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Sample records for grooved oil seal

  1. CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.

  2. Grooving corrosion of seam welded oil pipelines

    Directory of Open Access Journals (Sweden)

    Mohamed Hanafy El-Sayed

    2014-10-01

    Full Text Available 24” pipeline carrying oil was failed in the form of longitudinal crack at the 6 O’clock position resulting in oil spill. The failed pipe was investigated to reveal the main cause of its failure. The procedure of investigation was built on studying the intact pipe, rupture area, parent material, and intact weld. Results of chemical analysis, mechanical properties, and microstructure of the pipe material were confirmed with the specified standard. Cracks were originated from weld defected sites, initiated by grooving corrosion, propagated by inertia at the normal designed pressure condition, and stopped when stress relief is attained. It is recommended to use high quality ERW pipe, with its seam weld line positioned around the 12 O’clock during installation, to minimize and decelerate grooving corrosion. It is also important to perform regular or routine inspection, on suitable intervals, determined by past experience.

  3. Optimization design of main parameters for double spiral grooves face seal

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The optimization design of the parameters, such as the groove depth, groove number, ratio of the groove width to the land width, and spiral angle of a new kind of double spiral grooves face seal, which works under the condition of high velocity, high sealing pressure and ultra-low temperature, is presented under the assump-tion of fixed closure force by finite element analysis method. The results show that the stiffness of the maximum film can be obtained when the ratio of the groove width to the land width is 0.5 and the spiral angle is about 75 degrees, when the influence of the groove number on the sealing performance is not obvious.

  4. Optimization design of main parameters for double spiral grooves face seal

    Institute of Scientific and Technical Information of China (English)

    LIU Zhong; LIU Ying; LIU XiangFeng

    2007-01-01

    The optimization design of the parameters, such as the groove depth, groove number, ratio of the groove width to the land width, and spiral angle of a new kind of double spiral grooves face seal, which works under the condition of high velocity, high sealing pressure and ultra-low temperature, is presented under the assumption of fixed closure force by finite element analysis method. The results show that the stiffness of the maximum film can be obtained when the ratio of the groove width to the land width is 0.5 and the spiral angle is about 75 degrees, when the influence of the groove number on the sealing performance is not obvious.

  5. Numerical Simulation of the Flow Field in Circumferential Grooved Liquid Seals

    Directory of Open Access Journals (Sweden)

    Meng Zhang

    2013-01-01

    Full Text Available Circumferential grooved liquid seals are utilized inside turbomachinery to provide noncontacting control of internal incompressible fluid leakage. Accurate prediction of the flow field is fundamental in producing robust and efficient designs. To validate the capabilities of the computational fluid dynamics FLUENT for incompressible fluid seal flow, comparisons of velocity parameters are made to the published experimental results and other CFD code for a circumferential grooved liquid seal. This work employs a pressure-based CFD code FLUENT to calculate the flow field in the seal, using four different turbulence models respectively. The velocity contours are compared with experimental values. It shows good overall agreement of the axial, radial, and azimuthal velocities in the through-flow jet, shear layer, and recirculation zone. Quantitative comparisons of velocity profiles at the center of the groove are made to experiment. This study verifies the prediction accuracy of three turbulence models. Various structures were considered to obtain a better understanding of the circumferential grooved liquid flow characteristics. The best groove structure to control leakage was also found within the limited designed seal. This study will provide a useful reference for designing the circumferential grooved liquid seal.

  6. 表面微凹槽对机械密封性能的影响∗%The Sealing Performance of Mechanical Seals with Micro-grooves

    Institute of Scientific and Technical Information of China (English)

    张晓浩; 王晓雷

    2015-01-01

    采用FLUENT软件分析微凹槽结构对机械密封性能的影响,探讨凹槽深度比(凹槽深度与油膜厚度比值)、凹槽宽度比(微凹槽宽度与内环圆弧的直线长度比值)和凹槽长度比(微凹槽长度与圆环宽度比值)对开启力、液膜刚度、泄漏率的影响。结果表明:凹槽深度比、凹槽宽度比均存在一个最佳值使开启力和液膜刚度达到最大值,开槽深度与油膜厚度有着密切的关系;在凹槽宽度比一定时,凹槽宽度越大,开启力和液膜刚度也越大,而泄漏率基本保持不变,这表明毫米级宽度凹槽比微米级凹槽具有更好的密封性能;凹槽长度比越大,开启力和液膜刚度也越大,但是泄漏率也会同时增大。%The software FLUENT was used to analyze the effects on sealing performance of mechanical seals textured with micro⁃grooves. The effects of groove depth ratio ( ratio of the groove length to oil film thickness) , width ratio ( ratio of the groove width to length of inner arc straight line) and length ratio ( ratio of the groove length to the width of cirque) on sealing performance including opening force, leakage and stiffness of fluid film were discussed. The results show that groove depth ratio and width ratio can all be optimized to achieve max opening force and stiffness film, so the groove depth is closely related to film thickness. Under the same width ratio, opening force and film stiffness are increased as groove width and length increasing, while leakage ratio remains unchanged basically, which indicates that groove width of milli⁃meter scale is better than micrometer scale in sealing performance. The opening force and stiffness of fluid film will in⁃crease as length ratio increases, however leakage will also increase at the same time.

  7. Flow dynamics of a spiral-groove dry-gas seal

    Science.gov (United States)

    Wang, Bing; Zhang, Huiqiang; Cao, Hongjun

    2013-01-01

    The dry-gas seal has been widely used in different industries. With increased spin speed of the rotator shaft, turbulence occurs in the gas film between the stator and rotor seal faces. For the micro-scale flow in the gas film and grooves, turbulence can change the pressure distribution of the gas film. Hence, the seal performance is influenced. However, turbulence effects and methods for their evaluation are not considered in the existing industrial designs of dry-gas seal. The present paper numerically obtains the turbulent flow fields of a spiral-groove dry-gas seal to analyze turbulence effects on seal performance. The direct numerical simulation (DNS) and Reynolds-averaged Navier-Stokes (RANS) methods are utilized to predict the velocity field properties in the grooves and gas film. The key performance parameter, open force, is obtained by integrating the pressure distribution, and the obtained result is in good agreement with the experimental data of other researchers. Very large velocity gradients are found in the sealing gas film because of the geometrical effects of the grooves. Considering turbulence effects, the calculation results show that both the gas film pressure and open force decrease. The RANS method underestimates the performance, compared with the DNS. The solution of the conventional Reynolds lubrication equation without turbulence effects suffers from significant calculation errors and a small application scope. The present study helps elucidate the physical mechanism of the hydrodynamic effects of grooves for improving and optimizing the industrial design or seal face pattern of a dry-gas seal.

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

    Science.gov (United States)

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

    2016-05-01

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

  9. Palatal radicular groove: Clinical implications of early diagnosis and surgical sealing

    Directory of Open Access Journals (Sweden)

    P Corrêa-Faria

    2011-01-01

    Full Text Available Palatal radicular groove is a discreet alteration in tooth morphology, characterized by an invagination that begins near the cingulum of the tooth and moves in an apical direction. Clinically, palatal radicular groove may be associated with periodontal and/or endodontic problems. This paper describes a clinical case of a young patient with palatal radicular groove with no signs of periodontal disease or endodontic impairment. An early diagnosis was made and treatment consisted of surgical sealing of the defect. After a 2-year period, reexaminations demonstrated adequate hygiene, maintenance of tooth vitality and periodontal health. The early diagnosis and sealing of the groove observed surgically made the root surface smooth, avoiding subgingival bacterial plaque buildup, and preventing possible periodontal and/or pulp impairment stemming from the defect.

  10. Presentation of computer code SPIRALI for incompressible, turbulent, plane and spiral grooved cylindrical and face seals

    Science.gov (United States)

    Walowit, Jed A.

    1994-01-01

    A viewgraph presentation is made showing the capabilities of the computer code SPIRALI. Overall capabilities of SPIRALI include: computes rotor dynamic coefficients, flow, and power loss for cylindrical and face seals; treats turbulent, laminar, Couette, and Poiseuille dominated flows; fluid inertia effects are included; rotor dynamic coefficients in three (face) or four (cylindrical) degrees of freedom; includes effects of spiral grooves; user definable transverse film geometry including circular steps and grooves; independent user definable friction factor models for rotor and stator; and user definable loss coefficients for sudden expansions and contractions.

  11. Finite Element Analysis of the Misalignment Effects on the Dynamic Force Coefficients of Spiral Groove Gas Face Seals

    Science.gov (United States)

    Faria, Marco Tulio C.

    This paper presents a finite element procedure specially devised to analyze the misalignment effects on the behavior of spiral groove gas face seals operating at high speeds. In this study, the seal stationary face is slightly misaligned and the flexibly mounted face is perfectly aligned. Predictions of some steady-state and dynamic performance characteristics versus misalignment angle are presented for spirally grooved gas seals operating under stringent conditions. Curves of dynamic force coefficients versus the static misalignment angle of the seal face indicate that the seal misalignment affects considerably the dynamic response of gas lubricated face seals. At high speeds, the static seal misalignment not only results in increased stiffness coefficients but also leads to negative damping coefficients, which may be a sign of the seal susceptibility to excessive angular motions.

  12. Performance comparison and parametric study on spiral groove gas film face seals

    Institute of Scientific and Technical Information of China (English)

    LIU Yuchuan; SHEN Xinmin; XU Wanfu; WANG Zhili

    2004-01-01

    Several spiral groove gas film face seals (SGFS) with different layouts are compared quantitatively to analyze their merits and faults and application behaviors. In addition, a parametric study on downstream mode SGFS is conducted to determine its optimal parameters under certain working conditions. In the computation of gas film pressure on the face, finite element method (FEM) is applied to adapt to complicated geometrical boundary.

  13. Grooving corrosion of seam welded oil pipelines

    OpenAIRE

    2014-01-01

    24” pipeline carrying oil was failed in the form of longitudinal crack at the 6 O’clock position resulting in oil spill. The failed pipe was investigated to reveal the main cause of its failure. The procedure of investigation was built on studying the intact pipe, rupture area, parent material, and intact weld. Results of chemical analysis, mechanical properties, and microstructure of the pipe material were confirmed with the specified standard. Cracks were originated from weld defected sites...

  14. Pressure drop and cavitation investigations on static helical-grooved square, triangular and curved cavity liquid labyrinth seals

    Energy Technology Data Exchange (ETDEWEB)

    Asok, S.P., E-mail: asoksp@yahoo.co [Department of Mechanical Engineering, Mepco Schlenk Engineering College (MSEC), Sivakasi, Tamilnadu 626005 (India); Sankaranarayanasamy, K. [National Institute of Technology, Trichy (India); Sundararajan, T. [Indian Institute of Technology Madras, Chennai (India); Vaidyanathan, G. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam (India); Kumar, K. Udhaya [Department of Mechanical Engineering, MSEC, Sivakasi (India)

    2011-03-15

    Research highlights: Design and testing of newer and novel helical-grooved profiles of labyrinths capable of ensuring high pressure drops even at low liquid flow rates. Implementation of genetic algorithm in the optimization of labyrinth seal through surrogate modelling means. Application of CFD in three-dimensional fluid flow and cavitation analysis for static helical grooved labyrinth seals. - Abstract: Sodium cooled Fast Breeder Reactors (FBR) form the second stage of India's Nuclear power programme. Through a narrow annular space in the grid plate assembly of a prototype FBR, a very low leakage flow of liquid metal sodium should pass, experiencing a stipulated high pressure drop, and without much cavitation. To achieve this, a suitable labyrinth seal is required to be developed for use in the annulus. Water is employed as the model testing liquid which is estimated to experience a pressure drop ratio of 10.5 at the rated leakage flow. Previously studied circular or sinusoidal-grooved square, triangular or curved cavity labyrinth seals were unable to meet this value. In the present work, Computational Fluid Dynamics (CFD) analyses are carried out on Helical-grooved Square cavity Labyrinth Seals (HSLS), using commercial code Fluent. It is found that the geometrical configuration of the grooves plays a major role on the pressure drop. Experimental results reveal close agreement with CFD predictions. An optimal configuration of this square cavity seal is identified by applying genetic algorithm (GA) using commercial packages. It meets just about 24% of the targeted value. Later, using parametric CFD analyses, a Helical-grooved Triangular cavity Labyrinth Seal (HTLS) and different Helical-grooved Curved cavity Labyrinth Seals (HCLS) are analysed. The most favourable profile is tested and found to reach the required pressure drop. CFD cavitation analyses predict the intensity of cavitation in these seals to be below prohibitive levels.

  15. Prediction of leakage and rotordynamic coefficients for the circumferential-groove pump seal using CFD analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; Ha, Tae Woong [Gachon University, Seongnam (Korea, Republic of)

    2016-05-15

    The circumferential-groove seal is commonly used in various turbopumps to reduce leakage. The main goal of this paper is to develop the method of three-dimensional CFD analysis for determining leakage and rotordynamic coefficients of the circumferential-groovepump seal. A relative coordinate system was defined for steady-state simulation to calculate the velocity and pressure distributions of the seal clearance at each rotor whirl speed. Instead of setting the inlet and outlet pressures as the boundary conditions in the three dimensional CFD analysis, as it is more commonly done, we used the inlet velocity and outlet pressure obtained from a preliminary two dimensional CFD analysis. For prediction leakage, the presented analysis shows improvement from the bulk-flow model analysis. For the prediction of rotordynamic coefficients of K, k and C, the presented analysis provides results in closer agreement with the experimental values than those of the bulk-flow model analysis at several rotor speeds.

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

    Science.gov (United States)

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

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

  17. A finite element solution of the Reynolds equation of lubrication with film discontinuities: application to helical groove seals

    Science.gov (United States)

    Jarray, M.; Souchet, D.; Henry, Y.; Fatu, A.

    2017-02-01

    Helical groove seal, is one of the very few non-contact seals that have the capability to effectively seal a liquid. It finds use mainly in turbines and compressors. Although its reliability, this type of seals has not been investigated thoroughly because of its complex characteristics. This work presents a numerical analysis of a helical groove seal operating in laminar regime by means of solving the Reynolds equations for incompressible fluid film in steady state. Equations governing the fluid flow were solved by the finite element method. Although the simplifying assumptions of Reynolds model help to keep the computational time at an acceptable level, the inertia effects are neglected which may lead to unreliable results especially where the film thickness is discontinuous. The present approach, inspired by Arghir et al. [1] is able to take into account concentrated inertia effects, as described by a generalized Bernoulli equation. Comparisons made with the classical Reynolds model show that the film discontinuities should be taken into account when dealing with helically grooved seals. In addition, the leakage of fluid towards the air side was investigated for different parameters such as the groove angle and depth.

  18. An Improved Design of Spiral Groove Mechanical Seal%螺旋槽机械密封的改进设计

    Institute of Scientific and Technical Information of China (English)

    周剑锋; 顾伯勤; 陈晔

    2007-01-01

    The coupling effect among the flow of fluid film, the frictional heat of fluid film and the thermal deformation of sealing rings is inherent in mechanical seals. The frictional heat transfer analysis was carried out to optlmize the geometrical parameters of the sealing rings, such as the length, the inner radius and the outer radius. The geometrical parameters of spiral grooves, such as the spiral angle, the end radius, the groove depth, the ratio of the groove width to the weir width and the number of the grooves, were optimized by regarding the maximum bearing force of fluid film as the optimization objective with the coupling effect considered. The depth of spiral groove was designed to gradually increase from the end radius of spiral groove to the outer radius of end face in order to decrease the weakening effect of thermal deformation on the hydrodynamic effect of spiral grooves. The end faces of sealing rings were machined to form a divergent gap at inner radius, and a parallel gap will form to reduce the leakage rate when the thermal deformation takes place. The improved spiral groove mechanical seal possesses good heat transfer performance and sealing ability.

  19. Oil Leakage from the Seal Ring of a Scroll Compressor

    Science.gov (United States)

    Kobayashi, Naoki; Fukui, Atsushi; Horiguchi, Hironori; Tsujimoto, Yoshinobu; Toyama, Toshiyuki

    In scroll compressors for air conditioners, there is a compressor with back-pressure chamber spaced by seal ring behind orbiting scroll. High pressure in the backpressure chamber presses the orbiting scroll to fixed scroll. In the case that lubrication oil and refrigerant gas with high pressure and temperature in the backpressure chamber leak to low pressure chamber through the seal ring, the efficiency of compressor decreases and the oil circulation rate can increase. In the present study the leakage characteristics of lubrication oil from the backpressure chamber to the low pressure chamber were investigated. In experiment, it was found that the oil leakage is larger for higher rotational speed of rotating disk, higher viscosity of oil and smaller pressure difference between the backpressure and low-pressure chambers. This could be explained by the calculation in which the seal ring was assumed to have a tilt angle. It was also found in the calculation that oil leakage is larger due to the thicker oil film between the seal ring and the rotating disk in the case of higher rotational speed of the disk, higher viscosity of oil and smaller pressure difference between the backpressure and low-pressure chambers.

  20. Application of hydrophilic magnetic fluid to oil seal

    Science.gov (United States)

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

    1999-07-01

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

  1. 7.35% efficiency rear-irradiated flexible dye-sensitized solar cells by sealing liquid electrolyte in a groove.

    Science.gov (United States)

    Wang, Xiaopeng; Tang, Qunwei; He, Benlin; Li, Ru; Yu, Liangmin

    2015-01-11

    We report the feasibility of assembling rear-irradiated flexible dye-sensitized solar cells employing a transparent Ni-Se alloy counter electrode along with a groove stored TiO2 and liquid electrolyte. The flexible device with the NiSe counter electrode and anode at a groove depth of 36 μm yielded a maximum efficiency of 7.35%.

  2. Forensic identification of seal oils using lipid profiles and statistical models.

    Science.gov (United States)

    Broadwater, Margaret H; Seaborn, Gloria T; Schwacke, John H

    2013-03-01

    Seal blubber oils are used as a source of omega-3 polyunsaturated fatty acids in Canada but prohibited in the United States and (FA) European Union. Thus, a reliable method is needed to identify oils originating from seals versus fish. Two lipid profiling methods, fatty acid analysis using gas chromatography and triacylglycerol (TAG) analysis using liquid chromatography and mass spectrometry, were applied with statistical models to discriminate commercial oils and blubber samples harvested from marine fish and seals. Significant differences were observed among FA profiles, and seal samples differed from each of the fish oils (p ≤ 0.001). FA and TAG profiles were used to discriminate sample groups using a random forest classifier; all samples were classified correctly as seals versus fish using both methods. We propose a two-step method for the accurate identification of seal oils, with preliminary identification based on FA profile analysis and confirmation with TAG profiles.

  3. Navy GTE seal development activity

    Science.gov (United States)

    Grala, Carl P.

    1993-10-01

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

  4. Three Dimensional Numerical Simulation on the Micro-gap Flow Field of Spiral Groove Gas Film Seal%螺旋槽气膜密封微间隙流场的三维数值模拟

    Institute of Scientific and Technical Information of China (English)

    马纲; 赵伟; 沈心敏

    2012-01-01

    根据端面、柱面气膜密封的结构特点,建立端面螺旋槽与柱面螺旋槽气膜密封三维数值分析模型,基于有限体积法利用Fluent软件对端面、柱面气膜密封三维流场特性进行数值模拟研究.与试验结果和相关文献的算例比较验证了该三维数值模拟方法的正确性,为进一步进行密封界面表面状态模拟分析及气膜密封的设计应用提供了理论基础.%Based on the structure characteristics of the gas face and cylinder seal,the three dimensional model of spiral groove gas face and cylindrical seal were built, and the three dimensional micro-gap flow field was simulated by Fluent. The numerical simulation results agree well with the experimental data and theoretical value, which proves that it is feasible to simulate the micro-gap flow field of spiral groove gas film seal by the three dimensional numerical method. This research provides theoretical basis for further analysis of seal interface state and the design of gas film seal.

  5. 齿间浅槽结构对直通篦齿封严特性影响的实验%Experiments of leakage effects of rub-grooves on straight-through labyrinth seals

    Institute of Scientific and Technical Information of China (English)

    纪国剑; 吉洪湖; 王政伟

    2011-01-01

    在早期研究的结果上,提出了一种齿间浅槽结构的直通齿衬套,即在与篦齿齿腔正对的衬套上加工制成浅槽.这种齿间浅槽破坏了壁面射流附面层的轴向连续性,导致射流流经浅槽后向篦齿齿腔发生小角度偏转,这样能有效地降低直通篦齿的透气效应,进而降低泄漏量.实验结果表明,相比于传统的光滑衬套,浅槽泄漏系数显著降低,其中矩形浅槽下降15%,平行四边形浅槽下降30%,封严性能大大提高,这进一步说明迎来流方向,较小的迎风角有利于射流偏转,而当射流离开浅槽时,较大的开槽角度增加了射流的流动阻力,更利于射流的偏转.%Based on early studies, a straight-through labyrinth seal was developed,which has a bush with a rub-groove machined opposite the teeth cavity. The rub-groove manufactured on the smooth bush opposite to the tooth cavity destroys the continuity of the wall jet boundary layer, which lead to the jet flow change it direction and greatly improve sealing effect. The experimental studies show that it has a better sealing effect. The leakage coefficient of labyrinth seal with the rectangle rub-grooves is decreased 15% and the parallelogram rub-grooves 30%. Little windward angle of rub-grooves leads to jet deflection and big leeward angle of rub-grooves is beneficial to increase the resistance of the jet and also leads to jet deflection.

  6. Performance optimization of grooved slippers for aero hydraulic pumps

    Institute of Scientific and Technical Information of China (English)

    Chen Juan; Ma Jiming; Li Jia; Fu Yongling

    2016-01-01

    A computational fluid dynamics (CFD) simulation method based on 3-D Navier–Stokes equation and Arbitrary Lagrangian–Eulerian (ALE) method is presented to analyze the grooved slip-per performance of piston pump. The moving domain of grooved slipper is transformed into a fixed reference domain by the ALE method, which makes it convenient to take the effects of rotate speed, body force, temperature, and oil viscosity into account. A geometric model to express the complex structure, which covers the orifice of piston and slipper, vented groove and the oil film, is constructed. Corresponding to different oil film thicknesses calculated in light of hydrostatic equilibrium theory and boundary conditions, a set of simulations is conducted in COMSOL to analyze the pump characteristics and effects of geometry (groove width and radius, orifice size) on these characteristics. Furthermore, the mechanics and hydraulics analyses are employed to validate the CFD model, and there is an excellent agreement between simulation and analytical results. The simulation results show that the sealing land radius, orifice size and groove width all dramatically affect the slipper behavior, and an optimum tradeoff among these factors is conducive to optimizing the pump design.

  7. Performance optimization of grooved slippers for aero hydraulic pumps

    Directory of Open Access Journals (Sweden)

    Juan Chen

    2016-06-01

    Full Text Available A computational fluid dynamics (CFD simulation method based on 3-D Navier–Stokes equation and Arbitrary Lagrangian–Eulerian (ALE method is presented to analyze the grooved slipper performance of piston pump. The moving domain of grooved slipper is transformed into a fixed reference domain by the ALE method, which makes it convenient to take the effects of rotate speed, body force, temperature, and oil viscosity into account. A geometric model to express the complex structure, which covers the orifice of piston and slipper, vented groove and the oil film, is constructed. Corresponding to different oil film thicknesses calculated in light of hydrostatic equilibrium theory and boundary conditions, a set of simulations is conducted in COMSOL to analyze the pump characteristics and effects of geometry (groove width and radius, orifice size on these characteristics. Furthermore, the mechanics and hydraulics analyses are employed to validate the CFD model, and there is an excellent agreement between simulation and analytical results. The simulation results show that the sealing land radius, orifice size and groove width all dramatically affect the slipper behavior, and an optimum tradeoff among these factors is conducive to optimizing the pump design.

  8. Supercritical fluid chromatography of fish, shark and seal oils

    DEFF Research Database (Denmark)

    Borch-Jensen, Christina; Mollerup, Jørgen

    1996-01-01

    esters, cholesterol esters, diglycerides, triglycerides and ether lipids. Methods for the analysis of the marine oils depend on components present in the oil. When co-eluting lipid groups were present, modifications such as hydrogenation or TLC fractionation of the oils had to be made. In this paper...

  9. 基于数值模拟的矩形凹槽对直通型篦齿封严特性影响研究%Investigation on Effects of Rectangular Groove on Leakage of Straight-Trough Labyrinth Seal Based on Numerical Simulation

    Institute of Scientific and Technical Information of China (English)

    刘高文; 蒋兆午; 务卫涛; 夏全忠

    2013-01-01

    为了提升封严篦齿的封严性能,对在机匣上开设矩形凹槽的直通篦齿结构中的流动特征和封严性能进行了数值模拟,获得了凹槽篦齿的涡流结构、泄漏系数和封严效率,并与光滑篦齿的结果进行了对比.研究了凹槽尺寸、相对位置及压比和转速的影响.计算表明,矩形凹槽宽深比是影响凹槽篦齿封严性能的重要参数,当宽深比大于临界值时,相对于光滑齿的封严效率可大幅提升到15%左右.凹槽与篦齿间的轴向相对位置在一定范围内对凹槽齿的泄漏系数影响微小.数据还显示,压比和转速对凹槽齿的封严性能影响微小.%To promote the leakage performance of labyrinth seal,numerical simulations on the flow and seal characters of straight through labyrinth seal with a rectangular groove on the still case were carried out. Data of vortex structure,leakage coefficient and seal efficiency for the grooved labyrinth seal were obtained and compared with that of a smooth labyrinth seal. The effects of groove sizes,relative position between groove and tooth,pressure ratio and rotating speed were studied. Results show that the most important parameter that influences the leakage performance of grooved labyrinth seal is the ratio of groove width over depth. The seal efficiency can be increased up to 15% when the width/depth ratio of groove is larger than a critical value. The influence of the relative position between groove and tooth is less important if only the groove is just located between two teeth. Data also reveal that the influences of pressure ratio and rotating speed on the leakage performance of grooved labyrinth seal are small.

  10. Effects of feeding sunflower oil or seal blubber oil to horses with recurrent airway obstruction

    Science.gov (United States)

    Khol-Parisini, Annabella; van den Hoven, René; Leinker, Sandra; Hulan, Howard W.; Zentek, Juergen

    2007-01-01

    A crossover feeding trial was performed with 9 horses suffering from recurrent airway obstruction (RAO). The study aimed to determine whether ingestion of sunflower oil (SFO), rich in linoleic acid, or seal blubber oil (SBO), a source of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs), changes the fatty acid (FA) ratios in plasma and leukocyte membrane phospholipids (PLs) or the leukocyte numbers or proportions of cell types in the airways. We also investigated diet-related changes in respiratory rate, maximum change in pleural pressure (ΔPplmax), dynamic compliance (Cdyn), and pulmonary resistance (RL). Each animal was fed hay and oats supplemented with 320 mg/kg body weight (BW) of either SFO or SBO for 10 wk. Before and after the feeding periods, we performed FA analyses, cytologic testing of the pulmonary epithelial lining fluid (PELF), clinical scoring, and pulmonary function testing. The results demonstrated that supplementary FAs were readily ingested and incorporated into leukocyte cell membranes. The n-6:n-3 FA ratios in plasma and leukocyte PLs were reduced after SBO supplementation, as were the PELF leukocyte counts (P < 0.05). On the other hand, pulmonary function and clinical signs were not markedly changed by the different dietary FAs. These results indicate a possible influence of dietary n-3 PUFAs on the pulmonary inflammation of horses with RAO. Further studies are warranted to address effects on inflammatory mediators and clinical outcome. PMID:17193883

  11. Tritium contamination and decontamination of sealing oil for vacuum pump

    Energy Technology Data Exchange (ETDEWEB)

    Takeishi, T.; Kotoh, K.; Kawabata, Y.; Tanaka, J.I. [Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Kawamura, S.; Iwata, M. [ATOX Co. Ltd, Technoly Development Center, Kashiwa, Chiba (Japan)

    2015-03-15

    The existence of tritium-contaminated oils from vacuum pumps used in tritium facilities, is becoming an important issue since there is no disposal way for tritiated waste oils. On recovery of tritiated water vapor in gas streams, it is well-known that the isotope exchange reaction between the gas phase and the liquid phase occurs effectively at room temperature. We have carried out experiments using bubbles to examine the tritium contamination and decontamination of a volume of rotary-vacuum-pump oil. The contamination of the pump oil was made by bubbling tritiated water vapor and tritiated hydrogen gas into the oil. Subsequently the decontamination was processed by bubbling pure water vapor and dry argon gas into the tritiated oil. Results show that the water vapor bubbling was more effective than dry argon gas. The experiment also shows that the water vapor bubbling in an oil bottle can remove and transfer tritium efficiently from the tritiated oil into another water-bubbling bottle.

  12. 螺旋槽干气密封的热量平衡膜厚研究%Research on Heat Equilibrium Film Thickness of Spiral Groove Dry Gas Seal

    Institute of Scientific and Technical Information of China (English)

    产文; 宋鹏云

    2015-01-01

    干气密封在运转过程中,端面气膜因黏性剪切会产生一定的热量,气体从密封进口到出口因膨胀会吸收一定的热量。定量计算剪切热量和膨胀热量及研究其平衡关系,对干气密封的设计和操作非常重要。针对空气润滑的螺旋槽干气密封,基于间隙等体积的思想,利用当量间隙来等效密封槽台区的槽区和台区间隙,以及利用考虑绝热指数的端面气膜压力控制方程,分别获得剪切热量和膨胀热量的计算式;利用最小二乘拟合法分别获得剪切热量和膨胀热量随气膜厚度变化的表达式,并求得热量平衡膜厚。分别研究转速、槽深、槽宽坝宽比和热量传递系数对热量平衡膜厚的影响规律。结果表明,热量平衡膜厚随转速、热量传递系数的增加而逐渐增加;随槽深、槽宽坝宽比的增加而逐渐减小。%During the operation of dry gas seal, some heat ( frictional heat) will be generated by viscous shear in the end face gas film, and the gas will absorb some heat ( expansion heat) due to expansion when the gas flows from the inlet into the outlet�It is very importance for the design and operation of the dry gas seal to calculation the frictional heat and ex⁃pansion heat quantitatively and research the heat equilibrium�For the air lubricated spiral groove dry gas seal, the calcula⁃tion formula of the frictional heat was obtained by substituting equivalent clearance for the clearances of groove and land based on the concept of equal volume of the clearance, and the calculation formula of the expansion heat was obtained by solving the governing equations of film pressure modified by adiabatic exponent�The expressions of frictional heat and ex⁃pansion heat varying with the film thickness were obtained by using least square fitting method, respectively�The film thickness of heat equilibrium was got by solving the heat equilibrium equations�The variation of

  13. No Protection against DSS-induced Colitis by Short-term Pretreatment with Seal or Fish Oils in Rats

    Directory of Open Access Journals (Sweden)

    Gülen Arslan

    2007-01-01

    Full Text Available Background: Omega-3 (n-3 polyunsaturated fatty acids (PUFAs have modulating effects in several chronic inflammatory conditions. The aim of the present study was to test whether prior short-term dietary supplementation with n-3 (fish or seal oil or n-6 (soy oil PUFA rich oils would protect the development of dextran sulfate sodium (DSS-induced colitis in rats.Methods: Forty-eight male Wistar rats were divided into 6 groups: no intervention, sham, DSS, seal oil + DSS, fi sh oil +DSS and soy oil + DSS. Following 7 days of acclimatisation, 1 mL oil (seal, fish or soy or distilled water (sham was administered by gavage day 8 to 14. Colitis was induced by 5% DSS in drinking water from day 15 to 21. Rats were sacrificed on day 23. Histological colitis (crypt and inflammation scores, faecal granulocyte marker protein (GMP and quantitative fatty acid composition in red blood cells were measured.Results: Pretreatment with fish or seal oils did not significantly influence DSS induced inflammation. In fact, all the oils tended to exacerbate the inflammation. Soy oil increased the mean crypt score (P < 0.04, but not the inflammation score or GMP. The ratio of n-6 to n-3 fatty acids (FAs was 11 to 1 and 10 to 1 in standard diet and in red blood cells of control rats, respectively. Following administration of DSS, the ratio fell in all treatment groups (P < 0.001. The lowest ratios were seen in the groups receiving DSS + fi sh or seal oils (around 6 to 1.Conclusion: Short-term pretreatment with fish or seal oils did not protect against subsequent induction of colitis by DSS in this rat model. Whether the high ratio of n-6 to n-3 FAs in the standard diet concealed effects of n-3 FA supplementation should be further investigated.

  14. An Approximate Analytical Method of the Gas Film Pressure of the Outward Pumping Spiral Groove Dry Gas Seals%螺旋槽泵出型干气密封端面气膜压力近似解析计算

    Institute of Scientific and Technical Information of China (English)

    宋鹏云; 丁志浩

    2011-01-01

    Most of the spiral groove dry gas seals are inward pumping with the sealed high pressure gas being at the outside diameter sides. Recently,the outward pumping spiral groove dry gas seals have come to use with the pressured gas being at the inside diameter sides, but the sealed fluid, common liquid, being at the outside diameter sides of the sealing rings. An approximate analytical method was presented to calculate the gas film pressure between the two seal faces of the spiral groove dry gas seals,which stemmed from the narrow groove theory improved by Muijderman. An example was presented, and compared with corresponding inward pumping one. The calculated results show that the open force of the outward pumping is smaller than that of the corresponding inward pumping structure.%大多数螺旋槽干气密封采用高压密封气体在密封环外侧的泵入式结构.近来,出现了高压气体在密封环内侧的泵出型螺旋槽干气密封,而这类密封常用来密封液体介质.采用Muijderman完善的螺旋槽窄槽理论,给出泵出型螺旋槽干气密封端面气膜力的一种近似解析计算方法,给出计算案例,并与泵入型结构进行对比.计算结果表明,同样条件下,泵出型干气密封的端面开启力小于泵入型.

  15. TAML level 5 sealed junctions offer solutions for thermal production of heavy oil with multilateral wells

    Energy Technology Data Exchange (ETDEWEB)

    Fipke, S.R. [Halliburton, Houston, TX (United States)

    2009-07-01

    Multilateral wells are used in heterogenous heavy oil reservoirs to provide increased reservoir exposure. New level 5 junction designs have recently been developed by the Technical Advancement for Multilaterals (TAML) Association to provide the minimum temperature and pressure ratings required to effectively seal junctures and control the steam injection process during enhanced oil recovery (EOR) processes. This study described 2 new conceptual multilateral technology (MLT) design alternatives for use in steam assisted gravity drainage (SAGD) operations, notably stacked multilateral injectors above a multilateral producer, and a multilateral horizontally-applied steam drainage (ML-HASD). The designs addressed the thermal expansion, heat loss, and steam placement challenges caused by the steam flow's close proximity to the cooler oil being produced in the same borehole. It was concluded that both designs avoid the production problems associated with multilateral SAGD operations. 6 refs., 6 figs.

  16. Analysis of Oil Seal Radial Force by Ansys%基于Ansys的油封径向力分析

    Institute of Scientific and Technical Information of China (English)

    黄乐; 郭飞; 贾晓红; 索双富; 范清

    2013-01-01

    The experimental method to measure the radial force of inside framework oil seal is limited by the size of oil seal during measuring,and it is hard to estimate the oil seal radial force before the design.The finite element analysis (FEA) method was presented to predict the radial force of an oil seal,and the FEA model of inside framework oil seal was built.The radial force of oil seal was calculated by using the Ansys software,and the results were compared with the data measured by oil seal radial force measuring instrument.The result shows that these two results are fundamentally similar.%采用实验方法测量内骨架油封径向力时受油封规格的限制,且不能在设计前就预测油封径向力的大小.提出油封径向力的有限元分析方法,建立内骨架油封的有限元分析模型.采用限元分析软件Ansys计算了油封的径向力,并将计算结果与油封径向力测量仪测得的数据进行比较,结果证明采用有限元分析方法计算得到的油封径向力与实测结果基本吻合.

  17. 螺旋槽机械密封摩擦副界面流固耦合分析%Fluid-solid Coupling Analysis of the Friction Pair Interface for Spiral Groove Mechanical Seal

    Institute of Scientific and Technical Information of China (English)

    李宁; 穆塔里夫•阿赫迈德; 吕星刚

    2016-01-01

    Based on the 3D finite element models of the fluid-film and solid of the friction pair interface for spiral groove me-chanical seal,the fluid-film between the faces of the static and dynamic is simulated ,and the law of the pressure distribution was obtained,the result show that pressure distribution is nonlinear.After that,the pressure was imported into static analysis module as one boundary condition of dynamic ring,then the one-way fluid-solid weak coupling was achieved by automatic iterative of the two steps.,the values indicate that the maximum deformation occurs on the spiral groove in the face of dynamic ring,while the maxi-mum stress occurs on the end of the spiral groove.Further,the effect of the rotational speed of dynamic ring,the pressure differ-ence and the viscosity on the maximum deformation and stress were also studied,the result provide a beneficial reference for the optimization of sealing performance.%基于建立的三维螺旋槽机械密封摩擦副界面的流、固有限元模型,数值模拟了动静环端面间的流体膜,得到液膜的压力分布规律,结果显示压力呈非线性分布;然后将得到的压力值作为边界条件之一导入到动环端面的静力学分析中,利用两者接触面间的自动迭代计算实现单向弱流固耦合分析,结果表明:最大变形发生在动环端面螺旋槽处,而最大应力发生在螺旋槽顶端;并进一步研究了动环的转速以及介质压力和粘度对最大变形和最大应力的影响规律,为密封性能的优化提供了有益的参考。

  18. Performance Analysis of Spiral Groove Dry Gas Seal with MATLAB%基于MATLAB的螺旋槽干气密封性能分析

    Institute of Scientific and Technical Information of China (English)

    刘亚莉; 张强; 赵丽丽; 董华东; 戚俊清

    2012-01-01

    Based on Muijderman equation, the performance parameters of dry gas seal were calculated with MATLAB. Having calculation results compared with experimental data and CFD simulation results proves the reliability of employing MATLAB to analyze flow field over seal face. This provides a simple and visual method for researching pressure distribution over dry gas seal face and to optimize the seal performance parameters, as well as to increase its operation reliability.%基于穆特曼方程,以MATLAB计算干气密封性能参数,计算结果与实验数据、CFD软件模拟结果比较表明:MATLAB编程解决密封端面流场分析的方法可靠.为进一步研究螺旋槽干气密封端面压力分布规律,优化密封性能、提高运行稳定性提供了一种简单直观的方法.

  19. Oil-sealed femtoliter fiber-optic arrays for single molecule analysis.

    Science.gov (United States)

    Zhang, Huaibin; Nie, Shuai; Etson, Candice M; Wang, Raymond M; Walt, David R

    2012-06-21

    This paper describes a novel method for fabricating and sealing high-density arrays of femtoliter reaction chambers. We chemically etch one end of a 2.3 mm diameter glass optical fiber bundle to create an array of microwells. We then use a contact printing method to selectively modify the surface of the material between microwells with a hydrophobic silane. This modification makes it possible to fill the wells with aqueous solution and then seal them with a droplet of oil, forming an array of isolated reaction chambers. Individual β-galactosidase molecules trapped in these reaction chambers convert a substrate into a fluorescent product that can be readily detected because a high local concentration of product is achieved. This binary readout can be used for ultra-sensitive measurements of enzyme concentration. We observed that the percentage of wells showing enzyme activity was linearly dependent on the concentration of soluble β-galactosidase in the picomolar range. A similar response was also observed for streptavidin-β-galactosidase captured by biotinylated beads. These arrays are also suitable for performing single-molecule kinetics studies on hundreds to thousands of enzyme molecules simultaneously. We observed a broad distribution of catalytic rates for individual β-galactosidase molecules trapped in the microwells, in agreement with previous studies using similar arrays that were mechanically sealed. We have further demonstrated that this femtoliter fiber-optic array can be integrated into a PDMS microfluidic channel system and sealed with oil on-chip, creating an easy to use and high-throughput device for single-molecule analysis.

  20. Oil-sealed femtoliter fiber-optic arrays for single molecule analysis†‡

    Science.gov (United States)

    Zhang, Huaibin; Nie, Shuai; Etson, Candice M.; Wang, Raymond M.

    2012-01-01

    This paper describes a novel method for fabricating and sealing high-density arrays of femtoliter reaction chambers. We chemically etch one end of a 2.3 mm diameter glass optical fiber bundle to create an array of microwells. We then use a contact printing method to selectively modify the surface of the material between microwells with a hydrophobic silane. This modification makes it possible to fill the wells with aqueous solution and then seal them with a droplet of oil, forming an array of isolated reaction chambers. Individual β-galactosidase molecules trapped in these reaction chambers convert a substrate into a fluorescent product that can be readily detected because a high local concentration of product is achieved. This binary readout can be used for ultra-sensitive measurements of enzyme concentration. We observed that the percentage of wells showing enzyme activity was linearly dependent on the concentration of soluble β-galactosidase in the picomolar range. A similar response was also observed for streptavidin-β-galactosidase captured by biotinylated beads. These arrays are also suitable for performing single-molecule kinetics studies on hundreds to thousands of enzyme molecules simultaneously. We observed a broad distribution of catalytic rates for individual β-galactosidase molecules trapped in the microwells, in agreement with previous studies using similar arrays that were mechanically sealed. We have further demonstrated that this femtoliter fiber-optic array can be integrated into a PDMS microfluidic channel system and sealed with oil on-chip, creating an easy to use and high-throughput device for single-molecule analysis. PMID:22311152

  1. P TFE油封技术发展趋势%Development Trend of PTFE Oil Seal Technologies

    Institute of Scientific and Technical Information of China (English)

    胡泽华; 张红烨

    2015-01-01

    介绍聚四氟乙烯油封的研究发展过程以及目前国内外材料和结构的研究现状,展望聚四氟乙烯油封的发展趋势,指出PTFE油封总体技术方案应从流体动力学分析、油封结构深层次研发、油封唇口材料的深层次应用及油封台架试验验证方面入手,针对改善高转速下油封的跟随性、高温下唇口过盈力的保持及降低高线速度下唇口磨损方面进行重点技术研究,通过对油封腰部韧性、唇口回复性及油封润滑状态等方面的控制,来保证产品达到使用要求的性能与寿命。%The research and development process of Polytetrafluoroethylene ( PTFE) oil seal,and research status of its materials and structures at home and abroad were presented. Development trend of PTFE oil seal was prospected. It was pointed out that the overall technical scheme of PTFE oil seal should be started from the aspects of fluid dynamics analy⁃sis,the structure development of oil seal, the application of lip materials and the test verification of oil seal by bench test, study the key technologies including improving the following of oil lips in high rotational speed,maintaining the lip interfer⁃ence force of oil seal at high temperature and reducing the wear of seal lip under high linear speed,and ensure that prod⁃ucts met the requirements of the performance and use life through controlling the lubrication status of oil seal,the lip recov⁃ery and the toughness on the waist of seal lip.

  2. Maritime Renaissance: oil begins to make up for lost seals and fish

    Energy Technology Data Exchange (ETDEWEB)

    Reid, W.

    2000-12-04

    The economic recovery of Newfoundland as a result of success in the Hibernia oilfield off the coast of Newfoundland is discussed. Oil production and the transport of oil from the Hibernia to the mainland by rugged double-hulled tankers that are about five times bigger than any other ship in Canada in terms of carrying capacity is a welcome event, considering that the seal hunt and the fishing industry that formerly provided sustenance to the people of Newfoundland have died as a result of world-wide pressure by animal rights groups, and indiscriminate overfishing. Transport of the crude oil from the Hibernia field is provided by Canship Ugland, a St. John's-based firm which now operates a fleet of three tankers. Each of the three vessels are capable of carrying 850,000 barrels of oil, or more than four times Hibernia's daily production. The 'Vinland' the latest of the three tankers to be commissioned, was built in South Korea, is 272 metres long and 46 metres wide. The ship is expected to carry oil from the rig 315 kms offshore to the Newfoundland Terminal at Whiffen Head, where the oil is picked up by smaller vessels. The 'Vinland' is equipped with the dynamic positioning feature which lets the ship maintain its maneuverability and position even if half her power is lost. The company employs people from all over the province and puts millions of dollars annually into the Newfoundland economy. 1 photo.

  3. Short communication: Feeding linseed oil to dairy goats with competent reticular groove reflex greatly increases n-3 fatty acids in milk fat.

    Science.gov (United States)

    Martínez Marín, A L; Gómez-Cortés, P; Carrión Pardo, D; Núñez Sánchez, N; Gómez Castro, G; Juárez, M; Pérez Alba, L; Pérez Hernández, M; de la Fuente, M A

    2013-01-01

    A crossover experiment was designed to compare the effects of 2 ways of feeding linseed oil on milk fat fatty acid (FA) composition. Ten lactating goats, trained to keep competent their inborn reticular groove reflex, received a daily dose of linseed oil (38 g/d) either with their solid (concentrate) feed (CON) or emulsified in skim milk and bottle-fed (BOT). Two groups of 5 goats received alternative and successively each of the treatments in two 15-d periods. α-Linolenic acid in milk fat rose up to 13.7% in the BOT versus 1.34% in the CON treatment. The n-6 to n-3 FA ratio was significantly reduced in goats receiving bottle-fed linseed oil (1.49 vs. 0.49). Contents of rumen biohydrogenation intermediates of dietary unsaturated FA were high in milk fat of goats under the CON treatment but low in those in the BOT treatment. These results point to a clear rumen bypass of the bottle-fed linseed oil. This strategy allows obtaining milk fat naturally very rich in n-3 FA and very low in trans FA. Translating this approach into practical farm conditions could enable farmers to produce milk enriched in specific FA. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. SEAL AND SEAL DEVICE OF FLOATING ROOF OIL TANK%浮顶油罐的密封及密封装置

    Institute of Scientific and Technical Information of China (English)

    张晓东; 陈建平

    2001-01-01

    During the process of oil storage and transport,not only made thequantity loss,but also made the quality decreasing. Many methods were adopted,among them the most effective method was the application of floating roof.The floating roof roller frame seal thchnology developed at home realized dual seal and had the advantages of good adaptability,large sealing force,small friction force and multi-function combination etc.after put into operation,relative good economic benifit and social effect wew achieved.%油品在储存和转运过程中,不仅造成数量的损失,还会导致油品质量的下降。为此,人们采取了许多方法,其中最有效的方法是浮顶的应用。国内开发的浮顶滚轮骨架密封技术,实现了双重密封且具备适应性强、密封力大、摩擦力小及多功能组合等优点。投用后,获得了较好的经济效益和社会效益。

  5. Optimization design of oil grooves parameters in hydro-viscous drive%液黏调速离合器油槽结构参数优化设计

    Institute of Scientific and Technical Information of China (English)

    崔红伟; 潘鑫; 姚寿文; 闫清东

    2013-01-01

    为了减小液黏调速离合器的带排转矩,降低摩擦副的空载功率损失,以双圆弧油槽摩擦副为研究对象,建立基于计算流体动力学流场数值分析、实验设计方法、响应曲面法及数值优化算法为一体的液黏调速离合器摩擦副集成优化设计平台.分析液黏调速离合器摩擦副油槽参数对带排转矩的影响,对结构参数进行优化设计.结果表明:随着油槽宽度和油槽深度的增大,液黏调速离合器转矩均呈现下降的趋势,但是随着油槽数目的增多,液黏调速离合器转矩呈现单调上升的趋势.优化后,减小了液黏调速离合器的带排转矩,提高了发动机的实际输出功率.%The double arc oil grooves friction pairs in HVD was analyzed in order to reduce the drag torque of hydro-viscous drive (HVD) and decrease the no-load power loss of friction pairs.The iSIGHT integrated optimization design platform of friction pairs in HVD was built based on the computational fluid dynamics flow numerical simulation,the design of experiment (DOE),the response surface methodology (RSM)and the numerical optimization algorithm.The influencing and sensitivity analysis of frictional pairs oil grooves parameters on drag torque was analyzed.The grooves structure parameters were optimized.Results indicate that the drag torque is monotonously decreased with the increasing of the width and depth of oil grooves,and the drag torque is monotonously increased with the increasing of the number of oil grooves.The optimized friction pairs can reduce the drag torque of HVD by increasing the width and depth of oil grooves and reducing the numbers of oil grooves,thus improve the power output of engine.

  6. AFSC/NMML/CCEP: Characterizing and quantifying California sea lion and Pacific harbor seal use of offshore oil and gas platforms in California, 2013-2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — California sea lions (Zalophus californianus) and Pacific harbor seals (Phoca vitulina) use offshore oil and gas platforms as resting and foraging areas. Both...

  7. Design and operation problems related to water curtain system for underground water-sealed oil storage caverns

    Institute of Scientific and Technical Information of China (English)

    Zhongkui Li; Baoqi Lu; Jing Zou; Bin Xu; Zhizeng Zhang

    2016-01-01

    The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years’ experiences obtained from the first large-scale (millions of cubic meters) underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of“filling joints with water”is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles for design and

  8. Design and operation problems related to water curtain system for underground water-sealed oil storage caverns

    Directory of Open Access Journals (Sweden)

    Zhongkui Li

    2016-10-01

    Full Text Available The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years' experiences obtained from the first large-scale (millions of cubic meters underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of “filling joints with water” is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles

  9. Analyse the Cause of for Lubricating Oil into a Dry Gas Seal%一次干气密封进油事故的原因分析

    Institute of Scientific and Technical Information of China (English)

    张泳

    2011-01-01

    Dry gas seal is a new type and non-contact shaft seal,the seals must be running in a clean and dry state;The article for lubricating oil into dry gas seal reason is analyzed.%干气密封是一种新型、非接触式轴封,其密封端面必须处于清洁、干燥状态下运行;本文针对干气密封一次进油事故原因进行了分析。

  10. 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

  11. 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.

  12. Direction of improvement of the radial-face seals of rotor supports of the aircraft engines

    Directory of Open Access Journals (Sweden)

    Petr Bondarchuk

    2014-10-01

    Full Text Available Today the radial-face contacts seals are the most wide-spread type of sealers of the aircraft engine rotor supports. In the paper the main shortcomings of the radial-face contact seals are specified the removal of which will result in increase in the operating range in terms of the pressure and temperature of the sealing air, reduction of leakages and extension of life-time. On the basis of the literature, patents and catalogues of the manufacturing companies the modern trends of improvement of the sealing structure are considered. The innovative technical solution for the radial-face contact seal with oil lubrication has been developed allowing increasing its efficiency. In order to increase the sealing reliability the hydrodynamic grooves of unique form made with the use of a laser are used. High sealing efficiency is ensured due to the simultaneous application of principles of hydrostatic and hydrodynamic lubrication. The method of calculation of seal properties has been suggested. The results of testing the new type of sealing for the engine rotor support as part of a moving-base simulator and aircraft gas-turbine engine have been presented.

  13. Mathematical Model of Piston Ring Sealing in Combustion Engine

    Directory of Open Access Journals (Sweden)

    Koszałka Grzegorz

    2015-01-01

    Full Text Available This paper presents a mathematical model of piston-rings-cylinder sealing (TPC of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The paper contains descriptions of: assumptions used for developing the model, the model itself, its numerical solution as well as its computer application for carrying out simulation tests.

  14. Mathematical Model of Piston Ring Sealing in Combustion Engine

    OpenAIRE

    Koszałka Grzegorz; Guzik Mirosław

    2015-01-01

    This paper presents a mathematical model of piston-rings-cylinder sealing (TPC) of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The pape...

  15. Forming method of axial micro grooves inside copper heat pipe

    Institute of Scientific and Technical Information of China (English)

    LI Yong; XIAO Hui; LIAN Bin; TANG Yong; ZENG Zhi-xin

    2008-01-01

    The high-speed oil-filled ball spinning and drawing process was put forward to manufacture the axially grooved heat pipe with highly efficient heat-transfer performance, and the forming mechanism of micro-grooves inside the pipe was investigated. The key factors influencing the configurations of micro-grooves were analyzed. When the spinning depth varies between 0.4 mm and 0.5 mm, drawing speed varies from 200 mm/min to 450 mm/min, rotary speed is beyond 6 000 r/min and working temperature is less than 50 ℃, the grooved tubes are formed with high quality and efficiency. The ball spinning process uses full oil-filling method to set up the steady dynamic oil-film that reduces the drawing force and improves the surface quality of grooved copper tube.

  16. 湿式摩擦离合器摩擦片油槽对瞬态传热的影响%Influence of friction disk oil groove of wet friction clutch on transient heat transfer

    Institute of Scientific and Technical Information of China (English)

    张世军; 林腾蛟; 吕和生

    2009-01-01

    计算了湿式摩擦离合器摩擦片的热流密度和对流换热系数,建立了考虑油槽结构的摩擦片三维瞬态热传导有限元模型.借助ANSYS软件,分析了不同油槽宽度摩擦片的瞬态温度场,给出了摩擦片最高温度随时间的变化曲线和径向温度分布规律.结果表明,摩擦片最高温度出现在结合时间段中间附近,随油槽宽度增加摩擦片最高温度略有降低;由于油槽的影响,摩擦片径向温度呈阶跃分布,结合完成后摩擦片表面出现椭圆形热斑.%The heat flow density and convectional heat ex-change coefficient of friction disk in wet friction clutch were calcu-lated, and the finite element model of 3D transient heat conduction of friction disk was estabhshed with the consideration of oil groove structure. By the aid of ANSYS software, the transient temperature field of friction disk with different oil groove widths was analyzed, and the highest temperature variation curve of the friction disk that varies with time and distribution low of radial directional tempera-ture were presented. The result showed that the highest temperature of friction disk arises nearby the middle segment of engaging time,and the highest temperature of friction disk would be slightly low-ered along with the increment of oil groove width. On account of the effect of oil groove the radial directional temperature of friction disk presented a stepped distribution. Elliptical hot spots appeared on the surface of friction disk after the engagement was accomplished.

  17. Pancreatic groove cancer

    Science.gov (United States)

    Ku, Yuan-Hao; Chen, Shih-Chin; Shyr, Bor-Uei; Lee, Rheun-Chuan; Shyr, Yi-Ming; Wang, Shin-E.

    2017-01-01

    Abstract Pancreatic groove cancer is very rare and can be indistinguishable from groove pancreatitis. This study is to clarify the characteristics, clinical features, managements, and survival outcomes of this rare tumor. Brief descriptions were made for each case of pancreatic groove cancer encountered at our institute. Individualized data of pancreatic groove cancer cases described in the literature were extracted and added to our database to expand the study sample size for a more complete analysis. A total of 33 patients with pancreatic groove cancer were included for analysis, including 4 cases from our institute. The median tumor size was 2.7 cm. The most common symptom was nausea or vomiting (89%), followed by jaundice (67%). Duodenal stenosis was noted by endoscopy in 96% of patients. The histopathological examination revealed well differentiated tumor in 43%. Perineural invasion was noted in 90%, and lymphovascular invasion and lymph node involvement in 83%. Overall 1-year survival rate was 93.3%, and 3- or 5-year survival rate was 62.2%, with a median survival of 11.0 months. Survival outcome for the well-differentiated tumors was better than those of the moderate/poorly differentiated ones. Early involvement of duodenum causing vomiting is often the initial presentation, but obstructive jaundice does not always happen until the disease progresses. Tumor differentiation is a prognostic factor for survival outcome. The possibility of pancreatic groove cancer should be carefully excluded before making the diagnosis of groove pancreatitis for any questionable case. PMID:28079795

  18. Effects of n-3 polyunsaturated fatty acids from seal oils on nonalcoholic fatty liver disease associated with hyperlipidemia

    Institute of Scientific and Technical Information of China (English)

    Feng-Shang Zhu; Su Liu; Xi-Mei Chen; Zhi-Gang Huang; Dong-Wei Zhang

    2008-01-01

    AIM: To investigate the efficacy and safety of n-3 polyunsaturated fatty acids (PUFA) from seal oils for patients with nonalcoholic fatty liver disease (NAFLD) associated with hyperlipidemia. METHODS: One hundred and forty-four patients with NAFLD associated with hyperlipidemia were included in the 24-wk, randomized, controlled trial. The patients were randomized into two groups. Group A (n = 72) received recommended diet and 2 g n-3 PUFA from seal oils, three times a day. Group B (n = 72) received recommended diet and 2 g placebo, three times a day. Primary endpoints were fatty liver assessed by symptom scores, liver alanine aminotransferase (ALT) and serum lipid levels after 8, 12, 16, and 24 wk. Hepatic fat infiltration was detected by ultrasonography at weeks 12 and 24 after treatment. RESULTS: A total of 134 patients (66 in group A, 68 in group B) were included in the study except for 10 patients who were excluded from the study. After 24 wk of treatment, no change was observed in body weight, fasting blood glucose (FBG), renal function and blood cells of these patients. Total symptom scores, ALT and triglyceride (TG) levels decreased more significantly in group A than in group B (P < 0.05). As expected, there was a tendency toward improvement in aspartate aminotransferase (AST), 7-glutamyltranspeptidase (GGT), and total cholesterol (TCHO) and high-density lipoprotein (HDL) cholesterol levels (P < 0.05) after administration in the two groups. However, no significant differences were found between the two groups. The values of low-density lipoprotein (LDL) were significantly improved in group A (P < 0.05), but no significant change was found in group B at different time points and after a 24-wk treatment. After treatment, complete fatty liver regression was observed in 19.70% (13/66) of the patients, and an overall reduction was found in 53.03% (35/66) of the patients in group A. In contrast, in group B, only five patients (7.35%, 5/68) achieved complete fatty

  19. Analysis on Oil Seal Leakage for Sprocket Assembly of Armored Face Conveyors%刮板输送机链轮轴组油封漏油分析

    Institute of Scientific and Technical Information of China (English)

    朱秀梅

    2014-01-01

    Armored face conveyor works in bad environment.Its floating oil seal installed in sprocket assembly is always failed and causes oil leakage,which may cause the lubricating oil waste and pollute the work environment,and even cause the damage of the bearing inside sprocket assembly.Various factors caused seal failure were analyzed from the quality of sprocket assembly floating oil seal,component installation,the habits of users and other aspects.It has a certain reference role to improve the seal reliability in sprocket assembly.%刮板输送机工作环境恶劣,其链轮轴组的浮动油封经常失效导致漏油,轻则造成润滑油浪费、工作环境被污染,重则导致链轮轴组内轴承损坏。从链轮轴组浮动油封自身质量、组件安装、用户使用等各环节对造成密封失效的各种因素进行分析,对提高链轮轴组密封可靠性有一定参考作用。

  20. 用于外浮顶油罐的BSMF型二次密封%BSMF TYPE SECONDARY SEAL FOR USE IN EXTERNAL FLOATING ROOF OIL TANK

    Institute of Scientific and Technical Information of China (English)

    方小芳; 姚定湘; 刘宗良

    2001-01-01

    石油及其产品在储存过程中的蒸发损耗,不仅造成油品数量的损失和环境污染,还导致油品质量的下降和增加不安全因素,因此对储油罐的密封是人们一直关注的问题。用于外浮顶油罐的二次密封,可以弥补一次密封的不足而使油品蒸发降低,大大减轻油气对环境造成的污染和减小不安全因素,并可保护一次密封免受阳光、雨雪、风沙的影响,从而保证储存油品的质量。%During the process of storage for petroleum and itsproduction,the evaporation loss not only makes the oil quanlity loss and envoriment pollution,but also makes the oil quality decrease and increase the unsafe factors.So the seal of oil tank is a problem with general great interesting.The secondary seal for the use of external floating roof oil tank may remedy the defect of fist seal,and makes oil evaporation decrease,So the envoroment pollution,caused by oil gas,reduces and the unsafe factors decrease.It can protects the first seal against the enfluence of sun light,rain and snow,wind and sand,and secure the quality of storage oil.

  1. 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

  2. 催化油浆泵密封失效分析及对策分析%Catalytic Slurry Oil Pump Seal Failure Analysis and Countermeasure Analysis

    Institute of Scientific and Technical Information of China (English)

    李健宗

    2016-01-01

    催化油浆泵输送的主要介质为高温的油浆,密度相较大,其中还含有坚硬的固体催化剂颗粒。由于受到工况介质等许多因素的影响,会使催化油浆泵出现机械密封失效的问题,导致油浆泄漏。对催化油浆密封失效的原因及其解决对策进行简要的分析。%the main transmission medium for high temperature catalytic slurry oil pump slurry oil,compared with big density, which also contains hard solid catalyst particles.Due to the influence of many factors such as working medium,can make the catalytic slurry oil pump mechanical seal failure problems,result in slurry oil leakage.The catalytic slurry oil seal failure made a brief analysis of the causes and countermeasures.

  3. Analysis Groove Characteristics of Friction Dishes in Wet Speeding Clutch

    Institute of Scientific and Technical Information of China (English)

    HongYue; LiuJin; JinShiliang

    2004-01-01

    The impacts of different groove shapes, numbers, and angle of friction dish on transmitting torque, speed, push pressure in wet speeding clutch are discussed in this paper. Since the wet speeed governing clutch works within hydrodynamic lubrication mixture lubrication. boundary, lubrication and contact situation, the oils combining with a-hydrocarbon or polyester are getting widely used as lubricant.The power-law fluid model with Patir-Cheng average flow model, GT asperity contact model and oil film inertia are applied for average Reynolds equation setting, In order to investigate the relationship between average push pressure within hydrodynamic lubrication and mixture lubrication, average transmitting torque and output speed, the numeral calculation and analysis are presented. According to calculation, it is found that the groove shape, groove angle and groove numbers affect the average transfer torque and push pressure with the speed rate.

  4. Film riding seals for rotary machines

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-07

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

  5. Sealing Performance Analysis and Optimization Design of Front-end Oil Seal of Diesel Engine%柴油机曲轴前油封密封性能分析及优化设计

    Institute of Scientific and Technical Information of China (English)

    李玉婷; 廖日东; 李杰

    2013-01-01

    利用ABAQUS软件建立某柴油机曲轴前油封的二维轴对称模型,在静态条件下计算分析油封材料参数、安装过盈量、前唇角以及后唇角对油封唇口最大Von Mises应力、接触压力及其分布的影响。结果表明,随橡胶硬度的增加,唇口最大接触压力几乎呈线性增长,适当提高橡胶硬度可改善密封性能;在曲轴未接触防尘唇前,唇口接触压力随安装过盈量的增大逐渐增大,当曲轴接触油封防尘唇后,油封密封唇口接触压力将减小,因此,在曲轴不接触油封的前提下应选择较大的安装过盈量;当前唇角为45°时,唇口最大接触压力取得最大值,而随后唇角的增加,唇口接触压力呈增大趋势。根据计算结果,对初始曲轴油封的材料和结构进行优化设计。试验证明,改进后的油封具有更好的密封性能。%The two-dimensional axial symmetric finite element model of the front-en d oil seal of a diesel engine was estab-lished by using ABAQUS.The effects of the material parameters,the amount of interference,and the low-angle and high-angle on the Von Mises stress,the size and distribution of the oil seal contact pressure under static conditions were analyzed and calculated.The results show that,along with increasing of rubber hardness,the max contact pressure on the lip is increased almost linearly.Sealing performance can be improved by suitably increasing rubber hardness.The contact pressure on the lip is increased gradually along with increasing of the amount of interference before the contact of crankshaft with dust-proof lip, and after that the contact pressure is decreased.Therefore,the larger value of interference must be chosen in the premise that the crankshaft is not in contact with the dust-proof lip.The maximum contact pressure value is reached the maximum value when the low-angle is at 45°,While along with increasing of the high-angle,the contact pressure along

  6. Groove / Solar energy cataloque; Groove aurinkoenergian yritysluettelo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-01

    According to Tekes, renewable energy offer Finnish companies opportunities for renewal and international growth. Especially in the field of solar energy, development is fast and the market is growing rapidly. The purpose of this catalogue is to provide information about organizations active in the field of solar energy so that different players can find each other more easily. Information is provided about organizations active both on the supply side (solar energy solution and service providers) and demand side (cities, construction contractors, real estate owners) as well as research teams at universities and research centers. We hope that this catalogue will help different actors to find each other both nationally and internationally so that good development and demonstration projects in the field of solar energy can get started. Tekes participates for instance in Solar Eranet, a joint effort of several funding organizations in Europe support transnational solar projects. This catalogue is provided by Tekes program Groove - Growth from renewables. Tekes' programmes and initiatives are topical entities targeted at financial and expert service areas. Within the programmes and initiatives, businesses and public research units can develop new know-how, build networks and have an impact on the development of their field. (orig.)

  7. Cognitive Interventions and Nutritional Supplements (The CINS Trial): A Randomized Controlled, Multicenter Trial Comparing a Brief Intervention With Additional Cognitive Behavioral Therapy, Seal Oil, and Soy Oil for Sick-Listed Low Back Pain Patients.

    Science.gov (United States)

    Reme, Silje E; Tveito, Torill H; Harris, Anette; Lie, Stein Atle; Grasdal, Astrid; Indahl, Aage; Brox, Jens Ivar; Tangen, Tone; Hagen, Eli Molde; Gismervik, Sigmund; Ødegård, Arit; Fryland, Livar; Fors, Egil A; Chalder, Trudie; Eriksen, Hege R

    2016-10-15

    A randomized controlled trial. The aim of this study was to evaluate whether a tailored and manualized cognitive behavior therapy (CBT) or nutritional supplements of seal oil and soy oil had any additional benefits over a brief cognitive intervention (BI) on return to work (RTW). Brief intervention programs are clinically beneficial and cost-effective for patients with low back pain (LBP). CBT is recommended for LBP, but evidence on RTW is lacking. Seal oil has previously been shown to have a possible effect on muscle pain, but no randomized controlled trials have so far been carried out in LBP patients. Four hundred thirteen adults aged 18 to 60 years were included. Participants were sick-listed 2 to 10 months due to LBP. Main outcome was objectively ascertained work participation at 12-month follow-up. Participants were randomly assigned to BI (n = 100), BI and CBT (n = 103), BI and seal oil (n = 105), or BI and soy oil (n = 105). BI is a two-session cognitive, clinical examination program followed by two booster sessions, while the CBT program is a tailored, individual, seven-session manual-based treatment. At 12-month follow-up, 60% of the participants in the BI group, 50% in the BI and CBT group, 51% in the BI and seal oil group, and 53% in the BI and soy oil group showed reduced sick leave from baseline, and had either partly or fully RTW. The differences between the groups were not statistically significant (χ = 2.54, P = 0.47). There were no significant differences between the treatment groups at any of the other follow-up assessments either, except for a significantly lower sick leave rate in the BI group than the other groups during the first 3 months of follow-up (χ = 9.50, P = 0.02). CBT and seal oil had no additional benefits over a brief cognitive intervention on sick leave. The brief cognitive intervention alone was superior in facilitating a fast RTW. 2.

  8. 提高唇形油封寿命的装配新工艺开发%New assembly technology development on increase of lip-shaped oil seal life

    Institute of Scientific and Technical Information of China (English)

    孙丽英; 张宏伟

    2011-01-01

    Various shafts surface treatment were adopted,and the seal abrasive experiments were carried on fitting with the lip-shaped oil seal,so the shaft surface treatment technology was obtained with good seal,little abrasion and long service life.The assembly technology was analyzed and tested on the oil seal quality and the lifespan effect,and three-dimension Pro/e assembly technology was obtained,which could better ensure the oil seal assembly quality and remarkably increase the lip-shaped oil seal life and airtight performance.%采用多种轴表面处理方式,并与唇形油封进行配合密封磨损试验,得到一种密封良好、磨损小、使用寿命长的轴表面处理工艺;就装配工艺对油封质量及寿命的影响进行了分析及试验,得出采用三维Pro/e装配工艺可更好地保证油封的装配质量,显著提高唇形油封的寿命及密封性能。

  9. Rotary seal with improved film distribution

    Energy Technology Data Exchange (ETDEWEB)

    Dietle, Lannie Laroy; Schroeder, John Erick

    2015-09-01

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

  10. 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.

  11. 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.

  12. 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.

  13. The Failure Mechanisms and Corrective Actions for a Connecting Rod Oil Seal of Straight Line Reciprocating Compressor%直线往复压缩机连杆油封失效原因分析及对策

    Institute of Scientific and Technical Information of China (English)

    耿爱农; 李辛沫; 陈君立; 阮勤江

    2011-01-01

    The causes of sealing failure of a connecting rod oil seal for a straight line reciprocating type compressor were analyzed, it was pointed that the main failure reasons in vibrating and rocking conditions were occurred from the seal lip' s elliptical strain deformation and reciprocating hysteresis behavior. Some appropriate measures were adopted:to set rigid follower sleeve to ensure the seal lip roundness,to set the limit moving ring to improve the seal ring lip' s following performance. The test confirms that the sealing property of the oil seal is significantly increased by using above corrective actions and the expected goals is achieved.%分析一种直线往复压缩机连杆油封在振动及摇摆环境下的密封失效原因,指出其故障根源来自于油封唇口的椭圆应变以及往复迟滞行为,对此采取了相应的措施:设置刚性随动套以保证油封唇口的圆度周正,设置限移环片以改善油封唇口的跟随性.经试验证实,上述改进措施明显提高了连杆油封的密封效果,达到了预期的目标.

  14. Room to Groove?

    DEFF Research Database (Denmark)

    Seabrooke, Leonard

    . As long as they stay within the parameters of legitimate financial practice to signal institutional isomorphism, the `groove', creditors may well allow borrowers room for change in self-determined ways. This paper maps out the historical and conceptual terrain concerning civilizing ideas about...... the legitimacy of financial practices within global capital markets, and investigates relationships between Western `civilizers' and Emerging Market Economies during the last two periods of financial globalization, the late-nineteenth/ early-twentieth centuries and the late-twentieth century.......The use of a `standard of civilization', a preferred form of socio-political organization, in global capital markets presents both constraints and opportunities for creditors and borrowers. When imposed, civilizing standards may change how a borrower would prefer to conduct their affairs. Creditors...

  15. 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

  16. Analysis of the Typical Faults of Single-ring Sealed Oil System of 300MW Unit%300MW机组单流环式密封油系统典型故障及分析

    Institute of Scientific and Technical Information of China (English)

    王晓辉

    2013-01-01

    The paper introduced the classification and features of seal oil system of hydrogen cooling generator, and analyzes the typical failure of single ring seal oil system in Matou Power Generation Company.%  介绍了氢冷发电机组密封油系统的分类和特点,并针对马头发电公司单流环密封油系统出现过的几次的典型故障做了详细的分析。

  17. Structural Design on Tooth Seal of Oil-Free Scroll Compressor%无油涡旋压缩机齿端面密封机构的设计∗

    Institute of Scientific and Technical Information of China (English)

    李海生; 陈英华; 吴开波; 张小卫; 王建松

    2015-01-01

    针对涡旋压缩机齿端面介质泄漏的特点,提出一种齿端面密封机构模型,通过齿端面开设的密封槽内安装自润滑材料密封条和弹簧,实现涡旋齿轴向间隙的密封。通过分析不同位置的密封条所受压差力情况,将密封条的工作状态分为无压差和有压差2种工况,分别建立密封机构的简化力学模型,通过密封条和动涡盘的受力分析,研究弹簧力、压差力和背压气体力3种载荷对密封机构工作过程的影响。结合受力分析结果,从密封槽深度、弹簧位移、背压腔直径等三方面,实现密封机构的结构设计,获得满足密封机构正常工作时的结构参数取值范围,为涡旋齿端面密封机构的设计提供了理论依据。%According to the leakage characteristics of the scroll tooth of scroll compressor, a mechanism model of sealing was presented in order to realize the sealing of axial clearance.The mechanism model consists of the seal element,and the seal element is made of self⁃lubricating materials and spring and is installed into the seal groove of scroll tooth.Through an⁃alyzing the differential pressure force of different positions, there are two kinds of working conditions for seal element,in⁃cluding with differential pressure condition and without differential pressure condition.The simplified mechanical model of the sealing mechanism was established according to the different working conditions,respectively.Through force analysis of the seal element and the orbiting scroll,the working process of the sealing mechanism under the action of the spring force, pressure difference and back pressure force of the orbiting scroll was studied.The structure design of the sealing mechanism was discussed in the light of the force analysis results in order to insure the normal work of sealing mechanism,and the structural parameters’ ranges were obtained,including the spring displacement,the seal groove

  18. Piston rod seal for a Stirling engine

    Science.gov (United States)

    Shapiro, Wilbur

    1984-01-01

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

  19. 航空液压油箱密封结构的改进及可靠性建模分析%Improvement and Reliability Modeling Analysis of Aviation Hydraulic Oil Tank Sealing Structure

    Institute of Scientific and Technical Information of China (English)

    焦留芳; 鲁兴红

    2015-01-01

    为提高航空液压油箱使用寿命,通过分析某液压油箱的密封结构,指出液压油箱中比较关键或容易出现问题的密封结构,并进行一系列改进。根据密封件的失效机制及失效原因,通过对失效条件进行组合、简化,建立密封结构可靠性分析模型,评估密封改进方案的可行性。航空液压油箱寿命试验和实际应用均验证了可靠性模型的正确性。密封件的可靠性建模分析方法,可用于液压油箱密封方案设计、设计方案评估、故障分析等。%In order to improve the service life of a aviation hydraulic oil tank,its sealing structure was analyzed. The sealing structures of the hydraulic tank which are key or prone to problems were pointed out,and a series of improvements were performed.According to the failure mechanism and the failure reason of the seal,the reliability analysis model of the sealing structure was established through combining and simplifying the failure conditions,and the feasibility of the seal improvement scheme was evaluated.The correctness of the reliability model was verified by the life tests and the practical application of aviation hydraulic tank. The reliability analysis method of the seal parts can be used for the design of the sealing scheme,the design scheme and the fault analysis of the hydraulic oil tank.

  20. Design and Analysis of Dumbbell-shaped Seal Ring of Hydraulic Oil Pumping System%液压抽油系统哑铃型密封圈设计与分析

    Institute of Scientific and Technical Information of China (English)

    朱拾东; 张建军; 刘猛; 师峻峰; 赵瑞东

    2013-01-01

    In the hydraulic oil pumping system with water as power fluid,the conventional O-ring and other sealing rings cannot meet the sealing requirements of not collusion for high and low pressure fluid. A new type of dumbbell-shaped seal ring was designed and its sealing mechanism was analyzed. The contact deformation and the contact stress distribution on the contact sealing interface under the action of the liquid pressure were analyzed by finite element analysis software. The results show that the designed dumbbell-shaped sealing structure can meet the sealing requirements of 16 MPa differential pressure of the hydraulic oil pumping system.%  在以水作为动力液介质的液压抽油系统中,常规的O型密封圈及其他密封圈都不能满足高、低压流体之间不串通的密封要求。设计了一种新型的哑铃型密封结构,并分析其密封机制;利用有限元软件分析在液体压力作用下密封圈的接触变形、接触密封界面上的接触应力分布。结果表明,设计的哑铃型密封结构可以满足要求液压抽油系统16 MPa压差的密封要求。

  1. 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.

  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. 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.

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

    Science.gov (United States)

    Liu, Tonggang; Cheng, Yusheng; Yang, Zhiyi

    2005-03-01

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

  5. An innovative approach in the management of palatogingival groove using Biodentine™ and platelet-rich fibrin membrane

    OpenAIRE

    Dexton Antony Johns; Vasundhara Yayathi Shivashankar; Shobha, K; Manu Johns

    2014-01-01

    Palatogingival groove is an anatomical malformation that often causes severe periodontal defects. Treatments of such an anomaly present a clinical challenge to the operator. Careful endodontic and periodontal procedures may restore the form and function. In the present case; root canal therapy, apicectomy, and sealing of the groove with Biodentine TM were done. Bone graft was placed followed by platelet-rich fibrin (PRF) membrane. This treatment modality resulted in gain in attachment, reduct...

  6. Soft Wire Seals For High Temperatures And Pressures

    Science.gov (United States)

    Tsou, Peter

    1996-01-01

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

  7. Discovery of Grooves on Gaspra

    Science.gov (United States)

    Veverka, J.; Thomas, P.; Simonelli, D.; Belton, M.J.S.; Carr, M.; Chapman, C.; Davies, M.E.; Greeley, R.; Greenberg, R.; Head, J.; Klaasen, K.; Johnson, T.V.; Morrison, D.; Neukum, G.

    1994-01-01

    We report the discovery of grooves in Galileo high-resolution images of Gaspra. These features, previously seen only on Mars' satellite Phobos, are most likely related to severe impacts. Grooves on Gaspra occur as linear and pitted depressions, typically 100-200 m wide, 0.8 to 2.5 km long, and 10-20 m deep. Most occur in two major groups, one of which trends approximately parallel to the asteroid's long axis, but is offset by some 15??; the other is approximately perpendicular to this trend. The first of these directions falls along a family of planes which parallel three extensive flat facets identified by Thomas et al., Icarus 107. The occurrence of grooves on Gaspra is consistent with other indications (irregular shape, cratering record) that this asteroid has evolved through a violent collisional history. The bodywide congruence of major groove directions and other structural elements suggests that present-day Gaspra is a globally coherent body. ?? 1994 Academic Press. All rights reserved.

  8. 海豹油脂肪乳的稳定性研究%Investigation on stabilities of seal oil based lipid emulsion

    Institute of Scientific and Technical Information of China (English)

    苏健芬; 周玥鋆; 柳晓蕊; 缪旭; 刘旭; 吴传斌

    2013-01-01

    Objective To investigate the stabilities of seal oil based lipid emulsions ( SOLE ). Methods The contents of main fatty acids EPA, DPA and DHA were measured by GC. The pH variation and values of free fatty acid and peroxidation were monitored, and the particle size and zeta potential of the emulsion were determined by TEM (Transmission electron microscopy) and zetasizer, respectively. Dilution experiments, influential factor experiments, accelerated trials [(25 ± 2)℃, preventing from light) , and long-term tirals (4 ± 2) ℃ , for 6 months ] were carried out to investigate the chemical and physical stabilities of the seal oil based lipid emulsions. Results The results of dilution experiments showed that injection of water and glucose had insignificant effects on the lipid emulsions in 10 hours, however, injection of sodium chloride led to obvious increase in particle size. The color of the emulsions changed to some extent under lamplight or elevated temperature while no obvious change in particle size was observed. However, the particle size increased evidently when the emulsions were frozen. The results of the accelerated and long-time trials showed all the measuring parameters kept unchanged, which suggested the emulsion was stable under the proper storing conditions. Conclusion The seal oil based lipid emulsion is stable for at least 6 months at room temperature or in 4 ℃ fridge, avoiding light, heating and freezing.%目的 考查海豹油脂肪乳的稳定性.方法 采用GC法测定海豹油脂肪乳中EPA、DPA、DHA的含量,并考察脂肪乳的pH、游离脂肪酸值和过氧化值,以表征其化学稳定性;以粒径和电位变化为指标考察其物理稳定性;同时,开展配伍稀释试验、影响因素试验、加速试验以及长期留样试验.结果 海豹油脂肪乳与注射用水和5%葡萄糖注射液在10h内有良好配伍稳定性,但与NaCl射液混合后乳滴粒径显著增大,两者不适宜配伍使用.影响因素

  9. Grooved organogel surfaces towards anisotropic sliding of water droplets.

    Science.gov (United States)

    Zhang, Pengchao; Liu, Hongliang; Meng, Jingxin; Yang, Gao; Liu, Xueli; Wang, Shutao; Jiang, Lei

    2014-05-21

    Periodic micro-grooved organogel surfaces can easily realize the anisotropic sliding of water droplets attributing to the formed slippery water/oil/solid interface. Different from the existing anisotropic surfaces, this novel surface provides a versatile candidate for the anisotropic sliding of water droplets and might present a promising way for the easy manipulation of liquid droplets for water collection, liquid-directional transportation, and microfluidics.

  10. 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...

  11. The minimum scale of grooving on faults

    NARCIS (Netherlands)

    Candela, T.; Brodsky, E.E.

    2016-01-01

    At the field scale, nearly all fault surfaces contain grooves generated as one side of the fault slips past the other. Grooves are so common that they are one of the key indicators of principal slip surfaces. Here, we show that at sufficiently small scales, grooves do not exist on fault surfaces. A

  12. The minimum scale of grooving on faults

    NARCIS (Netherlands)

    Candela, T.; Brodsky, E.E.

    2016-01-01

    At the field scale, nearly all fault surfaces contain grooves generated as one side of the fault slips past the other. Grooves are so common that they are one of the key indicators of principal slip surfaces. Here, we show that at sufficiently small scales, grooves do not exist on fault surfaces. A

  13. 硅胶圈在立车方滑枕润滑油回收盘中的应用%The Application of Silicone Seal Ring in Vertical Lathe Square Ram's Lube Oil Drain Pan

    Institute of Scientific and Technical Information of China (English)

    周丹; 王冠田

    2014-01-01

    In this paper, to solve the reliability problem of silicone seal ring in vertical lathe Square ram's lube oil drain pan, a kind of silicone ring to seal around the square ram is used to ensure the recycling of oil effectively, test-ed and achieved good results.%针对立车刀架方滑枕润滑油回收盘密封圈可靠性问题,应用硅胶圈实施对方滑枕周边密封,从而保证润滑油得到有效回收,经过试验取得了良好效果。

  14. Evaporation from open microchannel grooves.

    Science.gov (United States)

    Kachel, Sibylle; Zhou, Ying; Scharfer, Philip; Vrančić, Christian; Petrich, Wolfgang; Schabel, Wilhelm

    2014-02-21

    The evaporation of water from open u-shaped microchannel grooves was investigated with particular emphasis on the roles of channel width and air flow conditions. Given the small dimensions of the microchannels, all measurements were conducted in a range where convection and diffusion are of equal importance and known correlations for the calculation of mass transfer coefficients cannot be applied. The evaporation rates were measured using a new optical method and a gravimetric method. Both measurement methods yielded mass transfer coefficients that are in agreement with each other. The observed relation between mass transfer coefficient, air velocity and channel width vastly differs from the predictions obtained from macroscopic structures. With respect to diagnostic devices we conclude that analyte concentration in an open microchannel groove strongly increases even within short times due to the evaporation process and we show that wider channels are more favourable in terms of minimizing the relative evaporation rate.

  15. Condition monitoring of reciprocating seal based on FBG sensors

    Science.gov (United States)

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

    2016-07-01

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

  16. 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 ...

  17. Differential diagnosis of groove pancreatic carcinomas vs. groove pancreatitis: Usefulness of the portal venous phase

    Energy Technology Data Exchange (ETDEWEB)

    Ishigami, Kousei, E-mail: Ishigamikousei@aol.co [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan); Tajima, Tsuyoshi; Nishie, Akihiro; Kakihara, Daisuke [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan); Fujita, Nobuhiro [Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Asayama, Yoshiki; Ushijima, Yasuhiro; Irie, Hiroyuki [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan); Nakamura, Masafumi; Takahata, Shunichi [Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Ito, Tetsuhide [Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan)

    2010-06-15

    Purpose: To clarify if the portal venous phase is helpful for the differential diagnosis of groove pancreatic carcinomas and groove pancreatitis. Materials and methods: MDCT and MRI of groove pancreatic carcinomas (n = 7) and groove pancreatitis (n = 15) were retrospectively reviewed by two radiologists independently. The signal intensity on T2-weighted images was subjectively assessed. The presence or absence of common bile duct (CBD) and main pancreatic duct (MPD) strictures, calcifications, and cystic lesions was evaluated. Additionally, the appearance of groove pancreatic carcinoma and that of groove pancreatitis in the portal venous phase on dynamic MDCT and MRI were compared. Results: There were no significant differences in the signal intensity on T2-weighted images and in the presence or absence of CBD and MPD strictures, calcifications, and cystic lesions between groove pancreatic carcinomas and groove pancreatitis. However, patchy focal enhancement in the portal venous phase was more commonly observed in groove pancreatitis than groove pancreatic carcinoma (Reviewers 1 and 2: 14/15 [93.3%] vs. 1/7 [14.3%], P < 0.0001). In addition, peripheral enhancement was only seen in groove pancreatic carcinomas (Reviewer 1: 4/7 [57.1%] vs. 0/15 [0%], P < 0.005, and Reviewer 2: 3/7 [42.9%] vs. 0/15 [0%], P < 0.05). Conclusion: The portal venous phase may be helpful for the differential diagnosis of groove pancreatic carcinomas and groove pancreatitis.

  18. Laser grooving of surface cracks on hot work tool steel

    Directory of Open Access Journals (Sweden)

    D. Klobčar

    2011-10-01

    Full Text Available The paper presents the analysis of laser grooving of 1.2343 tool steel hardened to 46 HRC. The effect of laser power and grooving speed on groove shape (i.e. depth and width, the material removal rate and the purity of produced groove as a measure of groove quality was investigated and analyzed using response surface methodology. Optimal parameters of laser grooving were found, which enables pure grooves suitable for laser welding.

  19. 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.

  20. Planting hole sealed by sand promoting growth of oil sunflower in saline-alkaline fields mulched with plastic film%沙封覆膜种植孔促进盐碱地油葵生长

    Institute of Scientific and Technical Information of China (English)

    杜社妮; 白岗栓; 于健; 任志宏

    2014-01-01

    Oil sunflower is a pioneer crop growing in saline-alkaline soil. However, its germination rate and seedling growth can be inhibited when soil salinity is extremely high and thus its yields can be decreased. In order to improve germination rate and survival rate of oil sunflower, increase its yields and outputs, a field experiment was conducted to investigate the effect of two planting hole sealing methods (sealed by soil and sealed by sand) on rhizosphere soil moisture and soil salinity in severe saline-alkaline soils of Hetao irrigation area, Inner Mongolia, China. Eight rhizosphere soil samples at depth of 0-40 cm were taken with 5 cm as a sampling layer from the plots of planting hole sealed by sand and planting hole sealed by soil at the sowing, germination and seedling stages of oil sunflower to determine the soil moisture and salinity. Meanwhile, soil moisture and soil salinity under the plastic film mulch and in open field between plastic film mulching were also detected. Germination rate, seedling survival rate, seedling growth, yields, and output from the plots of planting hole sealed by sand and planting hole sealed by soil were calculated. The results showed that the soil moisture at depth of 0-15 cm decreased but soil salinity increased from sowing stage to seedling stage, and significant or extremely significant differences were detected between different growth stages. In seedling germination and seedling stage, rhizosphere soil moisture at 0-10 cm depth in the treatment of planting hole sealed by sand decreased by 3.86%and 4.83%than that in the treatment of planting hole sealed by soil, decreased by 4.79%and 9.73%than that in the treatment of plastic film much, while the rhizosphere soil salinity at 0-15 cm depth in the treatment of planting hole sealed by sand decreased by 16.46%and 40.99%than that in the treatment of planting hole sealed by soil, decreased by 30.53% and 33.72% than that in the treatment of open field between plastic film mulch, and

  1. Influence of musical groove on postural sway.

    Science.gov (United States)

    Ross, Jessica M; Warlaumont, Anne S; Abney, Drew H; Rigoli, Lillian M; Balasubramaniam, Ramesh

    2016-03-01

    Timescales of postural fluctuation reflect underlying neuromuscular processes in balance control that are influenced by sensory information and the performance of concurrent cognitive and motor tasks. An open question is how postural fluctuations entrain to complex environmental rhythms, such as in music, which also vary on multiple timescales. Musical groove describes the property of music that encourages auditory-motor synchronization and is used to study voluntary motor entrainment to rhythmic sounds. The influence of groove on balance control mechanisms remains unexplored. We recorded fluctuations in center of pressure (CoP) of standing participants (N = 40) listening to low and high groove music and during quiet stance. We found an effect of musical groove on radial sway variability, with the least amount of variability in the high groove condition. In addition, we observed that groove influenced postural sway entrainment at various temporal scales. For example, with increasing levels of groove, we observed more entrainment to shorter, local timescale rhythmic musical occurrences. In contrast, we observed more entrainment to longer, global timescale features of the music, such as periodicity, with decreasing levels of groove. Finally, musical experience influenced the amount of postural variability and entrainment at local and global timescales. We conclude that groove in music and musical experience can influence the neural mechanisms that govern balance control, and discuss implications of our findings in terms of multiscale sensorimotor coupling. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. Thermal Bridge Effects in Window Grooves

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report thermal bridge effects in window grooves are analyzed. The analysis is performed using different thicknesses of the window groove insulation, to evaluate what the optimal solution is.All analysis in the report is performed using both 2- and 3-dimensional numerical analysis....

  3. Gratings in plasmonic V-groove waveguides

    DEFF Research Database (Denmark)

    Smith, Cameron; Cuesta, Irene Fernandez; Kristensen, Anders

    2011-01-01

    We introduce visible light optical gratings to surface plasmon V-groove waveguides. Gradient e-beam dosage onto silicon stamp enables structuring V-grooves of varying depth. Nanoimprint lithography maintains a Λ=265 nm corrugation for gold surface devices....

  4. Gratings in plasmonic V-groove waveguides

    DEFF Research Database (Denmark)

    Smith, Cameron; Cuesta, Irene Fernandez; Kristensen, Anders

    2011-01-01

    We introduce visible light optical gratings to surface plasmon V-groove waveguides. Gradient e-beam dosage onto silicon stamp enables structuring V-grooves of varying depth. Nanoimprint lithography maintains a Λ=265 nm corrugation for gold surface devices....

  5. Film Thickness Model for Grease-Lubricated Bearing Seals with an Axial Contacting Lip

    NARCIS (Netherlands)

    Baart, P.; van Zoelen, M.T.; Lugt, Pieter Martin

    2013-01-01

    A theoretical model is presented to predict the oil film thickness in an axial sealing contact based on grease properties and operating conditions. It is assumed that a small amount of grease will form an oil reservoir on the rotating part and slowly supply oil to the sealing contact. The oil bleed

  6. Accelerated cross-linking of silicones for liquid-applied sealing of plastic oil pans in the serial production of combustion engines; Beschleunigtes Vernetzen von Silikonen zur Fluessigabdichtung von Oelwannen aus Kunststoff in der Serienproduktion von Verbrennungsmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Preuss, Michael

    2012-07-01

    The author of the contribution under consideration reports on the development of different processes of an accelerated cross-linking of silicones and investigates different sealing concepts for plastic components using a plastic oil pan as an example. Thus, 2K silicones cross-linking at ambient temperature as well as 1K silicones with an accelerated curing due to an additional heat load are developed. The target is an accelerated crosslink of silicones without minimization of the processing period and weakening of the adhesive strength.

  7. 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.

  8. Regenerator seal

    Science.gov (United States)

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

    1981-01-01

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

  9. Diagnostics and Treatment of Palatal Radicular Grooves

    Institute of Scientific and Technical Information of China (English)

    James Deschner; Birgit Rath; Wang Zheng; Ding Yi

    2006-01-01

    The palatal radicular groove represents a developmental anomaly that mainly affects the maxillary incisor teeth. This anomaly is probably caused by an infolding of the enamel organ and Hertwig's epithelial root sheath during odontogenesis. The groove often originates in the central fossa or cingulum and continues towards the root apex for various distances. The anatomical defect can act as a funnel for plaque and, therefore, result in extensive bone and attachment loss. A complete lack of closure of the calcified tissues along the groove, that is a direct communication between pulp and periodontium, rarely occurs. However, accessory canals between the pulp cavity and periodontal tissues frequently exist along the groove and are main entrances of infectious material into the pulp cavity, facilitating the development of endodontic lesions. Grooves can also complicate restorative therapy or interfere with the accessibility for scaling and root planing. Patients usually present with pain and gingival inflammation in the maxillary incisor region. Bleeding on probing and increased pocket depths are strictly confined to the area of the groove in an otherwise periodontally healthy patient. Radiographs may show a parapulpal line that represents the radiographic image of the groove. Treatment of the anomaly by scaling and root planing alone or in combination with procedures such as odontoplasty, flap surgery, application of an enamel matrix derivative or guided tissue regeneration can be successful. A short case report of a patient treated successfully with an enamel matrix derivative for localized attachment loss due to this anomaly is presented.

  10. Application of Recycled Sealing Oil of Mixer in Tire Flap%废密炼机转子密封油在轮胎垫带胶中的应用

    Institute of Scientific and Technical Information of China (English)

    柴克鹏; 杨兴云

    2014-01-01

    对混有炭黑、小料和混炼胶的废密炼机转子密封油(废机油)进行回收再利用,研究其在轮胎垫带胶中的应用。结果表明:废机油静置后分离出的上层澄清液体,以不大于4%的比例(质量含量)掺入芳烃油中,不影响芳烃油的正常使用;添加2份废机油中间层和下层分离产物,并调整加料顺序,试验配方胶料的加工性能和物理性能与生产配方相当,试验配方成品垫带的物理性能满足企业标准要求,停放后成品垫带表面无油污渗出,不变色,外观未出现异常现象。将废机油回收并用于芳烃油和垫带胶中,具有良好的经济效益和环保效应。%The waste sealing oil of mixer was recycled and applied in the tire lfap. The recycled oil contained carbon black, additives and some rubber compound. After allowed standing, the recycle oil was separated into clear oil in the upper layer and residue mixture in the middle and bottom layers. The upper layer clear oil was then added into aromatic oil and showed no negative effect on the normal use of the aromatic oil if the percentage of recycled oil did not exceed 4%. The residue mixture in the middle and bottom layers was applied in the tire lfap at the addition level of 2 phr. By adjusting the mixing process, the processing properties and physical properties of the rubber compound showed no change, and the performance of the ifnished lfap met the requirements of enterprise standard. The experimental results also showed that, there was no stain or oil bleed, no color change or appearance change after storage of the finished products. The application of recycled oil in the aromatic oil and the flap compound would deliver good economic and environmental beneifts.

  11. Cold welding sealing of copper-water micro heat pipe ends

    Institute of Scientific and Technical Information of China (English)

    TANG Yong; LU Long-sheng; DENG Da-xiang; YUAN Dong

    2009-01-01

    The quality of micro heat pipe(MHP) is strongly affected by sealing technology. Based on the analysis of requirements of sealing technology, a cold welding technology was presented to seal MHP. In the cold welding process, compression force was used to flatten micro groove copper(MGC) tube. Then the bonding of MGC tube was reached because of intensively plastic deformation of MGC tube under pressure. It is found that the plastic deformation area of the cold welding of MGC tube can be divided into three sections. The deformation of micro grooves in each section was investigated; the influence of the dimensions of cylindrical heads on the weld joint shape and strength was studied; and a comparison between smooth copper tube and MGC tube was done. The results show that a groove compression stage exists in the cold welding of MGC tube besides a flattened stage and a melting stage.

  12. An innovative approach in the management of palatogingival groove using Biodentine™ and platelet-rich fibrin membrane

    Science.gov (United States)

    Johns, Dexton Antony; Shivashankar, Vasundhara Yayathi; Shobha, K; Johns, Manu

    2014-01-01

    Palatogingival groove is an anatomical malformation that often causes severe periodontal defects. Treatments of such an anomaly present a clinical challenge to the operator. Careful endodontic and periodontal procedures may restore the form and function. In the present case; root canal therapy, apicectomy, and sealing of the groove with Biodentine™ were done. Bone graft was placed followed by platelet-rich fibrin (PRF) membrane. This treatment modality resulted in gain in attachment, reduction in pocket depth, and deposition of bone in the osseous defect. A 24 month follow-up is included. PMID:24554867

  13. An innovative approach in the management of palatogingival groove using Biodentine™ and platelet-rich fibrin membrane.

    Science.gov (United States)

    Johns, Dexton Antony; Shivashankar, Vasundhara Yayathi; Shobha, K; Johns, Manu

    2014-01-01

    Palatogingival groove is an anatomical malformation that often causes severe periodontal defects. Treatments of such an anomaly present a clinical challenge to the operator. Careful endodontic and periodontal procedures may restore the form and function. In the present case; root canal therapy, apicectomy, and sealing of the groove with Biodentine™ were done. Bone graft was placed followed by platelet-rich fibrin (PRF) membrane. This treatment modality resulted in gain in attachment, reduction in pocket depth, and deposition of bone in the osseous defect. A 24 month follow-up is included.

  14. Level Set Modeling of Transient Electromigration Grooving

    OpenAIRE

    Khenner, M.; Averbuch, A.; Israeli, M.; Nathan, M; Glickman, E.

    2000-01-01

    A numerical investigation of grain-boundary (GB) grooving by means of the Level Set (LS) method is carried out. GB grooving is emerging as a key element of electromigration drift in polycrystalline microelectronic interconnects, as evidenced by a number of recent studies. The purpose of the present study is to provide an efficient numerical simulation, allowing a parametric study of the effect of key physical parameters (GB and surface diffusivities, grain size, current density, etc) on the e...

  15. Effectiveness of transverse grooves in rigid pavement

    Science.gov (United States)

    Gurney, G. F.; Bryden, J. E.

    1982-10-01

    Transverse grooves were installed at 11 intersection approaches on worn rigid pavement to reduce a high rate of wet road accidents. In most cases, accident reductions were experienced only at intersections with multiple negative operational characteristics, including higher approach speeds, limited sight distances, and frequent vehicle stopping for turns or stop signs. Intersections with no more than one negative characteristic generally did not benefit from grooving.

  16. Gap and channeled plasmons in tapered grooves: a review

    DEFF Research Database (Denmark)

    Smith, C. L. C.; Stenger, Nicolas; Kristensen, Anders

    2015-01-01

    ) that are confined laterally between the tapered groove sidewalls and propagate either along the groove axis or normal to the planar surface, and channeled plasmon polaritons (CPPs) that occupy the tapered groove profile and propagate exclusively along the groove axis. Both GSPs and CPPs exhibit an assortment...

  17. Seal design alternatives study

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-06-01

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

  18. WEAR AND SEALING CHARACTERISTICS OF ENGINE VALVE GUIDE

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  19. Analysis on Second Sealing Oil and Gas Space Discharge in Floating Roof Tank%浮顶储罐二次密封油气空间放电分析

    Institute of Scientific and Technical Information of China (English)

    胡海燕; 刘宝全; 刘全桢; 张婷婷; 高鑫

    2011-01-01

    In order to avoid floating roof tank sealing ring fire caused by shunts discharge in the second sealing oil and gas space due to lightning, this paper established a 2 m diameter tank model and carried out a shunts spark discharge experiment and an air gap breakdown discharge experiment, so as to systematically research shunts discharge risk in the second sealing oil and gas space.Experimental results show that Shunts attached to the shell by its own flexibility can generate sparks when the lighting current flow reaches a peak of about 400 Amperes; If there are gaps between shunts and the shell during lightning high voltage stock, potential difference between the roof and shell may break down the gaps and cause sparks,when the gap between 20 -30 mm, discharging voltage is about 26 -40 kV.Therefore, shunts spark discharge is inevitable as tank suffering from lightning.Finally, combined with the actual operation of the storage tanks, improvement measures were put forward, such as canceling shunts on the second seal and submerged paraffin scraper device reliable electrical connection with floating roof and avoiding shunts discharge in the second sealing oil and gas space, so as to greatly reduce floating roof tank lightning fire accident.%为避免浮顶储罐在遭受雷击时由于导电片设施在二次密封油气空间中放电引起密封圈火灾,在实验室建立了2 m直径油罐模型,开展导电片火花放电起始电流试验、导电片与罐壁形成空气间隙击穿放电初始电压试验,系统研究导电片在二次密封油气空间中的放电危险性.试验结果表明:导电片靠自身弹性与罐壁贴合时,雷电流大约在400 A时导电片开始产生点燃性火花放电;如导电片与罐壁贴合不良形成空气间隙,雷击情况下雷电流泄放瞬时浮顶与罐壁之间的电位差足以使一定大小的间隙击穿放电,当间隙大小为20~30 mm时,放电电压为26~40 kV.因此,储罐在遭受雷击时,导电片火

  20. Micro Groove for Trapping of Flowing Cell

    Directory of Open Access Journals (Sweden)

    Yusuke Takahashi

    2015-06-01

    Full Text Available Micro grooves have been designed to trap a biological cell, which flows through a micro channel in vitro. Each micro groove of a rectangular shape (0.002 mm depth, 0.025 mm width and 0.2 mm length has been fabricated on the surface of the polydimethylsiloxane (PDMS disk with the photolithography technique. Variation has been made on the angle between the longitudinal direction of the groove and the flow direction: zero, 0.79, or 1.57 rad. A rectangular flow channel (0.1 mm depth x 5 mm width x 30 mm length has been constructed with a silicone film of 0.1 mm thick, which has been sandwiched by two transparent PDMS disks. Two types of biological cells were used in the test alternatively: C2C12 (mouse myoblast cell line originated with cross-striated muscle of C3H mouse, or 3T3-L1 (mouse fat precursor cells. A constant flow (2.8 x 10-11 m3/s of a suspension of cells was introduced with a syringe pump. The behavior of cells moving over the micro grooves was observed with an inverted phase contrast microscope. The results show that the cell is trapped with the micro grooves under the wall shear rate of 3 s-1 for a few seconds and that the trapped interval depends on the kind of cells.

  1. Solving Confliction Problem Between the Gas Turbine Generator Seal-oil System and Building Steel Structure%燃机发电机密封油系统与钢结构碰撞问题之解决

    Institute of Scientific and Technical Information of China (English)

    陈闻菲; 杨承佐

    2014-01-01

    国内某燃机联合循环电厂在建设阶段发生了的发电机密封油系统布置与厂房钢结构碰撞的问题。在听取设计人员及专家意见后,分析了问题产生的原因,提出了解决办法。%The confliction between gas turbine gen-erator seal-oil system and GT (Gas turbine) building steel structure happened during the constructive stage of a do-mestic CCPP (Combined cycle power plant). After listening to the opinions of the experts, cause to result in the problem was analyzed and solving way was suggested.

  2. Plastic Sealed Thermal Expansion Packer for Thermal Recovery

    Institute of Scientific and Technical Information of China (English)

    Liu Li; Jiang Hua

    1995-01-01

    @@ According to the requirements of wellbore heatinsulation technique and selective zonal steaminjection technique in heavy-oil steam-injection recovery process, the Oil Recovery Technique Department of Liaohe Petroleum Exploration and Production Bureau and Shuguang Oil Recovery Plant have cooperatively designed and developed a plastic sealed thermal expansion packer for thermal recovery.

  3. Analysis of Mechanical Seals for High-Speed Centrifugal Gas Compressors

    Directory of Open Access Journals (Sweden)

    K.N. Nwaigwe

    2012-08-01

    Full Text Available A study aimed at seal selection efficiency for centrifugal pumps in the oil and gas industry is presented. A detailed analysis of mechanical seals in use in exploration and production activities of the oil and gas sector was undertaken. The approach of analysis was using seal design equations as mathematical models for simulating the performance of the mechanical seal. The results showed a mechanical seal with balance value of 0.5, an increased surface area between mating surfaces; provided with a flush system to enhance cooling and with seal face gap of 50 mm or less between the mating surfaces for minimal or zero leakage. The obtained results can aid the industries in seal selection and seal manufacturers in seal specifications.

  4. Musical groove modulates motor cortex excitability: a TMS investigation.

    Science.gov (United States)

    Stupacher, Jan; Hove, Michael J; Novembre, Giacomo; Schütz-Bosbach, Simone; Keller, Peter E

    2013-07-01

    Groove is often described as a musical quality that can induce movement in a listener. This study examines the effects of listening to groove music on corticospinal excitability. Musicians and non-musicians listened to high-groove music, low-groove music, and spectrally matched noise, while receiving single-pulse transcranial magnetic stimulation (TMS) over the primary motor cortex either on-beat or off-beat. We examined changes in the amplitude of the motor-evoked potentials (MEPs), recorded from hand and arm muscles, as an index of activity within the motor system. Musicians and non-musicians rated groove similarly. MEP results showed that high-groove music modulated corticospinal excitability, whereas no difference occurred between low-groove music and noise. More specifically, musicians' MEPs were larger with high-groove than low-groove music, and this effect was especially pronounced for on-beat compared to off-beat pulses. These results indicate that high-groove music increasingly engages the motor system, and the temporal modulation of corticospinal excitability with the beat could stem from tight auditory-motor links in musicians. Conversely, non-musicians' MEPs were smaller for high-groove than low-groove music, and there was no effect of on- versus off-beat pulses, potentially stemming from suppression of overt movement. In sum, high-groove music engages the motor system, and previous training modulates how listening to music with a strong groove activates the motor system.

  5. Research on leakage loss and sealing of the scroll vacuum pump of oil-filter%滤油机涡旋真空泵泄漏损耗及密封研究

    Institute of Scientific and Technical Information of China (English)

    张贤明; 陈栋; 王立存; 杨旭; 张国进

    2013-01-01

    The research of backing scroll vacuum pump is an important aspect of the development of vacuum oil-filter.The existing clearance between two scroll disks causes the leakage loss when scroll vacuum pump is working,which will affect its ultimate vacuum and working performance.Analyze the radial and tangential leakage of scroll vacuum pump,then the power consumption of leakage was calculated.The principle and characteristics of sealing strips introduced,and some sealing measures were put forward,which has very important theoretical significance and practical value to improve the pumping speed and working performance of scroll vacuum pump.The scroll vacuum pump will be popularized in the waste oil treatment industry in the future.%在真空滤油机研发过程中,对其真空获得设备前置涡旋真空泵的研究是一个重要的方面.涡旋真空泵在运行过程中,动、静涡旋盘之间间隙的存在导致了气体泄漏损耗,该因素会影响涡旋真空泵的极限真空度及其工作性能.分析了涡旋真空泵的径向泄漏及切向泄漏,计算了泄漏消耗的功率,说明了密封条原理和特点,提出了径向间隙和轴向间隙的密封措施,对提高涡旋真空泵抽速、改善其机构性能方面具有重要理论意义和工程实用价值,涡旋真空泵将在油处理行业得到进一步推广应用.

  6. Mixed convection in a baffled grooved channel

    Indian Academy of Sciences (India)

    Aayush K Sharma; Pallab S Mahapatra; Nirmal K Manna; Koushik Ghosh

    2015-05-01

    In the present numerical work, flow structure and heat transfer characteristics are investigated in a baffled grooved channel, differentially heated from the sides. The baffle is placed vertically downward from the top wall of grooved channel geometry, with the motive of diverting outside forced flow towards the inside of the square cavity. In-house CFD code based on finite volume method has been used to solve the 2D equations of continuity, momentum and energy. The effect of change in baffle position and height is investigated in the range of Richardson numbers 0.1 to 10. For the present study, external flow from both left and right of the grooved channel are considered. A remarkable enhancement of heat transfer is observed in presence of baffle. The study has also pointed out that for optimal performance, the position and height of the baffle need to be adjusted depending on the direction of external flow.

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

    Science.gov (United States)

    Hendricks, Robert C. (Editor)

    2006-01-01

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

  8. A Case of Right Atrioventricular Groove Paraganglioma

    Institute of Scientific and Technical Information of China (English)

    Yi ZHANG; Tie-cheng PAN

    2009-01-01

    @@ Cardiac paraganglioma is an extremely rare clinical en-tities of the heart. The usual investigations for pheochro-mocytoma are necessary, however the most useful, spe-cific to primary cardiac tumors, are coronary angiogra-phy and echocardiography. While complete surgical ex-cision is the standard treatment of mainstay. We report a case of a 55-year-old woman with cardiac paraganglioma located in fight atriaoventricular groove of the heart. As we know, this is the first case that cardiac paraganglioma located in fight atriaoventricular groove of the heart in English literature.

  9. Graphene Plasmons in Triangular Wedges and Grooves

    DEFF Research Database (Denmark)

    Gonçalves, P. A. D.; Dias, E. J. C.; Xiao, Sanshui

    2016-01-01

    and electric-field distributions. We have found that the dispersion of wedge/groove graphene plasmons follows the same functional dependence as their flat-graphene plasmon counterparts, but now scaled by a (purely) geometric factor in which all the information about the system’s geometry is contained. We...... and tunability of graphene plasmons guided along the apex of a graphene-covered dielectric wedge or groove. In particular, we present a quasi-analytic model to describe the plasmonic eigenmodes in such a system, including the complete determination of their spectrum and corresponding induced potential...

  10. Rectangular-to-circular groove waveguide junction

    Institute of Scientific and Technical Information of China (English)

    CUI; Licheng; (崔立成); YANG; Hongsheng; (杨鸿生)

    2003-01-01

    Mode matching method is used to analyze the scattering characteristics of the rectangular-to-circular groove waveguide junction. Firstly, the scattering matrix equation is obtained by matching the electromagnetic fields at the boundary of the junction. The scattering coefficients can be obtained from the equation. Secondly the scattering characteristics of the iris with rectangular window positioned in circular groove waveguide are briefly analyzed. Thirdly, the convergent problem is discussed and the numerical results are given. At last experiment is made and good agreement is found between the calculated results and the measured results.

  11. 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.

  12. 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...

  13. Seal Out Tooth Decay

    Science.gov (United States)

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

  14. Turbomachine Interface Sealing

    Science.gov (United States)

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

    2005-01-01

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

  15. Seals For Cryogenic Turbomachines

    Science.gov (United States)

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

    1988-01-01

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

  16. Appraisal of transverse nasal groove: A study

    Directory of Open Access Journals (Sweden)

    Belagola D Sathyanarayana

    2012-01-01

    Full Text Available Background: Transverse nasal groove is a condition of cosmetic concern which awaits due recognition and has been widely described as a shallow groove that extends transversely over the dorsum of nose. However, we observed variations in the clinical presentations of this entity, hitherto undescribed in literature. Aims: We conducted a clinicoepidemiological study of transverse nasal lesions in patients attending our outpatient department. Methods: We conducted a prospective observational study. We screened all patients attending our out-patient department for presence of transverse nasal lesions, signs of any dermatosis and associated other skin conditions. Results: One hundred patients were recruited in the study. Females (80% predominated over males. Most patients were of 15-45 years age group (70%. Majority of the transverse nasal lesions were classical transverse nasal groove (39% and others included transverse nasal line (28%, strip (28%, ridge (4% and loop (1%. Seborrhoeic diathesis was the most common condition associated with transverse nasal lesion. Conclusions: Occurrence of transverse nasal line, strip, ridge and loop, in addition to classical transverse nasal groove implies that latter is actually a subset of transverse nasal lesions. Common association of this entity with seborrheic dermatitis, seborrhea and dandruff raises a possibility of whether transverse nasal lesion is a manifestation of seborrheic diathesis.

  17. Optimization of Grooved Micromixer for Microengineering Technologies

    DEFF Research Database (Denmark)

    Sabotin, I.; Tristo, G.; Bissacco, Giuliano

    2013-01-01

    Due to the absence of turbulent flow and the slow diffusion process, mixing of solutions at micro-scale is a difficult task. This paper describes the optimization route towards the efficient design of a bottom grooved micromixer. Based on thoroughly discussed mixing mechanisms, the optimization w...

  18. 大港油田沙一段中部泥岩盖层封闭油气能力和时间有效性%Sealing oil-gas time and ability effectiveness of mudstone caprocks in middle Es1 in Dagang Oilfield

    Institute of Scientific and Technical Information of China (English)

    付广; 王岐; 史集建

    2012-01-01

    To study controlling of mudstone caprocks of middle Esl to oil-gas accumulation, using the methods of geological statistics and historical evolution, the development, the micro-sealing ability and sealing effectiveness of mudstone caprocks in middle Esl of Dagang Oilfield were studied. The results show that the mudstone caprocks of middle Esl which distributes all over the research region except southern part of Beidagang buried-hill structural belt is regional caprock for oil-gas to accumulation and distribution. Moreover, mudstone caprock of middle Esl owns stronger-strong sealing ability. In the late and middle of Ed and the middle of Nm it began forming separately sealing ability for oil-gas reservoirs with lower and middle reserves abundance. The two periods are earlier than expulsion oil-gas period in the great deal of Es3 sourcerock. It is effective to seal oil-gas in the time, but it has not yet gotten the formation period of oil-gas reservoirs with high reserves abundance now. Oil-gas reservoirs with middle and lower reserves abundance are only formed under mudstone caprock of middle Esl. The displacement pressure of mudstone caprock of middle Esl in most oil-gas reservoirs is higher than the together of displacement pressure of reservoir and surplus pressure of oil-gas reservoirs. It is effective lo seal oil-gas in ability. Sealing oil-gas effectiveness of the mudstone caprock of middle Esl controls oil-gas accumulation under mudstone caprock of middle Esl, but reserves abundance of oil-gas reservoirs is lower.%为了研究沙一段中部泥岩盖层在油气成藏中的作用,采用地质统计和历史演化的研究方法对大港油田沙一段中部泥岩盖层发育、微观封闭能力及封油气有效性进行研究.结果表明:沙一段中部泥岩盖层除北大港潜山构造带的南部局部缺失外,全区分布,是油气聚集与分布的区域性盖层.具有较强-强的封闭能力,在东营组中后期和明化镇组中期分别形

  19. 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.

  20. Vacuum Infusion Molding Process (Part 2 VIMP Based on Grooves)

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying-dan; DENG Jing-lan; WANG Ji-hui; TAN Hua

    2003-01-01

    The optimal parameters for flow grooves and supply grooves were determined by a series of experiments , and the influences of various molding conditions on the mold filling process were analyzed. Furthermore ,the whole VIMP procedure based on grooves was introduced in detail taking the manufacture of a sandwich panel as an example.

  1. Zero leakage sealings

    Science.gov (United States)

    Kotesovec, Bernhard; Steinrück, Herbert

    2010-11-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Yang Jian; Yang Huayong; Xu Bing

    2004-01-01

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

  4. A New Design of Magnetic Fluid Seal for Liquids

    Institute of Scientific and Technical Information of China (English)

    LIU Tong-gang; YANG Zhi-yi

    2005-01-01

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

  5. Solar cell with doped groove regions separated by ridges

    Energy Technology Data Exchange (ETDEWEB)

    Molesa, Steven Edward; Pass, Thomas; Kraft, Steve

    2017-01-31

    Solar cells with doped groove regions separated by ridges and methods of fabricating solar cells are described. In an example, a solar cell includes a substrate having a surface with a plurality of grooves and ridges. A first doped region of a first conductivity type is disposed in a first of the grooves. A second doped region of a second conductivity type, opposite the first conductivity type, is disposed in a second of the grooves. The first and second grooves are separated by one of the ridges.

  6. Graphene Plasmons in Triangular Wedges and Grooves

    CERN Document Server

    Gonçalves, P A D; Xiao, Sanshui; Vasilevskiy, M I; Mortensen, N Asger; Peres, N M R

    2016-01-01

    The ability to effectively guide electromagnetic radiation below the diffraction limit is of the utmost importance in the prospect of all-optical plasmonic circuitry. Here, we propose an alternative solution to conventional metal-based plasmonics by exploiting the deep subwavelength confinement and tunability of graphene plasmons guided along the apex of a graphene-covered dielectric wedge or groove. In particular, we present a quasi-analytic model to describe the plasmonic eigenmodes in such a system, including the complete determination of their spectrum and corresponding induced potential and electric field distributions. We have found that the dispersion of wedge/groove graphene plasmons follows the same functional dependence as their flat-graphene plasmons counterparts, but now scaled by a (purely) geometric factor in which all the information about the system's geometry is contained. We believe our results pave the way for the development of novel custom-tailored photonic devices for subwavelength waveg...

  7. Diamond grooving of rapidly solidified optical aluminium

    Science.gov (United States)

    Abou-El-Hossein, Khaled; Hsu, Wei-Yao; Ghobashy, Sameh; Cheng, Yuan-Chieh; Mkoko, Zwelinzima

    2015-10-01

    Traditional optical aluminium grades such as Al 6061 are intensively used for making optical components for applications ranging from mould insert fabrication to laser machine making. However, because of their irregular microstructure and relative inhomogeneity of material properties at micro scale, traditional optical aluminium may exhibit some difficulties when ultra-high precision diamond turned. Inhomogeneity and micro-variation in the material properties combined with uneven and coarse microstructure may cause unacceptable surface finish and accelerated tool wear, especially in grooving operation when the diamond tool edge is fully immersed in the material surface. Recently, new grades of optical aluminium that are featured by their ultra-fine microstructure and improved material properties have been developed to overcome the problem of high tool wear rates. The new aluminium grades have been developed using rapid solidification process which results in extremely small grain sizes combined with improved mechanical properties. The current study is concerned with investigating the performance of single-point diamond turning when grooving two grades of rapidly solidified aluminium (RSA) grades: RSA905 which is a high-alloyed aluminium grade and RSA443 which has a high silicon content. In this study, two series of experiments employed to create radial microgrooves on the two RSA grades. The surface roughness obtained on the groove surface is measured when different combinations of cutting parameters are used. Cutting speed is varied while feed rate and depth of cut were kept constant. The results show that groove surface roughness produced on RSA443 is higher than that obtained on RSA905. Also, the paper reports on the effect of cutting speed on surface roughness for each RSA grade.

  8. 地下水封储油库围岩稳定性数值分析%Numerical analysis on the stability of surrounding rock for underground water-sealing oil storage in rock caverns

    Institute of Scientific and Technical Information of China (English)

    胡谋鹏; 粱久正; 许杰

    2013-01-01

    An underground water-sealing oil storage in rock caverns in Liaoning Province follows a low level of ground stress in the low-stress area. After its excavation, surrounding rock deformation and fracture are controlled under the combination between single structure plane and multi-group structure plane. Therefore, it is required to first analyze whether the surrounding rock suffer stress problems or structure plane problems and equivalent to value selection of surrounding rock parameters on the importance. Geological strength index (GSI) proposed by Hoek and Brown are based on rock quality evaluation. It can reduce subjectivity in determining the shear strength indicator to define rock mass mechanics parameters by the empirical formula. The underground water-sealed oil storage in rock caverns in Liaoning Province is taken as the object of study. Using the surrounding rock parameter value selection method based on GSI system as well as FLAC3D software, numerical analysis on the surrounding rock stability is conducted and its results are interpreted based on displacement criteria and stress criterion to determine the surrounding rock stability, thus having a guiding significance in engineering practice.%辽宁某地下水封储油硐库地应力水平不高,属于低应力区,开挖后围岩变形破坏受单一结构面和多组结构面的组合控制,因此首先需要分析围岩属于应力型问题还是属于结构面型问题,其重要性等同于围岩参数取值的重要性.Hoek和Brown提出的地质强度指标(GSI)法基于岩体质量评价,应用经验公式确定岩体力学参数,可以一定程度上减少确定抗剪强度指标过程中的主观成分.以辽宁某地下水封储油库工程储油硐室为研究对象,采用基于GSI系统的围岩参数取值方法,借助FLAC3D软件对围岩稳定性进行数值分析,利用位移判据和应力判据对数值分析结果进行解释,进而判断围岩的稳定性,对工程实践具有一定的指导意义.

  9. Simplification of vector ray tracing by the groove function.

    Science.gov (United States)

    Hu, Zhongwen; Liu, Zuping; Wang, Qiuping

    2005-01-01

    Tracing rays through arbitrary diffraction gratings (including holographic gratings of the second generation fabricated on a curved substrate) by the vector form is somewhat complicated. Vector ray tracing utilizes the local groove density, the calculation of which highly depends on how the grooves are generated. Characterizing a grating by its groove function, available for almost arbitrary gratings, is much simpler than doing so by its groove density, essentially being a vector. Applying the concept of Riemann geometry, we give an expression of the groove density by the groove function. The groove function description of a grating can thus be incorporated into vector ray tracing, which is beneficial especially at the design stage. A unified explicit grating ray-tracing formalism is given as well.

  10. Dynamic sealing principles

    Science.gov (United States)

    Zuk, J.

    1976-01-01

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

  11. Replacement of nickel sealing rings by expanded graphite sealing rings -upgrading of SG primary collector flange connection

    Energy Technology Data Exchange (ETDEWEB)

    Cikryt, F.; Bednarek, L.; Kusyn, L. [Vitkovice, Ostrava (Switzerland)

    1997-12-31

    One of the most loaded parts of a steam generator of VVER 440 MW type are the bolts and thread holes of the primary collector cover sealing set. The strength calculations and tensometric measurings performed during operation proved the high degree of a load on the bolts. The conditions of the stress limitation are not met in some cases according to the pertinent standards. The untightnesses at nickel rings occurred during putting the units of Jaslovske Bohunice and Dukovany nuclear power stations into operation. With regard to improve the reliability, the producer has taken measures to improve the quality of the rings and users have introduced more strict regulations for bolts tightening. Due to these measures the high reliability of the set has been obtained from point of view of the tightness, but substantial reduction of bolts and holes threads loading have not been obtained. Several years operation experience proved relatively low service of bolts, damage of thread holes and sealing grooves. As the degree of mechanical load is one of the vital parameters influencing the damage of sealing set, in 1996 we started with the works aimed at a possibility of nickel sealing rings replacement for a more modern type of sealing which assure the higher reliability and service life of the individual part of sealing set under the reduced load.

  12. Repository seals requirements study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-03

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-08-25

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

  14. Applications of quantum message sealing

    CERN Document Server

    Worley, G G

    2005-01-01

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

  15. 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...

  16. Saving Seal Cutting

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

  17. 超稠油高温调剖封窜技术%High Temperature Profile Control and Channel Blocking Sealing Technology for Super Heavy Oil Researviors

    Institute of Scientific and Technical Information of China (English)

    郝建玉

    2012-01-01

    The cyclic steam stimulation is a recovery method of super heavy oil in Liaohe oilfield. The porosity of Du84 block of Xinglongtai oilfield in super heavy oil reservoir is generally 25% to 30%, air permeability is generally higher than 1306 × 10-3 μm2. Because of its high porosity and high permeability, steam channeling easily occurs to cause that heat energy of the injected steam can not be fully utilized, which can reduce production effect of the steam injection well. Water cut in adjacent well after the steam channeling increases, temperature rises, which can affect the production or cause to shut in well. Steam channeling aggravates casing deformation or damage. The high temperature resistant plugging agent can effectively block high permeability layer, adjust the steam absorption difference between low permeability layer and high permeability layer, change the flow direction of injected steam, which can alleviate the steam channeling, eliminate interference among wells, expand the injected steam swept volume, improve cycle oil production.%蒸汽吞吐开采是辽河油田超稠油主要开采方式.曙光油田杜84块兴隆台超稠油油藏孔隙度一般为25%~30%,空气渗透率一般高于1306×10-3 μm2,具有高孔隙度,高渗透率的特点,极易发生汽窜,导致注入蒸汽热能不能充分利用,直接降低了注汽井生产效果,使油藏动用不均的矛盾加剧.邻井受窜后含水升高液量突升,温度升高,影响其生产效果或关井防喷.汽窜加剧油层套管变形或损坏.研制的耐高温堵剂有效封堵高渗透层,调整地层高低渗透层带间的吸汽差异,改变注入蒸汽的走向,达到缓解汽窜、消除井间干扰、扩大注入蒸汽波及体积、提高周期采油量的目的.

  18. Steady State Thermo-Hydrodynamic Analysis of Two-Axial groove and Multilobe Hydrodynamic Bearings

    Directory of Open Access Journals (Sweden)

    C. Bhagat

    2014-12-01

    Full Text Available Steady state thermo-hydrodynamic analysis of two axial groove and multi lobe oil journal bearings is performed in this paper. To study the steady state thermo-hydrodynamic characteristics Reynolds equation is solved simultaneously along with the energy equation and heat conduction equation in bush and shaft. The effect of groove geometry, cavitation in the fluid film, the recirculation of lubricant, shaft speed has also been taken into account. Film temperature in case of three-lobe bearing is found to be high as compared to other studied bearing configurations. The data obtained from this analysis can be used conveniently in the design of such bearings, which are presented in dimensionless form.

  19. Subvertical grooves of interproximal facets in Neandertal posterior teeth.

    Science.gov (United States)

    Villa, G; Giacobini, G

    1995-01-01

    Subvertical grooves, located on the interproximal facets of most Neandertal posterior teeth, are less frequently noted on the teeth of other hominids, including modern humans. These grooves, 0.1-0.5 mm in width, are strictly localized within the facet area. Scanning electron microscopic (SEM) examination of grooves present on Neandertal teeth from Caverna delle Fate (Liguria, Italy) and Genay (Côte d'Or, France) demonstrated that they were produced during the life of these individuals. Characteristics of the groove surface suggest an erosion-abrasion mechanism of formation. These grooves, which developed in parts of the dentition exposed to marked stress, originated in areas characterized by changes in the orientation of enamel prism bundles (i.e., Hunter-Schreger bands). Observations carried out on modern human molars showed a subvertical disposition of these bands near interproximal ridges facilitating subvertical microfractures. Possible correlations between enamel structure, masticatory stress, and interproximal groove formation in Neandertals are discussed.

  20. Research on Cavitation Regions of Upstream Pumping Mechanical Seal Based on Dynamic Mesh Technique

    Directory of Open Access Journals (Sweden)

    Huilong Chen

    2014-08-01

    Full Text Available In order to study the cavitation area of the Upstream Pumping Mechanical Seal, three-dimensional microgap inner flow field of the Upstream Pumping Mechanical Seal was simulated with multiphase flow cavitation model and dynamic mesh technique based on hydrodynamic lubrication theory. Furthermore, the simulated result was compared with the experimental data. The results show that the simulated result with the Zwart-Gerber-Belamri cavitation model was much closer to the experimental data. The area of cavitation inception mainly occurred at the concave side of the spiral groove and surrounding region without spiral grooves, which was nearly covered by the inner diameter to roots of grooves; in addition, the region near the surface of the stationary ring was primary cavitation location. The area of cavitation has little relationship with the medium pressure; however, it became larger following increasing rotating speed in the range of researched operating conditions. Moreover the boundary of cavitated area was transformed from smooth to rough, which occurred in similar film thickness. When cavitation number was decreasing, which was conducive to improving the lubrication performance of sealed auxiliary, it made the sealing stability decline.

  1. Dual-phase CT findings of groove pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Zaheer, Atif, E-mail: azaheer1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Pancreatitis Center, Division of Gastroenterology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Haider, Maera, E-mail: mhaider3@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Kawamoto, Satomi, E-mail: skawamo1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Hruban, Ralph H., E-mail: rhruban1@jhmi.edu [Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, the Johns Hopkins University School of Medicine, Baltimore, MD 21231 (United States); Fishman, Elliot K., E-mail: efishma1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States)

    2014-08-15

    Purpose: Groove pancreatitis is a rare focal form of chronic pancreatitis that occurs in the pancreaticoduodenal groove between the major and minor papillae, duodenum and pancreatic head. Radiologic appearance and clinical presentation can result in suspicion of malignancy rendering pancreaticoduodenectomy inevitable. This study reports dual phase CT findings in a series of 12 patients with pathology proven groove pancreatitis. Materials and methods: Retrospective review of preoperative CT findings in 12 patients with histologically proven groove pancreatitis after pancreaticoduodenectomy. Size, location, attenuation, presence of mass or cystic components in the pancreas, groove and duodenum, calcifications, duodenal stenosis and ductal changes were recorded. Clinical data, laboratory values, endoscopic ultrasonographic and histopathological findings were collected. Results: Soft tissue thickening in the groove was seen in all patients. Pancreatic head, groove and duodenum were all involved in 75% patients. A discrete lesion in the pancreatic head was seen in half of the patients, most of which appeared hypodense on both arterial and venous phases. Cystic changes in pancreatic head were seen in 75% patients. Duodenal involvement was seen in 92% patients including wall thickening and cyst formation. The main pancreatic duct was dilated in 7 patients, with an abrupt cut off in 3 and a smooth tapering stricture in 4. Five patients had evidence of chronic pancreatitis with parenchymal calcifications. Conclusion: Presence of mass or soft tissue thickening in the groove with cystic duodenal thickening is highly suggestive of groove pancreatitis. Recognizing common radiological features may help in diagnosis and reduce suspicion of malignancy.

  2. Grooved roll for a high speed twin roll caster

    OpenAIRE

    T. Haga; HIROOKA, K.; H. Watari; S. Kumai

    2008-01-01

    Purpose: Purpose of this paper is investigation of the effect of roll-surface on the strip-surface. Improvement ofsmall cracks on the strip-surface was tried and effect of groove at the roll surface on the strip surface was shown.Design/methodology/approach: Method used in the present study was high speed twin roll caster withgrooved roll. Two kinds of grooves were used: one was parallel groove and the other was cross groove machinedby knurling and bite attached to a lathe.Findings: Findings ...

  3. Sensorimotor coupling in music and the psychology of the groove.

    Science.gov (United States)

    Janata, Petr; Tomic, Stefan T; Haberman, Jason M

    2012-02-01

    The urge to move in response to music, combined with the positive affect associated with the coupling of sensory and motor processes while engaging with music (referred to as sensorimotor coupling) in a seemingly effortless way, is commonly described as the feeling of being in the groove. Here, we systematically explore this compelling phenomenon in a population of young adults. We utilize multiple levels of analysis, comprising phenomenological, behavioral, and computational techniques. Specifically, we show (a) that the concept of the groove is widely appreciated and understood in terms of a pleasurable drive toward action, (b) that a broad range of musical excerpts can be appraised reliably for the degree of perceived groove, (c) that the degree of experienced groove is inversely related to experienced difficulty of bimanual sensorimotor coupling under tapping regimes with varying levels of expressive constraint, (d) that high-groove stimuli elicit spontaneous rhythmic movements, and (e) that quantifiable measures of the quality of sensorimotor coupling predict the degree of experienced groove. Our results complement traditional discourse regarding the groove, which has tended to take the psychological phenomenon for granted and has focused instead on the musical and especially the rhythmic qualities of particular genres of music that lead to the perception of groove. We conclude that groove can be treated as a psychological construct and model system that allows for experimental exploration of the relationship between sensorimotor coupling with music and emotion.

  4. Wetting morphologies and their transitions in grooved substrates

    Energy Technology Data Exchange (ETDEWEB)

    Seemann, Ralf; Bommer, Stefan; Herrmann, Carsten; Michler, Dominik [Experimental Physics, Saarland University, D-66123 Saarbruecken (Germany); Brinkmann, Martin; Herminghaus, Stephan; Khare, Krishnacharya; Kostourou, Konstantina; Gurevich, Evgeny [Max Planck Institute for Dynamics and Self-Organization, D-37073 Goettingen (Germany); Law, Bruce M; McBride, Sean, E-mail: r.seemann@physik.uni-saarland.de [Department of Physics, Kansas State University, Manhattan, KS 66506 (United States)

    2011-05-11

    When exposed to a partially wetting liquid, many natural and artificial surfaces equipped with complex topographies display a rich variety of liquid interfacial morphologies. In the present article, we focus on a few simple paradigmatic surface topographies and elaborate on the statics and dynamics of the resulting wetting morphologies. It is demonstrated that the spectrum of wetting morphologies increases with increasing complexity of the groove structure. On elastically deformable substrates, additional structures in the liquid morphologies can be observed, which are caused by deformations of the groove geometry in the presence of capillary forces. The emergence of certain liquid morphologies in grooves can be actively controlled by changes in wettability and geometry. For electrically conducting solid substrates, the apparent contact angle can be varied by electrowetting. This allows, depending on groove geometry, a reversible or irreversible transport of liquid along surface grooves. In the case of irreversible liquid transport in triangular grooves, the dynamics of the emerging instability is sensitive to the apparent hydrodynamic slip at the substrate. On elastic substrates, the geometry can be varied in a straightforward manner by stretching or relaxing the sample. The imbibition velocity in deformable grooves is significantly reduced compared to solid grooves, which is a result of the microscopic deformation of the elastic groove material close to the three phase contact line.

  5. Laminar streak enhancement using streamwise grooves

    Science.gov (United States)

    Martel, Carlos; Martín, Juan Ángel

    2011-11-01

    Laminar streak promotion in a flat plate boundary layer results in an increase of the stability of the Tollmien-Schlichting waves with respect to that of the 2D Blasius profile. This stabilization delays the laminar-turbulent transition, increasing the laminar phase of the flow. The stabilization effect is stronger for higher streak amplitudes, and therefore simple ways of generating high amplitude stable streaks are sought to be used as boundary layer flow control methods. In a recent experiment [Tallamelli & Franson,AIAA 2010-4291] high amplitude stable steady streaks have been produced using Miniature Vortex Generators (MGVs), where one array of MGVs is used to excite the streak and a second array is used downstream to enhance their amplitude. In this presentation we numerically explore the possibility of enhancing the streaks using a different passive mechanism: streamwise grooves carved in the plate. We will present some numerical simulations for different values of the spanwise period of the streaks and of the grooves, and we will show the combinations that provide maximum streak amplitude.

  6. Sealing device for providing a seal in a turbomachine

    Science.gov (United States)

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

    2016-08-16

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

  7. 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...

  8. 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...

  9. 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...

  10. Ribbon Seal Distribution Map

    Data.gov (United States)

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

  11. 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...

  12. Optics of a single ultrasharp groove in metal

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Bozhevolnyi, Sergey

    2016-01-01

    Optical properties of a single ultrasharp groove of subwavelength width cut in an otherwise flat metal surface are examined theoretically. We calculate optical extinction, scattering, and absorption cross-section spectra for a wide range of groove profiles, establishing several fundamental trends...

  13. Investigation of seal technology for Francis turbine

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Wei

    2012-06-01

    loss. Furthermore, the straight-through labyrinth seal with the bilateral cavity produce less leakage loss than with the unilateral cavity given identical cavity dimensions. However, the cavity location has only slight influences on the leakage flow.In addition, it is proven via experiments that the leakage flow rate is proportional to the clearance gap and pressure difference. It is also found numerically that vortices are formed when the flow enters a bigger cross section. These vortices consume the kinetic energy to a large extent, thereby reducing the leakage flow. Lastly, the experimental set-up of the rotor-stator system is built up as a simplification of a Francis turbine runner in the Waterpower laboratory at NTNU for two purposes. One is to investigate how the rotational speed of smooth disk affects the leakage flow rate, and the other is to study what are the effects of the geometries of rotating disk on the leakage flow rate and disk friction torque. With dimensional analysis, the function of flow coefficient and friction coefficient for the gap flow between one stationary and one rotating wall is derived. From the measurements for the smooth disk (SD), it is found that the leakage loss can be reduced by increasing the rotational speed due to the dominance of flow coefficient. While the leakage flow rises up due to the dominated pressure difference between the above and below the rotating disk. Comparing the measurements of the smooth disk (SD) and the disk with straight grooves (DSG), it is revealed that the geometry of the rotating disk has an impact on the leakage flow, and the performance of DSG is better than SD. Stage I only exists during the range of the current testing for DSG. However, the geometry of the disk has only slight effects on the disk friction torque.(au)

  14. Effective slippage on superhydrophobic trapezoidal grooves

    CERN Document Server

    Zhou, Jiajia; Schmid, Friederike; Vinogradova, Olga I

    2013-01-01

    We study the effective slippage on superhydrophobic grooves with trapezoidal cross-sections of various geometries (including the limiting cases of triangles and rectangular stripes), by using two complementary approaches. First, dissipative particle dynamics (DPD) simulations of a flow past such surfaces have been performed to validate an expression [E.S.Asmolov and O.I.Vinogradova, J. Fluid Mech. \\textbf{706}, 108 (2012)] that relates the eigenvalues of the effective slip-length tensor for one-dimensional textures. Second, we propose theoretical estimates for the effective slip length and calculate it numerically by solving the Stokes equation based on a collocation method. The comparison between the two approaches shows that they are in excellent agreement. Our results demonstrate that the effective slippage depends strongly on the area-averaged slip, the amplitude of the roughness, and on the fraction of solid in contact with the liquid. To interpret these results, we analyze flow singularities near slippi...

  15. Olfactory groove meningiomas: approaches and complications.

    Science.gov (United States)

    Aguiar, Paulo Henrique Pires de; Tahara, Adriana; Almeida, Antonio Nogueira; Simm, Renata; Silva, Arnaldo Neves da; Maldaun, Marcos Vinicius Calfatt; Panagopoulos, Alexandros Theodoros; Zicarelli, Carlos Alexandre; Silva, Pedro Gabriel

    2009-09-01

    Olfactory groove meningiomas (OGM) account for 4.5% of all intracranial meningiomas. We report 21 patients with OGMs. Tumors were operated on using three surgical approaches: bifrontal (7 patients), fronto-pterional (11 patients) and fronto-orbital (3 patients). Total tumor removal (Simpson Grade 1) was achieved in 13 patients and Simpson II in 8 patients. Perioperative mortality was 4.76%. The average size of the OGM was 4.3+/-1.1cm. The overall recurrence rate was 19%. We preferred to use the pterional approach, which provides quick access to the tumor with less brain exposure. It also allows complete drainage of cisternal cerebrospinal fluid, providing a good level of brain relaxation during surgery. However, for long, thin tumors, hemostasis can be difficult using this approach.

  16. Nuclear instrumentation cable end seal

    Science.gov (United States)

    Cannon, Collins P.; Brown, Donald P.

    1979-01-01

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

  17. Crystallization of Poly(3-hexylthiophene Nanofiber in a Narrow Groove

    Directory of Open Access Journals (Sweden)

    Satoshi Kushi

    2016-06-01

    Full Text Available Whisker-type poly(3-hexylthiophene-2,5-diyl (P3HT nanofibers were aligned by restricting their growth direction using an approximately 100–1000 nm wide narrow groove fabricated by thermal nanoimprinting. In grooves made of an amorphous fluoropolymer (CYTOP™ with widths of less than 1500 nm, the nanofibers oriented uniaxially perpendicular to the groove and their length was limited to the width of the groove. This result indicates that the nucleation of nanofibers tends to be selectively promoted near the interface of CYTOP™ with fluoro-groups, and nanofiber growth perpendicular to the wall is promoted because P3HT molecules are supplied more frequently from the center of the groove. Furthermore, the orientation induced anisotropic conductivity, and the conductivity parallel to the oriented nanofibers was more than an order of magnitude higher than that perpendicular to the oriented nanofibers.

  18. Accurate analysis of arbitrarily-shaped helical groove waveguide

    Institute of Scientific and Technical Information of China (English)

    Liu Hong-Tao; Wei Yan-Yu; Gong Yu-Bin; Yue Ling-Na; Wang Wen-Xiang

    2006-01-01

    This paper presents a theory on accurately analysing the dispersion relation and the interaction impedance of electromagnetic waves propagating through a helical groove waveguide with arbitrary groove shape, in which the complex groove profile is synthesized by a series of rectangular steps. By introducing the influence of high-order evanescent modes on the connection of any two neighbouring steps by an equivalent susceptance under a modified admittance matching condition, the assumption of the neglecting discontinuity capacitance in previously published analysis is avoided, and the accurate dispersion equation is obtained by means of a combination of field-matching method and admittancematching technique. The validity of this theory is proved by comparison between the measurements and the numerical calculations for two kinds of helical groove waveguides with different groove shapes.

  19. SIMULATION AND EXPERIMENT OF BUBBLY FLOW INSIDE THROTTLING GROOVE

    Institute of Scientific and Technical Information of China (English)

    FU Xin; DU Xuewen; ZOU Jun; YANG Huayong; JI Hong

    2007-01-01

    The relationship between pressure distribution and cavitation (noise) inside throttling groove is investigated by numerical simulation and experimental method. A valve pocket with several transducers is performed to detect the pressure distributions inside the valve chamber, and the results fit quite well with the computational fluid dynamics(CFD) analysis. High-speed imaging techniques are employed to investigate the cavitation mechanisms, in particular bubble inception and cluster formation near the throttling groove. A spectrum analyzer is used to measure the sound pressure level of noise generated by the bubble flow. It is found that the pressure distributions inside the groove are sensitive to the valve port configuration and back pressure. The pressure distribution determines the bubble size and number passing through the valve grooves and the sound pressure level of noise induced by collapsing bubbles. The inlet pressure mainly affects the saturation degree of bubbly flow inside the groove and the intensity of sound pressure level accordingly.

  20. Characteristics of Multiplexed Grooved Nozzles for High Flow Rate Electrospray

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Tae; Kim, Woo Jin; Kim, Sang Soo [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2007-10-15

    The electrospray operated in the cone-jet mode can generate highly charged micro droplets in an almost uniform size at flow rates. Therefore, the multiplexing system which can retain the characteristics of the cone-jet mode is inevitable for the electrospray application. This experiment reports the multiplexed grooved nozzle system with the extractor. The effects of the grooves and the extractor on the performance of the electrospray were evaluated through experiments. Using the grooved nozzle, the stable cone-jet mode can be achieved at the each groove in the grooved mode. Furthermore, the number of nozzles per unit area is increased by the extractor. The multiplexing density is 12 jets per cm{sup 2} at 30 mm distance from the nozzle tip to the ground plate. The multiplexing system for the high flow rate electrospray is realized with the extractor which can diminish the space charge effect without sacrificing characteristics of the cone-jet mode.

  1. Forming method of micro heat pipe with compound structure of sintered wick on grooved substrate

    Science.gov (United States)

    Li, Xibing; Li, Mingjian; Li, Ming; Wu, Ruchen; Wan, Yingsi; Cheng, Tian

    2016-03-01

    Micro heat pipes (MHPs) with excellent heat transfer performance have been the ideal radiating components to meet increasingly higher requirements posed by high heat-flux products. Based on MHPs' working principle, this study deduced capillary limit of a novel MHP with compound structure of sintered wick on grooved substrate, and probed into its forming mechanism: first, high-speed oil-filled spinning was applied to fabricating micro grooves, with optimal spinning and drawing speeds determined; then a mini-type vibration machine was used to help fill copper powders fast and uniformly, with appropriate sintering temperature and time fixed; the manufacturing method that integrates vacuum-pumping-cold-welding with secondary-degassing-cold-welding to increase vacuumizing efficiency. The results of experiments on its heat transfer performance show that the MHPs with sintered-wick-on-grooved-substrate structure fabricated through the proposed forming method can not only acquire much better heat transfer performance, but have advantages such as higher productivity and lower cost.

  2. Sliding seal for mining machine power transmission

    Energy Technology Data Exchange (ETDEWEB)

    Levenstein, V.M.

    1993-07-06

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

  3. 罐壁式泡沫系统扑救密封圈火灾试验研究%Experiment research on tank-shell foam extinguishing system of rim seal fire

    Institute of Scientific and Technical Information of China (English)

    任常兴; 王婕; 张欣; 吴伟; 李晋; 涂建新; 徐大军

    2013-01-01

    According to the characteristics and shortage of tank-shell fire fighting system of open-top large floating roof oil tanks , an experiment oil groove of rim seal fire with 30 meters long was designed by the related code , and some foam extinguishing experiments of 3%aqueous film-forming foam concentrate ( AFFF) and 6%fluoroprotein foam concentrate ( FP) were conducted .In the experiment process , foam expansion ratio and 25%drainage time of 3%AFFF and 6%FP were tested on spot , and accorded with the standard of fire extinguish agent , but were both less than testing report value of lab .Moreover, foam flow speed in the foam weir plate and overspread rate on the fire oil surface were determined , and oil fire development condition was observed and recorded .The temperature and heat flow of oil groove fire were contrasted and analyzed with different foam and application rate of foam solu -tion.Furthermore, the effectiveness of tank-shell foam extinguishing system of open-top large floating roof oil tanks for rim seal fire was descried and discussed .The test results showed that 3%AFFF and 6%FP may control and ex-tinguish even the rim seal fire with the effective application density of foam concentrate , and foam type and applica-tion density have important effect on the time of total flooding oil surface .This experiment has some positive refer-ence and engineering application value for foam extinguishing rim seal fire of large floating roof oil tanks with low liquid level.%针对大型浮顶罐罐壁式泡沫灭火系统的特点及不足,依据相关规范要求设计了30m长的密封圈火灾模拟试验油槽,开展了3%型水成膜泡沫液和6%型氟蛋白泡沫液灭火试验。现场测定了泡沫的发泡倍数和析液时间,符合规范要求但略低于检测值。试验过程测定了泡沫在泡沫堰板内的流动速度和燃烧油面的蔓延速度,观察了不同的泡沫液和泡沫混合液供给强度下

  4. Ambient temperature does not affect the tactile sensitivity of mystacial vibrissae in harbour seals.

    Science.gov (United States)

    Dehnhardt, G; Mauck, B; Hyvärinen, H

    1998-11-01

    Vibrissae provide pinnipeds with tactile information primarily in the aquatic environment, which is characterized by its high thermal conductivity and large potential cooling power. Since studies of thermal effects on human tactile sensitivity have revealed that cooling below normal skin temperature impairs sensitivity, the present study investigates the tactile sensitivity of the vibrissal system of harbour seals at varying ambient temperatures. Using plates bearing gratings of alternating grooves and ridges, the texture difference thresholds of two adult seals were determined under water. We took advantage of the natural difference in ambient temperature between summer and winter. Mean water temperature was 1. 2 degreesC during the winter and 22 degreesC during the summer. During the cold season, the thermal status of both seals was examined using an infrared-sensitive camera system. The texture difference threshold of both seals remained the same (0.18 mm groove width difference) under both test conditions. The thermographic examination revealed that the skin areas of the head where the mystacial and supraorbital vibrissae are located show a substantially higher degree of thermal emission than do adjacent skin areas. This suggests that, in the vibrissal follicles of harbour seals, no vasoconstriction occurs during cold acclimation, so that the appropriate operating temperature for the mechanoreceptors is maintained.

  5. THE ORIGINS OF SEALS AND SEALING IN CHINA

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

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

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

    Science.gov (United States)

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

    2012-01-10

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

  7. Electrospinning of Grooved Polystyrene Fibers: Effect of Solvent Systems

    Science.gov (United States)

    Liu, Wanjun; Huang, Chen; Jin, Xiangyu

    2015-05-01

    Secondary surface texture is of great significance to morphological variety and further expands the application areas of electrospun nanofibers. This paper presents the possibility of directly electrospinning grooved polystyrene (PS) fibers using both single and binary solvent systems. Solvents were classified as low boiling point solvent (LBPS): dichloromethane (DCM), acetone (ACE), and tetrahydrofuran (THF); high boiling point solvent (HBPS): N, N-dimethylformamide (DMF) and cyclohexanone (CYCo); and non-solvent (NS): 1-butanol (BuOH). By the systematic selection and combination of these solvents at given parameters, we found that single solvent systems produced non-grooved fibers. LBPS/DMF solvent systems resulted in fibers with different grooved textures, while LBPS/CYCo led to fibers with double grooved texture. Grooved fibers can also be fabricated from LBPS/LBPS, NS/LBPS, and NS/HBPS systems under specific conditions. The results indicated that the difference of evaporation rate (DER) between the two solvents played a key role in the formation of grooved texture. The formation of this unique texture should be attributed to three separate mechanisms, namely void-based elongation, wrinkle-based elongation, and collapsed jet-based elongation. Our findings can serve as guidelines for the preparation of ultrafine fibers with grooved secondary texture.

  8. 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...

  9. Grooved Fuel Rings for Nuclear Thermal Rocket Engines

    Science.gov (United States)

    Emrich, William

    2009-01-01

    An alternative design concept for nuclear thermal rocket engines for interplanetary spacecraft calls for the use of grooved-ring fuel elements. Beyond spacecraft rocket engines, this concept also has potential for the design of terrestrial and spacecraft nuclear electric-power plants. The grooved ring fuel design attempts to retain the best features of the particle bed fuel element while eliminating most of its design deficiencies. In the grooved ring design, the hydrogen propellant enters the fuel element in a manner similar to that of the Particle Bed Reactor (PBR) fuel element.

  10. 低温油封冷却器的结构优化及数值模拟%Structure Optimization and Numerical Simulation of Low-Temperature Oil Seal Cooler

    Institute of Scientific and Technical Information of China (English)

    高海; 喻九阳; 徐建民; 郑小涛; 林纬

    2016-01-01

    Aiming at the shell-and-tube heat transfer existing stagnant zones at the back of baffle,we optimized the structure of the baffle in shell-side of the heat exchanger,and studied the effects of the baffle with round and taper hole on the performance of heat transfer and pressure-drop of the low-temperature oil seal cooler by numeri⁃cal simulation respectively. Result shows that the baffle with round hole is more conductive to reduce stagnant zones at the back of baffle and improve the performance of heat transfer of the cooler when the velocity of shell-side entrance is less than 1.3 m/s;and the baffle with taper hole is more advantageous to enhance the heat transfer of the cooler when the velocity of shell-side entrance is more than 2 m/s. Moreover,the baffles with round and taper hole are beneficial to reduce the pressure-drop of shell-side with almost the same effects.%针对管壳式换热器折流板背部存在流动死区的问题,对换热器壳程折流板的结构进行优化,并且通过数值模拟分别研究了折流板开圆孔和锥形孔对低温油封冷却器换热性能和压降的影响.数值模拟结果表明,当壳程入口速度低于1.3 m/s,折流板开圆孔更有利于减小折流板背部流动死区,改善冷却器壳程的强化传热性能;当壳程入口流速大于2m/s时,折流板开锥形孔更有利于冷却器壳程的强化传热.折流板开圆孔和锥形孔均有利于减小冷却器壳程压降,两者对压降的影响无明显差别.

  11. Sealing coupling. [LMFBR

    Science.gov (United States)

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

    1982-09-20

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

  12. Anterior Interhemispheric Approach for Olfactory Groove Meningioma

    Directory of Open Access Journals (Sweden)

    Imam Hidayat

    2016-09-01

    Full Text Available Objective: To evaluate the surgical technique with bifrontal interhemispheric approach for total removal of tumor in olfactory groove meningioma (OGM. Methods: This study described a case of a 38-year-old woman with bilateral blindness, anosmia, and behaviour changes. Imaging studies show a tumor mass in midfrontal base. Surgery using a bifrontal interhemispheric approach was performed and total removal was achieved and postoperative computed tomography (CT scan was performed to confirm the result. Histopathological findings established a diagnosis of meningioma. Results: A coronal skin incision behind the hairline was utilized. The scalp was elevated, taking care to reserve the vascularized pericranium medial to the linea temporalis of each side, and preserving the 2 supraorbital nerves. Eight burr holes were used, with the two initial holes made on each side of the orbitotemporal region, and the other four holes at the midline. A bifrontal craniotomy was performed. The tumor was first detached from its attachment with bipolar cautery and debulked. During this step, the main tumor feeder arteries from the anterior and posterior ethmoidal artery were interrupted, and the tumor devascularized. Total tumor removal through surgical intervention was achieved and confirmed by head CT-scan postoperatively. Conclusions: This case report supports the suitability of the bifrontal interhemispheric approach for OGM resection with additional radiation therapy.

  13. CHANGING LAW OF 4-CLASS RAPE OIL STORED IN OIL TANK AT CONVENTIONAL SEALED CONDITION%常规密闭储存条件下罐存四级菜籽油品质变化规律初探

    Institute of Scientific and Technical Information of China (English)

    薛文秀

    2012-01-01

    选择同一时期入库、入库质量均符合国家四级以上质量标准规定、在同一地理位置采用常规密闭储藏的罐存四级菜籽油,在近两年的储存期间,对其定期抽样测定酸值及过氧化值变化情况.结果表明,经过近两年的密闭储存,酸值、过氧化值均有不同程度的上升,但酸值上升的幅度非常小,过氧化值虽有明显升高,但上升幅度也不大.%4-class rape oil stored at the same time and the same place was chosen in this test. Its acid value and peroxide value were taken the regular measurement during 2 years storage. The results showed that both acid value and peroxide acid had increased in varying degrees, but acid value had a little rise, while peroxide acid had obviously rise, but the tendency of change kept stable.

  14. Fractures of the proximal humerus involving the intertubercular groove

    Energy Technology Data Exchange (ETDEWEB)

    Ahovuo, J.; Paavolainen, P.; Bjoerkenheim, J.M. (Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Helsinki Univ. Central Hospital (Finland). Div. of Traumatology and Orthopaedic Surgery)

    The purpose of this study was to analyse the involvement of the gliding surface of the biceps tendon in fractures of the proximal humerus. Fifteen patients had a fracture of the proximal humerus verified with antero-posterior and axillary radiographs. Tangential radiographs of the intertubercular groove, obtained from the shoulder joint, showed involvement of the intertubercular groove in 13 patients (87%), which could not be shown with other projections. Groove radiographs revealed in 3 patients a dislocation of the fragments of the greater tuberosity large enough to require surgical treatment, but which had not been found using conventional techniques. Therefore, a groove radiograph should be used to precise fractures of the proximal humerus. (orig.).

  15. Heat transfer and thermal stress analysis in grooved tubes

    Indian Academy of Sciences (India)

    Veysel Özceyhan; Necdet Altuntop

    2005-08-01

    Heat transfer and thermal stresses, induced by temperature differencesin the internally grooved tubes of heat transfer equipment, have been analysed numerically. The analysis has been conducted for four different kinds of internally grooved tubes and three different mean inlet water velocities. Constant temperature was applied from the external surface of the tube. Energy and governing flow equations were solved using finite difference scheme. Finite element method (FEM) was used to compute the thermal stress fields. Grooving effects on the thermal stress ratio have been discussed. As a result, maximum thermal stress occurs in the case of $p = d$ for all water inlet velocities. The maximum thermal stress ratio positions inside the tube have been indicated as MX for all investigated cases. In the light of the thermal stress values, various designs can be applied to reduce thermal stress in grooved tubes.

  16. Interproximal grooving in the Atapuerca-SH hominid dentitions.

    Science.gov (United States)

    Bermúdez de Castro, J M; Arsuaga, J L; Pérez, P J

    1997-03-01

    The dental sample recovered from the Sima de los Huesos (SH) Middle Pleistocene cave site of the Sierra de Atapuerca (Spain) includes 296 specimens. Interproximal wear grooves have been observed in 20 maxillary and mandibular posterior teeth belonging to at least five of the 32 individuals identified so far in the SH hypodigm. Interproximal grooving affected only the adults, and at an age between 25 and 40 years. The appearance, morphology, and location pattern of the SH wear grooves are similar to those reported in other fossil hominids and in more recent human populations. Two alternative proposals, the toothpicking and the fiber or sinew processing hypotheses, compete for explaining the formation of this anomalous wear. The characteristics observed in the wear grooves of the SH teeth are compatible only with the habitual probing of interdental spaces by means of hard and inflexible objects. Dietary grit may also have contributed to the abrasion of the root walls during the motion of the dental probes.

  17. Femtosecond laser-induced blazed periodic grooves on metals.

    Science.gov (United States)

    Hwang, Taek Yong; Guo, Chunlei

    2011-07-01

    In this Letter, we generate laser-induced periodic surface structures (LIPSSs) on platinum following femtosecond laser pulse irradiation. For the first time to our knowledge, we study the morphological profile of LIPSSs over a broad incident angular range, and find that the morphological profile of LIPSSs depends significantly on the incident angle of the laser beam. We show that LIPSS grooves become more asymmetric at a larger incident angle, and the morphological profile of LIPSSs formed at an incident angle over 55° eventually resembles that of a blazed grating. Our study suggests that the formation of the blazed groove structures is attributed to the selective ablation of grooves through the asymmetric periodic surface heating following femtosecond pulse irradiation. The blazed grooves are useful for controlling the diffraction efficiency of LIPSSs.

  18. Measurement and analysis of grain boundary grooving by volume diffusion

    Science.gov (United States)

    Hardy, S. C.; Mcfadden, G. B.; Coriell, S. R.; Voorhees, P. W.; Sekerka, R. F.

    1991-01-01

    Experimental measurements of isothermal grain boundary grooving by volume diffusion are carried out for Sn bicrystals in the Sn-Pb system near the eutectic temperature. The dimensions of the groove increase with a temporal exponent of 1/3, and measurement of the associated rate constant allows the determination of the product of the liquid diffusion coefficient D and the capillarity length Gamma associated with the interfacial free energy of the crystal-melt interface. The small-slope theory of Mullins is generalized to the entire range of dihedral angles by using a boundary integral formulation of the associated free boundary problem, and excellent agreement with experimental groove shapes is obtained. By using the diffusivity measured by Jordon and Hunt, the present measured values of Gamma are found to agree to within 5 percent with the values obtained from experiments by Gunduz and Hunt on grain boundary grooving in a temperature gradient.

  19. Groove shape characteristics of echelle gratings with high diffraction efficiency

    Science.gov (United States)

    Zhang, Shanwen; Mi, Xiaotao; Zhang, Qian; Jirigalantu; Feng, Shulong; Yu, Haili; Qi, Xiangdong

    2017-03-01

    The groove shape characteristics of echelle gratings with high diffraction efficiency are investigated. Using the coordinate transformation method (C method), an r-2 aluminum echelle with 79 grooves/mm is optimized through rigorous numerical simulations and shows high diffraction efficiency of 76-81% in the high Littrow orders. A grating is found to be essentially an echelle if it contains a series of reflective facets with a specific tilt angle that are located far from the nonworking facet of the grating and have a deep groove depth; any groove shape that meets these conditions can be called an echelle grating. The underlying mechanism is analyzed phenomenologically using electromagnetic theory. The universal model proposed here, which represents a new cognitive understanding of the concept of the echelle, is ready for use in manufacturing applications and offers a new perspective for the fabrication of these gratings.

  20. Ceramic to metal seal

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-01-01

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

  1. 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)

  2. Mechanical Face Seal Dynamics.

    Science.gov (United States)

    1985-12-01

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

  3. 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

  4. Detection of grey seal

    NARCIS (Netherlands)

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

    2014-01-01

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

  5. 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

  6. [Developmental radicular groove as a cause of endodontic failure].

    Science.gov (United States)

    Fabra Campos, H; Millet Part, J

    1989-01-01

    A clinical case of apical injury on an upper lateral incisor with endodontical and surgical failures in its treatment is presented. Extraction of the incisor and its study at the stereoscopic microscope showed the existence of a developmental groove running from the cingulum to the end of the root, establishing a communication between the crevice and the apical part of the tooth. Bacterial infection through the groove could provide an explanation for treatment failure.

  7. Surface reproduction of elastomeric materials: viscosity and groove shape effects

    OpenAIRE

    Mahmood, N.; Abu Kasim, N.H.; Azuddin, M.; Kasim, N.L. Abu

    2010-01-01

    Objective: To evaluate the effect of viscosity and type of grooves on surface detail reproduction of elastomeric impression materials. Methods: Express putty/light-, Impregum medium- and heavy/light-bodied and Aquasil medium- and putty/light-bodied elastomeric impression materials were chosen for this study. Five impressions were made using a cylindrical aluminum reference block with U- and V- shaped grooves and to produce 35 master dies. Each master die was immersed in distilled water at 370...

  8. Polymer scaffolds with preferential parallel grooves enhance nerve regeneration.

    Science.gov (United States)

    Mobasseri, Atefeh; Faroni, Alessandro; Minogue, Ben M; Downes, Sandra; Terenghi, Giorgio; Reid, Adam J

    2015-03-01

    We have modified the surface topography of poly ɛ-caprolactone (PCL) and polylactic acid (PLA) blended films to improve cell proliferation and to guide the regeneration of peripheral nerves. Films with differing shaped grooves were made using patterned silicon templates, sloped walls (SL), V-shaped (V), and square-shaped (SQ), and compared with nongrooved surfaces with micropits. The solvent cast films were tested in vitro using adult adipose-derived stem cells differentiated to Schwann cell-like cells. Cell attachment, proliferation, and cell orientation were all improved on the grooved surfaces, with SL grooves giving the best results. We present in vivo data on Sprague-Dawley rat sciatic nerve injury with a 10-mm gap, evaluating nerve regeneration at 3 weeks across a polymer nerve conduit modified with intraluminal grooves (SL, V, and SQ) and differing wall thicknesses (70, 100, 120, and 210 μm). The SL-grooved nerve conduit showed a significant improvement over the other topographical-shaped grooves, while increasing the conduit wall thickness saw no positive effect on the biological response of the regenerating nerve. Furthermore, the preferred SL-grooved conduit (C) with 70 μm wall thickness was compared with the current clinical gold standard of autologous nerve graft (Ag) in the rat 10-mm sciatic nerve gap model. At 3 weeks postsurgery, all nerve gaps across both groups were bridged with regenerated nerve fibers. At 16 weeks, features of regenerated axons were comparable between the autograft (Ag) and conduit (C) groups. End organ assessments of muscle weight, electromyography, and skin reinnervation were also similar between the groups. The comparable experimental outcome between conduit and autograft, suggests that the PCL/PLA conduit with inner lumen microstructured grooves could be used as a potential alternative treatment for peripheral nerve repair.

  9. Droplet impact on regular micro-grooved surfaces

    Institute of Scientific and Technical Information of China (English)

    Hu Hai-Bao; Huang Su-He; Chen Li-Bin

    2013-01-01

    We have investigated experimentally the process of a droplet impact on a regular micro-grooved surface.The target surfaces are patterned such that micro-scale spokes radiate from the center,concentric circles,and parallel lines on the polishing copper plate,using Quasi-LIGA molding technology.The dynamic behavior of water droplets impacting on these structured surfaces is examined using a high-speed camera,including the drop impact processes,the maximum spreading diameters,and the lengths and numbers of fingers at different values of Weber number.Experimental results validate that the spreading processes are arrested on all target surfaces at low velocity.Also,the experimental results at higher impact velocity demonstrate that the spreading process is conducted on the surface parallel to the micro-grooves,but is arrested in the direction perpendicular to the micro-grooves.Besides,the lengths of fingers increase observably,even when they are ejected out as tiny droplets along the groove direction,at the same time the drop recoil velocity is reduced by micro-grooves which are parallel to the spreading direction,but not by micro-grooves which are vertical to the spreading direction.

  10. Mechanical Seals for Primary Circuit of Nuclear Power Plants%核电站一回路用机械密封

    Institute of Scientific and Technical Information of China (English)

    王玉明; 黄伟峰; 李永健

    2011-01-01

    sodium-cooled fast reactors were introduced.One was inert gas buffered,oil lubricated,three-stage series seal,and the other was the spiral groove mechanical seal directly lubricated by the liquid metal.

  11. Regenerator cross arm seal assembly

    Science.gov (United States)

    Jackman, Anthony V.

    1988-01-01

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

  12. Seals Having Textured Portions for Protection in Space Environments

    Science.gov (United States)

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

    2016-01-01

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

  13. Effects of Low Earth Orbit on Docking Seal Materials

    Science.gov (United States)

    Imka, Emily C.; Asmar, Olivia C.; deGroh, Henry C., III; Banks, Bruce A.

    2014-01-01

    Spacecraft docking seals are typically made of silicone elastomers. When such seals are exposed to low Earth orbit (LEO) conditions, they can suffer damage from ultraviolet (UV) radiation and atomic oxygen (AO, or monoatomic oxygen, the predominant oxygen species in LEO). An experiment flew on the International Space Station (ISS) to measure the effects of LEO on seal materials S0383-70 and ELA-SA-401 and various mating counterface materials which included anodized aluminum. Samples flown in different orientations received different amounts of UV and AO. The hypotheses were that most of the damage would be from UV, and 10 days or more of exposure in LEO would badly damage the seals. Eighteen seals were exposed for 543 days in ram (windward), zenith (away from Earth), or wake (leeward) orientations, and 15 control samples (not flown) provided undamaged baseline leakage. To determine post-flight leak rates, each of the 33 seals were placed in an O-ring groove of a leak test fixture and pressure tested over time. Resistance temperature detectors (RTDs), pressure transducers, and LabVIEW (National Instruments) programs were used to measure and analyze the temperature and pressure and calculate leakage. Average leakage of control samples was 2.6 x 10(exp -7) lbs/day. LEO exposure did not considerably damage ELA-SA-401. The S0383-70 flight samples leaked at least 10 times more than ELA-SA-401 in all cases except one, demonstrating that ELA-SA-401 may be a more suitable sealing material in LEO. AO caused greater damage than UV; samples in ram orientation (receiving an AO fluence of 4.3 x 10(exp 21) atoms/(sq cm) and in wake (2.9x 10(exp 20) atoms/(sq cm)) leaked more than those in zenith orientation (1.58 x 10(exp 20) atoms/(sq cm)), whereas variations in UV exposure did not seem to affect the samples. Exposure to LEO did less damage to the seals than hypothesized, and the data did not support the conjecture that UV causes more damage than AO.

  14. Sealing the Mitochondrial Respirasome

    OpenAIRE

    Winge, Dennis R.

    2012-01-01

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

  15. A sealing element

    Energy Technology Data Exchange (ETDEWEB)

    Obi, F.; Takada, K.

    1983-09-22

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

  16. Closure and Sealing Design Calculation

    Energy Technology Data Exchange (ETDEWEB)

    T. Lahnalampi; J. Case

    2005-08-26

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

  17. TECHNOLOGY ROADMAPPING FOR IAEA SEALS.

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-13

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

  18. Continuous blood fractionation using an array of slanted grooves

    Science.gov (United States)

    Bernate, Jorge A.; Chengxun, Liu; Lagae, Liesbet; Drazer, German

    2011-11-01

    Blood is a complex fluid having different specialized biological functions and containing a plethora of clinical information. The separation of different blood components is a crucial step in many research and clinical applications. In this work we take advantage of the flow characteristics in microfluidic devices in which the bottom surface is patterned with slanted rectangular grooves to continuously fractionate blood. We exploit the flow in the vicinity of the patterned surface when the dimensions of the grooves are much smaller than the dimensions of the main channel. In these devices, we observed that the grooves act as open channels guiding flow along them with the flow over them being in the direction of the main channel. We present experiments in which the different blood components are deflected laterally to a different extent by the flow along the grooves depending on their sedimentation velocity, which allows their continuous fractionation. In particular, the heavier red blood cells experience the largest deflection while the lighter white blood cells deflect the least, allowing their passive and minimally invasive isolation. In addition, this fluidic platform can also be used to separate magnetically labeled circulating cancer cells which can be retained in the flow along the grooves using a sufficiently strong magnetic force.

  19. Effects of hydrocarbon physical properties on caprock’s capillary sealing ability

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new mechanics formula of caprock’s capillary sealing ability has been established in this paper, in which the boundary layer resistance was considered and characterized by starting pressure gradient. The formula shows that capillary sealing ability of caprock is determined not only by the capillary force of rock and the buoyancy of hydrocarbon column, but also by the starting pressure gradient of hydrocarbons and the thickness of caprock. The buoyancy of hydrocarbon column, the starting pressure gradient of hydrocarbon, and the capillary force of caprock are affected by hydrocarbon density, hydrocarbon viscosity, and hydrocarbon-water interface tension respectively. Based on hydrocarbon property data of reservoirs of Jiyang Depression and equations from literature, the effects of hydrocarbon density, hydrocarbon viscosity, and hydrocarbon-water interface tension on the sealing ability of caprock are analyzed. Under formational conditions, the sealing ability of oil caprock can vary up to dozens times because of the variations of the oil density, oil viscosity, and oil-water interface tension. Thus, the physical characters of hydrocarbon should be considered when evaluating the capillary sealing ability of caprocks. Study of the effects of physical characters on sealing ability of caprock can provide guidance to exploring special physical property hydrocarbon resources, such as viscous oils, and hydrocarbon resources in special pressure-temperature environments.

  20. Refrigerating machine oil

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, K.

    1981-03-17

    Refrigerating machine oil to be filled in a sealed motorcompressor unit constituting a refrigerating cycle system including an electric refrigerator, an electric cold-storage box, a small-scaled electric refrigerating show-case, a small-scaled electric cold-storage show-case and the like, is arranged to have a specifically enhanced property, in which smaller initial driving power consumption of the sealed motor-compressor and easier supply of the predetermined amount of the refrigerating machine oil to the refrigerating system are both guaranteed even in a rather low environmental temperature condition.

  1. Comparison Research on Performance of Labyrinth-like Screw Seal and Labyrinth Seal%类迷宫螺旋密封与迷宫密封的性能对比研究

    Institute of Scientific and Technical Information of China (English)

    高远; 王凡; 张秀珩; 焦圳; 崔淮

    2014-01-01

    往复式压缩机迷宫密封加工过程中,为简化加工工艺,将传统迷宫密封加工成类迷宫螺旋密封。为比较类迷宫螺旋密封与迷宫密封的密封性能差异,分析类迷宫螺旋密封的密封机制,将类迷宫螺旋密封的能量耗散分成类迷宫密封能量耗散和槽向能量损失,采用CFD方法对类迷宫螺旋密封的密封性能进行数值模拟。结果表明,类迷宫螺旋密封的密封性能虽不及传统迷宫密封,但密封效果相差在5%以内,综合考虑加工工艺、经济效益等因素,采用类迷宫螺旋密封代替迷宫密封是完全可行的。%To simplify the processing technology,the labyrinth-like screw seal is used to replace the traditional labyrinth seal during the machining process of labyrinth reciprocating compressor.The sealing performance between the labyrinth seal and the labyrinth-like screw seal was compared,and the sealing mechanism of labyrinth-like screw seal was analyzed.By dividing the energy dissipation of labyrinth-like screw seal into the energy dissipation of labyrinth-like seal and the energy loss at groove direction,the sealing performance of the labyrinth-like screw seal was simulated by using CFD method.The results show that the sealing performance of the labyrinth-like screw seal is less than that of traditional labyrinth seal,but the sealing effect difference is within 5%.It is completely feasible to use the labyrinth-like screw seal instead of the laby-rinth seal with considering processing technology,economic benefit and other factors.

  2. Mechanisms of rectangular groove-induced multiple-microdroplet coalescences

    Science.gov (United States)

    Shen, Feng; Li, Yi; Wang, Guiren; Liu, Zhaomiao

    2017-01-01

    The mechanism of microdroplet coalescence is a fundamental issue for droplet-based microfluidics. We developed an asymmetric expansion (a rectangular groove) along one side of a microchannel to achieve multiple-microdroplet trapping, collision, and coalescence. Compared with reported symmetric expansions, this asymmetric groove could easily trap microdroplets and control two or three microdroplet coalescences precisely without a requirement for temporal and spatial synchronization. To reveal the mechanisms of multiple-droplet coalescences in a groove, we observed five different coalescence patterns under different flow conditions. Moreover, we characterized the flow behavior quantitatively by simulating the velocity vector fields in both the microdroplets and continuous phase, finding good agreement with experiments. Finally, a map of coalescence forms with different capillary numbers (0.001droplet-based microfluidic devices.

  3. The experimental and numerical investigation of a grooved vapor chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ming [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China); Liu Zhongliang [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)], E-mail: liuzhl@bjut.edu.cn; Ma Guoyuan [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)

    2009-02-15

    An effective thermal spreader can achieve more uniform heat flux distribution and thus enhance heat dissipation of heat sinks. Vapor chamber is one of highly effective thermal spreaders. In this paper, a novel grooved vapor chamber was designed. The grooved structure of the vapor chamber can improve its axial and radial heat transfer and also can form the capillary loop between condensation and evaporation surfaces. The effect of heat flux, filling amount and gravity to the performance of this vapor chamber is studied by experiment. From experiment, we also obtained the best filling amount of this grooved vapor chamber. By comparing the thermal resistance of a solid copper plate with that of the vapor chamber, it is suggested that the critical heat flux condition should be maintained to use vapor chamber as efficient thermal spreaders for electronics cooling. A two-dimensional heat and mass transfer model for the grooved vapor chamber is developed. The numerical simulation results show the thickness distribution of liquid film in the grooves is not uniform. The temperature and velocity field in vapor chamber are obtained. The thickness of the liquid film in groove is mainly influenced by pressure of vapor and liquid beside liquid-vapor interface. The thin liquid film in heat source region can enhance the performance of vapor chamber, but if the starting point of liquid film is backward beyond the heat source region, the vapor chamber will dry out easily. The optimal filling ratio should maintain steady thin liquid film in heat source region of vapor chamber. The vapor condenses on whole condensation surface, so that the condensation surface achieves great uniform temperature distribution. By comparing the experimental results with numerical simulation results, the reliability of the numerical model can be verified.

  4. V-groove plasmonic waveguides fabricated by nanoimprint lithography

    DEFF Research Database (Denmark)

    Fernandez-Cuesta, I.; Nielsen, R.B.; Boltasseva, Alexandra

    2007-01-01

    Propagation of channel plasmon-polariton modes in the bottom of a metal V groove has been recently demonstrated. It provides a unique way of manipulating light at nanometer length scale. In this work, we present a method based on nanoimprint lithography that allows parallel fabrication of integra......Propagation of channel plasmon-polariton modes in the bottom of a metal V groove has been recently demonstrated. It provides a unique way of manipulating light at nanometer length scale. In this work, we present a method based on nanoimprint lithography that allows parallel fabrication...

  5. Sealing the mitochondrial respirasome.

    Science.gov (United States)

    Winge, Dennis R

    2012-07-01

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

  6. Nonlinear dynamic analysis of a rotor-bearing-seal system under two loading conditions

    Science.gov (United States)

    Ma, Hui; Li, Hui; Niu, Heqiang; Song, Rongze; Wen, Bangchun

    2013-11-01

    The operating speed of the rotating machinery often exceeds the second or even higher order critical speeds to pursue higher efficiency. Thus, how to restrain the higher order mode instability caused by the nonlinear oil-film force and seal force at high speed as far as possible has become more and more important. In this study, a lumped mass model of a rotor-bearing-seal system considering the gyroscopic effect is established. The graphite self-lubricating bearing and the sliding bearing are simulated by a spring-damping model and a nonlinear oil-film force model based on the assumption of short bearings, respectively. The seal is simulated by Muszynska nonlinear seal force model. Effects of the seal force and oil-film force on the first and second mode instabilities are investigated under two loading conditions which are determined by API Standard 617 (Axial and Centrifugal Compressors and Expander-compressors for Petroleum, Chemical and Gas Industry Services, Seventh Edition). The research focuses on the effects of exciting force forms and their magnitudes on the first and second mode whips in a rotor-bearing-seal system by using the spectrum cascades, vibration waveforms, orbits and Poincaré maps. The first and second mode instability laws are compared by including and excluding the seal effect in a rotor system with single-diameter shaft and two same discs. Meanwhile, the instability laws are also verified in a rotor system with multi-diameter shaft and two different discs. The results show that the second loading condition (out-of-phase unbalances of two discs) and the nonlinear seal force can mainly restrain the first mode instability and have slight effects on the second mode instability. This study may contribute to a further understanding about the higher order mode instability of such a rotor system with fluid-induced forces from the oil-film bearings and seals.

  7. 浮标的双油囊浮力调节装置密封试验方法研究%Study of the Seal Test Method of the Double Oil Tanks Buoyancy Adjusting Device Based on the Autonomous Profiling Floats

    Institute of Scientific and Technical Information of China (English)

    杨江涛

    2014-01-01

    This paper briefly explain the function of the autonomous profiling floats and analyzed the advantages and disad-vantages of the buoyancy adjusting device which used by the floats.The paper advance the double oil tanks structure of the buoyancy adjusting device and also explain it. Then it has focused on the pressure seal test method and introduced the test process and inspection method. It has also provided the reference for the same kind of test method.%对剖面漂流浮标作了简要说明,并对目前常用的浮力调节装置结构形式优缺点进行了分析,介绍了双油囊结构形式的浮力调节装置,对其结构进行了说明,并阐述了对其耐压密封试验的方法。

  8. ELISE NMR: Experimental liquid sealing of NMR samples

    Science.gov (United States)

    Wieruszeski, Jean-Michel; Landrieu, Isabelle; Hanoulle, Xavier; Lippens, Guy

    2006-08-01

    We present a simple, generally applicable approach to prevent sample evaporation when working at elevated temperatures in high resolution NMR. It consists of experimentally sealing the NMR sample by a second liquid (Experimental Liquid Sealing, ELISE). For aqueous samples, we identified the mineral oil commonly used in PCR application as the best candidate, because it contains only a very limited amount of water-soluble contaminants, is stable over time and heat resistant. The procedure does not interfere with shim settings, and is compatible with a wide variety of samples, including oligosaccharides and proteins. For chloroform samples, a simple drop of water allows to efficiently seal the sample, avoiding solvent evaporation even over lengthy time periods.

  9. An Experimental Investigation of Silicone-to-Metal Bond Strength in Composite Space Docking System Seals

    Science.gov (United States)

    Gaier, James R.; Siamidis, John; Larkin, Elizabeth M. G.

    2010-01-01

    The National Aeronautics and Space Administration (NASA) is currently developing a new universal docking mechanism for future space exploration missions called the Low Impact Docking System (LIDS). A candidate LIDS main interface seal design is a composite assembly of silicone elastomer seals vacuum molded into grooves in an electroless nickel plated aluminum retainer. The strength of the silicone-tometal bond is a critical consideration for the new system, especially due to the presence of small areas of disbond created during the molding process. In the work presented herein, seal-to-retainer bonds of subscale seal specimens with different sizes of intentional disbond were destructively tensile tested. Nominal specimens without intentional disbonds were also tested. Tension was applied either uniformly on the entire seal circumference or locally in one short circumferential length. Bond failure due to uniform tension produced a wide scatter of observable failure modes and measured load-displacement behaviors. Although the preferable failure mode for the seal-to-retainer bond is cohesive failure of the elastomer material, the dominant observed failure mode under the uniform loading condition was found to be the less desirable adhesive failure of the bond in question. The uniform tension case results did not show a correlation between disbond size and bond strength. Localized tension was found to produce failure either as immediate tearing of the elastomer material outside the bond region or as complete peel-out of the seal in one piece. The obtained results represent a valuable benchmark for comparison in the future between adhesion loads under various separation conditions and composite seal bond strength.

  10. Groove Pancreatitis: A Case Report and Review of Literature

    Directory of Open Access Journals (Sweden)

    Vallath Balakrishnan

    2007-09-01

    Full Text Available Context Groove pancreatitis is a rare type of segmental pancreatitis characterized by fibrous scars of the anatomic space between the dorsocranial part of the head of the pancreas, the duodenum, and the common bile duct. Case report A 40-year-old man, with a past history of chronic alcohol consumption presented with epigastric pain radiating to the back and intermittent vomiting and a weight loss of 9 kg. A CT of the abdomen revealed swelling of the pancreatic head, a hypodense mass and duodenal wall thickening with luminal narrowing. Peripancreatic fluid and dense strands were also seen. Upper gastrointestinal endoscopy revealed an edematous, shiny, reddish raised mucosa having a polypoid appearance with narrowing of the second portion of the duodenum. Histological examination of the duodenal biopsy specimens showed preservation of the crypt-villus ratio, and the submucosa showed Brunner gland hyperplasia. These findings appeared consistent with the diagnosis of groove pancreatitis. Presently, the patient is on conservative medical management with analgesics, proton pump inhibitors and a pancreatic enzyme supplement. Conclusions Groove pancreatitis often masquerades as pancreatic head carcinoma. This condition should be kept in mind when making the differential diagnosis between pancreatic masses and duodenal stenosis. In all cases of focal pancreatitis involving the head or uncinate process of the pancreas with involvement of the adjacent duodenum, the possibility of groove pancreatitis should be considered.

  11. Computational analysis of frictional drag over transverse grooved ...

    African Journals Online (AJOL)

    user

    ... gaining interest as it plays important role in aircraft and submarine fuel efficiencies and noise ..... for the flow to relax, the flow reaches the last groove with less energy caused by the ... freestream velocity of air, mm ... wall shear stress, N/m2 ...

  12. Tailoring channeled plasmon polaritons in metallic V-grooves

    DEFF Research Database (Denmark)

    Smith, Cameron; Thilsted, Anil Haraksingh; Marie, Rodolphe

    2013-01-01

    of propagating plasmons to optimize the trade-off between lateral confinement and loss [2]. Accordingly, the traits of CPPs in metallic V-grooves suggest their widespread implementation, with applications ranging from ultracompact photonic circuitry [3] to lab-on-a-chip sensing. Current CPP research focuses...

  13. Syncopation, body-movement and pleasure in groove music.

    Science.gov (United States)

    Witek, Maria A G; Clarke, Eric F; Wallentin, Mikkel; Kringelbach, Morten L; Vuust, Peter

    2014-01-01

    Moving to music is an essential human pleasure particularly related to musical groove. Structurally, music associated with groove is often characterised by rhythmic complexity in the form of syncopation, frequently observed in musical styles such as funk, hip-hop and electronic dance music. Structural complexity has been related to positive affect in music more broadly, but the function of syncopation in eliciting pleasure and body-movement in groove is unknown. Here we report results from a web-based survey which investigated the relationship between syncopation and ratings of wanting to move and experienced pleasure. Participants heard funk drum-breaks with varying degrees of syncopation and audio entropy, and rated the extent to which the drum-breaks made them want to move and how much pleasure they experienced. While entropy was found to be a poor predictor of wanting to move and pleasure, the results showed that medium degrees of syncopation elicited the most desire to move and the most pleasure, particularly for participants who enjoy dancing to music. Hence, there is an inverted U-shaped relationship between syncopation, body-movement and pleasure, and syncopation seems to be an important structural factor in embodied and affective responses to groove.

  14. Steady progression of osteoarthritic features in the canine groove model

    NARCIS (Netherlands)

    Marijnissen, A.C.A.; Roermund, P.M. van; Verzijl, N.; Tekoppele, J.M.; Bijlsma, J.W.J.; Lafeber, F.P.J.G.

    2002-01-01

    Objective: Recently we described a canine model of osteoarthritis (OA), the groove model with features of OA at 10 weeks after induction, identical to those seen in the canine anterior cruciate ligament transection (ACLT) model. This new model depends on cartilage damage accompanied by transient int

  15. Syncopation, body-movement and pleasure in groove music.

    Directory of Open Access Journals (Sweden)

    Maria A G Witek

    Full Text Available Moving to music is an essential human pleasure particularly related to musical groove. Structurally, music associated with groove is often characterised by rhythmic complexity in the form of syncopation, frequently observed in musical styles such as funk, hip-hop and electronic dance music. Structural complexity has been related to positive affect in music more broadly, but the function of syncopation in eliciting pleasure and body-movement in groove is unknown. Here we report results from a web-based survey which investigated the relationship between syncopation and ratings of wanting to move and experienced pleasure. Participants heard funk drum-breaks with varying degrees of syncopation and audio entropy, and rated the extent to which the drum-breaks made them want to move and how much pleasure they experienced. While entropy was found to be a poor predictor of wanting to move and pleasure, the results showed that medium degrees of syncopation elicited the most desire to move and the most pleasure, particularly for participants who enjoy dancing to music. Hence, there is an inverted U-shaped relationship between syncopation, body-movement and pleasure, and syncopation seems to be an important structural factor in embodied and affective responses to groove.

  16. Novel scaffold design with multi-grooved PLA fibers

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Sangwon; King, Martin W [Fiber and Polymer Science, North Carolina State University, Raleigh, NC (United States); Gamcsik, Mike P, E-mail: martin_king@ncsu.edu [Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina Chapel Hill, NC (United States)

    2011-08-15

    A novel prototype nonwoven textile structure containing polylactide (PLA) multigrooved fibers has been proposed as a possible scaffold material for superior cell attachment and proliferation. Grooved cross-sectional fibers with larger surface area were obtained by a bi-component spinning system and the complete removal of the sacrificial component was confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and x-ray photon spectroscopy (XPS) analysis. These PLA nonwoven scaffolds containing the grooved fibers exhibited enhanced wettability, greater flexibility and tensile properties, and a larger surface area compared to a traditional PLA nonwoven fabric containing round fibers. To evaluate cellular attachment on the two types of PLA nonwoven scaffolds, NIH 3T3 fibroblasts were cultured for up to 12 days. It was evident that the initial cellular attachment was superior on the scaffold with grooved fibers, which was confirmed by MTT viability assay (p < 0.01) and SEM analysis. In the future, by modulating the size of the grooves on the fibers, such a scaffold material with a large surface area could serve as an alternative matrix for culturing different types of cells.

  17. Steady progression of osteoarthritic features in the canine groove model

    NARCIS (Netherlands)

    Marijnissen, A.C.A.; Roermund, P.M. van; Verzijl, N.; Tekoppele, J.M.; Bijlsma, J.W.J.; Lafeber, F.P.J.G.

    2002-01-01

    Objective: Recently we described a canine model of osteoarthritis (OA), the groove model with features of OA at 10 weeks after induction, identical to those seen in the canine anterior cruciate ligament transection (ACLT) model. This new model depends on cartilage damage accompanied by transient int

  18. Gulf and Dilmun Type seals

    DEFF Research Database (Denmark)

    Laursen, Steffen

    2011-01-01

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

  19. 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.

  20. Seals. Grades 3-6.

    Science.gov (United States)

    New England Aquarium, Boston, MA.

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

  1. 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.

  2. Aerodynamic seals for rotary machine

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-09

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

  3. Gas-path seal technology

    Science.gov (United States)

    Zuk, J.

    1976-01-01

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

  4. Groove pancreatitis: A rare form of chronic pancreatitis

    Directory of Open Access Journals (Sweden)

    Bharivi Jani

    2015-01-01

    Full Text Available Context: Groove pancreatitis is a rare form of chronic pancreatitis affecting the "groove" of the pancreas among the pancreatic head, duodenum, and common bile duct. The exact cause is unknown, although there are associations with long-term alcohol abuse, smoking, peptic ulcer disease, heterotopic pancreas, gastric resection, biliary disease, and anatomical or functional obstruction of the minor papilla. The diagnosis can be challenging. Endoscopic ultrasound (EUS and magnetic resonance cholangiopancreatography are the preferred imaging modalities. The treatment of choice is conservative although surgical intervention can sometimes be required. Case Report: A 57-year-old male with a history of human immunodeficiency virus and hepatitis B presented with 4 days of epigastric pain. Abdominal exam revealed absent bowel sounds and epigastric tenderness. He had a creatinine of 1.72 mg/dL, potassium of 2.9 mmol/L, and a normal lipase level of 86 U/L. Liver enzymes and total bilirubin were normal. Computed tomography abdomen showed high-grade obstruction of the second portion of the duodenum without any obvious mass. An esophagogastroduodenoscopy showed a mass at the duodenal bulb causing luminal narrowing, with biopsies negative for malignancy. Magnetic resonance imaging revealed a mass in the region of the pancreatic head and descending duodenum. EUS revealed a 3 cm mass in the region of pancreatic head with irregular borders and no vascular invasion. Fine needle aspiration (FNA was nondiagnostic. The patient then underwent a Whipple′s procedure. Pathology of these specimens was negative for malignancy but was consistent with para-duodenal or groove pancreatitis. Conclusion: The low incidence of groove pancreatitis is partly due to lack of familiarity with the disease. Groove pancreatitis should be considered in the differential for patients presenting with pancreatic head lesions and no cholestatic jaundice, especially when a duodenal obstruction

  5. 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...

  6. 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...

  7. Robustness of Modeling of Out-of-Service Gas Mechanical Face Seal

    Science.gov (United States)

    Green, Itzhak

    2007-01-01

    Gas lubricated mechanical face seal are ubiquitous in many high performance applications such as compressors and gas turbines. The literature contains various analyses of seals having orderly face patterns (radial taper, waves, spiral grooves, etc.). These are useful for design purposes and for performance predictions. However, seals returning from service (or from testing) inevitably contain wear tracks and warped faces that depart from the aforementioned orderly patterns. Questions then arise as to the heat generated at the interface, leakage rates, axial displacement and tilts, minimum film thickness, contact forces, etc. This work describes an analysis of seals that may inherit any (i.e., random) face pattern. A comprehensive computer code is developed, based upon the Newton- Raphson method, which solves for the equilibrium of the axial force and tilting moments that are generated by asperity contact and fluid film effects. A contact mechanics model is incorporated along with a finite volume method that solves the compressible Reynolds equation. Results are presented for a production seal that has sustained a testing cycle.

  8. Realization and characterization of high precision micro grooves on green ceramic

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Andrijasevic, Daniela; Hansen, Hans Nørgaard

    2006-01-01

    rectangular feature underneath. For manufacturing of the grooves a grooving process was chosen and a tool was manufactured by micro electro discharge milling. The accuracy of the tool was evaluated by means of a SEM. Grooves were measured using a stylus profilometer. The results showed that the required...

  9. Experimental studies and performance analyses on polyurethane and nitrile rubber rod seals

    Science.gov (United States)

    Mirza, M.; Temiz, V.; Kamburoǧlu, E.

    2012-09-01

    The aim of this study is to determine the friction and leakage properties of rod seals made of polyethylene and nitrile rubber with different design geometries, under various pressure and lubricating oil viscosity conditions, in order to make assumptions about their general sealing characteristics and their pros and cons under certain working conditions that involve a range of fluid pressures. The test specimens consist of commercial rod seals of various designs and materials and were mounted on a hard chrome coated shaft subject to reciprocating motion. The test rig is capable of measuring friction force by means of strain measurements on a load cell transmitting the linear motion of a screw shaft to the test shaft. The test results of the reciprocating rod seal samples were evaluated according to leakage amount and friction resistance as a function of materials, design geometries and fluid pressures as well as the lubricating oil viscosity.

  10. Rim seal arrangement having pumping feature

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ching-Pang; Myers, Caleb

    2017-04-25

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

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  12. Resistance of full veneer metal crowns with different forms of axial grooves

    Science.gov (United States)

    Hidayat, A. S.; Masulili, C.; Indrasari, M.

    2017-08-01

    Dental crowns or bridges can occasionally come loose or separate from the tooth during chewing, particularly when they are situated on small, short, and conical teeth. The main cause of this separation is a lack of retention and resistance to the tooth. There are several methods available to increase the retention and resistance of the crown during both inlay and onlay preparation, including parallelism, groove preparation, crown build-up, and surface roughness. The aim of this study was to determine the differences in resistance of full veneer metal crowns with various forms of groove preparation. The study involved the compressive strength testing of a total of 24 specimens, namely six specimens without groove preparation, six specimens with box-shaped grooves, six specimens with V-shaped grooves, and six specimens with half round grooves. The mean values of the metal crowns that separated from the teeth during testing were 27.97 ± 1.08 kgF for the crowns with box-shaped grooves, 6.15 ± 0.22 kgF for those with V-shaped grooves, 1.77 ± 0.12 kgF for those with half round grooves, and 0.95 ± 0.13 kgF for those without grooves. This study found that the resistance is best in crowns with box-shaped grooves, followed by those with V-shaped grooves, half round grooves, and those without groove. When clinicians are working on short and conical molar teeth, it is therefore recommended that box-shaped grooves are used to increase the resistance of the crown.

  13. 迷宫密封式液压缸泄漏量建模与分析%Modeling and Analysis on Leakage of Labyrinth Seals of Hydraulic Cylinder

    Institute of Scientific and Technical Information of China (English)

    李春风; 吴松林

    2014-01-01

    针对液压缸直通式迷宫密封泄漏量分析困难的问题,基于PHOENICS软件对采用k-ε湍流模型的活塞杆导向套中的迷宫密封流场进行了计算,分析了缝隙中液压油为紊流时迷宫密封的凹槽数目、凹槽深度、凹槽宽度及凹槽间距对泄漏量的影响,并利用迷宫中凹槽的摩擦因数曲线验证了结论的正确性。结果表明:凹槽宽度约为间隙的20~30倍,凹槽深度约为间隙的3~5倍,凹槽间距大于间隙的50倍,凹槽深度宽度比为0.2,凹槽间距宽度比大于2.5,为最佳防泄漏条件。%According to the problem that it was difficult to analyze the leakage of straight-through labyrinth seals of hydraulic cyl-inder,k-εturbulent model was used to calculate the leakage of the labyrinth seal in piston rod guide sleeve based on PHOENICS soft-ware.The influences of groove number,groove depth,groove width and groove distance on leakage were analyzed,which correctness was verified by using the groove friction coefficient curve.It is shown that groove width is about 20 ~30 times of clearance,groove depth is about 3~5 times of clearance,groove distance is greater than 50 times of clearance,the groove depth to width ratio is about 0.2 and the groove distance to width ratio is greater than 2.5 have better effect on preventing leakage.

  14. Self-Sealing Wet Chemistry Cell for Field Analysis

    Science.gov (United States)

    Beegle, Luther W.; Soto, Juancarlos; Lasnik, James; Roark, Shane

    2012-01-01

    In most analytical investigations, there is a need to process complex field samples for the unique detection of analytes, especially when detecting low concentration organic molecules that may identify extraterrestrial life. Wet chemistry based instruments are the techniques of choice for most laboratory- based analysis of organic molecules due to several factors including less fragmentation of fragile biomarkers, and ability to concentrate target species resulting in much lower limits of detection. Development of an automated wet chemistry preparation system that can operate autonomously on Earth and is also designed to operate under Martian ambient conditions will demonstrate the technical feasibility of including wet chemistry on future missions. An Automated Sample Processing System (ASPS) has recently been developed that receives fines, extracts organics through solvent extraction, processes the extract by removing non-organic soluble species, and delivers sample to multiple instruments for analysis (including for non-organic soluble species). The key to this system is a sample cell that can autonomously function under field conditions. As a result, a self-sealing sample cell was developed that can autonomously hermetically seal fines and powder into a container, regardless of orientation of the apparatus. The cap is designed with a beveled edge, which allows the cap to be self-righted as the capping motor engages. Each cap consists of a C-clip lock ring below a crucible O-ring that is placed into a groove cut into the sample cap.

  15. Gas film disturbance characteristics analysis of high-speed and high-pressure dry gas seal

    Science.gov (United States)

    Chen, Yuan; Jiang, Jinbo; Peng, Xudong

    2016-08-01

    The dry gas seal(DGS) has been widely used in high parameters centrifugal compressor, but the intense vibrations of shafting, especially in high-speed condition, usually result in DGS's failure. So the DGS's ability of resisting outside interference has become a determining factor of the further development of centrifugal compressor. However, the systematic researches of which about gas film disturbance characteristics of high parameters DGS are very little. In order to study gas film disturbance characteristics of high-speed and high-pressure spiral groove dry gas seal(S-DGS) with a flexibly mounted stator, rotor axial runout and misalignment are taken into consideration, and the finite difference method and analytical method are used to analyze the influence of gas film thickness disturbance on sealing performance parameters, what's more, the effects of many key factors on gas film thickness disturbance are systematically investigated. The results show that, when sealed pressure is 10.1MPa and seal face average linear velocity is 107.3 m/s, gas film thickness disturbance has a significant effect on leakage rate, but has relatively litter effect on open force; Excessively large excitation amplitude or excessively high excitation frequency can lead to severe gas film thickness disturbance; And it is beneficial to assure a smaller gas film thickness disturbance when the stator material density is between 3.1 g/cm3 to 8.4 g/cm3; Ensuring sealing performance while minimizing support axial stiffness and support axial damping can help to improve dynamic tracking property of dry gas seal. The proposed research provides the instruction to optimize dynamic tracking property of the DGS.

  16. Dance, Music, Meter and Groove: A Forgotten Partnership.

    Science.gov (United States)

    Fitch, W Tecumseh

    2016-01-01

    I argue that core aspects of musical rhythm, especially "groove" and syncopation, can only be fully understood in the context of their origins in the participatory social experience of dance. Musical meter is first considered in the context of bodily movement. I then offer an interpretation of the pervasive but somewhat puzzling phenomenon of syncopation in terms of acoustic emphasis on certain offbeat components of the accompanying dance style. The reasons for the historical tendency of many musical styles to divorce themselves from their dance-based roots are also briefly considered. To the extent that musical rhythms only make sense in the context of bodily movement, researchers interested in ecologically valid approaches to music cognition should make a more concerted effort to extend their analyses to dance, particularly if we hope to understand the cognitive constraints underlying rhythmic aspects of music like meter and groove.

  17. Dance, Music, Meter and Groove: A Forgotten Partnership

    Directory of Open Access Journals (Sweden)

    W Tecumseh eFitch

    2016-03-01

    Full Text Available I argue that core aspects of musical rhythm, especially groove and syncopation, can only be fully understood in the context of their origins in the participatory social experience of dance. Musical meter is first considered in the context of bodily movement. I then offer an interpretation of the pervasive but somewhat puzzling phenomenon of syncopation in terms of acoustic emphasis on certain offbeat components of the accompanying dance style. The reasons for the historical tendency of many musical styles to divorce themselves from their dance-based roots are also briefly considered. To the extent that musical rhythms only make sense in the context of bodily movement, researchers interested in ecologically valid approaches to music cognition should make a more concerted effort to extend their analyses to dance, particularly if we hope to understand the cognitive constraints underlying rhythmic aspects of music like meter and groove.

  18. Scattering by a groove in an impedance plane

    Science.gov (United States)

    Bindiganavale, Sunil; Volakis, John L.

    1993-09-01

    An analysis of two-dimensional scattering from a narrow groove in an impedance plane is presented. The groove is represented by a impedance surface and the problem reduces to that of scattering from an impedance strip in an otherwise uniform impedance plane. On the basis of this model, appropriate integral equations are constructed using a form of the impedance plane Green's functions involving rapidly convergent integrals. The integral equations are solved by introducing a single basis representation of the equivalent current on the narrow impedance insert. Both transverse electric (TE) and transverse magnetic (TM) polarizations are treated. The resulting solution is validated by comparison with results from the standard boundary integral method (BIM) and a high frequency solution. It is found that the presented solution for narrow impedance inserts can be used in conjunction with the high frequency solution for the characterization of impedance inserts of any given width.

  19. Dynamic multileaf collimation without `tongue-and-groove' underdosage effects

    Science.gov (United States)

    van Santvoort, J. P. C.; Heijmen, B. J. M.

    1996-10-01

    In all commercially available multileaf collimators, a `tongue-and-groove' - or similar - construction is used for reduction of leakage radiation between adjacent leaves. These constructions can cause serious underdosages in intensity-modulated photon beams. A method for leaf trajectory calculation for dynamic multileaf collimation, which fully avoids these underdosage effects, is presented. The method is based on pairwise synchronizations of trajectories of adjacent leaf pairs, such that the delivered beam intensity in each `tongue-and-groove' region is always equal to the smallest of the two prescribed intensities for the two corresponding leaf pairs. The effectiveness of the method has been proven for a large number of intensity-modulated fields, using the dynamic multileaf collimation mode of our MM50 Racetrack Microtron. Compared to dynamic multileaf collimation without synchronization, beam-on times are always equal or longer. For the cases that we studied, the beam-on time was typically increased by 5 to 15%.

  20. Dynamic multileaf collimation without 'tongue-and-groove' underdosage effects.

    Science.gov (United States)

    van Santvoort, J P; Heijmen, B J

    1996-10-01

    In all commercially available multileaf collimators, a 'tongue-and-groove'--or similar--construction is used for reduction of leakage radiation between adjacent leaves. These constructions can cause serious underdosages in intensity-modulated photon beams. A method for leaf trajectory calculation for dynamic multileaf collimation, which fully avoids these underdosage effects, is presented. The method is based on pairwise synchronizations of trajectories of adjacent leaf pairs, such that the delivered beam intensity in each 'tongue-and-groove' region is always equal to the smallest of the two prescribed intensities for the two corresponding leaf pairs. The effectiveness of the method has been proven for a large number of intensity-modulated fields, using the dynamic multileaf collimation mode of our MM50 Racetrack Microtron. Compared to dynamic multileaf collimation without synchronization, beam-on times are always equal or longer. For the cases that we studied, the beam-on time was typically increased by 5 to 15%.

  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...

  2. 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...

  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. 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...

  5. Seal device for ferromagnetic containers

    Science.gov (United States)

    Meyer, Ross E.; Jason, Andrew J.

    1994-01-01

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

  6. Quantum String Seal Is Insecure

    CERN Document Server

    Chau, H F

    2006-01-01

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

  7. Channel plasmon polariton propagation in nanoimprinted V-groove waveguides

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Bundgaard; Fernandez-Cuesta, I.; Boltasseva, Alexandra;

    2008-01-01

    We present the results of optical characterization of metal V-groove waveguides using scanning near-field microscopy, showing broadband transmission with subwavelength confinement and propagation lengths exceeding 100 mu m. An updated fabrication method using a combination of UV and nanoimprint l...... lithography is presented. The developed approach is mass-production compatible, adaptable to different designs, and offers wafer-scale parallel fabrication of plasmonic components based on profiled metal surfaces....

  8. Experimental investigations on an axial grooved cryogenic heat pipe

    Directory of Open Access Journals (Sweden)

    Senthil Kumar Muniappan

    2012-01-01

    Full Text Available This paper deals with development and studies of a trapezoidal axial grooved nitrogen heat pipe. A special liquid nitrogen cryostat has been designed and developed for evaluating the performance of heat pipe where the condenser portion is connected to the cold sink externally. Experiments have been performed on the heat pipe as well as on an equivalent diameter copper rod at different heat loads. The steady state performance of the heat pipe is compared with that of copper rod.

  9. V-groove gratings on silicon for infrared beam splitting.

    Science.gov (United States)

    Rajkumar, N; McMullin, J N

    1995-05-10

    Infrared beam-splitting transmission gratings that utilize anisotropically etched v-grooves on silicon wafers are proposed. With scalar diffraction theory to find the amplitudes of the different diffraction orders, a numerical search is used to find optimum designs for 1:3, 1:5, and 1:7 splitters with efficiencies greater than 70% with a standard deviation in intensity of no more than 7%.

  10. Groove model of tibia-femoral osteoarthritis in the rat.

    Science.gov (United States)

    de Visser, Huub M; Weinans, Harrie; Coeleveld, Katja; van Rijen, Mattie H P; Lafeber, Floris P J G; Mastbergen, Simon C

    2017-03-01

    Several experimental models of osteoarthritis in rats are used to study the pathophysiology of osteoarthritis. Many mechanically induced models have the limitation that permanent joint instability is induced by, for example, ligament transection or meniscal damage. This permanent instability will counteract the potential beneficial effects of therapy. The groove model of osteoarthritis uses a one-time trigger, surgically induced cartilage damage on the femoral condyles, and has been validated for the canine tibia-femoral compartment. The present study evaluates this model for the rat knee joint. The articular cartilage of the weight bearing surface of both femoral condyles and trochlea were damaged (grooved) without damaging the underlying subchondral bone. Severity of joint degeneration was histologically assessed, in addition to patella cartilage damage, and subchondral bone characteristics by means of (contrast-enhanced) micro-CT. Mild histological degeneration of the surgically untouched tibial plateau cartilage was observed in addition to damage of the femoral condyles, without clear synovial tissue inflammation. Contrast enhanced micro-CT demonstrated proteoglycan loss of the surgically untouched patella cartilage. Besides, a more sclerotic structure of the subchondral bone was observed. The tibia-femoral groove model in a rat results in mild knee joint degeneration, without permanent joint instability and joint inflammation. This makes the rat groove model a useful model to study the onset and progression of post-traumatic non-inflammatory osteoarthritis, creating a relatively sensitive model to study disease modifying osteoarthritic drugs. © 2016 The Authors. Journal of Orthopaedic Research published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 35:496-505, 2017.

  11. Self Sealing Magmas

    Science.gov (United States)

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

    2015-04-01

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

  12. Thermal Characteristics of Grooved Heat pipe with Hybrid Nanofluids

    Directory of Open Access Journals (Sweden)

    W S Han

    2011-01-01

    Full Text Available In the present study, the specially designed grooved heat pipe charged with nanofluids was investigated in terms of various parameters such as heat transfer rate(50∼300W with 50 W interval, volume concentration(0.005%, 0.05%, 0.1%, and hybrid combinations, inclination(5°, 45°, 90°, cooling water temperature (1℃, 10℃, and 20℃, surface state, transient state and so on. Hybrid nanofluids with different volume concentration ratios with Ag-H2O and Al2O3-H2O were used as working fluids on a grooved heat pipe(GHP. Comparing with the pure water system, nanofluidic and hybrid nanofluidic system shows greater overall thermal resistance with increasing nano-particle concentration. Also hybrid nanofluids make the system deteriorate in terms of thermal resistance. The post nanofluid experimental data regarding GHP show that the heat transfer performance is similar to the results of nanofluid system. The thermal performance of a grooved heat pipe with nanofluids and hybrid nanofluids were varied with driving parameters but they led to worse system performance.

  13. Repair welding process of friction stir welding groove defect

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-jie; ZHANG Hui-jie

    2009-01-01

    The groove defect formed in the friction stir welding dramatically deteriorates weld appearances and mechanical properties of the joints owing to its larger size and penetration. Therefore, the friction stir repair welding was utilized to remove such a groove defect, and the focus was placed on the mechanical properties and microstructural characteristics of the repair joints so as to obtain an optimum repair welding process. The experimental results indicate that the groove defect can be removed by friction stir repair welding, and the offset repair welding process is superior to the symmetrical repair welding process. In the symmetrical repair welding process, a large number of fine cavity defects and an obvious aggregation of hard-brittle phase Al2Cu occur, accordingly the mechanical properties of the repair joint are weakened, and the fracture feature of repair joint is partially brittle and partially plastic. A good-quality repair joint can be obtained by the offset repair welding process, and the repair joint is fractured near the interface between the weld nugget zone and thermal-mechanically affected zone.

  14. The flow past a cactus-inspired grooved cylinder

    Science.gov (United States)

    El-Makdah, Adnan M.; Oweis, Ghanem F.

    2013-02-01

    The star-shaped cross section of giant cylindrical cactus plants is thought to be aerodynamically favorable for protection against toppling by strong winds. Particle image velocimetry is used to investigate the flow details within the surface grooves and in the immediate wake of a cactus-inspired model cylinder with eight longitudinal grooves, at biologically relevant Reynolds numbers between 50 × 103 and 170 × 103. The wake flow is analyzed and compared to a similarly sized circular cylinder. At the lowest Re tested, the wakes from the two geometries are similar. At higher Re, the cactus wake exhibits superior behavior as seen from the mean and turbulent velocities, suggesting that the flow mechanisms are Re dependent. The flow within the surface grooves reveals counter rotating rollers, while the geometrical ridges act as vortex generators known to help with the surface flow attachment. Lastly, a simplistic analysis is described to recover, qualitatively, certain time-dependent flow features from the randomly acquired PIV realizations.

  15. Parasitic capacitance characteristics of deep submicrometre grooved gate MOSFETs

    Science.gov (United States)

    Sreelal, S.; Lau, C. K.; Samudra, G. S.

    2002-03-01

    Grooved gate metal-oxide-semiconductor field-effect transistors (MOSFETs) are known to alleviate many of the short channel and hot carrier effects that arise when MOSFET devices are scaled down to very short channel lengths. However, they exhibit much higher parasitic capacitance with stronger bias dependence when compared to conventional planar devices. In this paper, we present a model for gate-to-drain and gate-to-source capacitance characteristics of a deep submicrometre grooved gate MOSFET. Both the intrinsic and extrinsic parts of the capacitance are modelled separately. In particular, the model presents a novel but simple way to account for the accumulation layer formation in the source/drain region of MOSFETs due to the application of the gate voltage. The results are compared with those obtained from a two-dimensional device simulator. The close match between the modelled and simulated data establishes the validity of the model. The model is then used to account for the superiority of capacitance characteristics of planar device structures and to arrive at optimization guidelines for grooved gate devices to match these characteristics.

  16. Status of Understanding for Seal Materials

    Science.gov (United States)

    Brown, P. F.

    1984-01-01

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

  17. Brush Seals for Improved Steam Turbine Performance

    Science.gov (United States)

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

    2006-01-01

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

  18. A NUMERICAL SIMULATION OF 3-D INNER FLOW IN UP-STREAM PUMPING MECHANICAL SEAL

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin-feng; YUAN Shou-qi; FU Yong-hong; FANG Yu-jian

    2006-01-01

    Numerical simulation of 3-D inner flow between Up-stream Pumping Mechanical Face Seals (UPMFS) faces was initially done by CFD software, which made the flow visualization come true.Simulation results directly discover the action of hydrodynamic lubrication, and by comparison with that of Conventional Mechanic Face Seals (CMFS), the advantage over bigger bearing capability, less friction and much less leakage are explained clearly.Otherwise there are also some different ideas and results from precedent analysis and computational research results: dynamic and static pressure profiles can be obtained respectively instead of the analytic total pressure distribution only, pressure distribution is nonlinear, while always be solved as linear, lower pressure is observed at the area of inner diameter caused by the grooves, but its possible cavitations effects to the performance of UPMFS still need further study.

  19. Grease lubrication mechanisms in bearing seals

    OpenAIRE

    2011-01-01

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

  20. Excitation by flows in seals and clearances. Part 1: Introduction: Fluid-structure-interactions in rotordynamics. Part 2: Identification of rotordynamic coefficients of annular seals

    Science.gov (United States)

    Nordmann, R.

    The fluid-structure interactions in rotor dynamics and the identification of rotor dynamic coefficients of annular seals are studied. The different fluid forces acting in the neck ring, the interstage seals, the balance pistons, the impellers and the oil film bearings of pumps are reviewed. These forces can have a large influence on the bending vibrations of a pump rotor. Theoretical and experimental models of fluid elements and of rotordynamics are presented. Simulations of the rotordynamic behavior show that the fluid forces of most elements can be described by linear-force relations. A theoretical model and an indentification procedure are presented to determine the dynamic coefficients of seals. The identified parameters confirm the assumptions in modeling and point out that the stiffness and damping characteristics of seals are significant for the stability behavior of pumps.

  1. Analyses of Problems of Dry Gas Seals in a Cycle Compressor of Hydrocracking Unit%加氢裂化装置干气密封的故障分析与改造

    Institute of Scientific and Technical Information of China (English)

    钟伟明; 李纪云; 许静

    2011-01-01

    针对某厂加氢裂化装置循环压缩机轴端用T型槽干气密封(T-DGS)在开工不久和首次改造后使用过程中连续两次失效造成停车的事故,对干气密封进行解体分析,提出密封失效的原因和相应的技改措施,在解决现场装置中存在的主密封气短路、密封气带液、火炬气反窜等问题之后,机组开车一次成功,确保了生产装置的安全稳定运行.有关成果将为现场T-DGS出现相似问题的及时解决及T-DGS的设计提供有益指导.%Dry gas seals with T-grooves were disintegrated and analyzed for resolving the problems related to the two continuous failures when they were used in a cycle compressor of hydrocracking unit. The causes for the failures of such T-grooved dry gas seals and their solutions were presented. The cycle compressor with the improved T-grooved gas seal had operated successfully at one time after the problems were resolved, which mainly- referred to primary sealed gas short-circle, sealed gas condensed to liquid,flare gas returning. The unit was sure to be running in normal condition. The methods and experiences presented here should be useful to the problems resolved and the geometrical designs of a T-grooved dry gas seal.

  2. Reservoir characterization and seal integrity of Jemir field in Niger Delta, Nigeria

    Science.gov (United States)

    Adagunodo, Theophilus Aanuoluwa; Sunmonu, Lukman Ayobami; Adabanija, Moruffdeen Adedapo

    2017-05-01

    Ignoring fault seal and depending solely on reservoir parameters and estimated hydrocarbon contacts can lead to extremely unequal division of reserves especially in oil fields dominated by structural traps where faults play an important role in trapping of hydrocarbons. These faults may be sealing or as conduit to fluid flow. In this study; three-dimensional seismic and well log data has been used to characterize the reservoirs and investigate the seal integrity of fault plane trending NW-SE and dip towards south in Jemir field, Niger-Delta for enhanced oil recovery. The petrophysical and volumetric analysis of the six reservoirs that were mapped as well as structural interpretation of the faults were done both qualitatively and quantitatively. In order to know the sealing potential of individual hydrocarbon bearing sand, horizon-fault intersection was done, volume of shale was determined, thickness of individual bed was estimated, and quality control involving throw analysis was done. Shale Gouge Ratio (SGR) and Hydrocarbon Column Height (HCH) (supportable and structure-supported) were also determined to assess the seal integrity of the faults in Jemir field. The petrophysical analysis indicated the porosity of traps on Jemir field ranged from 0.20 to 0.29 and the volumetric analyses showed that the Stock Tank Original Oil in Place varied between 5.5 and 173.4 Mbbl. The SGR ranged from leaking (60%) fault plane suggesting poor to moderate sealing. The supportable HCH of Jemir field ranged from 98.3 to 446.2 m while its Structure-supported HCH ranged from 12.1 to 101.7 m. The porosities of Jemir field are good enough for hydrocarbon production as exemplified by its oil reserve estimates. However, improper sealing of the fault plane might enhance hydrocarbon leakage.

  3. Tailoring the grooved texture of electrospun polystyrene nanofibers by controlling the solvent system and relative humidity

    Science.gov (United States)

    2014-01-01

    In this study, we have successfully fabricated electrospun polystyrene (PS) nanofibers having a diameter of 326 ± 50 nm with a parallel grooved texture using a mixed solvent of tetrahydrofuran (THF) and N,N-dimethylformamide (DMF). We discovered that solvent system, solution concentration, and relative humidity were the three key factors to the formation of grooved texture and the diameter of nanofibers. We demonstrated that grooved nanofibers with desired properties (e.g., different numbers of grooves, widths between two adjacent grooves, and depths of grooves) could be electrospun under certain conditions. When THF/DMF ratio was higher than 2:1, the formation mechanism of single grooved texture should be attributed to the formation of voids on the jet surface at the early stage of electrospinning and subsequent elongation and solidification of the voids into a line surface structure. When THF/DMF ratio was 1:1, the formation mechanism of grooved texture should be ascribed to the formation of wrinkled surface on the jet surface at the early stage of electrospinning and subsequent elongation into a grooved texture. Such findings can serve as guidelines for the preparation of grooved nanofibers with desired secondary morphology. PMID:25114643

  4. Research on Sealing Structure of Electro-hydraulic Servo Swing Motor%电液伺服摆动马达密封结构研究∗

    Institute of Scientific and Technical Information of China (English)

    李阁强; 赵巧莉; 李跃松; 郭冰菁

    2015-01-01

    为研究电液伺服摆动马达密封结构的性能,建立其密封件的有限元仿真模型,在相同预压缩量、不同介质压力条件下,对矩形密封结构、梯形密封结构、星形密封结构进行仿真分析,根据仿真结果比较3种密封结构的密封效果。结果表明,星形密封结构因其截面有4个密封唇,在沟槽中不易产生扭曲,耐压力较强,其密封有效性优于矩形密封结构,更适合用于大功率液压密封系统;梯形密封结构在靠近流体端具有较陡的压力梯度,在一端具有较缓的压力梯度,可以减小油膜厚度,从而减少泄漏量,因而其密封效果优于星形和矩形密封。%The finite element simulation model of the sealing structure of electro⁃hydraulic servo swing motor was estab⁃lished to study the performance of sealing structure�Three kinds of sealing structures, the rectangular sealing structure, the trapezoidal sealing structure, the star sealing structure were investigated by simulation method under the conditions of the same pre⁃compression and different medium pressure, and the sealing effect of three kinds of sealing structures were com⁃pared according to the results of simulation analysis�The results show that the star seal structure has four sealing lips on the cross⁃section and can avoid the distortion of seal structure in the groove, its sealing effectiveness is better than the rec⁃tangular seal structure and it is more suitable for high⁃power hydraulic sealing system�For the trapezoidal seal structure has a steeper pressure gradient near the fluid end and a moderate pressure gradient at one end, the leakage is reduced, and good sealing effect is achieved compared with the star and rectangular seal structure�

  5. 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.

  6. Tamper-Indicating Quantum Seal*

    Science.gov (United States)

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

    2016-01-01

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

  7. 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.

  8. Subpixel accuracy for extracting groove center based on corner detection

    Institute of Scientific and Technical Information of China (English)

    Liu Suyi; Wang Guorong; Shi Yonghua

    2006-01-01

    Subpixel accuracy for V-groove center in robot welding is researched and a software measure to increase the accuracy of seam tracking by laser is presented.LOG( Laplacian of Gaussian ) operator is adopted to detect image edge.Vgroove center is extracted by corner detection of extremum curvature.Subpixel position is obtained by Lagarange polynomial interpolation algorithm.Experiment results show that the method is brief and applied, and is sufficient for the real time of robot welding by laser sensors.

  9. Coronary sinus and atrioventricular groove avulsion after motor vehicle crash

    Directory of Open Access Journals (Sweden)

    Bradley M Dennis

    2014-01-01

    Full Text Available Simultaneous cardiac and pericardial rupture from blunt chest trauma is a highly lethal combination with rarely reported survival. We report of a case of young patient with a right atrioventricular groove injury, pericardial rupture and a unique description of a coronary sinus avulsion following blunt chest trauma. Rapid recognition of this injury is crucial to patient survival, but traditional diagnostic adjuncts such as ultrasound, echocardiography and computed tomography are often unhelpful. Successful repair of these injuries requires high suspicion of injury, early cardiac surgery involvement of and possible even placement of the patient on cardiopulmonary bypass.

  10. Revamping Grooving Process for Sustainability using Fuzzy Expert System

    Directory of Open Access Journals (Sweden)

    Iqba Asif

    2016-01-01

    Full Text Available The article presents an application of a fuzzy expert system for renovating a metal cutting process to cope with the sustainability requirements. The work seeks a sustainable balance between energy consumption, productivity and tool damage. Cylindrical grooving experiments were performed to generate data related to quantification of the effects of material hardness, cutting speed, width of cut and feed rate on the aforementioned sustainability measures. A fuzzy knowledge-base was developed that suggests the most suitable adjustments of the controlled variables that would lead to achievement of various combinations of the objectives.

  11. Ligands recognizing the minor groove of DNA: development and applications.

    Science.gov (United States)

    Wemmer, D E

    Polyamide ligands comprised of pyrrole, imidazole and hydroxypyrrole rings have been developed over the past decade which can be used to target many different, predetermined DNA sequences through recognition of functional groups in the minor groove. The design principles for these ligands are described with a description of the characterization of their binding. Variations containing linked recognition modules have been described which allow high affinity and specificity recognition of DNA sequences of over 15 base pairs. Recent applications of these ligands in affecting biological response through competition with proteins for DNA binding sites are reviewed. Copyright 2001 John Wiley & Sons, Inc.

  12. Syncopation affects free body-movement in musical groove

    DEFF Research Database (Denmark)

    Witek, Maria A. G.; Popescu, Tudor; Clarke, Eric F

    2016-01-01

    One of the most immediate and overt ways in which people respond to music is by moving their bodies to the beat. However, the extent to which the rhythmic complexity of groove-specifically its syncopation-contributes to how people spontaneously move to music is largely unexplored. Here, we measured...... on the body-part. We demonstrate that while people do not move or synchronise much to rhythms with high syncopation when dancing spontaneously to music, the relationship between rhythmic complexity and synchronisation is less linear than in simple finger-tapping studies....

  13. Deep-groove nickel gratings for solar thermal absorbers

    Science.gov (United States)

    Ahmad, N.; Núñez-Sánchez, S.; Pugh, J. R.; Cryan, M. J.

    2016-10-01

    This paper presents measured and modelled optical absorptance and reflectance for deep-groove nickel nano-gratings in the 450-950 nm wavelength range. The structures have been fabricated using focused ion beam etching and characterised using Fourier spectroscopy and the field distributions on the gratings have been studied using finite difference time domain modelling. Realistic grating structures have been modelled based on focused ion beam cross sections and these results are in good agreement between measured and modelled results. The roles of surface plasmon polaritons and slot modes are highlighted in the strong broadband absorbance that can be achieved with these structures.

  14. Mechanical seal with textured sidewall

    Energy Technology Data Exchange (ETDEWEB)

    Khonsari, Michael M.; Xiao, Nian

    2017-02-14

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

  15. 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.

  16. A review of interproximal wear grooves on fossil hominin teeth with new evidence from Olduvai Gorge.

    Science.gov (United States)

    Ungar, P S; Grine, F E; Teaford, M F; Pérez-Pérez, A

    2001-04-01

    Interproximal (approximal) grooves at the cementum-enamel junction of premolar and molar teeth have been observed in a broad range of human ancestors and related extinct species from 1.84 million years ago to the present. Many hypotheses have been presented to explain the aetiology of these grooves, though their form and positioning are most consistent with tooth-picking behaviours. This paper reviews occurrences of interproximal grooves in the cheek teeth of modern and fossil humans, evaluates hypotheses on their cause, and reports on a previously undescribed groove found in OH 60, a molar tooth from Olduvai Gorge. This specimen is among the earliest to show such grooving, and is most likely attributable to Homo erectus. It is concluded that, because interproximal grooves have been observed only on Homo teeth, they probably reflect a behaviour or behaviours unique to that genus.

  17. Kinetics of thermal grooving during low temperature recrystallization of pure aluminum

    DEFF Research Database (Denmark)

    Zhang, Yubin; Godfrey, Andy; Juul Jensen, Dorte

    2013-01-01

    The migration of a recrystallization boundary in pure aluminum was followed during in situ annealing in a scanning electron microscope. The microstructure was characterized using the electron channeling contrast technique, and a typical stop-go grain boundary motion was observed during annealing...... time. The kinetics of thermal grooving are determined. Effects of the surface oxidation layer on the formation of thermal grooving as well as the overall influence of grooves on boundary migration are discussed. © (2013) Trans Tech Publications, Switzerland....

  18. HEAT TRANSFER ENHANCEMENT AND PRESSURE DROP OF GROOVED ANNULUS OF DOUBLE PIPE HEAT EXCHANGER

    Directory of Open Access Journals (Sweden)

    Putu Wijaya Sunu

    2017-05-01

    Full Text Available This investigation was performed to experimentally investigate the enhancement of heat transfer and the friction of an annulus in a double pipe heat exchanger system with rectangular grooves in the turbulent flow regime. The shell is made of acrylic and its diameter is 28 mm. The tube is made of aluminium and its diameter is 20 mm. Grooves were incised in the annulus room with a circumferential pattern, with a groove space of 2 mm, a distance between the grooves of 8mm and a groove height of 0.3 mm. The experiments consist of temperature and pressure measurement and a flow visualization. Throughout the investigation, the cold fluid flowed in the annulus room. The Reynold number of cold fluid varied from about 31981 to 43601 in a counter flow condition. The volume flow rate of hot fluid remains constant with Reynold number about 30904. Result showed the effect of grooves, which are applied in the annulus room. The grooves induce the pressure drop, the pressure drop in the grooved annulus was greater by about 15.88% to 16.72% than the one in the smooth annulus. The total heat transfer enhancement is of 1.09–1.11. Moreover, the use of grooves in the annulus of the heat exchanger not only increase the heat transfer process, but also increase the pressure drop, which is related to the friction factor.

  19. 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

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Space qualification of high capacity grooved heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.; Mullender, B.; Druart, J. [SABCA, Societe Anomyme Belgel de Construction Aeronautique (Belgium); Supper, W.; Beddows, A. [ESTEC-The (Netherlands)

    1996-12-31

    Based on the thermal requirements of the future telecommunication satellites, the development of a High Capacity Grooved Heat Pipe (HPG), was contracted by ESA to SABCA leading to an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. After an intensive acceptance test campaign whose results showed a good confidence in the design and the fulfillment of the required specifications of heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt metres for a vapour temperature of 20 deg C), similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles). Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods. This HGP heat pipe family is now being submitted to a space qualification program according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycle, thermal soak, ageing). (authors) 9 refs.

  5. Capillary Contact Angle in a Completely Wet Groove

    Science.gov (United States)

    Parry, A. O.; Malijevský, A.; Rascón, C.

    2014-10-01

    We consider the phase equilibria of a fluid confined in a deep capillary groove of width L with identical side walls and a bottom made of a different material. All walls are completely wet by the liquid. Using density functional theory and interfacial models, we show that the meniscus separating liquid and gas phases at two phase capillary coexistence meets the bottom capped end of the groove at a capillary contact angle θcap(L) which depends on the difference between the Hamaker constants. If the bottom wall has a weaker wall-fluid attraction than the side walls, then θcap>0 even though all the isolated walls are themselves completely wet. This alters the capillary condensation transition which is now first order; this would be continuous in a capped capillary made wholly of either type of material. We show that the capillary contact angle θcap(L) vanishes in two limits, corresponding to different capillary wetting transitions. These occur as the width (i) becomes macroscopically large, and (ii) is reduced to a microscopic value determined by the difference in Hamaker constants. This second wetting transition is characterized by large scale fluctuations and essential critical singularities arising from marginal interfacial interactions.

  6. 新型干法水泥回转窑设备托轮轴承密封系统的改造%Transformation of Dry Cement Kiln Equipment Supporting Roller Bearing Seal System

    Institute of Scientific and Technical Information of China (English)

    陈风; 曾军林; 古惠芬; 钟日先; 潘春伟

    2014-01-01

    According to the working characteristics of the cement kiln roller sealing system,a new sealing solution,the two-way K-type oil seals with hose clamps was presented. The selection of K-type oil seal materials and the mold structure of the K-type oil seal production were investigated. The optimal interference values of the K-type oil seals were obtained by using ANSYS finite element analysis software. The designed two-way K-type oil seal with hose clamps has good following performance and high sealing reliability,which can realize the good sealing of the kiln supporting roller.%根据水泥回转窑托轮密封系统的工作特点,提出一种新的密封方案---带喉箍的双向K型油封。探讨双向K型油封材料的选取和密封制作模具的结构,借助有限元ANSYS工具分析得到双向K型油封的最优过盈量。带喉箍的双向K型油封的跟随性好,密封可靠性高,能保证旋窑托轮良好的密封。

  7. 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

  8. 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.

  9. Multi-layer seal for electrochemical devices

    Science.gov (United States)

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

    2010-11-16

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

  10. Application of fault seal analysis techniques in the Western Desert, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, S.M.; Wilkes, M. [BG Exploration and Production Ltd., Reading (United Kingdom); Vivian, N. [Ranger Oil (United Kingdom) Ltd., Guildford (United Kingdom); Cook, R.J. [BG R and T, Loughborough (United Kingdom); Hussein, H. [BG Egypt S.A., Cairo (Egypt)

    1998-12-31

    The Western Desert if one of Egypt`s major hydrocarbon provinces. Most discoveries to date have been in the Cretaceous, with the Jurassic being the most underexplored interval, with the highest potential for new discoveries. Although trap styles vary, the majority are structural fault blocks, requiring fault seal on one or more bounding faults. Despite the number of excellent reservoirs present in the Western Desert, large field sizes are rare, with less than 50 MMBOE STOIIP (million barrels oil equivalent, oil initially in place) being predominant. This apparent failure to regularly prove larger field sizes can be considered a direct function of trap failure resulting from absence of fault seal. A number of fault seal analysis techniques including fault-plane profiles, smear-gouge ratios, incremental strain analysis and structural sections are available to directly address trap integrity. Case histories from the Western Desert are used to demonstrate the use of these techniques, and to highlight potential pitfalls. (author)

  11. Pre-sealing risk analysis

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-01-07

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

  12. Predicting Leakage in Labyrinth Seals

    Science.gov (United States)

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

    1985-01-01

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

  13. Aerodynamic seal assemblies for turbo-machinery

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-29

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

  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 enda

  15. Annular Pressure Seals and Hydrostatic Bearings

    Science.gov (United States)

    2006-11-01

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

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

    Institute of Scientific and Technical Information of China (English)

    QIAN Ji-guo; YANG Zhi-yi

    2008-01-01

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

  17. Prevalence of palate-gingival groove in patients of Dhulikhel Hospital

    Directory of Open Access Journals (Sweden)

    D Shreshta

    2015-06-01

    Full Text Available Background: Palato-gingival groove is a rare developmental anomaly leading to pulpal and periodontal diseases. Radicular extensions of these grooves are areas for plaque accumulation which are difficult to clean. Its clinical and radiographic findings mimic endo-perio lesions leading to diagnostic dilemma, ineffective treatment attempts and treatment failures. Objectives: To investigate the prevalence of coronal and radicular palato-gingival groove in dental patients visiting Dhulikhel Hospital and its association with gingival disease. Methods: Patients (N=231 visiting dental out-patient department of Dhulikhel Hospital, were examined for the presence or absence of palato-gingival groove in maxillary anteriors. Loe and Silness Gingival index was also recorded for all the patients using University of North Caroline-15 periodontal probe. Chisquare test was used to test the association of the presence of palato-gingival groove and gingival disease. P value of <0.05 was considered to be significant. Results: A total of 1362 maxillary anterior teeth were included in the study. The prevalence of coronal palatogingival groove among 1362 teeth was 6.6%. Coronal palato-gingival grooves were more common in females (56.6% than in male (43.3% patients. Prevalence of radicular groove was only 0.88% for lateral incisors and 0.2% for canines. There was no significant association between palate-gingival groove and gingival disease (P=0.91. Conclusion: The prevalence of palato-gingival groove is common in dental patients visiting Dhulikhel Hospital. Gingival disease is not significantly associated with palate-gingival groove. DOI: http://dx.doi.org/10.3126/jcmsn.v10i1.12765 Journal of College of Medical Sciences-Nepal, 2014, Vol.10(1; 32-36

  18. Optimally oriented grooves on dental implants improve bone quality around implants under repetitive mechanical loading.

    Science.gov (United States)

    Kuroshima, Shinichiro; Nakano, Takayoshi; Ishimoto, Takuya; Sasaki, Muneteru; Inoue, Maaya; Yasutake, Munenori; Sawase, Takashi

    2017-01-15

    The aim was to investigate the effect of groove designs on bone quality under controlled-repetitive load conditions for optimizing dental implant design. Anodized Ti-6Al-4V alloy implants with -60° and +60° grooves around the neck were placed in the proximal tibial metaphysis of rabbits. The application of a repetitive mechanical load was initiated via the implants (50N, 3Hz, 1800 cycles, 2days/week) at 12weeks after surgery for 8weeks. Bone quality, defined as osteocyte density and degree of biological apatite (BAp) c-axis/collagen fibers, was then evaluated. Groove designs did not affect bone quality without mechanical loading; however, repetitive mechanical loading significantly increased bone-to-implant contact, bone mass, and bone mineral density (BMD). In +60° grooves, the BAp c-axis/collagen fibers preferentially aligned along the groove direction with mechanical loading. Moreover, osteocyte density was significantly higher both inside and in the adjacent region of the +60° grooves, but not -60° grooves. These results suggest that the +60° grooves successfully transmitted the load to the bone tissues surrounding implants through the grooves. An optimally oriented groove structure on the implant surface was shown to be a promising way for achieving bone tissue with appropriate bone quality. This is the first report to propose the optimal design of grooves on the necks of dental implants for improving bone quality parameters as well as BMD. The findings suggest that not only BMD, but also bone quality, could be a useful clinical parameter in implant dentistry.

  19. Sorption kinetics and mechanism of various oils into kapok assembly.

    Science.gov (United States)

    Dong, Ting; Wang, Fumei; Xu, Guangbiao

    2015-02-15

    Sorption rates of kapok fibers on different oils, such as diesel, cooking oil, used motor oil, and motor oil, were quantitatively evaluated by using a wicking method. Kapok fibers absorbing different oils exhibited large differences in terms sorption coefficients. Microscopic observations of oil wetting on a single kapok showed that the four oils had varying wettability and adhesiveness to kapok, but that all of them penetrated into kapok lumens quickly because of the fiber's low surface energy, which was 40.64 mN/m, and extreme hydrophobicity, with a water contact angle up to 151°. After treatment with chloroform, there were slight changes in oil absorbencies to kapok, but the sorption coefficients for the four oils increased markedly. SEM demonstrated that chloroform treatments caused the smooth surface of the kapok fibers to become highly roughened, with densely vertical grooves that provided more available surface and a larger driving force for oil sorption through the fiber assembly.

  20. Symmetries in Images on Ancient Seals

    CERN Document Server

    Sparavigna, Amelia

    2008-01-01

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

  1. The effect of combined hypergravity and micro-grooved surface topography on the behaviour of fibroblasts.

    NARCIS (Netherlands)

    Loesberg, W.A.; Walboomers, X.F.; Loon, J.J. van; Jansen, J.A.

    2006-01-01

    This study evaluated in vitro the differences in morphological behaviour between fibroblast cultured on smooth and micro-grooved substrata (groove depth: 1 mum, width: 1, 2, 5, 10 microm), which undergo artificial hypergravity by centrifugation (10, 24 and 50 g; or 1 g control). The aim of the study

  2. Beaming light from a subwavelength slit surrounded by an array of grooves with different depth

    Science.gov (United States)

    Luo, Xiangang; Wang, Changtao; Du, Chunlei; Shi, Haofei; Gao, Hongtao; Ma, Junxian; Fu, Yongqi; Li, Haiying

    2005-08-01

    In this paper, we discussed the beam focusing of light emerged from a subwavlength metallic slit surrounded by a set of grooves with constant space and width but variant depth at the exit side surface. Based on the numerical model presented by L. Martin-Moreno, F. J. Garcia-Vidal etc. (published in PRL 167401), we attempted to optimize grooves depth to obtain general beam manipulation, such as beam focusing. This attempt did not prove successful for many cases with variant focal length in our optimization practice, although some specific results display agreeable beam focusing with elongated focal depth. Further numerical computation shows that the excited electromagnetic field intensity around groove openings has a strong dependence on the groove depth, but the phase only vary with a maximum change value of π by tuning the groove depth. This property restricts greatly the modulation of electromagnetic field by just changing each groove depth. More geometrical parameters, including groove space and width, are recommended for optimization in the design of nano metallic groove and slit structures for specific beam manipulation.

  3. Current Teaching of Proximal Retention Grooves for Class II Amalgam Preparations.

    Science.gov (United States)

    Moore, David L.

    1992-01-01

    A survey gathered information on methods of class II amalgam preparation taught in 59 dental schools. Focus was on the teaching and testing of proximal retention groove use, stated rationale for placing retention grooves, and the relationship of the instruction to board criteria for cavity preparation. (MSE)

  4. Study of the cavitating instability on a grooved Venturi profile

    CERN Document Server

    Danlos, Amélie; Ravelet, Florent; Coutier-Delgosha, Olivier; Bakir, Farid

    2012-01-01

    Cavitation is a limiting phenomenon in many domains of fluid mechanics. Instabilities of a partial cavity developed on an hydrofoil, a converging-diverging step or in an inter-blade channel in turbomachinery, have already been investigated and described in many previous works. The aim of this study is to evaluate a passive control method of the sheet cavity. According to operating conditions, cavitation can be described by two different regimes: an unstable regime with a cloud cavitation shedding and a stable regime with only a pulsating sheet cavity. Avoiding cloud cavitation can limit structure damages since a pulsating sheet cavity is less agressive. The surface condition of a converging-diverging step, like a Venturi-type obstacle, is here studied as a solution for a passive control of the cavitation. This study discusses the effect of an organized roughness, in the shape of longitudinal grooves, on the developed sheet cavity. Analyzes conducted with Laser Doppler Velocimetry, visualisations and pressure ...

  5. Study of surface plasmon chirality induced by Archimedes' spiral grooves.

    Science.gov (United States)

    Ohno, Tomoki; Miyanishi, Shintaro

    2006-06-26

    A chirality of surface plasmons excited on a silver film with Archimedes' spiral grooves during incidence of a circularly polarized light is analytically and numerically studied by using the finite-difference time-domain (FDTD) modeling method. We found that the surface of a plasmon has selective chirality, which is given by the sum of the chiralities of the incident light and the spiral structure. The surface plasmons with the chirality lead to zero-order, first-order, and high-order evanescent Bessel beams with electric charge distributions on the film. This selectivity could be widely applied for chiral detection of the incident light and chiral excitation of several optical modes in nanophotonics.

  6. Design of ANSYS-based Cathode with Complex Groove

    Institute of Scientific and Technical Information of China (English)

    范植坚; 赵刚刚; 张丽娟

    2012-01-01

    The profile of cathode with complex groove needs to be modified time after time during design of electrochemical machining (ECM) cathode.A design scheme using finite element method (FEM) for cathode with complex profile is put forward to shorten the period of cathode design.Based on Laplace equation,the potential distribution on parameter-transformation model was calculated by using ANSYS,which is compared to the potential distribution calculated by substituting conductivity and current efficiency into Laplace equation.According to the difference between the results calculated and simulated by ANSYS,the cathode profile was modified by adjusting the cathode boundary.The experiments show that the dimensions and shape of workpiece machined by numerically simulated cathode conform well with the blueprint.

  7. Dance, Music, Meter and Groove: A Forgotten Partnership

    Science.gov (United States)

    Fitch, W. Tecumseh

    2016-01-01

    I argue that core aspects of musical rhythm, especially “groove” and syncopation, can only be fully understood in the context of their origins in the participatory social experience of dance. Musical meter is first considered in the context of bodily movement. I then offer an interpretation of the pervasive but somewhat puzzling phenomenon of syncopation in terms of acoustic emphasis on certain offbeat components of the accompanying dance style. The reasons for the historical tendency of many musical styles to divorce themselves from their dance-based roots are also briefly considered. To the extent that musical rhythms only make sense in the context of bodily movement, researchers interested in ecologically valid approaches to music cognition should make a more concerted effort to extend their analyses to dance, particularly if we hope to understand the cognitive constraints underlying rhythmic aspects of music like meter and groove. PMID:26973489

  8. Finite Element Analysis of 6300 Deep Groove Ball Bearing

    Institute of Scientific and Technical Information of China (English)

    DENG Chi; YANG Guang-hui

    2013-01-01

    Rolling bearing is widely used in mechanical support, its general components are the inner ring, outer ring, the ball, retainer etc.. Now many companies in developed countries and university in the rolling bearing as the research object, and has made great progress in design theory, the experiment method and production technology etc. We will use the finite element ANSYS to establish the model of deep groove ball bearing. Through the contact analysis, we can get the contact stress between the rings and balls, strain, contact state, penetration, sliding distance and the friction stress distribution. These values are compared to the theoretical values with Hertz theory, and they have better consistency, provide the good theoretical basis for the optimization design of rolling bearings.

  9. IN-SITU STRESS FIELD AND GEOLOGICAL TECTONIC ANALYSIS AT HUANGDAO WATER-SEALED UNDERGROUND OIL CARVEN SITE%黄岛地下水封油库地应力场及地质构造作用分析

    Institute of Scientific and Technical Information of China (English)

    王章琼; 晏鄂川; 季惠斌

    2016-01-01

    初始地应力场对地下洞室围岩稳定性影响十分显著,但由于地质条件的复杂性,通过单一方法得到的地应力场可靠性不高.以黄岛地下水封洞库工程为例,分析了研究区区域地质构造背景及近场断裂构造;通过水压致裂法进行了地应力测试,得到最大主应力方向主要集中在 NWW 向,优势方向为N73°W;通过地质构造分析法分析了研究区地应力场,探讨了区域构造运动历史对研究区现今构造应力场的影响,认为最大主应力方向为 NW—NNW.构造分析法与水压致裂法所得最大主应力方向大致均为 NW,但存在一定偏差;主要原因可能是研究区地质构造复杂,受构造变形边界条件影响,派生的局部应力场发生偏转.这表明,在分析地应力场时应结合区域地质构造作用分析及实测地应力进行综合评价.研究结果对于地应力场的综合确定方法具有一定参考价值.%The initial in-situ stress field has significant influence on the stability of surrounding rock of underground carven.Nevertheless,the in-situ stress field result obtained by a single method is usually not of high reliability because of the complexity of geological conditions.This paper takes the Huangdao underground water-sealed cavern as example and analyzes its regional tectonic background and near-field faults.The in-situ stress field is tested by hydraulic fracturing method.The maximum principal stress is obtained.Its directions are is mainly oriented NWW.Its advantage direction is N73°W.The stress field of study area is analyzed by geological structure analysis method.The impact of regional tectonic history on present tectonic stress field of study area is discussed.It is found that the maximum principal stress direction is NW~NNW.The maximum principal stress directions obtained by construction analysis and hydraulic fracturing method are roughly NW.But there is a certain bias.The main reason is probably due to the

  10. Repository Sealing Program Plan: repository in salt

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-01-01

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

  11. 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.

  12. New phacoemulsification tip with a grooved, threaded-tip construction.

    Science.gov (United States)

    Watanabe, Akinari

    2011-07-01

    To visually compare ultrasonic tip vibrations between a phaco tip with internal grooves (threaded tip) and a standard phaco tip during continuous-mode ultrasound (US) using ultra-high-speed digital video imaging. Watanabe Eye Clinic, Hyogo, Japan. Experimental study. The threaded tip was constructed by creating grooves inside a standard phaco tip using a screw. An ultra-high-speed digital video camera was used to record the image during continuous-mode US. Samples used in the test chamber during phacoemulsification included a piece of chestnut as a representative human lens sample and actual human lens fragments. Ultra-high-speed digital images showed that the threaded tip created a larger amount of cavitation than the standard phaco tip during US oscillation. Phacoemulsification of the sample using the standard phaco tip produced a chattering motion, making it difficult to maintain a steady tip position. The threaded tip produced little chattering motion, making it relatively easy to maintain a steady tip position. Once a piece of sample was gripped by the threaded tip, it was shaved and aspirated into the threaded tip without chattering motion. The mean effective phacoemulsification time (EPT) of the threaded tip was significantly shorter than that of the normal phaco tip (6.0 seconds ± 1.9 [SD] versus 15.4 ± 1.3 seconds; P=.002). The threaded tip created larger amounts of cavitation and had strong destructive and holding power. This threaded construction is simple to produce and appears to be very effective for phacoemulsification. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. Dielectric effect on the rf characteristics of a helical groove travelling wave tube

    Institute of Scientific and Technical Information of China (English)

    Wei Yan-Yu(魏彦玉); Wang Wen-Xiang(王文祥); Sun Jia-Hong(孙嘉鸿); Liu Sheng-Gang(刘盛纲); Baofu Jia; Gun-Sik Park

    2002-01-01

    A new type of partial-dielectric-loaded helical groove slow-wave structure (SWS) for millimetre wave travellingwave tube (TWT) is presented in this paper. The radio-frequency characteristics including the dispersion properties,the longitudinal electric field distribution and the beam-wave coupling impedance of this structure are analysed. Theresults show that the dispersion of the helical groove circuit is weakened, the phase velocity is reduced and the positionof the maximum Ez is moved from the mouth to the inside of the groove after partially filling the dielectric materialsin the helical groove SWS. Therefore, the dielectric-loaded helical groove SWS is suitable for a multi-beam TWT withbroad band and high gain.

  14. Source-model technique analysis of electromagnetic scattering by surface grooves and slits.

    Science.gov (United States)

    Trotskovsky, Konstantin; Leviatan, Yehuda

    2011-04-01

    A computational tool, based on the source-model technique (SMT), for analysis of electromagnetic wave scattering by surface grooves and slits is presented. The idea is to use a superposition of the solution of the unperturbed problem and local corrections in the groove/slit region (the grooves and slits are treated as perturbations). In this manner, the solution is obtained in a much faster way than solving the original problem. The proposed solution is applied to problems of grooves and slits in otherwise planar or periodic surfaces. Grooves and slits of various shapes, both smooth ones as well as ones with edges, empty or filled with dielectric material, are considered. The obtained results are verified against previously published data.

  15. Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

    Science.gov (United States)

    Byrdsong, T. A.

    1973-01-01

    An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

  16. Dispersion characteristics of planar grating with arbitrary grooves for terahertz Smith-Purcell radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Miaomiao, E-mail: mona486@yeah.net; Li, Ke, E-mail: like3714@163.com [Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Wenxin, E-mail: lwenxin@mail.ie.ac.cn; Wang, Yong, E-mail: wangyong3845@sina.com [Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-03-15

    In this paper, a novel method of getting the dispersion relations in planar grating with arbitrary grooves for terahertz Smith-Purcell radiation is investigated analytically. The continuous profile of the groove is approximately replaced by a series of rectangular steps. By making use of field matches method and the continuity of transverse admittance, the universal dispersion equation for grating with arbitrarily shaped grooves is derived. By solving the dispersion equation in presence of electron beam, the growth rate is obtained directly and the dependence on beam parameters is analyzed. Comparisons of the dispersion characteristics among some special groove shapes have been made by numerical calculation. The results show that the rectangular-step approximation method provides a novel approach to obtain the universal dispersion relation for grating with arbitrary grooves for Smith-Purcell radiation.

  17. Dielectric effect on the rf characteristics of a helical groove travelling wave tube

    Science.gov (United States)

    Wei, Yan-Yu; Wang, Wen-Xiang; Sun, Jia-Hong; Liu, Sheng-Gang; Baofu, Jia; Gun-Sik, Park

    2002-03-01

    A new type of partial-dielectric-loaded helical groove slow-wave structure (SWS) for millimetre wave travelling wave tube (TWT) is presented in this paper. The radio-frequency characteristics including the dispersion properties, the longitudinal electric field distribution and the beam-wave coupling impedance of this structure are analysed. The results show that the dispersion of the helical groove circuit is weakened, the phase velocity is reduced and the position of the maximum Ez is moved from the mouth to the inside of the groove after partially filling the dielectric materials in the helical groove SWS. Therefore, the dielectric-loaded helical groove SWS is suitable for a multi-beam TWT with broad band and high gain.

  18. Experimental Study of Turbulent Boundary Layers on Groove/Smooth Flat Surfaces

    Institute of Scientific and Technical Information of China (English)

    Hongwei MA; Qiao TIAN; Hui WU

    2005-01-01

    This paper presents an experimental investigation of the turbulent boundary layers on both groove and smooth flat surfaces. The flow structures were shown in a water tunnel using the hydrogen-bubble flow visualization technique. The measurement results indicate that: (1) the grooves can effectively reduce accumulation of low-speed fluids, decrease the number of the low-speed streaks and depress oscillation of the streaks in the sublayer; (2) the grooves can restrain forming of the horseshoe vortices in the buffer region; (3) the grooves bate oscillation and kinking of the quasi-streamwise vortices and restrain production of the hairpin vortices and the ring vortices, reducing both frequency and intensity of the turbulence bursting; (4) the grooves directly affect the flow structures in the sublayer of the boundary layer and then modulate the flow field up to the buffer region and the logarithmic region by restraining development and interaction of the vortices.

  19. Treatment of a Developmental Groove and Supernumerary Root Using Guided Tissue Regeneration Technique

    Directory of Open Access Journals (Sweden)

    Zahra Alizadeh Tabari

    2016-01-01

    Full Text Available Introduction. The radicular groove is a developmental groove which is usually found on the palatal or lateral aspects of the maxillary incisor teeth. The present case is a maxillary lateral incisor with a small second root and a deep radicular groove. The developmental groove caused a combined periodontal-endodontic lesion. Methods. Case was managed using a combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal treatment. After completion of root canal treatment, guided tissue regeneration (GTR was carried out using decalcified freeze dried bone allograft (DFDBA and a bioabsorbable collagenous membrane. Tooth also was splinted for two months. Results. After 12 months the tooth was asymptomatic. The periapical radiolucency disappeared and probing depth did not exceed 3 mm. Conclusion. Combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal regenerative treatment can be a predictable technique in treating combined endodontic-periodontal lesions caused by radicular groove.

  20. A simple method for fabrication of high-aspect-ratio all-silicon grooves

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yuncan; Pan, An; Si, Jinhai, E-mail: jinhaisi@mail.xjtu.edu.cn; Chen, Tao; Chen, Feng; Hou, Xun

    2013-11-01

    A simple method using 800-nm femtosecond laser irradiation and chemical selective etching has been proposed for fabrication of high-aspect-ratio all-silicon grooves. Grooves with the maximum aspect ratio of 44 were produced. A scanning electronic microscopy equipped with an energy dispersive X-ray spectroscopy was employed to characterize the morphology and chemical composition of the grooves respectively. The formation mechanism of the grooves was attributed to the chemical reaction of the laser induced refractive index change microstructures and hydrofluoric acid solution. The dependences of the aspect ratio of the grooves on the laser irradiation parameters, such as: the numerical aperture of the microscope objective lens, the laser average power and the laser scanning velocity, are discussed.

  1. Treatment of a Developmental Groove and Supernumerary Root Using Guided Tissue Regeneration Technique.

    Science.gov (United States)

    Alizadeh Tabari, Zahra; Homayouni, Hamed; Pourseyediyan, Tahere; Arvin, Armita; Eiland, Derrick; Moradi Majd, Nima

    2016-01-01

    Introduction. The radicular groove is a developmental groove which is usually found on the palatal or lateral aspects of the maxillary incisor teeth. The present case is a maxillary lateral incisor with a small second root and a deep radicular groove. The developmental groove caused a combined periodontal-endodontic lesion. Methods. Case was managed using a combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal treatment. After completion of root canal treatment, guided tissue regeneration (GTR) was carried out using decalcified freeze dried bone allograft (DFDBA) and a bioabsorbable collagenous membrane. Tooth also was splinted for two months. Results. After 12 months the tooth was asymptomatic. The periapical radiolucency disappeared and probing depth did not exceed 3 mm. Conclusion. Combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal regenerative treatment can be a predictable technique in treating combined endodontic-periodontal lesions caused by radicular groove.

  2. Thermal performance of heat pipe with different micro-groove structures

    Institute of Scientific and Technical Information of China (English)

    白鹏飞; 汤勇; 唐彪; 陆龙生

    2008-01-01

    Four kinds of micro heat pipe of trapezoidal groove wick structure with different numbers of grooves or aspect ratios were studied and compared about thermal transfer performances in order to optimize the manufacture of micro heat pipe with groove wick structure. The results show that these micro heat pipes have excellent performance in heat transfer; the equivalent thermal conductivity coefficient is two orders of magnitude compared with that of copper; the number and aspect ratio of grooves have a prominent effect on the performance of such thermal transfer. The optimum number of grooves is lower than 60 and the best aspect ratio is near to 1.5. The temperature and thermal transport rate are almost directly proportional relationship, but this relationship will be broken up suddenly when the critical heat flux is reached.

  3. An Optimum Method for a Grooved 2D Planar Ion Trap Design

    Institute of Scientific and Technical Information of China (English)

    JI Wei-Bang; WAN Jin-Yin; CHENG Hua-Dong; LIU Liang

    2011-01-01

    We investigate an effective grooved 2D ion chip design and optimize the ratio between the size of the rf electrodes and the groove.We calculate the optimal size of the groove using the analyticai model,which was introduced by House,and the optimum result is obtained. We aiso obtain the simulated scattering points with the finite element analysis method.The analytical curve and simulated scattering points are coincident with each other.It is shown that this analytical model also fits for the grooved planar ion chip.Thus the optimum grooved 2D planar ion chip design could be obtained.It is effective for scalable quantum information processing.

  4. Treatment of a Developmental Groove and Supernumerary Root Using Guided Tissue Regeneration Technique

    Science.gov (United States)

    Alizadeh Tabari, Zahra; Pourseyediyan, Tahere; Eiland, Derrick

    2016-01-01

    Introduction. The radicular groove is a developmental groove which is usually found on the palatal or lateral aspects of the maxillary incisor teeth. The present case is a maxillary lateral incisor with a small second root and a deep radicular groove. The developmental groove caused a combined periodontal-endodontic lesion. Methods. Case was managed using a combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal treatment. After completion of root canal treatment, guided tissue regeneration (GTR) was carried out using decalcified freeze dried bone allograft (DFDBA) and a bioabsorbable collagenous membrane. Tooth also was splinted for two months. Results. After 12 months the tooth was asymptomatic. The periapical radiolucency disappeared and probing depth did not exceed 3 mm. Conclusion. Combined treatment procedure involving nonsurgical root canal therapy and surgical periodontal regenerative treatment can be a predictable technique in treating combined endodontic-periodontal lesions caused by radicular groove. PMID:27965900

  5. 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

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

    Institute of Scientific and Technical Information of China (English)

    朱汉华; 刘正林; 温诗铸; 严新平

    2004-01-01

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

  7. 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.

  8. Hermetic seal for a shaft

    Science.gov (United States)

    Lombardi, F. (Inventor)

    1982-01-01

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

  9. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Directory of Open Access Journals (Sweden)

    Li-Ann eLeow

    2014-10-01

    Full Text Available Slowed gait in Parkinson’s disease (PD patients can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the beat, which might be difficult for PD patients who tend to show weak beat perception. One solution may be to use high groove music, which has high beat salience that may facilitate synchronization, and affective properties which may improve motivation to move. As a first step in understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low groove music, high groove music, and metronome cues. High groove music was predicted to elicit better synchronization than low groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1 preferred tempo: beat rate matched to preferred step rate and (2 faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high groove music, and worst with low groove music. In addition, high groove music elicited longer and faster steps than low groove music, both at preferred tempo and at faster tempo. Low groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  10. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Science.gov (United States)

    Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A

    2014-01-01

    Slowed gait in patients with Parkinson's disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the "beat," which might be difficult for patients with PD who tend to show weak beat perception. One solution may be to use high-groove music, which has high beat salience that may facilitate synchronization, and affective properties, which may improve motivation to move. As a first step to understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low-groove music, high-groove music, and metronome cues. High-groove music was predicted to elicit better synchronization than low-groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1) preferred tempo: beat rate matched to preferred step rate and (2) faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high-groove music, and worst with low-groove music. In addition, high-groove music elicited longer and faster steps than low-groove music, both at preferred tempo and at faster tempo. Low-groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  11. The Use of Fiberglass and Ceramic Cylinders to Support the Root Pass in C-Steel Welds with a Double-V Groove

    Directory of Open Access Journals (Sweden)

    Ricardo Fernandes Gurgel

    2015-09-01

    Full Text Available Abstract The aim of this work is to evaluate the effectiveness of fiberglass and ceramic fiber cylinders as root-pass weld backing for a double-V groove in 16 mm-thick carbon steel. Three different cylinder diameters were tested: 4.8, 9.5 mm (fiberglass and 6.4 mm (ceramic fiber. The welding process used was GMAW. The welding technique and the following process variables were investigated: root opening, current and travel speed. The results show that cylindrical fiberglass and ceramic fiber backings not only have excellent refractory properties, but also seal the root opening and contain the weld pool sufficiently to produce a root bead free of discontinuities and with a satisfactory shape and geometry. Working points were defined, together with a possible operating range for the welding parameters. It was concluded that cylindrical fiberglass and ceramic fiber weld backings hold great promise for use in root-pass welds in double-V grooves in applications in the naval and metallurgical industry.

  12. Experimental studies on heat transfer and friction factor characteristics of a turbulent flow for internally grooved tubes

    Directory of Open Access Journals (Sweden)

    Ponnusamy Selvaraj

    2016-01-01

    Full Text Available This paper reports experimental studies on friction factor, Nusselt number, and thermal hydraulic performance of a tube equipped with the classic three modified internally grooved tubes. Heat transfer and friction factor characteristics and pres- sure drop results have been obtained experimentally for a fully developed water flow in a grooved tube is also reported. Tests were performed for Reynolds number ranges from 5000-13500 for different geometric grooved tubes (circular, square, and rapezium. The ratio of length-to-diameter is 38.69 D. Among the grooved tubes, heat transfer enhancement obtained up to 47% for circular grooved tube, 31% for square grooved tube, and 52% for trapezoidal grooved tube in comparison with the smooth tube. It has been observed that the friction factor high in the case of square grooved tube than those of other tubes.

  13. Characteristics of Arbitrarily-Shaped Helical Groove Slow-Wave Structure Loaded with a Concentric Dielectric-Rod

    Science.gov (United States)

    Gong, Yu-Bin; Wei, Yan-Yu; Liu, Hong-Tao

    2010-12-01

    The dielectric-rod is loaded on the central axis of the arbitrarily-shaped helical groove slow-wave structure. Meanwhile, the profile of the groove is replaced by a series of continuous rectangular steps. The unified dispersion equation of the arbitrarily-shaped helical groove waveguide loaded with a concentric dielectric-rod is obtained by means of a combination of filed-matching method and admittance-matching technique. Then, the effect of the change of groove shape and the dielectric-rod parameters on the dispersion and coupling impedance is approached by theory calculation. The results show that: loaded with dielectric-rod, the bandwidth of the helical groove traveling wave tube (TWT) is effectively broadened, but the coupling impedance is reduced. Among the five different groove shapes, the triangle-type groove has the widest bandwidth but the smallest coupling impedance, and the swallow-tailed-type groove has the narrowest bandwidth but the largest coupling impedance.

  14. Determination of Tongue and Groove parameters for multileaf collimators; Determinaco de parametros de Tongue and Groove de colimadores de multilaminas

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Aluisio; Almeida, Carlos E. de, E-mail: alu_neto@hotmail.com [Universidade Estadual do Rio de Janeiro (UERJ), RJ (Brazil). Laboratorio de Ciencias Radiologicas; Nguyen, Bihn [Prowess Inc., Concord, CA (United States)

    2012-08-15

    The Tongue and Groove effect (TandG) is characterized by an additional attenuation between adjacent and opposing leaves on multileaf collimators (MLCs) in adjacent or complementary fields. This is a typical situation in of intensity-modulated radiotherapy treatments. The aim of this study was to measure the width and transmission of TandG effect for two commercial MLCs: Varian Millennium 120 (6 MV and 16 MV beams) and BrainLab m3 (only for 6 MV). The methodology used was based on the creation of MLC shapes that emphasizes TandG effect, the irradiation of these fields on radiochromic film and the sensitometric evaluation of the films in order to determine the TandG width and transmission. The results for TandG width for studied MLCs were 2.5, 1.8 and 2 mm, respectively, whit transmission TandG values of 87, 90 and 85%. (author)

  15. Toward a predictive model for elastomer seals

    Science.gov (United States)

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

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

  16. Numerical Analysis of Magnetic Fluid Sealing Performance

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

  17. Effect of groove on socket welds under the condition of vibration fatigue

    Science.gov (United States)

    Xiu, Junjie; Jing, Hongyang; Han, Yongdian; Zhao, Lei; Xu, Lianyong

    2013-02-01

    Root failures of socket welds in small bore piping caused by vibration mainly occur at nuclear power plants (NPPs). It was observed that at higher stress level failures tended to originate at the toe while for the case of lower stress failures tended to occur at the root. The groove can increase the penetration depth (PD) of root, which is beneficial to the fatigue life. The effect of groove was also investigated by finite element method (FEM). The simulation results show that groove can decline the stress distribution, stress triaxiality and maximum principal plastic strain in the weld root, and the 5 mm groove suffering σmax (the highest stress of root failure) is almost same as no groove subjecting to σf (fatigue limit). The test results show that the socket weld with groove can increase the natural frequency and damping of specimen, which make the system more difficult to vibrate. Moreover, the groove can also improve the fatigue property of specimen which do not exist the root failure even under high cycle fatigue (HCF).

  18. Phase-Field Modeling of Grain-Boundary Grooving Under Electromigration

    Science.gov (United States)

    Mukherjee, Arnab; Ankit, Kumar; Mukherjee, Rajdip; Nestler, Britta

    2016-12-01

    In the present work, we study the phenomenon of grain-boundary grooving under electromigration using a phase-field method. The specific focus of the work is to explore the role of grain boundaries as potential electromigration pathways. We consider the evolution of grooves under the combined influence of capillary and electromigration-mediated surface diffusion and electromigration-induced grain-boundary diffusion. Mechanisms of grooving are elucidated using flux density maps that indicate various regimes depending upon the direction of net material transport. When grain-boundary atomic mobility is lower than the surface mobility, the groove depth is found to be lower than that evolving solely under surface diffusion (no electromigration). At comparable or larger values of grain-boundary atomic mobility, grooving is initially expedited but shows groove replenishment at later stages. A detailed investigation using the phase-field method reveals the influence of an incumbent healing mechanism on grain-boundary grooving which is electrically induced. The drift characteristics such as edge and root displacement and velocity are examined in light of this assuaging effect.

  19. Effective slip for flow through a channel bounded by lubricant-impregnated grooved surfaces

    Science.gov (United States)

    Sun, Rui; Ng, Chiu-On

    2017-04-01

    This study aims to investigate effective slip arising from pressure-driven flow through a slit channel bounded by lubricant-impregnated grooved surfaces. The problem for flow over longitudinal grooves is solved analytically using the methods of domain decomposition and eigenfunction expansion, while that for flow over transverse grooves is solved numerically using the front tracking method. It is found that the effective slip length and the lubricant flow rate can depend strongly on the geometry of the microstructure, the direction of flow, and the lubricant viscosity. In particular, the effective slip can be effectively enhanced by increasing the thickness of a lubricating film atop the ribs. Under the same conditions, a flow that is parallel to the lubricant-impregnated grooves will have a larger effective slip, but also a larger lubricant flow rate, when compared with the case of flow normal to the grooves. It is also shown that, in the case of transverse grooves, because of the downward displacement of the interface between the working/lubricating fluids, the effective slip length and lubricant flow rate may vary non-monotonically with the groove depth.

  20. Microcirculation within grooved substrates regulates cell positioning and cell docking inside microfluidic channels.

    Science.gov (United States)

    Manbachi, Amir; Shrivastava, Shamit; Cioffi, Margherita; Chung, Bong Geun; Moretti, Matteo; Demirci, Utkan; Yliperttula, Marjo; Khademhosseini, Ali

    2008-05-01

    Immobilization of cells inside microfluidic devices is a promising approach for enabling studies related to drug screening and cell biology. Despite extensive studies in using grooved substrates for immobilizing cells inside channels, a systematic study of the effects of various parameters that influence cell docking and retention within grooved substrates has not been performed. We demonstrate using computational simulations that the fluid dynamic environment within microgrooves significantly varies with groove width, generating microcirculation areas in smaller microgrooves. Wall shear stress simulation predicted that shear stresses were in the opposite direction in smaller grooves (25 and 50 microm wide) in comparison to those in wider grooves (75 and 100 microm wide). To validate the simulations, cells were seeded within microfluidic devices, where microgrooves of different widths were aligned perpendicularly to the direction of the flow. Experimental results showed that, as predicted, the inversion of the local direction of shear stress within the smaller grooves resulted in alignment of cells on two opposite sides of the grooves under the same flow conditions. Also, the amplitude of shear stress within microgrooved channels significantly influenced cell retainment in the channels. Therefore, our studies suggest that microscale shear stresses greatly influence cellular docking, immobilization, and retention in fluidic systems and should be considered for the design of cell-based microdevices.

  1. The Effect of Expert Performance Microtiming on Listeners' Experience of Groove in Swing or Funk Music

    Science.gov (United States)

    Senn, Olivier; Kilchenmann, Lorenz; von Georgi, Richard; Bullerjahn, Claudia

    2016-01-01

    This study tested the influence of expert performance microtiming on listeners' experience of groove. Two professional rhythm section performances (bass/drums) in swing and funk style were recorded, and the performances' original microtemporal deviations from a regular metronomic grid were scaled to several levels of magnitude. Music expert (n = 79) and non-expert (n = 81) listeners rated the groove qualities of stimuli using a newly developed questionnaire that measures three dimensions of the groove experience (Entrainment, Enjoyment, and the absence of Irritation). Findings show that music expert listeners were more sensitive to microtiming manipulations than non-experts. Across both expertise groups and for both styles, groove ratings were high for microtiming magnitudes equal or smaller than those originally performed and decreased for exaggerated microtiming magnitudes. In particular, both the fully quantized music and the music with the originally performed microtiming pattern were rated equally high on groove. This means that neither the claims of PD theory (that microtiming deviations are necessary for groove) nor the opposing exactitude hypothesis (that microtiming deviations are detrimental to groove) were supported by the data. PMID:27761117

  2. The Effect of Expert Performance Microtiming on Listeners' Experience of Groove in Swing or Funk Music.

    Science.gov (United States)

    Senn, Olivier; Kilchenmann, Lorenz; von Georgi, Richard; Bullerjahn, Claudia

    2016-01-01

    This study tested the influence of expert performance microtiming on listeners' experience of groove. Two professional rhythm section performances (bass/drums) in swing and funk style were recorded, and the performances' original microtemporal deviations from a regular metronomic grid were scaled to several levels of magnitude. Music expert (n = 79) and non-expert (n = 81) listeners rated the groove qualities of stimuli using a newly developed questionnaire that measures three dimensions of the groove experience (Entrainment, Enjoyment, and the absence of Irritation). Findings show that music expert listeners were more sensitive to microtiming manipulations than non-experts. Across both expertise groups and for both styles, groove ratings were high for microtiming magnitudes equal or smaller than those originally performed and decreased for exaggerated microtiming magnitudes. In particular, both the fully quantized music and the music with the originally performed microtiming pattern were rated equally high on groove. This means that neither the claims of PD theory (that microtiming deviations are necessary for groove) nor the opposing exactitude hypothesis (that microtiming deviations are detrimental to groove) were supported by the data.

  3. The effect of expert performance microtiming on listeners’ experience of groove in swing or funk music

    Directory of Open Access Journals (Sweden)

    Olivier Senn

    2016-10-01

    Full Text Available This study tested the influence of expert performance microtiming on listeners' groove experience. Two professional rhythm section (bass/drums performances in swing and funk style were recorded, and the performances' original microtemporal deviations from a regular metronomic grid were scaled to several magnitude levels. Music expert (n=79 and non-expert (n=81 listeners rated the groove qualities of stimuli using a newly developed questionnaire that measures three dimensions of the groove experience (Entrainment, Enjoyment, and the absence of Irritation. Findings show that music expert listeners were more sensitive to microtiming manipulations than non-experts. Across both expertise groups and for both styles, groove ratings were high for microtiming magnitudes equal or smaller than those originally performed and decreased for exaggerated microtiming magnitudes. In particular, both the fully quantized music and the music with the originally performed microtiming pattern were rated equally high on groove. This means that neither the claims of PD theory (that microtiming deviations are necessary for groove nor the opposing exactitude hypothesis (that microtiming deviations are detrimental to groove were supported by the data.

  4. Electrowetting actuated microfluidic transport in surface grooves with triangular cross section.

    Science.gov (United States)

    Barman, Jitesh; Swain, Digendranath; Law, Bruce M; Seemann, Ralf; Herminghaus, Stephan; Khare, Krishnacharya

    2015-01-27

    Liquids show different static wetting morphologies in open triangular grooves depending upon the wedge angle (ψ) of the groove and the liquid contact angle (θ) with the substrate. Switching between different morphologies can be achieved either by varying the contact angle of the liquid or by changing the wedge angle of the groove. In the present work we manipulate the apparent contact angle of a liquid by electrowetting to switch between liquid morphologies, from droplet to filament, to achieve microfluidic transport of the liquid into open triangular grooves. The static length of liquid filaments in grooves is analyzed as a function of applied voltage for different applied ac frequencies. The dynamic advancement of the filament lengths in grooves is analyzed as a function of time for different applied voltages for two different liquids: first with contact angle greater than the wedge angle and second with contact angle smaller than the wedge angle. Later an exact electrical model is derived to explain the liquid transport in triangular grooves actuated by electrowetting which includes the precise geometry of the liquid morphology.

  5. Well Integrity and Sealing in CO2 Sequestration Wells

    Science.gov (United States)

    Sweatman, R.; Santra, A.; Kulakofsky, D.

    2009-12-01

    CO2 sequestration is a cost-effective and safe way to help mitigate climate change. Sustained well integrity and zonal isolation of CO2 by cement for the required 1000 year trapping period may be challenging. Some researchers report that cement fails when exposed to CO2 leading to potential leakage into the atmosphere or other underground zones. Others show cement samples from 30-50 year old CO2 wells that maintain the well’s sealing integrity, even though carbonization was found. This presentation provides reasons likely for this disparity between research lab test results and actual well performance data along with best practices to provide efficient cement-based systems for maintaining CO2 containment in storage and EOR (enhanced oil recovery) reservoirs. This discussion includes the geochemical conditions surrounding wells and the positive, long-term effects on cement durability, sealing integrity, and the protection of well casing from CO2 induced corrosion. Also discussed are recent laboratory results testing cement samples surrounded by formation material treated at two different downhole conditions. In one case the cement specimens were treated with a 40% humid CO2 at 140°F and 2000 psi whereas in the second case they were treated with saturated CO2 in water at 200°F and 2000 psi for various time intervals. Results show that samples of carefully designed cement systems had carbonization without any sign of loss of mechanical or sealing integrity which could lead to zonal isolation and well integrity failures. We also will report on a new lab method proposed to determine CO2 sealing performance by cement in a relatively short time period compared to previous methods. In summary, we will discuss a comprehensive approach that may be taken to help ensure longer term effective well integrity and CO2 containment in new CO2 wells and remedial solutions for old wells and for plugging and abandoning wells.

  6. 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.

  7. Coalbed methane reservoir boundaries and sealing mechanism

    Institute of Scientific and Technical Information of China (English)

    SU Xianbo; LIN Xiaoying; LIU Shaobo; SONG Yan

    2005-01-01

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

  8. Recent developments in sequence selective minor groove DNA effectors.

    Science.gov (United States)

    Reddy, B S; Sharma, S K; Lown, J W

    2001-04-01

    DNA is a well characterized intracellular target but its large size and sequential nature make it an elusive target for selective drug action. Binding of low molecular weight ligands to DNA causes a wide variety of potential biological responses. In this respect the main consideration is given to recent developments in DNA sequence selective binding agents bearing conjugated effectors because of their potential application in diagnosis and treatment of cancers as well as in molecular biology. Recent progress in the development of cross linked lexitropsin oligopeptides and hairpins, which bind selectively to the minor groove of duplex DNA, is discussed. Bis-distamycins and related lexitropsins show inhibitory activity against HIV-1 and HIV-2 integrases at low nanomolar concentrations. Benzoyl nitrogen mustard analogs of lexitropsins are active against a variety of tumor models. Certain of the bis-benzimidazoles show altered DNA sequence preference and bind to DNA at 5'CG and TG sequences rather than at the preferred AT sites of the parent drug. A comparison of bifunctional bizelesin with monoalkylating adozelesin shows that it appears to have an increased sequence selectivity such that monoalkylating compounds react at more than one site but bizelesin reacts only at sites where there are two suitably positioned alkylation sites. Adozelesin, bizelesin and carzelesin are far more potent as cytotoxic agents than cisplatin or doxorubicin. A new class of 1,2,9,9a-tetrahydrocyclo-propa[c]benz[e]indole-4-one (CBI) analogs i.e., CBI-lexitropsin conjugates arising from the latter leads are also discussed.A number of cyclopropylpyrroloindole (CPI) and CBI-lexitropsin conjugates related to CC-1065 alkylate at the N3 position of adenine in the minor groove of DNA in a sequence specific manner, and also show cytotoxicities in the femtomolar range. The cross linking efficiency of PBD dimers is much greater than that of other cross linkers including cisplatin, and melphalan. A new

  9. Bottom-Fill Method for Stopping Leaking Oil Wells

    CERN Document Server

    Bloomfield, Louis A

    2010-01-01

    Hardware failure at the top of a deep underwater oil well can result in a catastrophic oil leak. The enormous pressure lifting the column of oil in that well makes it nearly impossible to stop from the top with seals or pressurization. We propose to fill the bottom of the well with dense and possibly streamlined objects that can descend through the rising oil. As they accumulate, those objects couple to the oil via viscous and drag forces and increase the oil's effective density. When its effective density exceeds that of the earth's crust, the oil will have essentially stopped flowing.

  10. Impact, Spreading and Bouncing of Water Drops on Steel Surfaces with U and V Grooves

    Science.gov (United States)

    R, Kannan; S, Chandra

    2012-11-01

    The impact, spreading and bouncing of water drops (2 mm dia) was photographed as for velocities ranging from (0.26-1.1m/s) on two textured stainless steel plates, one with U-shaped and the other with V-shaped grooves running the length of the surface. Grooves were made using wire EDM, and groove volume per unit width (0.043mm3) was kept approximately the same for both surfaces and the groove depths were 236 μm and 194 μm for the U (TS1) and V grooved (TS2) surfaces, respectively. Surface wetting by gently deposited drops was different on TS1 and TS2; drops on TS1 rested on the tips of the protrusions (C-B state) while on TS2 liquid penetrated the spaces between the grooves (Wenzel state). At low We (We drops impacting on TS1 spread at the same rate in both directions, perpendicular and parallel to the channel direction. Conversely, the spreading on TS2 was anisotropic, with liquid travelling faster along compared to across the grooves. This anisotropy grew more pronounced as We increased and was observed on both TS1 and TS2 for We >10. The changes in the spreading behavior with increasing impact velocity (and therefore greater We) corresponded to a greater volume of liquid penetrating into the grooves. Photographs showed that when droplets were at their maximum spread the amount of liquid penetrating into the grooves increased sharply for We >10 on TS1. This increased S/L contact area and enhanced spreading along channels. Recoiling drops completely bounced off the surface during impact on TS1, but not on TS2. Bouncing was observed for We <35.

  11. The generation and its sealing condition of natural gas in the Tadong area

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Focusing on the two natural gas exploration geological problems with abundant source of oil cracking gas in the late stage and the sealing condition of the oil cracking gas reservoir,the kinetics of oil cracking gas and the evaluation parameters of gas cap rock are adopted to the study on the natural gas accumulation conditions in the Tadong area. Both the study on the kinetics of oil cracking gas and the statistical results of reservoir bitumen reveal that the geological formation of oil cracking gas in the Tadong area is located in the top of Cambrian. Two kinds of oil cracking gas geological models at least,namely well Mandong-1’s early rapid generation model(Middle Ordovician-end Silurian) and peak cracking model(with the natural gas conversion rate >90%) ,namely well Yingnan-2’s two-stage generation model of oil cracking gas,have been set up. The oil cracking gas of Yingnan-2 in the late stage is very significant in the evaluation of natural gas exploration in the Tadong area. The evaluation results of the cap rock show that the microscopic parameters of cap rock from the lower assemblage of Cambrian-Ordovician are better than those from the upper assemblage. The former has strong capillary sealing ability and higher cap rock breakthrough pressure than the upper assemblage,with strong sealing ability,so that natural gas dissipates mainly by diffusion. According to the above investigations,the lower assemblage Cambrian-Ordovician natural gas of Kongquehe slope,Tadong low uplift and Yingjisu depression in the Tadong area prospects well.

  12. 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.

  13. Face seal assembly for rotating drum

    Science.gov (United States)

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

    1982-01-01

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

  14. An Improvement on the Method for Calculating the Capillary Limit of Axial—Grooved Heat Piper

    Institute of Scientific and Technical Information of China (English)

    ChenHanzhuo; MaTongze

    1993-01-01

    A new model has been developed to predict the capillary limit of axial-grooved heat pipe.In the model the concepts of liquid saturation or liquid fraction of the cross-sectional area of groove,the modified relative permeability,absolute permeability of groove and Leverrt's function are used.The Leverrt's function is well represented by the functionf(s)=1(1/√5)(1/2-)0.175.In the model the effects of gravitational force,capillary force and viscous force are considered.The calcuated results are in good agreement with existing experimental data reported in the literature.

  15. Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

    Science.gov (United States)

    Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

    2017-07-01

    The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

  16. Antineoplastic DNA-binding compounds: intercalating and minor groove binding drugs.

    Science.gov (United States)

    Mišković, Katarina; Bujak, Maro; Baus Lončar, Mirela; Glavaš-Obrovac, Ljubica

    2013-12-01

    DNA intercalating and minor groove binding compounds are new weapons in the battle against malignant diseases. These antineoplastic agents target the DNA molecule and interfere with the cell cycle leading to rapidly proliferating cell death. They are mainly derivates of a naturally occurring organic compound derived from a microorganism or plant. Intercalators usually act as topoisomerase I and/or II poisons, while the mechanisms of DNA minor groove binders are a combination of several steps including topoisomerase poisoning. This paper gives an overview of some of the developed DNA intercalating and minor groove binding compounds, as well as an explanation of their chemical structures, origins, and application in chemotherapy.

  17. Byzantine seals from the Ras fortress

    Directory of Open Access Journals (Sweden)

    Ivanišević Vujadin

    2013-01-01

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

  18. 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).

  19. 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.

  20. Sealing Occlusal Dentin Caries in Permanent Molars

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  1. Self-acting geometry for noncontact seals

    Science.gov (United States)

    Allen, G. P.

    1981-01-01

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

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

    Science.gov (United States)

    Bredbenner, A. M.

    1977-01-01

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

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

    Science.gov (United States)

    Keba, John E.

    1999-01-01

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

  4. Reconstruction of a Supporting Roller Bearing Sealing System of Cold Rolling Equipment%某冷轧设备支撑辊轴承密封系统的改造

    Institute of Scientific and Technical Information of China (English)

    王文虎; 曾军林

    2015-01-01

    通过对某冷轧设备支撑辊轴承密封系统失效原因的分析,提出一种由防尘防垢密封、金属迷宫密封、骨架水封和骨架油封构成的组合密封方案,其中防尘防垢密封可防止外部乳化液、冷却水进入支撑辊;骨架水封与支撑环起到封油和防水、防切削液等进入的作用;骨架油封可有效防止密封内部油液的泄漏。改造后的密封系统密封效果良好,使用寿命大大延长。%Through the analysis of failure reasons of a supporting roller bearing sealing system for cold rolling equip-ment,a combination sealing solution composed of dustproof and anti-fouling seal,metal labyrinth seal,skeleton water seal and skeleton oil seal was proposed.The dustproof and anti-fouling seal can prevent external emulsion and cooling water en-tering the support rollers,the skeleton water seal and support ring act as sealing oil and preventing the water and cutting fluid entering the support rollers,and skeleton oil seal can effectively prevent the internal oil leakage.After transformation, the sealing system has good sealing effect,and service life is greatly extended.

  5. Sealed nickel-cadmium battery

    Energy Technology Data Exchange (ETDEWEB)

    1989-08-15

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

  6. Well sealing via thermite reactions

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, William Edward; Dunn, Sandra Dalvit

    2016-11-15

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

  7. 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.

  8. Characterisation of a grooved heat pipe with an anodised surface

    Science.gov (United States)

    Solomon, A. Brusly; Ram Kumar, A. M.; Ramachandran, K.; Pillai, B. C.; Senthil Kumar, C.; Sharifpur, Mohsen; Meyer, Josua P.

    2017-03-01

    A grooved heat pipe (GHP) is an important device for managing heat in space applications such as satellites and space stations, as it works efficiently in the absence of gravity. Apart from the above application, axial GHPs are used in many applications, such as electronic cooling units for temperature control and permafrost cooling. Improving the performance of GHPs is essential for better cooling and thermal management. In the present study, the effect of anodization on the heat transfer characteristics of a GHP is studied with R600a as a working fluid. In addition, the effects of fill ratio, inclination angle and heat inputs on the heat transfer performance of a GHP are studied. Furthermore, the effect of heat flux on dimensional numbers, such as the Webber, Bond, Kutateladze and condensation numbers, are studied. The inclination angle, heat input and fill ratio of GHPs are varied in the range of 0°-90°, 25-250 W and 10-70 % respectively. It is found that the above parameters have a significant effect on the performance of a GHP. Due to the anodisation, the maximum enhancement in heat transfer coefficient at the evaporator is 39 % for a 90° inclination at a heat flux of 11 kW/m2. The reported performance enhancement of a GHP may be due to the large numbers of nucleation sites created by the anodisation process and enhancement in the capillary force due to the coating.

  9. Characterisation of a grooved heat pipe with an anodised surface

    Science.gov (United States)

    Solomon, A. Brusly; Ram Kumar, A. M.; Ramachandran, K.; Pillai, B. C.; Senthil Kumar, C.; Sharifpur, Mohsen; Meyer, Josua P.

    2016-06-01

    A grooved heat pipe (GHP) is an important device for managing heat in space applications such as satellites and space stations, as it works efficiently in the absence of gravity. Apart from the above application, axial GHPs are used in many applications, such as electronic cooling units for temperature control and permafrost cooling. Improving the performance of GHPs is essential for better cooling and thermal management. In the present study, the effect of anodization on the heat transfer characteristics of a GHP is studied with R600a as a working fluid. In addition, the effects of fill ratio, inclination angle and heat inputs on the heat transfer performance of a GHP are studied. Furthermore, the effect of heat flux on dimensional numbers, such as the Webber, Bond, Kutateladze and condensation numbers, are studied. The inclination angle, heat input and fill ratio of GHPs are varied in the range of 0°-90°, 25-250 W and 10-70 % respectively. It is found that the above parameters have a significant effect on the performance of a GHP. Due to the anodisation, the maximum enhancement in heat transfer coefficient at the evaporator is 39 % for a 90° inclination at a heat flux of 11 kW/m2. The reported performance enhancement of a GHP may be due to the large numbers of nucleation sites created by the anodisation process and enhancement in the capillary force due to the coating.

  10. Minor groove binder distamycin remodels chromatin but inhibits transcription.

    Directory of Open Access Journals (Sweden)

    Parijat Majumder

    Full Text Available The condensed structure of chromatin limits access of cellular machinery towards template DNA. This in turn represses essential processes like transcription, replication, repair and recombination. The repression is alleviated by a variety of energy dependent processes, collectively known as "chromatin remodeling". In a eukaryotic cell, a fine balance between condensed and de-condensed states of chromatin helps to maintain an optimum level of gene expression. DNA binding small molecules have the potential to perturb such equilibrium. We present herein the study of an oligopeptide antibiotic distamycin, which binds to the minor groove of B-DNA. Chromatin mobility assays and circular dichroism spectroscopy have been employed to study the effect of distamycin on chromatosomes, isolated from the liver of Sprague-Dawley rats. Our results show that distamycin is capable of remodeling both chromatosomes and reconstituted nucleosomes, and the remodeling takes place in an ATP-independent manner. Binding of distamycin to the linker and nucleosomal DNA culminates in eviction of the linker histone and the formation of a population of off-centered nucleosomes. This hints at a possible corkscrew type motion of the DNA with respect to the histone octamer. Our results indicate that distamycin in spite of remodeling chromatin, inhibits transcription from both DNA and chromatin templates. Therefore, the DNA that is made accessible due to remodeling is either structurally incompetent for transcription, or bound distamycin poses a roadblock for the transcription machinery to advance.

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  12. 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.

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

    Science.gov (United States)

    2016-01-01

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

  14. 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.

  15. 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.

  16. Investigation of four classical groove patterns with three typical tool types for use in the rigid tool smoothing process

    Science.gov (United States)

    Wu, Hsing-Yu; Meng, Kai

    2016-07-01

    When a surface experiencing robotic processing to improve its optical performance (such as removing mid-spatial frequencies, localized grinding errors, and regional surface scratches), spindle speed, tool travel speed, pressure, slurry density as well as groove patterns are main factors to influence surface finishes. Based on the desired material removal rate, the Preston equation can provide optimized pressures and velocities between the tool and processed surface. Various groove patterns, however, can hardly predict by the equation because different patterns can cause unique tool deformation and pressure distribution, leading to determine unique smoothing result. In this paper, four typical groove patterns are studied: non-groove, grid grove, annular groove and radial groove with three typical tool types are evaluated by Finite Element Method (FEM) and statistics. Characteristics of these tools and groove patterns are presented in the end of this paper.

  17. The resistance of high frequency inductive welded pipe to grooving corrosion in salt water

    Energy Technology Data Exchange (ETDEWEB)

    Duran, C.; Triess, E.; Herbsleb, G.

    1986-09-01

    When exposed to neutral, salt-containing waters, electric resistant welded pipe in carbon and low alloy steels with increased sulfur contents may suffer preferential corrosion attack in the weld area. Because of its appearance, this type of corrosion is called grooving corrosion. The susceptibility to grooving corrosion may be determined and quantitatively described by means of an accelerated potentiostatic exposure test. The importance of type, concentration, and temperature of the electrolytic solution; potential; test duration; and the sulfur content of the steel in the accelerated corrosion test and the susceptibility of steels to grooving corrosion are described. Line pipe in high frequency inductive (HFI) welded carbon and low alloy steels are resistant to grooving corrosion particularly because of their low sulfur content.

  18. Groove Pancreatitis with Several Cystic Lesions around the Pancreatic Head Treated Conservatively: Report of a Case

    Directory of Open Access Journals (Sweden)

    Ryusuke Ito

    2008-11-01

    Full Text Available A 61-year-old man was admitted to our hospital with epigastric pain and vomiting. Enhanced abdominal computed tomography revealed inflammatory change of the pancreatic groove and focal wall thickening of the second portion of the duodenum with several cystic lesions around the head of the pancreas. We diagnosed atypical type of groove pancreatitis. The patient made a satisfactory recovery by conservative medication treatment for acute on chronic pancreatitis and cystic lesions disappeared in parallel with pancreatitis. Groove pancreatitis is a rare form of chronic pancreatitis, and to the best of our knowledge, our patient is the first case in the English literature of groove pancreatitis with cystic lesions around the head of the pancreas, which disappeared after conservative treatment for pancreatitis.

  19. Investigation of mechanism: spoof SPPs on periodically textured metal surface with pyramidal grooves

    Science.gov (United States)

    Tian, Lili; Liu, Jianlong; Zhou, Keya; Gao, Yang; Liu, Shutian

    2016-08-01

    In microwave and terahertz frequency band, a textured metal surface can support spoof surface plasmon polaritons (SSPPs). In this paper, we explore a SSPPs waveguide composed of a metal block with pyramidal grooves. Under the deep subwavelength condition, theoretical formulas for calculation of dispersion relations are derived based on the modal expansion method (MEM). Using the obtained formulas, a general analysis is given about the properties of the SSPPs in the waveguides with upright and downward pyramidal grooves. It is demonstrated that the SSPPs waveguides with upright pyramidal grooves give better field-confinement. Numerical simulations are used to check the theoretical analysis and show good agreement with the analytical results. In addition, the group velocity of the SSPPs propagating along the waveguide is explored and two structures are designed to show how to trap the SSPPs on the metal surface. The calculation methodology provided in this paper can also be used to deal with the SSPPs waveguides with irregular grooves.

  20. Theory of groove-envelope phase effects in self-diffraction

    CERN Document Server

    Reislöhner, Jan; Pfeiffer, Adrian N

    2016-01-01

    If two laser beams cross in a medium under shallow angle, the laser-induced grating consists of only a few grooves. In this situation, the phase between the grooves of the grating and its envelope is a decisive parameter for nonlinear effects. Here, models are established for reproducing the groove-envelope phase effects that have been observed in the interference pattern of self-diffraction. Four-wave mixing leads to interferences that are dominant in the spatial region between the orders of diffraction and with tilted interference fringes in the diagram of transverse coordinate vs. pulse delay. The vertical interference fringes that are dominant directly on the diffraction orders, experimentally observed at high intensity close to the damage threshold, require a model beyond four-wave mixing. A model is suggested that is based on optical transmission changes with confinement to regions in the medium that are smaller than the groove spacing.

  1. The potential impact of groove modes on Type II planetary migration

    CERN Document Server

    Meschiari, Stefano

    2008-01-01

    In this letter, we briefly describe the evolution of a variety of self-gravitating protoplanetary disk models that contain annular grooves (e.g. gaps) in their surface density. These grooves are inspired by the density gaps that are presumed to open in response to the formation of a giant planet. Our work provides an extension of the previously studied groove modes that are known in the context of stellar disks. The emergence of spiral gravitational instabilities (GI) is predicted via a generalized eigenvalue code that performs a linear analysis, and confirmed with hydrodynamical simulations. We find the presence of a groove drives a fast-growing two-armed mode in moderately massive disks, and extends the importance of self-gravitating instabilities down to lower disk masses than for which they would otherwise occur. We discuss the potential importance of this instability in the context of planet formation, e.g. the modification of the torques driving Type II migration.

  2. Buckling Analysis of Supporting Legs and Steel Groove in Uranium Liquor Critical Facility

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The main structure of the uranium liquor critical facility is sit on the long steel tubal supporting legs, and the main vessel is connected with the supporting legs by steel groove, it is possible for the supporting

  3. Large eddy simulation of the subcritical flow over a V grooved circular cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Alonzo-García, A. [Instituto Politécnico Nacional, SEPI-ESIME Zacatenco, U.P. Adolfo López Mateos Edif. 5, 3er. Piso, LABINTHAP, Av. Instituto Politénicno Nacional s/n, Col. Lindavista, C.P. 07738, México D.F., México (Mexico); Gutiérrez-Torres, C. del C., E-mail: cgutierrezt@ipn.mx [Instituto Politécnico Nacional, SEPI-ESIME Zacatenco, U.P. Adolfo López Mateos Edif. 5, 3er. Piso, LABINTHAP, Av. Instituto Politénicno Nacional s/n, Col. Lindavista, C.P. 07738, México D.F., México (Mexico); Jiménez-Bernal, J.A. [Instituto Politécnico Nacional, SEPI-ESIME Zacatenco, U.P. Adolfo López Mateos Edif. 5, 3er. Piso, LABINTHAP, Av. Instituto Politénicno Nacional s/n, Col. Lindavista, C.P. 07738, México D.F., México (Mexico); and others

    2015-09-15

    Highlights: • We compared numerically the turbulent flow over a smooth circular cylinder and a V grooved cylinder in the subcritical regime. • Turbulence intensities in both streamwise and normal direction suffered attenuations. • The swirls structures on grooves peaks seemed to have a cyclic behavior. • The evolution of the flow inside grooves showed that swirls structures located in peaks suffered elongations in the normal direction. • The secondary vortex structures formed in the grooved cylinder near wake were smaller in comparison of the smooth cylinder flow. - Abstract: In this paper, a comparative numerical study of the subcritical flow over a smooth cylinder and a cylinder with V grooves (Re = 140,000) is presented. The implemented technique was the Large Eddy Simulation (LES), which according to Kolmogorov's theory, resolves directly the most energetic largest eddies and models the smallest and considered universal high frequency ones. The Navier-Stokes (N-S) equations were solved using the commercial software ANSYS FLUENT V.12.1, which applied the finite volume method (FVM) to discretize these equations in their unsteady and incompressible forms. The grid densities were 2.6 million cells and 13.5 million cells for the smooth and V grooved cylinder, respectively. Both meshes were composed of structured hexahedral cells and close to the wall of the cylinders, additional refinements were employed in order to obtain y{sup +<5} values. All cases were simulated during at least 15 vortex shedding cycles with the aim of obtaining significant statistical data. Results: showed that for both cases (smooth and V grooved cylinder flow), the numerical code was capable of reproducing the most important physical quantities of the subcritical regime. Velocity distribution and turbulence intensity in the flow direction suffered a slight attenuation along the wake, as a consequence of grooves perturbation, which also caused an increase in the pressure

  4. A Novel Design of Grooved Fibers for Fiber-Optic Localized Plasmon Resonance Biosensors

    Directory of Open Access Journals (Sweden)

    Lai-Kwan Chau

    2009-08-01

    Full Text Available Bio-molecular recognition is detected by the unique optical properties of self-assembled gold nanoparticles on the unclad portions of an optical fiber whose surfaces have been modified with a receptor. To enhance the performance of the sensing platform, the sensing element is integrated with a microfluidic chip to reduce sample and reagent volume, to shorten response time and analysis time, as well as to increase sensitivity. The main purpose of the present study is to design grooves on the optical fiber for the FO-LPR microfluidic chip and investigate the effect of the groove geometry on the biochemical binding kinetics through simulations. The optical fiber is designed and termed as U-type or D-type based on the shape of the grooves. The numerical results indicate that the design of the D-type fiber exhibits efficient performance on biochemical binding. The grooves designed on the optical fiber also induce chaotic advection to enhance the mixing in the microchannel. The mixing patterns indicate that D-type grooves enhance the mixing more effectively than U-type grooves. D-type fiber with six grooves is the optimum design according to the numerical results. The experimental results show that the D-type fiber could sustain larger elongation than the U-type fiber. Furthermore, this study successfully demonstrates the feasibility of fabricating the grooved optical fibers by the femtosecond laser, and making a transmission-based FO-LPR probe for chemical sensing. The sensor resolution of the sensor implementing the D-type fiber modified by gold nanoparticles was 4.1 × 10-7 RIU, which is much more sensitive than that of U-type optical fiber (1.8 × 10-3 RIU.

  5. Beta testing of MTI seal codes

    Science.gov (United States)

    Scharrer, Joseph

    1994-01-01

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

  6. Seal Technology in Gas Turbine Engines

    Science.gov (United States)

    1978-08-01

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

  7. Earlier pupping in harbour seals, Phoca vitulina

    NARCIS (Netherlands)

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

    2010-01-01

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

  8. 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...

  9. Space Environment Effects on Silicone Seal Materials

    Science.gov (United States)

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

    2010-01-01

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

  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. Field Test and Evaluation of Engineered Biomineralization Technology for Sealing Existing Wells

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, Alfred [Montana State Univ., Bozeman, MT (United States)

    2015-12-21

    This research project addresses one of the goals of the U.S. Department of Energy (DOE) Carbon Storage Program (CSP) aimed at developing Advanced Wellbore Integrity Technologies to Ensure Permanent Geologic Carbon Storage. The technology field-tested in this research project is referred to as microbially induced calcite precipitation (MICP), which utilizes a biologically-based process to precipitate calcium carbonate. If properly controlled MICP can successfully seal fractures, high permeability zones, and compromised wellbore cement in the vicinity of wellbores and in nearby caprock, thereby improving the storage security of geologically-stored carbon dioxide. This report describes an MICP sealing field test performed on a 24.4 cm (9.625 inch) diameter well located on the Gorgas Steam Generation facility near Jasper, Alabama. The research was aimed at (1) developing methods for delivering MICP promoting fluids downhole using conventional oil field technologies and (2) assessing the ability of MICP to seal cement and formation fractures in the near wellbore region in a sandstone formation. Both objectives were accomplished successfully during a field test performed during the period April 1-11, 2014. The test resulted in complete biomineralization sealing of a horizontal fracture located 340.7 m (1118 feet) below ground surface. A total of 24 calcium injections and six microbial inoculation injections were required over a three day period in order to achieve complete sealing. The fractured region was considered completely sealed when it was no longer possible to inject fluids into the formation without exceeding the initial formation fracture pressure. The test was accomplished using conventional oil field technology including an 11.4 L (3.0 gallon) wireline dump bailer for injecting the biomineralization materials downhole. Metrics indicating successful MICP sealing included reduced injectivity during seal formation, reduction in pressure falloff, and

  12. Direct numerical simulation of Taylor-Couette flow with grooved walls: torque scaling and flow structure

    CERN Document Server

    Zhu, Xiaojue; Verzicco, Roberto; Lohse, Detlef

    2015-01-01

    We present direct numerical simulations of Taylor-Couette flow with grooved walls at a fixed radius ratio $\\eta=r_i/r_o=0.714$ with inner cylinder Reynolds number up to $Re_i=3.76\\times10^4$, corresponding to Taylor number up to $Ta=2.15\\times10^9$. The grooves are axisymmetric V-shaped obstacles attached to the wall with a tip angle of $90^\\circ$. Results are compared with the smooth wall case in order to investigate the effects of grooves on Taylor-Couette flow. We focus on the effective scaling laws for the torque, flow structures, and boundary layers. It is found that, when the groove height is smaller than the boundary layer thickness, the torque is the same as that of the smooth wall cases. With increasing $Ta$, the boundary layer thickness becomes smaller than the groove height. Plumes are ejected from tips of the grooves and a secondary circulation between the latter is formed. This is associated to a sharp increase of the torque and thus the effective scaling law for the torque vs. $Ta$ becomes much ...

  13. NMR studies of DNA oligomers and their interactions with minor groove binding ligands

    Energy Technology Data Exchange (ETDEWEB)

    Fagan, Patricia A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1996-05-01

    The cationic peptide ligands distamycin and netropsin bind noncovalently to the minor groove of DNA. The binding site, orientation, stoichiometry, and qualitative affinity of distamycin binding to several short DNA oligomers were investigated by NMR spectroscopy. The oligomers studied contain A,T-rich or I,C-rich binding sites, where I = 2-desaminodeoxyguanosine. I•C base pairs are functional analogs of A•T base pairs in the minor groove. The different behaviors exhibited by distamycin and netropsin binding to various DNA sequences suggested that these ligands are sensitive probes of DNA structure. For sites of five or more base pairs, distamycin can form 1:1 or 2:1 ligand:DNA complexes. Cooperativity in distamycin binding is low in sites such as AAAAA which has narrow minor grooves, and is higher in sites with wider minor grooves such as ATATAT. The distamycin binding and base pair opening lifetimes of I,C-containing DNA oligomers suggest that the I,C minor groove is structurally different from the A,T minor groove. Molecules which direct chemistry to a specific DNA sequence could be used as antiviral compounds, diagnostic probes, or molecular biology tools. The author studied two ligands in which reactive groups were tethered to a distamycin to increase the sequence specificity of the reactive agent.

  14. Structure of a pheromone receptor-associated MHC molecule with an open and empty groove.

    Directory of Open Access Journals (Sweden)

    2005-08-01

    Full Text Available Neurons in the murine vomeronasal organ (VNO express a family of class Ib major histocompatibility complex (MHC proteins (M10s that interact with the V2R class of VNO receptors. This interaction may play a direct role in the detection of pheromonal cues that initiate reproductive and territorial behaviors. The crystal structure of M10.5, an M10 family member, is similar to that of classical MHC molecules. However, the M10.5 counterpart of the MHC peptide-binding groove is open and unoccupied, revealing the first structure of an empty class I MHC molecule. Similar to empty MHC molecules, but unlike peptide-filled MHC proteins and non-peptide-binding MHC homologs, M10.5 is thermally unstable, suggesting that its groove is normally occupied. However, M10.5 does not bind endogenous peptides when expressed in mammalian cells or when offered a mixture of class I-binding peptides. The F pocket side of the M10.5 groove is open, suggesting that ligands larger than 8-10-mer class I-binding peptides could fit by extending out of the groove. Moreover, variable residues point up from the groove helices, rather than toward the groove as in classical MHC structures. These data suggest that M10s are unlikely to provide specific recognition of class I MHC-binding peptides, but are consistent with binding to other ligands, including proteins such as the V2Rs.

  15. Structure of a Pheromone Receptor-Associated Mhc Molecule With An Open And Empty Groove

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R.; Huey-Tubman, K.E.; Dulac, C.; Bjorkman, P.J.; /Caltech /Harvard U.

    2006-10-06

    Neurons in the murine vomeronasal organ (VNO) express a family of class Ib major histocompatibility complex (MHC) proteins (M10s) that interact with the V2R class of VNO receptors. This interaction may play a direct role in the detection of pheromonal cues that initiate reproductive and territorial behaviors. The crystal structure of M10.5, an M10 family member, is similar to that of classical MHC molecules. However, the M10.5 counterpart of the MHC peptide-binding groove is open and unoccupied, revealing the first structure of an empty class I MHC molecule. Similar to empty MHC molecules, but unlike peptide-filled MHC proteins and non-peptide-binding MHC homologs, M10.5 is thermally unstable, suggesting that its groove is normally occupied. However, M10.5 does not bind endogenous peptides when expressed in mammalian cells or when offered a mixture of class I-binding peptides. The F pocket side of the M10.5 groove is open, suggesting that ligands larger than 8-10-mer class I-binding peptides could fit by extending out of the groove. Moreover, variable residues point up from the groove helices, rather than toward the groove as in classical MHC structures. These data suggest that M10s are unlikely to provide specific recognition of class I MHC-binding peptides, but are consistent with binding to other ligands, including proteins such as the V2Rs.

  16. Grooved surface topography alters matrix-metalloproteinase production by human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Brydone, Alistair S; Dominic Meek, R M [Department of Orthopaedics, Southern General Hospital, 1345 Govan Road, Glasgow G51 4TF (United Kingdom); Dalby, Matthew J; Berry, Catherine C; McNamara, Laura E, E-mail: alibrydone@gmail.com [Centre for Cell Engineering, Joseph Black Building, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2011-06-15

    Extracellular matrix (ECM) remodelling is an essential physiological process in which matrix-metalloproteinases (MMPs) have a key role. Manipulating the manner in which cells produce MMPs and ECMs may enable the creation of a desired tissue type, i.e. effect repair, or the prevention of tissue invasion (e.g. metastasis). The aim of this project was to determine if culturing fibroblasts on grooved topography altered collagen deposition or MMP production. Human fibroblasts were seeded on planar or grooved polycaprolactone substrates (grooves were 12.5 {mu}m wide with varying depths of 240 nm, 540 nm or 2300 nm). Cell behaviour and collagen production were studied using fluorescence microscopy and the spent culture medium was assessed using gel zymography to detect MMPs. Total collagen deposition was high on the 240 nm deep grooves, but decreased as the groove depth increased, i.e. as cell contact guidance decreased. There was an increase in gelatinase on the 2300 nm deep grooved topography and there was a difference in the temporal expression of MMP-3 observed on the planar surface compared to the 540 nm and 2300 nm topographies. These results show that topography can alter collagen and MMP production. A fuller understanding of these processes may permit the design of surfaces tailored to tissue regeneration e.g. tendon repair.

  17. Large Eddy Simulation of the Subcritical Flow over a U-Grooved Circular Cylinder

    Directory of Open Access Journals (Sweden)

    A. Alonzo-García

    2014-07-01

    Full Text Available With the aim of numerically replicating a drag reduction phenomenon induced by grooves presence, this paper presents a comparative large eddy simulation study of the flow over a smooth circular cylinder, and the flow over a U-grooved cylinder, at Re = 140,000, which is near transition between the subcritical and critical flow regimes. The grid densities were 2.6 million cells and 20.7 million cells for the smooth and the U-grooved cylinder, respectively. Both meshes were composed of hexahedral cells disposed in a structured form with additional refinements in near-wall regions, in order to obtain y+< 5 values. The cases were simulated during 25 vortex shedding cycles with the purpose of obtaining significant statistic data through the commercial software FLUENT V.12.1, which solved the Navier-Stokes equations in their unsteady and incompressible forms. Regarding the U-grooved cylinder flow, parameters such as the drag coefficient, lengths of recirculation, the transition from subcritical to critical flow, and the formation of a wake formed by secondary vortices of smaller sizes were predicted satisfactorily by the LES technique. From the manner in which the flow separates at different angles for both valleys and peaks of the U-grooves, a distinctive transitional mechanism induced by grooves presence is conjectured.

  18. Temperature Approach Optimization in the Double Pipe Heat Exchanger with Groove

    Directory of Open Access Journals (Sweden)

    Sunu Putu Wijaya

    2016-01-01

    Full Text Available Heat transfer in double pipe heat exchanger with circumference-rectangular grooves has been investigated experimentally. The volume flowrate of cold and hot water were varied to determine its influence on the approach temperature of the outlet terminals. In this experimental design, the grooves were incised in annular room that is placed on the outside surface of the inner pipe. The shell diameter is 38.1 mm and tube diameter 19.4 mm with 1 m length, which is made of aluminum. The flow pattern of the two fluids in the heat exchanger is a parallel flow. The working fluid is water with volume flow rate of 27.1, 23.8 and 19.8 l/minute. The temperature of water on the inlet terminals are 50±1°C for hot stream and 30±1°C for cold stream. Temperature measurements conducted on each terminal of the inlet and outlet heat exchanger. The results showed that the grooves induced the approach temperature. The change of the approach temperature from the grooves compared to that of without grooves decreased by 37.9%. This phenomenon indicates an increase in heat transfer process and performance of the heat exchanger. Groove improves the heat surface area of the inner pipe, increasing the momentum transfer and in the other hand, reducing the weight of heat exchangers itself.

  19. Relationship Between Measured Friction Coefficients and Two Tread Groove Design Parameters for Footwear Pads

    Institute of Scientific and Technical Information of China (English)

    LI Kai Way; CHEN Chin Jung; LIN Ching-Hua; HSU Yao Wen

    2006-01-01

    The shoe sole geometrical design parameters are believed to be important factors affecting the coefficient of friction (COF) between the shoe/floor interface. This study is concerned with the relationship between the measured COF and the tread groove orientation and width on the footwear pad. Friction measurements using the Brungraber Mark Ⅱ slipmeter were conducted. Six tread groove width/orientations designs on the footwear pads under 27 footwear material/floor/contamination conditions were tested. The results show that tread orientation and width affect the measured COF significantly. Wider grooved footwear pads result in higher COF values and footwear pads with tread grooves perpendicular to the friction measurement direction have higher COF values. A regression model using measured COF as the dependent variable and tread groove width, groove orientation, footwear material, floor, and contamination conditions as independent variables was established. The models are significant at p<0.0001 with R2 of 0.97, which may be used in predicting the COF at the shoe-floor interface.

  20. Numerical modeling and verification of gas flow through a network of crossed narrow v-grooves

    Science.gov (United States)

    Bejhed, Johan; Nguyen, Hugo; Åstrand, Peter; Eriksson, Anders; Köhler, Johan

    2006-10-01

    The gas flow through a network of crossing thin micro-machined channels has been successfully modeled and simulated. The crossings are formed by two sets of v-grooves that intersect as two silicon wafers are bonded together. The gas is distributed from inlets via a manifold of channels to the narrow v-grooves. The narrow v-grooves could work as a particle filter. The fluidic model is derived from the Navier-Stokes equation and assumes laminar isothermal flow and incorporates small Knudsen number corrections and Poiseuille number calculations. The simulations use the finite element method. Several elements of the full crossing network model are treated separately before lumping them together: the straight v-grooves, a single crossing in an infinite set and a set of exactly four crossings along the flow path. The introduction of a crossing effectively corresponds to a virtual reduction of the length of the flow path, thereby defining a new effective length. The first and last crossings of each flow path together contribute to a pressure drop equal to that from three ordinary crossings. The derived full network model has been compared to previous experimental results on several differently shaped crossed v-groove networks. Within the experimental errors, the model corresponds to the mass flow and pressure drop measurements. The main error source is the uncertainty in v-groove width which has a profound impact on the fluidic behavior.

  1. Effect of DNA groove binder distamycin A upon chromatin structure.

    Directory of Open Access Journals (Sweden)

    Parijat Majumder

    Full Text Available BACKGROUND: Distamycin A is a prototype minor groove binder, which binds to B-form DNA, preferentially at A/T rich sites. Extensive work in the past few decades has characterized the binding at the level of double stranded DNA. However, effect of the same on physiological DNA, i.e. DNA complexed in chromatin, has not been well studied. Here we elucidate from a structural perspective, the interaction of distamycin with soluble chromatin, isolated from Sprague-Dawley rat. METHODOLOGY/PRINCIPAL FINDINGS: Chromatin is a hierarchical assemblage of DNA and protein. Therefore, in order to characterize the interaction of the same with distamycin, we have classified the system into various levels, according to the requirements of the method adopted, and the information to be obtained. Isothermal titration calorimetry has been employed to characterize the binding at the levels of chromatin, chromatosome and chromosomal DNA. Thermodynamic parameters obtained thereof, identify enthalpy as the driving force for the association, with comparable binding affinity and free energy for chromatin and chromosomal DNA. Reaction enthalpies at different temperatures were utilized to evaluate the change in specific heat capacity (ΔCp, which, in turn, indicated a possible binding associated structural change. Ligand induced structural alterations have been monitored by two complementary methods--dynamic light scattering, and transmission electron microscopy. They indicate compaction of chromatin. Using transmission electron microscopy, we have visualized the effect of distamycin upon chromatin architecture at di- and trinucleosome levels. Our results elucidate the simultaneous involvement of linker bending and internucleosomal angle contraction in compaction process induced by distamycin. CONCLUSIONS/SIGNIFICANCE: We summarize here, for the first time, the thermodynamic parameters for the interaction of distamycin with soluble chromatin, and elucidate its effect on

  2. Clinical, radiological, surgical, and pathological determinants of olfactory groove schwannoma

    Directory of Open Access Journals (Sweden)

    Andi Sadayandi Ramesh

    2014-01-01

    Full Text Available Background: Olfactory groove schwannomas (OGS are rare anterior cranial fossa base tumors with only 41 cases reported in literature. Olfactory ensheathing cell schwannoma (OECS has similar clinico-radiological features as OGS, but a different cell of origin. In recent years, there is growing interest in OECS as more cases are being reported. Aims: The objective was to study the clinico-radiological features of OGS and define the histological differentiation from OECS. Materials and Methods: We retrospectively analyzed clinical, radiological, surgical and histopathological picture of all cases of OGS managed in our institute. Immuno histochemical studies were performed in these tumors for differentiating from OECS. A comprehensive review of articles published until date describing the operative treatment was done. Results: All three cases had presented with seizures, two had anosmia and papilledema. Gross-total resection was achieved in all our patients. One patient expired in the postoperative period due to septicemia. Positive expression to newer immuno histochemical biomarker CD57 (Leu7, with negative staining to smooth muscle α-actin (SMA was helpful in confirming the diagnosis of OGS and differentiating it from OECS in all our cases. Conclusions: OECS, though rare has to be differentiated from OGS using immuno histochemistry. Gross-total resection of OGS with preservation of olfactory function is often possible and curative. Although these tumors are commonly treated with microsurgical skull base approaches, an endoscopic endonasal approach can be considered in some cases, with repair using mucoperiosteal pedicled flap to prevent cerebrospinal fluid leak.

  3. Experimental study of partially flattened axial grooved heat pipes

    Institute of Scientific and Technical Information of China (English)

    TAO HanZhong; ZHANG Hong; ZHUANG Jun; Jerry W. BOWMANS

    2008-01-01

    This article made experimental study on mini-axial grooved heat pipes (AGHP) with 11 flattening forms. It analyzed how the flattening form, flattening thickness and working temperature affect axial tem-perature distribution, thermal resistance, heat transfer limit and the phase-change heat transfer coeffi-cients in evaporator and condenser sections. The result indicates that all forms of AGHPs can maintain good isothermal performance under normal operating condition. The geometric shape of AGHP has obvious impact on heat transfer limit. With respect to an AGHP with 2 mm-thick evaporator section, when the thickness of its condenser section increases from 2 to 3 mm, its heat transfer limit increases by 81%; with respect to an AGHP with 3 mm-thick evaporator section, when the thickness of its con-denser section increases from 2 to 3 mm, its heat transfer limit increases by 134%; with respect to an AGHP with 4 mm-thick condenser section, when the thickness of its evaporator section increases from 2 to 3 mm, its heat transfer limit increases by 26%. When the thickness of the evaporator section in-creases by 1 mm, the heat transfer limit will increase by 9%-26%, while when the thickness of the condenser section increases by 1 mm, the heat transfer limit will increase by 20%-86%. The thickness of the condenser section has greater impact on heat transfer performance of an AGHP than the thick-ness of the evaporator section does. The study content of this article will help understand the heat transfer performance of AGHP, and electronic thermal design process.

  4. 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.

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

    Science.gov (United States)

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

    2015-03-01

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

  6. [Methods for sealing of corneal perforations].

    Science.gov (United States)

    Samoilă, O; Totu, Lăcrămioara; Călugăru, M

    2012-01-01

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

  7. Film riding seal assembly for turbomachinery

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-07

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

  8. 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.

  9. Radiation Safety of Sealed Radioactive Sources

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, Kathryn H.

    2015-01-01

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

  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. Self-cleaning effect of sealing caps for infrared hollow fiber delivering pulsed Er:YAG laser light

    Science.gov (United States)

    Shi, Yi Wei; Iwai, Katsumasa; Matsuura, Yuji; Miyagi, Mitsunobu; Jelinkova, Helena

    2006-03-01

    A sealing cap had been proposed as an output device for hollow optical fibers in delivering laser light underwater. Properties of sealing cap were experimentally discussed when used in ablation on soft tissue for Er:YAG laser. A self-cleaning effect of the sealing cap was observed when various targets were used for different laser light power. Debris from pork fat formed a uniform oil layer on the output surface of the cap, and the oil layer is relatively transparent in Er:YAG laser light wavelength band. When the target was pork muscle, almost no debris could attach on the surface of the cap. The self-cleaning effect was more obvious when ablation was conducted underwater because of the protection of the water film between the target and the cap's surface.

  12. An atomistic model for cross-linked HNBR elastomers used in seals

    Science.gov (United States)

    Molinari, Nicola; Sutton, Adrian; Stevens, John; Mostofi, Arash

    2015-03-01

    Hydrogenated nitrile butadiene rubber (HNBR) is one of the most common elastomeric materials used for seals in the oil and gas industry. These seals sometimes suffer ``explosive decompression,'' a costly problem in which gases permeate a seal at the elevated temperatures and pressures pertaining in oil and gas wells, leading to rupture when the seal is brought back to the surface. The experimental evidence that HNBR and its unsaturated parent NBR have markedly different swelling properties suggests that cross-linking may occur during hydrogenation of NBR to produce HNBR. We have developed a code compatible with the LAMMPS molecular dynamics package to generate fully atomistic HNBR configurations by hydrogenating initial NBR structures. This can be done with any desired degree of cross-linking. The code uses a model of atomic interactions based on the OPLS-AA force-field. We present calculations of the dependence of a number of bulk properties on the degree of cross-linking. Using our atomistic representations of HNBR and NBR, we hope to develop a better molecular understanding of the mechanisms that result in explosive decompression.

  13. Durability test device for MR fluids with permanent magnet and V-shaped groove

    Science.gov (United States)

    Abe, Isao; Kikuchi, Takehito; Noma, Junichi

    2017-05-01

    Magnetorheological fluids (MRFs) are functional fluids whose viscosity changes when magnetic fields are applied. Therefore, these fluids are used in force and torque controllable devices. However, particle sedimentation is one of the drawbacks of conventional MRFs. To solve this problem, Kurimoto Co. Ltd developed a new fluid with sub-micron order Fe particles and a silicone-based solvent known as NanoMRF. The particle distributions of this material are stable over several months. However, its durability has not yet been fully discussed. Therefore, we developed new equipment to test endurance and examined the durability of the magnetorheological effect of the NanoMRF as well as a commercially available MRF. Our results show that the durability of the fluids was affected by the stability of the solvent. In particular, the durability is drastically improved when the solvent is supplemented by the peripheral sealing oil. The oxidation of particles is remarkably varied by the kind of solvent as well as the stability of the oxidation film on the surface of the particles. The energy of the collapse and reproduction of the particles was used not only to generate friction among the particles but also to decompose the solvent molecules.

  14. 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.

  15. Effects of Collector Temperature on the Performance of Grooved Electrode Thermionic Converters

    Science.gov (United States)

    Momozaki, Yoichi; El-Genk, Mohamed S.

    2003-01-01

    Experiments are conducted to compare the performance of the smooth electrodes, grooved emitter, and grooved collector converters at the same emitter and collector temperatures. The focus of the experiments is to investigate the effects of collector temperature on the performance of grooved electrode converters. The converters with various electrode configurations and a 0.5 mm gap are tested at emitter temperatures, TE = 1473 - 1673 K, collector temperatures, TC = 773 - 1023 K, and cesium pressures, PCs = 10 - 500 Pa. All electrodes are planar and fabricated with polycrystalline Molybdenum. The grooved electrodes have concentric macro-grooves 0.5 mm wide, 0.5 mm deep, and 1.0 mm apart. The output electrical power density and the conversion efficiency are calculated from the measured I-V curves and the maximum power density and conversion efficiency are determined from the calculated PD-V and ɛ-V envelopes. At TE = 1473 K, the electrical power density for the smooth electrodes converter at the optimum collector temperature (873 K) is 2.25 W/cm2 at ɛ = 13.8 %, decreasing to 1.46 W/cm2 at ɛ = 12.4 % as TC increases by only 75 K to 948 K. However, the corresponding decrease in the electrical power density for the grooved collector converter is only 0.04 W/cm2 (from 1.24 W/cm2 at ɛ = 11.4 % and TC = 873 K to 1.20 W/cm2 at ɛ =10.7 % and TC = 948 K) and that for the grooved emitter converter is 0.12 W/cm2 (from 0.82 W/cm2 at ɛ = 8.1 % and TC = 873 K to 0.70 W/cm2 at ɛ = 6.8 % and TC = 948 K). At the higher emitter temperatures of 1573 K and 1673 K, similar results are obtained. In all experimental conditions, however, the grooved emitter converter shows the lowest power density and conversion efficiency, followed by the grooved collector converter, and the smooth electrodes converter, except for TF = 1673 K and TC = 1023 K at which the converter with a grooved collector operates at the highest power density (2.38 W/cm2) and conversion efficiency (14.0 %).

  16. Essential oils as fumigants for bed bugs (Hemiptera: Cimicidae)

    Science.gov (United States)

    In Petri dish assays, fumigation of a pyrethroid-susceptible strain of bed bugs Cimex lectularius L. (Hemiptera: Cimicidae) with various essential oils resulted in mortality that approached or equaled 100%, after 5 days. However, when bed bugs were exposed to the same essential oils in sealed, comme...

  17. 表面粗糙度对矩形动密封特性的影响∗%Effect of Surface Roughness on Dynamic Sealing Performance of Rectangular Elastomeric Seals

    Institute of Scientific and Technical Information of China (English)

    张付英; 赵龙; 李佳波

    2015-01-01

    Based on the numerical calculation flow of sealing property coupling of the elastic deformation, hydrodynam⁃ics and interference contact, the dynamic seal performances calculation of rectangular elastomeric seal was realized by u⁃sing Matlab software to program, and the parameters of oil film thickness, leakage and friction were got� The influence of surface roughness on the lubrication state and leakage was analyzed�The calculation results show that when the reciproca⁃ting velocity is constant, the lubrication state between sealing part and shift surface is changed from fluid lubrication into mixed lubrication with the increase of sealing ring roughness, and the leakage of sealing is also increased in a geometric, indicating that the roughness of seals has important influence on the serve life and sealing performance of the sealing ring�Reciprocating motion speed is also one of the key parameters that affect seal performance of rectangular sealing ring, when sealing pressure is certain, the critical speed for no leakage is reduced with the increase of sealing roughness.%基于耦合了密封圈的弹性变形、流体动力分析和过盈接触的密封性能数值计算流程,利用Matlab 软件编程实现矩形动密封特性的数值计算,得到矩形密封圈的油膜厚度、泄漏量及摩擦力等密封性能参数,分析表面粗糙度对矩形密封圈的润滑状态和泄漏量的影响。结果表明:往复运动速度一定时,随着密封圈粗糙度的增加,密封偶合面的润滑状态由流体润滑转变为润滑润滑状态,密封的泄漏量也呈几何式增加,说明粗糙度对密封圈的工作寿命和密封性能有较大的影响;往复运动速度也是影响矩形密封圈密封性能的关键工作参数之一,密封压力一定时,随着粗糙度的增加,不发生泄漏的临界速度降低。

  18. 气相色谱法测定肠外营养用海豹油脂肪乳中主要脂肪酸的含量%Content determination of main fatty acid in Seal Oil Based Lipid Emulsion for parenteral nutrition by GC

    Institute of Scientific and Technical Information of China (English)

    苏健芬; 江桂生; 郭喆霏; 卓世添; 董怡萱; 吴传斌

    2011-01-01

    目的:建立气相色谱法测定肠外营养用海豹油脂肪乳(20%)中各主要脂肪酸(fatty acid,FA),包括肉豆蔻酸、棕榈酸、棕榈油酸、油酸、花生酸、二十碳五烯酸(eicosapentaenoic acid,EPA)、二十二碳五烯酸(docosapentaenoic acid,DPA)、二十二碳六烯酸(docosahexaenoic acid,DHA)含量的方法.方法:比较三种甲酯衍生化方法的优劣,包括三氟化硼酯化法、甲醇一氢氧化钾室温酯化法和甲醇-氢氧化钠加热回流酯化法.气相色谱柱为HP-InnoWaX柱(30 mx0.320mm,0.25 μm),采用FID检测器,标准曲线法定量.进样量1μl,分流比1:10.进样口温度220℃,检测器温度280℃,采用程序升温,起始温度155℃,保持1 min,以25℃/min升到205℃,再以1℃/min升到235℃,最后以3℃/min升至250℃,保持5 min.流速2.0ml/min.结果:从酯化操作过程和酯化效果来看,室温酯化法的效果较优.八种主要脂肪酸中,油酸含量最高(7.2%)、EPA含量最低(0.9%),其他6种脂肪酸含量介乎1.3%~5.8%之间.线性范围在0.009 973~10.322 mg/ml之间,平均回收率为98.4%~101.2%,RSD均小于2.0%(n=3).结论:本法方便、准确、重现性好,可作为本制剂的质量控制方法.%Objective: To establish a GC method for determining the content of main fatty acid (FA) in seal oil based lipid emulsion (20%) for parenteral nutrition, including myristic acid, palmitic acid, palmitoleic acid, oleic acid, arachic acid, EPA, DPA, DHA. Methods: Find out the best method among three esterification methods, comprising boron trifluoride esterification, methanol -potassium hydroxide esterification under room temperature and methanol- sodium hydroxide under heated condition. HP-InnoWax column (30 m×0.320 mm, 0.25 μm) and FID were used, calibration curve method was employed to quantify. The injector and detector temperature were 220℃ and 280℃ respectively. The initial temperature was kept at 155℃ for 1 min, then raised to 205℃ at the rate of 25

  19. Instantaneous slip length in superhydrophobic microchannels having grooves with curved or dissimilar walls

    Science.gov (United States)

    Hemeda, A. A.; Vahedi Tafreshi, H.

    2015-10-01

    Superhydrophobic (SHP) surfaces can be used to reduce the skin-friction drag in a microchannel. This is due to the peculiar ability of these surfaces to entrap air in their pores and thereby reduce the contact area between water and the solid surface. The favorable drag-reduction effect, however, can quickly deteriorate if the surface geometry is not designed properly. The deterioration can be sudden, caused by exposure to excessive pressures, or gradual, due to the dissolution of the entrapped air into the ambient water. The formulations presented here provide a means for studying the time-dependent drag-reduction in a microchannel enhanced with transverse or longitudinal SHP grooves of varying wall profiles or wettabilities. Moreover, different mathematical approaches are developed to distinguish the performance of a sharp-edged groove from that of a groove with round entrance. The work starts by deriving an equation for the balance of forces on the air-water interface (AWI) inside a groove and solving this differential equation, along with Henry's law, for the rate of dissolution of the entrapped air into water over time. It was shown that the performance of a SHP groove depends mostly on the interplay between the effects of the apparent contact angle of the AWI and the initial volume of the groove. The instantaneous slip length is then calculated by solving the Navier-Stokes equations for flow in microchannels with SHP grooves. Our results are compared with the studies in the literature whenever available, and good agreement has been observed.

  20. 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.

  1. 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.

  2. Compliant Glass Seals for SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-01

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

  3. 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.

  4. Vacuum-sealed casting process under pressure

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  5. 摩擦片表面沟槽对离合器带排转矩的影响%Influences of surface grooves on friction plate on drag torque of wet clutch

    Institute of Scientific and Technical Information of China (English)

    刘继凯; 马彪; 李和言

    2015-01-01

    According to mass flow balance on disengaged wet clutches ,the flow equation an d oil film equivalent shrinking radius of radial grooved and flat friction plate were deduced .Based on experimen‐tal data of drag torque ,the flow calculation and drag torque model of double arc grooved friction plate were obtained ,considering the flow correction factor .Results show that when relative sliding velocity on average radius is less than 8 .83 m/s ,drag torque of double arc grooved friction plate is close to that of radial grooved friction plate ,w hen relative sliding velocity is more than 9 .39m/s ,drag torque of double arc grooved friction plate can be estimated with flat friction plate .Also ,increasing groove width or groove depth can decrease drag torque effectively .%根据湿式离合器分离状态下油液质量流量守恒关系,推导了全油膜状态下径向槽摩擦片和平直摩擦片润滑油流量方程和油膜等效收缩半径方程.基于摩擦片带排转矩的实验数据,引入流量修正系数,建立了双圆弧槽摩擦片润滑油流量表达式和带排转矩模型.仿真实验结果表明:当摩擦界面平均半径处的相对摩滑线速度小于8.83 m/s时,双圆弧槽型摩擦片的带排转矩特性接近于径向槽摩擦片;当相对摩滑线速度大于9.39 m/s时,双圆弧槽摩擦片的带排转矩特性可以用平直摩擦片评估,且增大槽宽或槽深,均可以有效降低带排转矩.

  6. Analysis of thermal expansion effects on leakage in self-sealed journal bearings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper, based on a simplified model, researched the problem of liquid lubricantleakage caused by thermal expansion effects in a self-sealed journal bearing, The analysis indi-cated that mismatch between thermal expansion coefficient of oil-holding-space in bearing, σT, andthat of liquid lubricant, αoi, is a subtle factor inducing leakage when bearing temperature varies.Measures like properly selecting liquid lubricant and carefully designing bearing structure could betaken to reduce the leakage by matching αT and αoil, Several such ideas concerning bearing mate-rial choosing and structure designing were presented.

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

    Directory of Open Access Journals (Sweden)

    2007-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-15

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

  9. Grooved Terrain on Ganymede: First Results from Galileo High-Resolution Imaging

    Science.gov (United States)

    Pappalardo, R.T.; Head, J.W.; Collins, G.C.; Kirk, R.L.; Neukum, G.; Oberst, J.; Giese, B.; Greeley, R.; Chapman, C.R.; Helfenstein, P.; Moore, Johnnie N.; McEwen, A.; Tufts, B.R.; Senske, D.A.; Herbert, Breneman H.; Klaasen, K.

    1998-01-01

    High-resolution Galileo imaging has provided important insight into the origin and evolution of grooved terrain on Ganymede. The Uruk Sulcus target site was the first imaged at high resolution, and considerations of resolution, viewing geometry, low image compression, and complementary stereo imaging make this region extremely informative. Contrast variations in these low-incidence angle images are extreme and give the visual impression of topographic shading. However, photometric analysis shows that the scene must owe its character to albedo variations. A close correlation of albedo variations to topography is demonstrated by limited stereo coverage, allowing extrapolation of the observed brightness and topographic relationships to the rest of the imaged area. Distinct geological units are apparent across the region, and ridges and grooves are ubiquitous within these units. The stratigraphically lowest and most heavily cratered units ("lineated grooved terrain") generally show morphologies indicative of horst-and-graben-style normal faulting. The stratigraphically highest groove lanes ("parallel ridged terrain") exhibit ridges of roughly triangular cross section, suggesting that tilt-block-style normal faulting has shaped them. These extensional-tectonic models are supported by crosscutting relationships at the margins of groove lanes. Thus, a change in tectonic style with time is suggested in the Uruk Sulcus region, varying from horst and graben faulting for the oldest grooved terrain units to tilt block normal faulting for the latest units. The morphologies and geometries of some stratigraphically high units indicate that a strike-slip component of deformation has played an important role in shaping this region of grooved terrain. The most recent tectonic episode is interpreted as right-lateral transtension, with its tectonic pattern of two contemporaneous structural orientations superimposed on older units of grooved terrain. There is little direct evidence for

  10. The colonic groove or furrow: a comparative morphological study of six species of African mole-rats (Rodentia, Bathyergidae).

    Science.gov (United States)

    Kotzé, S H; van der Merwe, E L; Ndou, R; O'Riain, M J; Bennett, N C

    2009-08-01

    Herbivorous mammals such as nutrias, guinea pigs, chinchillas, and mole-rats have a longitudinal mucosal colonic groove (furrow) in their ascending colon, which is thought to play a role in the colonic separation mechanism (CSM). It is not known whether this groove is structurally modified to adapt to this function in mole-rat species. The morphology of this groove was studied in 32 mol-rats, four species, one of which consisted of three subspecies, endemic to southern Africa and two species found in eastern Africa. The macroscopic morphology of the groove was documented, and samples for histological examination were taken. The groove was wide at its origin at the cecocolic junction and was lined on either side by a row of papillae with the opposing papillae slightly offset in arrangement. The papillated groove gradually decreased in size toward the distal part of the ascending colon where it disappeared. This pattern was similar in all species except in Heterocephalus glaber, where the papillae were absent and the groove was lined by two longitudinal ridges. A histological examination of cross sections revealed that the mucosa covering the inner and outer walls of the groove was rich in mucous-secreting goblet cells. The walls of the groove contained smooth muscle extending from the inner circular smooth muscle layer at the base to the tips of the papillae in all species examined as well as arteries, lymphatic vessels, and prominent sinusoid-like veins. The groove could be demonstrated both macroscopically and histologically in three Bathyergus suillus fetuses of varying sizes. The sinusoid-like veins present in all grooves, regardless of macroscopic shape, suggest that they have a role in the functioning of the groove. (c) 2009 Wiley-Liss, Inc.

  11. What musicians do to induce the sensation of groove in simple and complex melodies, and how listeners perceive it

    Directory of Open Access Journals (Sweden)

    Guy eMadison

    2014-08-01

    Full Text Available Groove is the experience of wanting to move when hearing music, such as snapping fingers or tapping feet. This is a central aspect of much music, in particular of music intended for dancing. While previous research has found considerable consistency in ratings of groove across individuals, it remains unclear how groove is induced, that is, what are the physical properties of the acoustic signal that differ between more and less groove-inducing versions. Here, we examined this issue with a performance experiment, in which 4 musicians performed 6 simple and 6 complex melodies in two conditions with the intention of minimizing and maximizing groove. Analyses of rhythmical and temporal properties from the performances demonstrated some general effects. For example, more groove was associated with more notes on faster metrical levels and syncopation, and less groove was associated with deadpan timing and destruction of the regular pulse. We did not observe that deviations from the metrical grid (i.e. micro-timing were a predictor of groove. A listener experiment confirmed that the musicians’ manipulations had the intended effects on the experience of groove. A Brunswikian lens model was applied, which estimates the performer-perceiver communication across the two experiments. It showed that the communication achievement for simple melodies was 0.62, and that the matching of performers’ and listeners’ use of 9 rhythmical cues was 0.83. For complex melodies with an already high level of groove, the corresponding values were 0.39 and 0.34, showing that it was much more difficult to take out groove from musical structures designed to induce groove.

  12. STUDY ON RECTANGULAR WAVEGUIDE GRATING SLOW-WAVE STRUCTURE WITH COSINE-SHAPED GROOVES

    Institute of Scientific and Technical Information of China (English)

    Lu Zhigang; Wei Yanyu; Gong Yubin; Wu Zhoumiao; Wang Wenxiang

    2007-01-01

    This paper focuses on a new rectangular waveguide grating Slow-Wave Structure(SWS)with cosine-shaped grooves and studies the propagation characteristics of the wave in the SWS.By using the approximate field-matching conditions,the dispersion equation and the coupling impedance of this circuit are obtained.The dispersion curves and coupling impedances of the fundamental wave are calculated and the influences of the various geometrical dimensions are discussed.The results show that the bandwidth of the cosine-shaped groove SWS is much wider than that of rectangular-shaped groove one.And reducing the groove width can broaden the frequency-band and decrease the phase-velocity,while increment of the groove-depth can also decrease phase-velocity.For above cases,the coupling impedance is more than 16Ω.The present analysis will be helpful on further study and design of the RF systems used in millimeter wave Traveling Wave Tube(TWT).

  13. Measuring phacoemulsification groove depth using probe tip dimensions and biometry lens thickness readings

    Directory of Open Access Journals (Sweden)

    Dunne K

    2016-08-01

    Full Text Available Kevin Dunne, Alex J Buller Department of Ophthalmology, Hawkes Bay District Health Board, Hastings, New Zealand Aim: To describe a useful technique utilizing lens thickness from biometric data as well as phacoemulsification (phaco probe tip dimensions, in order to more accurately determine safe groove depth during divide and conquer techniques for cataract surgery. Methods: Single center, selection of patients for cataract surgery deemed low risk and suitable for surgical teaching cases. Individual lens thickness measurements from biometry were calculated with known phaco tip dimensions to give an individualized safe number of phaco tip depths for grooving during divide and conquer. This technique was then applied during cataract surgery. Results: Utilization of this technique allows calculation and determination of an appropriate number of phaco tip depths of grooving for each individual patient. This technique was applied as a teaching tool for surgical trainees, with subsequent successful safe cataract surgeries completed. No posterior capsule ruptures were noted for these cases. Conclusion: By combining the biometric measurements of an individual patient’s lens thickness together with known phaco tip dimensions, individualized safe groove depths can be theoretically determined and applied during divide and conquer cataract surgery. Keywords: cataract, divide and conquer, groove depth, lens thickness, probe tip

  14. Wide polytef (Gore-Tex) implants in lip augmentation and nasolabial groove correction.

    Science.gov (United States)

    Conrad, K; MacDonald, M R

    1996-06-01

    To describe a new technique of polytef (Gore-Tex) implantation into the upper and lower lips and nasolabial grooves by using large implants as a method that achieves effective cosmetic improvement. A private cosmetic surgery center. Thirty-three (female) patients who desired fuller lips and 62 patients (52 female and 10 male) who requested less prominent cheek lip grooves. Significant patient satisfaction after 12 to 54 months. Conspicuous aesthetic effect that related to both lip and nasolabial groove correction was documented. All patients but 4 (2 in each group) were pleased with the final outcome of the treatment. In the opinion of the authors, the threading technique of polytef implantation creates inconspicuous improvement-both in lip augmentation and nasolabial groove correction. Large polytef implants that were inserted through a tunneling technique produced consistently good results. Implants (lip augmentation: width, < or = 10 mm, and thickness, 4 mm; nasolabial groove correction: width, 8 mm, and thickness, < or = 8 mm) were found to be safe, simple, and effective.

  15. Multiphysics Modeling of a Single Channel in a Nuclear Thermal Propulsion Grooved Ring Fuel Element

    Science.gov (United States)

    Kim, Tony; Emrich, William J., Jr.; Barkett, Laura A.; Mathias, Adam D.; Cassibry, Jason T.

    2013-01-01

    In the past, fuel rods have been used in nuclear propulsion applications. A new fuel element concept that reduces weight and increases efficiency uses a stack of grooved discs. Each fuel element is a flat disc with a hole on the interior and grooves across the top. Many grooved ring fuel elements for use in nuclear thermal propulsion systems have been modeled, and a single flow channel for each design has been analyzed. For increased efficiency, a fuel element with a higher surface-area-to-volume ratio is ideal. When grooves are shallower, i.e., they have a lower surface area, the results show that the exit temperature is higher. By coupling the physics of turbulence with those of heat transfer, the effects on the cooler gas flowing through the grooves of the thermally excited solid can be predicted. Parametric studies were done to show how a pressure drop across the axial length of the channels will affect the exit temperatures of the gas. Geometric optimization was done to show the behaviors that result from the manipulation of various parameters. Temperature profiles of the solid and gas showed that more structural optimization is needed to produce the desired results. Keywords: Nuclear Thermal Propulsion, Fuel Element, Heat Transfer, Computational Fluid Dynamics, Coupled Physics Computations, Finite Element Analysis

  16. CFD and Experimental Analysis of a Falling Film outside Smooth and Helically Grooved Tubes

    Directory of Open Access Journals (Sweden)

    Cenk Onan

    2014-08-01

    Full Text Available Simultaneous heat and mass transfer are investigated in a falling film outside grooved and smooth tubes. A numerical analysis of the helically trapezoidal-grooved and reference smooth tube was performed in the computational fluid dynamics program “Ansys Fluent 14.” The three-dimensional model drawings in the x, y, and z coordinates are used, and the effects of the falling film outside the helically grooved tube on the surface temperature and surface heat transfer coefficient are determined. The average surface temperature, heat transfer coefficient, and Nu values are determined experimentally for a constant heat flux. An uncertainty analysis and Nu correlation for the grooved tube are also provided in this study. The Reynolds number varied between 50 and 350 for the falling film and between 1500 and 3500 for air. Using a computational fluid dynamics (CFD analysis for the reference smooth tube, the experimental results are validated within 2–12% difference. The experimental results are also within 6–13% of the grooved tubes.

  17. A novel design of spiral groove bearing in a hydrodynamically levitated centrifugal rotary blood pump.

    Science.gov (United States)

    Han, Qing; Zou, Jun; Ruan, Xiaodong; Fu, Xin; Yang, Huayong

    2012-08-01

    Good washout is very important in spiral groove bearing (SGB) designs when applied to blood pumps due to the micrometer scales of lubrication films and groove depths. To improve washout, flow rate or leakage through SGBs should be as large as possible. However, this special goal violates conventional SGB designs in which no leakage is desired as the leakage would decrease load-carrying capacity significantly. So, a design concept is formed fulfilling the two goals of high load-carrying capacity and large flow rate: let groove width decrease along flow path and the mating surface of the rotor rotate with a direction facilitating the flow through the grooves. Under this concept, a novel SGB is designed, contrary to conventional ones, with groove width decreasing with increasing spiral radius. This SGB is mounted on the motionless upper plate of our designed centrifugal blood pump, with the mating surface of rotor rotating with a direction facilitating the outward flow. To assess SGB designs, a characteristic plane is originally presented relating to pressure-normalized load-carrying capacity and flow rate. Comparisons between various kinds of SGB designs are made, and computational fluid dynamics (CFD) results are plotted in this characteristic plane from which load/flow performances can be directly read out. CFD and comparison results show that the new designs have superior load/flow characteristics. However, the impact of SGB designs upon hemolysis/thrombus formation is still to be verified according to the concept presented.

  18. Finite Element Analysis of Elastomeric Seals for LIDS

    Science.gov (United States)

    Oswald, Jay J.; Daniels, Christopher C.

    2007-01-01

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

  19. ' OILS MARKETED IN DAR ES SALAAM

    African Journals Online (AJOL)

    five years suffer from acute and chronic protein and energy deficiencies. At the current ... increasing the diversity of consumable food products in order to alleviate ... have recommended an average daily intake of 55 g-fat per capita to ... The oils in the sealed bottles were similarly analyzed for peroxide value over 60 days. 50 ...

  20. Properties of Sealing Materials in Groundwater Wells

    DEFF Research Database (Denmark)

    Köser, Claus

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

  1. 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)

  2. 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...

  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. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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.

  9. 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...

  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. 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,...

  12. The study of microstructure and mechanical properties of twin-roll cast AZ31 magnesium alloy after constrained groove pressing

    Science.gov (United States)

    Zimina, M.; Bohlen, J.; Letzig, D.; Kurz, G.; Cieslar, M.; Zník, J.

    2014-08-01

    Microstructure investigation and microhardness mapping were done on the material with ultra-fine grained structure prepared by constrained groove pressing of twin-roll cast AZ31 magnesium strips. The microstructure observations showed significant drop of the grain size from 200 gm to 20 gm after constrained groove pressing. Moreover, the heterogeneities in the microhardness along the cross-section observed in the as-cast strip were replaced by the bands of different microhardness in the constrained groove pressed material. It is shown that the constrained groove pressing technique is a good tool for the grain refinement of magnesium alloys.

  13. Reactor coolant pump shaft seal stability during station blackout

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-05-01

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

  14. 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.

  15. Aerodynamical sealing by air curtains

    Science.gov (United States)

    Frank, Daria; Linden, Paul

    2015-11-01

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

  16. Repairing sealing surfaces on aluminum castings

    Science.gov (United States)

    Hanna, T. L.

    1980-01-01

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

  17. Design, construction and testing of underground seals

    CSIR Research Space (South Africa)

    Cook, AP

    2000-01-01

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

  18. The Advantage of Sensor Sealing Laser Welding

    Institute of Scientific and Technical Information of China (English)

    YAN Yezhi; XU yu

    2007-01-01

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

  19. 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.

  20. Some Aspects of Sealed Nickel Cadmium Cells

    Directory of Open Access Journals (Sweden)

    P. K. Saha

    1967-11-01

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

  1. Application study of magnetic fluid seal in hydraulic turbine

    Science.gov (United States)

    Yu, Z. Y.; Zhang, W.

    2012-11-01

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

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

    Science.gov (United States)

    Brown, Erik P

    2014-09-30

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Erik P.

    2017-02-28

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

  4. 2010 oil sands performance report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    With the depletion of traditional energy resources and the rising demand for energy, oil sands have become an important energy resource for meeting energy needs. Oil sands are a mixture of water, sand, clay and bitumen which is recovered either through open pit mining or in situ drilling techniques. The bitumen is then converted into syncrude or sold to refineries for the production of gasoline, diesel or other products. Shell has oil sands operations in Alberta and the aim of this report is to present its 2010 performance in terms of CO2, water, tailings, land, and reclamation and engagement. This document covers several of Shell's operations in the Muskeg River and Jackpine mines, Scotford upgrader, Peace River, Orion, Seal, Cliffdale and Chipmunk. It provides useful information on Shell's oil sands performance to governments, environmental groups, First Nations, local communities and the public.

  5. Predicting edge seal performance from accelerated testing

    Science.gov (United States)

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

    2014-10-01

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

  6. Adhesive sealing of the pulp chamber.

    Science.gov (United States)

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

    2001-08-01

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

  7. Palm Oil

    Science.gov (United States)

    Palm oil is obtained from the fruit of the oil palm tree. Palm oil is used for preventing vitamin A deficiency, cancer, ... blood pressure, high cholesterol, and cyanide poisoning. Palm oil is used for weight loss and increasing the ...

  8. Diesel oil

    Science.gov (United States)

    Oil ... Diesel oil ... Diesel oil poisoning can cause symptoms in many parts of the body. EYES, EARS, NOSE, AND THROAT Loss of ... most dangerous effects of hydrocarbon (such as diesel oil) poisoning are due to inhaling the fumes. NERVOUS ...

  9. 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.

  10. Ancient schwannoma at the olfactory groove mimicking meningioma: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Young Jin; Jeong, Hae Woong [Dept. of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2015-12-15

    Schwannomas are benign slow-growing nerve sheath tumors, which can develop in any peripheral or central nerve that contains Schwann cells. Schwannomas located near the olfactory groove are extremely rare and radiological diagnosis can be difficult. Moreover, ancient schwannoma is an uncommon variant, and radiologic findings are rarely reported. Herein, we reported a surgically confirmed case of ancient schwannoma at the olfactory groove in a 44-year-old woman presenting with headache and visual disturbance. Brain magnetic resonance imaging (MRI) showed a solid and cystic extra-axial mass located in the subfrontal area mimicking an olfactory groove meningioma. Histopathologic diagnosis of ancient schwannoma was confirmed by immunohistochemical staining for S100, CD56, vimentin, and other markers. Furthermore, we described the clinical manifestations, MRI characteristics, and histopathologic findings of the case, and presented a review of related literature.

  11. V-groove-based compact FBG package for thermal tuning and mechanical stability

    Science.gov (United States)

    Zhang, Li; Fang, Wei; Wang, Di; Chen, Di-Jun; Cai, Hai-Wen; Qu, Rong-Hui

    2016-04-01

    We demonstrated a V-groove-based fiber Bragg grating (FBG) package that has been glue-filled and cured to make it a bulky component with much improved mechanical stability. The V-groove can be executed with many types of materials including plastics, ceramics, semiconductors, and metals, providing an easy method for redesigning the thermal tuning performance of FBGs by selecting among a wide variety of materials and processes. We achieved more than 10-nm thermal wavelength tuning and thermal sensitivity ranging from 15 to 160 pm/K. The original FBG spectrum can be maintained without any degradation because the fiber is buried in the V-groove. The compact package does not increase the original grating length and turns the FBG into a planar waveguide grating, improving FBG applications in telecommunications, external cavity lasers, and sensing areas.

  12. Mode Ⅱ fracture mechanism of direct shearing specimen with guiding grooves of rock

    Institute of Scientific and Technical Information of China (English)

    饶秋华; 孙宗颀; 王桂尧; 徐纪成; 张静宜

    2001-01-01

    Fracture mechanism of direct shear specimen with guiding grooves of rock was investigated experimentally and numerically in order to explore a favorable stress condition for creating Mode Ⅱ fracture and guide design of specimen configuration for determining Mode Ⅱ fracture toughness of rock, KⅡC. The experimental and numerical results demonstrate that Mode Ⅱ fracture can be successfully achieved in the direct shearing specimen with guiding groove because the guiding grooves added in the notch plane can generate a favorable stress condition for Mode Ⅱ fracture, i.e. tensile stress at the notch tip is completely depressed and shear stress at the notch tip is very high in the notch plane. The optimum design of the specimen configuration for KⅡC testing should aim to reduce tensile stress to be compressive stress or be lower than tensile strength and greatly increase shear stress at crack tip.

  13. Tunable graphene based plasmonic absorber with grooved metal film in near infrared region

    Science.gov (United States)

    Zare, Mohammad Sadegh; Nozhat, Najmeh; Rashiditabar, Reza

    2017-09-01

    In this paper, we have proposed a graphene based absorber with two absorption peaks at near infrared wavelengths. The metal-graphene nanostructure is composed of a single layer of graphene on a metal film with L-shaped grooves. The results show that by utilizing only one graphene layer the absorption of the structure is increased to more than 0.9 due to the localized surface plasmon resonance (LSPR) in the grooves that amplifies the interaction of light and graphene. We have shown that the full width at half maximum (FWHM) of the absorber is enhanced by decreasing the perpendicular L-shaped grooves length. Also, the absorption spectrum of the proposed structure can be tuned by changing the geometric parameters and chemical potential of graphene.

  14. Palatogingival Groove: Recognizing and Managing the Hidden Tract in a Maxillary Incisor: A Case Report

    Science.gov (United States)

    Sharma, Sarang; Deepak, Passi; Vivek, Sharma; Ranjan Dutta, Shubha

    2015-01-01

    Palatogingival grooves are developmental malformations quite notorious for precipitating endodontic - periodontal lesions. Owing to their inconspicuous occurrence, funnel-shaped morphology and variable extent on tooth root, they promote adherence of plaque and bacteria to levels significant for the development of pathology. Several treatment approaches have been recognized in literature for the management of this anomaly. Here in this report, a 25-year-old patient reported with the complaint of pain and swelling in maxillary right lateral incisor. Clinical examination confirmed an endodontic - periodontal lesion in relation to palatogingival groove. Endodontic treatment was instituted, followed by odontoplasty of the groove and restoration with newer calcium silicate cement, Biodentine. Combined endodontic - periodontal approach was successful in resolving the pathology with complete healing seen both clinically and radiographically. Timely diagnosis, prevention and management are highly recommended to prevent tooth loss due to complications arising secondary to their presence. PMID:26124612

  15. Nexus between directionality of THz waves and structural parameters in groove-patterned InAs

    CERN Document Server

    Yim, Jong-Hyuk; Jeong, Hoonil; Song, Jin-Dong; Jho, Young-Dahl

    2012-01-01

    We have performed terahertz (THz)-time domain spectroscopy in various geometries, for characterizing the directivity of THz waves emitted from groove-patterned InAs structures. First, we have distinguished the THz emission mechanisms as a function of epilayer thickness. The carrier drift was predominant in thin sample group (10-70 nm) which the electronic diffusion motion was overriding the oppositely aligned drifting dipoles in thick sample group (370-900 nm) as revealed via amplitude and phase variations. By combined use of the electron-beam lithography and the inductively coupled plasma etching in 1 {\\mu}m-thick InAs epilayers, we have further fabricated either asymmetric V-groove patterns or symmetric parabolic patterns. The THz amplitude was enhanced, particularly along line-of-sight transmissive direction when the groove patterns act as microscale reflective mirrors periodically separated by a scale of diffusion length.

  16. "Fluid bearing" effect of enclosed liquids in grooves on drag reduction in microchannels

    Science.gov (United States)

    Chen, Haosheng; Gao, Yang; Stone, Howard A.; Li, Jiang

    2016-12-01

    We report details of the fluid motion formed within and above grooves when a laminar continuous phase fluid flows over a second immiscible fluid enclosed in a grooved microchannel. Vortical structures within the transverse grooves were caused by a slip velocity at the fluid-fluid interface and act as "fluid bearings" on the boundary to lubricate the flow of the continuous phase. We investigated the drag reduction in the laminar flow in the microchannel by measuring slip at the boundaries and calculating an effective slip length, taking into account the influence of the effect of the viscosity ratio of the two fluids on the effective slip length. The "fluid bearing" effect can be used to transport high viscosity fluids using low viscosity fluids trapped in cavities to reduce drag.

  17. Profile Control of a Borosilicate-Glass Groove Formed by Deep Reactive Ion Etching

    CERN Document Server

    Akashi, T

    2008-01-01

    Deep reactive ion etching (DRIE) of borosilicate glass and profile control of an etched groove are reported. DRIE was carried out using an anodically bonded silicon wafer as an etching mask. We controlled the groove profile, namely improving its sidewall angle, by removing excessively thick polymer film produced by carbonfluoride etching gases during DRIE. Two fabrication processes were experimentally compared for effective removal of the film : DRIE with the addition of argon to the etching gases and a novel combined process in which DRIE and subsequent ultrasonic cleaning in DI water were alternately carried out. Both processes improved the sidewall angle, and it reached 85o independent of the mask-opening width. The results showed the processes can remove excessive polymer film on sidewalls. Accordingly, the processes are an effective way to control the groove profile of borosilicate glass.

  18. Combined treatment of a lateral incisor with palato-radicular groove: 1 year follow-up

    Directory of Open Access Journals (Sweden)

    Gülen Kamak

    2014-01-01

    Full Text Available Periodontic - endodontic lesion with a palato-radicular groove as a contributing factor for periodontitis is the most important diagnostic and therapeutic challenges faced by periodontists and the maxillary lateral incisors are the most frequently affected teeth. These developmental grooves promotes the accumulation of plaque and calculus, which destroys the sulcular epithelium and later deeper parts of the periodontium, finally resulting in the formation of a severe localized periodontal lesion since proper cleaning of that site is difficult, if not impossible, for the patient. There are different types of treatment such as scaling and root planning, odontoplasty, amalgam restoration, and extraction of the tooth to treat palatogingival groove and associated periodontal bone defects. In this case, a successful management of an endodontic-periodontal combined lesion by combined treatment and guided tissue regeneration was presented.

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

    DEFF Research Database (Denmark)

    2014-01-01

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

  20. Comparative evaluation of three heat transfer enhancement strategies in a grooved channel

    Energy Technology Data Exchange (ETDEWEB)

    Herman, C.; Kang, E. [Dept. of Mechanical Engineering, Johns Hopkins Univ., Baltimore, MD (United States)

    2001-09-01

    Results of a comparative evaluation of three heat transfer enhancement strategies for forced convection cooling of a parallel plate channel populated with heated blocks, representing electronic components mounted on printed circuit boards, are reported. Heat transfer in the reference geometry, the asymmetrically heated parallel plate channel, is compared with that for the basic grooved channel, and the same geometry enhanced by cylinders and vanes placed above the downstream edge of each heated block. In addition to conventional heat transfer and pressure drop measurements, holographic interferometry combined with high-speed cinematography was used to visualize the unsteady temperature fields in the self-sustained oscillatory flow. The locations of increased heat transfer within one channel periodicity depend on the enhancement technique applied, and were identified by analyzing the unsteady temperature distributions visualized by holographic interferometry. This approach allowed gaining insight into the mechanisms responsible for heat transfer enhancement. Experiments were conducted at moderate flow velocities in the laminar, transitional and turbulent flow regimes. Reynolds numbers were varied in the range Re = 200-6500, corresponding to flow velocities from 0.076 to 2.36 m/s. Flow oscillations were first observed between Re = 1050 and 1320 for the basic grooved channel, and around Re = 350 and 450 for the grooved channels equipped with cylinders and vanes, respectively. At Reynolds numbers above the onset of oscillations and in the transitional flow regime, heat transfer rates in the investigated grooved channels exceeded the performance of the reference geometry, the asymmetrically heated parallel plate channel. Heat transfer in the grooved channels enhanced with cylinders and vanes showed an increase by a factor of 1.2-1.8 and 1.5-3.5, respectively, when compared to data obtained for the basic grooved channel; however, the accompanying pressure drop penalties