WorldWideScience

Sample records for replacement cylinder head

  1. Ulnar head replacement.

    Science.gov (United States)

    Herbert, Timothy J; van Schoonhoven, Joerg

    2007-03-01

    Recent years have seen an increasing awareness of the anatomical and biomechanical significance of the distal radioulnar joint (DRUJ). With this has come a more critical approach to surgical management of DRUJ disorders and a realization that all forms of "excision arthroplasty" can only restore forearm rotation at the expense of forearm stability. This, in turn, has led to renewed interest in prosthetic replacement of the ulnar head, a procedure that had previously fallen into disrepute because of material failures with early implants, in particular, the Swanson silicone ulnar head replacement. In response to these early failures, a new prosthesis was developed in the early 1990s, using materials designed to withstand the loads across the DRUJ associated with normal functional use of the upper limb. Released onto the market in 1995 (Herbert ulnar head prosthesis), clinical experience during the last 10 years has shown that this prosthesis is able to restore forearm function after ulnar head excision and that the materials (ceramic head and noncemented titanium stem), even with normal use of the limb, are showing no signs of failure in the medium to long term. As experience with the use of an ulnar head prosthesis grows, so does its acceptance as a viable and attractive alternative to more traditional operations, such as the Darrach and Sauve-Kapandji procedures. This article discusses the current indications and contraindications for ulnar head replacement and details the surgical procedure, rehabilitation, and likely outcomes.

  2. Detection of cylinder pressure in diesel engines using cylinder head vibration and time series methods

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper investigates the vibration characteristics of diesel engine cylinder heads by means of the time series method.With the concept of "Assumed System", the vibration transfer function of real cylinder head structures is established using the autoregressive-moving average models (ARMA models) of cylinder head surface vibration signals.Then this transfer function is successfully used to reconstruct the gas pressure trace inside the cylinder from measured cylinder head vibration signals.This offers an effective means for diesel engine cylinder pressure detection and condition monitoring.

  3. Design and Analysis of Cylinder and Cylinder head of 4-stroke SI Engine for weight reduction

    Directory of Open Access Journals (Sweden)

    Ravindra R. Navthar

    2012-03-01

    Full Text Available The present paper deals with design of cylinder & cylinder head with air cooling system for 4 strokes 4 cylinder SI engine. The main objective of design is to reduce weight to power ratio & will result in producing high specific power. The authors have proposed preliminary design cylinder & cylinder head of a horizontallyopposed SI engine, which develops 120 BHP and posses the maximum rotational speed of 6000rpm. Four stroke opposed engine is inherently well balanced due to opposite location of moving masses and also it provides efficient air cooling. For the requirement of weight reduction the material selected for design of cylinder and cylinder head is Aluminum alloy that is LM-13. The cylinder bore coating using NIKASIL coating was done to improve strength of cylinder with minimum weight..

  4. Pareter Study of Some Key Structures for Cylinder Head

    Institute of Scientific and Technical Information of China (English)

    张儒华; 左正兴; 曹丽亚; 廖日东

    2004-01-01

    Using the method of the pareter study, some important dimensions of the cylinder head of an internal-combustion engine are analyzed. Under the mechanical load, the variational rules of the von Mises maximum stress on cylinder head are obtained, which are influenced by the thickness of the floor plate, head plate, jobbing sheet, standing partition board, and side plate of inlet port and exhaust port. A hypothesis is verified that there is an ideal matching point ong those above-mentioned main pareters. The quantificational proportion relations, between these key structural pareters and von Mises maximum stress of cylinder head, can provide a good help for the cylinder head's structural design.

  5. Integrated hydraulic cooler and return rail in camless cylinder head

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, Craig D [Clawson, MI; Neal, Timothy L [Ortonville, MI; Swain, Jeff L [Flushing, MI; Raimao, Miguel A [Colorado Springs, CO

    2011-12-13

    An engine assembly may include a cylinder head defining an engine coolant reservoir, a pressurized fluid supply, a valve actuation assembly, and a hydraulic fluid reservoir. The valve actuation assembly may be in fluid communication with the pressurized fluid supply and may include a valve member displaceable by a force applied by the pressurized fluid supply. The hydraulic fluid reservoir may be in fluid communication with the valve actuation assembly and in a heat exchange relation to the engine coolant reservoir.

  6. Ulnar Head Replacement and Related Biomechanics

    Science.gov (United States)

    Sauerbier, Michael; Arsalan-Werner, Annika; Enderle, Elena; Vetter, Miriam; Vonier, Daniel

    2013-01-01

    A stable distal radioulnar joint (DRUJ) is mandatory for the function and load transmission in the wrist and forearm. Resectional salvage procedures such as the Darrach procedure, Bowers arthroplasty, and Sauvé-Kapandji procedure include the potential risk of radioulnar instability and impingement, which can lead to pain and weakness. Soft tissue stabilizing techniques have only limited success rates in solving these problems. In an attempt to stabilize the distal forearm mechanically following ulnar head resection, various endoprostheses have been developed to replace the ulnar head. The prostheses can be used for secondary treatment of failed ulnar head resection, but they can also achieve good results in the primary treatment of osteoarthritis of the DRUJ. Our experience consists of twenty-five patients (follow-up 30 months) with DRUJ osteoarthritis who were treated with an ulnar head prosthesis, with improvement in pain, range of motion, and grip strength. An ulnar head prosthesis should be considered as a treatment option for a painful DRUJ. PMID:24436786

  7. Geometric structures on cylinder heads; Geometrische Zusammenhaenge an Zylinderkoepfen

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, F. [Fachhochschule Iserlohn (Germany); Barte, S.; Bulla, M.

    1997-07-01

    Nowadays, efficient engine development without the use of powerful simulation programs is no longer conceivable. This is true for almost all levels in development. Thus, the overriding goal of all calculation methods certainly has to be an integral calculation concept with which individual components are clearly defined and can be calculated with regard to their interaction and operating behaviour. This objective was taken as the basis on which the Iserlohn technical college in Germany develops a program that facilitates a first efficient and fast design of the cylinder head geometry in the concept phase of development. The logical conclusion will be a virtually calculated engine; this concept certainly smooths the path there. (orig.) [Deutsch] Eine effiziente Motorentwicklung ohne den Einsatz leistungsfaehiger Simulationsprogramme, ist heute nicht mehr denkbar. Dies gilt fuer fast alle Ebenen der Entwicklung. Das uebergeordnete Ziel aller Berechnungsmethoden muss daher sicherlich ein integrales Berechnungskonzept sein, mit dem einzelne Bauteile eindeutig definiert sind und in ihrem Zusammenwirken und Betriebsverhalten berechnet werden koennen. Unter dieser Zielsetzung wurde an der FH Iserlohn ein Programm entwickelt, das eine erste effiziente und schnelle Auslegung der Zylinderkopfgeometrie in der Konzeptphase der Entwicklung ermoeglicht. Das fuehrt in letzter Konsequenz zum virtuell berechenbaren Motor; der Weg dorthin scheint eindeutig vorbestimmt. (orig.)

  8. PIV measurements of coolant flow field in a diesel engine cylinder head

    Science.gov (United States)

    Ma, Hongwei; Zhang, Zhenyang; Xue, Cheng; Huang, Yunlong

    2015-04-01

    This paper presents experimental measurements of coolant flow field in the water jacket of a diesel engine cylinder head. The test was conducted at three different flow rates using a 2-D PIV system. Appropriate tracing particles were selected and delivery device was designed and manufactured before the test. The flow parameters, such as velocity, vorticity and turbulence, were used to analyze the flow field. The effects of vortex which was located between the intake valve and the exhaust valve were discussed. The experimental results showed an asymmetric distribution of velocity in the water jacket. This led to an asymmetric thermal distribution, which would shorten the service life of the cylinder head. The structure optimization to the water jacket of cylinder head was proposed in this paper. The experimental system, especially the 2-D PIV system, is a great help to study the coolant flow structure and analyze cooling mechanism in the diesel engine cylinder head.

  9. Low-noise design of cylinder heads. Geraeuschoptimierte Auslegung von Zylinderkoepfen

    Energy Technology Data Exchange (ETDEWEB)

    Roepke, P.; Schwaderlapp, M.; Kley, P.

    1994-06-01

    Due to the continuous noise reduction on combustion engines the components which were assessed uncritical years ago become of interest today. The cylinder head is such a component which gains more and more importance because of the high mechanical excitation and the large mounted accessories like manifolds and valve cover. FEV Motorentechnik in Aachen, Germany, therefore developed methods for low-noise design of cylinder head structures which were developed during long-term experimental and computational investigations. (orig./HW)

  10. Gas engine cylinder head, and a method of retrofitting the head with a precombustion chamber unit

    Energy Technology Data Exchange (ETDEWEB)

    Bisel, G.; Wilke, C.F.

    1993-07-27

    A gas engine cylinder head is described, comprising: a cylinder head body; wherein the body has first, aligned, spark plug-receiving apertures formed therein; the body also has second, aligned, precombustion chamber unit-receiving apertures formed therein; a spark plug set in the first apertures; and a precombustion chamber unit set in the second apertures; wherein one of the second apertures is formed in an outermost portion of the body and another of the second apertures is formed in an inner portion of the body; the another aperture has a first diameter portion and a second diameter portion, and an annular land obtains between the first and second diameter portions; the unit has an intermediate portion which is set upon the land, and cooperates with the first diameter portion of the another aperture to form an annular void there between in which to accommodate fluid flow; and further including a fluid seal interposed between the intermediate portion of the unit and the land; a sleeve in penetration of the one aperture and enclosing the unit there within; wherein the unit has a precombustion chamber formed there within; the sleeve has a plurality of fluid-accommodating ports formed therein; the ports are parallel, and radially aligned, with the chamber; an end of the sleeve is engaged with the intermediate portion of the unit for holding the intermediate portion upon the land; an opposite end of the sleeve opens externally of the body accommodating admittance of ambient atmosphere there into; the unit comprises (a) a spark plug, and (b) a fuel conduit; and the spark plug and the conduit are confined within, and spaced apart from, the sleeve to permit ambient atmosphere entering the sleeve to flow about the spark plug and the conduit.

  11. Production technique of vermicular graphite iron cylinder head of vehicle diesel engine

    Institute of Scientific and Technical Information of China (English)

    Zhou Gen; Liu Wanhua

    2008-01-01

    The 25 years' production and application have proved that vermicular graphite iron cylinder heads with vermicularity ≥50% satisfy the machinability and performance demand of diesel engine. The method, in which using cupola-induction furnace duplex melting and pour-over process with rare earth-ferrosilicon or rare earth silicon compound as vermicularizing alloy plus rare earth-magnesium-ferrosilicon as stirring alloy, is an optimal verroicularizing process for obtaining satisfied vermicularity. Using top kiss risers, enlarging kissing areas and expanding covering width and making ingates to freeze eadier are the effective measures to eliminate shrinkage, blowhole and oxide inclusions in the vermicular graphite iron cylinder heads.

  12. Production technique of vermicular graphite iron cylinder head of vehicle diesel engine

    Directory of Open Access Journals (Sweden)

    Zhou Gen

    2008-11-01

    Full Text Available The 25 years’production and application have proved that vermicular graphite iron cylinder heads with vermicularity ≥50% satisfy the machinability and performance demand of diesel engine. The method, in which using cupola-induction furnace duplex melting and pour-over process with rare earth-ferrosilicon or rare earthsilicon compound as vermicularizing alloy plus rare earth-magnesium-ferrosilicon as stirring alloy, is an optimal vermicularizing process for obtaining satisfi ed vermicularity. Using top kiss risers, enlarging kissing areas and expanding covering width and making ingates to freeze earlier are the effective measures to eliminate shrinkage, blowhole and oxide inclusions in the vermicular graphite iron cylinder heads.

  13. New cylinder head concept for reducing costs, weight and friction losses; Neues Zylinderkopfkonzept - Reduzierung von Kosten, Masse und Reibungsverlusten

    Energy Technology Data Exchange (ETDEWEB)

    Heywood, Jonathan [ThyssenKrupp Presta Chemnitz GmbH, Chemnitz (Germany). Simulation/Testing R and D Valve Train Systems

    2009-11-15

    The camshaft bearing in an internal combustion engine plays a major role in the design of the cylinder head. The name Presta Integrated Cam Assembly (PICA) describes a large number of different development approaches for the cylinder head area. ThyssenKrupp presents a solution for reducing costs, weight and friction losses while at the same time providing lower engine-out emissions. (orig.)

  14. Production of robust contours with braze coatings for cylinder head gaskets; Erzeugung konturgenauer Auftragsschichten fuer Zylinderkopfdichtungen

    Energy Technology Data Exchange (ETDEWEB)

    Cierocki, K.; Heilig, M. [Goetze Payen GmbH, Herford (Germany); Koch, J.; Koschlig, M. [Degussa AG, Hanau (Germany)

    1998-12-01

    Multilayer gaskets made of steel for cylinder heads are state of the art at the automotive industry. To simplify the construction by replacing one layer a precise braze coating of the gasket contour was developed (BrazeSkin-Process). The used filler metal consists of a Ni-based filler suspension, which is applied by a serigraphy process. Within this work the development up to now and the potential in the near future are described. (orig.) [Deutsch] In der Automobilindustrie werden auf heutigem Stand der Technik Mehr-Lagen-Dichtungen (MLS) als Zylinderkopf-Dichtung eingesetzt. Hierbei kommen den einzelnen Lagen unterschiedliche Funktionen zu. Die Aufgaben einer Vereinfachung des Aufbaus durch Einsparung einer Lage wurde durch die Erzeugung einer konturgenauen Beschichtung auf einer der Zwischenlagen um die Zylinderbohrung herum geloest. Zur Erzeugung dieser Beschichtung wurde eine Lotsuspension entwickelt, die einer Produktgruppe mit dem Begriff BrazeSkin zugerechnet wird. Diese Lotsuspension besteht aus einem gefuellten Ni-Basis-Lot, das mittels Siebdruck aufgetragen wird. Im Durchlaufofen werden die aufgedruckten Flaechen unter Schutzgas geloetet. Aufgrund der Fuellung mit einem hochschmelzenden Zusatz entsteht im Loetprozess eine Legierung, die gleichermassen die Grundzuege eines Verbundwerkstoffes und eines Reaktionslotes beinhaltet. Hierdurch wird auch die Forderung nach einer mass- und konturgenauen Schichtdicke erfuellt. Der Grad der Serienreife fuer die erste Anwendung wurde jetzt erreicht. Eine Beschreibung der Entwicklung sowie zukuenftige Entwicklungsmoeglichkeiten werden aufgezeigt. (orig.)

  15. Study on diesel cylinder-head cooling using nanofluid coolant with jet impingement

    Directory of Open Access Journals (Sweden)

    Su Zhong-Gen

    2015-01-01

    Full Text Available To improve the heat-transfer performance of a diesel-engine cylinder head, nanofluid coolant as a new fluid was investigated, and jet impingement technology was then used to study on how to better improve heat-transfer coefficient at the nose bridge area in the diesel-engine cylinder head. Computational fluid dynamic simulation and experiments results demonstrated that using the same jet impingement parameters, the different volume shares of nanofluids showed better cooling effect than traditional coolant, but the good effect of the new cooling method was unsuitable for high volume share of nanofluid. At the same volume share of nanofluid, different jet impingement parameters such as jet angles showed different heat-transfer performance. This result implies that a strong association exists between jet impingement parameters and heat-transfer coefficient. The increase in coolant viscosity of the nanofluid coolant using jet impingement requires the expense of more drive-power cost.

  16. Structure and mechanical properties of vermicular cast iron in cylinder head casting

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2009-01-01

    Full Text Available The paper discusses the problem of grain density and ferrite content in microstructure of vermicular graphite iron cast in bars of different section diameters and cylinder head casting. The experimental results regarding the section effect demonstrate that the nodule count, grain density and ferrite content are all function of the cast bar diameter in this particular case ranging from 0.6 to 8.0 cm and microstructure and mechanical properties in the cylinder head. The nodule count (or grain density has been reported to increase, while ferrite content was decreasing with decreasing casting diameter. The density number of the grains Nv has been related (by regression analysis to the undercooling degree

  17. Confronting hip resurfacing and big femoral head replacement gait analysis

    Directory of Open Access Journals (Sweden)

    Panagiotis K. Karampinas

    2014-03-01

    Full Text Available Improved hip kinematics and bone preservation have been reported after resurfacing total hip replacement (THRS. On the other hand, hip kinematics with standard total hip replacement (THR is optimized with large diameter femoral heads (BFH-THR. The purpose of this study is to evaluate the functional outcomes of THRS and BFH-THR and correlate these results to bone preservation or the large femoral heads. Thirty-one patients were included in the study. Gait speed, postural balance, proprioception and overall performance. Our results demonstrated a non-statistically significant improvement in gait, postural balance and proprioception in the THRS confronting to BFH-THR group. THRS provide identical outcomes to traditional BFH-THR. The THRS choice as bone preserving procedure in younger patients is still to be evaluated.

  18. Hip replacement in femoral head osteonecrosis: current concepts.

    Science.gov (United States)

    Scaglione, Michelangelo; Fabbri, Luca; Celli, Fabio; Casella, Francesco; Guido, Giulio

    2015-01-01

    Osteonecrosis of the femoral head is a destructive disease that usually affects young adults with high functional demands and can have devastating effects on hip joint. The treatment depends on extent and location of the necrosis lesion and on patient's factors, that suggest disease progression, collapse probability and also implants survival. Non-idiopathic osteonecrosis patients had the worst outcome. There is not a gold standard treatment and frequently it is necessary a multidisciplinary approach. Preservation procedures of the femoral head are the first choice and can be attempted in younger patients without head collapse. Replacement procedure remains the main treatment after failure of preserving procedures and in the late-stage ONFH, involving collapse of the femoral head and degenerative changes to the acetabulum. Resurfacing procedure still has good results but the patient selection is a critical factor. Total hip arthroplasties had historically poor results in patients with osteonecrosis. More recently, reports have shown excellent results, but implant longevity and following revisions are still outstanding problems.

  19. The Effects of Cylinder Head Gasket Opening on Engine Temperature Distribution for a Water-Cooled Engine

    Science.gov (United States)

    Jang, J. Y.; Chi, G. X.

    2017-02-01

    In a liquid-cooled engine, coolant is pumped throughout the water jacket of the engine, drawing heat from the cylinder head, pistons, combustion chambers, cylinder walls, and valves, etc. If the engine temperature is too high or too low, various problems will occur. These include overheating of the lubricating oil and engine parts, excessive stresses between engine parts, loss of power, incomplete burning of fuel, etc. Thus, the engine should be maintained at the proper operating temperature. This study investigated the effects of different cylinder head gasket opening on the engine temperature distributions in a water-cooled motorcycle engine. The numerical predictions for the temperature distribution are in good agreement with the experimental data within 20%.

  20. Comparative Evaluation of Cast Aluminum Alloys for Automotive Cylinder Heads: Part I—Microstructure Evolution

    Science.gov (United States)

    Roy, Shibayan; Allard, Lawrence F.; Rodriguez, Andres; Watkins, Thomas R.; Shyam, Amit

    2017-05-01

    The present study stages a comparative evaluation of microstructure and associated mechanical and thermal response for common cast aluminum alloys that are used for manufacturing automotive cylinder heads. The systems considered are Al-Cu (206-T6), Al-Si-Cu (319-T7), and Al-Si (356-T6, A356-T6, and A356 + 0.5Cu-T6). The focus of the present manuscript is on the evaluation of microstructure at various length scales after aging, while the second manuscript will deal with the mechanical and thermal response of these alloys due to short-term (aging) and long-term (pre-conditioning) heat treatments. At the grain-scale, the Al-Cu alloy possessed an equiaxed microstructure as opposed to the dendritic structure for the Al-Si-Cu or Al-Si alloys which is related to the individual solidification conditions for these alloy systems. The composition and morphology of intermetallic precipitates within the grain and at the grain/dendritic boundary are dictated by the alloy chemistry, solidification, and heat treatment conditions. At the nanoscale, these alloys contain various metastable strengthening precipitates (GPI and θ^'' in Al-Cu alloy, θ^' in Al-Si-Cu alloy, and β^' in Al-Si alloys) with varying size, morphology, coherency, and thermal stability.

  1. Flow coefficient measurements for an engine cylinder head under transient flow conditions with continuous valve lift change

    OpenAIRE

    Daesan Oh; Choong Hoon Lee

    2015-01-01

    A flow coefficient measurement system which is operated under an unsteady intake flow condition in the intake port of a diesel engine cylinder head was developed. In order to determine the actual engine intake flow condition, the valve lift of the intake valve, whose rod is in contact with the camshaft, is varied continuously by rotating the camshaft directly. While varying the rotation speed of the camshaft, the flow coefficients were calculated by measuring various sensor signals, in this c...

  2. Cylinder head covers with integrated, switched cyclone-type oil mist separator; Zylinderkopfhauben mit integriertem geschalteten Zyklon-Oelnebelabscheider

    Energy Technology Data Exchange (ETDEWEB)

    Hintze, S.; Janssen, H.; Karl, W.; Soares, J. [Polytec Automotive GmbH und Co. KG, Lohne (Germany)

    2006-05-15

    Polytec Automotive has developed a new engine ventilation system for integration into cylinder head covers with operating features which distinguish it from all other systems presently on the market. The performance curve for this new switched, patented cyclone separator has been optimized at low flow rates and tuned to reduce the pressure in the high flow range. The wide operating range allows the separating performance of this switched cyclone-type separator to be adjusted to all engines, ensuring universal application. (orig.)

  3. Computer-aided design for the Audi five-valve cylinder head concept; Rechnergestuetzte Auslegung des Audi-Fuenfventil-Zylinderkopfkonzeptes

    Energy Technology Data Exchange (ETDEWEB)

    Hannibal, W.; Lukas, F.

    1994-12-01

    Numerical methods are being used increasingly in the design of cylinder-head concepts when developing modern multi-valve automobile engine. The enclosed article illustrates calculations and methods used to design the Audi five-valve cylinder-head concept. At Audi, the necessary calculations are divided up according to their main emphasis and carried out decentrally by individual design and test departments. Complex numerical calculation procedures are developed in a central methods development department. By adopting technical calculation procedures at an early stage, development times in the cylinderhead concept phase can be reduced, risk factors assessed more accurately and costs cut. The technical calculations have had a considerable influence on the product quality of the cylinder heads. (orig.) [Deutsch] In der Entwicklung moderner Mehrventilmotoren fuer Pkw-Antriebe werden vermehrt numerische Methoden zur Auslegung des Zylinderkopfkonzeptes eingesetzt. Im vorliegenden Artikel werden Berechnungsumfaenge und Methoden dargestellt, die zur Auslegung des Audi-Fuenfventil-Zylinderkopfkonzeptes genutzt werden. Die Berechnung bei Audi werden schwerpunktmaessig dezentral in den einzelnen Konstruktions- und Versuchsabteilungen durchgefuehrt. Zusaetzlich werden in einer zentralen Abteilung fuer Methodenentwicklung aufwendige numerische Berechnungsverfahren entwickelt. Durch den fruehen Einsatz technischer Berechnungen koennen in der Konzeptphase der Entwicklung neuer Zylinderkoepfe Entwicklungszeiten verkuerzt, Risikofaktoren besser abgeschaetzt und Kosten verringert werden. Die technischen Berechnungen haben einen wesentlichen Einfluss auf die Produktqualitaet der Zylinderkoepfe gehabt. (orig.)

  4. Comparative Evaluation of Cast Aluminum Alloys for Automotive Cylinder Heads: Part II—Mechanical and Thermal Properties

    Science.gov (United States)

    Roy, Shibayan; Allard, Lawrence F.; Rodriguez, Andres; Porter, Wallace D.; Shyam, Amit

    2017-05-01

    The first part of this study documented the as-aged microstructure of five cast aluminum alloys namely, 206, 319, 356, A356, and A356+0.5Cu, that are used for manufacturing automotive cylinder heads (Roy et al. in Metall Mater Trans A, 2016). In the present part, we report the mechanical response of these alloys after they have been subjected to various levels of thermal exposure. In addition, the thermophysical properties of these alloys are also reported over a wide temperature range. The hardness variation due to extended thermal exposure is related to the evolution of the nano-scale strengthening precipitates for different alloy systems (Al-Cu, Al-Si-Cu, and Al-Si). The effect of strengthening precipitates (size and number density) on the mechanical response is most obvious in the as-aged condition, which is quantitatively demonstrated by implementing a strength model. Significant coarsening of precipitates from long-term heat treatment removes the strengthening efficiency of the nano-scale precipitates for all these alloys systems. Thermal conductivity of the alloys evolve in an inverse manner with precipitate coarsening compared to the strength, and the implications of the same for the durability of cylinder heads are noted.

  5. Influences of Sand Core on Microstructure of Cylinder Heads%砂芯对缸盖组织的影响

    Institute of Scientific and Technical Information of China (English)

    程俊伟; 焦耀峰

    2012-01-01

    在对渗漏缸盖的分析解剖中,时常发现一些壁薄部位的石墨和基体组织异常.采用Cu-Sn合金强化措施,只是消除了部分壁薄部位的基体组织异常.本文分析了缸盖组织异常产生的原因,确认砂芯变形或砂芯下不到位引起铸件壁薄,砂芯壁薄和热效应导致石墨和基体组织异常.%The cause has been analysed that abnormal microstructure of cylinder head with abnormal graphite and base found in some sectors with thin wall during dissection of the cylinder head with leakage. It has been notarized to that thin wall due to distortion of sand core or with sand core without proper position while abnormal graphite and base due to thin wall of the sand core and heat effect.

  6. Influences of Casting Pressure Conditions on the Quality and Properties of a Magnesium Cylinder Head Cover Die Casting

    Institute of Scientific and Technical Information of China (English)

    Wenhui LIU; Yangai LIU; Shoumei XIONG; Baicheng LIU; Y. Matsumoto; M. Murakami

    2005-01-01

    Casting pressure conditions have great influences on the casting defects, such as gas porosity, shrinkage porosity and gas holes. A Mg cylinder head cover die casting was used to experimentally study the influences of casting pressure,the loading time and the piston position of pressure intensification on the variation of pressure and the quality of casting. The results show that casting pressure, the loading time and the piston position of pressure intensification have great influences on the pressure variations in the mold, the quality and performance of casting. The external quality, the density and the tensile strength of casting were improved with the increase of casting pressure and the piston position of pressure intensification and the decrease of the loading time of pressure intensification.

  7. METHODOLOGY FOR ESTIMATION OF HEAT-STRESSED STATE FOR CYLINDER HEAD OF DIESEL ENGINE WITH AIR COOLING

    Directory of Open Access Journals (Sweden)

    A. N. Avramenko

    2016-01-01

    Full Text Available Performance tuning improvement of modern diesel engines exerts an influence on technical and economic, ecological and resource indices of an internal combustion engine (ICE. In its turn, that requires a complex estimation and improvement of engine indices. As is known, working process and thermal intensity of combustion chamber parts are interconnected between themselves. Changes in design, operating and adjustment parameters of systems and structural elements of internal combustion engines that enable air-fuel mixing and combustions processes stressed state of combustion chamber parts. Joint estimation of operating cycle parameters and strength indices of ICE parts makes it possible to solve a number of problems originating in the process of designing new engine models and further development of the existing ones. The paper provides results of comparative estimation on heat-stressed state of a cylinder head for a high-speed diesel engine Д21A (2Ч10,5/12 while operating a rated power mode. In order to simulate and specify a heat-stressed state for description of boundary heat conductivity conditions the following adjoint “gas – wall” problems have been solved: the first one – for combustion chamber of a diesel engine (an internal problem – simulation of a working cycle for a diesel engine; the second one – for cooling edges while blowing over them by air flow (an external problem. Calculations have been made in three-dimensional non-stationary presentation within the Cartesian coordinates. In order to simulate a working cycle of the diesel engine a computational grid describing combustion chamber configuration, inlet and outlet channels has been used in the paper. Solution of the external problem for cooling edge surface in case of blowing over them by air flow has permitted to specify temperatures and heat-transfer coefficient and later to improve an accuracy while estimating level of temperatures and stresses of the cylinder head.

  8. Compacted graphite iron-A material solution for modern diesel engine cylinder blocks and heads

    Institute of Scientific and Technical Information of China (English)

    Steve Dawson; SinterCast; Sweden

    2009-01-01

    The demands for improved fuel economy,performance and emissions continue to pose challenges for engine designers and the materials they choose. This is particularly true for modern diesel engines,where the primary path to achieving improved engine performance and emissions is to increase the Peak Firing Pressure in the combustion chamber. The resulting increase in thermal and mechanical loading has required a change from conventional grey cast iron to Compacted Graphite Iron (CGI) in order to satisfy durability requirements without increasing the size or the weight of the engines. With at least 75% higher tensile strength,45% higher stiffness and approximately double the fatigue strength of conventional grey cast iron,CGI satisfies durability requirements and also provides the dimensional stability required to meet emissions legislation throughout the life of the engine.Currently,there are no CGI diesel engines running on the roads in North America. This is set to change considerably as new commercial vehicle and pick-up SUV diesel engines are launched with CGI cylinder blocks in 2008 and 2009. These initial programs will provide over 2 million CGI diesel engines when ramped to mature volume,potentially accounting for 10%-15% of the North American passenger vehicle fleet within the next four years.

  9. Compacted graphite iron – A material solution for modern diesel engine cylinder blocks and heads

    Directory of Open Access Journals (Sweden)

    Dr. Steve Dawson

    2009-08-01

    Full Text Available The demands for improved fuel economy, performance and emissions continue to pose challenges for engine designers and the materials they choose. This is particularly true for modern diesel engines, where the primary path to achieving improved engine performance and emissions is to increase the Peak Firing Pressure in the combustion chamber. The resulting increase in thermal and mechanical loading has required a change from conventional grey cast iron to Compacted Graphite Iron (CGI in order to satisfy durability requirements without increasing the size or the weight of the engines. With at least 75% higher tensile strength, 45% higher stiffness and approximately double the fatigue strength of conventional grey cast iron, CGI satisfi es durability requirements and also provides the dimensional stability required to meet emissions legislation throughout the life of the engine. Currently, there are no CGI diesel engines running on the roads in North America. This is set to change considerably as new commercial vehicle and pick-up SUV diesel engines are launched with CGI cylinder blocks in 2008 and 2009. These initial programs will provide over 2 million CGI diesel engines when ramped to mature volume, potentially accounting for 10%–15% of the North American passenger vehicle fleet within the next four years.

  10. Traumatic breakage of the ceramic head of prosthesis in total hip replacement.

    Science.gov (United States)

    Moreschini, O; Braidotti, P

    1991-09-01

    The authors describe breakage of the 32 mm alumina AL2 O3 ceramic head in 3 cases of total hip replacement using two different models of prosthesis (Charnley-Müller and Mittelmeier). All three patients were of average height, weight, and activity (Brown et al., 1985; Callaghan et al., 1988), and the breakage had been caused by an accidental fall. The same mechanism of injury, in people the same age as our subjects, can cause femoral neck fractures. Reoperation was necessary in order to replace the component. The implants all appeared to be positioned correctly, and the patients had reported no symptoms. Before the trauma that caused breakage, there had been no other injuries worth noting. All patients were satisfied with their hip replacements.

  11. Why large-head metal-on-metal hip replacements are painful: the anatomical basis of psoas impingement on the femoral head-neck junction.

    Science.gov (United States)

    Cobb, J P; Davda, K; Ahmad, A; Harris, S J; Masjedi, M; Hart, A J

    2011-07-01

    Large-head metal-on-metal total hip replacement has a failure rate of almost 8% at five years, three times the revision rate of conventional hip replacement. Unexplained pain remains a feature of this type of arthroplasty. All designs of the femoral component of large-head metal-on-metal total hip replacements share a unique characteristic: a subtended angle of 120° defining the proportion of a sphere that the head represents. Using MRI, we measured the contact area of the iliopsoas tendon on the femoral head in sagittal reconstruction of 20 hips of patients with symptomatic femoroacetabular impingement. We also measured the articular extent of the femoral head on 40 normal hips and ten with cam-type deformities. Finally, we performed virtual hip resurfacing on normal and cam-type hips, avoiding overhang of the metal rim inferomedially. The articular surface of the femoral head has a subtended angle of 120° anteriorly and posteriorly, but only 100° medially. Virtual surgery in a normally shaped femoral head showed a 20° skirt of metal protruding medially where iliopsoas articulates. The excessive extent of the large-diameter femoral components may cause iliopsoas impingement independently of the acetabular component. This may be the cause of postoperative pain with these implants.

  12. 发动机铝缸盖底注式铸造工艺研究%Production of Aluminum Engine Cylinder Head by Bottom Pouring Casting

    Institute of Scientific and Technical Information of China (English)

    姜银方; 龙昆; 袁国定

    2012-01-01

    Poor surface quality, slag inclusion, porosity and other casting defects easily appear in the aluminum engine cylinder head produced by traditional top-filling casting. To eliminate the problems which were difficult to control, a new bottom pouring method was proposed based on the structural characteristics and technical requirements of engine cylinder head. Gating system was determined for permanent mold casting aluminum alloy engine cylinder head, and cooling method of waterways combined with compressed air was adopted to achieve a sequential solidification of aluminum alloy melt from the bottom to top, which could ensure a smooth filling of molten metal, good exhaust capacity, and also reduce the slag deposition fully. Comparative analysis on casting quality shows that the bottom pouring design is reasonable and feasible, and good surface quality, few casting defects such as porosity, slag hole, and so on, could be realized, significantly improving quality of cylinder head.%为解决采用传统顶注式铸造工艺生产发动机汽缸盖过程中存在的表面质量差,夹渣、气孔等铸造缺陷难以控制的问题,针对铝缸盖结构特点与技术要求,提出了一种新型的金属型底注式铸造工艺.确定了铝缸盖铸件在金属型重力铸造条件下的浇注系统,并采用水道与压缩空气联合冷却的方法,实现铸件自下而上顺序凝固,保证了金属液平稳充型、排气、积渣充分.经铸件质量的对比分析,表明该底注式铸造工艺设计合理、可行,生产的铸件表面品质好,气孔、渣孔等缺陷少,缸盖品质有显著提高.

  13. 蠕墨铸铁缸盖铸件的铸造工艺模拟%Casting Process Simulation of Vermicular Iron Cylinder Head

    Institute of Scientific and Technical Information of China (English)

    李涛; 王泽忠

    2013-01-01

    介绍了4缸4气门高压共轨柴油发动机缸盖铸件的结构,利用数值模拟软件对3种铸造工艺进行模拟分析,认为方案三对于消除缩松类缺陷有明显的优势,并对该方案进行了优化和完善.生产结果显示,在蠕化率为85%的情况下,仍然没有出现缩孔、缩松类缺陷,且铸件满足各项力学性能要求.%An introduction was given to the configuration of cylinder head used for a co-track diesel engine which has 4 cylinders,4 valves per cylinder and high working pressure.A numeral simulation software was used to simulate and analyze three sorts of casting methods.It was considered that the third method has obvious advantage in aspect to eliminate shrinkage porosities,and therefore the third method optimization and perfection was conducted.The production result showed that under the condition of 85% vermicularizing rate still no shrinkage defect occurring,and all mechanical properties met requirements.

  14. Replacement

    Directory of Open Access Journals (Sweden)

    S. Radhakrishnan

    2014-03-01

    Full Text Available The fishmeal replaced with Spirulina platensis, Chlorella vulgaris and Azolla pinnata and the formulated diet fed to Macrobrachium rosenbergii postlarvae to assess the enhancement ability of non-enzymatic antioxidants (vitamin C and E, enzymatic antioxidants (superoxide dismutase (SOD and catalase (CAT and lipid peroxidation (LPx were analysed. In the present study, the S. platensis, C. vulgaris and A. pinnata inclusion diet fed groups had significant (P < 0.05 improvement in the levels of vitamins C and E in the hepatopancreas and muscle tissue. Among all the diets, the replacement materials in 50% incorporated feed fed groups showed better performance when compared with the control group in non-enzymatic antioxidant activity. The 50% fishmeal replacement (best performance diet fed groups taken for enzymatic antioxidant study, in SOD, CAT and LPx showed no significant increases when compared with the control group. Hence, the present results revealed that the formulated feed enhanced the vitamins C and E, the result of decreased level of enzymatic antioxidants (SOD, CAT and LPx revealed that these feeds are non-toxic and do not produce any stress to postlarvae. These ingredients can be used as an alternative protein source for sustainable Macrobrachium culture.

  15. 考虑非线性因素的气缸盖刚强度分析与评估%Analysis and Evaluation of Strength and Stiffness for Cylinder Head Based on Non-linear Factors

    Institute of Scientific and Technical Information of China (English)

    徐岩; 田小飞; 王艳霞

    2011-01-01

    The strength and deformation of cylinder head under different conditions were researched, the three-dimensional solid model of cylinder head-gasket-liner-block composites was built and finally mesh generation and simulation analysis were carried out. The non-linear factor of cylinder head and gasket contact, as well as that of gasket material, was taken into consideration in the calculatioa Based on the mechanical intensity calculation of normal conditions, the intensifying potentials of cylinder head were analyzed under the condition that the maximum cylinder pressure increased to 18 Mpa and 20 Mpa respectively. The stress distribution of largely concerned sites and the deformation of cylinder head fire surface were analyzed before and after strengthening.%对不同工况下气缸盖的强度和变形情况进行了研究,建立了气缸盖—气缸垫—气缸套—机体的组合体三堆实体模型,进行了网格划分及仿真分析.考虑了气缸盖与气缸垫之间接触非线性因素以及气缸垫的材料非线性因素对气缸盖刚强度的影响,在进行正常工况机械强度计算的基础上,缸内最高燃烧压力增加为18 MPa和20 MPa工况下,对气缸盖的强化潜力进行了对比分析,分析了强化前后工程中比较关注部位的应力分布以及气缸盖底板火力面的变形分布情况.

  16. Head-On’ Scattering of a Tubular Cylinder of Finite Length for Radar Target Identification Purposes

    Science.gov (United States)

    1985-03-01

    NUMBER OF PAGES 156 T4. MONITORING AGENCY NAME S AODRESS(11 dlff[erent from Contrallind Office) IS. SECURITY CLASS. (of this report) UNCLASSIFIED I ISO ...TABLE XVII CYLINDER 14 MEASUYREMENT DATA FPEQ CRSEC PHAtSE (GHZ) (SOR~.METER) (DEG./ iSO 103.13 .310089 517;27 10.20 100158 .33 103.30 .001176 .42...14149 1.17 14.13970 -. 14609 1.18 13.07867 -. 15085 1.19 12.25699 -. 16902 1 20 11 34913 -. 17255 1.21 11 02020 -. 13638 1.22 7.10885 -. 13333

  17. Prevention of Blowhole of Model 4L22B Cylinder Head%4L22B缸盖气孔缺陷的防止

    Institute of Scientific and Technical Information of China (English)

    邢继伦; 李善付; 孙晓刚

    2012-01-01

    通过采取降低水套芯发气量、在水套芯内部设置气路、对排气针优化改进,设计烘芯板、采用整体组芯进行回火等措施,降低了缸盖气孔缺陷,使气孔废品率由原来的20%降低到5%以下.%With measures such as use of lower gas generation jacket core, with gas path arranged inside the water jacket core, optimization design of the venging needle, core drying plate, tempering of the whole group of core, cylinder head hole defect has reduced and stomatal scrap rate has lowered from 20% to under 5%.

  18. Developed Design for Humeral Head Replacement Using 3D Surface Mapping

    Science.gov (United States)

    Salah, H. R.

    2014-12-01

    Assessment of dimensional and geometrical data on the humeral head replacement (HHR) objects is essential for solving the relevant designing problems in the physics of reverse engineering (RE). In this work, 2D-assessment for human humerus was performed using the computed tomography (CT) technique within the RE plan, after which the 2D images of humeral objects were converted into 3D images. The conversion was successful and indicated a clear difference in the 2D and 3D estimates of sizes and geometry of the humerus. The authors have analyzed and confirmed experimentally the statistical information on the relevant anatomical objects. The results of finite-element simulation of the compressive stresses affecting the geometry of 3D surface mapping were analyzed using SolidWorks software. For developing the biomechanical design of an HHR object suitable biomaterials were selected, and different metal-based biomaterials are discussed as applied at various loads. New methodology is presented for the size estimation of humeral head - both anatomical and artificial - in 3D-shape. A detailed interpretation is given for the results of CT D-measurements. Izmēru un ģeometrisko datu novērtējums, kas attiecas uz pleca kaula galviņas nomaiņas (PKGN) objektiem, nepieciešams, lai risinātu virkni reversīvās inženierijas (RI) problēmu. Šajā darbā cilvēka pleca kaula galviņas divdimensiju novērtējums tika veikts ar datortomogrāfijas palīdzību (RI) ietvaros, un pēc tam objekta divdimensiju attēlojums tika pārveidots trīsdimensiju. Pārveidojums bija sekmīgs, parādot pleca kaula galviņas izmēru un ģeometrijas atšķirības starp 2D un 3D novērtējumiem. Autori izanalizēja un eksperimentāli apstiprināja statistisko informāciju pēc dotā veida anatomiskiem objektiem. Saspiešanas sasprindzinājumi, kuri ietekmē trīsdimensiju virsmas attēlojuma ģeometriju, tika analizēti ar gala-elementu simulācijas metodi, lietojot programmu Solid

  19. Dynamic biomechanics of the human head in lateral impacts

    OpenAIRE

    Zhang, Jiangyue; Yoganandan, Narayan; Pintar, Frank A.

    2009-01-01

    The biomechanical responses of human head (translational head CG accelerations, rotational head accelerations, and HIC) under lateral impact to the parietal-temporal region were investigated in the current study. Free drop tests were conducted at impact velocities ranging from 2.44 to 7.70 m/s with a 40 durometer, a 90 durometer flat padding, and a 90 durometer cylinder. Specimens were isolated from PMHS subjects at the level of occipital condyles, and the intracranial substance was replaced ...

  20. Effect of Bubble Size on Cylinder Head Boiling Heat Transfer%气泡尺寸对气缸盖沸腾换热的影响

    Institute of Scientific and Technical Information of China (English)

    何联格; 左正兴; 向建华

    2013-01-01

    In Eulerian multiphase flow model to simulate the gas-liquid two-phase flow boiling heat transfer, the bubble size of discrete phase is often treated as the constant. However, bubbles exist in different shapes and sizes, and bubble size is vital important to the simulation results. Using ANSYS Workbench as the simulation platform, and by considering the effects of different bubble sizes in the computational fluid dynamics module CFX, the gas-liquid two-phase flow boiling heat transfer model was applied in the fluid-solid coupling heat transfer system, which consists of cylinder head and cooling water jacket. Gas-liquid two-phase flow field distribution in cooling water jacket and cylinder head temperature distribution was obtained and validated by the experimental data. Results show that, in the case of bubble size=l mm, simulation results agree well with the experimental data. Gas-liquid two-phase flow boiling heat transfer can effectively reduce the peak temperature of cylinder head flame-face in the nose region of exhaust port and decreases heat load at this position.%在应用欧拉多相流模型仿真计算气液两相流沸腾换热时,离散相的气泡尺寸常常被看作常数,而实际上往往气泡具有不同的形状和尺寸,因此研究气泡尺寸大小对仿真计算结果的影响显得至关重要.以ANSYS Workbench为仿真计算平台,在计算流体动力学模块CFX中,用气液两相流沸腾换热计算模型,对不同气泡尺寸下柴油机气缸盖与冷却水腔所组成的流固耦合传热系统进行了整场离散、整场求解,得到了冷却水腔中气液两相流流场分布特性和气缸盖温度场分布,通过与试验结果的对比分析证明了计算模型的有效性.结果表明,在气泡尺寸大小为1 mm的情况下,仿真结果更接近试验结果,并且考虑气液两相流沸腾换热能够有效地降低气缸盖火力面排气道鼻梁区的最高温度,以此降低此处的热负荷.

  1. Hypopituitarism due to sports related head trauma and the effects of growth hormone replacement in retired amateur boxers.

    Science.gov (United States)

    Tanriverdi, F; Unluhizarci, K; Karaca, Z; Casanueva, F F; Kelestimur, F

    2010-06-01

    Traumatic brain injury (TBI) has been recently recognized as a leading cause of pituitary dysfunction. Current data clearly demonstrated that sports related head trauma due to boxing, kickboxing, and soccer might results in pituitary hormone deficiencies, isolated growth hormone (GH) deficiency in particular. In the present report physiologic dose GH replacement therapy (GHRT) was performed in two GH deficient retired amateur boxers for the first time. The boxers received recombinant GH for 6 months. After 6 months of GHRT there were substantial improvements, but not complete normalization, in the body composition parameters, lipid profiles and quality of life scores in both boxers. These preliminary results suggest that GHRT may have beneficial effects in retired boxers with severe isolated GH deficiency due to sports related head trauma. But more data with higher number of boxers and longer GHRT duration are warranted.

  2. A Case of Acute Prosthesis Migration after Femoral Head Replacement due to Osteomalacia by FGF23-Induced Tumor

    Directory of Open Access Journals (Sweden)

    Shinya Hayashi

    2012-01-01

    Full Text Available Fibroblast growth factor 23 (FGF23 was recently identified as an important factor involved in the development of hypophosphatemic rickets and osteomalacia. We experienced a rare case of acute prosthesis migration after hemihip arthroplasty due to FGF23-induced tumor. The patient underwent femoral head replacement because of femoral neck fracture, but prosthesis migration was occurred at 1 week after operation. The patient took various examinations, and FGF23-induced tumor was found in his right wrist. The tumor was resected, and he underwent total hip arthroplasty 8 month later. Finally, he was able to obtain free gait without pain.

  3. Development of Vermicular Cast Iron Cylinder Block and Head%蠕墨铸铁缸体缸盖的铸造技术开发

    Institute of Scientific and Technical Information of China (English)

    王成刚; 刘文辉; 马顺龙; 王东旭; 吴景波

    2012-01-01

    蠕墨铸铁在国外高性能发动机缸体缸盖上的应用日益普遍.本文主要介绍采用蠕墨铸铁进行6DL发动机缸体缸盖的样件技术开发,在蠕化率、抗拉强度、基体组织、蠕化衰退以及铸造工艺等方面进行了系统的试验研究,并成功开发出具有国际同类产品水平的批量产品样件.%The development for sample piece of vermicular cast iron cylinder block and head used for 6DL engine was carried out. The vermicular graphite percentage, tensile strength, matrix structure, vermicularity degeneration of the iron as well as the casting process were studied. Finally, the sample pieces with high quality for batch production were developed successfully.

  4. Cobalt toxicity after revision total hip replacement due to fracture of a ceramic head.

    Science.gov (United States)

    Pelayo-de Tomás, J M; Novoa-Parra, C; Gómez-Barbero, P

    Symptomatic cobalt toxicity from a failed total hip replacement is a rare, but devastating complication. Potential clinical findings include cardiomyopathy, hypothyroidism, skin rash, visual and hearing impairment, polycythaemia, weakness, fatigue, cognitive impairment, and neuropathy. The case is presented of a 74year-old man in whom, after a ceramic-ceramic replacement and two episodes of prosthetic dislocation, it was decided to replace it with a polyethylene-metal total hip arthroplasty (THA). At 6months after the revision he developed symptoms of cobalt toxicity, confirmed by analytical determination (serum cobalt level=651.2μg/L). After removal of the prosthesis, the levels of chromium and cobalt in blood and urine returned to normal, with the patient currently being asymptomatic. It is recommended to use a new ceramic on ceramic bearing at revision, in order to minimise the risk of wear-related cobalt toxicity following breakage of ceramic components. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Multiaxial Stress Analysis of Diesel Engine Cylinder Head Based on Transient Response%基于瞬态响应的柴油机缸盖多轴应力分析

    Institute of Scientific and Technical Information of China (English)

    陈少林; 龙鑫; 杨迪; 张涛

    2012-01-01

    为了给缸盖的疲劳寿命预测提供准确的边界条件,以某型柴油机缸盖为研究对象,运用Ansys有限元分析软件,采用直接积分法对其进行了标定工况的瞬态计算,并将计算结果与有限元静力学分析结果进行了对比.考察瞬态计算得到的应力多轴状态,研究高应力梯度部位多轴应力的变化趋势,结果表明:气缸盖在工作时,结构上的多轴比例载荷与多轴非比例载荷状态共存.%In order to provide the accurate boundary conditions for fatigue life prediction of cylinder head, the transient calculation of rated condition for a diesel engine cylinder head was carried out with the direct integral method based on ANSYS FEA software and the calculated results were compared with the finite element statics results. The rnultiaxial stress state by transient calculation was discussed and the variation tendency of multiaxial stress in the high-stress gradient location was researched. The results show that the states of structural multiaxial proportional load and multiaxial non-proportional load coexist when the cylinder head is working.

  6. Investigation of Sub-Assembly of Product for Environment Impact Assessment: Quantitative Evaluation of Shroud Fan Cover assembly and Cylinder Head Cover assembly

    Directory of Open Access Journals (Sweden)

    Ms. SUMAN SHARMA

    2011-09-01

    Full Text Available We live in a changing world. In many countries the systems are under change. The changes are largely driven by environmental considerations and one driving force is the threat of global climate change. When making new strategic decisions related to manufacturing any product it becomes important to consider the environmentalimplications. The total consumption of materials and energy during the Life cycle of product is greatly affecting the environment. The proper selection of engineering materials for manufacturing of a product can minimize the environmental impact. The environmental impact of products and processes has become a key issue that has led companies to investigate ways to minimize their effects on the environment. LCA is a means of deriving a quantitative evaluation of environmental impact of product design and thereby refining product quality and characteristics. The overall aim of the present work is to evaluate the environmental impact of some important sub-assembliesof a two wheeler for main stages of life cycle i.e. manufacturing stages of raw material and part manufacturing. An investigation has been done on two sub-assemblies of engine group of Activa i.e. shroud fan cover and cylinder head cover. It has been presented using EDIP (Environmental Design of Industrial Product as LCA method as per ISO 14040. The study reveals that the environmental impact is more in the case of manufacturing of steel and rubber parts as compared to plastic and aluminium parts of selected subassemblies and eco-toxicityand human toxicity is more as compared to other impact categories.

  7. 10 years of control, repair and replacement of reactor vessel heads; Dix ans de controles, reparations et remplacements de couvercles de cuves

    Energy Technology Data Exchange (ETDEWEB)

    Goyau, G. [AREVA/FRAMATOME ANP, Div. Service Composants Primaires, 75 - Paris (France)

    2004-06-01

    The occurring of a leak on the primary cooling system at the level of the vessel head of the Bugey-3 reactor during a prescribed hydrostatic test in 1991 has led to more than 10 years of controls, reparations and replacements of vessel heads on French or exported units. This article recalls and details the consequences of this generic defects concerning: -) the devising of special control equipment based on Foucault currents and ultra-sounds, -) the designing of specific repairing tools, and -) the strategy of replacing the vessel head that is now followed in most cases. By end 2003 the total number of vessel head that Framatome-ANP had changed throughout the world, reached 53 units. (A.C.)

  8. Tribological characterization of surface-treated commercially pure titanium for femoral heads in total hip replacement: a feasibility study.

    Science.gov (United States)

    Cotogno, G; Holzwarth, U; Franchi, M; Rivetti, S; Chiesa, R

    2006-12-01

    Most noncemented total hip replacements combine a titanium alloy stem, a CoCrMo femoral head and an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup. In spite of its nickel content of up to 1% and the resulting biocompatibility issues in some clinical situations, the higher cost and some difficulties in machining, CoCrMo alloy is preferred to titanium alloys thanks to its outstanding tribological properties, higher hardness and elastic modulus. Nowadays most of the heads of hip prostheses use CoCrMo as bearing material. The present study investigates the effect of various surface treatments and combinations of treatments, such as electrochemical oxidation (anodization), laser surface melting and barrel polishing, on the tribological properties of commercially pure grade 2 titanium. The aim of the study was to characterize surface treatments capable of improving the tribological properties of titanium surface to the same extent as CoCrMo. The tribological properties were characterized by multidirectional pin-on-flat screening wear tests, using UHMWPE pins as bearing surface. The experiments showed the possibility of improving the wear resistance of titanium to the degree of CoCrMo. Although further efforts will be required to optimize the treatments studied, the results are encouraging enough to warrant pursuing this direction of investigation.

  9. A comparison of leg length and femoral offset discrepancies in hip resurfacing, large head metal-on- metal and conventional total hip replacement: a case series

    Directory of Open Access Journals (Sweden)

    Herman Katie A

    2011-12-01

    Full Text Available Abstract Background A discrepancy in leg length and femoral offset restoration is the leading cause of patient dissatisfaction in hip replacement surgery and has profound implications on patient quality of life. The aim of this study is to compare biomechanical hip reconstruction in hip resurfacing, large-diameter femoral head hip arthroplasty and conventional total hip replacement. Method Sixty patient's post-operative radiographs were reviewed; 20 patients had a hip resurfacing (HR, 20 patients had a Large Head Metal-on-metal (LHM hip replacement and 20 patients had a conventional small head Total Hip Replacement (THR. The leg length and femoral offset of the operated and unoperated hips were measured and compared. Results Hip resurfacing accurately restored hip biomechanics with no statistical difference in leg length (P = 0.07 or femoral offset (P = 0.95 between the operated and non-operative hips. Overall HR was superior for reducing femoral offset discrepancies where it had the smallest bilateral difference (-0.2%, P = 0.9. The traditional total hip replacement was least effective at restoring the hip anatomy. Conclusion The use of a larger-diameter femoral head in hip resurfacing does not fully account for the superior biomechanical restoration, as LHM did not restore femoral offset as accurately. We conclude that restoration of normal hip biomechanics is best achieved with hip resurfacing.

  10. Influence of Properties of Foundry Raw Sand on Quality of Cylinder Block and Head Castings%铸造用砂的性能对缸体和缸盖铸件质量的影响

    Institute of Scientific and Technical Information of China (English)

    刘鸿勋

    2013-01-01

    介绍了我国风积砂、海砂、湖砂和河砂四大砂系的资源和生产状况,分析了擦洗砂和焙烧砂各主要参数对缸体、缸盖铸件质量的影响情况和常用特种砂在提高铸件质量方面的作用,强调了生产缸体、缸盖铸件时用砂的选择与组合原则.%An introduction was made to the present resource and production situation of four Chinese main sand series including eolian sand,sea sand, lake sand and river sand. The influences of the main parameters of scrubbed sand and baked sand on quality of cylinder block and head castings and the effect of commonly used special sand in casting quality improvement were analyzed, as well as the selection and combination principle of raw sand used for cylinder block and head castings production was stressed.

  11. Age at menopause and hormone replacement therapy as risk factors for head and neck and oesophageal cancer (Review).

    Science.gov (United States)

    McCarthy, Caroline E; Field, John K; Marcus, Michael W

    2017-10-01

    There were ~986,000 cases of head and neck cancer (HNC) and oesophageal cancer diagnosed worldwide in 2012. The incidence of these types of cancer is much higher in males than females, although this disparity decreases in the elderly population, suggesting a role for hormones as a risk factor. This systematic review investigates the potential role of female hormones [age at menopause and use of hormone replacement therapy (HRT)] as risk factors for HNC/oesophageal squamous cell carcinoma (SCC). The electronic databases MEDLINE, Web of Science, EMBASE and Cochrane were searched. Only studies with at least 50 cases of HNC/oesophageal SCC, with data on age at menopause, smoking, alcohol, age and socioeconomic status or educational attainment, were included. The Newcastle Ottawa Scale was used for assessing risk of bias. Eight studies met the inclusion criteria (5 oesophageal SCC, 2 HNC and 1 combined oesophageal SCC and HNC). HRT was shown to reduce the risk of HNC (HR, 0.78; 95% CI, 0.61-0.99) in one study. Our results showed that earlier age at menopause is a risk factor for oesophageal SCC, with women entering menopause at 50 years. Similar, but less striking, results were observed for HNC. HRT was found to reduce the risk of HNC/oesophageal SCC, but the evidence is inconclusive. We, therefore, recommend that consideration should be given to collecting data on reproductive factors and exposure to HRT, as routine practice, in future epidemiological and clinical studies of these cancers. The concept of oestrogen deficiency as a risk for HNC/oesophageal SCC deserves further exploration in future laboratory and clinical studies.

  12. 铝合金缸盖火花塞孔预铸及其金相组织%Pre-casted Spark Plug Hole on Aluminum Alloy Cylinder Head and Its Metallographic Structure

    Institute of Scientific and Technical Information of China (English)

    张炳荣; 田身军; 徐帅; 项大伟; 张守银

    2012-01-01

    For aluminum alloy cylinder head by permanent mold gravity casting, specimens were taken from casting in order to compare SDAS (secondary dendrite arm spacing) with and without pre-casting spark plug hole. The hole formed by pre-cast insert shows reduced SDAS and increased tensile strength. The porosity around hole has been improved too.%金属型重力铸造铝合金缸盖预铸火花塞孔,晶间距(SDAS)。预铸状态孔壁的SDAS明显减小,围的组织疏松。从铸件本体取样对比预铸前后孔壁的二次枝抗拉强度等力学性能提高,改善了火花塞周

  13. Effect of Partial Replacement of Nitrate by Amino Acid and Urea on Nitrate Content of Non-heading Chinese Cabbage and Lettuce in Hydroponic Condition

    Institute of Scientific and Technical Information of China (English)

    CHEN Gui-lin; GAO Xiu-rui; ZHANG Xian-bin

    2002-01-01

    In this paper, the authors studied the effect of different mixtures of glyeine (Gly), isoleucine (Iso), proline (Pro), and urea solutions used as a partial (20%) replacment of nitrate in the nitrate content and quality of non-heading Chinese cabbage and lettuce in hydroponice. Five treatments were done 12 d before harvest. Compared to the control group, Gly had the best effect in reducing the nitrate content of both vegetable leaves and petioles; the mixture of Giy, Iso and Pro ranked second and urea the least. Treatments with amino acid could also increase soluble sugar and protein contents and enhance total-N in leaves significantly.In contrast, amino acid enhanced NRA in non-heading Chinese cabbage, while they decreased it slightly in lettuce. The results showed that amino acids and urea could reduce the nitrate content of both vegetables, but they had almost the same effect on non-heading Chinese cabbage. Moreover, amino acids were more effective than urea in lettuce. As a result, it was concluded that partial replacement of nitrate with amino acids not only reduced the nitrate content but also improved the quality of vegetables.

  14. Prediction of Diesel Engine Performance under Variable Operating Conditions Based on Vibration Signal of Cylinder Head%基于缸盖振动信号的柴油机多工况性能预测

    Institute of Scientific and Technical Information of China (English)

    邓名华

    2001-01-01

    The cylinder pressure was determined from the vibration signal of a diesel engi ne c ylinder head by means of the wavelet analysis and time-series methods.The heat release r ate was calculated by analyzing the indicated pressure diagram.With t he he lp of a dual Wiebe functions fitting model on heat release rate,a set of form ulas was established about the dual Wiebe parameter variation under variable op erating conditions of the engine,and thus a satisfactory result was obtained in predi cting the heat release rates under variable operating conditions.This paper comb ines the cycle simulating calculation of the engine working process with the above rese arch on heat release rate,thus accomplishing the research on predicting the perf o rmance of a diesel engine under variable operating conditions according to the v ibration signal of the diesel engine cylinder head.%采用小波分析法和时间序列分析法从柴油机缸盖表面振动信号识别气缸压力,通过对示功图进行分析计算得到了相应的放热规律;采用双韦柏函数对放热规律进行拟合,建立了双韦柏参数的多工况变化关系式,实现了放热规律的多工况计算,并与工作过程数值计算相结合,从柴油机缸盖振动信号预测多工况性能。

  15. Nursing of artificial femoral head replacement on elderly patients%老年人工股骨头置换的护理

    Institute of Scientific and Technical Information of China (English)

    顾敏君

    2011-01-01

    目的 探讨老年人工股骨头置换术围手术期的护理.方法根据老年人的心理特点,全面评估患者条件,完善术前准备,积极预防手术并发症,并加强护理和康复指导.结果72例老年患者均顺利度过围手术期,痊愈出院.结论老年人工股骨头置换的护理保证了手术的成功,并有效减少了手术并发症,对提高患者的生活质量具有重要意义.%Objective To investigate the nursing of artificial femoral head replacement on elderly patients. Methods According to the psychological characteristics of elderly patients, we assessed the patients' conditions comprehensively, improved the preoperative preparation, prevented the surgical complications actively, and strengthened the nursing and rehabilitation guidance. Results All 72 elderly patients successfully survived the perioperative period and got cured. Conclusion The nursing of the elderly patients with femoral head replacement ensured the success of the operation and reduced the surgical complications. It is of importance to improve the life qualities of the elderly patients.

  16. Computerized Virtual Reality Simulation in Preclinical Dentistry: Can a Computerized Simulator Replace the Conventional Phantom Heads and Human Instruction?

    Science.gov (United States)

    Plessas, Anastasios

    2017-07-10

    In preclinical dental education, the acquisition of clinical, technical skills, and the transfer of these skills to the clinic are paramount. Phantom heads provide an efficient way to teach preclinical students dental procedures safely while increasing their dexterity skills considerably. Modern computerized phantom head training units incorporate features of virtual reality technology and the ability to offer concurrent augmented feedback. The aims of this review were to examine and evaluate the dental literature for evidence supporting their use and to discuss the role of augmented feedback versus the facilitator's instruction. Adjunctive training in these units seems to enhance student's learning and skill acquisition and reduce the required faculty supervision time. However, the virtual augmented feedback cannot be used as the sole method of feedback, and the facilitator's input is still critical. Well-powered longitudinal randomized trials exploring the impact of these units on student's clinical performance and issues of cost-effectiveness are warranted.

  17. Measures to Reduce Gas-Shrinkage Porosity of M3000R Vermicular Graphite Iron Cylinder Head%减少M3000R蠕铁缸盖气缩孔的措施

    Institute of Scientific and Technical Information of China (English)

    刘治军; 邓劲珊

    2012-01-01

    介绍了M3000R蠕铁缸盖的生产工艺,统计发现气缩孔主要出现在气门导管孔、螺栓孔等相对厚大的热节部位.分析“气”的来源主要有:造型材料发出的气体;熔炼过程带入的[N]、[O]在凝固过程析出N2、CO,浇注时卷入的气体.通过优化冲天炉配料和送风参数、严格控制蠕化剂的加入量、在导管孔处加外冷铁、在螺栓孔处加内冷铁等措施,M3000R缸盖的气缩孔废品率由2007年的9.9%下降到2010年的0.2%,总废品率也由2007年的15.9%下降到2010年的2.95%.%The casting method of M3000 vermicular iron cylinder head was introduced. It was revealed that the main reason causing rejection was the blowhole-shrinkage occurring in the heavy section hot spots such as the valve guiding holes, bolt holes, etc. It was considered by analysis that the gas source included the gas produced by molding materials, [N] and [0] gas brought into iron melt during melting process which separated out as N2and CO in solidification process, and the gas brought in the melt during pouring process. By adopting the measures such as optimizing the melting charge mixture and blasting parameters of cupola melting, strictly controlling the adding amount of vermicularizing alloy, setting pipe-shaped chills in the boll holes and top chills at top of the valve guiding holes, etc., the blowhole-9hrinkage-caused rejection rate of cylinder head has been reduced from 9.9% in 2007 to 0.2% in 2010, and the general rejection rate also reduced from 15.9% in 2007 to 2. 95% in 2010.

  18. Influence of geometry and materials on the axial and torsional strength of the head-neck taper junction in modular hip replacements: A finite element study.

    Science.gov (United States)

    Fallahnezhad, Khosro; Farhoudi, Hamidreza; Oskouei, Reza H; Taylor, Mark

    2016-07-01

    The assembly force is important in establishing the mechanical environment at the head-neck taper junction of modular hip replacements. Previous experimental results of the assembled taper junctions with different material combinations (Co-28Cr-6Mo and Ti-6Al-4V) reported similar axial strengths (pull-off loads), but lower torsional strengths (twist-off moments) for the CoCr/CoCr junction. However, mechanics of the junction and the strength behaviour have not been understood yet. A three dimensional finite element model of an isolated femoral head-neck junction was developed to explore the assembly and disassembly procedures, particularly the axial and torsional strengths for different material combinations and geometries. Under the same assembly load, the contacting length between the CoCr head and titanium neck was greater than that of in CoCr/CoCr. The contact length in the titanium neck was more sensitive to the assembly force when compared to the CoCr neck. For instance, with increasing the assembly force from 1890 to 3700N, the contact length increased by 88% for CoCr/Ti and 59% for CoCr/CoCr junctions. The torsional strength of the junction was related to the lateral deformation of the neck material due to the applied moment. The angular mismatch existing between the head and neck components was found to play the main role in the torsional strength of the junction. The smaller mismatch angle the higher torsional strength. It is suggested to consider reducing the mismatch angle, particularly in CoCr/CoCr junctions, and ensure a sufficiently high assembly force is applied by impaction for this combination.

  19. Revision hip arthroplasty in patients with a previous total hip replacement for osteonecrosis of the femoral head.

    Science.gov (United States)

    Park, Youn-Soo; Moon, Young-Wan; Lee, Keun-Ho; Lim, Seung-Jae

    2014-12-01

    Patients with osteonecrosis of the femoral head are typically relatively young and active and often require high rates of revision after primary total hip arthroplasty. However, outcomes of revision hip arthroplasty in this patient population have rarely been reported in the literature. The authors conducted a retrospective review of 72 patients (75 hips) who underwent revision hip arthroplasty with a primary diagnosis of osteonecrosis of the femoral head. Mean age at index revision was 53.3 years (range, 34-76). Components of acetabular revision included a cementless porous-coated cup in 58 hips and an acetabular cage in 3 hips. Components of femoral revision included a fully grit-blasted tapered stem in 30 hips and a proximally porous-coated modular stem in 9 hips. Mean duration of follow-up was 7 years (range, 3-17). Mean Harris Hip Score improved from 49 points preoperatively to 90 points postoperatively. At final follow-up, 11 hips (14.7%) required reoperation because of aseptic loosening (6 hips), infection (2 hips), recurrent dislocation (1 hip), periprosthetic fracture (1 hip), and ceramic fracture (1 hip). Kaplan-Meier survivor-ship with an endpoint of re-revision for any reason was 81% and for mechanical failure was 87.5% for the cup and 100% for the stem at 10 years. Unlike the previous report, the authors' study showed a lower failure rate of the femoral stem after revision hip arthroplasty using modern cementless femoral components in patients with osteonecrosis of the femoral head. Aseptic cup loosening or osteolysis is the most common mechanism of failure at medium-term follow-up. Copyright 2014, SLACK Incorporated.

  20. 蠕墨铸铁缸盖蠕化率的超声波声速法检测%Vermicularity Test of Vermicilar Iron Cylinder Head with Ultrasonic Velocity Method

    Institute of Scientific and Technical Information of China (English)

    谢文琪; 喻平; 周楚清; 薛增光; 魏海芸

    2011-01-01

    The application scope of ultrasonic velocity test method was introduced. An investigation was conducted on using ultrasonic velocity method to inspect on-line the vermicularity of the vermicular iron cylinder head and the inspection method of the finished part. As the result of the investigation, the corresponding relationship between the vermicularity and the sonic velocity was obtained with the regressionality higher than 90%. The penetrating method can be used to conduct the on-line inspection of the vermicular iron production process, and the pulse reflection method can be used to conduct the material judgement of the casting body.%介绍了超声波声速法的适用范围,试验研究了利用超声波声速法进行蠕铁缸盖蠕化率的在线检测和产品检验的方法.通过试验得到了蠕化率与声速间的对应关系,回归性可达90%以上.采用穿透法可实现对蠕铁生产过程的在线检测,采用脉冲反射法可实现进行铸件本体材料的判断.

  1. A fragile lattice: replacing bacteriophage lambda's head stability gene D with the shp gene of phage 21 generates the Mg2+-dependent virus, lambda shp.

    Science.gov (United States)

    Wendt, Jennifer L; Feiss, Michael

    2004-08-15

    Phage lambda DNA packaging is accompanied by prohead expansion, due to structural changes in gpE, the major capsid protein. Rearrangement of the gpE lattice creates binding sites for trimers of gpD, the head stabilization protein. lambda-Like phage 21's shp gene is homologous to lambda's D gene. gpD and gpShp share 49% amino acid identity. To ask whether gpShp could stabilize the lambda head shell, we replaced lambda's D gene with shp, creating lambda shp. Unlike lambda or 21, lambda shp was strictly dependent on the presence of 10(-2) M Mg2+, and lambda shp virions were very sensitive to chelating agents. Density gradient studies indicated that the lambda gpE lattice was underpopulated with gpShp. gpD's N-terminus has been proposed to contact gpE, and we found that lambda D/shp, which produces a chimeric protein with the N-terminus of gpD and the C-terminus of gpShp, was Mg2+-independent and more stable than lambda shp.

  2. The Development of the Cleaning Unit for the Engine Cylinder Head Multilayer Water Jacket%发动机缸盖多层水套智能清洁单元的研制

    Institute of Scientific and Technical Information of China (English)

    王海洋

    2015-01-01

    In order to reach the emissions standard and reduce the fatal fault because of the cuttings and deb-ris in the engine ,it is quite neccessary to improve the cleanliness of automobile engine lubrication system and reduce the particle size. The engine cylinder head inner cavity holes’ burr and the cuttings and debris in multilayer water jacket cavity are one of the important factors affecting the cleanliness and granularity. Base on this point, a new kind of intelligent cleaning unit is introduced. This unit consists of the material number identification module, the industrial robot module integrated with a waterproof corrosion resistant gripper, the targeted cross hole deburring device, the endoscopic pre-judging device, the multilayer water jacket cavi-ty fixed-point remove cuttings and clean up dirt device, the quality comparison pre-judging via high-speed photographic technique device, the plug-in clean collision avoidance system, the workpiece extremely dry device, the cleaning fluid regeneration device, the pneumatic control system, the intelligent control system and the remote fault diagnosis system. This unit not only solves the problem of engine cylinder head cleanli-ness and the granularity, but also good to solve the problems about the traditional washing machine which creates the wasting of resources and causes the environmental pollution. Therefore, it is valuable to apply and spread.%为了减少发动机内切屑、杂物等造成汽车动力总成致命故障和排放超标问题,需要提高汽车发动机润滑系统清洁度和减小颗粒度。发动机缸盖内腔孔系毛刺和多层水套型腔切屑、杂物是影响其清洁度和颗粒度的最重要因素。基于此,提出了一种全新的智能清洁单元。它由物料的数字标识、集成防水耐蚀机械手的工业智能机器人、交叉孔靶向去毛刺装置、内窥镜预判装置、多层水套定向除屑清污装置、高速照相比对质量预判装置、探入

  3. 49 CFR 178.50 - Specification 4B welded or brazed steel cylinders.

    Science.gov (United States)

    2010-10-01

    ... and a service pressure of at least 150 but not over 500 psig. Cylinders closed in by spinning process..., and valve protection rings to the tops and bottoms of cylinders by welding or brazing is authorized... permanently in any of the following locations on the cylinder: (1) On shoulders and top heads when they are...

  4. Cylinder monitoring program

    Energy Technology Data Exchange (ETDEWEB)

    Alderson, J.H. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Cylinders containing depleted uranium hexafluoride (UF{sub 6}) in storage at the Department of Energy (DOE) gaseous diffusion plants, managed by Martin Marietta Energy Systems, Inc., are being evaluated to determine their expected storage life. Cylinders evaluated recently have been in storage service for 30 to 40 years. In the present environment, the remaining life for these storage cylinders is estimated to be 30 years or greater. The group of cylinders involved in recent tests will continue to be monitored on a periodic basis, and other storage cylinders will be observed as on a statistical sample population. The program has been extended to all types of large capacity UF{sub 6} cylinders.

  5. Delamination of Composite Cylinders

    Science.gov (United States)

    Davies, Peter; Carlsson, Leif A.

    The delamination resistance of filament wound glass/epoxy cylinders has been characterized for a range of winding angles and fracture mode ratios using beam fracture specimens. The results reveal that the delamination fracture resistance increases with increasing winding angle and mode II (shear) fraction (GΠ/G). It was also found that interlaced fiber bundles in the filament wound cylinder wall acted as effective crack arresters in mode I loading. To examine the sensitivity of delamina-tion damage on the strength of the cylinders, external pressure tests were performed on filament-wound glass/epoxy composite cylinders with artificial defects and impact damage. The results revealed that the cylinder strength was insensitive to the presence of single delaminations but impact damage caused reductions in failure pressure. The insensitivity of the failure pressure to a single delamination is attributed to the absence of buckling of the delaminated sublaminates before the cylinder wall collapsed. The impacted cylinders contained multiple delaminations, which caused local reduction in the compressive load capability and reduction in failure pressure. The response of glass/epoxy cylinders was compared to impacted carbon reinforced cylinders. Carbon/epoxy is more sensitive to damage but retains higher implosion resistance while carbon/PEEK shows the opposite trend.

  6. Prediction of External Corrosion for Steel Cylinders--2007 Report

    Energy Technology Data Exchange (ETDEWEB)

    Schmoyer, Richard L [ORNL

    2008-01-01

    Depleted uranium hexafluoride (DUF{sub 6}) is stored in over 62,000 containment cylinders at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. Over 4,800 of the cylinders at Portsmouth were recently moved there from the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. The cylinders range in age up to 56 years and come in various models, but most are 48-inch diameter 'thin-wall'(312.5 mil) and 'thick-wall' (625 mil) cylinders and 30-inch diameter '30A' (including '30B') cylinders with 1/2-inch (500 mil) walls. Most of the cylinders are carbon steel, and they are subject to corrosion. The United States Department of Energy (DOE) manages the cylinders to maintain them and the DUF{sub 6} they contain. Cylinder management requirements are specified in the System Requirements Document (LMES 1997a), and the activities to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). This report documents activities that address DUF{sub 6} cylinder management requirements involving measuring and forecasting cylinder wall thicknesses. As part of these activities, ultrasonic thickness (UT) measurements are made on samples of cylinders. For each sampled cylinder, multiple measurements are made in an attempt to find, approximately, the minimum wall thickness. Some cylinders have a skirt, which is an extension of the cylinder wall to protect the head (end) and valve. The head/skirt interface crevice is thought to be particularly vulnerable to corrosion, and for some skirted cylinders, in addition to the main body UT measurements, a separate suite of measurements is also made at the head/skirt interface. The main-body and head/skirt minimum thickness data are used to fit models relating minimum thickness to cylinder age, nominal thicknesses, and cylinder functional groups defined in terms of plant site, storage yard

  7. Design of the Structure and Optimization of Technological Parameters of Magnesium Alloy Cylinder Head Through AnyCasting%基于AnyCasting的镁合金缸盖结构设计与工艺参数优化

    Institute of Scientific and Technical Information of China (English)

    黄裕飞; 李晓棠; 陈流; 杨立权; 冯瀚

    2012-01-01

    在实际压铸试验的基础上,提出了合理的铸件结构和压铸工艺参数.利用AnyCasting软件求解了不同工艺参数和铸件结构对铸件充型、凝固过程的影响规律.在现有的镁合金汽车缸盖铸件条件下,根据凝固规律重点研究了铸件中可能存在的缩松、缩孔分布与尺寸.结果表明:优化的铸件结构以及优化的压铸工艺参数(浇注温度680℃,模具温度190℃,冲头低速速度0.2 m/s,高速压射速度为6m/s,真空度30 kPa)能够明显降低铸件凝固时间以及减少铸件内部缩松、缩孔数量;同时在优化设计的基础上,结合阿基米德原理和力学性能测试验证了工艺参数和铸件结构的合理性,生产出了具有致密微观组织的镁合金零件.%The reasonable structure and die-casting parameters are put forward on the basis of the actual die-casting experiment. The influence laws of different process parameters and casting structure to casting mould filling and solidification process were solved through AnyCasting software. According to solidification laws, the distribution and size of shrinkage and dispersed shrinkage that may exist in the casting were studied especially under existing cast condition of the magnesium alloy cylinder head. The result shows the optimization of the casting structure and the optimization of the die-casting parameters (pouring temperature 680 ℃, mold temperature 190 ℃, plunger injection lowest speed 0.2 m/s, injection highest speed 6 m/s, vacuum degree 30 kPa) can significantly cut the solidification time and reduce the quantity of the shrinkage and dispersed shrinkage of the casting. The rationality of the technology parameters and the structure of the casting were proved on the basis of optimization design, the Archimedes principle and mechanical properties test, and magnesium alloy parts with compact microstructure were produced.

  8. Approximation by Cylinder Surfaces

    DEFF Research Database (Denmark)

    Randrup, Thomas

    1997-01-01

    We present a new method for approximation of a given surface by a cylinder surface. It is a constructive geometric method, leading to a monorail representation of the cylinder surface. By use of a weighted Gaussian image of the given surface, we determine a projection plane. In the orthogonal...

  9. Tandem Cylinder Noise Predictions

    Science.gov (United States)

    Lockhard, David P.; Khorrami, Mehdi R.; CHoudhari, Meelan M.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2007-01-01

    In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to

  10. Efficacy Observation on Artificial Humeral Head Replacement Treating Senile Proximal Humerus Complex Fractures%人工肱骨头置换术治疗高龄肱骨近端复杂骨折疗效观察

    Institute of Scientific and Technical Information of China (English)

    邓崇礼; 梁祖建; 张百挡

    2014-01-01

    目的:探讨人工肱骨头置换术治疗高龄肱骨近端复杂骨折的疗效。方法:对26例高龄肱骨近端复杂骨折患者行人工肱骨头置换术治疗,观察其临床疗效。结果:优6例,良13例,可5例,差2例,优良率为73.08%。结论:人工肱骨头置换术治疗高龄肱骨近端复杂骨折能有效减轻创伤后肩关节疼痛,提供肩关节早期活动,获得良好关节功能。%Objective:To investigate the curative effects of artificial humeral head replacement treating senile proximal humerus complex fractures. Methods:26 cases of patients with senile proximal humerus complex fractures underwent artificial humeral head replacement, whose efficacy was observed. Results:6 cases were excellent, 13 cases were good, 5 cases were qualified, 2 cases were poor, the excellent and good rate was 73.08%. Conclusion:Artificial humeral head replacement treating senile proximal humerus complex fractures can effectively reduce the posttraumatic shoul-der pain and provide early activity of shoulder joint, which get good joint function.

  11. Antennas on circular cylinders

    DEFF Research Database (Denmark)

    Knudsen, H. L.

    1959-01-01

    antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...... cylindrical surfaces have the sane characteristic constants and different constants are treated separately. Extensive numerical computations of the field radiated from the slot antennas described here are being carried out, but no numerical results are yet available...

  12. Approximation by Cylinder Surfaces

    DEFF Research Database (Denmark)

    Randrup, Thomas

    1997-01-01

    We present a new method for approximation of a given surface by a cylinder surface. It is a constructive geometric method, leading to a monorail representation of the cylinder surface. By use of a weighted Gaussian image of the given surface, we determine a projection plane. In the orthogonal...... projection of the surface onto this plane, a reference curve is determined by use of methods for thinning of binary images. Finally, the cylinder surface is constructed as follows: the directrix of the cylinder surface is determined by a least squares method minimizing the distance to the points...... in the projection within a tolerance given by the reference curve, and the rulings are lines perpendicular to the projection plane. Application of the method in ship design is given....

  13. 12V柴油机机体精铣缸面、精镗气缸孔数控专机的结构设计与分析%Structural Design and Analysis for a Special CNC Machine for Precise Milling Head Face and Precise Boring Cylinder Hole of a V12 Diesel Engine Block

    Institute of Scientific and Technical Information of China (English)

    马敏莉; 王建章

    2013-01-01

    介绍了12V柴油机机体精铣缸面、精镗气缸孔数控专机设计的关键技术及设计要点.设计中根据12V机体零件精铣缸面、精镗气缸孔的工序要求,有针对性地设计了机床的各个主要部件,解决了缸面平面度、缸套孔止口深度1100.05mm、底面0.3.~0.5.mm斜面、ф16300.25孔与止口的过渡圆角R0.50-0.2 mm、各缸止口与缸面的平行度、各缸孔与缸面的垂直度等加工中的瓶颈问题,确保零件工序精度及加工效率.%Key technologies and aspects involving in the design of a special CNC machine for precise milling head face and precise boring cylinder hole of a V12 diesel engine were explained.Based on the sequential requirements of the process for precision machining head face and bore,major components of a special CNC machine were designed,solving critical machining challenges such as engine blockhead flatness,parallelism between the blockhead and the flange of all cylinders,perpendicularity between cylinder bores and the blockhead,and at the same time providing an engine liner depth of 110+0.05 mm,an inclined bottom of 0.3 ° ~ 0.5 ° mm,and the transitional round of R0.50-0.2mm between the ф1630+0.25 hole and the flange.So required machining precisions and productivity are ensured.

  14. Prediction of External Corrosion for Steel Cylinders - 1998 Report

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, B.F.

    1998-01-01

    The United States Department of Energy (DOE) currently manages the UF, Cylinder Project. The project was formed to maintain and safely manage depleted uranium hexafluoride (UF{sub 6}) stored in approximately 50,000 carbon steel cylinders. The cylinders located at three DOE sites: the K-25 site at Oak Ridge, Tennessee (K-25); the Paducah Gaseous Diffusion Plant in Paducah, Kentucky (PGDP), and the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The System Requirements Document (SRD) (LMES 1997a) delineates the requirements of the project. The appropriate actions needed to fulfill these requirements are then specified within the System Engineering Management Plan (SEMP) (LMES 1997b). The report presented herein documents activities that in whole or in part satisfy specific requirements and actions stated in the UF{sub 6} Cylinder Project SRD and SEMP with respect to forecasting cylinder conditions. The wall thickness projections made in this report are based on the assumption that the corrosion trends noted will continue. Some activities planned may substantially reduce the rate of corrosion, in which case the results presented here are conservative. The results presented here are intended to supercede and enlarge the scope of those presented previously (Lyon 1995,1996, 1997). In particular, projections are made for thin-walled cylinders (nominal initial thickness 312.5 mils) and thick-walled cylinders (nominal initial thickness 625 mils). In addition, a preliminary analysis is conducted for the minimum thickness at the head/skirt interface for skirted cylinders.

  15. Correlation of Cooling Data from an Air-Cooled Cylinder and Several Multicylinder Engines

    Science.gov (United States)

    Pinkel, Benjamin; Ellerbrock, Herman H , Jr

    1940-01-01

    The theory of engine-cylinder cooling developed in a previous report was further substantiated by data obtained on a cylinder from a Wright r-1820-g engine. Equations are presented for the average head and barrel temperatures of this cylinder as functions of the engine and the cooling conditions. These equations are utilized to calculate the variation in cylinder temperature with altitude for level flight and climb. A method is presented for correlating average head and barrel temperatures and temperatures at individual points on the head and the barrel obtained on the test stand and in flight. The method is applied to the correlation and the comparison of data obtained on a number of service engines. Data are presented showing the variation of cylinder temperature with time when the power and the cooling pressure drop are suddenly changed.

  16. Rolling Cylinder Phase 1

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Taraborrelli, Valeria Taraborrelli

    Margheritini and Valeria Taraborrelli(valeria.taraborrelli@hotmail.it) with a total of 3 day visit from the developers. Laboratory tests in irregular waves will be performed by Lucia Margheritini. The report is aimed at the first stage testing of the Rolling Cylinder wave energy device. This phase includes...

  17. THE EXPERIMENT WITH FARADAY CYLINDER

    Institute of Scientific and Technical Information of China (English)

    薛英

    2004-01-01

    Suppose there are two electricity testers, A and B(Figure A) . And a metal cylinder C which is almost closed (called Faraday Cylinder)is fixed to tester B, making both tester B and cylinder C charged. As a result, the aluminium foil on tester B opens.

  18. Dynamic biomechanics of the human head in lateral impacts.

    Science.gov (United States)

    Zhang, Jiangyue; Yoganandan, Narayan; Pintar, Frank A

    2009-10-01

    The biomechanical responses of human head (translational head CG accelerations, rotational head accelerations, and HIC) under lateral impact to the parietal-temporal region were investigated in the current study. Free drop tests were conducted at impact velocities ranging from 2.44 to 7.70 m/s with a 40 durometer, a 90 durometer flat padding, and a 90 durometer cylinder. Specimens were isolated from PMHS subjects at the level of occipital condyles, and the intracranial substance was replaced with brain simulant (Sylgard 527). Three tri-axial accelerometers were instrumented at the anterior, posterior, and vertex of the specimen, and a pyramid nine accelerometer package (pNAP) was used at the contra-lateral site. Biomechanical responses were computed by transforming accelerations measured at each location to the head CG. The results indicated significant "hoop effect" from skull deformation. Translational head CG accelerations were accurately measured by transforming the pNAP, the vertex accelerations, or the average of anterior/posterior acceleration to the CG. The material stiffness and structural rigidity of the padding changed the biomechanical responses of the head with stiffer padding resulting in higher head accelerations. At the skull fracture, HIC values were more than 2-3x higher than the frontal skull fracture threshold (HIC=1000), emphasizing the differences between frontal and lateral impact. Rotational head accelerations up to 42.1 krad/s(2) were observed before skull fracture, indicating possible severe brain injury without skull fracture in lateral head impact. These data will help to establish injury criteria and threshold in lateral impacts for improved automotive protection and help clinicians understand the biomechanics of lateral head impact from improved diagnosis.

  19. 49 CFR 178.35 - General requirements for specification cylinders.

    Science.gov (United States)

    2010-10-01

    ...) The word “spun” or “plug” must be placed near the DOT specification marking when an end closure in the finished cylinder has been welded by the spinning process, or effected by plugging. (ii) As prescribed in... shoulder, top head, or neck. (5) The size of each marking must be at least 0.25 inch or as space permits...

  20. Dropwise Condensation on Hydrophobic Cylinders

    CERN Document Server

    Park, Kyoo-Chul; Hoang, Michelle; McManus, Brendan; Aizenberg, Joanna

    2016-01-01

    In this work, we studied the effect of the diameter of horizontal hydrophobic cylinders on droplet growth. We postulate that the concentration gradient created by natural convection around a horizontal circular cylinder is related to the droplet growth on the cylinder by condensation. We derive a simple scaling law of droplet growth and compare it with experimental results. The predicted negative exponent of drop diameter (d) as a function of cylinder diameter (D) at different time points is similar to the general trend of experimental data. Further, this effect of cylinder diameter on droplet growth is observed to be stronger than the supersaturation conditions created by different surface temperatures.

  1. Alternative method of retesting UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Christ, R. [Nuclear Crago + Service GmbH, Hanau (Germany)

    1991-12-31

    The paper describes an alternative method to perform the periodic inspection of UF{sub 6} cylinders. The hydraulic test is replaced by ultrasonic checking of wall thickness and by magnetic particle testing of all the weld seams. Information about the legal background, the air leak test and the qualification of inspectors is also given.

  2. Humeral head replacement in the treatment of 3,4 parts fracture of the proximal humerus in elderly%人工肱骨头置换治疗老年肱骨近端三、四部分骨折

    Institute of Scientific and Technical Information of China (English)

    季卫平; 李浩; 黄自强; 华以雄; 朱云龙

    2012-01-01

    Objective To explore the elderly proximal humerus 3,4 part fractures of the humeral head arthroplasty indications, techniques and postoperative rehabilitation to restore shoulder function. Methods 15 elderly cases of proximal humeral 3,4 parts fracture patients were performed humeral head replacement. Preoperative measuring health side of the greater tuberosity low to the top of the head of the humerus distance, intraoperative reset size nodules, as far as possible the reasonable control of the false body height and sloping, try to repair the damage rotator cuff, three phase planned postoperative rehabilitation treatment. Results 15 cases have been followed up, followed up for 9 ~77 months. 11 cases were completely not painful, 2 cases of joint line after a tenderness, and 1 case lift on shoulder movement, and 1 case with mild pain shoulder instability Neer score standard display, excellent in 7 patients, good in 6, and poor in 2. Conclusions For the old proximal humeral fractures serious 3 ,4 parts, especially the head shattered fracture patients, the humeral head replacement is expected to get a good curative effect of treatment. In familiar anatomical and shoulder function based on the characteristics of the operation indication, strictly grasp, follow the head of the humerus replacement process the key technology of method, should as far as possible reserves during the greater tuberosity and soft tissue belongs to, close to anatomical reattachment, repair rotator cuff injury. With planned postoperative rehabilitation training, quickly shoulder activities can be restored.%目的 探讨老年肱骨近端三、四部分骨折行人工肱骨头置换术的适应证、技术要点及术后康复治疗对肩关节功能恢复的影响.方法 对15例老年肱骨近端三、四部分骨折患者行人工肱骨头置换.术前测量健侧大结节最低点至肱骨头最高点的距离;术中尽量复位大小结节,合理控制假体高度及后倾角度,尽

  3. Artificial Femoral Head Replacement in Treatment of 36 Patients with Osteoporotic Femoral Intertrochanteric Fracture%人工股骨头置换治疗骨质疏松性股骨粗隆间骨折36例

    Institute of Scientific and Technical Information of China (English)

    桑晓文; 杨利学; 谭龙旺; 孙智平; 张快强

    2014-01-01

    目的观察人工股骨头置换治疗骨质疏松性股骨粗隆间骨折的临床效果。方法对2008年1月-2013年6月收治的36例骨质疏松性股骨粗隆间骨折行加长柄双极骨水泥人工股骨头置换术,术后常规予鲑鱼降钙素联合钙剂抗骨质疏松治疗。结果术后Harris关节功能评分平均88分(68~94分),其中优18例,良13例,可4例,差1例,优良率为86.1%。2例术后活动后出现髋部轻度疼痛,1例下肢深静脉栓塞;本组均无髋关节脱位、假体周围再骨折、假体松动及下陷、大小粗隆骨折不愈合等并发症发生。结论人工股骨头置换术治疗骨质疏松性股骨粗隆间骨折可减少力学及内固定相关风险,且并发症少,效果良好。%Objective To observe the effect of artificial femoral head replacement in treatment of osteoporotic femoral inter-trochanteric fracture. Methods A total of 36 inpatients with osteoporotic femoral intertrochanteric fracture underwent long-stem ce-mented artificial femoral head replacement during January 2008 and June 2013, and routine salmon calcitonin combined with calcium of anti osteoporosis treatment was performed after operations. Results The postoperative Harris hip score was 88 (68-94), which included excellent in 18 cases, good in 13 cases, common in 4 cases and poor in 1 case, and the excellent and good rate was 86.1%. Two patients had postoperative hip mild pain after activity, and one patient had deep vein thrombosis of lower extremity, but there were no complications such as dislocation of hip joint, periprosthetic fracture, prosthesis loosening, subsidence and greater trochanteric fracture nonunion. Conclusion Artificial femoral head replacement in treatment of osteoporotic femoral intertrochanter-ic fracture can reduce the risks of mechanics and internal fixation with fewer complications and better effect.

  4. A PORTABLE DENTAL STERILIZING CYLINDER

    Science.gov (United States)

    The report describes an aluminum cylinder in which dental instruments could be sterilized under emergency field conditions and at the same time be...protected against corrosion. The procedure involves loading the cylinder with dental instruments, flushing it with ethylene oxide-Freon gas, closing it...and then immersing it in boiling water for l hour. In preliminary experiments with a prototype of the sterilizing cylinder, dental instruments were

  5. Effect of femoral head size on the wear of metal on metal bearings in total hip replacements under adverse edge-loading conditions.

    Science.gov (United States)

    Al-Hajjar, Mazen; Fisher, John; Williams, Sophie; Tipper, Joanne L; Jennings, Louise M

    2013-02-01

    Metal-on-metal (MoM) bearings have shown low-wear rates under standard hip simulator conditions; however, retrieval studies have shown large variations in wear rates and mechanisms. High-wear in vivo has caused catastrophic complications and has been associated with steep cup-inclination angle (rotational malpositioning). However, increasing the cup-inclination angle in vitro has not replicated the increases in wear to the same extent as those observed in retrievals. Clinically relevant wear rates, patterns, and particles were observed in vitro for ceramic-on-ceramic bearings when microseparation (translational malpositioning) conditions were introduced into the gait cycle. In the present study, 28 and 36-mm MoM bearings were investigated under adverse conditions. Increasing the cup angle from 45° to 65° resulted in a significant increase in the wear rate of the 28 mm bearings. However, for the 36 mm bearings, head-rim contact did not occur under the steep cup-angle condition, and the wear rate did not increase. The introduction of microseparation to the gait cycle significantly increased the wear rate of the MoM bearings. Cup angle and head size did not influence the wear rate under microseparation conditions. This study indicated that high-in vivo wear rates were associated with edge loading due to rotational malpositioning such as high-cup-inclination angle and translational malpositioning that could occur due to several surgical factors. Translational malpositioning had a more dominant effect on the wear rate. Preclinical simulation testing should be undertaken with translational and rotational malpositioning conditions as well as standard walking cycle conditions defined by the ISO standard. Copyright © 2012 Wiley Periodicals, Inc.

  6. Dynamic Response Analysis for Embedded Large-Cylinder Breakwaters Under Wave Excitation

    Institute of Scientific and Technical Information of China (English)

    王元战; 祝振宇; 周枝荣

    2004-01-01

    A numerical model is developed for dynamic analysis of large-cylinder breakwaters embedded in soft soil. In the model, the large cylinder is taken as a rigid body divided into elements and the soft soil is replaced by discrete 3D nonlinear spring-dashpot systems. The numerical model is used to simulate the dynamic response of a large-cylinder breakwater to breaking wave excitation. The effects of the dynamic stress-strain relationship models of the soil, the radius and embedded depth of the cylinder, the nonlinear behaviors of the soil, and the limit strength condition of the soil on the dynamic responses of the large-cylinder structure are investigated with an example given. It is indicated that the above-mentioned factors have significant effects on the dynamic responses of an embedded large cylinder breakwater under breaking wave excitation.

  7. 一种WSN簇头更换过程中的信息转移方法%A Method of Information Transfer in the Process of WSN Cluster Head Replacement

    Institute of Scientific and Technical Information of China (English)

    苑津莎; 张路路; 赵曼

    2016-01-01

    In this paper,the concept of cluster ID is put forward,and a new method is put forward based on which the routing information and key information are transferred to the next cluster head in the replacement process. When the cluster ID is used,the data packets can be sent directly to the cluster ID in the next hop node,which can avoid the complicated process of the cluster head.According to the existing cluster key and application of Diffie Hellman algorithm generated key between the new cluster head nodes.Finally,we use formalization of BAN logic analysis method,the security of the protocol is proved.%提出簇ID的概念,在此基础上提出了一种簇头更换过程中将路由信息、密钥信息转移到下一个簇头节点的方法.利用簇ID通信时,可以直接发送数据包给下一跳节点内的簇ID,避免了查询簇头的繁琐过程,使簇头转移过程简化.根据现有簇头与簇头之间的簇间密钥,应用Diffie-Hellman算法生成新簇头节点间密钥,最后运用BAN逻辑的形式化分析方法,对该协议的安全性进行了证明.

  8. Ankle replacement

    Science.gov (United States)

    Ankle arthroplasty - total; Total ankle arthroplasty; Endoprosthetic ankle replacement; Ankle surgery ... You may not be able to have a total ankle replacement if you have had ankle joint infections in ...

  9. Knee Replacement

    Science.gov (United States)

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  10. Rolling Cylinder Phase 1bis

    DEFF Research Database (Denmark)

    Margheritini, Lucia

    Cylinder Phase 1: proof of concept and first optimization”, DCE report 115, ISSN 1901-726X, and it is recommended that the two are consulted together as they were firstly agreed to be in one document. The present report aims at estimate the efficiency of the Rolling Cylinder long model (previously...

  11. Natural convection from circular cylinders

    CERN Document Server

    Boetcher, Sandra K S

    2014-01-01

    This book presents a concise, yet thorough, reference for all heat transfer coefficient correlations and data for all types of cylinders: vertical, horizontal, and inclined. This book covers all natural convection heat transfer laws for vertical and inclined cylinders and is an excellent resource for engineers working in the area of heat transfer engineering.

  12. Approximation of Surfaces by Cylinders

    DEFF Research Database (Denmark)

    Randrup, Thomas

    1998-01-01

    We present a new method for approximation of a given surface by a cylinder surface. It is a constructive geometric method, leading to a monorail representation of the cylinder surface. By use of a weighted Gaussian image of the given surface, we determine a projection plane. In the orthogonal...

  13. Bipolar femoral head replacement for the treatment of femoral neck fractures in elder Parkinson's disease patients%双极人工股骨头治疗老年帕金森患者股骨颈骨折

    Institute of Scientific and Technical Information of China (English)

    庄泽; 曾春; 曾花; 王昆

    2012-01-01

    BACKGROUND: Due to the muscle imbalance outcomes, Parkinson's patients are easy to fall and have a high risk of femoral neck fracture. OBJECTIVE: To explore the treatment outcomes of bipolar femoral head replacement for the femoral neck fractures in elder Parkinson's patients METHODS: A retrospective analysis was carried out on the clinical data of the 14 Parkinson's disease patients of femoral neck fractures, a total of 14 hips, who were treated with bipolar femoral head replacement. The patients were divided into three phases by Hoehn-Yahr classification, 3 cases in I phase, 4 cases in II phase, 5 cases in III phase and 2 cases in IV phase. The average surgery age was 62 to 83 years old. The Harris score, Fugl-Meyer scale and Unified Parkinson's Disease Rating Scale score were used as follow-up judgment. RESULTS AND CONCLUSION: The average follow-up time was 1 to 6 years. Harris score of 14 patients was postoperatively 85.4 better than preoperatively 22.3 (P < 0.05), Fugl-Meyer score was postoperatively 81.6 better than preoperatively 52.5 (P < 0.05). There was no significant difference of Unified Parkinson's Disease Rating Scale score before and after operation, and the Parkinson's disease controlled stable. No prosthesis loosening, dislocation or other complications. Early and mid-term follow-up showed under the effective medical control of the neurology drugs, bipolar femoral head replacement is a safe and effective treatment of femoral neck fracture for Hoehn-Yahr I -IV Parkinson's patient. There is relationship between the hip joint function and the control of the Parkinson's disease after replacement.%背景:帕金森患者由于肌力不平衡等原因更容易跌倒,发生股骨颈骨折的风险高.目的:观察双极人工股骨头置换对老年帕金森病合并股骨颈骨折患者的治疗效果.方法:回顾分析14例帕金森病合并股骨颈骨折行双极人工股骨头置换患者的临床资料,共14髋,Hoehn-Yahr分级Ⅰ期3例,Ⅱ期4

  14. Prediction of External Corrosion for Steel Cylinders 2003 Report

    Energy Technology Data Exchange (ETDEWEB)

    Schmoyer, RLS

    2003-09-24

    '' thin-wall cylinders: 102 cylinders at Paducah, 104 at ETTP, and 117 at Portsmouth; and 72 thick-wall cylinders at Portsmouth. However, because of missing values, repeated measures on the same cylinders, outliers, and other data problems, not all of these measurements are necessarily used in the corrosion analysis, and some previous measurements may simply be replaced with the new ones. In this edition of the report, cylinder subpopulation definitions and counts are updated using the latest (as of June 2003) information from the Cylinder Inventory Database (CID). Cylinders identified in the CID as painted during the last ten years are excluded from subpopulations considered at-risk of failing minimum thickness criteria, because it is assumed that painting fully arrests corrosion for ten years. As in the previous edition of the report, two different approaches to corrosion modeling are pursued: (1) a direct approach in which minimum thickness is modeled directly as a function of age, subpopulation, and initial thickness estimates; and (2) an indirect approach, in which maximum pit depth is modeled, and the pit-depth model is then combined with a model of initial thickness to compute estimates of minimum thickness.

  15. Metal on Metal Surface Replacement of Hip in Young Patients with Rheumatoid Arthritis of Aseptic Necrosis of Femoral Head%金属对金属人工全髋表面置换术的临床应用

    Institute of Scientific and Technical Information of China (English)

    夏庆; 陈统一; 姜晓幸; 姚振钧

    2001-01-01

    Purpose Present study investigated the role of metal on metal surface replacement of the hip in treating the young patients suffering rheumatoid arthritis or aseptic necrosis of femoral head. Methods Between Jan. 1995 and Dec. 1996.16 patients with 17 hips( rheumatoid arthritis 14, aseptic necrosis of femoral head 3) were resurfaced with hybrid metal on metal surface replacement prothesis. Patients were evaluated by self assessment form,hip function examination. Radiographs and Harris hip score. The average follow up time was 58.2 months. Results No patient received revision. Radiographs showed that all implants were in position satisfyingly. No loosening were revealed. The result of self assessment showed that patients were satisfied with 16 hips. The Harris score rose from preoperative 44(31 - 52) to postoperative 91 (79- 96). Conclusions The metal on metal surface replacement of hip is a useful treatment to release pain and keep the hip function of young patients suffering rheumatoid arthritis or aseptic necrosis of femoral head.%目的探讨金属对金属人工全髋表面置换术治疗类风湿性关节炎和股骨头无菌性坏死的临床价值。 方法从1995年1月至1996年12月,对16例患者17个髋关节(其中类风湿性关节炎14个,股骨头无菌性坏 死3个)行混合型金属对金属人工全髋表面置换术,术后行问卷调查、髋关节功能检查、X线和Harris评分分析, 平均随访58.2月。结果所有患者没有一例行翻修手术,X线显示所有表面置换假体植入位置满意,没有假体 松动、移位现象出现。问卷调查显示患者对16个髋关节的术后情况表示非常满意。Harris评分平均指数从术前 的44(31~52)分提高到术后的91(79~96)分。结论金属对金属人工全髋表面置换术不失为患类风湿性关节 炎和股骨头无菌性坏死的年青患者为保存关节功能,改善疼痛的一种有价值的治疗方法。

  16. Adaptronic tools for superfinishing of cylinder bores

    Science.gov (United States)

    Roscher, Hans-Jürgen; Hochmuth, Carsten; Hoffmann, Michael; Praedicow, Michael

    2012-04-01

    Today in the production of internal combustion engines it is possible to make pistons as well as cylinders, for all practical purposes, perfectly round. The negative consequences of the subsequent assembly processes and operation of the engine is that the cylinders and pistons are deformed, resulting in a loss of power and an increase in fuel consumption. This problem can be solved by using an adaptronic tool, which can machine the cylinder to a predetermined nonround geometry, which will deform to the required geometry during assembly and operation of the engine. The article describes the actuatory effect of the tool in conjunction with its measuring and controlling algorithms. The adaptronic tool consists out the basic tool body and three axially-staggered floating cutter groups, these cutter groups consist out of guides, actuators and honing stones. The selective expansion of the tool is realised by 3 piezoelectric multilayer-actuators deployed in a series - parallel arrangement. It is also possible to superimpose actuator expansion on the conventional expansion. A process matrix is created during the processing of the required and actual contour data in a technology module. This is then transferred over an interface to the machine controller where it is finally processed and the setting values for the piezoelectric actuators are derived, after which an amplifier generates the appropriate actuator voltages. A slip ring system on the driveshaft is used to transfer the electricity to the actuators in the machining head. The functioning of the adaptronic form-honing tool and process were demonstrated with numerous experiments. The tool provides the required degrees of freedom to generate a contour that correspond to the inverse compound contour of assembled and operational engines.

  17. Scalar cylinder-plate and cylinder-cylinder Casimir interaction in higher dimensional spacetime

    CERN Document Server

    Teo, L P

    2015-01-01

    We study the cylinder-plate and the cylinder-cylinder Casimir interaction in the $(D+1)$-dimensional Minkowski spacetime due to the vacuum fluctuations of massless scalar fields. Different combinations of Dirichlet (D) and Neumann (N) boundary conditions are imposed on the two interacting objects. For the cylinder-cylinder interaction, we consider the case where one cylinder is inside the other, and the case where the two cylinders are outside each other. By computing the transition matrices of the objects and the translation matrices that relate different coordinate systems, the explicit formulas for the Casimir interaction energies are derived. Using perturbation technique, we compute the small separation asymptotic expansions of the Casimir interaction energies up to the next-to-leading order terms. The leading terms coincide with the respective results obtained using proximity force approximation, which is of order $d^{-D+1/2}$, where $d$ is the distance between the two objects. The results on the next-to...

  18. Approximation of Surfaces by Cylinders

    DEFF Research Database (Denmark)

    Randrup, Thomas

    1998-01-01

    We present a new method for approximation of a given surface by a cylinder surface. It is a constructive geometric method, leading to a monorail representation of the cylinder surface. By use of a weighted Gaussian image of the given surface, we determine a projection plane. In the orthogonal...... projection of the surface onto this plane, a reference curve is determined by use of methods for thinning of binary images. Finally, the cylinder surface is constructed as follows: the directrix of the cylinder surface is determined by a least squares method minimizing the distance to the points...... in the projection within a tolerance given by the reference curve, and the rulings are lines perpendicular to the projection plane. Application of the method in ship design is given....

  19. Application of NIOSH lifting equation in manual lift of cylinder head%NIOSH 手工提举方程在缸盖搬运中的应用

    Institute of Scientific and Technical Information of China (English)

    蒋林艳; 黄民继; 孙爱民; 李言明; 麦浪; 黄华仲; 刘甘霖; 陈春霞

    2014-01-01

    To improve productivity and balance the energy and stamina of operators , human potential under the premise of safety, the NIOSH lifting equation was used to the ergonomics safety assessment on manual lift of cylin -der head in machine shop.The study on horizontal distance (H), vertical distance(V), lift distance(D)and fre-quency(F)of the operator was conducted , and the weight and height coefficients of revised NIOSH lifting equation were revised.The results showed that, after a reasonable adjustment of the four major parameters , the efficiency can be improved without robots and other equipments , simultaneously, the safety and health of the operator could be ensured.%为了平衡操作人员的精力和体力,在保证人安全的前提下,提高生产力。采用 NIOSH(Na-tional Institute of Occupational Safety and Health )提举方程对机加工车间缸盖搬运上线工位进行人机工程安全评估,通过对操作工作业的水平距离(H)、垂直距离(V)、提升距离(D)以及频率(F)进行研究,并对修订版 NIOSH 提举方程的重量常量与高度系数进行了修正。结果表明,经过合理调整四大参数,可在不设起吊、机器人等设备的情况下,保证人的身心健康,节约成本,提高人的工作效能。

  20. 纳米流冷却液射流方式强化缸盖局部冷却的试验分析%Analysis of strengthening local cooling on diesel cylinder head using nano-fluids with jet impingement technology

    Institute of Scientific and Technical Information of China (English)

    郑伟; 苏忠根; 张振东; 程强

    2013-01-01

      为解决柴油机缸盖高热密度区域的冷却问题,本文采用射流方式的纳米流对其进行强化冷却.通过配置不同体积比的Cu、MgO、Al2O3纳米流,对自制的带有射流装置的柴油机缸盖进行传热性能对比研究.结果表明,与传统冷却液水相比,射流方式下3种纳米流冷却液均能不同程度地提升缸盖高热密度区域的传热性能,局部最大增加比率超过110%;在体积比≤2%时,3种纳米流冷却液射流传热系数都呈现出随粒子浓度的增加而增加的趋势,但随浓度的进一步增加反而降低;3种纳米流冷却液的射流传热系数随射流速度的增加而增加,但MgO纳米流在低射流速度下的射流传热系数最小,甚至比传统冷却液低2%~4%;3种纳米流冷却液的射流传热系数随射流高度的增加而增加,但射流高度过高会减小射流传热系数;随射流角度的增加射流传热系数也增加,射流角度的降低不仅降低射流传热系数还会加重测试点温度不一致的现象,过低射流角度时测试点温度值最大差距近30℃;射流传热系数随射流初始温度的增加而增加,但65℃之后,传热系数则随着射流初始温度的升高而下降;随着粒子浓度增高,电动泵消耗功率随之增加,本试验最大功率损耗为115 W.本文的研究成果是一种柴油机冷却技术的应用基础研究,可为实现缸盖局部高热密度区域的良好散热提供一种新的科研思路.%Diesel engines, as an important power source for machinery, are increasingly subject to people’s attention. Only with better cooling systems can they put up better work performance. Because coolant flow in the cylinder heads is difficult, how to better cool this part is becoming a hot point in the researching world. To solve the problem of cooling the high heat density areas in diesel cylinder heads, our study used nanofluids with jet impingement technology, due to better capacity of

  1. Directed Replacement

    CERN Document Server

    Karttunen, L

    1996-01-01

    This paper introduces to the finite-state calculus a family of directed replace operators. In contrast to the simple replace expression, UPPER -> LOWER, defined in Karttunen (ACL-95), the new directed version, UPPER @-> LOWER, yields an unambiguous transducer if the lower language consists of a single string. It transduces the input string from left to right, making only the longest possible replacement at each point. A new type of replacement expression, UPPER @-> PREFIX ... SUFFIX, yields a transducer that inserts text around strings that are instances of UPPER. The symbol ... denotes the matching part of the input which itself remains unchanged. PREFIX and SUFFIX are regular expressions describing the insertions. Expressions of the type UPPER @-> PREFIX ... SUFFIX may be used to compose a deterministic parser for a ``local grammar'' in the sense of Gross (1989). Other useful applications of directed replacement include tokenization and filtering of text streams.

  2. Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines

    Science.gov (United States)

    Yonushonis, T. M.; Wiczynski, P. D.; Myers, M. R.; Anderson, D. D.; McDonald, A. C.; Weber, H. G.; Richardson, D. E.; Stafford, R. J.; Naylor, M. G.

    1999-01-01

    In-cylinder components and tribological system concepts were designed, fabricated and tested at conditions anticipated for a 55% thermal efficiency heavy duty diesel engine for the year 2000 and beyond. A Cummins L10 single cylinder research engine was used to evaluate a spherical joint piston and connecting rod with 19.3 MPa (2800 psi) peak cylinder pressure capability, a thermal fatigue resistant insulated cylinder head, radial combustion seal cylinder liners, a highly compliant steel top compression ring, a variable geometry turbocharger, and a microwave heated particulate trap. Components successfully demonstrated in the final test included spherical joint connecting rod with a fiber reinforced piston, high conformability steel top rings with wear resistant coatings, ceramic exhaust ports with strategic oil cooling and radial combustion seal cylinder liner with cooling jacket transfer fins. A Cummins 6B diesel was used to develop the analytical methods, materials, manufacturing technology and engine components for lighter weight diesel engines without sacrificing performance or durability. A 6B diesel engine was built and tested to calibrate analytical models for the aluminum cylinder head and aluminum block.

  3. 乙型血友病性肩关节炎肱骨头坏死置换治疗1例%Humeral head replacement in a hemophilia B omarthritis patient

    Institute of Scientific and Technical Information of China (English)

    祁伟仲; 林荔军; 李奇

    2016-01-01

    背景:过去对乙型血友病性关节炎的手术治疗多面临手术难度大、术中出血难以估计、创面愈合困难等情况。而在围手术期间将患者凝血Ⅸ因子活性控制在安全范围时,可保证手术的安全进行,创面愈合好,康复情况佳,远期未见明显并发症。目的:探讨乙型血友病性肩关节炎行肱骨头置换的围手术期诊治要点,分析对预后及康复的重要性。方法:通过文献复习,总结乙型血友病性关节炎行外科治疗的意义及围手术期并发症的防治处理。对1例乙型血友病性肩关节炎诊断后,在监控凝血因子活性,输注人凝血酶原复合物及冰冻血浆的条件下行肱骨头置换治疗。结果与结论:①通过监控治疗,患者在凝血Ⅸ因子活性由7%上升到50%的情况下接受肱骨头置换手术;②置换后3 d内将凝血Ⅸ因子控制在>30%,3 d至2周内控制在>20%时,术后未见明显并发症;③结果提示,乙型血友病性关节炎行外科治疗较常见,对其病情评估及处理十分重要。肱骨头置换围手术期采用人凝血酶原复合物替代治疗,将凝血因子活性控制于适宜范围,可有效预防患者置换后并发症的发生。%BACKGROUND:In the past, the surgical treatment of patients with hemophilia B was difficult, the bleeding was difficult to estimate, and the wound healing was difficult. In the perioperative period, the control of coagulation factor IX activity in a safe range can ensure the safety of the operation, resulting in wel wound healing, good recovery, and no significant complications appeared in the long term. OBJECTIVE:To study essentials of perioperative diagnosis and treatment in omarthritis patients with hemophilia B undergoing humeral head replacement, and to analyze the importance on prognosis and rehabilitation. METHODS:The significance of surgical treatment for hemophilia B patients with arthritis, the prevention

  4. Knee Replacement

    Science.gov (United States)

    ... need knee replacement surgery usually have problems walking, climbing stairs, and getting in and out of chairs. Some ... a total living space on one floor since climbing stairs can be difficult. Install safety bars or a ...

  5. Replacing penalties

    Directory of Open Access Journals (Sweden)

    Vitaly Stepashin

    2017-01-01

    Full Text Available УДК 343.24The subject. The article deals with the problem of the use of "substitute" penalties.The purpose of the article is to identify criminal and legal criteria for: selecting the replacement punishment; proportionality replacement leave punishment to others (the formalization of replacement; actually increasing the punishment (worsening of legal situation of the convicted.Methodology.The author uses the method of analysis and synthesis, formal legal method.Results. Replacing the punishment more severe as a result of malicious evasion from serving accused designated penalty requires the optimization of the following areas: 1 the selection of a substitute punishment; 2 replacement of proportionality is serving a sentence other (formalization of replacement; 3 ensuring the actual toughening penalties (deterioration of the legal status of the convict. It is important that the first two requirements pro-vide savings of repression in the implementation of the replacement of one form of punishment to others.Replacement of punishment on their own do not have any specifics. However, it is necessary to compare them with the contents of the punishment, which the convict from serving maliciously evaded. First, substitute the punishment should assume a more significant range of restrictions and deprivation of certain rights of the convict. Second, the perfor-mance characteristics of order substitute the punishment should assume guarantee imple-mentation of the new measures.With regard to replacing all forms of punishment are set significant limitations in the application that, in some cases, eliminates the possibility of replacement of the sentence, from serving where there has been willful evasion, a stricter measure of state coercion. It is important in the context of the topic and the possibility of a sentence of imprisonment as a substitute punishment in cases where the original purpose of the strict measures excluded. It is noteworthy that the

  6. Pressure cylinders under fire condition

    Directory of Open Access Journals (Sweden)

    Jan Hora

    2016-03-01

    Full Text Available The presence of pressure cylinders under fire conditions significantly increases the risk rate for the intervening persons. It is considerably problematic to predict the pressure cylinders behaviour during heat exposition, its destruction progress and possible following explosion of the produced air–gas mixture because pressure cylinders and its environment generate a highly complicated dynamic system during an uncontrolled destruction. The large scale tests carried out by the Pilsen Fire and Rescue Department and the Rapid Response Unit of the Czech Republic Police in October 2012 and in May 2014 in the Military area Brdy and in the area of the former Lachema factory in Kaznějov had several objectives, namely, to record, qualify and quantify some of the aspects of an uncontrolled heat destruction procedure of an exposed pressure cylinder in an enclosed space and to qualify and describe the process of a controlled destruction of a pressure cylinder by shooting through it including basic tactical concepts. The article describes the experiments that were carried out.

  7. Replacement of alloy 600 by alloy 690 for steam generator tubes and closure heads in PWR; Gains apportes par le changement de materiau dans les generateurs de vapeur et les couvercles de cuve des REP: passage de l'alliage 600 a l'alliage 690

    Energy Technology Data Exchange (ETDEWEB)

    Bioulac, M.; Cipiere, M.F.; Poudroux, G. [FRAMATOME ANP, 92 - Paris-La-Defence (France); Champigny, F.; Mercier, L.; Rouillon, Y.; Vaillant, F. [Electricite de France (EDF), 75 - Paris (France)

    2004-07-01

    The replacement of alloy 600 by alloy 690 for steam generator tubes, tube plugs and closure head penetrations has well fulfilled its expectation concerning resistance to stress corrosion. The first steam generators fitted with tubes in alloy 690 have been operating for 14 years, the first plugs were set more than 20 years ago and the first closure head equipped with adapters in alloy 690 was installed in 1993. The feedback experience on non-destructive testing for these 3 components have shown no cracks. As a consequence the maintenance program has been reduced. A majority of nuclear power plant operators throughout the world have also selected the alloy 690. (A.C.)

  8. Blower Cooling of Finned Cylinders

    Science.gov (United States)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1937-01-01

    Several electrically heated finned steel cylinders enclosed in jackets were cooled by air from a blower. The effect of the air conditions and fin dimensions on the average surface heat-transfer coefficient q and the power required to force the air around the cylinders were determined. Tests were conducted at air velocities between the fins from 10 to 130 miles per hour and at specific weights of the air varying from 0.046 to 0.074 pound per cubic foot. The fin dimensions of the cylinders covered a range in pitches from 0.057 to 0.25 inch average fin thicknesses from 0.035 to 0.04 inch, and fin widths from 0.67 to 1.22 inches.

  9. Study on postoperative invisible blood loss in patients with bipolar artificial femoral head replacement surgery%双极人工股骨头置换患者术后隐形失血的研究

    Institute of Scientific and Technical Information of China (English)

    农文海; 宋猛先; 黄毅; 莫金平; 潘文奇

    2014-01-01

    Objective To evaluate the postoperative invisible blood loss in patients with bipolar artificial femoral head replacement surgery. Methods The clinical data of 62 patients with bipolar artificial femoral head re-placement surgery admitted in our hospital from January 2006 to June 2013 were analyzed. The volume of postopera-tive invisible blood loss, changes in perioperative Hct and variation of invisible blood loss in patients with different age, sex, body mass index (BMI), with or without preoperative chronic diseases, with or without postoperative ve-nous thrombosis in lower limbs and different postoperative anticoagulation protocols were observed and documented. Results The postoperative invisible blood loss was (560.82 ± 89.16) ml, accounting for 62.22% of the total blood loss. 2 days after operation, the Hct reached a minimum value, and it increased steadily in the 3rd postoperative day. The postoperative blood loss volume in patients with BMI>25 kg/m2 was more than those with BMI≤25 kg/m2, and the difference was statistically significant (P0.05). Conclusion The postoperative invisible blood loss plays an impor-tant role in prognosis, which is mainly influenced by BMI.%目的:评价初次进行双极人工股骨头置换术患者的隐性失血状况。方法选取2006年1月至2013年6月在我院进行双极人工股骨头置换术的62例患者的临床资料,观察并统计患者术后隐性出血量、围术期血细胞比容(Hct)的变化以及评估在不同年龄、性别、体质量指数、术前是否合并慢性疾病、术后是否下肢静脉血栓及术后抗凝方式患者围术期的隐性出血情况。结果患者术后隐性失血量为(560.82±89.16) ml,占总失血量的62.22%;术后第2天是患者Hct的最低值,在术后第3天以后患者的Hct呈现出平稳上升趋势;患者体质量指数>25 kg/m2的术后隐性失血量明显多于≤25 kg/m2者,差异有统计学意义(P0.05)。结论隐性失血是影响患

  10. Filament winding cylinders. I - Process model

    Science.gov (United States)

    Lee, Soo-Yong; Springer, George S.

    1990-01-01

    A model was developed which describes the filament winding process of composite cylinders. The model relates the significant process variables such as winding speed, fiber tension, and applied temperature to the thermal, chemical and mechanical behavior of the composite cylinder and the mandrel. Based on the model, a user friendly code was written which can be used to calculate (1) the temperature in the cylinder and the mandrel, (2) the degree of cure and viscosity in the cylinder, (3) the fiber tensions and fiber positions, (4) the stresses and strains in the cylinder and in the mandrel, and (5) the void diameters in the cylinder.

  11. PERCOLATION OF RANDOM CYLINDER AGGREGATES

    Directory of Open Access Journals (Sweden)

    Dominique Jeulin

    2011-05-01

    Full Text Available The percolation threshold ρc of Boolean models of cylinders with their axis parallel to a given direction is studied by means of simulations. An efficient method of construction of percolating connected components was developed, and is applied to one or two scales Boolean model, in order to simulate the presence of aggregates. The invariance of the percolation threshold with respect to affine transformations in the common direction of the axis of cylinders is approximately satisfied on simulations. The prediction of the model (ρc close to 0.16 is consistent with experimental measurements on plasma spray coatings, which motivated this study.

  12. Esophageal replacement.

    Science.gov (United States)

    Kunisaki, Shaun M; Coran, Arnold G

    2017-04-01

    This article focuses on esophageal replacement as a surgical option for pediatric patients with end-stage esophageal disease. While it is obvious that the patient׳s own esophagus is the best esophagus, persisting with attempts to retain a native esophagus with no function and at all costs are futile and usually detrimental to the overall well-being of the child. In such cases, the esophagus should be abandoned, and the appropriate esophageal replacement is chosen for definitive reconstruction. We review the various types of conduits used for esophageal replacement and discuss the unique advantages and disadvantages that are relevant for clinical decision-making. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Tests of the CMS Phase 1 Upgrade FPIX Half Cylinders

    Science.gov (United States)

    Chen, Xuan; CMS Collaboration

    2017-01-01

    The pixel detector is an integral part of the CMS silicon tracker, designed to measure the position and momentum of charged particles produced in high-energy collisions at the Large Hadron Collider (LHC). The phase 1 upgrade of the CMS forward pixel detector will replace the existing forward pixel detector at the end of 2016. This upgrade will include three forward disks on each end, and is organized in four mechanical support structures, called half-cylinders. Each half-cylinder contains frontend readout electronic boards, power regulators, cables and fibers in addition to the three half disks with the active pixel modules. Full system tests are being performed on the half cylinders after each step of assembly and after its completion. I will describe the various steps of the testing and qualification procedure, focusing on the final assembly and the full system test for the integrated half-cylinder. I will also discuss the results obtained for the completed detector before its shipment to CERN.

  14. Wear Performance of Sequentially Cross-Linked Polyethylene Inserts against Ion-Treated CoCr, TiNbN-Coated CoCr and Al2O3 Ceramic Femoral Heads for Total Hip Replacement

    Directory of Open Access Journals (Sweden)

    Christian Fabry

    2015-02-01

    Full Text Available The aim of the present study was to evaluate the biotribology of current surface modifications on femoral heads in terms of wettability, polyethylene wear and ion-release behavior. Three 36 mm diameter ion-treated CoCr heads and three 36 mm diameter TiNbN-coated CoCr heads were articulated against sequentially cross-linked polyethylene inserts (X3 in a hip joint simulator, according to ISO 14242. Within the scope of the study, the cobalt ion release in the lubricant, as well as contact angles at the bearing surfaces, were investigated and compared to 36 mm alumina ceramic femoral heads over a period of 5 million cycles. The mean volumetric wear rates were 2.15 ± 0.18 mm3·million cycles−1 in articulation against the ion-treated CoCr head, 2.66 ± 0.40 mm3·million cycles−1 for the coupling with the TiNbN-coated heads and 2.17 ± 0.40 mm3·million cycles−1 for the ceramic heads. The TiNbN-coated femoral heads showed a better wettability and a lower ion level in comparison to the ion-treated CoCr heads. Consequently, the low volumes of wear debris, which is comparable to ceramics, and the low concentration of metal ions in the lubrication justifies the use of coated femoral heads.

  15. On certain geodesic conjugacies of flat cylinders

    Indian Academy of Sciences (India)

    C S ARAVINDA; H A GURURAJA

    2017-06-01

    We prove $C^0$-conjugacy rigidity of any flat cylinder among two different classes of metrics on the cylinder, namely among the class of rotationally symmetric metrics and among the class of metrics without conjugate points.

  16. Anisotropic Poisson Processes of Cylinders

    CERN Document Server

    Spiess, Malte

    2010-01-01

    Main characteristics of stationary anisotropic Poisson processes of cylinders (dilated k-dimensional flats) in d-dimensional Euclidean space are studied. Explicit formulae for the capacity functional, the covariance function, the contact distribution function, the volume fraction, and the intensity of the surface area measure are given which can be used directly in applications.

  17. Natural convective heat transfer from square cylinder

    Science.gov (United States)

    Novomestský, Marcel; Smatanová, Helena; Kapjor, Andrej

    2016-06-01

    This article is concerned with natural convective heat transfer from square cylinder mounted on a plane adiabatic base, the cylinders having an exposed cylinder surface according to different horizontal angle. The cylinder receives heat from a radiating heater which results in a buoyant flow. There are many industrial applications, including refrigeration, ventilation and the cooling of electrical components, for which the present study may be applicable

  18. Comparison of aerodynamic noise from three nose-cylinder combinations

    Science.gov (United States)

    Guenther, R. A.; Reding, M. P.

    1970-01-01

    Results of experiments with three different cylinder and blunted nose combinations are discussed. Combinations include smooth cylinder with single 15 deg cone, smooth cylinder with double cone of 25 and 10 deg, and longitudinally corrugated cylinder with similar double cone.

  19. 25 CFR 700.183 - Determination of replacement housing benefit.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Determination of replacement housing benefit. 700.183... RELOCATION PROCEDURES Replacement Housing Payments § 700.183 Determination of replacement housing benefit. (a) Amount of benefit. The replacement housing benefit for a certified eligible head-of-household is...

  20. Wake-induced vibrations in Tandem Cylinders

    Science.gov (United States)

    Mysa, Ravi Chaithanya; Jaiman, Rajeev Kumar

    2015-11-01

    The upstream cylinder is fixed in the tandem cylinders arrangement. The downstream cylinder is placed at a distance of four diameters from the upstream cylinder in the free stream direction and is mounted on a spring. The dynamic response of the downstream cylinder is studied at Reynolds number of 10,000. The transverse displacement amplitude of the downstream cylinder is larger compared to that of single cylinder in the post-lock-in region. The transverse dynamic response of the downstream cylinder in the post-lock-in region is characterized by a dominant low frequency component compared to shed frequency, which is nearer to the structural natural frequency. The interaction of upstream wake with the downstream cylinder is carefully analyzed to understand the introduction of low frequency component in the transverse load along with the shed frequency. We found that the stagnation point moves in proportional to the velocity of the cylinder and is in-phase with the velocity. The low frequency component in the stagnation point movement on the downstream cylinder is sustained by the interaction of upstream wake. The frequencies in the movement of the stagnation point is reflected in the transverse load resulting in large deformation of the cylinder. The authors wish to acknowledge support from A*STAR- SERC and Singapore Maritime Institute.

  1. Large-N limit of the non-local 2D Yang-Mills and generalized Yang-Mills theories on a cylinder

    CERN Document Server

    Saaidi, K; Saaidi, Khaled; Khorrami, Mohammad

    2002-01-01

    The large-group behavior of the nonlocal YM$_2$'s and gYM$_2$'s on a cylinder or a disk is investigated. It is shown that this behavior is similar to that of the corresponding local theory, but with the area of the cylinder replaced by an effective area depending on the dominant representation. The critical areas for nonlocal YM$_2$'s on a cylinder with some special bounary conditions are also obtained.

  2. 人工肱骨头置换治疗肱骨外科颈骨折17例体会%Experience in 17 cases of fracture of surgical neck of humerus replacement by artificial humeral head

    Institute of Scientific and Technical Information of China (English)

    邹文

    2013-01-01

    Objective To investigate the clinical efficacy of humeral head replacement treatment for fracture of surgical neck of humerus and the technical application notes .Methods From June 2008 to June 2012 ,the clinical da-tas from 17 patients with fracture of surgical neck of humerus were analyzed .Results Followed up for 6 -36 months ,average 20 months ,there was no neurological damage ,fractures around the prostheses and complications of dislocations .According to Rowe's score system evaluation ,5 cases score were excellent ,8 cases score were good ,3 ca-ses score were general ,1 cases score was poor ,and the excellent and good rate was 76 .5% (13/17) .Conclusion The arthroplasty of artificial humerus might be an effective method for surgical treatment of fracture of surgical neck of humerus .%  目的探讨人工肱骨头置换术治疗肱骨外科颈骨折的临床疗效以及该技术的应用和注意事项。方法回顾性分析2008年6月至2012年6月本院收治的17例肱骨外科颈骨折患者的临床资料,对手术进程、伤口愈合情况及并发症进行回顾分析。结果手术顺利,术后伤口均一期愈合,随访6~36个月,平均20个月,无神经损伤、假体周围骨折及脱位并发症。按Ro w e氏评分系统评价:优5例,良8例,一般3例,差1例,优良率76.5%(13/17)。结论人工肱骨头置换术是治疗肱骨外科颈骨折的一种有效方法。

  3. Artificial femoral head replacement for proximal femoral malignant tumors in middle-aged and elderly patients%中老年人股骨上段恶性肿瘤人工股骨头置换治疗效果分析

    Institute of Scientific and Technical Information of China (English)

    赵洪普; 徐秋玉; 吕玉明; 曾勉东; 钟志宏

    2012-01-01

    目的 探讨中老年人股骨上段恶性肿瘤人工股骨头置换治疗的近期疗效.方法 6例原发性骨肿瘤和11例转移性骨肿瘤患者,均接受了瘤段骨切除和人工股骨头置换手术治疗.术后2周开始二膦酸盐类药物口服或静脉治疗,随访中就患者的临床表现、局部影像学、疼痛情况及患侧肢体术后功能进行评定.结果 术后所有患髋疼痛基本缓解,关节活动功能恢复满意,可满足日常行走和负重需要.随访3~40个月,观察期内无假体松动、脱位及近假体骨折等,手术局部无肿瘤复发.术后以髋关节Harris评分,关节功能优良率为88.2%.结论 对中老年人股骨近段骨间室内恶性肿瘤采用人工股骨头重建,可有效缓解疼痛,保留肢体功能,提高生存质量.%Objective To evaluate the short-term effect of artificial femoral head replacement ( AFHR )for proximal femoral malignant tumors in middle-aged and elderly patients. Methods Seventeen patients with proximal femoral malignant tumors,including,6 cases of primary tumors and 11 cases of me-tastatic, were treated with local resection and AFHR. Two weeks later, bisphosphonates were administrated orally or intravenously. Clinical manifestation, pain complaints and limb function were evaluated during the follow-up period. Results In all patients, the hip joint pain was almost relived and the functional recovery was satisfactory, which were sufficient for normal walking and weight-bearing activities. Function and daily life were restored after operation. The hip function was evaluated with Harris s score, AND excellent or good outcomes were obtained by 88. 2%( 15 of 17 cases ). The follow-up period ranged from 3 to 40 months( average,18.7 months ). Prosthesis loosening, prosthesis dislocation, peri-prosthetic fracture and local tumor recurrence were not observed. Conclusion In middle-aged and elderly patients, proximal femoral replacement can provide good pain relief, hip

  4. Biomechanical characteristics of bipolar femoral head prosthesis replacement and internal fixation for femoral neck fractures in the elderly%股骨头双极假体置换及内固定修复老年股骨颈骨折的生物力学特征

    Institute of Scientific and Technical Information of China (English)

    姜源涛; 焦建宝; 薛金伟; 王云飞

    2016-01-01

    背景:双极人工股骨头假体在股骨颈骨折患者中虽然能够取得理想的修复效果,但是临床上对于双极人工股骨头假体的生物力学性能尚存在较大的争议。目的:比较股骨头双极假体置换及内固定修复老年股骨颈骨折的生物力学性能。方法:选取23具(46侧)老年股骨颈骨折股骨标本进行分析,随机将标本分为内固定组和股骨头双极假体置换组,每组23侧。内固定组标本行常规金属植入物内固定,股骨头双极假体置换组行股骨头双极假体置换。在万能试验机上测定股骨假体柄的力学性能,比较股骨头双极假体置换及内固定的生物力学性能。结果与结论:①股骨头双极假体置换组的最大承载负荷显著高于内固定组(P<0.05);最大承载负荷趋势图显示,股骨头双极假体置换组最大承载负荷显著高于内固定组(P<0.05);②股骨头双极假体置换组轴向拔出试验位移显著短于内固定组(P<0.05);轴向拔出试验位移趋势图显示,股骨头双极假体置换组轴向拔出试验位移显著短于内固定组(P<0.05);③结果提示,与内固定植入物相比,股骨头双极假体置换修复老年股骨颈骨折更加稳定,修复效果更佳,能够提高患者髋关节功能,获得良好的初始稳定性。%BACKGROUND:Bipolar femoral head prosthesis has achieved the desired repair effect in patients with femoral neck fracture, but there is stil much controversy on the biomechanical properties of bipolar artificial femoral head prosthesis. OBJECTIVE:To compare biomechanical properties of the bipolar femoral head prosthesis replacement and internal fixation in the repair of femoral neck fracture in the elderly. METHODS:Twenty-three (46 sides) senile femoral neck fracture specimens were analyzed and randomized into internal fixation group(n=23)and bipolar femoral head prosthesis replacement group (n=23). Specimens in the internal

  5. Generalized Bistability in Origami Cylinders

    Science.gov (United States)

    Reid, Austin; Adda-Bedia, Mokhtar; Lechenault, Frederic

    Origami folded cylinders (origami bellows) have found increasingly sophisticated applications in space flight, medicine, and even experimental nuclear physics. In spite of this interest, a general understanding of the dynamics of an origami folded cylinder has been elusive. By solving the fully constrained behavior of a periodic fundamental origami cell defined by unit vectors, we have found an analytic solution for all possible rigid-face states accessible from a cylindrical Miura-ori pattern. Although an idealized bellows has two rigid-face configurations over a well-defined region, a physical device, limited by nonzero material thickness and forced to balance hinge with plate-bending energy, often cannot stably maintain a stowed configuration. We have identified and measured the parameters which control this emergent bistability, and have demonstrated the ability to fabricate bellows with tunable deployability.

  6. Cylinder components properties, applications, materials

    CERN Document Server

    2016-01-01

    Owing to the ever-increasing requirements to be met by gasoline and diesel engines in terms of CO2 reduction, emission behavior, weight, and service life, a comprehensive understanding of combustion engine components is essential today. It is no longer possible for professionals in automotive engineering to manage without the corresponding expertise, whether they work in the field of design, development, testing, or maintenance. This technical book provides in-depth answers to questions about design, production, and machining of cylinder components. In this second edition, every section has been revised and expanded to include the latest developments in the combustion engine. Content Piston rings Piston pins and piston pin circlips Bearings Connecting rods Crankcase and cylinder liners Target audience Engineers in the field of engine development and maintenanceLecturers and students in the areas of mechanical engineering, engine technology, and vehicle constructionAnyone interested in technology Publisher MAH...

  7. Design of Automated Rotory Cage Type Fixture for Cylinder Block

    Directory of Open Access Journals (Sweden)

    Y.S.Kapnichor

    2014-08-01

    Full Text Available Project gives feasible solution to move and rotate the component with full proofing fixturing for special purpose operations like drilling, Tapping, deburring, washing, drying involve in manufacturing and assembly unit of industry. Rotary cage type fixture is made for handling the cylinder head inside the cleaning machine use for making fully ready component before assembly operation .System is useful to save time manpower and deliver perfect cleaned and dry component .system involved all the mechanical components along with the sensors used to restrict the rotating operations, stop and go operations etc.

  8. Counting Polyominoes on Twisted Cylinders

    OpenAIRE

    Barequet, Gill; Moffie, Micha; Ribó, Ares; Rote, Günter

    2005-01-01

    International audience; We improve the lower bounds on Klarner's constant, which describes the exponential growth rate of the number of polyominoes (connected subsets of grid squares) with a given number of squares. We achieve this by analyzing polyominoes on a different surface, a so-called $\\textit{twisted cylinder}$ by the transfer matrix method. A bijective representation of the "states'' of partial solutions is crucial for allowing a compact representation of the successive iteration vec...

  9. Fire testing of bare uranium hexafluoride cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, W.A. [PAI Corp., Oak Rige, TN (United States)

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover the valves failed and UF{sub 6} was released. The remaining cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  10. Fire testing of bare uranium hexafluoride cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, W.A. [PAI Corp., Oak Ridge, TN (United States)

    1991-12-31

    In 1965, the Oak Ridge Gaseous Diffusion Plant (ORGDP), now the K-25 Site, conducted a series of tests in which bare cylinders of uranium hexafluoride (UF{sub 6}) were exposed to engulfing oil fires for the US Atomic Energy Commission (AEC), now the US Department of Energy (DOE). The tests are described and the results, conclusions, and observations are presented. Two each of the following types of cylinders were tested: 3.5-in.-diam {times} 7.5-in.-long cylinders of Monel (Harshaw), 5.0-in.-diam {times} x 30-in.-long cylinders of Monel, and 8-in.-diam {times} 48-in.-long cylinders of nickel. The cylinders were filled approximately to the standard UF{sub 6} fill limits of 5, 55, and 250 lb, respectively, with a U-235 content of 0.22%. The 5-in.- and 8-in.-diam cylinders were tested individually with and without their metal valve covers. For the 3.5-in.-diam Harshaw cylinders and the 5.0-in.-diam cylinder without a valve cover, the valves failed and UF{sub 6} was released. The remaining 6 cylinders ruptured explosively in time intervals ranging from about 8.5 to 11 min.

  11. Volvo's six-cylinder naturally aspirated inline gasoline engine; Reihensechszylinder-Otto-Saugmotor von Volvo

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, P.; Rengmyr, S.; Backlund, S.; Hylander, M.; Saellstroem, G.; Svensson, M. [Volvo Car Corporation, Goeteborg (Sweden)

    2007-09-15

    The six-cylinder 3.2-litre naturally aspirated gasoline engine is the base for a new family of six-cylinder all-aluminium engines to be used in Volvo cars and Premier Automotive Group (PAG) products. The engine replaces the successful 2.9-litre six-cylinder Volvo engine, first introduced in the early 1990s. It has improved performance, lower emissions and better fuel consumption, plus it addresses the need for a more compact engine for transverse installations with 6-speed automatic and manual gearboxes. (orig.)

  12. Feasibility Study of Electromechanical Cylinder Drivetrain for Offshore Mechatronic Systems

    Directory of Open Access Journals (Sweden)

    Daniel Hagen

    2017-04-01

    Full Text Available Currently, there is an increasing focus on the environmental impact and energy consumption of the oil and gas industry. In offshore drilling equipment, electric motors tend to replace traditionally used hydraulic motors, especially in rotational motion control applications. However, force densities available from linear hydraulic actuators are still typically higher than those of electric actuators. Therefore, usually the remaining source of hydraulic power is thereby the hydraulic cylinder. This paper presents a feasibility study on the implementation of an electromechanical cylinder drivetrain on an offshore vertical pipe handling machine. The scope of this paper is to investigate the feasibility of a commercial off-the-shelf drivetrain. With a focus on the motion performance, numerical modeling and simulation are used when sizing and selecting the components of the considered electromechanical cylinder drivetrain. The simulation results are analyzed and discussed together with a literature study regarding advantages and disadvantages of the proposed solution considering the design criteria of offshore drilling equipment. It is concluded that the selected drivetrain can only satisfy the static motion requirements since the required transmitted power is higher than the recommended permissible power of the transmission screw. Consequently, based on the recommendation of the manufacturer, avoidance of overheating cannot be guaranteed for the drivetrain combinations considered for the case study presented in this paper. Hence, to avoid overheating, the average speed of the motion cycle must be decreased. Alternatively, external cooling or temperature monitoring and control system that prevents overheating could be implemented.

  13. Fatigue Tests with Densit Cylinders - D4

    DEFF Research Database (Denmark)

    Ellegaard, Peter

    This report contains descriptions and results of a series of fatigue tests performed during the autumn of 2005 at the Stuctural Research Laboratory, Aalborg University. Cylinders with a diameter of 45 mm and a height of 90 mm were used as test specimens; the material was Densit Ducorit D4. Four...... cylinders were tested statically under compression and the rest of the cylinders (30) were tested under fatigue conditions with a load varying sinusoidally....

  14. Rarita-Schwinger Type operators on Cylinders

    OpenAIRE

    2011-01-01

    Here we define Rarita-Schwinger operators on cylinders and construct their fundamental solutions. Further the fundamental solutions to the cylindrical Rarita-Schwinger type operators are achieved by applying translation groups. In turn, a Borel-Pompeiu Formula, Cauchy Integral Formula and a Cauchy Transform are presented for the cylinders. Moreover we show a construction of a number of conformally inequivalent spinor bundles on these cylinders. Again we construct Rarita-Schwinger operators an...

  15. Two interacting cylinders in cross flow

    Science.gov (United States)

    Alam, Md. Mahbub; Meyer, J. P.

    2011-11-01

    Cylindrical structures in a group are frequently seen on land and in the ocean. Mutual flow interaction between the structures makes the wake very excited or tranquil depending on the spacing between the structures. The excited wake-enhancing forces in some cases cause a catastrophic failure of the structures. This paper presents results of an experimental investigation of Strouhal number (St), time-mean, and fluctuating forces on, and flow structures around, two identical circular cylinders at stagger angle α = 0 °-180 ° and gap-spacing ratio T/D=0.1-5, where T is the gap width between the cylinders, and D is the diameter of a cylinder. While forces were measured using a load cell, St was from spectral analysis of fluctuating pressures measured on the side surfaces of the cylinders. A flow visualization test was conducted to observe flow structures around the cylinders. Based on forces, St, and flow structures, 19 distinct flow categories in the ranges of α and T/D investigated are observed, including one quadristable flow, three kinds of tristable flows, and four kinds of bistable flows. The quadristable, tristable, and bistable flows ensue from instabilities of the gap flow, shear layers, vortices, separation bubbles, and wakes, engendering a strong jump or drop in forces and St of the cylinders. The two cylinders interact with each other in six different mechanisms, namely interaction between boundary layer and cylinder, shear layer or wake and cylinder, shear layer and shear layer, vortex and cylinder, vortex and shear layer, and vortex and vortex. While the interaction between vortex and cylinder results in a very high fluctuating drag, that between vortex and shear layer results in a high fluctuating lift. On the other hand, the interaction between shear layer or wake and cylinder weakens mean and fluctuating forces and flow unsteadiness. A mutual discussion of forces, St, and flow structures is presented in this paper.

  16. Cylinder valve packing nut studies

    Energy Technology Data Exchange (ETDEWEB)

    Blue, S.C. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    The design, manufacture, and use of cylinder valve packing nuts have been studied to improve their resistance to failure from stress corrosion cracking. Stress frozen photoelastic models have been analyzed to measure the stress concentrations at observed points of failure. The load effects induced by assembly torque and thermal expansion of stem packing were observed by strain gaging nuts. The effects of finishing operations and heat treatment were studied by the strain gage hole boring and X-ray methods. Modifications of manufacturing and operation practices are reducing the frequency of stress corrosion failures.

  17. Quantum Mechanics on the cylinder

    CERN Document Server

    González, J A; Tosiek, J

    2003-01-01

    A new approach to deformation quantization on the cylinder considered as phase space is presented. The method is based on the standard Moyal formalism for R^2 adapted to (S^1 x R) by the Weil--Brezin--Zak transformation. The results are compared with other solutions of this problem presented by Kasperkovitz and Peev (Ann. Phys. vol. 230, 21 (1994)0 and by Plebanski and collaborators (Acta Phys. Pol. vol. B 31}, 561 (2000)). The equivalence of these three methods is proved.

  18. INTERACTION OF A FLOATING ELLIPTIC CYLINDER WITH A VIBRATING CIRCULAR CYLINDER

    Institute of Scientific and Technical Information of China (English)

    SUN Ren; CHWANG Allen T.

    2006-01-01

    The nonlinear hydrodynamic interaction between a floating elliptic cylinder and a vibrating circular cylinder immersed in an infinite fluid was investigated. By taking the added masses of the two-cylinder system into account, the dynamical equations of motion were formulated from the Lagrange equations of motion. The dynamical behaviors of these two cylinders were analyzed numerically for some typical situations, and the results show that the presence of a vibrating circular cylinder has a significant influence on the planar motion of a floating elliptic cylinder. The hydrodynamic interaction between them results in complicated nonlinear behaviors of the floating cylinder. It is found that oscillatory motion of the elliptic cylinder takes place in response to the vibrating mode of the circular one.

  19. Inner cylinder of the CMS vacuum tank.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The vacuum tank of the CMS magnet system consists of inner and outer stainless-steel cylinders and houses the superconducting coil. The inner cylinder contains all the barrel sub-detectors, which it supports via a system of horizontal rails. The cylinder is pictured here in the vertical position on a yellow platform mounted on the ferris-wheel support structure. This will allow it to be pivoted and inserted into the outer cylinder already attached to the innermost ring of the barrel yoke.

  20. Fire exposure of empty 30B cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Ziehlke, K.T. [MJB Technical Associates, Inc., Knoxville, TN (United States)

    1991-12-31

    Cylinders for UF{sub 6} handling, transport, and storage are designed and built as unfired pressure vessels under ASME Boiler and Pressure Vessel Code criteria and standards. They are normally filled and emptied while UF{sub 6} is in its liquid phase. Transport cylinders such as the Model 30B are designed for service at 200 psi and 250{degrees}F, to sustain the process conditions which prevail during filling or emptying operations. While in transport, however, at ambient temperature the UF{sub 6} is solid, and the cylinder interior is well below atmospheric pressure. When the cylinders contain isotopically enriched product (above 1.0 percent U-235), they are transported in protective overpacks which function to guard the cylinders and their contents against thermal or mechanical damage in the event of possible transport accidents. Two bare Model 30B cylinders were accidentally exposed to a storage warehouse fire in which a considerable amount of damage was sustained by stored materials and the building structure, as well as by the cylinder valves and valve protectors. The cylinders were about six years old, and had been cleaned, inspected, hydrotested, and re-certified for service, but were still empty at the time of the fire. The privately-owned cylinders were transferred to DOE for testing and evaluation of the fire damage.

  1. Overseas shipments of 48Y cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, R.T.; Furlan, A.S. [Cameco Corp., Port Hope, Ontario (Canada)

    1991-12-31

    This paper describes experiences with two incidents of overseas shipments of uranium hexafluoride (UF{sub 6}) cylinders. The first incident involved nine empty UF{sub 6} cylinders in enclosed sea containers. Three UF{sub 6} cylinders broke free from their tie-downs and damaged and contaminated several sea containers. This paper describes briefly how decontamination was carried out. The second incident involved a shipment of 14 full UF{sub 6} cylinders. Although the incident did not cause an accident, the potential hazard was significant. The investigation of the cause of the near accident is recounted. Recommendations to alleviate future similar incidents for both cases are presented.

  2. Optimization and improvement of Halbach cylinder design

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian Robert Haffenden; Smith, Anders;

    2008-01-01

    that this parameter was optimal for long Halbach cylinders with small rex. Using the previously mentioned additional blocks of magnets can improve the parameter by as much as 15% as well as improve the homogeneity of the field in the cylinder bore. ©2008 American Institute of Physics......In this paper we describe the results of a parameter survey of a 16 segmented Halbach cylinder in three dimensions in which the parameters internal radius, rin, external radius, rex, and length, L, have been varied. Optimal values of rex and L were found for a Halbach cylinder with the least...

  3. Overview of studies on the effect of recycled aggregates sourced from tested cylinders on concrete material and structural properties

    Directory of Open Access Journals (Sweden)

    Bilal Hamad

    2017-01-01

    Full Text Available The paper presents an overview of a two-phase research program that was designed at the American University of Beirut (AUB to investigate the effect of replacing different percentages of natural coarse aggregates (NCA with recycled coarse aggregates (RCA on the properties of the produced concrete. The source of RCA was tested cylinders in batching plants which would help recycling and reusing portion of the waste products of the concrete industry. In the first phase, the fresh and hardened mechanical properties of the produced concrete mix were investigated. The variables were the concrete strength (28 or 60 MPa and the percentage replacement of NCA with RCA from crushed tested cylinders [0 (control, 20, 40, 60, 80, or 100%. Normal strength tested cylinders were used as source of the recycled aggregates for the normal strength concrete (NSC mix and high strength tested cylinders were used for the high strength concrete (HSC mix. Tests included plastic state slump and hardened state mechanical properties including cylinder compressive strength, cylinder splitting tensile strength, modulus of elasticity, and standard beams flexural strength. The results indicated no significant effect on the slump and around 10% average reduction in the hardened mechanical properties for both investigated levels of concrete compressive strength. In the second phase, the structural behavior of normal strength concrete (NSC reinforced concrete beams prepared by replacing different percentages of NCA with RCA from tested concrete cylinders was studied. For each of three modes of failure (flexural, shear, or bond splitting, three beams with different percentages replacement [0 (control, 40, or 100 percent] were tested. One replicate was prepared for each beam to validate the test results. Results indicated no significant difference in the ultimate load reached or load-deflection behavior that could be related to the percentage replacement of NCA with RCA.

  4. Grain refinement of gravity die cast secondary AlSi7Cu3Mg alloys for automotive cylinder heads%重力铸造汽车气缸盖用AlSi7Cu3Mg 二次合金的晶粒细化

    Institute of Scientific and Technical Information of China (English)

    Giordano CAMICIA; Giulio TIMELLI

    2016-01-01

    The effects of AlTi5B1 grain refinement and cooling rate on the microstructure and mechanical properties of a secondary AlSi7Cu3Mg alloy were reported. Metallographic and image analysis techniques have been used to quantitatively examine the macrostructural and microstructural changes occurring with the addition of grain-refining agent at different cooling rates by using a step casting die. The results indicate that the addition of AlTi5B1 produces a fine and uniform grain structure throughout the casting and this effect is more pronounced in the slowly solidified regions. Increasing the cooling rate, lower amount of grain refiner is necessary to produce a uniform grain size throughout the casting. On the other hand, the initial contents of Ti and B, present as impurity elements in the supplied secondary alloy, are not sufficient to produce an effective grain refinement. The results from the step casting geometry were applied to investigate a gasoline 16V cylinder head, which was produced by gravity semi-permanent mould technology. The grain refinement improves the plastic behaviour of the alloy and increases the reliability of the casting, as evidenced by the Weibull statistics.%研究了 AlTi5B1晶粒细化和冷却速率对 AlSi7Cu3Mg 二次合金显微组织和力学性能的影响。采用阶梯铸模在不同冷却速率下制备添加晶粒细化剂的合金,并利用金相和图像分析技术定量研究了合金的宏观组织和显微组织。研究结果表明,添加 AlTi5B1后,整个铸件具有细小均匀的晶粒组织,且在慢速凝固区域效果更显著。当冷却速率增加时,少量细化剂就可使铸件获得细小均匀组织。另外,原材料中的 Ti 和 B 以杂质的形式存在,不足以形成有效的晶粒细化效果。利用阶梯铸造法的研究结果研究了重力半固模铸造16V 汽油发动机气缸盖。Weibull 统计结果表明,晶粒细化改善了合金的塑形变形行为,提高了铸件的可靠性。

  5. [Estrogen replacement].

    Science.gov (United States)

    Søgaard, A J; Berntsen, G K; Magnus, J H; Tollan, A

    1998-02-10

    Recent research on long-term postmenopausal hormone replacement therapy (HRT) indicates a positive effect on both total mortality and morbidity. This has raised the question of widespread preventive long-term use of HRT. Possible side-effects and ideological issues related to preventive HRT have led to debate and uncertainty among health professionals, in the media, and in the population at large. In order to evaluate the level of knowledge about and attitudes towards HRT, a randomly selected group of 737 Norwegian women aged 16-79 was interviewed by the Central Bureau of Statistics. One in three women had received information about HRT in the last two years, mainly through weekly magazines and physicians. The proportion who answered the questions on knowledge correctly varied from 36% to 47%. Those who had been given information by a physician possessed accurate knowledge, had more positive attitudes towards HRT and were more willing to use HRT than women who had reviewed information through other channels. Women with a higher level of education were better informed and more knowledgeable than others, but were nevertheless more reluctant to use HRT than those who were less educated. The limited number of women who actually receive information on HRT, the low level of knowledge and the ambivalent attitudes toward HRT are a major challenge to the public health service.

  6. Flow control behind a circular cylinder via a porous cylinder in deep water

    Directory of Open Access Journals (Sweden)

    Akilli H.

    2013-04-01

    Full Text Available In this present work, the effects of surrounding outer porous cylinder on vortex structure downstream of a circular inner cylinder are investigated experimentally in deep water flow. The porosity of outer cylinder were selected as β = 0.4, 0.5, 0.6, 0.65, 0.7, 0.75, 0.8 and 0.85. Porosity is defined as the ratio of the gap area on the body to the whole body surface area. The ratio of outer cylinder diameter to inner cylinder diameter, Do/Di was selected as 2.0, i.e. the inner cylinder diameter is Di = 30 mm where the outer cylinder diameter is Do = 60 mm. All experiments were carried out above a platform. The water height between the base of the platform and the free surface was adjusted as 340 mm. Free stream velocity is U = 156 mm/s, which corresponds to the Reynolds number of Rei = 5,000 based on the inner cylinder diameter. It has been observed that the outer porous cylinders have influence on the attenuation of vortex shedding in the wake region for all porosities. The turbulent intensity of the flow is reduced at least 45% by the presence of outer porous cylinder compared to the bare cylinder case. The porosities β = 0.4 and 0.5 are most suitable cases to control the flow downstream of the circular cylinder.

  7. Hard sphere packings within cylinders.

    Science.gov (United States)

    Fu, Lin; Steinhardt, William; Zhao, Hao; Socolar, Joshua E S; Charbonneau, Patrick

    2016-03-07

    Arrangements of identical hard spheres confined to a cylinder with hard walls have been used to model experimental systems, such as fullerenes in nanotubes and colloidal wire assembly. Finding the densest configurations, called close packings, of hard spheres of diameter σ in a cylinder of diameter D is a purely geometric problem that grows increasingly complex as D/σ increases, and little is thus known about the regime for D > 2.873σ. In this work, we extend the identification of close packings up to D = 4.00σ by adapting Torquato-Jiao's adaptive-shrinking-cell formulation and sequential-linear-programming (SLP) technique. We identify 17 new structures, almost all of them chiral. Beyond D ≈ 2.85σ, most of the structures consist of an outer shell and an inner core that compete for being close packed. In some cases, the shell adopts its own maximum density configuration, and the stacking of core spheres within it is quasiperiodic. In other cases, an interplay between the two components is observed, which may result in simple periodic structures. In yet other cases, the very distinction between the core and shell vanishes, resulting in more exotic packing geometries, including some that are three-dimensional extensions of structures obtained from packing hard disks in a circle.

  8. Viscoelastic flow simulations through an array of cylinders.

    Science.gov (United States)

    Gillissen, J J J

    2013-02-01

    Polymer solution flow is studied numerically in a periodic, hexagonal array of cylinders as a model for a porous medium. We use a lattice Boltzmann method supplemented by a polymer stress, where the polymers are modeled as finitely extensible, nonlinear, elastic dumbbells. The simulated, nonmonotonic behavior of the effective viscosity μ(eff) as a function of the Weissenberg number We is in qualitative agreement with experiments in the literature. An analytical model, which replaces the flexible polymers by rods and that replaces the flow field in the porous medium by a superposition of shear and elongation, correctly reproduces the simulated μ(eff) as a function of the polymer extensibility parameter b in the limit of large We.

  9. Derivation of the magnetic field on a metal cylinder excited by a longitudinal magnetic dipole transmitter: II. Cylinder in a two-layer dissipative dielectric medium

    Science.gov (United States)

    Freedman, Robert

    2016-11-01

    We derive an exact convergent analytical solution for the complex frequency-dependent magnetic field on the surface of an infinitely long and perfectly conducting metal cylinder situated in a cylindrically layered dissipative medium. The inhomogeneous medium consists of two exterior cylindrical layers that are concentric with the cylinder. The magnetic field on the cylinder is excited by a longitudinally oriented oscillating magnetic dipole transmitter on the cylinder surface. An exact analytical solution to this problem has not been previously published and is of theoretical as well as practical importance, e.g., in modeling the responses of electromagnetic wave propagation well logging tools. It is shown that the magnetic field on the cylinder surface can be expressed as a real-axis integral; however, the integrand oscillates rapidly and diverges for large values of the integration variable. The real-axis integral is replaced by the sum of two convergent branch line integrals and a sum over the residues of the complex poles in the integrand of the real-axis integral. The poles correspond physically to waveguide modes that propagate with discrete wave numbers. A pole search algorithm is developed to locate the positions of the poles and compute their residues. Phase shifts and attenuations of the magnetic field between receivers for a 1.1 GHz well logging tool are computed to elucidate the pole spectra and the relative contributions of the waveguide modes and the branch cut integrals for different thicknesses of the innermost dielectric layer and for different layer properties.

  10. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Replacement of motor....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Heads of Contracting Activities may arrange to sell, as exchange sales, used motor vehicles...

  11. A Convenient Storage Rack for Graduated Cylinders

    Science.gov (United States)

    Love, Brian

    2004-01-01

    An attempt is made to find a solution to the occasional problem of a need for storing large numbers of graduated cylinders in many teaching and research laboratories. A design, which involves the creation of a series of parallel channels that are used to suspend inverted graduated cylinders by their bases, is proposed.

  12. Optimization and improvement of Halbach cylinder design

    CERN Document Server

    Bjørk, R; Smith, A; Pryds, N

    2014-01-01

    In this paper we describe the results of a parameter survey of a 16 segmented Halbach cylinder in three dimensions in which the parameters internal radius, $r_{\\mathrm{\\scriptsize{in}}}$, external radius, $r_{\\mathrm{\\scriptsize{ex}}}$, and length, $L$, have been varied. Optimal values of $r_{\\mathrm{\\scriptsize{ex}}}$ and $L$ were found for a Halbach cylinder with the least possible volume of magnets with a given mean flux density in the cylinder bore. The volume of the cylinder bore could also be significantly increase by only slightly increasing the volume of the magnets, for a fixed mean flux density. Placing additional blocks of magnets on the end faces of the Halbach cylinder also improved the mean flux density in the cylinder bore, especially so for short Halbach cylinders with large $r_{\\mathrm{\\scriptsize{ex}}}$. Moreover magnetic cooling as an application for Halbach cylinders was considered. A magnetic cooling quality parameter, $\\Lambda_{\\mathrm{cool}}$, was introduced and results showed that this...

  13. NUMERICAL STUDY OF NATURAL CONVECTION FROM TWO PARALLEL HORIZONTAL CYLINDERS ENCLOSED BY CIRCULAR CYLINDER

    Directory of Open Access Journals (Sweden)

    Mahmood Husain Ali

    2013-05-01

    Full Text Available In this paper, numerical solution is presented for the steady state, two dimensional natural convection heat transfer from two parallel horizontal cylinders enclosed by circular cylinder. The inner cylinders are heated and maintained at constant surface temperature, while the outer cylinder is cooled at constant surface temperature. Boundary fitted coordinate system is used to solve governing equations. The vorticity-stream function and energy equations is solved using explicit finite deference method and stream function equation solved by successive iteration method. (20Deferent cases are studied cover rang of Rayleigh number from (1,000 to (25,000 based on the inner cylinder diameter. These cases study the effect of the  varying inner cylinders position horizontally and vertically within outer cylinder on the heat transfer and buoyancy that causes the flow. Outputs are displayed in terms of streamline, isothermal contours and local and average Nusselt number. The results showed that the position of the inner cylinders highly affects the heat transfer and flow movements in the gap. At low Rayleigh numbers the average Nusselt number increases with increase of horizontal distance between inner cylinders but the state is reversed at high Rayleigh numbers, while the average Nusselt number is increases with inner cylinder moving down at all Rayleigh numbers. The optimal position of inner cylinders for maximum and minimum heat transfer is located at each Rayleigh number so can be employed in isolation process or cooling process.

  14. Quantum walk on a cylinder

    CERN Document Server

    Bru, Luis A; Di Molfetta, Giuseppe; Pérez, Armando; Roldán, Eugenio; Silva, Fernando

    2016-01-01

    We consider the 2D alternate quantum walk on a cylinder. We concentrate on the study of the motion along the open dimension, in the spirit of looking at the closed coordinate as a small or "hidden" extra dimension. If one starts from localized initial conditions on the lattice, the dynamics of the quantum walk that is obtained after tracing out the small dimension shows the contribution of several components, which can be understood from the study of the dispersion relations for this problem. In fact, these components originate from the contribution of the possible values of the quasi-momentum in the closed dimension. In the continuous space-time limit, the different components manifest as a set of Dirac equations, with each quasi-momentum providing the value of the corresponding mass. We briefly discuss the possible link of these ideas to the simulation of high energy physical theories that include extra dimensions.

  15. Design of a single cylinder optical access to the combustion engine Scania D12

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Juergen

    2000-11-01

    In this work a maximum optical access to a diesel engine is developed. The combustion-process in the engine should be representative to the one in a standard engine, so the geometry of the combustion chamber is modified as little as possible. A Scania single cylinder, 2-litre engine was subjected to modifications allowing the optical access. Solutions to these problems are obtained by using the method of Product-Development, mainly based on the literature by Prof Dr.-Ing. Birkhofer at the Technical University of Darmstadt, Germany. An optical engine design of the Bowditch type was the chosen main working principle. This engine contains an extended cylinder, partly made of glass, a glass piston-crown and a mirror placed inside the extended piston. The laser sheet is led into the combustion chamber through the glass part of the cylinder, then gets reflected inside the combustion chamber and is led through the glass piston crown and via the mirror out of the engine. A redesign of the valve-train, using extended push-rods, is necessary. The demand to examine the combustion at Top-Dead-Centre (TDC) and the necessity of supporting the glass, give the reasons to do work on the cylinder head. This in return brings sealing problems, which have been solved. Another problem that occurs with that type of engine is that is has to run without oil-lubrication. Piston rings made of Rylon are used to solve this problem. A special feature of the engine that has been constructed here is that the inner surface of the glass may be cleaned without removing the cylinder head. This is obtained by a construction with a movable cylinder. In cleaning-state the cylinder is driven up and down together with the piston, while the head is supported by an outer structure. When running the engine, the cylinder is fixed to the structure. Furthermore this report contains the necessary calculations and integrity assessments on the critical parts of the construction. All calculations, except the

  16. Curative effect of dabigatran etexilate versus low molecular weight heparin to prevent lower extremity deep venous thrombosis following femoral head prosthetic replacement%达比加群酯与低分子肝素预防髋关节置换术后下肢深静脉血栓的作用比较

    Institute of Scientific and Technical Information of China (English)

    赵伟; 曲虹; 丁美精; 胡小辉

    2016-01-01

    Objective To observe the clinical effects and security of low molecular weight heparin and dabigatran etexilate against deep venous thrombosis( DVT) following femoral head prosthetic replacement. Methods Totally 73 femoral head prosthetic replacement pa-tients were randomized into three groups: routine treatment group with 24 cases, dabigatran etexilate group with 25 cases and low heparin group with 24 cases. Change of platelet count and prothrombin time of the patients in three groups were observed and compared. Occurrence of DVT was observed under color Doppler of lower limbs. Results There was significant differences in DVT prevention between routine treat-ment group,the dabigatran etexilate group and low heparin group groups ( ( P 0.05)。 DE组和LMWH组在治疗期间均无严重出血。结论达比加群酯与低分子肝素均具有较好的预防髋关节置换后DVT的发生,达比加群酯疗效及安全性与低分子肝素作用相当。

  17. VORTEX INDUCED VIBRATIONS OF FINNED CYLINDERS

    Institute of Scientific and Technical Information of China (English)

    SHA Yong; WANG Yong-xue

    2008-01-01

    This article presents the results of a numerical simulation on the vortex induced vibration of various finned cylinders at low Reynolds number. The non-dimensional, incompressible Navier-Stokes equations and continuity equation were adopted to simulate the fluid around the cylinder. The cylinder (with or without fins) in fluid flow was approximated as a mass-spring system. The fluid-body interaction of the cylinder with fins and uniform flow was numerically simulated by applying the displacement and stress iterative computation on the fluid-body interfaces. Both vortex structures and response amplitudes of cylinders with various arrangements of fins were analyzed and discussed. The remarkable decrease of response amplitude for the additions of Triangle60 fins and Quadrangle45 fins was found to be comparable with that of bare cylinder. However, the additions of Triangle00 fins and Quadrangle00 fins enhance the response amplitude greatly. Despite the assumption of two-dimensional laminar flow, the present study can give a good insight into the phenomena of cylinders with various arrangements of fins.

  18. Expansion of Metallic Cylinders under Explosive Loading

    Directory of Open Access Journals (Sweden)

    M.S. Bola

    1992-07-01

    Full Text Available The behaviour of expanding metallic cylinders under explosive loading was studied. Using ultra high speed photography, the expansion characteristics of aluminium and copper metallic cylinders have been evaluated with different c/m ratio, and by changing the nature of high explosive. The results obtained are comparable to those predicted by the Gurney's energy and momentum balance equations. A cylinder test has been established for comparative to the metal by octol, TNT, PEK-1, baratol and composition B are calculated. The results are in close agreement with those calculated by Kury et al.

  19. ELECTRODE SELECTION FOR RECOVERY OF THE CYLINDER LIDS OF THE TGM8K LOCOMITIVE ENGINE

    Directory of Open Access Journals (Sweden)

    Pablo Oñoz Gutiérrez

    2017-01-01

    Full Text Available The objective of this work was to determine the best-suited electrode to carry out the recovery of cylinder lids (cylinders heads of the TGM8K locomotives, by applying manual welding for electric arc. The test specimens of nodular cast iron, obtained from a discarded head, which were welded with two types electrodes, ENi-CI (UTP8 and ENiFe-CI ( UTP86FN following a technology of appropriate welding were prepared. The specimens were subject of thermic fatigue tests in an experimental installation created with this purpose, in which a process of heating and more severe cooling than in the head working conditions was simulated. During the thermic fatigue tests, in the specimens welded with electrodes ENi-CI appeared cracks at the thermic influence zone after 145 cycles, while in the specimens welded with electrodes ENiFe-CI, appeared at the 585 cycles on average. Based on the study results, the authors conclude that ENiFe-CI electrodes are the best-suited for the recovery of the cylinder lids.

  20. Magnetohydrodynamic Flow Between Concentric Rotating Porous Cylinders

    Directory of Open Access Journals (Sweden)

    S. N. Dube

    1971-10-01

    Full Text Available An attempt has been made to study the steady laminar flow of a incompressible electrically conducting fluid between infinitely long concentric rotating porous cylinders under the influence of radial magnetic field. A solution has been obtained under the assumption of uniform conditions along the axis of the cylinders. The cylinders being porous, a hyperbolic radial velocity distribution has been superimposed over the circumferential velocity produced due to rotation. There is a Bernoulli type pressure variation in the radial in the direction. When the inner cylinder is at rest the shearing stress at it and the torque transmitted to it decrease as R (=v/Sub/1y/Sub1/v= v/Sub2y/Sub2/v increases and the magnetic parameter lambda (=4sigma mue/sube/sup2A/Sup2/Mue will further decrease them.

  1. Theory of interacting dislocations on cylinders.

    Science.gov (United States)

    Amir, Ariel; Paulose, Jayson; Nelson, David R

    2013-04-01

    We study the mechanics and statistical physics of dislocations interacting on cylinders, motivated by the elongation of rod-shaped bacterial cell walls and cylindrical assemblies of colloidal particles subject to external stresses. The interaction energy and forces between dislocations are solved analytically, and analyzed asymptotically. The results of continuum elastic theory agree well with numerical simulations on finite lattices even for relatively small systems. Isolated dislocations on a cylinder act like grain boundaries. With colloidal crystals in mind, we show that saddle points are created by a Peach-Koehler force on the dislocations in the circumferential direction, causing dislocation pairs to unbind. The thermal nucleation rate of dislocation unbinding is calculated, for an arbitrary mobility tensor and external stress, including the case of a twist-induced Peach-Koehler force along the cylinder axis. Surprisingly rich phenomena arise for dislocations on cylinders, despite their vanishing Gaussian curvature.

  2. Suppression of Brazier Effect in Multilayered Cylinders

    Directory of Open Access Journals (Sweden)

    Hiroyuki Shima

    2014-01-01

    Full Text Available When a straight hollow tube having circular cross-section is bent uniformly into an arc, the cross-section tends to ovalize or flatten due to the in-plane stresses induced by bending; this ovalization phenomenon is called the Brazier effect. The present paper is aimed at theoretical formulation of the Brazier effect observed in multilayered cylinders, in which a set of thin hollow cylinders are stacked concentrically about the common axis. The results indicate that mechanical couplings between stacked cylinders are found to yield pronounced suppression of the cross-sectional ovalization. Numerical computations have been performed to measure the degree of suppression in a quantitative manner and to explore how it is affected by the variations in the bending curvature, the number of stacked cylinders, and the interlayer coupling strength.

  3. Sub-wavelength resonances in polygonal metamaterial cylinders

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Breinbjerg, Olav

    2008-01-01

    It has been shown that the sub-wavelength resonances of circular MTM cylinders also occur for polygonal MTM cylinders. This is the case for lossless and non-dispersive cylinders as well as lossy and dispersive cylinders. The sub-wavelength resonances are thus not limited to structures of canonical...

  4. Dynamic Fracture Simulations of Explosively Loaded Cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Carly W. [Univ. of California, Davis, CA (United States). Dept. of Civil and Environmental Engineering; Goto, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-11-30

    This report documents the modeling results of high explosive experiments investigating dynamic fracture of steel (AerMet® 100 alloy) cylinders. The experiments were conducted at Lawrence Livermore National Laboratory (LLNL) during 2007 to 2008 [10]. A principal objective of this study was to gain an understanding of dynamic material failure through the analysis of hydrodynamic computer code simulations. Two-dimensional and three-dimensional computational cylinder models were analyzed using the ALE3D multi-physics computer code.

  5. W-76 PBX 9501 cylinder tests

    Energy Technology Data Exchange (ETDEWEB)

    Hill, L.G.; Catanach, R.A.

    1998-07-01

    Five 1-inch diameter cylinder tests were fired in support of the W-76 high explosive surveillance program. Three of the tests used baseline material, and two used stockpile return material. The diagnostics were electrical pins to measure detonation velocity and a streak camera to measure wall motion. The data was analyzed for cylinder energy, Gurney energy, and detonation velocity. The results of all three measures were consistent for all five tests, to within the experimental accuracy.

  6. Study of Multi-Cylinder Engine Manifolds

    Science.gov (United States)

    1944-10-31

    were developed so that mnifolds for any number of cylinders could be analyzed for max- I= zm volumetrie efficiency. Eletricaleebanioal analoCies can be...deceleration of the air& The vibrations are almot Identical to thse In single cylinder intake pipes. The mmi- a= volumetrie efficiency bould be...pipe 14 in. total volume 7- In- 3 area of pipew 0.86 in 2 Table I gives the actual and calculated speeds for peak volumetri efficiencies for a sIngle

  7. Statistical analyses of a screen cylinder wake

    Science.gov (United States)

    Mohd Azmi, Azlin; Zhou, Tongming; Zhou, Yu; Cheng, Liang

    2017-02-01

    The evolution of a screen cylinder wake was studied by analysing its statistical properties over a streamwise range of x/d={10-60}. The screen cylinder was made of a stainless steel screen mesh of 67% porosity. The experiments were conducted in a wind tunnel at a Reynolds number of 7000 using an X-probe. The results were compared with those obtained in the wake generated by a solid cylinder. It was observed that the evolution of the statistics in the wake of the screen cylinder was different from that of a solid cylinder, reflecting the differences in the formation of the organized large-scale vortices in both wakes. The streamwise evolution of the Reynolds stresses, energy spectra and cross-correlation coefficients indicated that there exists a critical location that differentiates the screen cylinder wake into two regions over the measured streamwise range. The formation of the fully formed large-scale vortices was delayed until this critical location. Comparison with existing results for screen strips showed that although the near-wake characteristics and the vortex formation mechanism were similar between the two wake generators, variation in the Strouhal frequencies was observed and the self-preservation states were non-universal, reconfirming the dependence of a wake on its initial condition.

  8. Clinical effectiveness analysis of PHILOS locking plates and humeral head replacement for treatment of complex fractures of proximal humerus in elderly%PHILOS锁定钢板与人工肱骨头置换治疗老年复杂肱骨近端骨折的效果对比

    Institute of Scientific and Technical Information of China (English)

    张敏; 白鹏程; 张媺; 江建平; 王辉; 金绍林; 冯孝志; 周明

    2015-01-01

    Objective To analyze the effect of PHILOS locking plate fixation and the artificial humerus head replacement on proxi-mal complex humerus fracture. Methods The clinical data of 43 patients aged over 60 with three or four parts fractures in proximal humerus were retrospectively studied,including 32 cases of PHILOS group and 11 cases of artificial humerus head replacement group. Two groups were compared in operation time,surgical blood loss and NEER score and the incidence of postoperative complications. Results All patients obtained similar outpatient follow-up for 6~20 months with an average of 11. 63 months. There was no difference in operation time and blood loss of the two groups(P>0. 05). After treatment,according to NEER grading evaluation of curative effect,no obvious statistical significance difference existed between the two groups (P>0. 05). However,the postoperative complication rate of PHILOS group was higher than that of artificial humerus head replacement group;postoperative plate and acromion impingement occurred in 2 cases,screw through the shoulder joint in 2 cases,but there was no functional impact,and there was 1 case of displacement of the greater tuberosity postoperatively,1 case of humerus head necrosis,while there were no complications in artificial femoral head replacement group. Conclusion PHILOS or steel plate internal fixation and the artificial humerus head replacement can be used in the treatment of senile complex humeral proximal fractures. There are no obvious differences in the quality of life and shoulder joint function recovery,but the incidence of postoperative complications in artifi-cial humerus head replacement group is lower than that of PHILOS group.%目的:对比分析PHILOS锁定钢板内固定术与人工肱骨头置换术治疗老年复杂肱骨近端骨折的临床疗效。方法回顾性分析60岁以上老年肱骨近端三、四部分骨折患者43例临床资料,其中PHILOS组32例,人工肱骨头置换组11

  9. Head Injuries

    Science.gov (United States)

    ... object that's stuck in the wound. previous continue Concussions Concussions — the temporary loss of normal brain function due ... also a type of internal head injury. Repeated concussions can permanently damage the brain. In many cases, ...

  10. Head Tilt

    Science.gov (United States)

    ... Healthy Living Healthy Living Healthy Living Nutrition Fitness Sports Oral Health Emotional Wellness Growing Healthy Sleep Safety & ... When this happens, the neck muscles go into spasm, causing the head to tilt to one side. ...

  11. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay Safe: Baseball Concussions Concussions: Getting Better Sports and Concussions Dealing ...

  12. Head MRI

    Science.gov (United States)

    ... heart valves Heart defibrillator or pacemaker Inner ear (cochlear) implants Kidney disease or dialysis (you may not ... to: Abnormal blood vessels in the brain ( arteriovenous malformations of the head ) Tumor of the nerve that ...

  13. RESULTS RESULTING FROM AUTOFRETTAGE OF CYLINDER

    Institute of Scientific and Technical Information of China (English)

    ZHU Ruilin

    2008-01-01

    Autofrettage is used to introduce advantageous residual stresses into wall of a cylinder and to even distributions of total stresses. Basic theory on autofrettage has been functioning for several decades. It is necessary to reveal profound relations between parameters in the theory. Therefore, based on the 3rd strength theory, δei/δy, δei/δy, δei′/δy, δei′/δy and their relations, as well as p/δy, are studied under ideal conditions, where δei/δy is equivalent stress of total stresses at elastoplastic juncture/yield strength, δei/δy is equivalent stress of total stresses at inside surface/yield strength, δei′/δy is equivalent stress of residual stresses at elastoplastic juncture/yield strength, δei′/δy is equivalent stress of residual stresses at inside surface/yield strength, p/δy is load-bearing capacity of an autofrettaged cylinder/yield strength. Theoretical study on the parameters results in noticeable results and laws. The main idea is: to satisfy |δei′|=δy, the relation between kj and k is , where k is outside/inside radius ratio of a cylinder, kj is ratio of elastoplastic juncture radius to inside radius of a cylinder; when the plastic region covers the whole wall of a cylinder, for compressive yield not to occur after removing autofrettage pressure, the ultimate k is k=2.218 46, with k=2.218 46, a cylinder's ultimate load-bearing capacity equals its entire yield pressure, or =lnk; when kj≤=1.648 72, no matter how great k is, compressive yield never occurs after removing pa; the maximum and optimum load-bearing capacity of an autofrettaged cylinder is just two times the loading which an unautofrettaged cylinder can bear elastically, or , thus the limit of the load-bearing capacity of an autofrettaged cylinder is also just 2 times that of an unautofrettaged cylinder.

  14. Cast iron-base alloy for cylinder/regenerator housing

    Science.gov (United States)

    Witter, Stewart L.; Simmons, Harold E.; Woulds, Michael J.

    1985-01-01

    NASACC-1 is a castable iron-base alloy designed to replace the costly and strategic cobalt-base X-40 alloy used in the automotive Stirling engine cylinder/generator housing. Over 40 alloy compositions were evaluated using investment cast test bars for stress-rupture testing. Also, hydrogen compatibility and oxygen corrosion resistance tests were used to determine the optimal alloy. NASACC-1 alloy was characterized using elevated and room temperature tensile, creep-rupture, low cycle fatigue, heat capacity, specific heat, and thermal expansion testing. Furthermore, phase analysis was performed on samples with several heat treated conditions. The properties are very encouraging. NASACC-1 alloy shows stress-rupture and low cycle fatigue properties equivalent to X-40. The oxidation resistance surpassed the program goal while maintaining acceptable resistance to hydrogen exposure. The welding, brazing, and casting characteristics are excellent. Finally, the cost of NASACC-1 is significantly lower than that of X-40.

  15. 生物型与骨水泥型人工股骨头置换治疗高龄股骨颈骨折%Biotype and bone cement-type artificial femoral head replacement for the treatment of femoral neck fracture in elderly patients

    Institute of Scientific and Technical Information of China (English)

    史建国; 邱南海

    2013-01-01

      BACKGROUND: With the maturity and development of artificial joint materials, processes and technology, artificial femoral head replacement has been widely used for the treatment of femoral neck fracture, especial y the elderly patients with displaced femoral neck fracture. OBJECTIVE: To observe the clinical efficacy of biotypes and cementless artificial femoral head replacement for the treatment of elderly femoral neck fracture combined with heart disease. METHODS: Thirty-five elderly femoral neck fracture patients with heart disease treated in the Department of Orthopedic Center, Tianjin Nursing Home from January 2004 to December 2009 were selected, including 16 cases of coronary heart disease combined with angina pectoris, eight cases of myocardial infarction coronary heart disease, eight cases of asymptomatic coronary heart disease and three cases of ischemic cardiomyopathy and coronary heart disease. And 18 cases were treated with biotypes artificial femoral head replacement, 17 cases were treated with cementless artificial femoral head replacement. RESULTS AND CONCLUSION: One of the 35 patients was dead in the surgery, other 34 cases were fol owed-up for 8 to 36 months. Three cases of complications occurred in surgery were belongs to cementless group, and one patient died during surgery, two cases had to drop in blood pressure and suffered from difficulty breathing in surgery, whose life characteristics returned to normal after efforts to save. In the fol ow-up process, part of the prosthesis implanted in the two cases of patients with severe osteoporosis appears sinking in the biotype group, the excel ent rate of biotype group was 89%(16/18), and the cementless group was 94%(16/17). It suggests that biotype artificial femoral head replacement is suitable for the patients with severe heart disease, while the cementless artificial femoral head replacement is suitable for osteoporosis patients.%  背景:随着人工关节材料、工艺及技术的

  16. Prosthetic replacement of condylar head for management of traumatic temporomandibular joint ankylosis%髁突置换治疗创伤性颞下颌关节强直五例

    Institute of Scientific and Technical Information of China (English)

    安金刚; 张益; 何锦泉; 贺洋; 李江明

    2009-01-01

    Objective To preliminarily evaluate the method of using titanium condylar protheses in management of traumatic temporomandibular joint ankylosis.Methods Between August 2006 and April 2008,titanium condylar replacement was performed in 5 male patients.Preoperative CT datum of patient was obtained and a resin model was then produced and used as a reference to select a suitable titanium condyle for reconstruction of the joint.In the operation,the bony ankylosis was removed.According to the preoperation planning,the selected prosthesis was inserted and fixed to the distal mandibular segment.The results were assessed by means of examinations and measurements postoperatively and during follow-up.Results The 5 patients received alloplastic replacement of 6 condyles.Three patients were under follow-up and follow-up time ranged from 8 months to 2 years and 6 months.The mean mouth opening was 30 mm.Two patients had good occlusion and one patient developed a slight open bite.Conclusions Prosthetic condylar replacement can provide a choice for management of traumatic temporomandibular joint ankylosis.%目的 总结用人工髁突置换治疗创伤性颞下颌关节强直(temporomandibular joint ankylosis,TMJA)的临床效果.方法 2006年8月至2008年4月北京大学口腔医学院·口腔医院口腔颌面外科共5例创伤性TMJA患者接受人工髁突置换手术,患者均为男性.术前行CT检查后,用快速成形技术制作三维头模,在头模上模拟切除关节骨球、关节成形、选择适宜的人工髁突,术中依术前设计安放并固定人工髁突.术后1周和复查时评价手术效果.结果 5例共植入6侧人工髁突(1例为双侧).3例复查时间为术后8~30个月,另外2例失访.复查时张口度平均为30 mm,2例咬合关系良好,1例前牙区有约1 mm的开骀.结论 人工髁突置换可以作为创伤性TMJA手术治疗的方法之一,其临床效果还需进一步验证.

  17. Guided Circumferential Waves in Layered Poroelastic Cylinders

    Directory of Open Access Journals (Sweden)

    Shah S.A.

    2016-12-01

    Full Text Available The present paper investigates the propagation of time harmonic circumferential waves in a two-dimensional hollow poroelastic cylinder with an inner shaft (shaft-bearing assembly. The hollow poroelastic cylinder and inner shaft are assumed to be infinite in axial direction. The outer surface of the cylinder is stress free and at the interface, between the inner shaft and the outer cylinder, it is assumed to be free sliding and the interfacial shear stresses are zero, also the normal stress and radial displacements are continuous. The frequency equation of guided circumferential waves for a permeable and an impermeable surface is obtained. When the angular wave number vanish the frequency equation of guided circumferential waves for a permeable and an impermeable surface degenerates and the dilatational and shear waves are uncoupled. Shear waves are independent of the nature of surface. The frequency equation of a permeable and an impermeable surface for bore-piston assembly is obtained as a particular case of the model under consideration when the outer radius of the hollow poroelastic cylinder tends to infinity. Results of previous studies are obtained as a particular case of the present study. Nondimensional frequency as a function of wave number is presented graphically for two types of models and discussed. Numerical results show that, in general, the first modes are linear for permeable and impermeable surfaces and the frequency of a permeable surface is more than that of an impermeable surface.

  18. UF{sub 6} cylinder fire test

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.H. [Oak Ridge K-25 Site, Oak Ridge, TN (United States)

    1991-12-31

    With the increasing number of nuclear reactors for power generation, there is a comparable increase in the amount of UF{sub 6} being transported. Likewise, the probability of having an accident involving UF{sub 6}-filled cylinders also increases. Accident scenarios which have been difficult to assess are those involving a filled UF{sub 6} cylinder subjected to fire. A study is underway at the Oak Ridge K-25 Site, as part of the US DOE Enrichment Program, to provide empirical data and a computer model that can be used to evaluate various cylinder-in-fire scenarios. It is expected that the results will provide information leading to better handling of possible fire accidents as well as show whether changes should be made to provide different physical protection during shipment. The computer model being developed will be capable of predicting the rupture of various cylinder sizes and designs as well as the amount of UF{sub 6}, its distribution in the cylinder, and the conditions of the fire.

  19. Dynamic Simulation of the Harvester Boom Cylinder

    Directory of Open Access Journals (Sweden)

    Rongfeng Shen

    2017-04-01

    Full Text Available Based on the complete dynamic calculation method, the layout, force, and strength of harvester boom cylinders were designed and calculated. Closed simulations for the determination of the dynamic responses of the harvester boom during luffing motion considering the cylinder drive system and luffing angle position control have been realized. Using the ADAMS mechanical system dynamics analysis software, six different arm poses were selected and simulated based on the cylinder as the analysis object. A flexible model of the harvester boom luffing motion has been established. The movement of the oil cylinder under different conditions were analyzed, and the main operation dimensions of the harvester boom and the force condition of the oil cylinder were obtained. The calculation results show that the dynamic responses of the boom are more sensitive to the luffing acceleration, in comparison with the luffing velocity. It is seen that this method is very effective and convenient for boom luffing simulation. It is also reasonable to see that the extension of the distance of the bottom of the boom is shortened by adjusting the initial state of the boom in the working process, which can also effectively reduce the workload of the boom—thus improving the mechanical efficiency.

  20. Flexural vibrations of finite composite poroelastic cylinders

    Indian Academy of Sciences (India)

    Sandhya Rani Bandari; Srisailam Aleti; Malla Reddy Perati

    2015-04-01

    This paper deals with the flexural vibrations of composite poroelastic solid cylinder consisting of two cylinders that are bonded end to end. Poroelastic materials of the two cylinders are different. The frequency equations for pervious and impervious surfaces are obtained in the framework of Biot’s theory of wave propagation in poroelastic solids. The gauge invariance property is used to eliminate one arbitrary constant in the solution of the problem. This would lower the number of boundary conditions actually required. If the wavelength is infinite, frequency equations are degenerated as product of two determinants pertaining to extensional vibrations and shear vibrations. In this case, it is seen that the nature of the surface does not have any influence over shear vibrations unlike in the case of extensional vibrations. For illustration purpose, three composite cylinders are considered and then discussed. Of the three, two are sandstone cylinders and the third one is resulted when a cylindrical bone is implanted with Titanium. In either case, phase velocity is computed against aspect ratios.

  1. Base Stress of the Opened Bottom Cylinder Structures

    Institute of Scientific and Technical Information of China (English)

    刘建起; 孟晓娟

    2004-01-01

    The base stress of the opened bottom cylinder structure differs greatly from that of the structure with a closed bottom. By investigating the inner soil pressure on the cylinder wall and the base stress of the cylinder base, which were obtained from the model experiments, the interactions among the filler inside the cylinder,subsoil and cylinder are analyzed. The adjusting mechanism of frictional resistance between the inner filler and the wall of the cylinder during the overturning of the cylinder is discussed. Based on the experimental study, a method for calculating the base stress of the opened bottom cylinder structure is proposed. Meanwhile, the formulas for calculating the effective anti-overturning ratio of the opened bottom cylinder are derived.

  2. Determining the Mechanism of In-Service Cylinder Distortion in Aluminum Engine Blocks with Cast-In Gray Iron Liners

    Science.gov (United States)

    Lombardi, Anthony; Ravindran, Comondore; Sediako, Dimitry; MacKay, Robert

    2014-12-01

    In recent years, stringent government legislation on vehicle fuel efficiency has pushed the automotive industry to replace steel and cast iron power train components with light weight Al alloys. However, unlike their ferrous-based equivalents, Al-Si alloy engine blocks are prone to permanent dimensional distortion in critical locations such as the cylinder bore regions. Understanding the mechanisms that cause distortion will promote the use of Al alloys over ferrous alloys for power train applications and enable automotive manufacturers to meet emission standards and reduce fuel consumption. In this study, neutron diffraction was used to evaluate residual stress along the Al cylinder bridge and the gray cast iron liners of distorted and undistorted engine blocks. Microstructural analysis was carried out using OM, SEM, and TEM, while mechanical testing was accomplished via ambient and elevated temperature [~453 K (180 °C)] tensile testing. The results suggest that the distorted engine block had high tensile residual stress in the Al cylinder bridge, reaching a maximum of 170 MPa in the hoop direction, which triggered permanent dimensional distortion in the cylinders when exposed to service conditions. In addition, the middle of the cylinder had the highest magnitude of distortion since this region had a combination of high tensile residual stress (hoop stress of 150 MPa) and reduced strength compared with the bottom of the cylinder.

  3. Cobalt, chromium and molybdenum ions kinetics in the human body: data gained from a total hip replacement with massive third body wear of the head and neuropathy by cobalt intoxication.

    Science.gov (United States)

    Pazzaglia, U E; Apostoli, P; Congiu, T; Catalani, S; Marchese, M; Zarattini, G

    2011-09-01

    A patient with a total hip replacement developed optic, acoustic and peripheral neuropathy from metal ions intoxication, due to the wear products released from the prosthesis. Subsequently the kinetics of the metal ions was studied. Massive wear and acute intoxication allowed a study of the metal ions kinetics and of EDTA treatment. Plasma and other organic fluids were saturated by each of the metal ions released from the exposed surface according to the solubility of each ion; a larger fraction of Co ions was bound within red cells, while the plasmatic fraction appeared more movable. In a patient with a prosthesis subjected to wear, the ions released are from the prosthetic and from the debris surface (spread in the body). The latter is a function of the number and size of particles. Revision of the prosthesis from the point of view of the metal ions kinetics corresponded to a reduction of the releasing surface because of debris washed out by irrigation and tissue excision; however, the metal particles spread by lymphatic circulation continued to release ions even though the source of wear had been removed. Early diagnosis of high metal wear can be ascertained with mass spectrometry and after revision high levels of metal ions can only be reduced with repeated chelating treatment. It is preferable not to revise fractured ceramic components with a polyethylene-metal articulation.

  4. Using artificial femoral head replacement treated of elderly intertrochanteric fracture--Analysis of curative effect of 103 cases%人工股骨头置换术治疗高龄股骨粗隆间骨折--附103例疗效分析

    Institute of Scientific and Technical Information of China (English)

    钟群华; 王大伟; 陈烨; 苑井宽

    2014-01-01

    目的:分析高龄(>75岁)股骨粗隆间骨折患者采用人工股骨头置换术的疗效。方法:对2004.1~2013.10我院103例高龄股骨粗隆间骨折患者采用人工股骨头假体置换治疗。其中女性67例,男性36例,最大年龄102岁,最小年龄75岁,平均83岁。结果:术中、术后死亡2例,余患者均得到随访,随访时间1~9年(平均3.5年),参照Harris法评分[1]优65例,良26例,可6例,差4例。疗效优良率达88.34%。所有随访患者无发生脱位,经复查X片,假体、髋臼完好无松动93例,髋臼磨损5例,假体周围骨折2例,假体松动1例。结论:证实人工股骨头置换术治疗高龄股骨粗隆间骨折具有减少患者卧床时间,早日下地负重功能锻炼,减少术后并发症等优点。%Objective: to the curative effect of using artificial femoral head replacement treated of the age (>75 years) intertrochanteric fracture patients. Methods: For the elderly which over 75-years-old of intertrochanteric fractures 103 patients were treated with artificial femoral head replacement from January 2004 to October 2013.In the 103 patients which have 67 women, 36 men, the ages between 75 years and 102 years, average 83 years old. Results: Intraoperative and postoperative had death 2 cases, others patients all follow-up, follow-up time of 101 cases are 1 year to 9 years, which averages 3.5 years. Under Harris score [1], 65 cases had excellence, 26 good, 6 mediate, 4 bad, the excellence rate was 88.34%; All the follow-up of patients were no dislocation. Reviewing X-ray films, 93 cases artificial femoral head and acetabulum are good and no loose;5 cases had acetabulum attrition rate;2 cases had prosthesis around fracture;5 cases had prosthesis loose. Conclusion:Application of artificial femoral head replacement in the treatment of elderly intertrochanteric femoral fractures, have shorten patients stay in bed time, early do functional exercise, reduce

  5. Flow interaction between a streamwise oscillating cylinder and a downstream stationary cylinder

    Science.gov (United States)

    Xu, S. J.; Gan, L.; Zhou, Y.

    2016-11-01

    In this paper, we present some experimental results about the physical effects of a cylinder's streamwise oscillation motion on a downstream one in a tandem arrangement. The upstream cylinder undergoes a controlled simple harmonic oscillation at amplitudes A/ d = 0.2-0.8, where d is the cylinder diameter, and the frequency ratio of f_e/f_s = 0-3.0, where f_e is the cylinder oscillation frequency and f_s is the natural frequency of vortex shedding from a single stationary cylinder. Under these conditions, the vortex shedding is locked to the controlled oscillation motion. Flow visualisation using the planar laser-induced fluorescence and qualitative measurements using hot-wire anemometry reveal three distinct flow regimes behind the downstream cylinder. For f_e/f_s > (f_e/f_s)_c, where (f_e/f_s)_c is a critical frequency ratio which depends on A/ d and Reynolds number Re, a so-called SA-mode occurs. The upstream oscillating cylinder generates binary vortices symmetrically arranged about the centreline, each containing a pair of counter-rotating vortices, and the downstream cylinder sheds vortices alternately at 0.5f_e. For 0.7-1.0 < f_e/f_s < (f_e/f_s)_c a complex vortex street that consists of two outer rows of vortices generated by the oscillating cylinder and two inner rows of vortices shed from the downstream stationary cylinder, which is referred to as AA-mode. For 0.3-0.6 < f_e/f_s< 0.8-1.0, one single staggered vortex street (A-mode) is observed. It is also found that, when f_e/f_s is near unity, the streamwise interaction of the two cylinders gives rise to the most energetic wake in the cross-stream direction, in terms of its maximum width, and the wake is AA-mode-like. The effects of other parameters such as the spacing between the two cylinders, Re and A/ d on the flow pattern are also discussed in details. The observations are further compared to the stationary tandem cylinder cases.

  6. Vortex noise from nonrotating cylinders and airfoils

    Science.gov (United States)

    Schlinker, R. H.; Amiet, R. K.; Fink, M. R.

    1976-01-01

    An experimental study of vortex-shedding noise was conducted in an acoustic research tunnel over a Reynolds-number range applicable to full-scale helicopter tail-rotor blades. Two-dimensional tapered-chord nonrotating models were tested to simulate the effect of spanwise frequency variation on the vortex-shedding mechanism. Both a tapered circular cylinder and tapered airfoils were investigated. The results were compared with data for constant-diameter cylinder and constant-chord airfoil models also tested during this study. Far-field noise, surface pressure fluctuations, and spanwise correlation lengths were measured for each configuration. Vortex-shedding noise for tapered cylinders and airfoils was found to contain many narrowband-random peaks which occurred within a range of frequencies corresponding to a predictable Strouhal number referenced to the maximum and minimum chord. The noise was observed to depend on surface roughness and Reynolds number.

  7. Sky reconstruction for the Tianlai cylinder array

    Science.gov (United States)

    Zhang, Jiao; Zuo, Shi-Fan; Ansari, Reza; Chen, Xuelei; Li, Yi-Chao; Wu, Feng-Quan; Campagne, Jean-Eric; Magneville, Christophe

    2016-10-01

    We apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on spherical harmonic decomposition, and can be applied to a cylindrical array as well as dish arrays and we can compute the instrument response, synthesized beam, transfer function and noise power spectrum. We consider cylinder arrays with feed spacing larger than half a wavelength and, as expected, we find that the arrays with regular spacing have grating lobes which produce spurious images in the reconstructed maps. We show that this problem can be overcome using arrays with a different feed spacing on each cylinder. We present the reconstructed maps, and study the performance in terms of noise power spectrum, transfer function and beams for both regular and irregular feed spacing configurations.

  8. Combustion, performance and emissions characteristics of a newly developed CRDI single cylinder diesel engine

    Indian Academy of Sciences (India)

    Avinash Kumar Agarwal; Paras Gupta; Atul Dhar

    2015-09-01

    For improving engine performance, combustion and controlling emissions from compression ignition (CI) engines, common rail direct injection (CRDI) technology offers limitless possibilities by controlling fuel injection parameters such as fuel injection pressure, start of injection (SOI) timing, rate of fuel injection and injection duration. CRDI systems available commercially are quite complex and use a large number of sensors, hardware and analytical circuits, which make them very expensive and unfeasible for cheaper single cylinder engines, typically used in agricultural sector and decentralized power sector. This paper covers experimental investigations of a simpler version of CRDI system developed for a constant-speed, single-cylinder engine. Modifications in the cylinder head for accommodating solenoid injector, designing injector driver circuit and development of high pressure stage controls were some of the engine modification and development tasks undertaken. SOI timing is an important parameter for improving engine's combustion characteristics. SOI timings were varied between 25° and 40° BTDC for investigating engine's performance, emissions and combustion characteristics. Advanced fuel injections showed higher heat release rate (HRR), cylinder pressure and rate of pressure rise (RoPR) because of relatively longer ignition delay experienced. Lowest brake specific fuel consumption (BSFC) was obtained for 34° CA BTDC SOI. Reduction in engine out emissions except NOx was observed for advanced fuel injection timings for this newly developed CRDI system.

  9. UF{sub 6} cylinder inspections at PGDP

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, G.W.; Whinnery, W.N. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Routine inspections of all UF{sub 6} cylinders at the Paducah Gaseous Diffusion Plant have been mandated by the Department of Energy. A specific UF{sub 6} cylinder inspection procedure for what items to inspect and training for the operators prior to inspection duty are described. The layout of the cylinder yards and the forms used in the inspections are shown. The large number of cylinders (>30,000) to inspect and the schedule for completion on the mandated time table are discussed. Results of the inspections and the actions to correct the deficiencies are explained. Future inspections and movement of cylinders for relocation of certain cylinder yards are defined.

  10. Bistable Head Positioning Arm Latch

    Science.gov (United States)

    Wasson, Ken; Endo, Juro; Mita, Masahiro; Abelein, Nathan

    A simple, low cost, yet effective device has been developed for immobilizing the head-arm assembly in a disk drive or similar mechanism during power-off conditions. The latching scheme also provides a consistent means of releasing the head-arm assembly from the immobilized position upon power up of the disk drive. The latch uses no electrical power in either immobilized or released state. This design is immune to extreme torque and linear shock forces applied to the disk drive case. The latch system can use the energy stored in the spinning disks to drive the head-arm assembly toward a safe position while simultaneously arming the latch mechanism to secure the head-arm assembly in the safe position upon arrival. A low energy five msec pulse of current drives the latch from one state to the other. Solenoids as presently used in latch mechanisms are bulky, expensive, have variable force characteristics, and often generate contaminants. The latch described in this paper is expected to replace such solenoids. It may also replace small magnet latches, which have limited latch force and apply unwanted torque to a proximate head positioning arm.

  11. Flow over an inline oscillating circular cylinder in the wake of a stationary circular cylinder

    Science.gov (United States)

    Zhang, Yang; Zhu, Keqiang

    2017-02-01

    Flow interference between an upstream stationary cylinder and an inline oscillating cylinder is studied with the lattice Boltzmann method. With a fixed Reynolds number Re = 100 and pitch ratio L/D = 4, the effects of oscillation amplitude A/D = [0.25, 1] and frequency f e/f s = [0.5, 2] are investigated. The wake response state is categorized into lock-in and non-lock-in. The lock-in zone in the bifurcation diagram of amplitude versus frequency is discontinuous. Response states of upstream and downstream wakes are similar under the conditions of small amplitude or low frequency. However, with large oscillating parameters, the two wakes are prone to be in different states as the flow field becomes irregular. Two distinct flow regimes have been identified, i.e., single-cylinder and two-cylinder shedding regimes. The presence of single-cylinder shedding regime is attributed to the low shedding frequency of the downstream cylinder at large amplitude. Hydrodynamic forces of the oscillating tandem system are discussed. The results reveal that forces on the two cylinders behave differently and that the absence of vortices in the gap flow significantly reduces the forces exerting on the tandem system.

  12. Casimir Energy for a Dielectric Cylinder

    CERN Document Server

    Cavero-Pelaez, I; Cavero-Pelaez, Ines; Milton, Kimball A.

    2004-01-01

    In this paper we calculate the Casimir energy for a dielectric-diamagnetic cylinder with the speed of light differing on the inside and outside. Although the result is in general divergent, special cases are meaningful. The well-known results for a uniform speed of light are reproduced. The self-stress on a purely dielectric cylinder is shown to vanish through second order in the deviation of the permittivity from its vacuum value, in agreement with the result calculated from the sum of van der Waals forces.

  13. Electromagnetic Invisibility of Elliptic Cylinder Cloaks

    Institute of Scientific and Technical Information of China (English)

    YAO Kan; LI Chao; LI Fang

    2008-01-01

    Structures with unique electromagnetic properties are designed based on the approach of spatial coordinate transformations of Maxwell's equations.This approach is applied to scheme out invisible elliptic cylinder cloaks,which provide more feasibility for cloaking arbitrarily shaped objects.The transformation expressions for the anisotropic material parameters and the field distribution are derived.The cloaking performances of ideal and lossy elliptic cylinder cloaks are investigated by finite element simulations. It is found that the cloaking performance will degrade in the forward direction with increasing loss.

  14. Stress tests on cylinders and aluminum panels

    Science.gov (United States)

    Sobel, L. H.; Agarwal, B. L.

    1974-01-01

    An optimization study of composite stiffened cylinders is discussed. The mathematical model for the buckling has been coupled successfully with the optimization program AESOP. The buckling analysis is based on the use of the smeared theory for the buckling of stiffened orthotropic cylindrical shells. The loading, radius, and length of the cylinder are assumed to be known parameters. An optimum solution gives the value of cross-sectional dimensions and laminate orientations. The different types of buckling modes are identified. Mathematical models are developed to show the relationships of the parameters.

  15. A Hybrid Approach To Tandem Cylinder Noise

    Science.gov (United States)

    Lockard, David P.

    2004-01-01

    Aeolian tone generation from tandem cylinders is predicted using a hybrid approach. A standard computational fluid dynamics (CFD) code is used to compute the unsteady flow around the cylinders, and the acoustics are calculated using the acoustic analogy. The CFD code is nominally second order in space and time and includes several turbulence models, but the SST k - omega model is used for most of the calculations. Significant variation is observed between laminar and turbulent cases, and with changes in the turbulence model. A two-dimensional implementation of the Ffowcs Williams-Hawkings (FW-H) equation is used to predict the far-field noise.

  16. EC Hidraulic Drive Cylinder Relief Vlave Test

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.; /Fermilab

    1991-04-03

    This engineering note documents the testing of the set pressure of the EC hydraulic drive cylinder relief valve. The purpose of the relief valve is to provide a safety measure in the event that oil becomes trapped in the rod side of the cylinder and pressure is applied to the cap side. The note includes an explanation of the procedure used and a summary of the result of the testing done on February 14, 1991 by Gary Trotter. The result was that the cylinder relief valve relieved at the correct set pressure of 10,500 psig. The basic concern is for the protection of the cylinder. The pump is capable of providing up to 10,500 psi of pressure to either side of the cylinder. The cylinder is rated for 10,500 psi. Under normal operating conditions, the valves would be open, and the pumping pressure would automatically flow oil into one side, and remove oil from the other side. If, however, the valve for the other side was closed, so that oil could not be removed, then the pressure would build in that side. If the rod side is pressurized to the maximum pump pressure of 10,500 psi, the cross sectional area ratio of 2.29 results in a pressure of approximately 4600 psi in the cap side, which is well under the rated pressure. If, however, the cap side is pressurized to 10,500 psi, the cross sectional area would produce a pressure of approximately 24,000 psi in the rod side, which could damage the cylinder. Therefore, the pressure on the rod side must be limited to the rated pressure of 10,500 psi. In reality, the maximum operating force on the piston would be under 11,000 Ibs., which would result in the maximum cylinder pressure being under 8000 psi to the rod side, and under 3500 psi to the cap side. Therefore, the relief is only needed as a safety precaution in the case that oil becomes trapped.

  17. Controllable parabolic-cylinder optical rogue wave.

    Science.gov (United States)

    Zhong, Wei-Ping; Chen, Lang; Belić, Milivoj; Petrović, Nikola

    2014-10-01

    We demonstrate controllable parabolic-cylinder optical rogue waves in certain inhomogeneous media. An analytical rogue wave solution of the generalized nonlinear Schrödinger equation with spatially modulated coefficients and an external potential in the form of modulated quadratic potential is obtained by the similarity transformation. Numerical simulations are performed for comparison with the analytical solutions and to confirm the stability of the rogue wave solution obtained. These optical rogue waves are built by the products of parabolic-cylinder functions and the basic rogue wave solution of the standard nonlinear Schrödinger equation. Such rogue waves may appear in different forms, as the hump and paw profiles.

  18. 人工肱骨头置换治疗老年肱骨近端陈旧性骨折的疗效分析%Efficacy of humeral head replacement for the treatment of old fracture proximal humerus in elderly

    Institute of Scientific and Technical Information of China (English)

    刘大海; 李开南; 母建松; 兰海

    2016-01-01

    Background Senile proximal humerus old fracture may cause shoulder pain, function limitation and other issues,which seriously affects the quality of life of the patient.This type of fracture was often caused by improper conservative therapy or failure of initial surgery.For patients with intact glenoid and cartilage surface,hemiarthroplasty can quickly restore integrity of the shoulder joint,and its efficacy for senile comminuted proximal humerus fresh fractures has been confirmed. However,there was no report on its effectiveness on senile proximal humerus old fractures.This retrospective study analyzed 22 cases of senile comminuted proximal humerus old fracture patients who received hemiarthroplasty between January 2009 and December 2013 in our hospital (old fracture group),and compared to 68 cases of senile comminuted proximal humerus fresh fracture patients who received hemiarthroplasty at the same time period.The results are reported below.Methods From January 2009 to December 2013,we chose total of 90 cases of proximal humeral fractures with no glenoid and cartilage surface damages,among which there were 22 cases of old fracture patients,13 cases of male and 9 cases of female,aged 70-85 years old,with average age of 77.0 years old.There were 1 2 cases of 3-6 months proximal humeral fractures,8 cases of 6-9 months and 2 cases of 9-1 2 months.Neer classification:three-part fractures in 6 cases,four-part fractures in 1 6 cases.There were 1 1 patients with humeral head dislocation,5 cases with rib fractures and pulmonary contusion,3 cases with visceral organ inj ury and 1 case with epidural hematoma;fifteen patients had shoulder muscle atrophy,and two cases had humeral head necrosis.There were 68 cases in the fresh fracture group,including 37 males and 31 females,aged 70-83 years old,with average age of 76.3 years old;Neer classification:three-part fractures in 23 cases and four-part fractures in 45 cases,including 28 cases of patients with humeral head

  19. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  20. Steady viscous flows in an annulus between two cylinders produced by vibrations of the inner cylinder

    CERN Document Server

    Ilin, K

    2010-01-01

    We study the steady streaming between two infinitely long circular cylinders produced by small amplitude transverse vibrations of the inner cylinder about the axis of the outer cylinder. The Vishik-Lyusternik method is employed to construct an asymptotic expansion of the solution of the Navier-Stokes equations in the limit of high-frequency vibrations for Reynolds numbers of order of unity. The effect of the Stokes drift of fluid particles is also studied. It is shown that it is nonzero not only within the boundary layers but also in higher order terms of the expansion of the averaged outer flow.

  1. Shoulder Joint Replacement

    Science.gov (United States)

    ... Shoulder Replacement Options Shoulder replacement surgery is highly technical. It should be performed by a surgical team ... area and will meet a doctor from the anesthesia department. You, your anesthesiologist, and your surgeon will ...

  2. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  3. VNR CMS Pixel detector replacement

    CERN Document Server

    2017-01-01

    Joel Butler, spokesperson of the CMS collaboration explains how a team from many different partner institutes installed a new detector in CMS. This detector is the silicon pixel detector and they’ve been working on it for about five years, to replace one of our existing detectors. This detectors measures particles closer to the beam than any of the other components of this huge detector behind me. It gives us the most precise picture of tracks as they come out of the collisions and expand and travel through the detector. This particular device has twice as many pixels, 120 million, as opposed to about 68 million in the old detector and it can take data faster and pump it out to the analysis more quickly. 00’53’’ Images of the descent, insertion and installation of first piece of the Pixel detector on Tue Feb 28. Images of the descent, insertion and installation of second piece of the Pixel and the two cylinders being joined.

  4. Flow mediated interactions between two cylinders at finite Re numbers

    Science.gov (United States)

    Gazzola, Mattia; Mimeau, Chloe; Tchieu, Andrew A.; Koumoutsakos, Petros

    2012-04-01

    We present simulations of two interacting moving cylinders immersed in a two-dimensional incompressible, viscous flow. Simulations are performed by coupling a wavelet-adapted, remeshed vortex method with the Brinkman penalization and projection approach. This method is validated on benchmark problems and applied to simulations of a master-slave pair of cylinders. The master cylinder's motion is imposed and the slave cylinder is let free to respond to the flow. We study the relative role of viscous and inertia effects in the cylinders interactions and identify related sharp transitions in the response of the slave. The observed differences in the behavior of cylinders with respect to corresponding potential flow simulations are discussed. In addition, it is observed that in certain situations the finite size of the slave cylinders enhances the transport so that the cylinders are advected more effectively than passive tracers placed, respectively, at the same starting position.

  5. The ideal dimensions of a Halbach cylinder of finite length

    CERN Document Server

    Bjørk, R

    2014-01-01

    In this paper the smallest or optimal dimensions of a Halbach cylinder of a finite length for a given sample volume and desired flux density are determined using numerical modeling and parameter variation. A sample volume that is centered in and shaped as the Halbach cylinder bore but with a possible shorter length is considered. The external radius and the length of the Halbach cylinder with the smallest possible dimensions are found as a function of a desired internal radius, length of the sample volume and mean flux density. It is shown that the optimal ratio between the outer and inner radius of the Halbach cylinder does not depend on the length of the sample volume. Finally, the efficiency of a finite length Halbach cylinder is considered and compared with the case of a cylinder of infinite length. The most efficient dimensions for a Halbach cylinder are found and it is shown that the efficiency increases slowly with the length of the cylinder.

  6. Breached cylinder incident at the Portsmouth gaseous diffusion plant

    Energy Technology Data Exchange (ETDEWEB)

    Boelens, R.A. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

    1991-12-31

    On June 16, 1990, during an inspection of valves on partially depleted product storage cylinders, a 14-ton partially depleted product cylinder was discovered breached. The cylinder had been placed in long-term storage in 1977 on the top row of Portsmouth`s (two rows high) storage area. The breach was observed when an inspector noticed a pile of green material along side of the cylinder. The breach was estimated to be approximately 8- inches wide and 16-inches long, and ran under the first stiffening ring of the cylinder. During the continuing inspection of the storage area, a second 14-ton product cylinder was discovered breached. This cylinder was stacked on the bottom row in the storage area in 1986. This breach was also located adjacent to a stiffening ring. This paper will discuss the contributing factors of the breaching of the cylinders, the immediate response, subsequent actions in support of the investigation, and corrective actions.

  7. Drag Coefficient of Thin Flexible Cylinder

    Science.gov (United States)

    Subramanian, Chelakara; Gurram, Harika

    2015-11-01

    Measurements of drag coefficients of thin flexible cylindrical wires are described for the Reynolds number range between 250 - 1000. Results indicate that the coefficient values are about 20 to 30 percent lower than the reported laminar flow values for rigid cylinders. Possible fluid dynamics mechanism causing the reduction in drag will be discussed.

  8. Frequency spectra of laminated piezoelectric cylinders

    Science.gov (United States)

    Siao, J. C.-T.; Dong, S. B.; Song, J.

    1994-07-01

    A finite-element method is presented for determining the vibrational characteristics of a circular cylinder composed of bonded piezoelectric layers. Finite-element modeling occurs in the radial direction only using quadratic polynomials and the variationally derived partial differential equations are functions of the hoop and axial coordinates (theta, z) and time t. Using solution form Q exp (i(xi(z) + n(theta) + (omega)t)), with Q as the nodal amplitudes, leads to an algebraic eigensystem where any one of the three parameters (n, xi, omega), the circumferential or axial wave number or natural frequency, can act as the eigenvalue. Integer values always are assigned to n, leaving two possible eigenvalue problems. With omega as the eigenvalue and real values assigned to xi, the solutions represent propagating waves or harmonic standing vibrations in an infinite cylinder. When xi is the eigenvalue and real values assigned to omega, this eigensystem admits both real and complex eigendata. Real xi's represent propagating waves or harmonic standing vibrations as noted before. Complex conjugate pairs of xi 's describe end vibrations, which arise when an incident wave impinges upon a free end of a cylindrical bar. They are standing waves whose amplitudes decay sinusoidally or exponentially from the free end into the interior. Two examples are given to illustrate the method of analysis, viz., a solid piezoelectric cylinder of PZT-4 ceramic material and a two-layer cylinder of PZT-4 covering an isotropic material.

  9. In-Cylinder Heat Transfer Modelling

    Directory of Open Access Journals (Sweden)

    Žák Zdeněk

    2016-12-01

    Full Text Available The goal of the paper is to discuss specific features of the in-cylinder heat transfer calculation based on widely used empirical formulas. The potential of in-house codes compared with commercially available software packages is presented. The principles of user models in the GT-SUITE environment are also explained. The results of calibrated models are briefly discussed.

  10. Acoustic signal analysis of underwater elastic cylinder

    Institute of Scientific and Technical Information of China (English)

    LI Xiukun; YANG Shi'e

    2001-01-01

    The echoes of underwater elastic cylinder comprise two types of acoustic components: Geometrical scattering waves and elastic scattering waves. The transfer function is appropriate to characterize the echo of targets. And the discrete wavelet transform of amplitude spectrum is presented and used to identify the resonant components of underwater targets.PACS numbers: 43.30, 43.60

  11. The Experience Cylinder, an immersive interactive platform

    DEFF Research Database (Denmark)

    Andreasen, Troels; Gallagher, John Patrick; Møbius, Nikolaj

    2011-01-01

    This paper describes the development of an experimental interactive installation, a so-called "experience cylinder", intended as a travelogue and developed specifically to provide a narrative about the Viking ship Sea Stallion’s (Havhingst) voyage from Roskilde to Dublin and back. The installatio...

  12. Spin-Up in a Rectangular Cylinder

    Science.gov (United States)

    1993-12-01

    cylinder by scaling as follows: I I IElt , and p = E’,X, 3.22 where we have scaled the radial and vertical flow to be higher order in Ekman number than the...two flow visualization systems, and the rectangular tank with prepared water. Fig- ure 4.1 is a schematic of this system, which we describe below.I I

  13. Framework of Digital Machining Process Planning Platform for Cylinder Body Part

    Institute of Scientific and Technical Information of China (English)

    MA Yu-min; FAN Liu-qun; ZHU Zhi-hao; ZHANG Hao

    2007-01-01

    Digital factory technology is an advanced manufacturing technology served as to establish a bridge between the process of product development and manufacturing. In terms of application for digital factory technology in machining, especially in machining of a complicated part such as a cylinder body part, a concept of digital process planning and its framework are proposed. Its components including machining domain knowledge model, machining knowledge base, machining resource base and process planning system are studied. A machining knowledge model in tree form and an object-driven knowledge reasoning mechanism are used for machining knowledge base. The process planning system is a user interface that leads a planner to finish the planning process. A case about a cylinder head part is given to demonstrate how the platform works. The framework of digital process planning is the foundation of some intelligent CAPP systems and helps to production line planning.

  14. 喉罩复合无肌松技术在老年患者股骨头置换术中的应用研究%Advantage analysis of Laryngeal mask combined with non-muscle relaxant technology for elderly patients with femoral head replacement

    Institute of Scientific and Technical Information of China (English)

    李敏仙; 顾颖红

    2015-01-01

    目的 探讨喉罩复合无肌松麻醉方法在老年患者股骨头置换术中的临床价值.方法 该院2013年3月至2014年5月行股骨头置换手术的老年患者共50例 ,随机将其分为试验组和对照组各25例.试验组患者给予喉罩复合无肌松麻醉方法 ,对照组给予常规麻醉方法 ,比较2组患者各时间的心率(HR)、平均血压(MAP)和氧饱和度(SPO2 ) ,临床效果及肌松效果、辅助麻醉用药 ,不良反应率.结果 对照组患者各时间点的HR、MAP、SPO2比较 ,差异均有统计学意义(P0 .05).试验组患者的清醒时间、拔管时间和咽喉疼痛发生率显著低于对照组 ,差异均有统计学意义(P0 .05).试验组患者的肌松效果满意率显著高于对照组 ,差异有统计学意义(P0 .05).结论 喉罩复合无肌松技术应用于老年股骨头置换手术临床效果较好 ,且安全性高.%Objective To analyze the advantage of Laryngeal mask combined with non-muscle relaxant technology for elderly patients with Femoral head replacement .Methods A total of 50 consecutives from March 2013 to May 2014 for Femoral head replacement arriving at our hospital ,They were divided randomly into experiment and control groups ,and each of 25 cases .The patients in experiment group received Laryngeal mask combined with non-muscle relaxant technology ,the patients in control group received common anesthesia method ,then heart rate ,Mean arterial pressure ,Oxygen saturation at every times ,clinical effect and muscle relaxation effect ,assisted anesthesia drug ,adverse reaction rate were compared in two groupsResults The HR ,MAP and SPO2 at every times in control group were all significant differnces in different time(P0 .05) .The recovery time ,extubation time and throat pain rate in experiment group were all significant less than control group (P0 .05) .The satisfaction rate of muscle relaxation effect in experiment group was all significantly higher than that in control group (P0

  15. 罗哌卡因术后镇痛在高龄人工股骨头置换术后早期功能锻炼中的应用%Application of ropivacaine in patient controlled analgesia for the aged patients in early functional exercise of artificial femoral head replacement

    Institute of Scientific and Technical Information of China (English)

    程江霞; 彭晓红; 秦汉; 胡锦涛; 杨春梅

    2012-01-01

    目的:观察罗哌卡因术后镇痛用于老年人工股骨头置换术后早期功能锻炼的效果和安全性.方法:选择期单侧人工股骨头置换术高龄患者120例,行腰硬联合麻醉,术后镇痛随机分为3组:A组为安慰剂组,B组为0.75%布比卡因75mg+90mL0.9%的氯化钠注射液组,C组为1%罗哌卡因150mg+85mL0.9%的氯化钠注射液组,观察并记录术后3组患者不同时点的视觉模拟评分(VAS),开启PCA泵患者按压次数(D),患者的生命体征及不良反应,术后2周内并发症发生率及术后6个月髋关节功能的评价.结果:与安慰剂A组比较,术后B组和C组的VAS明显低于A组(P<0.05),B组与C组无明显差异(P>0.05);术后B组和C组的并发症少于A组(P<0.05),C组术后6个月髋关节功能优良率明显高于A组(P<0.05);与B组比较,C组术后并发症减少.结论:小剂量的罗哌卡因对这类患者镇痛效果好,术后肌力恢复快,术后并发症少,应用于老年全髋关节置换术的早期功能锻炼安全、有效.%OBJECTIVE To observe the effect and safety of ropivacaine in patient-controlled analgesia for the aged patients in artificial femoral head replacement in early functional exercise METHODS 120 aged patients who would receive unilateral elective prosthetic femoral head replacement were divided randomly into three groups:group A was placebo group (n - 40): the pump was filled with 100mL physiological saline (n·40),group B:the pump was filled with 0. 75% bupivacaine 75 mg and 90 mL physiological saline (n = 40) sgroup C:the pump was filled with 1% ropivacaine 75 mg and 90 mL physiological saline (n = 40) .received simple lumbar anesthesia. The visual analogue scale in the different time points, the press times after open PCVA, the patients' vital signs and postoperative adverse reaction,the complications two weeks after operation were recorded; and e-valuated the hip function six weeks after operation. RESULTS Compared with the placebo

  16. Inner and outer cylinders of the CMS vacuum tank.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The vacuum tank of the CMS magnet system consists of inner and outer stainless-steel cylinders and houses the superconducting coil. The inner cylinder contains all the barrel sub-detectors, which it supports via a system of horizontal rails. The cylinder is pictured here in the vertical position on a yellow platform mounted on the ferris-wheel support structure. This will allow it to be pivoted and inserted into the already installed outer cylinder, through which this photo was taken.

  17. 49 CFR 173.316 - Cryogenic liquids in cylinders.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder than...

  18. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  19. Electromagnetic Wave Scattering By the Coated Impedance Cylinder

    Directory of Open Access Journals (Sweden)

    V.I. Vyunnik

    2010-01-01

    Full Text Available In this work the boundary conditions for the impedance circular cylinder coated by a low contrast dielectric thin layer are derived. Expression for the reduced impedance of the cylinder is obtained. Conditions and applicability limits of the proposed approach are defined. Influence of the coating impedance on the reduced impedance of the cylinder is investigated.

  20. Turbulent Taylor–Couette flow with stationary inner cylinder

    NARCIS (Netherlands)

    Ostilla-Monico, R.; Verzicco, Roberto; Lohse, Detlef

    2016-01-01

    A series of direct numerical simulations were performed of Taylor–Couette (TC) flow, the flow between two coaxial cylinders, with the outer cylinder rotating and the inner one fixed. Three cases were considered, where the Reynolds number of the outer cylinder was $Re_{o}=5.5\\times 10^{4}$Reo=5.5×104

  1. Investigation of breached depleted UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    DeVan, J.H. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. An investigation team was immediately formed to determine the cause of the failures and their impact on future storage procedures and to recommend corrective actions. Subsequent investigation showed that the failures most probably resulted from mechanical damage that occurred at the time that the cylinders had been placed in the storage yard. In both cylinders evidence pointed to the impact of a lifting lug of an adjacent cylinder near the front stiffening ring, where deflection of the cylinder could occur only by tearing the cylinder. The impacts appear to have punctured the cylinders and thereby set up corrosion processes that greatly extended the openings in the wall and obliterated the original crack. Fortunately, the reaction products formed by this process were relatively protective and prevented any large-scale loss of uranium. The main factors that precipitated the failures were inadequate spacing between cylinders and deviations in the orientations of lifting lugs from their intended horizontal position. After reviewing the causes and effects of the failures, the team`s principal recommendation for remedial action concerned improved cylinder handling and inspection procedures. Design modifications and supplementary mechanical tests were also recommended to improve the cylinder containment integrity during the stacking operation.

  2. Sub-wavelength metamaterial cylinders with multiple dipole resonances

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Breinbjerg, Olav

    2009-01-01

    It has been shown that the sub-wavelength resonances of the individual MTM cylinders also occur for electrically small configurations combining 2 or 4 cylinders. For the 2-and 4-cylinder configurations the overall size is 1/20 and 1/12.5 of the smallest wavelength, respectively. These MTM...... configuration thus offer the possibility for multi-resonant electrically small configurations....

  3. Controlling a negative loaded hydraulic cylinder using pressure feedback

    DEFF Research Database (Denmark)

    Hansen, M.R.; Andersen, T.O.

    2010-01-01

    showing that without extra measures such a system will be unstable in a substantial part of the cylinder stroke. The stability criterion is expressed in hard quantities: Cylinder volumes, cylinder area ratio and overcenter valve pilot area ratio. A pressure feed back scheme that has as target to maintain...

  4. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  5. Turbulent Taylor–Couette flow with stationary inner cylinder

    NARCIS (Netherlands)

    Ostilla-Monico, R.; Verzicco, R.; Lohse, D.

    2016-01-01

    A series of direct numerical simulations were performed of Taylor–Couette (TC) flow, the flow between two coaxial cylinders, with the outer cylinder rotating and the inner one fixed. Three cases were considered, where the Reynolds number of the outer cylinder was $Re_{o}=5.5\\times 10^{4}$Reo=5.5×104

  6. 老年人股骨颈骨折股骨头置换术中短柄假体的有限元分析%Finite element analysis of the short-stem prothesis in femoral head replacement among the elderly femoral neck fractures

    Institute of Scientific and Technical Information of China (English)

    吕大伟; 苏琴; 姚咏明; 赵晓东

    2015-01-01

    目的:针对老年人股骨颈骨折后假体置换术,使用有限元分析的方法对股骨短柄假体与常规股骨假体的生物力学特性进行对比。方法利用薄层CT资料建立股骨三维有限元模型,利用我院股骨中空多孔股骨假体相关参数建立两种髋关节股骨假体三维有限元模型;应用Ansys 5.7有限元分析软件考察两种假体植入后的应力分布,并进行比较。结果短柄假体所受最大mises应力较常规股骨假体明显减小;力学传导模式仍为远端应力集中,最大mises应力仍出现在张力侧。结论老年人股骨颈骨折关节置换术中短柄假体力学特性优越。%Objective To compare biomechanical properties of the short-stem prosthesis with conventional prosthesis with the finite element analysis method for the elderly femoral neck fracture after femoral head replace -ment.Methods Three-dimensional finite element models of the upper femur and prosthesis were established .The stress distribution difference between the short-stem prosthesis and conventional prosthesis was compared by using fi-nite element analysis software Ansys 5.7.Results The maximum mises stress of the short-stem prosthesis de-creased significantly,while stress distribution model remained the same .Conclusion The short-stem prosthesis presents superior mechanical properties in femoral head replacement among the elderly femoral neck fractures .

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  8. ADAPTIVE CONTROLLER AND ITS APPLICATION IN FORCE SYSTEM OF ASYMMETRIC CYLINDER CONTROLLED BY SYMMETRIC VALVE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Partial pressure, system vibration and asymmetric system dynamic performance exit in asymmetric cylinder controller by symmetric valve hydraulic system. To solve this problem in the force control system, model reference adaptive controller is designed using equilibrium point stability theory and output error equation polynomial. The reference model is selected in such a way that it meets the system dynamic performance. Hardware configuration of asymmetric cylinder controlled by asymmetric valve hydraulic system is replaced by intelligent control algorithm, thus the cost is lowered and easy to application. Simulation results demonstrate that the proposed adaptive control sheme has good adaptive ability and well solves asymmetric dynamic performance problem. The designed adaptive controller is fairly robust to load disturbance and system parameter variation.

  9. Development of Advanced In-Cylinder Components and Tribological Systems for Low Heat Rejection Diesel Engines. Phases 2, 3, and 4

    Science.gov (United States)

    1999-06-01

    parameters to produce zirconia -based thermal barrier coatings on V903 piston crowns and cylinder heads were developed by translating UTRC’s experience...52 3.4.1 Nickel Aluminide Crown for Articulated Pistons...52 3.4.2 Titanium Aluminide Crown for Articulated Pistons ........................... 53 3.4.3 Conclusions - Alternative Piston

  10. The ideal dimensions of a Halbach cylinder of finite length

    DEFF Research Database (Denmark)

    Bjørk, Rasmus

    2011-01-01

    but with a possible shorter length is considered. The external radius and the length of the Halbach cylinder with the smallest possible dimensions are found as a function of a desired internal radius, length of the sample volume and mean flux density. It is shown that the optimal ratio between the outer and inner...... radius of the Halbach cylinder does not depend on the length of the sample volume. Finally, the efficiency of a finite length Halbach cylinder is considered and compared with the case of a cylinder of infinite length. The most efficient dimensions for a Halbach cylinder are found and it is shown...

  11. Performance of Air-cooled Engine Cylinders Using Blower Cooling

    Science.gov (United States)

    Schey, Oscar W; Ellerbrock, Herman H , Jr

    1936-01-01

    An investigation was made to obtain information on the minimum quantity of air and power required to cool conventional air cooled cylinders at various operating conditions when using a blower. The results of these tests show that the minimum power required for satisfactory cooling with an overall blower efficiency of 100 percent varied from 2 to 6 percent of the engine power depending on the operating conditions. The shape of the jacket had a large effect on the cylinder temperatures. Increasing the air speed over the front of the cylinder by keeping the greater part of the circumference of the cylinder covered by the jacket reduced the temperatures over the entire cylinder.

  12. Radiation levels on empty cylinders containing heel material

    Energy Technology Data Exchange (ETDEWEB)

    Shockley, C.W. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Empty UF{sub 6} cylinders containing heel material were found to emit radiation levels in excess of 200 mr/hr, the maximum amount stated in ORO-651. The radiation levels were as high as 335 mr/hr for thick wall (48X and 48Y) cylinders and 1050 mr/hr for thin wall (48G and 48H) cylinders. The high readings were found only on the bottom of the cylinders. These radiation levels exceeded the maximum levels established in DOT 49 CFR, Part 173.441 for shipment of cylinders. Holding periods of four weeks for thick-wall cylinders and ten weeks for thin-wall cylinders were established to allow the radiation levels to decay prior to shipment.

  13. Evaluation of Concrete Cylinder Tests Using Finite Elements

    DEFF Research Database (Denmark)

    Saabye Ottosen, Niels

    1984-01-01

    Nonlinear axisymmetric finite element analyses are performed on the uniaxial compressive test of concrete cylinders. The models include thick steel loading plates, and cylinders with height‐to‐diameter ratios (h/d) ranging from 1‐3 are treated. A simple constitutive model of the concrete...... is employed, which accounts for the strain hardening and softening in the pre‐ and postfailure regions, respectively. When h/d  =  2, the failure mode is found to consist of undisturbed end cones and the occurrence of strain softening, especially in the outer region of the cylinder middle. For shorter...... cylinders the strain softening is more pronounced along the surface of the cylinder middle, whereas longer cylinders exhibit a more uniform distribution of strain softening. The failure modes for force and displacement controlled tests are found to be similar. If long cylinders are to provide the true...

  14. Features of Flow Past Square Cylinder with a Perforated Plate

    Institute of Scientific and Technical Information of China (English)

    汪健生; 徐亚坤; 程浩杰

    2016-01-01

    A numerical investigation was performed on the reduction of the fluid forces acting on the square cylin-der in the laminar flow regime with a perforated plate. The effects of geometric parameters such as the distance between the square cylinder and the perforated plate on the wake of the square cylinder were discussed. Further-more, the flow characteristics such as the drag coefficient, lift coefficient, Strouhal number and flow pattern were obtained. It can be concluded that the drag force of the square cylinder reduces to some extent due to the addition of the perforated plate. The flow structure varies when the perforated plate is located behind the square cylinder. Moreover, the recirculation zone augments with the increase ofL/D, and the vortex trace on the upper and lower surface of the square cylinder moves gradually backwards until a stable recirculation zone formed between the square cylinder and the perforated plate.

  15. Upgraded Analytical Model of the Cylinder Test

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P. Clark; Lauderbach, Lisa; Garza, Raul; Ferranti, Louis; Vitello, Peter

    2013-03-15

    A Gurney-type equation was previously corrected for wall thinning and angle of tilt, and now we have added shock wave attenuation in the copper wall and air gap energy loss. Extensive calculations were undertaken to calibrate the two new energy loss mechanisms across all explosives. The corrected Gurney equation is recommended for cylinder use over the original 1943 form. The effect of these corrections is to add more energy to the adiabat values from a relative volume of 2 to 7, with low energy explosives having the largest correction. The data was pushed up to a relative volume of about 15 and the JWL parameter ω was obtained directly. The total detonation energy density was locked to the v=7 adiabat energy density, so that the Cylinder test gives all necessary values needed to make a JWL.

  16. Locomotion gaits of a rotating cylinder pair

    Science.gov (United States)

    van Rees, Wim M.; Novati, Guido; Koumoutsakos, Petros; Mahadevan, L.

    2015-11-01

    Using 2D numerical simulations of the Navier-Stokes equations, we demonstrate that a simple pair of rotating cylinders can display a range of locomotion patterns of biological and engineering interest. Steadily counter-rotating the cylinders causes the pair to move akin to a vortex dipole for low rotation rates, but as the rotational velocity is increased the direction of motion reverses. Unsteady rotations lead to different locomotion gaits that resemble jellyfish (for in-phase rotations) and undulating swimmers (for out-of-phase rotations). The small number of parameters for this simple system allows us to systematically map the phase space of these gaits, and allows us to understand the underlying physical mechanisms using a minimal model with implications for biological locomotion and engineered analogs.

  17. Intergalactic Filaments as Isothermal Gas Cylinders

    CERN Document Server

    Harford, A Gayler

    2010-01-01

    Using a cosmological simulation at redshift 5, we find that the baryon-rich cores of intergalactic filaments radiating from galaxies commonly form isothermal gas cylinders. The central gas density is typically about 500 times the cosmic mean total density, and the temperature is typically 1-2 times 10^4 K, just above the Lyman alpha cooling floor. These findings argue that the hydrodynamic properties of the gas are more important than the dark matter in determining the structure. Filaments form a major pipeline for the transport of gas into the centers of galaxies. Since the temperature and ionization state of the gas completely determine the mass per unit length of an isothermal gas cylinder, our findings suggest a constraint upon gas transport into galaxies by this mechanism.

  18. Anomalous magnetoresistance in magnetized topological insulator cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Siu, Zhuo Bin, E-mail: a0018876@nus.edu.sg [NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 (Singapore); Data Storage Institute, Agency for Science, Technology and Research, Singapore 117608 (Singapore); Jalil, Mansoor B. A. [NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 (Singapore)

    2015-05-07

    The close coupling between the spin and momentum degrees of freedom in topological insulators (TIs) presents the opportunity for the control of one to manipulate the other. The momentum can, for example, be confined on a curved surface and the spin influenced by applying a magnetic field. In this work, we study the surface states of a cylindrical TI magnetized in the x direction perpendicular to the cylindrical axis lying along the z direction. We show that a large magnetization leads to an upwards bending of the energy bands at small |k{sub z}|. The bending leads to an anomalous magnetoresistance where the transmission between two cylinders magnetized in opposite directions is higher than when the cylinders are magnetized at intermediate angles with respect to each other.

  19. Upgraded Analytical Model of the Cylinder Test

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P. Clark [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Lauderbach, Lisa [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Garza, Raul [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Ferranti, Louis [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Vitello, Peter [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

    2013-03-15

    A Gurney-type equation was previously corrected for wall thinning and angle of tilt, and now we have added shock wave attenuation in the copper wall and air gap energy loss. Extensive calculations were undertaken to calibrate the two new energy loss mechanisms across all explosives. The corrected Gurney equation is recommended for cylinder use over the original 1943 form. The effect of these corrections is to add more energy to the adiabat values from a relative volume of 2 to 7, with low energy explosives having the largest correction. The data was pushed up to a relative volume of about 15 and the JWL parameter ω was obtained directly. Finally, the total detonation energy density was locked to the v = 7 adiabat energy density, so that the Cylinder test gives all necessary values needed to make a JWL.

  20. Head Position and Internally Headed Relative Clauses.

    Science.gov (United States)

    Basilico, David

    1996-01-01

    Examines "Head Movement" in internally headed relative clauses (IHRCs). The article shows that in some cases, head movement to an external position need not take place and demonstrates that this movement of the head to a sentence-internal position results from the quantificational nature of IHRCs and Diesing's mapping hypothesis (1990, 1992). (56…

  1. NASA head sworn in

    Science.gov (United States)

    James C. Fletcher was sworn in on May 12, 1986, as administrator of the National Aeronautics and Space Administration (NASA). At a news conference after he was sworn in, Fletcher said that NASA would deal with both its technical problems and its procedural problems before the shuttle will fly again. According to press accounts, he stressed that funds should be made available to replace the Challenger orbiter, which was lost in an explosion on January 28.Fletcher, who had also headed the agency from 1971 to 1977, succeeds James M. Beggs, who was indicted in December 1985 for conspiring to defraud the federal government while serving as a senior executive at the General Dynamics Corporation.

  2. Aeronautical Information System Replacement -

    Data.gov (United States)

    Department of Transportation — Aeronautical Information System Replacement is a web-enabled, automation means for the collection and distribution of Service B messages, weather information, flight...

  3. Parabolic cylinder functions of large order

    Science.gov (United States)

    Jones, D. S.

    2006-06-01

    The asymptotic behaviour of parabolic cylinder functions of large real order is considered. Various expansions in terms of elementary functions are derived. They hold uniformly for the variable in appropriate parts of the complex plane. Some of the expansions are doubly asymptotic with respect to the order and the complex variable which is an advantage for computational purposes. Error bounds are determined for the truncated versions of the asymptotic series.

  4. Four-Cylinder Stirling Engine Control Simulation

    Science.gov (United States)

    Daniele, C. J.; Lorenzo, C. F.

    1986-01-01

    Four-cylinder, Stirling-engine, transient-engine-simulation computer program developed. Program intended for control analysis. Associated engine model simplified to shorten computer calculation time. Model includes engine mechanical-drive dynamics and vehicle-load effects. Computer program also includes subroutines that allow acceleration of engine by addition of hydrogen to system and braking of engine by short circuiting of working spaces.

  5. Clinical application and therapeutic effectiveness of large diameter head metal-on-metal total hip replacement%金属对金属大直径股骨头全髋关节置换术的临床应用及近期疗效观察

    Institute of Scientific and Technical Information of China (English)

    刘二涛; 徐皓; 陈建梅; 姚晓东; 李金泉

    2013-01-01

    Objective To explore the short-term results of total hip replacement THR ) using large diameter heads( LDH )in metal-on-metal( MOM )articulation. Methods A consecutive series of 34 patients( 34 hips )who underwent THR using LDH in MOM articulation were studied. The results were e-valuated both clinically and radio graphically. Clinical outcomes were evaluated according to the Harris e-valuation score and the R0M( Range of motion ). Acetabular position, components migration and bone changes around the implant were measured radiographically. Results The average follow-up period of all 34 patients was 18. 7 months. There was no bright line around the prosthesis. No complications such as os-teolysis, prosthetic loosening, heterotopic ossification and prosthesis fracture occurred. The average Harris hip score at the last follow-up was significantly improved compared with the preoperative scores( 87. 82 points versus 35. 29 points ). The postoperative ROM of all patients improved remarkably. Conclusion The short-term results of LDH in MOM total hip replacement on hip osteoarthritis, aseptic femoral head necrosis, femur neck fracture and congenital hip hypoplasia are excellent. But the long-term results of THR using LDH in MOM articulation still need further investigation.%目的 总结金属对金属大直径股骨头全髋关节置换术(total hip replacement,THR)的近期疗效.方法 回顾性分析行金属对金属大直径股骨头THR患者34例34髋.临床评估以Harris评分及髋关节活动度为标准.影像学根据双髋关节正位片,观察髋臼、股骨假体的位置及周围骨质的改变.结果 34例患者平均随访18.7个月.术后均无假体周围透亮线产生,无骨溶解、假体松动、异位骨化及假体断裂等并发症.Harris评分由术前的20~48分,平均(35.29±8.59)分,提高至术后随访时的76~96分,平均(87.82±5.12)分.所有患者髋关节活动度术后显著提高.结论 采用金属对金属大直径股骨

  6. Axisymmetric planar cracks in finite hollow cylinders of transversely isotropic material: Part II—cutting method for finite cylinders

    Science.gov (United States)

    Pourseifi, M.; Faal, R. T.; Asadi, E.

    2017-06-01

    This paper is the outcome of a companion part I paper allocated to finite hollow cylinders of transversely isotropic material. The paper provides the solution for the crack tip stress intensity factors of a system of coaxial axisymmetric planar cracks in a transversely isotropic finite hollow cylinder. The lateral surfaces of the hollow cylinder are under two inner and outer self-equilibrating distributed shear loadings. First, the stress fields due to these loadings are given for both infinite and finite cylinders. In the next step, the state of stress in an infinite hollow cylinder with transversely isotropic material containing axisymmetric prismatic and radial dislocations is extracted from part I paper. Next, using the distributed dislocation technique, the mixed mode crack problem in finite cylinder is reduced to Cauchy-type singular integral equations for dislocation densities on the surfaces of the cracks. The problem of a cracked finite hollow cylinder is treated by cutting method; i.e., the infinite cylinder is cut to a finite one by slicing it using two annular axisymmetric cracks at its ends. The cutting method is validated by comparing the state of stress of a sliced intact infinite cylinder with that of an intact finite cylinder. The paper is furnished to several examples to study the effect of crack type and location in finite cylinders on the ensuing stress intensity factors of the cracks and the interaction between the cracks.

  7. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  8. The curative effect evaluations of 46 Bone cement type artificial bipolar femoral head replacement for femoral neck fracture in the elderly patients%骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折46例疗效分析

    Institute of Scientific and Technical Information of China (English)

    张庆凯; 李忠义; 马也

    2014-01-01

    目的:探讨骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折的疗效。方法:我院2009-12至2012-12共收治并采用骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折患者46例,其中,男性15例,女性31例,年龄在65—91岁之间,平均78.8岁;左侧19例,右侧27例,均为单侧股骨颈骨折;致伤原因:摔伤所致35例,交通事故所致11例。骨折按Garden分型:Ⅲ型33例,Ⅳ13例。通过手术时间,出血量及术后肢体功能Harris评分等,评价手术效果。结果:46例患者全部获得随访,随访时间为6-36个月,平均20.5个月。假体松动2例,肺内感染2例,股骨头脱位1例,并发症发生率为:11%;经处理后,患者痊愈。所有患者肢体功能恢复良好。术前Harris评分:43.2±8.3分,术后6个月及12个月分别为91.4±3.2分93.2±4.6分,较置换前明显提高,P<0.01,差异有统计学意义。结论:骨水泥型人工双极股骨头置换治疗老年人股骨颈骨折具有固定牢固,返修率小,术后并发症少,肢体功能恢复良好等优点,是治疗该类疾病一种较为良好的选择。%Objective:To report and discuss The curative effect of surgical treatment with Bone cement type artificial bipolar femoral head replacement for Femoral neck fracture in the elderly patients.Method:From December 2009 to December 2012,46 cases with Femoral neck fractures in the elderly patients were treated with Bone cement type artificial bipolar femoral head replacement in our hospital, Including 15 males and 31 females ,with an average of 78.8 years old .(range,65 to 91 years old).19 cases in the left,27 cases in the right. And al the cases were unilateral fractures. The causes of injury:35 cases were related to fal ing ,11 cases were related to traffic accident. According to Garden classification ,33 cases were of typeⅢ, 14 cases were of typeⅣ. Evaluate the curative effect by the

  9. Enteral feeding in acute head injury: replacement or therapy?

    OpenAIRE

    Arthur Schelp; Angela Pellizon; Roberto Burini

    1992-01-01

    Os autores apresentam revisão geral sobre a fisiopatogenia do trauma, ressaltando os estados de hipereatabolismo e hipermetabolismo, suas consequências nutricionais, com as particularidades do trauma encefálico. São feitas, também, considerações sobre as vias, composição e volumes das dietas enterais a serem administradas a pacientes com trauma agudo encefálico, assim como são apontadas questões a serem melhor elucidadas. The authors raise a discussion on nutritional needs of severely trau...

  10. Differences in scour around a single surface-piercing cylinder and a submerged cylinder

    Science.gov (United States)

    Beninati, M. L.; Volpe, M. A.; Riley, D. R.; Krane, M.

    2011-12-01

    The equilibrium state of scour for a single surface piercing cylinder and a submerged cylinder of specific aspect ratio are presented. The equilibrium state is defined by a scour depth and associated time interval for a given set of flow conditions. Control variables such as sediment coarseness (or grain size) and cylinder size are held constant, while the flow intensity is varied. Sediment bed form topology is characterized with a series of two-dimensional slices across the bed for both the surface-piercing and submerged cylinder cases. Test results will help identify the geometry and pattern of the scour around the cylinders to aid in the optimal design of marine hydrokinetic (MHK) support structures in an effort to help minimize the deleterious impact of these devices on the local substrate. This study is performed in the small-scale testing platform in the hydraulic flume facility (32 ft long, 4 ft wide and 1.25 ft deep) in the Environmental Fluid Mechanics and Hydraulics Laboratory (EFM&H) at Bucknell University. The cylinders, of the same material and diameter, are placed centrally in the sediment filled test section (2.5 ft long, 2 ft wide and 0.75 ft deep) of the platform. Flow field measurements are taken with a 16-MHz Micro Acoustic Doppler Velocimeter while water depth is acquired using an ultrasonic distance sensor. These devices are attached to a gantry system that can be accurately positioned anywhere in the test section. Clear-water conditions (in the absence of live-bed scour) are maintained to study the effect of the horseshoe and wake vortices on the displacement of sediment around the cylinder as well as downstream of the device. Bed form topology is measured using an HR Wallingford 2D Sediment Bed Profiler with a low-powered laser distance sensor to accurately characterize changes in bed form around the cylinders. Additionally, specifications for testing such as operational procedures for start-up and shut-down of the facility are given.

  11. Thermal shock in a circumferentially cracked hollow cylinder with cladding

    Science.gov (United States)

    Nied, H. F.

    1984-01-01

    An theoretical analysis is presented which demonstrates the effect of cladding on the thermal resistance of a circumferentially cracked hollow cylinder. The cladding is assumed to be bonded to the inner wall of the hollow cylinder. The axisymmetric circumferential crack may be either embedded in the cylinder wall or may be an edge crack which passes through the clad and opens into the inner wall of the hollow cylinder. The problem is formulated mathematically and a solution is found which is in the form of a single integral equation. The integral equation is solved numerically and yields estimates of transient temperature distributions, thermal stresses in the uncracked cylinder, and stress intensity factors as a function of time for various cladding thickness to cylinder wall thickness ratios. It is shown that yielding of the clad under certain conditions can result in a reduction in the magnitude of the stress intensity factor for the crack tip in the elastic base material.

  12. Effect of Surface Coatings on Cylinders Exposed to Underwater Shock

    Directory of Open Access Journals (Sweden)

    Y.W. Kwon

    1994-01-01

    Full Text Available The response of a coated cylinder (metallic cylinder coated with a rubber material subjected to an underwater explosion is analyzed numerically. The dynamic response of the coated cylinder appears to be adversely affected when impacted by an underwater shock wave under certain conditions of geometry and material properties of the coating. When adversely affected, significant deviations in values of axial stress, hoop stress, and strain are observed. The coated cylinder exhibits a larger deformation and higher internal energy in the metallic material. Rubber coatings appeared to inhibit energy dissipation from the metallic material to the surrounding water medium. A parametric study of various coatings was performed on both aluminum and steel cylinders. The adverse effect of the coating decreased when the stiffness of the rubber layer increased, indicating the existence of a threshold value. The results of this study indicate that the stiffness of the coating is a critical factor to the shock hardening of the coated cylinder.

  13. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    BACKGROUND: Outpatient clinic visits are a window of opportunity to address health risk behaviors and promote a healthier lifestyle among young people. The HEADS (Home, Education, Eating, Activities, Drugs [i.e. substance use including tobacco, alcohol, and illegal drugs], Sexuality [including...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...... patients. Young patients reported that smoking, alcohol, illegal drugs, sexuality, and contraception were addressed significantly more at adult clinics in comparison to pediatric clinics. After controlling for age, gender and duration of illness, according to young patients, adjusted odds ratios...

  14. On what controls the spacing of spontaneous adiabatic shear bands in collapsing thick-walled cylinders

    Directory of Open Access Journals (Sweden)

    Lovinger Zev

    2015-01-01

    Full Text Available Shear bands formation in collapsing thick walled cylinders occurs in a spontaneous manner. The advantage of examining spontaneous, as opposed to forced shear localization, is that it highlights the inherent susceptibility of the material to adiabatic shear banding without prescribed geometrical constraints. The Thick-Walled Cylinder technique (TWC provides a controllable and repeatable technique to create and study multiple adiabatic shear bands. The technique, reported in the literature uses an explosive cylinder to create the driving force, collapsing the cylindrical sample. Recently, we developed an electro-magnetic set-up using a pulsed current generator to provide the collapsing force, replacing the use of explosives. Using this platform we examined the shear band evolution at different stages of formation in 7 metallic alloys, spanning a wide range of strength and failure properties. We examined the number of shear bands and spacing between them for the different materials to try and figure out what controls these parameters. The examination of the different materials enabled us to better comprehend the mechanisms which control the spatial distribution of multiple shear bands in this geometry. The results of these tests are discussed and compared to explosively driven collapsing TWC results in the literature and to existing analytical models for spontaneous adiabatic shear localization.

  15. Testing and Integration of the Service Cylinders for the CMS Phase 1 pixel detector

    CERN Document Server

    Ngadiuba, Jennifer

    2016-01-01

    The present 3-layer CMS pixel detector will be replaced with a new 4-layer pixel system, referred to as Phase~1 upgrade, during the LHC extended technical stop in winter 2016/2017. The upgraded detector will allow to maintain the excellent tracking performance of CMS at the upcoming higher luminosity conditions at the LHC. The addition of an extra layer, closer to the beam pipe, demands a complete redesign of its services. The barrel pixel detector is attached to four half cylinders which carry the services along the beam pipe, accommodate the cooling lines and house the electronics for detector readout and control. The service cylinders are a complex system in design as well as in production due to the large number of channels and tight space requirements. In this document we present the design of the system and discuss the construction and testing of the service cylinders for the barrel pixel detector. Furthermore, we present results of the testing and calibrations carried out with a set of new digital dete...

  16. Treatment of osteonecrosis of the femoral head using autologous cultured osteoblasts: a case report

    Directory of Open Access Journals (Sweden)

    Kim Seok-Jung

    2008-02-01

    Full Text Available Abstract Introduction Osteonecrosis of the femoral head is a progressive disease that leads to femoral head collapse and osteoarthritis. Our goal in treating osteonecrosis is to preserve, not to replace, the femoral head. Case presentation We present the case of a patient with bilateral osteonecrosis of the femoral head treated with autologous cultured osteoblast injection. Conclusion Although our experience is limited to one patient, autologous cultured osteoblast transplantation appears to be effective for treating the osteonecrosis of femoral head.

  17. Urban chaos and replacement dynamics in nature and society

    Science.gov (United States)

    Chen, Yanguang

    2014-11-01

    Replacements resulting from competition are ubiquitous phenomena in both nature and society. The evolution of a self-organized system is always a physical process substituting one type of components for another type of components. A logistic model of replacement dynamics has been proposed in terms of technical innovation and urbanization, but it fails to arouse widespread attention in the academia. This paper is devoted to laying the foundations of general replacement principle by using analogy and induction. The empirical base of this study is urban replacement, including urbanization and urban growth. The sigmoid functions can be employed to model various processes of replacement. Many mathematical methods such as allometric scaling and head/tail breaks can be applied to analyzing the processes and patterns of replacement. Among varied sigmoid functions, the logistic function is the basic and the simplest model of replacement dynamics. A new finding is that replacement can be associated with chaos in a nonlinear system, e.g., urban chaos is just a part of replacement dynamics. The aim of developing replacement theory is at understanding complex interaction and conversion. This theory provides a new way of looking at urbanization, technological innovation and diffusion, Volterra-Lotka’s predator-prey interaction, man-land relation, and dynastic changes resulting from peasant uprising, and all that. Especially, the periodic oscillations and chaos of replacement dynamics can be used to explain and predict the catastrophic occurrences in the physical and human systems.

  18. Vortex shedding noise of a cylinder with hairy flaps

    OpenAIRE

    Kamps, L.; Geyer, T. F.; Sarradj, E.; Brücker, C.

    2017-01-01

    This study describes the modification of acoustic noise emitted from cylinders in a stationary subsonic flow for a cylinder equipped with flexible hairy flaps at the aft part as a passive way to manipulate the flow and acoustics. The study was motivated by the results from previous water tunnel measurements, which demonstrated that hairy flaps can modify the shedding cycle behind the cylinder and can reduce the wake deficit. In the present study, wind tunnel experiments were conducted on such...

  19. Analysis of a functionally graded piezothermoelastic hollow cylinder

    Institute of Scientific and Technical Information of China (English)

    CHEN Ying; SHI Zhi-fei

    2005-01-01

    A long thick-walled hollow cylinder ofpiezothermoelastic materials was studied in this work. The gradient property of the piezoelectric parameter g31 was taken into account. The theory of elasticity was applied to obtain the exact solutions of the cylinder subjected simultaneously to thermal and electric loadings. As an application, these solutions have been successfully used to study the inverse problems of the material. For comparison, numerical results have been carried out for both graded and double-layered cylinders.

  20. Recording Rapidly Changing Cylinder-wall Temperatures

    Science.gov (United States)

    Meier, Adolph

    1942-01-01

    The present report deals with the design and testing of a measuring plug suggested by H. Pfriem for recording quasi-stationary cylinder wall temperatures. The new device is a resistance thermometer, the temperature-susceptible part of which consists of a gold coating applied by evaporation under high vacuum and electrolytically strengthened. After overcoming initial difficulties, calibration of plugs up to and beyond 400 degrees C was possible. The measurements were made on high-speed internal combustion engines. The increasing effect of carbon deposit at the wall surface with increasing operating period is indicated by means of charts.

  1. 42 CFR 84.201 - Head harnesses; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... Cartridge Respirators § 84.201 Head harnesses; minimum requirements. (a)(1) Facepieces for chemical cartridge respirators other than single-use vinyl chloride shall be equipped with adjustable and replaceable... chloride respirators shall be equipped with adjustable head harnesses designed and constructed to...

  2. Replacing a Missing Tooth

    Science.gov (United States)

    ... vessels in the tooth pulps are rather large. Drilling down these teeth for crowns may expose the ... porcelain replacement tooth is held in place by metal extensions cemented to the backs of the adjacent ...

  3. Hormone Replacement Therapy

    Science.gov (United States)

    ... before and during menopause, the levels of female hormones can go up and down. This can cause ... hot flashes and vaginal dryness. Some women take hormone replacement therapy (HRT), also called menopausal hormone therapy, ...

  4. Knee joint replacement

    Science.gov (United States)

    ... of your kneecap. Your kneecap is called the patella. The replacement part is usually made from a ... long. Then your surgeon will: Move your kneecap (patella) out of the way, then cut the ends ...

  5. Knee joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series—Normal anatomy To use the ... to slide 4 out of 4 Overview The knee is a complex joint. It contains the distal ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  8. Cylinder Imbalance Detection of Six Cylinder DI Diesel Engine Using Pressure Variation

    Directory of Open Access Journals (Sweden)

    S.H.Gawande

    2010-04-01

    Full Text Available In this research paper a simplified methodology is presented to detect cylinder imbalance in operating sixcylinder DI diesel engine. The detailed torsional vibration analysis helps to find vibratory frequencies, mode shapes, and vibratory stresses to provide constraints on critical speed in operating engine. The crank shaft is considered to be a rigid body so that the variation of the angular speed could be directly correlated to the cylinder pressure. Actuallythe variation of crank shaft speed has a complex function being influence by torsional stiffness of crank shaft, the mass moment of inertia of reciprocating and rotating masses and the average speed and load on the engine. The information carried by the harmonic order permits to established correlation between measurement and average gaspressure of the engine and to detect torque imbalance and identify faulty cylinder. In this work the detail pressure variation study is carried out on operating six cylinder engine of type SL90 Engine-SL8800TA model manufactured by Kirloskar Oil Engine Pune.

  9. Medical Gas Cylinder with Mismatched Colour and Pin Index

    Directory of Open Access Journals (Sweden)

    Mukherjee S

    2014-08-01

    Full Text Available The medical gas cylinders have various safety features to prevent the administration of wrong gas to the patient. Most of the features have visual impact (colour, label, markings on the cylinder body except pin index system on the cylinder valve, so error in this feature is difficult to analyze and is highly unpredictable. We had received one such cylinder in our institution where all other features (label, colour, marking pointed to nitrous oxide except the pin index which resembled with that of oxygen

  10. Experimental free convection heat transfer from inclined square cylinders

    Science.gov (United States)

    Ali, Mohamed

    2016-10-01

    Natural convection from axisymmetric objects such as vertical or horizontal cylinders and spheres are two dimensional. However, for inclined circular or noncircular cylinders the flow and heat transfer is three dimensional and hence more complex and needs more attention. This study investigates the steady state mechanism of natural convection from inclined square cylinders in air. Five different cylinders of 1 m length, 8 × 8, 7 × 7, 6 × 6, 4 × 4 and 2.5 × 2.5 cm2 cross sections are used. The cylinders are heated using inserted heating element of 6 mm in diameter. Self-adhesive thermocouples are used at the upper, bottom and at one side of the cylinders for temperature measurement. Three inclination angles to the horizontal 30, 45 and 60o are used for each cylinder with uniform heat flux boundary conditions. For each cylinder, about ten heat fluxes are used to generate the heat transfer data. Local and average heat transfer coefficient is determined for each cylinder at each inclination angle for each uniform heat flux. Laminar and transition to turbulent regimes are obtained and characterized. Local critical axial distance where heat transfer coefficient changes the mode is obtained for each heat flux. Local and averaged Nusselt numbers are correlated with the modified Rayleigh numbers for all angles.

  11. Clinical implementation of MR‐guided vaginal cylinder brachytherapy

    National Research Council Canada - National Science Library

    Owrangi, Amir M; Jolly, Shruti; Balter, James M; Cao, Yue; Maturen, Katherine E; Young, Lisa; Zhu, Tong; Prisciandaro, Joann I

    2015-01-01

    ...)‐guided vaginal brachytherapy using commercially available solid applicator models. To test the fidelity of solid applicator models to digitize vaginal cylinder applicators, three datasets were evaluated...

  12. Quantum phase transition in ultra small doubly connected superconducting cylinders

    Science.gov (United States)

    Sternfeld, I.; Koret, R.; Shtrikman, H.; Tsukernik, A.; Karpovski, M.; Palevski, A.

    2008-02-01

    The kinetic energy of Cooper pairs, in doubly connected superconducting cylinders, is a function of the applied flux and the ratio between the diameter of the cylinder and the zero temperature coherence length d/ ξ(0). If d >ξ(0) the known Little-Parks oscillations are observed. On the other hand if d ξ(0), we observed the LP oscillations. In the Al cylinders we did not observe a transition to the superconducting state due to the proximity effect, resulted from an Au layer coating the Al. However, we did observe Altshuler-Aronov-Spivak (h/2e) oscillations in these cylinders.

  13. Stability of Flow around a Cylinder in Plane Poiseuille Flow

    Science.gov (United States)

    Dou, Hua-Shu; Ben, An-Qing; Fluid Mechanics Research Team

    2013-11-01

    Simulation of Navier-Stokes equations is carried out to study the stability of flow around a cylinder in plane Poiseuille flow. The energy gradient method is employed to analyze the mechanism of instability of cylinder wake. The ratio of the channel width to the cylinder diameter is 30, and the Reynolds number based on the cylinder diameter and incoming centerline velocity is 26 and 100, respectively. The incoming flow is given as being laminar. It is found that the instability of the cylinder wake, starting near the front stagnation point upstream. The recirculation zone behind the cylinder has no effect on the stability of the wake. In the wake behind the recirculation zone, the flow stability is controlled by the energy gradient in the shear layer along the two sides of the wake. At high Re, the energy gradient of averaged flow in the channel interacts with the wake vortex, strengthening the wake vortex structure. Due to the large ratio of the channel width to the cylinder diameter, the disturbance caused by the cylinder mainly occurs in the vicinity of the centerline and has little effect on the flow near the wall. The velocity profile on the two sides of the cylinder wake in the downstream channel remains laminar (parabolic profile). Professor in Fluid Mechanics; AIAA Associate Fellow.

  14. An update on corrosion monitoring in cylinder storage yards

    Energy Technology Data Exchange (ETDEWEB)

    Henson, H.M.; Newman, V.S.; Frazier, J.L. [Oak Ridge K-25 Site, TN (United States)

    1991-12-31

    Depleted uranium, from US uranium isotope enrichment activities, is stored in the form of solid uranium hexafluoride (UF{sub 6}) in A285 and A516 steel cylinders designed and manufactured to ASME Boiler and Pressure Vessel Code criteria. In general, storage facilities are open areas adjacent to the enrichment plants where the cylinders are exposed to weather. This paper describes the Oak Ridge program to determine the general corrosion behavior of UF{sub 6} cylinders, to determine cylinder yard conditions which are likely to affect long term storage of this material, and to assess cylinder storage yards against these criteria. This program is targeted at conditions specific to the Oak Ridge cylinder yards. Based on (a) determination of the current cylinder yard conditions, (b) determination of rusting behavior in regions of the cylinders showing accelerated attack, (c) monitoring of corrosion rates through periodic measurement of test coupons placed within the cylinder yards, and (d) establishment of a computer base to incorporate and retain these data, the technical division is working with the enrichment sites to implement an upgraded system for storage of this material until such time as it is used or converted.

  15. Inflation of polymer melts into elliptic and circular cylinders

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Christensen, Jens Horslund; Gøttsche, Søren

    2000-01-01

    A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top of the infla......A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top...

  16. ANALYTICAL AND MATHCAD INTERSECTION BETWEEN TWO PERPENDICULAR AXES CYLINDERS

    Directory of Open Access Journals (Sweden)

    PETRESCU Ligia

    2015-06-01

    Full Text Available The intersection of two surfaces is a common line to both surfaces. This line is often called transition line. The authors propose an analytical and a computer graphics intersection between two perpendicular axes cylinders. The analytical expression of such intersection will be obtained and transposed on the development of one cylinder. The distance between the two cylinders axes is essential in the aspect of the transition line. This transition line can be also obtained, using the computer, by the MathCAD programme. Some samples are relevant in this subject, according to the distance between the cylinders.

  17. Product Platform Replacements

    DEFF Research Database (Denmark)

    Sköld, Martin; Karlsson, Christer

    2012-01-01

    Purpose – It is argued in this article that too little is known about product platforms and how to deal with them from a manager's point of view. Specifically, little information exists regarding when old established platforms are replaced by new generations in R&D and production environments...... originality and value is achieved by focusing on product platform replacements believed to represent a growing management challenge....

  18. Replication of engine block cylinder bridge microstructure and mechanical properties with lab scale 319 Al alloy billet castings

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, A., E-mail: a2lombar@ryerson.ca [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard Street East, Toronto, Ontario M5B2K3 (Canada); D' Elia, F.; Ravindran, C. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard Street East, Toronto, Ontario M5B2K3 (Canada); MacKay, R. [Nemak of Canada Corporation, 4600 G.N. Booth Drive, Windsor, Ontario N9C4G8 (Canada)

    2014-01-15

    In recent years, aluminum alloy gasoline engine blocks have in large part successfully replaced nodular cast iron engine blocks, resulting in improved vehicle fuel efficiency. However, because of the inadequate wear resistance properties of hypoeutectic Al–Si alloys, gray iron cylinder liners are required. These liners cause the development of large tensile residual stress along the cylinder bores and necessitate the maximization of mechanical properties in this region to prevent premature engine failure. The aim of this study was to replicate the engine cylinder bridge microstructure and mechanical properties following TSR treatment (which removes the sand binder to enable easy casting retrieval) using lab scale billet castings of the same alloy composition with varying cooling rates. Comparisons in microstructure between the engine block and the billet castings were carried out using optical and scanning electron microscopy, while mechanical properties were assessed using tensile testing. The results suggest that the microstructure at the top and middle of the engine block cylinder bridge was successfully replicated by the billet castings. However, the microstructure at the bottom of the cylinder was not completely replicated due to variations in secondary phase morphology and distribution. The successful replication of engine block microstructure will enable the future optimization of heat treatment parameters. - Highlights: • A method to replicate engine block microstructure was developed. • Billet castings will allow cost effective optimization of heat treatment process. • The replication of microstructure in the cylinder region was mostly successful. • Porosity was more clustered in the billet castings compared to the engine block. • Mechanical properties were lower in billet castings due to porosity and inclusions.

  19. Improvement on Cylinder-to-Cylinder Variation in PCCI Engines Using Variable Start of Injection and Exhaust Valve Closing Timings

    OpenAIRE

    Axelsson, Aðalsteinn; Shaver, Greg

    2013-01-01

    Premixed charge compression ignition (PCCI) is widely considered to be a possible method of meeting increasingly strict emissions regulations in internal combustion engines. PCCI can reduce harmful emissions substantially and at the same time increase efficiency relative to conventional combustion modes. Because of the nature of PCCI, changes in in-cylinder conditions have a greater impact than in conventional diesel engines. Therefore cylinder to cylinder variations are amplified which leads...

  20. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  1. The capillary interaction between two vertical cylinders

    KAUST Repository

    Cooray, Himantha

    2012-06-27

    Particles floating at the surface of a liquid generally deform the liquid surface. Minimizing the energetic cost of these deformations results in an inter-particle force which is usually attractive and causes floating particles to aggregate and form surface clusters. Here we present a numerical method for determining the three-dimensional meniscus around a pair of vertical circular cylinders. This involves the numerical solution of the fully nonlinear Laplace-Young equation using a mesh-free finite difference method. Inter-particle force-separation curves for pairs of vertical cylinders are then calculated for different radii and contact angles. These results are compared with previously published asymptotic and experimental results. For large inter-particle separations and conditions such that the meniscus slope remains small everywhere, good agreement is found between all three approaches (numerical, asymptotic and experimental). This is as expected since the asymptotic results were derived using the linearized Laplace-Young equation. For steeper menisci and smaller inter-particle separations, however, the numerical simulation resolves discrepancies between existing asymptotic and experimental results, demonstrating that this discrepancy was due to the nonlinearity of the Laplace-Young equation. © 2012 IOP Publishing Ltd.

  2. CYLINDER LENS ALIGNMENT IN THE LTP

    Energy Technology Data Exchange (ETDEWEB)

    TAKACS, P.Z.

    2005-07-26

    The Long Trace Profiler (LTP), is well-suited for the measurement of the axial figure of cylindrical mirrors that usually have a long radius of curvature in the axial direction but have a short radius of curvature in the sagittal direction. The sagittal curvature causes the probe beam to diverge in the transverse direction without coming to a focus on the detector, resulting in a very weak signal. It is useful to place a cylinder lens into the optical system above the mirror under test to refocus the sagittal divergence and increase the signal level. A positive cylinder lens can be placed at two positions above the surface: the Cat's Eye reflection position and the Wavefront-Matching position. The Cat's Eye position, is very tolerant to mirror misalignment, which is not good if absolute axial radius of curvature is to be measured. Lateral positioning and rotational misalignments of lens and the mirror combine to produce unusual profile results. This paper looks at various alignment issues with measurements and by raytrace simulations to determine the best strategy to minimize radius of curvature errors in the measurement of cylindrical aspheres.

  3. Study on Strength of Concrete Using Robo Sand as a Partial Replacement of Fine Aggregate

    Directory of Open Access Journals (Sweden)

    S.Rukmangadhara Rao,

    2015-12-01

    Full Text Available Robo sand is one of the most used among such materials to replace river sand, which can be used as an alternative to fine aggregate in concrete. In the present investigation workability and strength of concrete was evaluated by replacement of natural sand by Robo sand in proportions of 0%, 50%, 75%, and 100% is studied for M25and M35grade concrete cubes, cylinders and prisms. Slump cone method is taken for finding workability. For strength parameters for each grade of concrete Cubes, Cylinders and Prisms were casted and tested at the age of 7 and 28 days. In this present experimental study on concrete having grades of M25 and M35 are prepared by replacing natural sand by Robo sand. Concrete specimens were tested for evaluation of compressive strength and water absorption.

  4. Effects of Cylinder Radius, Setover and Heel-Toe Difference on Cylinder-Flat Gauge of a Card

    Institute of Scientific and Technical Information of China (English)

    SUN peng-zi; JU Yan-qing; ZHANG Ming-guang

    2007-01-01

    In order to provide manufacturers of carding machines and relevant accessories with theoretical references, how cylinder radius, setover and heel-toe difference affect cylinder-flat gauge of a carding machine was theoretically studied. The relationship between cylinder-flat gauge and cylinder radius, setover and heel-toe difference was geometrically discussed. Numerical calculation and illustration about the relationship were made with MATLAB in accordance with practical settings. A general formula about the relationship is derived. A concept, the small-gauge zone length, has been defined for the first time, and some relevant results thus obtained. Given setover and heel-toe difference, the greater the cylinder radius, the greater the average gauge. If a smaller overall cylinder-flat gauge is desirable, it is not necessary to emphasize the tangential direction of the heel of clothed surface to the cylinder. Their intersection within a small zone is acceptable. In many cases, small-gauge zone can reduce average gauge which may be helpful to the carding action; given cylinder radius and setover, the smaller the heel-toe difference, the more helpful to reduce the overall gauge; given cylinder radius and heel-toe difference, the small-gauge zone length will increase with the increase of setover, so does the difference between the smallest gauge and outlet gauge.

  5. Prediction of External Corrosion for Steel Cylinders--2004 Report

    Energy Technology Data Exchange (ETDEWEB)

    Schmoyer, RLS

    2004-07-07

    Depleted uranium hexafluoride (UF{sub 6}) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from 4 to 53 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF{sub 6} Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF{sub 6} and the cylinders containing it. This report documents activities that address UF{sub 6} Cylinder Project requirements and actions involving forecasting cylinder wall thicknesses. These requirements are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). The report documents cylinder wall thickness projections based on models fit to ultrasonic thickness (UT) measurement data. UT data is collected at various locations on randomly sampled cylinders. For each cylinder sampled, the minimum UT measurement approximates the actual minimum thickness of the cylinder. Projections of numbers of cylinders expected to fail various thickness criteria are computed from corrosion models relating minimum wall thickness to cylinder age, initial thickness estimates, and cylinder subpopulations defined in terms of plant site, yard, top or bottom storage positions, nominal thickness, etc. In this report, UT data collected during FY03 is combined with UT data collected in earlier years (FY94-FY02), and all of the data is inventoried chronologically and by various subpopulations. The UT data is used to fit models of maximum pit depth and minimum thickness, and the fitted models are used to extrapolate minimum thickness estimates into the future and in

  6. UF{sub 6} pressure excursions during cylinder heating

    Energy Technology Data Exchange (ETDEWEB)

    Brown, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    As liquid UF{sub 6} inside a cylinder changes from a liquid to a solid, it forms a porous solid which occupies approximately the same volume as that of the liquid before cooling. Simultaneously as the liquid cools, UF{sub 6} vapor in the cylinder ullage above the liquid desublimes on the upper region of the inner cylinder wall. This solid is a dense, glass-like material which can accumulate to a significant thickness. The thickness of the solid coating on the upper cylinder wall and directly behind the cylinder valve area will vary depending on the conditions during the cooling stage. The amount of time lapsed between UF{sub 6} solidification and UF{sub 6} liquefaction can also affect the UF{sub 6} coating. This is due to the daily ambient heat cycle causing the coating to sublime from the cylinder wall to cooler areas, thus decreasing the thickness. Structural weakening of the dense UF{sub 6} layer also occurs due to cylinder transport vibration and thermal expansion. During cylinder heating, the UF{sub 6} nearest the cylinder wall will liquefy first. As the solid coating behind the cylinder valve begins to liquefy, it results in increased pressure depending upon the available volume for expansion. At the Paducah Gaseous Diffusion Plant (PGDP) during the liquefaction of the UF{sub 6} in cylinders in the UF{sub 6} feed and sampling autoclaves, this pressure increase has resulted in the activation of the systems rupture discs which are rated at 100 pounds per square inch differential.

  7. Heading and head injuries in soccer.

    Science.gov (United States)

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  8. Numerical Study of Head/Helmet Interaction Due to Blast Loading

    Science.gov (United States)

    2014-10-01

    in our calculation. The skull is connected to the body through seven cervical vertebrae and six cervical disks. Only the head/neck is modeled with...into a cylinder, as shown in Figure 2. The skull, lower jaw and the cervical vertebrae are modeled as a single bone material, which is shown in green...appropriate boundary conditions. Within short time period (~5 ), the head movement is small and the complex cervical geometries are simplified

  9. 解剖型锁定加压钢板与人工肱骨头置换治疗肱骨近端骨折的效果比较%Effect comparison between anatomical locking plate fixation and humeral head replacement in the treatment of proximal humerus fractures

    Institute of Scientific and Technical Information of China (English)

    郑创义

    2015-01-01

    目的:比较解剖型锁定加压钢板与人工肱骨头置换治疗肱骨近端骨折的疗效。方法选取本院骨科2005年1月~2014年3月收治的肱骨近端骨折患者45例,根据手术方法将患者分为内固定术组(n=27)和肱骨头置换术组(n=18)。内固定术组给予骨折切开复位、解剖型锁定加压钢板固定,肱骨头置换术组给予人工肱骨头置换方法治疗。术后定期复查X线片,了解并发症发生情况。同时在末次复诊时按照Constant-Murley肩关节评分标准进行功能评分。结果术后随访8~36个月,平均18个月。内固定术组中的主要并发症是肱骨头坏死(6例)、骨折畸形愈合(7例)和骨性关节炎(2例);肱骨头置换术组的并发症是大结节、小结节(或两者均有之)骨质吸收(6例)、关节不稳定(1例)、异位骨化(1例)。内固定组的并发症发生率(55.6%)显著高于肱骨头置管术组(44.4%)(P<0.05),优良率(77.8%)显著高于肱骨头置换组(66.7%)(P<0.05),Constant-Murley评分显著高于肱骨头置换组(P<0.05)。结论解剖型锁定加压钢板治疗肱骨近端骨折的疗效优于人工肱骨头置换,值得临床推广。%Objective To compare the therapeutic effects of anatomical locking plate fixation (ALPF) and humeral head replacement (HHR) on proximal humerus fractures. Methods 45 patients with proximal humerus fractures at the ortho-pedics department in our hospital from January 2005 to March 2014 were selected and divided into ALPF group (n=27) and HHR group (n=18) based on operation methods.ALPF group were received anatomical proximal humeral locking plate fixation,while HHR group underwent humeral head replacement. X-rays was regularly reviewed after surgery to e-valuate complications,and Constant-Murley score system was used to assess the shoulder joint function at the last re-turn visit. Results All patients were followed up for 8

  10. Critical point drying: contamination in transitional fluid supply cylinders.

    Science.gov (United States)

    Hoagland, K D; Rosowski, J R; Cohen, A L

    1980-01-01

    We call attention to the occurrence of an oily residue in the CPD bomb after critical point drying, as well as the presence of rust, dirt, and an oily residue in CO2 and Freon supply cylinders. Bottled gas is often tested for purity once after manufacturing and then is pumped and stored, perhaps several times, before the consumer's cylinders are filled. The cylinders may be in use for over 40 years, and may never be chemically cleaned, although they are hydrostatically pressure tested every five years, with the date of each test stamped on the cylinder. To the bottled gas industry we recommend regular inspection of tanks for bottom contamination, and vacuum and chemical cleaning when contamination is found. To users of bottled gas for critical point drying, we recommend becoming aware of the procedures of cylinder inspection, cleaning, and circulation among users. We suggest reporting to the gas supplier any contamination produced by inadvertently backfilling the supply cylinder. Although a common awareness of the problem of supply cylinder residues should lead to failures, the best assurance of clean, oil-free, dry liquid CO2 and other transitional fluids may be in the development of in-line filters which would remove particles, oil and moisture between the supply cylinder and the CPD bomb. We also suggest the use of gas grades higher than commercial, such as welding anhydrous (CO2) or specialty gases.

  11. Turbulent Taylor-Couette flow with stationary inner cylinder

    CERN Document Server

    Ostilla-Monico, Rodolfo; Lohse, Detlef

    2016-01-01

    A series of direct numerical simulations of Taylor-Couette (TC) flow, the flow between two coaxial cylinders, with the outer cylinder rotating and the inner one fixed, were performed. Three cases, with outer cylinder Reynolds numbers $Re_o$ of $Re_o=5.5\\cdot10^4$, $Re_o=1.1\\cdot10^5$ and $Re_o=2.2\\cdot10^5$ were considered. The radius ratio $\\eta=r_i/r_o$ was fixed to $\\eta=0.909$ to mitigate the effects of curvature. The vertical aspect ratio $\\Gamma$ was fixed to $\\Gamma=2.09$. Being linearly stable, outer cylinder rotation TC flow is known to have very different behavior than pure inner cylinder rotation TC flow. Here, we find that the flow nonetheless becomes turbulent, but the torque required to drive the cylinders and level of velocity fluctuations was found to be smaller than those for pure inner cylinder rotation at comparable Reynolds numbers. The mean angular momentum profiles showed a large gradient in the bulk, instead of the constant angular momentum profiles of pure inner cylinder rotation. The ...

  12. 76 FR 38697 - High Pressure Steel Cylinders From China

    Science.gov (United States)

    2011-07-01

    ..., 2011 (76 FR 28807). The conference was held in Washington, DC, on June 1, 2011, and all persons who... COMMISSION High Pressure Steel Cylinders From China Determinations On the basis of the record \\1\\ developed... injured by reason of imports from China of high pressure steel cylinders, provided for in subheading...

  13. 77 FR 37712 - High Pressure Steel Cylinders From China

    Science.gov (United States)

    2012-06-22

    ... Commission, Washington, DC, and by publishing the notice in the Federal Register on January 23, 2012 (77 FR... COMMISSION High Pressure Steel Cylinders From China Determinations On the basis of the record \\1\\ developed... imports of high pressure steel cylinders from China, provided for in subheading 7311.00.00 of...

  14. 30 CFR 56.16006 - Protection of gas cylinder valves.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of gas cylinder valves. 56.16006 Section 56.16006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Storage and Handling § 56.16006 Protection of gas cylinder valves. Valves on compressed gas...

  15. 30 CFR 57.16006 - Protection of gas cylinder valves.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of gas cylinder valves. 57.16006 Section 57.16006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Storage and Handling § 57.16006 Protection of gas cylinder valves. Valves on compressed gas...

  16. Temperature Profile of a Fluid between Two Rotating Porous Cylinders

    Directory of Open Access Journals (Sweden)

    Bal Krishan

    1970-07-01

    Full Text Available An exact expression for the temperature profile between two concentric rotating porous cylinders has been obtained. The results are presented graphically. For the wide gap, there is a sharp rise in temperature when the ratio between the angular velocities of the outer and the inner cylinders tends to zero.

  17. Modeling Heat and Mass Transfer from Fabric-Covered Cylinders

    Directory of Open Access Journals (Sweden)

    Phillip Gibson

    2009-03-01

    Full Text Available Fabric-covered cylinders are convenient analogs forclothing systems. The geometry is well defined andincludes many of the effects that are important ingarments. Fabric-covered cylinder models are usedin conjunction with laboratory measurements ofmaterial properties to calculate heat and mass transferproperties of clothing under specific conditions ofenvironmental wind speed, temperature, and relativehumidity.

  18. Unsteady Viscous Flow over an Expanding Stretching Cylinder

    Institute of Scientific and Technical Information of China (English)

    方铁钢; 章骥; 钟永芳; 陶华

    2011-01-01

    We study the viscous How over an expanding stretching cylinder. The solution is exact to the Navier-Stokes equations. The stretching velocity of the cylinder is proportional to the axial distance from the origin and decreases with time. There exists a unique solution for the How with all the studied values of Reynolds number and the unsteadiness parameter. Reversal Hows exist for an expanding stretching cylinder. The velocity decays faster for a larger Reynolds number and a more rapidly expanding cylinder.%We study the viscous flow over an expanding stretching cylinder.The solution is exact to the Navier-Stokes equations.The stretching velocity of the cylinder is proportional to the axial distance from the origin and decreases with time.There exists a unique solution for the flow with all the studied values of Reynolds number and the unsteadiness parameter.Reversal flows exist for an expanding stretching cylinder.The velocity decays faster for a larger Reynolds number and a more rapidly expanding cylinder.

  19. Mobile Robot Localization by Remote Viewing of a Colored Cylinder

    Science.gov (United States)

    Volpe, R.; Litwin, T.; Matthies, L.

    1995-01-01

    A system was developed for the Mars Pathfinder rover in which the rover checks its position by viewing the angle back to a colored cylinder with different colors for different angles. The rover determines distance by the apparent size of the cylinder.

  20. Poiseuille flow-induced vibrations of two cylinders in tandem

    Science.gov (United States)

    Lin, Jianzhong; Jiang, Renjie; Chen, Zhongli; Ku, Xiaoke

    2013-07-01

    Laminar flows past two tandem cylinders which are free to move transversely in a parallel-wall channel were studied numerically by the lattice Boltzmann method. With fixed Reynolds number Re=100, blockage ratio β=1/4 and structural damping ξ=0, the effect of streamwise separation between two cylinders at a range of S/D=[1.1, 10] on the motions of cylinders and fluids was studied for both mass ratios of m(*)=1 and m(*)=0.1. A variety of distinct vibration regimes involving periodic, quasi-periodic and non-periodic vibrations with corresponding flow patterns were observed. A detailed analysis of the vibration amplitudes, vibration frequencies and relative equilibrium positions for both mass ratios demonstrated that as S/D increases, the interaction of the two cylinders first enhances and then reduces. In the strong coupling regime, both cylinders oscillate periodically around the centerline of the channel with large vibration amplitudes and high vibration frequencies. By comparing with the case of an isolated cylinder, a further study indicated that the gap flow plays an important role in such a dynamic system, and the vortex cores formation behind the front cylinder causes the interaction of the cylinders decouple rapidly. Based on the present observations, such a dynamic model system can be considered as a novel type of vortex-induced vibrations (VIV) and is expected to find applications in fluid mixing and heat transfer.

  1. Curing A Large Composite Cylinder Without An Autoclave

    Science.gov (United States)

    Frazer, Robert E.

    1992-01-01

    Proposed technique provides application of heat and pressure to cure fiber-wound composite cylinder too large to fit in autoclave. Tube wound around cylinder applies pressure. Blanket distributes pressure. Pressure expels gas bubbles from material. Heat applied by conventional methods.

  2. 76 FR 77964 - High Pressure Steel Cylinders From the People's Republic of China: Preliminary Determination of...

    Science.gov (United States)

    2011-12-15

    ...'' or ``affiliated persons'': (A) Members of a family, including brothers and sisters (whether by the... International Trade Administration High Pressure Steel Cylinders From the People's Republic of China... Commerce (``Department'') preliminarily determines that high pressure steel cylinders (``steel cylinders...

  3. Effect of constant heat flux at outer cylinder on stability of viscous ...

    African Journals Online (AJOL)

    DR OKE

    dimensional linear stability analysis of the Couette flow between two axial cylinders for ... variable or constant heat flux at the inner cylinder while the outer cylinder is ... differential equations have been obtained to govern the stability of the ...

  4. Rotating cylinder drag balance with application to riblets

    Science.gov (United States)

    Hall, T.; Joseph, D.

    2000-12-01

    Experimental results are reported and discussed for a rotating cylinder drag balance designed to predict drag reduction by surfaces like riblets. The apparatus functions by measuring the torque applied to the inner cylinder by a fluid, such as water, that is set in motion by the controlled rotation of the outer cylinder. The instrument was validated by calibration for laminar flow and comparison of turbulent flow results to the those of G. I. Taylor. The ability to predict drag reduction was demonstrated by testing 114 m symmetric sawtooth riblets, which gave a maximum reduction of about 5% and an overall drag reduction range of 5cylinder surface and to use cylinders for which the curvature of the flow is minimized.

  5. ``Reverse'' Lock-in Regime on a Freely Oscillating Cylinder

    Science.gov (United States)

    Atsavapranee, P.; Voorhees, A. V.; Benaroya, H.; Wei, T.

    1998-11-01

    DPIV and flow visualizations were used to characterize the flow in the near wake of a freely oscillating cylinder. A rigid cylinder with a low mass ratio was fixed at one end to a leaf spring and free to oscillate, pendulum-like, at the other end in the cross stream plane. It was found that only a subset of the synchronization range follows the behavior of a ``classical'' lock-in, i.e., when the difference between the natural Strouhal frequency and the natural frequency of the cylinder is small enough, vortex shedding frequency deviates from the linear Strouhal dependence and follows instead the cylinder natural frequency. However, over a range of flow speed in which the response amplitude of the cylinder is significant, it was found that the frequency of oscillation and of vortex shedding follow instead the natural Strouhal frequency, instead of the mechanical natural frequency.

  6. Acoustic resonances in cylinder bundles oscillating in a compressibile fluid

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.H.; Raptis, A.C.

    1984-12-01

    This paper deals with an analytical study on acoustic resonances of elastic oscillations of a group of parallel, circular, thin cylinders in an unbounded volume of barotropic, compressible, inviscid fluid. The perturbed motion of the fluid is assumed due entirely to the flexural oscillations of the cylinders. The motion of the fluid disturbances is first formulated in a three-dimensional wave form and then casted into a two-dimensional Helmholtz equation for the harmonic motion in time and in axial space. The acoustic motion in the fluid and the elastic motion in the cylinders are solved simultaneously. Acoustic resonances were approximately determined from the secular (eigenvalue) equation by the method of successive iteration with the use of digital computers for a given set of the fluid properties and the cylinders' geometry and properties. Effects of the flexural wavenumber and the configuration of and the spacing between the cylinders on the acoustic resonances were thoroughly investigated.

  7. The Characteristic of Thermoelastic Waves in Transversely Isotropic Finite Cylinders

    Directory of Open Access Journals (Sweden)

    Bai Hao

    2017-01-01

    Full Text Available A theoretical as well as a numerical investigation of the propagation of thermoelastic waves and vibration of transversely isotropic cylinders of finite length is discussed. Lord-Shulman theory is adopted here to model the thermoelastic deformation of cylinders. A semi analytical finite element (SAFE method is employed to study dispersion of thermoelastic waves and natural frequencies of vibration of finite cylinders with traction free curved surfaces having both ends insulated and constrained by frictionless rigid walls. Numerical results obtained by the SAFE method for the frequencies of vibration of a sapphire rod are found to be in excellent agreement with published results. Natural frequencies of vibration for first three axisymmetric and asymmetric modes are presented graphically for a silicon nitride thermoelastic cylinder. Also, numerical results showing dispersion of both propagating and evanescent circumferential waves in infinite and finite cylinders are presented also.

  8. Investigation of breached depleted UF sub 6 cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Barber, E.J.; Butler, T.R.; DeVan, J.H.; Googin, J.M.; Taylor, M.S.; Dyer, R.H.; Russell, J.R.

    1991-09-01

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton steel cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. Both holes, concealed by UF{sub 4} reaction products identical in color to the cylinder coating, were similarly located near the front stiffening ring. The UF{sub 4} appeared to have self-sealed the holes, thus containing nearly all of the uranium contents. Martin Marietta Energy Systems, Inc., Vice President K.W. Sommerfeld immediately formed an investigation team to: (1) identify the most likely cause of failure for the two breached cylinders, (2) determine the impact of these incidents on the three-site inventory, and (3) provide recommendations and preventive measures. This document discusses the results of this investigation.

  9. Investigation of breached depleted UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Barber, E.J.; Butler, T.R.; DeVan, J.H.; Googin, J.M.; Taylor, M.S.; Dyer, R.H.; Russell, J.R.

    1991-09-01

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton steel cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. Both holes, concealed by UF{sub 4} reaction products identical in color to the cylinder coating, were similarly located near the front stiffening ring. The UF{sub 4} appeared to have self-sealed the holes, thus containing nearly all of the uranium contents. Martin Marietta Energy Systems, Inc., Vice President K.W. Sommerfeld immediately formed an investigation team to: (1) identify the most likely cause of failure for the two breached cylinders, (2) determine the impact of these incidents on the three-site inventory, and (3) provide recommendations and preventive measures. This document discusses the results of this investigation.

  10. Scattering characteristics of conducting cylinder coated with nonuniform magnetized ferrite

    Institute of Scientific and Technical Information of China (English)

    Hu Bin-Jie; Edward Yung Kai-Ning; Zhang Jun; Toutain Serge

    2005-01-01

    An analytical technique, referred to as the scattering matrix method (SMM), is developed to analyse the scattering of a planar wave from a conducting cylinder coated with nonuniform magnetized ferrite. The SMM solution for the nonuniform ferrite coating can be reduced to the expressions for the scattering and penetrated coefficients in four particular cases: nonuniform magnetized ferrite cylinder, uniform magnetized ferrite-coated conducting cylinder, uniform ferrite cylinder as well as homogeneous dielectric-coated conducting cylinder. The resonant condition for the nonuniform ferrite coating is obtained. The distinctive differences in scattering between the nonuniform ferrite coating and the nonuniform dielectric coating are demonstrated. The effects of applied magnetic fields and wave frequencies on the scattering characteristics for two types of the linear profiles are revealed.

  11. Vacuum compatible miniature CCD camera head

    Science.gov (United States)

    Conder, Alan D.

    2000-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  12. Visual Image Sensor Organ Replacement

    Science.gov (United States)

    Maluf, David A.

    2014-01-01

    This innovation is a system that augments human vision through a technique called "Sensing Super-position" using a Visual Instrument Sensory Organ Replacement (VISOR) device. The VISOR device translates visual and other sensors (i.e., thermal) into sounds to enable very difficult sensing tasks. Three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. Because the human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns, the translation of images into sounds reduces the risk of accidentally filtering out important clues. The VISOR device was developed to augment the current state-of-the-art head-mounted (helmet) display systems. It provides the ability to sense beyond the human visible light range, to increase human sensing resolution, to use wider angle visual perception, and to improve the ability to sense distances. It also allows compensation for movement by the human or changes in the scene being viewed.

  13. Fluid flows in a librating cylinder

    CERN Document Server

    Sauret, Alban; Bars, Michael Le; Dizès, Stéphane Le; 10.1063/1.3680874

    2012-01-01

    The flow in a cylinder driven by time harmonic oscillations of the rotation rate, called longitudinal librations, is investigated. Using a theoretical approach and axisymmetric numerical simulations, we study two distinct phenomena appearing in this librating flow. First, we investigate the occurrence of a centrifugal instability near the oscillating boundary, leading to the so-called Taylor-G\\"ortler vortices. A viscous stability criterion is derived and compared to numerical results obtained for various libration frequencies and Ekman numbers. The strongly nonlinear regime well above the instability threshold is also documented. We show that a new mechanism of spontaneous generation of inertial waves in the bulk could exist when the sidewall boundary layer becomes turbulent. Then, we analyse the librating flow below the instability threshold and characterize the mean zonal flow correction induced by the nonlinear interaction of the boundary layer flow with itself. In the frequency regime where inertial mode...

  14. Material point method simulations of fragmenting cylinders

    CERN Document Server

    Banerjee, Biswajit

    2012-01-01

    Most research on the simulation of deformation and failure of metals has been and continues to be performed using the finite element method. However, the issues of mesh entanglement under large deformation, considerable complexity in handling contact, and difficulties encountered while solving large deformation fluid-structure interaction problems have led to the exploration of alternative approaches. The material point method uses Lagrangian solid particles embedded in an Eulerian grid. Particles interact via the grid with other particles in the same body, with other solid bodies, and with fluids. Thus, the three issues mentioned in the context of finite element analysis are circumvented. In this paper, we present simulations of cylinders which fragment due to explosively expanding gases generated by reactions in a high energy material contained inside. The material point method is the numerical method chosen for these simulations discussed in this paper. The plastic deformation of metals is simulated using ...

  15. Network design for cylinder gas distribution

    Directory of Open Access Journals (Sweden)

    Tejinder Pal Singh

    2015-01-01

    Full Text Available Purpose: Network design of the supply chain is an important and strategic aspect of logistics management. In this paper, we address the network design problem specific to packaged gases (cylinder supply chain. We propose an integrated framework that allows for the determination of the optimal facility locations, the filling plant production capacities, the inventory at plants and hubs, and the number of packages to be routed in primary and secondary transportation. Design/methodology/approach: We formulate the problem as a mixed integer program and then develop a decomposition approach to solve it. We illustrate the proposed framework with numerical examples from real-life packaged gases supply chain. The results show that the decomposition approach is effective in solving a broad range of problem sizes. Findings: The main finding of this paper is that decomposing the network design problem into two sub-problems is very effective to tackle the real-life large scale network design problems occurring in cylinder gas distribution by optimizing strategic and tactical decisions and approximating the operational decisions. We also benchmark the results from the decomposition approach by solving the complete packaged gases network design model for smaller test cases. Originality/value: The main contribution of our work is that it integrates supply chain network design decisions without fixing the fillings plant locations with inventory and resource allocation decisions required at the plants. We also consider the transportation costs for the entire supply chain including the transhipment costs among different facilities by deciding the replenishment frequency.

  16. The Federal Cylinder Project: A Guide to Field Cylinder Collections in Federal Agencies. Volume 8, Early Anthologies.

    Science.gov (United States)

    Lee, Dorothy Sara, Ed; And Others

    This catalog describes wax cylinder recordings of music collected by two pioneers in ethnomusicology. The 101 cylinders in the Benjamin Ives Gilman Collection recorded at the 1893 World's Columbian Exposition in Chicago contain Fijian, Samoan, Uvean, Javanese, Turkish, and Kwakiutl or Vancouver Island Indian music. The Gilman Collection is…

  17. Clinical Randomized Controlled Trials of Artificial Femoral Head Replacement and Dynamic Hip Screw Internal ;Fixation in Treatment of Senile Intertrochanteric Fracture%人工股骨头置换术与动力髋螺钉内固定术治疗老年转子间骨折的临床随机对照研究

    Institute of Scientific and Technical Information of China (English)

    汤岱; 李博

    2016-01-01

    目的:比较人工股骨头置换术与动力髋螺钉内固定术治疗老年转子间骨折的临床疗效,为临床选择合适的手术方式提供依据。方法选择符合标准的患者60例,按照入院先后顺序分为观察组和对照组各30例,观察组采用人工股骨头置换术,对照组采用动力髋螺钉内固定术,比较两者手术一般情况及术后髋关节恢复情况。结果两组患者伤后到手术时间差异无统计学意义(P>0.05);观察组患者手术时间、术中出血量及术后卧床时间均优于对照组,差异有统计学意义(P0.05);观察组髋关节功能优8例、良18例、中3例、差1例,优良率86.67%,对照组优3例、良17例、中4例、差6例,优良率为66.67%,差异有统计学意义( P0. 05);The operation time,intraoperative blood loss and postopera-tive bedrest time of the observation group were superior to the control group and there was significant difference in observation group compared to control group (P0. 05);The situation of hip joint function in ob-servation group was 8 excellent cases,18 good cases,3 medium cases and 1 poor case,the excellent and good rate was 86. 67%, while the control group was3,17,4,6,66. 67%respectively,the difference was statistically significant (P<0. 05). Conclusion Artificial femoral head replacement for senile in-tertrochanteric fracture has shorter operation time, less intraoperative blood loss, postoperative early weight bearing, low incidence of complications,and is beneficial to the hip joint function recovery.

  18. Robotic mitral valve replacement.

    Science.gov (United States)

    Senay, Sahin; Gullu, Ahmet Umit; Kocyigit, Muharrem; Degirmencioglu, Aleks; Karabulut, Hasan; Alhan, Cem

    2014-01-01

    Robotic surgical techniques allow surgeons to perform mitral valve surgery. This procedure has gained acceptance, particularly for mitral valve repair in degenerative mitral disease. However, mitral repair may not always be possible, especially in severely calcified mitral valve of rheumatic origin. This study demonstrates the basic concepts and technique of robotic mitral valve replacement for valve pathologies that are not suitable for repair.

  19. Replacing America's Job Bank

    Science.gov (United States)

    Vollman, Jim

    2009-01-01

    The Job Central National Labor Exchange (www.jobcentral.com) has become the effective replacement for America's Job Bank with state workforce agencies and, increasingly, with community colleges throughout the country. The American Association of Community Colleges (AACC) has formed a partnership with Job Central to promote its use throughout the…

  20. Replacing America's Job Bank

    Science.gov (United States)

    Vollman, Jim

    2009-01-01

    The Job Central National Labor Exchange (www.jobcentral.com) has become the effective replacement for America's Job Bank with state workforce agencies and, increasingly, with community colleges throughout the country. The American Association of Community Colleges (AACC) has formed a partnership with Job Central to promote its use throughout the…

  1. Repair of prestressed concrete cylinder with localized delamination

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shen, E-mail: swang@bechtel.com; Munshi, Javeed A., E-mail: jamunshi@bechtel.com

    2015-12-15

    For prestressed concrete cylindrical structures such as nuclear containments, tanks and silos, the curvature effect of the tendons introduces radial tensile stresses in the concrete shell which are generally neglected in the design of such structures. For example, many prestressed concrete nuclear containments in US, especially those which were not designed following radial reinforcement requirement of ACI-359, are reinforced only in the circumferential (hoop) and meridional (vertical) directions but not in the radial direction. This leaves these structures vulnerable to potential laminar cracking and delamination, especially during post-tensioning and/or detensioning process. Should delamination occur, the structure needs to be repaired by either replacing cracked concrete or by “pinning” the delaminated concrete layers together by post-installed anchors. The latter option of post-installed anchors is less invasive from construction stand point and generally suitable for repairing small or localized delamination only. A comprehensive study is undertaken to explore various aspects and design consideration of post-installed anchors for prestressed concrete cylinders. The radial tension demand is first established by combining a mechanical based model with a detailed finite element analysis. With such design demand for post-installed anchors established, the next step aims at developing the tightness requirement of existing delamination cracks for effective use of post-installed anchors. A comprehensive literature search and evaluation is carried out for shear transfer capacity across cracks of various widths. The findings are used to develop specific recommendations for acceptable crack widths to ensure adequate in-plane shear transfer capacity for various design load conditions. A design process for post-installed anchors is proposed for repairing a delaminated prestressed concrete cylindrical structure at the end of the paper, supplemented by an illustrative

  2. Formation of whispering gallery modes by scattering of an electromagnetic plane wave by two cylinders

    Science.gov (United States)

    Abramov, Arnold; Kostikov, Alexander

    2017-03-01

    We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder.

  3. FORCE REDUCTION OF FLOW AROUND A SINUSOIDAL WAVY CYLINDER

    Institute of Scientific and Technical Information of China (English)

    ZOU Lin; LIN Yu-feng

    2009-01-01

    A large eddy simulation of cross-flow around a sinusoidal wavy cylinder at Re=3000 was performed and the load cell measurement was introduced for the validation test. The mean flow field and the near wake flow structures were presented and compared with those for a circular cylinder at the same Reynolds number. The mean drag coefficient for the wavy cylinder is smaller than that for a corresponding circular cylinder due to the formation of a longer wake vortex generated by the wavy cylinder. The fluctuating lift coefficient of the wavy cylinder is also greatly reduced. This kind of wavy surface leads to the formation of 3-D free shear layers which are more stable than purely 2-D free shear layers. Such free shear layers only roll up into mature vortices at further downstream position and significantly modify the near wake structures and the pressure distributions around the wavy cylinder. Moreover, the simulations in laminar flow condition were also performed to investigate the effect of Reynolds number on force reduction control.

  4. Study of the clinical application of salmon calcitonin in the prevention of aseptic loosening of the prosthesis after artificial femoral head replacement%鲑鱼降钙素在预防人工股骨头置换术后假体无菌性松动的临床应用研究

    Institute of Scientific and Technical Information of China (English)

    陈述祥; 刘彦; 区文欢; 康乐; 丁林坚; 司徒坚; 廖志鹏; 陈丽君

    2014-01-01

    Objective To investigate the clinical efficacy of salmon calcitonin in the prevention of aseptic loosening of the prosthesis after artificial femoral head replacement.Methods One hundred and forty-six patients who received artificial femoral head replacement from January 2010 to January 2011 in the Department of Orthopedics and Traumatology of Wuyi Hospital of Traditional Chinese Medicine were followed up.They were randomly divided into treatment group and control group, with 73 cases in each group.Patients in control group received oral calcium tablets daily (Caltrate D, containing 600mg calcium and 125u vitamin D).Patients in the treatment group received subcutaneous injection of calcitonin salmon (Miacalcic 50U) daily besides calcium tablets.The treatment lasted for 6 months.Bone mineral density ( BMD ) around the prosthesis ( ROI ) in both groups were examined before and 4-, 8-, 12-, and 24-week after the operation.Serum bone metabolic markers osteocalcin ( BGP) and type I collagen peptide ( C end of heterogeneous beta,β-CTX) were deterimined in patients of both groups before and 4-, 12-, and 24-week after the operation.BMD and bone metabolic markers before and after the operation were comparied and analyzed. Results After 24-week of operation, BMD of ROI in the treatment group increased nearly 5%, while BMD of ROI in the control group decreased 6%.The difference between the two groups was significant ( P005).However, these indexes were significantly different comparing to those in the control group (P <0.05 or P <0.01). Conclusion The treatment of salmon calcitonin ( Miacalcic) combined with basic therapy can significantly improve bone mass around the prosthesis, which is one of the effective methods for prevention of aseptic loosening.%目的:探讨鲑鱼降钙素在预防人工股骨头置换术后假体无菌性松动的临床应用效果。方法通过随访江门市五邑中医院骨伤科二区2010年1月至2011年1月146例人工股骨头

  5. Effects of radiation heat transfer space non-uniformity of combustion chamber components on in-cylinder soot emission formation in diesel engine

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Combustion chamber components (cylinder head-cylinder liner-piston assembly-fuel film) were treated as a coupled body. Based on the three-dimensional numerical simulation of heat transfer of the coupled body, the multi-dimensional simulation computation coupling flow and solid on working process and combustion chamber components of internal combustion engine was performed using Discrete Transfer Radiation Model (DTRM) radiation heat transfer model, zoning solution method and boundary coupling method. The simulation was applied to the influence investigation of the space non-uniformity in radiation heat transfer among combustion chamber components on the generation of in-cylinder soot emissions. The results show that the space non-uniformity in heat transfer among the combustion chamber components has great influence on the generation of in-cylinder NOx emissions. The difference value of total soot in cylinder when exhaust valves are opened is 1.3% (no radiation), 0.8% (radiation). So the effect of radiation heat transfer space non-uniformity of combustion chamber components on total soot production can be ignored. While in local area radiation heat transfer space non-uniformity has certain effect on soot production inside whole combustion chamber space, and has less effect on soot production in the area near the wall of combustion chamber components.

  6. Wake flow behind two side-by-side square cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Shun C., E-mail: scyen@mail.ntou.edu.t [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China); Liu, Jung H. [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China)

    2011-02-15

    This study investigates the flow structures, form drag coefficients and vortex-shedding characteristics behind a single-square cylinder and two side-by-side cylinders in an open-loop wind tunnel. The Reynolds number (Re) and gap ratio (g*) are 2262 < Re < 28,000 and 0 {<=} g* {<=} 12, respectively. The flow patterns around the square cylinders are determined using the smoke-wire scheme. Experimental results indicate that the flow structures behind two side-by-side square cylinders are classified into three modes -single mode, gap-flow mode and couple vortex-shedding. The gap-flow mode displays anti-phase vortex shedding induced from the interference between the two square cylinders. However, the couple vortex-shedding mode exhibits in-phase vortex shedding that is caused by the independent flow behavior behind each square cylinder. The surface-pressure profile, form drag coefficient for each square cylinder (C{sub D}-bar) and vortex-shedding frequency were measured and calculated using a pressure transducer and a hot-wire anemometer. For two side-by-side cylinder configurations, the maximum C{sub D}-bar of 2.24 occurs in the single mode, while the minimum C{sub D}-bar of 1.68 occurs in the gap-flow mode. Additionally, the C{sub D}-bar in the coupled vortex-shedding mode is intermediate and approximately equal to that of a single (isolated) square cylinder. Moreover, the single mode has the highest Strouhal number (St) and the gap-flow mode has the lowest St.

  7. Adaptive individual-cylinder thermal state control using intake air heating for a GDCI engine

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Gregory T.; Sellnau, Mark C.

    2016-08-09

    A system for a multi-cylinder compression ignition engine includes a plurality of heaters, at least one heater per cylinder, with each heater configured to heat air introduced into a cylinder. Independent control of the heaters is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the heater for that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder compression ignition engine, including determining a combustion parameter for combustion taking place in a cylinder of the engine and controlling a heater configured to heat air introduced into that cylinder, is also provided.

  8. Strength of Concrete Containing Rubber Particle as Partial Cement Replacement

    Directory of Open Access Journals (Sweden)

    Abdullah Siti Radziah

    2016-01-01

    Full Text Available Uncontrolled issues of disposal waste tire rubber create huge environmental impact and health hazards. An alternative viable solution to minimize these problems is by utilizing the waste rubber tires in construction materials, which in turn can reduce the use of natural resources and eventually lessen the cost of construction. This paper mainly focuses on the use of waste rubber tires particles in concrete with different set of composition ranging from 3 to 12% of cement replacement. Concrete cubes size of 150mm x 150mm x 150mm were prepared for compressive strength test, and concrete cylinders size of 150m x 300mm were prepared for splitting tensile test. The result shows that the compressive and split tensile strength of concrete with rubber as cement replacements is 6-21% lower than the normal concrete.

  9. The Interaction Vortex Flow Around Two Bluff Cylinders

    OpenAIRE

    Hirao K.; Yokoi Y.

    2013-01-01

    In this study, the interaction vortex flow features around a pair of parallel arranged bluff cylinders were observed by visualizing water flow experiment at the range of the gap ratio G/d=0~3. It was obtained that the result of established wind tunnel test and the result of this water tank test agreed about the characteristics of vortex shedding when varying the distance of circular cylinder gap. The flow pattern and vortex shedding frequency of another type bluff cylinder (triangular and squ...

  10. Characteristics of Electrorheological Fluid Flow Between Two Concentric Cylinders

    Institute of Scientific and Technical Information of China (English)

    PENG Jie; ZHU Ke-Qin; XI Bao-Shu

    2000-01-01

    The characteristics of Couette flow of electrorheological fluid (ERF) between concentric cylinders is dependent on the parameter β, which is in the yield stress formula of ERF. In the case of β > 2, the yield region locates between the yield surface and the outer cylinder. In the case of β < 2, the yield region locates between the yield surface and the inner cylinder. When β=2, there is no yield surface. Steady and time dependent numerical results in relation to different β are presented and discussed.

  11. Numerical simulation of VAWT on the effects of rotation cylinder

    Science.gov (United States)

    Xing, Shuda; Cao, Yang; Ren, Fuji

    2017-06-01

    Based on Finite Element Analysis Method, studying on Vertical Axis Wind Turbine (VAWT) which is added rotating cylinder in front of its air foils, especially focusing on the analysis of NACA6 series air foils about variation of lift to drag ratio. Choosing the most suitable blades with rotary cylinder added on leading edge. Analysis indicates that the front rotating cylinders on the VAWT is benefit to lift rise and drag fall. The most suitable air foil whose design lift coefficient is 0.8, the blades relative thickness is 20%, and the optimistic tip speed ratio is about 7.

  12. Viscous Swirling Flow over a Stretching Cylinder

    Institute of Scientific and Technical Information of China (English)

    Tiegang FANG; ShanshanYAO

    2011-01-01

    We investigate a viscous How over a cylinder with stretching and torsional motion. There is an exact solution to the Navier-Stokes equations and there exists a unique solution for all the given values of the flow Reynolds number. The results show that velocity decays faster for a higher Reynolds number and the How penetrates shallower into the ambient Huid. All the velocity proHles decay algebraically to the ambient zero velocity.%We investigate a viscous flow over a cylinder with stretching and torsional motion.There is an exact solution to the Navier-Stokes equations and there exists a unique solution for all the given values of the flow Reynolds number.The results show that velocity decays faster for a higher Reynolds number and the flow penetrates shallower into the ambient fluid.All the velocity profiles decay algebraically to the ambient zero velocity.Exact solutions of the Navier-Stokes (NS) equations play important roles in the development of fluid mechanics.In the review articles,[1,2] Wang summarized the available exact solutions of the unsteady state and of the steady-state NS equations.Swirl flows have important engineering applications in many fields such as the cyclone for separation of solid,liquid and gas,swirl atomizers,swirl combustion devices,heat transfer enhancement and others.[3,4] A famous example of flows involving rotation or swirl is the rotating disk problem studied by von Karman.[5-8] The flow induced by a stretching boundary is also important in the extrusion processes in plastic and metal industries.[9-11] Crane[12] presented an exact solution of the two-dimensional NS equations for a stretching sheet problem with a closed analytical form.The stretching wall problem was extended by Wang[13]to a three-dimensional setting.The flow between two stretching disks was studied by Fang and Zhang recently.[14] The combined effects of disk stretching and rotation on the von Karman flow was investigated by Fang.[15] The flow inside a channel or a

  13. Reluctance Machine for a Hollow Cylinder Flywheel

    Directory of Open Access Journals (Sweden)

    Magnus Hedlund

    2017-03-01

    Full Text Available A hollow cylinder flywheel rotor with a novel outer rotor switched reluctance machine (SRM mounted on the interior rim is presented, with measurements, numerical analysis and analytical models. Practical experiences from the construction process are also discussed. The flywheel rotor does not have a shaft and spokes and is predicted to store 181 Wh / kg at ultimate tensile strength (UTS according to simulations. The novel SRM is an axial flux machine, chosen due to its robustness and tolerance for high strain. The computed maximum tip speed of the motor at UTS is 1050 m / s . A small-scale proof-of-concept electric machine prototype has been constructed, and the machine inductance has been estimated from measurements of voltage and current and compared against results from analytical models and finite element analysis (FEA. The prototype measurements were used to simulate operation during maximal speed for a comparison towards other high-speed electric machines, in terms of tip speed and power. The mechanical design of the flywheel was performed with an analytical formulation assuming planar stress in concentric shells of orthotropic (unidirectionally circumferentially wound carbon composites. The analytical approach was verified with 3D FEA in terms of stress and strain.

  14. Cylinder Block Fixture for Mistake Proofing.

    Directory of Open Access Journals (Sweden)

    L.B.Raut

    2014-10-01

    Full Text Available The project idea basically developed from trunnion tables which are one type of fixture having ability to rotate about its axis and able to fix the component at any angle, so there is no requirement of angle plate and sine plates, drilling process is also computer controlled so no guide bush is required, So robust design for extra rigidity, flexibility and simple to use. In this project task is difficult as design rotary cage type fixture for component like cylinder block, which is heavy of 76 kg. it is not possible to rotate or handle component manually and proceed on them to make this process accident proof and automated for this purpose we are designing a rotary cage which rotate 360 degree and allow indexing to process on the component. Processes are to be operated on the component are drilling tapping and air blow washing ,Since drilling don’t need clamping here components self weight will enough to carry drilling force and tapping force coming through power tools. Therefore, rotary cage type fixture is critical importance.

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  16. Flow past rotating and stationary circular cylinders near a plane screen. II - Characteristics of flow past a stationary cylinder

    Science.gov (United States)

    Kovalenko, V. M.; Byehkov, N. M.; Kisel, G. A.; Dikovskaia, N. D.

    1984-03-01

    Measurements have been made of pressure distributions and pulsations in a cross flow past a circular cylinder placed near a plane screen of finite length. The experiments reported here have been carried out under low turbulence conditions over a range of Reynolds numbers that includes the critical values. The boundary layer separation points and the evolution of the front critical point and other characteristic zones with the distance to the screen are determined. The components of the aerodynamic force acting on the cylinder and the Strouhal number are calculated on the basis of the predominant pulsation frequencies on the cylinder.

  17. Head injuries: a study evaluating the impact of the NICE head injury guidelines

    Science.gov (United States)

    Hassan, Z; Smith, M; Littlewood, S; Bouamra, O; Hughes, D; Biggin, C; Amos, K; Mendelow, A; Lecky, F

    2005-01-01

    Background: The NICE head injury guidelines recommend a different approach in the management of head injury patients. It suggests that CT head scan should replace skull x ray (SXR) and observation/admission as the first investigation. We wished to determine the impact of NICE on SXR, CT scan, and admission on all patients with head injury presenting to the ED setting and estimate the cost effectiveness of these guidelines, which has not been quantified to date. Design: Study of head injury patients presenting to two EDs before and after implementation of NICE guidelines Methods: The rate of SXR, CT scan, and admission were determined six months before and one month after NICE implementation in both centres. The before study also looked at predicted rates had NICE been applied. This enabled predicted and actual cost effectiveness to be determined. Result: 1130 patients with head injury were studied in four 1 month periods (two in each centre). At the teaching hospital, the CT head scan rate more than doubled (3% to 7%), the SXR declined (37% to 4%), while the admission rate more than halved (9% to 4%). This represented a saving of £3381 per 100 head injury patients: greater than predicted with no adverse events. At the District General Hospital, the CT head scan rate more than quadrupled (1.4% to 9%), the SXR dropped (19 to 0.57%), while the admission rate declined (7% to 5%). This represented a saving of £290 per 100 head injury patients: less than predicted. Conclusion: The implementation of the NICE guidelines led to a two to fivefold increase in the CT head scan rate depending on the cases and baseline departmental practice. However, the reduction in SXR and admission appears to more than offset these costs without compromising patient outcomes. PMID:16299190

  18. Erosion patterns on a granular bed around a vertical cylinder

    Directory of Open Access Journals (Sweden)

    Lachaussée Florent

    2017-01-01

    Full Text Available We report on two different patterns that can be observed at the bed surface close to a vertical cylinder when submitted to a strong enough steady water flow. The classical scour pattern observed at the cylinder foot and due to the “horseshoe” vortex around occurs at a critical velocity Uc1 below the critical velocity Uc0 for erosion without any cylinder, thus under clear-water conditions. But we observe also another pattern downstream the cylinder which consists of two symmetrical ovoid holes that look like “bunny ears”. This new scour pattern referred as BES can be observed at lower velocities that the horseshoe scour (HSS, above a critical velocity Uc2 < Uc1 , with a timescale formation much higher that the one of HSS.

  19. Controlling a negative loaded hydraulic cylinder using pressure feedback

    DEFF Research Database (Denmark)

    Hansen, M.R.; Andersen, T.O.

    2010-01-01

    the high pass filtered pressure gradient equal tozero is introduced. It yields lead compensation with a markedly improved performance. The sizing of the filter is described taking into account the bandwidth of the directional control valve. The suggested control scheme is implemented and examined......This paper is concerned with the inherent oscillatory nature of pressure compensated velocity control of a hydraulic cylinder subjected to a negative load and suspended by means of an over-center valve. Initially, a linearized stability analysis of such a hydraulic circuit is carried out clearly...... showing that without extra measures such a system will be unstable in a substantial part of the cylinder stroke. The stability criterion is expressed in hard quantities: Cylinder volumes, cylinder area ratio and overcenter valve pilot area ratio. A pressure feed back scheme that has as target to maintain...

  20. Wave propagation in coated cylinders with reference to fretting fatigue

    Indian Academy of Sciences (India)

    M Ramesh; Satish V Kailas; K R Y Simha

    2008-06-01

    Fretting fatigue is the phenomenon of crack initiation due to dynamic contact loading, a situation which is commonly encountered in mechanical couplings subjected to vibration. The study of fretting fatigue in high frequency regime has gained importance in recent years. However the stress wave effects at high frequency y loading is scanty in the literature. The objective of present investigation is to study stress wave propagation in cylinders with reference to high frequency fretting. The case of a coated cylinder is considered since coating is often provided to improve tribological properties of the component. Rule of mixtures is proposed to understand the dispersion phenomenon in coated or layered cylinder knowing the dispersion relation for the cases of homogeneous cylinders made of coating and substrate materials separately. The possibility of stress wave propagation at the interface with a particular phase velocity without dispersion is also discussed. Results are given for two different thicknesses of coating.

  1. Grinding efficiency improvement of hydraulic cylinders parts for mining equipment

    National Research Council Canada - National Science Library

    Aleksandr Korotkov; Vitaliy Korotkov; Leonid Mametyev; Lidia Korotkova; Tatiana Terjaeva

    2017-01-01

    The aim of the article is to find out ways to improve parts treatment and components of mining equipment on the example of hydraulic cylinders parts, used as pillars for mine roof supports, and other actuator mechanisms...

  2. Motion by Volume Preserving Mean Curvature Flow Near Cylinders

    CERN Document Server

    Hartley, David

    2012-01-01

    Center manifold analysis can be used in order to investigate the stability of the stationary solutions of various PDEs. This can be done by considering the PDE as an ODE between certain Banach spaces and linearising about the stationary solution. Here we investigate the volume preserving mean curvature flow using such a technique. We will consider surfaces with boundary contained within two parallel planes such that the surface meets these planes orthogonally. With this set up the stationary solution is a cylinder. We will find that for initial surfaces that are sufficiently close to a cylinder the flow will exist for all time and converge to a cylinder exponentially. In particular, we show that there exists global solutions to the flow that converge to a cylinder, which are initially non-axially symmetric. A similar case where the initial surfaces are compact without boundary has previously been investigated by Escher and Simonett (1998).

  3. Theoretical investigation of noise transmission into a finite cylinder

    Science.gov (United States)

    Li, Deyu; Vipperman, Jeffrey S.

    2004-05-01

    A new mathematical model for characterizing noise transmission into a finite elastic cylindrical structure with application to a ChamberCore composite cylinder is presented. A plane wave obliquely impinges on the structure, the external sound field is approximated by the solution for an infinite cylinder, and the internal sound field is solved with the structural and acoustic modal interaction method. The noise reduction spectrum for characterizing noise transmission into the cylinder is defined, and the analytical model for the calculation of the noise reduction spectrum is developed. The analytical results show that the cavity resonances dominate the noise transmission into the finite cylinder, and the longitudinal acoustic modes play an important role in the noise transmission at the low frequencies. These results are matched with experimental results.

  4. NONLINEAR FREE SURFACE ACTION WITH AN ARRAY OF VERTICAL CYLINDERS

    Institute of Scientific and Technical Information of China (English)

    HUANG J. B.

    2004-01-01

    Nonlinear diffraction of regular waves by an array of bottom-seated circular cylinders is investigated in frequency domain, based on a Stokes expansion approach. A complete semi-analytical solution is developed which allows an efficient evaluation of the second-order potentials in the entire fluid domain, and the wave forces on the structure. Expressions are derived for the second-order potential in the vicinity of individual cylinders. These expressions have a simple form, thus providing an effective means for investigating the wave enhancement due to nonlinear interactions with multiple cylinders. Based on the present method, the wave run-up and free-surface elevations around an array of two, three and four cylinders are investigated numerically.

  5. On the flow in an annulus surrounding a whirling cylinder

    Science.gov (United States)

    Brennen, C.

    1976-01-01

    When fluid in an annulus between two cylinders is set in motion by whirling movements of one or both of the cylinders, dynamic forces are imposed by the fluid on the cylinders. Knowledge of these forces is frequently important, indeed often critical, to the engineer designing rotor systems or journal bearings. Quite general solutions of the Navier-Stokes equations are presented for this problem and are limited only by restrictions on the amplitude of the whirl motion. From these solutions, the forces are derived under a wide variety of circumstances, including large and small annular widths, high and low Reynolds numbers, and the presence and absence of a mean flow created by additional net rotation of one or both of the cylinders.

  6. LOW VELOCITY INDICATOR USING SHED VORTICITY FREQUENCY OF CYLINDER.

    Science.gov (United States)

    of accurately determining the velocity of a fluid and its rate of change . Static pressure variations across the top and bottom of the cylinder...instrument is highly feasible for determining velocity and its rate of change . (Author)

  7. Materials for a Stirling engine heater head

    Science.gov (United States)

    Noble, J. E.; Lehmann, G. A.; Emigh, S. G.

    1990-01-01

    Work done on the 25-kW advanced Stirling conversion system (ASCS) terrestrial solar program in establishing criteria and selecting materials for the engine heater head and heater tubes is described. Various mechanisms contributing to incompatibility between materials are identified and discussed. Large thermal gradients, coupled with requirements for long life (60,000 h at temperature) and a large number of heatup and cooldown cycles (20,000) drive the design from a structural standpoint. The pressurized cylinder is checked for creep rupture, localized yielding, reverse plasticity, creep and fatigue damage, and creep ratcheting, in addition to the basic requirements for bust and proof pressure. In general, creep rupture and creep and fatigue interaction are the dominant factors in the design. A wide range of materials for the heater head and tubes was evaluated. Factors involved in the assessment were strength and effect on engine efficiency, reliability, and cost. A preliminary selection of Inconel 713LC for the heater head is based on acceptable structural properties but driven mainly by low cost. The criteria for failure, the structural analysis, and the material characteristics with basis for selection are discussed.

  8. 49 CFR 178.38 - Specification 3B seamless steel cylinders.

    Science.gov (United States)

    2010-10-01

    ... cylinders welded or formed by spinning is, under no condition, to be less than two times the minimum wall...-pressure parts, and only to the tops and bottoms of cylinders having a service pressure of 500 psig or less... wall thickness. (m) Leakage test. All spun cylinders and plugged cylinders must be tested for leakage...

  9. Effect of Backpacking and Internal Pressurization on Stresses Transmitted to Buried Cylinders.

    Science.gov (United States)

    Various aspects of the behavior of buried cylinders associated with backpacking , internal pressurization, and slippage at the interface are...considered. Parametric curves are presented for horizontally and vertically buried cylinders with and without backpacking . Four configurations of statically...loaded, horizontally buried cylinders were considered: no backpacking , rectangular backpacking placed above the cylinder, backpacking placed around

  10. Two-Fluid Couette Flow between Concentric Cylinders.

    Science.gov (United States)

    1984-01-01

    CONCENTRIC CYLINDERS Yuriko Renardy and Daniel D. Joseph* Technical Summary Report #2622 January 1984 ABSTRACT -1W considers,he flow of two immiscible...CYLINDERS Yuriko Renardy and Daniel D. Joseph* Introduction We consider linear stability of the flow of two immiscible fluids separated by an interface...AUTiOR(,) 8. CONTRACT OR GRANT NUMBER(@) Yuriko Renardy and Daniel D. Joseph DAAGZ9-80-C-0041 11. PERFORMING ORGANIZATION NAME AND ADDRESS 10

  11. ROBUST CYLINDER FITTING IN THREE-DIMENSIONAL POINT CLOUD DATA

    Directory of Open Access Journals (Sweden)

    A. Nurunnabi

    2017-05-01

    Full Text Available This paper investigates the problems of cylinder fitting in laser scanning three-dimensional Point Cloud Data (PCD. Most existing methods require full cylinder data, do not study the presence of outliers, and are not statistically robust. But especially mobile laser scanning often has incomplete data, as street poles for example are only scanned from the road. Moreover, existence of outliers is common. Outliers may occur as random or systematic errors, and may be scattered and/or clustered. In this paper, we present a statistically robust cylinder fitting algorithm for PCD that combines Robust Principal Component Analysis (RPCA with robust regression. Robust principal components as obtained by RPCA allow estimating cylinder directions more accurately, and an existing efficient circle fitting algorithm following robust regression principles, properly fit cylinder. We demonstrate the performance of the proposed method on artificial and real PCD. Results show that the proposed method provides more accurate and robust results: (i in the presence of noise and high percentage of outliers, (ii for incomplete as well as complete data, (iii for small and large number of points, and (iv for different sizes of radius. On 1000 simulated quarter cylinders of 1m radius with 10% outliers a PCA based method fit cylinders with a radius of on average 3.63 meter (m; the proposed method on the other hand fit cylinders of on average 1.02 m radius. The algorithm has potential in applications such as fitting cylindrical (e.g., light and traffic poles, diameter at breast height estimation for trees, and building and bridge information modelling.

  12. MATHEMATICAL METHODS TO DETERMINE THE INTERSECTION CURVES OF THE CYLINDERS

    Directory of Open Access Journals (Sweden)

    POPA Carmen

    2010-07-01

    Full Text Available The aim of this paper is to establish the intersection curves between cylinders, by using the Mathematica program. This thing can be obtained by introducing the curves equations, which are inferred, in Mathematica program. This paper take into discussion three right cylinders and another inclined to 45 degrees. The intersection curves can also be obtained by using the classical methods of the descriptive geometry.

  13. Mathematic modelling of circular cylinder deformation under inner grouwth

    Directory of Open Access Journals (Sweden)

    A. V. Siasiev

    2009-09-01

    Full Text Available A task on the intensive deformed state (IDS of a viscoelastic declivous cylinder, which is grown under the action of inner pressure, is considered. The process of continuous increase takes a place on an internal radius so, that a radius and pressure change on set to the given law. The special case of linear law of creeping is considered, and also numeral results are presented as the graphs of temporal dependence of tensions and moving for different points of cylinder.

  14. Mechanisms of active control for noise inside a vibrating cylinder

    Science.gov (United States)

    Lester, Harold C.; Fuller, Chris R.

    1987-01-01

    The active control of propeller-induced noise fields inside a flexible cylinder is studied with attention given to the noise reduction mechanisms inherent in the present coupled acoustic shell model. The active noise control model consists of an infinitely long aluminum cylinder with a radius of 0.4 m and a thickness of 0.001 m. Pressure maps are shown when the two external sources are driven in-phase at a frequency corresponding to Omega = 0.22.

  15. Radiation dose rates from UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Friend, P.J. [Urenco, Capenhurst (United Kingdom)

    1991-12-31

    This paper describes the results of many studies, both theoretical and experimental, which have been carried out by Urenco over the last 15 years into radiation dose rates from uranium hexafluoride (UF{sub 6}) cylinders. The contents of the cylinder, its history, and the geometry all affect the radiation dose rate. These factors are all examined in detail. Actual and predicted dose rates are compared with levels permitted by IAEA transport regulations.

  16. Vertical force acting on partly submerged spindly cylinders

    Directory of Open Access Journals (Sweden)

    Xinbin Zhang

    2014-04-01

    Full Text Available When an object is placed on a water surface, the air-water interface deforms and a meniscus arises due to surface tension effects, which in turn produces a lift force or drag force on the partly submerged object. This study aims to investigate the underlying mechanism of the vertical force acting on spindly cylinders in contact with a water surface. A simplified 2-D model is presented, and the profile of the curved air-water interface and the vertical force are computed using a numerical method. A parametric study is performed to determine the effects of the cylinder center distance, inclined angle, static contact angle, and radius on the vertical force. Several key conclusions are derived from the study: (1 Although the lift force increases with the cylinder center distance, cylinders with smaller center distances can penetrate deeper below the water surface before sinking, thereby obtaining a larger maximum lift force; (2 An increase in the inclined angle reduces the lift force, which can enable the lower cylinders fall more deeply before sinking; (3 While the effect of static contact angle is limited for angles greater than 90°, hydrophobicity allows cylinders to obtain a larger lift force and load capacity on water; (4 The lift force increases rapidly with cylinder radius, but an increase in radius also increases the overall size and weight of cylinders and decreases the proportion of the surface tension force. These findings may prove helpful in the design of supporting legs of biologically-inspired miniature aquatic devices, such as water strider robots.

  17. Primary instabilities and bicriticality in fiber suspensions between rotating cylinders

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The linear stability of fiber suspensions between two concentric cylinders rotating independently is studied. The modified stability equation is obtained based on the fiber orientation model and Hinch-Leal closure approximation. The primary instabilities and bicritical curves have been calculated numerically. The critical Reynolds number, wavenumber and wave speeds of fiber suspensions as functions of the aspect ratio, volume concentration of the fibers and the gap width of cylinders are obtained.

  18. Simulation of Flow Around Cylinder Actuated by DBD Plasma

    Science.gov (United States)

    Wang, Yuling; Gao, Chao; Wu, Bin; Hu, Xu

    2016-07-01

    The electric-static body force model is obtained by solving Maxwell's electromagnetic equations. Based on the electro-static model, numerical modeling of flow around a cylinder with a dielectric barrier discharge (DBD) plasma effect is also presented. The flow streamlines between the numerical simulation and the particle image velocimetry (PIV) experiment are consistent. According to the numerical simulation, DBD plasma can reduce the drag coefficient and change the vortex shedding frequencies of flow around the cylinder.

  19. Cylinder expansion test and gas gun experiment comparison

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-30

    This is a summer internship presentation by the Hydro Working Group at Los Alamos National Laboratory (LANL) and goes into detail about their cylinder expansion test and gas gun experiment comparison. Specifically, the gas gun experiment is detailed along with applications, the cylinder expansion test is detailed along with applications, there is a comparison of the methods with pros and cons and limitations listed, the summer project is detailed, and future work is talked about.

  20. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A

    2008-01-01

    BACKGROUND AND AIMS OF THE STUDY: Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European...... countries. METHODS: A multi-institutional, non-randomized, retrospective analysis was conducted among 2,932 patients who underwent AVR surgery at seven tertiary cardiac surgery centers throughout Europe. Demographic and perioperative variables including valve size and type, body surface area (BSA) and early...

  1. Total ankle joint replacement.

    Science.gov (United States)

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.

  2. Flow induced vibrations in arrays of irregularly spaced cylinders

    Science.gov (United States)

    Taub, Gordon; Michelin, Sébastien

    2014-11-01

    Historically the main industrial applications of cylinder arrays in cross flows favored regular arrangements of cylinders. For this reason, most past studies of Flow Induced Vibrations (FIV) in large cylinder arrays have focused on such arrangements. Recently there has been some interest in generating renewable energy using FIV of bluff bodies. In such applications it will likely be beneficial to enhance, rather than suppress FIV. It is not known a priori if regular or irregularly spaced arrays are most adequate for this type of application. In this study, wind tunnel experiments were conducted on one regularly spaced array and four different irregularly spaced arrays of cylinders in a cross flow. Each arrangement of cylinders was examined under eight different orientations to a cross flow ranging between 10 m/s and 17 m/s. The average amplitude of vibration of the cylinders was found to highly depend on arrangement and orientation. The typical amplitude of vibration of the rods in the irregular arrangements were found to be an order of magnitude larger than that of the regular array. A simple model was proposed in order to predict if a given arrangement was likely to produce large oscillations, and the validity of the model was examined. This research was supported by a Marie Curie International Reintegration Grant within the 7th European Community Framework Program (Grant PIRG08-GA-2010-276762).

  3. Wave Run-up on A Coaxial Perforated Circular Cylinder

    Institute of Scientific and Technical Information of China (English)

    ZHU Da-tong

    2011-01-01

    This paper describes a plane regular wave interaction with a combined cylinder which consists of a solid inner column and a coaxial perforated outer cylinder. The outer perforated surface is a thin porous cylinder with an annular gap between it and the inner cylinder. The non-linear boundary condition at the perforated wall is a prime focus in the study;energy dissipation at the perforated wall occurs through the resistance to the fluid across the perforated wall. Explicit analytical formulae are presented to calculate the wave run-up on the outer and inner surfaces of the perforated cylinderand the surface of the inner column. The theoretical results of the wave run-up are compared with previous experimental data. Numerical results have also been obtained: when the ratio of the annular gap between the two cylinders to incidentwavelength (b-a)/L≤0.1, the wave run-up on the inner surface of the perforated cylinder and the surface of inner column can partially or completely exceed the incident wave height.

  4. Kinematics investigations of cylinders rolling down a ramp using tracker

    Science.gov (United States)

    Prima, Eka Cahya; Mawaddah, Menurseto; Winarno, Nanang; Sriwulan, Wiwin

    2016-02-01

    Nowadays, students' exploration as well as students' interaction in the application stage of learning cycle can be improved by directly model real-world objects based on Newton's Law using Open Source Physics (OSP) computer-modeling tools. In a case of studying an object rolling down a ramp, a traditional experiment method commonly uses a ticker tape sliding through a ticker timer. However, some kinematics parameters such as the instantaneous acceleration and the instantaneous speed of object cannot be investigated directly. By using the Tracker video analysis method, all kinematics parameters of cylinders rolling down a ramp can be investigated by direct visual inspection. The result shows that (1) there are no relations of cylinders' mass as well as cylinders' radius towards their kinetics parameters. (2) Excluding acceleration data, the speed and position as function of time follow the theory. (3) The acceleration data are in the random order, but their trend-lines closely fit the theory with 0.15% error. (4) The decrease of acceleration implicitly occurs due to the air friction acting on the cylinder during rolling down. (5) The cylinder's inertial moment constant has been obtained experimentally with 3.00% error. (6) The ramp angle linearly influences the cylinders' acceleration with 2.36% error. This research implied that the program can be further applied to physics educational purposes.

  5. A characteristic analysis of the fluidic muscle cylinder

    Science.gov (United States)

    Kim, Dong-Soo; Bae, Sang-Kyu; Hong, Sung-In

    2005-12-01

    The fluidic muscle cylinder consists of an air bellows tube, flanges and lock nuts. It's features are softness of material and motion, simplicity of structure, low production cost and high power efficiency. Recently, unlikely the pneumatic cylinder, the fluidic muscle cylinder without air leakage, stick slip, friction, and seal was developed as a new concept actuator. It has the characteristics such as light weight, low price, high response, durable design, long life, high power, high contraction, which is innovative product fulfilling RT(Robot Technology) which is one of the nation-leading next generation strategy technologies 6T as well as cleanness technology. The application fields of the fluidic muscle cylinder are so various like fatigue tester, brake, accelerator, high technology testing device such as driving simulator, precise position, velocity, intelligent servo actuator under special environment such as load controlling system, and intelligent robot. In this study, we carried out the finite element modeling and analysis about the main design variables such as contraction ration and force, diameter increment of fluidic muscle cylinder. On the basis of finite element analysis, the prototype of fluidic muscle cylinder was manufactured and tested. Finally, we compared the results between the test and the finite element analysis.

  6. Characteristic analysis and experimental evaluation of artificial pneumatic cylinder

    Science.gov (United States)

    Kim, Dong-Soo; Bae, Sang-Kyu; Choi, Kyung-Hyun

    2005-12-01

    The fluidic muscle cylinder consists of an air bellows tube, flanges and lock nuts. Its features are softness of material and motion, simplicity of structure, low production cost and high power efficiency. Recently, unlikely the pneumatic cylinder, the fluidic muscle cylinder without air leakage, stick slip, friction, and seal was developed as a new concept actuator. It has the characteristics such as light weight, low price, high response, durable design, long life, high power, high contraction, which is innovative product fulfilling RT(Robot Technology) which is one of the nation-leading next generation strategy technologies 6T as well as cleanness technology. The application fields of the fluidic muscle cylinder are so various like fatigue tester, brake, accelerator, high technology testing device such as driving simulator, precise position, velocity, intelligent servo actuator under special environment such as load controlling system, and intelligent robot. In this study, we carried out the finite element modeling and analysis about the main design variables such as contraction ration and force, diameter increment of fluidic muscle cylinder. On the basis of finite element analysis, the prototype of fluidic muscle cylinder was fabricated and tested. Finally, we compared the results between the test and the finite element analysis.

  7. Laminar vortex shedding behind a cooled circular cylinder

    Science.gov (United States)

    Trávníček, Zdeněk; Wang, An-Bang; Tu, Wen-Yun

    2014-02-01

    This paper addresses the functional demonstration of a hot air flow generator driven by convective heat transfer and the airflow behind a cooled circular cylinder in cross flow in the low velocity range. The wake flow was investigated experimentally using flow visualization, hot-wire anemometry, and laser Doppler anemometry. An evaluation of the free-stream velocity from the vortex shedding frequency was derived for the isothermal and non-isothermal cases and demonstrated using simple stroboscope measurements. The results confirm that cylinder cooling destabilizes the wake flow in air, i.e., the laminar steady regime can be changed into the vortex shedding regime, and the vortex shedding frequency increases as the cylinder temperature decreases. This thermal effect of cylinder cooling is consistent with its counterpart, the known effect of flow stabilization by cylinder heating. The effective temperature and effective Reynolds number concept have been further quantitatively evaluated, and the extension of their validity to the case of cooled cylinders has been confirmed.

  8. The Interaction Vortex Flow Around Two Bluff Cylinders

    Directory of Open Access Journals (Sweden)

    Hirao K.

    2013-04-01

    Full Text Available In this study, the interaction vortex flow features around a pair of parallel arranged bluff cylinders were observed by visualizing water flow experiment at the range of the gap ratio G/d=0~3. It was obtained that the result of established wind tunnel test and the result of this water tank test agreed about the characteristics of vortex shedding when varying the distance of circular cylinder gap. The flow pattern and vortex shedding frequency of another type bluff cylinder (triangular and square cylinder were also investigated. As a result of the experiment, it was shown that the flow pattern of wake flow was divided into three kinds (coupled vortex streets, biased gap flow and single vortex street regardless of the cylinder section shape and cylinder size. Then, the region of the appearance of flow pattern was shown about each case. In the case where two each other independent vortex streets were formed, three typical flow patterns of vortex formation (in-phase coupled vortex streets, out-of-phase coupled vortex streets and complication coupled vortex streets were observed. It was known that three configuration of vortex formation appear intermittently and alternatively.

  9. Vortex Shedding in the Wake of a Dual Step Cylinder

    CERN Document Server

    Morton, Chris

    2012-01-01

    A dual-step cylinder is comprised of a large diameter cylinder (D) with low aspect ratio (L/D) attached co-axially to the mid-span of a small diameter cylinder (d). The fluid dynamics video presented in this investigation is used to illustrate the effect of aspect ratio on dual step cylinder wake development for Re = 2100, D/d = 2, and 0.2 < L/D < 3. In addition, the video provides visualization of such flow phenomena as interaction of spanwise vortices, development of streamwise vortex filaments, and formation of Kelvin-Helmholtz rollers. The experiments were performed in a water flume at the University of Waterloo. A hydrogen bubble flow visualization technique was employed to visualize vortical structures downstream of each cylinder model. High-resolution images of the flow were obtained with a high speed Photron camera and post-processed using Adobe Photoshop CS4. The results show a plethora of vortices developing in the wake of the dual step cylinder. For 1 < L/D < 3, spanwise vortex shedding...

  10. Regimes of flow induced vibration for tandem, tethered cylinders

    Science.gov (United States)

    Nave, Gary; Stremler, Mark

    2015-11-01

    In the wake of a bluff body, there are a number of dynamic response regimes that exist for a trailing bluff body depending on spacing, structural restoring forces, and the mass-damping parameter m* ζ . For tandem cylinders with low values of m* ζ , two such regimes of motion are Gap Flow Switching and Wake Induced Vibration. In this study, we consider the dynamics of a single degree-of-freedom rigid cylinder in the wake of another in these regimes for a variety of center-to-center cylinder spacings (3-5 diameters) and Reynolds numbers (4,000-11,000). The system consists of a trailing cylinder constrained to a circular arc around a fixed leading cylinder, which, for small angle displacements, bears a close resemblance to the transversely oscillating cylinders found more commonly in existing literature. From experiments on this system, we compare and contrast the dynamic response within these two regimes. Our results show sustained oscillations in the absence of a structural restoring force in all cases, providing experimental support for the wake stiffness assumption, which is based on the mean lift toward the center line of flow.

  11. The Interaction Vortex Flow Around Two Bluff Cylinders

    Science.gov (United States)

    Yokoi, Y.; Hirao, K.

    2013-04-01

    In this study, the interaction vortex flow features around a pair of parallel arranged bluff cylinders were observed by visualizing water flow experiment at the range of the gap ratio G/d=0~3. It was obtained that the result of established wind tunnel test and the result of this water tank test agreed about the characteristics of vortex shedding when varying the distance of circular cylinder gap. The flow pattern and vortex shedding frequency of another type bluff cylinder (triangular and square cylinder) were also investigated. As a result of the experiment, it was shown that the flow pattern of wake flow was divided into three kinds (coupled vortex streets, biased gap flow and single vortex street) regardless of the cylinder section shape and cylinder size. Then, the region of the appearance of flow pattern was shown about each case. In the case where two each other independent vortex streets were formed, three typical flow patterns of vortex formation (in-phase coupled vortex streets, out-of-phase coupled vortex streets and complication coupled vortex streets) were observed. It was known that three configuration of vortex formation appear intermittently and alternatively.

  12. Quantum phase transition in ultra small doubly connected superconducting cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Sternfeld, I. [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)], E-mail: itayst@post.tau.ac.il; Koret, R. [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Shtrikman, H. [Department of Condensed Matter, Weizmann Institute of Science, Rehovot 76100 (Israel); Tsukernik, A. [Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv 69978 (Israel); Karpovski, M.; Palevski, A. [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

    2008-02-15

    The kinetic energy of Cooper pairs, in doubly connected superconducting cylinders, is a function of the applied flux and the ratio between the diameter of the cylinder and the zero temperature coherence length d/{xi}(0). If d >{xi}(0) the known Little-Parks oscillations are observed. On the other hand if d <{xi}(0), the superconducting state is energetically not favored around odd multiples of half flux quanta even at T{approx}0, resulting in the so called destructive regime [Y. Liu, et al., Science 294 (2001) 2332]. We developed a novel technique to fabricate superconducting doubly connected nanocylinders with both diameter and thickness less than 100 nm, and performed magnetoresistance measurements on such Nb and Al cylinders. In the Nb cylinders, where d >{xi}(0), we observed the LP oscillations. In the Al cylinders we did not observe a transition to the superconducting state due to the proximity effect, resulted from an Au layer coating the Al. However, we did observe Altshuler-Aronov-Spivak (h/2e) oscillations in these cylinders.

  13. The Jackson Cross-Cylinder. Part 1: Properties

    Directory of Open Access Journals (Sweden)

    W. F. Harris

    2007-01-01

    Full Text Available The Jackson cross-cylinder is a lens of fundamental importance in optometry with a key role in the refraction routine.  And yet it appears not to be as well understood as perhaps it should be.  The purpose of this paper is to examine the linear optical character of the Jackson cross-cylinder and, in particular, those properties associated with the operations performed on the lens in the refraction routine, namely flipping and turning.  Corresponding to these operations in physical space are steps in an abstract space, symmetric dioptric power space.  The powers of all Jackson cross-cylinders lie in the plane of antistigmatic powers in the abstract space.  In particular the powers of an F Jackson cross-cylinder (for example, a 0.5-D Jackson cross-cylinder has  5 . 0 = F  D lie on a circle of radius F centred onnull power.  Flipping the lens takes one diametrically across the circle; turning the lens takes one around the circle at twice the rate.  A subsequent paper shows how these operations work in defining the cylinder in the refraction routine.

  14. Supercritical flows past a square cylinder with rounded corners

    Science.gov (United States)

    Cao, Yong; Tamura, Tetsuro

    2017-08-01

    Large-eddy simulations were used to investigate the supercritical aerodynamics of a square cylinder with rounded corners in comparison with those in the subcritical regime. First, the numerical methods, especially the dynamic mixed model, were validated on the basis of their prediction of supercritical flows past a circular cylinder. Then, the supercritical flows past a rounded-corner square cylinder were simulated and systematically clarified. Strong Reynolds number (Re) effects existed in the forces and local pressures as Re increased from o(104) to o(106). Changeover of flow patterns occurred as Re increased. At the supercritical Re, the free stream overall flowed along the cross sections of the cylinder, separated from the leeward corners and generated Karman vortices behind the cylinder. This pattern resulted in a much smaller recirculation region behind the cylinder compared with the subcritical flow. At the micro level, the flow experienced laminar separation and flow reattachment near the frontal corners, followed by the spatial development of turbulent boundary layers (TBLs) on the side faces and turbulent separation near the leeward corners. The feedback by large-scale primary vortex shedding and the small-scale turbulent motions in the high-frequency region with a slope of -5/3 were detected in the TBL. Their interaction affected the spanwise correlations of wall pressure fluctuations. The TBL on the side face differed from the zero-pressure-gradient flat-plate one; it was subjected to pressure gradients varying in space and time.

  15. Cold head maintenance with minimal service interruption

    Science.gov (United States)

    Radovinsky, A. L.; Michael, P. C.; Zhukovsky, A.; Forton, E.; Paradis, Y.; Nuttens, V.; Minervini, J. V.

    2015-12-01

    Turn-key superconducting magnet systems are increasingly conduction-cooled by cryogenerators. Gifford-McMahon systems are reliable and cost effective, but require annual maintenance. A usual method of servicing is replacing the cold head of the cryocooler. It requires a complicated design with a vacuum chamber separate from the main vacuum of the cryostat, as well as detachable thermal contacts, which add to the thermal resistance of the cooling heat path and reduce the reliability of the system. We present a rapid warm-up scheme to bring the cold head body, which remains rigidly affixed to the cold mass, to room temperature, while the cold mass remains at cryogenic temperature. Electric heaters thermally attached to the cold head stations are used to warm them up, which permits conventional cold head maintenance with no danger of contaminating the inside of the cold head body. This scheme increases the efficiency of the cooling system, facilitates annual maintenance of the cold head and returning the magnet to operation in a short time.

  16. Flow-induced vibrations of two tandem cylinders in a channel

    Directory of Open Access Journals (Sweden)

    Jiang Ren-Jie

    2012-01-01

    Full Text Available We numerically studied flow-induced vibrations of two tandem cylinders in transverse direction between two parallel walls. The effect of the horizontal separation between two cylinders, ranging from 1.1 to 10, on the motions of the cylinders and the flow structures were investigated and a variety of periodic and non-periodic vibration regimes were observed. The results show that when two cylinders are placed in close proximity to each other, compared with the case of an isolated cylinder, the gap flow plays an important role. As the separation ratio is increased, the fluid-structure interaction decouples and the cylinders behave as two isolated cylinders.

  17. [Avascular necrosis of the femoral head].

    Science.gov (United States)

    Porubský, Peter; Trč, Tomáš; Havlas, Vojtěch; Smetana, Pavel

    Avascular necrosis of the femoral head in adults is not common, but not too rare diseases. In orthopedic practice, it is one of the diseases that are causing implantation of hip replacement at a relatively early age. In the early detection and initiation of therapy can delay the implantation of prosthesis for several years, which is certainly more convenient for the patient and beneficial. This article is intended to acquaint the reader with the basic diagnostic procedures and therapy.

  18. 帕瑞昔布钠镇痛对老年急诊股骨头置换术患者神经系统的影响%Effects of parecoxib sodium analgesia on serum concentrations of neuron-specific enolase and S-100β and postoperative cognitive function of elderly patients undergoing acute replacement of femoral head

    Institute of Scientific and Technical Information of China (English)

    李井柱; 李晓征; 王晓敏; 王明山; 于海芳; 时飞; 苗丹; 毕燕琳

    2013-01-01

    重并发症发生.结论 帕瑞昔布钠围手术期镇痛减轻中枢神经系统损伤,改善老年患者术后认知功能,利于患者康复.%Objective To explore the effects of parecoxib sodium analgesia on serum concentrations of neuron-specific enolase (NSE) and S-100β and postoperative cognitive function of elderly patients undergoing acute replacement of femoral head.Methods After the approval of institutional review board and the provision of informed consent,80 patients over 70 years old,undergoing acute replacement of femoral head under combined spinal and epidural anesthesia and midazolam sedation at Qingdao Municipal Hospital and Qingdao Hiser Medical Center from January 2011 to May 2012,were randomly assigned into control group (group C,n =40) and parecoxib group (group P,n =40).In group P,parecoxib sodium 20/ 40 mg (based on weight 50 kg) was administered via an intravenous injection after admission with 12 hours intervals for six times.In group C,morphine 2/4 mg was given initially.Additional morphine 2 mg was given to maintain the pain visual analog scale (VAS) of 3 points or less in both groups.Primary observation indices:(1) postoperative time and additional amount of morphine; (2) rate of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) at 3 days,1 week,3 months and 6 months postoperation (T1-T4) ; (3) serum levels of NSE and S-1005 were measured at the timepoints of before analgesia (t0),before anesthesia (t1),end of surgery (t2) and 6 hours,24 hours,48 hours postoperation (t3-t5); (4) other serious complications.Results Compared with group C,the additional amount of morphine,postoperative time,rate of POD and POCD at T1-T4,the level of NSE at t2-t5 and S-100 β at t1-t5 were lower in group P (P <0.05).No other serious complications were observed.Conclusions Parecoxib sodium analgesia reduces the rate of POD and POCD in elderly patients with neuroprotective effects.

  19. Frictional properties of lubrication greases with the addition of nickel nanoparticles in pneumatic cylinder

    Science.gov (United States)

    Chang, Ho; Lan, Chou-Wei; Guo, Jia-Bin

    2011-12-01

    This paper studies the influence of addition of 100 nm diameter nickel nano-particles on the friction properties of synthetic grease (Li base, VG100) in pneumatic cylinder. The friction force test of pneumatic cylinder equipment measures the frictional force between seal and cylinder bore in pneumatic cylinders. The lubricants with addition of nickel nano-particles were used for lubricating the contact interface between seal and cylinder bore. The friction force test equipment employ a load cell force sensor to measure the friction force between seals and cylinder bores. Results obtained from experimental tests are compared to determine the friction force between seals and cylinder bore in pneumatic cylinders. The study leads to the conclusion that the addition of nickel nano-particles to synthetic grease results in a decrease in friction force between seals and cylinder bores in pneumatic cylinder. This tribological behavior is closely related to the deposition of nano-particles on the rubbing surfaces

  20. Adaptive individual-cylinder thermal state control using piston cooling for a GDCI engine

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Gregory T; Husted, Harry L; Sellnau, Mark C

    2015-04-07

    A system for a multi-cylinder compression ignition engine includes a plurality of nozzles, at least one nozzle per cylinder, with each nozzle configured to spray oil onto the bottom side of a piston of the engine to cool that piston. Independent control of the oil spray from the nozzles is provided on a cylinder-by-cylinder basis. A combustion parameter is determined for combustion in each cylinder of the engine, and control of the oil spray onto the piston in that cylinder is based on the value of the combustion parameter for combustion in that cylinder. A method for influencing combustion in a multi-cylinder engine, including determining a combustion parameter for combustion taking place in in a cylinder of the engine and controlling an oil spray targeted onto the bottom of a piston disposed in that cylinder is also presented.

  1. The Optimum Replacement of Weapon

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao; ZHANG Jin-chun

    2002-01-01

    The theory of LCC (Life Cycle Cost) is applied in this paper. The relation between the economic life of weapon and the optimum replacement is analyzed. The method to define the optimum replacement time of weapon is discussed.

  2. Improvement of cylinder block line for high productivity. Koseisansei cylinder block seizo line no kakuritsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, M. (Aisin Takaoka Co. Ltd., Tokyo (Japan)); Ito, M. (Toyota Motor Corp., Aichi (Japan))

    1991-05-25

    This paper is a technical report of improvig manufacturing line in an automotive cylinder block casting factory, and enhancing the productivity. Gists of the improvement can be summarized in the following three items: Standardization of the production corresponding to product acceptance condition by the subsequent process; elimination of waste in time by means of establishing production framework, including material handling; and accumulation of small scale automations. The result was the productivity in 1989 increased by 1.2 times that in around 1975 as a result of improved rate of operation, and number of workers reduced to half, supported particularly by manpower saving in core making and finishing processes. For instance, core making machines were given size reduction in the facility and die, and multiple core making function, in which one die makes different cores for the same part. The multiple core making function, which can reduce number of machines necessary to make one cylinder block, has a large advantage not only facilitating arrangemets for small quantity production parts, but also dealing with stepwise capacity increase and eliminating the necessity of keeping spare dies. 16 figs., 1 tab.

  3. LARGE EDDY SIMULATION AND SPECTRUM ANALYSIS OF FLOW AROUND TWO SQUARE CYLINDERS ARRANGED SIDE BY SIDE

    Institute of Scientific and Technical Information of China (English)

    魏英杰; 朱蒙生; 何钟怡

    2004-01-01

    Large eddy simulation cooperated with the second order full extension ETG (Euler-Taylor-Galerkin) finite element method was applied to simulate the flow around two square cylinders arranged side by side at a spacing ratio of 1.5. The second order full extension ETG finite element method was developed by Wang and He. By means of Taylor expansion of terms containing time derivative, time derivative is replaced by space derivative. The function of it is equal to introducing an artificial viscosity term. The streamlines of the flow at different moments were obtained. The time history of drag coefficient, lift coefficient and the streamwise velocity on the symmetrical points were presented. Furthermore, the symmetrical problem of the frequency spectrum of flow around two square cylinders arranged side by side were studied by using the spectral analysis technology. The data obtained at the initial stage are excluded in order to avoid the influence of initial condition on the results. The power spectrums of drag coefficient, lift coefficient, the streamwise velocity on the symmetrical points were analyzed respectively.The results show that although the time domain process of dynamic parameters is nonsymmetrical, the frequency domain process of them is symmetrical under the symmetrical boundary conditions.

  4. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self‐funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty‐three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  5. Total disc replacement.

    Science.gov (United States)

    Vital, J-M; Boissière, L

    2014-02-01

    Total disc replacement (TDR) (partial disc replacement will not be described) has been used in the lumbar spine since the 1980s, and more recently in the cervical spine. Although the biomechanical concepts are the same and both are inserted through an anterior approach, lumbar TDR is conventionally indicated for chronic low back pain, whereas cervical TDR is used for soft discal hernia resulting in cervicobrachial neuralgia. The insertion technique must be rigorous, with precise centering in the disc space, taking account of vascular anatomy, which is more complex in the lumbar region, particularly proximally to L5-S1. All of the numerous studies, including prospective randomized comparative trials, have demonstrated non-inferiority to fusion, or even short-term superiority regarding speed of improvement. The main implant-related complication is bridging heterotopic ossification with resulting loss of range of motion and increased rates of adjacent segment degeneration, although with an incidence lower than after arthrodesis. A sufficiently long follow-up, which has not yet been reached, will be necessary to establish definitively an advantage for TDR, particularly in the cervical spine. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    HR/SOC

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. The old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015), in order to fill in a 'fiche individuelle' form, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format. The French card in their possession. An A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done...

  7. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division; Cards.Service@cern.ch

    2001-01-01

    The French Ministry of Foreign Affairs is currently replacing all diplomatic cards, special cards and employment permits («attestations de fonctions») held by members of the personnel and their families. These cards are replaced by secure, computerized equivalents. The old cards may no longer be used after 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015) between 8h30 and 12h30, in order to fill in a «fiche individuelle» form, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format, the French card in their possession, an A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done so, are also requested...

  8. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. The old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel are asked to go to the cards office (33/1-015), taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format, The French card in their possession, an A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done so, are also requested to take these items to the c...

  9. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. A 'personnel office' stamped photocopy of the old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015), between 8:30 and 12:30, in order to fill a 'fiche individuelle' form (in black ink only), which has to be personally signed by themselves and another separately signed by members of their family, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format (signed on the back) The French card in their possession an A4 photocopy of the same Fre...

  10. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University's aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  11. Faster Replacement Paths

    CERN Document Server

    Williams, Virginia Vassilevska

    2010-01-01

    The replacement paths problem for directed graphs is to find for given nodes s and t and every edge e on the shortest path between them, the shortest path between s and t which avoids e. For unweighted directed graphs on n vertices, the best known algorithm runtime was \\tilde{O}(n^{2.5}) by Roditty and Zwick. For graphs with integer weights in {-M,...,M}, Weimann and Yuster recently showed that one can use fast matrix multiplication and solve the problem in O(Mn^{2.584}) time, a runtime which would be O(Mn^{2.33}) if the exponent \\omega of matrix multiplication is 2. We improve both of these algorithms. Our new algorithm also relies on fast matrix multiplication and runs in O(M n^{\\omega} polylog(n)) time if \\omega>2 and O(n^{2+\\eps}) for any \\eps>0 if \\omega=2. Our result shows that, at least for small integer weights, the replacement paths problem in directed graphs may be easier than the related all pairs shortest paths problem in directed graphs, as the current best runtime for the latter is \\Omega(n^{2.5...

  12. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses ... of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical ...

  14. Locating Ectopic Foci on a Cylinder

    Science.gov (United States)

    Kuklik, Pawel; Zebrowski, Jan J.

    2003-07-01

    Arrhythmia is a condition in which an additional ectopic pacemaker is present in the tissue of the heart. Localization of ectopic foci is essential for successful radio-frequency ablation, an important surgical way of treating arrhythmia. In one of the possible mechanisms, arrhythmia induced by an ectopic foci located in one of the main blood vessels leading out or onto the heart. The therapeutic procedure in this case is usually ablation of the whole junction of the blood vessel with heart wall. In this way, whatever excitation occurs inside the vessel, it cannot penetrate the ventricles perturbing their contraction cycle. Such an ablation procedure is long and burdened with the risk of the perforation. A more safe method would involve the localization of the source of the excitation (i.e. the ectopic foci) and its ablation. The methods used in cardiology at present involve complicated localization systems and are time-consuming with the patient spending a long time on the operating table. Recently, Hall and Glass have developed numerical methods which allow to quickly to model the localization of the ectopic foci in a flat, square sample of an inhomogeneous medium. Here, we demonstrate an extension of this model for the case of a cylinder containing an ectopic foci, that can be a model of a blood vessel with the source of the ectopic beat inside it. Three methods of localization are implemented. Standard electrodes containing several active tips are used to stimulate the medium locally and locate the foci judging from the reaction of the system. The first one uses electrode activation times to compute the location of the ectopic site. The second one localizes it by measuring the resetting response of the foci, and the third one, uses wavefront curvature. Specifically for the cylindrical geometry of the blood vessel, we developed a localization procedure that allows to quickly localize the pacemaker.

  15. Experimental investigation of the interaction of two cylinders in the flow pattern

    Directory of Open Access Journals (Sweden)

    Vitkovičová Rut

    2015-01-01

    Full Text Available This article discusses the behaviour and interaction of two circular cylinders in the flow pattern when one of the cylinders affects wake of the second cylinder. The wake behind the cylinder was investigated experimentally by using a time resolved PIV and CTA method. Velocity fields were obtained for several regimes of Reynolds numbers and several positions of the second cylinder. A frequency of vortex shedding was gained from the acquired images.

  16. Toleration, Synthesis or Replacement?

    DEFF Research Database (Denmark)

    Holtermann, Jakob v. H.; Madsen, Mikael Rask

    2016-01-01

    to have considerable problems keeping a clear focus on the key question: What are the implications of this empirical turn in terms of philosophy of legal science, of the social understanding of IL, and, not least, of the place of doctrinal scholarship after the alleged Wende? What is needed, we argue......, in order to answer is not yet another partisan suggestion, but rather an attempt at making intelligible both the oppositions and the possibilities of synthesis between normative and empirical approaches to law. Based on our assessment and rational reconstruction of current arguments and positions, we...... therefore outline a taxonomy consisting of the following three basic, ideal-types in terms of the epistemological understanding of the interface of law and empirical studies: toleration, synthesis and replacement. This tripartite model proves useful with a view to teasing out and better articulating...

  17. The impulsive motion of a small cylinder at an interface

    Science.gov (United States)

    Vella, Dominic; Li, Jie

    2010-05-01

    We study the unsteady motion caused by an impulse acting at time t =0 on a small cylinder floating horizontally at a liquid-gas interface. This is a model for the impact of a cylinder onto a liquid surface after the initial splash. Following the impulse, the motion of the cylinder is determined by its weight per unit length (pulling it into the bulk liquid) and resistance from the liquid, which acts to keep the cylinder at the interface. The range of cylinder radii r and impact speeds U considered is such that the resistance from the liquid comes from both the interfacial tension and hydrodynamic pressures. We use two theoretical approaches to investigate this problem. In the first, we apply the arbitrary Lagrangian Eulerian (ALE) method developed by Li et al. ["An arbitrary Lagrangian Eulerian method for moving-boundary problems and its application to jumping over water," J. Comput. Phys. 208, 289 (2005)] to compute the fluid flow caused by the impulse and the (coupled) motion of the cylinder. We show that at early times the interfacial deformation is given by a family of shapes parametrized by r /t2/3. We also find that for a given density and radius there is a critical impulse speed below which the cylinder is captured by the interface and floats but above which it pierces the interface and sinks. Our second theoretical approach is a simplified one in which we assume that the interface is in equilibrium and derive an ordinary differential equation for the motion of the cylinder. Solving this we again find the existence of a critical impulse speed for sinking giving us some quantitative understanding of the results from the ALE simulations. Finally, we compare our theoretical predictions with the results of experiments for cylinder impacts by Vella and Metcalfe ["Surface tension dominated impact," Phys. Fluids 19, 072108 (2007)]. This comparison suggests that the influence of contact line effects, neglected here, may be important in the transition from floating

  18. Composite reinforced metallic cylinder for? high-speed rotation

    Science.gov (United States)

    Pradhan, Sahadev, , Dr.

    2017-01-01

    The objective of the present study is to design and development of the composite reinforced thin metallic cylinder to increase the peripheral speed significantly and thereby? improve the separation performance in a centrifugal gas separation processes through? proper optimization of the internal parameters. According to Dirac equation (Cohen? (1951)), the maximum separative work for a centrifugal gas separation process increase? with 4th power of the peripheral speed. Therefore, it has been intended to reinforce the? metallic cylinder with composites (carbon fibers: T-700 and T- 1000 grade with suitable? epoxy resin) to increase the stiffness and hoop stress so that the peripheral speed can? be increased significantly, and thereby enhance the separative output. Here, we have developed the mathematical model to investigate the elastic stresses of? a laminated cylinder subjected to mechanical, thermal and thermo-mechanical loading? A detailed analysis is carried out to underline the basic hypothesis of each formulation? Further, we evaluate the steady state creep response of the rotating cylinder and analyze? the stresses and strain rates in the cylinder.

  19. Analysis of Aerodynamic Noise Generated from Inclined Circular Cylinder

    Institute of Scientific and Technical Information of China (English)

    YasutakeHaramoto; ShoujiYasuda; 等

    2000-01-01

    Making clear the generation mechanism of fluid dynamic noise is essential to reduce noise deriving from turbomachinery.The analysis of the aerodynamic noise generated from circular cylinder is carried out numerically and experimentally in a low noise wind tunnel.in this study,aerodynamic sound radiated from a circular cylinder in uniform flow is predicted numericaslly by the following two step method,First,the three-dimensional unsteady incompressible Navier-Stokes equation is solved using the high order accurate upwind scheme.Next.the sound pressure level at the observed point is calculated from the fluctuating surface pressure on the cylinder.based on modified Lighthill-Curl's equation.It is worth to note that the noise generated from the model is reduced rapidly when it is inclined against the mean flow.In other works,the Peak level of the radiated noise decreases apidly with inclination of the circular cylinder.The simulated SPL for the inclined circular cylinder is compared with the measured value .and good agreement is obtained for the peak spectrum fequency of the sound pressue level and tendency of noise reduction,So we expect that the change of flow structures makes reduction of the aerodynamic noise from the inclined models.

  20. Analysis of aerodynamic noise generated from inclined circular cylinder

    Science.gov (United States)

    Haramoto, Yasutake; Yasuda, Shouji; Matsuzaki, Kazuyoshi; Munekata, Mizue; Ohba, Hideki

    2000-06-01

    Making clear the generation mechanism of fluid dynamic noise is essential to reduce noise deriving from turbomachinery. The analysis of the aerodynamic noise generated from circular cylinder is carried out numerically and experimentally in a low noise wind tunnel. In this study, aerodynamic sound radiated from a circular cylinder in uniform flow is predicted numerically by the following two step method. First, the three-dimensional unsteady incompressible Navier-Stokes equation is solved using the high order accurate upwind scheme. Next, the sound pressure level at the observed point is calculated from the fluctuating surface pressure on the cylinder, based on modified Lighthill-Curl’s equation. It is worth to note that the noise generated from the model is reduced rapidly when it is inclined against the mean flow. In other words, the peak level of the radiated noise decreases rapidly with inclination of the circular cylinder. The simulated SPL for the inclined circular cylinder is compared with the measured value, and good agreement is obtained for the peak spectrum frequency of the sound pressure level and tendency of noise reduction. So we expect that the change of flow structures makes reduction of the aerodynamic noise from the inclined models.

  1. Modeling flow for modified concentric cylinder rheometer geometry

    Science.gov (United States)

    Ekeruche, Karen; Connelly, Kelly; Kavehpour, H. Pirouz

    2016-11-01

    Rheology experiments on biological fluids can be difficult when samples are limited in volume, sensitive to degradation, and delicate to extract from tissues. A probe-like geometry has been developed to perform shear creep experiments on biological fluids and to use the creep response to characterize fluid material properties. This probe geometry is a modified concentric cylinder setup, where the gap is large and we assume the inner cylinder rotates in an infinite fluid. To validate this assumption we perform shear creep tests with the designed probe on Newtonian and non-Newtonian fluids and vary the outer cylinder container diameter. We have also created a numerical model based on the probe geometry setup to compare with experimental results at different outer cylinder diameters. A creep test is modeled by applying rotation to the inner cylinder and solving for the deformation of the fluid throughout the gap. Steady state viscosity values are calculated from creep compliance curves and compared between experimental and numerical results.

  2. Prediction of External Corrosion for Steel Cylinders 2001 Report

    Energy Technology Data Exchange (ETDEWEB)

    Schmoyer, RLS

    2001-09-17

    The United States Department of Energy (DOE) currently manages the UF{sub 6} Cylinder Project. The project was formed to maintain and safely manage the depleted uranium hexafluoride (UF{sub 6}) stored in approximately 50,000 carbon steel cylinders. The cylinders are located at three DOE sites: the ETTP site (K-25) at Oak Ridge, Tennessee; the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The System Requirements Document (SRD) (LMES 1997a) delineates the requirements of the project. The appropriate actions needed to fulfill these requirements are then specified within the System Engineering Management Plan (SEMP) (LMES 1997b). This report documents activities that in whole or in part satisfy specific requirements and actions stated in the UF{sub 6} Cylinder Project SRD and SEMP with respect to forecasting cylinder conditions. The results presented here supercede those presented previously (Lyon 1995, 1996, 1997, 1998, 2000). Many of the wall thickness projections made in this report are conservative, because they are based on the assumption that corrosion trends will continue, despite activities such as improved monitoring, relocations to better storage, and painting.

  3. Flow around a semicircular cylinder with passive flow control mechanisms

    Science.gov (United States)

    Hamed, A. M.; Vega, J.; Liu, B.; Chamorro, L. P.

    2017-03-01

    Wind tunnel experiments were performed to study the effect of passive flow control strategies on the wake and drag of a semicircular cylinder of infinite aspect ratio. High-resolution planar particle image velocimetry was used to obtain flow statistics around the semicircular cylinder at Reynolds number Re≈ 3.2× 10^4 based on the cylinder diameter. The control mechanisms under consideration include rigid flaps of various lengths placed at the edges of the structure and a small slot along the symmetry plane of the cylinder. Mean velocity fields reveal the distinctive effects of each passive mechanism on the flow, such as velocity recovery, size of the recirculation bubble and location of the reattachment point. The distributions of turbulence kinetic energy and kinematic shear stress show the modulation of each passive control mechanism on the wake, including the onset and location of the maximum turbulence levels. Instantaneous and mean fields of swirling strength further highlight the role of the passive mechanisms in the vortex dynamics. Drag coefficient for the various cases was estimated indirectly from the flow measurements using a momentum balance. This approach shows that long flaps and slot were able to reduce drag with respect to the base case. The rigid flaps with length coincident with the diameter of the cylinder offered the best performance with drag reduction of ˜25%.

  4. Performance of a Horizontal Triple Cylinder Type Pulping Machine

    Directory of Open Access Journals (Sweden)

    Sukrisno Widyotomo

    2011-05-01

    Full Text Available Pulping is one important step in wet coffee processing method. Pulping process usually uses a machine which constructed by wood or metal materials. A horizontal single cylinder type of fresh coffee cherries pulping machine is the most popular machine in coffee processing. One of the weaknesses of a horizontal single cylinder type of fresh coffee cherries pulping machine is higher in broken beans. Broken bean is one of mayor aspects in defect system that contribute to low quality. Indonesian Coffee and Cocoa Research Institute has designed and tested a horizontal double cylinder type of fresh coffee cherries pulping machine which resulted in 12.6—21.4% of broken beans. To reduce percentage of broken beans, Indonesian Coffee and Cocoa Research Institute has developed and tested a horizontal triple cylinder type of fresh coffee cherries pulping machine. Material tested was fresh mature Robusta coffee cherries, 60—65% (wet basis moisture content; has classified on 3 levels i.e. unsorted, small and medium, and clean from metal and foreign materials. The result showed that the machine produced 6,340 kg/h in optimal capacity for operational conditions, 1400 rpm rotor rotation speed for unsorted coffee cherries with composition 55.5% whole parchment coffee, 3.66% broken beans, and 1% beans in wet skin.Key words : coffee, pulp, pulper, cylinder, quality.

  5. Mechanism of Secondary Instability of Flow around a Circular Cylinder

    Science.gov (United States)

    Dou, Hua-Shu; Ben, An-Qing; Fluid Mechanics Research Team Team

    2016-11-01

    Flow around a circular cylinder in infinite domain is simulated with large eddy simulation at Re =200, and the mechanism of the origin of secondary vortex street is analyzed. The simulation results show that the vortex street generated in the cylinder near wake disappears as the flow moving downstream. Secondary instability occurs in far wake of the cylinder after the primary vortex street dying away. The processes of first instability and secondary instability in the cylinder wake are recorded in the simulation. The instability of the entire flow field is studied with the energy gradient theory. It is found that it is the high value of the energy gradient function generated by the zero velocity gradients that leads to the instability. As the vortex developing at rear of the cylinder, the value of the energy gradient function becomes low downstream, which leads to the vortex dying away. At further downstream, the value of the energy gradient function is enlarged again because of the role of perturbation, which leads to the secondary instability. It can be concluded that the interaction of the variation of the value of the energy gradient function and the perturbation leads to the occurrence of secondary instability.

  6. Study of the wake flow around a circular cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Sung; Kim, Sang Il; Seung, Sam Sun [Kangwon National University, Chuncheon (Korea, Republic of)

    2015-11-15

    This experimental study investigated the wake flow around an elastically supported circular cylinder. In this study, the Reynolds numbers are varied in the region of 1.4x10{sup 4}≤Re≤3.2x10{sup 4}. Under these conditions, we have captured the process of the wake mechanism and the moving path of the vortex by measuring the velocity at each position in the wake around the cylinder. Further, these facts from the wind tunnel test are proved by a flow visualization test through a water channel. From the result, we have arrived at the following conclusions : i) The process (formationgrowthcollapse) of vortex is observed in the wake around the cylinder, ii) The vortex efflux angle is approximately 16 degrees⁓17 degrees under the experimental conditions. These angles have no relationship with the velocity change and the existence of flow-induced vibrations of the cylinder, and iii) The moving path of the vortex center is obtained by spectrum analysis of the fluctuating velocity behind the cylinder. These are confirmed by conducting visualization tests.

  7. Spatial damping of propagating sausage waves in coronal cylinders

    Science.gov (United States)

    Guo, Ming-Zhe; Chen, Shao-Xia; Li, Bo; Xia, Li-Dong; Yu, Hui

    2015-09-01

    Context. Sausage modes are important in coronal seismology. Spatially damped propagating sausage waves were recently observed in the solar atmosphere. Aims: We examine how wave leakage influences the spatial damping of sausage waves propagating along coronal structures modeled by a cylindrical density enhancement embedded in a uniform magnetic field. Methods: Working in the framework of cold magnetohydrodynamics, we solve the dispersion relation (DR) governing sausage waves for complex-valued, longitudinal wavenumber k at given real angular frequencies ω. For validation purposes, we also provide analytical approximations to the DR in the low-frequency limit and in the vicinity of ωc, the critical angular frequency separating trapped from leaky waves. Results: In contrast to the standing case, propagating sausage waves are allowed for ω much lower than ωc. However, while able to direct their energy upward, these low-frequency waves are subject to substantial spatial attenuation. The spatial damping length shows little dependence on the density contrast between the cylinder and its surroundings, and depends only weakly on frequency. This spatial damping length is of the order of the cylinder radius for ω ≲ 1.5vAi/a, where a and vAi are the cylinder radius and the Alfvén speed in the cylinder, respectively. Conclusions: If a coronal cylinder is perturbed by symmetric boundary drivers (e.g., granular motions) with a broadband spectrum, wave leakage efficiently filters out the low-frequency components.

  8. Hydrogen Bubbles as a Visualization Tool for Cylinder Shedding

    Science.gov (United States)

    Sigurdson, Lorenz; Gilbert, Stuart

    2004-11-01

    We examine the behavior of hydrogen bubbles formed by electrolysis of water on a 2.54 mm cylindrical electrode in a water tunnel. The Reynolds Number based on cylinder diameter varies from 400 to 1100, and tunnel velocities range from 17 to 50 cm/s. At the lowest velocity buoyancy is a strong effect which inhibits accurate flow tracking by the bubbles. This effect largely disappears by 25 cm/s. As the tunnel velocity increases, bubble size decreases, reflected light for photography is reduced, and bubbles begin to track the von Karman vortex street vortex cores near the cylinder. The vortex cores have a sufficiently low pressure to capture the bubbles. Vortex street wavelength is seen to discretely increase as vortices proceed downstream. The location of this scale-change becomes nearer the cylinder as Re increases. Voids of bubbles occur in continuous linear downstream segments originating near the cylinder. They seem to be due to vortex modification in the wake similar to what other cylinder shedding researchers have found.

  9. Numerical simulation of low-Reynolds number flows past two tandem cylinders of different diameters

    Directory of Open Access Journals (Sweden)

    Yong-tao WANG

    2013-10-01

    Full Text Available The flow past two tandem circular cylinders of different diameters was simulated using the ?nite volume method. The diameter of the downstream main cylinder (D was kept constant, and the diameter of the upstream control cylinder (d varied from 0.1D to D. The studied Reynolds numbers based on the diameter of the downstream main cylinder were 100 and 150. The gap between the control cylinder and the main cylinder (G ranged from 0.1D to 4D. It is concluded that the gap-to-diameter ratio (G/D and the diameter ratio between the two cylinders (d/D have important effects on the drag and lift coef?cients, pressure distributions around the cylinders, vortex shedding frequencies from the two cylinders, and ?ow characteristics.

  10. Electromagnetic Casimir Forces of Parabolic Cylinder and Knife-Edge Geometries

    CERN Document Server

    Graham, Noah; Emig, Thorsten; Rahi, Sahand Jamal; Jaffe, Robert L; Kardar, Mehran

    2011-01-01

    An exact calculation of electromagnetic scattering from a perfectly conducting parabolic cylinder is employed to compute Casimir forces in several configurations. These include interactions between a parabolic cylinder and a plane, two parabolic cylinders, and a parabolic cylinder and an ordinary cylinder. To elucidate the effect of boundaries, special attention is focused on the "knife-edge" limit in which the parabolic cylinder becomes a half-plane. Geometrical effects are illustrated by considering arbitrary rotations of a parabolic cylinder around its focal axis, and arbitrary translations perpendicular to this axis. A quite different geometrical arrangement is explored for the case of an ordinary cylinder placed in the interior of a parabolic cylinder. All of these results extend simply to nonzero temperatures.

  11. Head and Neck

    DEFF Research Database (Denmark)

    Højgaard, Liselotte; Berthelsen, Anne Kiil; Loft, Annika

    2014-01-01

    Positron emission tomography (PET)/computed tomography with FDG of the head and neck region is mainly used for the diagnosis of head and neck cancer, for staging, treatment evaluation, relapse, and planning of surgery and radio therapy. This article is a practical guide of imaging techniques......, including a detailed protocol for FDG PET in head and neck imaging, physiologic findings, and pitfalls in selected case stories....

  12. Iron replacement therapy

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Coskun, Mehmet; Weiss, Günter

    2016-01-01

    PURPOSE OF REVIEW: Approximately, one-third of the world's population suffers from anemia, and at least half of these cases are because of iron deficiency. With the introduction of new intravenous iron preparations over the last decade, uncertainty has arisen when these compounds should be admini...... treatment, when to follow-up for relapse, which dosage and type of therapy should be recommended or not recommended, and if some patients should not be treated....... be administered and under which circumstances oral therapy is still an appropriate and effective treatment. RECENT FINDINGS: Numerous guidelines are available, but none go into detail about therapeutic start and end points or how iron-deficiency anemia should be best treated depending on the underlying cause...... of iron deficiency or in regard to concomitant underlying or additional diseases. SUMMARY: The study points to major issues to be considered in revisions of future guidelines for the true optimal iron replacement therapy, including how to assess the need for treatment, when to start and when to stop...

  13. Numerical and Experimental Investigation of Circulation in Short Cylinders

    CERN Document Server

    Kageyama, A; Goodman, J; Chen, F; Shoshan, E; Kageyama, Akira; Ji, Hantao; Goodman, Jeremy; Chen, Fei; Shoshan, Ethan

    2004-01-01

    In preparation for an experimental study of magnetorotational instability (MRI) in liquid metal, we explore Couette flows having height comparable to the gap between cylinders, centrifugally stable rotation, and high Reynolds number. Experiments in water are compared with numerical simulations. Simulations show that endcaps corotating with the outer cylinder drive a strong poloidal circulation that redistributes angular momentum. Predicted azimuthal flow profiles agree well with experimental measurements. Spin-down times scale with Reynolds number as expected for laminar Ekman circulation; extrapolation from two-dimensional simulations at $Re\\le 3200$ agrees remarkably well with experiment at $Re\\sim 10^6$. This suggests that turbulence does not dominate the effective viscosity. Further detailed numerical studies reveal a strong radially inward flow near both endcaps. After turning vertically along the inner cylinder, these flows converge at the midplane and depart the boundary in a radial jet. To minimize th...

  14. Actuator placement for active sound and vibration control of cylinders

    Science.gov (United States)

    Kincaid, Rex K.

    1995-01-01

    Active structural acoustic control is a method in which the control inputs (used to reduce interior noise) are applied directly to a vibrating structural acoustic system. The control concept modeled in this work is the application of in-plane force inputs to piezoceramic patches bonded to the wall of a vibrating cylinder. The cylinder is excited by an exterior noise source -- an acoustic monopole -- located near the outside of the cylinder wall. The goal is to determine the force inputs and sites for the piezoelectric actuators so that (1) the interior noise is effectively damped; (2) the level of vibration of the cylinder shell is not increased; and (3) the power requirements needed to drive the actuators are not excessive. We studied external monopole excitations at two frequencies. A cylinder resonance of 100 Hz, where the interior acoustic field is driven in multiple, off-resonance cylinder cavity modes, and a cylinder resonance of 200 Hz are characterized by both near and off-resonance cylinder vibration modes which couple effectively with a single, dominant, low-order acoustic cavity mode at resonance. Previous work has focused almost exclusively on meeting objective (1) and solving a complex least-squares problem to arrive at an optimal force vector for a given set of actuator sites. In addition, it has been noted that when the cavity mode couples with cylinder vibration modes (our 200 Hz case) control spillover may occur in higher order cylinder shell vibrational modes. How to determine the best set of actuator sites to meet objectives (1)-(3) is the main contribution of our research effort. The selection of the best set of actuator sites from a set of potential sites is done via two metaheuristics -- simulated annealing and tabu search. Each of these metaheuristics partitions the set of potential actuator sites into two disjoint sets: those that are selected to control the noise (on) and those that are not (off). Next, each metaheuristic attempts to

  15. Thermo-Mechanical Analyses of Dynamically Loaded Rubber Cylinders

    Science.gov (United States)

    Johnson, Arthur R.; Chen, Tzi-Kang

    2002-01-01

    Thick rubber components are employed by the Army to carry large loads. In tanks, rubber covers road wheels and track systems to protect roadways. It is difficult for design engineers to simulate the details of the hysteretic heating for large strain viscoelastic deformations. In this study, an approximation to the viscoelastic energy dissipated per unit time is investigated for use in estimating mechanically induced viscoelastic heating. Coupled thermo-mechanical simulations of large cyclic deformations of rubber cylinders are presented. The cylinders are first compressed axially and then cyclically loaded about the compressed state. Details of the algorithm and some computational issues are discussed. The coupled analyses are conducted for tall and short rubber cylinders both with and without imbedded metal disks.

  16. Stirring by multi-cylinder in potential flow

    CERN Document Server

    Zhang, Yuanzhao

    2014-01-01

    We analyze the mixing efficiency of multiple-cylinder in potential flow to assess the effect of schooling in ocean-biomixing. The model is a generalization of Thiffeault & Childress's work [Physics Letters A 374, 3487 (2010)], where fluid particle displacements due to a single inviscid swimmer were analyzed to produce an effective diffusivity. Here we climb the population ladder to see how the interaction among swimmers would influence the motion of particles in the flow. Two cylinders moving synchronously through the flow in various angles and separations were studied, with several important patterns revealed---when the separation is small (less than $\\frac{1}{3}$ body length), two cylinders moving side-by-side ($\\theta=\\pi/2$) has the highest mixing efficiency, while the chasing configuration ($\\theta=0$) takes over for larger separations. But regardless of the angle and separation, the normalized effective diffusivity is constantly higher than single-swimmer value, which indicates schooling effect as a...

  17. Casimir effect at nonzero temperature for wedges and cylinders

    CERN Document Server

    Ellingsen, Simen Å; Milton, Kimball A

    2010-01-01

    We consider the Casimir-Helmholtz free energy at nonzero temperature $T$ for a circular cylinder and perfectly conducting wedge closed by a cylindrical arc, either perfectly conducting or isorefractive. The energy expression at nonzero temperature may be regularized to obtain a finite value, except for a singular corner term in the case of the wedge which is present also at zero temperature. Assuming the medium in the interior of the cylinder or wedge be nondispersive with refractive index $n$, the temperature dependence enters only through the non-dimensional parameter $2\\pi naT$, $a$ being the radius of the cylinder or cylindrical arc. We show explicitly that the known zero temperature result is regained in the limit $aT\\to 0$ and that previously derived high temperature asymptotics for the cylindrical shell are reproduced exactly.

  18. Chaos Control in the Wake of an Oscillating Cylinder

    Science.gov (United States)

    Balasubramanian, Ganapathi R.; Olinger, David J.

    1997-11-01

    The nonlinear dynamics of vortex shedding behind circular cylinders are investigated using a previously developed spatial-temporal map lattice. The map studied consists of a series of circle map oscillators placed along the cylinder span coupled with a simple diffusion model. Chaotic states associated with disordered vortex shedding patterns are observed when forcing the cylinder outside the classical lock-on region. These are controlled through application of a small-amplitude periodic perturbation of a system parameter, as proposed by Ott, Grebogi, and Yorke. Periodic lace-like structures and parallel shedding patterns are realized by driving the chaotic system to the desired target state. A wide range of forcing frequency-amplitude combinations are studied along with manipulation of vortex lock-on region extents. Preliminary extensions of these chaos control techniques to a two-dimensional wake flow using finite element techniques are also discussed.

  19. Instability of Taylor-Couette Flow between Concentric Rotating Cylinders

    CERN Document Server

    Dou, H S; Phan-Thien, N; Yeo, K S; Dou, Hua-Shu; Khoo, Boo Cheong; Phan-Thien, Nhan; Yeo, Koon Seng

    2005-01-01

    The energy gradient theory is used to study the instability of Taylor-Couette flow between concentric rotating cylinders. In our previous studies, the energy gradient theory was demonstrated to be applicable for wall bounded parallel flows. It was found that the critical value of the energy gradient parameter K at subcritical transition is about 370-389 for wall bounded parallel flows (which include plane Poiseuille flow, pipe Poiseuille flow and plane Couette flow) below which no turbulence occurs. In this paper, the detailed derivation for the calculation of the energy gradient parameter in the flow between concentric rotating cylinders is provided. The theoretical results for the critical condition of primary instability obtained are in very good agreement with the experiments found in literature. The mechanism of spiral vortices generation for counter-rotating of two cylinders is also explained using the energy gradient theory. The energy gradient theory can also serve to relate the condition of flow tran...

  20. Stitching interferometry of a full cylinder without using overlap areas

    Science.gov (United States)

    Peng, Junzheng; Chen, Dingfu; Yu, Yingjie

    2017-08-01

    Traditional stitching interferometry requires finding out the overlap correspondence and computing the discrepancies in the overlap regions, which makes it complex and time-consuming to obtain the 360° form map of a cylinder. In this paper, we develop a cylinder stitching model based on a new set of orthogonal polynomials, termed Legendre Fourier (LF) polynomials. With these polynomials, individual subaperture data can be expanded as a composition of the inherent form of a partial cylinder surface and additional misalignment parameters. Then the 360° form map can be acquired by simultaneously fitting all subaperture data with the LF polynomials. A metal shaft was measured to experimentally verify the proposed method. In contrast to traditional stitching interferometry, our technique does not require overlapping of adjacent subapertures, thus significantly reducing the measurement time and making the stitching algorithm simple.

  1. Image analysis of moving seeds in an indented cylinder

    DEFF Research Database (Denmark)

    Buus, Ole; Jørgensen, Johannes Ravn

    2010-01-01

    -Spline surfaces. Using image analysis, the seeds will be tracked using a kalman filter and the 2D trajectory, length, velocity, weight, and rotation will be sampled. We expect a high correspondence between seed length and certain spatially optimal seed trajectories. This work is done in collaboration with Westrup...... threshold. The threshold is dependent on a number of different parameters. Besides the seed length, the rotation, general size, shape, and surface texture of each seed, are also known to influence the final sorting result. Such knowledge comes from previous experimentation with the indented cylinder. In our...... work we will seek to understand more about the internal dynamics of the indented cylinder. We will apply image analysis to observe the movement of seeds in the indented cylinder. This work is laying the groundwork for future studies into the application of image analysis as a tool for autonomous...

  2. Heat of detonation, the cylinder test, and performance munitions

    Energy Technology Data Exchange (ETDEWEB)

    Akst, I.B.

    1989-01-01

    Heats of detonation of CHNO explosives correlate well with copper cylinder test expansion data. The detonation products/calorimetry data can be used to estimate performance in the cylinder test, in munitions, and for new molecules or mixtures of explosives before these are made. Confidence in the accuracy of the performance estimates is presently limited by large deviations of a few materials from the regression predictions; but these same deviations, as in the insensitive explosive DINGU and the low carbon systems, appear to be sources of information useful for detonation and explosives research. The performance correlations are functions more of the detonation products and thermochemical energy than they are of the familiar parameters of detonation pressure and velocity, and the predictions are closer to a regression line on average than are those provided by CJ calculations. The prediction computations are simple but the measurements (detonation calorimetry/products and cylinder experiments) are not. 17 refs., 5 tabs.

  3. Filament winding cylinders. II - Validation of the process model

    Science.gov (United States)

    Calius, Emilio P.; Lee, Soo-Yong; Springer, George S.

    1990-01-01

    Analytical and experimental studies were performed to validate the model developed by Lee and Springer for simulating the manufacturing process of filament wound composite cylinders. First, results calculated by the Lee-Springer model were compared to results of the Calius-Springer thin cylinder model. Second, temperatures and strains calculated by the Lee-Springer model were compared to data. The data used in these comparisons were generated during the course of this investigation with cylinders made of Hercules IM-6G/HBRF-55 and Fiberite T-300/976 graphite-epoxy tows. Good agreement was found between the calculated and measured stresses and strains, indicating that the model is a useful representation of the winding and curing processes.

  4. Heat transfer in a conical porous cylinder with partial heating

    Science.gov (United States)

    Yunus Khan, T. M.; Anjum Badruddin, Irfan; Quadir, G. A.

    2016-09-01

    The current work simulates the heat transfer across a porous medium fixed in an annular conical cylinder. The geometry is such that the lower part is conical annulus supporting a regular annular cylinder. The porous medium is fixed between inner and outer radius of conical annular cylinder. The inner radius until conical section is heated with constant temperature Th whereas the outer radius is cooled to isothermal temperature Tc such that Th>Tc . The heat transfer phenomenon in this case can be described by two coupled partial differential equations which are solved using finite element method by using 3-node triangular elements. The heat transfer characteristics in this case are quite different from other geometries being discussed in the literature. It is observed that the fluid flow is stronger in the conical section as compared to the cylindrical part of porous geometry. A very few isothermal lines penetrate into the cylindrical porous region as compared to that of conical section.

  5. Sensitivity analysis of small circular cylinders as wake control

    Science.gov (United States)

    Meneghini, Julio; Patino, Gustavo; Gioria, Rafael

    2016-11-01

    We apply a sensitivity analysis to a steady external force regarding control vortex shedding from a circular cylinder using active and passive small control cylinders. We evaluate the changes on the flow produced by the device on the flow near the primary instability, transition to wake. We numerically predict by means of sensitivity analysis the effective regions to place the control devices. The quantitative effect of the hydrodynamic forces produced by the control devices is also obtained by a sensitivity analysis supporting the prediction of minimum rotation rate. These results are extrapolated for higher Reynolds. Also, the analysis provided the positions of combined passive control cylinders that suppress the wake. The latter shows that these particular positions for the devices are adequate to suppress the wake unsteadiness. In both cases the results agree very well with experimental cases of control devices previously published.

  6. Optimal control of circular cylinder wakes using long control horizons

    CERN Document Server

    Flinois, Thibault L B

    2015-01-01

    The classical problem of minimizing the drag of a circular cylinder by using body rotation is revisited in an adjoint-based optimal control framework. The cylinder's unsteady and fully unconstrained rotation rate is optimized at Reynolds numbers of 100 and 200 and over horizons that are longer than in previous studies, where they are typically of the order of a vortex shedding period or shorter. In the best configuration, the drag is reduced by $19\\%$, the vortex shedding is effectively suppressed, and this low drag state is maintained with minimal cylinder rotation after transients. Without closed-loop control, which maintains a specific phase relationship between the actuation and the shedding, the wake is not stabilized. A comparison is also given between the performance of optimizations for different horizon lengths and cost functions. It is shown that the long horizons used are necessary in order to stabilize the vortex shedding efficiently.

  7. Efficient manipulation of graphene absorption by a simple dielectric cylinder.

    Science.gov (United States)

    Xiao, Ting-Hui; Gan, Lin; Li, Zhi-Yuan

    2015-07-27

    We theoretically study the absorption property of graphene manipulated by a dielectric cylinder through an analytical method. The distinctive absorption properties of incident waves with different polarizations (TM and TE) are analyzed and they are strongly correlated with the structure resonance and material dispersion. Besides, the characteristics of graphene absorption tuned by the cylinder radius and refractive index as well as the chemical potential of graphene are systematically investigated. It is found that enhancement and continuous tunability of graphene absorption can be achieved by utilizing the whispering gallery mode produced in the dielectric cylinder and harnessing the graphene optical conductivity via tuning its chemical potential by exterior electrical grating. The theoretical studies open up a simple while efficient means to manipulate the absorption of graphene in a broad frequency range via the geometric and physical configuration of hybrid graphene-microstructures.

  8. Fast transforms for rapid isolation of misfiring cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Rizzoni, G.

    1987-01-01

    This paper presents a method for the isolation of misfiring cylinders in an internal combustion engine. The method is based on the measurement of the extrema of engine angular velocity. It has been shown that a number of indices can be derived from such a measurement, to provide an indication of engine performance degradation. In this study, an onboard microprocessor-based instrument samples the extrema of the engine velocity waveform in real time, generating an N or 2N vector representing each engine cycle, where N is the number of cylinders. The system is capable of detecting individual or multiple cylinder misfires, both complete and partial. Experimental verification has been carried out in a passenger vehicle. The intent of this paper is to outline the theory underlying the method, and to demonstrate its feasibility by performing some simple experiments on a production engine.

  9. Measurement of the flow past a cactus-inspired cylinder

    Science.gov (United States)

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

    2012-11-01

    Desert cacti are tall cylindrical plants characterized by longitudinal u- or v-shaped grooves that run parallel to the plant axis, covering its surface area. We study the wake flow modifications resulting from the introduction of cactus-inspired surface grooves to a circular cylinder. Particle image velocimetry PIV is implemented in a wind tunnel to visualize and quantify the wake flow from a cactus cylinder in cross wind and an equivalent circular cylinder at Re O(1E5). The cactus wake exhibits superior behavior over its circular counterpart as seen from the mean and turbulent velocity profiles. The surface flow within the grooves is also probed to elucidate the origins of the wake alterations. Lastly, we use simple statistical analysis based only on the wake velocity fields, under the assumption of periodicity of the shedding, to recover the time varying flow from the randomly acquired PIV snapshots.

  10. The Working Mechanism and An Analytic Method of the Deep Embedded Large Cylinder Structure

    Institute of Scientific and Technical Information of China (English)

    孙克俐; 周锡礽; 钱荣

    2004-01-01

    The large cylinder is a new-type structure that has been applied to harbor and offshore engineering. An analytic method of the relationship between loads and the structure displacement is developed based on the failure mode of deep embedded large cylinder structures. It can be used to calculate directly the soil resistance and the ultimate bearing capacity of the structure under usage. A new criterion of the large cylinder structure, which discriminates the deep embedded cylinder from the shallow embedded cylinder, is defined. Model tests prove that the proposed method is feasible for the analysis of deep embedded large cylinder structures.

  11. Pulsatility role in cylinder flow dynamics at low Reynolds number

    KAUST Repository

    Qamar, Adnan

    2012-01-01

    We present dynamics of pulsatile flow past a stationary cylinder characterized by three non-dimensional parameters: the Reynolds number (Re), non-dimensional amplitude (A) of the pulsatile flow velocity, and Keulegan-Carpenter number (KC = Uo/Dωc). This work is motivated by the development of total artificial lungs (TAL) device, which is envisioned to provide ambulatory support to patients. Results are presented for 0.2 ≤ A ≤ 0.6 and 0.57 ≤ KC ≤ 2 at Re = 5 and 10, which correspond to the operating range of TAL. Two distinct fluid regimes are identified. In both regimes, the size of the separated zone is much greater than the uniform flow case, the onset of separation is function of KC, and the separation vortex collapses rapidly during the last fraction of the pulsatile cycle. The vortex size is independent of KC, but with an exponential dependency on A. In regime I, the separation point remains attached to the cylinder surface. In regime II, the separation point migrates upstream of the cylinder. Two distinct vortex collapse mechanisms are observed. For A < 0.4 and all KC and Re values, collapse occurs on the cylinder surface, whereas for A > 0.4 the separation vortex detaches from the cylinder surface and collapses at a certain distance downstream of the cylinder. The average drag coefficient is found to be independent of A and KC, and depends only on Re. However, for A > 0.4, for a fraction of the pulsatile cycle, the instantaneous drag coefficient is negative indicating a thrust production. © 2012 American Institute of Physics.

  12. Vortex shedding noise of a cylinder with hairy flaps

    Science.gov (United States)

    Kamps, Laura; Geyer, Thomas F.; Sarradj, Ennes; Brücker, Christoph

    2017-02-01

    This study describes the modification of acoustic noise emitted from cylinders in a stationary subsonic flow for a cylinder equipped with flexible hairy flaps at the aft part as a passive way to manipulate the flow and acoustics. The study was motivated by the results from previous water tunnel measurements, which demonstrated that hairy flaps can modify the shedding cycle behind the cylinder and can reduce the wake deficit. In the present study, wind tunnel experiments were conducted on such a modified cylinder and the results were compared to the reference case of a plain cylinder. The acoustic spectrum was measured using two microphones while simultaneously recording the flap motion. To further examine the flow structures in the downstream vicinity of the cylinder, constant temperature anemometry measurements as well as flow visualizations were also performed. The results show that, above a certain Reynolds number, the hairy flaps lead to a jump in the vortex shedding frequency. This phenomenon is similarly observed in the water flow experiments as a jump in the non-dimensional Strouhal number that is related to the change of the shedding cycle. This jump appears to be coupled to a resonant excitation of the flaps. The specific Reynolds number at which the jump occurs is higher in the present case, which is attributed to the lower added mass in air as compared with the one in water. The flow visualizations confirmed that such action of the flaps lead to a more slender elongated shape of the time-averaged separation bubble. In addition, the hairy flaps induce a noticeable reduction of the tonal noise as well as broadband noise as long as the flaps do not touch each other.

  13. Stratified spin-up in a sliced, square cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Munro, R. J. [Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Foster, M. R. [Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2014-02-15

    We previously reported experimental and theoretical results on the linear spin-up of a linearly stratified, rotating fluid in a uniform-depth square cylinder [M. R. Foster and R. J. Munro, “The linear spin-up of a stratified, rotating fluid in a square cylinder,” J. Fluid Mech. 712, 7–40 (2012)]. Here we extend that analysis to a “sliced” square cylinder, which has a base-plane inclined at a shallow angle α. Asymptotic results are derived that show the spin-up phase is achieved by a combination of the Ekman-layer eruptions (from the perimeter region of the cylinder's lid and base) and cross-slope-propagating stratified Rossby waves. The final, steady state limit for this spin-up phase is identical to that found previously for the uniform depth cylinder, but is reached somewhat more rapidly on a time scale of order E{sup −1/2}Ω{sup −1}/log (α/E{sup 1/2}) (compared to E{sup −1/2}Ω{sup −1} for the uniform-depth cylinder), where Ω is the rotation rate and E the Ekman number. Experiments were performed for Burger numbers, S, between 0.4 and 16, and showed that for S≳O(1), the Rossby modes are severely damped, and it is only at small S, and during the early stages, that the presence of these wave modes was evident. These observations are supported by the theory, which shows the damping factors increase with S and are numerically large for S≳O(1)

  14. Low head, high volume pump apparatus

    Science.gov (United States)

    Avery, Don E.; Young, Bryan F.

    1989-01-01

    An inner cylinder and a substantially larger outer cylinder are joined as two verticle concentric cylinders. Verticle partitions between the cylinders divide the space between the cylinders into an inlet chamber and an outlet chamber which is substantially larger in volume than the inner chamber. The inner cylinder has a central pumping section positioned between upper and lower valve sections. In the valve section ports extend through the inner cylinder wall to the inlet and outlet chambers. Spring loaded valves close the ports. Tension springs extend across the inlet chamber and compression springs extend across the inner cylinder to close the inlet valves. Tension springs extend across the inner cylinder the close the outlet valves. The elastomeric valve flaps have rigid curved backing members. A piston rod extends through one end cover to move a piston in the central section. An inlet is connected to the inlet chamber and an outlet is connected to the outlet chamber.

  15. Assembly for electrical conductivity measurements in the piston cylinder device

    Science.gov (United States)

    Watson, Heather Christine [Dublin, CA; Roberts, Jeffrey James [Livermore, CA

    2012-06-05

    An assembly apparatus for measurement of electrical conductivity or other properties of a sample in a piston cylinder device wherein pressure and heat are applied to the sample by the piston cylinder device. The assembly apparatus includes a body, a first electrode in the body, the first electrode operatively connected to the sample, a first electrical conductor connected to the first electrode, a washer constructed of a hard conducting material, the washer surrounding the first electrical conductor in the body, a second electrode in the body, the second electrode operatively connected to the sample, and a second electrical conductor connected to the second electrode.

  16. Image analysis of moving seeds in an indented cylinder

    DEFF Research Database (Denmark)

    Buus, Ole; Jørgensen, Johannes Ravn

    2010-01-01

    -Spline surfaces. Using image analysis, the seeds will be tracked using a kalman filter and the 2D trajectory, length, velocity, weight, and rotation will be sampled. We expect a high correspondence between seed length and certain spatially optimal seed trajectories. This work is done in collaboration with Westrup...... work we will seek to understand more about the internal dynamics of the indented cylinder. We will apply image analysis to observe the movement of seeds in the indented cylinder. This work is laying the groundwork for future studies into the application of image analysis as a tool for autonomous...

  17. Nonlinear Fracture Mechanics and Plasticity of the Split Cylinder Test

    DEFF Research Database (Denmark)

    Olesen, John Forbes; Østergaard, Lennart; Stang, Henrik

    2006-01-01

    demonstrates the influence of varying geometry or constitutive properties. For a split cylinder test in load control it is shown how the ultimate load is either plasticity dominated or fracture mechanics dominated. The transition between the two modes is related to changes in geometry or constitutive......The split cylinder testis subjected to an analysis combining nonlinear fracture mechanics and plasticity. The fictitious crack model is applied for the analysis of splitting tensile fracture, and the Mohr-Coulomb yield criterion is adopted for modelling the compressive crushing/sliding failure. Two...

  18. Topology of vortex creation in the cylinder wake

    DEFF Research Database (Denmark)

    Brøns, Morten; Bisgaard, Anders Villefrance

    2010-01-01

    We analyze the topology of the two-dimensional flow around a circular cylinder at moderate Reynolds numbers in the regime where the vortex wake is created. A normal form for the stream function close to the cylinder is presented and used to predict the streamline pattern both in the steady...... and the periodic regime, where two different vortex shedding scenarios are identified. The theoretical predictions are verified numerically. For the vorticity, a very different topology occurs with infinite nested sequences of iso-curves moving downstream. General equations of motion for critical points...

  19. Design guide for single circular cylinder in turbulent crossflow. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Mulcahy, T.M.

    1982-03-01

    A design procedure is proposed for predicting the dynamic structural response of a circular cylinder in turbulent crossflow. The procedure is based on recently obtained data for a stationary, rigid cylinder and on existing information. The procedure is not applicable to conditions where the wake vortex shedding frequency locks into a structural natural frequency. This report is self-contained in that all the information and structural analysis methods employed in the procedure are reviewed and developed. Also, an example is given to illustrate the use of the method for a typical reactor component. The calculated responses are found to be very small.

  20. Four-Cylinder Stirling-Engine Computer Program

    Science.gov (United States)

    Daniele, C. J.; Lorenzo, C. F.

    1986-01-01

    Computer program developed for simulating steady-state and transient performance of four-cylinder Stirling engine. In model, four cylinders interconnected by four working spaces. Each working space contains seven volumes: one for expansion space, heater, cooler, and compression space and three for regenerator. Thermal time constant for regenerator mass associated with each regenator gas volume. Former code generates results very quickly, since it has only 14 state variables with no energy equation. Current code then used to study various aspects of Stirling engine in much more detail. Program written in FORTRAN IV for use on IBM 370 computer.

  1. Plasmonic modes and extinction properties of a random nanocomposite cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Basic Sciences, Kermanshah University of Technology, Kermanshah, Iran and Department of Nano Science, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

    2014-04-15

    We study the properties of surface plasmon-polariton waves of a random metal-dielectric nanocomposite cylinder, consisting of bulk metal embedded with dielectric nanoparticles. We use the Maxwell-Garnett formulation to model the effective dielectric function of the composite medium and show that there exist two surface mode bands. We investigate the extinction properties of the system, and obtain the dependence of the extinction spectrum on the nanoparticles’ shape and concentration as well as the cylinder radius and the incidence angle for both TE and TM polarization.

  2. An experiment in heat conduction using hollow cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno, M; Marquez, A; Gallego, S; Neipp, C; Belendez, A, E-mail: a.belendez@ua.es [Departamento de Fisica, IngenierIa de Sistemas y TeorIa de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)

    2011-07-15

    An experimental apparatus was designed and built to allow students to carry out heat conduction experiments in hollow cylinders made of different materials, as well as to determine the thermal conductivity of these materials. The evolution of the temperature difference between the inner and outer walls of the cylinder as a function of time is analysed, and when the process reaches the steady state regime the thermal conductivity can be easily calculated. Several materials such as wood, plastic and metals are considered and the values of their thermal conductivities, obtained experimentally, are compared with those given in the reference list.

  3. [Cortisone-induced humerus head necrosis in acute myeloid leukemia: cartilage-preserving arthroscopic spongioplasty].

    Science.gov (United States)

    Heid, A; Dickschas, J; Schoeffl, V

    2013-02-01

    Osteonecrosis is a long known side effect in patients receiving cortisone or chemotherapy. A young patient was diagnosed with acute myeloid leukemia (AML) in 2005. After receiving combined cortisone and chemotherapy the patient was in complete remission. In 2007 a total hip replacement was necessary due to femoral head necrosis. Years after the joint replacement the patient reported acute shoulder pain without trauma. In this article an alternative procedure to an endoprothesis in a young patient with a humeral head osteonecrosis is presented.

  4. Head Injuries in Children

    Science.gov (United States)

    Pennington, Nicole

    2010-01-01

    School nurses play a crucial role in injury prevention and initial treatment when injuries occur at school. The role of school nurses includes being knowledgeable about the management of head injuries, including assessment and initial treatment. The school nurse must be familiar with the outcomes of a head injury and know when further evaluation…

  5. Using your shoulder after replacement surgery

    Science.gov (United States)

    Joint replacement surgery - using your shoulder; Shoulder replacement surgery - after ... You have had shoulder replacement surgery to replace the bones of your shoulder joint with artificial parts. The parts include a stem made of metal and a ...

  6. Effect of High Porosity Screen on the Near Wake of a Circular Cylinder

    Directory of Open Access Journals (Sweden)

    Sahin B.

    2013-04-01

    Full Text Available The change in flow characteristics downstream of a circular cylinder (inner cylinder surrounded by a permeable cylinder (outer cylinder made of a high porosity screen was investigated in shallow water using Particle Image Velocimetry (PIV technique. The diameter of the inner cylinder, outer cylinder and the water height were kept constant during the experiments as d = 50 mm, D = 100 mm and hw = 50 mm, respectively. The depth-averaged free stream velocity was also kept constant as U = 180 mm/s which corresponded to a Reynolds number of Red = 9000 based on the inner cylinder diameter. It was shown that the outer permeable cylinder had a substantialeffect on the vortex formation and consequent vortex shedding downstream of the circular cylinder, especially in the near wake. The time averaged vorticity layers, streamlines and velocity vector field depict that the location of the interaction of vortices considerably changed by the presence of the outer cylinder. Turbulent statistics clearly demonstrated that in comparison to the natural cylinder, turbulent kinetic energy and Reynolds stresses decreased remarkably downstream of the inner cylinder. Moreover, spectra of streamwise velocity fluctuations showed that the vortex shedding frequency significantly reduced compared to the natural cylinder case.

  7. Refractive cylinder outcomes after calculating toric intraocular lens cylinder power using total corneal refractive power

    Directory of Open Access Journals (Sweden)

    Davison JA

    2015-08-01

    Full Text Available James A Davison,1 Richard Potvin21Wolfe Eye Clinic, Marshalltown, IA, USA; 2Science in Vision, Akron, NY, USAPurpose: To determine whether the total corneal refractive power (TCRP value, which is based on measurement of both anterior and posterior corneal astigmatism, is effective for toric intraocular lens (IOL calculation with AcrySof® Toric IOLsPatients and methods: A consecutive series of cataract surgery cases with AcrySof toric IOL implantation was studied retrospectively. The IOLMaster® was used for calculation of IOL sphere, the Pentacam® TCRP 3.0 mm apex/ring value was used as the keratometry input to the AcrySof Toric IOL Calculator and the VERION™ Digital Marker for surgical orientation. The keratometry readings from the VERION reference unit were recorded but not used in the actual calculation. Vector differences between expected and actual residual refractive cylinder were calculated and compared to simulated vector errors using the collected VERION keratometry data.Results: In total, 83 eyes of 56 patients were analyzed. Residual refractive cylinder was 0.25 D or lower in 58% of eyes and 0.5 D or lower in 80% of eyes. The TCRP-based calculation resulted in a statistically significantly lower vector error (P<0.01 and significantly more eyes with a vector error ≤0.5 D relative to the VERION-based calculation (P=0.02. The TCRP and VERION keratometry readings suggested a different IOL toric power in 53/83 eyes. In these 53 eyes the TCRP vector error was lower in 28 cases, the VERION error was lower in five cases, and the error was equal in 20 cases. When the anterior cornea had with-the-rule astigmatism, the VERION was more likely to suggest a higher toric power and when the anterior cornea had against-the-rule astigmatism, the VERION was less likely to suggest a higher toric power.Conclusion: Using the TCRP keratometry measurement in the AcrySof toric calculator may improve overall postoperative refractive results

  8. Mactaquac intake tendons removal and replacement

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, I. [NB Power Generation Corp., Mactaquac Generating Station, Keswick Ridge, NB (Canada); Mee, A. [Hatch Energy, Niagara Falls, ON (Canada)

    2007-07-01

    In 1988 and 1989, multi-strand tendons were installed in the intake structure of the Mactaquac generating station. In order to control displacements caused by alkali aggregate reaction (AAR), they were installed in preparation for a slot cutting program in the intake structure to guard against the possibility of a sliding failure of a section of the structure along a plane coincident with the bottom of the water passage. Unique problems for the designers were present in the expansion affect of AAR that were compounded by field conditions that resulted in further difficulties. For example, concrete expansion required the installation of a thick shim pack under the upper anchor head and the periodic testing of the tendons. Once tested, shims could be gradually removed to maintain the correct load over the life of the tendon. However, during the first round of testing and de-stressing five years after the original installation, it was found that some of the tendons had already failed. Over half of the tendons have been replaced in the 20 years since the installation. This paper discussed the original design considerations and examined the conditions that contributed to the premature failure of the tendons. It outlined the history of tendon testing procedures, tendon failure modes and tendon replacement methods. Specifically, the paper discussed the remedial techniques that were employed and the iterations that lead to the current repair approach, while considering the unique field conditions. The application of various corrosion protection schemes and installation and testing methodologies were discussed. It was concluded that tendons were successfully installed in numerous concrete dams around the world but have needed replacement for a variety of reasons. 1 ref., 10 figs.

  9. TR PIV Experimental Investigation on Bypass Transition Induced by a Cylinder Wake

    Institute of Scientific and Technical Information of China (English)

    TANG Zhan-Qi; JIANG Nan

    2011-01-01

    @@ The process of laminar to turbulent transition induced by a cylinder wake is studied by time-resolved(TR)particle image velocimetry(PIV) in a water channel.The combination of multi-scale local-averaged structure function analysis with criteria is used to identify the generation of secondary transverse vortex structure andto track its evolution along the streamvise.At the beginning of transition,with the decent of cylinder wake vortex,the secondary vortex structure is induced near the vall.As the secondary vortex moves dovnstream,it is induced to lift up by the wake vortex,meanwhile they are diffused and dissipated.According to the method of spatial conditional average,a low-speedhump is found in the near-wallregion along the bypass transition zone,accompanied by a low-speed region in the free stream occupied by the vake vortex.With further downstream,the hump in the near-wall region becomes more and more obvious.At the later stage of transition zone,hairpin vortex can be seen by conditional-averaged low-pass filtered vorticity.The hairpin head is almost vertical to the wall with an inclination angle of about 90°,which is attributed to the additional lift-up behavior induced by wake vortex.It can be concluded that in the process of bypass transition,the wake vortex would not only induce the secondary vortex but also leaven its growth and evolution,resulting in the robust and rapidly growing hairpin vortex.%The process of laminar to turbulent transition induced by a cylinder wake is studied by time-resolved (TR)particle image velocimetry (PIV) in a water channel. The combination of multi-scale local-averaged structure function analysis with criteria is used to identify the generation of secondary transverse vortex structure and to track its evolution along the streamwise. At the beginning of transition, with the decent of cylinder wake vortex, the secondary vortex structure is induced near the wall. As the secondary vortex moves downstream, it is induced to lift

  10. Educating My Replacement

    Science.gov (United States)

    Tarter, Jill

    , in partnership with the dedicated teachers out there, I think I can help promote the critical thinking skills and scientific literacy of the next generation of voters. Hopefully, I can also help train my replacement to be a better scientist, capable of seizing all the opportunities generated by advances in technology and our improved understanding of the universe to craft search strategies with greater probability of success than those I have initiated.

  11. The Heads and Tails of Buoyant Autocatalytic Balls

    CERN Document Server

    Rogers, Michael C

    2012-01-01

    Buoyancy produced by autocatalytic reaction fronts can produce fluid flows that advect the front position, giving rise to interesting feedback between chemical and hydrodynamic effects. In a large diameter, extended cylinder that is relatively free of boundary constraints, localized initiation of an iodate-arsenous acid (IAA) reaction front on the bottom boundary generates a rising autocatalytic plume. Such plumes have several differences from their non-reactive counterparts. Using numerical simulation, we have found that if reaction is initiated using a spherical ball of product solution well above the bottom boundary, the subsequent flow can evolve much like an autocatalytic plume: the ball develops a reacting head and tail that is akin to the head and conduit of an autocatalytic plume, except that the tail is disconnected from the boundary. In the limit of large initial autocatalytic balls, however, growth of a reacting tail is suppressed and the resemblance to plumes disappears. Conversely, very small bal...

  12. 49 CFR 572.132 - Head assembly and test procedure.

    Science.gov (United States)

    2010-10-01

    ... 880105-100X), a six-axis neck transducer (drawing SA572-S11) or its structural replacement (drawing 78051.... (3) Suspend and orient the head assembly as shown in Figure 19 of 49 CFR 572. The lowest point on...

  13. [Ascending aorta replacement late after aortic valve replacement].

    Science.gov (United States)

    Hayashi, Yasunari; Ito, Toshiaki; Maekawa, Atsuo; Sawaki, Sadanari; Fujii, Genyo; Hoshino, Satoshi; Tokoro, Masayoshi; Yanagisawa, Junji

    2013-07-01

    Replacement of the asceding aorta is indicated in patients undergoing aortic valve replacement( AVR), if the diameter of the ascending aorta is greater than 5.0 cm. If the diameter of the asceding aorta is from 4.0 to 5.0 cm, it was arguable whether replacement of the ascending aorta should be performed. Nine patients who underwent reoperative ascending aorta replacement after AVR were reviewed retrospectively. Reoperation on the asending aorta replacement was performed 11.8±7.2 years (range 1y5m~23y3m) after AVR. Mean patient age was 69.9±6.3 (range 60~81). In 2 cases, reoperations were performed early year after AVR. Although ascending aorta was dilated at the 1st operation, replacement wasn't performed for the age and minimally invasive cardiac surgery (MICS). In 3 cases, reoperations were performed more than 10 years later. On these cases, ascending aorta aneurysm and dissection occurred with no pain and were pointed out by computed tomography(CT) or ultrasonic cardiogram(UCG). We think that patients with dilatation of the ascending aorta should undergo AVR and aorta replacement at the 1st operation regardness of age. It is important that patients who underwent AVR should undergo a regular checkup on the ascending aorta.

  14. Elastic and viscoelastic solutions to rotating functionally graded hollow and solid cylinders

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Analytical solutions to rotating functionally graded hollow and solid long cylinders are developed. Young's modulus and material density of the cylinder are as* sumed to vary exponentially in the radial direction, and Poisson's ratio is assumed to be constant. A unified governing equation is derived from the equilibrium equations, compat-ibility equation, deformation theory of elasticity and the stress-strain relationship. The governing second-order differential equation is solved in terms of a hypergeometric func-tion for the elastic deformation of rotating functionally graded cylinders. Dependence of stresses in the cylinder on the inhomogeneous parameters, geometry and boundary conditions is examined and discussed. The proposed solution is validated by comparing the results for rotating functionally graded hollow and solid cylinders with the results for rotating homogeneous isotropic cylinders. In addition, a viscoelastic solution to the rotating viscoelastic cylinder is presented, and dependence of stresses in hollow and solid cylinders on the time parameter is examined.

  15. 49 CFR 178.39 - Specification 3BN seamless nickel cylinders.

    Science.gov (United States)

    2010-10-01

    .... A reasonably smooth and uniform surface finish is required. Cylinders closed in by spinning process... nonpressure parts, and only to the tops and bottoms of cylinders. Neckrings and footrings must be of weldable...

  16. A Clustering Genetic Algorithm for Cylinder Drag Optimization

    Science.gov (United States)

    Milano, Michele; Koumoutsakos, Petros

    2002-01-01

    A real coded genetic algorithm is implemented for the optimization of actuator parameters for cylinder drag minimization. We consider two types of idealized actuators that are allowed either to move steadily and tangentially to the cylinder surface (“belts”) or to steadily blow/suck with a zero net mass constraint. The genetic algorithm we implement has the property of identifying minima basins, rather than single optimum points. The knowledge of the shape of the minimum basin enables further insights into the system properties and provides a sensitivity analysis in a fully automated way. The drag minimization problem is formulated as an optimal regulation problem. By means of the clustering property of the present genetic algorithm, a set of solutions producing drag reduction of up to 50% is identified. A comparison between the two types of actuators, based on the clustering property of the algorithm, indicates that blowing/suction actuation parameters are associated with larger tolerances when compared to optimal parameters for the belt actuators. The possibility of using a few strategically placed actuators to obtain a significant drag reduction is explored using the clustering diagnostics of this method. The optimal belt-actuator parameters obtained by optimizing the two-dimensional case is employed in three-dimensional simulations, by extending the actuators across the span of the cylinder surface. The three-dimensional controlled flow exhibits a strong two-dimensional character near the cylinder surface, resulting in significant drag reduction.

  17. Convection from a Slender Cylinder in a Ventilated Room

    DEFF Research Database (Denmark)

    Heiselberg, Per; Sandberg, Mats

    In this paper the equations, based on integral formulation, for the boundary layer flow in the constant heat flux case and in the constant temperature case have been solved, and both a flat plate and a cylinder solution are presented. Results are compared with measurements carried out in the turb...

  18. Properties of Sub-wavelength Resonances in Metamaterial Cylinders

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Clausen, N.C.J.; Pedersen, R.R.;

    2008-01-01

    The analytical solution for the canonical configuration with electric line source illumination of concentric metamaterial cylinders is employed to study the properties of the observed sub-wavelength resonances. The near- and far-field distributions, the frequency and geometry bandwidths...

  19. Design of nested Halbach cylinder arrays for magnetic refrigeration applications

    Energy Technology Data Exchange (ETDEWEB)

    Trevizoli, Paulo V., E-mail: trevizoli@polo.ufsc.br; Lozano, Jaime A.; Peixer, Guilherme F.; Barbosa Jr, Jader R.

    2015-12-01

    We present an experimentally validated analytical procedure to design nested Halbach cylinder arrays for magnetic cooling applications. The procedure aims at maximizing the magnetic flux density variation in the core of the array for a given set of design parameters, namely the inner diameter of the internal magnet, the air gap between the magnet cylinders, the number of segments of each magnet and the remanent flux density of the Nd{sub 2}Fe{sub 14}B magnet grade. The design procedure was assisted and verified by 3-D numerical modeling using a commercial software package. An important aspect of the optimal design is to maintain an uniform axial distribution of the magnetic flux density in the region of the inner gap occupied by the active magnetocaloric regenerator. An optimal nested Halbach cylinder array was manufactured and experimentally evaluated for the magnetic flux density in the inner gap. The analytically calculated magnetic flux density variation agreed to within 5.6% with the experimental value for the center point of the magnet gap. - Highlights: • An analytical procedure to design nested Halbach cylinder arrays is proposed. • An optimal magnet configuration was built based on the analytical procedure. • The procedure was validated with 3D COMSOL simulations and experimental data.

  20. Rainbow technique for multi-parameter measurement of absorbing cylinder

    Institute of Scientific and Technical Information of China (English)

    Feihu Song; Chuanlong Xu; Shimin Wang

    2013-01-01

    Rainbow refractometry is widely used to measure the radius and real part of refractive index of a cylinder.However,studies on the detection of imaginary part of the refractive index with rainbow technique were scarce.This paper presents a new method for simultaneously measuring the radius,real and imaginary part of the refractive index of a cylinder,on the basis of the Airy theory and the Bouguer theory.The rainbows produced by the illuminated cylinder at a capillary exit are captured by a CCD camera in a labscale system,and then processed by the proposed method.Experimental results showed that the radius,real and imaginary part of the refractive index can be accurately determined when the SNR (signal to noise ratio) of the ripple structure is sufficiently high.However,the SNR of the ripple structure gradually decreases with decreasing scattering intensity of the cylinder,leading to larger measurement errors of the radius and real part of the refractive index.The relative error of the imaginary part of the refractive index derived from the measurement errors of the radius and real part of the refractive index,is less than 3.4%.

  1. DNS of 2D turbulent flow around a square cylinder

    NARCIS (Netherlands)

    Wissink, JG

    1997-01-01

    Two-dimensional 'turbulent' flow around a rectangular cylinder has been simulated at Re = 10,000 using a sixth-order-accurate finite volume method for the discretization of convection and diffusion. The spatial discretization consists of a combination of a seventh-order upwind-biased method for the

  2. Oscillation of cylinders of rectangular cross section immersed in fluid

    Science.gov (United States)

    Brumley, Douglas R.; Willcox, Michelle; Sader, John E.

    2010-05-01

    The ability to calculate flows generated by oscillating cylinders immersed in fluid is a cornerstone in micro- and nanodevice development. In this article, we present a detailed theoretical analysis of the hydrodynamic load experienced by an oscillating rigid cylinder, of arbitrary rectangular cross section, that is immersed in an unbounded viscous fluid. We also consider the formal limit of inviscid flow for which exact analytical and asymptotic solutions are derived. Due to its practical importance in application to the atomic force microscope and nanoelectromechanical systems, we conduct a detailed assessment of the dependence of this load on the cylinder thickness-to-width ratio. We also assess the validity and accuracy of the widely used infinitely-thin blade approximation. For thin rectangular cylinders of finite thickness, this approximation is found to be excellent for out-of-plane motion, whereas for in-plane oscillations it can exhibit significant error. A database of accurate numerical results for the hydrodynamic load as a function of the thickness-to-width ratio and normalized frequency is also presented, which is expected to be of value in practical application and numerical benchmarking.

  3. Resonances and dipole moments in dielectric, magnetic, and magnetodielectric cylinders

    DEFF Research Database (Denmark)

    Dirksen, A.; Arslanagic, Samel; Breinbjerg, Olav

    2011-01-01

    An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis...... of metamaterials, is given with an emphasis on their strength, bandwidth, and isolation....

  4. Mechanisms of noise control inside a finite cylinder

    Science.gov (United States)

    Lester, H. C.

    1988-01-01

    Preliminary results are presented for a simple elastic cylinder/acoustic cavity model. The validity of the mode matching method, which was used to couple the shell vibrations to the interior acoustic response, has been validated by comparison with Junger's (1985) method. In addition, the importance of both structural and acoustic damping in the medium response was shown to be dramatic.

  5. Experimental Thermal Analysis of Diesel Engine Piston and Cylinder Wall

    Directory of Open Access Journals (Sweden)

    Subodh Kumar Sharma

    2015-01-01

    Full Text Available Knowledge of piston and cylinder wall temperature is necessary to estimate the thermal stresses at different points; this gives an idea to the designer to take care of weaker cross section area. Along with that, this temperature also allows the calculation of heat losses through piston and cylinder wall. The proposed methodology has been successfully applied to a water-cooled four-stroke direct-injection diesel engine and it allows the estimation of the piston and cylinder wall temperature. The methodology described here combines numerical simulations based on FEM models and experimental procedures based on the use of thermocouples. Purposes of this investigation are to measure the distortion in the piston, temperature, and radial thermal stresses after thermal loading. To check the validity of the heat transfer model, measure the temperature through direct measurement using thermocouple wire at several points on the piston and cylinder wall. In order to prevent thermocouple wire entanglement, a suitable pathway was designed. Appropriate averaged thermal boundary conditions such as heat transfer coefficients were set on different surfaces for FE model. The study includes the effects of the thermal conductivity of the material of piston, piston rings, and combustion chamber wall. Results show variation of temperature, stresses, and deformation at various points on the piston.

  6. Bubbly flows around a two-dimensional circular cylinder

    Science.gov (United States)

    Lee, Jubeom; Park, Hyungmin

    2016-11-01

    Two-phase cross flows around a bluff body occur in many thermal-fluid systems like steam generators, heat exchangers and nuclear reactors. However, our current knowledge on the interactions among bubbles, bubble-induced flows and the bluff body are limited. In the present study, the gas-liquid bubbly flows around a solid circular cylinder are experimentally investigated while varying the mean void fraction from 5 to 27%. The surrounding liquid (water) is initially static and the liquid flow is only induced by the air bubbles. For the measurements, we use the high-speed two-phase particle image velocimetry techniques. First, depending on the mean void fraction, two regimes are classified with different preferential concentration of bubbles in the cylinder wake, which are explained in terms of hydrodynamic force balances acting on rising bubbles. Second, the differences between the two-phase and single-phase flows (while matching their Reynolds numbers) around a circular cylinder will be discussed in relation to effects of bubble dynamics and the bubble-induced turbulence on the cylinder wake. Supported by a Grant (MPSS-CG-2016-02) through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

  7. Buckling Experiment on Anisotropic Long and Short Cylinders

    Directory of Open Access Journals (Sweden)

    Atsushi Takano

    2016-07-01

    Full Text Available A buckling experiment was performed on anisotropic, long and short cylinders with various radius-to-thickness ratios. The 13 cylinders had symmetric and anti-symmetric layups, were between 2 and 6 in terms of the length-to-radius ratio, between 154 and 647 in radius-to-thickness ratio, and made of two kinds of carbon fiber reinforced plastic (CFRP prepreg with high or low fiber modulus. The theoretical buckling loads for the cylinders were calculated from the previously published solution by using linear bifurcation theory considering layup anisotropy and transverse shear deformation and by using deep shell theory to account for the effect of length and compared with the test results. The theoretical buckling loads for the cylinders were calculated from the previously published solution by using linear bifurcation theory considering layup anisotropy and transverse shear deformation and by using deep shell theory to account for the effect of length. The knockdown factor, defined as the ratio of the experimental value to the theoretical value, was found to be between 0.451 and 0.877. The test results indicated that a large length-to-radius ratio reduces the knockdown factor, but the radius-to-thickness ratio and other factors do not affect it.

  8. Prediction of External Corrosion for Steel Cylinders--2002 Report

    Energy Technology Data Exchange (ETDEWEB)

    Schmoyer, RLS

    2002-07-31

    The United States Department of Energy (DOE) manages the UF{sub 6} Cylinder Project. The project was formed to maintain and safely manage the depleted uranium hexafluoride (UF{sub 6}) stored in approximately 50,000 carbon steel cylinders. The cylinders are located at three DOE sites: the East Tennessee Technology Park (ETTP) site in Oak Ridge, Tennessee; the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The System Requirements Document (SRD) (LMES 1997a) delineates the requirements of the project, and the actions needed to fulfill these requirements are specified in the System Engineering Management Plan (SEMP) (LMES 1997b). This report documents activities that in whole or part satisfy specific requirements and actions stated in the UF{sub 6} Cylinder Project SRD and SEMP with respect to forecasting cylinder conditions. The results presented here supercede those presented by Lyon (1995, 1996, 1997, 1998, 2000), and Schmoyer and Lyon (2001). Many of the wall thickness projections made in this report are conservative, because they are based on the assumption that corrosion trends will continue, despite activities such as improved monitoring, relocations to better storage, painting, and other improvements in storage conditions relative to the conditions at the times most of the wall thickness measurements were made. For thin-wall cylinders (design nominal wall thickness 312.5 mils), the critical minimum wall thicknesses criteria used in this report are 0 (breach), 62.5 mils, and 250 mils (1 mil = 0.001 in.). For thick-wall cylinders (design nominal wall thickness 625 mils), the thickness criteria used in this report are 0, 62.5 mils, and 500 mils. The criteria triples are preliminary boundaries identified within the project that indicate (1) loss of material (UF{sub 6}), (2) safe handling and stacking operations, and (3) standards for off-site transport and contents transfer

  9. Coriolis effects on nonlinear oscillations of rotating cylinders and rings

    Science.gov (United States)

    Padovan, J.

    1976-01-01

    The effects which moderately large deflections have on the frequency spectrum of rotating rings and cylinders are considered. To develop the requisite solution, a variationally constrained version of the Lindstedt-Poincare procedure is employed. Based on the solution developed, in addition to considering the effects of displacement induced nonlinearity, the role of Coriolis forces is also given special consideration.

  10. UF{sub 6} cylinder lifting equipment enhancements

    Energy Technology Data Exchange (ETDEWEB)

    Hortel, J.M. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

    1991-12-31

    This paper presents numerous enhancements that have been made to the Portsmouth lifting equipment to ensure the safe handling of cylinders containing liquid uranium hexafluoride (UF{sub 6}). The basic approach has been to provide redundancy to all components of the lift path so that any one component failure would not cause the load to drop or cause any undesirable movement.

  11. Temporary patching of damaged UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, A.L. [Martin Marietta Energy Systems, Inc., OH (United States)

    1991-12-31

    Patching techniques based on application of epoxy resins have been developed for temporarily repairing UF{sub 6} cylinders which have sustained relatively minor damage and must be safely emptied. The method is considerably faster and simpler than metallurgical weld repairs. Laboratory tests, detailed operational procedures, and case histories of experience at the Portsmouth Gaseous Diffusion Plant are described.

  12. Viscoelastic flow simulations through an array of cylinders

    NARCIS (Netherlands)

    Gillissen, J.J.J.

    2013-01-01

    Polymer solution flow is studied numerically in a periodic, hexagonal array of cylinders as a model for a porous medium. We use a lattice Boltzmann method supplemented by a polymer stress, where the polymers are modeled as finitely extensible, nonlinear, elastic dumbbells. The simulated, nonmonotoni

  13. Large eight.cylinder Stirling engine for biofuels

    DEFF Research Database (Denmark)

    Carlsen, Henrik; Biedermann, F.; Bovin, Jonas Kabell

    2003-01-01

    A large Stirling engine with an electric power output of 70 kW has been developed for small-scale CHP using wood chips and other sorts of biomass as fuel. The development of the engine is based on the results from the development of a four-cylinder Stirling engine with a power output of 35 kW, wh...

  14. Imperfection effects on the buckling of hydrostatically loaded cylinders

    DEFF Research Database (Denmark)

    Pinna, Rodney; Madsen, Søren

    2015-01-01

    The presence of geometric and other imperfections in cylinders has been known to result in collapse loads well below those predicted from eigenvalue analysis for a long time. As the designer's ability to routinely employ non-linear FEA has increased, the importance of modelling such imperfections...

  15. Numerical and asymptotic aspects of parabolic cylinder functions

    NARCIS (Netherlands)

    Temme, N.M.

    2000-01-01

    Several uniform asymptotics expansions of the Weber parabolic cylinder functions are considered, one group in terms of elementary functions, another group in terms of Airy functions. Starting point for the discussion are asymptotic expansions given earlier by F.W.J. Olver. Some of his results are

  16. Integral representations for computing real parabolic cylinder functions

    NARCIS (Netherlands)

    Gil, A.; Segura, J.; Temme, N.M.

    2005-01-01

    Integral representations are derived for the parabolic cylinder functions U(a,x), V(a,x) and W(a,x) and their derivatives. The new integrals will be used in numerical algorithms based on quadrature. They follow from contour integrals in the complex plane, by using methods from asymptotic analysis (s

  17. Representing plants as rigid cylinders in experiments and models

    Science.gov (United States)

    Vargas-Luna, Andrés; Crosato, Alessandra; Calvani, Giulio; Uijttewaal, Wim S. J.

    2016-07-01

    Simulating the morphological adaptation of water systems often requires including the effects of plants on water and sediment dynamics. Physical and numerical models need representing vegetation in a schematic easily-quantifiable way despite the variety of sizes, shapes and flexibility of real plants. Common approaches represent plants as rigid cylinders, but the ability of these schematizations to reproduce the effects of vegetation on morphodynamic processes has never been analyzed systematically. This work focuses on the consequences of representing plants as rigid cylinders in laboratory tests and numerical simulations. New experiments show that the flow resistance decreases for increasing element Reynolds numbers for both plants and rigid cylinders. Cylinders on river banks can qualitatively reproduce vegetation effects on channel width and bank-related processes. A comparative review of numerical simulations shows that Baptist's method that sums the contribution of bed shear stress and vegetation drag, underestimates bed erosion within sparse vegetation in real rivers and overestimates the mean flow velocity in laboratory experiments. This is due to assuming uniform flow among plants and to an overestimation of the role of the submergence ratio.

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  20. Effects of GFF Bands on Normal and High Strength Concrete Cylinders

    OpenAIRE

    Jayaprakash, J; Abdul Aziz Abdul Samad; Noridah Mohamad; K.K. Choong; M.J. Megat Azmi; H.A.B. Badorul

    2010-01-01

    This paper exemplifies the effects of externally confined Glass Fibre Fabric (GFF) bands on normal and high strength concrete cylinders. Twelve normal and high strength concrete cylinders were cast and tested in the laboratory environment under axial compression to failure. The experimental results show that the degree of confinement of discrete GFF confined high strength concrete cylinders was significantly better than normal strength concrete cylinders with GFF bands, however...

  1. RELIABILITY ANALYSIS OF THE PRIMARY CYLINDER OF THE 10 MN HYDRAULIC PRESS

    Institute of Scientific and Technical Information of China (English)

    Zhao Jingyi; Zhuoru; Wang Yiqun

    2000-01-01

    According to the demand of high reliability of the primary cylinder of the hydraulic press,the reliability model of the primary cylinder is built after its reliability analysis.The stress of the primary cylinder is analyzed by finite element software-MARC,and the structure reliability of the cylinder based on stress-strength model is predicted,which would provide the reference to the design.

  2. Influence of hydrodynamic slip on convective transport in flow past a circular cylinder

    Science.gov (United States)

    Rehman, Nidhil M. A.; Kumar, Anuj; Shukla, Ratnesh K.

    2017-06-01

    appearance of additional local maxima in Nu_{θ } at locations that are in close proximity to the mean secondary stagnation points. As a consequence, Nu exhibits a non-monotonic variation with l_s increasing initially from its lowermost value for a no-slip surface and then decreasing before rising gradually toward the upper asymptotic limit for a shear-free cylinder. A non-monotonic dependence of the spanwise-averaged Nu on l_s is observed in three dimensions as well with the three-dimensional wake instabilities that appear at sufficiently low l_s, strongly influencing the convective thermal transport from the cylinder. The analogy between heat transfer and single-component mass transfer implies that our results can directly be applied to determine the dependency of convective mass transfer of a single solute on hydrodynamic slip length in similar configurations through straightforward replacement of Nu and Pr with Sherwood and Schmidt numbers, respectively.

  3. Influence of hydrodynamic slip on convective transport in flow past a circular cylinder

    Science.gov (United States)

    Rehman, Nidhil M. A.; Kumar, Anuj; Shukla, Ratnesh K.

    2017-02-01

    appearance of additional local maxima in Nu_{θ } at locations that are in close proximity to the mean secondary stagnation points. As a consequence, Nu exhibits a non-monotonic variation with l_s increasing initially from its lowermost value for a no-slip surface and then decreasing before rising gradually toward the upper asymptotic limit for a shear-free cylinder. A non-monotonic dependence of the spanwise-averaged Nu on l_s is observed in three dimensions as well with the three-dimensional wake instabilities that appear at sufficiently low l_s , strongly influencing the convective thermal transport from the cylinder. The analogy between heat transfer and single-component mass transfer implies that our results can directly be applied to determine the dependency of convective mass transfer of a single solute on hydrodynamic slip length in similar configurations through straightforward replacement of Nu and Pr with Sherwood and Schmidt numbers, respectively.

  4. Maneuvering impact boring head

    Science.gov (United States)

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  5. [Genetic basis of head and neck cancers and gene therapy].

    Science.gov (United States)

    Özel, Halil Erdem; Özkırış, Mahmut; Gencer, Zeliha Kapusuz; Saydam, Levent

    2013-01-01

    Surgery and combinations of traditional treatments are not successful enough particularly for advanced stage head and neck cancer. The major disadvantages of chemotherapy and radiation therapy are the lack of specificity for the target tissue and toxicity to the patient. As a result, gene therapy may offer a more specific approach. The aim of gene therapy is to present therapeutic genes into cancer cells which selectively eliminate malignant cells with no systemic toxicity to the patient. This article reviews the genetic basis of head and neck cancers and important concepts in cancer gene therapy: (i) inhibition of oncogenes; (ii) tumor suppressor gene replacement; (iii) regulation of immune response against malignant cells; (iv) genetic prodrug activation; and (v) antiangiogenic gene therapy. Currently, gene therapy is not sufficient to replace the traditional treatments of head and neck cancers, however there is no doubt that it will have an important role in the near future.

  6. Optimization Study on a Single-cylinder Compressed Air Engine

    Institute of Scientific and Technical Information of China (English)

    YU Qihui; CAI Maolin; SHI Yan; XU Qiyue

    2015-01-01

    The current research of compressed air engine (CAE) mainly focused on simulations and system integrations. However, energy efficiency and output torque of the CAE is limited, which restricts its application and popularization. In this paper, the working principles of CAE are briefly introduced. To set a foundation for the study on the optimization of the CAE, the basic mathematical model of working processes is set up. A pressure-compensated valve which can reduce the inertia force of the valve is proposed. To verify the mathematical model, the prototype with the newly designed pressure-compensated intake valve is built and the experiment is carried out, simulation and experimental results of the CAE are conducted, and pressures inside the cylinder and output torque of the CAE are obtained. Orthogonal design and grey relation analysis are utilized to optimize structural parameters. The experimental and optimized results show that, first of all, pressure inside the cylinder has the same changing tendency in both simulation curve and experimental curve. Secondly, the highest average output torque is obtained at the highest intake pressure and the lowest rotate speed. Thirdly, the optimization of the single-cylinder CAE can improve the working efficiency from an original 21.95% to 50.1%, an overall increase of 28.15%, and the average output torque increases also increases from 22.047 5 N • m to 22.439 N • m. This research designs a single-cylinder CAE with pressure-compensated intake valve, and proposes a structural parameters design method which improves the single-cylinder CAE performance.

  7. Development of steel head joints with fiberglass sucker rod on the base of contact stresses investigation

    Energy Technology Data Exchange (ETDEWEB)

    Kopey, B.V.; Kopey, L.B. [Ivano-Frankivsk State Technical Oil and Gas University (Ukraine); Maksymuk, A.V.; Shcherbyna, N.M. [National Ukrainian Academy of Sciences (Ukraine)

    1998-12-31

    The methods of calculation of contact stresses during cylinder shell tube - steel bandage interaction are presented. Tymoshenko`s generalized theory of shells serves as a basis for investigating steel head to fiberglass sucker rod joint strength. This theory allows to consider mechanical performance of composite materials. The problem is reduced to solving Fredholm integral equation of second degree. The numeric analysis is performed. Several joints of composite body with steel head are proposed. The full-size sucker rod fatigue tests are performed to determine the fatigue limit under the bending and axial cyclic loads in the medium of oil well fluids. (orig.)

  8. 49 CFR 178.45 - Specification 3T seamless steel cylinder.

    Science.gov (United States)

    2010-10-01

    ...) Type, size, and service pressure. A DOT 3T cylinder is a seamless steel cylinder with a minimum water... eliminate these defects provided the minimum wall thickness is maintained. (5) Welding or brazing on a cylinder is not permitted. (d) Wall thickness. The minimum wall thickness must be such that the wall...

  9. SOME OBSERVATIONS OF TWO INTERFERING VIV CIRCULAR CYLINDERS OF UNEQUAL DIAMETERS IN TANDEM

    Institute of Scientific and Technical Information of China (English)

    HUANG Shan; SWORN Andy

    2011-01-01

    Analysis of model test results was carried out to investigate the hydrodynamic interaction between a pair of elastically-supported rigid cylinders of dissimilar diameters in a water flume.The two cylinders are placed in tandem with one situated in the wake of the other.The diameter of the upstream cylinder is twice as large as that of the downstream cylinder.The spacing between the two cylinders ranges from 1 to 10 times the larger cylinder diameter.The Reynolds numbers are within the sub-critical range.The cylinders are free to oscillate in both the in-line and the cross-flow directions.The reduced velocity ranges from 1 to 10 and the low damping ratio of the model test set-up at 0.006 gives a combined m.ass-damping parameter of 0.02.It is found that the lift on and the cross-flow motion of the downstream cylinder have the frequency components derived from the upstream cylinder's vortex shedding as well as from its own vortex shedding,and the relative importance of the two sources of excitation is influenced by the spacing between the two cylinders.The downstream cylinder's VIV response appears to be largely dependent upon the actual reduced velocity of the cylinder.

  10. Formation of whispering gallery modes by scattering of an electromagnetic plane wave by two cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, Arnold, E-mail: qulaser@gmail.com [Kuang-Chi Institute of Advanced Technology, Shenzhen, 518057 (China); Kostikov, Alexander [Donbass State Engineering Academy, 84303, Kramatorsk, Donetsk (Ukraine)

    2017-03-26

    We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder. - Highlights: • We consider scattering of electromagnetic plane waves by two cylinders. • WGMs occur because of the presence of additional cylinder at specific location. • The accuracy for the locations is much less than required for specific values of single cylinder. • The interference of waves scattered by additional cylinders and incident on the main is responsible for the effect.

  11. On Uniform Motion of a Periodic System of Absolutely Rigid Stamps, in the Hollow Cylinder

    Directory of Open Access Journals (Sweden)

    Amirjanyan H. A.

    2011-03-01

    Full Text Available Axissymetric stress state of the infinite hollow cylinder when on the inner surface of the cylinder acts a periodic system of uniformly moving circular stamps and the outer surface is free of loads or rigidly clamped is considered The behavior of the contact stresses, acting under the stamp, in dependence on the physical and geometrical parameters of the cylinder is studied.

  12. 49 CFR 178.68 - Specification 4E welded aluminum cylinders.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 4E welded aluminum cylinders. 178.68 Section 178.68 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... FOR PACKAGINGS Specifications for Cylinders § 178.68 Specification 4E welded aluminum cylinders....

  13. 49 CFR 178.36 - Specification 3A and 3AX seamless steel cylinders.

    Science.gov (United States)

    2010-10-01

    ... these defects. The thickness of the bottoms of cylinders welded or formed by spinning is, under no... the attachment of neckrings and footrings which are non-pressure parts and only to the tops and... test. All spun cylinders and plugged cylinders must be tested for leakage by gas or air pressure after...

  14. 49 CFR 178.37 - Specification 3AA and 3AAX seamless steel cylinders.

    Science.gov (United States)

    2010-10-01

    ... cylinders welded or formed by spinning is, under no condition, to be less than two times the minimum wall... which are non-pressure parts, and only to the tops and bottoms of cylinders having a service pressure of... required, without cracking, to 6 times the wall thickness of the cylinder. (m) Leakage test. All spun...

  15. 49 CFR 173.40 - General packaging requirements for toxic materials packaged in cylinders.

    Science.gov (United States)

    2010-10-01

    ... concrete or steel, impacting at an orientation most likely to cause damage. “Deformation”means a cylinder... packaged in cylinders. 173.40 Section 173.40 Transportation Other Regulations Relating to Transportation... Transportation § 173.40 General packaging requirements for toxic materials packaged in cylinders. When this...

  16. 49 CFR 178.59 - Specification 8 steel cylinders with porous fillings for acetylene.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 8 steel cylinders with porous fillings for acetylene. 178.59 Section 178.59 Transportation Other Regulations Relating to Transportation... cylinders with porous fillings for acetylene. (a) Type and service pressure. A DOT 8 cylinder is a...

  17. 49 CFR 178.60 - Specification 8AL steel cylinders with porous fillings for acetylene.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 8AL steel cylinders with porous fillings for acetylene. 178.60 Section 178.60 Transportation Other Regulations Relating to Transportation... cylinders with porous fillings for acetylene. (a) Type and service pressure. A DOT 8AL cylinder is...

  18. A numerical investigation of sub-wavelength resonances in polygonal metamaterial cylinders

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Breinbjerg, Olav

    2009-01-01

    of polygonal cylinders excited by a nearby electric line current is analyzed numerically and it is shown, through detailed analysis of the near-field distribution and radiation resistance, that these polygonal cylinders do indeed support sub-wavelength resonances similar to those of the circular cylinders...

  19. Femoral head fracture without hip dislocation

    Institute of Scientific and Technical Information of China (English)

    Aditya K Aggarwal; Ashwani Soni; Daljeet Singh

    2013-01-01

    Femoral head fractures without dislocation or subluxation are extremely rare injuries.We report a neglected case of isolated comminuted fracture of femoral head without hip dislocation or subluxation of one year duration in a 36-year-old patient who sustained a high energy trauma due to road traffic accident.He presented with painful right hip and inability to bear full weight on right lower limb with Harris hip score of 39.He received cementless total hip replacement.At latest follow-up of 2.3 years,functional outcome was excellent with Harris hip score of 95.Such isolated injuries have been described only once in the literature and have not been classified till now.The purpose of this report is to highlight the extreme rarity,possible mechanism involved and a novel classification system to classify such injuries.

  20. Electrocatalysts Prepared by Galvanic Replacement

    OpenAIRE

    Athanasios Papaderakis; Ioanna Mintsouli; Jenia Georgieva; Sotiris Sotiropoulos

    2017-01-01

    Galvanic replacement is the spontaneous replacement of surface layers of a metal, M, by a more noble metal, Mnoble, when the former is treated with a solution containing the latter in ionic form, according to the general replacement reaction: nM + mMnoblen+ → nMm+ + mMnoble. The reaction is driven by the difference in the equilibrium potential of the two metal/metal ion redox couples and, to avoid parasitic cathodic processes such as oxygen reduction and (in some cases) hydrogen evolution too...