable seals for the 500 MWe, Prototype Fast Breeder Reactor (PFBR) using a 50/50 blend formulation of Viton GBL-200S/600S based on advanced polymer architecture (APA). A commercial cold feed screw extruder with 90 mm diameter screw was used along with continuous cure by microwave (2.45 GHz) and hot air heating (190 {sup o}C) at a line speed of 1 m/min to produce the seals. The blend formulation promises significant improvement in the performance and safety of the seals. This article depicts the relevant characteristics of the original inflatable seal compound that was used as reference to achieve the objectives through synchronized optimization of material and production technologies. The production trials are outlined and the blend formulation used with minor factory modifications to produce the test seals is reported. Progressive refinements of the original, Viton A-401C based compound to the blend formulation is presented along with an assessment of potential performance gains. Possible uses of the reported formulation and production technique for other large

  12. Evaluation of marginal integrity of four bulk-fill dental composite materials: in vitro study.

    Science.gov (United States)

    Orłowski, Mirosław; Tarczydło, Bożena; Chałas, Renata

    2015-01-01

    The aim of the study was to compare under in vitro conditions marginal sealing of 4 different bulk-fill materials composite restorations of class II. Comparative evaluation concerned 4 composites of a bulk-fill type: SonicFill, Tetric EvoCeram Bulk Fill, Filtek Bulk Fill, and SDR. The study used 30 third molars without caries. In each tooth 4 cavities of class II were prepared. The prepared tooth samples were placed in a 1% methylene blue solution for 24 h, and after that in each restoration the depth of dye penetration along the side walls was evaluated. The highest rating (score 0, no dye penetration) was achieved by 93.33% of the restorations made of the SDR material, 90% of restorations of SonicFill system, 86.66% of restorations of the composite Filtek Bulk Fill, and 73.33% of restorations of the Tetric EvoCeram Bulk Fill. The performed study showed that bulk-fill flowable or sonic-activated flowable composite restorations have better marginal sealing (lack of discoloration) in comparison with bulk-fill paste-like composite.

  13. Enterococcus faecalis leakage in MTA silver amalgam and glass ionomer as root-end filling materials

    OpenAIRE

    Pineda Mejía, Martha Elena; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.; Salcedo Moncada, Doris; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.; Castro Rodríguez, Antonia; Departamento Académico Estomatología Biosocial. Facultad Odontología UNMSM. Lima Perú.; Palacios Alva, Elmo; Departamento Académico Médico Quirúrgico. Facultad Odontología UNMSM. Lima Perú.; Moromi Nakata, Hilda; Departamento Académico de Ciencias Básicas. Facultad Odontología UNMSM. Lima Perú.; Martínez Cadillo, Elba; Departamento Académico de Ciencias Básicas. Facultad Odontología UNMSM. Lima Perú.; Ortiz Cárdenas, Ántero; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.; Watanabe Velásquez, Rómel; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.; Zambrano de la Peña, Livia; Departamento Académico Médico Quirúrgico. Facultad Odontología UNMSM. Lima Perú.; Ochoa Tataje, Julio; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.; Lara Téllez, Lourdes; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.; Ayala de la Vega, Gerardo; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.; Ventocilla Huasupoma, María; Departamento Académico Estomatología Rehabilitadora. Facultad Odontología UNMSM. Lima Perú.

    2014-01-01

    One of the aims of a root-end filling material placed in an apicectomy treatment is to provide apical seal that can inhibits the coronary migration of antigens to perirradicular tissues. Many materials are used for this end; however, to date there has not been any material that satisfies all the requirements of an ideal material. With the purpose of making a comparative analysis of the apical sealing abilities of three root-end filling materials: silver amalgam, glass ionomer and MTA (mineral...

  14. Case Study of Envelope Sealing in Existing Multiunit Structures

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Conlin, F.; Podorson, D.

    2012-10-01

    Envelope air sealing was included in the retrofit of a 244 unit low-rise multifamily housing complex in Durham, N.C. Pre- and post-retrofit enclosure leakage tests were conducted on 51 units and detailed diagnostics were performed on 16. On average, total leakage was reduced by nearly half, from 19.7 ACH50 to 9.4 ACH50. Costs for air sealing were $0.31 per square foot of conditioned floor area, lower than estimates found in the National Residential Efficiency Measures Database (NREMD) and other sources, perhaps due in part to the large-scale production nature of the project. Modeling with BEopt software -- using an estimate of 85% of the envelope air leakage going to the outside (based on guarded tests performed at the site) -- calculated a space conditioning energy cost savings of 15% to 21% due to the air sealing retrofit. Important air leakage locations identified included plumbing and electrical penetrations, dropped ceilings/soffits, windows, ducts and wall-to-floor intersections. Previous repair activity had created significant leakage locations as well. Specifications and a pictorial guide were developed for contractors performing the work.

  15. Comparative evaluation of sealing ability of different obturation materials

    Directory of Open Access Journals (Sweden)

    Melih Irena

    2010-01-01

    Full Text Available Introduction Root canal filling materials are intended to prevent microleakage and passing of microorganisms and their toxins along the root canal space and into the periradicular tissues. Objective Objective of this in vitro study was to evaluate and compare apical leakage of root canals obturated using a modified warm vertical condensation technique and different materials. Methods Sixty-five extracted single-root teeth were prepared according to the crown-down/ step-back technique. Each canal was rinsed with 3% NaOCl during and after the preparation. The teeth were divided into 3 groups. Every group was obturated by the same technique, but with different materials: RealSeal system (SybronEndo, gutta-percha with AH Plus (Dentsply Maillefer and gutta-percha with Acroseal sealer (Septodont. The remaining 20 teeth were in the control group. The teeth were immersed in 1% methylene blue for 72 hours. After that period, the roots were split longitudinally, and dye penetration was measured using a stereomicroscope. Results Dye penetration occurred in all groups. The least dye penetration occurred in the RealSeal group (0.33}0.29 mm, while the highest dye penetration occurred in the Acroseal group (1.11}0.52 mm. According to the Student's t-test, Acroseal showed significantly more leakage (p<0.001 than RealSeal and AH Plus materials. The microleakage of RealSeal system was not significantly different (p>0.05 from that of AH Plus sealer with gutta-percha. Conclusion The results suggested that new material Resilon (RealSeal and conventional combination AH Plus with gutta-percha had the least apical dye penetration and provided the best sealing.

  16. 9 CFR 381.98 - Official seal.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Official seal. 381.98 Section 381.98... Certificates; Certification Procedures § 381.98 Official seal. The official mark for use in sealing means of... and a serial number as shown below, and any seals approved by the Administrator for applying such mark...

  17. 36 CFR 901.6 - Seal.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Seal. 901.6 Section 901.6... CORPORATION § 901.6 Seal. The Corporation may adopt a corporate seal which shall have the name of the Corporation and year of incorporation printed upon it. The seal may be used by causing it or a facsimile...

  18. 39 CFR 3002.3 - Official seal.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Official seal. 3002.3 Section 3002.3 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL ORGANIZATION § 3002.3 Official seal. (a) Authority. The Seal described in this section is hereby established as the official seal of the Postal Rate Commission...

  19. 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 official...

  20. 14 CFR 65.133 - Seal.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Seal. 65.133 Section 65.133 Aeronautics and...: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Parachute Riggers § 65.133 Seal. Each certificated parachute rigger must have a seal with an identifying mark prescribed by the Administrator, and a seal press. After...

  1. 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 of...

  2. 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...

  3. 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....

  4. A test fixture for measuring high-temperature hypersonic-engine seal performance

    Science.gov (United States)

    Steinetz, Bruce M.

    1990-01-01

    A test fixture for measuring the performance of several high temperature engine seal concepts was installed at the NASA Lewis Research Center. The test fixture was developed to evaluate seal concepts under development for advanced hypersonic engines such as those being considered for the National Aerospace Plane. The fixture can measure static seal leakage performance from room temperature up to 1500 F and air pressure differentials up to 100 psi. Performance of the seals can be measured while sealing against flat or engine simulated distorted walls, where distortions can be as large as 0.150 in. in only an 18 in. span. The fixture is designed to evaluate seals 3 feet long, a typical engine panel length. The seal channel can be configured to test square, circular, or rectangular seals that are nominally 0.5 in. high. The sensitivity of leakage performance to lateral or axial loading can also be measured using specially designed high temperature lateral and axial bellows preload systems. Leakage data for a candidate ceramic wafer engine seal is provided by way of example to demonstrate the test fixture's capabilities.

  5. Microstructure Filled Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reese, T. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-24

    We propose replacing the gas fill in a hohlraum with a low average density, variable uniformity 3D printed structure. This creates a bimodal hohlraum which acts like a vacuum hohlraum initially during the picket, but could protect the capsule from glint or direct illumination, and then once expanded, homogenizes to behave like a variable z gas-fill during peak portion of the drive. This is motivated by a two main aims: 1) reduction of the Au bubble velocity to improve inner beam propagation, and 2) the introduction of a low density, high-Z, x-ray converter to improve x-ray production in the hohlraum and uniformity of the radiation field seen by the capsule.

  6. Seal testing of large diameter rocket motors

    Science.gov (United States)

    Moore, N. B.; Hellums, John W.; Bechtel, Thomas; Kittredge, Ken; Crossfield, Craig

    1991-01-01

    This investigative program examines leakage testing of elastomeric O-ring seals for a solid rocket casing and provides direction towards an improved nondestructive postassembly test. It also details test equipment for the Space Shuttle systems solid rocket boosters (SRB). The results are useful to designers of hardware for pressure containment vessels which use O-ring seals. Using several subscale seal and groove configuration test fixtures equipped with either two or three O-ring seals in series, seal integrity is investigated with both a pressure decay and flowmeter methods. Both types of test equipment adequately detect the practical range of expected seal leak rates of 1 to 0.0001 sccs. The flowmeter leak test equipment appears to reduce testing time substantially. Limited seal leakage testing is performed on full-sized rocket motor segment seals, a pre-Challenger short stack, providing comparison of bore seals to test specimen bore and face seals. The conclusions are that seal reliability, verified via a performance pressure test, can be affected by temperature, quantity of grease, test pressure, and seal pressure load direction. Potential seal failure scenarios including contamination, seal damage, and sealing surface damage are discussed. Recommendations are made for an improved test procedure.

  7. Velocity and temperature field characteristics of water and air during natural convection heating in cans.

    Science.gov (United States)

    Erdogdu, Ferruh; Tutar, Mustafa

    2011-01-01

    Presence of headspace during canning is required since an adequate amount allows forming vacuum during the process. Sealing technology may not totally eliminate all entrapped gases, and headspace might affect heat transfer. Not much attention has been given to solve this problem in computational studies, and cans, for example, were mostly assumed to be fully filled with product. Therefore, the objective of this study was to determine velocity and temperature evolution of water and air in cans during heating to evaluate the relevance of headspace in the transport mechanism. For this purpose, canned water samples with a certain headspace were used, and required governing continuity, energy, and momentum equations were solved using a finite volume approach coupled with a volume of fluid element model. Simulation results correlated well with experimental results validating faster heating effects of headspace rather than insulation effects as reported in the literature. The organized velocity motions along the air-water interface were also shown. Practical Application: Canning is a universal and economic method for processing of food products, and presence of adequate headspace is required to form vacuum during sealing of the cans. Since sealing technology may not totally eliminate the entrapped gases, mainly air, headspace might affect heating rates in cans. This study demonstrated the increased heating rates in the presence of headspace in contrast with some studies in the literature. By applying the effect of headspace, required processing time for thermally processed foods can be reduced leading to more rapid processes and lower energy consumptions.

  8. A device for sealing the dead end sectors of mine water conduits

    Energy Technology Data Exchange (ETDEWEB)

    Privalov, N.I.; Akselrod, V.M.; Romanchuk, A.L.

    1983-01-01

    To increase the operational reliability when used on fire suppressing and irrigating pipelines, a branch pipe, equipped on one end with a lattice, is attached to the corresponding flange coaxially. The cavity of the branch pipe is filled with an easily melted material, while the seal is connected with the lattice by means of a spring.

  9. Air-coupled acoustic thermography for in-situ evaluation

    Science.gov (United States)

    Zalameda, Joseph N. (Inventor); Winfree, William P. (Inventor); Yost, William T. (Inventor)

    2010-01-01

    Acoustic thermography uses a housing configured for thermal, acoustic and infrared radiation shielding. For in-situ applications, the housing has an open side adapted to be sealingly coupled to a surface region of a structure such that an enclosed chamber filled with air is defined. One or more acoustic sources are positioned to direct acoustic waves through the air in the enclosed chamber and towards the surface region. To activate and control each acoustic source, a pulsed signal is applied thereto. An infrared imager focused on the surface region detects a thermal image of the surface region. A data capture device records the thermal image in synchronicity with each pulse of the pulsed signal such that a time series of thermal images is generated. For enhanced sensitivity and/or repeatability, sound and/or vibrations at the surface region can be used in feedback control of the pulsed signal applied to the acoustic sources.

  10. Further Investigations of Hypersonic Engine Seals

    Science.gov (United States)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange, Jeffrey J.

    2004-01-01

    Durable, flexible sliding seals are required in advanced hypersonic engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures of 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA's Glenn Research Center is developing advanced seals and preloading devices to overcome these shortfalls. An advanced ceramic wafer seal design and two silicon nitride compression spring designs were evaluated in a series of compression, scrub, and flow tests. Silicon nitride wafer seals survived 2000 in. (50.8 m) of scrubbing at 2000 F against a silicon carbide rub surface with no chips or signs of damage. Flow rates measured for the wafers before and after scrubbing were almost identical and were up to 32 times lower than those recorded for the best braided rope seal flow blockers. Silicon nitride compression springs showed promise conceptually as potential seal preload devices to help maintain seal resiliency.

  11. Evaluation and Modeling of Edge-Seal Materials for Photovoltaic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kempe, M. D.; Dameron, A. A.; Moricone, T. J.; Reese, M. O.

    2011-02-01

    Because of the sensitivity of some photovoltaic devices to moisture-induced corrosion, they are packaged using impermeable front- and back-sheets along with an edge seal to prevent moisture ingress. Evaluation of edge seal materials can be difficult because of the low permeation rates involved and/or non-Fickian behavior. Here, using a Ca film deposited on a glass substrate, we demonstrate the evaluation of edge seal materials in a manner that effectively duplicates their use in a photovoltaic application and compare the results with standard methods for measuring water vapor transport. We demonstrate how moisture permeation data from polymer films can be used to estimate moisture ingress rates and compare the results of these two methods. Encapsulant materials were also evaluated for comparison and to highlight the need for edge seals. Of the materials studied, desiccant filled polyisobutylene materials demonstrate by far the best potential to keep moisture out for a 20 to 30 year lifetime.

  12. Tribology and Microstructure of PS212 with a Cr2O3 Seal Coat

    Science.gov (United States)

    Sliney, Harold E.; Benoy, Patricia A.; Korenyi-Both, Andras; Dellacorte, Christopher

    1994-01-01

    PS212 is a plasma sprayed metal bonding chrome carbide coating with solid lubricant additives which has lubricating properties at temperatures up to about 900 deg C. The coating is diamond ground to achieve an acceptable tribological surface. But, as with many plasma spray coatings, PS212 is not fully-dense. In this study, a chromium oxide base seal coating is used in an attempt to seal any porosity that is open to the surface of the PS212 coating, and to study the effect of the sealant on the tribological properties of PS212. The results indicate that the seal coating reduces friction and wear when it is applied and then diamond ground leaving a thin layer of seal coating which fills in the surface pits of the PS212 coating.

  13. Testing of isolation barrier sealing surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Graves, C.E.

    1994-12-15

    Isolation barrier doors are to be installed in the 105KE and 105KW basins as part of the 1994 unreviewed safety question (USQ) resolution plan to isolate the fuel storage basin from the fuel discharge chute. Included in this installation is the placement of new sealing surfaces for the barriers by affixing stainless steel plates to existing carbon steel angle bars with a specially formulated epoxy adhesive/sealant material. The sealant is a two-part component consisting of an epoxy resin (the condensation product of bisphenol A and epichlorohydrin) and a curing agent (a proprietary cycloaliphatic polyamine). The sealant is solvent free (complying with air pollution regulations) and capable of withstanding the surrounding radiation fields over an estimated 15-year service life. The epoxy sealant experiences negligible water damage partly because of its hydrophobic (water-repelling) nature. With bond tensile strengths measured at greater than 862 kPa (125 lbf/in{sup 2}), the epoxy sealant is judged acceptable for its intended application. The four-hour pot life of the epoxy sealant provides sufficient time to apply the epoxy, examine the epoxy bead for continuity, and position the stainless steel sealing plates.

  14. 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.

  15. Turbine interstage seal with self-balancing capability

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-26

    An interstage seal for a turbine of a gas turbine engine, the interstage seal having a seal carrier with an axial extending seal tooth movable with a stator of the engine, and a rotor with a seal surface that forms the interstage seal with the seal tooth, where a magnetic force produced by two magnets and a gas force produced by a gas pressure acting on the seal carrier forms a balancing force to maintain a close clearance of the seal without the seal tooth contacting the rotor seal surfaces during engine operation. In other embodiments, two pairs of magnets produce first and second magnetic forces that balance the seal in the engine.

  16. Fluid Dynamics of Bottle Filling

    Science.gov (United States)

    McGough, Patrick; Gao, Haijing; Appathurai, Santosh; Basaran, Osman

    2011-11-01

    Filling of bottles is a widely practiced operation in a large number of industries. Well known examples include filling of ``large'' bottles with shampoos and cleaners in the household products and beauty care industries and filling of ``small'' bottles in the pharmaceutical industry. Some bottle filling operations have recently drawn much attention from the fluid mechanics community because of the occurrence of a multitude of complex flow regimes, transitions, and instabilities such as mounding and coiling that occur as a bottle is filled with a fluid. In this talk, we present a primarily computational study of the fluid dynamical challenges that can arise during the rapid filling of bottles. Given the diversity of fluids used in filling applications, we consider four representative classes of fluids that exhibit Newtonian, shear-thinning, viscoelastic, and yield-stress rheologies. The equations governing the dynamics of bottle filling are solved either in their full 3D but axisymmetric form or using the slender-jet approximation.

  17. 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.

  18. Permeability of currently available microtiter plate sealing tapes fail to fulfil the requirements for aerobic microbial cultivation.

    Science.gov (United States)

    Sieben, Michaela; Giese, Heiner; Grosch, Jan-Hendrik; Kauffmann, Kira; Büchs, Jochen

    2016-12-01

    Microtiter plate (MTP) sealing tapes are commonly applied in bioprocess development and high throughput screening in order to maintain sterile conditions and avoid liquid evaporation. However, only a few of the commercially available sealing tapes are adequately characterized to guarantee both minimal evaporation and sufficient oxygen supply for aerobic cultivation. Therefore, 12 commercially available sealing tapes are analyzed concerning their water vapor and oxygen permeability. The water vapor permeability is assessed by gravimetrically quantifying the liquid loss due to evaporation. Thereby, the sealing tapes are revealed significant differences. Highly permeable sealing tapes are resulted in liquid loss of up to 25% of the initial filling volume after 8 h at 37°C and 45% ambient humidity. Additionally, the tremendous impact of evaporative cooling on the liquid temperature is detected discovering deviations of up to 3.8°C from the set temperature. The oxygen permeability is assessed by measuring the oxygen transfer rate (OTR). Three out of the 12 tested sealing tapes are impermeable to oxygen while the remaining sealing tapes are ensured sufficient oxygen supply. As a result, all examined sealing tapes are inadequate with respect to either water or oxygen permeation. Based on these novel experimental results, prospective improvements of MTP sealing tapes are presented using a model approach. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Active bypass flow control for a seal in a gas turbine engine

    Science.gov (United States)

    Ebert, Todd A.; Kimmel, Keith D.

    2017-01-10

    An active bypass flow control system for controlling bypass compressed air based upon leakage flow of compressed air flowing past an outer balance seal between a stator and rotor of a first stage of a gas turbine in a gas turbine engine is disclosed. The active bypass flow control system is an adjustable system in which one or more metering devices may be used to control the flow of bypass compressed air as the flow of compressed air past the outer balance seal changes over time as the outer balance seal between the rim cavity and the cooling cavity wears. In at least one embodiment, the metering device may include a valve formed from one or more pins movable between open and closed positions in which the one pin at least partially bisects the bypass channel to regulate flow.

  20. Mechanical seal with textured sidewall

    Science.gov (United States)

    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.

  1. Diurnal variations in a sealed radon chamber

    Science.gov (United States)

    Gilboy, W. B.; James, P. R.; Farmer, C. P.; Beard, J. E.

    1990-12-01

    During experiments to calibrate a radon-in-air counter, some unexpected diurnal variations have been observed. Inside the sealed stainless-steel chamber of a nominal volume of 3 litres, ionised 218Po atoms from the alpha-decay of 222Rn are attracted by an electric field to a ZnS(Ag) scintillation screen via which subsequent α-decay events are detected. Results for this configuration are presented and also for a modified version in which the scintillation screen is replaced by a high-resolution α-detector. Ambient temperature changes were suspected to be responsible for the observed counting-efficiency variation and this has been confirmed by operating the wall of the chamber at various temperatures between 0°C and about 40°C, which revealed a positive temperature coefficient of ˜1%/°C at 25°C. Possible reasons for this effect are considered.

  2. Sealed source peer review plan

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, Alexander [Los Alamos National Laboratory; Leonard, Lee [RETIRED; Burns, Ron [CONTRACTOR

    2009-01-01

    Sealed sources are known quantities of radioactive materials that have been encapsulated in quantities that produce known radiation fields. Sealed sources have multiple uses ranging from instrument calibration sources to sources that produce radiation fields for experimental applications. The Off-Site Source Recovery (OSR) Project at Los Alamos National Laboratory (LANL), created in 1999, under the direction of the Waste Management Division of the U.S. Department of Energy (DOE) Albuquerque has been assigned the responsibility to recover and manage excess and unwanted radioactive sealed sources from the public and private sector. LANL intends to ship drums containing qualified sealed sources to the Waste Isolation Pilot Plant (WIPP) for disposal. Prior to shipping, these drums must be characterized with respect to radiological content and other parameters. The U. S. Environmental Protection Agency (EPA) requires that ten radionulcides be quantified and reported for every container of waste to be disposed in the WIPP. The methods traditionally approved by the EPA include non-destructive assay (NDA) in accordance with Appendix A of the Contact-Handled Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (DOE, 2002) (CH WAC). However, because of the nature and pedigree of historical records for sealed sources and the technical infeasibility of performing NDA on these sources, LANL proposes to characterize the content of these waste drums using qualified existing radiological data in lieu of direct measurement. This plan describes the process and documentation requirements for the use of the peer review process to qualify existing data for sealed radiological sources in lieu of perfonning radioassay. The peer review process will be performed in accordance with criteria provided in 40 CFR {section} 194.22 which specifies the use of the NUREG 1297 guidelines. The plan defines the management approach, resources, schedule, and technical requirements

  3. The Behavioural Response of Australian Fur Seals to Motor Boat Noise

    Science.gov (United States)

    Tripovich, Joy S.; Hall-Aspland, Sophie; Charrier, Isabelle; Arnould, John P. Y.

    2012-01-01

    Australian fur seals breed on thirteen islands located in the Bass Strait, Australia. Land access to these islands is restricted, minimising human presence but boat access is still permissible with limitations on approach distances. Thirty-two controlled noise exposure experiments were conducted on breeding Australian fur seals to determine their behavioural response to controlled in-air motor boat noise on Kanowna Island (39°10′S, 146°18′E). Our results show there were significant differences in the seals' behaviour at low (64–70 dB) versus high (75–85 dB) sound levels, with seals orientating themselves towards or physically moving away from the louder boat noise at three different sound levels. Furthermore, seals responded more aggressively with one another and were more alert when they heard louder boat noise. Australian fur seals demonstrated plasticity in their vocal responses to boat noise with calls being significantly different between the various sound intensities and barks tending to get faster as the boat noise got louder. These results suggest that Australian fur seals on Kanowna Island show behavioural disturbance to high level boat noise. Consequently, it is recommended that an appropriate level of received boat sound emissions at breeding fur seal colonies be below 74 dB and that these findings be taken into account when evaluating appropriate approach distances and speed limits for boats. PMID:22623998

  4. The behavioural response of Australian fur seals to motor boat noise.

    Science.gov (United States)

    Tripovich, Joy S; Hall-Aspland, Sophie; Charrier, Isabelle; Arnould, John P Y

    2012-01-01

    Australian fur seals breed on thirteen islands located in the Bass Strait, Australia. Land access to these islands is restricted, minimising human presence but boat access is still permissible with limitations on approach distances. Thirty-two controlled noise exposure experiments were conducted on breeding Australian fur seals to determine their behavioural response to controlled in-air motor boat noise on Kanowna Island (39°10'S, 146°18'E). Our results show there were significant differences in the seals' behaviour at low (64-70 dB) versus high (75-85 dB) sound levels, with seals orientating themselves towards or physically moving away from the louder boat noise at three different sound levels. Furthermore, seals responded more aggressively with one another and were more alert when they heard louder boat noise. Australian fur seals demonstrated plasticity in their vocal responses to boat noise with calls being significantly different between the various sound intensities and barks tending to get faster as the boat noise got louder. These results suggest that Australian fur seals on Kanowna Island show behavioural disturbance to high level boat noise. Consequently, it is recommended that an appropriate level of received boat sound emissions at breeding fur seal colonies be below 74 dB and that these findings be taken into account when evaluating appropriate approach distances and speed limits for boats.

  5. 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.

  6. Self-Sealing Cryogenic Fitting

    Science.gov (United States)

    Jia, Lin Xiang; Chow, Wen Lung; Moslemian, Davood; Lin, Gary; Melton, Greg

    1994-01-01

    Self-sealing fitting for cryogenic tubes remains free of leakage from room temperature to liquid-helium temperature even at internal pressure as high as 2.7 MPa. Fitting comprises parts made of materials with different coefficients of thermal expansion to prevent leakage gaps from forming as temperature decreases. Consists of coupling nut, two flared tube ends, and flared O-ring spacer. Spacer contracts more than tube ends do as temperature decreases. This greater contraction seals tube ends more tightly, preventing leakage.

  7. Feasibility of using microencapsulated phase change materials as filler for improving low temperature performance of rubber sealing materials.

    Science.gov (United States)

    Tiwari, Avinash; Shubin, Sergey N; Alcock, Ben; Freidin, Alexander B; Thorkildsen, Brede; Echtermeyer, Andreas T

    2017-11-01

    The feasibility of a novel composite rubber sealing material to improve sealing under transient cooling (in a so-called blowdown scenario) is investigated here. A composite of hydrogenated nitrile butadiene rubber (HNBR) filled with Micro Encapsulated Phase Change Materials (MEPCM) is described. The fillers contain phase change materials that release heat during the phase transformation from liquid to solid while cooling. This exotherm locally heats the rubber and may improve the function of the seal during a blowdown event. A representative HNBR-MEPCM composite was made and the critical thermal and mechanical properties were obtained by simulating the temperature distribution during a blowdown event. Simulations predict that the MEPCM composites can delay the temperature decrease in a region of the seal during the transient blowdown. A sensitivity analysis of material properties is also presented which highlights possible avenues of improvement of the MEPCMs for sealing applications.

  8. Mindfulness in action : discovering how Navy SEALs build capacity for mindfulness in high-reliability organizations

    OpenAIRE

    Fraher, Amy; Branicki, Layla; Grint, Keith

    2017-01-01

    This study of US Navy Sea Air and Land (SEALs) commandos contributes to the research investigating mindfulness in High-Reliability Organizations (HROs) by identifying micro- and macro-level influences that allow SEALs to build capacity for mindful behaviors and flexible responses despite the complexity of their missions, unpredictability of their operating environments, and inherent danger of their work. Although HRO literature defines five hallmarks of mindfulness, how frontline people worki...

  9. Geological conditions for lateral sealing of active faults and relevant research methods

    Directory of Open Access Journals (Sweden)

    Guang Fu

    2017-01-01

    Full Text Available Many researchers worked a lot on geologic conditions for lateral sealing of faults, but none of their studies took the effect of internal structures of fault zones on the lateral sealing capacity of faults. Therefore, the lateral sealing of active faults has rarely been discussed. In this paper, based on the analysis of the composition and structure characteristics of fault fillings, the geological conditions for lateral sealing of active faults and relevant research method were discussed in reference to the lateral sealing mechanisms of inactive fault rocks. It is shown that, in order to satisfy geologically the lateral sealing of active faults, the faults should be antithetic and the faulted strata should be mainly composed of mudstone, so that the displacement pressure of fault fillings is higher than or equal to that of reservoir rocks in oil and gas migration block. Then, a research method for the lateral sealing of active faults was established by comparing the displacement pressure of fillings in the fault with that of reservoir rocks in oil and gas migration block. This method was applied to three antithetic faults (F1, F2 and F3 in No. 1 structure of the Nanpu Sag, Bohai Bay Basin. As revealed, the fillings of these three active faults were mostly argillaceous at the stage of natural gas accumulation (the late stage of Neogene Minghuazhen Fm sedimentation, and their displacement pressures were higher than that of reservoir rocks in the first member of Paleogene Dongying Fm (F1 and F3 and the Neogene Guantao Fm (F2. Accordingly, they are laterally sealed for natural gas, which is conducive to the accumulation and preservation of natural gas. Industrial gas flow has been produced from the first member of Paleogene Dongying Fm in Well Np101, the Guantao Fm in Well Np1-2 and the first member of Paleogene Dongying Fm in Well Np1, which is in agreement with the analysis result. It is verified that this method is feasible for investigating the

  10. Preparing for faster filling

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the programmed technical stop last week, operators focussed on preparing the machine for faster filling, which includes multibunch injection and a faster pre-cycle phase.   The LHC1 screen shot during the first multibunch injection operation. The LHC operational schedule incorporates a technical stop for preventive maintenance roughly every six weeks of stable operation, during which several interventions on the various machines are carried out. Last week these included the replacement of a faulty magnet in the SPS pre-accelerator, which required the subsequent re-setting of the system of particle extraction and transfer to the LHC. At the end of last week, all the machines were handed back for operation and work could start on accommodating all the changes made into the complex systems in order for normal operation to be resumed. These ‘recovery’ operations continued through the weekend and into this week. At the beginning of this week, operators succeeded in pro...

  11. Plasma-sprayed dual density ceramic turbine seal system

    Science.gov (United States)

    Clingman, D. L.; Schechter, B.; Cross, K. R.; Cavanagh, J. R.

    1979-01-01

    Dual density, plasma sprayed ceramic coating systems were investigated for possible application as abradable turbine tip seal systems in small gas turbine engines. Abradability, erosion resistance, internal leakage, and microstructural characterization were investigated for polyester and cenosphere filled zirconium oxide composites. Results indicate the polyester system is more abradable but displays significantly less erosion resistance than the cenosphere system. It is also stated that the absence of significant blade tip damage during abradability testing of both systems suggests additional effort may result in a more nearly optimum balance of abradability and erosion resistance.

  12. Improved and lower cost sealing of aerospace structure

    Science.gov (United States)

    Angeloni, D. J.; Thomas, J. H.; Lauer, H. K.

    1979-01-01

    An improved sealing method has been developed for the exposed metal fastener surfaces of the Solid Rocket Booster vehicle for the Space Shuttle launch system. The method employs properly sized flexible plastic caps filled with catalyzed polysulfide sealant, frozen and stored. At the time of use, the caps and sealant are thawed and positioned on the fasteners. The sealant covers the exposed portion of the fastener and prevents salt water damage. The method is one of high reliability with low installation and inspection costs.

  13. Sealed Attics Exposed to Two Years of Weathering in a Hot and Humid Climate

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; Railkar, Sudhir [GAF; Shiao, Ming C [ORNL; Desjarlais, Andre Omer [ORNL

    2016-01-01

    Field studies in a hot, humid climate were conducted to investigate the thermal and hygrothermal performance of ventilated attics and non-ventilated semi-conditioned attics sealed with open-cell and with closed-cell spray polyurethane foam insulation. Moisture pin measurements made in the sheathing and absolute humidity sensor data from inside the foam and from the attic air show that moisture is being stored in the foam. The moisture in the foam diffuses to and from the sheathing dependent on the pressure gradient at the foam-sheathing interface which is driven by the irradiance and night-sky radiation. Ventilated attics in the same hot, humid climate showed less moisture movement in the sheathing than those sealed with either open- or closed-cell spray foam. In the ventilated attics the relative humidity drops as the attic air warms; however, the opposite was observed in the sealed attics. Peaks in measured relative humidity in excess of 80 90% and occasionally near saturation (i.e., 100%) were observed from solar noon till about 8 PM on hot, humid days. The conditioned space of the test facility is heated and cooled by an air-to-air heat pump. Therefore the partial pressure of the indoor air during peak irradiance is almost always less than that observed in the sealed attics. Field data will be presented to bring to light the critical humidity control issues in sealed attics exposed to hot, humid climates.

  14. HMSRP Hawaiian Monk Seal Telemetry Tag Deployments

    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...

  15. HMSRP Hawaiian Monk Seal Argos Location 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 satellite...

  16. Seal Apparatus and Methods to Manufacture Thereof

    Science.gov (United States)

    Richard, James A. (Inventor)

    2013-01-01

    In some implementations, apparatus and methods are provided through which a dynamic cryogenic seal is manufactured. In some implementations, the seal includes a retainer and a spring-seal assembly, the assembly being comprised of a main spring housing and fluorine-containing polymer seals. In some implementations, either a radial seal, or an axial (or "piston seal") is provided. In some implementations, methods of manufacturing the dynamic cryogenic seal are also provided. In some implementations, the methods include assembling the components while either heated or cooled, taking advantage of thermal expansion and contraction, such that there is a strong interference fit between the components at room temperature. In some implementations, this process ensures that the weaker fluorine-containing polymer seal is forced to expand and contract with the stronger retainer and spring and is under constant preload. In some implementations, the fluorine-containing polymer is therefore fluidized and retained, and can not lift off.

  17. 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...

  18. 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...

  19. 7 CFR 330.110 - Seals.

    Science.gov (United States)

    2010-01-01

    ... OF AGRICULTURE FEDERAL PLANT PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS... inspector. (c) Notice of sealing. When an inspector seals any opening, product or article, he shall explain...

  20. 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

  1. Film riding seals for rotary machines

    Science.gov (United States)

    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.

  2. 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...

  3. 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...

  4. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  5. 39 CFR 2.4 - Seal.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Seal. 2.4 Section 2.4 Postal Service UNITED STATES... (ARTICLE II) § 2.4 Seal. (a) The Seal of the Postal Service is filed by the Board in the Office of the Secretary of State, and is required by 39 U.S.C. 207 to be judicially noticed. The Seal shall be in the...

  6. 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

  7. 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.

  8. Two-dimensional photonic crystals from semiconductor material with polymer filled holes

    NARCIS (Netherlands)

    Van der Heijden, R.; Kjellander, C.; Carlström, C.F.; Snijders, J.; Van der Heijden, R.W.; Bastiaansen, K.; Broer, D.; Karouta, F.; Nötzel, R.; Van der Drift, E.

    2006-01-01

    Polymer filling of the air holes of indiumphosphide based two-dimensional photonic crystals is reported. The filling is performed by infiltration with a liquid monomer and solidification of the infill in situ by thermal polymerization. Complete hole filling is obtained with infiltration under

  9. 29 CFR 4002.11 - Seal.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Seal. 4002.11 Section 4002.11 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION GENERAL BYLAWS OF THE PENSION BENEFIT GUARANTY CORPORATION § 4002.11 Seal. The seal of the Corporation shall be in such form as may be approved from time to...

  10. 14 CFR 187.7 - Copies; seal.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Copies; seal. 187.7 Section 187.7... REGULATIONS FEES § 187.7 Copies; seal. The fees for furnishing photostatic or similar copies of documents and for affixation of the seal for a certification or validation are the same as those provided in subpart...

  11. 19 CFR 201.0 - Seal.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Seal. 201.0 Section 201.0 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION § 201.0 Seal. (a) Pursuant to... Trade Commission has adopted an official seal, the depiction of which follows: EC05OC91.026 (b) Custody...

  12. 1 CFR 18.8 - Seal.

    Science.gov (United States)

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Seal. 18.8 Section 18.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION AND TRANSMITTAL OF DOCUMENTS GENERALLY § 18.8 Seal. Use of a seal on an original document or...

  13. Solid rocket booster joint seal analyses

    Science.gov (United States)

    Moore, Carleton J.

    1987-01-01

    O-ring response and sealing in pressurized shell structures is examined. The study found that the key elements in the failure of the seal to be joint opening and rotation, assembly out of roundness, and O-ring seal response.

  14. 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

  15. Annular Pressure Seals and Hydrostatic Bearings

    National Research Council Canada - National Science Library

    San Andres, Luis

    2006-01-01

    ..., in particular those handling large density fluids. Highlights on the bulk-flow analysis of annular seals are given with details on the performance of two water seals long and short, featuring the advantages of an anti-swirl brake to enhance the seal...

  16. Aerodynamic seal assemblies for turbo-machinery

    Science.gov (United States)

    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.

  17. Low-profile self-sealing sample transfer flexure box.

    Science.gov (United States)

    Simon, Kevin; Porz, Lukas; Swamy, Tushar; Chiang, Yet-Ming; Slocum, Alexander

    2017-08-01

    A flexural bearing mechanism has enabled the development of a self-sealing box for protecting air sensitive samples during transfer between glove boxes, micro-machining equipment, and microscopy equipment. The simplicity and self-actuating feature of this design makes it applicable to many devices that operate under vacuum conditions. The models used to design the flexural mechanism are presented in detail. The device has been tested in a Zeiss Merlin GEMINI II scanning electron microscope with Li 3 PS 4 samples, showing effective isolation from air and corrosion prevention.

  18. Immobilisation of southern elephant seals and leopard seals with cyclohexamine anaesthetics and xylazine.

    Science.gov (United States)

    Mitchell, P J; Burton, H R

    1991-10-12

    Ketamine and xylazine were given to 55 southern elephant seals (Mirounga leonina) for stomach lavaging, and to three leopard seals (Hydrurga leptonyx). The elephant seals showed prolonged apnoea and two of them died owing to aspiration of stomach contents. Two of the leopard seals died from unknown causes. Tiletamine and zolazepam were given to five elephant seals and one leopard seal. Two of the elephant seals and the leopard seal died from unknown causes. Xylazine alone was administered to 34 leopard seals. Sedation was poor at low dose rates (less than 1.7 mg/kg) but four of the seals given higher dose rates died owing to the aspiration of stomach contents.

  19. Influence of dental materials used for sealing caries lesions on laser fluorescence measurements.

    Science.gov (United States)

    Celiberti, Paula; Carvalho, Thiago S; Raggio, Daniela P; Mendes, Fausto M

    2012-03-01

    The aim of this study was to determine the influence of thickness and aging on the intrinsic fluorescence of sealing materials and their ability to block fluorescence from the underlying surface as assessed using a laser fluorescence device. Cavities of 0.5 mm and 1 mm depth were drilled into acrylic boards which were placed over two surfaces with different fluorescence properties: a low-fluorescence surface, to assess the intrinsic fluorescence of the sealing materials, and a high-fluorescence surface, to assess the fluorescence-blocking ability of the sealing materials. Ten cavities of each depth were filled with different sealing materials: Adper Scotchbond Multi-Purpose, Adper Single Bond 2, FluroShield, Conseal f and UltraSeal XT Plus. Fluorescence was measured with a DIAGNOdent pen at five different time points: empty cavity, after polymerization, and 1 day, 1 week and 1 month after filling. The individual values after polymerization, as well as the area under the curve for the different periods were submitted to ANOVA and the Tukey test (p caries by laser fluorescence.

  20. Turbine Seal Research at NASA GRC

    Science.gov (United States)

    Proctor, Margaret P.; Steinetz, Bruce M.; Delgado, Irebert R.; Hendricks, Robert C.

    2011-01-01

    Low-leakage, long-life turbomachinery seals are important to both Space and Aeronautics Missions. (1) Increased payload capability (2) Decreased specific fuel consumption and emissions (3) Decreased direct operating costs. NASA GRC has a history of significant accomplishments and collaboration with industry and academia in seals research. NASA's unique, state-of-the-art High Temperature, High Speed Turbine Seal Test Facility is an asset to the U.S. Engine / Seal Community. Current focus is on developing experimentally validated compliant, non-contacting, high temperature seal designs, analysis, and design methodologies to enable commercialization.

  1. Energy conversion device with improved seal

    Science.gov (United States)

    Miller, Gerald R.; Virkar, Anil V.

    1980-01-01

    An energy conversion device comprising an improved sealing member adapted to seal a cation-permeable casing to the remainder of the device. The sealing member comprises a metal substrate which (i) bears a nonconductive and corrosion resistant coating on the major surface to which said casing is sealed, and (ii) is corrugated so as to render it flexible, thereby allowing said member to move relative to said casing without cracking the seal therebetween. Corrugations may be circumferential, radial, or both radial and circumferential so as to form dimples. The corrugated member may be in form of a bellows or in a substantially flat form, such as a disc.

  2. The efficiency of night insulation using aerogel-filled polycarbonate panels during the heating season

    Science.gov (United States)

    Adelsberger, Kathleen

    Energy is the basis for modern life. All modern technology from a simple coffee maker to massive industrial facilities is powered by energy. While the demand for energy is increasing, our planet is suffering from the consequences of using fossil fuels to generate electricity. Therefore, the world is looking at clean energy and solar power to minimize this effect on our environment. However, saving energy is extremely important even for clean energy. The more we save the less we have to generate. Heat retention in buildings is one step towards achieving passive heating. Therefore, efforts are made to prevent heat from escaping buildings through the glass during cold nights. Movable insulation is a way to increase the insulation value of the glass to reduce heat loss towards the outdoor. This thesis examines the performance of the aerogel-filled polycarbonate movable panels in the Ecohawks building, a building located on the west campus of The University of Kansas. Onsite tests were performed using air and surface temperature sensors to determine the effectiveness of the system. Computer simulations were run by Therm 7.2 simulation software to explore alternative design options. A cost analysis was also performed to evaluate the feasibility of utilizing movable insulation to reduce the heating bills during winter. Results showed that sealed movable insulation reduces heat loss through the glazing by 67.5%. Replacing aerogel with XPS panels reduces this percentage to 64.3%. However, it reduces the cost of the insulation material by 98%.

  3. Intermittent Surface Water Connectivity: Fill and Spill vs. Fill ...

    Science.gov (United States)

    Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining difference in responses was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes. Under the Safe and Sustainable Water Resources National Program, work is being done to qu

  4. 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.

  5. Is a drill-less dental filling possible?

    Science.gov (United States)

    Quock, Ryan L; Patel, Shalizeh A; Falcao, Felipe A; Barros, Juliana A

    2011-09-01

    Dental caries, a bacterial process that results in the acidic destruction of tooth structure, has historically been managed by the mechanical excavation of diseased tooth structure and then restoration with a synthetic material. The mechanical excavation of the infected site is most commonly achieved by a dental handpiece, or "drill"; this handpiece may induce stress and anxiety in many patients. Alternatively, a drill-less filling will involve the utilization of silver diamine fluoride (38%) to arrest and prevent dental caries, followed by restoration with a bonded filling material to achieve adequate seal at the lesion margins. This is a minimally invasive procedure that addresses both microbial and mechanical issues posed by dental caries. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Coronal and apical sealing ability of a new endodontic cement

    Science.gov (United States)

    Zafar, Morvarid; Iravani, Maryam; Eghbal, Mohammad Jafar; Asgary, Saeed

    2009-01-01

    INTRODUCTION: This in vitro study aims to evaluate the coronal and apical sealing ability of gutta-percha (GP) root filling used with either mineral trioxide aggregate (MTA), new endodontic cement (NEC) or AH26 as filler/sealers. MATERIALS AND METHODS: Forty eight single-rooted extracted teeth were selected, decoronated and then instrumented. Samples were randomly divided into three experimental (n=12) and two control groups (n=6). In group 1, root canals were filled using lateral condensation technique (L); while single cone technique (S) was used for groups 2 and 3. AH26, MTA and NEC were the root canal sealer/fillers in groups 1, 2 and 3, respectively. Samples were immersed in 1% methylene-blue dye and then independently centrifuged apically and coronally. The roots were split longitudinally and linear extent of dye penetration was measured with a stereomicroscope from apical and coronal directions. Data were analyzed using One-way ANOVA and T-test. RESULTS: No statistical differences in mean apical dye penetration between groups LGP/AH26, SGP/MTA and SGP/NEC were found; SGP/NEC group showed significantly less coronal dye penetration (P<0.001). CONCLUSION: Considering the limitations of this in vitro study, it was concluded that the simple single cone technique with NEC can provide favorable coronal and apical seal. PMID:23864871

  7. A comparison of the sealing ability of various temporary restorative materials to seal the access cavity: Anin vitrostudy.

    Science.gov (United States)

    Markose, Aji; Krishnan, Ramesh; Ramesh, Maya; Singh, Shishir

    2016-10-01

    In multiple-appointment root canal treatment, a temporary filling material is used to seal the access cavity between visits. The primary function of this material is to prevent the contamination of the root canal system by fluids, organic debris, and bacteria from the oral cavity. A total of fifty extracted noncarious unrestored human maxillaryanterior teeth with intact crowns and roots were selected The canals were instrumented using stepback technique and sodium hypochlorite (3%) and hydrogen peroxide (3%) were used as irrigants for each specimen alternatively. The coronal two-thirds of each canal were flared using Gates-Glidden drills up to no. 3 size and obturated with Gutta-percha using zinc oxide-eugenol (ZnOE) as sealer. The teeth were then randomly selected and divided into six groups out of which four were experimental groups and two control groups. The teeth were then immersed in 2% methylene blue dye solution for 3 days. All sealing materials and Gutta-percha were gently removed from the walls of the canal, and the entire circumference of the canal wall examined for dye penetration. The lowest mean leakage was in the Fermit-N group followed by Cavit-W, ZnOE, intermediate restorative materials (IRM), and positive control. Fermit-N showed better sealing ability compared to cavit, ZnOE and IRM.

  8. A comparison of the sealing ability of various temporary restorative materials to seal the access cavity: An in vitro study

    Directory of Open Access Journals (Sweden)

    Aji Markose

    2016-01-01

    Full Text Available Introduction: In multiple-appointment root canal treatment, a temporary filling material is used to seal the access cavity between visits. The primary function of this material is to prevent the contamination of the root canal system by fluids, organic debris, and bacteria from the oral cavity. Material and Methods: A total of fifty extracted noncarious unrestored human maxillaryanterior teeth with intact crowns and roots were selected The canals were instrumented using stepback technique and sodium hypochlorite (3% and hydrogen peroxide (3% were used as irrigants for each specimen alternatively. The coronal two-thirds of each canal were flared using Gates-Glidden drills up to no. 3 size and obturated with Gutta-percha using zinc oxide-eugenol (ZnOE as sealer. The teeth were then randomly selected and divided into six groups out of which four were experimental groups and two control groups. The teeth were then immersed in 2% methylene blue dye solution for 3 days. All sealing materials and Gutta-percha were gently removed from the walls of the canal, and the entire circumference of the canal wall examined for dye penetration. Results: The lowest mean leakage was in the Fermit-N group followed by Cavit-W, ZnOE, intermediate restorative materials (IRM, and positive control. Conclusion: Fermit-N showed better sealing ability compared to cavit, ZnOE and IRM.

  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. 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.

  11. Ampoule sealing apparatus and process

    Science.gov (United States)

    Debnam, Jr., William J. (Inventor); Clark, Ivan O. (Inventor)

    1988-01-01

    An apparatus 10 for effecting sealing of a fused quartz ampoule 24 while maintaining a vacuum on the ampoule via system 12 is disclosed. A plug 28 of fused quartz is lowered into the vertically disposed ampoule 24 (while maintaining the vacuum thereon) and heat sealed therein to prevent any vapor escape from, or contamination of, the contained semiconductor growth charge 29 during subsequent semiconductor crystal growth processes. A rotary vacuum feed-through mechanism 16 selectively rotates axle 34 and spool 32 to unwind wire 30 for lowering of plug 28 into the reduced diameter portion 24b of ampoule 24. Ampoule 24 is hermatically connected to vacuum housing 18 by quick release flange 20 wherein O-ring 22 retains ampoule 24.

  12. Hermetically Sealed Aluminum Electrolytic Capacitor

    Science.gov (United States)

    Alwitt, Robert S.; Liu, Yanming; Elias, William

    1996-01-01

    Aluminum electrolytic capacitors are presently not allowed on NASA missions because they outgas water and organic vapors, as well as H2. As a consequence, for some applications, much larger and heavier packages of tantalum capacitors must be used. A hermetically sealed aluminum capacitor has been developed. This contains a nongassing electrolyte that was developed for this application so internal pressure would remain low. Capacitors rated from 250 V to 540 V have been operated under full load for thousands of hours at 85 and 105 C with good electrical performance and absence of gas generation. Electrolyte chemistry and seal engineering will be discussed, as well as the extension of this design concept to lower voltage ratings.

  13. Comparison of Adhesion and Retention Forces for Two Candidate Docking Seal Elastomers

    Science.gov (United States)

    Hartzler, Brad D.; Panickar, Marta B.; Wasowski, Janice L.; Daniels, Christopher C.

    2011-01-01

    To successfully mate two pressurized vehicles or structures in space, advanced seals are required at the interface to prevent the loss of breathable air to the vacuum of space. A critical part of the development testing of candidate seal designs was a verification of the integrity of the retaining mechanism that holds the silicone seal component to the structure. Failure to retain the elastomer seal during flight could liberate seal material in the event of high adhesive loads during undocking. This work presents an investigation of the force required to separate the elastomer from its metal counter-face surface during simulated undocking as well as a comparison to that force which was necessary to destructively remove the elastomer from its retaining device. Two silicone elastomers, Wacker 007-49524 and Esterline ELASA-401, were evaluated. During the course of the investigation, modifications were made to the retaining devices to determine if the modifications improved the force needed to destructively remove the seal. The tests were completed at the expected operating temperatures of -50, +23, and +75 C. Under the conditions investigated, the comparison indicated that the adhesion between the elastomer and the metal counter-face was significantly less than the force needed to forcibly remove the elastomer seal from its retainer, and no failure would be expected.

  14. Seal for fluid forming tools

    Science.gov (United States)

    Golovashchenko, Sergey Fedorovich [Beverly Hills, MI; Bonnen, John Joseph Francis [Milford, MI

    2012-03-20

    An electro-hydraulic forming tool for forming a sheet metal blank in a one-sided die has first and second rigid rings that engage opposite sides of a sheet metal blank. The rigid rings are contained within slots on a die portion and a hydraulic force applicator portion of the forming tool. The seals are either resiliently biased by an elastomeric member or inherently resiliently biased into contact with the blank.

  15. Seals, Concrete Anchors, and Connections

    Science.gov (United States)

    1989-02-01

    coupling rigid mounted blast doors to shock iso - lated specialty doors (RFI, gas sealed, fire rated, etc.), providing portals between two rigid...26- 38500 27- 38500 3/8 x 5 50 3421 3/8 x 2-5/8 ." 1 26-12234 27-12234 112 X 2.3/4 50 3422 3/8 x 3 b0 26-12400 27-12400 1/2 X 4 50 3423 318 x 4 50

  16. Globally sourced mineral commodities used in U.S. Navy SEAL gear—An illustration of U.S. net import reliance

    Science.gov (United States)

    Brainard, Jamie; Nassar, Nedal T.; Gambogi, Joseph; Baker, Michael S.; Jarvis, Michael T.

    2018-01-25

    A U.S. Navy SEAL (an acronym for sea, air, land) carries gear containing at least 23 nonfuel mineral commodities for which the United States is greater than 50 percent net import reliant. The graphics display the leading world producers of selected nonfuel mineral commodities used to manufacture U.S. Navy SEAL gear. SEALs are members of the U.S. Navy's special operations forces.

  17. Service life estimation of liquid silicone rubber seals in polymer electrolyte membrane fuel cell environment

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Tong; Van Zee, J.W. [Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Lin, C.-W. [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University (China); Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Chien, C.H. [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University (China); Chao, Y.J. [Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States)

    2011-02-01

    Polymer electrolyte membrane fuel cell (PEMFC) is a promising power source for many applications such as automobiles. Sealing around the perimeter of the cell is required to prevent the gases/liquids inside the cell from leaking and polymers are usually used for the seal or gasket materials. They in general possess the viscoelastic property which induces stress relaxation of the material under constant strain. The stress relaxation behavior of liquid silicone rubber, a type of polymer used as seals in PEMFCs, is studied in this work. A Prony series is used to predict the compression stress relaxation curve at different strain levels. Applying the time-temperature superposition, master curves are generated and used for predicting the service life of this material as seals in PEMFCs. The estimated lives in water and in air are compared. (author)

  18. Service life estimation of liquid silicone rubber seals in polymer electrolyte membrane fuel cell environment

    Science.gov (United States)

    Cui, Tong; Lin, C.-W.; Chien, C. H.; Chao, Y. J.; Van Zee, J. W.

    Polymer electrolyte membrane fuel cell (PEMFC) is a promising power source for many applications such as automobiles. Sealing around the perimeter of the cell is required to prevent the gases/liquids inside the cell from leaking and polymers are usually used for the seal or gasket materials. They in general possess the viscoelastic property which induces stress relaxation of the material under constant strain. The stress relaxation behavior of liquid silicone rubber, a type of polymer used as seals in PEMFCs, is studied in this work. A Prony series is used to predict the compression stress relaxation curve at different strain levels. Applying the time-temperature superposition, master curves are generated and used for predicting the service life of this material as seals in PEMFCs. The estimated lives in water and in air are compared.

  19. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  20. High temperature dynamic engine seal technology development

    Science.gov (United States)

    Steinetz, Bruce M.; Dellacorte, Christopher; Machinchick, Michael; Mutharasan, Rajakkannu; Du, Guang-Wu; Ko, Frank; Sirocky, Paul J.; Miller, Jeffrey H.

    1992-01-01

    Combined cycle ramjet/scramjet engines being designed for advanced hypersonic vehicles, including the National Aerospace Plane (NASP), require innovative high temperature dynamic seals to seal the sliding interfaces of the articulated engine panels. New seals are required that will operate hot (1200 to 2000 F), seal pressures ranging from 0 to 100 psi, remain flexible to accommodate significant sidewall distortions, and resist abrasion over the engine's operational life. This report reviews the recent high temperature durability screening assessments of a new braided rope seal concept, braided of emerging high temperature materials, that shows promise of meeting many of the seal demands of hypersonic engines. The paper presents durability data for: (1) the fundamental seal building blocks, a range of candidate ceramic fiber tows; and for (2) braided rope seal subelements scrubbed under engine simulated sliding, temperature, and preload conditions. Seal material/architecture attributes and limitations are identified through the investigations performed. The paper summarizes the current seal technology development status and presents areas in which future work will be performed.

  1. Vacuum filling of complex microchannels with liquid metal.

    Science.gov (United States)

    Lin, Yiliang; Gordon, Olivia; Khan, M Rashed; Vasquez, Neyanel; Genzer, Jan; Dickey, Michael D

    2017-09-12

    This paper describes the utilization of vacuum to fill complex microchannels with liquid metal. Microchannels filled with liquid metal are useful as conductors for soft and stretchable electronics, as well as for microfluidic components such as electrodes, antennas, pumps, or heaters. Liquid metals are often injected manually into the inlet of a microchannel using a syringe. Injection can only occur if displaced air in the channels has a pathway to escape, which is usually accomplished using outlets. The positive pressure (relative to atmosphere) needed to inject fluids can also cause leaks or delamination of the channels during injection. Here we show a simple and hands-free method to fill microchannels with liquid metal that addresses these issues. The process begins by covering a single inlet with liquid metal. Placing the entire structure in a vacuum chamber removes the air from the channels and the surrounding elastomer. Restoring atmospheric pressure in the chamber creates a positive pressure differential that pushes the metal into the channels. Experiments and a simple model of the filling process both suggest that the elastomeric channel walls absorb residual air displaced by the metal as it fills the channels. Thus, the metal can fill dead-ends with features as small as several microns and branched structures within seconds without the need for any outlets. The method can also fill completely serpentine microchannels up to a few meters in length. The ability to fill dense and complex geometries with liquid metal in this manner may enable broader application of liquid metals in electronic and microfluidic applications.

  2. The effect of Er,Cr:YSGG laser irradiation on the push-out bond strength of RealSeal self-etch sealer.

    Science.gov (United States)

    Ehsani, Sara; Bolhari, Behnam; Etemadi, Ardavan; Ghorbanzadeh, Abdollah; Sabet, Yazdan; Nosrat, Ali

    2013-12-01

    The aim of this study was to evaluate the effect of an erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on the push-out bond strength of RealSeal Self-Etch (SE) sealer. Various methods are used for smear layer removal in endodontics, such as the application of Er,Cr:YSGG lasers. This laser system may influence the bond strength of resin-based sealers. Sixty single-rooted extracted teeth were selected. After root canal preparation, samples were divided into two experimental groups and one positive control group (n=20 per group). In group 1, the smear layer was removed by irrigation with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl). In group 2, the smear layer was removed using a 2.78 μm Er,Cr:YSGG laser with radial firing tips (RFT3) (parameters: 1.5 W, 140 μs, 20 Hz, and 15% water to 15% air ratio), moving at 2 mm/sec in an apico-coronal direction. Group 3 served as a positive control group. Five specimens from each group were selected for scanning electron microscope (SEM) observation. The remaining 45 roots were obturated with RealSeal SE/Resilon and subjected to push-out tests. Data were analyzed using one way analysis of variance (ANOVA) and Tamhane's test. The results showed no significant difference between push-out bond strength of root canal fillings in the EDTA+NaOCl group and the 1.5 W laser group (p>0.05). The positive control group showed the lowest push-out bond strength. The results of the present study indicate that the application of an Er,Cr:YSGG laser with radial firing tips did not adversely affect the push-out bond strength of RealSeal SE sealer to dentin.

  3. 24 CFR 3280.505 - Air infiltration.

    Science.gov (United States)

    2010-04-01

    ... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.505 Air infiltration...-to-ceiling and wall-to-floor connections shall be caulked or otherwise sealed. When walls are...

  4. Apical root-end filling with tricalcium silicate-based cement in a patient with diabetes mellitus: A case report

    OpenAIRE

    Biočanin Vladimir; Milić Marija; Vučetić Milan; Baćević Miljana; Vasović Dina; Živadinović Milka; Ćetković Dejan; Ćalasan Dejan; Brković Božidar

    2016-01-01

    Introduction. The material used for root-end filling has to be biocompatible with adjacent periapical tissue and to stimulate its regenerative processes. Tricalcium silicate cement (TSC), as a new dental material, shows good sealing properties with dentin, high compression strengths and better marginal adaptation than commonly used root-end filling materials. Although optimal postoperative healing of periapical tissues is mainly influenced by characteristics of end-root material used, it coul...

  5. 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.

  6. Hypersonic engine seal development at NASA Lewis Research Center

    Science.gov (United States)

    Steinetz, Bruce M.

    1994-01-01

    NASA Lewis Research Center is developing advanced seal concepts and sealing technology for advanced combined cycle ramjet/scramjet engines being designed for the National Aerospace Plane (NASP). Technologies are being developed for both the dynamic seals that seal the sliding interfaces between articulating engine panels and sidewalls, and for the static seals that seal the heat exchanger to back-up structure interfaces. This viewgraph presentation provides an overview of the candidate engine seal concepts, seal material assessments, and unique test facilities used to assess the leakage and thermal performance of the seal concepts.

  7. Surgical endodontic therapy: retrofilling of apex with amalgam and SuperSeal. Retrospective study.

    Science.gov (United States)

    Pljevljak, N; Minasi, R; Brauner, E; Galli, M

    2011-06-01

    The aim of this study was to make a retrospective analysis on teeth with apicectomized roots, closed off by retrograde with amalgam and SuperSeal-Ogna® (cement oxide of zinc and eugenol modified by acidity ethoxy-benzoic acid), in order to achieve clinical evaluation and radiographic evidence of treated dental elements and surrounding tissue SuperSeal (Ogna®). The study was conducted on 420 teeth, single and multi rooted, pertaining to 366 patients (189 women and 177 men) endodontically treated, in between 1998 and 2007. The teeth were treated with endodontic technique step-back and closed off with gutta-percha. Following the roots were apicectomyzed and then was prepared a retrograde cavity using retrotip steel mounted on the ultrasonic device. After carrying out the retrograde cavity all the samples were divided into two groups . The retrograde filling in Group A was made in Superseal, group B with amalgama. Both groups were divided in those teeths who was treated with use of optical microscope and in groups of teeths preformed without microscope. Nevertheless amalgam against the SuperSeal offers almost the same quality of the seal and the same prognosis. However SuperSeal as a material of choice, proved excellent, for carrying out the retrograde fillings free of some side effects, such as dimensional instability, mercury poisoning and pigmentation of tissues (tattoos from amalgam). In any case, whatever the type of material is, the operative microscope significantly affects the occurrence of failure. This demonstrates the importance of the microscope in order to obtain greater visibility and accuracy of the apex seal, more than minor sacrifice of healthy tissue.

  8. 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).

  9. 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.

  10. Mars containers - Dust on teflon sealing surfaces

    Science.gov (United States)

    Lauer, H. V., Jr.; Allton, J. H.

    As part of an evaluation of suitable hermetic seals for containers for Martian rock and soil samples, teflon o-ring static face seals were challenged with silica gel, basalt, and bentonite dust in several size ranges: 20-45 microns, 45-75 microns, and 75-125 microns. Seals were most tolerant of the soft bentonite dust and least tolerant of angular silica gel dust. Small amounts of 75-125 micron size particles can be accommodated by the teflon o-ring; however, the seals do not work well if smaller particles are concentrated enough to form layers more than 1 grain thick.

  11. 28 CFR 803.3 - Use of the seal.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Use of the seal. 803.3 Section 803.3... SEAL § 803.3 Use of the seal. (a) The Agency seal is used by Agency staff for official agency business as approved by the appropriate Director or designee. (b) Use of the Agency seal by any person or...

  12. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  13. Well sealing via thermite reactions

    Science.gov (United States)

    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. Surface Seal for Carbon Parts

    Science.gov (United States)

    Shuford, D. M.; Spruiell, J. P.

    1982-01-01

    Surface pores in parts made of graphite or reinforced-carbon/ carbon materials are sealed by a silicon carbide-based coating. Coating inhibits subsurface oxidation and lengthens part life. Starting material for coating is graphite felt, which is converted to silicon carbide felt by processing it according to a prescribed time/temperature schedule. Converted felt is pulverized in a ball mill and resulting powder is mixed with an equal weight of black silicon carbide powder. Powder mixture is combined with an equal weight of adhesive to form a paste.

  16. Tangit-system to seal wall penetrations; Tangit-System zur Abdichtung von Wanddurchfuehrungen. Neuverlegung und Instandsetzung

    Energy Technology Data Exchange (ETDEWEB)

    Wack, H. [Fraunhofer-Institut fuer Umwelt-, Sicherheits- und Energietechnik UMSICHT, Oberhausen (Germany)

    2003-06-01

    To connect a house to the municipal gas, water, electricity and heat supply, openings in the outside wall of a building are required to connect the corresponding pipes to the building. These connection lines in the openings of the brickwork must be positioned and sealed for later use in the building. The Tangit-System (Tangit Sealing Hose M 4082 and Tangit Expansion Resin M 3000) guarantees a permanent seal. The sealing hose consists of a flexible water-impervious outer casing that is filled with expandable polymer granules. If water comes into contact with the sealing hose in the event of a leak, the polymer granules expand and instantly seal the leak through their inherent volume expansion properties. When installing the house service connections the sealing hose is initially wrapped around the exterior of the service line. The house service connections are subsequently taken through the opening in the brickwork and positioned using Tangit Expansion Resin M 3000. The Tangit-System can be used in the field of new installation and repair. In the field of district heating first projects have been started in the beginning of 2003. First results are expected at the end of 2003. (orig.) [German] Fuer das Abdichten und Befestigen von Versorgungsleitungen bei der Wanddurchfuehrung wie sie fuer den Hausanschluss von Wasser, Gas, Strom, Telekommunikation oder Waermeversorgung benoetigt werden, existiert ein Abdichtungssystem, das sowohl bei der Instandsetzung von undicht gewordenen Anschluessen als auch bei der Neuverlegung angewendet werden kann. Der Autor beschreibt Funktionsweise und Einsatzmoeglichkeiten. (orig.)

  17. 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.

  18. 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

  19. The five year report of the Tunnel Sealing Experiment: an international project of AECL, JNC, ANDRA and WIPP

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, N.A.; Cournut, A.; Dixon, D. (and others)

    2002-07-01

    The Tunnel Sealing Experiment (TSX) was conducted to address construction and performance issues of full-scale seals for potential application to deep geological repositories for radioactive waste. The TSX was performed by an international partnership representing Japan, France, the United States and Canada. The experiment was installed at the 420-m depth of Atomic Energy of Canada Limited's Underground Research Laboratory in the granite rock of the Precambrian Canadian Shield. The experiment involved the construction of two full-scale tunnel seals at either end of a single excavation. One seal was an assembly of pre-compacted sand-bentonite blocks and the second seal was a single cast of Low-Heat High-Performance concrete. The objective of the TSX was to assess the applicability of technologies for construction of practicable concrete and bentonite bulkheads; to evaluate the performance of each bulkhead; and to identify and document the parameters that affect that performance. This report documents the construction and operation of the experiment over its first five years. During this period, the experiment was designed, tunnels were excavated, and the seals were constructed. The sand-filled region between the two bulkhead seals was filled and pressurized with water to 800 and 2000 kPa. A tracer test was conducted at a tunnel pressure of 800 kPa to assess the solute transport characteristics of full-scale tunnel seals. The most important outcome from the TSX is that functional full-scale repository seals can be constructed using currently available technology. Factors identified as potentially affecting seal performance included: excavation method and minimizing the excavation damaged zone (EDZ); keying bulkheads into the rock to interrupt the EDZ; compacted sand-bentonite placement method; treatment of clay bulkhead-rock interface; rate of clay saturation compared with the rate of water pressurization; clay bulkhead volume expansion; the resealing properties

  20. 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.

  1. 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.

  2. Crown sealing and buckling instability during water entry of spheres

    KAUST Repository

    Marston, J. O.

    2016-04-05

    We present new observations from an experimental investigation of the classical problem of the crown splash and sealing phenomena observed during the impact of spheres onto quiescent liquid pools. In the experiments, a 6 m tall vacuum chamber was used to provide the required ambient conditions from atmospheric pressure down to of an atmosphere, whilst high-speed videography was exploited to focus primarily on the above-surface crown formation and ensuing dynamics, paying particular attention to the moments just prior to the surface seal. In doing so, we have observed a buckling-type azimuthal instability of the crown. This instability is characterised by vertical striations along the crown, between which thin films form that are more susceptible to the air flow and thus are drawn into the closing cavity, where they atomize to form a fine spray within the cavity. To elucidate to the primary mechanisms and forces at play, we varied the sphere diameter, liquid properties and ambient pressure. Furthermore, a comparison between the entry of room-temperature spheres, where the contact line pins around the equator, and Leidenfrost spheres (i.e. an immersed superheated sphere encompassed by a vapour layer), where there is no contact line, indicates that the buckling instability appears in all crown sealing events, but is intensified by the presence of a pinned contact line. © 2016 Cambridge University Press.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zoeller, William [National Renewable Energy Lab. (NREL), Golden, CO (United States); Williamson, James [National Renewable Energy Lab. (NREL), Golden, CO (United States); Puttafunta, Srikanth [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-07-30

    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

  4. 19 CFR 122.188 - Issuance of temporary Customs access seal.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Issuance of temporary Customs access seal. 122.188 Section 122.188 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Access to Customs Security Areas § 122.188 Issuance of...

  5. Rodent Control: Seal Up! Trap Up! Clean Up!

    Science.gov (United States)

    ... successfully trapping rodents in and around the home. Seal Up! Seal up holes inside and outside the home to ... infested areas. Before cleaning, trap the rodents and seal up any entryways to ensure that no rodents ...

  6. Performance oriented guidance for Mississippi chip seals - volume I.

    Science.gov (United States)

    2013-12-01

    A five year laboratory study was conducted to investigate near surface properties of flexible pavements in relation to : how they are affected by bituminous surface treatments. Chip seals and scrub seals (a specialized type of chip seal) : were the f...

  7. AN IN VITRO ASSESSMENT OF CORONAL MICROLEAKAGE IN ROOT-FILLED TEETH

    Directory of Open Access Journals (Sweden)

    Sînziana Adina SCĂRLĂTESCU

    2013-03-01

    Full Text Available Aim. To evaluate the marginal seal of temporary restorations in endodontically-treated teeth by comparing three restorative materials and two techniques of root canal filling. Materials and method. Canal shaping was completed on 72 single-root teeth using a ProTaper system and root filling by lateral or vertical condensation. 8 teeth have been positively or negatively controlled. Citodur, glass ionomer or zinc oxide eugenol were inserted into the access cavity. All teeth were immersed for 9 days in India ink, then cleared and evaluated for dye penetration. Results. All groups of temporary restorations showed no significantly different marginal dye penetration. The glass ionomer cement presented the highest penetration. Conclusions. The restorative materials used could not stop dye penetration in the access cavity. They are not reliable for avoiding microleakage in root-filled teeth in case of long-term fillings.

  8. Damping device for a stationary labyrinth seal

    Science.gov (United States)

    El-Aini, Yehia M. (Inventor); Mitchell, William S. (Inventor); Roberts, Lawrence P. (Inventor); Montgomery, Stuart K. (Inventor); Davis, Gary A. (Inventor)

    2010-01-01

    A stationary labyrinth seal system includes a seal housing having an annular cavity, a plurality of damping devices, and a retaining ring. The damping devices are positioned within the annular cavity and are maintained within the annular cavity by the retaining ring.

  9. 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...... the absence of toxic effects of cadmium in ringed seal...

  10. 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.

  11. Sealing Occlusal Dentin Caries in Permanent Molars

    DEFF Research Database (Denmark)

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

    2017-01-01

    The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical and radiog......The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical...... longevity of sealings and restorations until retreatments, and 3) compare effectiveness of sealings and restorations to halt caries progression in sealed lesions and beneath restorations. Furthermore, we aimed to identify factors influencing longevity and the effectiveness of sealings and restorations.......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...

  12. Performance evaluation of chip seals in Idaho.

    Science.gov (United States)

    2010-08-01

    The intent of this research project is to identify a wide variety of parameters that influence the performance of pavements treated via chip seals within the State of Idaho. Chip sealing is currently one of the most popular methods of maintenance for...

  13. Population structure of ice-breeding seals.

    Science.gov (United States)

    Davis, Corey S; Stirling, Ian; Strobeck, Curtis; Coltman, David W

    2008-07-01

    The development of population genetic structure in ice-breeding seal species is likely to be shaped by a combination of breeding habitat and life-history characteristics. Species that return to breed on predictable fast-ice locations are more likely to exhibit natal fidelity than pack-ice-breeding species, which in turn facilitates the development of genetic differentiation between subpopulations. Other aspects of life history such as geographically distinct vocalizations, female gregariousness, and the potential for polygynous breeding may also facilitate population structure. Based on these factors, we predicted that fast-ice-breeding seal species (the Weddell and ringed seal) would show elevated genetic differentiation compared to pack-ice-breeding species (the leopard, Ross, crabeater and bearded seals). We tested this prediction using microsatellite analysis to examine population structure of these six ice-breeding species. Our results did not support this prediction. While none of the Antarctic pack-ice species showed statistically significant population structure, the bearded seal of the Arctic pack ice showed strong differentiation between subpopulations. Again in contrast, the fast-ice-breeding Weddell seal of the Antarctic showed clear evidence for genetic differentiation while the ringed seal, breeding in similar habitat in the Arctic, did not. These results suggest that the development of population structure in ice-breeding phocid seals is a more complex outcome of the interplay of phylogenetic and ecological factors than can be predicted on the basis of breeding substrate and life-history characteristics.

  14. 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,

  15. 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 Department...

  16. Temperature and Atomic Oxygen Effects on Helium Leak Rates of a Candidate Main Interface Seal

    Science.gov (United States)

    Penney, Nicholas; Wasowski, Janice L.; Daniels, Christopher C.

    2011-01-01

    Helium leak tests were completed to characterize the leak rate of a 54 in. diameter composite space docking seal design in support of the National Aeronautics and Space Administration s (NASA's) Low Impact Docking System (LIDS). The evaluated seal design was a candidate for the main interface seal on the LIDS, which would be compressed between two vehicles, while docked, to prevent the escape of breathable air from the vehicles and into the vacuum of space. Leak tests completed at nominal temperatures of -30, 20, and 50 C on untreated and atomic oxygen (AO) exposed test samples were examined to determine the influence of both test temperature and AO exposure on the performance of the composite seal assembly. Results obtained for untreated seal samples showed leak rates which increased with increased test temperature. This general trend was not observed in tests of the AO exposed specimens. Initial examination of collected test data suggested that AO exposure resulted in higher helium leak rates, however, further analysis showed that the differences observed in the 20 and 50 C tests between the untreated and AO exposed samples were within the experimental error of the test method. Lack of discernable trends in the test data prevented concrete conclusions about the effects of test temperature and AO exposure on helium leak rates of the candidate seal design from being drawn. To facilitate a comparison of the current test data with results from previous leak tests using air as the test fluid, helium leak rates were converted to air leak rates using standard conversion factors for viscous and molecular flow. Flow rates calculated using the viscous flow conversion factor were significantly higher than the experimental air leakage values, whereas values calculated using the molecular flow conversion factor were significantly lower than the experimentally obtained air leak rates. The difference in these sets of converted flow rates and their deviation from the

  17. Techniques of preoxygenation in patients with ineffective face mask seal

    Directory of Open Access Journals (Sweden)

    Pankaj Kundra

    2013-01-01

    Full Text Available Background: Ineffective face mask seal is the most common cause for suboptimal pre-oxygenation. Room air entrainment can be more with vital capacity (VC breaths when the mask is not a tight fit. Aims: This study was designed to compare 5 min tidal volume (TV breathing and eight VC breaths in patients with ineffective face mask seal. Methods: Twenty eight ASA I adults with ineffective face mask seal were randomized to breathe 100% oxygen at normal TV for 5 min (Group TV and eight VC breaths (Group VC in a cross over manner through circle system at 10 L/min. End tidal oxygen concentration (EtO 2 and arterial blood gas analysis was performed to evaluate oxygenation with each technique. Statistical Analysis: Data were analysed using SPSS statistical software, version 16. Friedman′s two-way analysis of variance by ranks was used for non-parametric data. Results: Significant increase in EtO 2 (median 90 and PaO 2 (228.85 was seen in group TV when compared to group VC (EtO 2 median 85, PaO 2 147.65, P<0.05. Mean total ventilation volume in 1 min in group VC was 9.4±3.3 L/min and more than fresh gas flow (10 L/min in seven patients. In group TV, the fresh gas flow (50 L/5 min was sufficient at normal TV (mean total ventilation in 5 min 36.7±6.3 L/min. Conclusions: TV breathing for 5 min provides better pre-oxygenation in patients with ineffective mask seal with fresh gas flow of 10 L/min delivered through a circle system.

  18. Dynamic Moisture Sorption and Desorption in Fumed Silica-filled Silicone Foam

    Energy Technology Data Exchange (ETDEWEB)

    Trautschold, Olivia Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-02

    Characterizing dynamic moisture sorption and desorption in fumed silica-filled silicone foam is necessary for determining material compatibilities and life predictions, particularly in sealed environments that may be exposed to a range of environmental conditions. Thermogravimetric analysis (TGA) and near infrared spectroscopy (NIR) were performed on S5470 fumed silica-filled silicone foam to determine the weight percent of moisture at saturation. Additionally, TGA was used to determine the time, temperature, and relative humidity levels required for sorption and desorption of physisorbed moisture in S5470.

  19. Seroprevalence of Antibodies against Seal Influenza A(H10N7) Virus in Harbor Seals and Gray Seals from the Netherlands

    NARCIS (Netherlands)

    R. Bodewes (Rogier); A.R. García (Ana Rubio); S.M. Brasseur (Sophie M.); G.J.S. Conteras (Guillermo J. Sanchez); M.W.G. van de Bildt (Marco); M.P.G. Koopmans D.V.M. (Marion); A.D.M.E. Osterhaus (Albert); T. Kuiken (Thijs)

    2015-01-01

    textabstractIn the spring and summer 2014, an outbreak of seal influenza A(H10N7) virus infection occurred among harbor seals (Phoca vitulina) off the coasts of Sweden and Denmark. This virus subsequently spread to harbor seals off the coasts of Germany and the Netherlands. While thousands of seals

  20. Seroprevalence of Antibodies against Seal Influenza A(H10N7) Virus in Harbor Seals and Gray Seals from the Netherlands

    NARCIS (Netherlands)

    Bodewes, Rogier; Garcia, Ana Rubio; Brasseur, Sophie M.; Conteras, Guillermo J.S.; De Bildt, Van Marco W.G.; Koopmans, Marion P.G.; Osterhaus, Albert D.M.E.; Kuiken, Thijs

    2015-01-01

    In the spring and summer 2014, an outbreak of seal influenza A(H10N7) virus infection occurred among harbor seals (Phoca vitulina) off the coasts of Sweden and Denmark. This virus subsequently spread to harbor seals off the coasts of Germany and the Netherlands. While thousands of seals were

  1. Seroprevalence of Antibodies against Seal Influenza A(H10N7) Virus in Harbor Seals and Gray Seals from the Netherlands

    NARCIS (Netherlands)

    Bodewes, Rogier|info:eu-repo/dai/nl/33230583X; Rubio García, Ana; Brasseur, Sophie M; Sanchez Conteras, Guillermo J; van de Bildt, Marco W G; Koopmans, Marion P G; Osterhaus, Albert D M E|info:eu-repo/dai/nl/074960172; Kuiken, Thijs

    2015-01-01

    In the spring and summer 2014, an outbreak of seal influenza A(H10N7) virus infection occurred among harbor seals (Phoca vitulina) off the coasts of Sweden and Denmark. This virus subsequently spread to harbor seals off the coasts of Germany and the Netherlands. While thousands of seals were

  2. 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.

  3. Effects of sonic booms on breeding gray seals and harbor seals on Sable Island, Canada.

    Science.gov (United States)

    Perry, Elizabeth A; Boness, Daryl J; Insley, Stephen J

    2002-01-01

    The Concorde produces audible sonic booms as it passes 15 km north of Sable Island, Nova Scotia, where gray and harbor seals occur year round. The purpose of this research was to assess how sonic booms affect these seals. The intensity of the booms was measured and three types of data (beach counts, frequency of behavior, and heart rate) were collected before and after booms during the breeding seasons of the two species. In addition to the data taken during breeding, beach counts were made before and after booms during the gray seal moult. The greatest range in overpressure within a single boom was 2.70 psf during gray seal breeding and 2.07 psf during harbor seal breeding. No significant differences were found in the behavior or beach counts of gray seals following sonic booms, regardless of the season. Beach counts and most behaviors of harbor seals also did not differ significantly following booms, however, harbor seals became more vigilant. The heart rates of four gray seal mothers and three pups showed no clear change as a result of booms, but six male harbor seals showed a nonsignificant tendency toward elevated heart rates during the 15-s interval of the boom. These results suggest sonic booms produced by the Concorde, in level flight at altitude and producing on average a sonic boom of 0.9 psf, do not substantially affect the breeding behavior of gray or harbor seals.

  4. Climate change and the northern elephant seal (Mirounga angustirostris) population in Baja California, Mexico.

    Science.gov (United States)

    García-Aguilar, María C; Turrent, Cuauhtémoc; Elorriaga-Verplancken, Fernando R; Arias-Del-Razo, Alejandro; Schramm, Yolanda

    2018-01-01

    The Earth's climate is warming, especially in the mid- and high latitudes of the Northern Hemisphere. The northern elephant seal (Mirounga angustirostris) breeds and haul-outs on islands and the mainland of Baja California, Mexico, and California, U.S.A. At the beginning of the 21st century, numbers of elephant seals in California are increasing, but the status of Baja California populations is unknown, and some data suggest they may be decreasing. We hypothesize that the elephant seal population of Baja California is experiencing a decline because the animals are not migrating as far south due to warming sea and air temperatures. Here we assessed population trends of the Baja California population, and climate change in the region. The numbers of northern elephant seals in Baja California colonies have been decreasing since the 1990s, and both the surface waters off Baja California and the local air temperatures have warmed during the last three decades. We propose that declining population sizes may be attributable to decreased migration towards the southern portions of the range in response to the observed temperature increases. Further research is needed to confirm our hypothesis; however, if true, it would imply that elephant seal colonies of Baja California and California are not demographically isolated which would pose challenges to environmental and management policies between Mexico and the United States.

  5. Evaluation of an innovative high temperature ceramic wafer seal for hypersonic engine applications. Ph.D. Thesis, 1991

    Science.gov (United States)

    Steinetz, Bruce M.

    1992-01-01

    A critical mechanical system in advanced hypersonic engines is the panel-edge seal system that seals gaps between the articulating engine panels and the adjacent engine splitter walls. Significant advancements in seal technology are required to meet the extreme demands placed on the seals, including the simultaneous requirements of low leakage, conformable, high temperature, high pressure, sliding operation. In this investigation, the design, development, analytical and experimental evaluation of a new ceramic wafer seal that shows promise of meeting these demands will be addressed. A high temperature seal test fixture was designed and fabricated to measure static seal leakage performance under engine simulated conditions. Ceramic wafer seal leakage rates are presented for engine-simulated air pressure differentials (up to 100 psi), and temperature (up to 1350 F), sealing both flat and distorted wall conditions, where distortions can be as large as 0.15 inches in only an 18 inch span. Seal leakage rates are low, meeting an industry-established tentative leakage limit for all combinations of temperature, pressure and wall conditions considered. A seal leakage model developed from externally-pressurized gas film bearing theory is also presented. Predicted leakage rates agree favorably with the measured data for nearly all conditions of temperature and pressure. Discrepancies noted at high engine pressure and temperature are attributed to thermally-induced, non-uniform changes in the size and shape of the leakage gap condition. The challenging thermal environment the seal must operate in places considerable demands on the seal concept and material selection. Of the many high temperature materials considered in the design, ceramics were the only materials that met the many challenging seal material design requirements. Of the aluminum oxide, silicon carbide, and silicon nitride ceramics considered in the material ranking scheme developed herein, the silicon nitride

  6. Conditioning of Spent Sealed Sources in Singapore

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Dae Seok; Kang, Il Sik; Jang, Kyung Duk; Shon, Jong Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    In 2010, IAEA (International Atomic Energy Agency) requested KAERI (Korea Atomic Energy Research Institute) to support Singapore for conditioning spent sealed sources. Once had been used for lightning conductor, check source or smoke detector, various sealed sources were collected and temporarily have been stored at HSA (Health Science Authority) under control of NEA (National Environment Agency) in Singapore. Based on experiences for conditioning of Ra-226 sources in various Asian countries since 2000, KAERI sent an expert team of three members to Singapore for safe management of spent sealed sources in 2011. As a result of conditioning operation, about 575.21 mCi of sealed sources were safely conditioned in 3 cement packages with cooperation of KAERI expert team, IAEA supervisor, NEA staffs and local labors. In this paper, procedure and result of the conditioning operation for the spent sealed sources in Singapore are discussed

  7. 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.

  8. Innovative Self-Healing Seals for Solid Oxide Fuel Cells (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Raj Singh

    2012-06-30

    Solid oxide fuel cell (SOFC) technology is critical to several national initiatives. Solid State Energy Conversion Alliance (SECA) addresses the technology needs through its comprehensive programs on SOFC. A reliable and cost-effective seal that works at high temperatures is essential to the long-term performance of the SOFC for 40,000 hours at 800°C. Consequently, seals remain an area of highest priority for the SECA program and its industry teams. An innovative concept based on self-healing glasses was advanced and successfully demonstrated through seal tests for 3000 hours and 300 thermal cycles to minimize internal stresses under both steady state and thermal transients for making reliable seals for the SECA program. The self-healing concept requires glasses with low viscosity at the SOFC operating temperature of 800°C but this requirement may lead to excessive flow of the glass in areas forming the seal. To address this challenge, a modification to glass properties by addition of particulate fillers is pursued in the project. The underlying idea is that a non-reactive ceramic particulate filler is expected to form glass-ceramic composite and increase the seal viscosity thereby increasing the creep resistance of the glass-composite seals under load. The objectives of the program are to select appropriate filler materials for making glass-composite, fabricate glass-composites, measure thermal expansion behaviors, and determine stability of the glass-composites in air and fuel environments of a SOFC. Self-healing glass-YSZ composites are further developed and tested over a longer time periods under conditions typical of the SOFCs to validate the long-term stability up to 2000 hours. The new concepts of glass-composite seals, developed and nurtured in this program, are expected to be cost-effective as these are based on conventional processing approaches and use of the inexpensive materials.

  9. The Application of Noninvasive Headspace Analysis to Media Fill Inspection.

    Science.gov (United States)

    Duncan, Derek; Cundell, Tony; Levac, Lauren; Veale, James; Kuiper, Suzanne; Rao, Ravi

    2016-01-01

    The results of a proof-of-principle study demonstrating a new analytical technique for detecting microbial growth directly in pharmaceutical containers are described. This analytical technique, laser-based headspace analysis, uses tunable diode laser absorption spectroscopy to nondestructively determine gas concentrations in the headspace of a media-filled pharmaceutical container. For detecting microbial growth, the levels of headspace oxygen and carbon dioxide are measured. Once aerobic microorganisms begin to divide after the lag phase and enter the exponential growth phase, there will be significant consumption of oxygen and concomitant production of carbon dioxide in the sealed container. Laser-based headspace analysis can accurately measure these changes in the headspace gas composition. The carbon dioxide and oxygen measurement data for the representative microorganisms Staphylococcus aureus, Bacillus subtilis, Candida albicans, and Aspergillus brasiliensis were modeled using the Baranyi-Roberts equation. The mathematical modeling allowed quantitative comparisons to be made between the data from the different microorganisms as well as to the known growth curves based on microbial count. Because laser-based headspace analysis is noninvasive and can be automated to analyze the headspace of pharmaceutical containers at inspection speeds of several hundred containers per minute on-line, some potential new applications are enabled. These include replacing the current manual human visual inspection with an automated analytical inspection machine to determine microbial contamination of media fill and pharmaceutical drug product vials. A novel analytical technique has been demonstrated for detecting microbial growth in media-filled pharmaceutical containers. This analytical technique, laser-based headspace analysis, uses tunable diode laser absorption spectroscopy to determine gas concentrations in the headspace of a pharmaceutical container. For detecting microbial

  10. 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

  11. Paleovalley fills: Trunk vs. tributary

    Science.gov (United States)

    Kvale, E.P.; Archer, A.W.

    2007-01-01

    A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills. Fills preserved within the trunk systems tend to be fluvially dominated and consist of bed-load deposits of coarse- to medium-grained sandstone and conglomerate. Conversely, the incised valleys of tributary systems tend to be filled with dark mudstone, thinly interbedded sandstones, and mudstones and siltstones. These finer grained facies exhibit marine influences manifested by tidal rhythmites, certain traces fossils, and macro- and microfauna. Examples of tributary and trunk systems, separated by no more than 7 km (4.3 mi) along strike, exhibit these styles of highly contrasting fills. Useful analogs for understanding this Pennsylvanian system include the Quaternary glacial sluiceways present in the lower Ohio, White, and Wabash river valleys of Indiana (United States) and the modern Amazon River (Brazil). Both the Amazon River and the Quaternary rivers of Indiana have (or had) trunk rivers that are (were) dominated by large quantities of bed load relative to their tributaries. The trunk valley systems of these analogs aggraded much more rapidly than their tributary valleys, which evolved into lakes because depositional rates along the trunk are (were) so high that the mouths of the tributaries have been dammed by bed-load deposits. These Holocene systems illustrate that sediment yields can significantly influence the nature of fill successions within incised valleys independent of rates of sea level changes or proximity to highstand coastlines. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  12. Analysis on the Viscous Pumping in a Magnetic Fluid Seal Under a Rotating Load and the Seal Design

    OpenAIRE

    長屋, 幸助; 大沼, 浩身; 佐藤,淳

    1990-01-01

    This paper discusses effects of viscous pumping in a magnetic fluid seal under a rotating load. The Reynolds equation was presented for the seal based on magnetic fluid mechanics, and the expressions for obtaining pressures in the seal, eccentricities of the rotating shaft due to the viscous pumping and seal pressures were given. Numerical Calculations were carried out for some sample problems, and the effect of magnetic flux densities on the pressure in the seal and the seal pressures were c...

  13. High pressure, high current, low inductance, high reliability sealed terminals

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

    2010-03-23

    The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

  14. Gas-Filled Capillary Model

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  15. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  16. 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.

  17. Balloon-Assisted Fistula Sealing Procedure for Symptomatic Tarlov Cysts.

    Science.gov (United States)

    Zheng, Xuesheng; Li, Shiting; Sheng, Hansong; Feng, Baohui; Zhang, Nu; Xie, Chaoran

    2016-04-01

    Tarlov cyst is an abnormal expansion of the spinal nerve sleeve, and it communicates with the subarachnoid cavity via a perineural fistula. This study presents our experience of a balloon-assisted fistula sealing procedure in treating Tarlov cyst. Twenty-two patients with symptomatic Tarlov cysts were surgically treated. An emulsion balloon was placed into the lumbar subarachnoid cistern through a trocar, so as to temporarily block cerebrospinal fluid flow, then the thecal sac was opened and the inlet of the fistula was sealed by suture of a muscular patch and reinforced by fibrin glue. Finally, the cyst wall was imbricated and the bony cavity was filled with pedicled muscle flaps. Comparing the preoperative and postoperative pain scores according to visual analog scale, 2 patients were slightly improved and 18 patients were substantially improved, including 3 completely pain-free cases. Only 2 patients were unchanged in pain, and both of them had multiple cysts. As a whole, the postoperative pain score was much better than the preoperative score (2.4 vs. 7.5; P Tarlov cyst, especially for the single cyst. It is a good complement to the cyst wall imbricating procedure. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Sealing glasses for titanium and titanium alloys

    Science.gov (United States)

    Brow, Richard K.; McCollister, Howard L.; Phifer, Carol C.; Day, Delbert E.

    1997-01-01

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B.sub.2 O.sub.3), barium oxide (BaO), lanthanum oxide (La.sub.2 O.sub.3), and at least one other oxide selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), calcium oxide (CaO), lithium oxide (Li.sub.2 O), sodium oxide (Na.sub.2 O), silicon dioxide (SiO.sub.2), or titanium dioxide (TiO.sub.2). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900.degree. C., and generally about 700.degree.-800.degree. C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

  19. Self-Representation on Byzantine Seals

    Directory of Open Access Journals (Sweden)

    Claudia Sode

    2015-10-01

    Full Text Available Sigillography brings to our attention a huge number of individuals that would otherwise have remained unknown. Thousands of seals survive that bear, together with religious images, inscriptions indicating the name of their owner, a title and the office held. Based upon the corpus of published seals, the article investigates the contribution of lead seals to our understanding of identity in Byzantium. The geographic expansion of Byzantium in the tenth and eleventh centuries brought a host of populations within the empire’s frontier which for the most part were not Greek-speaking, including Armenians, Georgians, and Christian Arabs. As a consequence, oriental languages appear on Byzantine seals. The seals often show an image of the Virgin or a Saint on one side and an inscription on the other side, or they bear inscriptions on both sides. The legends can be in Arabic or Syriac, Armenian or Georgian alone or are sometimes “mixed”, for instance in Arabic and Greek or Arabic and Syriac. The seal of Andronikos Rogerios – a Westerner who, however, seems to have been fully integrated into Byzantine society – clearly shows Western influence in the choice of the seals’s image. The article discusses the function of inscriptions and images found on seals as a means of understanding ethnic, social, cultural and linguistic identities.

  20. Contemporary root canal filling strategies

    NARCIS (Netherlands)

    Moinzadeh, A.T.

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation

  1. Can-Filled Crash Barrier

    Science.gov (United States)

    Wilson, A. H.

    1983-01-01

    Crash barrier composed largely of used aluminum beverage cans protects occupants of cars in collisions with poles or trees. Lightweight, can-filled barrier very effective in softening impact of an automobile in head-on and off-angle collisions. Preliminary results indicate barrier is effective in collisions up to 40 mi/h (64 km/h).

  2. Brain Responses to Filled Gaps

    Science.gov (United States)

    Hestvik, Arild; Maxfield, Nathan; Schwartz, Richard G.; Shafer, Valerie

    2007-01-01

    An unresolved issue in the study of sentence comprehension is whether the process of gap-filling is mediated by the construction of empty categories (traces), or whether the parser relates fillers directly to the associated verb's argument structure. We conducted an event-related potentials (ERP) study that used the violation paradigm to examine…

  3. Weaving and bonding method to prevent warp and fill distortion

    Science.gov (United States)

    Farley, Gary L. (Inventor)

    1997-01-01

    A method to prevent fiber distortion in textile materials employed in a modified weaving process. In a first embodiment, a tacifier in powder form is applied to the yarn and melted while on the fabric. Cool air is then supplied after the tacifier has melted to expedite the solidification of the tacifier. In a second embodiment, a solution form of a tacifier is used by dissolving the tacifier into a solvent that has a high evaporation rate. The solution is then sprayed onto the fabric or fill yarn as each fill yarn is inserted into a shed of the fabric. A third embodiment applies the tacifier in a liquid form that has not been dissolved in a solvent. That is, the tacifier is melted and is sprayed as a liquid onto the fabric or fill yarn as it is being extracted from a fill yarn spool prior to the fill yarn being inserted into the shed of the fabric. A fourth embodiment employs adhesive yarns contained as an integral part of the warp or fill yarn. Additional tacifier material is not required because a matrix is used as the tacifier. The matrix is then locally melted using heating elements on clamping bars or take-up rollers, is cooled, if necessary, and solidified.

  4. 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.

  5. Experimental Study and Application of Inorganic Solidified Foam Filling Material for Coal Mines

    National Research Council Canada - National Science Library

    Hu Wen; Duo Zhang; Zhijin Yu; Xuezhao Zheng; Shixing Fan; Bin Laiwang

    2017-01-01

    .... Building an airtight wall is an effective measure for controlling air leakage. A new type of inorganic solidified foam-filled material was developed and its physical and chemical properties were analyzed experimentally...

  6. Testing of sealed lead-acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Bush, D.M.; Sealey, J.D.; Miller, D.W.

    1984-02-01

    In early January 1981, Sandia National Laboratories began testing sealed lead-acid batteries which were being developed under Sandia contracts. The goal was to develop a totally maintenance-free sealed lead-acid battery capable of deep-discharge operation in a photovoltaic power system. Sealed lead-acid batteries and a group of conventional, flooded lead-acid batteries were exposed to a matrix test plan, with some approaching 1000 cycles. This performance was achieved with the standard National Electrical Manufacturers' Association cycle test, as well as the partial-state-of-charge cycle test. Modes of failure are being investigated.

  7. 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.

  8. Liquid butane filled load for a liner driven Pegasus experiment

    CERN Document Server

    Salazar, M A; Atchison, W; Armijo, E; Bartos, Yu; García, F; Randolph, B; Sheppard, M G

    2001-01-01

    Summary form only given, as follows. A hydrogen rich, low density liquid, contained within the internal volume of a cylindrical liner, was requested of the Polymers and Coatings Group (MST-7) of the Los Alamos Materials Science Division for one of the last liner driven experiments conducted on the Los Alamos Pegasus facility. The experiment required massive tungsten glide planes for inertial confinement of the liner fill media during implosion. Shallow sinusoidal perturbations were machined on the inside surface of the liner to seed instabilities, also true of the previous experiments. Butane was selected for a relatively low equilibrium vapor pressure, a practical attribute for use in the Pegasus vacuum power flow channel. Butane safety topics at Pegasus will be addressed. Glide planes were sealed to the liner by use of butane compatible o-rings. A sintered form of tungsten was used for the glide planes to facilitate machining the relatively complex shapes that were required. Porosity of the tungsten was sea...

  9. Microleakage of different temporary filling materials in primary teeth.

    Science.gov (United States)

    Odabas, Mesut Enes; Tulunoglu, Ozlem; Ozalp, Serife Ozdemir; Bodur, Haluk

    2009-01-01

    The aim of this study was to compare the sealing properties of IRM, Coltosol, Cavit G, Adhesor and Clip, which used as temporary filling material in coronal access openings in extracted human primary teeth. Standardized access cavities of 2 x 2 mm were prepared in the eighty-four, caries-free human primary anterior teeth. The teeth were divided randomly into five groups of 16 teeth each. Temporary restorative materials Group A: IRM (Dentsply), Group B: Coltosol (Coltone), Group C: Cavit G (3M), Group D: Adhesor (Spofa Dental) and Group E: Clip (Voco) were applied according to the manufacturer's directions. The specimens were immersed silver nitrate and placed in film developer under fluorescent for 24 hours. The sectioned specimens were evaluated under a digital microscope at x 20 magnifications and blindly scored for microleakage. Clip presented the least microleakage value whereas; Adhesor and IRM presented the higher microleakage values. There were statistically significant differences between Clip and the others groups, while there were no statistically significant differences in microleakage between IRM, Adhesor, Coltosol and Cavit G. However the leakage scores of Clip and Cavit G were congruent (p = 0.454). Amongst the five materials, Clip exhibited a better sealing ability.

  10. Study of the characteristics of plasma spray sealing aluminum silicon-polyester coatings

    Directory of Open Access Journals (Sweden)

    Mihailo R. Mrdak

    2012-07-01

    Full Text Available This study shows the homologation of the plasma spray parameters of soft abrasive AlSi - Polyester seals so that they can be applied on the TV2 - 117A compressor engines. The research has aimed at substituting existing sealants with a new class of materials in order to increase the sealing effect under the highest levels of pressure and to provide the air flow temperature of 100-125°C through the compressor. The Metco 601NS material and plasma spray technology were applied on the air labyrinth ring as a part of the TV2-117A turbojet engine compressor in order to obtain soft sealing. The deposit parameters were carefully selected in order to obtain coatings with the best characteristics depending on their application.The flow of helium was taken as a basic parameter in the parameter selection procedure. The coating with the best mechanical and structural properties was deposited on the air labyrinth ring to examine the effect of the coating application in an assembly. The microstructures of deposited layers were estimated with a light microscope and a (SEM Scanning Electron Microscope. The microstructural analysis of deposited layers was performed according to the Pratt - Whitney standard. The assessment of the mechanical properties of the coatings was done by examining the macrohardness of the sealing layers with the HR15Y method. The coating bond strength was tested by tensile testing. The effect of the air labyrinth ring sealing was tested inside the TV2-117A engine compressor on the test station for a period of 42 hour.

  11. Aerial surveys of seals at Rødsand seal sanctuary and adjacent haul-out sites

    DEFF Research Database (Denmark)

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

    This report describes the preliminary results of aerial surveys at Rødsand seal sanctuary, southeast Denmark and adjacent seal haul-out sites in southwestern Baltic. The work was carried out in connection with studies of potential effects of the Nysted offshore wind farm. Rødsand seal sanctuary...... is a part of seal management area 4, and the area is believed to hold a more or less closed population with little exchange to other areas. Although the harbour seal is relatively stationary there may be movements between the haul-out sites in the area. A possible reaction to disturbance from...... the construction and operation of the wind farm may be that the seals use other haul-out sites to a higher extend....

  12. 28 CFR 803.2 - Authority to affix seal.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Authority to affix seal. 803.2 Section... COLUMBIA AGENCY SEAL § 803.2 Authority to affix seal. The Director of CSOSA or PSA (as appropriate) and the Director's designees are authorized to affix the Agency seal (including replicas and reproductions) to...

  13. 4 CFR 202.3 - Prohibitions against misuse of seal.

    Science.gov (United States)

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false Prohibitions against misuse of seal. 202.3 Section 202.3 Accounts RECOVERY ACCOUNTABILITY AND TRANSPARENCY BOARD OFFICIAL SEAL § 202.3 Prohibitions against misuse of seal. (a) Falsely making, forging, counterfeiting, mutilating, or altering the Board seal or...

  14. 49 CFR 803.3 - Authority to affix Seal.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Authority to affix Seal. 803.3 Section 803.3 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL TRANSPORTATION SAFETY BOARD OFFICIAL SEAL § 803.3 Authority to affix Seal. (a) The Seal shall be in the custody and control of the...

  15. 4 CFR 202.2 - Authority to affix seal.

    Science.gov (United States)

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false Authority to affix seal. 202.2 Section 202.2 Accounts RECOVERY ACCOUNTABILITY AND TRANSPARENCY BOARD OFFICIAL SEAL § 202.2 Authority to affix seal. (a) The following officials of the Board are authorized to affix the official seal (including reproductions) to...

  16. 17 CFR 2.3 - Prohibitions against misuse of seal.

    Science.gov (United States)

    2010-04-01

    ... seal. 2.3 Section 2.3 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION OFFICIAL SEAL § 2.3 Prohibitions against misuse of seal. (a) Fraudulently or wrongfully affixing or impressing the Seal to or upon any certificate, instrument, document or paper or with knowledge of its fraudulent...

  17. 34 CFR 3.3 - Authority to affix seal.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Authority to affix seal. 3.3 Section 3.3 Education Office of the Secretary, Department of Education OFFICIAL SEAL § 3.3 Authority to affix seal. The Secretary and the Secretary's designees are authorized to affix the Official Seal, replicas, reproductions...

  18. Development of a magnetic liquid seal for clean robots

    Science.gov (United States)

    Mizumoto, M.; Inoue, H.

    1987-03-01

    A magnetic liquid seal is developed for clean robots used in semiconductor producing factories. This seal is made of a O-ring type elastic magnet in which magnetic liquid is attracted to the magnet directly. The results of experimental tests prove that the newly developed seal affords reliable sealing performance for clean robots in a cleanness class of 10 or less.

  19. 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...

  20. 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.

  1. 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...

  2. Fuel cell cassette with compliant seal

    Science.gov (United States)

    Karl, Haltiner, Jr. J.; Anthony, Derose J.; Klotzbach, Darasack C.; Schneider, Jonathan R.

    2017-11-07

    A fuel cell cassette for forming a fuel cell stack along a fuel cell axis includes a cell retainer, a plate positioned axially to the cell retainer and defining a space axially with the cell retainer, and a fuel cell having an anode layer and a cathode layer separated by an electrolyte layer. The outer perimeter of the fuel cell is positioned in the space between the plate and the cell retainer, thereby retaining the fuel cell and defining a cavity between the cell retainer, the fuel cell, and the plate. The fuel cell cassette also includes a seal disposed within the cavity for sealing the edge of the fuel cell. The seal is compliant at operational temperatures of the fuel cell, thereby allowing lateral expansion and contraction of the fuel cell within the cavity while maintaining sealing at the edge of the fuel cell.

  3. 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...

  4. 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)

  5. 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...

  6. 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,...

  7. Prevention of Stripping under Chip Seals

    Science.gov (United States)

    2017-10-01

    Eighteen chip-sealed roadways in eight cities and counties in Minnesota were evaluated both in the field (for condition surveys and density tests) and in the laboratory (for permeability, stripping, tensile-strength ratio, asphalt film thickness, and...

  8. Chip seal performance measures : best practices.

    Science.gov (United States)

    2015-03-01

    The Washington State Department of Transportation (WSDOT) has a long history of designing, constructing, : and maintaining chip seal or bituminous surface treatment pavements. However, to date WSDOT has not : developed pavement performance indicators...

  9. Onboard Acoustic Recording from Diving Elephant Seals

    National Research Council Canada - National Science Library

    Fletcher, Stacia

    1996-01-01

    The aim of this project was to record sounds impinging on free-ranging northern elephant seals, Mirounga angustirostris, a first step in determining the importance of LFS to these animals as they dive...

  10. 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)...

  11. Collyria seals in the Roman Empire.

    Science.gov (United States)

    Perez-Cambrodi, Rafael J; Pinero, David P; Mavrou, Ariadni; Cervino, Alejandro; Brautaset, Rune; Murube del Castillo, Juan

    2013-01-01

    Roman seals associated with collyria (Latin expression for eye drops/washes and lotions for eye maintenance) provide valuable information about eye care in the antiquity. These small, usually stone-made pieces bore engravings with the names of eye doctors and also the collyria used to treat an eye disease. The collyria seals have been found all over the Roman empire and Celtic territories in particular and were usually associated with military camps. In Hispania (Iberian Peninsula), only three collyria seals have been found. These findings speak about eye care in this ancient Roman province as well as about of the life of the time. This article takes a look at the utility and social significance of the collyria seals and seeks to give an insight in the ophthalmological practice of in the Roman Empire.

  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 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...

  14. 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...

  15. Infiltrating/sealing proximal caries lesions

    DEFF Research Database (Denmark)

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

    2012-01-01

    This randomized split-mouth controlled clinical trial aimed at assessing the therapeutic effects of infiltration vs. sealing for controlling caries progression on proximal surfaces. Out of 90 adult students/patients assessed at university clinics and agreeing to participate, 39, each with 3...... differences in lesion progression between infiltration and placebo (P = 0.0012) and between sealing and placebo (P = 0.0269). The study showed that infiltration and sealing are significantly better than placebo treatment for controlling caries progression on proximal lesions. No significant difference...... 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...

  16. Space filling curves in steganalysis

    Science.gov (United States)

    Westfeld, Andreas

    2005-03-01

    We introduce a new method to increase the reliability of current steganalytic techniques by optimising the sample order. Space filling curves (e.g., Hilbert curve) take advantage of the correlation of adjacent pixels and thus make the detection of steganographic messages with low change densities more reliable. The findings are applicable, but not limited to LSB steganalysis. An experimental comparison of five different sampling paths reveals that recursive principles achieve by far the best performance. All measures, such as mean distance, median autocorrelation, and the ability to detect even tiny modifications show substantial improvements compared to conventional methods. We elaborate the relationship between those parameters and quantify the effectiveness with a large test database of small images, which are usually hard to detect. Apart from quantitative advances, visualisation of steganalytic measures can also gain from the application of reverse space filling curves.

  17. 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.

  18. 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.

  19. Particle-filled microporous materials

    Science.gov (United States)

    McAllister, Jerome W.; Kinzer, Kevin E.; Mrozinski, James S.; Johnson, Eric J.; Dyrud, James F.

    1990-01-01

    A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated.

  20. CFD Applied for the Identification of Stiffness and Damping Properties for Smooth Annular Turbomachinery Seals in Multiphase Flow

    DEFF Research Database (Denmark)

    Voigt, Andreas Jauernik; Ludiciani, Piero; Nielsen, Kenny Krogh

    2016-01-01

    This paper presents a first venture into quantifying stiffness and damping coefficients for turbomachinery seals in multiphase flow using Computational Fluid Dynamics (CFD). The study focusses on the simplest seal type: the smooth annular seal. The investigation is conducted for both wet......-gas and bubbly flow regimes in which the primary phase is gas (air) and liquid (water), respectively. For the wet gas regime three different Liquid Volume Fraction (LVF) conditions are included in the study; 5%, 3% and 0%. Similarly for the bubbly flow regime three Gas Volume Fractions (GVF) conditions...... comparison basis for the experimental results to be obtained by applying the multiphase seal test facility currently in development, as part of a collaboration between Lloyd’s Register Consulting, the Technical University of Denmark, OneSubsea, TOTAL and Statoil....

  1. Intraoral Temperature Triggered Shape-Memory Effect and Sealing Capability of A Transpolyisoprene-Based Polymer

    Directory of Open Access Journals (Sweden)

    Gakuji Tsukada

    2015-11-01

    Full Text Available In dentistry, pure gutta-percha (trans-1,4-polyisoprene (TPI is widely used as a main component of root canal filling materials. TPI has an interesting shape memory formed through cross-linking, and this characteristic is expected to be very effective for development of novel dental treatments; in particular, modification of the shape recovery temperature to the intraoral temperature (37 °C will enhance the applicability of the shape-memory effect of TPI in root canal filling. In this study, trial test specimens consisting of varying proportions of TPI, cis-polyisoprene, zinc oxide, stearic acid, sulfur and dicumyl peroxide were prepared and the temperature dependence of their shape recovery, recovery stress and relaxation modulus were measured. Additionally, their sealing abilities were tested using glass tubing and a bovine incisor. As the ratio of cross-linking agent in the specimens increased, a decrease in recovery temperature and an increase in recovery stress and recovery speed were observed. In addition, the test specimen containing the highest concentration of cross-linking agent showed superior sealing ability under a thermal stimulus of 37 °C in both sealing ability tests.

  2. Sealing ability of mineral trioxide aggregate (MTA) combined with distilled water, chlorhexidine, and doxycycline.

    Science.gov (United States)

    Arruda, Roberta A A; Cunha, Rodrigo S; Miguita, Kenner B; Silveira, Cláudia F M; De Martin, Alexandre S; Pinheiro, Sérgio L; Rocha, Daniel G P; Bueno, Carlos E S

    2012-09-01

    The aim of this study was to evaluate the sealing ability of mineral trioxide aggregate (MTA Bio) combined with different mixing agents (distilled water, chlorhexidine, doxycycline), used as an apical root-end filling material. Forty-two extracted human teeth were divided into three groups (n = 12); six teeth were used as controls. Root-ends were resected at 90 degrees, 3 mm from the apex. Root-end cavities were prepared using ultrasonic tips and filled with MTA Bio plus distilled water, 2% chlorhexidine solution, or 10% doxycycline solution. Apical sealing was assessed by microleakage of 50% silver nitrate solution. Roots were longitudinally sectioned in a buccolingual plane and analyzed using an operating microscope (20× magnification). Depth of dye leakage into the dentinal walls was measured in millimeters. Results were analyzed using ANOVA and Tukey's test (P = 0.05). MTA Bio plus distilled water showed significantly higher mean leakage results (1.06 mm) when compared with MTA Bio plus doxycycline (0.61 mm), and higher, although not significant, results when compared with MTA Bio plus chlorhexidine (0.79 mm). In conclusion, replacing distilled water with two biologically active mixing agents (doxycycline and chlorhexidine) did not alter the sealing properties of MTABio. The antimicrobial properties of these combinations should be further investigated.

  3. Seroprevalence of Antibodies against Seal Influenza A(H10N7 Virus in Harbor Seals and Gray Seals from the Netherlands.

    Directory of Open Access Journals (Sweden)

    Rogier Bodewes

    Full Text Available In the spring and summer 2014, an outbreak of seal influenza A(H10N7 virus infection occurred among harbor seals (Phoca vitulina off the coasts of Sweden and Denmark. This virus subsequently spread to harbor seals off the coasts of Germany and the Netherlands. While thousands of seals were reported dead in Sweden, Denmark and Germany, only a limited number of seals were found dead in the Netherlands. To determine the extent of exposure of seals in the Netherlands to influenza A/H10N7 virus, we measured specific antibody titers in serum samples from live-captured seals and seals admitted for rehabilitation in the Netherlands by use of a hemagglutination inhibition assay and an ELISA. In harbor seals in 2015, antibodies against seal influenza A(H10N7 virus were detected in 41% (32 out of 78 pups, 10% (5 out of 52 weaners, and 58% (7 out of 12 subadults or adults. In gray seals (Halichoerus grypus in 2015, specific antibodies were not found in the pups (n = 26, but in 26% (5 out of 19 of the older animals. These findings indicate that, despite apparent low mortality, infection with seal influenza A(H10N7 virus was geographically widespread and also occurred in grey seals.

  4. Seroprevalence of Antibodies against Seal Influenza A(H10N7) Virus in Harbor Seals and Gray Seals from the Netherlands.

    Science.gov (United States)

    Bodewes, Rogier; Rubio García, Ana; Brasseur, Sophie M; Sanchez Conteras, Guillermo J; van de Bildt, Marco W G; Koopmans, Marion P G; Osterhaus, Albert D M E; Kuiken, Thijs

    2015-01-01

    In the spring and summer 2014, an outbreak of seal influenza A(H10N7) virus infection occurred among harbor seals (Phoca vitulina) off the coasts of Sweden and Denmark. This virus subsequently spread to harbor seals off the coasts of Germany and the Netherlands. While thousands of seals were reported dead in Sweden, Denmark and Germany, only a limited number of seals were found dead in the Netherlands. To determine the extent of exposure of seals in the Netherlands to influenza A/H10N7 virus, we measured specific antibody titers in serum samples from live-captured seals and seals admitted for rehabilitation in the Netherlands by use of a hemagglutination inhibition assay and an ELISA. In harbor seals in 2015, antibodies against seal influenza A(H10N7) virus were detected in 41% (32 out of 78) pups, 10% (5 out of 52) weaners, and 58% (7 out of 12) subadults or adults. In gray seals (Halichoerus grypus) in 2015, specific antibodies were not found in the pups (n = 26), but in 26% (5 out of 19) of the older animals. These findings indicate that, despite apparent low mortality, infection with seal influenza A(H10N7) virus was geographically widespread and also occurred in grey seals.

  5. Relationship between sealing ability of Activ GP and Gutta Flow and methods of calcium hydroxide removal.

    Science.gov (United States)

    Nikhil, Vineeta; Singh, Vijay; Singh, Simranjeet

    2012-01-01

    To evaluate the effect of method of calcium hydroxide intracanal dressing removal, on sealing ability of Gutta Flow and Activ GP. Seventy extracted mandibular premolars were sectioned at CEJ and canals were prepared with profile 4% rotary file till #40. Canals were filled with calcium hydroxide, coronally sealed with Cavit G and stored at 37°C. After 7 days, samples were divided on the basis of calcium hydroxide removal method (Master apical file, Navi Tip FX, and F File) and obturating material (Activ GP and Gutta Flow). Three coats of nail polish were applied except 2 mm around apical foramen and samples were immersed in India ink dye, sectioned, and observed under stereomicroscope for microleakage. The results were statistically analyzed with one way ANOVA-F with Tukey HSD test with the null hypothesis set as 5%. The seal of the canal system was adversely impacted by residual calcium hydroxide when Activ GP and Gutta Flow were used as obturating material and the sealing ability of Activ GP and Gutta Flow was better when MAF was used for removal of calcium hydroxide than F file or Navi tip FX.

  6. Semiconductor laser irradiation improves root canal sealing during routine root canal therapy.

    Science.gov (United States)

    Su, Dandan; Hu, Xingxue; Wang, Dashan; Cui, Ting; Yao, Ruyong; Sun, Huibin

    2017-01-01

    To evaluate the effect of semiconductor laser irradiation on root canal sealing after routine root canal therapy (RCT). Sixty freshly extracted single-rooted human teeth were randomly divided into six groups (n = 10). The anatomic crowns were sectioned at the cementoenamel junction and the remaining roots were prepared endodontically with conventional RCT methods. Groups A and B were irradiated with semiconductor laser at 1W for 20 seconds; Groups C and D were ultrasonically rinsed for 60 seconds as positive control groups; Groups E and F without treatment of root canal prior to RCT as negative control groups. Root canal sealing of Groups A, C and E were evaluated by measurements of apical microleakage. The teeth from Groups B, D and F were sectioned, and the micro-structures were examined with scanning electron microscopy (SEM). One way ANOVA and LSD-t test were used for statistical analysis (α = .05). The apical sealing of both the laser irradiated group and the ultrasonic irrigated group were significantly different from the control group (p0.5). SEM observation showed that most of the dentinal tubules in the laser irradiation group melted, narrowed or closed, while most of the dentinal tubules in the ultrasonic irrigation group were filled with tooth paste. The application of semiconductor laser prior to root canal obturation increases the apical sealing of the roots treated.

  7. Semiconductor laser irradiation improves root canal sealing during routine root canal therapy.

    Directory of Open Access Journals (Sweden)

    Dandan Su

    Full Text Available To evaluate the effect of semiconductor laser irradiation on root canal sealing after routine root canal therapy (RCT.Sixty freshly extracted single-rooted human teeth were randomly divided into six groups (n = 10. The anatomic crowns were sectioned at the cementoenamel junction and the remaining roots were prepared endodontically with conventional RCT methods. Groups A and B were irradiated with semiconductor laser at 1W for 20 seconds; Groups C and D were ultrasonically rinsed for 60 seconds as positive control groups; Groups E and F without treatment of root canal prior to RCT as negative control groups. Root canal sealing of Groups A, C and E were evaluated by measurements of apical microleakage. The teeth from Groups B, D and F were sectioned, and the micro-structures were examined with scanning electron microscopy (SEM. One way ANOVA and LSD-t test were used for statistical analysis (α = .05.The apical sealing of both the laser irradiated group and the ultrasonic irrigated group were significantly different from the control group (p0.5. SEM observation showed that most of the dentinal tubules in the laser irradiation group melted, narrowed or closed, while most of the dentinal tubules in the ultrasonic irrigation group were filled with tooth paste.The application of semiconductor laser prior to root canal obturation increases the apical sealing of the roots treated.

  8. Disposable plastic rodent feeders for use in an automated filling system.

    Science.gov (United States)

    Toler, James; Gleason, David; Clare, Lisa; Buckham, Susan; DeWit, Robert

    2008-09-01

    Rodent feeder devices are often made of reusable, sanitizable materials such as glass and stainless steel. As part of an initiative at the authors' facility to automate the feeder filling process, disposable plastic feeding cups were proposed as a preferable alternative to standard feeders for use in a filling machine. The authors tested and validated designs for rodent meal-type feeder assemblies that incorporated plastic cups. Assemblies included stainless steel shields that prevented rats and mice from chewing on the plastic cups while allowing them full access to food. The use of disposable feeder cups that are filled and sealed automatically reduces labor associated with sanitation, enables staff to prepare feeders for several weeks in advance and limits personnel contact with feed that may contain harmful chemicals.

  9. Understanding the Relationship Between Filling Pattern and Part Quality in Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    Jerald Brevick; R. Allen Miller

    2004-03-15

    The overall objective of this research project was to investigate phenomena involved in the filling of die cavities with molten alloy in the cold chamber die-casting process. It has long been recognized that the filling pattern of molten metal entering a die cavity influences the quality of die-cast parts. Filling pattern may be described as the progression of molten metal filling the die cavity geometry as a function of time. The location, size and geometric configuration of points of metal entry (gates), as well as the geometry of the casting cavity itself, have great influence on filling patterns. Knowledge of the anticipated filling patterns in die-castings is important for designers. Locating gates to avoid undesirable flow patterns that may entrap air in the casting is critical to casting quality - as locating vents to allow air to escape from the cavity (last places to fill). Casting quality attributes that are commonly flow related are non-fills, poor surface finish, internal porosity due to trapped air, cold shuts, cold laps, flow lines, casting skin delamination (flaking), and blistering during thermal treatment.

  10. Experiment on wear behavior of high pressure gas seal faces

    Science.gov (United States)

    Xu, Jing; Peng, Xudong; Bai, Shaoxian; Meng, Xiangkai; Li, Jiyun

    2014-11-01

    Current researches show that mechanical deformation of seal ring face makes fluid film clearance decrease at high pressure side, thus a divergent clearance is formed and face wear occurs more seriously at the high pressure side than that on the low pressure side. However, there is still lack of published experimental works enough to prove the theoretical results. In this paper, a spiral groove dry gas seal at high pressures is experimentally investigated so as to prove the face wear happened at the high pressure side of seal faces due to the face mechanical deformation, and the wear behavior affected by seal ring structure is also studied. The experimental results show that face wear would occur at the high pressure side of seal faces due to the deformation, thus the leakage and face temperature increase, which all satisfies the theoretical predictions. When sealed pressure is not less than 5 MPa, the pressure can provide enough opening force to separate the seal faces. The seal ring sizes have obvious influence on face wear. Face wear, leakage and face temperature of a dry gas seal with the smaller cross sectional area of seal ring are less than that of a dry gas seal with bigger one, and the difference of leakage rate between these two sizes of seal face width is in the range of 24%-25%. Compared with the effect of seal ring sizes, the effect of secondary O-ring seal position on face deformation and face wear is less. The differences between these two types of dry gas seals with different secondary O-ring seal positions are less than 5.9% when the rotational speed varies from 0 to 600 r/min. By linking face wear and sealing performance changes to the shift in mechanical deformation of seal ring, this research presents an important experimental method to study face deformation of a dry gas seal at high pressures.

  11. Labyrinth Seal Analysis. Volume 3. Analytical and Experimental Development of a Design Model for Labyrinth Seals

    Science.gov (United States)

    1986-01-01

    JAPANESE SOCIETY OF LUBRICATION ENGINEERS, VOL. 14, NO. St MAY, 1969, PP. 243-250. (JAPANESE) KOMOTORI, KAZUNARI. CONTACTFREE SEALS, CORONA PUBLISHING CO...CLEVELAND, OHIO, JULY, 1976. iODA 79-0024) SILL, ROBERT C. PLASMA-SPRAYEO ZIRCONIA GAS PATH SEAL TECHNOLOGY A STATE-OF-THE-ART REVIEW, NASA TM 79273

  12. Why do seals have cones? Behavioural evidence for colour-blindness in harbour seals.

    Science.gov (United States)

    Scholtyssek, Christine; Kelber, Almut; Dehnhardt, Guido

    2015-03-01

    All seals and cetaceans have lost at least one of two ancestral cone classes and should therefore be colour-blind. Nevertheless, earlier studies showed that these marine mammals can discriminate colours and a colour vision mechanism has been proposed which contrasts signals from cones and rods. However, these earlier studies underestimated the brightness discrimination abilities of these animals, so that they could have discriminated colours using brightness only. Using a psychophysical discrimination experiment, we showed that a harbour seal can solve a colour discrimination task by means of brightness discrimination alone. Performing a series of experiments in which two harbour seals had to discriminate the brightness of colours, we also found strong evidence for purely scotopic (rod-based) vision at light levels that lead to mesopic (rod-cone-based) vision in other mammals. This finding speaks against rod-cone-based colour vision in harbour seals. To test for colour-blindness, we used a cognitive approach involving a harbour seal trained to use a concept of same and different. We tested this seal with pairs of isoluminant stimuli that were either same or different in colour. If the seal had perceived colour, it would have responded to colour differences between stimuli. However, the seal responded with "same", providing strong evidence for colour-blindness.

  13. 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.

  14. Sealing Capability and SEM Observation of the Implant-Abutment Interface.

    Science.gov (United States)

    Lorenzoni, Fabio C; Coelho, Paulo G; Bonfante, Gerson; Carvalho, Ricardo M; Silva, Nelson R F A; Suzuki, Marcelo; Silva, Thelma Lopes; Bonfante, Estevam A

    2011-01-01

    To evaluate the sealing capability of external hexagon implant systems and assess the marginal fit, two groups (n = 10 each) were employed: SIN (Sistema de Implantes Nacional, Brazil) and Osseotite, (Biomet 3i, USA). Sealing capability was determined by placing 0.7 μL of 1% acid-red solution in the implant wells before the torque of their respective abutments. Specimens were then placed into 2.5 mL vials filled with 1.3 mL of distilled water with the implant-abutment interface submerged. Three samples of 100 μL water were collected at previously determinate times. The absorbance was measured with a spectrophotometer, and the data were analyzed by Two-way ANOVA (P implant-abutment interface of both groups. Gaps in the implant-abutment interface were observed along with leakage increased at the 144 hrs evaluation period.

  15. Sealing Capability and SEM Observation of the Implant-Abutment Interface

    Science.gov (United States)

    Lorenzoni, Fabio C.; Coelho, Paulo G.; Bonfante, Gerson; Carvalho, Ricardo M.; Silva, Nelson R. F. A.; Suzuki, Marcelo; Silva, Thelma Lopes; Bonfante, Estevam A.

    2011-01-01

    To evaluate the sealing capability of external hexagon implant systems and assess the marginal fit, two groups (n = 10 each) were employed: SIN (Sistema de Implantes Nacional, Brazil) and Osseotite, (Biomet 3i, USA). Sealing capability was determined by placing 0.7 μL of 1% acid-red solution in the implant wells before the torque of their respective abutments. Specimens were then placed into 2.5 mL vials filled with 1.3 mL of distilled water with the implant-abutment interface submerged. Three samples of 100 μL water were collected at previously determinate times. The absorbance was measured with a spectrophotometer, and the data were analyzed by Two-way ANOVA (P implant-abutment interface of both groups. Gaps in the implant-abutment interface were observed along with leakage increased at the 144 hrs evaluation period. PMID:21754934

  16. Possible effects of Bay fill on air quality

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Baylands Subcommittee is seeking background information on the effects and ramifications of developing those parts of San Francisco Bay that lie in Santa Clara...

  17. Filling the vacuum at LHCb

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    Last month, the Vacuum, Surfaces and Coatings (VSC) group was tasked with an unusually delicate operation in the LHCb experiment cavern: removing the LHC beam pipe while keeping the sensitive Vertex Locator vacuum vessel (VELO) completely isolated from the action.   The VSC group seal off the VELO beam pipe with a flange. Image: Gloria Corti. LHCb’s VELO detector is one of the crown jewels of the experiment. With detector elements surrounded by a vacuum, it gets as close as 5 cm from the beam. Fantastic for physics, but difficult for all-important access. “Because of the sensitivity of the VELO detector and its proximity to the beam, the collaboration decided not to bake (see box) its portion of the beam pipe,” says Giulia Lanza (TE-VSC-LBV), the expert in charge of the beam vacuum operation. “Our group was therefore asked to remove the rest of the LHC beam pipe while keeping the VELO portion of the pipe completely isolated. This work...

  18. 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.

  19. 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.

  20. Controlling the Filling and Capping Operation of a Bottling Plant using PLC and SCADA

    Directory of Open Access Journals (Sweden)

    Kunal Chakraborty

    2015-03-01

    Full Text Available This paper presents basic stages of operation of a bottling plant, i.e. the filling and capping process. The main aim of our paper is to control the filling and capping section of a bottling plant simultaneously. At first a set of empty bottle is run by using a conveyer towards filling section, after the operation, the filled bottles are sent towards the capping section. After successful capping operation, the sealed bottles terminate towards exit and a new set of empty bottle arrive, in this way the process continues. This paper includes the method using which, a bunch of bottles can be filled and capped at one instant of time. This method has made the operation more flexible and time saving. The filling and capping operations are controlled using Programmable Logic Controllers (PLC, as the PLC’s are very much user-efficient, cost-effective and easy to control. By using PLC automation the whole process is kept under control. SCADA (Supervisory Control and Data Acquisition is used to monitor the process by means of a display system.

  1. Modeling the Interaction of a Molten Seal and Solid Particles Using DEM and SPH Simulations: Application for a Passive New Scram System for LMR

    Directory of Open Access Journals (Sweden)

    S. Vanmaercke

    2012-09-01

    Full Text Available A new shutdown system that does not rely on absorber rods, is being developed at SCK.CEN and UCL for application in Liquid Metal Reactors (LMR. The system consists of tubes filled with absorber particles. During normal operation, these particles are kept above the active core by means of a metallic melt seal. In case of an accident, the system is activated by the temperature increase in the coolant. This leads to melting of the metal seal, releasing the absorber particles into the core. The resulting flow of the particles has been studied both experimentally, and with Discrete Element Method (DEM simulations. This paper focuses on the second important aspect of the safety system, being the melting and flowing of the metallic seal in interaction with the solid absorber particles moving through the molten seal.

  2. 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.

  3. Bio-inspired dental fillings

    Science.gov (United States)

    Deyhle, Hans; Bunk, Oliver; Buser, Stefan; Krastl, Gabriel; Zitzmann, Nicola U.; Ilgenstein, Bernd; Beckmann, Felix; Pfeiffer, Franz; Weiger, Roland; Müller, Bert

    2009-08-01

    Human teeth are anisotropic composites. Dentin as the core material of the tooth consists of nanometer-sized calcium phosphate crystallites embedded in collagen fiber networks. It shows its anisotropy on the micrometer scale by its well-oriented microtubules. The detailed three-dimensional nanostructure of the hard tissues namely dentin and enamel, however, is not understood, although numerous studies on the anisotropic mechanical properties have been performed and evaluated to explain the tooth function including the enamel-dentin junction acting as effective crack barrier. Small angle X-ray scattering (SAXS) with a spatial resolution in the 10 μm range allows determining the size and orientation of the constituents on the nanometer scale with reasonable precision. So far, only some dental materials, i.e. the fiber reinforced posts exhibit anisotropic properties related to the micrometer-size glass fibers. Dental fillings, composed of nanostructures oriented similar to the natural hard tissues of teeth, however, do not exist at all. The current X-ray-based investigations of extracted human teeth provide evidence for oriented micro- and nanostructures in dentin and enamel. These fundamental quantitative findings result in profound knowledge to develop biologically inspired dental fillings with superior resistance to thermal and mechanical shocks.

  4. Rice Husk Filled Polymer Composites

    Directory of Open Access Journals (Sweden)

    Reza Arjmandi

    2015-01-01

    Full Text Available Natural fibers from agricultural wastes are finding their importance in the polymer industry due to the many advantages such as their light weight, low cost and being environmentally friendly. Rice husk (RH is a natural sheath that forms around rice grains during their growth. As a type of natural fiber obtained from agroindustrial waste, RH can be used as filler in composites materials in various polymer matrices. This review paper is aimed at highlighting previous works of RH filled polymer composites to provide information for applications and further research in this area. Based on the information gathered, application of RH filled composites as alternative materials in building and construction is highly plausible with both light weight and low cost being their main driving forces. However, further investigations on physical and chemical treatment to further improve the interfacial adhesion with polymeric matrix are needed as fiber-polymer interaction is crucial in determining the final composite properties. Better understanding on how the used polymer blends as the matrix and secondary fillers may affect the properties would provide interesting areas to be explored.

  5. Silicone Gel-Filled Breast Implants

    Science.gov (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin it ... options Linkedin Pin it Email Print Description: Silicone gel-filled breast implants have a silicone outer shell ...

  6. Domain walls and spacetime-filling branes

    NARCIS (Netherlands)

    Bergshoeff, E; Wess, J; Ivanov, EA

    1999-01-01

    We discuss branes with one transversal direction (domain walls) and no transversal direction (spacetime-filling branes). In particular, we briefly discuss a relationship between spacetime-filling branes and superstring theories with sixteen supercharges.

  7. Tags and seals for arms control verification

    Energy Technology Data Exchange (ETDEWEB)

    DeVolpi, A.

    1990-09-18

    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 might be considered as single-point markers, seals as two-point couplings, and nets as volume containment. The functions of an arms control tag can be considered to be two-fold: to provide field verification of the identity of a treaty-limited item (TLI), and to have a means of authentication of the tag and its tamper-revealing features. Authentication could take place in the field or be completed elsewhere. For CFE, the goal of tags and seals can be to reduce the overall cost of the entire verification system.

  8. Dynamic tester for rotor seals and bearings

    Science.gov (United States)

    Vonpragenau, George L. (Inventor)

    1993-01-01

    A dynamic tester for testing vibration damping seals and bearings is constructed having a hollow shaft extending through the seal or bearing, with the shaft internally supported at each end by fluid bearings on hollow bosses connected to an interior of an enclosure, with no rolling members connected to the shaft is described. A high pressure working fluid is forced through the hollow bosses to operate the bearings. Additionally, the shaft is provided with a reaction turbine that angularly vents a portion of the high pressure working fluid in order to rotate the shaft at high speed, up to 40,000 rpm. The seal or bearing is mounted in a bushing, in turn supported by rods to a shaking device that vibrates the seal or bearing as the shaft is rotated. A plurality of proximity sensors are mounted from outside the enclosure to sense shaft and seal bushing vibrations, and a plurality of pressure ports are disposed in the enclosure to allow sensing of dynamic and static pressures of the testing apparatus.

  9. 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.

  10. The status of grey seals in Britain

    Directory of Open Access Journals (Sweden)

    C D Duck

    2013-10-01

    Full Text Available Grey seal pup production in Scotland was estimated through annual aerial surveys of the main grey seal breeding colonies. Between 3 and 7 counts of pups were obtained for each colony at intervals through the course of the breeding season. Pup production for individual colonies was estimated from the series of counts using a maximum likelihood model. At 3 colonies, 2 in England, annual pup production was estimated using ground counts. Between the early 1960s and the early 1990s, grey seal pup production progressively increased. At colonies in the Inner and Outer Hebrides, production appeared to stabilize during the 1990s and has remained so. Pup production at colonies in Orkney and in the North Sea has continued to increase but in recent years the rate of increase has declined. This may imply that the UK grey seal population is reaching some limit to its size. The observed changes in pup production imply that some density dependent factors are affecting the British grey seal population. Changes in either juvenile survival and/or female fecundity are the most likely options. Without knowing which of these, or what combination of these factors, is operating, estimating total population size is complicated.

  11. Application of polyimide actuator rod seals

    Science.gov (United States)

    Watermann, A. W.; Gay, B. F.; Robinson, E. D.; Srinath, S. K.; Nelson, W. G.

    1972-01-01

    Development of polyimide two-stage hydraulic actuator rod seals for application in high-performance aircraft was accomplished. The significant portion of the effort was concentrated on optimization of the chevron and K-section second-stage seal geometries to satisfy the requirements for operation at 450 K (350 F) with dynamic pressure loads varying between 200 psig steady-state and 1500 psig impulse cycling. Particular significance was placed on reducing seal gland dimension by efficiently utilizing the fatigue allowables of polyimide materials. Other objectives included investigation of pressure balancing techniques for first-stage polyimide rod seals for 4000 psig 450 K(350 F) environment and fabrication of a modular retainer for the two-stage combination. Seals were fabricated in 0.0254 m (1.0in.) and 0.0635 m (2.5in.) sizes and tested for structural integrity, frictional resistance, and endurance life. Test results showed that carefully designed second stages using polyimides could be made to satisfy the dynamic return pressure requirements of applications in high-performance aircraft. High wear under full system pressure indicated that further research is necessary to obtain an acceptable first-stage design. The modular retainer was successfully tested and showed potential for new actuator applications.

  12. Evaluation of effect of addition of 2% chlorhexidine on the sealing ability of Biodentine: An in vitro study

    Science.gov (United States)

    Suri, Navleen Kaur; Nikhil, Vineeta; Jha, Padmanabh; Jaiswal, Shikha

    2015-01-01

    Aim: To evaluate the effect of the addition of 2% chlorhexidine on the sealing ability of Biodentine. Materials and Methods: Forty-six extracted human premolar teeth with single canal and apical foramen were selected, cleaned, and decoronated to standardize the length of 17 mm. Canals were prepared using ProTaper rotary files till size F4. The samples were divided into 2 experimental groups of 20 samples each on the basis of absence/presence of 2% chlorhexidine in liquid: Group BM = Biodentine mixed with the provided liquid, Group BC = Biodentine mixed with 2% chlorhexidine in provided liquid. Three samples, each were assigned to control groups: Group BP (positive control) = No root end filling was placed, Group BN (negative control) = Root ends were filled as in Group BM, and entire external surface was coated with sticky wax. The samples were then evaluated for the apical sealing using fluid filtration method. Results: Results were analyzed using Student's t-test (P ≤ 0.05). Group BC showed the better sealing ability (3.06) as compared to Group BM (3.85). However, the difference was statistically insignificant (P > 0.05). Conclusion: Addition of 2% chlorhexidine to the liquid enhanced the sealing ability of Biodentine. PMID:26752844

  13. Clinical results with two different methods of root-end preparation and filling in apical surgery: mineral trioxide aggregate and adhesive resin composite

    DEFF Research Database (Denmark)

    von Arx, Thomas; Hänni, Stefan; Jensen, Simon Storgård

    2010-01-01

    The aim of apical surgery is to hermetically seal the root canal system after root-end resection, thereby enabling periradicular healing. The objective of this nonrandomized prospective clinical study was to report results of 2 different root-end preparation and filling methods, ie, mineral triox...

  14. 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.

  15. Filling of carbon nanotubes and nanofibres

    Directory of Open Access Journals (Sweden)

    Reece D. Gately

    2015-02-01

    Full Text Available The reliable production of carbon nanotubes and nanofibres is a relatively new development, and due to their unique structure, there has been much interest in filling their hollow interiors. In this review, we provide an overview of the most common approaches for filling these carbon nanostructures. We highlight that filled carbon nanostructures are an emerging material for biomedical applications.

  16. Comparative study of sealing ability of three root canal sealers

    Directory of Open Access Journals (Sweden)

    Khedmat S.

    2007-07-01

    Full Text Available Background and Aim: Complete obturation of the prepared root canal is an essential step in endodontic treatment. Combination of gutta-percha and a sealer is widely used in clinical practice for root canal obturation, thus microleakage studies on sealing properties of these materials constitute an important part of endodontic researches. The aim of this study was to evaluate the microleakage of three root canal sealers: Apexit, AH26 and Dorifill by electrochemical method.Materials and Methods: In this experimental study, 55 extracted human maxillary and mandibular cuspids were used. The coronal part of teeth were removed and the root canals were prepared using the step-back technique. The specimens were randomly divided into 3 groups of 17 samples each. Teeth in each group were filled with one of the sealers and gutta-percha by lateral condensation technique. 4 specimens served as positive and negative controls. An electrochemical method was used for evaluation of apical leakage with the electrical source potential of 10 V. Measurements of current flow through the test system were recorded every 72 hours. Data were analyzed by Kruskall Wallis and Mann Whitney tests. P<0.05 was considered as the level of significance.Results: All specimens of the three groups showed low initial leakage that increased during the test period. The mean leakage in Apexit group was higher than AH26 and Dorifill groups. The lowest mean leakage was related to Dorifill group. Although no statistically significant difference was observed between this sealer and AH26.Conclusion: The results of this study revealed that the best apical seal was obtained using Dorifill and AH26 sealers. The poorest result was observed in Apexit.

  17. Properties of Sealing Materials in Groundwater Wells

    DEFF Research Database (Denmark)

    Köser, Claus

    years collected data on water chemistry from groundwater wells throughout the country. Based on these data it has been found that the levels of pesticides and their degradation products have been exceeded in many cases. The content of pesticides and degradation products can be the results of leaky...... pellets as sealing material in groundwater wells. The way and the pattern, in which bentonite pellets are deposited, have been shown to have an effect on the swelling pressure of the bentonite seal. During the transport phase of pellets from the terrain to a given sedimentation depth, a sorting process...... 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....

  18. Numerical simulation of radial compressor stages with seals and technological holes

    Directory of Open Access Journals (Sweden)

    Syka Tomáš

    2014-03-01

    Full Text Available Article describes numerical simulations of an air flow in radial compressor stages in the NUMECA CFD software. Four different radial compressor stages were solved in this article. During the tasks evaluating the stepped and straight impeller seals and technological holes influence on working characteristics and the flow field was observed. Also the CFD results comparison with results from the empiric design tool is described.

  19. Influence of sealing post-treatments on the corrosion resistance of PEO coated AZ91 magnesium alloy

    Science.gov (United States)

    Mingo, B.; Arrabal, R.; Mohedano, M.; Llamazares, Y.; Matykina, E.; Yerokhin, A.; Pardo, A.

    2018-03-01

    The effect of three different post-treatments carried out on Plasma Electrolytic Oxidation (PEO) coated magnesium alloys are evaluated in terms of characterisation and corrosion resistance. Special interest is given to the role of a common additive (NaF) to the coating properties. The post-treatments are based on immersion sealing processes in aqueous solutions of inorganic salts (cerium and stannate based salts) and alcoholic solution of an organic acid (octodecylphosphate acid, ODP). Sealing mechanisms for each post-treatment are proposed. Cerium and stannate sealings are based on filling of the pores with the products of dissolution/precipitation reactions, while the ODP acid sealing is based on the formation of a thin layer of ODP over the coating through specific interactions between the polar part of the organic acid and the coating surface. All coatings are evaluated by salt fog test and analysed by electrochemical impedance spectroscopy. All sealings show a slight increase in the corrosion resistance of the coatings formed in the NaF-free electrolyte, but their positive influence is boosted in case of the coatings obtained in the NaF-containing electrolyte. This is related to the chemical and morphological changes at the coating surface induced by the presence of NaF in the electrolyte.

  20. A Literature Review of Sealed and Insulated Attics—Thermal, Moisture and Energy Performance

    Energy Technology Data Exchange (ETDEWEB)

    Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-08-01

    In this literature review and analysis, we focus on the thermal, moisture and energy performance of sealed and insulated attics in California climates. Thermal. Sealed and insulated attics are expected to maintain attic air temperatures that are similar to those in the house within +/- 10°F. Thermal stress on the assembly, namely high shingle and sheathing temperatures, are of minimal concern. In the past, many sealed and insulated attics were constructed with insufficient insulation levels (~R-20) and with too much air leakage to outside, leading to poor thermal performance. To ensure high performance, sealed and insulated attics in new California homes should be insulated at levels at least equivalent to the flat ceiling requirements in the code, and attic envelopes and ducts should be airtight. We expect that duct systems in well-constructed sealed and insulated attics should have less than 2% HVAC system leakage to outside. Moisture. Moisture risk in sealed and insulated California attics will increase with colder climate regions and more humid outside air in marine zones. Risk is considered low in the hot-dry, highly populated regions of the state, where most new home construction occurs. Indoor humidity levels should be controlled by following code requirements for continuous whole-house ventilation and local exhaust. Pending development of further guidance, we recommend that the air impermeable insulation requirements of the International Residential Code (2012) be used, as they vary with IECC climate region and roof finish. Energy. Sealed and insulated attics provide energy benefits only if HVAC equipment is located in the attic volume, and the benefits depend strongly on the insulation and airtightness of the attic and ducts. Existing homes with leaky, uninsulated ducts in the attic should have major savings. When compared with modern, airtight duct systems in a vented attic, sealed and insulated attics in California may still provide substantial benefit

  1. Experimental Research and CFD Calculations Based Investigations Into Gas Flow in a Short Segment of a Heavily Worn Straight Through Labyrinth Seal

    Directory of Open Access Journals (Sweden)

    Joachimiak Damian

    2017-06-01

    Full Text Available Steam turbines are used as propulsion components in not only power plants but also on merchant and naval ships. The geometry of the steam turbine seals changes throughout the machine life cycle. The rate of deterioration of these seals, in turn, affects heavily the efficiency of the thermal machine. However, the literature overview does not provide any research reports on flow phenomena occurring in heavily deteriorated seals. The paper describes the course and results of investigations into a model straight through labyrinth seal composed of 4 discs, each with the slot height of 2 mm. The investigations have been conducted with air as the working medium. Changes of gas flow parameters due to wear were analysed. Based on the experimental data, more intensive leakage was observed as the result of the increased slot height. The static pressure distribution along the examined segment was measured. The experimentally recorded distribution differed remarkably from the theoretical assumptions. Another part of the experimental research focused on comparing the gas velocities at points situated upstream of the first and second seal disc. The velocity measurements were carried out using a constant temperature wire probe. This part of the investigations provided opportunities for analysing the influence of seal wear on gas flow conditions in the seal segment. The paper compares the results of the experimental research with those obtained using the CFX software. The presented results of velocity distributions provide a clear picture of the nature of the gas flow in the seal, which enables its analysis.

  2. A Novel SOFC/SOEC Sealing Glass with a Low SiO2 Content and a High Thermal Expansion Coefficient  

    DEFF Research Database (Denmark)

    Kiebach, Wolff-Ragnar; Agersted, Karsten; Zielke, Philipp

    2017-01-01

    Solid oxide cells require seals that can function in harsh, elevated temperature environments. In the case of solid oxide electrolysis (SOEC), also a low Si content is desired, since Si impurities from the glass sealing can be transported to the active fuel electrode and poison the Ni-YSZ triple...... and the adhesion behavior of the glass were studied under relevant SOFC and SOEC conditions. The stability of sealed Crofer/Glass/NiO-YSZ assemblies in reducing atmosphere and in air was investigated for over 500 h at temperatures between 750 °C and 850 °C. Additionally, a cell component test was performed...

  3. Army gas-cooled reactor systems program: an evaluation of the state-of-the-art of high-speed seals

    Energy Technology Data Exchange (ETDEWEB)

    None

    1964-12-01

    A literature survey was conducted to determine and evaluate the various types of seals which might be acceptable for use in the ML-1 t-c set and, based on this evaluation, to recommend the next logical steps in the seal development program. The survey indicated that six seal concepts exist which might satisfy the ML-1 air cycle requirements. Theoretical evaluation revealed that four of the concepts were sufficiently attractive to warrant experimental evaluation; the fifth did not appear acceptable and insufficient data existed to permit an evaluation of the sixth concept. The six concepts and summary comments concerning each are shown.

  4. Miniature magnetic fluid seal working in liquid environments

    Energy Technology Data Exchange (ETDEWEB)

    Mitamura, Yoshinori, E-mail: ymitamura@par.odn.ne.jp [Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814 (Japan); Durst, Christopher A., E-mail: chris@procyrion.com [Procyrion, Inc., Houston, TX 77027 (United States)

    2017-06-01

    This study was carried out to develop a miniature magnetic fluid (MF) seal working in a liquid environment. The miniature MF seal is intended for use in a catheter blood pump. The requirements for the MF seal included a size of less than Ø4×4.5 mm, shaft diameter of 1 mm, sealing pressure of 200 mmHg, shaft speed of up to 40000 rpm, and life of one month. The miniature MF seal was composed of an NdFeB magnet (Ø4×Ø2×1) sandwiched between two pole pieces (Ø4×Ø1.1×0.5). A shield (Ø4×Ø1.2×1.5) was placed on the pole piece facing the liquid to minimize the influence of pump flow on the MF. The seal was installed on a Ø1 shaft. A seal was formed by injecting MF (Ms: 47.8 kA/m and η: 0.5 Pa·sec) into the gap between the pole pieces and the shaft. Total volume of the MF seal was 44 μL. A sealing pressure of 370 mmHg was obtained at motor speeds of 0-40,000 rpm. The seal remained perfect for 10 days in saline under the condition of a pump flow of 1.5 L/min (The test was terminated in accordance with plans). The seal remained intact after ethylene oxide sterilization during which the seal was exposed to high pressures. In conclusion, the newly developed MF seal will be useful for a catheter pump. - Highlights: • A miniature magnetic fluid seal working in a liquid environment was developed. • The seal can be installed on Ø1 mm shaft and can seal against 370 mmHg at 40000 rpm. • The magnetic fluid seal will be useful for a catheter blood pump.

  5. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement.

    Science.gov (United States)

    Van Metre, Peter C; Majewski, Michael S; Mahler, Barbara J; Foreman, William T; Braun, Christopher L; Wilson, Jennifer T; Burbank, Teresa L

    2012-06-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH(8)) in the 0.03-m samples above sealed lots (1320 ng m(-3)) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m(-3)). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m(-3)) was five times greater than above unsealed lots (26.0 ng m(-3)). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m(-2) h(-1), respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces. Published by Elsevier Ltd.

  6. 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.

  7. Push-out bond strength of RealSeal SE and AH Plus after using different irrigation solutions.

    Science.gov (United States)

    Stelzer, Reimund; Schaller, Hans-Günter; Gernhardt, Christian Ralf

    2014-10-01

    The aim of this investigation was to evaluate the influence of different endodontic irrigants (sodium hypochlorite [NaOCl], chlorhexidine [CHX], and EDTA) on the push-out bond strength of the obturation materials RealSeal SE (SybronEndo, Orange, CA) and AH Plus (Dentsply International Inc, York, PA). Two hundred human root canals were prepared and divided into 2 groups according to the filling material (RealSeal SE vs AH Plus). Each group was subdivided into 5 groups according to the irrigation protocol (0.9% saline [control], 3% NaOCl, 3% NaOCl with saline, 17% EDTA, and 2% CHX). After obturation, roots were sliced into 1-mm discs for push-out assessment. Compressive loading was performed using an universal testing machine at a speed of 0.5 mm/min. Two-way analysis of variance and the Kruskal-Wallis test were performed for pair-wise comparisons to assess the differences between the experimental groups. AH Plus exhibited a significantly higher bond strength than RealSeal SE (mean = 2.53 and 1.53 MPa, respectively; P .05). Within the AH Plus groups, no significant differences existed between the irrigants and saline alone (P > .05). The bond strength of RealSeal SE with saline alone or with NaOCl and saline did not differ from that of AH Plus with saline alone (P > .05). However, the push-out bond strength of RealSeal SE decreased by approximately half (P < .05 compared with RealSeal SE with saline alone) after rinsing with NaOCl alone, EDTA, or CHX. The bond strength of RealSeal SE is highly influenced by the irrigant used. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Solid state switch panel. [using hermetic sealing

    Science.gov (United States)

    Beenfeldt, E.

    1974-01-01

    An intensive study of various forms of transducers was conducted with application towards hermetically sealing the transducer pick off and all electronics. The results indicated that the Hall effect devices and a LED/phototransistor combination were the most practical for this type of application. Therefore, hardware was developed utilizing a magnet/Hall effect transducer for single action switches and LED/phototransistor transducers for rotary multiposition or potentiometer applications. A number of switches were built and models were hermetically sealed to prove the feasibility of this type of fabrication. One of each type of switch was subjected to temperature cycling, vibration, and EMI tests.

  9. 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...

  10. Salmonella and Campylobacter spp. in northern elephant seals, California

    National Research Council Canada - National Science Library

    Stoddard, Robyn A; Gulland, M D Frances; Atwill, E Rob; Lawrence, Judy; Jang, Spencer; Conrad, Patricia A

    2005-01-01

    Campylobacter and Salmonella spp. prevalence and antimicrobial drug sensitivity were determined in northern elephant seals that had not entered the water and seals that were stranded on the California coast...

  11. 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.

  12. Effectiveness of crack sealing on pavement serviceability and life.

    Science.gov (United States)

    2011-06-01

    This report presents the details of a study to evaluate effectiveness of Ohio Department of Transportations prevailing crack sealing program. Evaluation was performed through field monitoring a large number of crack sealed and control sections. Fi...

  13. 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.

  14. 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...

  15. Performance evaluation of seal coat materials and designs.

    Science.gov (United States)

    2011-01-01

    "This project presents an evaluation of seal coat materials and design method. The primary objectives of this research are 1) to evaluate seal coat performance : from various combinations of aggregates and emulsions in terms of aggregate loss; 2) to ...

  16. Performance oriented guidance for Mississippi chip seals - volume II.

    Science.gov (United States)

    2013-12-01

    A laboratory and field study was conducted related to long term chip seal performance. This reports primary : objective was to initiate development of a long term performance (LTP) test protocol for chip seals focused on : aggregate retention. Key...

  17. Kansas Department of Transportation 2014 chip seal manual.

    Science.gov (United States)

    2014-03-01

    A chip seal is a very effective thin surface treatment process used by maintenance managers to : preserve existing asphalt pavements. The Kansas Department of Transportation (KDOT) 2014 Chip Seal : Manual is a guide that provides guidelines, backgrou...

  18. Analysis of Influence of Goaf Sealing from Tailgate On the Methane Concentration at the Outlet from the Longwall

    Science.gov (United States)

    Tutak, Magdalena; Brodny, Jaroslaw

    2017-12-01

    One of the most common and most dangerous gas hazards in underground coal mine is methane hazard. Formation of dangerous, explosive concentrations of methane occurs the most often in the region of crossing of longwall with the ventilation gallery. Particularly it applies to longwalls ventilated in „U from bounds” system. Outflow of gases from the goaf to the tailgate takes place through the boundary surfaces of this sidewalk with goaf. Main cause of this process is a phenomenon of air filtration through the goaf with caving. This filtration is a result of migration of the part of ventilation air stream supplied to the longwall. This air is released into the goaf on the entire longwall length; however, its greater amount gets to the goaf with caving space at the crossing of maingate with exploitation longwall. Albeit, the biggest outflow of air mixture and gases from the goaf occurs in top gate in upper corner of the longwall. This is a result of pressure difference in this region. This phenomenon causes that to the space of heading besides the air also other gases present in the goaf, mainly methane, are released. Methane is an explosive gas. Most often boundaries of explosive mixtures of methane, air and inert gases are described by the so-called Coward triangle explosion. Within the limits of the occurrence of the concentration of explosive methane explosion initials may be endogenous fire, blasting or sparks arising from friction of moving lumps of rock. Therefore, in order to decrease its concertation in this region, by limiting its outflow from the goaf with caving different actions are taken. One of such action is sealing of goaf from top gate side. Analysis of impact of sealing of these goaf on the methane concentration at the outlet of longwall is main aim of studies researches. Model of tested region, together with boundary conditions (including parameters of flowing air and the methane content) was developed on the base of real data from one of the

  19. Ecology, tourism and management of harbour seals (Phoca vitulina)

    OpenAIRE

    Granquist, Sandra M.

    2016-01-01

    In cases where human and wildlife are co-using the same geographical areas and resources, management issues often get complex and stakeholder conflicts are common. The Icelandic harbour seal (Phoca vitulina) population is rapidly decreasing, but direct culling of seals still occurs. At the same time seals are becoming an important resource due to increased interest in wildlife watching. Despite the complicated management situation, the Icelandic harbour seal population is one of the least stu...

  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.